1999 Volume 55 Issue 2 Pages 25-29
Complete fibrosis of the mucosal proper layer and submucosal layer of esophageal wall is main mechanism to threat the esophageal varices by endoscopic injection sclerotherapy (EIS) using paravascular injection of a sclerosing agent. We thought direct thrombosis of small vessels with a diameter of 2mm or less, which might develop large variceal vessels in the future, was desirable as complete and also preventive measure. In this point of view, laser photocoagulation had advantage over EIS. However, the conventional Nd : YAG laser irradiation could not perform the complete thrombosis without vessel perforation. In this study, we developed a novel method of enhancing diode laser absorption by intravenous administration of indocyanine green (ICG) , which strongly absorbed 805nm diode laser light. In all cases, slow injection of 0.5mg/kg ICG in 30 sec. was followed by drip injection of same dose in 15 min. Repeat irradiation was performed with 1 sec. exposure of 25W output during drip injection. Histological specimen obtained just after irradiation reveals extensive fusion necrosis of fibrous tissue in mucosa and submucosa without obvious muscle damage. The obvious thrombosis in both venous and artery was not present, however, 7 days after these necrotic area was completely replaced by fibrosis. We applied this method to 4 patients who carried esophageal varices after large varicose veins were treated by EIS or Endoscopic Variceal Ligation (EVL) . Laser irradiation disappeared all small vessels, which previous procedures failed to treat, and endoscopy has showed no recurrent vessels 5 months after exposure. No complication such as pain, persistent bleeding, perforation and deteriorated liver function developed during the treatment and the observation period. Our laser method in combination with EIS or EVL might be a safe and effective therapeutic method by treating small vessels. The increasing dose of ICG injection still remains to be examined for more effective treatment for esophageal varices.
