High-flow Cerebrospinal Fluid Research Articles

Empty sella in somatotropic pituitary adenomas; a series of 23 cases.

We aimed to investigate empty sella syndrome in somatotrophic pituitary adenoma for possible etiology, complications, and treatment options. Among over 2,000 skull base masses that have been managed in our center since 2013, we searched for growth hormone-producing adenomas. Clinical, surgical, and imaging data were retrospectively collected from hospital records to check for sella that lacked pituitary tissue on routine imaging. In 220 somatotrophic adenomas, 23 patients had an empty sella with surgical and follow-up data. The mean age of the sample was 46 years with the same male-to-female ratio. Five cases had partial empty sella and the rest were complete empty sellas. The most common simultaneous hormonal disturbance was high prolactin levels. Six had adenoma invasion into the clivus or sphenoid sinus and 10 had cavernous sinus intrusion. Peri-operative low-flow and high-flow cerebrospinal fluid (CSF) leaks were encountered in one and two patients, respectively, which were successfully sealed by abdominal fat. The majority of cases required growth hormone replacement therapy while it was controlled without any replacement therapy in nine patients. No pituitary hormonal disturbance occurred after transsphenoidal surgery except for hypothyroidism in one patient. An empty sella filled with fluid can be detected frequently in pituitary adenomas, especially in the setting of acromegaly. The pituitary gland may be pushed to the roof of the sella and might be visible as a narrow rim on imaging or may be detected in unusual places out of the sella. The pathophysiology behind such finding originates from soft and hard tissue changes and CSF pressure alternations during abundant growth hormone production.

Utilization of Polydioxanone Plate for Endoscopic Anterior Skull Base Repair: Operative Technique and Long-Term Cohort Outcomes

Abstract Objective The purpose of this study is to report the technical procedure and our experience using a polydioxanone suture (PDS) plate with dural substitute as part of a fully resorbable gasket seal technique to repair anterior skull base defects. Methods A series of patients undergoing anterior skull base reconstruction utilizing our resorbable gasket seal technique from January 2014 to July 2022 was reviewed. Results A total of 155 patients were included. Nine (5.8%) of the included patients developed postoperative cerebrospinal fluid (CSF) leaks requiring reoperation. There were no cases of intraoperative cranial nerve injury or internal carotid artery injury. A total of 103 (66.5%) patients were observed to have an intraoperative CSF leak, including 57 low-flow leaks and 46 high-flow leaks; 1 of 57 (1.8%) patients with low-flow leaks and 8 of 46 (17.4%) patients with high-flow leaks developed a postoperative CSF leak. During the first 3 years that this technique was utilized at our center for the management of high-flow intraoperative CSF leaks, postoperative CSF leaks were documented in 4 of 12 (33.3%) patients, in comparison to 4 of 34 (11.8%) in the following years. Conclusion PDS plate reconstruction confers several advantages and can be used in a diverse set of operative scenarios in conjunction with other reconstruction options. There appeared to be an associated learning curve as surgeons at our center gained experience with this new technique. Our findings show that the PDS plate reconstruction is safe and effective in repairing the skull base.

Clinical and technical factors in endoscopic skull base surgery associated with reconstructive success.

In this study, we identified key discrete clinical and technical factors that may correlate with primary reconstructive success in endoscopic skull base surgery (ESBS). ESBS cases with intraoperative cerebrospinal fluid (CSF) leaks at four tertiary academic rhinology programs were retrospectively reviewed. Logistic regression identified factors associated with surgical outcomes by defect subsite (anterior cranial fossa [ACF], suprasellar [SS], purely sellar, posterior cranial fossa [PCF]). Of 706 patients (50.4% female), 61.9% had pituitary adenomas, 73.4% had sellar or SS defects, and 20.5% had high-flow intraoperative CSF leaks. The postoperative CSF leak rate was 7.8%. Larger defect size predicted ACF postoperative leaks; use of rigid reconstruction and older age protected against sellar postoperative leaks; and use of dural sealants compared to fibrin glue protected against PCF postoperative leaks. SS postoperative leaks occurred less frequently with the use of dural onlay. Body-mass index, intraoperative CSF leak flow rate, and the use of lumbar drain were not significantly associated with postoperative CSF leak. Meningitis was associated with larger tumors in ACF defects, nondissolvable nasal packing in SS defects, and high-flow intraoperative leaks in PCF defects. Sinus infections were more common in sellar defects with synthetic grafts and nondissolvable nasal packing. Depending on defect subsite, reconstructive success following ESBS may be influenced by factors, such as age, defect size, and the use of rigid reconstruction, dural onlay, and tissue sealants.

Risk factors for cerebrospinal fluid leak after extended endoscopic endonasal surgery for adult patients with craniopharyngiomas: a multivariate analysis of 364 cases.

Over the last decade, the extended endoscopic endonasal approach (EEEA) has evolved as a credible surgical alternative for removing craniopharyngiomas. However, postoperative cerebrospinal fluid (CSF) leak remains one of the most pressing concerns. Craniopharyngiomas often invade the third ventricle, resulting in a higher rate of third ventricle opening after surgery and potentially increasing the risk of postoperative CSF leak. Identifying the risk factors associated with CSF leak after EEEA for craniopharyngiomas may have more clinical value. Nevertheless, there is a lack of systematic studies on the topic. Previous studies yielded inconsistent results, probably due to heterogeneous pathologies or small sample sizes. Hence, the authors present the largest known single-institution case series of the use of purely EEEA for craniopharyngiomas to systematically study the risk factors for postoperative CSF leak. The authors retrospectively reviewed 364 cases of adult patients with craniopharyngiomas who were treated at their institution from January 2019 to August 2022, and they analyzed the risk factors for postoperative CSF leak. The overall rate of postoperative CSF leak was 4.7%. In the univariate analysis, larger dural defect size (OR 8.293, 95% CI 3.711-18.534, p < 0.001) and lower preoperative serum albumin level (OR 0.812, 95% CI 0.710-0.928, p = 0.002) were associated with higher rates of postoperative CSF leak. Predominantly cystic tumors (OR 0.325, 95% CI 0.122-0.869, p = 0.025) were linked to decreased risk of postoperative CSF leak. However, postoperative lumbar drainage (OR 2.587, 95% CI 0.580-11.537, p = 0.213) and third ventricle opening (OR 1.718, 95% CI 0.548-5.384, p = 0.353) were not related to postoperative CSF leak. In the multivariate analysis, larger dural defect size (OR 8.545, 95% CI 3.684-19.821, p < 0.001) and lower preoperative serum albumin level (OR 0.787, 95% CI 0.673-0.919, p = 0.002) were identified as independent risk factors for postoperative CSF leak. The authors' repair technique yielded a reliable reconstructive outcome for high-flow CSF leak in EEEA for craniopharyngioma. Lower preoperative serum albumin level and larger dural defect size were identified as independent risk factors for postoperative CSF leak, potentially providing new insights into minimizing the risk of postoperative CSF leak. Third ventricle opening was not associated with postoperative CSF leak. Lumbar drainage may not be necessary for high-flow intraoperative leak, but this finding may require validation with a prospective randomized controlled trial in the future.

Increased prevalence of aspiration pneumonitis in spontaneous cerebrospinal fluid leaks.

Aspiration pneumonitis (AP) secondary to cerebrospinal fluid (CSF) leak is underestimated and rarely discussed. This study aimed to evaluate the association between AP and CSF leaks. Clinical and surgical characteristics of CSF leak patients with and without AP between January 2010 and December 2022 were included and compared. This study included 159 patients, 16 with CSF otorrhea and 143 with CSF rhinorrhea. Among them, 40 (25.2%) had AP. Bilateral pneumonitis was identified in 32 cases, of which 11 showed severe pneumonitis in the right upper lung lobe. Twenty-one (52.5%) asymptomatic and 19 (47.5%) symptomatic cases were documented. The major clinical manifestations included cough (n=19, 47.5%) and expectoration (n=9, 22.5%). The prevalence of pneumonitis was significantly higher in the spontaneous group than in the traumatic group. High-flow CSF leak was associated with AP (42.5%vs. 16.8%, p=0.001). No significant differences were identified in defect locations between patients with and without AP. Patients with pneumonitis had a higher prevalence of meningitis (32.5%vs. 12.6%, p=0.003). Multiple logistic regression results revealed that meningitis, spontaneous and high-flow CSF leaks are independent factors for AP occurrence. Both the CSF leak and pulmonary complications resolved following successful surgical repair. AP secondary to CSF leaks is frequently underdiagnosed, with a higher incidence identified in spontaneous cases. The occurrence of AP was associated with high-flow CSF leak. A pneumonitis rate of 25.2% in cerebrospinal fluid (CSF) leak patients was reported for the first time. A higher prevalence of aspiration pneumonitis was identified in spontaneous CSF leak. Meningitis, spontaneous and high-flow CSF leaks are independent factors for aspiration pneumonitis occurrence.

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.

Thecal sac ligation in the setting of thoracic spondyloptosis with complete cord transection.

Traumatic spondyloptosis (TS) with complete spinal cord transection and unrepairable durotomy is particularly rare and can lead to a difficult-to-manage cerebrospinal fluid (CSF) leak. We performed a systematic review of the literature on TS and discuss the management strategies and outcomes of TS with cord transection and significant dural tear. We also report a novel case of a 26-year-old female who presented with thoracic TS with complete spinal cord transection and unrepairable durotomy with high-flow CSF leak. Of 93 articles that resulted in the search query, 13 described cases of TS with complete cord transection. The approach to dural repair was only described in 8 (n = 20) of the 13 articles. The dura was not repaired in two (20%) of the cases. Ligation of the proximal end of the dural defect was done in 15 (75%) of the cases, all at the same institution. One (5%) case report describes ligation of the distal end; one (5%) case describes the repair of the dura with duraplasty; and another (5%) case describes repair using muscle graft to partially reconstruct the defect. Suture ligation of the thecal sac in the setting of traumatic complete spinal cord transection with significant dural disruption has been described in the international literature and is a safe and successful technique to prevent complications associated with persisting high-flow CSF leakage. To the best of our knowledge, this is the first report of thecal sac ligation of the proximal end of the defect from the United States.

Reuse of Nasoseptal Flaps for Endoscopic Endonasal Skull Base Reconstruction

Structured Abstract Introduction Pedicled nasoseptal flap (NSF) placement is a critical component of skull base reconstruction after endoscopic endonasal approaches (EEAs). The effectiveness of NSF reuse has not been thoroughly studied. Prior reports using flaps harvested at one center and reused at another may have technical variability bias. Methods We identified patients who underwent both their initial and NSF-reused surgeries at Weill Cornell Medical College from 2004 to 2022 using a prospective database of all EEAs. Surgical pathology, intraoperative leak grade, use of cerebrospinal fluid (CSF) diversion and skull base coverage were examined. The primary outcome measure was occurrence of CSF leak. Results Fourteen patients (six women, eight men) underwent 14 first time and 14 revision operations with median age of 36.6 years (interquartile range [IQR]: 23.9–61.3) at the time of the NSF reuse. The median interval between the first NSF use and reuse was 70.6 months (IQR: 16.6–87). Eight patients were operated on for pituitary adenoma. Nonadenomas included three craniopharyngiomas and one case each of epidermoid, ependymoma, and chordoma. There were 16 high-flow, 8 low-flow intraoperative leaks, and 4 with no leak. CSF diversion was used in 24 operations. There were three postoperative leaks, one after a first operation and two after NSF reuse. All postoperative CSF leaks, whether first or second operations, occurred in cases with both high-flow intraoperative CSF leak and incomplete NSF coverage (p = 0.006). Conclusions NSF reuse is effective at preventing postoperative CSF leak. The primary predictors of leak are high-flow intraoperative leak and inadequate defect coverage with NSF, regardless of the operation number.

Application of a Novel Versatile Mini Posterior Nasoseptal Graft in Endoscopic Transsphenoidal Pituitary Adenoma Surgery.

Skull base reconstruction is a key technique in patients undergoing endoscopic transnasal skull base surgery. Although a pedicled nasoseptal flap (PNSF) is often used to repair large skull base defects with high-flow cerebrospinal fluid leakage, bone exposure of the donor site of the PNSF can result in long-term crusting. To design a novel and versatile mini posterior nasoseptal graft for the reconstruction of defects in the sellar floor or PNSF or pedicled nasoseptal rescue flap (PNSRF) donor site in patients undergoing pituitary adenoma surgery. Patients who underwent pituitary adenoma removal through an endoscopic endonasal approach and repair of a sellar defect or PNSF/PNSRF donor site using the mini posterior nasoseptal graft technique from January 2019 to January 2020 were retrospectively evaluated. Pituitary adenomas were removed using a binostril 4-hand technique through a transnasal transsphenoidal transsellar approach or an expanded transsellar approach. Mini posterior nasoseptal grafts were successfully used in 70 patients who underwent pituitary adenoma removal through an endoscopic transsphenoidal sellar approach. Mini posterior nasoseptal grafts repaired sellar defects in 40 patients and donor site defects of the contralateral PNSF/PNSRF in 30 patients. None of these patients experienced cerebrospinal fluid leakage or major complications. A mini posterior nasoseptal graft is a safe and effective technique for repairing sellar defects after endoscopic transnasal pituitary adenoma surgery. This technique can also be used to repair defects in PNSF/PNSRF donor sites.

P12 Patient-specific automated cerebrospinal fluid pressure control to augment spinal wound closure: a case series using LiquoGuard®

Abstract Introduction Post-operative spinal cerebrospinal fluid (CSF) leaks are a common and potentially serious surgical complication. The management of intra- and post-operative leaks is heterogeneous. Numerous studies advocate for dural repair and CSF diversion. The LiquoGuard7 allows automated and precise CSF pressure and volume control, with the calculation of patient-specific biometrics. We sought to summarize our experience with patient-specific CSF automated drainage with layered spinal wound closure. Methods This single-centre case series included patients undergoing complex spinal surgery where: 1) a high-flow intra- and/or postoperative CSF leak was expected and 2) concurrent CSF diversion was performed via lumbar drain attached to a LiquoGuard7®. CSF diversion was tailored to calculated CSF production rates and other case factors to maintain a neutral pressure across the operative site. Results Three patients were included, with a variety of pathologies (T7/T8 disc prolapse; T8-T9; T4-T5 metastatic spinal cord compression). The first two patients underwent CSF diversion to prevent post-op CSF leak, whilst case 3 required this in response to post-op CSF leak. CSF hyperproduction (140-150ml/hr) was evident in all cases. With patient-specific CSF diversion regimes, no cases required further intervention for CSF fistulae repair (including for pleural CSF effusion), wound breakdown or infection. Conclusion Automated patient-specific cerebrospinal fluid drainage may have a role in the closure of complex spinal wounds with high-flow CSF leaks, with a smaller risk profile than traditional manual drainage. Further larger studies are needed to explore the comparative benefits and cost-effectiveness of these devices.

Strategy of skull base reconstruction after endoscopic transnasal pituitary adenoma resection.

Endoscopic endonasal surgery (EES) is commonly performed for resection of lesions of the anterior/middle cranial fossa region. Cerebrospinal fluid (CSF) leakage is a major complication. Skull base reconstruction after EES is challenging. We describe our reconstruction strategy and technique and analyze its outcomes. We retrospectively analyzed 703 patients with pituitary adenoma who underwent EES in our center from January 2020 to August 2022. Clinical, imaging, operative, and pathologic data were recorded from the medical records and analyzed. Skull base reconstruction was performed to achieve the following three goals: seal the original leak, eliminate dead space, provide blood supply, and early ambulation. Reconstruction was tailored to individual patients based on grade of CSF leakage encountered during surgery. The number of patients with a grade 0, 1, 2, and 3 intraoperative CSF leak was 487, 101, 86, and 29, respectively. Overall incidence of postoperative CSF leakage was 0.14% (1/703). Fascia sutured and vascularized nasoseptal flap were selected for all grade 3 CSF leaks. One patient who experienced postoperative CSF leakage developed intracranial infection and were treated with lumbar CSF drainage that failed; eventually re-exploration surgery for repair was required. Other patients did not have complications such as CSF leak and infection. 29 patients with grade 3 CSF leakage did not complain of severe nasal complications after operation. No perioperative complications related to the strategy (overpacking, infections, or hematomas) occurred. Incidence of postoperative CSF leak according to intraoperative leak grade was as follows: grade 0, zero; grade 1, zero; grade 2, 1.16% (1/86); and grade 3, zero. The principles of sealing the original leak, eliminating dead space, providing blood supply, and early ambulation are key in skull base reconstruction after EES. Individualization of these principles can significantly reduce the incidence of postoperative CSF leakage and intracranial infection and reduce the use of lumbar CSF drainage. Skull base suture technique is safe and effective in patients with high-flow cerebrospinal fluid leaks.

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.

Advances in Pituitary Surgery.

Pituitary surgery has advanced considerably in recent years with the exploration and development of various endoscopic approaches and techniques. Different endoscopic skull base approaches are being applied to access sellar tumors in different locations. Moreover, extracapsular dissection and cavernous sinus exploration have enabled gross total resection of sellar tumors where it could not have been achieved in the past. Techniques for skull base reconstruction have also progressed, allowing surgeons to remove larger and more complicated tumors than before. This review article discusses different endoscopic skull base approaches, surgical techniques for removing pituitary adenomas, and reconstruction methods for repairing postoperative low-flow and high-flow cerebrospinal fluid leakage.

Clinical Impact of Hydroxyapatite on the Outcome of Skull Base Reconstruction for Intraoperative High-Flow CSF Leak: A Propensity Score Matching Analysis.

BackgroundDespite recent advances in skull base reconstructive techniques, including the multilayer technique during the last decade, complete reconstruction of grade 3 intraoperative high-flow cerebrospinal fluid (CSF) leak remains challenging. This study was designed to investigate the role of injectable hydroxyapatite (HXA) used in the multilayer technique on the clinical outcome of skull base reconstruction for intraoperative high-flow CSF leak.Materials and MethodsThis study enrolled 187 patients who experienced intraoperative high-flow CSF leak after endoscopic endonasal surgery for anterior skull base or suprasellar pathologies between January 2014 and July 2021. All skull base defects were reconstructed using the conventional multilayer technique including a vascularized naso-septal flap (NSF, n = 141) and the combined use of HXA with the conventional multilayer technique (HXA group, n = 46). We retrospectively evaluated the efficacy of the HXA group by 1:2 propensity score matching analysis.ResultsOverall, 17 of 187 patients (9.1%) showed postoperative CSF leaks, resulting in second reconstruction surgery. There were no statistical differences in patient age, sex, body mass index, tumor location, tumor type, and degree of resection, except for the follow-up period between the two groups. The HXA group showed a significantly lower incidence of postoperative CSF leak than the control group (0% vs. 12.1%, p < 0.05). Postoperative lumbar drain (LD) was performed in 8.7% of the HXA group compared to 46.1% of the control group (p < 0.01). CSF leak-related infection rates showed a decreasing tendency in the HXA group compared to the control group (0 vs. 7.1%, p = 0.06). A total of 46 patients in the HXA group were well matched with the control group (92 patients) at a 1:2 ratio. In the propensity score-matched control group, there were higher rates of postoperative CSF leaks than in the HXA group.ConclusionThe use of HXA combined with the conventional multilayer technique completely reduced postoperative CSF leaks in this study. This technique resulted in reduced CSF leakage, even without postoperative LD, and decreased infection rates. Further randomized comparative studies are required to confirm our findings.

Dural Sealants Do Not Reduce Postoperative Cerebrospinal Fluid Leak after Endoscopic Endonasal Skull Base Surgery.

Introduction The application of cranial tissue sealants to assist with postoperative closure is widespread, but data are lacking regarding its utility in endoscopic endonasal surgery (EEA). A prospective study was conducted to assess the effect of sealant usage on postoperative cerebrospinal fluid (CSF) leak rate following standard reconstruction. Methods A prospective trial of sealant usage after endoscopic endonasal skull base surgery was performed from May 2016 to June 2019 at a tertiary referral cranial base center. This study enrolled 300 consecutive adult and pediatric patients with skull base pathology who underwent EES in which an intraoperative CSF leak occurred. Patients were sequentially stratified into equally sized groups who did or did not receive sealant as part of their reconstruction. Results Three hundred consecutive adult and pediatric patients were enrolled in the study and had a confirmed intraoperative CSF leak. The intervention cohort with sealant (first 150 patients) had 21 postoperative CSF leaks (14% rate) compared with 9 postoperative CSF leaks (6% rate) in the control group without sealant ( p = 0.02). On multivariate analysis, sealant usage was associated with a higher rate of postoperative CSF leak (odds ratio [OR] = 2.7; p = 0.025). Male gender (OR = 2.4; p = 0.04) and high-flow intraoperative CSF leak (OR = 3.1; p = 0.038) were also found to be associated with postoperative CSF leak. Conclusion Among all patients undergoing EES with an intraoperative CSF leak, the addition of sealant to standard closure techniques did not reduce the rate of postoperative CSF leaks.

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.

Experience and modification of skull base reconstruction results in lower complications rates

To investigate the efficacy of nasal septum bone flap combined with vascularized pedicle nasoseptal flap (VP-NSF) in the treatment of high-flow cerebrospinal fluid (CSF) leakage in the endonasal endoscopic skull base surgery. A total of 156 patients in group A used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater- fascia lata-VP-NSF, and were treated with drainage of the lumbar cistern after surgery, in addition, a total of 94 patients in group B used a multi-layer skull base reconstruction method of fat-absorbable artificial dura mater-nasal septal bone flap-VP-NSF, and no lumbar cistern drainage was performed after surgery. Analyzed and compared the differences of postoperative cerebrospinal fluid rhinorrhea, intracranial infection, re-repair, average bed rest time, pulmonary infection and deep venous thrombosis of lower extremities were analyzed and compared in the two groups. In group A, 11 cases of cerebrospinal fluid rhinorrhea occurred after operation. In addition, 15 cases developed intracranial infection. During this period, there were 20 cases of pulmonary infection and 3 cases of deep venous thrombosis of lower extremities. In group B, there were 1 case of cerebrospinal fluid rhinorrhea (P < 0.05), 2 cases of intracranial infection (P < 0.05), 2 cases of pulmonary infection (P < 0.05), and 0 case of deep venous thrombosis of lower extremities (P > 0.05). Nasal septum bone flap combined with VP-NSF is effective in the treatment of high-flow CSF leaks in the endonasal endoscopic skull base surgery, which can avoid postoperative lumbar cistern drainage and is worth popularizing.

Graded Reconstruction Strategy Using a Multilayer Technique Without Lumbar Drainage After Endoscopic Endonasal Surgery

Sellar reconstruction following endoscopic endonasal surgery (EES) requires modification based on the degree of cerebrospinal fluid (CSF) leak. For high-flow (grade II or III according to Esposito etal. 2007) intraoperative CSF leak, lumbar drainage (LD), in addition to the multilayer closing technique, is generally recommended. However, LD occasionally has complications including postpuncture headache, overdrainage symptoms, and increased length of stay. We retrospectively evaluated the outcome of our graded reconstruction strategy using a multilayer technique with a novel material, without LD, after EES. Ninety-seven patients who underwent EES with grade II or III intraoperative CSF leak between June 2020 and March 2021 were retrospectively reviewed. For grade II CSF leak, fibrin sealant and a nasoseptal flap were placed; for grade III CSF leak, a multilayer technique was used in combination with collagen matrix, an acellular dermal graft, injectable hydroxyapatite (HXA), and a nasoseptal flap. Postoperatively, routine LD was not performed. This study included 48 (49.5%) grade II and 49 (50.5%) grade III CSF leaks. At follow-up (mean, 8.7 months), no patient showed postoperative CSF leak in either group. No HXA-associated complications occurred. A graded surgical repair strategy after EES could avoid postoperative CSF leak. Combined use of injectable HXA and acellular dermal grafts for high-flow CSF leak can limit LD requirement without significant risks.

Single Versus Double Hadad-Bassagasteguy Flap in Expanded Endoscopic Skull-Base Surgery.

The reconstruction of dural defects, after endoscopic removal of skull-base lesions, remains challenging when a large defect or a high flow intraoperative cerebrospinal fluid (CSF) leak is observed. The aim of this study is to describe our preliminary experience with a double Hadad-Bassagasteguy (H-B) flap technique for skull-base repair, comparing its efficacy with the use of a single H-B flap in our series. A retrospective chart review was conducted on patients who underwent exclusive endoscopic endonasal skull-base surgery at our Referral Skull Base Center from December 2014 to January 2018. Data on patient demographics, pathology, preoperative and postoperative imaging, intraoperative findings, surgical route, defect size, reconstruction techniques and repair materials, were analyzed. Patients were divided into double and single H-B flap groups. In the single and double H-B groups, the postoperative CSF leak rates were 37.5% (6 of 16 patients) and 4.5% (1 of 22 patients), respectively. The difference between the two groups was statistically significant (p = 0.0470). In patients with defects > 4cm or high-flow intraoperative CSF leakage related to the opening of the third ventricle, the double H-B flap was successfully placed with no occurrence of postoperative CSF leakage. The double H-B flap significantly reduced the postoperative CSF leakage rate after expanded transnasal skull-base surgery. Particularly in challenging cases, where a large skull-base defect or a high-flow intraoperative CSF leak was observed, this reconstructive method proved to be very effective, with no evidence of postoperative CSF fistulas.

Osaka Sliding Knot Seals Dural Defect Simply in Extended Endoscopic Endonasal Approach

An extended endoscopic endonasal approach (EEA) has become standard for parasellar and midline skull base lesions. However, postoperative leakage of cerebrospinal fluid (CSF) can result from dural defects after lesion removal. We present a simple and effective technique, the Osaka sliding knot, to prevent CSF leakage. Between November 2018 and March 2021, a total of 41 patients underwent reconstruction of skull base defects with intraoperative high-flow CSF leaks after extended EEA by using this closure technique, of whom only 1 patient experienced postoperative CSF leakage. This technically simple and efficient method seals the dural defect to prevent CSF leakage after surgeries using an extended EEA.