Transanal endoscopic microsurgery is more effective than traditional transanal excision for resection of rectal masses

[Transanal Endoscopic Microsurgery (TEM) is a surgical option to preserve fecal continence in selected low rectal cancers]

INTRODUCTION

Despite its existence for more than 40 years, the TEM method has not become widespread. The main reasons are the high acquisition costs, the sophisticated technology and alternative procedures (especially radical resection procedures), which provide greater oncological safety. However, avoiding major abdominal surgery with the creation of a stoma and higher complication rates can outweigh the higher risk of recurrence for some patients. We examined the results using V-TEM with reduced acquisition costs in the resection of adenomas and carcinomas and discussed its importance by literature .

METHOD

From 2003 to 2019, 154 patients with 170 findings were operated by V-TEM technology. Data on the operation and follow-up were collected and analyzed retrospectively.

RESULTS

The median age was 67 years, 89 patients were male and 65 female. V-TEM was performed on 79 carcinomas, 77 adenomas and 14 other findings. The complication rate was 21.2 %. R0 resection was achieved in 78.8 %. The adenoma recurrence rate was 7.3 %, the overall recurrence rate for carcinomas 11.9 %, local recurrences were observed in 6.8 %. The disease-specific survival is 100 % at 5 years and 94.2 % at ten years.

DISCUSSION

The successful use of TEM in adenomas and early carcinomas is undisputed. When treating carcinomas from a T1 high risk stage using TEM, recurrence rates higher than 10 % must be expected. Better results can be achieved with radical procedures, this is why they are considered the therapy of choice in these cases. However, there are no differences in terms of survival rates and TEM offers proven better postoperative quality of life. In particular, the combination of neoadjuvant procedures with TEM delivered promising results in more advanced stages. Further studies on TEM and the possibility of lower acquisition costs through modification to V-TEM could make the method more popular in the future.

Robotic transanal minimally invasive surgery (r-TAMIS): perioperative and short-term outcomes for local excision of rectal cancers

BACKGROUND

Transanal minimally invasive surgery (TAMIS) is an advanced technique for excision of early rectal cancers. Robotic TAMIS (r-TAMIS) has been introduced as technical improvement and potential alternative to total mesorectal excision (TME) in early rectal cancers and in frail patients. This study reports the perioperative and short-term oncological outcomes of r-TAMIS for local excision of early-stage rectal cancers.

METHODS

Retrospective analysis of a prospectively collected r-TAMIS database (July 2021-July 2023). Demographics, clinicopathological features, short-term outcomes, recurrences, and survival were investigated.

RESULTS

Twenty patients were included. Median age and body mass index were 69.5 (62.0-77.7) years and 31.0 (21.0-36.5) kg/m2. Male sex was prevalent (n = 12, 60.0%). ASA III accounted for 66.7%. Median distance from anal verge was 7.5 (5.0-11.7) cm. Median operation time was 90.0 (60.0-112.5) minutes. Blood loss was minimal. There were no conversions. Median postoperative stay was 2.0 (1.0-3.0) days. Minor and major complication rates were 25.0% and 0%, respectively. Seventeen (85.0%) patients had an adenocarcinoma whilst three patients had an adenoma. R0 rate was 90.0%. Most tumours were pT1 (55.0%), followed by pT2 (25.0%). One patient (5.0%) had a pT3 tumour. Specimen and tumour maximal median diameter were 51.0 (41.0-62.0) mm and 21.5 (17.2-42.0) mm, respectively. Median specimen area was 193.1 (134.3-323.3) cm2. Median follow-up was 15.5 (10.0-24.0) months. One patient developed local recurrence (5.0%).

CONCLUSIONS

r-TAMIS, with strict postoperative surveillance, is a safe and feasible approach for local excision of early rectal cancer and may have a role in surgically unfit and elderly patients who refuse or cannot undergo TME surgery. Future prospective multicentre large-scale studies are needed to report the long-term oncological outcomes.

Transanal minimally invasive surgery (TAMIS) for local excision of benign and malignant rectal neoplasia: a 7-year experience

PURPOSE

Transanal minimally invasive surgery (TAMIS) is an advanced transanal platform that can be utilised to perform high-quality local excision (LE) of rectal neoplasia. This study describes clinical and midterm oncological outcomes from a single unit's 7-year experience with TAMIS.

METHODS

Consecutive patients who underwent TAMIS LE at our institution between January 1st, 2016, and December 31st, 2022, were identified from a prospectively maintained database. Indication for TAMIS LE was benign lesions not amenable to endoscopic excision or histologically favourable early rectal cancers. The primary endpoints were resection quality, disease recurrence and peri-operative outcomes. The Kaplan-Meier survival analyses were used to describe disease-free survival (DFS) for patients with rectal adenocarcinoma that did not receive immediate salvage proctectomy.

RESULTS

There were 168 elective TAMIS LE procedures performed for 102 benign and 66 malignant lesions. Overall, a 95.2% negative margin rate was observed, and 96.4% of lesions were submitted without fragmentation. Post-operative morbidity was recorded in 8.3% of patients, with post-operative haemorrhage, being the most common complication encountered. The mean follow-up was 17 months (SD 15). Local recurrence occurred in 1.6%, and distant organ metastasis was noted in 1.6% of patients.

CONCLUSIONS

For carefully selected patients, TAMIS for local excision of early rectal neoplasia is a valid option with low morbidity that maintains the advantages of organ preservation.

Excision of malignant and pre-malignant rectal lesions by transanal endoscopic microsurgery in patients under 50 years of age

BACKGROUND

The most common technique for treating benign and early malignant rectal lesions is transanal endoscopic microsurgery (TEM). Local excision is an acceptable technique for high-risk and elderly patients, but there are hardly any data regarding young patients.

AIM

To describe TEM outcomes in patients under 50 years of age.

METHODS

We collected demographic, clinical, and pathological data from all patients under the age of 50 years who underwent the TEM procedure at Hasharon Rabin Medical Center from January 2005 to December 2018.

RESULTS

During the study period, a total of 26 patients under the age of 50 years underwent TEM procedures. Their mean age was 43.3 years. Eleven (42.0%) were male. The mean operative time was 67 min, and the mean tumor size was 2.39 cm, with a mean anal verge distance of 8.50 cm. No major intraoperative or postoperative complications were recorded. The median length of stay was 2 d. Seven (26.9%) lesions were adenomas with low-grade dysplasia, four (15.4%) were high-grade dysplasia adenomas, two were T1 carcinomas (7.8%), and three were T2 carcinomas (11.5%). No residual disease was found following endoscopic polypectomy in two patients (7.8%), but four (15.4%) had other pathologies. Surgical margins were negative in all cases. Local recurrence was detected in one patient 33 mo following surgery.

CONCLUSION

Among young adult patients, TEM for benign rectal lesions has excellent outcomes. It may also offer a balance between the efficacy of complete oncologic resection and postoperative quality of life in the treatment of rectal cancer. In some cases, it may be considered an alternative to radical surgery.

[Transanal Tumor Resection: Indication, Surgical Technique and Management of Complications]

Transanal resection procedures are special operations for the minimally invasive treatment of rectal tumours. Apart from benign tumours, this procedure is suitable for the excision of low-risk T1 rectal carcinomas, if these can be completely removed (R0 resection). With stringent patient selection, very good oncological results are achieved. Various international trials are currently evaluating whether local resection procedures are oncologically sufficient if there is a complete or near complete response after neoadjuvant radio-/chemotherapy. Numerous studies have shown that the functional results and the postoperative quality of life after local resection are excellent, especially considering the well-known functional deficits of alternative operations, such as low anterior or abdominoperineal resection.Severe complications are very rare. Most complications, such as urinary retention or subfebrile temperatures, are minor in nature. Suture line dehiscences are usually clinically unremarkable. Major complications comprise significant haemorrhage and the opening of the peritoneal cavity. The latter must be recognized intraoperatively and can usually be managed by primary suture. Infection, abscess formation, rectovaginal fistula, injury of the prostate or even urethra are extremely rare complications.

Robot-assisted TAMIS: a systematic review of feasibility and outcomes

BACKGROUND

In the advancement of transanal local excision, robot-assisted transanal minimal invasive surgery is the newest development. In the confined area of the rectum, robot-assisted surgery should, theoretically, be superior due to articulated utensils, video enhancement, and tremor reduction, however, this has not yet been investigated. The aim of this study was to review the evidence reported to-date on experience of using robot-assisted transanal minimal invasive surgery for treatment of rectal neoplasms.

METHODS

A comprehensive literature search of Embase and PubMed from May to August 2021were performed. Studies including patients diagnosed with rectal neoplasia or benign polyps who underwent robot-assisted transanal minimal invasive surgery were included. All studies were assessed for risk of bias through assessment tools. Main outcome measures were feasibility, excision quality, and complications.

RESULTS

Twenty-five studies with a total of 322 local excisions were included. The studies included were all retrospective, primarily case-reports, -series, and cohort studies. The median distance from the anal verge ranged from 3.5 to 10 cm and the median size was between 2.5 and 5.3 cm. Overall, 4.6% of the resections had a positive resection margin. The overall complication rate was at 9.5% with severe complications (Clavien-Dindo score III) at 0.9%.

CONCLUSION

Based on limited, retrospective data, with a high risk of bias, robot-assisted transanal minimal invasive surgery seems feasible and safe for local excisions in the rectum.

Long-term results of minimally invasive transanal surgery for rectal tumors in 249 consecutive patients

PURPOSE

To delineate the long-term results of minimally invasive transanal surgery (MITAS) for selected rectal tumors.

METHODS

We analyzed data, retrospectively, on consecutive patients who underwent MITAS between 1995 and 2015, to establish the feasibility, excision quality, and perioperative and oncological outcomes of this procedure.

RESULTS

MITAS was performed on 243 patients. The final histology included 142 cancers, 47 adenomas, and 52 neuroendocrine tumors (NET G1). A positive margin of 1.6% and 100% en bloc resection were achieved. The mean operative time was 27.4 min. Postoperative morbidity occurred in 7% of patients, with 0% mortality. The median follow-up was 100 months (up to ≥ 5 years or until death in 91.8% of patients). Recurrence developed in 2.9% of the patients. The 10-year overall survival rate was 100% for patients with NET G1 and 80.3% for those with cancer. The 5-year DFS was 100% for patients with Tis cancer, 90.6% for those with T1 cancer, and 87.5% for those with T2 or deeper cancers. MITAS for rectal tumors ≥ 3 cm resulted in perioperative and oncologic outcomes equivalent to those for tumors < 3 cm.

CONCLUSION

MITAS is feasible for the local excision (LE) of selected rectal tumors, including tumors ≥ 3 cm. It reduces operative time and secures excision quality and long-term oncological outcomes.

Initial Experience With Trans-anal Minimally Invasive Surgery (TAMIS) for Rectal Polyps and Early Colorectal Cancers at Cumberland Infirmary, Carlisle

INTRODUCTION

Bowel cancer is the fourth most common type of cancer in the United Kingdom in 2019. Total mesorectal excision is the standard procedure for the removal of rectal tumors, however, it comes with serious side effects. Therefore, less invasive procedures and sphincter preservation techniques have been developed, like conventional trans-anal excision, and trans-anal endoscopic microsurgery (TEM). In 2010, trans-anal minimally invasive surgery (TAMIS) was introduced as an alternative to TEM, which offers the same benefits as TEM but at a lower cost and without the need for specialized instrumentation. This study aims to assess the practicability and safety of this technique and to report its findings.  Methods: Retrospective data of all patients who underwent TAMIS at Cumberland Infirmary (Carlisle, UK) from July 2017 to July 2022 for large benign rectal polyps or early rectal cancer were collected. Variables collected included patients' age, gender, number of procedures per year, perioperative outcome, and histopathology outcome. The SPSS version 21 (IBM Corp., Armonk, NY, USA) was used for both descriptive and inferential analyses of the data.

RESULTS

During a five-year period, 42 patients underwent TAMIS at Cumberland Infirmary. The primary indication for TAMIS was distal rectal lesions, large rectal polyps up to 120 mm, and early rectal cancer (T1). The median age of the assessed patients at the time of surgery was 71 years with 64.29% (27) male and 35.71% (15) female. The mean operating time was 123 minutes (range 45 to 240 minutes). The surgical and pathological outcome included a mean polyp size of 6 cm (+/- 0.8 cm), a rate of specimen fragmentation at 19.04% (n=8), and a rate of positive margins at 04.76% (n=2), whereas histology of 73.81% (n=31) was tubulovillous adenoma and 11.91% (n=5) was adenocarcinoma. There was no 30-day postoperative mortality, however, the 30-day re-operation rate was 02.39% (n=1) and the recurrence rate which needed further intervention was 26.19% (n=11).

CONCLUSION

Our findings suggest that TAMIS produces positive results. The size of the lesions removed, and the effect of an early learning curve are reflected in the rate of specimen fragmentation and polyp recurrence. Nonetheless, TAMIS is a safe and effective alternative to total mesorectal excision for certain types of rectal lesions and should be used for more proximal and complex rectal lesions.

The outcome of local excision of large rectal polyps by transanal endoscopic microsurgery

Introduction

Local excision of large rectal polyps can be an alternative for radical rectal resection with total mesorectal excision. We aim to report the functional and oncological outcomes of transanal endoscopic microsurgery (TEM) for patients with large rectal polyps.

Methods

All demographic and clinical data of patients who underwent TEM for rectal polyp of 5 cm or more at the Hasharon Hospital from 2005 to 2018 were retrospectively reviewed.

Results

Twenty-eight patients were included. The mean age was 66 years. The mean polyp size was 6.2 cm (range: 5-8.5 cm) with a mean distance of 8.3 cm from the anal verge. Peritoneal entry during TEM was observed in five patients and additional laparoscopy after the completion of the TEM was performed in four patients. There were no major perioperative complications. Seven patients had minor complications. Final pathology revealed T1 carcinoma in five patients and T2 carcinoma in three patients. Re-TEM was performed in one patient with involved margins with adenoma. After a median follow-up of 64 months, one patient had local recurrence.

Conclusion

TEM is an acceptable technique for the treatment of large polyps with minor complications and a reasonable recurrence rate. TEM may be considered regardless of the size of the rectal polyp.

Role of one-step nucleic acid amplification in colorectal cancer lymph node metastases detection

Current histopathological staging procedures in colorectal cancer (CRC) depend on midline division of the lymph nodes (LNs) with one section of hematoxylin and eosin staining. Cancer cells outside this transection line may be missed, which could lead to understaging of Union for International Cancer Control Stage II high-risk patients. The one-step nucleic acid amplification (OSNA) assay has emerged as a rapid molecular diagnostic tool for LN metastases detection. It is a molecular technique that can analyze the entire LN tissue using a reverse-transcriptase loop-mediated isothermal amplification reaction to detect tumor-specific cytokeratin 19 mRNA. Our findings suggest that the OSNA assay has a high diagnostic accuracy in detecting metastatic LNs in CRC and a high negative predictive value. OSNA is a standardized, observer-independent technique, which may lead to more accurate staging. It has been suggested that in stage II CRC, the upstaging can reach 25% and these patients can access postoperative adjuvant chemotherapy. Moreover, intraoperative OSNA sentinel node evaluation may allow early CRC to be treated with organ-preserving surgery, while in more advanced-stage disease, a tailored lymphadenectomy can be performed considering the presence of aberrant lymphatic drainage and skip metastases.

Prognosis of Patients Over 60 Years Old With Early Rectal Cancer Undergoing Transanal Endoscopic Microsurgery – A Single-Center Experience

Aim

Transanal endoscopic microsurgery (TEM) is widely performed in early rectal cancer. This technique offers greater organ preservation and decreases the risk of subsequent surgery. However, postoperative local recurrence and distant metastasis remain challenges for patients with high-risk pathological factors. This single-center study reports the prognosis of early rectal cancer patients over 60 years old after TEM.

Methods

The data of the patients over 60 years old who underwent local anal resection were collected retrospectively. Moreover, the 5-year follow-up data were analyzed to determine the 5-year DFS and OS.

Results

47 early rectal cancer patients over 60 years old underwent TEM. There were 27 patients with high-risk factors and 20 patients without high-risk factors. Two patients underwent radical surgery after TEM and ten patients received adjuvant treatment. Local recurrence occurred in 7 patients, of which 4 underwent salvage surgery. The 5-year progression-free survival rate was 75.6%, which was lower in the high-risk patients group (69.6%) than in the non-high-risk patients group (83.3%) (P&gt;0.05). The 5-year OS was 90.2%, but there was no statistically significant difference between the two groups (high-risk patients 87.0%, non-high-risk patients 94.4%). Furthermore, there was no significant difference in DFS and OS between people over and under 70 years old.

Conclusion

Some high-risk factor patients over 60 years old do not have inferior 5-year DFS and OS to the non-high-risk patients. TEM is an option for old patients with high surgical risks. Even if postoperative pathology revealed high-risk factors, timely surgical treatment after local recurrence would be beneficial to improve the 5-year DFS and OS.

Assessment of the learning curve for the novel transanal minimally invasive surgery simulator model

BACKGROUND

Transanal minimally invasive surgery (TAMIS) is technically demanding and requires extensive training. We developed the TAMIS simulator model by remodeling an existing laparoscopic training system to educate trainees and analyzed their learning curves.

METHODS

Between March 2020 and June 2020, 12 trainees performed TAMIS simulator training sessions. The total operative time, including specimen removal and wound closure, was recorded. The wound closure and specimen quality, trainee self-confidence, and supervisor evaluation of technical performance were documented. A moving average was used to analyze the number of training sessions required to stabilize the procedure time, while a cumulative sum analysis was performed to identify that required to reach proficiency with each item.

RESULTS

Each trainee completed 20 TAMIS simulator training sessions. The median total procedure time was 13 min (range, 4-60 min), which stabilized after 15 training sessions. The median times for specimen removal and wound closure were 3 min (range, 1-18 min) and 10 min (range, 2-50 min), respectively, which stabilized after 7 and 15 training sessions, respectively. The mean specimen and wound closure quality scores were 2.9 ± 0.9 (on a scale from 1 to 4) and 2.3 ± 1.1 (on a scale from 1 to 4), respectively, competencies in which were achieved after 16 and 20 training sessions, respectively. The mean trainee self-confidence and supervisor evaluation of technical performance scores were 2.4 ± 1.2 (on a scale from 1 to 5) and 2.7 ± 1.2 (on a scale from 1 to 5), respectively, competencies in which were achieved after 20 and 17 training sessions, respectively.

CONCLUSION

Trainees required 15 training sessions to stabilize the procedure time and 16-20 training sessions to demonstrate competencies with the TAMIS simulator model. We expect this simulator model may help surgeons more rapidly acquire the skills required for TAMIS.

Comparison of advanced techniques for local excision of rectal lesions: a case series

Background

Robotic transanal minimally invasive surgery (R-TAMIS) is an appealing alternative to transanal minimally invasive surgery (TAMIS) and transanal endoscopic microsurgery (TEM) for benign and early malignant rectal lesions that are not amenable to traditional open transanal excision. However, no studies to our knowledge have directly compared the three techniques. This study sought to compare peri-operative and pathologic outcomes of the three approaches.

Methods

The records of 29 consecutive patients who underwent TEM, TAMIS, or R-TAMIS at a single academic center between 2016 and 2020 were reviewed. Intra-operative details, pathological diagnosis and margins, and post-operative outcomes were recorded. The three groups were compared using chi-square and Kruskal–Wallis tests.

Results

Overall, 16/29 patients were women and the median age was 57 (interquartile range (IQR): 28–81). Thirteen patients underwent TEM, six had TAMIS, and 10 had R-TAMIS. BMI was lower in the R-TAMIS patients (24.7; IQR 23.8–28.7), than in TEM (29.3; IQR 19.9–30.2), and TAMIS (30.4; IQR 26.6–32.9) patients. High grade dysplasia and/or invasive cancer was more common in TAMIS (80%) and R-TAMIS (66.7%) patients than in TEM patients (41.7%). The three groups did not differ significantly in tumor type or distance from the anal verge. No R-TAMIS patients had a positive surgical margin compared to 23.1% in the TEM group and 16.7% in the TAMIS group. Length of stay (median 1 day for TEM and R-TAMIS patients, 0 days for TAMIS patients) and 30-day readmission rates (7.7% of TEM, 0% of TAMIS, 10% of R-TAMIS patients) also did not differ among the groups. Median operative time was 110 min for TEM, 105 min for TAMIS, and 76 min for R-TAMIS patients.

Conclusions

R-TAMIS may have several advantages over other advanced techniques for transanal excisions. R-TAMIS tended to be faster and to more often result in negative surgical margins compared to the two other techniques.

Complex Procedures in Transanal Endoscopic Microsurgery: Intraperitoneal Entry, Ultra Large Rectal Tumors, High Lesions, and Resection in the Anal Canal

Transanal endoscopic microsurgery (TEM) allows the local excision of rectal tumors and achieves lower morbidity and mortality rates than total mesorectal excision. TEM can treat lesions up to 18 to 20 cm from the anal verge, obtaining good oncological results in T1 stage cancers and preserving sphincter function. TEM is technically demanding. Large lesions (>5 cm), those with high risk of perforation into the peritoneal cavity, those in the upper rectum or the rectosigmoid junction, and those in the anal canal are specially challenging. Primary suture after peritoneal perforation during TEM is safe and it does not necessarily require the creation of a protective stoma. We recommend closing the wall defect in all cases to avoid the risk of inadvertent perforation. It is important to identify these complex lesions promptly to transfer them to reference centers. This article summarizes complex procedures in TEM.

New Frontiers in Management of Early and Advanced Rectal Cancer

It is important to understand advances in treatment options for rectal cancer. We attempt to highlight advances in rectal cancer treatment in the form of a systematic review. Early-stage rectal cancer focuses on minimally invasive endoluminal surgery, with importance placed on patient selection as the driving factor for improved outcomes. To achieve a complete pathologic response, various neoadjuvant chemoradiation regimens have been employed. Short-course radiation therapy, total neoadjuvant chemotherapy, and others provide unique advantages with select patient populations best suited for each. With a clinical complete response, a "watch and wait" non-operative surveillance has been introduced with preliminary equivalency to radical resection. Various modalities for total mesorectal excision, such as robotic or transanal, have advantages and can be utilized in select patient populations. Tumors demonstrating solid organ or peritoneal spread, traditionally defined as unresectable lesions conveying a terminal diagnosis, have recently undergone advances in hepatic and pulmonary metastasectomy. Hepatic and pulmonary metastasectomy has demonstrated clear advantages in 5-year survival over standard chemotherapy. With the peritoneal spread of colorectal cancer, HIPEC with cytoreductive therapy has emerged as the preferred treatment. Understanding the various therapeutic interventions will pave the way for improved patient outcomes.

Completion surgery vs. primary TME for early rectal cancer: a national study

PURPOSE

While local excision by transanal endoscopic microsurgery (TEM) or transanal minimally invasive surgery (TAMIS) is an option for low-risk early rectal cancers, inaccuracies in preoperative staging may be revealed only upon histopathological evaluation of the resected specimen, demanding completion surgery (CS) by formal resection. The aim of this study was to evaluate the results of CS in a national cohort.

METHOD

This was a retrospective analysis of national registry data, identifying and comparing all Norwegian patients who, without prior radiochemotherapy, underwent local excision by TEM or TAMIS and subsequent CS, or a primary total mesorectal excision (pTME), for early rectal cancer during 2000-2017. Primary endpoints were 5-year overall and disease-free survival, 5-year local and distant recurrence, and the rate of R0 resection at completion surgery. The secondary endpoint was the rate of permanent stoma.

RESULTS

Forty-nine patients received CS, and 1098 underwent pTME. There was no difference in overall survival (OR 0.73, 95% CI 0.27-2.01), disease-free survival (OR 0.72, 95% CI 0.32-1.63), local recurrence (OR 1.08, 95% CI 0.14-8.27) or distant recurrence (OR 0.67, 95% CI 0.21-2.18). In the CS group, 53% had a permanent stoma vs. 32% in the pTME group (P = 0.002); however, the difference was not significant when adjusted for age, sex, and tumor level (OR 2.17, 0.95-5.02).

CONCLUSIONS

Oncological results were similar in the two groups. However, there may be an increased risk for a permanent stoma in the CS group.

Analysis of the therapeutic effect of transanal endoscopic microsurgery on large rectal adenoma

Purpose:

Rectal adenoma, a pre-cancerous lesion, is one of the indications for transanal endoscopic microsurgery (TEM). TEM has its unique advantages in the treatment of rectal adenomas. However, there are few reports on the therapeutic effects of large rectal adenoma (LRA). The objective of this study was to investigate the value of TEM in the treatment of LRA.

Materials and Methods:

We collected data from patients who underwent surgery at our center from 2007 to 2017. The postoperative pathology of all patients was rectal adenoma and the diameter of the adenoma was 3 cm or greater. Moreover, all patients underwent TEM. We followed up to observe the incidence of no wound healing, rectal stenosis and recurrence rate of rectal adenoma. The risk factors of adenoma recurrence and wound healing were analysed using single- and multiple-factor analysis.

Results:

The clinicopathological data of 85 patients with LRA were collected through a pre-set table. During the follow-up period, eight patients were lost to follow-up, and three (3.90%) patients developed rectal stenosis. After 2 years of post-operative follow-up, 20 (25.97%) patients had recurrence and 57 (74.03%) patients had no recurrence. Multivariate analysis showed that positive margin was an independent risk factor for recurrence of adenoma.

Conclusions:

TEM is feasible in the treatment of large rectal tumours in Centers of Expertise with the technique.

Transanal Minimally-Invasive Surgery (TAMIS): Experience with No Closure of the Rectal Defect

Background In transanal minimally-invasive surgery (TAMIS), the closure of the rectal defect is controversial, and endoluminal suture is one of the most challenging aspects. The goal of the present study is to evaluate the short- and medium-term complications of a consecutive series of patients with extraperitoneal rectal injuries who underwent TAMIS without closure of the rectal defect.

Materials and Methods A prospective, longitudinal, descriptive study conducted between August 2013 and July 2019 in which all patients with extraperitoneal rectal lesions, who were operated on using the TAMIS technique, were consecutively included. The lesions were: benign lesions ≥ 3 cm; neuroendocrine tumors ≤ 2 cm; adenocarcinomas in stage T1N0; and adenocarcinomas in stage T2N0, with high surgical risk, or with the patients reluctant to undergo radical surgery, and others with doubts about complete remission after the neoadjuvant therapy. Bleeding, infectious complications, rectal stenosis, perforations, and death were evaluated.

Results A total of 35 patients were treated using TAMIS without closure of the defect. The average size of the lesions was of 3.68 ± 2.1 cm (95% confidence interval [95%CI]: 0.7 cm to 9 cm), their average distance from the anal margin was of 5.7 ± 1.48 cm, and the average operative time was of 39.2 ± 20.5 minutes, with a minimum postoperative follow-up of 1 year. As for the pathologies, they were: 15 adenomas; 3 carcinoid tumors; and 17 adenocarcinomas. In all cases, the rectal defect was left open.

The overall morbidity was of 14.2%. Two patients (grade II in the Clavien-Dindo classification) were readmitted for pain treatment, and three patients (grade III in the Clavien-Dindo classification) were assisted due to postoperative bleeding, one of whom required reoperation.

Conclusion The TAMIS technique without closure of the rectal defect yields good results, and present a high feasibility and low complication rate.

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.

Concepts and prospects of minimally invasive colorectal cancer surgery

It is important that clinical radiologists understand and appreciate the minimally invasive surgery (MIS) options available to surgeons. Operative technologies are constantly evolving, and accurate, informed interpretation of clinical imaging is essential for optimum surgical management. Concurrent advancements in both MIS and radiological staging have certainly improved treatment decisions and outcomes. This article outlines the history, current concepts, evolving techniques, and future prospects of MIS as it pertains to colorectal cancer surgery.

Transanal minimal invasive surgery (TAMIS): safety and feasibility for the resection of benign and malignant lesions of the rectum

Objectives

Radical surgery for rectal tumours has high morbidity. Local excision of such tumours can be achieved without compromising oncologic safety. However tumours that are not accessible to local excision can be approached using Transanal Minimal Invasive Surgery (TAMIS). The aim of our study was to assess feasibility of TAMIS procedure in terms of complications, operating time, resection margin positivity, hospital stay and local recurrence rate.

Material and Methods

Forty eight patients with benign adenomas or early stage adenocarcinoma, within 4 to 12 cm from anal verge who were subjected to TAMIS over a period of 3 years were included in the study. Short and long term outcomes were assessed.

Results

TAMIS was performed for 36 benign adenomas and 12 adenocarcinomas, which were located at an average distance of 6.2 cm from anal verge. The mean operating time was 72 minutes. There were no intraoperative complications.1 (2.08%) patient suffered post operative bleeding, which was managed conservatively. 2 (4.16%) patients developed acute urinary retention who required indwelling catheterisation. Resection margin was positive in 3 (6.25%) benign cases. Average hospital stay was 2.7 days. Local recurrence occurred in 2 (4.16%) villous adenoma patients (after 11 and 13 months), whereas in malignant patients there was no recurrence at a follow up period ranging between 12 to 36 months.

Conclusion

TAMIS is a safe and feasible procedure for benign tumours and early rectal cancers, located in low and middle rectum.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Transanal endoscopic microsurgery under spinal anaesthesia

Background

Transanal endoscopic microsurgery (TEM) is considered the procedure of choice for rectal adenomas non-amendable for endoscopic excision and for early rectal cancer. TEM may gain more importance in patients who are considered unfit for major surgery. The option of spinal anaesthesia may offer many advantages for patients undergoing TEM while maintaining the principles of complete tumour excision. The aim of this study is to report the outcome of patients undergoing TEM under spinal anaesthesia.

Methods

Demographic and clinical data pertaining patients undergoing TEM under spinal anaesthesia between 2004 and 2015 were retrospectively collected.

Results

A total of 158 TEM procedures were recorded in the study period. Twenty-three patients (15%) underwent the procedure under spinal anaesthesia and were included in the study; 13 of them were male and ten were female. The mean age of the patients was 69.1 ± 10.6 years. Seventeen (74%) rectal lesions were adenomas, two (9%) were adenocarcinoma and four (17%) had involved margins after polypectomy. The mean tumour size was 2.1 cm (range, 0.5-3). Distance from the anal verge was 7.7 ± 2.2 cm. Seventeen (74%) lesions were in the posterior wall. The operative time was 73 min (range, 46-108) No adverse anaesthesia-related events were recorded, and the post-operative pain was reduced. The median time of hospitalisation was 2 days (range, 1-4). No major complications were noted, and the minor complications were treated conservatively. The surgical margins were free of tumour in all cases.

Conclusion

TEM under spinal anaesthesia had short duration of surgery, no increase in operative and post-operative complications or hospital length of stay. Avoiding the use of general anaesthesia, in such challenging procedure, may open new opportunities for patients determined to be unfit for general anaesthesia.

Long-term outcomes of patients with poor prognostic factors following transanal endoscopic microsurgery for early rectal cancer

AIM

Management of early rectal cancer following transanal microscopic anal surgery poses a management dilemma when the histopathology reveals poor prognostic features, due to high risk of local recurrence. The aim of this study is to evaluate the oncological outcomes of such patients who undergo surgery with total mesorectal excision (TME), receive adjuvant chemo/radiotherapy (CRDT/RT) or receive close surveillance only (no further treatment).

METHODS

We identified patients with poor prognostic factors-pT2 adenocarcinoma, poor differentiation, deep submucosal invasion (Kikuchi SM3), lymphovascular invasion, tumour budding or R1 resection margin-between 1 September 2012 and 31 January 2020 and report their oncological outcomes.

RESULTS

Of the 53 patients, 18 had TME, 14 had CRDT and 14 had RT; seven patients did not have any further treatment. The median follow-up was 48 months, 12 developed recurrence and six died. Overall, 5-year survival (OS) was 88.9% and disease-free survival (DFS) was 79.2%. Compared to the surgical group, in which there were eight recurrences and two deaths, there were zero recurrences or deaths in the CRDT group, log-rank test P = 0.206 for OS and P = 0.005 for DFS. The 5-year survival rates in the RT and surveillance only groups were OS 78.6%, DFS 85.7% and OS 71.5%, DFS 71% respectively. TME assessment in the surgical group revealed Grade 3 quality in seven of the 16 available reports.

CONCLUSION

These findings support the strategy of adjuvant CRDT as first line treatment for patients undergoing transanal endoscopic microsurgery for early rectal cancer with poor prognostic factors on initial histological assessment.

Transanal endoscopic surgery with a 3D printed device

BACKGROUND

The aim of this study was to investigate the effectiveness of devices manufactured with 3D printing for performing transanal endoscopic procedures without pneumorectum.

METHODS

Functional devices were designed in the Polytechnic School of Engineering of Gijón from 2016 to 2018 using three-dimensional (3D) solid modelling software (Solid-Works®), that allows customization of the device (diameter and length). The devices were made in acrylonitrile butadiene styrene (ABS) by additive manufacturing using an HP Designjet 3D Printer, with fused deposition modelling (FDM) technology. Tests were carried out on mixed simulators (with viscera) and cadavers with a prototype in the form of an open cylindrical base ellipsoid spindle with two bars. In this paper, we present the information of the first series of patients in which this device has been used to perform a full-thikness endoscopic resection of the rectal wall without pneumorectum. The characteristics of the patients, size, and location of the lesion, the type of anesthesia used, the duration of the procedure, hospital stay, complications, and pathology were analyzed. An endoscopic follow-up was also carried out for at least 2 years.

RESULTS

Seven interventions were carried out in six patients. The lesions were located at a mean distance of 5 cm from the anal verge and an average area of 11.8 cm². Four of the procedures were performed with general anesthesia and 3 with spinal anesthesia. Histopathology examination identified 3 adenomas, 3 pT1 and 1 pT2 adenocarcinomas. All excisions were full thickness. En bloc excision was possible in all cases. In only one case of a benign polyp there was a positive lateral margin. As regards complications, there was one case of postoperative rectal bleeding without the need for transfusions. There were no readmissions and no postoperative mortality.

CONCLUSIONS

An innovative device made with a 3D printer can be used successfully in transanal endoscopic resections of the rectal wall, with spinal anaesthesia and avoiding the need for pneumorectum.

Cost Analysis of Laparoscopic Low Anterior Resection vs. Transanal Endoscopic Microsurgery for Rectal Neoplasms

Despite the increasing application of transanal endoscopic microsurgery (TEM) for rectal lesions, the cost of the equipment may play a role in a hospital's hesitancy to invest in the platform. This study compares the cost of TEM to laparoscopic low anterior resection (LAR). Patients who underwent laparoscopic LAR (n = 24) for rectal neoplasm between 2006 and 2014 were case-matched based on sex, age, comorbidities, lesion size and location to patients who underwent TEM at a busy secondary care urban hospital. Procedure-related costs and costs associated with readmissions for complications and related subsequent surgeries in the first 3 years were calculated. There were 42 hospital admissions for 24 LAR patients, totalling 326 hospital days. For 24 TEM patients, there were 25 hospital admissions, totalling 56 hospital days. Subsequent operations for LAR patients included 2 washout and diverting ileostomies (8%), 2 adhesionolysis (8%), 4 ventral hernia repairs (16%) and 11 ileostomy reversals (46%). In the TEM group, there was one operation for recurrence (4%). The mean cost of LAR, including all related hospital costs in the subsequent 3 years, was CAD 14,851 (95% CI: CAD 10,124-19,579). The mean cost of TEM was CAD 2449 (95% CI: CAD 2133-2767; p < 0.0001), with a savings of CAD 12,402 per patient. TEM for rectal neoplasm is associated with significantly lower hospital costs, which far outweigh the costs of acquiring and maintaining the technology.

Diagnosis and Management of Rectal Neuroendocrine Tumors (NETs)

Rectal neuroendocrine tumors (NETs) are rare, with an incidence of 0.17%, but they represent 12% to 27% of all NETs and 20% of gastrointestinal NETs. Although rectal NETs are uncommon tumors, their incidence has increased over the past few years, and this is probably due to the improvement in detection rates made by advanced endoscopic procedures. The biological behavior of rectal NETs may be different: factors predicting the risk of metastases have been identified, such as size and grade of differentiation. The tendency for metastatic diffusion generally depends on the tumor size, muscular and lymphovascular infiltration, and histopathological differentiation. According to the current European Neuroendocrine Tumor Society (ENETS) guidelines, tumors that are smaller than 10 mm and well differentiated are thought to have a low risk of lymphovascular invasion, and they should be completely removed endoscopically. Rectal NETs larger than 20 mm have a higher risk of involvement of muscularis propria and high metastatic risk and are candidates for surgical resection. There is controversy over rectal NETs of intermediate size, 10–19 mm, where the metastatic risk is considered to be 10–15%: assessment of tumors endoscopically and by endoanal ultrasound should guide treatment in these cases towards endoscopic, transanal, or surgical resection.

Can transanal endoscopic microsurgery effectively treat T1 or T2 rectal cancer?A systematic review and meta-analysis

AIM

We aimed to compare the safety and oncological outcomes of transanal endoscopic microsurgery (TEM) and radical surgery (RS) for patients with T1 or T2 rectal cancer.

METHOD

We searched Pubmed, Embase, Cochrane Library databases for relevant studies comparing TEM with RS in rectal cancer published until April 2020. We focused on safety and oncological outcomes.

RESULTS

This meta-analysis included 3526 patients from 12 studies. Compared with RS, TEM had a shorter operative time (weighted mean difference [WMD] -110.02, 95% confidence interval [CI]: 143.98, -76.06), less intraoperative blood loss (WMD -493.63, 95% CI: 772.66, -214.59), lower perioperative morality (risk ratio [RR] 0.25, 95% CI: 0.06, 0.99), and fewer postoperative surgical complications (RR 0.23, 95% CI: 0.11,0.45). TEM was associated with more patients with a positive margin or a doubtfully complete margin than RS (RR 7.36, 95% CI: 3.66, 14.78). TEM was associated with higher local recurrence (RR 2.63, 95% CI: 1.60, 4.31) and overall recurrence (RR 1.60, 95% CI: 1.09, 2.36). TEM had a negative effect on 5-year overall survival (hazard ratio [HR] 1.51, 95% CI: 1.16, 1.96), especially in the T2 without neoadjuvant therapy (NAT) subgroup (HR 2.02, 95% CI: 1.32, 3.09), but in the subgroups of T1 or T2 with NAT before TEM, TEM did not yield a significantly lower overall survival than RS.

CONCLUSION

TEM seems appropriate for T1 rectal cancer with favourable histopathology. For patients with T2 rectal cancer, NAT before TEM may contribute to achieving oncological outcomes equivalent to that achieved with RS.

Education and Training in Transanal Endoscopic Surgery and Transanal Total Mesorectal Excision

There is a paradigm shift in surgical training, and new tool and technology are being used to facilitate mastery of the content and technical skills. The transanal procedures for rectal cancer-transanal endoscopic surgery (TES) and transanal total mesorectal excision (TaTME)-have a distinct learning curve for competence in the procedures, and require special training for familiarity with the "bottom-up" anatomy, procedural risks, and managing complex cases. These procedures have been models for structured education and training, using multimodal tools, to ensure safe implementation of TES and TaTME into clinical practice. The goal of this work was to review the current state of surgical education, the introduction and learning curve of the TES and TaTME procedures, and the established and future models for education of the transanal procedures for rectal cancer.

Current Challenges for Education and Training in Transanal Surgery

Transanal endoscopic microsurgery (TEM) is a technique that was introduced in the 1980s for improved exposure to upper rectal polyps. This technique, though initially difficult to master due to new skill acquisition for surgeons, has spared many patients proctectomy. There are many benign indications for transanal endoscopic surgery which has led to in vivo operating room training with fewer undesirable effects to the patient. With the explosion of laparoscopic technology this transanal technique is no longer limited to intraluminal pathology, but is now being used to remove the entire rectum. In transanal total mesorectal excision (taTME), benign indications are less common, translating to potentially more severe oncologic patient consequences during the early phase of adoption. For this reason, strict training criteria consensus guidelines have been developed by the experts in taTME. The current consensus statements agree that training surgeons should have performed a minimum of 10 laparoscopic TME procedures and should have some experience with transanal surgery. Surgeons need to attend a formal training course and should start clinically on benign or early malignant pathology without threated circumferential resection margins. Surgeons also need to have their first cases proctored until deemed proficient by the proctor and monitor their morbidity, oncologic, and functional outcomes prospectively.

Transanal minimally-invasive surgery (TAMIS): Technique and results from an initial experience

Transanal endoscopic microsurgery is a minimally-invasive approach for rectal lesions. Superior exposure and access to the entire rectum result in lesser risk of compromised margins and lower recurrence rates, when compared to conventional transanal excision. The aim of this study was to describe a single institution's initial experience with transanal minimally invasive surgery (TAMIS). This was a prospective review of our database. Eleven procedures from January 2012 to June 2013 were analyzed.

Results eleven operations were completed. Five men were evaluated. Mean age was 62.9 (40-86). Mean follow-up was 9.3 (2-17) months. Average tumor size was 3.8 (1.8-8) cm. Mean distance from anal verge was 6.3 (3-12) cm. Mean operating time was 53.73 (28-118) min. Postoperative complication rate was 9.1%. There were no readmissions. Mortality was null. Operative pathology disclosed the presence of adenoma in four patients, invasive adenocarcinoma in two, neuroendocrine carcinoma in three, and no residual lesion in one case. TAMIS is a minimallyinvasive procedure with low postoperative morbidity at the initial experience. TAMIS is a curative procedure for benign lesions and for selected early cancers. It is useful after neoadjuvant therapy for strictly selected cancers, pending the results of multi-institutional trials.

Functional outcome and quality of life following treatment for rectal cancer

Introduction Over the last decades, treatment for rectal cancer has substantially improved with development of new surgical options and treatment modalities. With the improvement of survival, functional outcome and quality of life are getting more attention.

Study objective To provide an overview of current modalities in rectal cancer treatment, with particular emphasis on functional outcomes and quality of life.

Results Functional outcomes after rectal cancer treatment are influenced by patient and tumor characteristics, surgical technique, the use of preoperative radiotherapy and the method and level of anastomosis. Sphincter preserving surgery for low rectal cancer often results in poor functional outcomes that impair quality of life, referred to as low anterior resection syndrome. Abdominoperineal resection imposes the need for a permanent stoma but avoids the risk of this syndrome. Contrary to general belief, long-term quality of life in patients with a permanent stoma is similar to those after sphincter preserving surgery for low rectal cancer.

Conclusion All patients should be informed about the risks of treatment modalities. Decision on rectal cancer treatment should be individualized since not all patients may benefit from a sphincter preserving surgery “at any price”. Non-resection treatment should be the future focus to avoid the need of a permanent stoma and bowel dysfunction.

Global Scientific Outputs of Microsurgery Publications: A Bibliometric Approach About Yesterday, Today, and Tomorrow

Introduction

Although there have been important developments in microsurgery in recent years, there is no current and comprehensive bibliometric study in the literature. In this study, we aimed to present a summary of the articles published on microsurgery between 1980 and 2019 with bibliometric analysis.

Methods

Articles published on microsurgery between 1980 and 2019 were withdrawn from the Web of Science database and analyzed by bibliometric methods. Citation analysis was performed to identify effective journals and articles. Keyword cluster and trends analyses were performed for a detailed analysis of the researched topics. Relationships between the article numbers of the countries and gross domestic product (GDP) and human development index (HDI) values were investigated using Spearman’s correlation coefficient. A linear regression analysis was used to estimate the number of articles to be published in the future.

Results

A total of 3,537 publications related to microsurgery were found. Bibliometric analyses were performed in 2,063 articles (58.3%) of these publications. The most active countries in publishing were the United States (504), Germany (286), and Italy (154), respectively. A statistically significant correlation was found between the article numbers and the GDP and HDI sizes of the countries (r = 0.758, p <0.001, r = 0.659, p <0.001).

Conclusion

The economic size and development levels of the countries were an important factor in academic productivity in microsurgery. Undeveloped countries should be encouraged by performing multidisciplinary studies in this regard.

Local excision for T1 rectal tumours: are we getting better?

AIM

The objective was to assess the effect of three different surgical treatments for T1 rectal tumours, radical resection (RR), open local excision (open LE) and laparoscopic local excision (laparoscopic LE), on overall survival (OS).

METHODS

Adults from the National Cancer Database (2008-2016) with a diagnosis of T1 rectal cancer were stratified by treatment type (LE vs RR). We assumed that laparoscopic LE equates to transanal minimally invasive surgery (TAMIS) or transanal endoscopic microsurgery. The primary outcome was 5-year OS. Subgroup analyses of the LE group stratified by time period [2008-2010 (before TAMIS) vs 2011-2016 (after TAMIS)] and approach (laparoscopic vs open) were performed.

RESULTS

Among 10 053 patients, 6623 (65.88%) underwent LE (74.33% laparoscopic LE vs 25.67% open LE) and 3430 (34.12%) RR. The use of LE increased from 52.69% in 2008 to 69.47% in 2016, whereas RR decreased (P < 0.001). In unadjusted analysis, there was no significant difference in 5-year OS between the LE and RR groups (P = 0.639) and between the two LE time periods (P = 0.509), which was consistent with the adjusted analysis (LE vs RR, hazard ratio 1.05, 95% CI 0.92-1.20, P = 0.468; 2008-2010 LE vs 2011-2016 LE, hazard ratio 1.09, 95% CI 0.92-1.29, P = 0.321). Laparoscopic LE was associated with improved OS in the unadjusted analysis only (P = 0.006), compared to the open LE group (hazard ratio 0.94, 95% CI 0.78-1.12, P = 0.495).

CONCLUSIONS

This study supports the use of a LE approach for T1 rectal tumours as a strategy to reduce surgical morbidity without compromising survival.

First clinical experience with single-port robotic transanal minimally invasive surgery (SP rTAMIS) for benign rectal neoplasms

BACKGROUND

The new da Vinci Single-Port (SP) robot is a single-arm four-channel robotic system well suited for endoluminal surgery. We report our initial experience performing SP robotic transanal minimally invasive surgery (SP rTAMIS) for rectal neoplasms.

METHODS

Under Institutional Review Board approval, two patients with rectal neoplasms were prospectively enrolled for elective SP rTAMIS. The primary endpoint was to report the safety and feasibility of successful procedure completion with the SP robot. Secondary endpoints included patient characteristics and perioperative metrics.

RESULTS

Both patients underwent successful SP rTAMIS resection of rectal neoplasms without intraoperative complications or conversions. The lesions were 4.0 cm and 3.0 cm in size, located 6 cm and 7 cm cephalad to the anorectal ring. Excisions were full thickness with no piecemeal extractions or specimen fragmentation. Estimated blood loss was 0 mL and 30 mL. The mean excised area was 13.4 cm² (22.7 cm² and 9.0 cm²). The mean docking time was 5.25 min (range 2-8 min) and mean console time was 122.5 min (98 min and 147 min). Patients tolerated a liquid diet on postoperative day (POD) 0 and were discharged on POD 1 after tolerating a low residue diet and having bowel function. Pathology showed two adenomas with negative margins. There was no immediate or delayed morbidity or mortality.

CONCLUSIONS

Our initial experience indicates that SP rTAMIS is a safe and feasible approach for local excision of rectal lesions. While SP rTAMIS is very promising, more experience with this approach is necessary to determine its widespread applicability.

Oncological Outcomes of Transanal Endoscopic Microsurgery Plus Adjuvant Chemoradiotherapy for Patients with High-Risk T1 and T2 Rectal Cancer

Background: Radical surgery is recommended for high-risk pathological stage T1 (pT1) or pT2 rectal cancer after transanal endoscopic microsurgery (TEM). However, in clinical practice, many patients may unfit or decline radical surgery. In recent years, adjuvant chemoradiotherapy (CRT) after TEM was considered as an alternative to radical surgery for these patients. This study aimed to assess oncological outcomes of adjuvant CRT after TEM for high-risk early rectal cancer. Materials and Methods: We collected retrospectively data of 97 patients who underwent TEM with pT1 and pT2 between January 2008 and December 2018. Of these, 35 patients were excluded. Of the remaining 62 patients, 42 were managed by TEM alone and 20 by TEM plus adjuvant CRT. Demographics, recurrence, and survival were analyzed between the two groups. Results: At a median follow-up of 52.5 months, the 3-year local recurrence-free survival and disease-free survival (DFS) in TEM alone group were significantly lower than those in TEM+CRT group (66.6% versus 93.3%, P = .035; 63.7% versus 93.3%, P = .022). Although the 3-year overall survival in TEM+CRT group was higher than TEM alone group (100% versus 83.3%), the difference was not statistically significant (P = .13). The local recurrence rate in TEM alone was 31%, compared with 5% in TEM+CRT group (P = .025). Multivariate analysis showed that adjuvant CRT was an independent prognostic factor for DFS (hazard ratio: 0.094; 95% confidence interval: 0.001-0.764; P = .027). Conclusions: Our study suggests that adjuvant CRT after TEM may be an alternative for pT1 high-risk and T2 rectal cancer who are not suitable or unwilling to undergo salvage radical surgery.

Evaluation of transanal minimally invasive surgery for submucosal rectal resection in cadaveric canine specimens

OBJECTIVE

To evaluate the feasibility of transanal minimally invasive surgery (TAMIS) for submucosal rectal resection in large breed dogs.

STUDY DESIGN

Cadaveric study.

SAMPLE POPULATION

Canine cadavers (n = 6) weighing between 37.5 and 60 kg.

METHODS

Dogs were positioned in sternal recumbency. After rectal cleansing, a transanal access platform was placed in the rectum, and a pneumorectum was established. An area of ventral rectal wall approximately 2 × 2 cm was resected in a submucosal plane by using laparoscopic instruments and submitted for histopathological evaluation. The rectal wall defect was closed with a single-layer continuous suture pattern with barbed suture. Postoperatively, the rectum was removed en bloc and evaluated for suture or surgical penetration of the serosal surface.

RESULTS

Submucosal rectal resection was successfully completed by using TAMIS in all dogs. The median length of resected specimens after fixation was 24.5 mm (range 9.8-26.5). In two of six dogs, suture was macroscopically visible on the serosal surface, but no dogs had evidence of iatrogenic full-thickness surgical penetration of the rectum. The median distance from the aborad extent of the suture closure line to the anocutaneous junction was 35 mm (range, 35-105).

CONCLUSION

Submucosal resection of the canine rectal wall was feasible in large breed dogs by using TAMIS. No evidence of full-thickness penetration of the rectal wall was seen in these cadaveric specimens.

CLINICAL SIGNIFICANCE

Transanal minimally invasive surgery may provide an alternative minimally invasive approach for resection for benign adenomatous rectal polyps in large breed dogs that might otherwise require a rectal pull-through.

Transanal Endoscopic Microsurgery (TEM) for rectal GI stromal tumor

BACKGROUND

Transanal endoscopic microsurgery (TEM) is effective in treating adenomas and select early rectal cancers. Our objective is to evaluate TEM in treating early rectal GISTs.

METHODS

Patients were identified in a prospective database with pathology confirmed rectal GIST prior to TEM over 10 years. Demographic, pathologic, operative and follow-up data was analysed and presented with descriptive statistics.

RESULTS

7 cases of rectal GIST were treated with TEM with a follow-up time of 31 months (0-71). Median tumor distance from the anal verge was 4 cm (2.5-6) and median tumor size was 3 cm (2-5.7). Negative margins were achieved in 4/7 patients. Those with positive margins were treated with repeat TEM or imatinib. 1 patient had local recurrence successfully treated by TEM.

CONCLUSIONS

Overall, TEM is safe for locally excising GISTs. As rectal GISTs are rare, a multicenter registry may better elucidate outcomes with this treatment.

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.

Learning Transanal Total Mesorectal Excision

A dynamic evolution is occurring in transanal surgery. Transanal techniques began with intraluminal surgical removal of rectal masses and have progressed to transanal total mesorectal excision (taTME) for rectal cancer. TaTME was first performed in 2009 by Sylla, Rattner, Delgado, and Lacy. This article documents the training pathway followed by pioneers in the taTME technique as well as consensus reports outlining the process of learning the taTME technique. A literature search was performed for taTME training, learning, and technique. Key elements in learning the taTME technique include appropriate indications, cadaver training, and outcomes reporting such as participating in a taTME registry. Consensus reports also agree on the following facets associated with improved outcomes: (1) appropriate case selection of mid and low rectal cancers, (2) prerequisite completion of an accredited training program in laparoscopic colorectal surgery and prior experience in transanal endoscopic surgery, (3) a two-team taTME approach from above and below is ideal, and (4) higher rectal cancer volume surgical practice. The unifying international recommendation for surgeons interested in learning the taTME technique conveys the following message: taTME is an advanced and complex technique that requires dedicated training and experience in TME surgery.

Evolution of Transanal Total Mesorectal Excision

Minimally invasive techniques continue to transform the field of colorectal surgery. Because traditional surgical approaches for rectal cancer are associated with significant mortality and morbidity, developing less invasive approaches to this disease is paramount. Natural orifice transluminal endoscopic surgery (NOTES), commonly known as "no incision surgery," represents the ultimate minimally invasive approach to disease. Although transgastric and transvaginal approaches for NOTES surgery were the initially explored, a transrectal approach for colorectal disease is intuitive given that it makes use of the resected organ for transluminal access. Furthermore, the transanal approach allows for improved, precise visualization of the presacral mesorectal plane compared with an abdominal viewpoint, particularly in the narrow, male pelvis. Finally, experience with existing transanal platforms that have been used for decades for local excision of rectal disease made the development of a transanal approach to total mesorectal excision (TME) feasible. Here, we will review the evolution of minimally invasive and transanal surgical techniques that allowed for the development of transanal TME and its introduction into clinical practice.

Endoscopic mucosal resection is effective for laterally spreading lesions at the anorectal junction

OBJECTIVE

The optimal approach for removing large laterally spreading lesions at the anorectal junction (ARJ-LSLs) is unknown. Endoscopic mucosal resection (EMR) is a definitive therapy for colorectal LSLs. It is unclear whether it is an effective modality for ARJ-LSLs.

DESIGN

EMR outcomes for ARJ-LSLs (distal margin of ≤20 mm from the dentate line) in comparison with rectal LSLs (distal margin of >20 mm from the dentate line) were evaluated within a multicentre observational cohort of LSLs of ≥20 mm. Technical success was defined as the removal of all polypoid tissue during index EMR. Safety was evaluated by the frequencies of intraprocedural bleeding, delayed bleeding, deep mural injury (DMI) and delayed perforation. Long-term efficacy was evaluated by the absence of recurrence (either endoscopic or histologic) at surveillance colonoscopy (SC).

RESULTS

Between July 2008 and August 2019, 100 ARJ-LSLs and 313 rectal LSLs underwent EMR. ARJ-LSL median size was 40 mm (IQR 35-60 mm). Median follow-up at SC4 was 54 months (IQR 33-83 months). Technical success was 98%. Cancer was present in three (3%). Recurrence occurred in 15.4%, 6.8%, 3.7% and 0% at SC1-SC4, respectively. Among 30 ARJ-LSLs that received margin thermal ablation, no recurrence was identified at SC1 (0.0% vs 25.0%, p=0.002). Technical success, recurrence and adverse events were not different between groups, except for DMI (ARJ-LSLs 0% vs rectal LSLs 4.5%, p=0.027).

CONCLUSION

EMR is an effective technique for ARJ-LSLs and should be considered a first-line resection modality for the majority of these lesions.

Feasibility and Advantages of Transanal Minimally Invasive Surgery (TAMIS) for Various Lesions in the Rectum

Purpose

We report our experience in the use of transanal minimally invasive surgery (TAMIS) and the feasibility and safety of this surgical technique in operating for various rectal diseases that require a transanal approach.

Methods

Between 2013 and 2019, 30 patients underwent TAMIS for a rectal lesion at Seoul National University Boramae Medical Center. The clinical data including age, gender, body mass index, tumour size, distance from the anal verge, diagnosis, operation time, postoperative complications, duration of hospital stay, and post-operative margin status were obtained retrospectively from the electronic medical records.

Results

The mean operation time was 52.1±33.5 and the mean duration of hospital stay after surgery was 4.3±4.2 days. Most of the patients had undergone TAMIS for neuroendocrine tumor (NET) (60%) followed by an adenoma (16.7%) and rectal cancer (13.3%). 4 patients (13.3%) had minor complications after TAMIS. 2 patients (50%) had complained of diarrhea, 1 patient (25%) complained of fecal incontinence and 1 patient (25%) been diagnosed fluid in the operation bed.

Conclusion

TAMIS is a useful method for local excision of rectal lesion located in mid to upper rectum as well as other rectal pathologies that require a transanal approach.