Background: For the management of endoscopically irretrievable polyps, several minimally invasive procedures are currently available as alternatives to conventional laparotomy. However, the high rate of malignant transformation despite initially benign histology continues to be a problem.
Methods: Within the framework of a prospective multicenter observational study, all patients with adenomatous polyps unsuitable for endoscopic removal and with benign histology were investigated. In addition to an analysis of the perioperative course and the definitive histology, the overall and disease-free survival rates of patients with malignant transformation of colorectal adenomas were also calculated.
Results: A total of 525 patients (median age 65.3 years; median body mass index 25.6 kg/m(2)) underwent a laparoscopic resection. Conversion to laparotomy became necessary in 17 (3.2%) cases. The perioperative morbidity rate was 20.8%, and malignant transformation occurred in a total of 18.1% of the adenomatous polyps. The median number of lymph nodes removed was 12, and lymph node metastases were seen in a total of 14.8% of the patients (T1--4.8%, T2--19.4%, T3--25%, T4--100%). Estimated 5-year overall and disease-free survival rates were 92.4% and 80.6%, respectively.
Conclusions: For the management of endoscopically unresectable polyps, laparoscopic resection is currently the technique of choice. In addition to the benefits of minimally invasive surgery, in the hands of an experienced surgeon it achieves results comparable with those of open surgery. In view of the high rate of malignant transformation and the absence of unequivocal factors predictive of already present malignant transformation, an oncologically radical operation is essential. In the elderly patient presenting with comorbidities limited resection aiming to minimize surgical trauma in potentially benign disease may be considered. In such a case, however, frozen-section histology is obligatory.