title: In vitro testing of current spread during ventricular catheter coagulation using diathermy. Technical note.
abstract: The authors report on the development of an anterior cerebral artery pseudoaneurysm that hemorrhaged after monopolar coagulation for a ventricular catheter lodged in the interhemispheric fissure. After observing this complication, the authors developed a simple bench test that can be performed by any neurosurgeon to determine the safest coagulation parameters for any given diathermy unit. A modified grounding pad was placed in a beaker of a protein solution consisting of egg whites. Ventricular catheters were then placed in the solution, and a monopolar diathermy current was applied to a metal stylet at various wattages and for different durations of time. Inducing coagulation at 40 W with a diathermy unit produced flames emanating from around the pores of the catheter tip. Flash flames were also observed at 35 W, forming a coagulum of egg white for a distance of up to 1 cm from the catheter tip. All heat was dissipated through the holes of the first 16 mm of the catheter. At 20 W the flame was minimal and coagulation appeared adequate, whereas at 15 W only bubbles were seen around the tip together with suboptimal coagulum formation. This technique is a simple and effective means of determining the optimal setting for monopolar diathermy and can be used to figure the optimal catheter coagulation wattage for a given diathermy unit. Considering the results of this study, the authors have lowered the current for coagulation in ventricular catheters to 20 W.
authors.affiliation: Department of Neurosurgery, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA. fboop@semmes-murphey.com
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Boop
authors.forename: Azedine
authors.initials: A
authors.lastname: Medhkour
authors.forename: John
authors.initials: J
authors.lastname: Honeycutt
authors.forename: Charles
authors.initials: C
authors.lastname: James
authors.forename: W Bruce
authors.initials: WB
authors.lastname: Cherny
authors.forename: Christopher
authors.initials: C
authors.lastname: Duntsch
mesh_terms: D017541:Aneurysm, False / Q000209:etiology / Q000601:surgery; D020771:Anterior Cerebral Artery / Q000293:injuries; D002543:Cerebral Hemorrhage / Q000209:etiology; D002552:Cerebral Ventricles / Q000601:surgery; D002648:Child; D002831:Choroid Plexus / Q000601:surgery; D004564:Electrocoagulation / Q000295:instrumentation* / Q000592:standards; D004868:Equipment Failure; D006801:Humans; D002532:Intracranial Aneurysm / Q000209:etiology / Q000601:surgery; D008297:Male; D008422:Materials Testing; D013345:Subarachnoid Hemorrhage / Q000209:etiology; D017287:Ventriculoperitoneal Shunt / Q000009:adverse effects / Q000295:instrumentation*