Recurrent Cerebrospinal Fluid Leak Research Articles

The Impact of Venous Stenting on Symptoms and Quality of Life in Patients with Idiopathic Intracranial Hypertension and Spontaneous Cerebrospinal Fluid Leak

Abstract Background Elevated intracranial pressure can cause skull base defects and a spontaneous cerebrospinal fluid (CSF) leak. Venous sinus stenting (VSS) has emerged as a promising treatment option for patients with a CSF leak in the setting of idiopathic intracranial hypertension (IIH). There is a lack of literature on symptomatology and quality of life (QOL) after VSS for IIH patients with a CSF leak. This study explores the effects of VSS on symptoms and QOL in IIH patients with a CSF leak. Methods This is a retrospective study on patients who have IIH complicated by a CSF leak and underwent VSS. A QOL questionnaire was developed from the migraine disability assessment test and the PROMIS-PI was given to patients included in this study. Results A total of 10 patients were included in this study. Nine patients underwent endoscopic closure of CSF prior to stent placement and one patient was treated with VSS only. There was no evidence of CSF leak recurrence in this population following VSS. Headaches improved in 5/8, tinnitus in 5/6, and visual disturbance in 4/5 patients. Diamox was discontinued in seven out of eight patients after VSS. There was an improvement in headache-specific questions (p = 0.0140) and overall QOL (p = 0.0061) on the QOL questionnaire. Discussion This preliminary study demonstrates that VSS is effective in alleviating many symptoms in IIH patients with a CSF leak, especially headaches. Diamox may be able to be discontinued in many patients following VSS. No CSF leak recurrence was noted in this patient population.

Minimally Invasive Approaches to Spinal Cerebrospinal Fluid Leak Repair: Current Strategies and a Novel Technique.

Spinal cerebrospinal fluid (CSF) leaks can be caused by tears in the dura and are challenging to treat. Traditional methods of treating spinal CSF leakage include nonsurgical management, epidural blood patches (EBP), and direct surgical repair. Minimally invasive surgery (MIS) is rapidly progressing within neurosurgery due to its advantages for patient safety and comfort. Existing MIS techniques to spine surgery utilize a rigid endoscope, which has limitations when reaching smaller areas requiring greater degrees of visualization. The simultaneous use of a flexible endoscope and wearable heads-up display (wHUD) improves access and visualization in these small areas while allowing the surgeon to maintain optimal ergonomics. In this article, we review minimally invasive approaches to spine surgery and the management of spinal CSF leaks. We also demonstrate a novel minimally invasive technique utilizing flexible endoscopy and a wHUD to treat a case of recurrent CSF leak. We describe the successful utilization of this technology and provide the groundwork for future practitioners to incorporate this approach into their practice.

Abstract 291: Iatrogenic Intracranial Hypotension with Pseudomeningocele, CSF Fistula and CSF Leaks Following Dural Repair and Spinal Cord Stimulator Placement

Background Intracranial hypotension (IH) is a rare complication of cerebrospinal fluid (CSF) leakage. It can occur either spontaneously (primary) or as a result of trauma or medical intervention (secondary or iatrogenic). The incidence of IH is approximately 5 per 10,000 cases annually. Iatrogenic IH can occur following procedures that involve dural injury, such as spinal surgery, spinal cord stimulator (SCS) lead migration, or lumbar puncture. Reduced CSF flow leads to a decrease in CSF volume and subsequent intracranial hypotension, manifesting as a postural headache. Diagnosis of a CSF leak or CSF venous fistula (CVF) is typically made using CT or MR myelography. Dynamic myelography is reserved for multiple level or high‐flow CSF leaks. Dural defects are commonly treated epidural blood patch or surgical repair. In CSF venous fistula (CVF), embolization therapy may be employed. Objective: We present a case of iatrogenic IH following traumatic dural injury due to SCS lead migration complicated by the development of a large pseudomeningocele, CVF and CSF leaks. Methods A 46‐year‐old female presented with disabling postural headaches. Her surgical history included an L4‐S1 posterior fusion and laminectomy complicated by durotomy and repair in 2003, followed by 2 epidural SCS placements and bilateral SI joint fusion. In 2010, she experienced intermittent headaches described as the worst of her life, which resolved after two months. Shortly before her current presentation, the headaches returned, accompanied by tinnitus, a sensation of underwater hearing, autonomic dysfunction, confusion, and brain fog, raising concern for a CSF leak. CT myelography revealed arachnoiditis and a large pseudomeningocele at L4‐L5, though no active CSF leak was identified. Nonetheless, the patient was referred to a CSF leak specialist and treated empirically with an epidural blood patch at T12‐L1, leading to cessation of her symptoms. Five months later, the patient suffered a fall, and her symptoms recurred. CT thoracic spine revealed migration of the lower SCS epidural lead into the thecal sac. A repeat CT myelogram showed a pseudomeningocele at the left L4‐L5 region with a possible extradural leak near the L4‐L5 pedicles and a CSF leak at the T12‐L1 SCS epidural lead. Due to suspected CSF leak at multiple levels, dynamic CT myelogram was employed. Dynamic CT myelogram revealed an expansion of contrast extravasation at the left L4‐L5 pedicles and vascular uptake of contrast in the left L4‐L5 neural foramina raising suspicion of a CVF versus systemic contrast absorption in the pseudomeningocele containing the CSF leak. The patient was treated with epidural blood patches at L3‐L4, L4‐L5, and T12‐L1, microsurgical repair of the pseudomeningocele with venous ligation, and a lumbar peritoneal shunt, which resulted in significant improvement of her postural headache symptoms. L4‐S1 posterior fusion revision was performed. SCS was unable to be removed due to fusion with the bone. Conclusion Iatrogenic IH can result from persistent, recurrent, or new CSF leaks even after dural repair. In patients who develop new or ongoing postural headaches following treatment, re‐evaluation of symptoms along with repeat CT myelography may be warranted to identify any underlying issues.

Peri-operative management of endoscopic endonasal cerebrospinal fluid leak repair: an international survey.

Peri-operative management of nasal cerebrospinal fluid (CSF) leaks is not consensual due to limited evidence. The main aim of this study was to identify key factors in peri-operative management of endoscopic endonasal CSF leak repair among international experts. A 60-item survey questionnaire collected opinions of members of international learned societies of ENT surgeons and neurosurgeons on nasal packing, post-operative instructions, antibiotic prophylaxis, and CSF volume depletion. The survey had 153 respondents (124 otorhinolaryngologists and 29 neurosurgeons). A resting position was recommended by 85% (130/151) of respondents for extended CSF leak of the anterior skull base, mainly in Fowler's position (72% (110/153)). Nasal packing was used by 85% (130/153) of respondents; 33.3% (51/153) used it to stabilize the reconstruction, and 22.2% (34/153) to prevent bleeding. It was usually removed after 48h in 44.4% of cases (68/153). CSF depletion was considered by 47.1% (72/153) of respondents in case of CSF leak recurrence and by 34.6% (53/153) in cases of increased intracranial pressure. All respondents gave specific postoperative instructions to patients including driving, running, swimming, diving restrictions and flighting restrictions. In subgroup analysis, ENT surgeons more often recommended a resting position than neurosurgeons (71% vs. 37.9% ; p = 0.0008) and prescribed more antibiotics (82.3% vs. 21.4% ; p < 0.0001). Although postoperative management after CSF closure remains challenging and not codified, this international survey revealed some points of consensus concerning resting position and restriction of post-operative activities. Prospective clinical studies must be undertaken to evaluate their efficiency.

Trans-Defect Underlay Watertight Duraplasty for Traumatic Anterior Skull Base Dural Defect: Technical Report

BackgroundWatertight duraplasty is essential for surgical management of traumatic anterior skull base (ASB) dural defect but challenging in the deep and narrow operative corridor. Here, the authors report the trans-defect underlay watertight duraplasty (TDUWD) technique for traumatic ASB dural defect. MethodsTDUWD was performed by inserting a free pericranium graft under the dural defect. The diameter of the pericranium graft was larger than the dural defect. The pericranium graft was sutured to the dural defect watertightly in an “inside-to-outside” direction, with the needle not penetrating the inner layer of pericranium graft. The pedicled pericranium flap was used as a second layer of reconstruction. The characteristics, complications and outcomes of patients who received TDUWD are reported. ResultsA total of 29 patients received TDUWD. Immediate postoperative cessation of cerebrospinal fluid (CSF) leak occurred in 28 patients. The other one patient recovered after lumber drainage. No patient needed a second operation or reported delayed recurrence of CSF leak. No complication related to the surgical technique was observed. ConclusionUse of TDUWD for traumatic ASB dural defect results in an immediate, one-stage and definitive correction of CSF leak and seems to be simple, safe, and reliable for large and deep located dural defects.

Spontaneous delayed CSF rhinorrhea associated with encephalocele following surgical resection of a giant frontoparietal meningioma, an extremely rare entity and overlook of English literature

Introduction and importance: Spontaneous cerebrospinal fluid (CSF) rhinorrhea without a history of head trauma is rare. The authors describe a scarce case of spontaneous, nontraumatic, delayed CSF rhinorrhea due to ethmoidal encephalocele associated with frontoparietal giant meningioma. Case presentation: A 49-year-old male complained of a slowly growing skull mass lasting 10 years since a blunt head trauma and progressive hemiparesis 3 months ago and was referred to our center. There was a heterogeneous extra-axial mass (77×77×70 mm) with calcified components at his right frontal lobe, demonstrating notable adjacent parenchymal edema and a midline shift to the left. There was a sizeable extra-axial mass (113×95×80 mm) in his right front-temporoparietal lobe associated with adjacent invasion to calvarium leading to the lytic and sclerotic appearance of the calvarial bone showing intense heterogeneous contrast enhancement and an adjacent enhancing dural tail. A considerable mass effect on the adjacent frontotemporal cortex is evident, with mild parenchymal edema leading to a notable midline shift to the left, right uncal herniation, and left ventriculomegaly. On postoperation day 5, the patient developed a recurrent CSF leak exacerbated by hydrocephalus. He was rescheduled to undergo endoscopic endonasal surgery and dural repair on postoperative day 7. The postoperative course was uneventful. Clinical discussion: Frontoparietal lobe encephaloceles represent the least common cause of spontaneous CSF rhinorrhea. Early diagnosis and surgical management remain crucial to minimize the subsequent complications. Conclusion: The ventricular anatomy and CSF fluid dynamics alteration following tumor surgical resection seem to contribute to an environment by which a herniated ethmoidal encephalocele developed a delayed nontraumatic CSF leak.

Subfascial drains are safe and effective in preventing postoperative cerebrospinal fluid leaks after intradural spine tumor surgery.

Delayed cerebrospinal fluid (CSF) leaks are a known complication following intradural spinal tumor surgery. The placement of subfascial drains in these patients undergoing requisite intradural surgery is controversial. Here, we demonstrated that placing a subfascial drain on partial suction for 48 h, with early ambulation, proved to be safe and effective in preventing early/delayed recurrent CSF fistulas. Medical records of 17 patients undergoing surgery for intradural spinal tumors over a 30-month were reviewed. All patients underwent intradural tumor resection followed by primary dural closure, placement of Gelfoam in a non-compressive fashion, application of fibrin sealant, and utilization of a subfascial drain placed on partial suction for 48 h postoperatively. Patients are mobilized the morning following surgery. We tracked the incidence of postoperative recurrent CSF leaks, over drainage, infection, wound dehiscence, pseudo meningocele formation, and the reoperation rate. For the 17 patients, our programmed average utilization of subfascial drains was 48 h. Moreover, the average drain output was 165 mL. Over the 1-year follow-up period, no patient developed a recurrent early/ delayed CSF leak, there were no wound complications, nor need for revision surgery. Utilizing subfascial drains on partial suction following the resection of intradural spinal tumors with primary dural closure proved to be safe and effective.

Short Postoperative Length of Stay After Lateral Cerebrospinal Fluid Leak Repair.

To characterize the short-term outcomes of patients undergoing surgical repair of lateral skull base cerebrospinal fluid (CSF) leaks followed by a shortened length of stay (LOS) protocol. Retrospective study. Tertiary medical center. Atotal of 156 adult patients from July 2016 to December 2022 who underwent repair of CSF leaks via transmastoid (TM), middle cranial fossa (MCF), or combined (TM/MCF) approaches were included. Data collected included: LOS, presentation to the emergency department (ED), need for readmission, major neurologic complications (stroke, seizure, and meningitis), and CSF leak recurrence. Approximately half of patients underwent a TM repair (49.4%), whereas the other half underwent either an MCF (3.8%) or combined TM/MCF repair (46.8%). No peri-/postoperative lumbar drains were used and only 2 (1.3%) patients were admitted to the intensive care unit after surgery. Mean LOS for the cohort was 1.1 ± 0.7 days and was longer for surgeries involving MCF (1.3 ± 0.6) compared to TM (0.8 ± 0.7). Ninety-two percent of TM cases were discharged within 24hours (32% on the same day) while for cases involving an MCF approach, 72.2% of patients were discharged within 24hours. Of the patients in the study, 6 (3.8%) presented to an ED for minor complications and no patient required readmission. Revision surgery was required for 3 (1.9%) patients for recurrent CSF leak. Our findings suggest that short LOS after surgical repair of lateral skull base defects in the treatment of CSF leak is safe and effective.

Factors Affecting Success Rates in Endoscopic Repair of CSF Rhinorrhea.

Our aim in this study is to assess the effect of factors such as age, etiology, defect size, application of lumbar drainage and surgical technique on Cerebrospinal Fluid (CSF) fistula repair success rates. The Electronic Medical Records (EMR) system of our clinic was retrospectively reviewed for cases that were operated between 2006 and 2020 for CSF fistula originating from anterior skull base with endoscopic transnasal technique. A total of 35 patients were included in the study. Patients were grouped according to the number of layers used in repair (two, three or four-layered reconstruction) and defect size (smaller than 5 mm, 5 to 10 mm and larger than 10mm), etiology, location of the defect and application of lumbar drainage as LD (+) and LD (-). Complications and CSF leak recurrence were compared between groups. Recurrence rates in patients who had 2 layered reconstructions were significantly higher compared to patients who had 3 or 4 layered reconstructions (p=0.049). The recurrence rate in LD (+) group (41.7%) was significantly lower compared to LD (-) group (4.3%) (p=0.012). There were no significant difference in recurrence rates between groups in terms of age, defect size, defect location and etiology. In endoscopic transnasal repair of anterior skull base-derived bos fistulas, planning the reconstruction at least 3 times and applying lumbar CSF drainage increases the success rates.

Idiopathic Intracranial Hypertension Is Associated with Recurrent CSF Leak and Reoperation for Spontaneous Temporal Encephalocele.

Objective Spontaneous temporal encephaloceles (STEs) are increasingly recognized as sequelae of idiopathic intracranial hypertension (IIH), which in turn may further complicate their management. We endeavored to review the University of Pennsylvania institutional experience on operative management of STEs, with a focus on factors which may influence surgical outcomes, particularly IIH. Design Retrospective chart review over 9 years from 2013 to 2022. Setting Single-center, two-hospital, tertiary care, academic setting. Participants Patients undergoing middle cranial fossa (43.9%), transmastoid (44.9%), or combined (11.2%) approaches for repair of STEs during the study period ( n = 107). Main Outcome Measures Postoperative complication rates, recurrence, and diagnosis of IIH. Results The majority of patients were female (64.5%), with a mean body mass index (BMI) of 37 kg/m 2 and mean age of 57 years. Twelve patients (9%) represented reoperations after failed primary repairs. Fourteen percent of patients undergoing primary surgical repair of STE were diagnosed with IIH, compared with 42% of patients undergoing reoperations ( p = 0.015). In addition, there was a significant difference in the average BMI of patients undergoing primary (36.4 kg/m 2 ) versus revision surgery (40.9 kg/m 2 , p = 0.04). Half of those undergoing reoperation were placed on postoperative acetazolamide compared with 11% of patients undergoing primary operations. No patient experienced recurrent leak after reoperation. Conclusion Based on our institutional experience, elevated BMI and the presence of IIH are significant predictors of reoperation for STE. In our experience, acetazolamide is a common adjunct management strategy in addition to reoperation for patients with recurrent cerebrospinal fluid leak in the setting of STE.

Pediatric Spontaneous Cerebrospinal Fluid Leak Repair: An Endoscopic Endonasal Approach.

Background: Spontaneous cerebrospinal fluid (CSF) rhinorrhea in the pediatric population is an exceedingly rare condition that occurs when the dura mater is breached, resulting in CSF drainage from the subarachnoid space into surrounding sinonasal tissue. Objective: This work delineates a step-by-step surgical approach to visually demonstrate the feasibility of an uninarial endoscopic endonasal approach for pediatric spontaneous CSF leak repair. Postoperative Outcome: A 2-year-old male with a 6-month history of clear rhinorrhea, intermittent headaches, and a previous episode of bacterial meningitis was evaluated as an inpatient consultation. Computed tomography cisternography revealed active CSF extravasation at the right sphenoid sinus roof. An endoscopic endonasal approach was performed including a complete sphenoethmoidectomy plus middle turbinectomy to provide access to the skull base defect. Once identified, a middle turbinate free mucosal graft was placed for cranial base reconstruction given the child's young agre. Sinonasal debridement 3 weeks following surgery under anesthesia revealed an intact viable graft with no evidence of CSF leak. There was no evidence of CSF leak recurrence or complications 1 year following surgery. Conclusion: The uninarial endoscopic endonasal approach is a safe and effective option for the surgical management of spontaneous CSF leak rhinorrhea in the pediatric population.

Lumbar Drain Use during Middle Fossa Approaches for Nonneoplastic Pathology of the Skull Base.

Introduction The middle fossa craniotomy (MFCs) is commonly utilized for spontaneous cerebrospinal fluid (CSF) leaks, encephaloceles, and superior semicircular canal dehiscence (SSCD). This study compares postoperative outcomes of MFCs with and without LD use. Methods A retrospective cohort study of adults over the age of 18 years presenting for the repair of nonneoplastic CSF leak, encephalocele, or SSCD via MFC from 2009 to 2021 was conducted. The main exposure of interest was the placement of an LD. The primary outcome was the presence of postoperative complications (acute/delayed neurologic deficit, meningitis, intracranial hemorrhage, and stroke). Secondary outcomes included operating room (OR) time, length of stay, recurrence, and need for reoperation. Results In total, 172 patients were included, 96 of whom received an LD and 76 who did not. Patients not receiving an LD were more likely to receive intraoperative mannitol ( n = 24, 31.6% vs. n = 16, 16.7%, p = 0.02). On univariate logistic regression, LD placement did not influence overall postoperative complications (OR: 0.38, 95% confidence interval [CI]: 0.05-2.02, p = 0.28), CSF leak recurrence (OR: 0.75, 95% CI: 0.25-2.29, p = 0.61), or need for reoperation (OR: 1.47, 95% CI: 0.48-4.96, p = 0.51). While OR time was shorter for patients not receiving LD (349 ± 71 vs. 372 ± 85 minutes), this difference was not statistically significant ( p = 0.07). Conclusion No difference in postoperative outcomes was observed in patients who had an intraoperative LD placed compared to those without LD. Operative times were increased in the LD cohort, but this difference was not statistically significant. Given the similar outcomes, we conclude that LD is not necessary to facilitate safe MCF for nonneoplastic skull base pathologies.

Management of recurrent cerebrospinal fluid leak, current practices and open challenges. A systematic literature review.

Management of recurrent cerebrospinal fluid leak, current practices and open challenges. A systematic literature review.

Fibrin Glue–Coated Collagen Complex Patch: A Novel Material for Surgical Repair of Spontaneous Temporal Bone Cerebrospinal Fluid Leak and Encephalocele

To compare outcomes of surgical repair of temporal bone encephalocele and cerebrospinal fluid (CSF) leak using fibrin glue-coated collagen (FGCC) complex patch versus other materials for repair of dura. Retrospective chart review. Tertiary care hospital. Fifty-two adult patients undergoing transmastoid (TM), middle fossa (MF) or combined approach repair of spontaneous MF CSF leak between 2016 and 2020. Exposure of bony defect via TM approach, MF craniotomy, or combined TM/MF, and repair of the associated dura defect with FGCC complex patch, or other materials (acellular collagen matrix, bovine collagen, autologous fascia, fibrin tissue sealant). Successful repair without recurrent CSF leak or encephalocele throughout follow-up. Cost of materials used in duraplasty. Sixty-four percent of patients were female. Mean (standard deviation) age at repair was 61.4 (12.1) years. Mean (standard deviation) body mass index was 35.0 (8.3) kg/m 2 . Forty-nine (94%) patients had successful repair without known recurrence of CSF leak or encephalocele over a median follow-up interval of 11.7 months. Average duraplasty material cost was significantly lower with FGCC in comparison with other nonautologous materials (FGCC+: $1259.94, FGCC-: $1652.58; p = 0.004). No significant differences in recurrence risk (FGCC+: 6.9%, FGCC-: 6.9%; p > 0.999) or operative time (FGCC+: 153.7 min, FGCC-: 155.4 min; p = 0.88) were detected based on material used for duraplasty. All materials studied demonstrate effective and sustained means of repair for MF CSF leak and encephalocele, including in the presence of multiple defects. Use of FGCC for duraplasty produces noninferior surgical results to other nonautologous materials in repair of spontaneous CSF leaks of the temporal bone and may be more cost-effective.

Surgical management of spontaneous middle cranial fossa defects: a systematic review and meta-analysis of available reconstructive techniques and materials.

Different materials and techniques have been proposed for surgical repair of spontaneous middle cranial fossa (MCF) defects. However, conclusive evidence supporting their selection and impact on clinical outcomes is lacking. The study aims to conduct a systematic review and meta-analysis on materials and techniques employed to repair MCF defects and evaluate complications and rates of recurrent cerebrospinal fluid (CSF) leaks. A PRISMA-guided systematic review and meta-analysis were performed using MESH terms and specific keywords including studies published before May 2022. Primary outcomes included recurrence of CSF leak and complication rates by type of reconstructive material and technique utilized. Meta-analyses of proportions were performed using random effects and confidence intervals for individual proportions were calculated using the Clopper-Pearson method. Twenty-nine studies were included (n = 471 cases). Materials employed for repair were categorized according to defect size: 65% of defects were of unknown size, 24% were small (< 1cm), and 11% were large (≥ 1cm). Rigid reconstruction (RR) was significantly favored over soft reconstruction (SR) for larger defects (94% of cases, p < 0.05). Complications and recurrent CSF leak rates of SR and RR techniques were comparable for defects of all sizes (p > 0.05). Complication rates reported for these procedures are low regardless of technique and material. RR was universally preferred for larger defects and analysis of complication and recurrence rates did not reveal differences regardless of defect size. While RR was more frequently reported in smaller defects, SR was used by several centers, particularly for smaller MCF floor defects.

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

Cerebrospinal fluid (CSF) rhinorrhea through a pneumatized optic strut is a known potential complication after an anterior clinoidectomy that is used to microsurgically clip a proximal internal carotid artery aneurysm. The original craniotomy site can be reopened to repair the skull base defect, but this technique has disadvantages. To avoid a repeat craniotomy and address the limitations of a transcranial approach, a straightforward alternative was used for skull base repair-the binostril endoscopic endonasal transsphenoidal approach. This retrospective case series describes the use of endoscopic transsphenoidal repair and outcomes for patients with CSF leaks after anterior clinoidectomy for aneurysm repair between January 1, 2015, and December 31, 2019. Four adult patients (3 women and 1 man) with a mean age of 59.5 years were reviewed. Skull base repair occurred on average 24 days (range, 4-75 days) after the index operation. After demucosalization of the parasellar sphenoid sinus, the fistula in the pneumatized optic strut was reconstructed with a free nasal mucosal graft with or without an autologous muscle graft. None of the patients developed a recurrent CSF leak at a mean follow-up of 12.5 months (range, 8-22 months), and none experienced complications. The endoscopic endonasal transsphenoidal approach was safe and effective for skull base repair in 4 patients with CSF rhinorrhea after an anterior clinoidectomy for aneurysm clipping.

3. Assessment of in vitro dural repair techniques with a hydrostatic pressure device

<h3>BACKGROUND CONTEXT</h3> Incidental durotomies are a relatively infrequent occurrence during lumbar spine surgery and are generally benign, without significant adverse consequences. Treatment with direct repair, with or without augmentation, is generally very effective and further cerebrospinal fluid (CSF) leak is uncommon. The strength and stability of a dural repair is dependent on several factors, including patient age, quality of dural tissue, the size and location of the durotomy, and the manner in which the repair is performed. There is limited in vitro evidence comparing the strength of different dural repair techniques and the resulting likelihood of recurrent CSF leak. <h3>PURPOSE</h3> To compare the strength and stability of various dural repair techniques in an in vitro human cadaveric durotomy model. <h3>STUDY DESIGN/SETTING</h3> An in vitro testing device was created to apply controlled, hydrostatic pressure to evaluate the integrity of a surgically-created durotomy. <h3>PATIENT SAMPLE</h3> Sixteen human cadaveric specimens. <h3>OUTCOME MEASURES</h3> The hydrostatic pressure required to cause a leak at the site of the dural repair. <h3>METHODS</h3> Complete human cadavers were placed in the prone position and the dura in the thoracic and lumbar spines was exposed through a midline incision and subsequent laminectomies. The dura was clamped 8 cm proximal and distal to the level of the durotomy and clamped with reliable, water-tight plastic rings. A 16-gauge plastic catheter was introduced into the lateral aspect of the dura and sutured in a water-tight fashion to serve as the source for instilling saline into the dura. The catheter was attached to a hydrostatic pressure measuring column to assess the intradural pressure. Linear durotomies of either 1 cm or 6 cm in length were made with a 15 blade in both the thoracic and lumbar spines of each cadaver. A dural repair was performed with either a 6-0 prolene or 2-0 silk suture. Repair technique were either multiple, simple interrupted sutures or a simple running repair with knots at the respective margins of the durotomy. An analysis of variant analysis (ANOVA) was employed to assess differences in leak rates with respect to applied hydrostatic pressure. <h3>RESULTS</h3> Eight repair groups (thoracic vs lumbar / 6-0 prolene vs 2-0 silk / running vs multiple interrupted) were studied for each of the 1 cm and 6 cm durotomies. There were no significant differences noted in the frequency or extent of spinal fluid leak at different hydrostatic pressures with respect to either suture type employed or suture technique performed. There was a slight difference in the mean applied hydrostatic pressure applied to create a fluid leak in the 6 cm durotomy (16 cm H2O) compared to the 1 cm durotomy (12 cm H2O) but this did not reach statistical significance. <h3>CONCLUSIONS</h3> In this in vitro study of the integrity of the repair of experimentally created durotomies, no significant difference was noted with respect to different suture type or technique of repair. Larger durotomies had a slight, not significant trend for recurrent leak at lower applied hydrostatic pressures. In general, expansion of the repaired dura with controlled delivery of intrathecal fluid, simulating an in vivo, intraoperative Valsalva maneuver, did not reveal significant differences in varying repair types. While this in vitro study does not directly replicate an in vivo scenario, the results do reinforce the necessity of a meticulous water tight suture repair to adequately treat incidental durotomies and thus avoid the troublesome consequences of a recurrent CSF leak. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Clinical Implementation of Platelet- and Extracellular Vesicle-Rich Product Preparation Protocols.

Extracellular vesicles (EVs) are considered essential mediators of regenerative roles of autologous platelet- and extracellular vesicle-rich plasma (PVRP) and platelet- and extracellular vesicle-rich gel (PVRG). PVRP and PVRG are novel blood-derived products gaining attraction in regenerative medicine. However, despite their reported good efficacy, their preparation protocols are too time-consuming. Moreover, patient-tailored preparation protocols are desired to optimize platelet and EV count in PVRP and PVRG. This article presents the clinical implementation of one-step, patient-tailored erythrocyte sedimentation rate (ESR)-based, PVRP and PVRG preparation protocols through the presentation of three cases: (1) large chronic tympanic membrane (TM) perforation, (2) osteoradionecrosis of the lateral skull base, and (3) cerebrospinal fluid (CSF) leak in the sphenoid sinus. These were treated with PVRP and PVRG, prepared according to our preclinically constructed mathematical sedimentation model of cells and EVs based on the patient's ESR. (1) TM healed completely after the treatment with 3.6 mL of PVRP and PVRG (high platelet and EV protocol). The speech discrimination score and air conduction pure tone average improved from 75% to 95% and from 65 to 25 dB, respectively. (2) The osteoradionecrotic surface area decreased from 46 to 18 cm2, and infection was eradicated after six applications of 13-65 mL of PVRG ("half-volume" protocol). (3) No CSF leak recurrence was detected after surgical closure with 30 mL of PVRG postoperatively. Reproducible preparation protocols proved effective, safe, fast, and straightforward enough for the surgical staff to prepare PVRP and PVRG intraoperatively. To alleviate preparation, a calculator is provided. This pilot study presents a sound basis for further studies, which are needed to assess the therapeutic effect of PVRP and PVRG. Impact statement We introduce a clinical implementation of a patient-tailored, erythrocyte sedimentation rate-based platelet- and extracellular vesicle-rich plasma (PVRP) and gel (PVRG) preparation protocol based on a mathematical model. Products proved beneficial in wound healing and were, to our knowledge, used for the first time in the treatment of osteoradionecrosis of the lateral skull base. Furthermore, this reproducible preparation protocol is fast and straightforward to implement in clinical practice. A calculator is provided to alleviate PVRP and PVRG preparation for various clinical scenarios.

Comparison of Outcomes of Surgical Repair of Spontaneous Temporal Bone CSF Leaks and Encephaloceles Using Bone Cement and Autologous Material.

To compare outcomes transmastoid repair of spontaneous middle fossa cerebrospinal fluid (CSF) leak using only bone cement (BC) versus only autologous material (AM) or combined materials (CM) with both bone cement and autologous material. Retrospective Chart Review. Tertiary Care Hospital. Forty-three adult patients undergoing transmastoid repair of spontaneous middle fossa CSF leak between 2014 and 2020 (BC:12, AM:15, CR:16). Cortical mastoidectomy, identification of defect, and repair with BC (Cranios® hydroxyapatite), AM (local bone, fascia, fat, and/or cartilage), or CM (Cranios® combined with autologous materials). Successful repair without recurrent CSF leak or encephalocele throughout follow up. Fifty-one percent of subjects were female. Mean age at repair was 58.6 years (SD 10.9). Mean BMI was 35.4 (SD 7.6; BC:36.3, AM:36.5, CM:33.6). Forty (93%) patients had successful repair without known recurrent CSF leak or encephalocele since surgery (BC:11, 91.6%; AM:14, 93.3%; CM:15, 93.8%; p = 0.49) over a mean length of follow up of 49.6 months (BC: 37.9, AM: 59.2, CR: 49.5). The difference in mean operative time amongst the groups was faster for patients using bone cement (BC: 100.2 min, AM: 182.8, CM: 133.2; p < 0.00001). BC, AM, and CM techniques each demonstrate effective and sustained means of repair for middle fossa CSF leak and encephalocele, even in the presence of multiple defects. Use of isolated BC offers a significant decrease in operative time with a noninferior outcome. Active CSF leak at the time of surgery is associated with increased risk of recurrence.

Modified Transpterygoid Approach to Sphenoid Meningoencephaloceles: A Shorter Run for a Longer Slide.

Cerebrospinal fluid (CSF) leaks and meningoencephaloceles originating in the lateral recess of the sphenoid sinus can be challenging. The traditional transpterygoid approach through the pterygopalatine fossa (PPF) is time consuming and places important structures at risk, which can lead to significant morbidity. We report a multi-institutional experience using a simplified, endoscopic modified transpterygoid approach (MTPA), which spares the PPF contents in the management of lateral sphenoid sinus meningoencephaloceles and CSF leaks. Multi-Institutional, Retrospective Case Series. Patients with lateral sphenoid recess CSF leaks and meningoencephaloceles between 2014 and 2020 who underwent the MTPA at two academic medical centers were identified. Repair techniques and outcomes were evaluated. Thirty-three patients underwent the MTPA for management. Skull base reconstruction was performed using a free mucosal graft (24/33, 72.7%), nasoseptal flap (4/33, 12.1%), bone grafts (3/33, 9.1%), and abdominal fat grafts (2/33, 6.1%). Lumbar drains and perioperative intracranial pressure measurements were routinely employed. Postoperative complications were uncommon and included three patients (9.7%) with temporary V2 anesthesia, one patient (3.2%) with prolonged V2 anesthesia, and one patient (3.2%) with subjective dry eye, all of which resolved at 9 months postoperatively. There were no recurrent CSF leaks resulting in a 100% success rate. Average follow-up was 13 months. The MTPA reduces morbidity and greatly simplifies access to the lateral sphenoid sinus for the management of CSF leaks and meningoencephaloceles, without compromising exposure. This technique avoids the need for extensive PPF dissection and should be considered for the management of benign lesions involving the lateral sphenoid sinus. 4 Laryngoscope, 131:2224-2230, 2021.