Trans-anal minimally invasive surgery (TAMIS): Case series on short-term outcomes and systematic review of the literature.

[BACKGROUND] Colorectal cancer is the third most common malignancy worldwide with rectal cancer accounting for approximately 30% of all new cases. Surgery is the standard of care in the treatment of localised malignancy and can be performed through open and various minimally invasive approaches. Trans-anal minimally invasive surgery (TAMIS) represents a rectal-sparing hybrid technique between single-port laparoscopy and trans-anal endoscopic microsurgery (TEM) for resection of benign and early-stage rectal cancers. We present our initial experience with TAMIS including short-term outcomes and provide an updated systematic review.

[METHODS] A retrospective case series of patients with rectal lesions who underwent TAMIS between February 2022 to June 2024 at a district general hospital in the UK was performed. Basic patient demographics, intra- and postoperative outcomes including complications were collected and analysed. A comprehensive search of various electronic databases for the systematic review was conducted including PubMed, Embase, MEDLINE, and Web of Knowledge. Studies (excluding case reports) including patients diagnosed with rectal malignancy or benign polyps and treated with TAMIS were included. Analysed outcome measures were excision quality and complications.

[RESULTS] Our case series cohort included a total of 25 patients with a mean age of 70.7 years (SD = 14.3). Mean distance of lesion from the anal verge was 5.8 cm (SD = 3.2), with intra-operative blood loss of 6.0 mls (SD = 10.5), and an operative duration of 67.0 min (SD = 38.9). Final histopathological analysis showed adenocarcinoma in 20%, morbidity rate of 12%, R0 resections in 72%, and 30-day re-admission rate of 16%. The mean length of stay was 2.4 days (SD = 1.8). A total of 48 studies, with 1964 patients were included in the systematic review, with a mixture of case series, comparative studies and published abstracts. Average age was 64.4 years (SD = 6.4) and 42.8% were female. Mean distance of lesion from the anal verge was 6.9 cm (SD = 1.3) with an operative duration of 71.2 min (SD = 18.5). Length of stay was 1.5 days (SD = 1.3), R0 resection rates of 91.8%, morbidity rate of 11.6%, and recurrence rate of 4.7%, respectively.

[CONCLUSION] Although TAMIS is a safe and feasible option in the treatment of benign polyps and early-stage malignancy, outcomes remain similar in the decade since the first published review. TAMIS is still a relatively new technique and it is anticipated that outcomes will likely improve with time.