Dural suturing for repair of cerebrospinal fluid leak in transnasal transsphenoidal surgery

An in vitro study of micromechanics, cellular proliferation and viability on both decellularized porcine dura grafts and native porcine dura grafts

Damage to the dura mater may occur during intracranial or spinal surgeries, which can result in cerebrospinal fluid leakage and other potentially fatal physiological changes. As a result, biological and synthetic derived scaffolds are typically used to repair dura mater post intracranial or spinal surgeries. The extracellular matrix of xenogeneic dura scaffolds has been shown to exhibit increased cell infiltration and regeneration than synthetic dura materials. In this study, we investigated the biocompatibility of native and decellularized porcine dura by seeding rat fibroblast cells onto the constructs. Cell proliferation, cell viability, and the mechanical properties of these dural grafts were evaluated post-re-seeding on days 3,7 and 14. Live-dead staining and resazurin salts were used to quantify cell viability and cell proliferation, respectively. Micro indentation was conducted to quantify the mechanical integrity of the native and acellular dura graft. The findings indicate that the acellular porcine dura graft creates a beneficial setting for infiltrating rat fibroblast cells. Cell viability, proliferation, and micro indentation results on the acellular grafts are comparable with the native control porcine dura tissue. In conclusion, the porcine scaffold material showed increased cell viability at each time point evaluated. The sustained mechanical response and favorable viability of the cells on the decellularized grafts provide promising insight into the potential use of porcine dura in clinical cranial dura mater graft applications.

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.

Kashimé: A Novel Knotless Surgical Suture to Simplify Dural Stitches in Endoscopic Transnasal Surgery

BACKGROUND

Dural suturing is an effective adjunct to skull base dural repair in endoscopic transnasal surgery, although it is technically cumbersome. Here, we presented a novel surgical suture "Kashimé" (Kono Seisakusho) that can be tightened without tying.

OBJECTIVE

To examine the efficacy of Kashimé for skull base dural repair in endoscopic transnasal surgery.

METHODS

Kashimé was used in 8 patients with skull base dural defects during nonpedicled flap-based multilayered skull base reconstruction to close or approximate the gaps between the dural edges or secure a free fascial graft. The time required for each dural stitch (passing a needle through the dura, pulling out the thread, and tightening it) and the incidence of postoperative cerebrospinal fluid leakage were the study end points.

RESULTS

Based on our preliminary experiences with 12 stitches used, no postoperative cerebrospinal fluid leakage was observed. The learning curve was steep, and the mean (±SD) time was 127 (±44) seconds for a single stitching procedure, except for the first case. Regarding the metal artifact, although a beam hardening artifact was not observed on computed tomography, a 4- to 9-mm diameter image defect was observed on magnetic resonance imaging.

CONCLUSION

Kashimé can help surgeons to complete a single dural stitch in endoscopic transnasal surgery for approximately 2 minutes. It may be an optimal tool for skull base reconstruction, but the efficacy and safety need to be investigated.

Continuous Dural Suturing for the Closure of Grade 1 to 2 Cerebrospinal Fluid Leakage After Pituitary Adenoma Removal Using an Endoscopic Endonasal Approach

In this study, we aim at evaluating continuous dural suturing in patients with grade 1 to 2 cerebrospinal fluid (CSF) leakage after pituitary adenoma removal using an endoscopic endonasal approach. The study population comprised 381 pituitary adenoma patients who underwent endoscopic endonasal removal of the tumor. The degree of intraoperative CSF leakage was graded based on Esposito method. Cranial base repair using continuous dural suturing was performed according to the grade of CSF leakage. Intraoperative grade 1 to 2 CSF leakage was identified in 143 patients (37.5%). Continuous dural suturing to repair the cranial base was accepted by 61 patients and refused by 82 patients. Among patients who accepted dural suturing, the incidence of postoperative CSF leakage was reduced and the length of hospital stay was shortened. Patients with low-flow leakage were treated using a reduced vascularized pedicled nasoseptal flap. In conclusion, our graded cranial base repair method using the dural suturing technique is simple and effective.

Risk Factors for Postoperative Cerebrospinal Fluid Leak after Graded Multilayer Cranial Base Repair with Suturing via the Endoscopic Endonasal Approach

This study analyzed risk factors for postoperative cerebrospinal fluid (CSF) leak after graded multilayer cranial base repair method with dural suturing. We performed surgery via the endoscopic endonasal approach (EEA) from 2012.6 to 2018.4, and those consecutive clinical data were prospectively accumulated and retrospectively analyzed. We tailored the repair method according to the intraoperative CSF leak grade. Among 388 surgeries via the EEA, there were 10 (2.6%) cases of postoperative CSF leak after graded repair with suturing. Postoperative CSF leak occurred in two of the 150 cases without intraoperative CSF leak (grade 0), one of the 104 cases with small (grade 1) intraoperative CSF leak, two of the 60 cases with moderate (grade 2) leak, and five of the 74 cases with large (grade 3) leak. Univariate analysis indicated that chordoma (P = 0.023), estimated tumor volume ≥ 7400 mm³ (P = 0.003), and maximum tumor diameter ≥ 32.5 mm (P = 0.001) were significant risk factors for postoperative CSF leak. Additionally, among cases with intraoperative grade 3 CSF leak, chordoma (P = 0.021), estimated tumor volume ≥ 23000 mm³ (P = 0.003), and maximum tumor diameter ≥ 45.5 mm (P = 0.001) were significant risk factors for postoperative CSF leak. Maximum tumor diameter, estimated tumor volume, and chordoma tumor pathology are related to a higher risk of postoperative CSF leak.

Endoscopic transnasal transsphenoidal management of sellar/suprasellar arachnoid cyst: A case report and literature review

Background

Arachnoid cysts (ACs) are collections of cerebrospinal fluids (CSFs) that develop within the arachnoid layer of the meninges. Sellar ACs are comparatively rare. In general, ACs account for approximately 1% of all intracranial mass lesions, and sellar ACs are 3% of all intracranial ACs. An endoscopic transnasal transsphenoidal approach for the treatment of ACs by fenestrating the cyst's wall and connecting with the subarachnoid space is the most optimal option.

Case Description

A 74-year-old woman whose sellar AC was diagnosed on magnetic resonance imaging a year ago was admitted to our hospital with complaints of bitemporal hemianopia and diminished visual acuity in the past 2 months. Sellar AC was diagnosed based on the clinical history and presentation, as well as neurologic, endocrinologic, and ophthalmologic examinations, including visual acuity and visual field examination, and additional imaging findings. The patient with a sellar/suprasellar AC was treated by an endoscopic transnasal transsphenoidal approach with cyst drainage and perforation of the lamina terminalis. Postoperatively, the visual disturbances improved markedly. No surgery-related complications occurred.

Conclusion

The endoscopic transnasal transsphenoidal approach remains a minimally invasive and preferred approach for the treatment of sellar/suprasellar ACs. Hermetically reconstructing the sellar floor is an effective method to prevent CSF leakage.

Clinical application of the “sellar barrier’s concept” for predicting intraoperative CSF leak in endoscopic endonasal surgery for pituitary adenomas with a machine learning analysis

Background

Recently, it was defined that the sellar barrier entity could be identified as a predictor of cerebrospinal fluid (CSF) intraoperative leakage. The aim of this study is to validate the application of the sellar barrier concept for predicting intraoperative CSF leak in endoscopic endonasal surgery for pituitary adenomas with a machine learning approach.

Methods

We conducted a prospective cohort study, from June 2019 to September 2020: data from 155 patients with pituitary subdiaphragmatic adenoma operated through endoscopic approach at the Division of Neurosurgery, Università degli Studi di Napoli “Federico II,” were included. Preoperative magnetic resonance images (MRI) and intraoperative findings were analyzed. After processing patient data, the experiment was conducted as a novelty detection problem, splitting outliers (i.e., patients with intraoperative fistula, n = 11/155) and inliers into separate datasets, the latter further separated into training (n = 115/144) and inlier test (n = 29/144) datasets. The machine learning analysis was performed using different novelty detection algorithms [isolation forest, local outlier factor, one-class support vector machine (oSVM)], whose performance was assessed separately and as an ensemble on the inlier and outlier test sets.

Results

According to the type of sellar barrier, patients were classified into two groups, i.e., strong and weak barrier; a third category of mixed barrier was defined when a case was neither weak nor strong. Significant differences between the three datasets were found for Knosp classification score (p = 0.0015), MRI barrier: strong (p = 1.405 × 10⁻⁶), MRI barrier: weak (p = 4.487 × 10⁻⁸), intraoperative barrier: strong (p = 2.788 × 10⁻⁷), and intraoperative barrier: weak (p = 2.191 × 10⁻¹⁰). We recorded 11 cases of intraoperative leakage that occurred in the majority of patients presenting a weak sellar barrier (p = 4.487 × 10⁻⁸) at preoperative MRI. Accuracy, sensitivity, and specificity for outlier detection were 0.70, 0.64, and 0.72 for IF; 0.85, 0.45, and 1.00 for LOF; 0.83, 0.64, and 0.90 for oSVM; and 0.83, 0.55, and 0.93 for the ensemble, respectively.

Conclusions

There is a true correlation between the type of sellar barrier at MRI and its in vivo features as observed during endoscopic endonasal surgery. The novelty detection models highlighted differences between patients who developed an intraoperative CSF leak and those who did not.

Application of dural suturing in the endoscopic endonasal approach to the sellar region

Objectives

The endoscopic endonasal approach (EEA) is widely used in the treatment of cranial base tumors. Skull base reconstruction is a crucial part of EEA, which has a great impact on patients’ prognosis. In this study, we report our experience with sellar dural suturing in cranial base reconstruction and retrospectively analyze its effect.

Methods

The clinical data of 134 patients who suffered intraoperative CSF leakage and underwent EEA surgery in the Department of Neurosurgery of the First Affiliated Hospital of Nanjing Medical University from October 2018 to November 2020 were retrospectively collected and analyzed. According to whether sellar dural suturing was performed during the operation, they were divided into a suture group (55 cases) and a control group (79 cases).

Results

The results showed that dural suturing of the sellar floor effectively reduced the postoperative hospitalization duration (p = 0.026) and the use rates of lumbar drainage (p = 0.047), autologous fat transplantation (p = 0.038), and pedicled nasoseptal flaps (p = 0.026).

Conclusion

Sellar dural suturing under endoscopy is a promising and effective method for cranial base reconstruction in EEA surgery and is worthy of clinical application.

Effects of cruciate embedding fascia-bone flap technique on grade II-III cerebral spinal fluid leak in endoscopic endonasal surgery

Background

Cerebral spinal fluid (CSF) leak remains an important issue in endoscopic endonasal surgery (EES). A standard protocol for skull base closure has not yet been established, and the application of rigid buttress has not been given sufficient attention. To emphasize the functions of support and fixation from rigid buttress in reconstruction, we introduced the cruciate embedding fascia-bone flap (CEFB) technique using autologous bone graft to buttress the fascia lata attachment to the partially sutured skull base dural defect and evaluated its efficacy in a consecutive case series of grade II–III CSF leaks in EES.

Methods

Data from consecutive patients diagnosed with sellar region lesions with grade II–III CSF leaks during EES were collected from May 2015 to May 2020. Skull base reconstructions were performed with the CEFB or the conventional pedicle vascularized nasoseptal flap (PNSF). Related clinical data were analysed. The combined use of the CEFB and PNSF was applied to an additional supplemental case series of patients with grade III leak and multiple high-risk factors.

Results

There were 110 and 65 patients included in the CEFB and PNSF groups, respectively. The CEFB demonstrated similar effects on the incidence of postoperative CSF leak (2.7%), intracranial infection (4.5%), and lumbar drainage (LD) placement (5.5%) as PNSF (3.1%, 3.1%, and 6.2%), but with less epistaxis (CEFB: 0%, PNSF: 6.2%) and nasal discomforts (CEFB: 0%, PNSF: 7.7%). The LD duration (CEFB: 6.67 ± 2.16 days, PNSF: 10.50 ± 2.38 days), bed-stay time (CEFB: 5.74 ± 1.58 days, PNSF: 8.83 ± 3.78 days) and hospitalization time (CEFB: 10.49 ± 5.51 days, PNSF: 13.58 ± 5.50 days) were shortened in the CEFB group. The combined use of CEFB and PNSF resulted in 0 postoperative CSF leaks in the supplemental case series of 23 highly susceptible patients.

Conclusion

This study suggested that the new CEFB technique has the potential to prevent postoperative CSF leak in EES. The results indicated that it can be used effectively without PNSF in suitable cases or applied in addition to a PNSF with high compatibility when necessary. Its effectiveness should be further verified with a larger cohort and better design in the next step.

Trial Registration Current Controlled Trials ChiCTR2100044764 (Chinese Clinical Trial Registry); date of registration: 27 March 2020. Retrospectively registered

Aspergillus sphenoiditis growth on long cut ends of a non-absorbable sellar floor dura closure suture

Background:

Cerebrospinal fluid (CSF) rhinorrhea is a common complication after transsphenoidal surgery (TSS). Suturing of sellar dura is effective in the prevention of postoperative CSF rhinorrhea, but it may cause rare postoperative infections. Herein, we report a case of Aspergillus sphenoiditis with the growth noted on cut ends of a polyvinylidene fluoride (PVDF) suture used for dural closure.

Case Description:

A previously healthy 51-year-old woman complained of abnormal odor 5 years after TSS for null cell adenoma. A white mass in the sphenoidal sinus was detected on rhinoscopy. Fungal balls were found clustered around the ends of a PVDF suture used for dural closure at the initial surgery. She underwent removal of both the fungal ball and dural suture. The pathological diagnosis was Aspergillus hyphae. It is thought that a dural suture protruding out of the sphenoid sinus mucosa can cause Aspergillus infection even in immunocompetent patients. A rapid and accurate diagnosis followed by surgical removal of the fungal ball and follow-up with oral antimycotic drugs result in good clinical outcomes.

Conclusion:

It is crucial to cut short the suture end and cover it with sphenoid sinus mucosa to avoid such complications.

Endoscopic endonasal resection of sinonasal teratocarcinosarcoma with intracranial breakthrough: illustrative case

BACKGROUND

Teratocarcinosarcoma traversing the anterior skull base is rarely reported in literature. The heterogenous and invasive features of the tumor pose challenges for surgical planning. With technological advancements, the endoscopic endonasal approach (EEA) has been emerging as a workhorse of anterior skull base lesions. To date, no case has been reported of EEA totally removing teratocarcinosarcomas with intracranial extensions.

OBSERVATIONS

The authors provided an illustrative case of a 50-year-old otherwise healthy man who presented with left-sided epistaxis for a year. Imaging studies revealed a 31 × 60-mm communicating lesion of the anterior skull base. Gross total resection via EEA was achieved, and multilayered skull base reconstruction was performed.

LESSONS

The endoscopic approach may be safe and effective for resection of extensive teratocarcinosarcoma of the anterior skull base. To minimize the risk of postoperative cerebrospinal fluid leaks, multilayered skull base reconstruction and placement of lumbar drainage are vitally important.

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review

PURPOSE

Postoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.

METHODS

Pubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.

RESULTS

193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.

CONCLUSIONS

Modern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

Single-Layer Fascia Patchwork Closure for the Extended Endoscopic Transsphenoidal Transtuberculum Transplanum Approach: Deep Suturing Technique and Preliminary Results

OBJECTIVE

To describe a single-layer fascia patchwork closure (FPWC) without nasoseptal flap (NSF) and compare postoperative cerebrospinal fluid (CSF) leakage between FPWC using NSF and single-layer FPWC without NSF for the extended endoscopic transsphenoidal transtuberculum transplanum approach.

METHODS

Forty-five cases of suprasellar tumor in 42 patients were treated with extended endoscopic transsphenoidal removal, resulting in extensive, high-flow CSF leakage. Following the intradural procedure for treatment of various suprasellar tumors, fascia lata was inlaid subdurally on the cranial base defect and patch-sutured around its entire circumference under endoscope visualization, using an average of 17 stitches. Septal bone or hydroxyapatite plate was used for the hard support material against pulsatile intracranial pressure. NSF was added in the earlier 17 cases. Closure was completed without NSF in the more recent 28 cases when the Valsalva maneuver confirmed watertight closure. Two recent cases required NSF after Valsalva maneuver and were included in the FPWC + NSF group.

RESULTS

Postoperative CSF leakage did not occur in the FPWC + NSF group but occurred in 2 patients in the single-layer FPWC group (7.1%) (P = 0.52). There was no significant difference in CSF leakage between single-layer FPWC and FPWC + NSF. The mean suturing time for FPWC was 85.8 minutes, and the shortest was 39 minutes in a recent case (mean, 17 stitches; n = 35, video analysis).

CONCLUSIONS

Single-layer FPWC may be a viable technical option for effective skull base reconstruction after the extended endoscopic transsphenoidal transtuberculum transplanum approach.

Comparative Evaluation of 3-Dimensional High Definition and 2-Dimensional 4-K Ultra-High Definition Endoscopy Systems in Endonasal Skull Base Surgery

BACKGROUND

The differences between 3-dimensional (3D) high definition (HD) and 2-dimensional (2D) 4-K ultra-HD (4K) endoscopy and their respective advantages remain unclear.

OBJECTIVE

To evaluate the utility of these endoscopy systems in endonasal skull base surgery.

METHODS

Consecutive series of endoscopic endonasal surgeries performed after introduction of 3D/HD and 2D/4K systems (July 2017) were retrospectively evaluated. Sporadic cases treated with either system, or a conventional 2D standard definition (SD) system, during the rental period from March 2016 were also included. Objective comparisons between the systems were made for newly diagnosed Knosp grade 0 to 3 pituitary adenomas. Surgical procedures were divided into nasal, sphenoidal, and intradural phases, and the surgical procedural time was compared for each phase. The time required for and accuracy of suturing the sellar floor dura was also evaluated.

RESULTS

A total of 74 cases were treated with 3D/HD and/or 2D/4K, and 12 cases with 2D/SD. 3D/HD was advantageous in the nasal phase because of its intuitive depth perception. 2D/4K was advantageous in the intradural phase because of its superior image quality. Surgical time of the nasal phase with 3D/HD, and that of the intradural phase with 2D/4K, were significantly shorter than that with 2D/SD. The time required for and accuracy of sellar floor dural suturing showed a trend toward improving in the order of 2D/SD, 2D/4K, and 3D/HD.

CONCLUSION

3D/HD and 2D/4K endoscopy systems have different advantages, which are useful in distinct surgical phases. Understanding the characteristics of endoscopy systems is important for selecting the most appropriate system for distinct surgical situations.

The sellar barrier on preoperative imaging predicts intraoperative cerebrospinal fluid leak: a prospective multicenter cohort study

BACKGROUND

The type of sellar barrier observed between a pituitary tumor and cerebrospinal fluid (CSF) on preoperative magnetic resonance imaging (MRI) may predict intraoperative CSF leak during endonasal pituitary surgery. This is the first multicentric prospective cohort trial to study the sellar barrier concept and CSF leak rate during endoscopic pituitary surgery.

METHODS

This multi-center, international study enrolled patients operated for pituitary adenomas via fully endoscopic endonasal surgery over a period of 4 months. The independent variable was the subtype of sellar barrier observed on preoperative MRI (strong, mixed or weak); the dependent variable was the presence of an intraoperative CSF leak. The primary goal was to determine the association between a particular type of sellar barrier and the risk of intraoperative CSF leak. Appropriate statistical methods were then applied for data analysis.

RESULTS

Over the study period, 310 patients underwent endoscopic endonasal surgery for pituitary tumor. Preoperative imaging revealed a weak sellar barrier in 73 (23.55%), a mixed sellar barrier in 75 (24.19%), and a strong sellar barrier in 162 (52.26%) patients. The overall rate of intraoperative CSF leak among all patients was 69 (22.26%). A strong sellar-type barrier was associated with significantly reduced rate of intraoperative CSF leak (RR = 0.08; 95% CI 0.03-0.19; p < 0.0001), while a weak sellar barrier associated with higher rates of CSF leak (RR = 8.54; 95% CI 5.4-13.5; p < 0.0001).

CONCLUSIONS

The preoperative MRI of pituitary patients can suggest intraoperative CSF leak rates, utilizing the concept of the sellar barrier. Patients with a weak sellar barrier carry a higher risk for an intraoperative CSF leak, whereas a strong sellar barrier on MRI seems to mitigate intraoperative CSF leak. We propose that preoperatively assessment of the sellar barrier can prepare surgeons for intraoperative CSF leak repair.

Development of a Semiautomatic Dura Mater Suturing Device for Preventing Cerebrospinal Fluid Leakage in Transsphenoidal Surgery

Dural suturing in transsphenoidal surgery requires well-honed technical skills. We have developed a semiautomatic dural suturing device and confirmed its effectiveness by comparing it with the conventional method. This device significantly shortens the suturing time compared with the conventional method. The dural suturing time in transsphenoidal surgery could be decreased significantly by use of this novel device.

Abdominal Fat Graft for Sellar Reconstruction: Retrospective Outcomes Review and Technical Note

BACKGROUND

The transsphenoidal approach is the standard of care for the treatment of pituitary adenomas and is increasingly employed for many anterior skull base tumors. Persistent postoperative cerebrospinal fluid (CSF) leaks can result in significant complications.

OBJECTIVE

To analyze our series of patients undergoing abdominal fat graft repair of the sellar floor defect following transsphenoidal surgery, describe and investigate our current, routine technique, and review contemporary and past methods of skull base repair.

METHODS

A recent consecutive series (2008-2017) of 865 patients who underwent 948 endonasal procedures for lesions of the sella and anterior skull base was retrospectively reviewed. Three hundred eighty patients underwent reconstruction of the sellar defect with an abdominal fat graft.

RESULTS

The diagnoses of the 380 patients receiving fat grafts were the following: 275 pituitary adenomas (72.4%), 50 Rathke cleft cysts (13.2%), 12 craniopharyngiomas (3.2%), and a variety of other sellar lesions. Fourteen patients had persistent postoperative CSF leak requiring reoperation and included: 5 pituitary adenomas (1.3%), 4 craniopharyngiomas (1.1%), 2 arachnoid cysts (0.53%), 2 prior CSF leaks (0.53%), and 1 Rathke cleft cyst (0.26%). Four patients (1.1%) developed minor abdominal donor site complications requiring reoperation: 1 hematoma, 2 wound complications, and 1 keloid formation resulting in secondary periumbilical infection.

CONCLUSION

Minimizing postoperative CSF leaks following endonasal anterior skull base surgery is important to decrease morbidity and to avoid a prolonged hospital stay. We present an evolved technique of abdominal fat grafting that is effective and safe and includes minimal morbidity and expense.

Continuous dural suturing for closure of grade 3 leaks after tumor removal via an endoscopic endonasal approach

Cerebrospinal fluid (CSF) leakage is a major complication after extended endonasal transsphenoidal surgery (EETSS), which is commonly used in the treatment of anterior skull base tumors. Dural suturing and graded reconstruction are promising techniques to further decrease the incidence of postoperative CSF (poCSF) leakage. The effect of continuous dural suturing in endoscopic surgery was investigated in this retrospective study. A total of 79 EETSS patients were included; the procedures were performed for subdural tumor removal by a single endoscopic neurosurgical team. Comparisons were applied between patients who did and did not undergo endoscopic dural suturing after tumor removal. Multivariate logistic regression analysis was performed to identify variables that significantly influenced the incidence of poCSF leakage. In all, 79 adult patients developed Esposito's grade 3 intraoperative high-flow CSF leakage. Ten patients (12.7%) experienced poCSF leakage. One of the 36 patients who underwent intraoperative dural suturing developed poCSF leakage, compared with nine of 43 patients who did not undergo dural suturing (p = 0.016). Regression analysis showed that dural suturing could significantly decrease the incidence of poCSF leakage (p = 0.049, OR 0.108, 95% CI 0.013-0.899). Prophylactic lumbar drainage could also help decrease the CSF leakage rate. Dural suturing under endoscopy is a promising and effective method for application in skull base reconstruction after subdural skull base tumor removal. With future progress, lumbar drainage and even nasoseptal flap placement could be replaced in certain groups of patients undergoing EETSS.

Simple dural closure using a knotless barbed suture in endoscopic transsphenoidal surgery: preliminary experience

Background: Several literatures reported that suturing dura was reliable in preventing cerebrospinal fluid (CSF) leak in transsphenoidal surgery. However, suturing and knotting is technically challenging and time consuming in the transsphenoidal approach.Objectives: To simplify the dural suturing procedure, a preliminary study of barbed suturing in endoscopic transsphenoidal surgery was introduced.Material and methods: We retrospectively reviewed the patients underwent dural closure using knotless suturing after endoscopic transsphenoidal surgery from August 2015 to September 2018. In the cases of no or low-flow CSF leak (Kelly's classification grade 0-2), the dura was sutured to restore anatomic structure and prevent postoperative CSF leak. In the cases of high-flow CSF leak (Kelly's classification grade 3), multilayered reconstruction including dural suturing was performed. The suturing time, intra- and postoperative CSF leak were recorded.Results: Thirty-three patients underwent dural barbed suturing. The mean suturing time was about 10 min. Intraoperative CSF leak was encountered in 16 patients, including 7 patients with grade 1 CSF leak, 5 patients with grade 2 CSF leak and 4 patients with grade 3 CSF leak. No one developed into postoperative CSF leak.Conclusion: Dural closure using a barbed suture is a simply and reliable technique.

Soft tissue grafts for dural reconstruction after meningioma surgery

The meninges are involved in various pathologies and are often directly or indirectly severed during surgical procedures, especially the dura mater. This can pose a real challenge for the surgeon, as a proper reconstruction of the meninges is important to prevent complications such as cerebrospinal fluid leak (CSF). A variety of techniques for dural reconstruction have been described, employing natural and artificial materials. A novel technique for dural reconstruction involves soft tissue grafts in the form of fibrous or fibromuscular flaps, which are placed on the dural defects to seal the gaps. These soft tissue grafts represent an appropriate scaffold for cell ingrowth and fibrosis, thus preventing CSF. In this pilot study, we described the application of soft tissue grafts for dural reconstruction in 10 patients who underwent convexity meningioma surgery.

Usefulness of the knot-tightener device following dural suturing in endonasal transsphenoidal surgery: technical report

Transsphenoidal surgery (TSS) has become a well-established standard surgical technique, but the cerebrospinal fluid leakage remains controversial. Direct suturing of the dura, which is a routine procedure within transcranial surgery, can be applied for closure of the sella turcica within TSS. However, as the dura is not accessible by the index finger, knot tying in the narrow and deep surgical corridor following dural suturing is extremely difficult, cumbersome, and time-consuming in TSS. Here, we present a new, simple, and effective technique for knot tying using our newly developed instrument the "knot tightener" (UC-6603: Medical U & A, Inc., Osaka, Japan) to solve this challenge. The knot tightener has a total length of 235 mm and is bayonet shaped. The tip is 5 × 10 mm in diameter and has one long arm and two short curved arms. The long arm has a dimple which can hook and hold a thread, fulfilling the role of an index finger. Together the two short curved arms make a half circle and are able to hook a thread easily. From the 28th of March 2011 to August 2018, we used the knot-tightener device for 566 patients who underwent endonasal TSS, to deliver and tie knots following stitching of the dura using 6-0 nylon. The device was able to easily deliver a knot from outside of the nostril to the sella turcica through the nasal cavity and successfully tighten it firmly. No complications were observed, confirming the safety of the newly designed instrument. The knot tightener can be considered to be an optimal tool for the challenging surgical procedure of knot tying following dural suturing in TSS. Its potential future applications may extend to include other neurosurgical procedures in anatomically restricted areas.

Application of a Minimally Invasive Liposuction Technique for Harvesting Fat during Transsphenoidal Surgery: A Technical Note

Secure reconstruction in transsphenoidal surgery (TSS) is important for the prevention of the major and serious complication of postoperative cerebrospinal fluid (CSF) leak. Although abdominal fat can be safely and effectively used as a reconstruction tissue, harvesting it from the abdominal wall is traumatic and invasive, resulting in cosmetic problems. In this report, we present a method of harvesting abdominal fat using a minimally invasive liposuction technique to avoid cosmetic issues. Since 2016, we have been using fat harvested from the abdominal wall by suctioning with a dedicated syringe for reconstruction after TSS in selected cases. The liquefied fat obtained by the liposuction technique was wrapped with an oxycellulose sheet and changed its form to what we termed “fatty candy”. In this form, the fat maintained its configuration and could be handled almost as easily as a conventional fat graft. In our experienced series, there was no case with wound complication nor postoperative or late-onset CSF leak during a postoperative follow-up of at least 3 months. The fat harvested by this simple and minimally invasive liposuction technique can be expected to provide an autologous graft that is adequate not only for prevention of cosmetic problems but also for prevention of postoperative CSF leak.

Anatomical Risk Factors for Intraoperative Cerebrospinal Fluid Leaks During Transsphenoidal Surgery for Pituitary Adenomas

BACKGROUND

Cerebrospinal fluid (CSF) fistulas are among the most clinically important and frequent complications of transsphenoidal surgery for pituitary adenomas. Between the adenoma and the CSF, a "barrier" exists that consists of ≤3 elements. These, from cephalad to caudad, are the arachnoid, dura mater (sellar diaphragm), and pituitary glandular tissue. The objective of the present study was to determine whether the presence or absence of any of these 3 anatomical elements would be associated with the development of an intraoperative CSF fistula.

METHODS

From November 2016 to June 2018, 40 patients with pituitary adenomas underwent surgery, by transsphenoidal endonasal access, under a microscope. All procedures were filmed in 3 dimensions. The intraoperative findings and preoperative magnetic resonance images were analyzed and compared. The patients who had developed a fistula were compared against those who had not.

RESULTS

In 20 patients, glandular tissue was identified between the tumor and subarachnoid space. In 13, dura mater was evident, and in 7, only the arachnoid was noted. An intraoperative CSF fistula occurred in 6 patients, all of whom had the arachnoid as the only barrier. The presence of a fistula was significantly more likely statistically for patients with an arachnoid-only barrier than for those with any other barrier composition (P < 0.001).

CONCLUSIONS

The anatomical architecture forming the roof of the pituitary fossa is an important determinant of intraoperative CSF fistula risk. When the barrier consists of only the arachnoid, the risk will be significantly greater than when the barrier contains additional elements. Preoperative magnetic resonance imaging would be useful to determine the type of the existing barrier.

Three types of dural suturing for closure of CSF leak after endoscopic transsphenoidal surgery

OBJECTIVE

Transsphenoidal surgery (TSS) is commonly used for anterior skull base surgery, especially in the sella turcica (sellar) region. However, because of its anatomical position, CSF leakage is a major complication of this approach. The authors introduced a new grading reconstruction strategy for anterior skull base surgery with continuous dural suturing in 2013. In this paper the authors report on their methods and results.

METHODS

All patients with sellar or anterior skull base lesions that were removed with TSS or extended TSS by a single neurosurgeon between April 2013 and March 2017 at Nagoya University Hospital and several cooperating hospitals were retrospectively identified. Three methods of suturing dura were considered, depending on the dural defect.

RESULTS

There were 176 TSS cases (141 conventional TSS cases and 35 extended endoscopic TSS cases) and 76 cases of Esposito's grade 2 or 3 intradural high-flow CSF leakage. In the high-flow CSF leak group, there were 3 cases of CSF leakage after the operation. The rates of CSF leakage after surgery corresponding to grades 2 and 3 were 2.9% (1/34) and 4.7% (2/42), respectively.

CONCLUSIONS

Dural suturing is a basic and key method for reconstruction of the skull base, and continuous suturing is the most effective approach. Using this approach, the frequency of cases requiring a nasoseptal flap and lumbar drainage can be reduced.

Sandwich technique using fibrin-coated collagen fleece for sellar reconstruction in large dural defects during transsphenoidal surgery

PURPOSE

Various surgical methods to prevent intraoperative and postoperative cerebrospinal fluid (CSF) leaks during transsphenoidal approach (TSA) surgeries have been reported, but surgical techniques to address large dural defects have been less thoroughly investigated in the literature. The authors retrospectively evaluated the usefulness of the sandwich technique using fibrin-coated collagen fleece (TachoSil) to prevent intraoperative CSF leakage from large dural defects in TSA surgery.

METHODS

In total, 101 cases of intraoperative CSF leaks were observed among 465 patients who underwent TSA surgery at a single university hospital between 2002 and 2014. Among them, cases with Grade 3 intraoperative CSF leakages and large diaphragmatic/dural defects were reconstructed via the sandwich technique using TachoSil or via the conventional technique using simple intrasellar packing with fat or synthetic materials, and these cases were enrolled in this study.

RESULTS

A total of 28 cases with Grade 3 intraoperative CSF leakages were identified and analyzed. The sandwich technique using TachoSil was applied in 13 cases, and the conventional technique was applied in 15 cases. The postoperative CSF leakage was significantly decreased by the sandwich technique as compared to the conventional technique (retrospectively, 0 cases vs. 4 cases (30.8%); P=0.044).

CONCLUSION

The sandwich technique using TachoSil can effectively prevent CSF leakage in cases with large dural defects during TSA surgery.

Cerebrospinal fluid leaks after transsphenoidal surgery - Effect of a polyethylene glycol hydrogel dural sealant

To investigate cerebrospinal fluid (CSF) leak rates after mainly endoscopic endonasal transsphenoidal surgery with and without polyethylene glycol hydrogel dural sealant (DuraSeal®), we prospectively collected data from a single-centre consecutive case series over four years from January 2007 to December 2010 inclusive. 250 patients were identified (135 male, 115 female; median age 52years, range 14-83). 180 patients received DuraSeal® (72%). 85 (34%) had intra-operative dural breach and 13 (5.2%) developed post-operative CSF leaks (3 without intra-operative dural breach) requiring lumbar drainage or formal repair. Of this group 5/251 (2.0%) patients required a formal repair. Post-operative CSF leak was seen in 5/189 (2.7%) of patients with pituitary adenoma, of which 2/5 (40%) were in cases undergoing revision surgery. 5/13 (38.4%) patients who developed a CSF leak presented with either Rathke's cleft cyst or craniopharyngioma. 3/71 patients not receiving DuraSeal® leaked (4.2%) and 10/180 patients receiving DuraSeal® leaked (5.6%). 11/234 patients without Tisseel (4.7%) and 2/16 receiving Tisseel (12.5%) leaked. 54 patients (22%) received intra-operative lumbar drains, one of whom developed subsequent CSF leak (1.9%), in contrast to 12/197 (6.1%) of patients without intra-operative lumbar drains who later developed CSF leak. The rate of post-operative CSF leak requiring re-exploration and nasoseptal flap repair was low (2.0%) in this mainly endoscopic case series without statistically significant benefit from either DuraSeal® or Tisseel. Intra-operative and post-operative lumbar drainage appears beneficial in patients at higher risk of post-operative CSF leak.

Endoscopic management of cerebrospinal fluid rhinorrhea

Cerebrospinal fluid (CSF) rhinorrhea occurs due to communication between the intracranial subarachnoid space and the sinonasal mucosa. It could be due to trauma, raised intracranial pressure (ICP), tumors, erosive diseases, and congenital skull defects. Some leaks could be spontaneous without any specific etiology. The potential leak sites include the cribriform plate, ethmoid, sphenoid, and frontal sinus. Glucose estimation, although non-specific, is the most popular and readily available method of diagnosis. Glucose concentration of > 30 mg/dl without any blood contamination strongly suggests presence and the absence of glucose rules out CSF in the fluid. Beta-2 transferrin test confirms the diagnosis. High-resolution computed tomography and magnetic resonance cisternography are complementary to each other and are the investigation of choice. Surgical intervention is indicated, when conservative management fails to prevent risk of meningitis. Endoscopic closure has revolutionized the management of CSF rhinorrhea due to its less morbidity and better closure rate. It is usually best suited for small defects in cribriform plate, sphenoid, and ethmoid sinus. Large defects can be repaired when sufficient experience is acquired. Most frontal sinus leaks, although difficult, can be successfully closed by modified Lothrop procedure. Factors associated with increased recurrences are middle age, obese female, raised ICP, diabetes mellitus, lateral sphenoid leaks, superior and lateral extension in frontal sinus, multiple leaks, and extensive skull base defects. Appropriate treatment for raised ICP, in addition to proper repair, should be done to prevent recurrence. Long follow-up is required before leveling successful repair as recurrences may occur very late.

A new multilayer reconstruction using nasal septal flap combined with fascia graft dural suturing for high-flow cerebrospinal fluid leak after endoscopic endonasal surgery

This study aimed to evaluate the usefulness and reliability of a new endoscopic multilayer reconstruction using nasal septal flap (NSF) to prevent high-flow cerebrospinal fluid leak after endoscopic endonasal surgery. This study was a retrospective review on 97 patients who underwent multilayer reconstructions using NSF combined with fascia graft dural suturing after endoscopic endonasal surgery between July 2012 and March 2014. Patients were divided into two groups, third ventricle opening group and nonopening group, based on the presence of a direct connection between the third ventricle and the paranasal sinus after tumor removal. Furthermore, we compared this procedure with our previous reconstruction after resection of craniopharyngioma. Finally, we checked the patients who had postoperative prolonged discomfort of the nasal cavity for over a year. Postoperative cerebrospinal fluid (CSF) leak occurred in three patients (3.1 %): one from the third ventricle opening group and the remaining two from the nonopening group. External lumbar drain was performed after surgery in only seven patients (7.2 %). The incidence of postoperative CSF leak was similar in both groups, whereas the rate of craniopharyngioma in the third ventricle opening group was significantly higher. The incidence of postoperative CSF leak after resection of craniopharyngioma was not statistically significant but obviously higher in the previous group (12.2 %) compared with that in the present group (2.3 %). Twelve patients (12.4 %) had postoperative nasal discomfort of the nasal cavity for over a year. Multilayer reconstruction using NSF combined with fascia graft dural suturing is a more reliable method for preventing postoperative high-flow CSF leakage after endoscopic endonasal surgery even if there is a direct connection between the third ventricle and the paranasal sinus. However, we should pay close attention especially to prolonged discomfort of the nasal cavity after harvesting NSF.

Repair and prevention of cerebrospinal fluid leakage in transsphenoidal surgery: a sphenoid sinus mucosa technique

Cerebrospinal fluid (CSF) leakage is a common but sometimes serious complication after transsphenoidal surgery (TSS). To avoid this postsurgical complication, we usually repair the CSF leaking area using an autologous material, such as fat, fascia, or muscle graft and sometimes nasonasal septal flap. In this report, we propose a technique using a novel autologous material, sphenoid sinus mucosa (SSM), to repair intraoperative CSF leakage or prevent it postoperatively. On 26 February 2007, we introduced the technique of using SSM to repair or prevent CSF leakage in TSS. Until 30th of June 2014, we performed 500 TSSs for patients with pituitary or parasellar lesions. They were 195 men and 305 women with a mean age of 48.5 years (range, 5-85 years). We used SSM for patching or suturing the arachnoid laceration or dural defect, in lieu of fat or fascia harvested from abdomen or thigh, or made pedicle flap of SSM instead of nasonasal septal flap to cover the sellar floor. Comparing the previous 539 cases not using these techniques before 26 February 2007, intraoperative CSF leakage increased from 49 to 69.4% (p < 0.0001) due to more aggressive surgical technique, mainly related to more extensive approaches and lesion removals, but the rate of using fat was reduced significantly from 35.5 to 19.4% (p = 0.00021) in small or moderate CSF leaks during TSS without increasing the reoperation rate for postoperative CSF leaks (1.86 vs 1.2%, p = 0.45). The technique of using SSM to repair intraoperative CSF leaks or prevent them postoperatively in TSS was considered useful, effective, less invasive, easier for graft harvesting (same surgical field), and providing natural anatomical reconstruction, without potential donor site morbidity. We can recommend it as a standard method for CSF leaks repair and prevention in TSS.

Cranial Base Repair Using Suturing Technique Combined with a Mucosal Flap for Cerebrospinal Fluid Leakage During Endoscopic Endonasal Surgery

OBJECTIVE

To evaluate a cranial base repair method using the dural suturing technique in combination with a mucosal flap in the endoscopic endonasal approach.

METHODS

We analyzed 190 patients (mean age, 52.3 years; age range, 3-86 years) who underwent 194 endoscopic endonasal approaches. The degree of intraoperative cerebrospinal fluid (CSF) leakage was graded based on previously published criteria: grade 0, absent; grade 1, small; grade 2, moderate; and grade 3, large. Cranial base repair using the dural suturing technique was performed according to the grade of CSF leakage: grades 1 and 2, autologous fat graft anchored by dural suturing covered with a sphenoid sinus mucosal flap, and grade 3, multilayered, inlay sutured and onlay nonsutured fascial grafts covered with a nasoseptal flap.

RESULTS

Intraoperative CSF leakage was observed in 125 of 194 cases (64.4%). The degree of CSF leakage was grade 0 in 69 cases, grade 1 in 51 cases, grade 2 in 30 cases, and grade 3 in 44 cases. A postoperative CSF leak was encountered in 2 of 125 repaired cases (1.6%). Both cases with CSF leak involved grade 3 CSF leak (4.5%), and both were successfully treated with lumbar drainage.

CONCLUSION

Our graded cranial base repair method using the dural suturing technique is simple and reliable.

Sellar Reconstruction and Rates of Delayed Cerebrospinal Fluid Leak after Endoscopic Pituitary Surgery

Objectives Delayed cerebrospinal fluid (CSF) leaks are a complication in transsphenoidal surgery, potentially causing morbidity and longer hospital stays. Sella reconstruction can limit this complication, but is it necessary in all patients? Design Retrospective review. Setting Single-surgeon team (2005-2012) addresses this trend toward graded reconstruction. Participants A total of 264 consecutive patients with pituitary adenomas underwent endoscopic transsphenoidal resections. Sellar defects sizable to accommodate a fat graft were reconstructed. Main outcomes Delayed CSF leak and autograft harvesting. Results Overall, 235 (89%) had reconstruction with autograft (abdominal fat, septal bone/cartilage) and biological glue. Delayed CSF leak was 1.9%: 1.7%, and 3.4% for reconstructed and nonreconstructed sellar defects, respectively (p = 0.44). Complications included one reoperation for leak, two developed meningitis, and autograft harvesting resulted in abdominal hematoma in 0.9% and wound infection in 0.4%. Conclusion In our patients, delayed CSF leaks likely resulted from missed intraoperative CSF leaks or postoperative changes. Universal sellar reconstruction can preemptively treat missed leaks and provide a barrier for postoperative changes. When delayed CSF leaks occurred, sellar reconstruction often allowed for conservative treatment (i.e., lumbar drain) without repeat surgery. We found universal reconstruction provides a low risk of delayed CSF leak with minimal complications.

Use of Tissue Glues in Endoscopic Pituitary Surgery: A Cost Comparison

Background:

Post-operative cerebrospinal fluid (CSF) leaks are a common complication of endoscopic pituitary surgery and account for a significant proportion of hospital costs associated with this procedure. Tisseel® is a tissue glue commonly used as an adjunct in dural repair but is not optimal for this purpose. DuraSeal® has several properties advantageous for dural repair but is not widely accepted in Canada partly due to its increased cost.

Objective:

A cost analysis of DuraSeal® versus Tisseel® in endoscopic pituitary surgery.

Methods:

A cost analysis was performed based on typical endoscopic pituitary surgery cases performed at our tertiary care institution. Operating room, hospital admission, and surgical sealant costs were obtained directly while estimates of patient recovery time and post-operative CSF leak rates were based on consensus values reported in the literature. Outcomes were reported for various possible clinical scenarios of sealant use.

Results:

In a model where surgical sealant is employed only in high-risk cases, use of DuraSeal® allows for a yearly cost savings of at least $4486.72. If surgical sealant is used in all cases, regular use of DuraSeal® versus Tisseel® either marginally reduces yearly costs or increases them by a maximum of $7619.25, depending on the case volume and estimated post-operative CSF leak rate.

Conclusion:

In most clinical scenarios, use of DuraSeal® in endoscopic pituitary surgery may reduce overall yearly hospital costs compared to Tisseel®.

Pontine encephalocele and abnormalities of the posterior fossa following transclival endoscopic endonasal surgery

OBJECT

Transclival endoscopic endonasal surgery (EES) has recently been used for the treatment of posterior fossa tumors. The optimal method of reconstruction of large clival defects following EES has not been established.

METHODS

A morphometric analysis of the posterior fossa was performed in patients who underwent transclival EES to compare those with observed postoperative anatomical changes (study group) to 50 normal individuals (anatomical control group) and 41 matched transclival cases with preserved posterior fossa anatomy (case-control group) using the same parameters. Given the absence of clival bone following transclival EES, the authors used the line between the anterior commissure and the basion as an equivalent to the clival plane to evaluate the location of the pons. Four parameters were studied and compared in the two populations: the pontine location/displacement, the maximum anteroposterior (AP) diameter of the pons, the maximum AP diameter of the fourth ventricle, and the cervicomedullary angle (CMA). All measurements were performed on midsagittal 3-month postoperative MR images in the study group.

RESULTS

Among 103 posterior fossa tumors treated with transclival EES, 14 cases (13.6%) with postoperative posterior fossa anatomy changes were identified. The most significant change was anterior displacement of the pons (transclival pontine encephalocele) compared with the normal location in the anatomical control group (p < 0.0001). Other significant deformities were expansion of the AP diameter of the pons (p = 0.005), enlargement of the fourth ventricle (p = 0.001), and decrease in the CMA (p < 0.0001). All patients who developed these changes had undergone extensive resection of the clival bone (> 50% of the clivus) and dura. Nine (64.3%) of the 14 patients were overweight (body mass index [BMI] > 25 kg/m(2)). An association between BMI and the degree of pontine encephalocele was observed, but did not reach statistical significance. The use of a fat graft as part of the reconstruction technique following transclival EES with dural opening was the single significant factor that prevented pontine displacement (p = 0.02), associated with 91% lower odds of pontine encephalocele (OR = 0.09, 95% CI 0.01-0.77). The effect of fat graft reconstruction was more pronounced in overweight/obese individuals (p = 0.04) than in normal-weight patients (p = 0.52). Besides reconstruction technique, other noticeable findings were the tendency of younger adults to develop pontine encephalocele (p = 0.05) and the association of postoperative meningitis with the development of posterior fossa deformities (p = 0.05). One patient developed a transient, recurrent subjective diplopia; all others remained asymptomatic.

CONCLUSIONS

Significant changes in posterior fossa anatomy that have potential clinical implications have been observed following transclival transdural EES. These changes are more common in younger patients or those with meningitis and may be associated with BMI. The use of a fat graft combined with the vascularized nasoseptal flap appears to minimize the risk of pontine herniation following transclival EES with dural opening.

Reconstructed bone chip detachment is a risk factor for sinusitis after transsphenoidal surgery

OBJECTIVES/HYPOTHESIS

Sphenoid sinusitis is a complication associated with endoscopic transsphenoidal pituitary surgery. Studies that address the relationship between methods of sellar defect reconstruction and postoperative sinusitis are rare. The purpose of this study was to investigate the incidence, the possible risk factors, and the causative pathogens of sphenoid sinusitis after endoscopic transsphenoidal pituitary surgery.

STUDY DESIGN

Prospective cohort study.

METHODS

We performed a prospective analysis of 182 patients with benign pituitary tumor who underwent endoscopic transsphenoidal pituitary surgery and sellar defect reconstruction with bone chip, from July 2008 through July 2011. All patients were followed up with nasal endoscopy for at least 6 weeks.

RESULTS

Fifty-seven (31.3%) patients developed postoperative sphenoid sinusitis. Comparing the sinusitis and nonsinusitis groups, we found that bone chip detachment was a significant risk factor for postoperative sinusitis, with a relative risk of 2.86 (64.1% vs. 22.4%). The most common pathogens present in cases of postoperative sinusitis were methicillin-sensitive Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus.

CONCLUSIONS

Regular follow-up with nasal endoscopy can prevent delayed diagnosis of postoperative sphenoid sinusitis. Culture-directed antibiotics with aggressive endoscopic debridement are an effective treatment for these patients. An optimal reconstruction strategy should be further developed to reduce bone chip detachment and secondary sinusitis.

Incidence and significance of intraoperative cerebrospinal fluid leak in endoscopic pituitary surgery using intrathecal fluorescein

OBJECTIVE

The true rate of intraoperative cerebrospinal fluid (iCSF) leak during pituitary surgery is not well known because small iCSF leaks are easily missed. Our objective is to determine the rate and significance of iCSF leak in endoscopic pituitary surgery with intrathecal (IT) fluorescein administration and determine factors predictive of iCSF leak.

METHODS

IT fluorescein was administered in 203 consecutive endoscopic, endonasal pituitary surgeries. The rate of iCSF leak was noted prospectively and correlated with tumor diameter and volume, gross total resection, and the learning curve. Postoperative CSF leak rate, complications, and nasoseptal flap utility were also investigated.

RESULTS

The rate of iCSF leak was 61% overall, 44% for tumors<2 cm compared to 72% for tumors≥2 cm and 35% for tumors<1.5 cm3 compared to 68% for those≥1.5 cm3 (P<0.001). Postoperative CSF leak was significantly lower after the first 50 cases (0.7% vs. 10%; P<0.005) with overall leak of 3%. For tumors>2 cm, the introduction of nasoseptal flap reduced the rate of postoperative CSF leak from 5.6% to 1.4%. We did not find any complications clearly related with the use of IT fluorescein.

CONCLUSION

The rate of iCSF leak during endoscopic pituitary surgery using IT fluorescein is higher than previously reported. Tumor diameter and volume are best predictors of the risk of iCSF leak. Based on this knowledge and a closure algorithm that includes a lumbar drain and nasoseptal flap for larger tumors (>2.5 cm), we can conclude that the postoperative CSF leak rate remains exceptionally low, particularly once the learning curve is overcome.

Useful 'sliding-lock-knot' technique for suturing dural patch to prevent cerebrospinal fluid leakage after extended transsphenoidal surgery

BACKGROUND

Postoperative cerebrospinal fluid (CSF) leakage is a major problematic complication after extended transsphenoidal surgery (TSS). Watertight closure of the sellar dura with a fascial patch graft is a method of choice for preventing CSF leakage; however, suturing and knotting in a deep and narrow operative field is technically challenging and time consuming. To present a simple and effective knotting technique named the 'sliding-lock-knot' technique, in which the knot can easily be slid to the suturing point and tied automatically using only a single string, without loosening.

METHODS

We use a 6-0 nylon suture and Mosquito forceps. At first, after putting a stitch, a single knot is made by hand out of the nasal cavity. Then the 'sliding-lock-knot' is made using a forceps as shown in the illustration. The knot slides deep into the operative field through the nostril and it is automatically tied only by pulling a string.

RESULTS

A 73-year-old woman presented with progressive visual deterioration. She had an intra-and suprasellar craniopharyngioma that was compressing the optic chiasm. She underwent an extended TSS, and the tumor was totally resected. The dural defect was closed with a fascial patch graft sutured on the dura using this technique, then covered with a vascularized mucoseptal flap. Neither CSF leakage nor meningitis was encountered during the postoperative period.

CONCLUSION

The 'sliding-lock-knot' technique is simple and useful for dural suturing in microscopic/endoscopic extended TSS. This technique is a helpful tool for preventing CSF leakage after this challenging surgical procedure.

Barrier-limited multimodality closure for reconstruction of wide sellar openings

BACKGROUND

Obtaining a watertight reconstruction with a fat graft with wide sellar exposures can be challenging, including the risk of reinstating mass effect with the fat graft. The alternative, a vascularized pedicle nasoseptal flap, may require several days to heal and still has a > 5% cerebrospinal fluid (CSF) leak rate.

OBJECTIVE

To assess the efficacy of a barrier-limited multimodality (BLMM) closure, consisting of an autograft fat-based watertight seal and limited by a membrane barrier, together with the vascularized nasoseptal flap.

METHODS

This is a retrospective review of 27 consecutive patients undergoing endonasal cranial base surgery limited to the sellar-parasellar region at the UCLA Medical Center who experienced an intraoperative CSF leak that was repaired with the BLMM technique. The results of 43 prior case-controlled reconstructions using a nasoseptal flap, without the full BLMM technique, were analyzed as a comparison group.

RESULTS

There were no postoperative CSF leaks in the patients reconstructed with the BLMM closure technique. The CSF leak rate for the comparison group receiving nasoseptal flaps was 19%.

CONCLUSION

A BLMM closure may further decrease the incidence of postoperative CSF leaks compared with predominant reliance on a nasoseptal flap. The novel membrane barrier allows a watertight inner closure by preventing herniation of the fat autograft into the resection cavity. An outer-layer nasoseptal flap provides a living barrier for optimal long-term defense.

Elevated body mass index and risk of postoperative CSF leak following transsphenoidal surgery

OBJECT

Postoperative CSF leakage can be a serious complication after a transsphenoidal surgical approach. An elevated body mass index (BMI) is a significant risk factor for spontaneous CSF leaks. However, there is no evidence correlating BMI with postoperative CSF leak after transsphenoidal surgery. The authors hypothesized that patients with elevated BMI would have a higher incidence of CSF leakage complications following transsphenoidal surgery.

METHODS

The authors conducted a retrospective review of 121 patients who, between August 2005 and March 2010, underwent endoscopic endonasal transsphenoidal surgeries for resection of primarily sellar masses. Patients requiring extended transsphenoidal approaches were excluded. A multivariate statistical analysis was performed to investigate the association of BMI and other risk factors with postoperative CSF leakage.

RESULTS

In 92 patients, 96 endonasal endoscopic transsphenoidal surgeries were performed that met inclusion criteria. Thirteen postoperative leaks occurred and required subsequent treatment, including lumbar drainage and/or reoperation. The average BMI of patients with a postoperative CSF leak was significantly greater than that in patients with no postoperative CSF leak (39.2 vs 32.9 kg/m(2), p = 0.006). Multivariate analyses indicate that for every 5-kg/m(2) increase in BMI, patients undergoing a transsphenoidal approach for a primarily sellar mass have 1.61 times the odds (95% CI 1.10-2.29, p = 0.016, by multivariate logistic regression) of having a postoperative CSF leak.

CONCLUSIONS

Elevated BMI is an independent predictor of postoperative CSF leak after an endonasal endoscopic transsphenoidal approach. The authors recommend that patients with BMI greater than 30 kg/m(2) have meticulous sellar reconstruction at surgery and close monitoring postoperatively.

Clinical efficacy of radiation-sterilized allografts for sellar reconstruction after transsphenoidal surgery

OBJECTIVE

The aim of this study was to assess the safety and efficacy of radiation-sterilized allografts of iliac bone and fascia lata from cadaver specimens to repair skull base defects after transsphenoidal surgery.

METHODS

Between May 2009 and January 2010, 31 consecutive patients underwent endonasal transsphenoidal surgery and all patients received sellar reconstruction using allografts following tumor removal. The allografts were obtained from the local tissue bank and harvested from cadaver donors. The specimens used in our approach were tensor fascia lata and the flat area of iliac bone. For preparation, allografts were treated with gamma irradiation after routine screening by culture, and then stored at -70℃.

RESULTS

The mean follow-up period after surgery was 12.6 months (range, 7.4-16 months). Overall, postoperative cerebrospinal fluid (CSF) leaks occurred in three patients (9.7%) and postoperative meningitis in one patient (3.2%). There was no definitive evidence of wound infection at the routine postoperative follow-up examination or during re-do surgery in three patients. Postoperative meningitis in one patient was improved with the use of antibiotics and prolonged CSF diversion.

CONCLUSION

We suggest that allograft materials can be a feasible alternative to autologous tissue grafts for sellar reconstruction following transsphenoidal surgery under selected circumstances such as no or little intraoperative CSF leaks.

Transnasal trans-sphenoidal endoscopic repair of CSF leak secondary to invasive pituitary tumours using a nasoseptal flap

Cerebrospinal fluid (CSF) leak following initiation of Dopamine agonist therapy for macroprolactinomas, although uncommon, has been described previously in the literature. Traditional management includes primary repair of the defect using either fat or fascia lata in conjunction with lumbar drain insertion. In this case series we outline two cases of CSF leak secondary to invasive pituitary tumour that were repaired successfully using a nasoseptal flap. We believe that this form of repair is effective and associated with minimal morbidity.

Low-grade CSF leaks in endoscopic trans-sphenoidal pituitary surgery: efficacy of a simple and fully synthetic repair with a hydrogel sealant

BACKGROUND

Intra-operative CSF leak during endoscopic trans-sphenoidal surgery is not uncommon. Surgical repair with a variety of autologous grafts, rigid buttresses and CSF diversion techniques that add time and complexity have been reported.

OBJECTIVE

To describe a simple and purely synthetic closure for low-grade CSF leaks following endoscopic trans-sphenoidal pituitary surgery.

METHODS

A retrospective review of all endoscopic trans-sphenoidal surgery undertaken for pituitary pathology between 2005 and 2010 was carried out. The grade of CSF leak and success of graded repair was noted. Patients with no CSF leak (grade 0) had gelatin sponge placed in the tumour cavity. In those with low-grade CSF leak through small arachnoid defects (grade 1), repair was carried out using gelatin sponge and hydrogel sealant overlay. CSF diversion was not employed for low-grade CSF leaks.

RESULTS

Of the 255 endoscopic trans-sphenoidal surgeries, 158 (62%) had no leak (grade 0) and 74 (29%) had a low-grade leak (grade 1). Repairs in all cases were of grade 0, and all but two cases of grade 1 CSF leak were successful at a mean follow-up of 29 months. The 2 (2.7%) post-operative CSF leaks were seen within 6 weeks of surgery. Both cases were related to bouts of sneezing and were repaired using further trans-sphenoidal surgery and/or lumbar CSF diversion.

CONCLUSIONS

A simple purely synthetic repair of low-grade CSF leaks is described. This repair is safe and comparable in efficacy whilst avoiding the morbidity related to more complex sellar reconstructions previously described.