Abstract
This paper presented the clinical course and the local changes in a 63 years old Japanese male, who was bitten on the outer side of left lower leg by Habu-snake (Trimeresurus flavoviridis), and histopathological findings on the excised muscular tissues in which necrosis was extensively present.
As systemic symptoms, nausea, vomiting, hiccup and tachycardia were recognized. Severe swelling, hemorrhage and discoloration were visible on the affected area, and the patient complained of considerable pain in the bitten site. About 3 hours after the attack, he was hospitalized to receive proper therapies. Although systemic signes were gradually improved, local changes did not show much improvement. On the 7th day after the bite extensive necrosis with stinky gas found on or near the bitten portion. In operation performed on the 14th day after the hospitalization, necrotic muscle tissues (ant. tibial muscle and extens. dig. long, muscle) were removed.
Morphologically these muscular tissues showed interstitial edema and necrosis of muscle fibers in cellular reaction was hardly found. In some parts of the tissues, especially near the bitten area, there were leucocytic infiltration, abscesses and inflammatory granulation tissues. Anterior tibial artery lying between the two excised muscles exhibited the so-called productive endoarteritis in the proxymal, partial necrosis of the wall accompanied by medial abscess and occlusion due to thrombus in the middle, and angionecrosis involving entire wall and collapse in the distal part. The veins running along anterior tibial artery showed almost similar lesions to thas, e of the artery, that is, mural necrosis, either total or partial and thromboangitis.
As for the pathogenesis of morphological alterations, it is considered that Habu-snake venom may directly act on vascular wall, causing injuries of endothelial cells and necrosis of the wall and thrombus. Furthermore hemorrhage, swelling and bacterial contamination in the bitten local tissues may promote the development of the changes.
