The potential of preoperative three-dimensional computed tomography for para-aortic lymphadenectomy in gynecological malignancies

The potential of preoperative three-dimensional computed tomography for para-aortic lymphadenectomy in gynecological malignancies | 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 The potential of preoperative three-dimensional computed tomography for para-aortic lymphadenectomy in gynecological malignancies Shintaro Yanazume, Fumitaka Ejima, Yusuke Kobayashi, Ayumi Kozai, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5872015/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background The evaluation of anatomical abnormalities involving urinary vessel variations prior to para-aortic lymphadenectomy in gynecological malignancies is challenging. In this context, the utility of preoperative three-dimensional (3D) computed tomography (3DCT) angiography in improving surgical outcomes was examined. Methods This observational study evaluated the utility of 3DCT in patients who underwent para-aortic lymphadenectomy between January 2023 and November 2024. 3D fusion images were constructed from the arterial phase (CTA), CT-venography (CTV), and CT-urography (CTU). A total of 72 patients were included and divided into two groups: Non-3DCT and 3DCT. Outcomes included detection rates of arterial, venous, or urinary tract variations and surgical outcomes, including complications, in both groups. Results The 3DCT group included 14/34 (41.2%) cases with renal vessel variations and two cases (5.9%) with double ureters; the non-3DCT group did not detect any anatomical abnormalities. In the 3DCT group, renal vessel and urinary tract variations were clearly shown. Postoperative complications tended to be slightly higher in the non-3DCT group, including lymphocyte infection, chylous leakage, and bowel obstruction. Postoperative CT revealed reduced contrast in the lower pole of the right kidney in the 3DCT case with the most complex urinary vessel variations. Furthermore, in the 3DCT group, 8/34 (23.5%) unilateral or bilateral renal arteries were located caudally to the lower edge of the renal vein. Conclusion In gynecological malignancies, 3DCT before para-aortic lymphadenectomy was superior in identifying urinary vessel variations over conventional contrast-enhanced CT; thus, aiding realistic preoperative simulations and potentially reducing surgeons' burden and perioperative complications. Gynecology three-dimensional computed tomography paraaortic lymph node dissection accessory urinary artery vessels variations Figures Figure 1 Figure 2 Figure 3 Introduction Pelvic and para-aortic lymphadenectomy (PANDx) is an important surgical intervention in gynecologic oncology. PANDx is routinely performed to enhance the prognosis of high-risk endometrial cancer, early stage ovarian and fallopian tube cancer, and for comprehensive surgical staging of cervical cancer [1–3]. Despite its potential to enhance patient outcomes, postoperative complications have been documented to elevate surgery-related systemic morbidity and the formation of lymphedema/lymphocysts, while substantially extending the duration of the surgery [4]. This procedure should be chosen on an individual basis whilst carefully balancing the anticipated benefits against the patient's health status and inherent risk factors [1]. In PANDx, urinary vessel variations were identified in 18.9–30.2% of gynecological cancer surgeries [5–7]. The most common variations were related to accessory renal arteries (6.8–30%) and retro-aortic left renal veins (2.1–3.4%); the most frequent urinary tract abnormality was a double left ureter (3.3–11.1%). Nevertheless, evaluation of anatomical abnormalities prior to surgical intervention presents significant challenges [6]. In PANDx for gynecological malignancies, only 3.4–5.7% of cases were identified as having anatomical variations on contrast-enhanced computed tomography (CT) prior to surgery [6, 8]. With the recent proliferation of minimally invasive surgical procedures, complications arising from factors other than technical issues have also been documented [9, 10]. Our recent publication [10] reports the incidence of right renal artery injury during robot-assisted PANDx. The study notes that the robotic camera's ability to access deep regions beneath the renal vein, coupled with the distinct visual perspective compared with traditional laparotomy, might have contributed to this surgical complication. To reduce such complications, it is important to understand urinary vessel and urinary tract variations as accurately as possible before surgery. Preoperative assessment of various organ systems has revealed that anatomical three-dimensional (3D) CT (3DCT) reconstruction significantly enhances the ability to devise precise surgical strategies [11–13] as the surgeon is presented with the various organs of interest in high anatomical detail prior to surgery [11–13]. Nevertheless, empirical evidence regarding the capacity of gynecological oncologists to assess PANDx preoperatively remains low. In the current study, the utility of preoperative 3DCT for improving surgical outcomes, including avoiding complications during PANDx, was examined. Patients And Methods 1. Study design This observational study investigated a clinical database to identify the utility of 3DCT in patients who had undergone PANDx between January 2023 and November 2024. The study protocol was approved by the Institutional Review Board of Kagoshima University Graduate School of Medical Sciences (approval # 230024). Participants were informed of the study and were offered the opportunity to opt out. A total of 72 patients were included and divided into two groups: Non-3DCT and 3DCT. The Non-3DCT group underwent contrast-enhanced CT without 3DCT. First, we evaluated the detection rates of arterial, venous, or urinary tract variations and surgical outcomes, including complications, in both groups. Evaluation of the uniformity of contrast enhancement of the kidney on postoperative contrast-enhanced CT was also performed to assess the impact of surgery on the renal arteries. Second, the presence of a renal artery caudal to the lower edge of the renal vein was investigated in the 3DCT group. 1. CT scan details for each group The Non-3DCT group underwent contrast-enhanced CT at hospitals other than Kagoshima University Hospital and the findings of renal vascular and urinary tract variations were described. Patients who had not undergone contrast-enhanced CT at their first visit to our hospital underwent 3DCT angiography; therefore, all patients in the 3DCT group underwent 3DCT angiography at our hospital. 3DCT angiography scans for gynecological cancers were performed using IQon spectral CT (64-row) manufactured by Philips, Inc. (Amsterdam, Netherlands). 3D-CT scans were constructed from the arterial phase (3D CTA) using 64 multi-detector row CT scans. Similarly, venous 3D was performed with 3DCT venography (3D CTV) and the urinary tract with 3DCT urography (3D CTU). In this study, two CT protocols were employed in our institute: one with an arterial phase (Protocol A) and one without (Protocol B). A nonionic contrast agent (Ioversol 320 mg I/mL, Optiray®, Guerbet) was used in both protocols, with an injection volume of 1.8 mL/kg body weight, up to a maximum of 100 mL. A 20 mL saline flush followed the contrast agent at the same injection rate. In Protocol A, the injection rate was set at injection volume/30 s, and arterial phase scans were initiated 18 s after the attenuation in the abdominal aorta increased to 150 HU, as measured by a dedicated monitoring system. In Protocol B, the injection rate was fixed at 1.5 mL/s, and no arterial phase was included. For both protocols, parenchymal and excretory phase scans were acquired at 80 s and 300 s after contrast injection, respectively. Three-dimensional reconstructions of the renal arteries, renal veins, and urinary tract were created using a workstation (Ziostation2, Ziosoft Inc., Tokyo, Japan) and fused to enhance visualization. In the Non-3DCT group, the images were evaluated by radiologists at each facility, while in the 3DCT group, the images were evaluated by a radiologist specializing in gynecology at our facility. Surgery was performed after viewing of the 3D images by a gynecologic oncologist. Postoperative contrast-enhanced CT data were only available for patients who underwent investigation of complications or recurrence during regular follow-up. 2. Details of the commonly performed surgical technique Standard surgical techniques for endometrial and ovarian cancers include peritoneal cytology, hysterectomy, bilateral salpingo-oophorectomy, PANDx, pelvic lymphadenectomy, and omentectomy/appendectomy (if indicated). For endometrial cancer, radical or semi-radical hysterectomy was performed when cervical invasion was expected. For cervical cancer, radical hysterectomy was performed, and para-aortic lymph node dissection was performed only in cases of expected metastasis to the higher para-aortic lymph nodes. PANDx was defined as resection of the lower edge of the left renal vein. Clinical data were collected by reviewing inpatient medical records, and post-surgical complications were assessed using the Clavien-Dindo Classification v.2.0. Operative time was defined as the time between the start and closure of the skin incision. Robotic surgeries were performed using the Da Vinci Xi Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA). Surgeries were performed by four gynecologic oncologists using the surgical techniques previously described [10], regardless of whether standard laparotomy or minimally invasive surgery was performed. In urinary vessel variation, a supplemental renal artery that originated from any region around the aorta was defined as an accessory urinary artery. 3. Statistical analysis Inter-group categorical comparisons were performed using Chi-squared or Fisher’s exact tests. Student's t-tests and Mann–Whitney U tests were used to evaluate the statistical significance of the differences between groups. Statistical significance was set at P < 0.05. All statistical analyses were performed on a personal computer using a statistical software package (SPSS for Windows, v.29; SPSS Inc., Chicago, IL, USA). Results A research flowchart is shown in Fig. 1. One patient with impaired renal function who did not undergo contrast-enhanced CT was excluded, and 72 patients were finally analyzed. The characteristics of the patients who underwent PANDx are shown in Table 1. In total, 16.7% of patients had para-aortic lymph node metastasis, and endometrial cancer was the most common disease. High-risk diseases, such as lymph node metastasis, tended to be more common in the 3DCT group; however, there was an almost identical trend between the two groups. The overall sensitivity and specificity of CT were 41.7% and 96.7%, respectively, for para-aortic lymph node metastases and 33.3% and 92.4%, respectively, for pelvic lymph node metastases. Detection rates of having variations, and surgical outcomes in both groups Details of the overall variations in renal vessels and the urinary tract detected by 3DCT are shown in Table 2. The 3DCT group identified 14/34 (41.2%) cases with renal vessel variations and two cases (5.9%) with double ureters, but the non-3DCT group failed to detect any abnormalities. Representative cases are shown in Fig. 2. Eight patients (23.5%) had an accessory renal artery that originated between lumbar 1 and 3. Of the six cases with variations in the right renal vein, only one had an accessory renal artery. In contrast, no subjects had variations in the left renal vein. The thickness, length, and flexure of the aorta and vena cava as well as the location of the aortic bifurcation tended to vary among individual cases. The surgical outcomes of each group and complications related to para-aortic lymph node dissection are shown in Table 3. There were no significant differences between the two groups in terms of blood loss, operation time, or the number of lymph nodes removed. As for intraoperative complications, we observed mild active bleeding from the surface of the vena cava in two cases in the non-3DCT group, while no injury to urinary vessels or urinary tract variations were observed intraoperatively. Postoperative complications tended to be slightly higher in the non-3DCT group, including lymphocyte infection, chylous leakage, and bowel obstruction. Uniformity of contrast enhancement of the kidney in postoperative CT CT was evaluated in 23/38 (60.5%) patients in the non-3DCT group and 29/34 (85.3%) in the 3DCT group, respectively. Upon comprehensive evaluation, a single patient failed to demonstrate uniform contrast enhancement. This isolated case, identified as Case 3 in the 3DCT group, showed reduced contrast enhancement in the lower polar region of the right kidney compared to the preoperative CT [Fig.2b (3)]. The clinical course of Case 3 was as follows: 50 years old, endometrial cancer stage 1 B (preoperative estimated stage 2), endometrioid carcinoma grade 1, BMI 20.4; surgical procedures included radical hysterectomy, bilateral salpingo-oophorectomy, retroperitoneal lymphadenectomy, resection of 24 pelvic lymph nodes, and resection of 17 para-aortic lymph nodes. The operation time was 325 min, and the blood loss was 1130 ml. No lymph node metastasis or evidence of disease recurrence was observed for 19 months. As shown in Table 2, the right renal artery had five branches, which was the most frequent renal vessel variation in this study. The main branch appeared to be the accessory aortic lower-polar renal artery [Fig.2b (1-2)]. The defect in contrast enhancement in the postoperative CT scan may indicate poor blood flow in the right lower pole of the kidney. No obvious hydronephrosis, signs of renal failure, or ureteral abnormalities were observed after surgery. Presence of the renal artery caudal to the lower edge of the renal vein (Table 4) In the 3DCT group, 8/34 (23.5%) unilateral or bilateral renal arteries, including urinary vessel variations, were located caudal to the lower edge of the renal vein. Importantly, in 4/19 (21.1%) cases with no accessory renal artery, the main renal artery was found caudal to the lower edge of the renal vein, and two of the four patients had bilateral involvement. All cases with the renal artery caudal to the lower edge of the renal vein in patients with not having accessory renal artery were shown in Fig. 3. Discussion This study presents the initial report of using 3DCT for the perioperative evaluation of PANDx in patients with gynecologic malignancies. Preoperative utilization of 3DCT provided clear identification of renal vessel and urinary tract variations, and the surgical procedure was performed without significant complications. The renal arteriovenous system exhibits significant anatomical diversity and utilization of 3DCT enables visualization of the renal artery's position inferior to that of the renal vein, potentially mitigating the risk of renal artery injury. For preoperative surgical planning, the anatomical location and extent of pelvic adhesions could be predicted with relative accuracy using internal examination and magnetic resonance imaging (MRI). Nonetheless, preoperative assessment of the para-aortic lymph node region proved insufficient when relying solely on contrast-enhanced CT imaging. In the non-3DCT group, we requested that the renal vessel and urinary tract variations be documented at facilities other than our institution; however, no such findings were recorded. Few studies have been published regarding renal vessel variations identified by contrast-enhanced CT prior to surgical intervention [6, 8]. The identification rate of urinary vessel and urinary tract variations in the perioperative period was only 12.1% based on preoperative contrast-enhanced CT and intraoperative surgical findings. These rates are significantly lower than those obtained in our study utilizing 3DCT [6, 8]. Most studies examining vascular variations in the periaortic region have been conducted using cadaveric analysis, intraoperative observation, and imaging techniques with contrast-enhanced CT. A comprehensive analysis of these data revealed that accessory urinary arteries were observed in 10–50% of cases, left renal veins in 1.3–3.2%, and right renal veins in 20–23%, which aligns with our observed frequency of accessory urinary vessels and demonstrates a high degree of accuracy in identifying these vessels in 3DCT imaging [7]. 3DCT is a technique that reconstructs anatomical structures in the human body in 3D based on tomographic images obtained through CT scans. This technique yields high-resolution, 3D visualizations of osseous structures, viscera, and vascular networks, allowing exceptional anatomical assessment. The efficacy of 3DCT has been extensively documented for multiple organ systems, including for elucidating vascular and bronchial structures prior to video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy [11]. Such 3D reconstruction techniques applied to two-dimensional CT images in hepatic resection procedures offer a valuable educational model. This approach enhances residents' comprehension of liver anatomical structures and surgical resection techniques [12]. 3DCT has been implemented primarily in urology for surgical planning and navigation to facilitate the surgeon's comprehension of surgical anatomy, particularly in the treatment of prostate and kidney cancers [13]. The arterial phase of 3DCT, which was also utilized in our study, is considered the most efficacious modality for visualizing renal arteries. Furthermore, 3DCT of donor kidneys accurately delineates renal arterial anatomy in 97.6% of patients and provides enhanced details of the venous anatomy compared to conventional angiography [14]. The singular documented case of para-aortic lesion-associated 3DCT in gynecological malignancy revealed a metastatic mass surpassing 10 cm in size. This lesion was positioned dorsally to the vena cava, aorta, and left kidney while encircling the left renal and lumbar arterial structures. The 3DCT imaging clearly displayed the lesion's dimensions and location, thereby facilitating appropriate surgical intervention [15]. Intraoperative and postoperative complications observed in the non-3DCT group were common complications associated with para-aortic lymph node dissection. Conversely, complications in the 3DCT group were limited to one case of chylous leakage and one case of contrast effect deficiency in the lower pole of the kidney. Although a precise comparison was not possible, it appears that the 3DCT group had slightly fewer complications. Although not recognized in this study, intraoperative hemorrhage was precipitated by iatrogenic vascular injury, inadequate tissue manipulation, and anatomical variations in the vasculature surrounding the aorta. A comprehensive understanding of anatomical vascular variations is needed to mitigate the incidence of complications [7]. In our investigation, Case 3 exhibited an asymptomatic contrast effect anomaly in the lower pole of the right kidney, which was incidentally discovered during routine CT follow-up. This finding contrasts with a comparable reported case in which detection occurred subsequent to postoperative pyrexia, which was presumed to be associated with an ischemic event [9]. The incidence of accessory renal artery injury remains undetermined [16, 17]. The superior portion of the ureter receives blood from the accessory aortic lower polar renal artery. Iatrogenic injury to this vessel may result in significant complications including ureteral necrosis, fistula development, and urinary leakage. Additionally, these arteries can induce ureteral obstruction, potentially leading to hydronephrosis [7, 18]. Despite preoperative identification of the accessory renal artery using 3DCT, it is plausible that this vessel was inadvertently ligated during surgery. To address the challenges posed by such intricate anatomical variations, the incorporation of an intraoperative navigation system could potentially serve as a valuable tool for minimizing any associated complications. Failure to recognize preoperative renal vessel variations can lead to critical outcomes for surgeons. The most significant complication associated with para-aortic lymph node dissection is potential injury to the main trunk of the renal artery. Minimally invasive surgery (MIS) enables enhanced visualization of the operative field and facilitates grasping and dissection procedures in confined spaces, resulting in frequent encounters with renal arteries. Traditionally, the renal artery was believed to be situated superior to the level of the renal vein; however, our research findings indicated that a renal artery's position inferior to the lower border of the renal vein was a frequent occurrence. Nevertheless, gynecological oncologists who typically perform dissection in a caudal-to-cranial direction must exercise heightened vigilance, particularly in MIS with a limited visual perspective. The construction of a 3D model may facilitate an enhanced focus on renal vessel and urinary tract anatomical variations during CT scan interpretation. These anatomical variations are readily apparent, enabling their identification without the need for active surveillance. However, 3DCT is not employed in standard gynecological cancer follow-up protocols because of its vessel-specific nature and the additional effort required for image processing. The identification of such variations requires preoperative collaboration between surgeons and radiologists. The integration of augmented reality (AR) technology into surgical procedures represents a potential avenue for advancing 3D-CT applications in the para-aortic region. This approach facilitates the incorporation of 3D virtual models into the operative field during MIS, enabling a real-time overlay of virtual imagery onto endoscopic views. 3DCT facilitates the precise identification of urinary vessel and tract variations and enables the execution of preoperative simulations analogous to actual surgical procedures for PANDx, potentially mitigating any operative challenges faced by surgeons and thus improving patient safety. Further comprehensive clinical trials are warranted to establish standardized 3DCT procedures and assess the reduction in adverse surgical events. Declarations Funding : The authors confirm that no financial assistance, grants, or other support were provided during the writing of this manuscript. Conflict of interest: The authors declare that they have no conflict of interest. Author contributions : Conceptualization: Shintaro Yanazume; Methodology: Fumitaka Ejima, Takashi Yoshiura, and Shintaro Yanazume; Formal analysis and investigation: Ayumi Kozai, Yusuke Kobayashi, and Shintaro Yanazume; Writing - original draft preparation: Shintaro Yanazume, Fumitaka Ejima; Writing - review and editing: Fumitaka Ejima, Takashi Yoshiura, and Hiroaki Kobayashi; Funding acquisition: not applicable; Resources: Mika Fukuda; Supervision: Shinichi Togami, Takashi Yoshiura, and Hiroaki Kobayashi. Data availability: The data for this study are shown in tables and figures; no other datasets were generated or analyzed during the current study. Consent to participate and publish The study protocol was approved by the Institutional Review Board of Kagoshima University Graduate School of Medical Sciences (approval # 230024). Participants were informed of the study and were offered the opportunity to opt out for participate and publish. References Abu-Rustum N, Yashar C, Arend R et al (2023) Uterine Neoplasms, Version 1.2023, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw 21:181–209 Liu J, Berchuck A, Backes FJ et al (2024) NCCN Guidelines(R) Insights: Ovarian Cancer/Fallopian Tube Cancer/Primary Peritoneal Cancer, Version 3.2024. J Natl Compr Canc Netw 22:512–519 Seino M, Nagase S, Tokunaga H et al (2024) Japan Society of Gynecologic Oncology 2022 guidelines for uterine cervical neoplasm treatment. J Gynecol Oncol 35:e15 Frost JA, Webster KE, Bryant A, Morrison J (2017) Lymphadenectomy for the management of endometrial cancer. Cochrane Database Syst Rev 10:CD007585 Klemm P, Frober R, Kohler C, Schneider A (2005) Vascular anomalies in the paraaortic region diagnosed by laparoscopy in patients with gynaecologic malignancies. Gynecol Oncol 96:278–282 Kovacevic N, Hocevar M, Vivod G, Merlo S (2023) Vascular and Urinary Tract Anatomic Variants Relevant to Para-Aortic Lymphadenectomy in Women with Gynecological Cancers. Cancers (Basel) 15 Kostov S, Selcuk I, Yordanov A et al (2022) Paraaortic Lymphadenectomy in Gynecologic Oncology-Significance of Vessels Variations. J Clin Med 11 Aljabri B, MacDonald PS, Satin R, Stein LS, Obrand DI, Steinmetz OK (2001) Incidence of major venous and renal anomalies relevant to aortoiliac surgery as demonstrated by computed tomography. Ann Vasc Surg 15:615–618 Eitan R, Abu-Rustum NR, Walker JL, Barakat RR (2003) Ligation of an anatomic variant of renal vasculature during laparoscopic periaortic lymph node dissection: a cause of postoperative renal infarction. Gynecol Oncol 91:416–420 Yanazume S, Kobayashi H, Ushiwaka T, Togami S, Kamio M (2024) Robotic dual-docking surgery for para-aortic lymphadenectomy in endometrial cancer: a prospective feasibility study. Int J Clin Oncol. https://10.1007/s10147-024-02635-8 Ikeda N, Yoshimura A, Hagiwara M, Akata S, Saji H (2013) Three dimensional computed tomography lung modeling is useful in simulation and navigation of lung cancer surgery. Ann Thorac Cardiovasc Surg 19:1–5 Yeo CT, MacDonald A, Ungi T et al (2018) Utility of 3D Reconstruction of 2D Liver Computed Tomography/Magnetic Resonance Images as a Surgical Planning Tool for Residents in Liver Resection Surgery. J Surg Educ 75:792–797 Porpiglia F, Amparore D, Checcucci E et al (2018) Current Use of Three-dimensional Model Technology in Urology: A Road Map for Personalised Surgical Planning. Eur Urol Focus 4:652–656 Rubin GD, Alfrey EJ, Dake MD et al (1995) Assessment of living renal donors with spiral CT. Radiology 195:457–462 Kato T, Seol KH, Youn JS, Hong DG (2018) Salvage para-aortic lymphadenectomy in recurrent cervical cancer after visualization with 3-dimensional computed tomography angiography. Obstet Gynecol Sci 61:626–630 Lee WM, Choi JS, Bae J, Jung US, Eom JM (2018) Encountering the Accessory Polar Renal Artery during Laparoscopic Para-Aortic Lymphadenectomy. J Minim Invasive Gynecol 25:10–11 Madsen M, Gorostidi M, Ruiz R, Jaunarena I, Cobas P, Lekuona A (2019) Accessory polar renal artery not pre-operatively visualized at extra-peritoneal para-aortic lymphadenectomy. Int J Gynecol Cancer 29:1226–1227 Tardo DT, Briggs C, Ahern G, Pitman A, Sinha S (2017) Anatomical variations of the renal arterial vasculature: An Australian perspective. J Med Imaging Radiat Oncol 61:643–649 Tables Tables 1 to 4 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.docx Table2.docx Table3.docx Table4.docx Cite Share Download PDF Status: Posted Version 1 posted 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-5872015","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":405831846,"identity":"1cbd2f39-a7ce-4330-881e-5ca054f9246c","order_by":0,"name":"Shintaro Yanazume","email":"","orcid":"","institution":"Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Shintaro","middleName":"","lastName":"Yanazume","suffix":""},{"id":405831847,"identity":"34e4a3c4-e50d-434a-a11a-c868edda42fe","order_by":1,"name":"Fumitaka Ejima","email":"","orcid":"","institution":"Kagoshima University Graduate School of Medical and Dental Sciences","correspondingAuthor":false,"prefix":"","firstName":"Fumitaka","middleName":"","lastName":"Ejima","suffix":""},{"id":405831848,"identity":"39fec7fe-218d-4b48-8747-9e03b8c08747","order_by":2,"name":"Yusuke Kobayashi","email":"","orcid":"","institution":"Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Yusuke","middleName":"","lastName":"Kobayashi","suffix":""},{"id":405831849,"identity":"a06215ba-79fd-4f9d-abae-87f8becc7b0a","order_by":3,"name":"Ayumi Kozai","email":"","orcid":"","institution":"Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Ayumi","middleName":"","lastName":"Kozai","suffix":""},{"id":405831850,"identity":"62edbbbe-d0ad-45f8-a904-e5f68b8f28d4","order_by":4,"name":"Mika Fukuda","email":"","orcid":"","institution":"Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Mika","middleName":"","lastName":"Fukuda","suffix":""},{"id":405831851,"identity":"6602cf02-1044-4140-8320-db6c27e963a3","order_by":5,"name":"Shinichi Togami","email":"","orcid":"","institution":"Kagoshima University","correspondingAuthor":false,"prefix":"","firstName":"Shinichi","middleName":"","lastName":"Togami","suffix":""},{"id":405831852,"identity":"0e8a6fdd-3ee5-4cc6-94cb-0243616c3151","order_by":6,"name":"Takashi Yoshiura","email":"","orcid":"","institution":"Kagoshima University Graduate School of Medical and Dental Sciences","correspondingAuthor":false,"prefix":"","firstName":"Takashi","middleName":"","lastName":"Yoshiura","suffix":""},{"id":405831853,"identity":"0d1ef3a5-5d34-4983-9961-065caa3d7395","order_by":7,"name":"Hiroaki Kobayashi","email":"data:image/png;base64,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","orcid":"","institution":"Kagoshima University","correspondingAuthor":true,"prefix":"","firstName":"Hiroaki","middleName":"","lastName":"Kobayashi","suffix":""}],"badges":[],"createdAt":"2025-01-21 09:08:39","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5872015/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5872015/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":75309014,"identity":"2751a345-4ca0-4bcf-8538-4b1a9d1f20f5","added_by":"auto","created_at":"2025-02-03 08:52:33","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":793968,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart summarizing the study. Abbreviations: CT, computed tomography; 3D, three-dimensional\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/0c103eae190f9168096e8dc0.png"},{"id":75310161,"identity":"516f20b3-72ba-4596-90f4-7de68ab89152","added_by":"auto","created_at":"2025-02-03 09:00:33","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":66669149,"visible":true,"origin":"","legend":"\u003cp\u003ea) Case 2: Right (Rt.) double renal pelvis and ureter (triangle arrow), b) Case 3: Five right renal arteries, and two left renal arteries, (1) ventral side (2) dorsal side (3) postoperative CT showed a contrast effect defect in the lower pole of the right kidney (yellow arrow), c) Case 10:Three bilateral renal arteries branch off from the abdominal aorta, d) Case 11:Two bilateral renal arteries branch off from the abdominal aorta, (1) ventral side (2) dorsal side, e) Case 12: Three left renal arteries branch off from the abdominal aorta, f) Case 14: Rt. two renal arteries, (1) ventral side (2) dorsal side, g) Case 15: Left (Lt.) double renal pelvis and ureter (triangle arrow)\u003c/p\u003e","description":"","filename":"FIg.2.png","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/1d10e43a7c4d6b785fc52175.png"},{"id":75310160,"identity":"6c21674f-8c91-4615-a1cb-aba13483710e","added_by":"auto","created_at":"2025-02-03 09:00:33","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":25378896,"visible":true,"origin":"","legend":"\u003cp\u003eAll cases with the renal artery (triangle arrow) caudal to the lower edge of the renal vein in patients with not having accessory renal artery, Case A-B: Bilateral renal arteries originate from the caudal side of the left renal vein, 1) ventral side, 2) dorsal side, Case C: Lt. renal arteries originate from the caudal side of the left renal vein, 1) ventral side, 2) dorsal side, Case D: Rt. renal arteries originate from the caudal side of left renal vein\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/b049c5261d8693bcd0d3c41c.png"},{"id":75312756,"identity":"4d94fe9e-0471-4738-b437-28f63408562b","added_by":"auto","created_at":"2025-02-03 09:17:10","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":84737713,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/63cdfca0-3b14-4482-beac-25107b803bba.pdf"},{"id":75310159,"identity":"5c70e9c7-3a3e-4f43-85ba-b13921965db6","added_by":"auto","created_at":"2025-02-03 09:00:33","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":21104,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/8b9d6962dc76696a6324551a.docx"},{"id":75309018,"identity":"74bfe3e6-9fac-466a-b5dd-a9fe193968e8","added_by":"auto","created_at":"2025-02-03 08:52:33","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":17771,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/a24ee3556ed20a4285a7c332.docx"},{"id":75309017,"identity":"49ed0cb4-9188-4f1e-b0bd-3cdf0feca765","added_by":"auto","created_at":"2025-02-03 08:52:33","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":17213,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.docx","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/15c35114b1effee2b7280c3d.docx"},{"id":75309027,"identity":"49d16e6f-50d1-4c29-b4cc-ecf314063a2b","added_by":"auto","created_at":"2025-02-03 08:52:33","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":15284,"visible":true,"origin":"","legend":"","description":"","filename":"Table4.docx","url":"https://assets-eu.researchsquare.com/files/rs-5872015/v1/4c043f45edd07018db179f39.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The potential of preoperative three-dimensional computed tomography for para-aortic lymphadenectomy in gynecological malignancies","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePelvic and para-aortic lymphadenectomy (PANDx) is an important surgical intervention in gynecologic oncology. PANDx is routinely performed to enhance the prognosis of high-risk endometrial cancer, early stage ovarian and fallopian tube cancer, and for comprehensive surgical staging of cervical cancer [1\u0026ndash;3]. Despite its potential to enhance patient outcomes, postoperative complications have been documented to elevate surgery-related systemic morbidity and the formation of lymphedema/lymphocysts, while substantially extending the duration of the surgery [4]. This procedure should be chosen on an individual basis whilst carefully balancing the anticipated benefits against the patient's health status and inherent risk factors [1].\u003c/p\u003e \u003cp\u003eIn PANDx, urinary vessel variations were identified in 18.9\u0026ndash;30.2% of gynecological cancer surgeries [5\u0026ndash;7]. The most common variations were related to accessory renal arteries (6.8\u0026ndash;30%) and retro-aortic left renal veins (2.1\u0026ndash;3.4%); the most frequent urinary tract abnormality was a double left ureter (3.3\u0026ndash;11.1%). Nevertheless, evaluation of anatomical abnormalities prior to surgical intervention presents significant challenges [6]. In PANDx for gynecological malignancies, only 3.4\u0026ndash;5.7% of cases were identified as having anatomical variations on contrast-enhanced computed tomography (CT) prior to surgery [6, 8].\u003c/p\u003e \u003cp\u003eWith the recent proliferation of minimally invasive surgical procedures, complications arising from factors other than technical issues have also been documented [9, 10]. Our recent publication [10] reports the incidence of right renal artery injury during robot-assisted PANDx. The study notes that the robotic camera's ability to access deep regions beneath the renal vein, coupled with the distinct visual perspective compared with traditional laparotomy, might have contributed to this surgical complication. To reduce such complications, it is important to understand urinary vessel and urinary tract variations as accurately as possible before surgery.\u003c/p\u003e \u003cp\u003ePreoperative assessment of various organ systems has revealed that anatomical three-dimensional (3D) CT (3DCT) reconstruction significantly enhances the ability to devise precise surgical strategies [11\u0026ndash;13] as the surgeon is presented with the various organs of interest in high anatomical detail prior to surgery [11\u0026ndash;13]. Nevertheless, empirical evidence regarding the capacity of gynecological oncologists to assess PANDx preoperatively remains low.\u003c/p\u003e \u003cp\u003eIn the current study, the utility of preoperative 3DCT for improving surgical outcomes, including avoiding complications during PANDx, was examined.\u003c/p\u003e "},{"header":"Patients And Methods","content":"\n\u003ch3\u003e1. Study design\u003c/h3\u003e\n\u003cp\u003eThis observational study investigated a clinical database to identify the utility of 3DCT in patients who had undergone PANDx between January 2023 and November 2024. The study protocol was approved by the Institutional Review Board of Kagoshima University Graduate School of Medical Sciences (approval # 230024). Participants were informed of the study and were offered the opportunity to opt out.\u003c/p\u003e \u003cp\u003eA total of 72 patients were included and divided into two groups: Non-3DCT and 3DCT. The Non-3DCT group underwent contrast-enhanced CT without 3DCT. First, we evaluated the detection rates of arterial, venous, or urinary tract variations and surgical outcomes, including complications, in both groups. Evaluation of the uniformity of contrast enhancement of the kidney on postoperative contrast-enhanced CT was also performed to assess the impact of surgery on the renal arteries. Second, the presence of a renal artery caudal to the lower edge of the renal vein was investigated in the 3DCT group.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1. CT scan details for each group\u003c/h2\u003e \u003cp\u003eThe Non-3DCT group underwent contrast-enhanced CT at hospitals other than Kagoshima University Hospital and the findings of renal vascular and urinary tract variations were described. Patients who had not undergone contrast-enhanced CT at their first visit to our hospital underwent 3DCT angiography; therefore, all patients in the 3DCT group underwent 3DCT angiography at our hospital. 3DCT angiography scans for gynecological cancers were performed using IQon spectral CT (64-row) manufactured by Philips, Inc. (Amsterdam, Netherlands). 3D-CT scans were constructed from the arterial phase (3D CTA) using 64 multi-detector row CT scans. Similarly, venous 3D was performed with 3DCT venography (3D CTV) and the urinary tract with 3DCT urography (3D CTU).\u003c/p\u003e \u003cp\u003eIn this study, two CT protocols were employed in our institute: one with an arterial phase (Protocol A) and one without (Protocol B). A nonionic contrast agent (Ioversol 320 mg I/mL, Optiray\u0026reg;, Guerbet) was used in both protocols, with an injection volume of 1.8 mL/kg body weight, up to a maximum of 100 mL. A 20 mL saline flush followed the contrast agent at the same injection rate. In Protocol A, the injection rate was set at injection volume/30 s, and arterial phase scans were initiated 18 s after the attenuation in the abdominal aorta increased to 150 HU, as measured by a dedicated monitoring system. In Protocol B, the injection rate was fixed at 1.5 mL/s, and no arterial phase was included. For both protocols, parenchymal and excretory phase scans were acquired at 80 s and 300 s after contrast injection, respectively. Three-dimensional reconstructions of the renal arteries, renal veins, and urinary tract were created using a workstation (Ziostation2, Ziosoft Inc., Tokyo, Japan) and fused to enhance visualization.\u003c/p\u003e \u003cp\u003eIn the Non-3DCT group, the images were evaluated by radiologists at each facility, while in the 3DCT group, the images were evaluated by a radiologist specializing in gynecology at our facility. Surgery was performed after viewing of the 3D images by a gynecologic oncologist. Postoperative contrast-enhanced CT data were only available for patients who underwent investigation of complications or recurrence during regular follow-up.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003e2. Details of the commonly performed surgical technique\u003c/h3\u003e\n\u003cp\u003eStandard surgical techniques for endometrial and ovarian cancers include peritoneal cytology, hysterectomy, bilateral salpingo-oophorectomy, PANDx, pelvic lymphadenectomy, and omentectomy/appendectomy (if indicated). For endometrial cancer, radical or semi-radical hysterectomy was performed when cervical invasion was expected. For cervical cancer, radical hysterectomy was performed, and para-aortic lymph node dissection was performed only in cases of expected metastasis to the higher para-aortic lymph nodes. PANDx was defined as resection of the lower edge of the left renal vein. Clinical data were collected by reviewing inpatient medical records, and post-surgical complications were assessed using the Clavien-Dindo Classification v.2.0. Operative time was defined as the time between the start and closure of the skin incision. Robotic surgeries were performed using the Da Vinci Xi Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA). Surgeries were performed by four gynecologic oncologists using the surgical techniques previously described [10], regardless of whether standard laparotomy or minimally invasive surgery was performed. In urinary vessel variation, a supplemental renal artery that originated from any region around the aorta was defined as an accessory urinary artery.\u003c/p\u003e\n\u003ch3\u003e3. Statistical analysis\u003c/h3\u003e\n\u003cp\u003eInter-group categorical comparisons were performed using Chi-squared or Fisher\u0026rsquo;s exact tests. Student's t-tests and Mann\u0026ndash;Whitney U tests were used to evaluate the statistical significance of the differences between groups. Statistical significance was set at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05. All statistical analyses were performed on a personal computer using a statistical software package (SPSS for Windows, v.29; SPSS Inc., Chicago, IL, USA).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA research flowchart is shown in Fig. 1. One patient with impaired renal function who did not undergo contrast-enhanced CT was excluded, and 72 patients were finally analyzed. The characteristics of the patients who underwent PANDx are shown in Table 1. In total, 16.7% of patients had para-aortic lymph node metastasis, and endometrial cancer was the most common disease. High-risk diseases, such as lymph node metastasis, tended to be more common in the 3DCT group; however, there was an almost identical trend between the two groups. The overall sensitivity and specificity of CT were 41.7% and 96.7%, respectively, for para-aortic lymph node metastases and 33.3% and 92.4%, respectively, for pelvic lymph node metastases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDetection rates of having variations, and surgical outcomes in both groups\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDetails of the overall variations in renal vessels and the urinary tract detected by 3DCT are shown in Table 2. The 3DCT group identified 14/34 (41.2%) cases with renal vessel variations and two cases (5.9%) with double ureters, but the non-3DCT group failed to detect any abnormalities. Representative cases are shown in Fig. 2. Eight patients (23.5%) had an accessory renal artery that originated between lumbar 1 and 3. Of the six cases with variations in the right renal vein, only one had an accessory renal artery. In contrast, no subjects had variations in the left renal vein. The thickness, length, and flexure of the aorta and vena cava as well as the location of the aortic bifurcation tended to vary among individual cases.\u003c/p\u003e\n\u003cp\u003eThe surgical outcomes of each group and complications related to para-aortic lymph node dissection are shown in Table 3. There were no significant differences between the two groups in terms of blood loss, operation time, or the number of lymph nodes removed. As for intraoperative complications, we observed mild active bleeding from the surface of the vena cava in two cases in the non-3DCT group, while no injury to urinary vessels or urinary tract variations were observed intraoperatively. Postoperative complications tended to be slightly higher in the non-3DCT group, including lymphocyte infection, chylous leakage, and bowel obstruction.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eUniformity of contrast enhancement of the kidney in postoperative CT\u003c/em\u003e\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCT was evaluated in 23/38 (60.5%) patients in the non-3DCT group and 29/34 (85.3%) in the 3DCT group, respectively. Upon comprehensive evaluation, a single patient failed to demonstrate uniform contrast enhancement. This isolated case, identified as Case 3 in the 3DCT group, showed reduced contrast enhancement in the lower polar region of the right kidney compared to the preoperative CT [Fig.2b (3)].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe clinical course of Case 3 was as follows: 50 years old, endometrial cancer stage 1 B (preoperative estimated stage 2), endometrioid carcinoma grade 1, BMI 20.4; surgical procedures included radical hysterectomy, bilateral salpingo-oophorectomy, retroperitoneal lymphadenectomy, resection of 24 pelvic lymph nodes, and resection of 17 para-aortic lymph nodes. The operation time was 325 min, and the blood loss was 1130 ml. No lymph node metastasis or evidence of disease recurrence was observed for 19 months. As shown in Table 2, the right renal artery had five branches, which was the most frequent renal vessel variation in this study. The main branch appeared to be the accessory aortic lower-polar renal artery [Fig.2b (1-2)]. The defect in contrast enhancement in the postoperative CT scan may indicate poor blood flow in the right lower pole of the kidney. No obvious hydronephrosis, signs of renal failure, or ureteral abnormalities were observed after surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePresence of the renal artery caudal to the lower edge of the renal vein (Table 4)\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the 3DCT group, 8/34 (23.5%) unilateral or bilateral renal arteries, including urinary vessel variations, were located caudal to the lower edge of the renal vein. Importantly, in 4/19 (21.1%) cases with no accessory renal artery, the main renal artery was found caudal to the lower edge of the renal vein, and two of the four patients had bilateral involvement. All cases with the renal artery caudal to the lower edge of the renal vein in patients with not having accessory renal artery were shown in Fig. 3.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study presents the initial report of using 3DCT for the perioperative evaluation of PANDx in patients with gynecologic malignancies. Preoperative utilization of 3DCT provided clear identification of renal vessel and urinary tract variations, and the surgical procedure was performed without significant complications. The renal arteriovenous system exhibits significant anatomical diversity and utilization of 3DCT enables visualization of the renal artery's position inferior to that of the renal vein, potentially mitigating the risk of renal artery injury.\u003c/p\u003e \u003cp\u003eFor preoperative surgical planning, the anatomical location and extent of pelvic adhesions could be predicted with relative accuracy using internal examination and magnetic resonance imaging (MRI). Nonetheless, preoperative assessment of the para-aortic lymph node region proved insufficient when relying solely on contrast-enhanced CT imaging. In the non-3DCT group, we requested that the renal vessel and urinary tract variations be documented at facilities other than our institution; however, no such findings were recorded. Few studies have been published regarding renal vessel variations identified by contrast-enhanced CT prior to surgical intervention [6, 8]. The identification rate of urinary vessel and urinary tract variations in the perioperative period was only 12.1% based on preoperative contrast-enhanced CT and intraoperative surgical findings. These rates are significantly lower than those obtained in our study utilizing 3DCT [6, 8]. Most studies examining vascular variations in the periaortic region have been conducted using cadaveric analysis, intraoperative observation, and imaging techniques with contrast-enhanced CT. A comprehensive analysis of these data revealed that accessory urinary arteries were observed in 10\u0026ndash;50% of cases, left renal veins in 1.3\u0026ndash;3.2%, and right renal veins in 20\u0026ndash;23%, which aligns with our observed frequency of accessory urinary vessels and demonstrates a high degree of accuracy in identifying these vessels in 3DCT imaging [7].\u003c/p\u003e \u003cp\u003e3DCT is a technique that reconstructs anatomical structures in the human body in 3D based on tomographic images obtained through CT scans. This technique yields high-resolution, 3D visualizations of osseous structures, viscera, and vascular networks, allowing exceptional anatomical assessment. The efficacy of 3DCT has been extensively documented for multiple organ systems, including for elucidating vascular and bronchial structures prior to video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy [11]. Such 3D reconstruction techniques applied to two-dimensional CT images in hepatic resection procedures offer a valuable educational model. This approach enhances residents' comprehension of liver anatomical structures and surgical resection techniques [12]. 3DCT has been implemented primarily in urology for surgical planning and navigation to facilitate the surgeon's comprehension of surgical anatomy, particularly in the treatment of prostate and kidney cancers [13].\u003c/p\u003e \u003cp\u003eThe arterial phase of 3DCT, which was also utilized in our study, is considered the most efficacious modality for visualizing renal arteries. Furthermore, 3DCT of donor kidneys accurately delineates renal arterial anatomy in 97.6% of patients and provides enhanced details of the venous anatomy compared to conventional angiography [14]. The singular documented case of para-aortic lesion-associated 3DCT in gynecological malignancy revealed a metastatic mass surpassing 10 cm in size. This lesion was positioned dorsally to the vena cava, aorta, and left kidney while encircling the left renal and lumbar arterial structures. The 3DCT imaging clearly displayed the lesion's dimensions and location, thereby facilitating appropriate surgical intervention [15].\u003c/p\u003e \u003cp\u003eIntraoperative and postoperative complications observed in the non-3DCT group were common complications associated with para-aortic lymph node dissection. Conversely, complications in the 3DCT group were limited to one case of chylous leakage and one case of contrast effect deficiency in the lower pole of the kidney. Although a precise comparison was not possible, it appears that the 3DCT group had slightly fewer complications. Although not recognized in this study, intraoperative hemorrhage was precipitated by iatrogenic vascular injury, inadequate tissue manipulation, and anatomical variations in the vasculature surrounding the aorta. A comprehensive understanding of anatomical vascular variations is needed to mitigate the incidence of complications [7].\u003c/p\u003e \u003cp\u003eIn our investigation, Case 3 exhibited an asymptomatic contrast effect anomaly in the lower pole of the right kidney, which was incidentally discovered during routine CT follow-up. This finding contrasts with a comparable reported case in which detection occurred subsequent to postoperative pyrexia, which was presumed to be associated with an ischemic event [9]. The incidence of accessory renal artery injury remains undetermined [16, 17]. The superior portion of the ureter receives blood from the accessory aortic lower polar renal artery. Iatrogenic injury to this vessel may result in significant complications including ureteral necrosis, fistula development, and urinary leakage. Additionally, these arteries can induce ureteral obstruction, potentially leading to hydronephrosis [7, 18]. Despite preoperative identification of the accessory renal artery using 3DCT, it is plausible that this vessel was inadvertently ligated during surgery. To address the challenges posed by such intricate anatomical variations, the incorporation of an intraoperative navigation system could potentially serve as a valuable tool for minimizing any associated complications. Failure to recognize preoperative renal vessel variations can lead to critical outcomes for surgeons.\u003c/p\u003e \u003cp\u003eThe most significant complication associated with para-aortic lymph node dissection is potential injury to the main trunk of the renal artery. Minimally invasive surgery (MIS) enables enhanced visualization of the operative field and facilitates grasping and dissection procedures in confined spaces, resulting in frequent encounters with renal arteries. Traditionally, the renal artery was believed to be situated superior to the level of the renal vein; however, our research findings indicated that a renal artery's position inferior to the lower border of the renal vein was a frequent occurrence. Nevertheless, gynecological oncologists who typically perform dissection in a caudal-to-cranial direction must exercise heightened vigilance, particularly in MIS with a limited visual perspective.\u003c/p\u003e \u003cp\u003eThe construction of a 3D model may facilitate an enhanced focus on renal vessel and urinary tract anatomical variations during CT scan interpretation. These anatomical variations are readily apparent, enabling their identification without the need for active surveillance. However, 3DCT is not employed in standard gynecological cancer follow-up protocols because of its vessel-specific nature and the additional effort required for image processing. The identification of such variations requires preoperative collaboration between surgeons and radiologists. The integration of augmented reality (AR) technology into surgical procedures represents a potential avenue for advancing 3D-CT applications in the para-aortic region. This approach facilitates the incorporation of 3D virtual models into the operative field during MIS, enabling a real-time overlay of virtual imagery onto endoscopic views.\u003c/p\u003e \u003cp\u003e3DCT facilitates the precise identification of urinary vessel and tract variations and enables the execution of preoperative simulations analogous to actual surgical procedures for PANDx, potentially mitigating any operative challenges faced by surgeons and thus improving patient safety. Further comprehensive clinical trials are warranted to establish standardized 3DCT procedures and assess the reduction in adverse surgical events.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: The authors confirm that no financial assistance, grants, or other support were provided during the writing of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e:\u0026nbsp;Conceptualization: Shintaro Yanazume; Methodology: Fumitaka Ejima, Takashi Yoshiura, and Shintaro Yanazume; Formal analysis and investigation: Ayumi Kozai, Yusuke Kobayashi, and Shintaro Yanazume; Writing - original draft preparation: Shintaro Yanazume, Fumitaka Ejima; Writing - review and editing: Fumitaka Ejima, Takashi Yoshiura, and Hiroaki Kobayashi; Funding acquisition: not applicable; Resources: Mika Fukuda; Supervision: Shinichi Togami, Takashi Yoshiura, and Hiroaki Kobayashi.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u003c/strong\u003e The data for this study are shown in tables and figures; no other datasets were generated or analyzed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate and publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by the Institutional Review Board of Kagoshima University Graduate School of Medical Sciences (approval # 230024). Participants were informed of the study and were offered the opportunity to opt out for participate and publish.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbu-Rustum N, Yashar C, Arend R et al (2023) Uterine Neoplasms, Version 1.2023, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw 21:181\u0026ndash;209\u003c/li\u003e\n\u003cli\u003eLiu J, Berchuck A, Backes FJ et al (2024) NCCN Guidelines(R) Insights: Ovarian Cancer/Fallopian Tube Cancer/Primary Peritoneal Cancer, Version 3.2024. J Natl Compr Canc Netw 22:512\u0026ndash;519 \u003c/li\u003e\n\u003cli\u003eSeino M, Nagase S, Tokunaga H et al (2024) Japan Society of Gynecologic Oncology 2022 guidelines for uterine cervical neoplasm treatment. J Gynecol Oncol 35:e15\u003c/li\u003e\n\u003cli\u003eFrost JA, Webster KE, Bryant A, Morrison J (2017) Lymphadenectomy for the management of endometrial cancer. Cochrane Database Syst Rev 10:CD007585\u003c/li\u003e\n\u003cli\u003eKlemm P, Frober R, Kohler C, Schneider A (2005) Vascular anomalies in the paraaortic region diagnosed by laparoscopy in patients with gynaecologic malignancies. Gynecol Oncol 96:278\u0026ndash;282\u003c/li\u003e\n\u003cli\u003eKovacevic N, Hocevar M, Vivod G, Merlo S (2023) Vascular and Urinary Tract Anatomic Variants Relevant to Para-Aortic Lymphadenectomy in Women with Gynecological Cancers. Cancers (Basel) 15\u003c/li\u003e\n\u003cli\u003eKostov S, Selcuk I, Yordanov A et al (2022) Paraaortic Lymphadenectomy in Gynecologic Oncology-Significance of Vessels Variations. J Clin Med 11\u003c/li\u003e\n\u003cli\u003eAljabri B, MacDonald PS, Satin R, Stein LS, Obrand DI, Steinmetz OK (2001) Incidence of major venous and renal anomalies relevant to aortoiliac surgery as demonstrated by computed tomography. Ann Vasc Surg 15:615\u0026ndash;618\u003c/li\u003e\n\u003cli\u003eEitan R, Abu-Rustum NR, Walker JL, Barakat RR (2003) Ligation of an anatomic variant of renal vasculature during laparoscopic periaortic lymph node dissection: a cause of postoperative renal infarction. Gynecol Oncol 91:416\u0026ndash;420\u003c/li\u003e\n\u003cli\u003eYanazume S, Kobayashi H, Ushiwaka T, Togami S, Kamio M (2024) Robotic dual-docking surgery for para-aortic lymphadenectomy in endometrial cancer: a prospective feasibility study. Int J Clin Oncol. https://10.1007/s10147-024-02635-8\u003c/li\u003e\n\u003cli\u003eIkeda N, Yoshimura A, Hagiwara M, Akata S, Saji H (2013) Three dimensional computed tomography lung modeling is useful in simulation and navigation of lung cancer surgery. Ann Thorac Cardiovasc Surg 19:1\u0026ndash;5\u003c/li\u003e\n\u003cli\u003eYeo CT, MacDonald A, Ungi T et al (2018) Utility of 3D Reconstruction of 2D Liver Computed Tomography/Magnetic Resonance Images as a Surgical Planning Tool for Residents in Liver Resection Surgery. J Surg Educ 75:792\u0026ndash;797\u003c/li\u003e\n\u003cli\u003ePorpiglia F, Amparore D, Checcucci E et al (2018) Current Use of Three-dimensional Model Technology in Urology: A Road Map for Personalised Surgical Planning. Eur Urol Focus 4:652\u0026ndash;656\u003c/li\u003e\n\u003cli\u003eRubin GD, Alfrey EJ, Dake MD et al (1995) Assessment of living renal donors with spiral CT. Radiology 195:457\u0026ndash;462\u003c/li\u003e\n\u003cli\u003eKato T, Seol KH, Youn JS, Hong DG (2018) Salvage para-aortic lymphadenectomy in recurrent cervical cancer after visualization with 3-dimensional computed tomography angiography. Obstet Gynecol Sci 61:626\u0026ndash;630\u003c/li\u003e\n\u003cli\u003eLee WM, Choi JS, Bae J, Jung US, Eom JM (2018) Encountering the Accessory Polar Renal Artery during Laparoscopic Para-Aortic Lymphadenectomy. J Minim Invasive Gynecol 25:10\u0026ndash;11\u003c/li\u003e\n\u003cli\u003eMadsen M, Gorostidi M, Ruiz R, Jaunarena I, Cobas P, Lekuona A (2019) Accessory polar renal artery not pre-operatively visualized at extra-peritoneal para-aortic lymphadenectomy. Int J Gynecol Cancer 29:1226\u0026ndash;1227\u003c/li\u003e\n\u003cli\u003eTardo DT, Briggs C, Ahern G, Pitman A, Sinha S (2017) Anatomical variations of the renal arterial vasculature: An Australian perspective. J Med Imaging Radiat Oncol 61:643\u0026ndash;649\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 4 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Gynecology, three-dimensional, computed tomography, paraaortic lymph node dissection, accessory urinary artery, vessels variations","lastPublishedDoi":"10.21203/rs.3.rs-5872015/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5872015/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe evaluation of anatomical abnormalities involving urinary vessel variations prior to para-aortic lymphadenectomy in gynecological malignancies is challenging. In this context, the utility of preoperative three-dimensional (3D) computed tomography (3DCT) angiography in improving surgical outcomes was examined.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis observational study evaluated the utility of 3DCT in patients who underwent para-aortic lymphadenectomy between January 2023 and November 2024. 3D fusion images were constructed from the arterial phase (CTA), CT-venography (CTV), and CT-urography (CTU). A total of 72 patients were included and divided into two groups: Non-3DCT and 3DCT. Outcomes included detection rates of arterial, venous, or urinary tract variations and surgical outcomes, including complications, in both groups.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe 3DCT group included 14/34 (41.2%) cases with renal vessel variations and two cases (5.9%) with double ureters; the non-3DCT group did not detect any anatomical abnormalities. In the 3DCT group, renal vessel and urinary tract variations were clearly shown. Postoperative complications tended to be slightly higher in the non-3DCT group, including lymphocyte infection, chylous leakage, and bowel obstruction. Postoperative CT revealed reduced contrast in the lower pole of the right kidney in the 3DCT case with the most complex urinary vessel variations. Furthermore, in the 3DCT group, 8/34 (23.5%) unilateral or bilateral renal arteries were located caudally to the lower edge of the renal vein.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eIn gynecological malignancies, 3DCT before para-aortic lymphadenectomy was superior in identifying urinary vessel variations over conventional contrast-enhanced CT; thus, aiding realistic preoperative simulations and potentially reducing surgeons' burden and perioperative complications.\u003c/p\u003e","manuscriptTitle":"The potential of preoperative three-dimensional computed tomography for para-aortic lymphadenectomy in gynecological malignancies","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-03 08:52:28","doi":"10.21203/rs.3.rs-5872015/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1775b400-16ae-4267-927b-0ee5dbcf9d2a","owner":[],"postedDate":"February 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-03T08:52:30+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-03 08:52:28","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5872015","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5872015","identity":"rs-5872015","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}