Serous fluid leakage is not infrequently an annoying complication of systemic-to-pulmonary artery shunt constructed with polytetrafluoroethylene (PTFE) tubular graft. Various causative factors have been postulated by many clinical and investigative studies, but still remain to be controversial. During the period from 1981 to 1989, 26 patients underwent PTFE shunt operations (16 modified Blalock-Taussig shunts and 10 central aortopulmonary shunts), among whom serous fluid leakage occurred in 10, an incidence of 38.5%. Possible roles of the operative methods, length and diameter of the graft, bodyweight, age and sex of the patients were examined but none of these demonstrated consistent correlation with this complication. The first 3 of the 10 patients in the series required prolonged period of drainage of the fluid. Meanwhile, unequivocally low serum values of fibrinogen in these patients presented a clue for the new therapeutic method. Intravenous administration of fibrinogen to the fourth patient results an almost instantaneous cessation of leakage and was applied to the subsequent 6 patients with excellent results. The duration of leakage was 2.7 +/- 2.6 days in the patients with fibrinogen treatment in contrast with 19.7 +/- 2.3 days in those without. In succeeding 4 patients, fibrinogen was used for the purpose of prevention instead of treatment, and the luminal surface of PTEF graft was coated with fibrinogen prior to the usage. Pretreatment of the graft was absolutely effective and did not allow leakage in any of the 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)