Complications and pitfalls of laser therapy.

228 patients have been studied in retrospect, in an attempt to delineate the limits and pitfalls of laser treatment of benign (n = 104) and malignant (n = 124) tumors. Benign colorectal adenomas (n = 78) were divided into 3 groups according to the size of the lesion. The occurrence of complications, the persistence and recurrence rate paralleled the size of the tumor. No relationship as to the number of sessions, the interval between them or the mean and/or total amount of energy was found. The prolonged time span of treatment in larger lesions was related to the formation of large ulcers and edema. Poor accessibility and difficult positioning of the laser beam interfered with adequacy of laser treatment. In familial polyposis (n = 26) laser photocoagulation appeared a highly effective, safe and easy procedure. In esophageal cancer (n = 16), gastric (n = 13) and colorectal malignancies (n = 95) laser therapy was very efficaceous in the palliation of bleeding and/or obstruction. Unfavorable anatomy and difficult accessibility were the main drawbacks. Problems in the assessment of pathology and submucosal extension impeded effective treatment of early cancer. Generally speaking, the presence of a whitish appearance, fibrosis of bloody tissue pointed toward a less favorable response, but much more has to be learned about the interaction between laser light and tissue properties.