Macroscopic assessment of mesorectal excision in rectal cancer: a useful tool for improving quality control in a multidisciplinary team.

ABSTRACT

BACKGROUND: High quality of surgical technique and the use of descriptive measures to assess and report surgical proficiency have been shown to influence locoregional tumor control in patients with rectal cancer. In this study, the authors have aimed to audit the implementation of a macroscopic assessment of mesorectal excision (MAME) and to investigate factors that influenced surgical quality and disease recurrence. METHODS: All curative resections for rectal cancer were prospectively evaluated for MAME between 1998 and 2007. Mesorectal specimens were graded into 3 types complete, nearly complete, and incomplete categories. Univariate and multivariate analyses identified independent risk factors for noncomplete mesorectum categories as well as local and overall tumor recurrence. RESULTS: Of 359 specimens, 294 (81.9%) underwent evaluation; 82.3% were "complete." Abdominoperineal resection (APR) was the sole covariate associated with inadequate mesorectal excision (odds ratio [OR]=2.7; P=.003). Independent predictors of local recurrence were circumferential resection margin (CRM) involvement (OR=3.6; P=.027) and noncomplete mesorectum (OR=4.4; P=.008). CRM+ (OR=3.1; P=.004), poorly differentiated tumors (OR=14.2; P=.010), nodal involvement (OR=2.9; P=.010), and APR (OR=2.9; P=.006) were independent risk factors for overall recurrence. In lower third tumors, noncomplete mesorectum occurred more frequently in APR compared with sphincter-saving procedures (31.1% vs 18.8%; P=.088). CONCLUSIONS: This study demonstrates the value of auditing MAME. Good proficiency of mesorectal excision is associated with lower tumor recurrences after curative surgery, and is a morphological tool found to be useful in clinical practice.