Objective: To assess a new technique of anatomically precise hepatic segmental resection and to compare the degree of precision and biochemical profiles with results after traditional segmental resection and a sham operation.
Design: Experimental study.
Setting: University hospital, Germany.
Material: 50 sheep (10 each had segments II, III, and IV removed by the new technique, and 10 each were studied in the traditional resection and sham operated groups).
Interventions: Operative ultrasonography and injection of methylene blue to identify segmental boundaries. In traditional operations boundaries were identified only from knowledge of the surface structure of the liver.
Main outcome measures: Degree of precision, duration of operation, blood loss, mortality, transaminase activities and liver function tests.
Results: Anatomically precise segmentectomies were achieved in 6/9 (67%) for segment II, 6/9 (67%) for segment III, and 4/8 (50%) for segment IV. Using the traditional technique (segment III only) there was only 1/10 anatomically precise resections, together with 5 perisegmentectomies and 4 incomplete resections (p < 0.02). The operations for anatomically precise resection lasted significantly longer, but resection time was similar. Blood loss, survival, and transaminase activities were similar for the two groups, but the margin of necrosis at the cut edge was significantly less in anatomically precise resections.
Conclusion: Anatomically precise hepatic resections are technically feasible with the use of intraoperative ultrasonography and selective staining of the segment(s) to be removed with methylene blue. Although it takes longer, there are no detrimental consequences compared with the considerably less accurate traditional technique.