Tailored vertebral artery mobilisation in complex craniovertebral junction surgery- a blessing in disguise

Tailored vertebral artery mobilisation in complex craniovertebral junction surgery- a blessing in disguise | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Tailored vertebral artery mobilisation in complex craniovertebral junction surgery- a blessing in disguise Ved Prakash Maurya, Ashutosh Kumar, Ananth Chaitanya J, Priyadarshi Dikshit, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5646143/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 30 Jan, 2026 Read the published version in Neurosurgical Review → Version 1 posted 14 You are reading this latest preprint version Abstract Background: The surgical exposure of the complex craniovertebral junction (CVJ) requires manipulation of the neurovascular structures and the atlantoaxial joint (C1-C2 joint) to access the pathological region. To achieve adequate C1-C2 joint manipulation, the mobilization of the vertebral artery (VA) is mandatory. The present retrospective observational study aims to describe the surgical nuances and share the experience of tailored vertebral artery mobilization for efficient management of CVJ pathologies. Methodology: All the operated cases of CVJ anomalies from January 2019 to December 2023 were included. The clinico-radiological scan, including their three-dimensional computerized tomography (3-D CT), was recorded with a VA angiogram course. The intraoperative details of these patients were collected from the neurosurgery operative records. The patients' details were obtained either by the outpatient department or by telephone. Results: A total of 18 patients were analyzed with a mean age of 49.21±18.30 years. The median pre-operative Nurick's grade amongst the study population was 4 (IQR: 3,4 and Range: 3-5). Twelve patients underwent bilateral vertebral artery mobilization, whereas the remaining six underwent unilateral vertebral artery mobilization. After surgery, at three months of follow-up visit, the median post-operative Nurick's grade was 3 (IQR: 2,3 and Range: 2-5), which was statistically significant (P=0.002). The mean follow-up duration was 23.2 months without any procedure-related mortality. Conclusions: Tailored vertebral artery mobilisation (VAM) is an excellent surgical strategy for negotiating through the atlantoaxial joint in a specific group of patients. It offers safe access to managing CVJ anomalies, keeping in mind the principles of micro neurosurgery. Vertebral artery Craniovertebral junction Nurick’s grade Atlantoaxial dislocation Vertebral angiogram Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The art of micro neurosurgery has significantly affected tissue handling in a better way, which in turn has translated into improved surgical outcomes. The pathology around the craniovertebral junction (CVJ) requires the amalgamation of three-dimensional orientation, neuroanatomical knowledge, and sound information about the developmental/ embryological variations around the area of CVJ. The spectrum of pathologies encountered around the craniovertebral junction is atlantoaxial dislocation (AAD), basilar invagination (BI), foramen magnum tumours (especially meningiomas), as well as the entire spectrum of Chiari malformations. The surgical exposure of this area requires significant manipulation of the neurovascular structures and the atlantoaxial joint (C1-C2 joint) to access the pathological region. In complex subtypes of CVJ anomalies, the vertebral artery (VA) course is often not along the expected trajectory. It is encountered in front of the joint when the patient is positioned in the prone position. To achieve adequate C1-C2 joint manipulation, the mobilisation of the VA is mandatory in a complex subset of patients having CVJ anomalies. The present retrospective observational study aims to describe the surgical nuances and share the experience of vertebral artery mobilisation around the craniovertebral junction during the management of CVJ anomalies. Methods And Material This retrospective observational study conformed to the ethical guidelines laid down in the Helsinki declaration (1964). The study being retrospective observational in nature the institute ethics committee has confirmed that no ethical approval is required. Departmental and institute protocols were followed regarding informed written consent for the publication of clinical findings. The operated cases of CVJ anomalies over the last five years, from January 2019 to December 2023, were collected. Their 3D CT with VA angiogram course, along with their operation details, were noted. The clinical, radiological and intraoperative details of surgically managed patients of craniovertebral junction pathology were collected from the neurosurgery operative records. The follow-up details of these patients over the last five years were collected from the hospital information and neurosurgery record-keeping system (Fig 1.). The latest follow-up of patients were obtained either in the outpatient department of neurosurgery or telephonically. Inclusion Criteria In all cases of CVJ anomaly, the preoperative vertebral angiogram showed an anomalous course of the VA. Exclusion Criteria • Cases of CVJ anomaly where the mobilisation of the vertebral artery was not required. • Cases of CVJ anomaly where C1-C2 stabilisation was deferred as per the discretion of the operating surgeon. 1. Clinical Evaluation All patients underwent detailed clinical evaluation, including sensory, motor, and autonomic systems, including any stigmata of syndromic association. The features of compressive myelopathy, the status of the lower cranial nerves, and functional status were assessed. The motor system was assessed on the basis of MRC grade, and the MAS score was used to assess the degree of spasticity. Nurick’s grade was used to assess the functional status of the patients. 2. Radiologic Evaluation and Preoperative Planning As per departmental policy, all patients diagnosed with CVJ spectrum disorder were subjected to a computerised tomography scan of the CVJ in flexion, extension, and neutral position. The 3D reconstruction of the radiology with vertebral artery angiogram was performed to orient the distorted anatomy better and ensure the patient's surgical safety. · CT Angiogram of Vertebral Artery The included patients were subjected to vertebral artery angiogram and evaluated by the neurosurgical team for the dominance and course of the VA (whether co-dominant or unilateral dominance). The course and alignment of the VA to the C1-C2 joint were evaluated on both sides to look for surgical feasibility and manoeuvrability during surgery if mobilisation of the VA was deemed necessary in a particular case. 3. Surgical Intervention In the present series, the trajectory and orientation of VA were noticed before these patients were taken up for surgical intervention. As mentioned earlier, the department maintains a robust policy of getting adequate information about VA before proceeding with joint manipulation and instrumentation in this area. The following were the standard surgical steps that were followed in all the cases where VA mobilisation was found to be mandatory at our centre: a. The patients were positioned prone with traction applied after Gardener Wells induction of anaesthesia, and about 10% of their body weight was applied to it. b. A midline skin incision extending from external occipital protuberance to C3 spinous process to achieve adequate exposure of the C1-C2 joint with proper proximal and distal exposure of the surgical landmarks. c. In the case of a unilateral dominant VA with the anomalous course, the side with dominant VA was operated first. This is a consensus of the surgeons that during the early period of the surgery, the operating surgeon and the surgical team are relatively much fresher, and the handling of surgical stress goes smoothly. In the case of bilateral codominant VAs, the right side of CVJ was addressed first, followed by the left one based on the handiness of the surgeon, as in our series, all the surgeons are right-handed. d. During surgery, the principles of micro neurosurgery helped identify the VA and differentiate it from the C2 nerve root and adjacent soft tissues. Fig 2.A-C demonstrate the neuroanatomical structure following surgical exposure of the CVJ region for better understanding. Fig 3. shows the radiology of a case before and after surgical stabilisation. Fig 4. and Fig 5. are the surgical images of the case who underwent tailored mobilisation of VA followed by screw insertion in C1 and C2. 4. Post operative care and follow up The operated patients received standard post-operative care as per the departmental policy. Following surgery, all these patients were managed exclusively in the neurosurgery ICU. They were extubated the next day morning after a period of overnight ventilation to alleviate vocal cord oedema due to the prone position and oedema around the operative cavity. Patients in whom an initial attempt of extubation failed were kept on mechanical ventilation with a low threshold for elective tracheostomy. Incentive spirometry was a routine practice in all the patients undergoing surgery at CVJ to avoid post-operative lung atelectasis. The patients were kept on rigid cervical collars to maintain neck stability for six weeks. The functional status was evaluated at six weeks and three months after surgery. The follow-up radiology was performed at six weeks to look for the condition of the implants and the extent of bony fusion. Results The mean age of the 18 cases included in the study was 49.21 ± 18.30 years, while the mean age of the control group was 48.20 ± 20.41 years (p = 0.87). The male-to-female ratio in the control group was 1.5:1, suggesting a higher involvement of male patients than females in the population under study. Twelve of the 18 cases underwent bilateral vertebral artery mobilization, whereas the remaining six underwent unilateral vertebral artery mobilization Table 1 . Table 1 Table showing the demography and clinical parameters of the patients. Parameters N = 18 Age 18 to 52 years (median = 28.6 yrs) Gender M: F = 1.5:1 Clinical spectrum of presentation Case number Pre-operative Nurick’s Grade Post-operative Nurick’s Grade Pre-operative MAS grade Post-operative MAS grade 1. 4 2 3 1 2. 4 2 3 1 3. 4 2 3 1 4. 4 3 3 2 5. 5 4 4 3 6. 3 3 3 2 7. 3 2 3 2 8. 4 3 3 2 9. 5 4 4 3 10. 3 2 2 1 11. 5 5 4 3 12. 4 4 3 2 13. 4 3 3 2 14. 3 2 2 1 15. 3 2 2 1 16. 4 3 3 2 17. 3 2 4 3 18. 4 3 3 1 Median (IQR) [Range] 4 (3, 4) [ 3 , 5 ] 3 (2, 3) [ 2 , 5 ] 3 (3, 3) [ 2 , 4 ] 2 (1,2) [ 1 , 3 ] P value 0.002 < 0.001 Wilcoxon signed rank test used. P < 0.05 significant In a single case with codominant VA sustained an injury to the V3 segment of VA, which was managed successfully with primary repair using 8 − 0 proline sutures. Joint remodelling (JRM) was achieved in all the joints where VA was mobilized. The free-hand C1 lateral mass screw placement was achieved with VA mobilization. The average blood loss was 450 ml (range: 250 to 950 ml) in bilateral VA mobilization cases vs no mobilization of VA; average blood loss- 400 ml. The median volume of blood loss in bilateral VA mobilization was 560ml, which was 415ml in those cases that underwent unilateral VA mobilization. The median volume of blood loss in the control group was 350 ml. There was a significantly high volume of blood loss amongst the group who underwent bilateral VA mobilization (p = 0.001) as compared to those who underwent unilateral VA mobilization (p = 0.840) when compared with the control group. The average surgical time in cases of no VA mobilization was 3.5 hrs; in cases with unilateral VA mobilization, it was 5.5 hrs vs. 6.5 hrs in bilateral VA mobilization. The duration of surgery was significantly prolonged amongst the group who underwent bilateral VA mobilization (p = 0.001) compared to those who underwent unilateral VA mobilization (p = 0.174) compared with the control group where vertebral artery mobilization was not performed Table 2 . Table 2 Table demonstrating the distribution of the blood loss, duration of surgery and hospital stay (N = 18, case and n = 18, control) Variable´s Minimum Maximum Q1 Q2 Q3 P value Blood Loss Bilateral (n = 12) 300 900 435 560 725 0.001 Unilateral (n = 6) 300 460 308 415 453 0.840 Control (n = 18) 250 550 295 350 500 Ref Duration of Surgery Bilateral (n = 12) 3 7 4 4.65 6.25 0.001 Unilateral (n = 6) 3.2 5 3.425 4 4.25 0.174 Control (n = 18) 3 4.5 3 3.5 4 Ref Duration of Hospital Stay# Cases 6 12 7 7 9.25 0.005 Control 6 8 6 7 7 Kruskal Wallis H test / #Mann Whitney U test used. P < 0.05 significant Postoperative care and hospital stay were offered as per departmental policy. Preoperative neck pain improved, and a hard cervical collar was applied to all the patients for three months. The duration of hospital stay was significantly higher among the case (9.25 days) than the control (7 days) group, which was statistically significant (p = 0.005). The hospital stay among the study population was higher because of the prolonged intensive care unit (ICU) stay in eight cases. Five out of eight cases underwent tracheostomy to facilitate early mobilization from the ICU and to avoid ventilator-associated pneumonia. The mean follow-up duration was 23.2 months (range:6–62 months, SD: 15.4). This retrospective observational study had no procedure-related mortality. The median pre-operative Nurick’s grade amongst the study population was 4 (IQR: 3,4 and Range: 3–5). After surgery, at three months of follow-up visit, the median post-operative Nurick’s grade amongst the same patients was 3 (IQR: 2,3 and Range: 2–5), which was statistically significant (P = 0.002). There was an improvement in bladder and bowel function after surgery, and two out of six (2/6) patients with autonomic dysfunction required clean intermittent catheterization during their last follow-up visit after 28 months of surgery. The median pre-operative modified Ashworth scale (MAS) grade amongst the study population was 3 (IQR: 3,3 and Range: 2–4). After surgery, at three months of follow-up visit, the median post-operative MAS grade was 2 (IQR: 1,2 and Range: 1–3), which was statistically significant (P < 0.001). The follow-up period at 3 months and 6 months showed improvement in spastic features/ weakness due to myelopathy, and the follow-up radiology was suggestive of correction of AAD. Statistical analysis- Continuous variables are presented in median and interquartile range (IQR) or mean with standard deviation and range, whereas categorical variables are presented in number (%). Kruskal Wallis H test was used to compare the medians between the three groups. Multiple comparisons were made using Bonferroni corrections for the significant p-value. Mann Whitney U test was used to compare the median between cases and controls. Nurick’s Grade ranged from 1 to 5, an ordinal variable was compared between before and after observations using Wilcoxon signed rank test. The analyses were performed using the Statistical Package for Social Sciences version- 23 (SPSS-23, IBM, Chicago, USA). P value < 0.05 was considered statistically significant. Discussion Goel and Harm’s posterior approach with C1-C2 fixation has brought a novel and revolutionary concept to the field of spine surgery worldwide [ 1 , 2 ]. Over the last two decades, the standard teaching for managing CVJ has been posterior stabilization with or without joint remodelling. The major obstacle in remodelling the C1-C2 joint was the anomalous course of VA and developmental aberration of the occipitocervical complex. The available literature suggests that there is a 20% chance of variation in the trajectory of VA across the CVJ [ 3 ]. This anatomical hindrance led to the development of a relatively safer surgical technique where the in-situ fusion of the craniovertebral junction utilizing occipitocervical fusion (O-C2 fusion) was practised, precluding the risk of VA injury [ 4 ]. A. The goal of CVJ surgery 1: Alleviation of compression from the neuraxis: The primary pathology of AAD spectrum disorders is instability at the C1-C2 joint because of widespread aetiology, which in turn leads to increased mobility leading to persistent microtrauma and compression at the cervicomedullary region of the neuraxis. This compression over CMJ leads to not only sensorimotor deficits but cranial nerve impairments along with autonomic disabilities. Stable reconstruction using C1-C2 instrumentation provides the best chance of decompression and excellent clinical outcomes [ 1 , 2 ]. 2: Fusion in the most acceptable bony alignment: The best way of achieving the same has been the reorientation of bony anatomy by C1/C2 joint remodelling and manipulation. Joint preparation and spacer-assisted or raw bone impaction help achieve robust bony fusion [ 5 , 6 ]. B. Obstacles to achieve the goal 1: Sagittal joint inclination: The sagittal angle between the C1-C2 articular surface of more than 32.5 degrees poses a significant challenge to achieving good alignment after joint remodelling. In this situation, the joint needs to be prepared, and the bony fusion is augmented by exposing the cancellous part of the articular surface. If the reduction index (RI) value is > 27.9% and the sagittal atlantoaxial joint inclination (SAAJI) value is < 32.5°, reduction and fixation can be achieved by the posterior approach alone; otherwise, a combination of anterior and posterior approaches would be necessary [ 7 , 8 ]. 2: Retroverted odontoid: The retroverted lie of the C2 odontoid/ dens may be due to pathologies of the os odontoideum, such as mobile os, pannus at the os due to rheumatoid arthritis and soft tissue collection adjacent to the atlantodental space. The posterior approach can address the compression from the ventral aspect in the background of favourable joint anatomy. Ventral decompression through a trans-oral approach is excellent and feasible and should be considered [ 9 ]. 3: Severe Platybasia: This is a surrogate marker of severe instability at CVJ and reflects a protective phenomenon leading to severe Platybasia. The central invagination of the odontoid of the axis is considered central dislocation and describes the subsidence of the cranial portion over the CVJ area. These complex subsets of pathologies warrant adequate joint remodelling to achieve fusion in a position that offers minimal ventral compression over the cord. 4: Anomalous VA course: Patients undergoing CVJ surgery experience a wide range of VA anomalous courses. This variation becomes more intricate in the background of the syndromic presentation of CVJ anomalies such as Klippel Feil syndrome or os odontoideum [ 10 , 11 ]. 4.1% of patients undergo CVJ surgery. Considering the factors mentioned earlier, the most challenging factor has been the Anomalous VA course, and as such, if the VA course is favourable, the other three factors can be addressed effectively. The anomalous course of VA, the biggest hurdle in accessing the C1-C2 joint, is the only modifiable of all the factors. The mobilization of VA offers better access to the area of interest in the CVJ region. The mobilization of VA offers the best solution to address the joint orientation, alleviating the ventral cord compression due to the retroverted odontoid. The appropriate address of anatomical aberration of VA provides the best chances of improvement in this complex set of pathologies, which in turn seems to be a ‘blessing in disguise’. Types of VA anomalies in our series The paper by JS et al. suggests that 1 to 41% of cases have an abnormal orientation of VA, and out of these, a variable number of patients have a unilateral or bilateral course [ 12 , 13 ]. The origin of PICA (posterior inferior cerebellar artery) from the VA poses a unique challenge to the surgeon in order to protect a significant vessel with the eloquent territory being supplied by PICA, in addition to the mobilization of the VA [ 14 ]. In the present series, we noticed 12 bilateral VAA and 6 cases with unilateral aberrant course. There was a case with a low-lying origin of PICA on the right side, with VA passing across the joint. During tailored mobilization of the traversing artery across the joint, the importance of focused mobilization was emphasized, and the trajectory of joint manipulation was assessed by bringing the PICA inferior and medial to the joint. Embryological background Over the last one and a half decades, with growing experience and a better understanding of the complex CVJ region, embryological/ developmental aberrations have been identified as the most critical factor. These developmental alterations most commonly involve the V3 and V4 segments (distal segments) of the VA. The available literature suggests variable frequency of incidence and their clinical significance. Several embryological explanations have been proposed to elaborate on the anomalous origin and course of VA's V3 and V4 segments [ 15 ]. The first theory suggests the appearance of an aberrant intradural VA at the C2 level with or without a normal course of VA. Lasjaunias et al. proposed that a reasonable number of developmental variations are due to changes in the segmental calibre of the distal VA and lateral spinal artery (LSA), one of the branches of VA [ 16 ]. According to Siclari et al., the developmental variations of the posterior spinal artery (PSA) lead to various variations in the distal segments of VA [ 14 ]. The second theory was proposed by Uchino et al. and Tokuda et al [ 17 , 18 ]. As per Uchino et al., in the situation where the first intersegmental artery (FIA) and the regular VA branch both persist, one branch of the VA takes the normal anatomical pathway, whereas the other branch enters the spinal canal between C1 and C2, which result in aberrant intradural VA at the C2 level with a standard running VA. Uchino et al. further proposed that if the first intersegmental artery (FIA) persists and continues to the PICA without fusion with the VA, it forms the extracranial C1/2 origin of the PICA. Yamazaki et al. reported that nearly 16% of patients have unilateral VA dominance.[ 8 ] The close association between unilateral hypoplasia/aplasia of the VA and segmentation of bony anomalies at the CVJ (occipitalised atlas, facet fusion or C2‑3 fusion) may be attributed to the typical embryonic stage in which re-segmentation of embryonic sclerotome and vascular sagittal rearrangement of intersegmental artery occur [ 10 ]. The FT forms around the developing VA. Its posterior aspect develops from the neural process, and the anterior portion is from a vestigial coastal element that fuses to the vertebral body, enclosing the VA. The size of the VA has a close developmental relationship with its corresponding FT. In a prospective study by Jayesh et al., the relationship between the diameter of the ipsilateral VA and its C1 FT showed a positive correlation [ 19 ]. C. Core answer to the problem The axis of CVJ surgery revolves around understanding the 3D orientation and anatomy of the C1-C2 joint and the structures responsible for keeping the alignment in place. Once we understand the orientation of joint morphology, we must make every attempt to bring the joint into better alignment, and by doing this, the compression over the neuraxis will be alleviated. D. How anomalous VA dictates the surgical strategy The course of the VA always follows the development and progress of the bony structures around the CVJ. Several structures dictate the course of VA around CVJ, such as the foramen transversarium of the axis and atlas vertebra. The embryological variations which lead to the anomalous course of the VA lead to various radiological aberrations around CVJ. These include occcipitalised atlas, hypoplasia of the posterior C1 arch and rotatory anomalies in various planes of movement. The goal of surgeries for AAD is to achieve the remodelling of the C1-C2 joint and encourage fusion between them to achieve stability of the CVJ. During the initial days of CVJ surgery, the presence of VA passing across the C1-C2 joint makes the accessibility to the joint space an impossible task. With available neurosurgery gadgets and experienced micro neurosurgeons, the feasibility of tailored mobilization of VA is now a reality. Radiology Conventional radiology in the form of CT CVJ with 3D reconstruction helps provide the orientation of joint alignment and orientation of the C1-C2 joint. The addition of VA angiography with CT CVJ provides a complete orientation of the vascular trajectory and any possibility of anomalous course around the CVJ [ 10 , 20 , 21 ]. Several publications have been available in the literature reflecting the use of vertebral angiograms in predicting the course and taking useful rescue measures to avoid any unexpected injury during surgical manipulation of these neurovascular structures. The utility of MRI cannot be over-emphasized because it provides an extent of compression at CVJ along with the changes in the cord, reflecting an impact on the prognosis [ 17 ]. In the present study, the MRI of the CVJ was performed to identify modifiable factors and etiologies that might contribute to the clinical presentation of the patients under study, e.g., Rheumatoid arthritis, tuberculosis of the CVJ, and Os odontoideum with a retroverted position. 3D reconstruction and 3D printing of the CVJ The vertebral artery angiogram provides a 2D orientation and relationship of the VA with the C1-C2 joints and the artery's course across the joint. The VA routinely passes through the foramen transversarium of C1 vertebrae and then travels horizontally over the posterior arch of C1 before becoming intradural in location. The 3D reconstruction of this angiogram provides a better orientation and the association of the vertebral artery with the C1-C2 joint in the close vicinity. The 3D printed models provide an actual three-dimensional stereoscopic orientation of the individual patient in real-time, which can be translated very well during surgery on the patient. The anatomy of the posterior arch of C1 is essential in almost all of the cases of VA crossing in front of the C1-C2 joint, as it gets occipitalised. The added advantage of 3D printed models over other available modalities is that they provide a virtual appearance of all the neuroanatomical structures which may be encountered during the surgery much prior to actual surgery. The surgeon can plan the surgical strategy and modify it accordingly depending upon the anatomy detected on an individual case basis [ 22 ]. Surgical Ergonomics Patient factors The surgery for CVJ is performed primarily in a prone position except for the trans-oral approach, where the patient lies in a supine position with neck extension. The prone position carries a specific risk due to the patient’s trunk lying on the table and head resting over the horseshoe. The role of cervical traction is indispensable, and we applied cervical traction in all our cases. Soft padding/ silicon pads of all the bony prominences and keeping the abdomen free from compression ensures favourable hemodynamics for CVJ surgery. The head resting over the head ring must ensure that the eyes are free from any compression, or else this results in catastrophic outcomes leading to blindness on many occasions [ 23 , 24 ]. Surgeon’s Factors The CVJ surgery is performed in a standing position with an operating microscope with high magnification. The surgeon must be comfortable with the fine adjustment of the microscope and its utility in handling neurovascular structures in limited exposure. The surgical experience of handling microsurgical instruments and high-speed drills simultaneously in the same operative field makes this surgery much more challenging. The surgical inclination, persistence, and patience to handle the long-duration surgery in a standing position with limited arm support are the factors which lead to early fatigue, resulting in decreased surgical precision and, in turn, increased chances of neurovascular injury [ 25 ]. Surgical safety and Outcomes The CVJ surgery through a posterior approach becomes much safer once the surgeon has the preoperative information and a 3-D orientation of the CVJ in mind. The availability of modern radiological modalities has provided a significant advancement in understanding the structures at risk, such as the vertebral artery with the anomalous course in surgery around the CVJ [ 26 ]. Sarat et al. described a case of the vertebral artery during dissecting across the C2 nerve root in their article. Specific surgical strategies need to be kept in mind to avoid VA injury [ 27 ]. There are instances where people have mistaken VA (V2 segment) with C2 nerve root, which resulted in significant injury and blood loss. The senior author suggested that a few basic principles be followed during surgery around the CVJ, especially during mobilization of VA and remodelling of the C1-C2 joint. • The VA runs vertically perpendicular to the lamina and always lies ventral to the C2 root. • The orientation of the C2 root is parallel to the C1 and C2 lamina and is horizontally placed posterior to the ascending/ V2 segment of VA. • In case of doubt, the Doppler can be used. If one does not have the facility of a Doppler, the lumen of the VA can be verified by using an Insulin needle syringe to detect the content of the aspirate, keeping in mind not to damage the vertebral venous plexus around it. • The dissection plane after cutting the C2 nerve root should be parallel to the VA and traced from the foramen transversarium of C2 towards the cranial end. • The vertebral venous plexus lies around the vertebral artery, which should be traced with the length of the VA. • The occipitalisation of the posterior arch of C1 vertebrae provides an additional advantage to the surgeons. The VA, in its ordinary course, can be considered to be locked in the foramen transversarium of the C1 vertebrae. However, in most congenital CVJ anomalies the occipitalised posterior C1 arch lacks the foramen transversarium. Hence, the course of VA is relatively straightforward towards the posterior lip of the foramen magnum before becoming intra-dural in location [ 19 ]. • The VA can be mobilised safely in a tailored fashion as the vasa vasorum and vas nervosum around the vertebral artery significantly resist vasospasm. Hence, VA mobilisation is much less vasospastic than that of intracranial vessels. • The tailored mobilisation of VA was helpful in joint remodelling where a spacer was placed between the C1-C2 joint. The VA was mobilised inferomedial and superolateral to achieve the adequate space required for instrumentation. • We at our Centre practised the free hand screw placement using the knock and drill technique in all the cases. This provides the added advantage of reducing the surgical time and significantly reducing radiation exposure to the patient and the surgical team [ 28 , 29 ]. The Blessings in disguise: The most complex and common subtype of VAA has been VA lying in front of the C1/C2 joint in a prone position without passing through the C1 Foramen transversarium as the C1 posterior arch is occipitalised. This variation provides the opportunity to mobilize the VA in a tailored way as per requirement on a case-to-case basis to achieve the core result of the most favourable bony re-orientation. The most helpful mobilization in this type of VAA has been inferomedial to expose the C1 lateral mass and the C1/C2 joint. Learning curve The importance of having detailed neuroanatomical knowledge and orientation of the pathological anatomy must be considered. Sound knowledge of the principles of micro neurosurgery and manoeuvrability of high-speed/ surgical drills are essential skills acquired during surgical practice. The usefulness of cadaveric laboratory and dissection of CVJ in human cadavers forms the foundation for neuroanatomical orientation and confidence to operate in such an eloquent area. The utility of the saw bone model is also a useful tool to realize the trajectory of the screws in virtual scenarios. The senior author suggests that younger colleagues take the initiative to attend cadaveric workshops on a regular basis and get accustomed to the course of the VA, the curves and bends, and the neural structures encountered in the close vicinity of the VA artery. Advantages: The present tailored procedure has reduced the additional surgical insult in approximately 95% of cases where an additional anterior approach in the form of trans-oral decompression and odontoidectomy or incomplete posterior procedure was used earlier. This also helped reduce the cost of additional procedures without significantly increasing the surgical time, blood loss, and perioperative morbidities. The literature suggests a 28% chance of deterioration after Occipitocervical fusion and trans-oral odontoidectomy. Potential Challenges: Managing complex CVJ anomalies wherein VA mobilization is deemed necessary requires a good-quality microscope, microsurgical instruments, and a setup geared for managing intraoperative and postoperative complications. The micro neurosurgical procedure of tailored VA mobilization itself has a steep learning curve, and one must be trained enough to repair the vascular injury or manage it timely through endovascular intervention. Conclusion The tailored VAM is a good option to negotiate through C1/C2 joint in a relatively small but unique subset of CVJ without adding to the surgical time, blood loss, morbidities, or mortality. The technique of tailored VAM offers safe access to managing CVJ anomalies if performed with adequate experience and keeping in mind the principles of micro neurosurgery. Statement and Declaration Acknowledgement: No one to acknowledge. Conflict of Interest: The authors have no conflict of interest to declare. Funding: The present study does not involve any source of funding. Competing Interest: NIL. Authors contribution: All authors contributed to the study conception and design. Material preparation was done by [Ved Prakash Maurya], data collection was done by [Ashutosh Kumar], [Anantha Chaitanya J], [Priyadarshi Dikshit], [Ravi Ranjan], [Kamlesh Singh Bhaisora], [Kuntal Kanti Das], [Shreyash Rai], [Pawan Kumar Verma], [Soumen Kanjilal], and analysis were performed by [Ved Prakash Maurya], [Anant Mehrotra], [Awadhesh Kumar Jaiswal] and [Arun Kumar Srivastava]. The first draft of the manuscript was written by [Ved Prakash Maurya] and all authors commented on previous versions of the manuscript. The illustrations in the manuscript were drawn by [Priyadarshi Dikshit]. All authors read and approved the final manuscript. Ethical approval: The present study being a retrospective observational study the Institute Ethics Committee has confirmed that no ethical approval is required to conduct this study. Consent to participate: Informed written consent was obtained from all the participants who were included in the study. Consent to publish: Theauthors affirm that human research participants provided informed consent for publication of the radiological and surgical images displayed in Figures 3.,Figure 4. and Figure 5. References Goel A, Laheri V (1994) Plate and screw fixation for atlantoaxial subluxation. Acta Neurochir (Wien) 129:47–53. 10.1007/BF01400872 Harms J, Melcher RP (2001) Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine 26:2467–2471. 10.1097/00007632-200111150-00014 Jeanneret B, Magerl F (1992) Primary posterior fusion C1/2 in odontoid fractures: Indications, technique, and results of transarticular screw fixation. J Spinal Disord 5:464–475. 10.1097/00002517-199212000-00012 Jain VK (2012) Atlantoaxial dislocation. Neurol India 60:9–17. 10.4103/0028-3886.93582 Salunke P, Sharma M, Sodhi HBS et al (2011) Congenital atlantoaxial dislocation: a dynamic process and role of facets in irreducibility. J Neurosurg Spine 15:678–685 Goel A (2004) Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation. J Neurosurg Spine 3:281–286. 10.3171/spi.2004.1.3.0281 Chandra PS, Goyal N (2015) The severity of basilar invagination and atlantoaxial dislocation correlates with sagittal joint inclination, coronal joint inclination, and craniocervical tilt: A description of new indices for the craniovertebral junction. Neurosurgery 76:E235–239. 10.1227/NEU.0000000000000600 Goel A, Shah A (2011) Atlantoaxial facet locking: Treatment by facet manipulation and fixation. Experience in 14 cases. J Neurosurg Spine 14:3–9. 10.3171/2010.9.SPINE1010 Srivastava SK, Aggarwal RA, Nemade PS et al (2016) Single-stage anterior release and posterior instrumented fusion for irreducible atlantoaxial dislocation with basilar invagination. Spine J 16:1–9. 10.1016/j.spinee. 2015.09.037 Yamazaki M, Okawa A, Furuya T et al (2012) Anomalous vertebral arteries in the extra–and intraosseous regions of the craniovertebral junction visualized by 3–dimensional computed tomographic angiography: Analysis of 100 consecutive surgical cases and review of the literature. Spine 37:E1389–E1397. 10.1097/BRS.0b013e31826a0c9f Yamazaki M, Koda M, Aramomi MA et al (2005) Anomalous vertebral artery at the extraosseous and intraosseous regions of the craniovertebral junction: Analysis by three–dimensional computed tomography angiography. Spine (Phila Pa 1976) 30:2452–2457. 10.1097/01.brs.0000184306.19870.a8 Menezes AH (2008) Craniocervical developmental anatomy and its implications. Childs Nerv Syst 24:1109–1122. 10.1007/s00381-008-0600-1 Sardhara J, Behari S, Jaiswal AK et al (2013) Syndromic versus nonsyndromic atlantoaxial dislocation: Do clinico–radiological differences have a bearing on management? Acta Neurochir (Wien) 155:1157–1167. 10.1007/s00701-013-1717-x Siclari F, Burger IM, Fasel JH et al (2007) Developmental anatomy of the distal vertebral artery in relationship to variants of the posterior and lateral spinal arterial systems. AJNR Am J Neuroradiol 28:1185–1190. 10.3174/ajnr. A0498 Kim MS (2016) Developmental anomalies of the distal vertebral artery and posterior inferior cerebellar artery: diagnosis by CT angiography and literature review. Surg Radiol Anat 38:997–1006. 10.1007/s00276-016-1654-5 Lasjaunias P, Vallee B, Person H et al (1985) The lateral spinal artery of the upper cervical spinal cord. Anatomy, normal variations, and angiographic aspects. J Neurosurg 63:235–241. 10.3171/jns.1985.63.2.0235 Uchino A, Saito N, Watadani T et al (2012) Vertebral artery variations at the C1–2 level diagnosed by magnetic resonance angiography. Neuroradiology 54:19–23. 10.1007/s00234-011-0849-z Epub 2011 Feb 22 Tokuda K, Miyasaka K, Abe H et al (1985) Anomalous atlantoaxial portions of vertebral and posterior inferior cerebellar arteries. Neuroradiology 27:410–413. 10.1007/BF00327604 Sardhara S, Behari S, Mohan MB et al (2015) Risk stratification of vertebral artery vulnerability during surgery for congenital atlanto–axial dislocation with or without an occipitalized atlas. Neurol India 63:382–391. 10.4103/0028-3886.158218 Hong JT, Kim IS, Kim JY et al (2016) Risk factor analysis and decision-making of surgical strategy for V3 segment anomaly: significance of preoperative CT angiography for posterior C1 instrumentation. Spine J 16:1055–1061 Wajanavisit W, Lertudomphonwanit T, Fuangfa P et al (2016) Prevalence of high riding vertebral artery and morphometry of C2 pedicles using a novel computed tomography reconstruction technique. Asian Spine J 10:1141–1148. 10.4184/asj.2016.10.6.1141 Epub 2016 Dec 8 Du Y-Q, Qiao G-Y, Yin Y-H et al (2020) Usefulness of 3D Printed Models in the Management of Complex Craniovertebral Junction Anomalies: Choice of Treatment Strategy, Design of Screw Trajectory, and Protection of Vertebral Artery. World Neurosurg 133:e722–e729. 10.1016/j.wneu.2019.09.139 Epub 2019 Oct 4 Stevens WR, Glazer PA, Kelley SD et al (1997) Ophthalmic complications after spinal surgery. Spine 22:1319–1324. 10.1097/00007632-199706150-00008 Singh G, Maurya VP, Bhaisora KS et al (2024) Unilateral Vision Loss After Posterior Fixation for Traumatic Atlantoaxial Dislocation: A Case Report with Literature Review. Indian J Neurotrauma. IJNT-2024-1-6. 10.1055/s-0044-1782610 Belykh E, Onaka NR, Abramov IT et al (2018) Systematic review of factors influencing surgical performance: practical recommendations for microsurgical procedures in neurosurgery. World Neurosurg 112:e182–e207. 10.1016/j.wneu.2018.01.005 Epub 2018 Jan 9 Bredow J, Oppermann J, Kraus B et al (2015) The accuracy of 3D fluoroscopy navigated screw insertion in the upper and subaxial cervical spine. Eur Spine J 24:2967–2976. 10.1007/s00586-015-3974-2 Epub 2015 Apr 30 Chandra PS, Ghonia R, Singh S et al (2021) Anomalous Vertebral Artery During Cranio Vertebral Junction Surgery Using DCER Approach. and Its Repair. Neurol India 69:315–317. 10.4103/0028-3886.314543 Srivastava AK, Sardhara J, Behari S et al (2017) Knock and Drill Technique: A Simple Tips for the Instrumentation in Complex Craniovertebral Junction Anomalies without using Fluoroscopy. J Neurosci Rural Pract 8:14–19. 10.4103/0976-3147.193555 Sasapardhi SB, Verma PK, Srivastava AK et al (2024) An institutional study on accuracy of freehand cervical C1 C2 screws placement by knock and drill technique in craniovertebral anomalous bony anatomy: An evaluation of more than 600 screws based on SGPGI screw accuracy criteria. J Craniovertebr Junction Spine 15:83–91. 10.4103/jcvjs.jcvjs_116_23.Epub 2024 Mar 13 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 30 Jan, 2026 Read the published version in Neurosurgical Review → Version 1 posted Editorial decision: Revision requested 19 Jan, 2025 Reviews received at journal 19 Jan, 2025 Reviews received at journal 15 Jan, 2025 Reviews received at journal 12 Jan, 2025 Reviewers agreed at journal 12 Jan, 2025 Reviewers agreed at journal 09 Jan, 2025 Reviewers agreed at journal 08 Jan, 2025 Reviews received at journal 08 Jan, 2025 Reviewers agreed at journal 07 Jan, 2025 Reviewers agreed at journal 07 Jan, 2025 Reviewers invited by journal 06 Jan, 2025 Editor assigned by journal 06 Jan, 2025 Submission checks completed at journal 19 Dec, 2024 First submitted to journal 15 Dec, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5646143","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":392332501,"identity":"767b10c1-fddb-4ef0-bb0d-f9399ab2d27c","order_by":0,"name":"Ved Prakash Maurya","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Ved","middleName":"Prakash","lastName":"Maurya","suffix":""},{"id":392332502,"identity":"00bc22aa-8780-4182-813d-03d57d7c1661","order_by":1,"name":"Ashutosh Kumar","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Ashutosh","middleName":"","lastName":"Kumar","suffix":""},{"id":392332503,"identity":"35b266c2-1b17-46f5-acca-97af49086796","order_by":2,"name":"Ananth Chaitanya J","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Ananth","middleName":"Chaitanya","lastName":"J","suffix":""},{"id":392332504,"identity":"1af8e62d-3ad7-47a8-94ca-08c047c83886","order_by":3,"name":"Priyadarshi Dikshit","email":"","orcid":"","institution":"2.\tAll India institute of Medical Sciences, Guwahati; India. 781101.","correspondingAuthor":false,"prefix":"","firstName":"Priyadarshi","middleName":"","lastName":"Dikshit","suffix":""},{"id":392332505,"identity":"50cc1bff-3c93-47bb-a39c-9056e7c12bdd","order_by":4,"name":"Ravi Ranjan","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Ravi","middleName":"","lastName":"Ranjan","suffix":""},{"id":392332506,"identity":"c099b88d-ad43-4fc7-b7d7-07160c90b18e","order_by":5,"name":"Kamlesh Singh Bhaisora","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Kamlesh","middleName":"Singh","lastName":"Bhaisora","suffix":""},{"id":392332507,"identity":"7f368c1b-051d-410c-a9cc-ef21468714b7","order_by":6,"name":"7.\tKuntal Kanti Das","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"7.\tKuntal","middleName":"Kanti","lastName":"Das","suffix":""},{"id":392332508,"identity":"41749f09-419b-44c6-b36b-d000e4d1f43c","order_by":7,"name":"Shreyash Rai","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Shreyash","middleName":"","lastName":"Rai","suffix":""},{"id":392332509,"identity":"d6f9ec73-d829-4a53-b3fb-86e3b880cd23","order_by":8,"name":"Pawan Kumar Verma","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Pawan","middleName":"Kumar","lastName":"Verma","suffix":""},{"id":392332510,"identity":"5a2a249c-2a2b-4712-874e-2cb2e1ceac26","order_by":9,"name":"Soumen Kanjilal","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Soumen","middleName":"","lastName":"Kanjilal","suffix":""},{"id":392332514,"identity":"16452a12-5695-4d79-af18-5043e607173a","order_by":10,"name":"Anant Mehrotra","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Anant","middleName":"","lastName":"Mehrotra","suffix":""},{"id":392332515,"identity":"808fa93c-a440-427d-80e3-47a408a996c5","order_by":11,"name":"Awadhesh Kumar Jaiswal","email":"","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":false,"prefix":"","firstName":"Awadhesh","middleName":"Kumar","lastName":"Jaiswal","suffix":""},{"id":392332516,"identity":"e3caf66c-7449-4dc5-8ddb-ad17f7a83385","order_by":12,"name":"Arun Kumar Srivastava","email":"data:image/png;base64,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","orcid":"","institution":"1.\tSanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow. India. 226014.","correspondingAuthor":true,"prefix":"","firstName":"Arun","middleName":"Kumar","lastName":"Srivastava","suffix":""}],"badges":[],"createdAt":"2024-12-15 06:38:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5646143/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5646143/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10143-025-04030-x","type":"published","date":"2026-01-30T15:59:19+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":72362690,"identity":"f780f54f-43c6-47df-8e9d-35ca1a3a64c1","added_by":"auto","created_at":"2024-12-26 06:09:16","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":249059,"visible":true,"origin":"","legend":"\u003cp\u003eConsort diagram showing the patient selection process for the study. [VA- vertebral artery, CVJ- craniovertebral junction, CT- computerised tomography.]\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5646143/v1/67815b78ed1391d55748b38a.png"},{"id":72362687,"identity":"f9cc6c47-76e2-4179-9038-10f182a7a4d2","added_by":"auto","created_at":"2024-12-26 06:09:16","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":664314,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA. \u003c/strong\u003ePosterior exposure of the CV Junction and upper cervical spine demonstrating occipitalised atlas (1), malformed retroverted C2 vertebra. There is an associated anomalous course of\u0026nbsp; 3\u003csup\u003erd\u003c/sup\u003e part of\u0026nbsp; vertebral arteries (3) with the surrounding venous plexus traversing posterior to the C1-C2 joint. \u003cstrong\u003eB. \u003c/strong\u003eThe C2 ganglia (4) are then divided C. with careful control of surrounding venous plexus. \u003cstrong\u003eC. \u003c/strong\u003eThe assimilated posterior arch of atlas is carefully drilled \u003cstrong\u003e(**) \u003c/strong\u003eto achieve foramen magnum decompression and the dural entry site of the vertebral artery is exposed. After this with gentle dissection, the vertebral artery is mobilized inferomedially, exposing the C1-C2 joint\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5646143/v1/603771b208287dd0ad7328ff.png"},{"id":72364458,"identity":"0de92fd9-abe1-4166-b966-2736afa0b3db","added_by":"auto","created_at":"2024-12-26 06:25:16","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":692274,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e. Preoperative T2 weighted MRI, sagittal section showing compression at cervico-medullary junction due to odontoid tip with T2 intensity changes within the cord. There is tonsillar herniation with cervico-dorsal syrinx (Chiari malformation type 1). \u003cstrong\u003eB\u003c/strong\u003e. CT-CVJ flexion showing atlanto-dental interval of 7mm with no basilar invagination. The C1 is occipitalised with C2-C3 fusion. \u003cstrong\u003eC\u003c/strong\u003e. On extension CT-CVJ, the ADI is completely reduced (mobile AAD). \u003cstrong\u003eD\u003c/strong\u003e. Coronal section of CT-CVJ showing asymmetrical joints. \u003cstrong\u003eE\u003c/strong\u003e. 3D CT reconstruction showing anomalous vertebral artery on the right side. It is coursing over the joint and under the C1 arch, going medially into the thecal sac at the level of the foramen magnum (persistent first cervical intersegmental artery). Bilateral high-riding vertebral arteries are present. \u003cstrong\u003eF\u003c/strong\u003e. Post-operative CT-CVJ showing complete reduction of ADI with no BI. \u003cstrong\u003eG\u003c/strong\u003e. Post-operative CT 3D reconstruction showing the divergent construct.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5646143/v1/daa8b28b380e4efbf9571fb7.png"},{"id":72363473,"identity":"e57ff43f-39a9-4fc6-ad61-c4ead8d79a7c","added_by":"auto","created_at":"2024-12-26 06:17:16","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":948005,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e. Standard posterior exposure of cranio-vertebral junction. (*C2 spinous process) \u003cstrong\u003eB\u003c/strong\u003e. The C2 ganglion is resected. \u003cstrong\u003eC\u003c/strong\u003e. The underlying joint capsule is cut. \u003cstrong\u003eD\u003c/strong\u003e. The vertebral artery has been completely skeletonized. (*C2 foramen transversarium).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5646143/v1/26a986de3633c9d3d6c58939.png"},{"id":72362694,"identity":"d3ea03d4-8b70-4b84-a1c4-6a49f15bdc10","added_by":"auto","created_at":"2024-12-26 06:09:16","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1016459,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e. The VA (thick arrow) is caudally mobilized to access the OC1 complex (*). The suction is pointing at the C1 C2 joint having a spacer in situ. \u003cstrong\u003eB\u003c/strong\u003e. The VA (thick arrow) is mobilized cranially to insert C2 direct pedicle screws. \u003cstrong\u003eC\u003c/strong\u003e. Once both the screws have been inserted, the VA (thick arrow) is secured by inserting fat (thin arrow) harvested from sub-cutaneous space between the VA and the screws. For the same reason, shank screws are used for the OC1 complex. \u003cstrong\u003eD\u003c/strong\u003e. The final construct in situ with VA passing between the two screws under the rod.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5646143/v1/1f622bacc3408d9c3506540c.png"},{"id":101690569,"identity":"2d8b23c3-f6a3-45b9-a775-c5601af13d32","added_by":"auto","created_at":"2026-02-02 16:05:48","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6014697,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5646143/v1/121591fd-87af-4ca8-8824-59b00307876c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eTailored vertebral artery mobilisation in complex craniovertebral junction surgery- a blessing in disguise\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe art of micro neurosurgery has significantly affected tissue handling in a better way, which in turn has translated into improved surgical outcomes. The pathology around the craniovertebral junction (CVJ) requires the amalgamation of three-dimensional orientation, neuroanatomical knowledge, and sound information about the developmental/ embryological variations around the area of CVJ. The spectrum of pathologies encountered around the craniovertebral junction is atlantoaxial dislocation (AAD), basilar invagination (BI), foramen magnum tumours (especially meningiomas), as well as the entire spectrum of Chiari malformations. The surgical exposure of this area requires significant manipulation of the neurovascular structures and the atlantoaxial joint (C1-C2 joint) to access the pathological region. In complex subtypes of CVJ anomalies, the vertebral artery (VA) course is often not along the expected trajectory. It is encountered in front of the joint when the patient is positioned in the prone position. To achieve adequate C1-C2 joint manipulation, the mobilisation of the VA is mandatory in a complex subset of patients having CVJ anomalies.\u003c/p\u003e \u003cp\u003eThe present retrospective observational study aims to describe the surgical nuances and share the experience of vertebral artery mobilisation around the craniovertebral junction during the management of CVJ anomalies.\u003c/p\u003e"},{"header":"Methods And Material","content":"\u003cp\u003eThis retrospective observational study conformed to the ethical guidelines laid down in the Helsinki declaration (1964). The study being retrospective observational in nature the institute ethics committee has confirmed that no ethical approval is required. Departmental and institute protocols were followed regarding informed written consent for the publication of clinical findings. The operated cases of CVJ anomalies over the last five years, from January 2019 to December 2023, were collected. Their 3D CT with VA angiogram course, along with their operation details, were noted.\u003c/p\u003e\n\u003cp\u003eThe clinical, radiological and intraoperative details of surgically managed patients of craniovertebral junction pathology were collected from the neurosurgery operative records. The follow-up details of these patients over the last five years were collected from the hospital information and neurosurgery record-keeping system \u003cstrong\u003e(Fig 1.).\u003c/strong\u003e The latest follow-up of patients were obtained either in the outpatient department of neurosurgery or telephonically.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion Criteria \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn all cases of CVJ anomaly, the preoperative vertebral angiogram showed an anomalous course of the VA. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion Criteria \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026bull; Cases of CVJ anomaly where the mobilisation of the vertebral artery was not required.\u003c/p\u003e\n\u003cp\u003e\u0026bull; Cases of CVJ anomaly where C1-C2 stabilisation was deferred as per the discretion of the operating surgeon.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1. Clinical Evaluation \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll patients underwent detailed clinical evaluation, including sensory, motor, and autonomic systems, including any stigmata of syndromic association. The features of compressive myelopathy, the status of the lower cranial nerves, and functional status were assessed. The motor system was assessed on the basis of MRC grade, and the MAS score was used to assess the degree of spasticity. Nurick\u0026rsquo;s grade was used to assess the functional status of the patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. Radiologic Evaluation and Preoperative Planning\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAs per departmental policy, all patients diagnosed with CVJ spectrum disorder were subjected to a computerised tomography scan of the CVJ in flexion, extension, and neutral position. The 3D reconstruction of the radiology with vertebral artery angiogram was performed to orient the distorted anatomy better and ensure the patient\u0026apos;s surgical safety.\u003c/p\u003e\n\u003cp\u003e\u0026middot; CT Angiogram of Vertebral Artery\u003c/p\u003e\n\u003cp\u003eThe included patients were subjected to vertebral artery angiogram and evaluated by the neurosurgical team for the dominance and course of the VA (whether co-dominant or unilateral dominance). The course and alignment of the VA to the C1-C2 joint were evaluated on both sides to look for surgical feasibility and manoeuvrability during surgery if mobilisation of the VA was deemed necessary in a particular case.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. Surgical Intervention \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the present series, the trajectory and orientation of VA were noticed before these patients were taken up for surgical intervention. As mentioned earlier, the department maintains a robust policy of getting adequate information about VA before proceeding with joint manipulation and instrumentation in this area. The following were the standard surgical steps that were followed in all the cases where VA mobilisation was found to be mandatory at our centre:\u003c/p\u003e\n\u003cp\u003ea. The patients were positioned prone with traction applied after Gardener Wells induction of anaesthesia, and about 10% of their body weight was applied to it. \u003c/p\u003e\n\u003cp\u003eb. A midline skin incision extending from external occipital protuberance to C3 spinous process to achieve adequate exposure of the C1-C2 joint with proper proximal and distal exposure of the surgical landmarks.\u003c/p\u003e\n\u003cp\u003ec. In the case of a unilateral dominant VA with the anomalous course, the side with dominant VA was operated first. This is a consensus of the surgeons that during the early period of the surgery, the operating surgeon and the surgical team are relatively much fresher, and the handling of surgical stress goes smoothly. In the case of bilateral codominant VAs, the right side of CVJ was addressed first, followed by the left one based on the handiness of the surgeon, as in our series, all the surgeons are right-handed.\u003c/p\u003e\n\u003cp\u003ed. During surgery, the principles of micro neurosurgery helped identify the VA and differentiate it from the C2 nerve root and adjacent soft tissues. \u003cstrong\u003eFig 2.A-C\u003c/strong\u003e demonstrate the neuroanatomical structure following surgical exposure of the CVJ region for better understanding. \u003cstrong\u003eFig 3.\u003c/strong\u003e shows the radiology of a case before and after surgical stabilisation. \u003cstrong\u003eFig 4. and Fig 5.\u003c/strong\u003e are the surgical images of the case who underwent tailored mobilisation of VA followed by screw insertion in C1 and C2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4. Post operative care and follow up\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe operated patients received standard post-operative care as per the departmental policy. Following surgery, all these patients were managed exclusively in the neurosurgery ICU. They were extubated the next day morning after a period of overnight ventilation to alleviate vocal cord oedema due to the prone position and oedema around the operative cavity. Patients in whom an initial attempt of extubation failed were kept on mechanical ventilation with a low threshold for elective tracheostomy. Incentive spirometry was a routine practice in all the patients undergoing surgery at CVJ to avoid post-operative lung atelectasis. The patients were kept on rigid cervical collars to maintain neck stability for six weeks. The functional status was evaluated at six weeks and three months after surgery. The follow-up radiology was performed at six weeks to look for the condition of the implants and the extent of bony fusion.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe mean age of the 18 cases included in the study was 49.21\u0026thinsp;\u0026plusmn;\u0026thinsp;18.30 years, while the mean age of the control group was 48.20\u0026thinsp;\u0026plusmn;\u0026thinsp;20.41 years (p\u0026thinsp;=\u0026thinsp;0.87). The male-to-female ratio in the control group was 1.5:1, suggesting a higher involvement of male patients than females in the population under study. Twelve of the 18 cases underwent bilateral vertebral artery mobilization, whereas the remaining six underwent unilateral vertebral artery mobilization Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTable showing the demography and clinical parameters of the patients.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameters\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eN\u0026thinsp;=\u0026thinsp;18\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003e18 to 52 years (median\u0026thinsp;=\u0026thinsp;28.6 yrs)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eM: F\u0026thinsp;=\u0026thinsp;1.5:1\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eClinical spectrum of presentation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eCase number\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePre-operative Nurick\u0026rsquo;s Grade\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003ePost-operative Nurick\u0026rsquo;s Grade\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003ePre-operative MAS grade\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003ePost-operative MAS grade\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e5.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e6.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e7.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e8.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e9.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e10.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e11.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e12.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e13.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e14.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e15.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e16.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e17.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e18.\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMedian (IQR) [Range]\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e4 (3, 4)\u003c/b\u003e\u003c/p\u003e \u003cp\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e3 (2, 3)\u003c/b\u003e\u003c/p\u003e \u003cp\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e3 (3, 3)\u003c/b\u003e\u003c/p\u003e \u003cp\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e2 (1,2)\u003c/b\u003e\u003c/p\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eP value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e\u003cb\u003e0.002\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eWilcoxon signed rank test used. \u003cb\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05 significant\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIn a single case with codominant VA sustained an injury to the V3 segment of VA, which was managed successfully with primary repair using 8\u0026thinsp;\u0026minus;\u0026thinsp;0 proline sutures. Joint remodelling (JRM) was achieved in all the joints where VA was mobilized. The free-hand C1 lateral mass screw placement was achieved with VA mobilization. The average blood loss was 450 ml (range: 250 to 950 ml) in bilateral VA mobilization cases vs no mobilization of VA; average blood loss- 400 ml.\u003c/p\u003e \u003cp\u003eThe median volume of blood loss in bilateral VA mobilization was 560ml, which was 415ml in those cases that underwent unilateral VA mobilization. The median volume of blood loss in the control group was 350 ml. There was a significantly high volume of blood loss amongst the group who underwent bilateral VA mobilization (p\u0026thinsp;=\u0026thinsp;0.001) as compared to those who underwent unilateral VA mobilization (p\u0026thinsp;=\u0026thinsp;0.840) when compared with the control group. The average surgical time in cases of no VA mobilization was 3.5 hrs; in cases with unilateral VA mobilization, it was 5.5 hrs vs. 6.5 hrs in bilateral VA mobilization.\u003c/p\u003e \u003cp\u003eThe duration of surgery was significantly prolonged amongst the group who underwent bilateral VA mobilization (p\u0026thinsp;=\u0026thinsp;0.001) compared to those who underwent unilateral VA mobilization (p\u0026thinsp;=\u0026thinsp;0.174) compared with the control group where vertebral artery mobilization was not performed Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTable demonstrating the distribution of the blood loss, duration of surgery and hospital stay (N\u0026thinsp;=\u0026thinsp;18, case and n\u0026thinsp;=\u0026thinsp;18, control)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u0026acute;s\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMinimum\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMaximum\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eQ1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eQ2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eQ3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eBlood Loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBilateral (n\u0026thinsp;=\u0026thinsp;12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e300\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e900\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e435\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e560\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e725\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUnilateral (n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e300\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e460\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e415\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e453\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.840\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl (n\u0026thinsp;=\u0026thinsp;18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e550\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e295\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e350\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e500\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eRef\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDuration of Surgery\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBilateral (n\u0026thinsp;=\u0026thinsp;12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUnilateral (n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.425\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.174\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl (n\u0026thinsp;=\u0026thinsp;18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eRef\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDuration of Hospital Stay#\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCases\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cp\u003eKruskal Wallis H test / #Mann Whitney U test used. \u003cb\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05 significant\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePostoperative care and hospital stay were offered as per departmental policy. Preoperative neck pain improved, and a hard cervical collar was applied to all the patients for three months.\u003c/p\u003e \u003cp\u003eThe duration of hospital stay was significantly higher among the case (9.25 days) than the control (7 days) group, which was statistically significant (p\u0026thinsp;=\u0026thinsp;0.005). The hospital stay among the study population was higher because of the prolonged intensive care unit (ICU) stay in eight cases. Five out of eight cases underwent tracheostomy to facilitate early mobilization from the ICU and to avoid ventilator-associated pneumonia.\u003c/p\u003e \u003cp\u003eThe mean follow-up duration was 23.2 months (range:6\u0026ndash;62 months, SD: 15.4). This retrospective observational study had no procedure-related mortality. The median pre-operative Nurick\u0026rsquo;s grade amongst the study population was 4 (IQR: 3,4 and Range: 3\u0026ndash;5). After surgery, at three months of follow-up visit, the median post-operative Nurick\u0026rsquo;s grade amongst the same patients was 3 (IQR: 2,3 and Range: 2\u0026ndash;5), which was statistically significant (P\u0026thinsp;=\u0026thinsp;0.002). There was an improvement in bladder and bowel function after surgery, and two out of six (2/6) patients with autonomic dysfunction required clean intermittent catheterization during their last follow-up visit after 28 months of surgery. The median pre-operative modified Ashworth scale (MAS) grade amongst the study population was 3 (IQR: 3,3 and Range: 2\u0026ndash;4). After surgery, at three months of follow-up visit, the median post-operative MAS grade was 2 (IQR: 1,2 and Range: 1\u0026ndash;3), which was statistically significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The follow-up period at 3 months and 6 months showed improvement in spastic features/ weakness due to myelopathy, and the follow-up radiology was suggestive of correction of AAD.\u003c/p\u003e \u003cp\u003e \u003cb\u003eStatistical analysis-\u003c/b\u003e Continuous variables are presented in median and interquartile range (IQR) or mean with standard deviation and range, whereas categorical variables are presented in number (%). Kruskal Wallis H test was used to compare the medians between the three groups. Multiple comparisons were made using Bonferroni corrections for the significant p-value. Mann Whitney U test was used to compare the median between cases and controls. Nurick\u0026rsquo;s Grade ranged from 1 to 5, an ordinal variable was compared between before and after observations using Wilcoxon signed rank test. The analyses were performed using the Statistical Package for Social Sciences version- 23 (SPSS-23, IBM, Chicago, USA). P value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eGoel and Harm\u0026rsquo;s posterior approach with C1-C2 fixation has brought a novel and revolutionary concept to the field of spine surgery worldwide [\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e]. Over the last two decades, the standard teaching for managing CVJ has been posterior stabilization with or without joint remodelling. The major obstacle in remodelling the C1-C2 joint was the anomalous course of VA and developmental aberration of the occipitocervical complex. The available literature suggests that there is a 20% chance of variation in the trajectory of VA across the CVJ [\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e]. This anatomical hindrance led to the development of a relatively safer surgical technique where the in-situ fusion of the craniovertebral junction utilizing occipitocervical fusion (O-C2 fusion) was practised, precluding the risk of VA injury [\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eA. The goal of CVJ surgery\u003c/h2\u003e\n \u003cp\u003e1: Alleviation of compression from the neuraxis: The primary pathology of AAD spectrum disorders is instability at the C1-C2 joint because of widespread aetiology, which in turn leads to increased mobility leading to persistent microtrauma and compression at the cervicomedullary region of the neuraxis. This compression over CMJ leads to not only sensorimotor deficits but cranial nerve impairments along with autonomic disabilities. Stable reconstruction using C1-C2 instrumentation provides the best chance of decompression and excellent clinical outcomes [\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003e2: Fusion in the most acceptable bony alignment: The best way of achieving the same has been the reorientation of bony anatomy by C1/C2 joint remodelling and manipulation. Joint preparation and spacer-assisted or raw bone impaction help achieve robust bony fusion [\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003eB. Obstacles to achieve the goal\u003c/h2\u003e\n \u003cp\u003e1: Sagittal joint inclination: The sagittal angle between the C1-C2 articular surface of more than 32.5 degrees poses a significant challenge to achieving good alignment after joint remodelling. In this situation, the joint needs to be prepared, and the bony fusion is augmented by exposing the cancellous part of the articular surface. If the reduction index (RI) value is \u0026gt;\u0026thinsp;27.9% and the sagittal atlantoaxial joint inclination (SAAJI) value is \u0026lt;\u0026thinsp;32.5\u0026deg;, reduction and fixation can be achieved by the posterior approach alone; otherwise, a combination of anterior and posterior approaches would be necessary [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003e2: Retroverted odontoid: The retroverted lie of the C2 odontoid/ dens may be due to pathologies of the os odontoideum, such as mobile os, pannus at the os due to rheumatoid arthritis and soft tissue collection adjacent to the atlantodental space. The posterior approach can address the compression from the ventral aspect in the background of favourable joint anatomy. Ventral decompression through a trans-oral approach is excellent and feasible and should be considered [\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003e3: Severe Platybasia: This is a surrogate marker of severe instability at CVJ and reflects a protective phenomenon leading to severe Platybasia. The central invagination of the odontoid of the axis is considered central dislocation and describes the subsidence of the cranial portion over the CVJ area. These complex subsets of pathologies warrant adequate joint remodelling to achieve fusion in a position that offers minimal ventral compression over the cord.\u003c/p\u003e\n \u003cp\u003e4: Anomalous VA course: Patients undergoing CVJ surgery experience a wide range of VA anomalous courses. This variation becomes more intricate in the background of the syndromic presentation of CVJ anomalies such as Klippel Feil syndrome or os odontoideum [\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e]. 4.1% of patients undergo CVJ surgery. Considering the factors mentioned earlier, the most challenging factor has been the Anomalous VA course, and as such, if the VA course is favourable, the other three factors can be addressed effectively.\u003c/p\u003e\n \u003cp\u003eThe anomalous course of VA, the biggest hurdle in accessing the C1-C2 joint, is the only modifiable of all the factors. The mobilization of VA offers better access to the area of interest in the CVJ region. The mobilization of VA offers the best solution to address the joint orientation, alleviating the ventral cord compression due to the retroverted odontoid. The appropriate address of anatomical aberration of VA provides the best chances of improvement in this complex set of pathologies, which in turn seems to be a \u0026lsquo;blessing in disguise\u0026rsquo;.\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eTypes of VA anomalies in our series\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eThe paper by JS et al. suggests that 1 to 41% of cases have an abnormal orientation of VA, and out of these, a variable number of patients have a unilateral or bilateral course [\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e]. The origin of PICA (posterior inferior cerebellar artery) from the VA poses a unique challenge to the surgeon in order to protect a significant vessel with the eloquent territory being supplied by PICA, in addition to the mobilization of the VA [\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eIn the present series, we noticed 12 bilateral VAA and 6 cases with unilateral aberrant course. There was a case with a low-lying origin of PICA on the right side, with VA passing across the joint. During tailored mobilization of the traversing artery across the joint, the importance of focused mobilization was emphasized, and the trajectory of joint manipulation was assessed by bringing the PICA inferior and medial to the joint.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003eEmbryological background\u003c/h2\u003e\n \u003cp\u003eOver the last one and a half decades, with growing experience and a better understanding of the complex CVJ region, embryological/ developmental aberrations have been identified as the most critical factor. These developmental alterations most commonly involve the V3 and V4 segments (distal segments) of the VA. The available literature suggests variable frequency of incidence and their clinical significance. Several embryological explanations have been proposed to elaborate on the anomalous origin and course of VA\u0026apos;s V3 and V4 segments [\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eThe first theory suggests the appearance of an aberrant intradural VA at the C2 level with or without a normal course of VA. Lasjaunias et al. proposed that a reasonable number of developmental variations are due to changes in the segmental calibre of the distal VA and lateral spinal artery (LSA), one of the branches of VA [\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e]. According to Siclari et al., the developmental variations of the posterior spinal artery (PSA) lead to various variations in the distal segments of VA [\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eThe second theory was proposed by Uchino et al. and Tokuda et al [\u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e]. As per Uchino et al., in the situation where the first intersegmental artery (FIA) and the regular VA branch both persist, one branch of the VA takes the normal anatomical pathway, whereas the other branch enters the spinal canal between C1 and C2, which result in aberrant intradural VA at the C2 level with a standard running VA. Uchino et al. further proposed that if the first intersegmental artery (FIA) persists and continues to the PICA without fusion with the VA, it forms the extracranial C1/2 origin of the PICA.\u003c/p\u003e\n \u003cp\u003eYamazaki et al. reported that nearly 16% of patients have unilateral VA dominance.[\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e] The close association between unilateral hypoplasia/aplasia of the VA and segmentation of bony anomalies at the CVJ (occipitalised atlas, facet fusion or C2‑3 fusion) may be attributed to the typical embryonic stage in which re-segmentation of embryonic sclerotome and vascular sagittal rearrangement of intersegmental artery occur [\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eThe FT forms around the developing VA. Its posterior aspect develops from the neural process, and the anterior portion is from a vestigial coastal element that fuses to the vertebral body, enclosing the VA. The size of the VA has a close developmental relationship with its corresponding FT. In a prospective study by Jayesh et al., the relationship between the diameter of the ipsilateral VA and its C1 FT showed a positive correlation [\u003cspan class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003eC. Core answer to the problem\u003c/h2\u003e\n \u003cp\u003eThe axis of CVJ surgery revolves around understanding the 3D orientation and anatomy of the C1-C2 joint and the structures responsible for keeping the alignment in place. Once we understand the orientation of joint morphology, we must make every attempt to bring the joint into better alignment, and by doing this, the compression over the neuraxis will be alleviated.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\n \u003ch2\u003eD. How anomalous VA dictates the surgical strategy\u003c/h2\u003e\n \u003cp\u003eThe course of the VA always follows the development and progress of the bony structures around the CVJ. Several structures dictate the course of VA around CVJ, such as the foramen transversarium of the axis and atlas vertebra. The embryological variations which lead to the anomalous course of the VA lead to various radiological aberrations around CVJ. These include occcipitalised atlas, hypoplasia of the posterior C1 arch and rotatory anomalies in various planes of movement. The goal of surgeries for AAD is to achieve the remodelling of the C1-C2 joint and encourage fusion between them to achieve stability of the CVJ. During the initial days of CVJ surgery, the presence of VA passing across the C1-C2 joint makes the accessibility to the joint space an impossible task. With available neurosurgery gadgets and experienced micro neurosurgeons, the feasibility of tailored mobilization of VA is now a reality.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\n \u003ch2\u003eRadiology\u003c/h2\u003e\n \u003cp\u003eConventional radiology in the form of CT CVJ with 3D reconstruction helps provide the orientation of joint alignment and orientation of the C1-C2 joint. The addition of VA angiography with CT CVJ provides a complete orientation of the vascular trajectory and any possibility of anomalous course around the CVJ [\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e21\u003c/span\u003e]. Several publications have been available in the literature reflecting the use of vertebral angiograms in predicting the course and taking useful rescue measures to avoid any unexpected injury during surgical manipulation of these neurovascular structures. The utility of MRI cannot be over-emphasized because it provides an extent of compression at CVJ along with the changes in the cord, reflecting an impact on the prognosis [\u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eIn the present study, the MRI of the CVJ was performed to identify modifiable factors and etiologies that might contribute to the clinical presentation of the patients under study, e.g., Rheumatoid arthritis, tuberculosis of the CVJ, and Os odontoideum with a retroverted position.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\n \u003ch2\u003e3D reconstruction and 3D printing of the CVJ\u003c/h2\u003e\n \u003cp\u003eThe vertebral artery angiogram provides a 2D orientation and relationship of the VA with the C1-C2 joints and the artery\u0026apos;s course across the joint. The VA routinely passes through the foramen transversarium of C1 vertebrae and then travels horizontally over the posterior arch of C1 before becoming intradural in location. The 3D reconstruction of this angiogram provides a better orientation and the association of the vertebral artery with the C1-C2 joint in the close vicinity.\u003c/p\u003e\n \u003cp\u003eThe 3D printed models provide an actual three-dimensional stereoscopic orientation of the individual patient in real-time, which can be translated very well during surgery on the patient. The anatomy of the posterior arch of C1 is essential in almost all of the cases of VA crossing in front of the C1-C2 joint, as it gets occipitalised. The added advantage of 3D printed models over other available modalities is that they provide a virtual appearance of all the neuroanatomical structures which may be encountered during the surgery much prior to actual surgery. The surgeon can plan the surgical strategy and modify it accordingly depending upon the anatomy detected on an individual case basis [\u003cspan class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\n \u003ch2\u003eSurgical Ergonomics\u003c/h2\u003e\n \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e\n \u003ch2\u003ePatient factors\u003c/h2\u003e\n \u003cp\u003eThe surgery for CVJ is performed primarily in a prone position except for the trans-oral approach, where the patient lies in a supine position with neck extension. The prone position carries a specific risk due to the patient\u0026rsquo;s trunk lying on the table and head resting over the horseshoe. The role of cervical traction is indispensable, and we applied cervical traction in all our cases. Soft padding/ silicon pads of all the bony prominences and keeping the abdomen free from compression ensures favourable hemodynamics for CVJ surgery. The head resting over the head ring must ensure that the eyes are free from any compression, or else this results in catastrophic outcomes leading to blindness on many occasions [\u003cspan class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e\n \u003ch2\u003eSurgeon\u0026rsquo;s Factors\u003c/h2\u003e\n \u003cp\u003eThe CVJ surgery is performed in a standing position with an operating microscope with high magnification. The surgeon must be comfortable with the fine adjustment of the microscope and its utility in handling neurovascular structures in limited exposure. The surgical experience of handling microsurgical instruments and high-speed drills simultaneously in the same operative field makes this surgery much more challenging. The surgical inclination, persistence, and patience to handle the long-duration surgery in a standing position with limited arm support are the factors which lead to early fatigue, resulting in decreased surgical precision and, in turn, increased chances of neurovascular injury [\u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec21\" class=\"Section2\"\u003e\n \u003ch2\u003eSurgical safety and Outcomes\u003c/h2\u003e\n \u003cp\u003eThe CVJ surgery through a posterior approach becomes much safer once the surgeon has the preoperative information and a 3-D orientation of the CVJ in mind. The availability of modern radiological modalities has provided a significant advancement in understanding the structures at risk, such as the vertebral artery with the anomalous course in surgery around the CVJ [\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eSarat et al. described a case of the vertebral artery during dissecting across the C2 nerve root in their article. Specific surgical strategies need to be kept in mind to avoid VA injury [\u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e]. There are instances where people have mistaken VA (V2 segment) with C2 nerve root, which resulted in significant injury and blood loss.\u003c/p\u003e\n \u003cp\u003eThe senior author suggested that a few basic principles be followed during surgery around the CVJ, especially during mobilization of VA and remodelling of the C1-C2 joint.\u003c/p\u003e\n \u003cp\u003e\u0026bull; The VA runs vertically perpendicular to the lamina and always lies ventral to the C2 root.\u003c/p\u003e\n \u003cp\u003e\u0026bull; The orientation of the C2 root is parallel to the C1 and C2 lamina and is horizontally placed posterior to the ascending/ V2 segment of VA.\u003c/p\u003e\n \u003cp\u003e\u0026bull; In case of doubt, the Doppler can be used. If one does not have the facility of a Doppler, the lumen of the VA can be verified by using an Insulin needle syringe to detect the content of the aspirate, keeping in mind not to damage the vertebral venous plexus around it.\u003c/p\u003e\n \u003cp\u003e\u0026bull; The dissection plane after cutting the C2 nerve root should be parallel to the VA and traced from the foramen transversarium of C2 towards the cranial end.\u003c/p\u003e\n \u003cp\u003e\u0026bull; The vertebral venous plexus lies around the vertebral artery, which should be traced with the length of the VA.\u003c/p\u003e\n \u003cp\u003e\u0026bull; The occipitalisation of the posterior arch of C1 vertebrae provides an additional advantage to the surgeons. The VA, in its ordinary course, can be considered to be locked in the foramen transversarium of the C1 vertebrae. However, in most congenital CVJ anomalies the occipitalised posterior C1 arch lacks the foramen transversarium. Hence, the course of VA is relatively straightforward towards the posterior lip of the foramen magnum before becoming intra-dural in location [\u003cspan class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003e\u0026bull; The VA can be mobilised safely in a tailored fashion as the vasa vasorum and vas nervosum around the vertebral artery significantly resist vasospasm. Hence, VA mobilisation is much less vasospastic than that of intracranial vessels.\u003c/p\u003e\n \u003cp\u003e\u0026bull; The tailored mobilisation of VA was helpful in joint remodelling where a spacer was placed between the C1-C2 joint. The VA was mobilised inferomedial and superolateral to achieve the adequate space required for instrumentation.\u003c/p\u003e\n \u003cp\u003e\u0026bull; We at our Centre practised the free hand screw placement using the knock and drill technique in all the cases. This provides the added advantage of reducing the surgical time and significantly reducing radiation exposure to the patient and the surgical team [\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e\n \u003ch2\u003eThe Blessings in disguise:\u003c/h2\u003e\n \u003cp\u003eThe most complex and common subtype of VAA has been VA lying in front of the C1/C2 joint in a prone position without passing through the C1 Foramen transversarium as the C1 posterior arch is occipitalised. This variation provides the opportunity to mobilize the VA in a tailored way as per requirement on a case-to-case basis to achieve the core result of the most favourable bony re-orientation. The most helpful mobilization in this type of VAA has been inferomedial to expose the C1 lateral mass and the C1/C2 joint.\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eLearning curve\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eThe importance of having detailed neuroanatomical knowledge and orientation of the pathological anatomy must be considered. Sound knowledge of the principles of micro neurosurgery and manoeuvrability of high-speed/ surgical drills are essential skills acquired during surgical practice. The usefulness of cadaveric laboratory and dissection of CVJ in human cadavers forms the foundation for neuroanatomical orientation and confidence to operate in such an eloquent area. The utility of the saw bone model is also a useful tool to realize the trajectory of the screws in virtual scenarios.\u003c/p\u003e\n \u003cp\u003eThe senior author suggests that younger colleagues take the initiative to attend cadaveric workshops on a regular basis and get accustomed to the course of the VA, the curves and bends, and the neural structures encountered in the close vicinity of the VA artery.\u003c/p\u003e\n \u003cdiv id=\"Sec23\" class=\"Section3\"\u003e\n \u003ch2\u003eAdvantages:\u003c/h2\u003e\n \u003cp\u003eThe present tailored procedure has reduced the additional surgical insult in approximately 95% of cases where an additional anterior approach in the form of trans-oral decompression and odontoidectomy or incomplete posterior procedure was used earlier. This also helped reduce the cost of additional procedures without significantly increasing the surgical time, blood loss, and perioperative morbidities. The literature suggests a 28% chance of deterioration after Occipitocervical fusion and trans-oral odontoidectomy.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec24\" class=\"Section2\"\u003e\n \u003ch2\u003ePotential Challenges:\u003c/h2\u003e\n \u003cp\u003eManaging complex CVJ anomalies wherein VA mobilization is deemed necessary requires a good-quality microscope, microsurgical instruments, and a setup geared for managing intraoperative and postoperative complications. The micro neurosurgical procedure of tailored VA mobilization itself has a steep learning curve, and one must be trained enough to repair the vascular injury or manage it timely through endovascular intervention.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe tailored VAM is a good option to negotiate through C1/C2 joint in a relatively small but unique subset of CVJ without adding to the surgical time, blood loss, morbidities, or mortality. The technique of tailored VAM offers safe access to managing CVJ anomalies if performed with adequate experience and keeping in mind the principles of micro neurosurgery.\u003c/p\u003e"},{"header":"Statement and Declaration","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement:\u003c/strong\u003e No one to acknowledge.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest:\u003c/strong\u003e The authors have no conflict of interest to declare.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;Funding:\u0026nbsp;\u003c/strong\u003eThe present study does not involve any source of funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interest: NIL.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eAuthors contribution:\u0026nbsp;\u003c/strong\u003eAll authors contributed to the study conception and design. Material preparation was done by [Ved Prakash Maurya], \u0026nbsp;data collection was done by [Ashutosh Kumar], [Anantha Chaitanya J], [Priyadarshi Dikshit], [Ravi Ranjan], [Kamlesh Singh Bhaisora], [Kuntal Kanti Das], [Shreyash Rai], [Pawan Kumar Verma], [Soumen Kanjilal], and analysis were performed by [Ved Prakash Maurya], [Anant Mehrotra], [Awadhesh Kumar Jaiswal] and [Arun Kumar Srivastava]. The first draft of the manuscript was written by [Ved Prakash Maurya] and all authors commented on previous versions of the manuscript. The illustrations in the manuscript were drawn by [Priyadarshi Dikshit]. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval:\u003c/strong\u003eThe present study being a retrospective observational study the Institute Ethics Committee has confirmed that no ethical approval is required to conduct this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate:\u003c/strong\u003e Informed written consent was obtained from all the participants who were included in the study.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eConsent to publish:\u0026nbsp;\u003c/strong\u003eTheauthors affirm that human research participants provided informed consent for publication of the radiological and surgical images displayed in Figures 3.,Figure 4. and Figure 5.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGoel A, Laheri V (1994) Plate and screw fixation for atlantoaxial subluxation. Acta Neurochir (Wien) 129:47\u0026ndash;53. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/BF01400872\u003c/span\u003e\u003cspan address=\"10.1007/BF01400872\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHarms J, Melcher RP (2001) Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine 26:2467\u0026ndash;2471. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/00007632-200111150-00014\u003c/span\u003e\u003cspan address=\"10.1097/00007632-200111150-00014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJeanneret B, Magerl F (1992) Primary posterior fusion C1/2 in odontoid fractures: Indications, technique, and results of transarticular screw fixation. J Spinal Disord 5:464\u0026ndash;475. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/00002517-199212000-00012\u003c/span\u003e\u003cspan address=\"10.1097/00002517-199212000-00012\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJain VK (2012) Atlantoaxial dislocation. Neurol India 60:9\u0026ndash;17. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/0028-3886.93582\u003c/span\u003e\u003cspan address=\"10.4103/0028-3886.93582\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSalunke P, Sharma M, Sodhi HBS et al (2011) Congenital atlantoaxial dislocation: a dynamic process and role of facets in irreducibility. J Neurosurg Spine 15:678\u0026ndash;685\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoel A (2004) Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation. J Neurosurg Spine 3:281\u0026ndash;286. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3171/spi.2004.1.3.0281\u003c/span\u003e\u003cspan address=\"10.3171/spi.2004.1.3.0281\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChandra PS, Goyal N (2015) The severity of basilar invagination and atlantoaxial dislocation correlates with sagittal joint inclination, coronal joint inclination, and craniocervical tilt: A description of new indices for the craniovertebral junction. Neurosurgery 76:E235\u0026ndash;239. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1227/NEU.0000000000000600\u003c/span\u003e\u003cspan address=\"10.1227/NEU.0000000000000600\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoel A, Shah A (2011) Atlantoaxial facet locking: Treatment by facet manipulation and fixation. Experience in 14 cases. J Neurosurg Spine 14:3\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3171/2010.9.SPINE1010\u003c/span\u003e\u003cspan address=\"10.3171/2010.9.SPINE1010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSrivastava SK, Aggarwal RA, Nemade PS et al (2016) Single-stage anterior release and posterior instrumented fusion for irreducible atlantoaxial dislocation with basilar invagination. Spine J 16:1\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.spinee. 2015.09.037\u003c/span\u003e\u003cspan address=\"10.1016/j.spinee. 2015.09.037\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamazaki M, Okawa A, Furuya T et al (2012) Anomalous vertebral arteries in the extra\u0026ndash;and intraosseous regions of the craniovertebral junction visualized by 3\u0026ndash;dimensional computed tomographic angiography: Analysis of 100 consecutive surgical cases and review of the literature. Spine 37:E1389\u0026ndash;E1397. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/BRS.0b013e31826a0c9f\u003c/span\u003e\u003cspan address=\"10.1097/BRS.0b013e31826a0c9f\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamazaki M, Koda M, Aramomi MA et al (2005) Anomalous vertebral artery at the extraosseous and intraosseous regions of the craniovertebral junction: Analysis by three\u0026ndash;dimensional computed tomography angiography. Spine (Phila Pa 1976) 30:2452\u0026ndash;2457. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/01.brs.0000184306.19870.a8\u003c/span\u003e\u003cspan address=\"10.1097/01.brs.0000184306.19870.a8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMenezes AH (2008) Craniocervical developmental anatomy and its implications. Childs Nerv Syst 24:1109\u0026ndash;1122. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00381-008-0600-1\u003c/span\u003e\u003cspan address=\"10.1007/s00381-008-0600-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSardhara J, Behari S, Jaiswal AK et al (2013) Syndromic versus nonsyndromic atlantoaxial dislocation: Do clinico\u0026ndash;radiological differences have a bearing on management? Acta Neurochir (Wien) 155:1157\u0026ndash;1167. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00701-013-1717-x\u003c/span\u003e\u003cspan address=\"10.1007/s00701-013-1717-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSiclari F, Burger IM, Fasel JH et al (2007) Developmental anatomy of the distal vertebral artery in relationship to variants of the posterior and lateral spinal arterial systems. AJNR Am J Neuroradiol 28:1185\u0026ndash;1190. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3174/ajnr. A0498\u003c/span\u003e\u003cspan address=\"10.3174/ajnr. A0498\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim MS (2016) Developmental anomalies of the distal vertebral artery and posterior inferior cerebellar artery: diagnosis by CT angiography and literature review. Surg Radiol Anat 38:997\u0026ndash;1006. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00276-016-1654-5\u003c/span\u003e\u003cspan address=\"10.1007/s00276-016-1654-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLasjaunias P, Vallee B, Person H et al (1985) The lateral spinal artery of the upper cervical spinal cord. Anatomy, normal variations, and angiographic aspects. J Neurosurg 63:235\u0026ndash;241. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3171/jns.1985.63.2.0235\u003c/span\u003e\u003cspan address=\"10.3171/jns.1985.63.2.0235\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUchino A, Saito N, Watadani T et al (2012) Vertebral artery variations at the C1\u0026ndash;2 level diagnosed by magnetic resonance angiography. Neuroradiology 54:19\u0026ndash;23. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00234-011-0849-z\u003c/span\u003e\u003cspan address=\"10.1007/s00234-011-0849-z\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003eEpub 2011 Feb 22\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTokuda K, Miyasaka K, Abe H et al (1985) Anomalous atlantoaxial portions of vertebral and posterior inferior cerebellar arteries. Neuroradiology 27:410\u0026ndash;413. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/BF00327604\u003c/span\u003e\u003cspan address=\"10.1007/BF00327604\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSardhara S, Behari S, Mohan MB et al (2015) Risk stratification of vertebral artery vulnerability during surgery for congenital atlanto\u0026ndash;axial dislocation with or without an occipitalized atlas. Neurol India 63:382\u0026ndash;391. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/0028-3886.158218\u003c/span\u003e\u003cspan address=\"10.4103/0028-3886.158218\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHong JT, Kim IS, Kim JY et al (2016) Risk factor analysis and decision-making of surgical strategy for V3 segment anomaly: significance of preoperative CT angiography for posterior C1 instrumentation. Spine J 16:1055\u0026ndash;1061\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWajanavisit W, Lertudomphonwanit T, Fuangfa P et al (2016) Prevalence of high riding vertebral artery and morphometry of C2 pedicles using a novel computed tomography reconstruction technique. Asian Spine J 10:1141\u0026ndash;1148. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4184/asj.2016.10.6.1141\u003c/span\u003e\u003cspan address=\"10.4184/asj.2016.10.6.1141\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003eEpub 2016 Dec 8\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDu Y-Q, Qiao G-Y, Yin Y-H et al (2020) Usefulness of 3D Printed Models in the Management of Complex Craniovertebral Junction Anomalies: Choice of Treatment Strategy, Design of Screw Trajectory, and Protection of Vertebral Artery. World Neurosurg 133:e722\u0026ndash;e729. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.wneu.2019.09.139\u003c/span\u003e\u003cspan address=\"10.1016/j.wneu.2019.09.139\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003eEpub 2019 Oct 4\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStevens WR, Glazer PA, Kelley SD et al (1997) Ophthalmic complications after spinal surgery. Spine 22:1319\u0026ndash;1324. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/00007632-199706150-00008\u003c/span\u003e\u003cspan address=\"10.1097/00007632-199706150-00008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh G, Maurya VP, Bhaisora KS et al (2024) Unilateral Vision Loss After Posterior Fixation for Traumatic Atlantoaxial Dislocation: A Case Report with Literature Review. Indian J Neurotrauma. IJNT-2024-1-6. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1055/s-0044-1782610\u003c/span\u003e\u003cspan address=\"10.1055/s-0044-1782610\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBelykh E, Onaka NR, Abramov IT et al (2018) Systematic review of factors influencing surgical performance: practical recommendations for microsurgical procedures in neurosurgery. World Neurosurg 112:e182\u0026ndash;e207. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.wneu.2018.01.005\u003c/span\u003e\u003cspan address=\"10.1016/j.wneu.2018.01.005\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003eEpub 2018 Jan 9\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBredow J, Oppermann J, Kraus B et al (2015) The accuracy of 3D fluoroscopy navigated screw insertion in the upper and subaxial cervical spine. Eur Spine J 24:2967\u0026ndash;2976. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00586-015-3974-2\u003c/span\u003e\u003cspan address=\"10.1007/s00586-015-3974-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003eEpub 2015 Apr 30\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChandra PS, Ghonia R, Singh S et al (2021) Anomalous Vertebral Artery During Cranio Vertebral Junction Surgery Using DCER Approach. and Its Repair. Neurol India 69:315\u0026ndash;317. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/0028-3886.314543\u003c/span\u003e\u003cspan address=\"10.4103/0028-3886.314543\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSrivastava AK, Sardhara J, Behari S et al (2017) Knock and Drill Technique: A Simple Tips for the Instrumentation in Complex Craniovertebral Junction Anomalies without using Fluoroscopy. J Neurosci Rural Pract 8:14\u0026ndash;19. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/0976-3147.193555\u003c/span\u003e\u003cspan address=\"10.4103/0976-3147.193555\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSasapardhi SB, Verma PK, Srivastava AK et al (2024) An institutional study on accuracy of freehand cervical C1 C2 screws placement by knock and drill technique in craniovertebral anomalous bony anatomy: An evaluation of more than 600 screws based on SGPGI screw accuracy criteria. J Craniovertebr Junction Spine 15:83\u0026ndash;91. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/jcvjs.jcvjs_116_23.Epub\u003c/span\u003e\u003cspan address=\"10.4103/jcvjs.jcvjs_116_23.Epub\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e 2024 Mar 13\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Vertebral artery, Craniovertebral junction, Nurick’s grade, Atlantoaxial dislocation, Vertebral angiogram","lastPublishedDoi":"10.21203/rs.3.rs-5646143/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5646143/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e \u0026nbsp;The surgical exposure of the complex craniovertebral junction (CVJ) requires manipulation of the neurovascular structures and the atlantoaxial joint (C1-C2 joint) to access the pathological region. To achieve adequate C1-C2 joint manipulation, the mobilization of the vertebral artery (VA) is mandatory. The present retrospective observational study aims to describe the surgical nuances and share the experience of tailored vertebral artery mobilization for efficient management of CVJ pathologies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethodology:\u003c/strong\u003e All the operated cases of CVJ anomalies from January 2019 to December 2023 were included. The clinico-radiological scan, including their three-dimensional computerized tomography (3-D CT), was recorded with a VA angiogram course. The intraoperative details of these patients were collected from the neurosurgery operative records. The patients' details were obtained either by the outpatient department or by telephone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e A total of 18 patients were analyzed with a mean age of 49.21±18.30 years. The median pre-operative Nurick's grade amongst the study population was 4 (IQR: 3,4 and Range: 3-5). Twelve patients underwent bilateral vertebral artery mobilization, whereas the remaining six underwent unilateral vertebral artery mobilization. After surgery, at three months of follow-up visit, the median post-operative Nurick's grade was 3 (IQR: 2,3 and Range: 2-5), which was statistically significant (P=0.002). The mean follow-up duration was 23.2 months without any procedure-related mortality.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Tailored vertebral artery mobilisation (VAM) is an excellent surgical strategy for negotiating through the atlantoaxial joint in a specific group of patients. It offers safe access to managing CVJ anomalies, keeping in mind the principles of micro neurosurgery.\u003c/p\u003e","manuscriptTitle":"Tailored vertebral artery mobilisation in complex craniovertebral junction surgery- a blessing in disguise","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-26 06:09:11","doi":"10.21203/rs.3.rs-5646143/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-01-19T18:34:51+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-19T08:10:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-15T13:03:44+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-12T18:25:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"321264911856383029671099739376135223707","date":"2025-01-12T11:50:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"41342687864413832857144418472999323842","date":"2025-01-09T10:40:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"226785014918303896895376778581609842961","date":"2025-01-08T22:09:30+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-08T13:46:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"227400217401771024402176859970320496929","date":"2025-01-07T08:20:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"301548627231578577616026579574986136692","date":"2025-01-07T05:03:04+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-01-06T21:58:13+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-06T21:57:23+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-12-19T11:02:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"Neurosurgical Review","date":"2024-12-15T06:26:12+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"7c428706-6079-4237-9130-dfa9adb8b4a2","owner":[],"postedDate":"December 26th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-02T16:02:13+00:00","versionOfRecord":{"articleIdentity":"rs-5646143","link":"https://doi.org/10.1007/s10143-025-04030-x","journal":{"identity":"neurosurgical-review","isVorOnly":false,"title":"Neurosurgical Review"},"publishedOn":"2026-01-30 15:59:19","publishedOnDateReadable":"January 30th, 2026"},"versionCreatedAt":"2024-12-26 06:09:11","video":"","vorDoi":"10.1007/s10143-025-04030-x","vorDoiUrl":"https://doi.org/10.1007/s10143-025-04030-x","workflowStages":[]},"version":"v1","identity":"rs-5646143","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5646143","identity":"rs-5646143","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}