What is the place of intersphincteric resection when operating on low rectal cancer?

Critical and Challenging Issues in the Surgical Management of Low-Lying Rectal Cancer

Despite innovative advancements, the management of distally located rectal cancer (RC) remains a formidable endeavor. The critical location of the tumor predisposes it to a circumferential resection margin that tends to involve the sphincters and surrounding organs, pelvic lymph node metastasis, and anastomotic complications. In this regard, colorectal surgeons should be aware of issues beyond the performance of total mesorectal excision (TME). For decades, abdominoperineal resection had been the standard of care for low-lying RC; however, its association with high rates of tumor recurrence, tumor perforation, and poorer survival has stimulated the development of novel surgical techniques and modifications, such as extralevator abdominoperineal excision. Similarly, difficult dissections and poor visualization, especially in obese patients with low-lying tumors, have led to the development of transanal TME or the "bottom-to-up" approach. Additionally, while neoadjuvant chemoradiotherapy has allowed for the execution of more sphincter-saving procedures without oncologic compromise, functional outcomes remain an issue. Nevertheless, neoadjuvant treatment can lead to significant tumor regression and complete pathological response, permitting the utilization of organ-preserving strategies. At present, an East and West dualism pervades the management of lateral lymph node metastasis, thereby calling for a more global and united approach. Moreover, with the increasing importance of quality of life, a tailored, individualized treatment approach is of utmost importance when taking into account oncologic and anticipated functional outcomes.

Intersphincteric resection for low rectal cancer

For low rectal cancer located < 5 cm from the anal verge, abdominoperineal resection (APR) with permanent sigmoid colostomy is usually used to ensure the R0 resection. Sphincter saving surgery has emerged in the last 20 years, and the introduction of intersphincteric resection (ISR) can successfully preserve the anal function and guarantee a radical tumor resection for patients with ultra-low lying tumors. Therefore, the use of APR has been consistently declining worldwide. Recently, a growing body of research on ISR has been reported. However, more evidence based results are needed to clarify some issues about ISR. In the current review, we discuss the indications for ISR and the oncological and functional outcomes following the procedure. Some technique issues of ISR are also discussed.

Low rectal cancer: Sphincter preserving techniques-selection of patients, techniques and outcomes

Low rectal cancer is traditionally treated by abdominoperineal resection. In recent years, several new techniques for the treatment of very low rectal cancer patients aiming to preserve the gastrointestinal continuity and to improve both the oncological as well as the functional outcomes, have been emerged. Literature suggest that when the intersphincteric resection is applied in T1-3 tumors located within 30-35 mm from the anal verge, is technically feasible, safe, with equal oncological outcomes compared to conventional surgery and acceptable quality of life. The Anterior Perineal PlanE for Ultra-low Anterior Resection technique, is not disrupting the sphincters, but carries a high complication rate, while the reports on the oncological and functional outcomes are limited. Transanal Endoscopic MicroSurgery (TEM) and TransAnal Minimally Invasive Surgery (TAMIS) should represent the treatment of choice for T1 rectal tumors, with specific criteria according to the NCCN guidelines and favorable pathologic features. Alternatively to the standard conventional surgery, neoadjuvant chemo-radiotherapy followed by TEM or TAMIS seems promising for tumors of a local stage T1sm2-3 or T2. Transanal Total Mesorectal Excision should be performed only when a board approved protocol is available by colorectal surgeons with extensive experience in minimally invasive and transanal endoscopic surgery.

Intersphincteric resection for treatment of ultra-low rectal cancer

Traditional treatment for ultra-low rectal cancer is abdominal perineal resection, but it is associated with poor quality of life. With the continued development of surgical techniques, intersphincteric resection has been greatly improved. Its unique advantages include improvement of sphincter preservation and anal function after surgery and no requirement of a permanent stoma. Although the ability of defecation control needs to be gradually restored, intersphincteric resection has similar postoperative survival rate, relapse rate and oncology results to abdominal perineal resection. Thus, intersphincteric resection should be the preferred treatment for ultra-low rectal cancer.