Summary
Eight years of experience with endoscopic Nd:YAG laser photocoagulation were analyzed in retrospect in an attempt to identify factors relating to both failures and complications of laser therapy, and to delineate its limits and pitfalls in benign and malignant tumors. Three hundred and seventy-eight patients were studied, including 42 with gastroesophageal cancer, 180 with colorectal adenoma and 156 with colorectal malignancy. Patients with gastroesophageal cancer (n = 42) were referred mainly for obstruction in esophageal cancer and for bleeding in gastric cancer, with successful palliation in 86 and 81 %. Hemorrhage was the only complication seen, twice during and twice after treatment. Pain, heat and smoke-induced complaints and sometimes temporary increased dysphagia were mentioned. Two white-surfaced tumors did not react at all. Patients with colorectal adenoma (n = 150) were divided into groups according to the size of the lesion. Definitive, histologically documented eradication of adenomatous tissue was achieved in 43 % of the extensive, in 69 % of the intermediate, and in 97 % of the small adenomas. Major complications, mainly stenosis and hemorrhage, occurred in 6.4 %, 7.6 % and none of the lesions, respectively, and minor complications were seen in 57.4, 30.8 and 13.8 %, respectively. Stenosis appeared to be related only to prior electrocoagulation and to excessive delivery of energy. Post-treatment hemorrhage occurred at about day 7. In familial polyposis (n = 30) surveillance of the rectal stump was successful in 84 %, with major and minor complications in 4 % and 12 %. In colorectal cancers (n = 156) treated for palliation of bleeding and obstruction, success was obtained in 91 %. Major complications (13 %) consisted mainly of stenosis and perforation. Ulceration and submucosal spread contributed to stenosis. Perforation seemed to be related to difficult anatomy or previous surgery. Difficult accessibility and visualization of the lesion, but also edema, whitish ulceration and bleeding interfered with the adequacy of laser treatment. In benign lesions, transient laser-induced dysplasia-mimicking tissue changes had to be differentiated from 'genuine' (pre)cancerous degeneration. A true carcinoma was detected at follow-up in 15 of the total colon adenoma group. The difficult endoscopic identification of residual adenomatous or malignant tissue interfered with proper treatment. In malignancy, limited penetration - a safety advantage - was a drawback in the treatment of tumors with submucosal spread. On the basis of the present study, a number of refinements are proposed that couple optimal benefit with maximal safety. Prospective studies should be performed to evaluate their merits.
Key words:
Laser photocoagulation - Nd:YAG laser - Laser complication - Laser failure - Gastrointestinal adenoma - Gastrointestinal cancer
