Prolonged intermittent clamping of the portal triad during hepatectomy. From 112 consecutive hepatectomies for malignant tumours performed with intermittent portal triad clamping, we have retrospectively selected the 20 cases in which clamping exceeded 90 min. Intermittent portal clamping of prolonged duration was used because of abnormal liver texture in 13 cases (mainly patients who had received intra-arterial chemotherapy) and/or because of technically difficult hepatectomy. The mean(s.d.) duration of intermittent portal clamping was 109(18) min and in two cases it exceeded 140 min (148 and 150 min). There was no postoperative mortality and the rate of postoperative morbidity was 35 per cent. Postoperative changes in biochemical liver tests were not major and transient hepatic failure occurred in only one patient following subtotal resection of the liver. We conclude that intermittent portal clamping is a useful manoeuvre in partial hepatectomy when resection is difficult or prolonged, or when the liver parenchyma is abnormal. Such clamping may be used for longer than 120 min without major complications. 