Failure Pressures of Dural Repairs in a Porcine Ex Vivo Model: Novel Use of Titanium Clips Versus Tissue Glue.

OBJECTIVE: Endoscopic skull base surgery is advancing, and it is important to have reliable methods to repair the resulting defect. The objective of this study was to determine the failure pressures of 2 commonly used methods to repair large dural defects: collagen matrix underlay with fibrin glue and collagen matrix underlay with polyethylene glue, as well as a novel repair method: fascia lata with nonpenetrating titanium vascular clips. METHODS: The failure pressure of the 3 dural repairs was determined in a closed testing apparatus. Defects in porcine dura were created and collagen matrix grafts were used as an underlay followed by either fibrin glue (FG/CMG) or polyethylene glycol glue (PEG/CMG). A third condition using a segment of fascia lata was positioned flush with the edges of the dural defect and secured with titanium clips (TC/FL). Saline was infused to simulate increasing intracranial pressure (ICP) applied to the undersurface of the grafts until the repairs failed. RESULTS: The mean failure pressure of the PEG/CMG repair was 34.506 ± 14.822 cm H2O, FG/CMG was 12.413 ± 5.114 cm H2O, and TC/FL was 8.330 ± 3.483 cm H2O. There were statistically significant differences in mean failure pressures among the 3 repair methods. CONCLUSION: In this ex vivo model comparing skull base repairs' ability to withstand cerebrospinal fluid leak, the repairs that utilized PEG/CMG tolerated the greatest amount of pressure and was the only repair that exceeded normal physiologic ICP's. Repair methods utilizing glues generally tolerated higher pressures compared to the novel repair using clips alone.

Laryngocardiac Reflex: A Case Report and Review of the Literature.

INTRODUCTION: The vagus nerve has sensory and motor function in the larynx, as well as parasympathetic function in the thorax and abdomen. Stimulation of the superior laryngeal nerve can cause reflexive bradycardia. CASE: We describe a case of a 45-year-old man with pre-syncopal symptoms while exercising, and bradycardia found during cardiology workup. Radiography and flexible laryngoscopy showed evidence of a right-sided, vascular laryngeal mass. Exercise testing before and after superior laryngeal nerve block showed reversal of the symptoms with the block. Subsequent resection of the lymphovascular malformation with CO2 laser eliminated the patient's symptoms. DISCUSSION: This is the first case reported of the laryngocardiac reflex producing symptomatic bradycardia as a result of exercise-induced engorgement of a supraglottic lymphovascular malformation, which was then cured by surgical excision. We discuss this case and the literature regarding lymphovascular malformations in the airway and the neural pathways of the laryngocardiac reflex.

Management of High-Velocity Injuries of the Head and Neck.

Trauma centers must prepare to manage high-velocity injuries resulting from a mass casualty incidents as global terrorism becomes a greater concern and an increasing risk. The most recent conflicts in Iraq and Afghanistan have significantly improved understanding of battlefield trauma and how to appropriately address these injures. This article applies combat surgery experience to civilian situations, outlines the physiology and kinetics of high-velocity injuries, and reviews applicable triage and management strategies.

Failure pressures after repairs of 2-cm × 2.5-cm rhinologic dural defects in a porcine ex vivo model.

BACKGROUND: The objective of this study was to determine failure pressures of 6 rhinologic repair techniques of large skull base/dural defects in a controlled, ex vivo model. METHODS: Failure pressures of 6 dural repairs in a porcine model were studied using a closed testing apparatus; 24-mm × 19-mm dural defects were created; 40-mm × 34-mm grafts composed of porcine Duragen (Integra), fascia lata, and Biodesign (Cook) were used either with or without Tisseel (Baxter International Inc.) to create 6 repairs: Duragen/no glue (D/NG), Duragen/Tisseel (D/T), fascia lata/no glue (FL/NG), fascia lata/Tisseel (FL/T), Biodesign/no glue (B/NG), and Biodesign/Tisseel (B/T). Saline was infused at 30 mL/hour, applying even force to the underside of the graft until repair failure. Five trials were performed per repair type for a total of 30 repairs. RESULTS: Mean failure pressures were as follows: D/NG 1.361 ± 0.169 cmH2 O; D/T 9.127 ± 1.805 cmH2 O; FL/NG 0.200 ± 0.109 cmH2 O; FL/T 7.833 ± 2.657 cmH2 O; B/NG 0.299 ± 0.109 cmH2 O; and B/T 2.67 ± 0.619 cmH2 O. There were statistically significant differences between glued (Tisseel) and non-glued repairs for each repair category (p < 0.05). CONCLUSION: All glued repairs performed better than non-glued repairs. Both D/T and FL/T repairs performed better than B/T repairs. No repair tolerated pressures throughout the full range of adult supine intracranial pressure.

Failure pressures of three rhinologic dural repairs in a porcine ex vivo model.

BACKGROUND: The objective of this work was to determine the failure pressures of 3 commonly performed repair techniques of 5-mm dural defects in a controlled setting. METHODS: This was a pig dura ex vivo study. A testing apparatus was fabricated to study failure pressures of 3 different repairs in a porcine model. Five-millimeter (5-mm) dural defects were created and plugged with autologous mucosa/Tisseel (MT) (Baxter International Inc.), fat graft (FG), and bath plug (BP) techniques. Saline solution was infused at 30 mL/hour to apply unidirectional pressure to the repair until failure occurred. Five dural repairs were performed for each arm of the trial, for a total of 15 trials. RESULTS: The mean failure pressure of the MT repair was 4.3 ± 1.9 cmH2 O, of the FG repair was 10.9 ± 4.2 cmH2 O, and of the BP repair was 20.7 ± 2.2 cmH2 O. Differences among mean failure pressures were statistically significant. CONCLUSION: The BP repair showed significantly higher tolerances for pressure than the other 2 repairs. The BP repair was the only technique that withstood adult physiologic supine cerebrospinal fluid (CSF) pressure.