Transanal endoscopic microsurgery (TEM): Significance in the operative therapy concept of rectal tumors

Local excision of rectal tumors was primarily carried out for adenomas or with a palliative intention. Over a course of more than 20 years local surgery has increasingly become established for early (T1) carcinomas. Among several local resection procedures, the less traumatizing transanal approach has become most accepted as compared to more aggressive techniques. The transanal endoscopic microsurgical (TEM) technique is most widely used. For 'low risk'T1 carcinomas low local recurrence rates are primarily reported, and both the tumor characteristics and the quality of the resection are relevant prognostic factors. For 'high risk'T1 or T2 carcinomas, high recurrence rates have to be expected. Among additional measures, immediate conventional radical re-operating is superior to adjuvant chemoradiotherapy. In addition, awaiting salvage surgery of local recurrences provides inferior oncological outcomes. Interestingly, favorable results have been obtained with neoadjuvant chemoradiotherapy of T2-3 rectal cancers and first studies consistently showed low recurrence rates. © 2007 Springer Medizin Verlag.