Long-term Risk of Shunt Failure After Brain Tumor Surgery

Long-term Risk of Shunt Failure After Brain Tumor Surgery | 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 Long-term Risk of Shunt Failure After Brain Tumor Surgery Sayied Abdol Mohieb Hosainey, Benjamin Lassen Lykkedrang, Torstein R Meling This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-522788/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Oct, 2021 Read the published version in Neurosurgical Review → Version 1 posted 5 You are reading this latest preprint version Abstract Long-term risks and survival times of ventriculoperitoneal (VP) shunts implanted due to hydrocephalus (HC) after craniotomy for brain tumors are largely unknown. The aim of this study was to establish the overall VP shunt survival rates during a decade post-shunt insertion and to determine risks of failure after brain tumor surgery in the long-term period. In this population-based cohort from a well-defined geographical region, all adult patients (> 18 years) from 2004-2013 who underwent craniotomies for intracranial tumors leading to VP shunt dependency were included. Our brain tumor database was cross-linked to procedure codes for shunt surgery (codes AAF) to extract brain tumor patients who became VP shunt dependent after craniotomy. The VP shunt survival times, i.e. the shunt longevity, was calculated from the day of shunt insertion after brain tumor surgery until the day of its failure. A total of 4174 patients underwent craniotomies, of whom 85 became VP shunt-dependent (2%) afterwards. Twenty-eight patients (33%) had one or more shunt failures during their long-term follow-up, yielding 1-, 5- and 10-year shunt success rates of 77%, 71%, and 67%, respectively. Patient age, sex, tumor location, primary/repeat craniotomy, ventricular entry, post-craniotomy hemorrhage, post-shunting meningitis/infection and multiple shunt revisions were not statistically significant risk factors for shunt failure. Median shunt longevity was 457.5 days and 21.5 days for those with and without pre-craniotomy HC, respectively (p < 0.01). This study can serve as benchmark for future studies. Neurology Brain tumor Complications Hydrocephalus Shunt failure VP shunt Survival Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Surgical resection of brain tumors is considered to be the primary choice of treatment for patients with debilitating neurological symptoms. The efficacy of craniotomy for brain tumors has been well established with regards to quality of life [4,2,33,28] and prolongation of life [16,27,28,39,42,43,20]. Although the primary aim may be to cure disease or restore neurological function [7], risks of surgery such as infection [30], bleeding [22,30,15], surgical morbidity and mortality [41,2,3,30], neurological deficits [25,5,31,6] and changes to cerebrospinal fluid (CSF) dynamics leading to hydrocephalus (HC) and subsequent ventriculoperitoneal (VP) shunt dependency [19,18] remain significant concerns to the neurosurgeon. VP shunt insertion is the most commonly performed procedure for treatment of HC as it provides an immediate and effective diversion of accumulated CSF in the brain due to changes in CSF dynamics. Even though the main goal of shunting is to provide relief of intracranial pressure and improve symptoms, shunt-failures remain a considerable challenge. Although studies of shunt-failures with respect to the congenital conditions in the pediatric population [23,38,26], hemorrhage-related HC [12], idiopathic conditions [34,1] and infections [26,29] have been published, reports on risks of long-term shunt longevity after brain tumor surgery remains scarce in the literature [37,36,12]. In this large population-based study of all adult patients who underwent brain tumor surgery from a well-defined geographical region spanning a period of ten years, we primarily wished to determine the 1-year, 5-year and 10-year shunt-failure rates in order to determine shunt longevities in the long-term period after craniotomy for brain tumors. The secondary endpoint was to identify possible risk factors of reduced long-term shunt longevity. Materials And Methods Collection of Data In this population-based cohort, our prospectively collected database was reviewed to identify all adult patients operated at a single regional health care center between 2004 and 2013. The following patient demographics were recorded: age at time of shunt insertion, sex, status of hydrocephalus prior to craniotomy (yes/no), tumor location (supratentorial/infratentorial), intra-axial or extra-axial tumor location (established on imaging diagnostics reported by neuroradiologists), primary/repeat (secondary) tumor resection, histology, ventricular opening during craniotomy (yes/no), post-craniotomy hemorrhage (yes/no), post-craniotomy meningitis/infection (yes/no) and number of shunt revision procedures with confirmed shunt failures. The first craniotomy in a specific location was defined as primary craniotomy and all subsequent craniotomies in the same location were defined as secondary. Therefore, a patient could have had more than one primary craniotomy, if operated on multiple/different locations. No patients were lost to follow-up. In order to identify patients who underwent VP shunting after brain tumor surgery, our tumor database was cross-linked with our surgical procedure codes database using the Nordic Medico-Statistical Committee Classification of Surgical Procedures (NCSP) codes for CSF-related procedures (operation codes AAF). Subsequently, ICD-10 codes (G91) were reviewed to verify each case. Those who had biopsies and those with pre-existing VP shunts prior to their craniotomies were excluded from this study. Time from insertion of VP shunt to shunt-failure was recorded. Suspicion of VP shunt-failure was initially based on clinical signs and symptoms of altered intracranial pressure and radiological signs of ventricular enlargement as depicted on CT and/or MR imaging including T2/FLAIR weighted sequences. A confirmed shunt-failure was if/when patients underwent a shunt revision procedure resulting in a replacement of the whole shunt or in part by its individual components such as catheter replacement, as a result of blockage and/or change or replacement of shunt valve. Otherwise, if the shunt was only tested for functionality without any replacements, shunt malfunction was ruled out. All patients underwent either MRI or CT head imaging at time of suspected shunt-failure. For patients with confirmed shunt-failure, we reviewed operation notes to determine whether the ventricles were opened during craniotomy for brain tumor in order to analyze this as a potential risk factor. We also recorded post-craniotomy hemorrhage (intraparenchymal and/or intraventricular) and infection (positive CSF and device cultures including CSF pleiocytosis with clinical picture of infection requiring shunt removal) to analyze as risk factors for reduced shunt longevity. The survival time of VP shunts, defined as VP shunt-longevity, was calculated from the day of shunt insertion post-craniotomy for brain tumor until the day of confirmed shunt failure. VP shunt-failure rates were determined at 1 year, 5 years and 10 years after shunt insertion and risk factors were analyzed with regards to overall long-term shunt-failure. Multiple VP shunt revisions was defined as shunt revision procedures ≥ 2 shunt revisions due to shunt-failure. We excluded duplication of patient identification numbers (IDs) in order to avoid multiple counts of the same patient in our analyses and to account for multiple surgical interventions on the same patient. Hence, patient-to-craniotomy ratio was ensured to be 1:1 in the final analysis for long-term shunt longevity and risks of failure. As such, one patient could have multiple craniotomies and multiple shunt revision procedures for analyzing risks of reduced shunt longevity. Statistical Analysis For analysis of long-term VP shunt-longevity, the Kaplan-Meier method was used to construct survival curves and was calculated from first day of VP shunt-insertion to date of first revision or shunt removal. The Kaplan–Meier survival curves were also dichotomized with respect to patients with and without pre-craniotomy hydrocephalus in the 1-year and 5-year period. Log rank test was applied to determine statistical significance of different risk factors for shunt-failure. Cox proportional hazard regression models were used to identify multiple potential predictor variables with respect to time to shunt-failure. Chi-square (X 2 ) and Fisher’s exact test were used for comparison between categorical variables. Analysis of variance (ANOVA) and Student’s t test were used for continuous variables. Statistical significance was set at p <0.05 and for all analyses the statistical software JMP (version 9.03) was used. Results Overall demographics In total, 4774 craniotomies were performed on 4174 adult patients. There were 85 patients (2% of patients) who became VP shunt dependent after brain tumor surgery. Of these, 28 patients (33%) had shunt revision with confirmed shunt-failure in the study period and constitute the study population (Figure 1, Table 1). There were 13 males (46.4%) and 15 (53.6%) females with a median age at time of shunt-failure of 61 years (range 26.1 – 79.8). Twelve patients (42.8%) had HC prior to craniotomy for brain tumor, while 16 patients (57.2%) did not. Tumors were located supratentorially in 25 patients (89.3%) and infratentorially in 3 patients (10.7%). Twenty-one patients (75%) underwent primary tumor surgery and 7 patients (25%) had repeat craniotomy for brain tumor. Nine patients (10.6%) had ventricular opening during tumor resection, one (3.6%) of whom had a short shunt longevity. None of those with shunt-failure had post-craniotomy hemorrhage and only 2 patients (7.1%) had shunt infections. Nine patients (32.1%) had more than one shunt revision procedure (Table 1). Long-term shunt longevity Overall, there were 65, 60, and 57 out of 85 patients who did not have any shunt malfunction at 1 year, 5 years and 10 years, respectively, yielding VP shunt success rates of 77%, 71% and 67% (Figure 2, Table 2). The median shunt-longevity was 20.5, 23 and 23.5 days, at 1 year, 5 years and 10 years, respectively (Figure 2, Table 2). Median shunt longevity was 457.5 days and 21.5 days, respectively, for those with and without pre-craniotomy HC (Figures 3 and 4, Table 3). Patients with pre-craniotomy HC had significantly lower risk of shunt-failure overall in the long-term in both univariate (HR 0.3, CI [0.1 – 0.7], p < .01) and multivariate analysis (HR 0.2, CI [0.1 – 0.5], p < .05) compared to patients without pre-craniotomy hydrocephalus (Figures 3 and 4, Table 3). Risk factors for reduced long-term shunt longevity Neither age nor sex were significantly associated with long-term shunt failure in univariate or multivariate analysis (Table 3). Similarly, tumor location (dichotomized into supratentorial/infratentorial compartment and intra-axial/extra-axial tumors), primary/repeat craniotomy, ventricular entry, post-craniotomy hemorrhage, post-shunting meningitis/infection and multiple shunt revisions/failures were not significantly associated with reduced shunt longevity in the long-term period (Table 3). Discussion The innate natural history of brain tumors or their surgical interventions may lead to HC that necessitates temporary CSF diversion procedures, such as external ventricular drainage (EVD) and/or endoscopic third ventriculostomy (ETV), or lead to permanent CSF diversion. Although the incidence and risk factors for development of postoperative HC leading to VP shunt dependency of patients with and without HC prior to a craniotomy for brain tumor have been previously described [19,18], the long-term outcomes of VP shunts in brain tumor patients are largely unknown. In our study, a total of 85 patients in a consecutive cohort of 4204 adult patients became VP shunt dependent after craniotomies for brain tumors (2% of patients). Of these, 28 patients (33%) had confirmed shunt-failures during the study period of 10 years, yielding cumulative shunt success rates at 1, 5, and 10 years of 77%, 71%, and 67%, respectively (Figure 2, Table 2). In the literature, reports of long-term shunt-failure rates in the adult population range from 11% at 1 year up to 34% at 10 years [24,29,45,36], with the majority of these consisting of various underlying etiologies including congenital diseases, normal pressure hydrocephalus, trauma, tumor, intracranial cysts etc. In a nationwide study on adult HC patients, Donoho et al. [12] found that 9% of patients required a shunt revision with a median time to shunt revision of only 41 days. However, their study included shunts due to all underlying conditions and 45% had shunt insertions due to obstructive HC. Furthermore, the authors did not state whether an obstructive HC was due to brain tumors and their shunt revision rates reflect the first 6 months only. In another study by Reddy et al. [36] on VP shunt complications in HC patients with intracranial tumors, 20% and 24% of patients experienced shunt failures requiring shunt revisions within 1 year and 5 years, respectively. Our lower shunt-failure rates might be explained by inclusion of brain tumor patients in adults only. However, the overall median time to shunt-failure was shorter in our study as compared to that of Donoho et al. [9], but this might be explained by tumor debris and higher protein content in the CSF of patients with brain tumors leading to shunt blockage compared to other non-oncological conditions. Recently, Hosainey et al. [17] studied risk factors of early VP shunt failure after brain tumor surgery and found that patients with pre-existing, non-treated HC prior to craniotomy had a significantly shorter shunt-free period before definitive shunting compared to those without pre-craniotomy HC. Interestingly, in the current study, shunted patients with HC prior to craniotomy had significantly longer shunt survival (Figures 3 and 4). This indicates that in patients with distinct pathologies and profoundly deranged CSF dynamics in the early postoperative course after brain tumor surgery, early VP shunting may serve as ‘prophylaxis’ against further CSF disturbances in the future and hence give prolonged shunt longevity due to early ‘normalized’ hydrodynamics by shunting. The median shunt longevity was 457.5 days and 21.5 days for those with and without untreated HC pre-craniotomy, respectively (Figures 3 and 4). In the literature, median shunt survival times range from 19 days in the short-term up to 20.1 years in the long-term [35,29,8,24,12]. However, these studies were not limited to brain tumor patients and include a plethora of underlying conditions. Early changes to CSF dynamics as a result of overloading venous outflow and CSF pathway obstruction caused by disease burden has been described in the literature [40,44]. Further neuronal cell death may also ensue [10,11] if the disease process is left untreated. This requires early VP shunt insertion in order to normalize intracranial processes and avoid brain damage caused by a disrupted hydrocephalic state. Nonetheless, another plausible explanation may be that although some patients with pre- and post-craniotomy HC underwent shunting in the early postoperative course, they might have experienced spontaneous resolution of their hydrocephalic condition in the long-term period. Therefore, a ‘silent’ shunt obstruction may have ensued, making them effectively shunt-independent, wherefore a shunt obstruction would be unnoticed due to lack of signs and symptoms. Neither patient age at time of shunt placement nor sex were associated with reduced shunt longevity (Table 3). Male gender has been associated with increased risk of shunt dysfunction [29,45], but it is not known if this was related to intracranial tumors. In a study by Reddy et al. [36] of VP shunt complications for hydrocephalus in patients with intracranial tumors, males had significantly lower 3- or 6-month survival rates compared to females (p < 0.001). This is in contrast to our findings. They also reported a 2% decrease in odds of shunt-failure with increasing age at time of shunt insertion [36]. Comparatively, some studies have associated younger age with higher risk of shunt-failure [12,36], whereas others have not reached this conclusion regarding age in the short-term [1,13,17] nor in the long-term period after shunting [24]. Tumor location was not significantly associated with reduced shunt longevity despite dichotomizations into supratentorial/infratentorial and intra-axial/extra-axial tumor location (Table 3). Although somewhat surprising, this is in line with previous studies that did not find extra-axial/intra-axial tumor location to be significantly associated with early shunt-failure after craniotomy for brain tumor [17]. In contrast, Khan et al. [24] studied factors affecting shunt survival in adults and found that extra-axial tumors were more common (13.2%) than intra-axial tumors (9.7%), but in line with our results, they reported that brain tumor location was not a significant risk factor of shunt failure. With respect to tumor histology, several extra-axial tumors such as choroid plexus tumors, craniopharyngiomas [19] and schwannomas [14], and periventricular intra-axial tumors [21] have been reported to have increased risk of postoperative HC and shunt dependency. Additional stratified risk analysis into those with and without pre-craniotomy HC did not reveal intra-axial/extra-axial tumors as statistically significant risk factors for reduced long-term shunt longevity in our study. Nonetheless, similar reports are scarce in the literature making comparative analysis to our study difficult. In our study, meningiomas had the highest incidence of shunt failure during follow-up (Table 1). Interestingly, these are extra-axial tumors and not usually located in the ventricles, but they might cause significant CSF dynamics changes after craniotomy if the tumor volume is large, particularly in the posterior fossa region, or if the area of resected/coagulated dura is large. Reddy et al. [36] reported that patients with benign tumors had higher risk of shunt revision, probably because of a shorter survival rate among patients with malignant brain tumors. In the above-mentioned study by Khan et al. [24], the effect of brain tumor histology did not reach statistical significance (p = 0.062). In the same vein, Rinaldo et al. [37] found no difference in the incidence of shunt revision surgery in high grade glioma patients as compared to NPH patients. We believe that the lower number of malignant brain tumor patients with reduced shunt longevity in our study might be due to the short overall survival of these patients, rendering shunt procedures futile when they present at advanced stages in the disease process. In addition to clinical diagnosis of shunt dysfunction, these patients may also suffer from ventriculomegaly as a consequence of radiation-induced brain atrophy, which is diagnosed radiologically. Lastly, patients with high grade gliomas invariably see clinical deterioration due to tumor progression and a shunt dysfunction in this context may be overlooked. In our study, primary/secondary surgery for brain tumor was not significantly associated with increased risk of reduced long-term shunt longevity (Table 3). Secondary/repeat surgery has been reported as a risk factor for postoperative HC and subsequent VP shunt dependency in patients with pre-craniotomy hydrocephalus [19] and one would expect repeat surgical intervention for recurrent brain tumor to cause even more CSF disturbance and shunt-failures. However, only seven patients in our study cohort underwent repeat craniotomy for brain tumor, leaving a low statistical power and a high risk of a statistical error type II. Only 2 patients (7.1%) had shunt infection during the follow-up (Table 1). Although post-shunting meningitis/infection was not significantly associated with reduced shunt longevity (Table 3), infection has been shown to be associated with higher risk of shunt failure in some studies [29]. Our rates of infection lie in the upper range of published reports [1,26,29,24], which can be explained by our inclusion criteria of adult patients with brain tumors only. However, the number of patients with infection were too few for adequate statistical power, possibly giving rise to false negative results in our study. Most of the shunt revisions happened during the first year after shunt insertion (Table 2). Whereas some have reported shunt-failures in the first 6 months [13,26,29,35], others have reported within the first year [32]. Nine patients in the study cohort (32.1%) underwent multiple shunt revisions (≥ 2 revisions) (Table 1), in keeping with other reports [45]. Korinek et al. [29] reported that previous shunt revision was an independent risk factor for infection leading to failure and Reddy et al. [36] reported single shunt revision procedures in 25 patients (13.4%) and multiple shunt revisions in 27 patients (14.4%) after initial shunt placement. Reddy et al. [36] also found that odds for multiple revisions among those with shunt system replacements were significantly higher (OR 24.39, p < 0.01) than those without any shunt replacement. They also showed that infection, shunt valve replacement and externalization were also significantly associated with multiple revisions. However, the significance was lost when the data was adjusted for the effects of other risk factors such as shunt system replacement and proximal shunt complication. Our study did not find that multiple revisions procedures (≥ 2 revision surgeries) were significantly associated with reduced shunt-longevity in the long-term (Table 3). Strength And Limitations Of The Study Our centralized neurosurgical health care center at Oslo University Hospital (Rikshospitalet and Ullevål) has a population-based referral of patients from a well-defined geographical region of Norway with approximately 2.8 million inhabitants. This reduces possible confounding effects of differences in access to health care services. As there is only one main neurosurgical department performing neurosurgical procedures from a defined geographical area, selection bias is avoided, which are inherently present in multicenter studies. Our study is unique in that we did not find any other large-scale studies with focus on analysis of long-term shunt longevity and possible risks associated with shunt-failure after craniotomies for brain tumors where all patients are included regardless of tumor histology. There is no selection bias, as the study includes all craniotomies performed within the study period from a histologically verifiable intracranial tumor. The design of our study is a retrospective analysis of a prospectively collected database. Additionally, by cross-linking our tumor database with the registry for neurosurgical procedures, we have included all craniotomies leading to shunt-dependency and have been able to perform shunt-survival and risk analysis as per our main aims of the study. Finally, no patients have been lost to follow up and to the extent of our knowledge, this is the largest study with respect to analyzing long-term shunt-survival and risks associated with shunt-failure in patients whom became shunt-dependent after craniotomy for brain tumors. The foremost limitation of this study is its retrospective analysis of prospectively collected data. Surgeon’s preferences with regards to treating hydrocephalus and timing of shunt revision might be a potential selection bias. Other variables such as tumor volume, shunt valve type and whether proximal or distal catheter malfunction/block were the cause of shunt-failure were not included in our analyses. The analysis of images with regards to shunt-failure was not performed in an automatized manner, due to lack of comparability across the different imaging modalities in absence of age-adjusted normal values and due to lack of comparability across the different imaging modalities. Even though CT/MRI was available for all patients included in the study, the presence or absence of ventriculomegaly leading to shunt-failure and subsequent revision may have been limited by human error. Adjuvant treatments such as radiotherapy, chemotherapy and coexisting comorbidities were not included in the analyses, which may contribute to the risks and rates associated with reduced shunt longevity in the long-term period. Although being a large study, the number of patients might be so low in the final analyses giving rise to statistical type I and II errors, thus failing to identify true prognostic factors for shunt-failures. As most published reports in the literature are biased with limitations to certain patient groups, tumor histologies and accounting for overall shunt-failure rates, comparative analysis to our study was difficult. Our study was confined only to adults whom had undergone craniotomies for brain tumors. Conclusions The overall 10-year shunt success rate after brain tumor surgery was 67%. Median shunt longevities were 457.5 days and 21.5 days in those with and without pre-craniotomy hydrocephalus. Patients with pre-craniotomy hydrocephalus had significantly longer shunt longevity than those without pre-craniotomy hydrocephalus. Early ‘prophylactic’ shunting of patient with persisting hydrocephalus after brain tumor surgery may yield prolonged shunt longevity in the long-term. This study can serve as benchmark for future studies. Declarations Funding There are no financial disclosures concerning the materials or methods used in this study or the findings specified in this paper. Conflict of interest The authors declare that they have no conflict of interest Availability of data and material Data may be given upon reasonable request Code availability Not applicable Ethical approval The study has been approved by the institutional ethics committee (Personvernombudets tilrådning 2013/14574) Consent to participate Not applicable Consent for publication Not applicable Authors’ contributions Concept and design: Sayied Abdol Mohieb Hosainey, Torstein R Meling. Material preparation and data collection: Sayied Abdol Mohieb Hosainey, Torstein R Meling. Data analysis: all authors. Original draft preparation: Sayied Abdol Mohieb Hosainey. Manuscript review and editing: all authors. Supervision: Torstein R Meling. All authors reviewed and commented on previous versions of the manuscript. All authors read and approved the final version of the manuscript. 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Acta Neurol Scand 127:161-169. doi:10.1111/j.1600-0404.2012.01692.x Korinek AM, Fulla-Oller L, Boch AL, Golmard JL, Hadiji B, Puybasset L (2011) Morbidity of ventricular cerebrospinal fluid shunt surgery in adults: an 8-year study. Neurosurgery 68:985-994; discussion 994-985. doi:10.1227/NEU.0b013e318208f360 Lassen B, Helseth E, Ronning P, Scheie D, Johannesen TB, Maehlen J, Langmoen IA, Meling TR (2011) Surgical mortality at 30 days and complications leading to recraniotomy in 2630 consecutive craniotomies for intracranial tumors. Neurosurgery 68:1259-1268; discussion 1268-1259. doi:10.1227/NEU.0b013e31820c0441 Lemee JM, Corniola MV, Da Broi M, Schaller K, Meling TR (2019) Early Postoperative Complications in Meningioma: Predictive Factors and Impact on Outcome. World Neurosurg 128:e851-e858. doi:10.1016/j.wneu.2019.05.010 Merkler AE, Ch'ang J, Parker WE, Murthy SB, Kamel H (2017) The rate of complications after ventriculoperitoneal shunt surgery. World neurosurgery 98:654-658 Nitta T, Sato K (1995) Prognostic implications of the extent of surgical resection in patients with intracranial malignant gliomas. Cancer 75:2727-2731 Pujari S, Kharkar S, Metellus P, Shuck J, Williams MA, Rigamonti D (2008) Normal pressure hydrocephalus: long-term outcome after shunt surgery. J Neurol Neurosurg Psychiatry 79:1282-1286. doi:10.1136/jnnp.2007.123620 Reddy GK, Bollam P, Caldito G (2014) Long-term outcomes of ventriculoperitoneal shunt surgery in patients with hydrocephalus. World Neurosurg 81:404-410. doi:10.1016/j.wneu.2013.01.096 Reddy GK, Bollam P, Caldito G, Willis B, Guthikonda B, Nanda A (2011) Ventriculoperitoneal shunt complications in hydrocephalus patients with intracranial tumors: an analysis of relevant risk factors. J Neurooncol 103:333-342. doi:10.1007/s11060-010-0393-4 Rinaldo L, Brown D, Lanzino G, Parney IF (2018) Outcomes following cerebrospinal fluid shunting in high-grade glioma patients. J Neurosurg 129:984-996. doi:10.3171/2017.6.JNS17859 Riva-Cambrin J, Kestle JR, Holubkov R, Butler J, Kulkarni AV, Drake J, Whitehead WE, Wellons JC, 3rd, Shannon CN, Tamber MS, Limbrick DD, Jr., Rozzelle C, Browd SR, Simon TD, Hydrocephalus Clinical Research N (2016) Risk factors for shunt malfunction in pediatric hydrocephalus: a multicenter prospective cohort study. J Neurosurg Pediatr 17:382-390. doi:10.3171/2015.6.PEDS14670 Rogne SG, Ronning P, Helseth E, Johannesen TB, Langberg CW, Lote K, Scheie D, Meling TR (2012) Craniotomy for brain metastases: a consecutive series of 316 patients. Acta Neurol Scand 126:23-31. doi:10.1111/j.1600-0404.2011.01590.x Rossitti S (2013) Pathophysiology of increased cerebrospinal fluid pressure associated to brain arteriovenous malformations: The hydraulic hypothesis. Surg Neurol Int 4:42. doi:10.4103/2152-7806.109657 Sawaya R, Hammoud M, Schoppa D, Hess KR, Wu SZ, Shi WM, Wildrick DM (1998) Neurosurgical outcomes in a modern series of 400 craniotomies for treatment of parenchymal tumors. Neurosurgery 42:1044-1055; discussion 1055-1046 Stummer W, Pichlmeier U, Meinel T, Wiestler OD, Zanella F, Reulen HJ, Group AL-GS (2006) Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant glioma: a randomised controlled multicentre phase III trial. Lancet Oncol 7:392-401. doi:10.1016/S1470-2045(06)70665-9 Vecht CJ, Avezaat CJ, van Putten WL, Eijkenboom WM, Stefanko SZ (1990) The influence of the extent of surgery on the neurological function and survival in malignant glioma. A retrospective analysis in 243 patients. J Neurol Neurosurg Psychiatry 53:466-471 Williams H (2008) The venous hypothesis of hydrocephalus. Med Hypotheses 70:743-747. doi:10.1016/j.mehy.2007.08.013 Wu Y, Green NL, Wrensch MR, Zhao S, Gupta N (2007) Ventriculoperitoneal shunt complications in California: 1990 to 2000. Neurosurgery 61:557-563 Tables Table 1. Overview characteristics of patients with post-craniotomy VP shunt dependency and reduced shunt longevity. Total VP shunt dependency after craniotomy (N/%) VP shunt failure (N/%) No VP shunt failure (N/%) Total 85 28 57 Age (median yrs) 61.9 61.0 62.7 Sex Male Female 44 (51.8) 41 (48.2) 13 (46.4) 15 (53.6) 27 (47.4) 30 (52.6) Pre-craniotomy hydrocephalus No Yes 46 (54.1) 39 (45.9) 16 (57.2) 12 (42.8) 30 (52.6) 27 (47.4) Tumor location Supratentorial Infratentorial 68 (80.0) 17 (20.0) 25 (89.3) 3 (10.7) 47 (82.5) 10 (17.5) Extra-axial tumor Intra-axial tumor 33 (38.8) 52 (61.2) 14 (50.0) 14 (50.0) 19 (33.3) 38 (66.7) Surgery Primary Secondary 64 (75.3) 21 (24.7) 21 (75.0) 7 (25.0) 43 (75.4) 14 (24.6) Histology HGG Meningioma Metastasis Other tumors Ependymoma Craniopharyngioma Schwannoma Choroid plexus tumor Pituitary adenoma LGG 21 (24.7) 21 (24.7) 18 (21.2) 8 (9.5) 4 (4.7) 4 (4.7) 3 (3.6) 2 (2.3) 2 (2.3) 2 (2.3) 6 (21.5) 9 (32.2) 4 (14.3) 2 (7.1) 2 (7.1) 1 (3.6) 2 (7.1) 0 0 2 (7.1) 15 (26.3) 12 (21.1) 14 (24.6) 6 (10.5) 2 (3.5) 3 (5.3) 1 (1.7) 2 (3.5) 2 (3.5) 0 Ventricular entry during craniotomy 9 (10.6) 1 (3.6) 8 (14.0) Post-craniotomy bleeding 8 (9.4) 0 8 (14.0) Post-craniotomy infection 4 (4.7) 2 (7.1) 2 (3.5) Multiple (≥ 2) shunt revisions – 9 (32.1) 0 Abbreviations: EVD = external ventricular drainage; ETV = endoscopic third ventriculostomy; HGG = high grade glioma; LGG = low grade glioma; VP = ventriculoperitoneal. Table 2. Shunt longevity time frames of selected variables after craniotomy for brain tumor. 1 year post VP-shunting 5 years post VP-shunting 10 years post VP-shunting Patients with shunt-failure (N) 20 5 3 Shunt-failure rate (cumulative %) 23 29 33 Sex (N/%) Male Female 12 (60) 8 (40) 1 (20) 4 (80) 0 3 (100) Shunt longevity days a 20.5 23.0 23.5 HC prior to craniotomy (N/%) Yes b No c 5 (25) 15 (75) 4 (80) 1 (20) 3 (100) 0 Tumor location (N/%) Supratentorial Infratentorial 18 (90) 2 (10) 4 (80) 1 (20) 3 (100) 0 Intra-axial (N/%) Extra-axial (N/%) 9 (45) 11 (55) 3 (60) 2 (40) 2 (67) 1 (33) Surgery (N/%) Primary Secondary 15 (75) 5 (25) 3 (60) 2 (40) 3 (100) 0 a : Time given as median unless otherwise specified b : Cases with persisting postoperative HC (after craniotomy) requiring VP shunting c : Cases with de novo (new onset) postoperative HC requiring VP shunting Abbreviations: HC = hydrocephalus; VP = ventriculoperitoneal. Table 3. Long-term shunt longevity and risk analysis of shunting with univariate and multivariate proportional hazards ration model Risk of long-term shunt-failure Univariate (HR, CI[95%]) Multivariate (HR, CI[95%]) Age at time of shunt failure 1.0 [0.9 – 1.1] 1.0 [0.9 – 1.1] Sex Male Female 1 0.5 [0.2 – 1.2] 1 0.9 [0.3 – 2.8] Pre-craniotomy HC No Yes 1 0.3 [0.1 – 0.7] a 1 0.2 [0.1 – 0.6] b Tumor location Supratentorial Infratentorial 1 0.8 [0.2 – 2.3] 1 0.6 [0.1 – 3.7] Intra-axial tumor Extra-axial tumor 1 0.9 [0.4 – 2.0] 1 0.5 [0.1 – 1.6] Surgery Primary Secondary 1 1.1 [0.4 – 2.3] 1 0.5 [0.1 – 2.1] Ventricular opening at craniotomy No Yes 1 1.2 [0.1 – 6.1] 1 1.4 [0.1 – 12.4] Post-craniotomy haemorrhage No Yes – c – c – c – c Post-craniotomy meningitis/infection No Yes 1 8.5 [0.5 – 66.3] 1 – c Multiple revisions (≥ 2 procedures) No Yes 1 1.3 [0.5 – 2.8] 1 0.4 [0.1 – 2.3] a: p < .01 b: p < .05 c: too few cases in variable parameters to determine HR for long term shunt longevity Cite Share Download PDF Status: Published Journal Publication published 29 Oct, 2021 Read the published version in Neurosurgical Review → Version 1 posted Editorial decision: Major revisions 28 Jul, 2021 Reviews received at journal 26 May, 2021 Reviewers invited by journal 25 May, 2021 Editor assigned by journal 18 May, 2021 First submitted to journal 12 May, 2021 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. 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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-522788","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":29312019,"identity":"2fed25dc-ad72-4c49-9c18-62fc955d728b","order_by":0,"name":"Sayied Abdol Mohieb Hosainey","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4UlEQVRIiWNgGAWjYNCCAgYeefbGxgcMDAeIUs/YwGDAIGPYc/iwAUlabBhuuKVJEKVFt739+WMeAxsexhk8ZtU8NXfk+BmYHz66gUeL2Zkzhs08Bmk87NI9Zrd5jj0zlmxgMzbOwaflRg4jUMthHsY5Z4Ba2A4nbjjAwyaNX0v6Q6CW/zwMN3LMinn+EaUlAeSwA0AtaWnMvG3EaAH6ZeYcg2QeUCBLzu07bCzZTMgvx9sffHhTYWcPisoPb74dluNnb374GJ8WEGDiQWEwE1AOAow/0BmjYBSMglEwCpABAM+KUCwuNHnVAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-4287-4545","institution":"Oslo Universitetssykehus","correspondingAuthor":true,"prefix":"","firstName":"Sayied","middleName":"Abdol Mohieb","lastName":"Hosainey","suffix":""},{"id":29312020,"identity":"0390b382-da5f-49c3-a2c7-2a7c98026ae3","order_by":1,"name":"Benjamin Lassen Lykkedrang","email":"","orcid":"","institution":"Department of Radiology, Hospital of Southern Norway, Kristiansand, Norway","correspondingAuthor":false,"prefix":"","firstName":"Benjamin","middleName":"Lassen","lastName":"Lykkedrang","suffix":""},{"id":29312021,"identity":"180f0f1d-17f6-4196-be84-ca786c7abbb8","order_by":2,"name":"Torstein R Meling","email":"","orcid":"","institution":"Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway","correspondingAuthor":false,"prefix":"","firstName":"Torstein","middleName":"R","lastName":"Meling","suffix":""}],"badges":[],"createdAt":"2021-05-13 07:41:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-522788/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-522788/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10143-021-01648-5","type":"published","date":"2021-10-29T10:34:23+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":9848419,"identity":"cddd5be9-ee3c-44b5-86af-6d51eb3ecd0c","added_by":"auto","created_at":"2021-06-01 18:44:41","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":20176,"visible":true,"origin":"","legend":"Flowchart illustrating all cases leading to VP shunt dependency and subsequently VP shunt-failure within the study period. ","description":"","filename":"Fig1Flowchart1200.jpg","url":"https://assets-eu.researchsquare.com/files/rs-522788/v1/91a6177292c245e79e121493.jpg"},{"id":9848092,"identity":"67757c54-6fec-40cb-ae42-74e2a8ff6191","added_by":"auto","created_at":"2021-06-01 18:41:41","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":43258,"visible":true,"origin":"","legend":"Kaplan – Meier curve showing overall 10-year shunt longevity for all patients in the entire study period.","description":"","filename":"Fig2OverallSV10yrs1200.jpg","url":"https://assets-eu.researchsquare.com/files/rs-522788/v1/b51c68b3db75993be1b74f4a.jpg"},{"id":9848420,"identity":"cc70436a-e588-4ab1-85d9-495989707236","added_by":"auto","created_at":"2021-06-01 18:44:41","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":39695,"visible":true,"origin":"","legend":"Kaplan – Meier curves demonstrating 1-year shunt longevity. Red continuous and blue dotted lines represent patients with and without pre-craniotomy hydrocephalus, respectively. ","description":"","filename":"Fig31yrSurvival1200.jpg","url":"https://assets-eu.researchsquare.com/files/rs-522788/v1/363ca527c84a0f059f4c06c1.jpg"},{"id":9848094,"identity":"91296041-756d-441b-9b19-79739da16b9d","added_by":"auto","created_at":"2021-06-01 18:41:41","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":40862,"visible":true,"origin":"","legend":"Kaplan – Meier curves demonstrating 5-year shunt longevity. Red continuous and blue dotted lines represent patients with and without pre-craniotomy hydrocephalus, respectively. ","description":"","filename":"Fig45yrSurvival1200.jpg","url":"https://assets-eu.researchsquare.com/files/rs-522788/v1/166e87ffca873788004001fd.jpg"},{"id":18472659,"identity":"43ef7ae3-ca63-4881-b207-811c4895036f","added_by":"auto","created_at":"2022-02-22 10:34:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":418603,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-522788/v1/13c25687-bdcb-4f1d-a833-f6510e349afb.pdf"}],"financialInterests":"","formattedTitle":"\u003cp\u003eLong-term Risk of Shunt Failure After Brain Tumor Surgery\u003c/p\u003e","fulltext":[{"header":"Introduction ","content":"\u003cp\u003eSurgical resection of brain tumors is considered to be the primary choice of treatment for patients with debilitating neurological symptoms. The efficacy of craniotomy for brain tumors has been well established with regards to quality of life [4,2,33,28] and prolongation of life [16,27,28,39,42,43,20]. Although the primary aim may be to cure disease or restore neurological function [7], risks of surgery such as infection [30], bleeding [22,30,15], surgical morbidity and mortality [41,2,3,30], neurological deficits [25,5,31,6] and changes to cerebrospinal fluid (CSF) dynamics leading to hydrocephalus (HC) and subsequent ventriculoperitoneal (VP) shunt dependency [19,18] remain significant concerns to the neurosurgeon.\u003c/p\u003e\n\u003cp\u003eVP shunt insertion is the most commonly performed procedure for treatment of HC as it provides an immediate and effective diversion of accumulated CSF in the brain due to changes in CSF dynamics. Even though the main goal of shunting is to provide relief of intracranial pressure and improve symptoms, shunt-failures remain a considerable challenge. Although studies of shunt-failures with respect to the congenital conditions in the pediatric population [23,38,26], hemorrhage-related HC [12], idiopathic conditions [34,1] and infections [26,29] have been published, reports on risks of long-term shunt longevity after brain tumor surgery remains scarce in the literature [37,36,12].\u003c/p\u003e\n\u003cp\u003eIn this large population-based study of all adult patients who underwent brain tumor surgery from a well-defined geographical region spanning a period of ten years, we primarily wished to determine the 1-year, 5-year and 10-year shunt-failure rates in order to determine shunt longevities in the long-term period after craniotomy for brain tumors. The secondary endpoint was to identify possible risk factors of reduced long-term shunt longevity.\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003ch2\u003eCollection of Data\u003c/h2\u003e\n\u003cp\u003eIn this population-based cohort, our prospectively collected database was reviewed to identify all adult patients operated at a single regional health care center between 2004 and 2013. The following patient demographics were recorded: age at time of shunt insertion, sex, status of hydrocephalus prior to craniotomy (yes/no), tumor location (supratentorial/infratentorial), intra-axial or extra-axial tumor location (established on imaging diagnostics reported by neuroradiologists), primary/repeat (secondary) tumor resection, histology, ventricular opening during craniotomy (yes/no), post-craniotomy hemorrhage (yes/no), post-craniotomy meningitis/infection (yes/no) and number of shunt revision procedures with confirmed shunt failures. The first craniotomy in a specific location was defined as primary craniotomy and all subsequent craniotomies in the same location were defined as secondary. Therefore, a patient could have had more than one primary craniotomy, if operated on multiple/different locations. No patients were lost to follow-up.\u003c/p\u003e\n\u003cp\u003eIn order to identify patients who underwent VP shunting after brain tumor surgery, our tumor database was cross-linked with our surgical procedure codes database using the Nordic Medico-Statistical Committee Classification of Surgical Procedures (NCSP) codes for CSF-related procedures (operation codes AAF). Subsequently, ICD-10 codes (G91) were reviewed to verify each case. Those who had biopsies and those with pre-existing VP shunts prior to their craniotomies were excluded from this study.\u003c/p\u003e\n\u003cp\u003eTime from insertion of VP shunt to shunt-failure was recorded. Suspicion of VP shunt-failure was initially based on clinical signs and symptoms of altered intracranial pressure and radiological signs of ventricular enlargement as depicted on CT and/or MR imaging including T2/FLAIR weighted sequences. A confirmed shunt-failure was if/when patients underwent a shunt revision procedure resulting in a replacement of the whole shunt or in part by its individual components such as catheter replacement, as a result of blockage and/or change or replacement of shunt valve. Otherwise, if the shunt was only tested for functionality without any replacements, shunt malfunction was ruled out. All patients underwent either MRI or CT head imaging at time of suspected shunt-failure.\u003c/p\u003e\n\u003cp\u003eFor patients with confirmed shunt-failure, we reviewed operation notes to determine whether the ventricles were opened during craniotomy for brain tumor in order to analyze this as a potential risk factor. We also recorded post-craniotomy hemorrhage (intraparenchymal and/or intraventricular) and infection (positive CSF and device cultures including CSF pleiocytosis with clinical picture of infection requiring shunt removal) to analyze as risk factors for reduced shunt longevity.\u003c/p\u003e\n\u003cp\u003eThe survival time of VP shunts, defined as VP shunt-longevity, was calculated from the day of shunt insertion post-craniotomy for brain tumor until the day of confirmed shunt failure. VP shunt-failure rates were determined at 1 year, 5 years and 10 years after shunt insertion and risk factors were analyzed with regards to overall long-term shunt-failure. Multiple VP shunt revisions was defined as shunt revision procedures \u0026ge; 2 shunt revisions due to shunt-failure. We excluded duplication of patient identification numbers (IDs) in order to avoid multiple counts of the same patient in our analyses and to account for multiple surgical interventions on the same patient. Hence, patient-to-craniotomy ratio was ensured to be 1:1 in the final analysis for long-term shunt longevity and risks of failure. As such, one patient could have multiple craniotomies and multiple shunt revision procedures for analyzing risks of reduced shunt longevity.\u003c/p\u003e\n\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\n\u003cp\u003eFor analysis of long-term VP shunt-longevity, the Kaplan-Meier method was used to construct survival curves and was calculated from first day of VP shunt-insertion to date of first revision or shunt removal. The Kaplan\u0026ndash;Meier survival curves were also dichotomized with respect to patients with and without pre-craniotomy hydrocephalus in the 1-year and 5-year period. Log rank test was applied to determine statistical significance of different risk factors for shunt-failure. Cox proportional hazard regression models were used to identify multiple potential predictor variables with respect to time to shunt-failure. Chi-square (X\u003csup\u003e2\u003c/sup\u003e) and Fisher\u0026rsquo;s exact test were used for comparison between categorical variables. Analysis of variance (ANOVA) and Student\u0026rsquo;s t test were used for continuous variables. Statistical significance was set at p \u0026lt;0.05 and for all analyses the statistical software JMP (version 9.03) was used.\u003c/p\u003e"},{"header":"Results","content":"\u003ch2\u003eOverall demographics\u003c/h2\u003e\n\u003cp\u003eIn total, 4774 craniotomies were performed on 4174 adult patients. There were 85 patients (2% of patients) who became VP shunt dependent after brain tumor surgery. Of these, 28 patients (33%) had shunt revision with confirmed shunt-failure in the study period and constitute the study population (Figure 1, Table 1). There were 13 males (46.4%) and 15 (53.6%) females with a median age at time of shunt-failure of 61 years (range 26.1 \u0026ndash; 79.8). Twelve patients (42.8%) had HC prior to craniotomy for brain tumor, while 16 patients (57.2%) did not. Tumors were located supratentorially in 25 patients (89.3%) and infratentorially in 3 patients (10.7%). Twenty-one patients (75%) underwent primary tumor surgery and 7 patients (25%) had repeat craniotomy for brain tumor. Nine patients (10.6%) had ventricular opening during tumor resection, one (3.6%) of whom had a short shunt longevity. None of those with shunt-failure had post-craniotomy hemorrhage and only 2 patients (7.1%) had shunt infections. Nine patients (32.1%) had more than one shunt revision procedure (Table 1).\u003c/p\u003e\n\u003ch2\u003eLong-term shunt longevity\u003c/h2\u003e\n\u003cp\u003eOverall, there were 65, 60, and 57 out of 85 patients who did not have any shunt malfunction at 1 year, 5 years and 10 years, respectively, yielding VP shunt success rates of 77%, 71% and 67% (Figure 2, Table 2). The median shunt-longevity was 20.5, 23 and 23.5 days, at 1 year, 5 years and 10 years, respectively (Figure 2, Table 2).\u003c/p\u003e\n\u003cp\u003eMedian shunt longevity was 457.5 days and 21.5 days, respectively, for those with and without pre-craniotomy HC (Figures 3 and 4, Table 3). Patients with pre-craniotomy HC had significantly lower risk of shunt-failure overall in the long-term in both univariate (HR 0.3, CI [0.1 \u0026ndash; 0.7], p \u0026lt; .01) and multivariate analysis (HR 0.2, CI [0.1 \u0026ndash; 0.5], p \u0026lt; .05) compared to patients without pre-craniotomy hydrocephalus (Figures 3 and 4, Table 3).\u003c/p\u003e\n\u003ch2\u003eRisk factors for reduced long-term shunt longevity\u003c/h2\u003e\n\u003cp\u003eNeither age nor sex were significantly associated with long-term shunt failure in univariate or multivariate analysis (Table 3). Similarly, tumor location (dichotomized into supratentorial/infratentorial compartment and intra-axial/extra-axial tumors), primary/repeat craniotomy, ventricular entry, post-craniotomy hemorrhage, post-shunting meningitis/infection and multiple shunt revisions/failures were not significantly associated with reduced shunt longevity in the long-term period (Table 3).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe innate natural history of brain tumors or their surgical interventions may lead to HC that necessitates temporary CSF diversion procedures, such as external ventricular drainage (EVD) and/or endoscopic third ventriculostomy (ETV), or lead to permanent CSF diversion. Although the incidence and risk factors for development of postoperative HC leading to VP shunt dependency of patients with and without HC prior to a craniotomy for brain tumor have been previously described [19,18], the long-term outcomes of VP shunts in brain tumor patients are largely unknown.\u003c/p\u003e\n\u003cp\u003eIn our study, a total of 85 patients in a consecutive cohort of 4204 adult patients became VP shunt dependent after craniotomies for brain tumors (2% of patients). Of these, 28 patients (33%) had confirmed shunt-failures during the study period of 10 years, yielding cumulative shunt success rates at 1, 5, and 10 years of 77%, 71%, and 67%, respectively (Figure 2, Table 2). In the literature, reports of long-term shunt-failure rates in the adult population range from 11% at 1 year up to 34% at 10 years [24,29,45,36], with the majority of these consisting of various underlying etiologies including congenital diseases, normal pressure hydrocephalus, trauma, tumor, intracranial cysts etc. In a nationwide study on adult HC patients, Donoho et al. [12] found that 9% of patients required a shunt revision with a median time to shunt revision of only 41 days. However, their study included shunts due to all underlying conditions and 45% had shunt insertions due to obstructive HC. Furthermore, the authors did not state whether an obstructive HC was due to brain tumors and their shunt revision rates reflect the first 6 months only. In another study by Reddy et al. [36] on VP shunt complications in HC patients with intracranial tumors, 20% and 24% of patients experienced shunt failures requiring shunt revisions within 1 year and 5 years, respectively. Our lower shunt-failure rates might be explained by inclusion of brain tumor patients in adults only. However, the overall median time to shunt-failure was shorter in our study as compared to that of Donoho et al. [9], but this might be explained by tumor debris and higher protein content in the CSF of patients with brain tumors leading to shunt blockage compared to other non-oncological conditions.\u003c/p\u003e\n\u003cp\u003eRecently, Hosainey et al. [17] studied risk factors of early VP shunt failure after brain tumor surgery and found that patients with pre-existing, non-treated HC prior to craniotomy had a significantly shorter shunt-free period before definitive shunting compared to those without pre-craniotomy HC. Interestingly, in the current study, shunted patients with HC prior to craniotomy had significantly longer shunt survival (Figures 3 and 4). This indicates that in patients with distinct pathologies and profoundly deranged CSF dynamics in the early postoperative course after brain tumor surgery, early VP shunting may serve as \u0026lsquo;prophylaxis\u0026rsquo; against further CSF disturbances in the future and hence give prolonged shunt longevity due to early \u0026lsquo;normalized\u0026rsquo; hydrodynamics by shunting. The median shunt longevity was 457.5 days and 21.5 days for those with and without untreated HC pre-craniotomy, respectively (Figures 3 and 4). In the literature, median shunt survival times range from 19 days in the short-term up to 20.1 years in the long-term [35,29,8,24,12]. However, these studies were not limited to brain tumor patients and include a plethora of underlying conditions. Early changes to CSF dynamics as a result of overloading venous outflow and CSF pathway obstruction caused by disease burden has been described in the literature [40,44]. Further neuronal cell death may also ensue [10,11] if the disease process is left untreated. This requires early VP shunt insertion in order to normalize intracranial processes and avoid brain damage caused by a disrupted hydrocephalic state. Nonetheless, another plausible explanation may be that although some patients with pre- and post-craniotomy HC underwent shunting in the early postoperative course, they might have experienced spontaneous resolution of their hydrocephalic condition in the long-term period. Therefore, a \u0026lsquo;silent\u0026rsquo; shunt obstruction may have ensued, making them effectively shunt-independent, wherefore a shunt obstruction would be unnoticed due to lack of signs and symptoms.\u003c/p\u003e\n\u003cp\u003eNeither patient age at time of shunt placement nor sex were associated with reduced shunt longevity (Table 3). Male gender has been associated with increased risk of shunt dysfunction [29,45], but it is not known if this was related to intracranial tumors. In a study by Reddy et al. [36] of VP shunt complications for hydrocephalus in patients with intracranial tumors, males had significantly lower 3- or 6-month survival rates compared to females (p \u0026lt; 0.001). This is in contrast to our findings. They also reported a 2% decrease in odds of shunt-failure with increasing age at time of shunt insertion [36]. Comparatively, some studies have associated younger age with higher risk of shunt-failure [12,36], whereas others have not reached this conclusion regarding age in the short-term [1,13,17] nor in the long-term period after shunting [24].\u003c/p\u003e\n\u003cp\u003eTumor location was not significantly associated with reduced shunt longevity despite dichotomizations into supratentorial/infratentorial and intra-axial/extra-axial tumor location (Table 3). Although somewhat surprising, this is in line with previous studies that did not find extra-axial/intra-axial tumor location to be significantly associated with early shunt-failure after craniotomy for brain tumor [17]. In contrast, Khan et al. [24] studied factors affecting shunt survival in adults and found that extra-axial tumors were more common (13.2%) than intra-axial tumors (9.7%), but in line with our results, they reported that brain tumor location was not a significant risk factor of shunt failure.\u003c/p\u003e\n\u003cp\u003eWith respect to tumor histology, several extra-axial tumors such as choroid plexus tumors, craniopharyngiomas [19] and schwannomas [14], and periventricular intra-axial tumors [21] have been reported to have increased risk of postoperative HC and shunt dependency. Additional stratified risk analysis into those with and without pre-craniotomy HC did not reveal intra-axial/extra-axial tumors as statistically significant risk factors for reduced long-term shunt longevity in our study. Nonetheless, similar reports are scarce in the literature making comparative analysis to our study difficult.\u003c/p\u003e\n\u003cp\u003eIn our study, meningiomas had the highest incidence of shunt failure during follow-up (Table 1). Interestingly, these are extra-axial tumors and not usually located in the ventricles, but they might cause significant CSF dynamics changes after craniotomy if the tumor volume is large, particularly in the posterior fossa region, or if the area of resected/coagulated dura is large. Reddy et al. [36] reported that patients with benign tumors had higher risk of shunt revision, probably because of a shorter survival rate among patients with malignant brain tumors. In the above-mentioned study by Khan et al. [24], the effect of brain tumor histology did not reach statistical significance (p = 0.062). In the same vein, Rinaldo et al. [37] found no difference in the incidence of shunt revision surgery in high grade glioma patients as compared to NPH patients. We believe that the lower number of malignant brain tumor patients with reduced shunt longevity in our study might be due to the short overall survival of these patients, rendering shunt procedures futile when they present at advanced stages in the disease process. In addition to clinical diagnosis of shunt dysfunction, these patients may also suffer from ventriculomegaly as a consequence of radiation-induced brain atrophy, which is diagnosed radiologically. Lastly, patients with high grade gliomas invariably see clinical deterioration due to tumor progression and a shunt dysfunction in this context may be overlooked.\u003c/p\u003e\n\u003cp\u003eIn our study, primary/secondary surgery for brain tumor was not significantly associated with increased risk of reduced long-term shunt longevity (Table 3). Secondary/repeat surgery has been reported as a risk factor for postoperative HC and subsequent VP shunt dependency in patients with pre-craniotomy hydrocephalus [19] and one would expect repeat surgical intervention for recurrent brain tumor to cause even more CSF disturbance and shunt-failures. However, only seven patients in our study cohort underwent repeat craniotomy for brain tumor, leaving a low statistical power and a high risk of a statistical error type II.\u003c/p\u003e\n\u003cp\u003eOnly 2 patients (7.1%) had shunt infection during the follow-up (Table 1). Although post-shunting meningitis/infection was not significantly associated with reduced shunt longevity (Table 3), infection has been shown to be associated with higher risk of shunt failure in some studies [29]. Our rates of infection lie in the upper range of published reports [1,26,29,24], which can be explained by our inclusion criteria of adult patients with brain tumors only. However, the number of patients with infection were too few for adequate statistical power, possibly giving rise to false negative results in our study. Most of the shunt revisions happened during the first year after shunt insertion (Table 2). Whereas some have reported shunt-failures in the first 6 months [13,26,29,35], others have reported within the first year [32].\u003c/p\u003e\n\u003cp\u003eNine patients in the study cohort (32.1%) underwent multiple shunt revisions (\u0026ge; 2 revisions) (Table 1), in keeping with other reports [45]. Korinek et al. [29] reported that previous shunt revision was an independent risk factor for infection leading to failure and Reddy et al. [36] reported single shunt revision procedures in 25 patients (13.4%) and multiple shunt revisions in 27 patients (14.4%) after initial shunt placement. Reddy et al. [36] also found that odds for multiple revisions among those with shunt system replacements were significantly higher (OR 24.39, p \u0026lt; 0.01) than those without any shunt replacement. They also showed that infection, shunt valve replacement and externalization were also significantly associated with multiple revisions. However, the significance was lost when the data was adjusted for the effects of other risk factors such as shunt system replacement and proximal shunt complication. Our study did not find that multiple revisions procedures (\u0026ge; 2 revision surgeries) were significantly associated with reduced shunt-longevity in the long-term (Table 3).\u003c/p\u003e"},{"header":"Strength And Limitations Of The Study","content":"\u003cp\u003eOur centralized neurosurgical health care center at Oslo University Hospital (Rikshospitalet and Ullev\u0026aring;l) has a population-based referral of patients from a well-defined geographical region of Norway with approximately 2.8 million inhabitants. This reduces possible confounding effects of differences in access to health care services. As there is only one main neurosurgical department performing neurosurgical procedures from a defined geographical area, selection bias is avoided, which are inherently present in multicenter studies. Our study is unique in that we did not find any other large-scale studies with focus on analysis of long-term shunt longevity and possible risks associated with shunt-failure after craniotomies for brain tumors where all patients are included regardless of tumor histology. There is no selection bias, as the study includes all craniotomies performed within the study period from a histologically verifiable intracranial tumor. The design of our study is a retrospective analysis of a prospectively collected database. Additionally, by cross-linking our tumor database with the registry for neurosurgical procedures, we have included all craniotomies leading to shunt-dependency and have been able to perform shunt-survival and risk analysis as per our main aims of the study. Finally, no patients have been lost to follow up and to the extent of our knowledge, this is the largest study with respect to analyzing long-term shunt-survival and risks associated with shunt-failure in patients whom became shunt-dependent after craniotomy for brain tumors.\u003c/p\u003e\n\u003cp\u003eThe foremost limitation of this study is its retrospective analysis of prospectively collected data. Surgeon\u0026rsquo;s preferences with regards to treating hydrocephalus and timing of shunt revision might be a potential selection bias. Other variables such as tumor volume, shunt valve type and whether proximal or distal catheter malfunction/block were the cause of shunt-failure were not included in our analyses. The analysis of images with regards to shunt-failure was not performed in an automatized manner, due to lack of comparability across the different imaging modalities in absence of age-adjusted normal values and due to lack of comparability across the different imaging modalities. Even though CT/MRI was available for all patients included in the study, the presence or absence of ventriculomegaly leading to shunt-failure and subsequent revision may have been limited by human error. Adjuvant treatments such as radiotherapy, chemotherapy and coexisting comorbidities were not included in the analyses, which may contribute to the risks and rates associated with reduced shunt longevity in the long-term period. Although being a large study, the number of patients might be so low in the final analyses giving rise to statistical type I and II errors, thus failing to identify true prognostic factors for shunt-failures. As most published reports in the literature are biased with limitations to certain patient groups, tumor histologies and accounting for overall shunt-failure rates, comparative analysis to our study was difficult. Our study was confined only to adults whom had undergone craniotomies for brain tumors.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe overall 10-year shunt success rate after brain tumor surgery was 67%. Median shunt longevities were 457.5 days and 21.5 days in those with and without pre-craniotomy hydrocephalus. Patients with pre-craniotomy hydrocephalus had significantly longer shunt longevity than those without pre-craniotomy hydrocephalus. Early \u0026lsquo;prophylactic\u0026rsquo; shunting of patient with persisting hydrocephalus after brain tumor surgery may yield prolonged shunt longevity in the long-term. This study can serve as benchmark for future studies.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThere are no financial disclosures concerning the materials or methods used in this study or the findings specified in this paper.\u003c/p\u003e\n\u003ch2\u003eConflict of interest\u003c/h2\u003e\n\u003cp\u003eThe authors declare that they have no conflict of interest\u003c/p\u003e\n\u003ch2\u003eAvailability of data and material\u003c/h2\u003e\n\u003cp\u003eData may be given upon reasonable request\u003c/p\u003e\n\u003ch2\u003eCode availability\u003c/h2\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003ch2\u003eEthical approval\u003c/h2\u003e\n\u003cp\u003eThe study has been approved by the institutional ethics committee (Personvernombudets tilr\u0026aring;dning 2013/14574)\u003c/p\u003e\n\u003ch2\u003eConsent to participate\u003c/h2\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003ch2\u003eConsent for publication\u003c/h2\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003ch2\u003eAuthors\u0026rsquo; contributions\u003c/h2\u003e\n\u003cp\u003eConcept and design: Sayied Abdol Mohieb Hosainey, Torstein R Meling. Material preparation and data collection: Sayied Abdol Mohieb Hosainey, Torstein R Meling. Data analysis: all authors. Original draft preparation: Sayied Abdol Mohieb Hosainey. Manuscript review and editing: all authors. Supervision: Torstein R Meling. All authors reviewed and commented on previous versions of the manuscript. All authors read and approved the final version of the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAnderson IA, Saukila LF, Robins JMW, Akhunbay-Fudge CY, Goodden JR, Tyagi AK, Phillips N, Chumas PD (2018) Factors associated with 30-day ventriculoperitoneal shunt failure in pediatric and adult patients. J Neurosurg 130:145-153. doi:10.3171/2017.8.JNS17399\u003c/li\u003e\n\u003cli\u003eBarker FG, 2nd (2004) Craniotomy for the resection of metastatic brain tumors in the U.S., 1988-2000: decreasing mortality and the effect of provider caseload. 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J Neurosurg Pediatr 17:382-390. doi:10.3171/2015.6.PEDS14670\u003c/li\u003e\n\u003cli\u003eRogne SG, Ronning P, Helseth E, Johannesen TB, Langberg CW, Lote K, Scheie D, Meling TR (2012) Craniotomy for brain metastases: a consecutive series of 316 patients. Acta Neurol Scand 126:23-31. doi:10.1111/j.1600-0404.2011.01590.x\u003c/li\u003e\n\u003cli\u003eRossitti S (2013) Pathophysiology of increased cerebrospinal fluid pressure associated to brain arteriovenous malformations: The hydraulic hypothesis. Surg Neurol Int 4:42. doi:10.4103/2152-7806.109657\u003c/li\u003e\n\u003cli\u003eSawaya R, Hammoud M, Schoppa D, Hess KR, Wu SZ, Shi WM, Wildrick DM (1998) Neurosurgical outcomes in a modern series of 400 craniotomies for treatment of parenchymal tumors. Neurosurgery 42:1044-1055; discussion 1055-1046\u003c/li\u003e\n\u003cli\u003eStummer W, Pichlmeier U, Meinel T, Wiestler OD, Zanella F, Reulen HJ, Group AL-GS (2006) Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant glioma: a randomised controlled multicentre phase III trial. Lancet Oncol 7:392-401. doi:10.1016/S1470-2045(06)70665-9\u003c/li\u003e\n\u003cli\u003eVecht CJ, Avezaat CJ, van Putten WL, Eijkenboom WM, Stefanko SZ (1990) The influence of the extent of surgery on the neurological function and survival in malignant glioma. A retrospective analysis in 243 patients. J Neurol Neurosurg Psychiatry 53:466-471\u003c/li\u003e\n\u003cli\u003eWilliams H (2008) The venous hypothesis of hydrocephalus. Med Hypotheses 70:743-747. doi:10.1016/j.mehy.2007.08.013\u003c/li\u003e\n\u003cli\u003eWu Y, Green NL, Wrensch MR, Zhao S, Gupta N (2007) Ventriculoperitoneal shunt complications in California: 1990 to 2000. Neurosurgery 61:557-563\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Overview characteristics of patients with post-craniotomy VP shunt dependency and reduced shunt longevity.\u003c/p\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; \u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u003cstrong\u003eTotal VP shunt dependency after craniotomy (N/%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e\u003cstrong\u003eVP shunt failure (N/%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e\u003cstrong\u003eNo VP shunt failure (N/%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eTotal\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e85\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e57\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eAge (median yrs)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e61.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e61.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e62.7\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eSex\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Male\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Female\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e44 (51.8)\u003c/p\u003e\n\u003cp\u003e41 (48.2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e13 (46.4)\u003c/p\u003e\n\u003cp\u003e15 (53.6)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e27 (47.4)\u003c/p\u003e\n\u003cp\u003e30 (52.6)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003ePre-craniotomy hydrocephalus\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e46 (54.1)\u003c/p\u003e\n\u003cp\u003e39 (45.9)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e16 (57.2)\u003c/p\u003e\n\u003cp\u003e12 (42.8)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e30 (52.6)\u003c/p\u003e\n\u003cp\u003e27 (47.4)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eTumor location\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Supratentorial\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Infratentorial\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e68 (80.0)\u003c/p\u003e\n\u003cp\u003e17 (20.0)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e25 (89.3)\u003c/p\u003e\n\u003cp\u003e3 (10.7)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e47 (82.5)\u003c/p\u003e\n\u003cp\u003e10 (17.5)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eExtra-axial tumor\u003c/p\u003e\n\u003cp\u003eIntra-axial tumor\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e33 (38.8)\u003c/p\u003e\n\u003cp\u003e52 (61.2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e14 (50.0)\u003c/p\u003e\n\u003cp\u003e14 (50.0)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e19 (33.3)\u003c/p\u003e\n\u003cp\u003e38 (66.7)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eSurgery\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Primary\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Secondary\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e64 (75.3)\u003c/p\u003e\n\u003cp\u003e21 (24.7)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e21 (75.0)\u003c/p\u003e\n\u003cp\u003e7 (25.0)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e43 (75.4)\u003c/p\u003e\n\u003cp\u003e14 (24.6)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eHistology\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; HGG\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Meningioma\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Metastasis\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Other tumors\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Ependymoma\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Craniopharyngioma\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Schwannoma\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Choroid plexus tumor\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Pituitary adenoma\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; LGG\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e21 (24.7)\u003c/p\u003e\n\u003cp\u003e21 (24.7)\u003c/p\u003e\n\u003cp\u003e18 (21.2)\u003c/p\u003e\n\u003cp\u003e8 (9.5)\u003c/p\u003e\n\u003cp\u003e4 (4.7)\u003c/p\u003e\n\u003cp\u003e4 (4.7)\u003c/p\u003e\n\u003cp\u003e3 (3.6)\u003c/p\u003e\n\u003cp\u003e2 (2.3)\u003c/p\u003e\n\u003cp\u003e2 (2.3)\u003c/p\u003e\n\u003cp\u003e2 (2.3)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e6 (21.5)\u003c/p\u003e\n\u003cp\u003e9 (32.2)\u003c/p\u003e\n\u003cp\u003e4 (14.3)\u003c/p\u003e\n\u003cp\u003e2 (7.1)\u003c/p\u003e\n\u003cp\u003e2 (7.1)\u003c/p\u003e\n\u003cp\u003e1 (3.6)\u003c/p\u003e\n\u003cp\u003e2 (7.1)\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003cp\u003e2 (7.1)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e15 (26.3)\u003c/p\u003e\n\u003cp\u003e12 (21.1)\u003c/p\u003e\n\u003cp\u003e14 (24.6)\u003c/p\u003e\n\u003cp\u003e6 (10.5)\u003c/p\u003e\n\u003cp\u003e2 (3.5)\u003c/p\u003e\n\u003cp\u003e3 (5.3)\u003c/p\u003e\n\u003cp\u003e1 (1.7)\u003c/p\u003e\n\u003cp\u003e2 (3.5)\u003c/p\u003e\n\u003cp\u003e2 (3.5)\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eVentricular entry during craniotomy\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e9 (10.6)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e1 (3.6)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e8 (14.0)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003ePost-craniotomy bleeding\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e8 (9.4)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e8 (14.0)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003ePost-craniotomy infection\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e4 (4.7)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e2 (7.1)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e2 (3.5)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"225\"\u003e\n\u003cp\u003eMultiple (\u0026ge; 2) shunt revisions\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"146\"\u003e\n\u003cp\u003e\u0026ndash;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"124\"\u003e\n\u003cp\u003e9 (32.1)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"122\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;Abbreviations: EVD = external ventricular drainage; ETV = endoscopic third ventriculostomy; HGG = high grade glioma; LGG = low grade glioma; VP = ventriculoperitoneal.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2.\u003c/strong\u003e Shunt longevity time frames of selected variables after craniotomy for brain tumor.\u003c/p\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e\u003cstrong\u003e1 year post VP-shunting\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e\u003cstrong\u003e5 years post VP-shunting\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e\u003cstrong\u003e10 years post VP-shunting\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003ePatients with shunt-failure (N)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e20\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eShunt-failure rate (cumulative %)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e23\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e29\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e33\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eSex (N/%)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Male\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Female\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e12 (60)\u003c/p\u003e\n\u003cp\u003e8 (40)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1 (20)\u003c/p\u003e\n\u003cp\u003e4 (80)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003cp\u003e3 (100)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eShunt longevity days\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e20.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e23.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e23.5\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eHC prior to craniotomy (N/%)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e5 (25)\u003c/p\u003e\n\u003cp\u003e15 (75)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e4 (80)\u003c/p\u003e\n\u003cp\u003e1 (20)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e3 (100)\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eTumor location (N/%)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Supratentorial\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Infratentorial\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e18 (90)\u003c/p\u003e\n\u003cp\u003e2 (10)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e4 (80)\u003c/p\u003e\n\u003cp\u003e1 (20)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e3 (100)\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eIntra-axial (N/%)\u003c/p\u003e\n\u003cp\u003eExtra-axial (N/%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e9 (45)\u003c/p\u003e\n\u003cp\u003e11 (55)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e3 (60)\u003c/p\u003e\n\u003cp\u003e2 (40)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e2 (67)\u003c/p\u003e\n\u003cp\u003e1 (33)\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"210\"\u003e\n\u003cp\u003eSurgery (N/%)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Primary\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Secondary\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"157\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e15 (75)\u003c/p\u003e\n\u003cp\u003e5 (25)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"166\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e3 (60)\u003c/p\u003e\n\u003cp\u003e2 (40)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"175\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e3 (100)\u003c/p\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003ea\u003c/sup\u003e: Time given as median unless otherwise specified\u003c/p\u003e\n\u003cp\u003e\u003csup\u003eb\u003c/sup\u003e: Cases with persisting postoperative HC (after craniotomy) requiring VP shunting\u003c/p\u003e\n\u003cp\u003e\u003csup\u003ec\u003c/sup\u003e: Cases with \u003cem\u003ede novo \u003c/em\u003e(new onset) postoperative HC requiring VP shunting\u003c/p\u003e\n\u003cp\u003eAbbreviations: HC = hydrocephalus; VP = ventriculoperitoneal.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 3. Long-term shunt longevity and risk analysis of shunting with univariate and multivariate proportional hazards ration model\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003e\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; \u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; \u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;Risk of long-term shunt-failure\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003eUnivariate (HR, CI[95%])\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003eMultivariate (HR, CI[95%])\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eAge at time of shunt failure\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e1.0 [0.9 \u0026ndash; 1.1]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e1.0 [0.9 \u0026ndash; 1.1]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eSex\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Male\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Female\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.5 [0.2 \u0026ndash; 1.2]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.9 [0.3 \u0026ndash; 2.8]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003ePre-craniotomy HC\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.3 [0.1 \u0026ndash; 0.7]\u003csup\u003e a\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.2 [0.1 \u0026ndash; 0.6]\u003csup\u003e b\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eTumor location\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Supratentorial\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Infratentorial\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.8 [0.2 \u0026ndash; 2.3]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.6 [0.1 \u0026ndash; 3.7]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eIntra-axial tumor\u003c/p\u003e\n\u003cp\u003eExtra-axial tumor\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.9 [0.4 \u0026ndash; 2.0]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.5 [0.1 \u0026ndash; 1.6]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eSurgery\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Primary\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Secondary\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e1.1 [0.4 \u0026ndash; 2.3]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.5 [0.1 \u0026ndash; 2.1]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eVentricular opening at craniotomy\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e1.2 [0.1 \u0026ndash; 6.1]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e1.4 [0.1 \u0026ndash; 12.4]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003ePost-craniotomy haemorrhage\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026ndash;\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u0026ndash;\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026ndash;\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u0026ndash;\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003ePost-craniotomy meningitis/infection\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e8.5 [0.5 \u0026ndash; 66.3]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e\u0026ndash;\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"274\"\u003e\n\u003cp\u003eMultiple revisions (\u0026ge; 2 procedures)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; No\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u0026nbsp; Yes\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e1.3 [0.5 \u0026ndash; 2.8]\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"170\"\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003cp\u003e0.4 [0.1 \u0026ndash; 2.3]\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003ea: p \u0026lt; .01\u003c/p\u003e\n\u003cp\u003eb: p \u0026lt; .05\u003c/p\u003e\n\u003cp\u003ec: too few cases in variable parameters to determine HR for long term shunt longevity\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\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":true,"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":"Brain tumor, Complications, Hydrocephalus, Shunt failure, VP shunt, Survival ","lastPublishedDoi":"10.21203/rs.3.rs-522788/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-522788/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eLong-term risks and survival times of ventriculoperitoneal (VP) shunts implanted due to hydrocephalus (HC) after craniotomy for brain tumors are largely unknown. The aim of this study was to establish the overall VP shunt survival rates during a decade post-shunt insertion and to determine risks of failure after brain tumor surgery in the long-term period. In this population-based cohort from a well-defined geographical region, all adult patients (\u0026gt; 18 years) from 2004-2013 who underwent\u0026nbsp;\u0026nbsp;craniotomies for intracranial tumors leading to VP shunt dependency were included. Our brain tumor database was cross-linked to procedure codes for shunt surgery (codes AAF) to extract brain tumor patients who became VP shunt dependent after craniotomy. The VP shunt survival times, i.e. the shunt longevity, was calculated from the day of shunt insertion after brain tumor surgery until the day of its failure. A total of 4174 patients underwent craniotomies, of whom 85 became VP shunt-dependent (2%) afterwards. Twenty-eight patients (33%) had one or more shunt failures during their long-term follow-up, yielding 1-, 5- and 10-year shunt success rates of 77%, 71%, and 67%, respectively. Patient age, sex, tumor location, primary/repeat craniotomy, ventricular entry, post-craniotomy hemorrhage, post-shunting meningitis/infection and multiple shunt revisions were not statistically significant risk factors for shunt failure. Median shunt longevity was 457.5 days and 21.5 days for those with and without pre-craniotomy HC, respectively (p \u0026lt; 0.01). This study can serve as benchmark for future studies.\u003c/p\u003e","manuscriptTitle":"Long-term Risk of Shunt Failure After Brain Tumor Surgery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-06-01 18:41:40","doi":"10.21203/rs.3.rs-522788/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revisions","date":"2021-07-28T10:21:57+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2021-05-26T04:14:00+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2021-05-25T08:09:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2021-05-19T00:13:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Neurosurgical Review","date":"2021-05-12T16:26:35+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":"c0fe24ca-0e48-4d99-ac0b-1d393f458730","owner":[],"postedDate":"June 1st, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":4676435,"name":"Neurology"}],"tags":[],"updatedAt":"2022-02-22T10:34:23+00:00","versionOfRecord":{"articleIdentity":"rs-522788","link":"https://doi.org/10.1007/s10143-021-01648-5","journal":{"identity":"neurosurgical-review","isVorOnly":false,"title":"Neurosurgical Review"},"publishedOn":"2021-10-29 10:34:23","publishedOnDateReadable":"October 29th, 2021"},"versionCreatedAt":"2021-06-01 18:41:40","video":"","vorDoi":"10.1007/s10143-021-01648-5","vorDoiUrl":"https://doi.org/10.1007/s10143-021-01648-5","workflowStages":[]},"version":"v1","identity":"rs-522788","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-522788","identity":"rs-522788","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}