Lymph node retrieval for colorectal cancer: Estimation of the minimum resection length to achieve at least 12 lymph nodes for the pathological analysis

•Adequate lymph node retrieval is important in colorectal cancer staging.•APR and Hartmann's had significant lower adequate lymph nodes retrievals.•Additional maneuvers are required to achieve the minimum length of bowel to resect and adequate sampling.

IntroductionAdequate lymph node retrieval is important in colorectal cancer staging for the selection of patients that necessitate adjuvant treatments. The minimum number of 12 lymph nodes is one of the premises and is dependent, among the other factors, from the length of bowel resected. We have reviewed our specimens to identify the high-risk operations for inadequate nodal sampling and estimate the minimum length of bowel needed to resect to achieve this purpose.Materials and methodsA retrospective review of colorectal specimens over 10 years of activity looking at data including location of the tumor, type of operation performed, length of bowel resected and number of lymph nodes retrieved.ResultsAbdominoperineal and Hartmann's resections produced significant lower adequate retrievals compared to other colorectal operations, corresponding to 45.4% and 59.1% of cases respectively. The measured average length of bowel was 30 cm and 25 cm respectively, increasing the length to 36 cm and 42 cm would increase the adequacy rate to 90%.ConclusionsAbdominoperineal and Hartmann's resections are, in our series, high-risk operations that frequently do not produce the minimum number of lymph nodes necessary. These operations may require additional maneuvers such as mobilization of the splenic flexure to achieve the minimum length of bowel to resect.