A Predictive Model for Intraoperative Cerebrospinal Fluid Leak During Endonasal Pituitary Adenoma Resection Using a Convolutional Neural Network

BACKGROUND

Cerebrospinal fluid (CSF) leak during endoscopic endonasal transsphenoidal surgery can lead to postoperative complications. The clinical and anatomic risk factors of intraoperative CSF leak are not well defined. We applied a two-dimensional (2D) convolutional neural network (CNN) machine learning model to identify risk factors from preoperative magnetic resonance imaging.

METHODS

All adults who underwent endoscopic endonasal transsphenoidal surgery at our institution from January 2007 to March 2023 who had accessible preoperative stereotactic magnetic resonance imaging were included. A retrospective classic statistical analysis was performed to identify demographic, clinical, and anatomic risk factors of intraoperative CSF leak. Stereotactic T2-weighted brain magnetic resonance imaging scans were used to train and test a 2D CNN model.

RESULTS

Of 220 included patients, 81 (36.8%) experienced intraoperative CSF leak. Among all preoperative variables, visual disturbance was the only statistically significant identified risk factor (P = 0.008). The trained 2D CNN model predicted CSF leak with 92% accuracy and area under receiver operating characteristic curve of 0.90 (sensitivity of 86% and specificity of 93%). Class activation mapping of this model revealed that anatomic regions of CSF flow were most important in predicting CSF leak.

CONCLUSIONS

Further review of the class activation mapping gradients revealed regions of the diaphragma sellae, clinoid processes, temporal horns, and optic nerves to have anatomic correlation to intraoperative CSF leak risk. Additionally, visual disturbances from anatomic compression of the optic chiasm were the only identified clinical risk factor. Our 2D CNN model can help a treating team to better anticipate and prepare for intraoperative CSF leak.

Conventional clinical signs and symptoms are poor predictors of postoperative cerebrospinal fluid leak: A single-centre cohort perspective

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leak remains a concerning complication of the endoscopic endonasal approach (EEA) for skull base pathology. Signs and symptoms suggesting CSF leak often trigger additional workup during the postoperative course. We systematically evaluate associations between subjectively reported clinical signs/symptoms noted during the immediate postoperative period and incidence of postoperative CSF leaks.

METHODS

Retrospective chart review was conducted at a tertiary academic medical centre including 137 consecutive patients with intraoperative CSF leak during EEA with primary repair between July 2018 and August 2022. Postoperative CSF leak associations with clinical signs and symptoms were evaluated using positive (PPV) and negative predictive values (NPV), sensitivity, specificity and odds ratio (OR) via univariate logistic regression.

RESULTS

Seventy-nine patients (57.7%) had high-flow leaks repaired and 5 (3.6%) developed CSF leaks postoperatively. Of reported symptoms, rhinorrhea was most common (n = 52, 38.0%; PPV [95% CI] = 7.6% [4.8%, 11.9%]), followed by severe headache (n = 47, 34.3%; 6.3% [3.1%, 12.5%]), dizziness (n = 43, 31.4%; 2.3% [0.4%, 12.1%]), salty or metallic taste (n = 20, 14.6%; 9.9% [3.3%, 25.8%]), and throat drainage (n = 10, 7.3%; 9.9% [1.7%, 41.4%]). Nausea or vomiting constituted the most reported sign concerning for CSF leak (n = 73, 53.3%; PPV [95% CI] = 4.1% [2.0%, 8.1%]). On univariate regression, no sign or symptom, including rhinorrhea (OR [95% CI] = 7.00 [0.76-64.44]), throat drainage (3.42 [0.35-33.86]), salty/metallic taste (4.22 [0.66-27.04]), severe headache (3.00 [0.48-18.62]), dizziness (0.54 [0.06-4.94]), fever (3.16 [0.50-19.99]), and nausea/vomiting (1.33 [0.22-8.21]), associated with postoperative CSF leak.

CONCLUSIONS

A range of subjectively reported symptoms and signs failed to predict postoperative CSF leak. Further investigation is warranted to inform appropriate attention and response.

3D Slicer reconstruction combined with neuroendoscopic keyhole approach for the treatment of cerebrospinal fluid rhinorrhea：2 cases report and literature review

Background and importance

Explore the techniques, advantages and disadvantages of 3D Slicer reconstruction combined with transcranial neuroendoscopy in cerebrospinal fluid rhinorrhea surgery.

Clinical presentation

We collected complete clinical data of two patients with cerebrospinal fluid rhinorrhea who underwent minimally invasive surgery using 3D Slicer reconstruction combined with transcranial neuroendoscopy through the supraorbital eyebrow arch keyhole approach in our hospital from June 2022 to May 2023. The patients were one male and one female, aged 50 and 63 years old. At the same time, a retrospective summary of relevant literature at home and abroad in recent years was conducted. 1 case had spontaneous cerebrospinal fluid rhinorrhea with secondary cribriform plate lesion, and the other 1 case had traumatic cerebrospinal fluid rhinorrhea. Both 2 patients were ineffective after long-term conservative treatment, and ultimately recovered after detailed preoperative evaluation and preparation and surgical treatment.

Conclusion

Cerebrospinal fluid rhinorrhea is a challenging disease in neurosurgery, and improper management can lead to serious complications such as meningitis. Our team used 3D Slicer reconstruction combined with transcranial endoscopic minimally invasive keyhole surgery to treat cerebrospinal fluid rhinorrhea, achieving good results, proving that this combined technology has certain advantages and is a new surgical technique worth promoting. However, the widespread application and promotion of this technology in anterior skull base surgery still require comprehensive and reliable prospective clinical studies to test.

Intrasellar Arachnoid Diverticulae as a Risk Factor for Intraoperative Cerebrospinal Fluid Leakage in Patients Undergoing Endoscopic Transsphenoidal Surgery

BACKGROUND AND OBJECTIVES

Intrasellar arachnoid diverticulae can often be identified on preoperative imaging in patients undergoing endoscopic transsphenoidal surgery. The objective of this study was to characterize arachnoid diverticulae both qualitatively and quantitatively in a large institutional cohort of patients with pituitary tumors and to evaluate its association with intraoperative cerebrospinal fluid (CSF) leak.

METHODS

Preoperative imaging studies of 530 patients who underwent primary endoscopic transsphenoidal resection of pituitary tumors were examined both quantitatively and qualitatively for the presence of an intrasellar arachnoid diverticulum. A matched cohort analysis was performed to compare patients with a "significant" (>50% sellar depth) diverticulum with those with nonsignificant/no diverticulum. Morphologically, diverticulae were separately classified as Type 1 (ventral CSF cleft with no tumor/gland tissue between sellar face and infundibulum) or Type 2 (central CSF cleft with tumor/gland tissue between sellar face and infundibulum).

RESULTS

Arachnoid diverticulae were noted in 40.2% of cases, and diverticulum depth was linearly correlated with tumor size and body mass index. A significant diverticulum was identified in 66 cases (12.5%) and was significantly associated with the functional tumor subtype ( P = .005) and intraoperative CSF leak ( P < .001). Type 1 clefts were associated with nonfunctional pathology ( P = .034) and the presence of suprasellar extension ( P = .035) and tended to be deeper than Type 2 clefts ( P < .001), with a higher incidence of intraoperative CSF leak ( P = .093). On logistic regression analysis, only the presence of a significant diverticulum was independently associated with intraoperative CSF leak (odds ratio 4.545; 95% CI 2.418-8.544; P < .001).

CONCLUSION

The presence of an intrasellar arachnoid diverticulum should alert the surgeon to an elevated risk of intraoperative CSF leak during transsphenoidal surgery for pituitary tumors. A relatively limited surgical exposure tailored to the craniocaudal extent of the sellar pathology should be considered in these patients.

Predictors and Complications of Cerebrospinal Fluid Leak after Endoscopic Endonasal Surgery: A Single Institution Retrospective Review

Background  The endoscopic endonasal approach (EEA) is a commonly used technique for resection of sellar, suprasellar, and anterior fossa masses. One of the most troublesome complications of this technique is cerebrospinal fluid (CSF) leak. In this study, we evaluate the risk factors and consequences of CSF leak on surgical outcomes. Methods  The current study is a retrospective single-institution cohort study evaluating patients who underwent EEA for sellar and/or suprasellar masses from July 2017 to March of 2020. Risk factors for intraoperative and postoperative CSF leak were evaluated, including sellar defect size, tumor volume and pathology, age, body mass index, prior endoscopic endonasal surgery, lumbar drain placement, nasoseptal and mucosal graft use, year of surgery, and cavernous sinus invasion. Postoperative infection, perioperative antibiotic use, and length of stay were also evaluated. Results  Our study included 175 patients. Sellar defect size ( p  = 0.015) and intraoperative CSF leak ( p  < 0.001) were significantly associated with an increased risk of postoperative CSF leak. Patients with nasoseptal flaps were more likely to have a postoperative CSF leak than those with free mucosal grafts ( p  = 0.025). Intraoperative CSF leak, Cushing's disease, and lumbar drain placement were associated with an increased length of stay. Conclusion  Sellar defect size, intraoperative CSF leak, and nasoseptal flap use were associated with an increased risk of postoperative CSF leak. Intraoperative CSF leak, Cushing's disease, and lumbar drain placement are all associated with an increased length of stay.

Risk Factors Associated with Postoperative CSF Leak in Extrasellar Tumors

Objective  While postoperative cerebrospinal fluid (CSF) leak rates of pituitary tumors have been frequently studied, there are fewer studies examining postoperative CSF leak rates for extrasellar tumors. The purpose of this study was to identify risk factors for the development of postoperative CSF leak in patients undergoing endoscopic surgery for extrasellar tumors. Methods  A retrospective chart review was done for patients who underwent endoscopic resection for extrasellar tumors between 2008 and 2020. Age, gender, tumor type, tumor location, tumor size, reconstruction technique, medical comorbidities, and other potential risk factors were identified. Data was analyzed to identify significant risk factors for development of postoperative CSF leak. Results  There were 100 patients with extrasellar tumors who developed intraoperative CSF leaks. Seventeen patients (17%) developed postoperative CSF leaks. Leaks occurred at a median of 2 days following surgery (range 0-34 days). Clival tumors had a significantly higher incidence of postoperative leak than those in other sites ( p  < 0.05). There were no significant differences in other locations, body mass index, tumor size, reconstruction technique, medical comorbidities, or other factors. There were nearly twice as many intraoperative grade III leaks in those who developed postoperative CSF leak, but this was not statistically significant ( p  = 0.12). Conclusion  Extrasellar tumors, particularly clival tumors, have a higher rate of postoperative CSF leak than pituitary tumors. Prophylactic lumbar drains can be considered for patients at high risk for developing postoperative CSF leak.

Risk factors of cerebrospinal fluid leakage after neuroendoscopic transsphenoidal pituitary adenoma resection: a systematic review and meta-analysis

Introduction

Cerebro spinal fluid (CSF) leakage is common and might lead to severe postoperative complications after endoscopic transsphenoidal pituitary adenoma resection. However, the risk factors of postoperative CSF leakage are still controversial. This article presents a systematic review to explore the explicit risk factors of CSF leakage after endoscopic transsphenoidal pituitary adenomere section.

Methods

PRISMA and AMSTAR guidelines were followed to assess the methodological quality of the systematic review. PubMed, Medline, Embase, Web of Science, Cochrane, Clinical Trails, CNKI, CBM, Wan Fang, and VIP databases were searched for all studies on postoperative CSF leak risk factors. The quality of the included studies was assessed by the Newcastle-Ottawa scale. Review Manager 5.4 software was used to calculate the pooled effect size of potential factors with statistical significance.

Results

A total of 6775 patients with pituitary adenoma across 18 articles were included, containing 482 cases of postoperative CSF leakage (accounting for 7.11%). All of the articles had a quality score > 5, indicating good quality. Meta-analysis showed that an increased risk of CSF leak was found for higher levels of BMI (MD=1.91, 95% CI (0.86,2.96), bigger tumor size [OR=4.93, 95% CI (1.41,17.26)], greater tumor invasion (OR=3.01, 95% CI (1.71, 5.31), the harder texture of tumor [OR=2.65, 95% CI (1.95,3.62)], intraoperative cerebrospinal fluid leakage [OR=5.61, 95% CI (3.53,8.90)], multiple operations [OR=2.27, 95% CI (1.60,3.23)].

Conclusion

BMI, multiple operations, tumor size, tumor invasion, hard texture, and intraoperative cerebrospinal fluid leakage are the risk factors of postoperative CSF leakage. Clinical doctors should pay attention to these risk factors, and conduct strict skull base reconstruction and careful postoperative management.

The State of Machine Learning in Outcomes Prediction of Transsphenoidal Surgery: A Systematic Review

The purpose of this analysis is to assess the use of machine learning (ML) algorithms in the prediction of postoperative outcomes, including complications, recurrence, and death in transsphenoidal surgery. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically reviewed all papers that used at least one ML algorithm to predict outcomes after transsphenoidal surgery. We searched Scopus, PubMed, and Web of Science databases for studies published prior to May 12, 2021. We identified 13 studies enrolling 5,048 patients. We extracted the general characteristics of each study; the sensitivity, specificity, area under the curve (AUC) of the ML models developed as well as the features identified as important by the ML models. We identified 12 studies with 5,048 patients that included ML algorithms for adenomas, three with 1807 patients specifically for acromegaly, and five with 2105 patients specifically for Cushing's disease. Nearly all were single-institution studies. The studies used a heterogeneous mix of ML algorithms and features to build predictive models. All papers reported an AUC greater than 0.7, which indicates clinical utility. ML algorithms have the potential to predict postoperative outcomes of transsphenoidal surgery and can improve patient care. Ensemble algorithms and neural networks were often top performers when compared with other ML algorithms. Biochemical and preoperative features were most likely to be selected as important by ML models. Inexplicability remains a challenge, but algorithms such as local interpretable model-agnostic explanation or Shapley value can increase explainability of ML algorithms. Our analysis shows that ML algorithms have the potential to greatly assist surgeons in clinical decision making.

Prediction of intraoperative cerebrospinal fluid leaks in endoscopic endonasal transsphenoidal pituitary surgery based on a deep neural network model trained with MRI images: a pilot study

Objective

This study aimed to investigate the reliability of a deep neural network (DNN) model trained only on contrast-enhanced T1 (T1CE) images for predicting intraoperative cerebrospinal fluid (ioCSF) leaks in endoscopic transsphenoidal surgery (EETS).

Methods

396 pituitary adenoma (PA) cases were reviewed, only primary PAs with Hardy suprasellar Stages A, B, and C were included in this study. The T1CE images of these patients were collected, and sagittal and coronal T1CE slices were selected for training the DNN model. The model performance was evaluated and tested, and its interpretability was explored.

Results

A total of 102 PA cases were enrolled in this study, 51 from the ioCSF leakage group, and 51 from the non-ioCSF leakage group. 306 sagittal and 306 coronal T1CE slices were collected as the original dataset, and data augmentation was applied before model training and testing. In the test dataset, the DNN model provided a single-slice prediction accuracy of 97.29%, a sensitivity of 98.25%, and a specificity of 96.35%. In clinical test, the accuracy of the DNN model in predicting ioCSF leaks in patients reached 84.6%. The feature maps of the model were visualized and the regions of interest for prediction were the tumor roof and suprasellar region.

Conclusion

In this study, the DNN model could predict ioCSF leaks based on preoperative T1CE images, especially in PAs in Hardy Stages A, B, and C. The region of interest in the model prediction-making process is similar to that of humans. DNN models trained with preoperative MRI images may provide a novel tool for predicting ioCSF leak risk for PA patients.

Fat in the Fossa and the Sphenoid Sinus: A Simple and Effective Solution to CSF Leaks in Transsphenoidal Surgery. Cohort Study and Systematic Review

Objectives  Cerebrospinal fluid (CSF) leak following endoscopic transsphenoidal surgery (TSS) remains a challenge and is associated with high morbidity. We perform a primary repair with f at in the pituitary f ossa and further fat in the s phenoid sinus (FFS). We compare the efficacy of this FFS technique with other repair methods and perform a systematic review. Design, Patients, and Methods  This is a retrospective analysis of patients undergoing standard TSS from 2009 to 2020, comparing the incidence of significant postoperative CSF rhinorrhea (requiring intervention) using the FFS technique compared with other intraoperative repair strategies. Systematic review of current repair methods described in the literature was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Results  In all, there were 439 patients, with 276 patients undergoing multilayer repair, 68 patients FFS repair, and 95 patients no repair. No significant differences were observed in baseline demographics between the groups. Postoperative CSF leak requiring intervention was significantly lower in the FFS repair group (4.4%) compared with the multilayer (20.3%) and no repair groups (12.6%, p  < 0.01). This translated to fewer reoperations (2.9% FFS vs. 13.4% multilayer vs. 8.4% no repair, p  < 0.05), fewer lumbar drains (2.9% FFS vs. 15.6% multilayer vs. 5.3% no repair, p  < 0.01), and shorter hospital stay (median days: 4 [3-7] FFS vs. 6 (5-10) multilayer vs. 5 (3-7) no repair, p  < 0.01). Risk factors for postoperative leak included female gender, perioperative lumbar drain, and intraoperative leak. Conclusion  Autologous fat on fat graft for standard endoscopic transsphenoidal approach effectively reduces the risk of significant postoperative CSF leak with reduced reoperation and shorter hospital stay.

Machine learning driven prediction of cerebrospinal fluid rhinorrhoea following endonasal skull base surgery: A multicentre prospective observational study

Background

Cerebrospinal fluid rhinorrhoea (CSFR) is a common complication following endonasal skull base surgery, a technique that is fundamental to the treatment of pituitary adenomas and many other skull base tumours. The CRANIAL study explored CSFR incidence and related risk factors, particularly skull base repair techniques, via a multicentre prospective observational study. We sought to use machine learning to leverage this complex multicentre dataset for CSFR prediction and risk factor analysis.

Methods

A dataset of 865 cases - 725 transsphenoidal approach (TSA) and 140 expanded endonasal approach (EEA) - with cerebrospinal fluid rhinorrhoea as the primary outcome, was used. Relevant variables were extracted from the data, and prediction variables were divided into two categories, preoperative risk factors; and repair techniques, with 6 and 11 variables respectively. Three types of machine learning models were developed in order to predict CSFR: logistic regression (LR); decision tree (DT); and neural network (NN). Models were validated using 5-fold cross-validation, compared via their area under the curve (AUC) evaluation metric, and key prediction variables were identified using their Shapley additive explanations (SHAP) score.

Results

CSFR rates were 3.9% (28/725) for the transsphenoidal approach and 7.1% (10/140) for the expanded endonasal approach. NNs outperformed LR and DT for CSFR prediction, with a mean AUC of 0.80 (0.70-0.90) for TSA and 0.78 (0.60-0.96) for EEA, when all risk factor and intraoperative repair data were integrated into the model. The presence of intraoperative CSF leak was the most prominent risk factor for CSFR. Elevated BMI and revision surgery were also associated with CSFR for the transsphenoidal approach. CSF diversion and gasket sealing appear to be strong predictors of the absence of CSFR for both approaches.

Conclusion

Neural networks are effective at predicting CSFR and uncovering key CSFR predictors in patients following endonasal skull base surgery, outperforming traditional statistical methods. These models will be improved further with larger and more granular datasets, improved NN architecture, and external validation. In the future, such predictive models could be used to assist surgical decision-making and support more individualised patient counselling.

Closure strategy for endoscopic pituitary surgery: Experience from 3015 patients

Introduction

Effective strategies are required to ensure optimal management of the crucial closure step in endoscopic pituitary surgery. Many surgical techniques have been reported but no significant consensus has been defined.

Methods

Between January 2006 and March 2022, 3015 adult patients with pituitary adenomas were operated on by a single expert neurosurgical team, using a mononostril endoscopic endonasal approach. Based of preoperative risk factors of and operative findings, a detailed closure strategy was used. Body mass index >40, sellar floor lysis, number of surgeries>2, large skull base destruction, prior radiotherapy were considered as preoperative risk factors for closure failure. All patients treated with an expanded endonasal approach were excluded.

Results

Patients were mostly women (F/M ratio: 1.4) with a median age of 50 (range: 18 -89). Intraoperative CSF leak requiring specific surgical management was observed in 319/3015 (10.6%) of patients. If intraoperative leak occurred, patients with predictive risk factors were managed using a Foley balloon catheter in case of sellar floor lysis or BMI>40 and a multilayer repair strategy with a vascularized nasoseptal flap in other cases. Postoperative CSF leak occurred in 29/3015 (1%) of patients, while meningitis occurred in 24/3015 (0.8%) of patients. In patients with intraoperative leak, closure management failed in 11/319 (3.4%) of cases.

Conclusion

Based on our significant 16-year experience, our surgical management is reliable and easy to follow. With a planned and stepwise strategy, the closure step can be optimized and tailored to each patient with a very low failure rate.

Impact of Postural Changes on Sinonasal Pressure After Endoscopic Endonasal Surgery

BACKGROUND

Postoperative management following endoscopic endonasal surgery (EES) is important to prevent cerebrospinal fluid leak and preserve the integrity of the nasoseptal flap. No consensus regarding an optimal posture in the postoperative period has been established. We hypothesized that sinonasal pressure (SNP) can represent intracranial pressure affecting the sellar floor in the absence of the sellar bone after surgery. This study provides evidence for the effect of postural changes and recommends optimal posture to reduce SNP following EES.

METHODS

The authors conducted a retrospective analysis of 50 patients who underwent reconstruction for skull base defects with nasoseptal flap after EES for resection of suprasellar tumor between March 2020 and August 2020. The Spiegelberg intracranial pressure probe was placed through the nostril over the nasoseptal flap. SNPs were measured in Fowler' (45° tilt) and supine positions, respectively, daily for the first 3 days immediately after EES.

RESULTS

For the first 3 days after surgery, the mean SNP in Fowler' position (24.82 mmHg; standard deviation, 12.23 mmHg) was lower than that in the supine position (28.42 mmHg; standard deviation, 12.33 mmHg) (P < 0.01). There were no significant differences in mean SNP for age, sex, tumor size, presence of hydrocephalus, and body mass index.

CONCLUSIONS

There was a significant correlation between Fowler' position and a decrease in SNP measurements. Placing a patient in Fowler' position after surgery can decrease the SNP. We recommend that patients should be placed in a Fowler' position as an optimal position after surgery.

Endoscopic Endonasal Transsphenoidal Approach to Repair Cerebrospinal Fluid Rhinorrhea After an Anterior Clinoidectomy for Aneurysm Clipping: Series of 4 Cases

BACKGROUND

Cerebrospinal fluid (CSF) rhinorrhea through a pneumatized optic strut is a known potential complication after an anterior clinoidectomy that is used to microsurgically clip a proximal internal carotid artery aneurysm. The original craniotomy site can be reopened to repair the skull base defect, but this technique has disadvantages.

OBJECTIVE

To avoid a repeat craniotomy and address the limitations of a transcranial approach, a straightforward alternative was used for skull base repair-the binostril endoscopic endonasal transsphenoidal approach.

METHODS

This retrospective case series describes the use of endoscopic transsphenoidal repair and outcomes for patients with CSF leaks after anterior clinoidectomy for aneurysm repair between January 1, 2015, and December 31, 2019.

RESULTS

Four adult patients (3 women and 1 man) with a mean age of 59.5 years were reviewed. Skull base repair occurred on average 24 days (range, 4-75 days) after the index operation. After demucosalization of the parasellar sphenoid sinus, the fistula in the pneumatized optic strut was reconstructed with a free nasal mucosal graft with or without an autologous muscle graft. None of the patients developed a recurrent CSF leak at a mean follow-up of 12.5 months (range, 8-22 months), and none experienced complications.

CONCLUSION

The endoscopic endonasal transsphenoidal approach was safe and effective for skull base repair in 4 patients with CSF rhinorrhea after an anterior clinoidectomy for aneurysm clipping.

Interpretable Machine Learning-Based Prediction of Intraoperative Cerebrospinal Fluid Leakage in Endoscopic Transsphenoidal Pituitary Surgery: A Pilot Study

Purpose  Transsphenoidal surgery (TSS) for pituitary adenomas can be complicated by the occurrence of intraoperative cerebrospinal fluid (CSF) leakage (IOL). IOL significantly affects the course of surgery predisposing to the development of postoperative CSF leakage, a major source of morbidity and mortality in the postoperative period. The authors trained and internally validated the Random Forest (RF) prediction model to preoperatively identify patients at high risk for IOL. A locally interpretable model-agnostic explanations (LIME) algorithm is employed to elucidate the main drivers behind each machine learning (ML) model prediction. Methods  The data of 210 patients who underwent TSS were collected; first, risk factors for IOL were identified via conventional statistical methods (multivariable logistic regression). Then, the authors trained, optimized, and audited a RF prediction model. Results  IOL reported in 45 patients (21.5%). The recursive feature selection algorithm identified the following variables as the most significant determinants of IOL: Knosp's grade, sellar Hardy's grade, suprasellar Hardy's grade, tumor diameter (on X, Y, and Z axes), intercarotid distance, and secreting status (nonfunctioning and growth hormone [GH] secreting). Leveraging the predictive values of these variables, the RF prediction model achieved an area under the curve (AUC) of 0.83 (95% confidence interval [CI]: 0.78; 0.86), significantly outperforming the multivariable logistic regression model (AUC = 0.63). Conclusion  A RF model that reliably identifies patients at risk for IOL was successfully trained and internally validated. ML-based prediction models can predict events that were previously judged nearly unpredictable; their deployment in clinical practice may result in improved patient care and reduced postoperative morbidity and healthcare costs.

Exploration of the causes of cerebrospinal fluid leakage after endoscopic endonasal surgery for sellar and suprasellar lesions and analysis of risk factors

Objective

Postoperative cerebrospinal fluid (CSF) leakage following endoscopic endonasal surgery (EES) is a frequent complication. This study aims to identify potential risk factors of postoperative CSF leakage.

Methods

A retrospective review of 360 patients who underwent EES was included. The associations between postoperative CSF leakage and patient demographics, medical history, tumor characteristics, and intraoperative repair techniques were analyzed; the diagnosis and repair of postoperative CSF leakage were also introduced.

Results

Postoperative CSF leakage occurred in 14 patients (3.9%), 2 of them cured by lumbar cistern drainage, 12 underwent endoscopic repair. Among these 12 cases, 3 were repaired twice, and the rest were cured the first time. During the repair surgery, insufficient embedded fat was detected in one case detected, seven with breached inner artificial dura, three had vascularized pedicle nasoseptal flap (VP-NSF) displacement, two with VP-NSF perforation, two with VP-NSF inactivation, and one with imperfect adherence to VP-NSF to the skull base. Eight cases had intracranial infections. Excluding one case who died of severe intracranial infection, the rest were cured and discharged without obvious sequelae. Multivariate analysis revealed that the suprasellar lesion, subarachnoid invasion, and intraoperative grade 3 flow CSF leakage were the risk factors of CSF leakage after operation, while the bone flap was a protective factor.

Conclusion

Bone flap combined with VP-NSF and iodoform gauze for skull base reconstruction is recommended in high-risk patients, while postoperative lumbar cistern drain remains dispensable.

Endoscopic pituitary surgery: A national database review

BACKGROUND

Pituitary tumors surgery is increasingly performed via endoscopic transsphenoidal approach (TSP). This study describes outcomes of TSP surgery in the United States.

METHODS

A retrospective cross-sectional analysis of adult patients with pituitary adenoma was performed using the Nationwide Readmissions Database, 2010-2015.

RESULTS

A total of 5891 patients were identified. The average age was 51.29 ± 0.29 years. The risk of postoperative epistaxis, diabetes insipidus, cerebrospinal fluid (CSF) leak, and other general postoperative complications was 0.71%, 10.20%, 8.35%, and 2.37%, respectively. Independent risk factors of CSF leak included: age <65-year, male, body mass index ≥25, and multiple comorbidities (p < 0.001 each). The prevalence of CSF leak was not associated with hospital TSP volume and teaching status.

CONCLUSION

This study provides a national epidemiological perspective on TSP in the United States. The risk of postoperative CSF leak appears to be associated with intrinsic patient factors rather than resource and expertise availability.

Factors Influencing Cerebrospinal Fluid Leaking following Pituitary Adenoma Transsphenoidal Surgery: A Meta-Analysis and Comprehensive Review

Background

Surgical resection is the main method to treat pituitary adenoma. Cerebrospinal fluid leakage (CSF Leak) is the main complication after transsphenoidal surgery. The impact of postoperative CSF Leak can be predicted in advance, and preventive measures can be taken in time. Clinically, a variety of factors may affect the occurrence of postoperative CSF Leak. In this study, meta-analysis was used to investigate the risk factors of postoperative CSF Leak as a clinical reference.

Methods

The databases PubMed, Medline, Embrase, Cochrane library, CNKI, and CBM were searched for all studies on the risk factors of postoperative CSF Leak. Studies were screened and finally included. The quality of the included studies was assessed by the Newcastle-Ottawa scale. We used Revman 5.4 software to conduct the pooled effect size of every potential statistically significant factor.

Results

13 articles with a total of 5967 patients with pituitary adenoma and 405 cases of postoperative CSF Leak were finally included, accounting for 6.79%. All of the 13 articles had a quality score > 5, indicating good quality. Meta-analysis showed that patient age (OR = 0.71, 95% CI (0.41, 1.20), P = 0.20) was not a factor influencing postoperative CSF Leak, while BMI (MD = 2.26, 95% CI (1.31, 3.20), P < 0.00001), tumor size (MD = 1.35, 95% CI (0.22, 2.49), P = 0.02), whether a second operation was performed (OR = 2.20, 95% CI (1.45, 3.33), P = 0.0002), and intraoperative CSF Leak (OR = 8.88, 95% CI (3.64, 21.69), P < 0.00001) were risk factors for postoperative CSF Leak in patients. Discussion. BMI, tumor size, reoperation, and intraoperative CSF Leak are the risk factors of postoperative CSF Leak. However, not all the factors were covered in this study, it is still worth continuing to deeply investigate in this topic.

Sinonasal Packing is Not a Requisite for Successful Cerebrospinal Fluid Leak Repair

Background Numerous methods have been described to repair nasal cerebrospinal fluid (CSF) leaks. Most studies have focused on optimizing CSF leak repair success, leading to closure rates of 90 to 95%.

Objective This study aimed to determine if excellent reconstruction rates could be achieved without using sinonasal packing.

Methods A prospective case series of 73 consecutive patients with various CSF leak etiologies and skull base defects was conducted to evaluate reconstruction success without sinonasal packing. The primary outcome measure was postoperative CSF leak. Secondary outcome measures were postoperative epistaxis requiring intervention in operating room or emergency department, infectious sinusitis, and 22-item sinonasal outcome test (SNOT-22) changes.

Results Mean age was 54.5 years and 64% were female. Multilayered reconstructions were performed in 55.3% of cases, with collagen or bone epidural inlay grafts, and nasal mucosal grafts or nasoseptal flaps for onlay layers. Onlay-only reconstructions with mucosal grafts or nasoseptal flaps were performed in 44.7% of cases. Tissue sealants were used in all cases, and lumbar drains were used in 40.8% of cases. There were two initial failures (97.4% initial success), but both resolved with lumbar drains alone (no revision surgeries). There were no instances of postoperative epistaxis requiring intervention in the operating room or emergency department. Infectious sinusitis occurred in 2.7% of patients in the first 3 months postoperatively. SNOT-22 did not change significantly from preoperatively to first postoperative visits, then improved over time.

Conclusion Nasal CSF leaks from various etiologies and defect sites were successfully repaired without using sinonasal packing, and patients experienced minimal sinonasal morbidity.

Machine Learning in Pituitary Surgery

Machine learning applications in neurosurgery are increasingly reported for diverse tasks such as faster and more accurate preoperative diagnosis, enhanced lesion characterization, as well as surgical outcome, complications and healthcare cost prediction. Even though the pertinent literature in pituitary surgery is less extensive with respect to other neurosurgical diseases, past research attempted to answer clinically relevant questions to better assist surgeons and clinicians. In the present chapter we review reported ML applications in pituitary surgery including differential diagnosis, preoperative lesion characterization (immunohistochemistry, cavernous sinus invasion, tumor consistency), surgical outcome and complication predictions (gross total resection, tumor recurrence, and endocrinological remission, cerebrospinal fluid leak, postoperative hyponatremia). Moreover, we briefly discuss from a practical standpoint the current barriers to clinical translation of machine learning research. On the topic of pituitary surgery, published reports can be considered mostly preliminary, requiring larger training populations and strong external validation. Thoughtful selection of clinically relevant outcomes of interest and transversal application of model development pipeline-together with accurate methodological planning and multicenter collaborations-have the potential to overcome current limitations and ultimately provide additional tools for more informed patient management.

Development and Validation of Nomogram to Preoperatively Predict Intraoperative Cerebrospinal Fluid Leakage in Endoscopic Pituitary Surgery: A Retrospective Cohort Study

Background

Pituitary adenomas (PAs) are the most common tumor of the sellar region. PA resection is the preferred treatment for patients with clear indications for surgery. Intraoperative cerebrospinal fluid (iCSF) leakage is a major complication of PA resection surgery. Risk factors for iCSF leakage have been studied previously, but a predictive nomogram has not yet been developed. We constructed a nomogram for preoperative prediction of iCSF leakage in endoscopic pituitary surgery.

Methods

A total of 232 patients who underwent endoscopic PA resection at the Department of Neurosurgery in Jinling Hospital between January of 2018 and October of 2020 were enrolled in this retrospective study. Patients treated by a board-certified neurosurgeon were randomly classified into a training cohort or a validation cohort 1. Patients treated by other qualified neurosurgeons were included in validation cohort 2. A range of demographic, clinical, radiological, and laboratory data were acquired from the medical records. The Least Absolute Shrinkage and Selection Operator (LASSO) algorithm and uni- and multivariate logistic regression were utilized to analyze these features and develop a nomogram model. We used a receiver operating characteristic (ROC) curve and calibration curve to evaluate the predictive performance of the nomogram model.

Results

Variables were comparable between the training cohort and validation cohort 1. Tumor height and albumin were included in the final prediction model. The area under the curve (AUC) of the nomogram model was 0.733, 0.643, and 0.644 in training, validation 1, and validation 2 cohorts, respectively. The calibration curve showed satisfactory homogeneity between the predicted probability and actual observations. Nomogram performance was stable in the subgroup analysis.

Conclusions

Tumor height and albumin were the independent risk factors for iCSF leakage. The prediction model developed in this study is the first nomogram developed as a practical and effective tool to facilitate the preoperative prediction of iCSF leakage in endoscopic pituitary surgery, thus optimizing treatment decisions.

Heterogeneity in Outcome Reporting in Endoscopic Endonasal Skull Base Reconstruction: A Systematic Review

Objective  Presently, there are no standards for reporting outcomes of endoscopic endonasal skull base reconstruction (ESBR). This is problematic as a lack of consistent reporting makes synthesizing findings in systematic reviews and meta-analysis challenging. Thus, the aim of this study was to systematically review and describe the patterns of reporting outcomes in ESBR as a foundation for developing reporting guidelines. Study Design  Present study is a systematic review. Methods  Embase, PubMed, CINAHL, Cochrane Library, and Web of Science were searched for all publications with ≥25 patients and a focus on ESBR. The reporting patterns of each study's variables and outcomes were assessed. Results  A total of 112 studies were included in the review. The most commonly reported demographic variables were the number of included patients ( n  = 112, 100%) and types of pathologies treated ( n  = 104, 92.9%). Meanwhile, the most routinely described preoperative variable was history of prior treatment ( n  = 48, 42.9%). Type of reconstruction was a commonly reported intraoperative variable ( n  = 110, 98.2%), though the rate of intraoperative cerebrospinal fluid (CSF) leak was noted in only 76 studies (67.9%). With regard to postoperative outcomes, postoperative CSF leak rate was routinely provided ( n  = 101, 90.2%), but reporting of other surgical complications was more inconsistent. Ultimately, of the 43 variables and outcomes reviewed, a median of 12 (range: 4-22) was reported in each study. Conclusion  There is significant heterogeneity in the outcomes reported in studies relating to ESBR. This highlights the need for the development of standard reporting guidelines to minimize bias and improve interstudy comparability.

Surgical Experience in Prevention of Postoperative CSF Leaks Using Abdominal Fat Grafts in Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenomas

Objective  Cerebrospinal fluid (CSF) leaks are the most common complication during endonasal endoscopic transsphenoidal approach (EETSA) and prevention of postoperative CSF leaks is critical. In this study, we report a single surgeon's experience of sellar floor reconstruction using abdominal fat grafts for prevention of postoperative CSF leaks in EETSA for pituitary adenomas. Study Design  This study is presented as case series with retrospective chart review. Setting  Present study was conducted at tertiary referral center. Participants  A total of 216 patients who underwent surgery via EETSA for pituitary adenomas between 2008 and 2018 at our institution were evaluated. When an intraoperative CSF leak occurred, sellar floor reconstruction was performed using a fat graft harvested from the abdomen via a 2-cm skin incision. Main Outcome Measures  Primary outcome and measures of this study was postoperative CSF leaks. Results  A total of 53 patients showed intraoperative CSF leaks (24.5%) and 2 patients showed postoperative CSF leaks (0.93%). There were no postoperative CSF leaks in any patients who showed intraoperative CSF leaks and received sellar floor reconstruction using fat grafts. There were also no postoperative CSF leaks in 12 patients who received preventative sellar floor reconstruction using fat grafts due to extensive arachnoid herniation without intraoperative CSF leaks. However, there were two postoperative CSF leaks in patients who did not show intraoperative CSF leaks and did not receive sellar floor reconstruction. Conclusion  The effectiveness of sellar floor reconstruction using abdominal fat grafts in patients receiving EETSA for pituitary adenoma was reported. We suggest that identification of intraoperative CSF leaks is important and preventive sellar floor reconstruction without evidence of intraoperative CSF leaks can also be beneficial.

The incidence of postoperative cerebrospinal fluid leakage after elective cranial surgery: a systematic review

Cerebrospinal fluid (CSF) leakage is a major complication after elective neurosurgical procedures. The aim of this systematic literature review is to summarize the incidence rates of postoperative cerebrospinal fluid leakage for neurosurgical procedures, classified by surgical approach. The Pubmed, Cochrane, Embase, and Web of Science databases were searched for studies reporting the outcome of patients undergoing elective neurosurgical procedures. The number of patients, surgical approach, and indication for surgery were recorded for each study. Outcomes related to CSF leakage such as clinical manifestation and treatment were reported as well. One hundred and thirteen studies were included, reporting 94,695 cases. Overall, CSF leaks were present in 3.8% of cases. Skull base surgery had the highest rate of CSF leakage with 6.2%. CSF leakage occurred in 5.9% of anterior skull base procedures, 6.4% of middle fossa, and 5.2% of transpetrosal surgeries. 5.8% of reported infratentorial procedures were complicated by CSF leakage versus 2.9% of supratentorial surgeries. CSF leakage remains a common serious adverse event after cranial surgery. There exists a need for standardized procedures to reduce the incidence of postoperative CSF leakage, as this serious adverse event may lead to increased health care costs.

Cerebrospinal Fluid Leak after Transsphenoidal Surgery: A Systematic Review and Meta-analysis

Background Cerebrospinal fluid (CSF) leak is widely recognized as a challenging and commonly occurring postoperative complication of transsphenoidal surgery (TSS).

The primary objective of this study is to benchmark the current prevalence of CSF leak after TSS in the adult population.

Methods The authors followed the PRISMA guidelines. The PubMed, Embase, and Cochrane Library databases were searched for articles reporting CSF leak after TSS in the adult population. Meta-analysis was performed using the Untransformed Proportion metric in OpenMetaAnalyst. For two between-group comparisons a generalized linear mixed model was applied.

Results We identified 2,408 articles through the database search, of which 70, published since 2015, were included in this systematic review. These studies yielded 24,979 patients who underwent a total of 25,034 transsphenoidal surgeries. The overall prevalence of postoperative CSF leak was 3.4% (95% confidence interval or CI 2.8–4.0%). The prevalence of CSF leak found in patients undergoing pituitary adenoma resection was 3.2% (95% CI 2.5–4.2%), whereas patients who underwent TSS for another indication had a CSF leak prevalence rate of 7.1% (95% CI 3.0–15.7%) (odds ratio [OR] 2.3, 95% CI 0.9–5.7). Patients with cavernous sinus invasion (OR 3.0, 95% CI 1.1–8.7) and intraoperative CSF leak (OR 5.9, 95% CI 3.8–9.0) have increased risk of postoperative CSF leak. Previous TSS and microscopic surgery are not significantly associated with postoperative CSF leak.

Conclusion The overall recent prevalence of CSF leak after TSS in adults is 3.4%. Intraoperative CSF leak and cavernous sinus invasion appear to be significant risk factors for postoperative CSF leak.

Optimizing pre-, intra-, and postoperative management of patients with sellar pathology undergoing transsphenoidal surgery

OBJECTIVE

Perioperative management of patients with sellar lesions is complex, requiring input from a multidisciplinary team of specialists for ongoing management of both endocrinological and neurosurgical issues. Here, the authors reviewed the experience of a single multidisciplinary center over 10 years to identify key postoperative practices that ensure positive outcomes for patients with sellar lesions who undergo transsphenoidal surgery.

METHODS

The authors performed a retrospective review of all transsphenoidal operations carried out by the senior author at a single center from April 2008 through November 2018. They included only adult patients and recorded perioperative management. They also reviewed the evolution of clinical practices for perioperative care at their institution to identify strategies for ensuring positive patient outcomes, and they reviewed the literature on select related topics.

RESULTS

In total, 1023 operations in 928 patients were reviewed. Of these, 712 operations were for pituitary adenomas (69.6%), and 122 were for Rathke cleft cysts (11.9%). The remainder included operations for craniopharyngiomas (3.6%), arachnoid cysts (1.7%), pituitary tumor apoplexy (1.0%), and other sellar pathologies (12.2%). Among the reviewed operations, the median hospital stay was 3 days (IQR 2-3). Patient management details during the pre-, intra-, and postoperative periods were identified, including both shared characteristics of all patients undergoing transsphenoidal surgery and unique characteristics that are specific to certain lesion types or patient populations.

CONCLUSIONS

Patients with sellar lesions who undergo transsphenoidal surgery require complex, multidisciplinary perioperative care to monitor for common adverse events and to improve outcomes, but there is a dearth of high-quality evidence guiding most perioperative practices. Here, the authors reviewed practices at their institution across more than 1000 transsphenoidal operations that may help ensure successful patient outcomes.

Cephalocaudal tumor diameter is a predictor of diabetes insipidus after endoscopic transsphenoidal surgery for non-functioning pituitary adenoma

PURPOSE

Diabetes insipidus (DI) develops commonly after endoscopic transsphenoidal surgery (ETS). We retrospectively investigated the incidence, onset, duration and predictors of DI after ETS in patients with non-functioning pituitary adenoma (NFPA).

METHODS

A total of 168 patients who underwent ETS to remove NFPAs were included. Various perioperative data on demographics, comorbidities, previous treatments, perioperative hormone deficiencies, tumor characteristics, surgery, anesthesia, intraoperative fluid balance, perioperative laboratory findings, postoperative complications, readmission and hospital length of stay were collected and analyzed. Patients were diagnosed with DI and treated with desmopressin when they showed urine output > 5 mL/kg/hr with a serum sodium concentration > 145 mmol/L or an increase ≥ 3 mmol/L in serum sodium concentration between two consecutive tests after surgery. DI was considered permanent when desmopressin was prescribed for > 6 months after surgery.

RESULTS

Seventy-seven (45.8%) patients experienced postoperative DI and 10 (6.0%) patients suffered from permanent DI. The median onset of DI and the median duration of transient DI were postoperative day 1 and 5 days, respectively. In multivariable logistic regression analysis, cephalocaudal tumor diameter (odds ratio [95% confidence interval] 2.59 [1.05-6.36], P = 0.038) was related to postoperative DI. In receiver operating characteristic analysis, its area under the curve was 0.68 (95% confidence interval 0.59-0.76, P < 0.001). Its optimal cutoff value that maximized the sum of sensitivity and specificity for postoperative DI was 2.7 cm.

CONCLUSIONS

Postoperative DI was observed in 45.8% of patients undergoing ETS to remove NFPAs. A large cephalocaudal tumor diameter was predictive of postoperative DI in such patients.

Endoscopic, Endonasal Transsphenoidal Surgery for Tumors of the Sellar and Suprasellar Region: A Monocentric Historical Cohort Study of 369 Patients

BACKGROUND

The endoscopic endonasal transsphenoidal approach (EETA) is an established technique for the resection of a large variety of benign sellar and suprasellar lesions, mostly pituitary adenomas. It has clear advantages over the microscopic approach, like a superior close-up view of the relevant anatomy and the tumor-gland interface, an enlarged working angle, as well as an increased panoramic vision inside the surgical area. We have been performing the EETA for over a decade, and this study will focus on perioperative and postoperative outcomes and complications and their association with the learning curve.

MATERIAL AND METHODS

All patients in our tertiary referral center (n = 369) undergoing an EETA for a lesion of the sellar and suprasellar region between January 1st 2008 and December 31st 2018 were included, and data were retrospectively retrieved from the electronic patient records.

RESULTS

Median follow-up after surgery was 55 months. Pituitary adenomas (n = 322) were the most frequent pathology. Headache (43.4%) and loss of vision (29.3%) were the most common presenting symptoms. Median procedure duration was significantly longer during the initial 5 years (106 versus 79 minutes; p <0.0001), but incidence of peri- and postoperative CSF leaks in the early years was not significantly higher. Knosp grade >2 was associated with perioperative CSF leak (p =0.002), and perioperative CSF leak was associated with postoperative CSF leak (p <0.001). Almost all cases of meningitis were preceded by a postoperative CSF leak. In 22.4% of patients, tumor recurrence required additional therapy. Perioperative (iatrogenic) mortality was 0.8%. The overall hospital stay decreased over time from an average of 7 to 5 days, and the case load increased yearly (p =0.015).

CONCLUSION

The EETA is an excellent technique with complication rates comparable to or even lower than those in large microsurgical series in the literature. EETA has a significant learning curve affecting the procedure duration. Throughout the first 10 years following the transition from the microscopic approach to the EETA in our cohort, the caseload increased and hospital stay was reduced, while no increase in peri- and postoperative complications was observed.

Creative and Innovative Methods and Techniques for the Challenges in the Management of Adult Craniopharyngioma

Craniopharyngioma remains a major challenge in daily clinical practice. The pathobiology of the tumor is still elusive, and there are no consensus or treatment guidelines on the optimal management strategy for this relatively rare tumor. However, recent technical and scientific advances, including genomic and radiomic profiling, innovation in surgical approaches, more precise radiotherapy protocols, targeted therapy, and restoration of lost functions all have the potential to significantly improve the outcome of patients with craniopharyngioma in the near future. Although many of these innovative tools in the new armamentarium of the clinician are still in their infancy, they could reduce craniopharyngioma-related morbidity and mortality and improve the patients' quality of life. In this article, we discuss these creative and innovative approaches that may offer solutions to the obstacles faced in treating craniopharyngioma and future possibilities in improving the care of these patients.

Simulation of Cerebrospinal Fluid Leak Repair Using a 3-Dimensional Printed Model

BACKGROUND

Acquiring proficiency for the repair of a cerebrospinal fluid (CSF) leak is challenging in great part due to its relative rarity, which offers a finite number of training opportunities.

OBJECTIVE

The purpose of this study was to evaluates the use of a 3-dimensional (3D) printed, anatomically accurate model to simulate CSF leak closure.

METHODS

Volunteer participants completed two simulation sessions. Questionnaires to assess their professional qualifications and a standardized 5-point Likert scale to estimate the level of confidence, were completed before and after each session. Participants were also queried on the overall educational utility of the simulation.

RESULTS

Thirteen otolaryngologists and 11 neurosurgeons, met the inclusion criteria. A successful repair of the CSF leak was achieved by 20/24 (83.33%), and 24/24 (100%) during the first and second simulation sessions respectively (average time 04:04 ± 1.39 and 02:10 ± 01:11). Time-to-close-the-CSF-leak during the second session was significantly shorter than the first (p < 0.001). Confidence scores increased across the training sessions (3.3 ± 1.0, before the simulation, 3.7 ± 0.6 after the first simulation, and 4.2 ± 0.4 after the second simulation; p < 0.001). All participants reported an increase in confidence and believed that the model represented a valuable training tool.

CONCLUSIONS

Despite significant differences with varying clinical scenarios, 3D printed models for cerebrospinal leak repair offer a feasible simulation for the training of residents and novice surgeons outside the constrictions of a clinical environment.

Reconstruction strategies for intraoperative CSF leak in endoscopic endonasal skull base surgery: systematic review and meta-analysis

BACKGROUND

Endoscopic endonasal surgery (EES) is one of the preferred options for skull base pathologies. Cerebrospinal fluid (CSF) leak is a significant complication of EES and neurosurgeons have proposed various reconstructive strategies to decrease this morbidity. We describe and compare the efficacy of these strategies.

METHODS

We searched PubMed, Cochrane Library, and Web of Science for publications between 1990 and November 2019. We defined a reconstruction hierarchy of seven levels from inside to outside: fat graft, intracranial intradural layer (inlay), intracranial extradural layer (onlay), buttress, mucosal flap, nasal packing and lumbar drainage. A single-arm analysis was performed for the primary outcome of CSF leak rate.

RESULTS

Of 3641 records identified, 48 studies met the inclusion criteria. Pituitary tumors had lower postoperative CSF leak rate than other diseases (1.8% vs. 6.5%, RD = -4.7% [-7.1%, -2.1%]). In high CSF flow group, the post-operative leak rate was reduced by application of mucosal flap (4.3% vs. without mucosal flap at 12.8%, RD = -8.5% [-15.1%, -1.9%]). The use of inlay showed potential of decreasing the post-operative leak rate (5.0% vs. 7.2%, RD = -2.2% [-7.7%, 3.3%]). In low CSF flow group, tampon was better than balloon for nasal packing (1.0% vs. 10.5%, RD = -9.5% [-16.5%, -2.4%]).

CONCLUSIONS

Mucosal flap and inlay for high-flow intraoperative CSF leak and tampon (compared with balloon) for low-flow intraoperative CSF leak, improved the postoperative CSF leak rate. Further studies are required to establish more robust evidence.

Vascular pedicled flaps for skull base defect reconstruction

OBJECTIVE

Techniques for reconstruction of skull base defects have advanced greatly since the introduction of the vascular pedicled nasoseptal flap in 2006. The objective of this review is to assess the current state of the field by examining both intranasal and extranasal techniques of vascular pedicled skull base defect repair, their indications and success rates, and novel techniques that are currently under investigation.

METHODS

A review of the literature describing the use of vascular pedicled flaps in skull base defect reconstruction was conducted using PubMed and Google Scholar.

RESULTS

The nasoseptal flap remains the most widely used vascular pedicled flap for endoscopic repair of skull base defects. Its ease of harvest, wide arch of rotation, and high success rates make it a popular choice among surgeons. Several variations including a "rescue" nasopseptal flap have been developed. Other less commonly used pedicled intranasal flaps include the middle turbinate flap and the posterior pedicled inferior turbinate flap. Additionally, several novel vascular pedicled flaps have been developed and tested in small cohorts of patients. Extranasal flaps such as the pericranial flap and the temporoparietal fascia flap are used less frequently than intranasal flaps. However, they remain valuable options for reconstruction in certain situations.

CONCLUSION

Advancements continue to be made in the field of skull base defect reconstruction using vascular pedicled flaps. Though the nasoseptal flap remains the most widely utilized option, additional intranasal techniques continue to be developed and tested to optimize surgical outcomes and patient care.

LEVEL OF EVIDENCE

NA.

Economic burden of readmission due to postoperative cerebrospinal fluid leak in Chinese patients

Aim: This real-world data study investigated the economic burden and associated factors of readmissions for cerebrospinal fluid leakage (CSFL) post-cranial, transsphenoidal, or spinal index surgeries. Methods: Costs of CSFL readmissions and index hospitalizations during 2014-2018 were collected. Readmission cost was measured as absolute cost and as percentage of index hospitalization cost. Factors associated with readmission cost were explored using generalized linear models. Results: Readmission cost averaged US$2407-6106, 35-94% of index hospitalization cost. Pharmacy costs were the leading contributor. Generalized linear models showed transsphenoidal index surgery and surgical treatment for CSFL were associated with higher readmission costs. Conclusion: CSFL readmissions are a significant economic burden in China. Factors associated with higher readmission cost should be monitored.

Drivers of In-Hospital Costs Following Endoscopic Transphenoidal Pituitary Surgery

OBJECTIVE

To characterize the patient and clinical factors that determine variability in hospital costs following endoscopic transphenoidal pituitary surgery.

METHODS

All endoscopic transphenoidal pituitary surgeries performed from January 1, 2015, to October 24, 2017, with complete data were evaluated in this retrospective single-institution study. The electronic medical record was reviewed for patient factors, tumor characteristics, and cost variables during each hospital stay. Multivariate linear regression was performed using Stata software.

RESULTS

The analysis included 190 patients and average length of stay was 4.71 days. Average total in-hospital cost was $28,624 (95% confidence interval $25,094-$32,155) with average total direct cost of $19,444 ($17,136-$21,752) and total indirect cost of $9181 ($7592-$10,409). On multivariate regression, post-operative cerebrospinal fluid (CSF) leak was associated with a significant increase in all cost variables, including a total cost increase of $40,981 ($15,474-$66,489, P = .002). Current smoking status was associated with an increased total cost of $20,189 ($6,638-$33,740, P = .004). Self-reported Caucasian ethnicity was associated with a significant decrease in total cost of $6646 (-$12,760 to -$532, P = .033). Post-operative DI was associated with increased costs across all variables that were not statistically significant.

CONCLUSIONS

Post-operative CSF leak, current smoking status, and non-Caucasian ethnicity were associated with significantly increased costs. Understanding of cost drivers of endoscopic transphenoidal pituitary surgery is critical for future cost control and value creation initiatives.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:760-764, 2021.

Intraoperative lumbar drainage can prevent cerebrospinal fluid leakage during transsphenoidal surgery for pituitary adenomas: a systematic review and meta-analysis

Background

Perioperative cerebrospinal fluid (CSF) leakage is a major complication of pituitary adenomas transsphenoidal surgery. Lumbar drainage (LD) is a common method of treating CSF leakage. But whether intraoperative LD can prevent CSF leakage during the perioperative period of pituitary adenomas transsphenoidal surgery remains controversial. Clarity on the appropriate use of LD is needed.

Methods

A systematic literature review was conducted in the PubMed, EMBASE, and Web of science databases. Articles were included when they compared intraoperative LD with intraoperative no-LD CSF leakage rates during pituitary adenomas transsphenoidal surgery.

Results

Overall, 5 studies containing 678 cases met the inclusion criteria. When data were provided on intraoperative CSF leakage rates, the meta-analysis showed a significant difference in favor of intraoperative LD. When data were provided on postoperative CSF leakage rates, the meta-analysis also demonstrated a significant difference in favor of intraoperative LD.

Conclusions

Although the results of this meta-analysis suggest intraoperative LD can reduce the risk of CSF leakage during the perioperative period of pituitary adenomas transsphenoidal surgery, the available evidence is indefinite. To some extent the results suggest intraoperative LD’s potential positive role. Further studies that include well-designed prospective, randomized controlled clinical trials are necessary for further verification.

Neural network-based identification of patients at high risk for intraoperative cerebrospinal fluid leaks in endoscopic pituitary surgery

OBJECTIVE

Although rates of postoperative morbidity and mortality have become relatively low in patients undergoing transnasal transsphenoidal surgery (TSS) for pituitary adenoma, cerebrospinal fluid (CSF) fistulas remain a major driver of postoperative morbidity. Persistent CSF fistulas harbor the potential for headache and meningitis. The aim of this study was to investigate whether neural network-based models can reliably identify patients at high risk for intraoperative CSF leakage.

METHODS

From a prospective registry, patients who underwent endoscopic TSS for pituitary adenoma were identified. Risk factors for intraoperative CSF leaks were identified using conventional statistical methods. Subsequently, the authors built a prediction model for intraoperative CSF leaks based on deep learning.

RESULTS

Intraoperative CSF leaks occurred in 45 (29%) of 154 patients. No risk factors for CSF leaks were identified using conventional statistical methods. The deep neural network-based prediction model classified 88% of patients in the test set correctly, with an area under the curve of 0.84. Sensitivity (83%) and specificity (89%) were high. The positive predictive value was 71%, negative predictive value was 94%, and F1 score was 0.77. High suprasellar Hardy grade, prior surgery, and older age contributed most to the predictions.

CONCLUSIONS

The authors trained and internally validated a robust deep neural network-based prediction model that identifies patients at high risk for intraoperative CSF. Machine learning algorithms may predict outcomes and adverse events that were previously nearly unpredictable, thus enabling safer and improved patient care and better patient counseling.

Preoperative radiographic and clinical factors associated with the visualization of intraoperative cerebrospinal fluid during endoscopic transsphenoidal resection of pituitary adenomas

Background:

Intraoperative visualization of cerebrospinal fluid (CSF) during endoscopic endonasal resection of skull base tumors is the most common factor contributing to the development of postoperative CSF leaks. No previous studies have solely evaluated preoperative factors contributing to intraoperative CSF visualization. The purpose of this study was to identify preoperative factors predictive of intraoperative CSF visualization.

Methods:

Retrospective review of patients who underwent transsphenoidal resection of pituitary adenomas was conducted. Clinical and radiographic variables were compared for those who had CSF visualized to those who did not. Nominal logistic regression models were built to determine predictive variables.

Results:

Two hundred and sixty patients were included in the study. All significant demographic and radiographic variables on univariate analysis were included in multivariate analysis. Two multivariate models were built, as tumor height and supraclinoid extension were collinear. The first model, which considered tumor height, found that extension into the third ventricle carried a 4.60-fold greater risk of CSF visualization (P = 0.005). Increasing tumor height showed a stepwise, linear increase in risk; tumors >3 cm carried a 19.02-fold greater risk of CSF visualization (P = 0.003). The second model, which considered supraclinoid tumor extension, demonstrated that extension into the third ventricle carried a 4.38-fold increase in risk for CSF visualization (P = 0.010). Supraclinoid extension showed a stepwise, linear increase in intraoperative CSF risk; tumors with >2 cm of extension carried a 9.26-fold increase in risk (P = 0.017).

Conclusion:

Our findings demonstrate that tumor height, extension into the third ventricle, and extension above the clinoids are predictive of intraoperative CSF visualization.

Endoscopic Anterior Skull Base Reconstruction: A Meta-Analysis and Systematic Review of Graft Type

OBJECTIVE

The influence of graft type (nonautologous vs. autologous) on surgical outcomes in endoscopic anterior skull base (EASB) reconstruction is not well understood. This review systematically evaluated rates of postoperative complications of EASB repairs that utilized autologous or nonautologous grafts.

METHODS

Original studies reporting EASB reconstruction outcomes were extracted from PubMed, Ovid, and the Cochrane Library from database inception to 2019. Risk ratios, risk differences, χ² tests, and multivariate logistic regression were used to evaluate outcome measures: postoperative cerebrospinal fluid (CSF) leaks, meningitis, and other major complications (OMCs).

RESULTS

A total of 2275 patients from 29 studies were analyzed. Rates of postoperative CSF leaks, meningitis, and OMCs were 4.0%, 1.6%, and 2.3%, respectively, using autologous grafts, and 5.0%, 0.3%, and 1.0%, respectively, using nonautologous grafts. Multivariate analysis of 118 patients demonstrated no significant differences in age, CSF flow rate, single or multilayer reconstruction, and presence of intraoperative CSF leak or lumbar drain. Meta-analyses of 6 studies yielded a risk ratio of 0.64 (95% confidence interval [CI], 0.19-2.14; P = 0.47) for postoperative CSF leakage, and risk differences of -0.01 (95% CI, -0.06 to 0.05; P = 0.80) and -0.02 (95% CI, -0.09 to 0.05; P = 0.51) for postoperative meningitis and OMCs, respectively. There were no significant differences in postoperative CSF leakage (P = 0.95) and OMCs (P = 0.41) between graft types among cases with intraoperative CSF leaks. However, meningitis rates were lower (P = 0.04) in the nonautologous group.

CONCLUSIONS

EASB reconstructions utilizing autologous and nonautologous grafts are associated with similar rates of postoperative CSF leakage and OMCs. In cases with intraoperative CSF leakage, nonautologous grafts were associated with reduced postoperative meningitis.

Endonasal Endoscopic Surgery for Pediatric Sellar and Suprasellar Lesions: A Systematic Review and Meta-analysis

OBJECTIVES

The advent of endonasal endoscopic skull base surgery (ESBS) has redefined the management of pediatric sellar and suprasellar lesions. To date, the outcomes of these procedures have not been systematically reviewed. This study performed a systematic review with meta-analysis of surgical outcomes for pediatric patients undergoing ESBS for sellar and suprasellar lesions.

DATA SOURCES

PubMed (National Library of Medicine, National Institutes of Health), Scopus (Elsevier), and Cochrane Library (Wiley).

REVIEW METHODS

Articles reporting on pediatric patients undergoing ESBS for craniopharyngiomas, pituitary adenomas, and Rathke's cleft cysts were reviewed. The primary outcome was postoperative cerebrospinal fluid (CSF) leak. Secondary outcomes included endocrine, visual, and other complications.

RESULTS

Twenty-five articles reporting on 554 patients were included. Overall postoperative CSF leak rate was 8.6%, with tumor-specific rates of 10.6% in craniopharyngiomas, 6.5% in pituitary adenomas, and 7.2% in Rathke's cleft cysts (P > .05). Older studies demonstrate higher postoperative CSF leak rates as compared with more recent studies (12.5% vs 6.1%, P = .0082). Younger children (8.9-12.6 years old) experienced a higher rate of postoperative CSF leaks as compared with older children (13.0-16.6 years old; 12.9% vs 4.9%, P = .0016). Additional postoperative complications included diabetes insipidus (26.7%), hypopituitarism (46.6%), visual deficits (2.6%), meningitis (3.4%), and weight gain (3.4%).

CONCLUSION

ESBS for pediatric sellar and suprasellar lesions is overall an effective management approach with an increasingly favorable risk-benefit profile. Younger children may be more susceptible to postoperative CSF leak as compared with older pediatric patients. Tumor type does not appear to be an independent risk factor for postoperative CSF leak in this population.

Investigation of Skull-Based Cerebrospinal Fluid Leak Repair: A Single-Institution Comprehensive Study of 116 Cases Over 10 Years

BACKGROUND

Cerebrospinal fluid (CSF) leaks have been historically difficult to diagnose and treat because their cause can widely vary. There are insufficient diagnostic predictors and no clinically accepted standards for their treatment. This large institutional study reports on the diagnosis, management, and outcomes of patients presenting with CSF leak over 10 years and aims to identify potential comorbidities and risk factors for primary and recurrent leaks.

METHODS

Patients diagnosed with CSF leak from 2007 to 2017 were analyzed retrospectively. The data included medical history, body mass index, surgical treatment, and postoperative outcomes.

RESULTS

A total of 116 cases were identified. The location of leaks was 91 CSF rhinorrhea and 28 CSF otorrhea (3 both). The average BMI for females was greater than that of males (P = 0.01). Causes of leak were 64 noniatrogenic, 47 iatrogenic, and 9 traumatic. A total of 108 patients underwent surgical treatment. Sixty-nine were treated by endoscopic approaches, 42 involved open approaches, and 83 involved the placement of a lumbar drain. Eighteen patients had a ventriculoperitoneal shunt and 6 had a lumbar-peritoneal shunt. A total of 78 patients (72.22%) had an associated encephalocele with the CSF leak. The average length of stay was 7.73 days (0.76). The average length of follow-up was 1.58 years (0.22). The primary repair rate was 80.17% (n = 93) and the overall repair outcome was 99.14% (n = 115).

CONCLUSIONS

The overall CSF repair outcome was 99.14% over 10 years at a single institution. Despite this high percentage, CSF leaks continue to be a complex problem and require vigorous multidisciplinary work with close follow-up and use of multiple imaging strategies.

CSF leak after endoscopic skull base surgery in children: A single institution experience

INTRODUCTION

The endoscopic expanded endonasal approach (EEA) has been shown to be a safe and effective surgical technique in the resection of pediatric skull base lesions. Cerebrospinal fluid (CSF) leaks are among the most common complications of this approach. Here we review skull base resections using EEA in pediatric patients at our single institution, to identify potential risk factors for this surgical complication.

METHODS

A retrospective chart review was conducted on pediatric patients at our single institution for patients 19 years-old and under, who underwent an EEA for resection of a skull base tumor.

RESULTS

Thirty-nine pediatric patients (ages 1-19 years) with 8 different tumor pathologies underwent an EEA for resection of their skull base tumors. 21 patients experienced an intraoperative CSF leak, of which 10 (48%) were "high-flow" leaks and 11 (52%) were "low-flow" leaks. Nasoseptal flaps were only used to repair the intraoperative "high flow" leaks (n = 10), and "low flow" and "no leaks" were repaired with allograft and fat. No patients experienced a post-operative CSF leak.

CONCLUSION

In our pediatric series, the skull base repair algorithm of using an NSF only in cases of "high flow" intraoperative leaks was effective, and no post-operative CSF leaks occurred. Not using an NSF in cases of "low-flow" or "no leak" cases allows for decreased anatomical disruption in the growing patient.

Development of Chronic Sphenoid Sinusitis After Sellar Reconstruction with Medpor Porous Polyethylene Implant

OBJECTIVE

The Medpor porous polyethylene implant is reported to be safe and effective for sellar reconstruction after transsphenoidal surgery (TSS). However, we have observed several cases of delayed chronic sphenoid sinusitis related to the implant. The purpose of this study is to describe the presentation and management of implant-related sphenoid sinusitis after sellar reconstruction.

METHODS

This is a retrospective study of patients who underwent endonasal TSS with Medpor sellar reconstruction between December 2008 and January 2013 at a tertiary care institution. Patient demographics, initial surgical management, sinonasal symptoms, postoperative imaging, sinusitis management, and resulting outcomes were analyzed.

RESULTS

From 2008-2013, 139 patients underwent sellar reconstruction using Medpor. Five patients (3.6%) presented between 8 and 60 months after surgery with chronic sphenoid sinusitis that required surgical management. All 5 patients presented as outpatients for management of headaches and nasal drainage, 4 patients experienced chronic nasal congestion, and 3 patients noted recurrent sinusitis. At the time of revision surgery, all 5 patients were found to have mucosal inflammation and edema surrounding the implant, and 4 of the 5 had an exposed or partially extruded implant that was removed.

CONCLUSIONS

Reconstruction of the sellar floor may be performed after TSS to prevent postoperative complications. Although porous polyethylene implants have previously been described as safe and effective for this purpose, surgeons should be aware of the risk of subsequent implant extrusion and chronic sphenoid sinusitis that can occur in a delayed manner.

The Role of the Lumbar Drain in Endoscopic Endonasal Skull Base Surgery: A Retrospective Analysis of 811 Cases

OBJECTIVE

With increasing use of the endoscopic endonasal transsphenoidal approach, wider attention is being paid to treatment and prevention of its complications. The aim of this study was to determine whether lumbar drainage (LD) has been effective in preventing and treating postoperative cerebrospinal fluid (poCSF) leakage or in assisting in achieving tumor gross total removal (GTR).

METHODS

Retrospective analysis of purely endoscopic endonasal transsphenoidal cases at a single center between 2008 and 2017 was done. We studied intraoperative cerebrospinal fluid (ioCSF) and poCSF leakage rates, duration of hospitalization, and GTR rate of the lesions, comparing patients with and without LD.

RESULTS

Among 811 endoscopic endonasal transsphenoidal procedures, LD was used in 38 cases. There was no statistically significant difference between patients with and without LD with regard to incidence of ioCSF leakage. A statistically significant difference was found in obese patients with LD, who had an apparently increased rate of poCSF leak. The length of stay of patients with LD was significantly longer than the control group without LD. The GTR rate was also higher in patients without LD.

CONCLUSIONS

Use of LD is correlated with longer immobilization and hospitalization without providing statistically significant advantages in terms of prevention or treatment of ioCSF and/or poCSF in low-risk and high-risk patients. Moreover, LD was not helpful in achieving GTR of tumors.