Increased tumor growth and spread after laparoscopy vs laparotomy - Influence of tumor manipulation in a rat model

Background: The use of laparoscopy for assessment and treatment of malignan t tumors remains controversial. The aim of this study was to evaluate the i mpact of tumor manipulation during laparoscopy compared with that of conven tional laparotomy on growth and spread of an intraperitoneal tumor in the r at in a randomized, controlled trial. Methods: Thirty 2-month-old male Lewis rats received a single-site intrapan creatic inoculation of a ductal adenocarcinoma. Fourteen days after cancer implanting, two groups of six animals each underwent a laparotomy (30 min 6 mmHg CO2 pneumoperitoneum). The tumor was manipulated in the one group, an d exclusively visualized in the other. In two other groups, a midline lapar otomy with (n = 6) or without (n = 6) tumor manipulation was performed. Ani mals in the control group (n = 6) underwent no procedure. Tumor volume, tum or mass, local regional invasion incidence, lymph node involvement, and liv er and lung metastases were evaluated on 28-day tumors. Results: No difference in tumor growth and spread was observed between lapa roscopy and laparotomy when tumor manipulation was not carried out. Tumor m anipulation increased tumor growth significantly in the laparotomy group, b ut not in the laparoscopy one. Tumor metastases were correlated to tumor gr owth and increased significantly after manipulation in both groups. There w as no port-site or conventional wound seeding in either the surgical proced ure. Conclusions: This study showed that manipulation is the main factor acting on tumor dissemination in both laparoscopy and laparotomy, Laparoscopic sur gery had a beneficial effect on local tumor growth compared with laparotomy in the case of tumor manipulation. This beneficial effect of laparoscopic surgery may be related to a better preservation of immune function in the e arly postoperative period.