Chapter 109: Local Excision for Stage I Rectal Cancer

INTRODUCTION

Total mesorectal excision (TME) remains the gold standard in the treatment of patients with early-stage rectal cancer. The reported oncological outcomes of this approach for stage I disease are excellent, with local recurrence (LR) rates of 3%, and 5-year survival as high as 93%.¹ But TME is a major operation associated with some mortality and significant morbidity. More than one in three patients develop perioperative complications.² Anastomotic leak with low rectal anastomosis occurs in approximately 10% of patients, and has been associated with poor oncological outcomes.^3,4 Injuries to the hypogastric and pelvic nerves can cause genitourinary dysfunction in up to 40% of patients⁵; functional disturbances such as tenesmus, bowel urgency, soiling, and fecal incontinence are also common.⁶ To prevent the consequences of anastomotic leak, many patients are given a temporary diverting loop ileostomy, which is inconvenient and adds to the burden of morbidity.⁷ In addition, between 20% and 30% of all rectal cancers—and a higher proportion of patients with distal rectal cancers—require an abdominoperineal excision (APE) of the rectum with a permanent colostomy, a procedure that significantly impacts patients’ quality of life.⁵

The first transanal excision of rectal cancer is attributed to Lisfranc in 1827.⁸ In 1884, Kraske described a posterior approach involving resection of the coccyx and partial sacrectomy.⁹ (This technique never gained popularity in the United States.) In the 1960s, York-Mason introduced the transsphincteric approach¹⁰ (originally described for tumors in the anterior rectal wall, this procedure is still the preferred technique for rectourethral fistulae repair in some specialty centers). It was Parks who introduced transanal excision (TAE) in the 1960s. Using a special set of speculums still utilized by many surgeons, TAE was performed without dividing the anal sphincter.¹¹ In the 1980s, a novel platform known as transanal endoscopic microsurgery (TEM) was introduced by Buess.¹² Since then two additional platforms—transanal endoscopic operation (TEO) and transanal minimally invasive surgery (TAMIS) have been developed. In these platforms, the rectum is distended by insufflation with CO₂, and tumor resection proceeds under direct endoscopic visualization with specially designed or conventional laparoscopic instruments. In addition to providing enhanced visualization and superior instrumentation, a significant advantage of these transanal endoscopic approaches (TEM, TEO, TAMIS) is the possibility of reaching tumors located in the mid and upper rectum, beyond the limits of conventional TAE.

The advantages of local excision (LE) compared to radical surgery (RS) are many: shorter operative time, minimal fluid requirement, minor blood loss, shorter hospital stay, and a quicker postoperative recovery. Morbidity and mortality rates are significantly lower after LE compared to RS, but LE is associated with a higher risk of LR, particularly in the setting of T2N0 tumors. Many patients who develop a LR after LE can undergo salvage RS, but their probability of survival is lower compared to patients treated initially with RS. Prospective data comparing long-term ...