eTAMIS: endoscopic visualization for transanal minimally invasive surgery

Robotic Transanal Total Mesorectal Excision (RTaTME): State of the Art

Total mesorectal excision (TME) is the gold standard technique for the surgical management of rectal cancer. The transanal approach to the mesorectum was introduced to overcome the technical difficulties related to the distal rectal dissection. Since its inception, interest in transanal mesorectal excision has grown exponentially and it appears that the benefits are maximal in patients with mid-low rectal cancer where anatomical and pathological features represent the greatest challenges. Current evidence demonstrates that this approach is safe and feasible, with oncological and functional outcome comparable to conventional approaches, but with specific complications related to the technique. Robotics might potentially simplify the technical steps of distal rectal dissection, with a shorter learning curve compared to the laparoscopic transanal approach, but with higher costs. The objective of this review is to critically analyze the available literature concerning robotic transanal TME in order to define its role in the management of rectal cancer and to depict future perspectives in this field of research.

Transanal minimally invasive surgery vs endoscopic mucosal resection for rectal benign tumors and rectal carcinoids: A retrospective analysis

BACKGROUND

Transanal minimally invasive surgery (TAMIS) is a good choice for resection of rectal neoplasms. Endoscopic mucosal resection (EMR) is also widely used in the treatment of benign rectal tumors such as rectal polyps and rectal adenomas. However, no studies have compared the outcome of TAMIS and EMR.

AIM

To compare the short-term outcomes after TAMIS and EMR for rectal carcinoid and benign tumors (including rectal polyps and adenomas).

METHODS

From January 2014 to January 2019, 44 patients who received TAMIS and 53 patients who received EMR at The Fifth People’s Hospital of Shanghai were selected. Primary outcomes (surgical-related) were operating time, blood loss, length of postoperative hospital stay, rate of resection margin involvement and lesion fragmentation rate. The secondary outcomes were complications such as hemorrhage, urinary retention, postoperative infection and reoperation.

RESULTS

No significant differences were observed in terms of blood loss (12.48 ± 8.00 mL for TAMIS vs 11.45 ± 7.82 mL for EMR, P = 0.527) and length of postoperative hospital stay (3.50 ± 1.87 d for TAMIS vs 2.72 ± 1.98 d for EMR, P = 0.065) between the two groups. Operating time was significantly shorter for EMR compared with TAMIS (21.19 ± 9.49 min vs 49.95 ± 15.28 min, P = 0.001). The lesion fragmentation rate in the EMR group was 22.6% (12/53) and was significantly higher than that (0%, 0/44) in the TAMIS group (P = 0.001). TAMIS was associated with a higher urinary retention rate (13.6%, 6/44 vs 1.9%, 1/53 P = 0.026) and lower hemorrhage rate (0%, 0/44 vs 18.9%, 10/53 P = 0.002). A significantly higher reoperation rate was observed in the EMR group (9.4%, 5/53 vs 0%, 0/44 P = 0.036).

CONCLUSION

Compared with EMR, TAMIS can remove lesions more completely with effective hemostasis and lower postoperative hemorrhage and reoperation rates. TAMIS is a better choice for the treatment of rectal carcinoids.

Transanal minimally invasive surgery (TAMIS) for rectal tumor: a case report and literature review

Transanal minimally invasive surgery (TAMIS) is mainly used for benign tumors of the rectum, but there are few reports on treating malignant tumors of the rectum with a large volume. The aim of this study was to evaluate the feasibility and safety of TAMIS for resection of rectal malignant tumors. A 57-year-old patient was pathologically diagnosed as rectal malignancy before surgery. Computed tomography (CT), magnetic resonance imaging (MRI), fludeoxyglucose-18F (18F-FDG), and endoscopic mucosal biopsy were performed to assess the tumor location and preoperative size. There were no contraindications in all preoperative examinations. We applied TAMIS technology to perform the operation on this patient, And the operative time, the amount of blood loss, the length of hospital stay, the cost of hospital stay, surgical complications, postoperative complications and other relevant data were all collected. The operation was successful, the operation time was 45 min, 10 mL of intraoperative blood loss, and the length of stay was 3 days, a tumor of a maximum diameter of 4 cm being completely removed. There were no related complications or recurrence during postoperative follow-up. The pathological results were tubular villous adenoma with low-grade intraepithelial neoplasia, and a focal area of high-grade intraepithelial neoplasia. The pathological stage was T1N0M0. At 3-month follow-up there were no signs of recurrence. The patient was followed up for 5 years after the operation and there was no tumor recurrence or metastasis in other parts and no other discomfort. TAMIS is less commonly used in rectal malignancies, especially for tumors with larger diameters. We successfully performed complete resection of a 4-cm rectal malignant tumor with TAMIS. Given its low risk, low cost, simple operation, and few complications, TAMIS can be used for more indications of rectum diseases.

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.

Cirugía mínimamente invasiva transanal (TAMIS): técnica y resultados de la experiencia inicial

Antecedentes: la cirugía transanal endoscópica es un abordaje mínimamente invasivo recientemente descrito, que provee una exposición superior y permite el acceso a las lesiones del recto en toda su extensión. Además, provee un riesgo menor de compromiso de los márgenes de resección, menores tasas de recurrencia y una menor morbimortalidad en comparación con la escisión transanal convencional o las remociones endoscópicas. Objetivos: se pretende describir la experiencia inicial y los resultados con la cirugía transanal mínimamente invasiva (transanal minimally invasive surgery, TAMIS) en términos de resecciones completas y posibles complicaciones relacionadas con el procedimiento. Materiales y métodos: esta una serie de casos con un seguimiento prospectivo de los pacientes con TAMIS. Se analizaron los resultados de 27 pacientes intervenidos en varios centros de Medellín, Colombia, entre enero de 2012 y diciembre de 2016, realizados con cirugía laparoscópica monopuerto (single-port laparoscopic surgery, SILS) (21 casos) o el GelPOINT® Path (6 casos), junto con el apoyo de la óptica del laparoscopio (16 pacientes) y del endoscopio flexible (11 pacientes). Resultados: se realizaron 27 TAMIS en el mismo número de pacientes, 10 mujeres (37 %) y 17 hombres fueron evaluados. Se realizó un seguimiento a los pacientes durante aproximadamente 12 meses, en promedio 32 meses. La edad promedio fue de 68 años (52-83 años). El tamaño promedio del tumor fue de 5,3 cm (2-9 cm) y la distancia promedio desde el margen anal fue de 7 cm (5-9 cm) Las complicaciones posoperatorias se dieron en 6 casos (22 %) Una perforación rectal se corrigió por vía laparoscópica en el mismo acto quirúrgico y otra por la misma vía transanal. Una estenosis rectal se manejó con dilatación digital, y hubo un caso de sangrado rectal menor, uno de retención urinaria y un paciente presentó un cáncer rectal avanzado a los tres meses de la resección con margen microscópico positivo (4 %). No hubo reingresos. La mortalidad por la intervención fue nula. La patología operatoria reportó la presencia de adenoma de bajo grado en 3 casos (11 %), de alto grado en 11 (41 %), adenocarcinoma in situ en 6 (22 %), tumor neuroendocrino en 5 pacientes (18 %), 1 caso de fibrosis cicatricial (4 %) y 1 de leiomioma (4 %). Limitaciones: los resultados no son extrapolables a la población general debido al poco número de intervenciones y la ejecución limitada a solo dos autores. Conclusiones: en nuestra experiencia inicial, TAMIS es un procedimiento mínimamente invasivo con una baja morbilidad posoperatoria, es curativa para lesiones benignas y para pacientes seleccionados con cáncer temprano.

Transluminal Cancer Surgery

Transluminal surgery, also known as natural orifices endoluminal surgery, can be considered the most minimally invasive approach of gaining access to an organ. Although some approaches, such as transgastric or transvaginal cholecystectomy, have remained experimental, peroral endoscopic myotomy to treat achalasia and transanal total mesorectal excision to treat low rectal cancer have become accepted, safe, and feasible approaches by trained surgeons for selected patients. This article recapitulates the development of transluminal surgery from its experimental beginnings to the validated procedure it has become today.

Transanal Total Mesorectal Excision (taTME) for Rectal Cancer: A Case Series Report of a Natural Orifice Surgical Technique

In the treatment of colorectal cancer, total mesorectal excision (TME) has risen as the gold standard in the surgical treatment of this disease in order to obtain negative distal and circumferential radial margins. Since introduction in 2010, transanal TME has aimed to decrease the rate of positive margins and improve the quality of the dissection while decreasing the complications associated with a transabdominal low pelvic dissection. We retrospectively reviewed 25 cases of transanal TME completed between December 2014 and August 2017. Most of the patients in our case series were male (60%) with an average age of 57.1 years, BMI of 28.4 kg/m2, and with an American Society of Anesthesiologists score of II. The average tumor was midrectal (about 5.9 cm from the anal verge), clinically T3-T4 (92%), and had undergone neoadjuvant therapy (96%). The average operation was about six hours and 44 minutes with ileostomy placed most of the time (92%). In all the cases where the TME quality was graded, the specimens were reported to have been complete (grade I). There were no positive distal, radial, or proximal margins. The average hospital stay was about 5.9 days. The rate of minor complications was about 48 per cent and major complications occurred about 16 per cent of the time.

Transanal total mesorectal excision (taTME) for rectal cancer: a training pathway

BACKGROUND

With increasing interest in natural orifice surgery, there has been a dramatic evolution of transanal and endoluminal surgical techniques. These techniques began with transanal endoluminal surgical removal of rectal masses and have progressed to transanal radical proctectomy for rectal cancer. The first transanal total mesorectal excision (taTME) was performed in 2009 by Sylla, Rattner, Delgado, and Lacy. The improved visibility and working space associated with the taTME technique is intriguing. This video manuscript outlines the training pathway followed by pioneers in the taTME technique, the process of implementation into clinical practice, and initial case report.

METHODS

A double board-certified colorectal surgeon with expertise in rectal cancer, minimally invasive total mesorectal excision, transanal endoscopic surgery (TES), and intersphincteric dissection, underwent taTME training in male cadaver models. Institutional review board (IRB) approval for a phase I clinical trial was achieved. The entire operative team including surgeons, nurses, and operative staff underwent taTME cadaver training the day prior to the first clinical case. The case was proctored by an expert in taTME.

RESULTS

A 66-year-old male with uT3N1M0 rectal cancer located in the posterior distal rectum, underwent taTME with laparoscopic abdominal assistance, hand sewn coloanal anastomosis, and diverting loop ileostomy. The majority of the TME was performed transanally with laparoscopic assistance for exposure, splenic flexure mobilization, and high ligation of the vascular pedicles. Operative time was 359 min. There were no intraoperative complications. Pathology revealed a ypT2N1 moderately differentiated invasive adenocarcinoma, grade I TME, 1 cm circumferential radial margin, and 2/13 positive lymph nodes.

CONCLUSION

Implementation of taTME into practice can be achieved by surgeons with expertise in minimally invasive TME, TES, pre-clinical taTME training in cadavers, case observation, proctoring, and ongoing mentorship. IRB peer review process and participation in a clinical registry are additional measures that should be employed.

Transanal Minimally Invasive Surgery

Transanal minimally invasive surgery (TAMIS) was first described in 2010 as a crossover between single-incision laparoscopic surgery and transanal endoscopic microsurgery (TEM) to allow access to the proximal and mid-rectum for resection of benign and early-stage malignant rectal lesions. The TAMIS technique can also be used for noncurative intent surgery of more advanced lesions in patients who are not candidates for radical surgery. Proper workup and staging should be done before surgical decision-making. In addition to the TAMIS port, instrumentation and set up include readily available equipment found in most operating suites. TAMIS has proven its usefulness in a wide range of applications outside of local excision, including repair of rectourethral fistula, removal of rectal foreign body, control of rectal hemorrhage, and as an adjunct in total mesorectal excision for rectal cancer. TAMIS is an easily accessible, technically feasible, and cost-effective alternative to TEM.

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.

Local excision for early rectal cancer: transanal endoscopic microsurgery and beyond

The goal of treatment for early stage rectal cancer is to optimize oncologic control while minimizing the long-term impact of treatment on quality of life. The standard of care treatment for most stage I and II rectal cancers is radical surgery alone, specifically total mesorectal excision (TME). For early rectal cancers, this procedure is usually curative but can have a substantial impact on quality of life, including the possibility of permanent colostomy and the potential for short and long-term bowel, bladder, and sexual dysfunction. Given the morbidity associated with radical surgery, alternative approaches to management of early rectal cancer have been explored, including local excision (LE) via transanal excision (TAE) or transanal endoscopic microsurgery (TEM) and transanal minimally invasive surgery (TAMIS). Compared to the gold standard of radical surgery, local procedures for strictly selected early rectal cancers should lead to identical oncological results and even better outcomes regarding morbidity, mortality, and quality of life.

Impact of technology on indications and limitations for transanal surgical removal of rectal neoplasms

Transanal surgery has and continues to be well accepted for local excision of benign rectal disease not amenable to endoscopic resection. More recently, there has been increasing interest in applying transanal surgery to local resection of early malignant disease. In addition, some groups have started utilizing a transanal route in order to accomplish total mesorectal excision (TME) for more advanced rectal malignancies. We aim to review the role of various transanal and endoscopic techniques in the local resection of benign and malignant rectal disease based on published trial data. Preliminary data on the use of transanal platforms to accomplish TME will also be highlighted. For endoscopically unresectable rectal adenomas, transanal surgery remains a widely accepted method with minimal morbidity that avoids the downsides of a major abdomino-pelvic operation. Transanal endoscopic microsurgery and transanal minimally invasive surgery offer improved visualization and magnification, allowing for finer and more precise dissection of more proximal and larger rectal lesions without compromising patient outcome. Some studies have demonstrated efficacy in utilizing transanal platforms in the surgical management of early rectal malignancies in selected patients. There is an overall higher recurrence rate with transanal surgery with the concern that neither chemoradiation nor salvage surgery may compensate for previous approach and correct the inferior outcome. Application of transanal platforms to accomplish transanal TME in a natural orifice fashion are still in their infancy and currently should be considered experimental. The current data demonstrate that transanal surgery remains an excellent option in the surgical management of benign rectal disease. However, care should be used when selecting patients with malignant disease. The application of transanal platforms continues to evolve. While the new uses of transanal platforms in TME for more advanced rectal malignancy are exciting, it is important to remain cognizant and not sacrifice long term survival for short term decrease in morbidity and improved cosmesis.

Transanal total mesorectal excision: a systematic review of the experimental and clinical evidence

Achieving a clear distal or circumferential resection margins with laparoscopic total mesorectal excision (TME) may be laborious, especially in obese males and when operating on advanced distal rectal tumors with a poor response to neoadjuvant treatment. Transanal (TaTME) is a new natural orifice translumenal endoscopic surgery modality in which the rectum is mobilized transanally using endoscopic techniques with or without laparoscopic assistance. We conducted a comprehensive systematic review of publications on this new technique in PubMed and Embase databases from January, 2008, to July, 2014. Experimental and clinical studies written in English were included. Experimental research with TaTME was done on pigs with and without survival models and on human cadavers. In these studies, laparoscopic or transgastric assistance was frequently used resulting in an easier upper rectal dissection and in a longer rectal specimen. To date, 150 patients in 16 clinical studies have undergone TaTME. In all but 15 cases, transabdominal assistance was used. A rigid transanal endoscopic operations/transanal endoscopic microsurgery (TEO/TEM) platform was used in 37 patients. Rectal adenocarcinoma was the indication in all except for nine cases of benign diseases. Operative times ranged from 90 to 460 min. TME quality was deemed intact, satisfactory, or complete. Involvement in circumferential resection margins was detected in 16 (11.8 %) patients. The mean lymph node harvest was equal or greater than 12 in all studies. Regarding morbidity, pneumoretroperitoneum, damage to the urethra, and air embolism were reported intraoperatively. Mean hospital stay varied from 4 to 14 days. Postoperative complications occurred in 34 (22.7 %) patients. TaTME with TEM is feasible in selected cases. Oncologic safety parameters seem to be adequate although the evidence relies on small retrospective series conducted by highly trained surgeons. Further studies are expected.

A systematic review of transanal minimally invasive surgery (TAMIS) from 2010 to 2013

Transanal minimally invasive surgery (TAMIS) was introduced as an alternative to transanal endoscopic microsurgery in 2010. Over the past 4 years, considerable international experience has been gained with this approach. Most published reports focus on TAMIS for local excision of rectal neoplasia, but there are other important applications such as transanal mesorectal excision for rectal cancer. This comprehensive review details the progress with TAMIS since its inception. Robotic transanal surgery is a natural evolution of TAMIS still in its early infancy, which is also reviewed. A comprehensive search of PubMed, EMBASE, the Cochrane Library, and Web of Knowledge was performed. Since the inception of TAMIS in 2009, 33 retrospective studies and case reports, and 3 abstracts have been published on TAMIS for local excision of rectal neoplasms, which represents a combined n = 390 TAMIS procedures performed worldwide using eight different types of TAMIS platforms. A total of 152 lesions were excised for benign disease including adenomas and high-grade dysplasias (39 %), 209 for malignancy for carcinomas in situ and adenocarcinomas (53.5 %). Twenty-nine (7.5 %) of TAMIS resections were for other pathology, of which the majority (23/29) were neuroendocrine lesions. The remaining resections were for mucocele, gastrointestinal stromal tumor, melanoma, and fibrosis. Robotic-TAMIS has also been reported, however, data are extremely limited as there are only 7 case reports (combined n = 11) in the published literature. Success with Robotic-TAMIS has been demonstrated with various patient positions and by use of a special glove port. Transanal total mesorectal excision using the TAMIS platform has also been demonstrated is several small series, and the feasibility of performing pure transanal total mesorectal excision has also been reported. Combined, n = 78 cases of transanal total mesorectal excision have been performed using TAMIS. The advantages of TAMIS-assisted transanal total mesorectal excision are discussed.

A systematic review of transanal minimally invasive surgery (TAMIS) from 2010 to 2013

Transanal minimally invasive surgery (TAMIS) was introduced as an alternative to transanal endoscopic microsurgery in 2010. Over the past 4 years, considerable international experience has been gained with this approach. Most published reports focus on TAMIS for local excision of rectal neoplasia, but there are other important applications such as transanal mesorectal excision for rectal cancer. This comprehensive review details the progress with TAMIS since its inception. Robotic transanal surgery is a natural evolution of TAMIS still in its early infancy, which is also reviewed. A comprehensive search of PubMed, EMBASE, the Cochrane Library, and Web of Knowledge was performed. Since the inception of TAMIS in 2009, 33 retrospective studies and case reports, and 3 abstracts have been published on TAMIS for local excision of rectal neoplasms, which represents a combined n = 390 TAMIS procedures performed worldwide using eight different types of TAMIS platforms. A total of 152 lesions were excised for benign disease including adenomas and high-grade dysplasias (39 %), 209 for malignancy for carcinomas in situ and adenocarcinomas (53.5 %). Twenty-nine (7.5 %) of TAMIS resections were for other pathology, of which the majority (23/29) were neuroendocrine lesions. The remaining resections were for mucocele, gastrointestinal stromal tumor, melanoma, and fibrosis. Robotic-TAMIS has also been reported, however, data are extremely limited as there are only 7 case reports (combined n = 11) in the published literature. Success with Robotic-TAMIS has been demonstrated with various patient positions and by use of a special glove port. Transanal total mesorectal excision using the TAMIS platform has also been demonstrated is several small series, and the feasibility of performing pure transanal total mesorectal excision has also been reported. Combined, n = 78 cases of transanal total mesorectal excision have been performed using TAMIS. The advantages of TAMIS-assisted transanal total mesorectal excision are discussed.

Transanal minimally invasive surgery for benign and malignant rectal neoplasia

BACKGROUND

Transanal minimally invasive surgery (TAMIS), an alternative technique to transanal endoscopic microsurgery, was developed in 2009. Herein, we describe our initial experience using TAMIS for benign and malignant rectal neoplasia.

METHODS

This is an institutional review board approved, retrospective case series report.

RESULTS

TAMIS was performed in 32 patients for rectal adenoma (13), adenocarcinoma (16), and carcinoid (3). There were 14 women, with mean age 62 ± 15 years and body mass index 28 ± 5 kg/m(2). Lesion size ranged from .5 to 8.5 cm, distance from the dentate line 1 to 11 cm, and circumference of the lesion 10% to 100%. The mean operative time was 123 ± 62 minutes. Mean hospital length of stay was 2.5 ± 2 days. Complications included urinary tract infection (1), Clostridium difficile diarrhea (1), atrial fibrillation (1), rectal stenosis (1), and rectal bleeding (1).

CONCLUSION

TAMIS using a disposable transanal access platform is a safe and effective method to remove rectal lesions in this case series.

Transanal endoscopic microsurgery

Transanal endoscopic microsurgery (TEMS) is a well established method of accurate resection of specimens from the rectum under binocular vision. This review examines its role in the treatment of benign conditions of the rectum and the evidence to support its use and compliment existing endoscopic treatments. The evolution of TEMS in early rectal cancer and the concepts and outcomes of how it has been utilised to treat patients so far are presented. The bespoke nature of early rectal cancer treatment is changing the standard algorithms of rectal cancer care. The future of TEMS in the organ preserving treatment of early rectal cancer is discussed and how as clinicians we are able to select the correct patients for neoadjuvant or radical treatments accurately. The role of radiotherapy and outcomes from combination treatment using TEMS are presented with suggestions for areas of future research.

Transanal minimally invasive surgery for total mesorectal excision (TAMIS-TME): results and experience with the first 20 patients undergoing curative-intent rectal cancer surgery at a single institution

BACKGROUND

Transanal TME is a new approach to performing minimally invasive rectal resection. It is particularly well suited for patients with locally advanced distal rectal cancer and obesity, where the abdominal approach is challenging. Transanal TME can be performed with either TAMIS or TEM. Here, we report our initial experience with transanal TME using TAMIS (TAMIS-TME).

METHODS

Patients were selected to undergo transanal TME using the TAMIS platform (TAMIS-TME) primarily for malignant disease, but also for select cases of benign disease. Transanal TME defines a "bottom-up" approach to en bloc rectal cancer resection. Transanal TME requires abdominal access for proximal colonic mobilization and is often done in conjunction with a laparoscopic approach.

RESULTS

During a 32-month period, 20 patients underwent TAMIS-TME with curative intent. The primary indication for transanal TME was distal, locally advanced rectal cancer. The median age of rectal cancer patients at the time of surgery was 57 years (range 36-73 years) with 30% (6) female and 70% (14) male. The median body mass index (BMI) measured was 24 kg/m(2) (range 18-41 kg/m(2)); this included six patients (30%) with obesity (BMI ≥ 30 kg/m(2)). Mean operating time was 243 min (range 140-495 min) with blood loss averaging 153 ml. Postoperative length of stay averaged 4.5 days (range 3-24 days). There was no 30-day postoperative mortality. Surgical complications included wound infection (n = 2), pelvic abscess (n = 4), and prolonged ileus (n = 4). The anastomotic leak rate was 6.7% (1/15). Of the 20 patients who underwent resection, 90% (18/20) had negative margins. Pathologic grading of the TME specimen revealed that 85% (17/20) of transanal TME specimens were found to have "completely" or "near-completely" intact mesorectal envelopes. Data collected during the 6-month median follow-up period revealed that only one patient had developed distant metastasis. There was no locoregional recurrence in any of the patients.

CONCLUSIONS

Transanal TME is a feasible method for oncologic resection of locally advanced mid- and distal-rectal cancer with curative intent. It has special application for patients with obesity and anatomic constraints such as a narrow male pelvis.

Current evidence in gastrointestinal surgery: natural orifice translumenal endoscopic surgery (NOTES)

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) is a technique that uses transvisceral access to perform surgical procedures entirely through a natural orifice. Despite the increasing awareness of NOTES, there remain obstacles to its technical feasibility and widespread acceptance. Furthermore, with the paucity of high-level supporting evidence, NOTES currently remains an experimental technique.

OBJECTIVE

This article reviews the goals, applications, technical and practical challenges, and future direction of NOTES in gastrointestinal surgery.

Robotic-assisted transanal surgery for total mesorectal excision (RATS-TME): a description of a novel surgical approach with video demonstration

A new era has emerged in rectal cancer surgery--transanal total mesorectal excision (TME). Various platforms have been used to facilitate this novel approach, including transanal minimally invasive surgery (TAMIS) and transanal endoscopic microsurgery. We have previously reported the use of TAMIS-TME. This is a report of the first human case of robotic-assisted transanal surgery for TME.