Right portal vein ligation: a new planned two-step all-surgical approach for complete resection of primary gastrointestinal tumors with multiple bilateral liver metastases.

Abstract

Although complete resection of liver metastases remains the only curative treatment for metastatic liver disease from colorectal and endocrine gastrointestinal (GI) tumors, only a small proportion of patients with liver metastases are candidates for potentially curative surgery. Among these, 4% to 21% are found to have unresectable disease because of multiplicity of the liver metastases, so a very small proportion of such patients can be eligible for complete resection. When the number and distribution of liver metastases create the need for extensive hepatic resection, the risk for postoperative liver failure and morbidity related to the small size of the remnant liver is increased. Additionally, substantial operative risk results from the combination of extensive hepatic resection with other major abdominal procedures at a single operation, such as extended hepatectomy with colorectal or pancreatic resections. On the other hand, minor hepatic surgery, such as left liver wedge resection, has been shown to be safe in combination with such extrahepatic procedures as those necessary to treat many GI primary tumors. So, multistep, multimodality therapies including surgery in several steps have been proposed and usually require resection of the primary tumor in one step, followed by extensive liver resection, with or without the use of percutaneous ablative therapy or systemic chemotherapy. Improved understanding of the benefits of liver regeneration has led to other approaches using intermediate steps between surgical procedures. In patients expected to have a small future liver remnant volume (FLR), most hepatic surgeons perform preoperative portal vein embolization (PVE), mainly to avoid postoperative liver failure and to decrease morbidity either after major hepatectomy in patients with injured liver parenchyma (such as that found in patients after extensive chemotherapy or in patients with chronic liver disease) or when major hepatectomy is associated to major abdominal procedures. But some investigators suggest that in patients with bilobar liver metastases from colorectal cancer, hypertrophy of the left liver induced by right PVE might accelerate the progression of left-sided disease and therefore caution against the reckless use of PVE in these cases. In order to use the benefits of diversion of portal flow to the FLR, to avoid the risk of progression of liver disease, and to minimize the risk and number of procedures necessary to treat patients with GI tumors with bilobar liver metastases, we developed a new planned two-step, totally surgical approach to clear all primary and metastatic disease. In the first step, the primary tumor and all left-sided liver metastases (Couinaud S1 to S4) are resected using straightforward resection techniques. Simultaneously, right portal vein ligation (RPVL) is performed to induce hypertrophy in the left lobe, which has been cleared of all detectable disease. Four to 8 weeks later, after hypertrophy of the diseasefree FLR, a second step consisting of a right or extended right hepatectomy is planned to completely clear the remaining right-sided liver metastases (Fig. 1). No competing interests declared.