Causes and Prevention of Functional Disturbances Following Low Anterior Resection for Rectal Cancer

Abstract

Surgical therapy of a colon carcinoma does not usually affect the patient’s quality of life in the medium or long term, if the tumor does not involve adjacent organs and there are no postoperative complications. In rectal cancer, however, dysfunctions such as anal continence disorders occur in quite a few patients following anterior resection, and particularly low anterior resection (LAR) with total mesorectal excisison (TME), as a result of the total or almost total loss of the rectum, and disorders of the bladder and sexual function can occur because the autonomic nerves, which regulate bladder and sexual function as well as anal continence, are often damaged due to their anatomical proximity. Not only have healing rates improved with the introduction and more general use of total mesorectal excision, the local recurrence rates have fallen below 10 %, in part below 5 %, with TME and neoadjuvant radiotherapy or radio chemotherapy, so that disorders which affect quality of life naturally take on more importance for the individual patient, especially if he has been healed, but are also considered to be increasingly important by the surgeon. In the past decade anal continence disturbance has become quantitatively more significant, since the majority of patients with a rectal tumor undergo anterior resection. Hence 70 90% of rectal tumors can currently be operated with sphincter-preserving surgery without violating oncological principles. Rectal cancer surgery thus aims both at preventing a local recurrence and at preserving anal continence and bladder and sexual function. The risk of injury to the autonomic nerves is naturally greater when the tumor is more advanced, when the surgery is more extensive and the cancer itself is closer to the autonomic nerves, as is the case when the tumor is localized in the lower or middle third of the ventral circumference of the rectum, so that bladder and sexual dysfunction occur most frequently in this tumor site or after abdomino-perineal excision (APE). Further risk factors for dysfunction are age , local postoperative complications and radioor radio-chemotherapy, in particular adjuvant therapy. If the appropriate surgical technique is applied, dysfunction can generally be avoided if the tumor is not so advanced that parts of the bladder, the prostate or the posterior vaginal wall and autonomic nerves also have to be resected. In such cases a preparation technique which causes no mechanical or thermal damage to the autonomic nerves is important. With ever increasing knowledge of the complex function of anal continence and the causes of postoperative disorders, surgical techniques and post-operative measures have been