Gasket seal closure for extended endonasal endoscopic skull base surgery: efficacy in a large case series

Long term results with medpor® reconstruction of the anterior skull base at a single institute

OBJECTIVES

To evaluate a technique of multi-layered CSF repair following endonasal anterior skull base surgery using medpor graft.

DESIGN

Retrospective review of consecutive case series from a single centre.

SUBJECTS

68 cases of repair of CSF leaks utilising medpor identified from a larger prospectively maintained database of endonasal endoscopic procedures at our centre.

METHODS

Retrospective review of a database of consecutive anterior skull base cases from 2016-2022, and further data collection from electronic hospital records.

RESULTS

During follow up there were 7 cases of post-op CSF leak (10.3%). There were no radiological complications, and no cases of medpor removal or extrusion. Rates of infection were low, there were 3 (4.4%) cases of confirmed bacterial meningitis within our cohort. The mean length of stay was 4.7 days (median 3 days), with 16 cases discharged on the first post-operative day.

CONCLUSIONS

Our experience of using medpor in anterior skull base reconstruction demonstrates that medpor is a readily available, easily handled, and reliable graft option with relatively low rates of infection and post-op CSF leak. Its use reduces the use of autologous graft materials and the associated donor site morbidity. Our long term follow up data further demonstrates the safety and efficacy of this technique.

Visual outcomes in tuberculum sellae meningiomas comparing transcranial and endoscopic endonasal approaches

Background

Tuberculum sellae meningiomas (TSM) account for 3-10% of intracranial meningiomas. Visual loss is the presenting symptom in up to 80% of cases. Surgical management poses a great challenge due to tumor proximity to neurovascular structures such as the optic nerve and the internal carotid artery (ICA); hence, there is controversy regarding the optimal approach. The aim of this study is to determine differences in visual outcomes between transcranial (TCA) and endoscopic endonasal (EEA) approaches.

Methods

A retrospective study including 29 patients with TSM surgically treated by TCA or EEA between 2011 and 2023 in a single referral center was conducted. Pre-and post-operative neuro-ophthalmologic evaluations, focusing on visual acuity and campimetry, were evaluated.

Results

Sixteen (55.16%) patients were intervened through a TCA and the remaining 13 (44.84%) via an EEA. The lesions in each group were similar in terms of pre- operative volume (15.12 vs 12.9 cm3, p = 0.497) and neurovascular invasion (optic canal invasion 48.26 vs 41.37%, p = 0.664; ICA 44.81 vs 31.03%, p = 0.797). There were no significant differences in visual outcomes between both approaches; TCA presented an improvement of 5.18 points in visual fields (p = 0.140), whereas EEA had an improvement of 17.39 points in visual acuity (p = 0.114).

Conclusion

EEA seems to offer greater improvement in visual acuity than TCA. However, the ideal approach should be individualized; taking into account the tumor's volume and invasiveness, as well as the patient's visual complaints.

Safety and efficacy of hydroset cranioplasty as an adjunct to gasket-seal and nasoseptal flap closure of the skull base. A case-controlled study

BACKGROUND

Cerebrospinal fluid leak after endoscopic skull base surgery remains a significant complication. Several investigators have suggested Hydroset cranioplasty to reduce leak rates. We investigated our early experience with Hydroset and compared the rate of nasal complications and CSF leak rates with case-controlled historic controls.

METHODS

We queried a prospective database of patients undergoing first time endoscopic, endonasal resection of suprasellar meningiomas and craniopharyngiomas from 2015 to 2023. We compared cases closed with a gasket seal, Hydroset, and a nasoseptal flap with those closed with only a gasket seal and nasoseptal flap. Demographics, technical considerations and postoperative outcomes (SNOT-22) were compared.

RESULTS

Seventy patients met inclusion criteria, twenty patients in the Hydroset group (meningioma n = 12; craniopharyngioma n = 8) and 50 control patients (meningioma n = 25; craniopharyngioma n = 25). CSF diversion was used in fewer Hydroset patients (75%, 15/20) compared with control group (94%, 47/50; p = 0.02). CSF leak was less frequent in the Hydroset than the control group (5% versus 12%, p = 0.38). One Hydroset patient required delayed nasal debridement. SNOT-22 responses demonstrated no significant difference in sinonasal complaints between groups (Hydroset average SNOT-22 score 22.45, control average SNOT-22 score 25.90; p = 0.58).

CONCLUSIONS

We demonstrate that hydroxyapatite reconstruction leads to improved CSF leak control above that provided by the gasket-seal and nasoseptal flap, without significant associated morbidity as long as the cement is fully covered with vascularized tissue.

Comparative analysis of transnasal endoscopic reconstruction techniques for managing cerebrospinal fluid rhinorrhea in skull base defects

The nasal skull base is located into the deep position of nasal cavity and closely related to important nerves and vessels. The complete removal of tumors in this area poses a complex surgical challenge.In order to investigate the clinical efficacy of utilizing free middle turbinate mucosa (FMT), fascia lata, and pedicled nasal septum flap (known as the Hadad-Bassagasteguy flap, HBF) for the treatment of cerebrospinal fluid (CSF) rhinorrhea, a retrospective analysis was conducted on clinical data from 65 patients who underwent skull base reconstruction following endoscopic resection of nasal-skull base tumors. The selection of the repair material was based on the size and location of the defect. For defects less than 1.5 cm (n = 24), FMT was chosen, while for defects greater than or equal to 1.5 cm (n = 16), HBF was preferred. In cases where HBF was not available or not suitable (specifically, when the defect was located on the posterior wall of the frontal sinus), fascia lata was selected (n = 25). The repair outcomes of all 65 patients were summarized, and subsequently, a comparison was made between the use of fascia lata and HBF. The overall success rate for one-time repairs was 93.8 %. Specifically, the success rates for repairs using FMT, fascia lata, and HBF were 91.7 %, 96.0 %, and 93.8 %, respectively. Throughout the follow-up period, there were 2 cases of postoperative CSF leakage out of 24 patients who underwent FMT reconstruction, 1 case out of 25 patients who underwent fascia lata reconstruction, and 1 case out of 16 patients who underwent HBF reconstruction. The occurrence of postoperative complications, such as intracranial infection, lung infection, and epistaxis, was observed in both the fascia lata group and the HBF group. However, there were no statistically significant differences between the two groups. The transnasal endoscopic reconstruction of skull base defect using HBF, fascia lata, and FMT demonstrated satisfactory repair effects in managing CSF rhinorrhea. Generally, FMT has been found to be a dependable repair material for small defects measuring less than 1.5 cm, while in the case of larger defects equal to or exceeding 1.5 cm, both HBF and fascia lata can be utilized with comparable repair outcomes. The selection of fascia lata becomes a viable option when HBF is unavailable or not suitable.

Clinical and Surgical Outcomes of Endoscopic Endonasal Approach for Giant Pituitary Adenomas: Analysis of Predictive Factors

BACKGROUND

Giant pituitary adenomas (GPAs) are defined as tumors with ≥40 mm in any maximum diameter, and these tend to invade multiple intracranial compartments. Hence, treatment remains a surgical challenge.

OBJECTIVE

To describe the clinical and surgical outcomes of the endoscopic endonasal approach (EEA) for GPA in a pituitary referral center in Latin America and to analyze associated predictive factors.

METHODS

37 patients with histologically-confirmed GPA treated solely through the EEA between a 2-year period were included. Preoperative and postoperative clinical and neuroimaging findings; surgical morbidity and mortality; and binary logistic regression analysis to assess predictive factors were analyzed.

RESULTS

Preoperative visual impairment prevalence was 97.3%. Mean tumor volume was 32 cc and gross total resection rate was 40.5%. Favorable visual acuity and visual fields outcome rate was 75% and 82.9%, respectively. In the multivariate analysis, bilateral cavernous sinus invasion (P = 0.018) and postoperative cerebrospinal fluid (CSF) leak (P = 0.036) were associated with an unfavorable visual acuity outcome, while radiation therapy (P = 0.035) was for visual fields. Similarly, intraoperative CSF leak was a predictive factor for postoperative CSF leak (10.8%) (P = 0.042) and vascular injury (13.5%) (P = 0.048).

CONCLUSIONS

In this first Mexican clinical series, we demonstrated that the EEA is a safe and effective technique for GPA, although early diagnosis and prompt intervention may promote further visual function preservation without significant endocrine morbidity.

Validity of the flap risk score in predicting nasoseptal flap use after endoscopic transsphenoidal pituitary mass resection

Introduction

There remains a paucity of literature examining the decision algorithm for use of nasoseptal flap (NSF) after endoscopic endonasal approaches (EEA) to pituitary adenoma resection. In 2018, we published the first ever flap risk score (FRS) to predict the use of NSF. We present here a validity study examining the FRS as applied to our center.

Methods

A retrospective review was completed of consecutive patients undergoing EEA from January 2015 to March 2021. The sensitivity, specificity, and predictive value of the FRS were calculated. A multivariate logistic model was used to determine the relative weight imaging characteristics in predicting need for NSF. The relative weighting of the FRS was then re-optimized.

Results

A total of 376 patients underwent EEA for pituitary adenoma resection, with 113 (30.1%) requiring NSF. The FRS had a sensitivity and specificity of 43.4% and 94.7%, respectively. Sphenoid sinus extension increased the odds of needing a NSF equivalent to 19 mm of tumor height, as opposed to 6 mm in the original 2018 cohort. The re-optimized model had sensitivity and specificity of 79.6% and 76.4%, respectively.

Conclusion

We present a validity study examining the utility of FRS in predicting the use of NSF after EEA for pituitary adenoma resection. Our results show that while FRS is still predictive of the need for NSF after EEA, it is not as predictive now as it was for its original cohort. Therefore, a more comprehensive model is necessary to more accurately stratify patients' preoperative risk for NSF.

Reliability of High-resolution Gadolinium-enhanced MR Cisternography and Gasket-seal Technique for Management of Anterior Skull Base Defects

PURPOSE

Precise preoperative localization of anterior skull base defects is important to plan surgical access, increase the success rate and reduce complications. A stable closure of the defect is vital to prevent recurrence of cerebrospinal fluid (CSF) rhinorrhea. The purpose of this retrospective case series was to evaluate the reliability of a new high-resolution gadolinium-enhanced compressed-sensing SPACE technique (CS T1 SPACE) for magnetic resonance (MR) cisternography to detect cerebrospinal fluid leaks of the anterior skull base and to assess the long-term success rate of the gasket-seal technique for closure of skull base defects.

METHOD

All patients with spontaneous or postoperative cerebrospinal fluid rhinorrhea and defects of the anterior skull base presenting to the Departments of Otorhinolaryngology and Neurosurgery between 2019 and 2020, receiving a computed tomography (CT) cisternography and MR cisternography (on a 3T whole-body MR scanner using a 64-channel head and neck coil) with CS T1 SPACE sequence and closure of the defect with the gasket-seal technique, were enrolled in the study. For the cisternography, iodinated contrast agent (15 ml Solutrast 250 M®), saline (4 mL) mixed with a 0.5 mL of gadoteridol was injected into the lumbar subarachnoid space.

RESULTS

A total of four patients were included in the study and MR cisternography with CS T1 SPACE sequence was able to precisely localize CSF leaks in all patients. The imaging results correlated with intraoperative findings. All defects could be successfully closed with the gasket-seal technique. The mean follow-up was 35.25 months (range 33-37 months).

CONCLUSION

MR cisternography with CS T1 SPACE sequence could be a promising technique for precise localization of CSF leaks and the gasket-seal technique resulted in good closure of the CSF fistula in this case series.

Endoscopic Sellar Defect Reconstruction with Avascular Modified Gasket Seal Technique for Sellar Tumors

Watertight repair of the skull base defect is necessary during endonasal skull base surgery to avoid postoperative CSF leak (poCSFl) and consequent intracranial complications. Various techniques have been described for reconstructing sphenoid-sellar defects with varying success rates. We have described the immediate and long-term outcomes following the reconstruction of sphenoid-sellar defects with our technique. A retrospective analysis of the patients following transsphenoidal sellar surgery underwent barrier restoring reconstruction by multi-layered (inlay-overlay) with autologous thigh fat, fascia lata, fibrin glue, knitted collagen, and absorbable gelatin sponge (modified gasket seal technique). A total of 44 patients were included in the study (n = 44). Reconstruction with modified gasket seal technique was done for all patients. 26 (59.1%) had intraoperative CSF leak (ioCSFl), and 9 (20.4%) patients had grade 3 Esposito-Kelly ioCSFl requiring adjunct short-term pressure reducing procedure (Lumbar drain) intraoperatively. 11/44 (25%) had poCSFl, 7/11 patients with poCSFl were managed conservatively, and 4/11 patients required rescue second surgery and ventriculoperitoneal shunting. 1 (2.3%) had severe meningitis and succumbed to it. Pneumocephalus was seen in 6 (13.6%). Multivariate analysis showed that revision surgery, GH-secreting tumors, and defects extending to the suprasellar region had higher chances of poCSFl (p < 0.001). All 43 alive patients had no CSF leak on long-term follow-up. The modified gasket seal technique is a viable technique for endoscopic sellar reconstruction for ioCSFl with an immediate success rate of 79.6% and 97.72% in the long term in preventing the postoperative CSF leak with a 13.6% rate of meningitis.

Sphenoid Sinus Mucosal Flap after Transsphenoidal Surgery-A Systematic Review

Background and Objectives: Skull base reconstruction is a crucial step during transsphenoidal surgery. Sphenoid mucosa is a mucosal membrane located in the sphenoid sinus. Preservation and lateral shifting of sphenoid mucosa as sphenoid mucosal flap (SMF) during the transsphenoidal exposure of the sella may be important for later closure. This is the first systematic review to evaluate the utility of sphenoid mucosal flap for sellar reconstruction after transsphenoidal surgery. Materials and Methods: A systematic literature search was performed in January 2023: Cochrane, EMBASE, PubMed, Scopus, and Web of Science. The following keywords and their combinations were used: "sphenoid mucosa", "sphenoid sinus mucosa", "sphenoid mucosal flap", "sphenoid sinus mucosal flap". From a total number of 749 records, 10 articles involving 1671 patients were included in our systematic review. Results: Sphenoid sinus mucosa used to be applied for sellar reconstruction as either a vascularized pedicled flap or as a free flap. Three different types of mucosal flaps, an intersinus septal flap, a superiorly based flap and an inferiorly based flap, were described in the literature. Total SMF covering compared to partial or no SMF covering in sellar floor reconstruction resulted in fewer postoperative CSF leaks (p = 0.008) and a shorter duration of the postoperative lumbar drain (p = 0.003), if applied. Total or partial SMF resulted in fewer local complications (p = 0.012), such as fat graft necrosis, bone graft necrosis, sinusitis or fungal infection, in contrast to no SMF implementation. Conclusions: SMF seems to be an effective technique for skull base reconstruction after transsphenoidal surgery, as it can reduce the usage of avascular grafts such as fat along with the incidence of local complications, such as fat graft necrosis, bone graft necrosis, sinusitis and fungal infection, or it may improve the sinonasal quality of life by maintaining favorable wound healing through vascular flap and promote the normalization of the sphenoid sinus posterior wall. Further clinical studies evaluating sphenoid mucosal flap preservation and application in combination with other techniques, particularly for higher-grade CSF leaks, are required.

Intraoperative ultrasound-assisted endoscopic endonasal transclival marsupialization of an ectopic retrosellar Rathke's cleft cyst: A rare case illustration and systematic review of the literature

Not every Rathke's cleft cyst (RCC) is confined within the sella between the posterior and anterior lobes of the pituitary gland. Intracranial ectopic RCCs are extremely rare, with only seven cases reported in the literature. In this study, the authors presented a rare case of a symptomatic ectopic retrosellar RCC posterior to the pituitary gland, causing extensive clival erosion. The surgical nuances of the wide marsupialization of the cyst through intraoperative ultrasound-assisted endoscopic endonasal transclival approach are described, and a systematic literature review of intracranial ectopic RCCs is conducted.

Dural reconstruction with or without a bone graft of paranasal and anterior skullbase malignancies: Retrospective single-center analysis of 11 cases and review of literature

Introduction

The reconstruction of frontobasal defects following oncologic resections of paranasal and anterior skull base (ASB) malignancies remains challenging. Ineffective reconstruction could lead to cerebrospinal fluid leak, meningitis, and tension pneumocephalus.

Research question

Aim of this investigation was to analyse postoperative complication rates with or without bone graft for anterior skull base reconstruction.

Material and methods

In this retrospective study, we included patients following resection of paranasal and/or anterior skull base malignancies between October 2013 and December 2022. Complications were analysed with regards to the type of skull base reconstruction.

Results

Eleven patients were identified (2 female, 9 male, age (median, SD) 64 ± 14.1 years (range 38-81). There were nine cases of paranasal sinus and nasal cavity carcinomas and two cases of olfactory neuroblastomas. Overall survival was 22.5 ± 28 months (range: 5-78), progression free survival was 17.0 ± 20.3 months (range: 11-78). Bone skull base reconstruction using a split graft was performed in three cases. Postoperative complications requiring surgical intervention were seen in 33% (one tension pneumocephalus) of cases in the bone reconstruction group and 50% (three patients with cerebrospinal fluid leak, one infection) in the non-bone reconstruction group.

Discussion and conclusion

The structural reinforcement of structural bone chip grafting might provide additional support of the ASB and prevent CSF leakage or encephalocele. Especially in large (>10 cm2) bone defects of advanced sinonasal malignancies extending into the middle cranial fossa, the full armamentarium of reconstruction possibilities should be considered.

Multilayer Anterior Skull Base Reconstruction with Cortical Rib Bone Graft: Preliminary Experience

OBJECTIVE

During the past decades, different methods have been described for anterior skull base reconstruction. Regarding larger skull base defects, few investigators have described the use of bone grafts to foster support and prevent frontal lobe sagging, herniation, or falling. The aim of this study is to describe the use of a rib bone graft, which could be an option in these cases due to its rigidity and dimensions.

METHODS

We retrospectively collected preoperative, intraoperative, and postoperative data at the last follow-up of 10 patients who underwent multilayer anterior skull base reconstruction, including rib bone graft, for large anterior cranial base defects at 2 tertiary care academic hospitals.

RESULTS

Eight patients underwent endoscopic craniectomy for sinonasal malignancies, and the other two underwent transnasal endoscopic surgery for congenital meningoencephalocele. Anterior skull base defects measured on average 3.8 cm ± 0.9 SD antero-posteriorly (range 2.5-5 cm) and 2.3 ± 0.9 SD latero-laterally (range 0.9-4 cm). Multilayer reconstruction was performed in all cases, including a rib bone graft positioned as intracranial extradural layer. No patient experienced thoracic complications during the postoperative period. No side effects related to the bone graft or meningoencephalocele occurrence were reported after a mean follow-up of 8.0 ± 6.3 months.

CONCLUSIONS

The use of a cortical rib bone graft could be a safe and effective option in skull base reconstruction when managing large defects after cancer removal.

"In situ bone flap" combined with vascular pedicled mucous flap to reconstruction of skull base defect

BACKGROUND

At present, neuroendoscopy technology has made rapid development, and great progress has been made in the operation of lesions in the saddle area of the skull base. However, the complications of cerebrospinal fluid and intracranial infection after the operation are still important and life-threatening complications, which may lead to poor prognosis.

AIM

To investigate the method of in situ bone flap combined with nasal septum mucosal flap for reconstruction of enlarged skull base defect by endonasal sphenoidal approach and to discuss its application effect.

METHODS

Clinical data of 24 patients undergoing transnasal sphenoidal endoscopic approach in the Department of Neurosurgery, Affiliated 2 Hospital of Nantong University from January 2019 to December 2022 were retrospectively analyzed. All patients underwent multi-layer reconstruction of skull base using in situ bone flap combined with nasal septum mucosa flap. The incidence of intraoperative and postoperative cerebrospinal fluid leakage and intracranial infection were analyzed, and the application effect and technical key points of in situ bone flap combined with nasal septum mucosa flap for skull base bone reconstruction were analyzed.

RESULTS

There were 5 cases of high flow cerebrospinal fluid (CSF) leakage and 7 cases of low flow CSF leakage. Postoperative cerebrospinal fluid leakage occurred in 2 patients (8.3%) and intracranial infection in 2 patients (8.3%), which were cured after strict bed rest, continuous drainage of lumbar cistern combined with antibiotic treatment, and no secondary surgical repair was required. The patients were followed up for 8 to 36 months after the operation, and no delayed cerebrospinal fluid leakage or intracranial infection occurred during the follow-up. Computed tomography reconstruction of skull base showed satisfactory reconstruction after surgery.

CONCLUSION

The use of in situ bone flap combined with vascular pedicled mucous flap to reconstruction of skull base defect after endonasal sphenoidal approach under neuroendoscopy has a lower incidence of cerebrospinal fluid leakage and lower complications, which has certain advantages and is worthy of clinical promotion.

Efficacy of hydroxyapatite-based skull base reconstruction for intraoperative high-flow cerebrospinal fluid leakage performed by less-experienced surgeons

Cerebrospinal fluid (CSF) leakage after endoscopic skull base surgery remains a challenge despite multilayer reconstruction including nasoseptal flap (NSF) has become a standard technique. Injectable hydroxyapatite (HXA) has shown promising results to prevent CSF leakage. This study aimed to validate the efficacy of HXA-based skull base reconstruction performed by less-experienced neurosurgeons who had short-term clinical experiences as independent surgeons. Between March 2018 and November 2022, 41 patients who experienced intraoperative high-flow CSF leakage following endoscopic endonasal surgery at two independent tertiary institutions were enrolled. Skull base reconstruction was performed using conventional multilayer techniques combined with or without HXA. The primary outcome was postoperative CSF leakage. The surgical steps and nuances were described in detail. The most common pathology was craniopharyngioma. Injectable HXA was used in 22 patients (HXA group) and conventional techniques were performed in 19 patients (control group). The HXA group achieved a significantly lower incidence of postoperative CSF leakage than the control group (0% vs. 26.3%, p = 0.016). No HXA-related complications were observed. The use of injectable HXA in skull base reconstruction was highly effective and safe. This technique and its favorable results might be readily reproduced by less-experienced neurosurgeons.

Multi-layered repair of high-flow CSF fistulae following endoscopic skull base surgery without nasal packing or lumbar drains: technical refinements to optimise outcome

AIMS

Post-operative CSF leak remains a significant problem following endoscopic skull base surgery, particularly when there is a high-flow intra-operative CSF leak. Most skull base repair techniques are accompanied by the insertion of a lumbar drain and/or the use of nasal packing which have significant shortcomings. Our aim was to review the results of a large series of endoscopic skull base cases where a high-flow intra-operative CSF leak rate was encountered and repaired to assess if modifications in technique could reduce the post-operative CSF leak rate.

METHODS

A retrospective review of a prospectively maintained database of skull base cases performed by a single surgeon over a 10-year period was performed. Data regarding patient demographics, underlying pathology, skull base repair techniques and post-operative complications were analysed.

RESULTS

One hundred forty-two cases with high-flow intra-operative CSF leak were included in the study. The most common pathologies were craniopharyngiomas (55/142, 39%), pituitary adenomas (34/142, 24%) and meningiomas (24/142, 17%). The CSF leak rate was 7/36 (19%) when a non-standardised skull base repair technique was used. However, with the adoption of a standardised, multi-layer repair technique, the post-operative CSF leak rate decreased significantly (4/106, 4% vs. 7/36, 19%, p = 0.006). This improvement in the rate of post-operative CSF leak was achieved without nasal packing or lumbar drains.

CONCLUSION

With iterative modifications to a multi-layered closure technique for high-flow intra-operative CSF leaks, it is possible to obtain a very low rate of post-operative CSF leak, without lumbar drains or nasal packing.

Intradural fat graft packing is not indispensable in preventing postoperative cerebrospinal fluid leakage in endoscopic endonasal pituitary adenoma surgeries

Objectives

Is intradural fat graft packing indispensable in preventing postoperative cerebrospinal fluid leakage in endoscopic endonasal pituitary adenoma surgeries? This study aimed to review the methods and outcomes of our graded sellar floor reconstruction strategy without fat graft packing in endoscopic endonasal pituitary adenoma surgeries.

Methods

From March 2018 to December 2022, 200 patients underwent endoscopic endonasal pituitary adenoma resection by a single author in our institute. We applied different graded skull base reconstruction strategies in different periods. Intradural fat graft packing was used to reconstruct the skull base in the early period, from March 2018 to June 2019, but fat graft was not used in the late period, from January 2020 to December 2022. The effect of these different graded skull base reconstruction strategies and whether intradural fat graft packing is necessary were evaluated by observing the incidence of postoperative cerebrospinal fluid leak.

Results

In the early period, fat graft was used to reconstruct skull base when the intraoperative cerebrospinal fluid (CSF) leakage existed. There were two patients who suffered from postoperative cerebrospinal fluid leak in this group. In the late period, fat graft was not used to reconstruct the skull base, and no patient suffered from postoperative cerebrospinal fluid leakage in this group.

Conclusions

Intradural fat graft packing is unnecessary in the endoscopic endonasal pituitary adenoma resection. The outcome of our graded sellar floor reconstruction strategy is satisfactory.

Long-term Outcomes of Non-vascularized Multilayer Fascial Closure Technique for Dural Repair in Endoscopic Transnasal Surgery: Efficacy, Durability, and Limitations

OBJECTIVE

Non-vascularized multilayer fascial closure technique (NMFCT) can be used instead of nasoseptal flap reconstruction for dural repair in endoscopic transnasal surgery (ETS); however, due to the lack of blood supply, its long-term durability and possible limitations need to be clarified.

METHODS

This was a retrospective study on patients who underwent ETS with intraoperative cerebrospinal fluid (CSF) leakage. We assessed the postoperative and delayed CSF leakage rates and the associated risk factors.

RESULTS

Among 200 ETSs with intraoperative CSF leakage, 148 (74.0%) ETSs were performed for skull base pathologies other than pituitary neuroendocrine tumor. The mean follow-up period was 34.4 months. Esposito grade 3 leakage was confirmed in 148 (74.0%) cases. NMFCT was used either with (67 [33.5%]) or without (133 [66.5%]) lumbar drainage. There were 10 cases (5.0%) of postoperative CSF leakage that necessitated reoperation. In 4 other cases (2.0%), CSF leakage was suspected but lumbar drainage alone successfully restored the condition. Multivariate logistic regression analyses revealed that posterior skull base location (P < 0.01, odds ratio 11.5, 95% CI 1.99-2.17 × 102) and craniopharyngioma pathology (P = 0.03, odds ratio 9.4, 95% CI 1.25-1.92 × 102) were significantly associated with postoperative CSF leakage. No delayed leakage occurred during the observation period except for 2 patients who underwent multiple radiotherapies.

CONCLUSIONS

NMFCT is a reasonable alternative with long-term durability, though vascularized flap may be a better choice for cases in which vascularity of the surrounding tissues is significantly impaired due to interventions including multiple radiotherapies.

Formal Closure of Endoscopic Endonasal Skull Base Defects With a "Bow Tie" Tri-Layer Graft

OBJECTIVE

Risk factors for a postoperative cerebrospinal fluid leak (CSF) after surgery include an intraoperative high flow of CSF, elevated body mass index, defect size, and defect site. In our prior series, a high postoperative CSF leak rate for tumors of the central skull base (planum, sella, and clivus) appeared to be due to graft migration. We changed our closure technique from a single layer of collagen +/- fat graft to a novel graft, termed a "Bow tie" (a tri-layer fat graft with two pieces of collagen matrix), and report our results in this study.

METHODS

Retrospective temporal epoch study of a single otolaryngologist's experience of closing skull base defects in our skull base center from 2005 to 2017.

RESULTS

One hundred and forty-nine patients met inclusion criteria in two time periods, pre- and post-introduction of the Bow tie technique. In epoch I, from 2005 to 2013, 79 patients had reconstruction with a single layer of dural graft (25 had additional free fat graft). In epoch II, from 2014 to 2017, 70 patients had reconstruction with the Bow tie.

RESULTS

CSF leak rates were 8.7% overall: 15.2% in epoch I and 1.4% in epoch II (p = 0.01). After controlling the procedure, defects with a size greater than 2 cm had a 5.7 greater likelihood of failure. Epoch II had a lower incidence of major complications.

CONCLUSION

Using a single surgeon's experience, the multilayer Bow tie has a significant reduction in postoperative CSF leak and associated major complications for defects of the central skull base.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1568-1575, 2023.

Skull base reconstruction using in situ bone flap in patients with pituitary adenomas treated by endoscopic endonasal approach

Objective

The objective of this study is to study the effect of in situ bone flap (ISBF) repositioning, a recently proposed rigid skull base reconstruction technique, on patients diagnosed with pituitary adenoma undergoing endoscopic endonasal approach (EEA).

Method

A retrospective analysis was conducted on 188 patients with pituitary adenomas who underwent EEA from February 2018 to September 2022. Patients were divided into the ISBF group and non-ISBF group, according to whether ISBF was used during skull base reconstruction.

Results

Of the 75 patients in the non-ISBF group, 6 had postoperative cerebrospinal fluid (CSF) leakage (8%), while only 1 of 113 patients in the ISBF group (0.8%) had postoperative CSF leakage, indicating that the incidence of postoperative CSF leakage in the ISBF group was significantly lower than that in the non-ISBF group (P = 0.033). In addition, we also found that the postoperative hospitalization days of patients in the ISBF group (5.34 ± 1.24) were significantly less than those in the non-ISBF group (6.83 ± 1.91, P = 0.015).

Conclusion

ISBF repositioning is a safe, effective, and convenient rigid skull base reconstruction method for patients with pituitary adenoma treated by EEA, which can significantly reduce the rate of postoperative CSF leakage and shorten postoperative hospital stays.

Anterior Skull Base Reconstruction

Anterior skull base reconstruction requires careful preoperative planning to use the most effective technique for the expected defect. Adherence to the principles of skull base reconstruction is imperative to minimize complications and improve patient outcomes.

Endoscopic Endonasal Approach in Craniopharyngiomas: Representative Cases and Technical Nuances for the Young Neurosurgeon

Craniopharyngiomas (CPs) are Rathke's cleft-derived benign tumors originating most commonly in the dorsum sellae and representing 2% of intracranial neoplasms. CPs represent one of the more complex intracranial tumors due to their invasive nature, encasing neurovascular structures of the sellar and parasellar regions, making its resection a major challenge for the neurosurgeon with important postoperative morbidity. Nowadays, an endoscopic endonasal approach (EEA) provides an "easier" way for CPs resection allowing a direct route to the tumor with direct visualization of the surrounding structures, diminishing inadvertent injuries, and providing a better outcome for the patient. In this article, we include a comprehensive description of the EEA technique and nuances in CPs resection, including three illustrated clinical cases.

Creation of low cost, simple, and easy-to-use training kit for the dura mater suturing in endoscopic transnasal pituitary/skull base surgery

Training kits for laparoscopes for deep suturing under endoscopes are commercially available; however, previously reported training kits for endoscopic transnasal transsphenoidal pituitary/skull base surgery (eTSS) were not available in the market. Moreover, the previously reported low cost, self-made kit has the drawback of being unrealistic. This study aimed to create a low cost training kit for eTSS dura mater suturing that was as close to real as possible. Most necessary items were obtained from the 100-yen store ($1 store) or from everyday supplies. As an alternative to the endoscope, a stick-type camera was used. Through the assembly of the materials, a simple and easy-to-use training kit was created, which is almost identical to the actual dural suturing situation. In eTSS, a simple and easy-to-use training kit for dural suturing was successfully created at a low cost. This kit is expected to be used for deep suture operations and the development of surgical instruments for training.

Preservation versus resection of middle turbinate in endoscopic transnasal transsphenoidal pituitary surgery

BACKGROUND

The strategic position of the middle turbinate (MT) within the nasal cavity makes it the first kick start to resect pituitary pathology through Endoscopic Transnasal Transsphenoidal Surgery (ETTS). This research aimed to determine if the type of endonasal endoscopic approach, MT resection (MTres) versus MT preservation (MTpre), for pituitary surgery affects olfaction and sinonasal function within a subjective as well as objective manner.

PATIENTS & METHODS

A prospective cohort comparative study was conducted to compare the sinonasal and olfaction outcomes pre and post operatively for both groups. Sinonasal symptoms were evaluated subjectively by Sino-Nasal Outcome Test (SNOT-22), while objectively by Peri-Operative Sinus Endoscope Score (POSE) along with Lund-Mackay radiological scoring system (LMS), and a Sniffin Sticks Identification test (SIT) (Burghart, Germany) was used to measure the olfaction intensity. In both groups were used on a pre-operative period and after one, three, and six months post operatively.

RESULTS

96 patients were recruited within predetermined criteria. It is found that there are no significant differences in SIT between both groups with a ρ value 0.439 post operatively. The average change in score (delta) was an increase of 0.3, with changes ranging from -3 to +4. There was no significant difference in sinonasal symptoms score among both groups, with ρ 0.07 posts operatively. There was a minor upsurge in POSE score and LMS in the preservation group but without remarkable differences with ρ value 0.1 and 0.2 subsequently. It is found that there are no significant differences in SIT between both groups with a ρ value 0.439 post operatively.

CONCLUSION

Despite these amendments to the nasal cavity, we approved that these changes do not affect the sinonasal functions.

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.

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.

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.

Endoscopic Reconstruction of the Anterior Skull Base Following Tumor Resection: Application of a Novel Bioabsorbable Plate

OBJECTIVE

Endoscopic repair of skull base defects is required following resection of intracranial pathology via the endoscopic endonasal approach (EEA). Many closure techniques have been described, but choosing between techniques remains controversial. We report outcomes of 560 EEA procedures of skull base reconstruction performed on 508 patients over a 15-year-period. Halfway through this period, we adopted the use of a rigid, bioabsorbable extrasellar plate for reconstruction, enabling a comparison between this technique and those used previously.

METHODS

All patients undergoing EEA from 2005 to 2019 at our institution were retrospectively reviewed. Demographic information, surgical pathology, tumor dimensions and radiographic features, reconstructive technique, and patient-related outcomes were collected and analyzed with univariate and multivariate statistical modeling.

RESULTS

Five-hundred sixty procedures were performed on 508 patients. The series complication rate was 8.2%. Overall, cerebrospinal fluid (CSF) leak rate was 5.0% but varied significantly across closure techniques (p < 0.001). Critically, the CSF leak rate in the 272 cases prior to our 2013 adoption of the Resorb-X Plate (RXP) was 8.5%, whereas leak rate in the subsequent 288 cases was 1.7%. RXP was protective against CSF leak (p = 0.001), whereas gross total resection (GTR) correlated with increased leak rate (p = 0.001). Patient BMI was significantly associated with risk of leak (p = 0.047). Other variables did not impact leak risk.

CONCLUSION

Reconstructive technique, extent of resection, and patient BMI significantly contributed to CSF leak rate. GTR was associated with increased leak risk while the RXP was protective. The bioabsorbable RXP is an effective option for rigid skull base repair with comparatively few complications.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1092-1098, 2023.

Comparison of Graft Materials in Multilayer Reconstruction with Nasoseptal Flap for High-Flow CSF Leak during Endoscopic Skull Base Surgery

Cerebrospinal fluid (CSF) leak is a crucial complication after endoscopic skull base surgery. Therefore, multilayer reconstruction with grafts is as essential as a reconstruction with pedicled flaps. Although widely used, the multilayer technique with autologous fascia lata has drawbacks, such as additional wound and donor site complications. We compared acellular dermal graft and banked homologous fascia lata graft (alternative grafts) with autologous fascia lata graft for high-flow CSF leak repair. We retrospectively enrolled 193 subjects who underwent endoscopic skull base reconstruction with multilayer fascial grafts and nasoseptal flap for high-flow CSF leaks from November 2014 to February 2020 at a single institution. Acellular dermal matrix (ADM), banked homologous fascia lata, and autologous fascia lata were used in 48 (24.9%), 102 (52.8%), and 43 (22.3%) patients, respectively. Postoperative CSF leaks occurred in 23 (11.9%) patients and meningitis in 8 (4.1%). There was no significant difference in postoperative CSF leak (p = 0.36) and meningitis (p = 0.17) across the graft groups. Additionally, we could not find out contributing risk factors for postoperative CSF leak and meningitis. ADM and banked homologous fascia lata are non-inferior to autologous fascia lata for endoscopic skull base reconstruction in water-tight reconstruction or safety without additional donor site morbidities.

Mayo Clinic Clival Chordoma Case Series: Impact of Endoscopic Training on Clinical Care

The management of clival chordoma in our group shifted around 2013 to mostly endoscopic, and proton beam was introduced for our multidisciplinary team. Consecutive patients who had surgical resection from 1987 to 2021 were reviewed. A total of 58 patients (39 patients after 2013) were analyzed. The mean tumor size was 3.7 cm, and the most common location was the upper clivus (43%). Compared to before 2013, after 2013, the endoscopic endonasal approach was more common (90%, p < 0.001), and more gross or near total resections (64%, p = 0.002) were attained. Ten cases (17%) were revision surgeries referred from elsewhere, and three cases (5%) underwent additional surgery elsewhere before adjuvant radiation. The postoperative cerebrospinal fluid leak occurred in 7%. Post-operative new cranial nerve deficits occurred in 32% before 2013, compared to 2.6% after 2013 (p = 0.004). For cases before 2013, 10 patients (53%) recurred during the median follow-up of 144 months (mean, 142 months), whereas for cases after 2013, seven patients (18%) recurred with a median follow-up of 35 months (mean, 42 months). 5-year progression-free survival was 58%, and 5-year overall survival was 87%. A specialized multidisciplinary team improved the resection rate compared to a historical cohort with an excellent morbidity profile.

Endonasal transsphenoidal surgery for planum sphenoidale versus tuberculum sellae meningiomas

OBJECTIVE

The aim of this study was to determine if the distinction between planum sphenoidale (PS) and tuberculum sellae (TS) meningiomas is clinically meaningful and impacts the results of the endoscopic endonasal approach (EEA).

METHODS

A consecutive series of patients who were 18 years of age or older and underwent EEA for newly diagnosed grade I PS meningiomas (PSMs) and TS meningiomas (TSMs) between October 2007 and May 2021 were included. The PS and TS were distinguished by drawing a line passing through the center of the TS and perpendicular to the PS on postcontrast T1-weighted MRI. Probabilistic heatmaps were created to display the actual distribution of tumor volumes. Tumor volume, extent of resection (EOR), visual outcome, and complications were assessed.

RESULTS

The 47 tumors were distributed in a smooth continuum. Using an arbitrary definition, 24 (51%) were PSMs and 23 (49%) were TSMs. The mean volume of PSMs was 5.6 cm3 compared with 4.5 cm3 for TSMs. Canal invasion was present in 87.5% of PSMs and 52% of TSMs. GTR was achieved in 38 (84%) of 45 cases in which it was the goal, slightly less frequently for PSMs (78%) compared with TSMs (91%), although the difference was not significant. Th mean EOR was 99% ± 2% for PSMs and 98% ± 11% for TSMs. Neither the suprasellar notch angle nor the percentage of tumor above the PS impacted the rate of GTR. After a median follow-up of 28.5 months (range 0.1–131 months), there were 2 (5%) recurrences after GTR (n = 38) both of which occurred in patients with PSMs. Forty-two (89%) patients presented with preoperative impaired vision. Postoperative vision was stable or improved in 96% of patients with PSMs and 91% of patients with TSMs. CSF leakage occurred in 4 (16.6%) patients with a PSM, which resolved with only lumbar drainage, and in 1 (4.3%) patient with a TSM, which required reoperation.

CONCLUSIONS

PSM and TSMs arise in a smooth distribution, making the distinction arbitrary. Those classified as PSMs were larger and more likely to invade the optic canals. Surgical outcome for both locations was similar, slightly favoring TSMs. The arbitrary distinction between PSMs and TSMs is less useful at predicting outcome than the lateral extent of the tumor, regardless of the site of origin.

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

The critical importance of a vascularized flap in preventing recurrence after endoscopic repair of spontaneous cerebrospinal fluid leaks and meningoencephaloceles

OBJECTIVE

Spontaneous CSF leaks into the anterior skull base nasal sinuses are often associated with meningoencephaloceles and occur in patients with idiopathic intracranial hypertension (IIH). Endonasal endoscopic repair has become the primary method of choice for repair. The authors sought to evaluate the success rate of endoscopic closure and to identify predictive factors for CSF leak recurrence.

METHODS

A consecutive series of endonasally repaired anterior skull base meningoencephaloceles was drawn from a prospectively acquired database. Lumbar punctures were not performed as part of a treatment algorithm. All patients had at least 5 months of follow-up. Chart review and phone calls were used to determine the timing and predictors of recurrence. Demographic information and details of operative technique were correlated with recurrence. Two independent radiologists reviewed all preoperative imaging to identify radiographic markers of IIH, as well as the location and size of the meningoencephalocele.

RESULTS

From a total of 54 patients there were 5 with recurrences (9.3%), but of the 39 patients in whom a vascularized nasoseptal (n = 31) or turbinate (n = 8) flap was used there were no recurrences (p = 0.0009). The mean time to recurrence was 24.8 months (range 9-38 months). There was a trend to higher BMI in patients whose leak recurred (mean [± SD] 36.6 ± 8.6) compared with those whose leak did not recur (31.8 ± 7.4; p = 0.182). Although the lateral recess of the sphenoid sinus was the most common site of meningoencephalocele, the fovea ethmoidalis was the most common site in recurrent cases (80%; p = 0.013). However, a vascularized flap was used in significantly more patients with sphenoid (78.3%) defects than in patients with fovea ethmoidalis (28.6%) defects (Fisher's exact test, p = 0.005). Radiographic signs of IIH were equally present in all patients whose leak recurred (75%) compared with patients whose leak did not recur (63.3%); however, an enlarged Meckel cave was present in 100% (2/2) of patients whose leaks recurred compared with 13.3% (4/30) of patients whose leaks did not recur (p = 0.03). The average meningoencephalocele diameter tended to be larger (1.73 ± 1.3 cm) in patients with recurrence compared to those without recurrence (1.2 ± 0.66 cm; p = 0.22). A ventriculoperitoneal shunt was already in place in 3 patients, placed perioperatively in 5, and placed at recurrence in 2, none of whose leaks recurred.

CONCLUSIONS

Recurrence after endonasal repair of spontaneous CSF leaks from meningoencephaloceles can be dramatically reduced with the use of a vascularized flap. Although failures of endonasal repair tend to occur in patients who have higher BMI, larger brain herniations, and no CSF diversion, the lack of vascularized flap was the single most important risk factor predictive of failure.

Clinical Efficacy of the Multilayered Skull Base Reconstruction Using In Situ Bone Flap in Endoscopic Endonasal Approach for Craniopharyngioma

Objective  The aim of the study is to summarize and analyze the efficacy of the multilayered skull base reconstruction using in situ bone flap in endoscopic endonasal approach (EEA) for craniopharyngiomas. Methods  A retrospective review of 65 patients who underwent resection of their histopathology confirmed craniopharyngiomas performed at a single institution. Based on the team's understanding and mastery of skull base reconstruction techniques, patients were divided into two groups according to the methods of reconstruction in two periods. First (March 2015 through August 2016), osseous reconstruction was not adopted and served as the control group (34 cases). Second (September 2016 through July 2019), in situ bone flap repair of the skull base (complete osseous reconstruction) served as observation group (31 cases). The length of hospitalization and nasal exudation, bed rest time of hospital discharge, the incidence of cerebrospinal fluid leaks, lumbar drainage, and intracranial/pulmonary infections were collected and compared. Results  Compared with the control group, patients in the observation group had obviously less lumbar drainage and CSF leakage ( p  < 0.05), but had no significant difference in cases of re-operation, meningitis, and pulmonary infection. At the meantime, cases of nasal exudation, bed rest, and hospitalization of the observation group were significantly reduced ( p  < 0.05) in the observation group. Conclusion  The multilayered reconstruction technique (especially using in situ bone flap, combined with vascularized pedicled nasoseptal flap) is a safe and effective method in achieving watertight closure after EEEA, and can significantly reduce the incidence of cerebrospinal fluid leaks, and facilitate rehabilitation in skull base reconstruction of craniopharyngiomas.

Nasoseptal flap and rigid reconstruction in endoscopic endonasal skull base surgeries: The longitudinal experience of a single center

BACKGROUND

Recently, endoscopic endonasal approaches (EEA) have been used for skull base defect reconstruction surgeries. The nasoseptal flap (NSF), a vascular pedicled flap, was introduced to decrease postoperative cerebrospinal fluid (CSF) leakage.

PURPOSES

This study aimed to outline the authors' institutional experience using NSF and rigid implants in anterior skull base defect reconstruction surgeries following EEA.

DESIGN

A retrospective cohort review of patients who underwent NSF reconstruction following EEA in the Otorhinolaryngology and Neurosurgery Departments at King Saud University Medical City, Riyadh, Saudi Arabia, from January 2015 to May 2021, divided into 2 time periods according to the reconstruction technique.

RESULT

Out of the 106 patients who underwent EEA, 77 underwent NSF reconstruction. The majority had expanded EEA (94.8%). The mean age was 40.21 ± 17.7 years, and the female gender represented 61% of the sample. More than half of the sample underwent right NSF (57.1%). Meningioma was the most common diagnosis (45.5%). The clivus was the most frequent site of lesions (23.4%). The overall rate of postoperative CSF leakage and lumbar drainage (LD) insertion was 15.6% and 51.9%, respectively. The duration of LD was a median of four days. The overall failure rate was 13%, declining from 20% in the first period to 5.4% in the second period. Rigid implants were used significantly more in the first period than in the second period (67.5% versus 16.2%, P < 0.001). Meningitis, the highest postoperative complication, was reported in 6 patients (7.8%). One patient died three weeks postoperatively after massive nasal bleeding. No significant difference was found between either side of the NFS regarding the CSF leakage and failure rate.

CONCLUSION

In the authors' experience, there has been an overt decline in failure rates and complications of EEA over the last three years due to increased experience among surgeons and a standardization of reconstruction techniques. Minimal reconstruction may provide satisfactory results by decreasing the use of rigid implants. An endoscopic endonasal approach with an NSF for anterior skull base defect reconstruction is considered a safe procedure with no significant difference between the sides of the flap.

Cerebrospinal fluid leak management in anterior basal skull fractures secondary to head trauma

OBJECTIVE

To summarize the presentation, diagnosis, and management of cerebrospinal fluid (CSF) leaks in the setting of traumatic anterior skull base fracture.

METHODS

Wide literature research has been performed as well as the authors' own clinical experience has been summarized.

RESULTS

Articles from the most recent 30 years have been reviewed and a typical case of our own has been presented. Based on the most updated evidence, a treatment algorithm for CSF leaks has been proposed.

CONCLUSION

Anterior skull base fracture accounts for about 4% of all head injuries and CSF leaks is a complication that commonly presents with clear fluid emanating from the nasal passage. A positive beta-2-transferrin study is highly specific for diagnosis, while thin-slice CT scanning and MRI cisternography are also useful tools. The majority of the CSF leaks tend to be resolved spontaneously, and conservative management is attempted first with or without the augmentation of a lumbar drain. Surgical management mainly includes open surgery and endoscopic surgery, which have their own pros and cons.

Modified Shoelace Dural Closure with Collagen Matrix in Extended Transsphenoidal Surgery

Extended endonasal transsphenoidal surgery (eTSS) offers a wide surgical field for various parasellar lesions; however, intraoperative high-flow cerebrospinal fluid (CSF) leakage is inevitable. Therefore, secure sellar reconstruction methods are essential to prevent postoperative CSF leakage. Although collagen matrix has been applied for dural reconstruction in neurosurgery, its suitability for application in extended eTSS remains unclear. Eighteen patients underwent modified shoelace dural closure using collagen matrix after lesionectomy via extended eTSS. In this technique, a collagen matrix, which was placed subdurally (inlay graft), was continuously sutured with both open dural edges like a shoelace. Then, another collagen matrix was placed epidurally (onlay graft), and rigid reconstruction was performed using the septal bone and a resorbable fixation mesh. Postoperative CSF leakage did not occur in 17 patients but did occur in 1 patient with tuberculum sellae meningioma. In this case, the CSF leakage point was detected just around the area between the coagulated dura and the adjacent collagen matrix. The collagen matrix harvested from this area was pathologically examined; neovascularization and fibroblastic infiltration into the collagen matrix were not detected. On the other hand, neovascularization and fibroblast infiltration into the collagen matrix were apparent on the surface of the collagen matrix harvested from the non-CSF leakage area. Our novel dural closure technique using collagen matrix could be an effective option for sellar reconstruction in extended eTSS; however, it should be applied in patients in whom normal dural edges are preserved.

The effects of cerebrospinal fluid (CSF) diversion on post-operative CSF leak following extended endoscopic anterior skull base surgery

There is a paucity of high quality evidence regarding the routine placement of lumbar drain (LD) in reducing post-operative (op) cerebrospinal fluid (CSF) leak after extended endoscopic trans-sphenoidal resection of anterior skull base lesions. In this study, we sought to compare the incidence of post-op CSF leak between patients with upfront LD insertion and those without it. This was a prospective randomized controlled trial conducted over a period of 5 years with patients undergoing extended endoscopic trans-sphenoidal surgery randomly assigned to either LD insertion at the time of surgery, or no LD placement. Thirty-eight patients with anterior skull base tumors were accrued from three tertiary hospitals of Melbourne. Post-op leak was confirmed by β2-transferrin-positive rhinorrhea, and/or worsening pneumocephalus on brain imaging. Skull base defect size and pedicled nasoseptal flap viability were assessed on post-op CT and MRI, respectively. There was no significant difference in post-op CSF leak incidence between the two subgroups (12.50% in LD arm vs. 9.10% in no LD arm). Patients with LD insertion however, demonstrated substantially raised complication rates, longer hospital lengths of stay and lower subjective quality of life measures at 12 months compared with those without LD. In conclusion, routine placement of LD at the time of surgery for extended anterior skull base trans-nasal approach did not reduce the risk of post-op CSF leak. Discretion is warranted when using LD as an adjunct due to its associated morbidities, prolonged hospital stay and adverse effect on patients' subjective outcome measures.

Sinonasal outcomes associated with the use of BioGlue® in endoscopic transsphenoidal pituitary surgery

Concerns have been raised in the neurosurgical literature regarding the use of BioGlue®, a tissue sealant initially developed for cardiothoracic surgery, due to reports of an increased incidence of infection, wound breakdown, and CSF fistulae. The aim of this study was to determine if the use of BioGlue® in skull base repair impacts on the sinonasal outcomes and the incidence of post-operative infection following endoscopic pituitary surgery. SNOT-22 questionnaires were completed pre-operatively, and at 6, 12, and 24 weeks post-operatively by 50 patients. Pre- and post-operative MRI scans were reviewed and assessed for evidence of post-operative sinusitis. Patient records were consulted to ascertain the incidence of post-operative infection. Repeated measures ANOVA and Wilcoxon signed rank test were used for data analysis. Statistical analysis revealed a significant difference in the mean SNOT-22 scores across the four time intervals (F(1.605, 78.642) = 9.180, p = 0.001). This difference was powered by a deterioration at 6 weeks that recovered completely by 12 weeks. The mean SNOT-22 score in the study cohort at 24 weeks was 16.84/110 (range 0-57, ± 2.04) which was lower than the mean pre-operative score and is consistent with mild rhinosinusitis. There were no cases of post-operative meningitis and 1/50 (2%) case of post-operative sinusitis in this cohort. The use of BioGlue® in endoscopic endonasal pituitary surgery does not appear to lead to significant sinonasal morbidity. Previous concerns about the use of BioGlue® in transcranial procedures may not apply to extradural application of this tissue sealant in endoscopic transnasal surgery.

Soft Gasket Seal Reconstruction after Endoscopic Endonasal Transtuberculum Resection of Craniopharyngiomas

BACKGROUND

The expanded endoscopic endonasal approach (EEA) is currently well-accepted for a variety of ventral skull base tumors. Such approach often results in a trans-dural defect and intraoperative cerebrospinal fluid (CSF) leak and adequate reconstruction is necessary to prevent postoperative CSF leak and its complications. Reconstruction is usually performed utilizing a variety of materials along with the nasoseptal flap (NSF).

OBJECTIVE

This work's aim is to describe a new reconstructive technique called 'Soft Gasket Seal' (SGS) in detail and compare it with the standard reconstructive technique at our institution for craniopharyngiomas operated via transtuberculum EEA.

METHODS

A retrospective chart review was achieved to identify patients who underwent transtubercular EEA for craniopharyngioma between 2010 and 2018, by the same neurosurgical and otolaryngology team using either the SGS or the standard reconstructive technique.

RESULTS

Of 36 patients who met criteria and were considered for analysis, 15 patients underwent the Soft Gasket Seal reconstruction and 21, the standard reconstruction. There were 16 female (44%) and 20 male (56%) patients. The median age was 42.2±20.9 years. The rate of postoperative CSF leak in the group of patients treated with the standard technique was 14.2%, and 6.6% in the SGS group (OR 0.43 [CI 95% 0.007 - 6.15, p = 0.62).

CONCLUSION

The SGS technique provides a simple reconstructive technique in conjunction with the NSF, showing a tendency of lower complications when compared to our standard technique, while avoiding donor site morbidity. Such results are encouraging, but further studies are necessary to confirm these findings.

Complication avoidance protocols in endoscopic pituitary adenoma surgery: a retrospective cohort study in 514 patients

PURPOSE

To evaluate the impact of using consistent complication-avoidance protocols in patients undergoing endoscopic pituitary adenoma surgery including techniques for avoiding anosmia, epistaxis, carotid artery injury, hypopituitarism, cerebrospinal fluid leaks and meningitis.

METHODS

All patients undergoing endoscopic adenoma resection from 2010 to 2020 were included. Primary outcomes included 90-day complication rates, gland function outcomes, reoperations, readmissions and length of stay. Secondary outcomes were extent of resection, short-term endocrine remission, vision recovery.

RESULTS

Of 514 patients, (mean age 51 ± 16 years; 78% macroadenomas, 19% prior surgery) major complications occurred in 18(3.5%) patients, most commonly CSF leak (9, 1.7%) and meningitis (4, 0.8%). In 14 of 18 patients, complications were deemed preventable. Four (0.8%) had complications with permanent sequelae (3 before 2016): one unexplained mortality, one stroke, one oculomotor nerve palsy, one oculoparesis. There were no internal carotid artery injuries, permanent visual worsening or permanent anosmia. New hypopituitarism occurred in 23/485(4.7%). Partial or complete hypopituitarism resolution occurred in 102/193(52.8%) patients. Median LOS was 2 days; 98.3% of patients were discharged home. Comparing 18 patients with major complications versus 496 without, median LOS was 7 versus 2 days, respectively p < 0.001. Readmissions occurred in 6%(31/535), mostly for hyponatremia (18/31). Gross total resection was achieved in 214/312(69%) endocrine-inactive adenomas; biochemical remission was achieved in 148/209(71%) endocrine-active adenomas. Visual field or acuity defects improved in 126/138(91.3%) patients.

CONCLUSION

This study suggests that conformance to established protocols for endoscopic pituitary surgery may minimize complications, re-admissions and LOS while enhancing the likelihood of preserving gland function, although there remains opportunity for further improvements.

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.

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.

Additive Manufacturing for Personalized Skull Base Reconstruction in Endoscopic Transclival Surgery: A Proof-of-Concept Study

BACKGROUND

Endoscopic transnasal transclival intradural surgery is limited by a high postoperative cerebrospinal fluid leak rate. The aim of this study was to investigate the role of three-dimensional printing to create a personalized, rigid scaffold for clival reconstruction.

METHODS

Two different types of clivectomy were performed in 5 specimens with the aid of neuronavigation, and 11 clival reconstructions were simulated. They were repaired with polylactide, three-dimensional-printed scaffolds that were manually designed in a computer-aided environment based either on the real or on the predicted defect. Scaffolds were printed with a fused filament fabrication technique and different offsets. They were positioned and fixed either following the gasket seal technique or with screws. Postdissection radiological evaluation of scaffold position was performed in all cases. In 3 specimens, the cerebrospinal fluid leak pressure point was measured immediately after reconstruction.

RESULTS

The production process took approximately 30 hours. The designed scaffolds were satisfactory when no offset was added. Wings were added during the design to allow for screw positioning, but broke in 30% of cases. Radiological assessment documented maximal accuracy of scaffold positioning when the scaffold was created on the real defect; accuracy was satisfactory when the predicted clivectomy was performed under neuronavigation guidance. The cerebrospinal fluid leak pressure point was significantly higher when the scaffold was fixed with screws compared with the gasket technique.

CONCLUSIONS

In this preclinical setting, additive manufacturing allows the creation of customized scaffolds that are effective in reconstructing even large and geometrically complex clival defects.

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.

Endonasal Endoscopic Fenestration of Rathke's Cleft Cysts: Whether to Leave the Fenestration Open or Closed?

Introduction  Rathke's cleft cysts (RCC) are generally treated with transsphenoidal fenestration and cyst drainage. If no cerebrospinal fluid (CSF) leak is created, the fenestration can be left open. If CSF is encountered, a watertight closure must be created to prevent postoperative CSF leak, though sellar closure has theoretically been linked with higher recurrence rate. In this study, we investigate the relationship between sellar closure, rate of postoperative CSF leak, and RCC recurrence. Methods  Retrospective review of a prospective database of all endoscopic endonasal RCC fenestrations and cases were divided based on closure. The "open" group included patients who underwent fenestration of the RCC, whereas the "closed" group included patients whose RCC was treated with fat and a rigid buttress ± a nasoseptal flap. The rate of intra- and postoperative CSF leak and radiographic recurrence was determined. Results  The closed group had a higher rate of suprasellar extension (odds ratio [OR]: 8.0, p  = 0.032) and intraoperative CSF leak ( p ≤ 0.001). There were 54.8% intraoperative CSF leaks and no postoperative CSF leaks. Radiologic recurrence rate for the closed group (35.0%) was three times higher than the open group (9.1%; risk ratio [RR] = 3.85, p  = 0.203), but not powered to show significance. None of the radiologic recurrences required reoperation. Conclusion  Maintaining a patent fenestration between an RCC and the sphenoid sinus is important in reducing the rate of radiographic recurrence. Closure of the fenestration may be required to prevent CSF leak. While closure increases the rate of radiographic recurrence, reoperation for recurrent RCC is still an uncommon event.

Intraoperative Indocyanine Green Angiography for Assessing Flap Perfusion in Skull Base Reconstruction: A Systematic Review

Objective This study was aimed to study the current use of intraoperative indocyanine green (ICG) angiography during skull base reconstruction and understand its efficacy in predicting postoperative magnetic resonance imaging (MRI) enhancement and flap.

Study Design The Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and Google Scholar databases were searched from the date of inception until August 2020 for studies of ICG flap perfusion assessment during skull base reconstruction. The primary outcome of interest was the development of cerebrospinal fluid (CSF) leak after skull base reconstruction. Secondary outcomes of interest included postoperative meningitis, flap MRI enhancement, flap necrosis, flap perfusion measurements, and total complications.

Results Search results yielded 189 studies, from which seven studies with a total of 104 patients were included in the final analysis. There were 44 nasoseptal flaps (NSF), two lateral nasal wall flaps (LNWF), 14 pericranial flaps (PCF), and 44 microvascular free flaps. The rates of CSF leak and postoperative MRI enhancement were 11 and 94%, respectively. There was one case of postoperative meningitis. Pooled analysis of the available data showed that intraoperative ICG flap perfusion was associated with flap enhancement on postoperative MRI (p = 0.008) and CSF leak (p = 0.315) by Fisher's exact test.

Conclusion The available literature suggests intraoperative ICG enhancement is associated with postoperative MRI enhancement. Given the small sample sizes in the literature and the rarity of complications associated with skull base reconstruction, intraoperative ICG enhancement has not been predictive of flap necrosis or postoperative complications such as CSF leak or meningitis.

Level of Evidence This study presents level 3 evidence as a systematic review of case studies, case reports, and retrospective and prospective trials with no blinding, controls, and inconsistently applied reference standards.