Extent of Peritoneal Resection for Peritoneal Metastases: Inferences from Pathophysiology

Abstract

Completeness of cytoreduction is one of the most important prognostic factors impacting outcomes of cytoreductive surgery (CRS). It is not known what extent of the surrounding normal peritoneum needs to be removed. We hypothesized that the extent of peritoneal resection should be different for different tumors and performed this study to find evidence to support this rationale. A review of literature pertaining to pathways and patterns of peritoneal cancer spread was performed to determine the scientific basis for the extent of peritonectomy required. We also reviewed the studies making a comparison between less and more extensive peritoneal resection. It is uncertain whether potential disease sites like the falciform ligament, umbilical round ligament, greater and lesser omenta should be resected in each patient in the absence of visible disease. Peritoneal metastases can give rise to secondary lymph node metastases. There is no consensus on the extent of lymphadenectomy to be performed for most PM except in case of peritoneal mesothelioma. Based on this review, we provide recommendations for the extent of peritoneal resection and the extent of lymph node dissection that should be performed for some common peritoneal tumors in view of existing evidence. We propose that a systematic method of synoptic reporting of pathological specimens of CRS should be developed and adopted by all peritoneal surface malignancy centers to capture important information regarding the disease distribution within the peritoneal cavity and morphology of peritoneal metastases from different tumors. This can in future be used to establish standard guidelines for such resections.