A randomized study of a coaxial fiber versus a naked fiber for endoscopic Nd:YAG laser therapy of esophageal and rectal tumors.

The aim of the study was to determine whether the number of Nd:YAG laser sessions necessary to produce the maximal endoscopic effect was different with the noncontact method using the coaxial fiber than with the contact method using the naked fiber inserted into the tumor. Over a 6-month period, 40 consecutive patients were treated for esophageal and rectal cancers or for benign tumors too large to be removed with a diathermy snare. All of the patients who were offered this treatment had been assessed as unsuitable for surgery and radiotherapy. Twenty patients were randomly assigned to the coaxial fiber group and 20 patients to the naked fiber group. Before treatment, patients in the two groups were not different with respect to age, sex, kind of tumor, contraindication for surgery and radiotherapy, luminal patency, and tumor circumferential extent. At the end of the treatment, the endoscopic score, the transit score, and the evolution of rectal hemorrhage and mucous secretions were not different between the two groups. The number of treatments required to achieve the maximal endoscopic benefit was 6.7 +/- 4.9 (range, 2 to 20) (median = 5) in the coaxial fiber group and 3.4 +/- 1 (range, 2 to 5) (median = 3) in the naked fiber group (p = 0.01). Treatment tolerance and complications were not different between the two groups, but the financial cost related to the fiber was lower in the naked fiber group than in the coaxial fiber group. Therefore, we recommend the contact method using the naked fiber inserted into the tumor in endoscopic Nd:YAG laser therapy for gastrointestinal tumors.