Transanal endoscopic microsurgery

Transanal endoscopic microsurgery (TEM), introduced by Buess et al.¹ in 1983, was initially designed to improve the results for local resection of rectal adenomas. The most common conventional technique of local resection of rectal tumors is the Parks’ per anal resection (PAR). This technique is safe and straightforward; however, the restricted view and limited range (lower rectum) are major drawbacks. The recurrence rates range from 4 to 57 percent.² the high recurrence rates after PAR are thought to be due to the limited view, leading to less precise excisions with a higher rate of specimen fragmentation and positive resection margins. Alternative local techniques for the resection of larger and/or tumors of the mid or upper rectum are the Kraske (suprasphincteric/transsacral) or Mason (transsphincteric) procedures. These are, however, technically demanding and associated with high postoperative morbidity rates of 24–41 percent and 11–70 percent, respectively.