Endoscopic Repair of Spontaneous Cerebrospinal Fluid Leaks in the Lateral Recess of the Sphenoid Sinus

Objective This study aimed to assess the effectiveness of 3 endoscopic endonasal approaches for the management of cerebrospinal fluid (CSF) leaks and meningoencephaloceles in the lateral recess of the sphenoid sinus (LRSS). Study Design Retrospective study. Setting University hospital. Methods This study retrospectively reviewed 49 patients with CSF leaks and meningoencephaloceles in the LRSS. Three endoscopic surgical repair approaches were indicated based on 5 different Rhoton’s types of the LRSS. The postoperative symptoms, complications, and follow-up outcomes were investigated and evaluated. Results The success rate of endoscopic surgical repair was 100% at a median follow-up of 75.06 (12-203.4) months. Endoscopic approaches to the LRSS included the prelacrimal recess (PLR) (18.37%), transsphenoidal (18.37%), and transpterygoid approaches (64.26%). All patients in the PLR approach (PLRA) group and most of the patients in the transpterygoid approach group had a full lateral type LRSS. Hypoesthesia and dry eyes were reported in 5 patients (55.56%) and 1 (11.12%) patient, respectively, from the PLRA group and in 6 (19.35%) and 5 (16.12%) patients, respectively, from the transpterygoid approach group. Conclusions Endoscopic closure is a safe and effective method for the treatment of CSF leaks and meningoencephaloceles in the LRSS. The transpterygoid approach and PLRA offer adequate exposure of the LRSS with extensive lateral pneumatization or a full LRSS. The endoscopic route of the PLRA is more direct than that of the transpterygoid approach. Careful preoperative imaging evaluation is crucial while selecting the optimal surgical approach for the repair of a skull base defect.

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

Background Numerous methods have been described to repair nasal cerebrospinal fluid (CSF) leaks. Most studies have focused on optimizing CSF leak repair success, leading to closure rates of 90 to 95%. Objective This study aimed to determine if excellent reconstruction rates could be achieved without using sinonasal packing. Methods A prospective case series of 73 consecutive patients with various CSF leak etiologies and skull base defects was conducted to evaluate reconstruction success without sinonasal packing. The primary outcome measure was postoperative CSF leak. Secondary outcome measures were postoperative epistaxis requiring intervention in operating room or emergency department, infectious sinusitis, and 22-item sinonasal outcome test (SNOT-22) changes. Results Mean age was 54.5 years and 64% were female. Multilayered reconstructions were performed in 55.3% of cases, with collagen or bone epidural inlay grafts, and nasal mucosal grafts or nasoseptal flaps for onlay layers. Onlay-only reconstructions with mucosal grafts or nasoseptal flaps were performed in 44.7% of cases. Tissue sealants were used in all cases, and lumbar drains were used in 40.8% of cases. There were two initial failures (97.4% initial success), but both resolved with lumbar drains alone (no revision surgeries). There were no instances of postoperative epistaxis requiring intervention in the operating room or emergency department. Infectious sinusitis occurred in 2.7% of patients in the first 3 months postoperatively. SNOT-22 did not change significantly from preoperatively to first postoperative visits, then improved over time. Conclusion Nasal CSF leaks from various etiologies and defect sites were successfully repaired without using sinonasal packing, and patients experienced minimal sinonasal morbidity.

Detection of Cerebrospinal Fluid Leaks Using the Endoscopic Fluorescein Test in the Post-Operative Period Following Pituitary and Ventral Skull Base Surgery

Objective: Diagnosis of cerebrospinal fluid (CSF) leaks is sometimes challenging in the postoperative period following pituitary and ventral skull base surgery. Intrathecal fluorescein (ITF) may be useful in this setting. Design: Retrospective chart review Setting: Tertiary care center Methods and Participants: All patients who underwent pituitary and ventral skull base surgery performed by a single rhinologist between January 2017–March 2020 were included. There were 103 patients identified. Eighteen patients received 20 ITF injections due to clinical suspicion for CSF leak during the postoperative period without florid CSF rhinorrhea on clinical exam. Computed tomography scans with new or increasing intracranial air and intra-operative findings were used to confirm CSF leaks. Clinical courses were reviewed for at least 6 months after initial concern for leak as the final determinate of CSF leak. Main Outcome Measures: Specificity and safety of ITF Results: Eleven (61%) ITF patients were female and 7 (39%) were male. Average patient age was 52.50±11.89. There were 6 patients with confirmed postoperative CSF leaks, 3 of whom had evaluations with ITF. ITF use resulted in 2 true positives, 1 false negative, 17 true negatives and 0 false positives. ITF sensitivity was 67%, specificity was 100%, and positive and negative predictive values were 100% and 94.4%, respectively. There were no adverse effects from ITF use. Conclusions: Existing modalities for detecting postoperative CSF leaks suffer from suboptimal sensitivity and specificity, delayed result reporting, or limited availability. Intrathecal fluorescein represents a specific and safe test with potential utility in the postoperative setting.

Incidence of Spinal CSF Leakage on CT Myelography in Patients with Nontraumatic Intracranial Subdural Hematoma

The aim of the present study was to demonstrate the incidence of spinal cerebrospinal fluid (CSF) leaks in patients with nontraumatic intracranial subdural hematoma (SDH) and determine clinical parameters favoring such leaks. This retrospective study was approved by the institutional review board. Patients diagnosed with nontraumatic intracranial SDH who underwent computed tomography (CT) myelography between January 2012 and March 2018 were selected. 60 patients (male: female, 39:21; age range, 20–82 years) were enrolled and divided into CSF leak-positive and CSF leak-negative groups according to CT myelography data. Clinical findings were statistically compared between the two groups. Spinal CSF leak was observed in 80% (48/60) of patients, and it was significantly associated with an age of <69 years (p = 0.006). However, patients aged ≥69 years also had a tendency to exhibit spontaneous intracranial hypotension (SIH)-induced nontraumatic intracranial SDH (60.87%; 14/23). Therefore, CT myelography is recommended to be performed for the evaluation of possible SIH in patients with nontraumatic intracranial SDH, particularly those aged <69 years. Patients aged ≥69 years are also good candidates for CT myelography because SIH tends to occur even in this age group.

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.

Surgical outcomes of endoscopic transsphenoidal pituitary adenoma resection in elderly versus younger patients

Introduction Pituitary adenomas (PAs) are one of the most common type of intracranial neoplasm with increased incidence in elderly patients. The outcomes of endoscopic transsphenoidal surgery (ETS) specifically on elderly patients remains unclear. Methods We performed a retrospective cohort study to compare elderly patients (age 65 years) with non-elderly patients (age <65 years) who underwent ETS for PA from January 2005 to December 2021. Surgical outcomes, including extent of resection, complication profile, length of stay, and endocrinopathy rates, were compared between elderly and non-elderly patients. Results A total of 690 patients were included with 197 (29%) being elderly. Elderly patients showed higher rates of hypertension (p<0.05), myocardial infarction (p<0.01), and atrial fibrillation (p=0.01) but not other comorbidities. Elderly patients also had more frequent optic nerve involvement (72% of cases vs. 61%, p=0.01). Tumor characteristics and other patient variables were otherwise similar between younger and elderly patients. Postoperative CSF leaks (2% vs. 2%, p=0.8), 30-day readmission, reoperation, postoperative complications, and postoperative endocrinopathies were similar between younger and older patients. Subdividing patients into age <65, 65-79, and >80 also did not demonstrate a worsening of surgical outcomes with age. Conclusion For well selected elderly patients in experienced endoscopic skull base centers, good surgical outcomes similarly to younger patients may be achieved.

From research to clinical practice: long-term impact of randomized clinical trial examining the effect of lumbar drains on cerebrospinal fluid leak rates following endonasal skull base surgery.

Intraoperative cerebrospinal fluid (CSF) leaks are associated with increased risk of post-operative CSF leaks despite multilayered reconstruction with vascularized tissue. A recent randomized controlled trial (RCT) examining the use of peri-operative lumbar drains (LD) in high-risk skull base defects identified a significant reduction in post-operative CSF leak incidence (21.2% vs. 8.2%; p=0.017). This study was conducted to assess the efficacy of the selective use of CSF diversion, for patients with intraoperative CSF leaks involving endoscopic endonasal approaches (EEA) to the skull base. Method: Consecutive endoscopic endonasal surgeries of the skull base from a pre-RCT cohort and post-RCT cohort were compared. The following case characteristics between the two cohorts were examined: patient age, body mass index (BMI), rate of revision surgery, tumor histology, use of CSF diversion, and vascularized reconstruction. The primary measured outcome was post-operative CSF leak. Results: The pre-RCT cohort included 76 patients and the post-RCT cohort, 77 patients, with dural defects in either the anterior or posterior cranial fossa (pituitary and parasellar/suprasellar surgeries excluded). There was a significant reduction in the incidence of post-operative CSF leak in the post-RCT cohort (27.6% vs. 12.9%; p=0.04). On subgroup analysis, there was a trend toward improvement in CSF leak rate of the anterior cranial fossa (19.2% vs 10.5%; p=0.27) whereas CSF leak rates of the posterior cranial fossa were significantly reduced compared to the pre-RCT cohort (41.4% vs 12.8%; p=0.02). Conclusion This study demonstrates that the integration of selective CSF diversion into the reconstructive algorithm improved post-operative CSF leak rates.

Machine learning-based clinical outcome prediction in surgery for acromegaly

Purpose Biochemical remission (BR), gross total resection (GTR), and intraoperative cerebrospinal fluid (CSF) leaks are important metrics in transsphenoidal surgery for acromegaly, and prediction of their likelihood using machine learning would be clinically advantageous. We aim to develop and externally validate clinical prediction models for outcomes after transsphenoidal surgery for acromegaly. Methods Using data from two registries, we develop and externally validate machine learning models for GTR, BR, and CSF leaks after endoscopic transsphenoidal surgery in acromegalic patients. For the model development a registry from Bologna, Italy was used. External validation was then performed using data from Zurich, Switzerland. Gender, age, prior surgery, as well as Hardy and Knosp classification were used as input features. Discrimination and calibration metrics were assessed. Results The derivation cohort consisted of 307 patients (43.3% male; mean [SD] age, 47.2 [12.7] years). GTR was achieved in 226 (73.6%) and BR in 245 (79.8%) patients. In the external validation cohort with 46 patients, 31 (75.6%) achieved GTR and 31 (77.5%) achieved BR. Area under the curve (AUC) at external validation was 0.75 (95% confidence interval: 0.59–0.88) for GTR, 0.63 (0.40–0.82) for BR, as well as 0.77 (0.62–0.91) for intraoperative CSF leaks. While prior surgery was the most important variable for prediction of GTR, age, and Hardy grading contributed most to the predictions of BR and CSF leaks, respectively. Conclusions Gross total resection, biochemical remission, and CSF leaks remain hard to predict, but machine learning offers potential in helping to tailor surgical therapy. We demonstrate the feasibility of developing and externally validating clinical prediction models for these outcomes after surgery for acromegaly and lay the groundwork for development of a multicenter model with more robust generalization.

Long-term Risks of Persistent Ventral Spinal CSF Leaks in SIH: Superficial Siderosis and Bibrachial Amyotrophy

Background and Objectives:Superficial siderosis, bibrachial amyotropy, and spinal cord herniation are unusual but serious long-term sequelae of persistent spontaneous spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH), particularly ventral spinal CSF leaks. However, the risk of developing such sequelae has not been established in this population. We undertook this study to determine the risk of these serious complications of persistent ventral spinal CSF leaks.Methods:This cohort study was conducted using data from a prospectively maintained data base of patients who meet the modified International Classification of Headache Disorders (ICHD)-III criteria for SIH. The patient population consisted of a consecutive group of patients with SIH and persistent ventral spinal CSF leaks, who were first seen within one year of onset of SIH symptoms and who had at least one year of follow-up.Results:Among 51 patients with SIH and a persistent ventral spinal CSF leak, superficial siderosis developed in six patients and bibrachial amyotropohy in two patients during 280 patient years of follow-up. The probability of these complications increased from 0% at 48 months, to 4.5% (95% confidence interval (CI): 1.0-28.0%) at 56 months, 10.5% (95% CI: 3.0-36.4%) at 96 months, 32.7% (95% CI: 15.0-62.8%) at 144 months, and 57.9% (95% CI: 30.2-87.6%) at 192 months. None of the patients developed spinal cord herniation.Discussion:Among patients with SIH and a persistent ventral spinal CSF leak, the risk of developing serious long-term sequelae is considerable. This study shows that early treatment of a ventral spinal CSF leak offers a unique opportunity to prevent neurologic disability from superficial siderosis and bibrachial amyotrophy.