Transanal Minimally Invasive Surgery for Benign and Malignant Rectal Lesions: Operative and Oncological Outcomes of a Single Center Experience

A Strict Patient Selection Protocol Could Be the Key to Success for Transanal Minimally Invasive Surgery (TAMIS)

OBJECTIVES

In recent years, the local excision of benign rectal lesions or early-stage rectal cancers using minimally invasive surgical techniques has replaced radical interventions that caused impairment in patients' quality of life. The aim of the present study was to investigate the feasibility of transanal minimally invasive surgery (TAMIS), as well as its excision quality, its oncologic outcomes, and its impact on anorectal function.

METHODS

Patients who underwent TAMIS at a single colorectal unit of a tertiary university hospital from 2015 until 2020 for benign rectal lesions or early-stage malignant rectal lesions, along with unsuitable patients for radical interventions, were included in the present study.

RESULTS

Twenty-five patients underwent TAMIS for rectal lesions. Their median distance from the anal verge was 7 cm (range 4-12 cm) and their median size was 3.8 cm (range 2-6 cm). The median operative duration was 75 minutes (range 30-150 minutes) and the median hospitalization interval was 2 days (range 1-6 days). In addition, the negative resection rate was 100% and the recurrence rate was 4% during an average follow-up period of 30 months (range 3-36 months). Two patients (8%) presented short-term complications, and in 1 patient (4%) a hybrid technique was required. Seventeen patients (68%) reported moderate incontinence symptoms 6 weeks postoperatively that subsided in all patients 3 months postoperatively.

CONCLUSIONS

TAMIS seemed to be a feasible technique with adequate oncologic outcomes and high excision quality, which preserved patients' quality of life. The impact of TAMIS on anorectal function after neoadjuvant chemoradiotherapy for rectal cancer should be further investigated, however.

Transanal minimally invasive surgery - A single-center experience

Background

Transanal minimally invasive surgery (TAMIS) was described in the literature 10 years ago. This procedure requires laparoscopic technical skills. It has been well accepted widely worldwide. TAMIS has been applied to multiple procedures, including excision for rectal polyps and cancer, with acceptable outcomes. The study aimed to assess the outcomes of TAMIS in a large district general hospital.

Methodology

A retrospective study on prospectively collected data on 52 consecutive patients of TAMIS performed in a single unit was conducted between May 2014 and February 2020. Data were collected on patient demographics, clinical diagnosis, peri-operative findings, pathological findings, adequacy of excision and complications. Patients were followed up as per the trust and national post-polypectomy guidelines.

Results

Among the 52 patients, TAMIS procedures were completed in 50 patients, of which 31 were female. The procedure was successful in 96.5% but had to abandon in two cases. There was no conversion to another procedure. Pre-operative indications were rectal polyps and one case was an emergency TAMIS in a patient who was bleeding following incomplete colonoscopic polypectomy. The final histology reported that the majority were benign polyps (46), and only 11 cases were malignant. The median distance of the lesion from the anal verge was 6 cm (3-10 cm). The median operative time was 55 min (8-175 min). A total of 45 (77.5%) lesions were completely excised and had negative microscopic margins. Most patients (64%) were discharged home the same day. No complications were observed at a median follow-up of 20 months (6-48 months). There was no mortality.

Conclusions

Our data suggest that TAMIS can be safely performed in a district general hospital for both benign and early rectal cancer. TAMIS was also able to control post-polypectomy bleeding and completion of rectal polypectomy. In selected cases, day-case TAMIS is safe and feasible.

Transanal minimally invasive surgery using laparoscopic instruments of the rectum: A review

Transanal minimally invasive surgery (TAMIS) was first described in 2010 as an alternative to transanal endoscopic microsurgery (TEM). The TAMIS technique can be access to the proximal and mid-rectum for resection of benign and early-stage malignant rectal lesions and also used for noncurative intent surgery of more advanced lesions in patients who are not candidates for radical surgery. TAMIS has a shorter learning curve, reduced device setup time, flexibility in instrument use, and versatility in application than TEM. Also, TAMIS shows similar results in a view of the operation time, conversion rate, reoperation rate, and complication to TEM. For these reasons, TAMIS is an easily accessible, technically feasible, and cost-effective alternative to TEM. Overall, TAMIS has enabled the performance of high-quality local excision of rectal lesions by many colorectal surgeons. As TAMIS becomes more broadly utilized such as pelvic abscess drainage, rectal stenosis, and treatment of anastomotic dehiscence, the acquisition of appropriate training must be ensured, and the continued assessment and assurance of outcome must be maintained.

Submucosal Enhancing Stripe as a Contrast Material-enhanced MRI-based Imaging Feature for the Differentiation of Stage T0-T1 from Early T2 Rectal Cancers

Background Accurate differentiation of stage T0-T1 rectal tumors from stage T2 rectal tumors facilitates the selection of appropriate surgical treatment. MRI is a recommended technique for local staging, but its ability to distinguish T1 from T2 tumors is poor. Purpose To explore the value of a submucosal enhancing stripe (SES), an uninterrupted enhancing band between the rectal tumor and the muscular layer on contrast material-enhanced T1-weighted images, as a potential imaging feature to differentiate T0-T1 from T2 rectal tumors. Materials and Methods This retrospective study included patients with pT0-T1 and pT2 rectal tumors who underwent pretreatment MRI and rectal tumor resection between January 2012 and November 2019. Two radiologists independently evaluated tumor characteristics (SES; status of muscularis propria [SMP]; and tumor shape, location, and size) at MRI. The associations of clinical and imaging characteristics with stage T0-T1 or T2 tumors were assessed, β values were calculated, and predictive models were built. The diagnostic accuracies for the differentiation of T0-T1 tumors from T2 tumors with SES and SMP were compared. Results Data from 431 patients (mean age, 60 years ± 10 [standard deviation]; 261 men) were evaluated. SES (β = 3.9; 95% CI: 3.1, 4.7; P < .001), SMP (β = 1.3; 95% CI: 0.7, 1.9; P < .001), and carpetlike shape (β = 1.6; 95% CI: 0.5, 2.8; P = .01) were independent factors distinguishing T0-T1 tumors from T2 tumors. The diagnostic accuracy was 87% (95% CI: 84, 90; 376 of 431) for SES and 67% (95% CI: 63, 72; 290 of 431) for SMP (P < .001). Conclusion Submucosal enhancing stripe (SES) at contrasted-enhanced MRI, status of muscularis propria (SMP) on T2-weighted images, and tumor shape can serve as independent imaging features to differentiate stage T0-T1 rectal tumors from stage T2 rectal tumors. Moreover, SES is a more accurate feature than is SMP. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Comparison of the transanal surgical techniques for local excision of rectal tumors: a network meta-analysis

BACKGROUND

In order to assess the various surgical modalities for local resection of rectal tumors, a systematic review of the current literature and a network meta-analysis (NMA) was designed and conducted.

METHODS

The present study adhered to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions principles. Scholar databases (Medline, Scopus, Web of Science) were systematically screened up to 23/12/2019. A Bayesian NMA, implementing a Markov chain Monte Carlo analysis, was introduced for the probability ranking of the available surgical methods. Odds ratio (OR) and weighted mean difference (WMD) of the categorical and continuous variables, respectively, were reported with the corresponding 95% confidence interval (95%CI).

RESULTS

Overall, 16 studies and 2146 patients were introduced in our study. Transanal minimal invasive surgery (TAMIS) displayed the highest performance regarding the overall postoperative morbidity, the perioperative blood loss, the length of hospitalization, and the peritoneal violation rate. Transanal endoscopic microsurgery (TEM) was the most efficient modality for resecting an intact specimen. Although transanal local excision (TAE) had the highest ranking considering operative duration, it was associated with a significant risk for positive resection margins and tumor recurrence.

CONCLUSIONS

In conclusion, TEM and TAMIS display superior oncological results over TAE. Due to several limitations, validation of these results requires further RCTs of a higher methodological level.