Morphology of the mesorectum in patients with primary rectal cancer.

PURPOSE: The size and contents of the pelvis differ between the genders, and this may affect mesorectal size and shape. The aim of this prospective pilot study was to examine radiologically the applied anatomy of the mesorectum. METHODS: Fifty-eight patients (35 male, 23 female) with primary rectal cancer who had suitable high-resolution staging pelvic magnetic resonance images between November 2002 and July 2004 were studied. Ten variables of mesorectal morphology were measured on axial images at the ischial spines. The associations between morphologic variables and gender and body mass index were examined. RESULTS: Compared with female patients, male patients had a larger area of overall mesorectal package (3,776 mm2 vs. 2,772 mm2, P = 0.001), larger area of mesorectal fat (2,562 mm2 vs. 1,842 mm2, P = 0.001), and higher ratio of anteroposterior to transverse diameter of the mesorectal package (0.82 vs. 0.56, P < 0.001). The anterior mesorectal fat buffer was significantly thinner in females than in males (2.9 mm vs. 7.8 mm, P < 0.001). Mesorectal fat area was greater in males with a body mass index >25 than with a body mass index <25. CONCLUSIONS: Males have a larger overall mesorectal package compared with females, mainly caused by mesorectal fat. The anterior mesorectal fat is significantly thinner in females than in males. Such morphologic differences may affect resection margin status.

Surgery for locally recurrent rectal cancer.

PURPOSE: Resection of locally recurrent rectal cancer after curative resection represents a difficult clinical problem and a surgical challenge. The aim of this study was to assess the outcome of a series of patients who underwent resection of locally recurrent rectal cancer with curative intent. METHODS: A retrospective review was performed of 64 patients who underwent surgical exploration with a view to cure for locally recurrent rectal cancer under the care of one surgeon between April 1997 and April 2004. Details were obtained on the primary tumor and the operation, the indication for investigation of recurrence, preoperative imaging, operative findings, morbidity and mortality, and histopathology. RESULTS: The median time interval between resection of primary tumor and surgery for locally recurrent disease was 31 (interquartile range, 21 to 48) months. Twenty-three patients had central disease, 10 patients had sacral involvement, 21 patients had pelvic sidewall involvement, and 10 patients had both sacral and sidewall involvement. Fifty-seven patients underwent resection of the tumor. Thirty-nine of the 57 patients underwent wide resection (abdominoperineal excision of rectum, anterior resection, or Hartmann's procedure) whereas 18 patients (31.6 percent) required radical resection (pelvic exenteration or sacrectomy). Curative, negative resection margins were obtained in 21 of 57 patients who had tumor excision (36.8 percent). Perioperative mortality was 1.6 percent. Significant postoperative morbidity occurred in 40 percent of patients. CONCLUSIONS: This study has shown that a significant proportion of patients with locally recurrent rectal cancer can undergo resection with negative margins.