gms | German Medical Science

Introduction: The prognosis of malignant tumours in the liver hilum (Klatzkin-Tumors) correlates with the oncological resection. Portal deprivation of the tumor bearing part of the liver was introduced to induce liver regeneration leading to an increase of the “future remnant liver”. Recently the indication was extended to cholestatic patients. However, these patients are at higher risk of impaired liver regeneration leading to hepatic dysfunction and lethal liver failure. The literature gives no information concerning the systemic influence of a “lobar” or localized cholestasis on liver regeneration after resection or in the complex course with portal vein embolization and resection.

This study is conducted to establish a small animal model of a “lobar” or “selective” cholestasis (sBDL) followed by selective portal vein ligation (sPVL), prior to a partial hepatectomy as third operation. Here we present the results of the sequence of sBDL and sPVL.

Material and methods: The first experiment was designed to assess the level and severity of adhesions after sBDL of LL and ML (n=3, Lewis rats, 250-280g BW) and their influence on the subsequent sPVL In this step, the suture material for the subsequent selective portal vein ligation (sPVL) of these two lobes was put in place to facilitate the second surgical intervention 7days after the sBDL. This experiment was finished at POD 7 after sPVL. At this time point the weight and volume of the whole liver and of each liver lobe was measured. Severity of adhesions were judged clinically according to the scoring system of Moreno and Zühlke after each operation (minimum score was 0 and the maximum score was 3).

The second experiment was designed to reduce adhesions by placing a rubber sheet of 1-2cm² (obtained from a sterile surgical glove) between the liver lobes after placing the suture lines around the portal vein branch.

Results: The first experiment revealed that sBDL caused extreme adhesions (adhesion level 3 acc to Moreno and Zühlke), leading to severe bleeding complications despite extreme delicate adhesiolysis and coagulation. The sPVL could be performed, but only because of the preplaced suture lines. Under theses conditions a third operation (resection of the cholestatic and atrophic liver lobes) seems to be impossible.

The second ongoing experiment demonstrates that the simple placement of a rubber sheet reduced the adhesion formation substantially in 7/12 rats from level 3 to level 1. sPVL was facilitated a lot as reflected in the reduced operation time (60±10 min versus 35±12 min).

To date the survival rate is 93% (14/15).

Conclusion: A mechanical adhesion barrier seems to reduce the severity of adhesions after the first and the second operation. As a consequence of this it should be possible to perform three operations in a safe and standardized sequence. With establishment of this complex model of “portal conditioning” in small rodents, we could investigate the liver regeneration in this complex therapeutic sequence for the first time. These data should help to establish the optimal procedure sequence for patients with hilar liver tumours at high risk for postoperative liver dysfunction.