To Total Mesorectal Excision Research Articles

Neuroanatomy of the Minor Pelvis-Significant Area in the Surgery of Rectal Carcinoma

For centuries, there are attempts to develop a strategy of appropriate rectal carcinoma management. However, surgery remains the essential element of therapy, being proposed by Morgagni in the eighteenth century. The anterior rectal resection method established by Dixon, in addition to Total Mesorectal Excision (TME), supplemented by combined therapy (radiotherapy, chemotherapy) initiated modern rectal carcinoma management techniques, aimed at oncological radicalism with sphincter preservation (Sphincter Saving Procedure – SSP, Sphincter Sparing Surgery – SSS, Sphincter Preserving Surgery – SPS) (1). Surgical intervention is considered as the standard oncological therapeutic method in case of rectal carcinoma patients, supplemented by combined therapy (radiotherapy, chemotherapy), depending on the stage of the disease and biology of the tumor. Surgery consists in the excision of the rectum and tumor (maintained margins free of neoplastic infiltration – R0 resection), as well as mesorectum with its vessels and lymph nodes. In case of tumors localized in the upper part of the rectum, tumor specific mesorectal resection (TSME) is preferred (2). In case of tumors localized in the medial and inferior part of the rectum low anterior resections are performed, in addition to total mesorectal excisions. Intestinal continuity is restored after the anastomosis of the proximal intestinal segment with a fragment of the rectal ampulla or at the level of the anal canal (coloanal anastomosis) (3). The technique proposed by Heald and Enker consisting in the excision of the mesorectum should always be respected, enabling to maintain the undamaged mesorectal (oncological radicalism) and Tolt’s fascia (NerveSparing Technique). Depending on the localization of the tumor rectal sphincters are preserved, and intestinal continuity is restored after the anastomosis of bowel segments free of neoplastic infiltration with all preserved techniques of anastomosis surgery (4). In most cases the reservoir part of the rectum is lost (different fragments of the rectal ampulla are preserved). Intestinal continuity restoration consisting in the simple anastomosis of the colon and rectal stump, and the creation of the neorectum cistern (by means of transverse coloplasty or other intestinal cisterns) do not guarantee normal functioning of the anorectum. Dixon’s (promoter of the anterior resection) suggestion that the procedure had no influence on the functioning of the sphincters proved to be erroneous (5). Combined oncological therapy of rectal carcinoma also exerts a negative effect on the genitourinary system. Urinary bladder and urethral sphincter dysfunction (urine retention and incontinence), as well as sexual disturbances both in male and female patients (impotence, lack of ejaculation, retrograde ejaculation, lack of orgasm) can result from the operation, especially in case of lower rectal carcinomas. The percentage of the above-mentioned postoperative complications ranges between 10 and 60% (6). The described disturbances result from damage to the autonomic innervation of the mentioned organs. The wide range of the above-mentioned disturbances depends on the experience of the surgeon, thus, being dependent of the learning

Local Excision After Preoperative Chemoradiation Results in an Equivalent Outcome to Total Mesorectal Excision in Selected Patients with T3 Rectal Cancer

We previously reported 26 patients who underwent preoperative chemoradiotherapy (CXRT) for T3 rectal cancer and were subsequently offered full-thickness local excision (LE) as an alternative to total mesorectal excision (TME). At nearly 4 years' follow-up, no difference in outcome was observed. This study compares outcomes in a larger cohort of patients and reevaluates the original 26 patients after longer follow-up. Retrospective review was performed of patients who underwent preoperative CXRT (radiation doses of 45, 50.4, or 52.5 Gy with concurrent 5-fluorouracil-based chemotherapy) followed by surgery for T3 rectal cancer. Forty-seven patients underwent LE (Kraske [n = 6] or transanal excision [n = 41]). 473 patients underwent TME (abdominoperineal resection [n = 141] or low anterior resection [n = 332]). Local recurrence, disease-free survival (DFS), disease-specific survival, and overall survival (OS) rates were compared. Median follow-up was 63 months for the LE group and 59 months for the TME group. Twenty-three LE patients (49%) had a complete response to CXRT, 17 (36%) had microscopic residual disease, and 7 (15%) had gross residual disease, compared with 108 (23%), 89 (19%), and 276 (58%) TME patients, respectively. There was no significant difference between the 10-year actuarial local recurrence rate for the LE group versus the TME group (10.6% and 7.6%, respectively; P = .52), and no significant difference in DFS, disease-specific survival, or OS rates between groups. In selected patients who demonstrate an excellent response to preoperative CXRT for T3 rectal cancer, full-thickness LE offers comparable local control, DFS, and OS to that achieved with proctectomy and TME.

Low Rectal Cancer: A Call for a Change of Approach in Abdominoperineal Resection

Despite the major improvements that have been made due to total mesorectal excision (TME), low rectal cancer still remains a challenge. By investigating a prospective randomized rectal cancer trial in which surgeons had undergone training in TME the factors responsible for the poor outcome were determined and a new method for assessing the quality of surgery was tested. Survival differed greatly between abdominoperineal resection (APR) and anterior resection (AR; 38.5% v 57.6%, P = .008). Low rectal carcinomas have a higher frequency of circumferential margin involvement (26.5% v 12.6%, P < .001). More positive margins were present in the patients operated with APR (30.4%) compared to AR (10.7%, P = .002). Furthermore, more perforations were present in these specimens (13.7% v 2.5%, P < .001). The plane of resection lies within the sphincteric muscle, the submucosa or lumen in more than 1/3 of the APR cases, and in the remainder lay on the sphincteric muscles. We systematically described and investigated the pathologic properties of low rectal cancer in general, and APR in particular, in a prospective randomized trial including surgeons who had been trained in TME. The poor prognosis of the patients with an APR is ascribed to the resection plane of the operation leading to a high frequency of margin involvement by tumor and perforation with this current surgical technique. The clinical results of this operation could be greatly improved by adopting different surgical techniques and possibly greater use of radiochemotherapy.

Surgery, radio- and chemotherapy for multimodal treatment of rectal cancer.

The possibilities and results of multimodal treatment in rectal cancer were reviewed with respect to the results of surgical treatment only. Based on the results of 4 studies, reducing local relapse rates and increasing long term survival rates significantly, postoperative radiochemotherapy (RCT) + chemotherapy (CT) should remain the recommended standard for R0 resected UICC II and III rectal cancers. The addition of RT to adjuvant CT reduces local relapses without significant impact on survival (NSABP R-02). Vice versa, the addition of CT to RT or an improved CT in the RCT-concept prolongs survival. Preoperative neoadjuvant radiotherapy (RT) reduced local relapse rates in 9 studies, and extended survival in one study that evaluated all eligible patients. Preoperative RT reduced local relapse rates in addition to total mesorectal excision (TME) but did not extend survival. The preoperative RCT + CT downstages resectable and nonresectable tumors and induces a higher sphincter preservation rate. Phase III data justifying its routine use in all UICC II + III stages are not yet available. This treatment may be routinely applied in nonresectable primary tumors or local relapses. Preoperative RCT (or RT) may evolve as standard, if the patient selection is improved and postoperative morbidity and long term toxicity reduced. Intraoperative RT could be added to this concept or be used together with preoperative/postoperative RT at the same indications. Postoperative adjuvant RT reduced local relapses significantly in a single trial, and no impact on survival time is reported. Since postoperative RT is inferior to preoperative RT, this treatment cannot be recommended, if RT is chosen as a single treatment modality in adjunction to surgery. The results of local tumor excisions may be improved with pre- or postoperative RCT + CT. In the future, multimodal treatment of rectal cancer might be more effective, if individualized according to prognostic factors.