Outcomes of Transanal Minimally Invasive TME Versus Laparoscopic Intersphincteric Resection Techniques for Rectal Cancer After Initial Neoadjuvant Chemo-radiotherapy: Double Blinded Study

Ideal surgery for rectal cancer should not only obtain adequate radial and circumferential margins, but also preserve normal sphincter function.In 1990, the results of a 'close shave' at anterior resection were reported, suggesting that a resection margin of 1 cm or less produced an oncological outcome similar to that of a resection margin greater than 1 cm.

Sphincter preservation presents several advantages; The lower risk of intraoperative rectal perforation and positive circumferential margin than APR, the lower risk of damaging the pelvic branches of the pelvic autonomic nerve and The preservation of the body image that may increase quality of life.

Recently, the clinical outcome of intersphincteric resection (ISR) as a laparoscopic approach (laparoscopic ISR) has been reported, but laparoscopic ISR for patients with bulky low rectal cancer remains challenging particularly for T3 tumors in patients with a narrow pelvis, because of the difficulty in understanding the accurate anatomy of the small pelvic cavity, in dissecting the TME or the tumor specific mesorectal excision (TSME) plane, and in transecting the lower rectum safely. Moreover, numerous studies have demonstrated that laparoscopic techniques have many advantages in colorectal surgery compared with open surgery.

Although Radical resection is the gold standard for the treatment of rectal cancer, TEM offers the advantage of combining a minimally invasive technique with evident benefits in terms of postoperative morbidity and recovery, long-term functional outcomes and subsequently improved quality of life. Transanal Endoscopic Microsurgery (TEM) developed at 1984 and eliminated most of local transanal excision limitations and triggered a significant improvement in the local excision procedures of rectal lesions. While TEM became the 'gold standard' for the treatment of large rectal adenomas and early rectal cancer, there are special concerns about the lack of adequate lymphadenectomy.

Preoperative chemoradiation therapy is widely used to treat locally advanced rectal cancer to increase resectability, and to enhance sphincter preservation, local control and possibly, survival rates. Surgery is performed six to eight weeks after radiotherapy.