Local excision for rectal cancer: a minimally invasive option

Nonoperative management and local excision after neoadjuvant chemoradiation therapy for rectal cancer

Locally advanced extraperitoneal rectal cancer represents a significant clinical challenge, and currently, the standard treatment is based on neoadjuvant chemoradiation therapy (CRT) followed by radical surgical resection with total mesorectal excision (TME). In the last 30 years, its management has undergone significant changes due to the improvement of complementary radio- and chemotherapy treatments, the improvement of minimally invasive surgical approaches and the diffusion of organ-sparing approaches, such as nonoperative management, commonly called "watch and wait" (NOM) and local excision (LE), in highly selected patients who achieve a major or complete response to neoadjuvant CRT. This review aimed to critically examine the efficacy and oncological safety of NOM and LE compared to those of standard TME in rectal cancer patients after neoadjuvant CRT. Both the pros and cons of these approaches were strictly analyzed, providing a comprehensive and critical overview of these novel management strategies for rectal cancer.

Current Surgical Methods in Local Rectal Excision

Background

The treatment of rectal cancer has evolved with the advancement of surgical techniques. Less invasive approaches are becoming more accepted as the primary treatment method.

Summary

Such methods as transanal excision, transanal endoscopic microsurgery, and transanal minimally invasive surgery can reduce morbidity and mortality rates. However, not all patients are suitable candidates for these procedures, and proper diagnostics are necessary to establish indications. Compared to total mesorectal excision, transanal excision techniques have been shown to have fewer complications and comorbidities while still being able to remove cancerous tissue entirely. Transanal excision is the simplest method, where the operator removes visible rectal lesions. The basic principle of transanal endoscopic microsurgery is to dilate the rectum mechanically and by air insufflation and then use special surgical instruments to remove suspicious lesions under the vision of a telescope. Transanal minimally invasive surgery combines transanal endoscopic microsurgery and single-incision laparoscopic surgery, making the hard-to-reach proximal rectum accessible to classic laparoscopic instruments.

Key Message

Local excision techniques, when used as a monotherapy for treating patients with rectal cancer, have established themselves as a curative and less radical treatment for strictly selected patients with early rectal carcinoma, leading to improved quality of life. When combined with other modalities such as neoadjuvant chemoradiotherapy, total neoadjuvant therapy, and immunotherapy, transanal surgery can be offered to patients with locally advanced rectal cancer as part of the organ preservation strategy. This review will discuss the patient selection and technical aspects of transanal surgery, showcasing its current role in treating rectal carcinoma.

Functional Outcomes after Transanal Surgery

Transanal surgery has gained in popularity during the latter part of the last decade for both rectal cancer and benign disease. The current role for local excision of early rectal neoplastic lesions has expanded due to better understanding of risk factors for lymph node metastasis and heightened awareness for the long-term sequelae of radical surgery. Transanal resection of the rectum (both for cancer or inflammatory bowel diseases) has now been established as a successful procedure that overcomes some of the limitations of the abdominal approaches. Once the feasibility, safety, and the oncologic results of transanal minimally invasive approaches for patients with rectal cancer have been acknowledged, quality of life and functional outcomes have become increasingly important issues. This article provides an overview of the different techniques currently available for the minimally invasive transanal treatment of rectal lesions, particularly focusing on functional outcomes.

Transanal endoscopic operation for rectal lesion: a rapid initial experience

BACKGROUND

In recent decades, transanal surgery for rectal lesions has become a valid alternative treatment for the treatment of small lesions of the rectum. Significant benefits in terms of morbidity and mortality are confirmed. There are multiple platforms for transanal surgery but the TEO system® is one of the best known.

METHODS

Between November 2017 and July 2019, 25 patients with rectal lesions suitable to transanal treatment came to our observation. In all reported cases, full-thickness rectum resections were performed. Demographic, histopathological, surgical morbidity/mortality and clinical outcome in all patients who underwent TEO were retrospectively evaluated from a prospectively collected database.

RESULTS

For a period of less than 2 years, 25 rectal lesions were excised by TEO. Sixteen lesions (64%) were low (<4 cm), 7 (28%) were mid-rectal (4-8 cm) and 2 (8%) were in the proximal rectum (>8 cm). Postoperative complications included: 3 (12%) bleedings, and 8 (32%) post-polipectomy syndrome.

CONCLUSIONS

Our initial experience suggests TEO is safe and feasible. Full-thickness resection guarantees adequate deep margins. Moreover, the limited number of cases requires the development of adequate reference centers.