Extreme liver resections with preservation of segment 4 only

AIM To evaluate safety and outcomes of a new technique for extreme hepatic resections with preservation of segment 4 only.METHODS The new method of extreme liver resection consists of a two-stage hepatectomy. The first stage involves a right hepatectomy with middle hepatic vein preservation and induction of left lobe congestion; the second stage involves a left lobectomy. Thus, the remnant liver is represented by the segment 4 only(with or without segment 1, ± S1). Five patients underwent the new two-stage hepatectomy(congestion group). Data from volumetric assessment made before the second stage was compared with that of 10 matched patients(comparison group) that underwent a single-stage right hepatectomy with middle hepatic vein preservation.RESULTS The two stages of the procedure were successfully carried out on all 5 patients. For the congestion group, the overall volume of the left hemiliver had increased 103%(mean increase from 438 m L to 890 m L) at 4 wk after the first stage of the procedure. Hypertrophy of the future liver remnant(i.e., segment 4 ± S1) was higher than that of segments 2 and 3(144% vs 54%, respectively, P < 0.05). The median remnant liver volume-to-body weight ratio was 0.3(range, 0.28-0.40)before the first stage and 0.8(range, 0.45-0.97) before the second stage. For the comparison group, the rate of hypertrophy of the left liver after right hepatectomy with middle hepatic vein preservation was 116% ± 34%. Hypertrophy rates of segments 2 and 3(123% ± 47%) and of segment 4(108% ± 60%, P > 0.05) were proportional. The mean preoperative volume of segments 2 and 3 was 256 ± 64 cc and increased to 572 ± 257 cc after right hepatectomy. Mean preoperative volume of segment 4 increased from 211 ± 75 cc to 439 ± 180 cc after surgery. CONCLUSION The proposed method for extreme hepatectomy with preservation of segment 4 only represents a technique that could allow complete resection of multiple bilateral liver metastases.