EFFECT OF CHEMOTHERAPY ON THE LARVAL MASS AND THE LONG-TERM COURSE OFALVEOLAR ECHINOCOCCOSIS

The efficacy of long-term chemotherapy in nonresectable alveolar echin ococcosis is debated, particularly because of the difficulty in defini ng therapeutic success. In this study the effect of chemotherapy on th e parasitic mass was evaluated in a series of 37 patients. The patient s had larval lesions documented by serial computed tomography studies at least 1.5 yr after chemotherapy (mean = 6.4 yr, range = 1.5 to 10.7 yr). The therapeutic regimen consisted of mebendazole (n = 34) or alb endazole (n = 3) as previously described. The maximal areas of the par asitic lesions were assessed morphometrically by means of digital imag e analysis, utilizing the point-integration method, before and after c hemotherapy. Marked regression of larval tissue occurred in 18 patient s (group A; 48.6%), stationary lesions were noted in 13 patients (grou p C; 35.1%) and progression was found in 6 patients (group B; 16.2%). The three groups did not differ significantly with regard to age, plas ma drug levels, duration of chemotherapy or initial size and compositi on of lesions (e.g., cystic cavities, degree of calcification). Despit e morphologically successful chemotherapy in most patients (e.g., 84%; groups A and C), late cholestatic complications after 1.5 to 11 yr of chemotherapy occurred in 10 patients (group A, n = 7; group C, n = 3; 4 of them died) and esophageal variceal bleeding occurred in 3 patien ts (relieved by sclerotherapy). These late complications were probably mainly due to posttherapy fibrosis of hilar structures. In conclusion , our data support the efficacy of chemotherapy. However, chemotherapy is not curative, and severe late complications were observed in patie nts with hilar (fibrotic) involvement.