Transanal endoscopic microsurgery with 3-D (TEM) or high-definition 2-D transanal endoscopic operation (TEO) for rectal tumors. A prospective, randomized clinical trial

Early Rectal Cancer: Advances in Diagnosis and Management Strategies

Colorectal cancer (CRC) is the second most prevalent cause of cancer-related death and the third most common cancer globally. Early-stage rectal cancer is defined by lesions confined to the bowel wall, without extension beyond the submucosa in T1 or the muscularis propria in T2, with no indication of lymph node involvement or distant metastasis. The gold standard for managing rectal cancer is total mesorectal excision (TME); however, it is linked to considerable morbidities and impaired quality of life. There is a growing interest in local resection and non-operative treatment of early RC for organ preservation. Local resection options include three types of transanal endoscopic surgery (TES): transanal endoscopic microsurgery (TEM), transanal endoscopic operations (TEO), and transanal minimally invasive surgery (TAMIS), while endoscopic resection includes endoscopic mucosal resection (EMR), underwater endoscopic mucosal resection (UEMR), and endoscopic submucosal dissection (ESD). Although the oncological outcome of local resection of early rectal cancer is debated in the current literature, some studies have shown comparable outcomes with radical surgery in selected patients. The use of adjuvant and neoadjuvant chemoradiotherapy in early rectal cancer management is also controversial in the literature, but a number of studies have reported promising outcomes. This review focuses on the available literature regarding diagnosis, staging, and management strategies of early rectal cancer and provides possible recommendations.

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.

Multicenter clinical trial for the resection of rectal polyps using a new laparoendoscopic hybrid transanal access device

INTRODUCTION

Complex polyps require the use of advanced endoscopic techniques or minimally invasive surgery for their approach. In rectal polyps it is of special relevance to reach a consensus on the best approach to avoid under- or overtreatment that increases unnecessary morbidity and mortality.

METHODS

We describe a prospective, multicenter, pilot clinical trial with a first-in-human medical device. It is hypothesized that UNI-VEC® facilitates transanal laparoendoscopic surgery for the removal of early rectal tumors. The primary objective is to evaluate that it is safe and meets the established functional requirements. Secondary objectives are to evaluate results, complications and level of satisfaction.

RESULTS

16 patients were recruited in 12 months with a minimum follow-up of 2 months. The mean size was 3.4 cm with the largest polyp being 6 cm. Regarding location, the mean was 6.6 cm from the anal margin. Endoscopic Mucosal Resection (EMR) (6.3%), Endoscopic Submucosal Dissection ESD (43.8%), REC (6.3%) and TAMIS (43.8%) were performed. The mean time was 73.25 min. The 56.3% used a 30° camera and 43.8% used the flexible endoscope as a viewing instrument. The 56.3% were benign lesions and 43.8% malignant. Complete resection is achieved in 87.5%. Regarding complications, mild bleeding (Clavien I) occurred in 25%, 6.3% and 21.4% at 24 h, 48 h and 7 days respectively. Continence was assessed according to the Wexner scale. At 7 days, 60% showed perfect continence, 26.7% mild FI and 13.3% moderate FI. At 30 days, 66.7% had perfect continence, 20% mild FI and 13.3% moderate FI. At 2 months, 4 patients were reviewed who at 30 days had a Wexner's degree higher than preoperative and perfect continence was demonstrated in 25% of the patients, 50% mild and 25% moderate. In no case did rectal perforation or major complications requiring urgent reintervention occur. As for the level of reproducibility, safety, level of satisfaction with the device and evaluation of the blister, the evaluation on a scale of 0 to 10 (9.43, 9.71, 9.29 and 9.50 respectively). All the investigators have previous experience with transanal devices.

CONCLUSIONS

The study demonstrates the efficacy and safety of UNI-VEC® for the treatment of rectal lesions. It will facilitate the implementation of hybrid procedures that seek to solve the limitations of pure endoscopic techniques by allowing the concomitant use of conventional laparoscopic and robotic instrumentation with the flexible endoscope.

Management of early rectal cancer; current surgical options and future direction

Rectal cancer is the second commonest cause of cancer death within the United Kingdom. Utilization of national screening programmes have resulted in a greater proportion of patients presenting with early-stage disease. The technique of transanal endoscopic microsurgery was first described in 1984 following which further options for local excision have emerged with transanal endoscopic operation and, more recently, transanal minimally invasive surgery. Owing to the risks of local recurrence, the current role of minimally invasive techniques for local excision in the management of rectal cancer is limited to the treatment of pre-invasive disease and low risk early-stage rectal cancer (T1N0M0 disease). The roles of chemotherapy and radiotherapy for the management of early rectal cancer are yet to be fully established. However, results of high-quality research such as the GRECCAR II, TESAR and STAR-TREC randomised control trials may highlight a wider role for local excision surgery in the future, when used in combination with oncological therapies. The aim of our review is to provide an overview in the current management of early rectal cancer, the surgical options available for local excision and the future multimodal direction of early rectal cancer treatment.

Non-conventional applications for Transanal endoscopic microsurgery. A single centre experience and a systematic review of literature

BACKGROUND

Transanal endoscopic microsurgery (TEM) and Transanal endoscopic operation (TEO) have been initially described for local excision of rectal adenomas and selected cases of rectal carcinomas. In the past decade, however, several new indications raised, and others could raise in the future. The aim of this review was to evaluate, both in the literature and in our personal experience, the use of TEM and TEO for nonconventional applications, different from rectal tumors.

METHODS

We conducted a systematic review of published papers and we selected articles reporting patients who underwent endoscopic surgery for other medical reason than polyp cancer resection, with TEM or TEO. PubMed, MEDLINE, EMBASE and bibliographies of the selected studies were searched for articles in English published up to May 2020 to identify all relevant articles. We excluded articles reporting TEM and TEO used for classical indications. We finally report our experience of non-conventional use of TEO in 5 patients with different diseases.

RESULTS

The research revealed 800 papers and among them we selected 52 articles for a total of 697 patients. Of all patients, only 52 had intraoperative or postoperative complications, with only 10 patients requiring major surgery.

CONCLUSIONS

Our study suggest that TEM and TEO may be valid alternatives to traditional surgery in situations other than its classical indication. These findings can positively impact on the care of patients, who could benefit from less invasive surgical procedures associated with lower morbidity.

Early-rectal Cancer Treatment: A Decision-tree Making Based on Systematic Review and Meta-analysis

Local excision (LE) has arisen as an alternative to total mesorectal excision for the treatment of early rectal cancer. Despite a decreased morbidity, there are still concerns about LE outcomes. This systematic-review and meta-analysis design is based on the "PICO" process, aiming to answer to three questions related to LE as primary treatment for early-rectal cancer, the optimal method for LE, and the potential role for completion treatment in high-risk histology tumors and outcomes of salvage surgery. The results revealed that reported overall survival (OS) and disease-specific survival (DSS) were 71%-91.7% and 80%-94% for LE, in contrast to 92.3%-94.3% and 94.4%-97% for radical surgery. Additional analysis of National Database studies revealed lower OS with LE (HR: 1.26; 95%CI, 1.09-1.45) and DSS (HR: 1.19; 95%CI, 1.01-1.41) after LE. Furthermore, patients receiving LE were significantly more prone develop local recurrence (RR: 3.44, 95%CI, 2.50-4.74). Analysis of available transanal surgical platforms was performed, finding no significant differences among them but reduced local recurrence compared to traditional transanal LE (OR:0.24;95%CI, 0.15-0.4). Finally, we found poor survival outcomes for patients undergoing salvage surgery, favoring completion treatment (chemoradiotherapy or surgery) when high-risk histology is present. In conclusion, LE could be considered adequate provided a full-thickness specimen can be achieved that the patient is informed about risk for potential requirement of completion treatment. Early-rectal cancer cases should be discussed in a multidisciplinary team, and patient's preferences must be considered in the decision-making process.

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.

Is Local Resection of Anal Canal Tumors Feasible with Transanal Endoscopic Surgery?

BACKGROUND

An important drawback of local surgery for lesions in the anal canal is the difficulty of achieving en bloc full-thickness resections. The aim of this study is to evaluate TEM/TEO in lesions of this type from the point of view of morbidity, mortality and the quality of the pathology specimen.

METHODS

This is an observational study with prospective data collection from June 2004 to July 2018. Two groups are defined: group A (rectal tumors with proximal margin between 0 and ≤4 cm from anal verge) and group B (distal margin > 4 cm from anal verge). A technical description is provided; resections and postoperative complications in both groups are compared.

RESULTS

During the study period, 757 patients underwent TEM/TEO. Finally, 692 patients were included, 192 patients in group A and 500 patients in group B. An en bloc surgical specimen was obtained in 176/192 patients (91.7%), although the defect was completely sutured in 132 (68.8%). In the comparative analysis, group A did not present significantly greater fragmentation of the resected piece [16/192 (8.3%) vs. 36/500 (7.2%), p = 0.630], although group A was associated with greater involvement of the surgical margin [28/192 (14.6%), 32/500 (6.4%), p = 0.001] and clinically relevant morbidity [16/192 (8.3%), 20/500 (4%), p = 0.034]. There was no mortality.

CONCLUSIONS

The use of TEM/TEO to remove lesions originating in the anal canal is feasible. But we have to take into account that there is an increase in complications, technical difficulties and affected margins resection.

Transanal endoscopic micro-surgery in elderly and very elderly patients: a safe option? Observational study with prospective data collection

BACKGROUND

Although the incidence of colorectal cancer increases with the patient's age, the elderly continue to be less likely to be scheduled for surgery. Transanal endoscopic micro-surgery (TEM) is a surgical alternative to total mesorectal excision (TME) in early stage rectal cancer and/or in selected patients that could decrease morbidity and mortality rates in this group of patients. Our main objective is to assess the safety and feasibility of TEM in elderly (75-84 years) and very elderly (≥ 85 years) patients.

METHODS

Observational study was conducted with prospective data collection of all consecutive patients who underwent TEM between April 2004 and January 2017. Patients were assigned to groups according to age. Descriptive and comparative analyses between groups were performed.

RESULTS

We analyzed 693 patients, 429 patients < 75 years (61.9%), 220 patients between the ages of 75 and 84 (31.7%), and 44 patients ≥ 85 years old (6.3%). The tendency in our series is to increase comorbidities with age. Palliative or consensus intent was more frequently performed in elderly (10.5%, 34/220), and very elderly (45.4%, 20/44), compared with the youngest (6.3%, 27/429), (p < 0.001). Global morbidity presented an increasing trend related to age from 20.3% in < 75 years, to 25.9% in elderly and 34.1% in very elderly. Surgical complications were recorded in 18.5% (128/693) of patients with no significant differences between groups. The most common one was rectal bleeding 16.1% (111/693). Significant differences were found in non-surgical complications, recorded in 7.3% (16/220) in the elderly, and 15.9% (7/44) in the group above 84 years (p = 0.013).

CONCLUSIONS

TEM presents acceptable morbidity rates mainly due to non-surgical-related adverse effects in elderly and very elderly patients and may be a feasible and safe alternative in this population in both curative and non-curative indications.

Morbidity after transanal endoscopic microsurgery: risk factors for postoperative complications and the design of a 1-day surgery program

BACKGROUND

Transanal endoscopic microsurgery (TEM) is a minimally invasive procedure with low morbidity. The definition of risk factors for postoperative complications would help to identify the patients likely to require more care and surveillance in an ambulatory or 1-day surgery (A-OdS) program. The main endpoints are overall 30-day morbidity and relevant morbidity. The secondary objectives are to detect risk factors for complications, rehospitalization, and the time of occurrence of the postoperative complications, and to describe the adverse effects following hospitalization that the A-OdS program would avoid.

METHODS

This is an observational study of consecutive patients undergoing TEM between June 2004 and December 2016. Overall and relevant morbidity based on the Clavien-Dindo (Cl-D) classification were recorded, as were demographic, preoperative, surgical, and pathology variables. Univariate and multivariate analyses of the risk factors were carried out.

RESULTS

Six hundred and ninety patients underwent surgery, of whom 639 were included in the study. Overall morbidity rate was 151/639 patients (23.6%); the clinically relevant morbidity rate was 36/639 (Cl-D > II) (5.6%) and mortality 2/639 (0.3%). The most frequent complication was rectal bleeding, recorded in 16.9% (108/639 patients) and grade I in 86/108 patients (78. 9%). The period with the greatest risk of complications was the first 2 days. The rehospitalization rate after 48 h was 7%. The risk factors for complications were as follows: tumor size > 6 cm (OR 3.2, 95% CI 1.3-7.8), anti-platelet medication (OR 2.3, 95% CI 1.1-5.1), and surgeon's experience < 150 procedures (OR 2.0, 95% CI 1-4.1).

CONCLUSIONS

TEM is a safe procedure. The low rates of morbidity, re-hospitalization, and postoperative complications in the first 2 days after surgery make the procedure suitable for A-OdS.

Transanal endoscopic surgery is effective and safe after endoscopic polypectomy of potentially malignant rectal polyps with questionable margins

AIM

To determine the percentage of residual lesion observed in the pathology study of transanal endoscopic surgery (TEM) specimens after endoscopic polypectomy of malignant rectal polyps with questionable margins, and the need for further surgery. Secondary aims: to determine the morbidity and mortality associated with this procedure and to identify the percentage of recurrence after excision by TEM.

METHODS

Observational study with prospective data collection of all patients undergoing TEM after endoscopic polypectomy for malignant rectal polyps or non-invasive high-grade neoplasia, from January 2004 to December 2016. An en bloc full-thickness wall excision of the scar was performed. Variables recorded: histology of TEM specimen, 30-day morbidity and mortality according to the Clavien-Dindo classification, need for salvage surgery and recurrence.

RESULTS

Fifty out of 690 patients undergoing TEM during the study period (36 adenocarcinomas, five non-invasive high-grade neoplasias and 9 neuroendocrine tumors) were included. Post-surgery histology showed residual lesion in 21 (42%) patients: 7 neuroendocrine tumors, 10 adenomas and 4 adenocarcinomas (two pT1, one pT2 and one pT3). The pT2 and pT3 patients (4%) underwent salvage surgery. No recurrence was observed, and mean follow-up was 29.1Â ± 21.6 months. The 30-day morbidity rate was 14%, but 4/7 with Clavien-Dindo grade I.

CONCLUSIONS

After endoscopic polypectomy of malignant rectal polyps with questionable margins, the presence of residual lesion in the pathology study of transanal resection specimens is high. TEM with full-thickness resection of these lesions is an appropriate treatment, allowing disease control and achieving minimal morbidity.

How to deal with rectal lesions more than 15 cm from the anal verge through transanal endoscopic microsurgery

BACKGROUND

The aim of this study is to assess postoperative morbidity and mortality in tumors with a proximal margin 15 cm or more from the anal verge operated with transanal endoscopic microsurgery (TEM).

METHODS

This observational study of consecutive rectal tumor patients undergoing TEM was carried out from July 2004 to June 2017. We compared the results of rectal tumors at distances of ≥15 cm (group A) and <15 cm (group B) from the anal verge.

RESULTS

During the study period 667 patients were included: 118 in group A and 549 in group B. In the comparative analysis there were no significant differences in morbidity (p = 0.23), mortality (p = 0.32) or free margin involvement (p = 0.545). Differences were observed in terms of lesion size (p < 0.001), surgical time (p < 0.001) and peritoneal cavity perforation, which were all increased in group A.

CONCLUSION

TEM for lesions in the rectosigmoid junction is feasible and is not associated with higher morbidity or mortality.

Local excision for rectal cancer: a minimally invasive option

Transanal excision (TAE) with conventional retractors and transanal endoscopic microsurgery (TEM) are two well established minimally invasive surgical options for the treatment of selected rectal cancers. TEM is nowadays considered the standard of care for the transanal excision of rectal tumors, since it is associated with significantly better quality of excision and lower rates of recurrence than TAE. When compared with rectal resection and total mesorectal excision, TEM has lower postoperative morbidity and better functional outcomes, with similar long-term survival rates in selected early rectal cancers. More recently, transanal minimally invasive surgery (TAMIS) has been developed as an alternative to TEM. Possible benefits of TAMIS are under evaluation.

[Minimally invasive approaches for transanal surgery]

Since the introduction of transanal endoscopic microsurgery (TEM) in the 1980 s, the minimally invasive transanal approach has been a treatment option for selected patients with colorectal diseases. Recently, transanal minimally invasive surgery (TAMIS) was introduced as an alternative technique. TAMIS is a hybrid between TEM and single-port laparoscopy and was followed by introduction of transanal total mesorectal excision (TaTME). Although the TaTME experience remains preliminary, it appears to be an attractive minimally invasive procedure for carefully selected patients with resectable rectal cancer. The objective of this review is to describe the latest technologies which enhanced progress of minimally invasive transanal approaches for endo- and extraluminal surgery in this area of colorectal surgery.

Neoadjuvant therapy and transanal endoscopic surgery in T2-T3 superficial, N0, M0 rectal tumors. Local recurrence, complete clinical and pathological response

INTRODUCTION

The association of preoperative chemoradiotherapy and transanal endoscopic surgery in T2 and superficial T3 rectal cancers presents promising results in selected patients. The main objective is to evaluate the long-term loco-regional and systemic recurrence and, as secondary objectives, to provide results of postoperative morbidity and the correlation between complete clinical and pathological response.

METHODS

This is a retrospective observational study including a consecutive series of patients with T2-T3 superficial rectal cancer, N0, M0 who refused radical surgery (2008-2016). The treatment consisted of preoperative chemotherapy (5-fluorouracil or capecitabine) combined with radiotherapy (50, 4Gy) and transanal endoscopic surgery after 8weeks. Preoperative, surgical, pathological and long-term oncologic results were analyzed.

RESULTS

Twenty-four patients were included in the study. Two of them required rescue radical surgery for unfavorable pathological results. A local recurrence (4.5%) was observed and 2patients presented systemic recurrence (9%), with a median follow-up of 45 months. A complete clinical tumor response was achieved in 12 patients (50%), and complete pathological tumor response in 9 patients (37.5%). Postoperative complications were observed in 5 patients (20.8%), and they were mild except one. There was no postoperative mortality.

CONCLUSIONS

In this stage of rectal cancer, our results seem to support this strategy, mainly when a complete pathological response is achieved. The complete clinical tumor response does not coincide with the pathological tumor response. Randomized prospective studies should be performed to standardize this treatment.

Transanal Endoscopic Operation for Benign Rectal Lesions and T1 Carcinoma

Background and Objectives:

Transanal endoscopic operation (TEO) is a minimally invasive technique used for local excision of benign and selected malignant rectal lesions. The purpose of this study was to investigate the feasibility, safety, and oncological outcomes of the procedure and to report the experience in 3 centers.

Methods:

Retrospective review of a prospectively collected database was performed of all patients with benign lesions or ≤cT1N0 rectal cancer who underwent TEO with curative intent at 3 Belgian centers (2012 through 2014).

Results:

Eighty-three patients underwent 84 TEOs for 89 rectal lesions (37 adenomas, 43 adenocarcinomas, 1 gastrointestinal stromal tumor, 1 lipoma, 2 neuroendocrine tumors, and 5 scar tissues). Operative time was associated with lesion size (P < .001). Postoperative complications occurred in 13 patients: 7 hemorrhages, 1 urinary tract infection, 1 urinary retention, 2 abscesses, 1 anastomotic stenosis, and 1 entrance into the peritoneal cavity. Median hospital stay was 3 days (range, 1–8). During a median follow-up of 13 months (range, 2–27), there was 1 recurrence.

Conclusion:

Although longer follow-up is still necessary, TEO appears to be an effective method of excising benign tumors and low-risk T1 carcinomas of the rectum. However, TEO should be considered as part of the diagnostic work-up. Furthermore, the resected specimen of a TEO procedure allows adequate local staging in contrast to an endoscopic piecemeal excision. Nevertheless, definitive histology must be appreciated, and in case of unfavorable histology, radical salvage resection still has to be performed.

Indications and Outcomes From 32 Consecutive Patients for the Treatment of Rectal Lesions by Transanal Minimally Invasive Surgery

BACKGROUND

The aim of this study was to evaluate the feasibility, safety, perioperative morbidity, and short-term outcomes of the transanal minimally invasive surgery (TAMIS) technique.

METHODS

This is a descriptive review of prospectively collected data from 32 consecutive patients who underwent TAMIS procedures in our colorectal unit over a 40-month period. GelPOINT Path port was used in all cases. Demographic data, indications, tumor characteristics, morbidity, and follow-up data were collected. Primary endpoints included feasibility, safety, perioperative morbidity, and resection quality.

RESULTS

Fifteen adenomas, 12 carcinomas, 1 gastrointestinal stromal tumor, and 1 neuroendocrine tumor were locally excised. Additionally, 3 pelvic abscesses were drained transanally using the TAMIS port. Mean distance from the anal verge was 5.6 ± 1.5 cm. Early postoperative complications occurred in 22%, with only one case of major complication (3.1%) requiring reoperation, and no postoperative mortality. Four carcinomas were understaged (33.3%) and 1 adenoma overstaged (6.7%) preoperatively. Three carcinomas were not suspected preoperatively (25%). Microscopic positive lateral margin was found in one case, and no affected deep margin was found. Fragmentation rate was 6.9%, 2 cases, both lesions over 20 cm². In cases of fit patients with high-risk carcinomas, 2 underwent immediate salvage surgery and another 2 refused and were treated with adjuvant radiotherapy. With a median follow-up of 26 months, the overall recurrence rate was 10.3%, 1 adenoma and 2 carcinomas.

CONCLUSION

TAMIS seems to be a safe and reproducible procedure for local excision of well-selected rectal lesions with low morbidity and good functional outcomes.

Transanal endoscopic surgery: past, present and future

Transanal endoscopic surgery is a safe, established technique to remove lesions in the rectum via the anus. This article reviews its evolution, approaches, indications and evidence for its role in treating benign rectal polyps. The future of transanal endoscopic surgery in rectal cancer and inflammatory bowel disease is also explored.

Local excision by transanal endoscopic surgery

Transanal endoscopic surgery (TES) consists of a series of anorectal surgical procedures using different devices that are introduced into the anal canal. TES has been developed significantly since it was first used in the 1980s. The key point for the success of these techniques is how accurately patients are selected. The main indication was the resection of endoscopically unresectable adenomas. In recent years, these techniques have become more widespread which has allowed them to be applied in conservative rectal procedures for both benign diseases and selected cases of rectal cancer. For more advanced rectal cancers it should be considered palliative or, in some controlled trials, experimental. The role of newer endoscopic techniques available has not yet been defined. TES may allow for new strategies in the treatment of rectal pathology, like transanal natural orifice transluminal endoscopic surgery or total mesorectal excision.

Hybrid NOTES: TEO for transanal total mesorectal excision: intracorporeal resection and anastomosis

BACKGROUND

Laparoscopic surgery for rectal TME achieves better patient recovery, lower morbidity, and shorter hospital stay than open surgery. However, in laparoscopic rectal surgery, the overall conversion rate is nearly 20%. Transanal TME combined with laparoscopy, known as Hybrid NOTES, is a less invasive procedure that provides adequate solutions to some of the limitations of rectal laparoscopy. Transanal TME via TEO with technical variants (intracorporeal resection and anastomosis, TEO review of the anastomosis) attempts to standardize and simplify the procedure.

METHOD

Prospective observational study was used describe and assess the technique in terms of conversion to open surgery, overall morbidity, surgical site infection and hospital stay. The sample comprised consecutive patients diagnosed with rectal tumor less than 10 cm from the anal verge who were candidates for low anterior resection using TME (except T4). Demographic, surgical, postoperative, and pathological variables were analyzed, as well as morbidity rates.

RESULTS

From September 2012 to August 2014, 32 patients were included. The conversion rate was 0%. Overall morbidity was 31.3%, SSI rate was 9.4%, and mean hospital stay was 8 days. Oncological radical criteria were achieved with pathological parameters of 94% of complete TME and a median circumferential margin of 13 mm.

CONCLUSION

The introduction of technical variants of TEO for transanal resection can facilitate a procedure that requires extensive experience in transanal and laparoscopic surgery. Studies of sphincter function, quality of life, and long-term oncological outcome are now necessary.

Transanal endoscopic surgery in rectal cancer

Total mesorectal excision (TME) is the standard treatment for rectal cancer, but complications are frequent and rates of morbidity, mortality and genitourinary alterations are high. Transanal endoscopic microsurgery (TEM) allows preservation of the anal sphincters and, via its vision system through a rectoscope, allows access to rectal tumors located as far as 20 cm from the anal verge. The capacity of local surgery to cure rectal cancer depends on the risk of lymph node invasion. This means that correct preoperative staging of the rectal tumor is necessary. Currently, local surgery is indicated for rectal adenomas and adenocarcinomas invading the submucosa, but not beyond (T1). Here we describe the standard technique for TEM, the different types of equipment used, and the technical limitations of this approach. TEM to remove rectal adenoma should be performed in the same way as if the lesion were an adenocarcinoma, due to the high percentage of infiltrating adenocarcinomas in these lesions. In spite of the generally good results with T1, some authors have published surprisingly high recurrence rates; this is due to the existence of two types of lesions, tumors with good and poor prognosis, divided according to histological and surgical factors. The standard treatment for rectal adenocarcinoma T2N0M0 is TME without adjuvant therapy. In this type of adenocarcinoma, local surgery obtains the best results when complete pathological response has been achieved with previous chemoradiotherapy. The results with chemoradiotherapy and TEM are encouraging, but the scientific evidence remains limited at present.