Glimpse into Pathophysiology of Sellar Arachnoid Cysts.

BACKGROUND: Sellar arachnoid cysts are a rare occurrence but may impinge on vital parasellar anatomy and thus are often symptomatic. The etiology of sellar arachnoid cysts is contentious, fueled by heterogeneity in cyst wall structure and contents between cases. The "ball-valve" mechanism is 1 of 2 predominant theories describing their formation, which contends that an aperture in the diaphragm allows cerebrospinal fluid to enter the cyst, propelled by pulsatile flow, but its egress is obscured by the pituitary during the ebb of the pressure wave. CASE DESCRIPTION: Here we present a case of a 51-year-old female with a symptomatic sellar arachnoid cyst. She underwent an endoscopic transsphenoidal fenestration which alleviated her symptoms. CONCLUSIONS: Intraoperative video evidence during arachnoid cyst fenestration supports the "ball-valve" theory of sellar arachnoid cyst development.

Interobserver Reliability of Spinal Adverse Events Severity System - Neuro (SAVES-N): A Prospective Adverse Event Reporting System for Neurosurgical Cases.

BACKGROUND: The reporting of adverse events (AEs) in neurosurgery uses inconsistent definitions and subjective grading systems. A standardized system for recording and describing AEs would allow valid comparisons to be drawn between different institutions, using different technologies, at different times. The Spinal Adverse Events Severity System - Neuro (SAVES-N) system is a modification of the well-validated SAVES-V2 system that encompasses complications from both cranial and spinal surgery. The objective of this study was to assess the interobserver reliability of SAVES-N in spinal and cranial neurosurgery. METHODS: Ten vignettes, including cranial and spinal neurosurgical cases, were assessed by groups of consultant neurosurgeons (n = 5) and neurosurgical registrars (n = 5) using the SAVES-N system. Interobserver reliability for the presence of AEs, the type of AE, and the SAVES severity grade of the AE were calculated using Gwet's AC2 and Fleiss' kappa and were interpreted using the thresholds described by Landis and Koch. RESULTS: Neurosurgeons had almost-perfect agreement (Gwet AC2 = 0.93), whereas registrars had substantial agreement (Gwet's AC2 = 0.74) in determining the presence or absence of AEs. Both neurosurgeons (Fleiss' kappa = 0.78) and registrars (Fleiss' kappa = 0.70) demonstrated substantial agreement within their groups as to the type of AE. Similarly, neurosurgeons (Gwet's AC2 = 0.94) and registrars (Gwet's AC2 = 0.81) both graded the severity of the AE with almost perfect agreement. CONCLUSIONS: The results of this study demonstrate that the scope of the well-validated SAVES-V2 system may be broadened to cranial neurosurgical cases by SAVES-N with substantial to almost-perfect interobserver reliability.

Obesity in Neurosurgery: A Narrative Review of the Literature.

Obesity is an important consideration in neurosurgical practice. Of Australian adults, 28.3% are obese and it is estimated that more than two thirds of Australia's population will be overweight or obese by 2025. This review of the effects of obesity on neurosurgical procedures shows that, in patients undergoing spinal surgery, an increased body mass index is a significant risk factor for surgical site infection, venous thromboembolism, major medical complications, prolonged length of surgery, and increased financial cost. Although outcome scores and levels of patient satisfaction are generally lower after spinal surgery in obese patients, obesity is not a barrier to deriving benefit from surgery and, when the natural history of conservative management is taken into account, the long-term benefits of surgery may be equivalent or even greater in obese patients than in nonobese patients. In cranial surgery, the impact of obesity on outcome and complication rates is generally lower. Specific exceptions are higher rates of distal catheter migration after shunt surgery and cerebrospinal fluid leak after posterior fossa surgery. Minimally invasive approaches show promise in mitigating some of the adverse effects of obesity in patients undergoing spine surgery but further studies are needed to develop strategies to reduce obesity-related surgical complications.