[Experimental studies on tissue injury by microwave tissue coagulator].
The tissue injury caused by Microwave Tissue Coagulator (MTC) was assessed clinically and experimentally with dogs. Following hepatic transection using MTC on condition that the output was 60 watts and radiation lasted for 60 seconds at one time, GOT, GPT, lactic acid, FDP and endotoxin concentration increased and coagulation parameters such as hepaplastin test were deteriorated transiently. Of tissue injury, following results were obtained. 1) The mechanism of tissue injury by MTC consists of direct heat injury and infarct by circulatory disturbance. The extent of injury from the needle electrode is approximately 10 mm in the former mechanism and 20mm in the latter. 2) Injury of vessels in Glisson's sheath was confirmed up to 50mm apart from the needle electrode by labelling index of bromodeoxyuridine in bile duct epithelial cells. 3) The granulation formation at the site of necrosis was considerably retarded by wound infection. Accordingly, when MTC is utilized on hepatectomy, followings should be noted: 1) To prevent the large intrahepatic vessels from heat injury, MTC may be utilized at the surface of the liver and the needle electrode must be punctured more than 10mm apart from them. 2) Bile leakage at the resected stump should be eliminated to prevent infection at the stump.
Asanuma
Y
Y
First Department of Surgery, Akita University School of Medicine, Japan.
Koyama
K
K
Sato
Y
Y
Sawai
T
T
D000818:Animals; D004285:Dogs; D004564:Electrocoagulation / Q000009:adverse effects* / Q000379:methods; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods; D007238:Infarction / Q000209:etiology / Q000473:pathology; D008099:Liver / Q000098:blood supply / Q000293:injuries* / Q000473:pathology; D008872:Microwaves / Q000009:adverse effects*; D013530:Surgical Wound Infection / Q000209:etiology / Q000473:pathology