CONTINUOUS SPINAL-ANESTHESIA - MECHANICAL AND TECHNICAL PROBLEMS OF CATHETER PLACEMENT

Background and Objective. Although continuous spinal anesthesia with m icrocatheters has a number of advantages, there are also some drawback s: technical problems in advancing the catheter, the possibility of tr aumatizing neural structures, the development of cauda equina syndrome , and maldistribution of the local anesthetic. Methods. Spinaloscopy w as performed with a 2-mm-diameter endoscope in fresh cadavers to visua lize the fate of the catheters, as well as the distribution of the loc al anesthetic administered through these fine-bore catheters. Midline and paramedian approach achieved an easy insertion of the 28-gauge cat heter as long as the 22-gauge needle was not advanced too far into the subarachnoid space, thereby making it impossible for the catheter to bend at the anterior wall of the dura mater. Results. Injection of met hylene blue-colored hyperbaric local anesthetic through the catheter r evealed an inhomogenous distribution with pooling in the caudal segmen ts. After the catheter tip leaves the needle, the catheter should be a dvanced only 2-3 cm to avoid coiling, possible damage of the nerve roo ts, or malpositioning in preformed pouches. Conclusion. To take advant age of continuous spinal anesthesia, a meticulous technique is require d.