Occlusion of multi-holed catheters used in continuous wound infusion in open gynecologic surgery: A pathological study

Background: Continuous wound infusion (CWI) with local anesthetics is useful as a method of pain management after abdominal surgery. However, there have been no studies regarding the obstruction of multi-holed catheters in this application. Methods: We conducted from July to November 2015. In the first portion of the study, we obtained 34 catheters used postoperatively with open gynecologic surgery, and evaluated the status of each hole in vitro. Each catheter had eight holes, and we investigated the number of open holes after the removal of the catheter. In the second portion of the study, we reviewed pathological specimens from four occluded catheters. Statistical analysis was performed using the statistical software MedCalc™ (MedCalc, Ostend, Belgium), and intergroup comparisons were made with independent sample t-test. Data are expressed by mean and standard deviation. Results: In each catheter, the number of remaining open holes was 0–7, and there were no catheters with all eight holes still open. Although the occlusion may be occurred after the end of infusion, 38.2% (n = 12) did not have any open holes remaining in our investigation. The composition of the emboli in the catheters was clotted blood and plasma, with a mass of fibrin and possibly some inflammation around the embolus. Conclusions: Occlusion of these catheters occurs at a very high rate, and the catheter embolus might be composed of clotted blood, plasma, and/or fibrin.