Transanal endoscopic microsurgery-based transanal access for colorectal surgery: experience on human cadavers

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.

Novel box trainer for taTME - prospective evaluation among medical students

Background

Transanal total mesorectal excision (taTME) has been subject to extensive research and increasing clinical application. It allows further reduction of trauma by accessing via a natural orifice. Manifold platforms and instruments have been introduced and heterogeneity in surgical techniques exists. Because of the technique’s complexity there is a persistent need for dedicated training devices and concepts.

Materials and methods

The key steps of taTME were analyzed and a box trainer with three modules resembling these steps was designed and manufactured. Twenty-one surgically inexperienced medical students performed five repetitions of the three tasks with the new box trainer. Time and error count were analyzed for assessment of a learning curve.

Results

A significant reduction of processing time could be demonstrated for tasks 1–3 (p < 0.001; p < 0.001; p = 0.001). The effect size was high for comparison of repetition 1 and 5 and decreased over the course (task 1: r = 0.88 vs. r = 0.21; task 2: r = 0.86 vs. r = 0.23; task 3: r = 0.74 vs. r = 0.44). Also, a significant reduction of errors was demonstrated for tasks 1 and 2. The decrease of effect size was analogously demonstrated.

Conclusions

The trainer might help to reduce the use of animal models for testing of platforms and instruments as well as gaining first-hand experience in transanal rectal resection.

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.

Combined robotic transanal total mesorectal excision (R-taTME) and single-site plus one-port (R-SSPO) technique for ultra-low rectal surgery-initial experience with a new operation approach

OBJECTIVE

Robot-assisted rectal surgery is gaining popularity, and robotic single-site surgery is also being explored clinically. We report our initial experience with robotic transanal total mesorectal excision (R-taTME) and radical proctectomy using the robotic single-site plus one-port (R-SSPO) technique for low rectal surgery.

METHODS

Between July 2015 and March 2016, 15 consecutive patients with ultra-low rectal lesions underwent R-taTME followed by radical proctectomy using the R-SSPO technique by a single surgeon. The clinical and pathological results were retrospectively analyzed.

RESULTS

The median operative time was 473 (range, 335-569) min, and the estimated blood loss was 33 (range, 30-50) mL. The median number of lymph nodes harvested was 12 (range, 8-18). The median distal resection margin was 1.4 (range, 0.4-3.5) cm, and all patients had clear circumferential resection margins. We encountered a left ureteric transection intraoperatively in one patient, and another patient required reoperation for postoperative adhesive intestinal obstruction. There was no 30-day mortality.

CONCLUSION

R-taTME followed by radical proctectomy using the R-SSPO technique for patients with low rectal lesions is technically feasible and safe without compromising oncologic outcomes. However, there were considerable limitations and a steep learning curve using current robotic technology.

Pure Natural Orifice Transluminal Endoscopic Surgery (NOTES) with a new elongated, curved Transanal Endoscopic Operation (TEO) device for rectosigmoid resection: a survival study in a porcine model

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has seen considerable new developments in its evolution to a platform for rectal and sigmoid resection, but to date no true single NOTES procedure has been convincing. This study investigates the safety and feasibility of a further developed transanal NOTES platform for single-access NOTES rectosigmoid resection.

METHODS

Ten large female pigs, mean weight 99.3 kg [standard deviation (SD) 7 kg, range 85.1-112.6 kg], underwent transanal rectosigmoid resection. Five animals were included in an acute study group with immediate postoperative euthanization. A second group included five animals in a survival study. Transanal rectosigmoid resections were performed with an elongated and curved transanal endoscopic operation (TEO) device. Coloanal anastomosis was performed using the transanal circular stapler technique. Survival follow-up was at 7 and 28 days via colonoscopy under sedation.

RESULTS

Single-access NOTES transanal rectosigmoid resection with coloanal anastomosis was performed in nine out of ten female pigs. Mean length of rectosigmoid specimens exteriorized was 18.7 cm (SD 2.9 cm, range 14-23 cm). Mean operating time was 124 min (SD 35.7 min, range 70-166 min). Within the survival group, no complications occurred during the monitoring phase. In one case, there was ascites and colitis at necropsy as well as fibrosis at the anastomosis site.

CONCLUSIONS

Pure transanal rectosigmoid resection is a feasible procedure. The approach via a single transanal access is demanding but viable with the elongated and curved TEO device. The newly developed scope offers an excellent view of the area cephalad to the promontory.

A systematic review of transanal total mesorectal excision: is this the future of rectal cancer surgery?

AIM

The surgical technique used for transanal total mesorectal excision (TaTME) was reviewed including the oncological quality of resection and the peri-operative outcome.

METHOD

A literature search of MEDLINE, Embase, Science Citation Index Expanded and Cochrane was performed in order to identify studies reporting on TaTME.

RESULTS

Thirty-six studies (eight case reports, 24 case series and four comparative studies) were identified, reporting 510 patients who underwent TaTME. The mean age ranged from 43 to 80 years and the mean body mass index from 21.7 to 31.8 kg/m(2) . The mean distance of the tumour from the anal verge ranged from 4 to 9.7 cm. The mean operation time ranged from 143 to 450 min and mean operative blood loss from 22 to 225 ml. The ratio of hand-sewn coloanal to stapled anastomoses performed was 2:1. One death was reported and the peri-operative morbidity rate was 35%. The anastomotic leakage rate was 6.1% and the reoperation rate was 3.7%. The mean hospital stay ranged from 4.3 to 16.6 days. The mesorectal excision was described as complete in 88% cases, nearly complete in 6% and incomplete in 6%. The circumferential resection margin was negative in 95% of cases and the distal resection margin was negative in 99.7%.

CONCLUSION

TaTME is a feasible and reproducible technique, with good quality of oncological resection. Standardization of the technique is required with formal training. Clear indications for this procedure need to be defined and its safety further assessed in future trials.

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.

Shifting Paradigms in Minimally Invasive Surgery: Applications of Transanal Natural Orifice Transluminal Endoscopic Surgery in Colorectal Surgery

Since the advent of laparoscopy, minimally invasive techniques such as single port laparoscopy, robotics, endoscopically assisted laparoscopy, and transanal endoscopic surgery continue to revolutionize the field of colorectal surgery. Transanal natural orifice transluminal endoscopic surgery (NOTES) represents a further paradigm shift by combining the advantages of these earlier techniques to reduce the size and number of abdominal incisions and potentially optimize rectal dissection, especially with respect to performance of an oncologically adequate total mesorectal excision (TME) for rectal cancer. Since the first experimental report of transanal rectosigmoid resection in 2007, the potential impact of transanal NOTES in colorectal surgery has been extensively investigated in experimental models and recently transitioned to clinical application. There have been 14 clinical trials of transanal TME (taTME) for rectal cancer that have demonstrated the feasibility and preliminary oncologic safety of this approach in carefully selected patients, with results comparable to outcomes after laparoscopic and open TME, including cumulative intraoperative and postoperative complication rates of 5.5 and 35.5%, respectively, 97.3% rate of complete or near-complete specimens, and 93.6% rate of negative margins. Transanal NOTES has also been safely applied to proctectomy and colectomy for benign indications. The consensus among published series suggests that taTME is most safely performed with transabdominal assistance by surgeons experienced with laparoscopic TME, transanal endoscopic surgery, and sphincter-preserving techniques including intersphincteric resection. Future applications of transanal NOTES may include evolution to a pure endoscopic transanal approach for TME, colectomy, and sentinel lymph node biopsy for rectal cancer, with a potential role for robotic assistance.

Transanal total mesorectal excision: a pure NOTES approach for selected patients

BACKGROUND

The concept of natural orifice transluminal endoscopic surgery (NOTES) has stimulated the development of various "incisionless" procedures. One of the most popular is the transanal approach for rectal lesions. The aims of this study were to report how we standardized NOTES technique for transanal mesorectal excision without abdominal assistance, discuss the difficulties and surgical outcomes of this technique and report its feasibility in a small group of selected patients.

METHODS

Three consecutive female patients underwent transanal NOTES rectal resection without transabdominal laparoscopic assistance for rectal lesions. Functional results were assessed with the Fecal Incontinence Quality of Life scale and the Wexner score.

RESULTS

The technical steps are described in details and complemented with a video. All procedures were completed without transabdominal laparoscopic help. The mesorectal plane was entirely dissected without any disruption, and distal and circumferential margins were tumor-free. No major complications were observed. Functional results show a significant impairment after surgery with improvement at 6 months to levels near those of the preoperative period.

CONCLUSIONS

The performance and publication of NOTES procedures are subject to much discussion. Despite the small number of patients, this procedure appears feasible and can be accomplished maintaining fecal continence and respecting oncologic principles.

Transanal minimally invasive surgery for total mesorectal excision (ETM) through transanal approach (TaETM) with robotic and Transanal Endoscopic Operations (TEO) combined access: step by step surgery

Rational

In the treatment of colorectal cancer, from 1982 Heald proposed standardization of the total mesorectal excision, with a significant reduction in the recurrence rate. But the treatment of lower rectal lesions is still a challenge.

Aim

To describe the association of robotic low anterior resection- TATA (Transanal Abdominal Transanal Resection), with transanal access using Transanal Endoscopic Operations - TEO in the treatment of lower rectal cancer.

Method

The TATA performs robotic abdominal approach and the TEO performs the perineal approach, developing total mesorectal excision (TME) transanally (TaETM).

Result

The TaETM technique was applied in a woman with rectal adenocarcinoma 5 cm from the anal verge that had been submitted to chemoradiation. The procedure was performed with satisfatory operative time and favorable oncological outcome (grade 3 mesorectal excision).

Conclusion

This is a promising minimally invasive procedure in the armamentarium of rectal cancer treatment, specially in challenging scenarios such as narrow pelvis, obesity and very low rectal tumors.

Initial experience of transanal total mesorectal excision with rigid or flexible transanal platforms in cadavers

BACKGROUND

Transanal total mesorectal excision (taTME) is expected to provide benefits in the removal of the complete mesorectum for low rectal lesions, and several clinical studies regarding this technique have been reported. However, a transanal platform has not yet been standardized, and diverse transanal endoluminal surgery access devices have been used, based on individual surgeon preferences. In the present study, we performed laparoscopy-assisted taTME in cadavers and compared the characteristics of four different platforms.

METHODS

Between January 2013 and April 2015, laparoscopy-assisted taTME was performed on six fresh cadavers. Flexible [SILS™ Port (Covidien), GelPOINT(®) Path Transanal Access Platform (Applied Medical)] and rigid [TEO(®) (Karl Storz Endoskope), TEM (Richard Wolf)] transanal access platforms were used on three cadavers each.

RESULTS

All cadavers were male, with a mean age of 69.2 (range 57-86) years. The mean operation time was 146.3 (range 140-155) min with flexible platforms and 206.7 (range 150-260) min with rigid platforms. The mean specimen length was 23 (range 18-26) cm. Complete or nearly complete mesorectal specimens were obtained in all cases, except for one case using the TEM platform. Flexible platforms (SILS and GelPOINT) provided a short set-up time, relatively atraumatic retraction, and easy application of familiar laparoscopic instruments; a narrow operative field was its limitation. The rigid platforms (TEO and TEM) enabled larger and more stable operative fields and space than did the SILS platform, but they were limited by a narrow view, prolonged set-up time, rigidity, and long channels relative to the short distance from the anus to the rectal closure site.

CONCLUSION

In this preliminary study, laparoscopy-assisted taTME was a feasible and safe procedure using both rigid and soft platforms, despite some limitations of each platform.

Future directions in surgery for colorectal cancer: the evolving role of transanal endoscopic surgery

SUMMARY 

The morbidity associated with radical surgery for rectal cancer has launched a revolution in increasingly less-invasive methods of resection, including a recent resurgence in transanal endoscopic surgical approaches. The next evolution in transanal surgery for rectal cancer is natural orifice translumenal endoscopic surgery (NOTES). To date, 14 series of transanal NOTES total mesorectal excision (TME) for rectal cancer have been published (n = 76). Overall, the intraoperative and postoperative complication rates of 8 and 28%, respectively, compare favorably to those expected from laparoscopic and open TME. Short-term follow-up after NOTES TME has yielded no cancer recurrence in average-risk patients. High-risk patients have cancer recurrence rates similar to those after laparoscopic TME. Overall, these early data support transanal NOTES TME as a safe and viable alternative to conventional TME. Advances in instrumentation, surgical expertise and neoadjuvant treatment may expand current indications for NOTES even further.

Transanal colorectal resection using natural orifice translumenal endoscopic surgery (NOTES)

The surgical management of rectal cancer has evolved over the past century, with total mesorectal excision (TME) emerging as standard of care. As a result of the morbidity associated with open TME, minimally invasive techniques have become popular. Natural orifice translumenal endoscopic surgery (NOTES) has been held as the next revolution in surgical techniques, offering the possibility of 'incisionless' TME. Early clinical series of transanal TME with laparoscopic assistance (n = 72) are promising, with overall intraoperative and postoperative complication rates of 8.3% and 27.8%, respectively, similar to laparoscopic TME. The mesorectal specimen was intact in all patients, and 94.4% had negative margins. There was no oncological recurrence in average-risk patients at short-term follow up, and 2-year survival rates in high-risk patients were comparable to that after laparoscopic TME. These preliminary studies demonstrate transanal NOTES TME with laparoscopic assistance to be clinically feasible and safe given careful patient selection, surgical expertise, and appropriate procedural training. We are hopeful that with optimization of transanal instruments and surgical techniques, pure transanal NOTES TME will become a viable alternative to open and laparoscopic TME in the future.

A pilot study of natural orifice transanal endoscopic total mesorectal excision with laparoscopic assistance for rectal cancer

BACKGROUND

The objective of this pilot study was to evaluate the feasibility and safety of natural orifice endoscopic transanal total mesorectal excision (TME) with laparoscopic assistance in a cohort study of five patients with stage I and IIA rectal cancer.

METHODS

Five eligible patients with node-negative rectal cancer located 4-12 cm from the anal verge were enrolled in an IRB-approved pilot study. All patients underwent transanal endoscopic TME with laparoscopic assistance, hand-sewn coloanal anastomosis, and a diverting loop ileostomy. Primary and secondary end points included adequacy of the mesorectal excision and 30-day postoperative complications, respectively.

RESULTS

Between November 2011 and May 2012, three males and two females underwent transanal endoscopic TME with laparoscopic assistance. Patient mean age and BMI were 48.6 ± 9.8 years and 25.7 ± 2.3 kg/m(2), respectively. Tumors were located an average of 5.7 ± 2.4 cm from the anal verge and preoperatively staged as T1N0M0 (2), T2N0M0 (1), and T3N0M0 (2). Mean operative time was 274.6 ± 85.4 min with no intraoperative complications. Partial intersphincteric resection was performed in conjunction with transanal endoscopic TME in three patients. Pathologic examination of TME specimens demonstrated complete mesorectal excision in all cases with negative proximal, distal, and radial margins. Mean length of hospital stay was 5.2 ± 2.6 days and three minor complications occurred, including one ileus and two cases of transient urinary dysfunction. At a mean early follow-up of 5.4 ± 2.3 months, all patients remain disease-free.

CONCLUSIONS

In this pilot study of five patients with rectal cancer, transanal endoscopic TME with laparoscopic assistance is feasible and safe, and is a promising alternative to open and laparoscopic TME. Evaluation of long-term functional and oncologic outcomes of this approach is needed before widespread adoption can be recommended.

TAMIS-assisted laparoscopic low anterior resection with total mesorectal excision in a cadaveric series

BACKGROUND

To demonstrate the feasibility of an innovative technique for the surgical management of rectal cancer, we performed transanal minimally invasive surgery assisted low anterior resection with total mesorectal excision (TAMIS-assisted LAR with TME) in a cadaver model. Transanal LAR via natural orifice transluminal endoscopic surgery has been reported in cadaveric series using rigid transanal platforms. This procedure has not been described using a combination of a single incision laparoscopy and TAMIS transanal endoscopic platform. We describe the first cadaveric series of TAMIS-assisted LAR with TME.

METHODS

TAMIS-assisted LAR with TME was successfully performed in five fresh human cadavers. The procedure was performed using the mini-Gelpoint single incision platform and the Gelpoint Path TAMIS platform (Applied Medical, Rancho Santa Margarita, CA). The variables recorded were age, body mass index (BMI), operative time, complications, and specimen length. The grade of the TME was determined by evaluation of the specimen by photo documentation by a gastrointestinal pathologist.

RESULTS

All cadavers were male with a mean age of 71 ± 8 years and mean BMI of 28 ± 3 kg/m(2). The mean operative time was 200 ± 55 min (range 128-249 min). The quality of the TME was grade I (complete) with intact mesorectum in all five cases. The mean specimen length was 36.8 ± 3.4 cm.

CONCLUSIONS

TAMIS-assisted LAR with TME was feasible. A high-quality TME can be achieved using this innovative technique. Transanal endoscopic total mesorectal dissection may revolutionize the surgical management of rectal cancer. However, multicenter clinical trials are needed to further evaluate the oncologic safety and surgical outcomes of transanal endoscopic TME using various platforms before widespread application of this new technique.

Recent advances of natural orifice transluminal endoscopic surgery in urological surgery

Natural orifice transluminal endoscopic surgery designates a surgical procedure that utilizes one or more patent natural orifices of the body with the intention to puncture a hollow viscera in order to enter the abdominal cavity. First carried out at the beginning of the 2000s in experimental models, it can be considered the natural evolution of laparoscopy towards the ideal of scarless surgery, as the avoidance of a large abdominal scar is associated with better cosmetic results and better recovery. However, the technology currently available does not allow the performance of complete pure natural orifice transluminal endoscopic surgery procedures. The surgical tools used are not specially designed for this approach, so difficulties in retracting organs, bleeding control and clashing of instruments are the main obstacle surgeons face. For this reason, the current available technique is the so-called hybrid approach, where a natural orifice approach is combined with some abdominal trocars, using the natural orifice as the exit door for the specimen removal. As not many comparative studies have been published evaluating the advantages of natural orifice transluminal endoscopic surgery in front of traditional laparoscopic surgery, a review of the history of natural orifice transluminal endoscopic surgery, and an assessment of the available evidence of this technique regarding renal and urological pelvic surgery are performed in this article.