Transanal rectosigmoid resection via natural orifice translumenal endoscopic surgery (NOTES) with total mesorectal excision in a large human cadaver series

Concepts and prospects of minimally invasive colorectal cancer surgery

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

Systematic review of transanal total mesorectal excision literature according to the ideal framework: The evolution never ends

BACKGROUND

Designing studies to assess critically novel procedures can be challenging; thus, the process to achieve robust evidence is frequently problematic. The aim of this systematic review was to evaluate if literature on transanal total mesorectal excision is evolving according to the Idea, Development, Exploration, Assessment, and Long-term results framework.

METHODS

Literature on transanal total mesorectal excision was searched according to the preferred reporting items for systematic reviews and meta-analyses statement, and these variables were recorded: bibliometric data, design, corresponding author's nationality, number of patients enrolled, and Idea, Development, Exploration, Assessment, and Long-term results stages (stage 0, stage 1, stage 2, stage 3, and stage 4).

RESULTS

Out of 447 articles retrieved, 247 were selected (76.5% single center and 23.5% multicenter collaborations), including 35 reviews, 15 meta-analyses, 24 other publications, and 173 articles classified according to Idea, Development, Exploration, Assessment, and Long-term results stages (19 stage 0, 27 stage 1, 111 stage 2, 7 stage 3, and 9 stage 4). Overall, impact factor produced was 634.10. Reviewing corresponding authors' nationalities, 32 countries were identified, and the most reported were the United States, China, and the United Kingdom; nearly all were from the Northern Hemisphere. Publication of stage 3 and 4 articles started in 2014, whereas stage 0 and 1 articles were stably published over time. The number of patients increased in correspondence with the Idea, Development, Exploration, Assessment, and Long-term results stages (case series with >51 patients, respectively, 100.0% stage 3, 77.8% stage 4, and 33.3% stage 2, P = .005).

CONCLUSION

The number of stage 3 and 4 articles is still low; however, the technical innovation of transanal total mesorectal excision is a non-stopping process with preclinical studies stably published over time.

Comparison of transanal total mesorectal excision and robotic total mesorectal excision for low rectal cancer after neoadjuvant chemoradiotherapy

BACKGROUND

To improve the quality of surgery for rectal cancer, both transanal total mesorectal excision (taTME) and robotic total mesorectal excision (R-TME) can be performed. However, few studies have compared outcomes of taTME and R-TME, especially for patients with low rectal cancer after undergoing neoadjuvant chemoradiation (nCRT). Thus, the objective of this study was to compare outcomes of taTME and R-TME for patients with low rectal cancer after undergoing nCRT.

METHODS

A total of 306 consecutive patients with low rectal cancer who underwent taTME or R-TME after nCRT between 2008 and 2018 were analyzed retrospectively. Patients were classified into two groups: 1) taTME surgery group (n = 94); and 2) R-TME surgery group (n = 212).

RESULTS

Clinicopathologic variables were comparable between the two groups. There was no significant difference in circumference margin involvement (1.1% in taTME vs. 2.8% in R-TME, p = 0.680) or distal resection margin (2.3 cm in taTME vs. 2.4 cm in R-TME, p = 0.629). Total operation time (239 min in taTME vs. 243 min in R-TME, p = 0.675) and major complications (including anastomosis site leakage, surgical site infection, and voiding difficulty) showed no significant difference between the two groups either.

CONCLUSIONS

Transanal and robotic TMEs have similar short-term outcomes for patients with rectal cancer after undergoing nCRT. High quality TME can be equally achieved with both transanal and robotic approaches.

International expert consensus guidance on indications, implementation and quality measures for transanal total mesorectal excision

AIM

To provide dynamic guidance from a rigorous and up-to-date consensus on the safe implementation and application of transanal total mesorectal excision (TaTME) from an international panel of expert surgeons and educationalists supported by 14 international surgical societies.

METHOD

An adapted Delphi method and focus group discussion approach was implemented for this consensus process, with expert advice from a guidelines methodologist. Statements were generated focusing on three main topics relating to the safe implementation of TaTME: (1) indications, (2) quality and outcome measures, (3) training and implementation of TaTME.

RESULTS

Five rounds of the Delphi consensus process were completed over a 13-month period. A total of 56 surgeons experienced in TaTME and surgical education participated in this project. By Delphi round four, 80.0% or greater agreement was reached for all statements except for two, which were further reviewed during a fifth round. More complex cases that are likely to benefit from TaTME were identified, with the recommendation that they should be referred to TaTME expert centres. The most agreed upon definition of expert centres is outlined.

CONCLUSION

We have provided a current framework of best practice related to implementation of TaTME. The statements are not indefinite and will continue to be 'dynamic' and updated as new evidence emerges.

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.

Transanal total mesorectal excision: the Slagelse experience 2013-2019

OBJECTIVE

To describe outcomes after transanal total mesorectal excision (TaTME) 5 years from implementation at a large-volume colorectal unit, including local recurrence, distant metastasis, and survival.

BACKGROUND

Transanal total mesorectal excision (TaTME) is a relatively new procedure for mid- and low-rectal cancer, with well-documented safety and feasibility. However, data on long-term results are limited.

METHODS

This study was based on a prospective data collection via a maintained database in a large colorectal unit. The database included patients who underwent TaTME from December 2013 through July 2019. We have updated the database through a review of patient charts, including radiology and pathology reports. Data collection included operative details, intraoperative findings, postoperative complications, pathologic results, and oncologic results.

RESULTS

During the study period, two hundred patients underwent TaTME in the study period (men = 147). The mean BMI was 26.7%, and the mean tumor height from the anal verge was 7.86 cm. Neoadjuvant treatment was given to 22% of patients. Anastomotic leakage occurred in 9.3% of patients, and the overall rate of postoperative complications was 24.5%. The TME specimen was incomplete in 11% of patients, and the CRM was positive in 5.5% of patients. Local recurrence (LR) occurred in seven patients with a follow-up of at least 2 years (4.7%). Distant metastasis (DM) occurred in 12% of patients. The overall survival was 90% and disease-free survival was 81%. The operating time was reduced in the later period of our experience.

CONCLUSIONS

This study showed that TaTME is feasible, safe, and had acceptable short-term outcomes and an acceptable rate of LR. The study included, however, one group that was non-randomized, and the follow-up was not long enough for most patients. Studies with longer follow-up data are awaited.

Transanal Surgery: A History of taTME Ancestry

Transanal total mesorectal excision (taTME) is the culmination of major developments in rectal cancer management and minimally invasive surgery. This surgical breakthrough holds great promise and excitement for the care of the rectal cancer patient. We would be remiss in discussing taTME to not acknowledge the role of transanal abdominal transanal proctosigmoidectomy, transanal endoluminal microsurgery, laparoscopy, and natural orifice transluminal endoscopic surgery that got us to this modern day explosion of the taTME approach. In this article, we detail and explain the convergence of these disparate experiences, how they culminated in the development of the taTME, and explore future directions in this field.

Transanal total mesorectal excision (taTME) for rectal cancer: beyond the learning curve

BACKGROUND

Transanal total mesorectal excision (taTME) is a surgical approach for low rectal cancer with a learning curve estimated at 40-50 cases. The experience among taTME surgeons beyond their learning curve is limited.

METHODS

A retrospective analysis of all taTME cases performed for rectal cancer at two tertiary care hospitals from 2014 to 2019 was conducted. Transanal surgeons had previously performed > 50 taTME cases. Demographic, perioperative, and short-term outcomes were analyzed.

RESULTS

Among 54 taTME patients, 74.1% were male and 27.8% had a BMI ≥ 30. Tumors were stage I (8), II (13), III (29), and IV (4). Complex cases included 4 local recurrences, 4 prior liver resections, and 2 with prior prostate cancer. Thirty tumors were located ≤ 6 cm from the anal verge. On staging MRI, 12 had a positive predicted circumferential radial margin (+CRM), and 4 had internal anal sphincter involvement (+IAS). Forty-seven patients received neoadjuvant therapy. A 2-team approach was used in 51 patients with laparoscopic (83.3%) or robotic (16.7%) abdominal assistance with a 9.2% conversion rate. Low anterior resection with sphincter salvage was achieved in 87% with 8 patients requiring intersphincteric resection. Anastomoses were hand-sewn in 57.4% and all patients were diverted. Median LOS was 5 days with a 42.6% 30-day morbidity rate and 3 postoperative mortalities (ARDS, pulmonary embolism and pseudomembranous colitis). Complete and near complete TME grade was achieved in 94.4% with a 3.7% rate of +CRM. At a median follow-up of 28 months, local and distant recurrence rates were 3.9% and 17.6%, respectively, with no cancer-related mortality.

CONCLUSION

Indications for taTME at experienced centers have expanded to include complex reoperative cases, local recurrences, metastatic cancer, and tumors with threatened CRM or IAS with evidence of post-treatment tumor regression. In the latter cases, taTME achieves good short-term outcomes and may facilitate R0 resection.

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-a critical appraisal]

INTRODUCTION

Total mesorectal excision (TME) is the international standard for rectal cancer surgery. In addition to laparoscopic TME (lapTME), transanal TME (taTME) was developed in recent years to reduce the rate of incomplete TME, conversion to open surgery and postoperative functional impairment. Despite limited evidence, this technique is becoming increasingly more popular and is already routinely used by many hospitals for rectal cancer in varying tumor level locations. The aim of this review was to evaluate the taTME compared to anterior rectal resection with lapTME as the standard of care in rectal cancer surgery based on currently available evidence.

METHOD

The databases PubMed and Medline were systematically searched for publications on transanal total mesorectal excision (taTME) and transanal minimally invasive surgery (TAMIS). Relevant studies were selected and further research based on the reference lists was undertaken.

RESULTS

A total of 16 studies analyzing 3782 patients were identified. The taTME does not lead to a higher rate of complete TME-resected specimens compared to the standard procedure. So far, superiority could not be demonstrated for complication rates or for functional or oncological results. Serious complications secondary to dissection in incorrect planes were observed. The anastomotic level generally seems to be closer to the sphincter after taTME versus anterior lapTME.

CONCLUSION

Considering current evidence, taTME failed to show superiority compared to conventional anterior lapTME. Although taTME has some potential advantages, it carries substantial risks. If performed outside of clinical trials, it should therefore only be used in carefully selected patients with a high possibility of conversion, following adequate patient informed consent and after intense and systematic training of the surgeon.

Feasibility of transanal total mesorectal excision (taTME) using the Medrobotics Flex® System

BACKGROUND

The use of transanal total mesorectal excision (taTME) for treatment of rectal cancer is growing, but anatomic constraints prevent access to the proximal rectum with rigid instruments. The articulated instrumentation of current surgical robots is promising in overcoming these limitations, but the bulky size of current platforms inhibits the proximal reach of dissection. Flexible robotic systems could overcome these constraints while maintaining a stable platform for dissection. The goal of this study was to evaluate feasibility of performing taTME using the semi-robotic Flex® System (Medrobotics Corp., Raynham, MA) in human cadavers.

METHODS

taTME was performed by two surgeons in six fresh human cadaveric specimens using the Flex® System, with or without transabdominal laparoscopic assistance. Both mid- and low-rectal lesions were simulated. Metrics including quality of visualization, maintenance of pneumorectum, maneuverability of instruments, effectiveness of pursestring suture placement, and dissection in an anatomically correct plane were evaluated.

RESULTS

The semi-robotic endoluminal platform allowed for excellent visualization, insufflation, and dissection during taTME. Adequate pursestring occlusion of the rectum was achieved in all six cases. In cadavers with simulated mid-rectal lesions (N = 4), dissection and anterior peritoneal entry was achieved in all cases, with abdominal assistance utilized in two of four cases. In cadavers with simulated low-rectal lesions (N = 2), dissection was incomplete and aborted due to difficulty maneuvering instruments in close proximity to the rigid transanal port.

CONCLUSIONS

Use of the Flex® system for taTME is feasible for mid-rectal dissection. Advantages over the traditional multi-armed robot include longer reach of instruments with the ability to dissect up to 17 cm from the anal verge, as well as tactile feedback. The current design of the flexible platform does not permit safe dissection in the distal rectum, although this constraint may be resolved with future adjustments to the equipment.

Evolution of transanal total mesorectal excision according to the IDEAL framework

Tremendous innovations have taken place in surgical procedures, but contrary to drug development, this process has been unregulated in the past. IDEAL promotes a structured framework for the safe implementation and assessment of a new surgical technique or intervention, by describing five stages for evaluating and reporting of innovations: Idea, Development, Exploration, Assessment and Long term. Transanal total mesorectal excision (TaTME) is a relatively new technique in rectal cancer surgery that has attracted huge interest and increasing adoption worldwide. This review article aims to provide an overview of the evolution of TaTME, according to the IDEAL framework, which guides us in the difficult yet exciting process of surgical innovation.

Transanal total mesorectal excision (TaTME): current status and future perspectives

Total mesorectal excision (TME) is the gold standard surgical treatment for mid- and low rectal cancer; however, it is associated with specific technical hurdles. Transanal TME (TaTME) is a new procedure developed to overcome these difficulties, through an enhanced visualization of the dissection plane. This potentially could result in a more accurate distal dissection with a lower rate of positive circumferential resection margins, increasing the rate of sphincter-saving procedures. The indications for TaTME are currently expanding, despite not being yet standardized, and structured training programs are ongoing to help overcome the steep learning curve related to the technique. The procedure is feasible and safe with similar intraoperative complications and readmission rates when compared with conventional open or laparoscopic TME. Favorable short-term oncologic results have been reported: in particular, TaTME is associated with mesorectal specimen of a better quality and a longer distal resection margin that is established at the beginning of the procedure under direct view. Robotics, when available, will probably overcome the steep learning curve related to the complexity of TaTME. Long-term follow-up and ongoing RCT trials data are awaited regarding functional results, local recurrence and survival, and to facilitate the comparison with standard laparoscopic or robotic rectal resections. The present review is focused on critically analyzing the theoretical benefits and risks of the procedure, its indications, short- and long-term results and future direction in the application of TaTME.

Transanal TME: new standard or fad?

Transanal total mesorectal excision (taTME) has been developed to overcome the difficulty of laparoscopic dissection and transection in the deep pelvis. TaTME has several clinical benefits over laparoscopic surgery, such as better exposure of the distal rectum and direct determination of distal resection margin. Although evidence demonstrating the true benefits of taTME over laparoscopic TME (LapTME) is still insufficient, accumulating data have revealed that, as compared with LapTME, taTME is associated with shorter operative time and a lower conversion rate without jeopardizing other short-term outcomes. However, taTME is a technically demanding procedure with specific complications such as urethral injury, and so sufficient experience of LapTME and step-by-step acquisition of the skills needed for this procedure are requisite. The role of transanal endoscopic surgery is expected to change, along with the recent progress in the treatment of rectal cancer, such as robotic surgery and the watch-and-wait strategy. Optimization of treatment will be needed in the future in terms not only of oncological but also of functional outcomes.

Evaluation of anatomical landmarks for transanal total mesorectal excision based on MRI

BACKGROUND

Transanal total mesorectal excision (taTME) is a novel sphincter-preserving procedure for low rectal cancer. This "bottom to up" approach is unfamiliar to colorectal surgeons and the crucial anatomical landmarks also remain unclear.

METHODS

Two hundred and five cases of pelvic magnetic resonance imaging (MRI) from 2015 to 2016 were reviewed. Curvature of posterior mesorectal fascia, distal mesorectal angle, length of posterior mesorectal fascia, main structures around the mesorectum were measured and analyzed. The landmarks identified on MRI were verified in taTME procedures of five rectal cancer patients.

RESULTS

The most of acute angles of posterior mesorectal fascia located at the joint of anococcygeal ligament-coccyx. Degree of distal mesorectal angle was independently correlated with gender and degree of angle of anococcygeal ligament-coccyx. Candidate landmarks evaluated by MRI with verification during taTME procedures included: anterior: seminal vesicle for male while cervix for female. And peritoneal reflection was a substitute landmark when cervix was hardly confirmed in operation; posterior: the joint of anococcygeal ligament-coccyx. The area between the joint of anococcygeal ligament-coccyx and S3S4 was a "transitional zone", the level of S3S4 could be the as the terminal landmark of transanal posterior dissection during taTME.

CONCLUSIONS

Preoperative MRI geometrical measurement of mesorectum might play an important role in evaluating the difficulty of taTME procedure before operation, as well as standardizing landmarks during taTME procedure.

Successful treatment of recurrent rectal implantation metastasis of ovarian cancer by natural orifice specimen extraction surgery: a case report

We first describe the application of natural orifice specimen extraction surgery in the treatment of a rectal implantation metastasis tumor from ovarian cancer. One patient diagnosed with recurrent rectal implantation metastasis 1 year after the removal of ovarian cancer successfully underwent transanal specimen extraction via laparoscopic rectectomy without an abdominal incision at the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College in March 2017. The operation time was 118 minutes, and the intraoperative blood loss was 5 mL. The specimen was extracted via the anus during the operation, and the resection margin was negative. The patient recovered well without complications. Anal function was normal, and the stoma and abdominal incision were well healed after 1 month of follow-up. This study supports the idea that the application of natural orifice specimen extraction surgery for rectal implantation metastasis from ovarian cancer is safe and feasible and can achieve satisfactory outcomes.

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 Endoscopic and Transabdominal Robotic Total Mesorectal Excision for Mid-to-Low Rectal Cancer: Comparison of Short-term Postoperative and Oncologic Outcomes by Using a Case-Matched Analysis

Purpose

This study aimed to compare short-term postoperative and oncologic outcomes of a transanal endoscopic total mesorectal excision (TME) to those of a transabdominal robotic TME.

Methods

A total of 62 patients with rectal cancer underwent transanal (n = 26) or robotic (n = 36) TME between June 2013 and December 2014. After case-matching by tumor location and TNM stage, 45 patients were included for analysis. The median follow-up period was 21.3 months. Operative, histopathologic and postoperative outcomes and recurrences were analyzed.

Results

Patients younger than 60 years of age were more frequently observed in the robotic TME group (75.0% vs. 47.6%, P = 0.059), but tumor location, cT and cN category, and preoperative chemoradiotherapy were not different between the 2 groups. Estimated blood loss was greater in the transanal group (283 mL vs. 155 mL, P = 0.061); however, the operation time and the rate of a diverting ileostomy and subsequent ileostomy repair were not different between the groups. The proximal resection margin was longer in the transanal TME group (20.8 cm ± 16.0 cm, P = 0.030), but the distal resection margins, involvements of the circumferential resection margin, TME quality, numbers of retrieved lymph nodes, postoperative complications, including anastomotic leak and voiding difficulty, and recurrence rates for the 2 groups were not statistically different.

Conclusion

Transanal endoscopic and transabdominal robotic TME showed similar histopathologic and postoperative outcomes with the exception of the estimated blood loss and the proximal resection margin for a select group of patients.

Transanal Total Mesorectal Excision: Why, When, and How

Transanal total mesorectal excision (taTME) has evolved over the past decade fueled by advances in minimally invasive surgery. The technique aims to overcome the constraints posed by a narrow rigid pelvis and poor TME visualization that are encountered during "top-down" rectal surgery. A more accurate pelvic dissection should subsequently result in safer oncological resections and better preservation of pelvic autonomic nerves. taTME is an advanced complex technique that requires dedicated training and experience in TME surgery. Initial results from small cohorts are promising and confirmation by randomized controlled trials is eagerly awaited.

Developing and assessing a cadaveric training model for transanal total mesorectal excision: initial experience in the UK and USA

AIM

Transanal total mesorectal excision (taTME) has become one of the most promising technical advancements in the surgical treatment of rectal cancer, with rising numbers of surgeons seeking training. We describe our experience with human cadaveric courses for taTME delivered in two countries.

METHOD

Four fresh human cadaveric workshops conducted in Oxford, UK, in 2015 and two in Chicago, USA, in 2013-2014, trained a total of 52 surgeons. Parameters of operative performance for each delegate were recorded. Previous surgical experience and uptake of taTME in the surgeons' clinical setting were surveyed.

RESULTS

Forty-seven taTME cases were performed on cadaveric models. Participating surgeons had previous experience in laparoscopic TME surgery and transanal approaches but limited taTME exposure. The purse-string remained occluded throughout in 93% of UK and 60% of US cases. Operative timings for key procedural steps were similar between the two countries with a mean time from start of circumferential dissection to peritoneal entry of 79.5 min (range 25-155). 96% of surgeons dissected transanally to a level S2 or above. The TME specimen quality was complete or near complete in 81%, with improvements noted between the first and second procedure performed. 81% of surgeons surveyed are currently performing taTME in their local hospitals.

CONCLUSION

Fresh-frozen cadavers provide excellent teaching models for complex pelvic surgery. A structured training curriculum including reading material, dry-lab purse-string practice and postcourse mentorship will provide surgeons with a more complete training package and ongoing support, to ultimately ensure the safe introduction of taTME in the clinical setting.

Re-appraisal and consideration of minimally invasive surgery in colorectal cancer

Throughout history, surgeons have been on a quest to refine the surgical treatment options for their patients and to minimize operative trauma. During the last three decades, there have been tremendous advances in the field of minimally invasive colorectal surgery, with an explosion of different technologies and approaches offered to treat well-known diseases. Laparoscopic surgery has been shown to be equal or superior to open surgery. The boundaries of laparoscopy have been pushed further, in the form of single-incision laparoscopy, natural-orifice transluminal endoscopic surgery and robotics. This paper critically reviews the pathway of development of minimally invasive surgery, and appraises the different minimally invasive colorectal surgical approaches available to date.

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.

Forensic clinical anatomy: A new field of study with application to medicolegal issues

Forensic clinical anatomy is a new practical application of the discipline of Clinical Anatomy for ascertaining and evaluating medicolegal questions. In particular, individual anatomy (normal anatomy, anatomical variations, age-, disease-, or surgery-related modifications) can acquire significant relevance in various fields of legal medicine such as child abuse, sudden death, medical responsibility and/or liability, personal injury and damage. Anatomical data of forensic interest frequently arise from the correct application of methods of ascertainment; anatomical methods may then be required for further comprehensive analysis. The rigorous interpretation of anatomical data, derived from the ascertainment phase and analyzed on the basis of pertinent literature, can be pivotal for the correct application of evaluation criteria in various forensic contexts. Clin. Anat. 30:2-5, 2017. © 2016 Wiley Periodicals, Inc.

Feasibility of transanal endoscopic total mesorectal excision for rectal cancer: results of a pilot study

Purpose

To evaluate the feasibility of transanal total mesorectal excision (TME) in patients with rectal cancer.

Methods

This study enrolled 12 patients with clinically node negative rectal cancer located 4–12 cm from the anal verge who underwent transanal endoscopic TME with the assistance of single port laparoscopic surgery between September 2013 and August 2014. The primary endpoint was TME quality; secondary endpoints included number of harvested lymph nodes and postoperative complications within 30 days (NCT01938027).

Results

The 12 patients included 7 males and 5 females, of median age 59 years and median body mass index 24.2 kg/m². Tumors were located on average 6.7 cm from the anal verge. Four patients (33.3%) received preoperative chemoradiotherapy. Median operating time was 195 minutes and median blood loss was 50 mL. There were no intraoperative complications and no conversions to open surgery. TME was complete or nearly complete in 11 patients (91.7%). Median distal resection and circumferential resection margins were 18.5 mm and 10 mm, respectively. Median number of harvested lymph nodes was 15. Median length of hospital stay was 9 days. There were no postoperative deaths. Six patients experienced minor postoperative complications, including urinary dysfunction in 2, transient ileus in 3, and wound abscess in 1.

Conclusion

This pilot study showed that high-quality TME was possible in most patients without serious complications. Transanal TME for patients with rectal cancer may be feasible and safe, but further investigations are necessary to evaluate its long-term functional and oncologic outcomes and to clarify its indications.

Lessons Learned from Traditional NOTES: A Historical Perspective

The idea of natural orifice surgery was conceived by Kantsevoy and Kalloo in the late 1990s. A group of surgeons formed the Apollo Group in 1997. Their vision and mission were to impact the practice of therapeutic endoscopy through innovation in techniques and technologies. The concept of natural orifice surgery was introduced at the initial meeting held on Kiawah Island, South Carolina in 1998. The original concept of flexible endoscopic surgery involved per-oral passage of a flexible endoscope into the stomach followed by entrance into the peritoneal cavity via a gastrostomy.

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.

Current status of trans-anal total mesorectal excision (TaTME) following the Second International Consensus Conference

This article documents the consensus of an expert group of surgeons from the Second International Trans-anal Total Mesorectal Excision (TaTME) Conference held in Paris in July 2014. It outlines three facets of the TaTME procedure: (i) the technique and its indications, (ii) training and adoption, and (iii) data collection and the TaTME registry.

Transanal vs laparoscopic total mesorectal excision for rectal cancer: initial experience from Denmark

AIM

Laparoscopic total mesorectal excision (LaTME) has improved short-term outcomes of rectal cancer surgery with comparable oncological results to open approach. LaTME can be difficult in the lowermost part of the rectum, leading potentially to higher rates of complications, conversion to open surgery and probably suboptimal oncological quality. Transanal TME (TaTME) can potentially solve these problems. The aim of this study was to compare the short-term results after TaTME with those after LaTME.

METHOD

A prospectively collected database of consecutive patients who underwent TaTME was maintained. Results were compared with those who underwent LaTME in the preceding period. Patients who underwent low anterior resection or intersphincteric abdominoperineal excision were included. Primary end-points were radical resection and specimen quality. Secondary end-points were complications, rates of conversion, operating time and hospital stay.

RESULTS

In total, 50 patients were included (TaTME = 25, LaTME = 25). The groups were comparative in demographic data and tumour characteristics. Circumferential resection margin was positive in one patient in the TaTME group vs four patients in the LaTME group (P = 0.349). All patients in the TaTME group had either complete or nearly complete specimen quality, while four patients in the LaTME group had incomplete specimen quality (P = 0.113). Less blood loss, shorter operating time and shorter hospital stay were found in the TaTME group (P values 0.016, 0.002 and 0.020 respectively). Intra-operative complications were comparable (P = 0.286).

CONCLUSION

The TaTME procedure had comparable pathological results and acceptable short-term postoperative outcomes compared to LaTME.

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.

Transanal total mesorectal excision: A valid option for rectal cancer?

Low anterior resection can be a challenging operation, especially in obese male patients and in particular after radiotherapy. Transanal total mesorectal excision (TaTME) might offer technical advantages over laparoscopic or open approaches particularly for tumors in the distal third of the rectum. The aim of this article is to review the current experience with TaTME. The limits and future developments are also explored. Although the experience with TaTME is still limited, it might be a promising alternative to laparoscopic TME, especially for difficult cases where laparoscopy is too demanding. The preliminary data on complications and short-term oncological outcomes are good, but also emphasize the importance of careful patient selection. Finally, there is a need for large-scale trials focusing on long-term outcomes and oncological safety before widespread adoption can be recommended.

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.

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.

Transanal Total Mesorectal Excision for Rectal Cancer: Outcomes after 140 Patients

BACKGROUND

The anatomic difficulties that we have to deal with in open surgery for rectal cancer have not been overcome with the laparoscopic approach. In the search for a solution, a change of concept arose: approaching the rectum from below. The main objectives of this study were to show the potential advantages of the hybrid transabdominal-transanal total mesorectal excision (taTME). This approach may improve quality of the mesorectal specimens. Second, proctectomy can be technically easier and more safely performed "down to up," which would result in shorter surgical times, lower conversion rates, and less morbidity.

STUDY DESIGN

A prospective series of hybrid taTME was conducted from October 2011 to November 2014.

RESULTS

During the study period, 140 procedures were performed. Mean operative time was 166 minutes. There were no conversions or intraoperative complications. Macroscopic quality assessment of the resected specimen was complete in 97.1% and nearly complete in 2.1%. Thirty-day morbidity was minor (Clavien-Dindo I + II) in 24.2% and major (Clavien-Dindo III + IV) in 10 %. No patient died within the first 30 days postsurgery (Clavien-Dindo V). The mean follow-up was 15 months, with a 2.3% local recurrence rate and a 7.6% rate of systemic recurrence.

CONCLUSIONS

Pathologic analysis showed a very good macroscopic quality of TME specimens, which is the most important prognostic factor in rectal cancer. Intraoperative outcomes regarding conversion, surgical times, and intraoperative complications are very satisfactory. Short-term morbidity and oncologic outcomes are as good as in other laparoscopic TME series.

A step toward NOTES total mesorectal excision for rectal cancer: endoscopic transanal proctectomy

BACKGROUND

Previous publications have suggested that endoscopic transanal proctectomy (ETAP) is a promising technique and may be an alternative to conventional low anterior resection for rectal cancer. The aim of this study was to evaluate the technical feasibility of ETAP, with a particular focus on postoperative and oncological results and on functional outcomes.

METHODS

This study was a multicenter prospective study of unselected consecutive patients with low rectal cancer requiring proctectomy and coloanal anastomosis. All patients underwent a standardized procedure. The study endpoints were the safety and adequacy of the oncological resection criteria. All patients were evaluated with the Wexner Fecal Incontinence Questionnaire after stoma closure.

RESULTS

Fifty-six consecutive patients (41 men) underwent ETAP between February 2010 and June 2012. The median age was 65 years (39-83), and the median body mass index was 27 (20-42). No intraoperative complications were encountered. There was no postoperative mortality, and the morbidity rate was 26%. The mesorectum was complete in 47 cases (84%) and nearly complete in 9 cases (16%). The median number of lymph nodes retrieved was 12 (range, 7-29) per patient. The median radial and distal margins were 8 mm (0-20) and 10 mm (3-40), respectively. R0 resection was achieved in 53 patients (94.6%). The median Wexner score was 4 (3-12). Thirteen (28%) patients reported stool fragmentation and difficult evacuation.

CONCLUSIONS

ETAP is a feasible alternative surgical option to conventional laparoscopy for rectal resection and may represent a promising step toward rectal natural orifice transluminal endoscopic surgery (NOTES).

Anatomical considerations for transanal minimal-invasive surgery: the caudal to cephalic approach

AIM

Nerve-sparing surgery during laparoscopic rectal mobilization is still limited by anatomical constraints such as obesity, the narrowness of the male pelvis, an ultra low rectal cancer or all of these. The transanal approach for total mesorectal excision has overcome the shortcomings of limited access to the rectal 'no-man's land' close to the pelvic floor. The aim of this anatomical study was to define a roadmap of anatomical landmarks for the caudal to cephalic approach so as to standardize nerve-sparing rectal mobilization procedures.

METHOD

Macroscopic dissections of the pelvis in a caudal to cephalic direction were performed in eight alcohol-glycerol embalmed cadavers. A roadmap of anatomical landmarks was created at different levels of section to demonstrate the sites of nerve injury.

RESULTS

Extrinsic autonomic nerves to the urogenital organs and the internal sphincter muscle are closely adjacent to the lowest portion of the rectum above the pelvic diaphragm.

CONCLUSION

This anatomical guide for the pelvic surgeon should facilitate a safe and nerve-sparing dissection of the mesorectal plane with a meticulous overview of the lowest autonomic nerve fibres. New anatomical insights by a 'caudal to cephalic' approach to the 'no-man's land' should help overcome anatomical constraints of a narrow, obese and male pelvis during rectal mobilization procedures.

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.

Evolution and future of laparoscopic colorectal surgery

The advances of laparoscopic surgery since the early 1990s have caused one of the largest technical revolutions in medicine since the detection of antibiotics (1922, Flemming), the discovery of DNA structure (1953, Watson and Crick), and solid organ transplantation (1954, Murray). Perseverance through a rocky start and increased familiarity with the chop-stick surgery in conjunction with technical refinements has resulted in a rapid expansion of the indications for minimally invasive surgery. Procedure-related factors initially contributed to this success and included the improved postoperative recovery and cosmesis, fewer wound complications, lower risk for incisional hernias and for subsequent adhesion-related small bowel obstructions; the major breakthrough however came with favorable long-term outcomes data on oncological parameters. The future will have to determine the specific role of various technical approaches, define prognostic factors of success and true progress, and consider directing further innovation while potentially limiting approaches that do not add to patient outcomes.

Current status of laparoscopy for the treatment of rectal cancer

Surgery for rectal cancer in complex and entails many challenges. While the laparoscopic approach in general and specific to colon cancer has been long proven to have short term benefits and to be oncologically safe, it is still a debatable topic for rectal cancer. The attempt to benefit rectal cancer patients with the known advantages of the laparoscopic approach while not compromising their oncologic outcome has led to the conduction of many studies during the past decade. Herein we describe our technique for laparoscopic proctectomy and assess the current literature dealing with short term outcomes, immediate oncologic measures (such as lymph node yield and specimen quality) and long term oncologic outcomes of laparoscopic rectal cancer surgery. We also briefly evaluate the evolving issues of robotic assisted rectal cancer surgery and the current innovations and trends in the minimally invasive approach to rectal cancer surgery.

On the suitability of Thiel cadavers for natural orifice transluminal endoscopic surgery (NOTES): surgical training, feasibility studies, and anatomical education

BACKGROUND

Surgical training in virtual, animal and cadaver models is essential for minimally invasive surgery. Thiel cadavers are suitable for laparoscopy, but there are few data about the use of embalmed (Tutsch method) and slightly embalmed (Thiel method) cadavers in procedures of Natural Orifice Transluminal Endoscopic Surgery (NOTES), which are usually developed and learned on swine models and fresh frozen cadavers. The aim of this study was thus to assess the use of these cadavers for NOTES approaches.

METHODS

The following surgical procedures were evaluated: transanal total mesorectal excision (four cadavers: one Tutsch, two Thiel, one fresh frozen), transanal ileorectal bypass (five cadavers: one Tutsch, three Thiel, one fresh frozen), and transvaginal appendectomy (two Tutsch cadaver).

RESULTS

The Thiel method ensured tissue flexibility and consistency suitable for performing the above surgical procedures with good results and without complications, with only a small increase in rigidity with respect to fresh specimens. Cadavers embalmed with higher formalin concentrations (Tutsch method) were more difficult to use, due to high tissue rigidity and resistance of the abdominal wall to pneumoperitoneum, although NOTES accesses were possible.

CONCLUSIONS

Thiel cadavers are suitable for transanal/transrectal and transvaginal NOTES approaches, for training surgical residents/specialists and also for surgical research. In minimally invasive surgery (and particularly in NOTES), integration between cadaver (fresh frozen and/or Thiel) and animal models would represent the gold standard, allowing guaranteed knowledge of and respect for human surgical anatomy and correct management of surgery on living subjects. NOTES approaches to human cadavers may also be proposed for the anatomical education of medical students.

What should we intend for minimally invasive treatment of colorectal cancer?

Non-inferiority of laparoscopic treatment of colorectal cancer (CRC) has been demonstrated in randomized controlled trials although operative and perioperative management varies widely among centers. Literature data in English language published up to April 15, 2014 were analyzed in order to give an up to date analysis that would highlights the key aspects of a modern and factual minimally invasive treatment of CRC. Laparoscopic resection is the first choice treatment of colon cancer. Laparoscopic resection of rectal cancer should be considered an investigational procedure to be performed in high volume centers with special interest in laparoscopy and colorectal surgery. Less invasive approaches should be taken into account with the aim of reducing surgical stress. The adoption of ERAS programs has demonstrated to optimize short-term results. Future research should be directed to prove possible long-term advantages, in terms of overall and disease-free survival, of minimally invasive treatment of CRC.

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.

Dynamic article: transanal rectal excision: a pilot study

BACKGROUND

Laparoscopic total mesorectal excision can be difficult in a narrow pelvis. Transanal minimally invasive surgery allows the surgeon to mobilize the most distal part of the rectum by using a single port positioned in the anal canal.

OBJECTIVE

We aim to assess the safety and feasibility of transanal rectal excision.

DESIGN AND SETTING

This pilot study was conducted in a university hospital and tertiary colorectal referral center in Belgium.

PATIENTS

Over a 12-month period, all consecutive patients with benign disease and ASA grade 3 patients with a rectal carcinoma who required either intersphincteric proctectomy or coloanal anastomosis were included.

INTERVENTION

After intersphincteric dissection or sleeve mucosectomy, a single-access multichannel port was inserted into the anal canal. A transanal rectal excision was performed by using conventional laparoscopic instruments. The planes were developed as cephalad as possible, until the pouch of Douglas was opened. A laparoscopically assisted approach was used to gain bowel length and was used in patients who required proctectomy. In the case of a reconstruction, a handsewn coloanal anastomosis was made.

MAIN OUTCOME MEASURES

Intraoperative challenges, conversion rate, operating time, blood loss, morbidity, and length of stay were assessed.

RESULTS

Fourteen patients underwent a transanal rectal excision for both benign (9) and malignant (5) disease. In 11 patients (79%), laparoscopically assisted transanal minimally invasive rectal excision was performed. The median (range) transanal operating time was 55 (35-95) minutes. Intraoperative difficulties hindering dissection occurred in 5 patients and were due to inadequate exposure, rectal perforation, or fibrosis secondary to radiotherapy for prostate cancer. There was minimal postoperative morbidity, with a median follow-up of 6.3 (1.5-13.8) months. All patients were discharged within 14 days postoperatively, and there were no readmissions.

LIMITATIONS

The study was limited by the small number of patients.

CONCLUSION

Transanal rectal excision is safe and feasible and could be a promising technique to facilitate distal rectal mobilization (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A125).

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.