A novel single-port technique for transanal rectosigmoid resection and colorectal anastomosis on an ex vivo experimental model

Peroral traction-assisted natural orifice trans-anal flexible endoscopic rectosigmoidectomy followed by intracorporeal colorectal anastomosis in a live porcine model

BACKGROUND

Compared to traditional open surgery, laparoscopic surgery has become a standard approach for colorectal cancer due to its great superiorities including less postoperative pain, a shorter hospital stay, and better quality of life. In 2007, Whiteford et al reported the first natural orifice trans-anal endoscopic surgery (NOTES) sigmoidectomy using transanal endoscopic microsurgery. To date, all cases of NOTES colorectal resection have included a hybrid laparoscopic approach with the use of established rigid platforms.

AIM

To introduce a novel technique of peroral external traction-assisted transanal NOTES rectosigmoidectomy followed by intracorporeal colorectal end-to-end anastomosis by using only currently available and flexible endoscopic instrumentation in a live porcine model.

METHODS

Three female pigs weighing 25-30 kg underwent NOTES rectosigmoid resection. After preoperative work-up and bowel preparation, general anesthesia combined with endotracheal intubation was achieved. One dual-channel therapeutic endoscope was used. Carbon dioxide insufflation was performed during the operation. The procedure of trans-anal NOTES rectosigmoidectomy included the following eight steps: (1) The rectosigmoid colon was tattooed with India ink by submucosal injection; (2) Creation of gastrostomy by directed submucosal tunneling; (3) Peroral external traction using endoloop ligation; (4) Creation of rectostomy on the anterior rectal wall by directed 3 cm submucosal tunneling; (5) Peroral external traction-assisted dissection of the left side of the colon; (6) Trans-anal rectosigmoid specimen transection, where an anvil was inserted into the proximal segment after purse-string suturing; (7) Intracorporeal colorectal end-to-end anastomosis using a circular stapler by a single stapling technique; and (8) Closure of gastrostomy using endoscopic clips. All animals were euthanized immediately after the procedure, abdominal exploration was performed, and the air-under-water leak test was carried out.

RESULTS

The procedure was completed in all three animals, with the operation time ranging from 193 min to 259 min. Neither major intraoperative complications nor hemodynamic instability occurred during the operation. The length of the resected specimen ranged from 7 cm to 13 cm. With the assistance of a trans-umbilical rigid grasper, intracorporeal colorectal, tension-free, end-to-end anastomosis was achieved in the three animals.

CONCLUSION

Peroral traction-assisted transanal NOTES rectosigmoidectomy followed by intracorporeal colorectal end-to-end anastomosis is technically feasible and reproducible in an animal model and is worthy of further improvements.

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.

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.

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 endoscopic microsurgery: Current application and future prospects

Rectal neoplasms pose serious harm to human health. The options of surgical procedure for these patients have been limited because of the special features of anal and rectal anatomy and physiology. Tumors with a diameter less than 3 cm can be resected through the anus or soft microscope; however, those with a large diameter and wide base which are cancerous and relapse easily still need conventional laparotomy procedures. Transanal endoscopic microsurgery (TEM) was designed to avoid laparotomy for these patients. Using special instruments, TEM allows to totally resect tumors located 4-25 cm from the anus with safe margin and lower rate of complications. Because of minimal invasiveness, shorter operative time and lower rate of complications, TEM can be widely applied in rectal polyps and adenomas. Currently, there are still arguments about TEM usage in early-stage and advanced rectal cancer. This paper reviews the current situation of application and research of TEM, with emphasis put on its indications, clinical efficiency and future development.

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 endoscopic microsurgery colorectal anastomosis: a critical step to natural orifice colorectal surgery in humans

BACKGROUND

Transanal endoscopic microsurgery is used in the surgical management of advanced rectal polyps and early rectal cancers. There are case reports of transanal endoscopic microsurgery colorectal anastomoses being performed with laparoscopic assistance in humans.

METHODS

The concept of a transanal endoscopic microsurgery colorectal anastomosis without laparoscopic assistance has been discussed and trialed on animal and cadaveric specimens; however, to date, there have been no technical reports of this particular procedure in the literature.

RESULTS

We present a technical note describing a transanal endoscopic microsurgery intraperitoneal colorectal anastomosis in a live human without laparoscopic assistance.

Transanal endoscopic microsurgery: a review

Rectal adenomas and cancers occur frequently. Small adenomas can be removed colonoscopically, whereas larger polyps are removed via conventional transanal excision. Owing to technical difficulties, adenomas of the mid- and upper rectum require radical resection. Transanal endoscopic microsurgery (TEM) was first designed as an alternative treatment for these lesions. However, since its development TEM has been also used for a variety of rectal lesions, including carcinoids, rectal prolapse and diverticula, early stage carcinomas and palliative resection of rectal cancers. The objective of this review is to describe the current status of TEM in the treatment of rectal lesions. Since the 1980s, TEM has advanced substantially. With low recurrence rates, it is the method of choice for resection of endoscopically unresectable adenomas. Some studies have shown benefits to its use in treating early T1 rectal cancers compared with radical surgery in select patients. However, for more advanced rectal cancers TEM should be considered palliative or experimental. This technique has also been shown to be safe for the treatment of other uncommon rectal tumours, such as carcinoids. Transanal endoscopic microsurgery may allow for new strategies in the treatment of rectal pathology where technical limitations of transanal techniques have limited endoluminal surgical innovations.

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.

Transanal natural orifice specimen extraction for laparoscopic anterior resection in rectal cancer

AIM: To investigate whether transanal natural orifice specimen extraction (NOSE) is a better technique for rectal cancer resection.

METHODS: A prospectively designed database of a consecutive series of patients undergoing laparoscopic low anterior resection for rectal cancer with various tumor-node-metastasis classifications from March 2011 to February 2012 at the First Affiliated Hospital of Sun Yat-Sen University was analyzed. Patient selection for transanal specimen extraction and intracorporeal anastomosis was made on the basis of tumor size and distance of rectal lesions from the anal verge. Demographic data, operative parameters, and postoperative outcomes were assessed.

RESULTS: None of the patients was converted to laparotomy. Respectively, there were 16 cases in the low anastomosis and five in the ultralow anastomosis groups. Mean age of the patients was 45.4 years, and mean body mass index was 23.1 kg/m². Mean distance of the lower edge of the lesion from the anal verge was 8.3 cm. Mean operating time was 132 min, and mean intraoperative blood loss was 84 mL. According to the principle of rectal cancer surgery, we performed D2 lymph node dissection in 13 cases and D3 in eight. Mean lymph nodes harvest was 17.8, and the number of positive lymph nodes was 3.4. Median hospital stay was 6.7 d. No serious postoperative complication occurred except for one anastomotic leakage. All patients remained disease free. Mean Wexner score was 3.7 at 11 mo after the operation.

CONCLUSION: Transanal NOSE for total laparoscopic low/ultralow anterior resection is feasible, safe and oncologically sound. Further studies with long-term outcomes are needed to explore its potential advantages.

Transanal endoscopic proctectomy: an innovative procedure for difficult resection of rectal tumors in men with narrow pelvis

BACKGROUND

In rectal surgery, some situations can be critical, such as anterior topography of locally advanced low tumors with a positive predictive radial margin, especially in a narrow pelvis of men who are obese. Transanal proctectomy is a new laparoscopic technique that uses the transanal endoscopic microsurgery device.

OBJECTIVE

The aim of this study is to evaluate the technical feasibility of laparoscopic transanal proctectomy in patients with unfavorable features.

DESIGN AND PATIENTS

This is a single-center, prospective analysis of selected patients with rectal cancer operated on from January 2009 to June 2011.

MAIN OUTCOME MEASURES

Intraoperative details and short-term postoperative outcome were described.

RESULTS

Thirty men with advanced or recurrent low rectal tumors associated with unfavorable anatomical and/or tumor characteristics underwent a sphincter-sparing transanal endoscopic proctectomy. Twenty-nine patients had received preoperative treatment. We report a 6% conversion rate, no postoperative mortality, and a 30% morbidity rate. At the beginning of our experience, a urethral injury was diagnosed in 2 patients and easily sutured intraoperatively, without postoperative after-effect. The mesorectal resection was graded as "good" in all patients. R0 resection was achieved in 26 patients (87%). The short-term stoma closure rate was 85%. After a median follow-up of 21 months, 4 patients experienced locoregional recurrence alone. Overall survival rates at 12 and 24 months were 96.6% (95% CI, 78.0-99.5) and 80.5% (95% CI, 53.0-92.9). Relapse-free survival rates at 12 and 24 months were 93.3% (95% CI, 75.9-98.3) and 88.9% (95% CI, 69.0-96.3).

LIMITATIONS

Although the transanal endoscopic proctectomy was performed by trained surgeons, we report a slight increase in early postoperative morbidity and relatively poor early outcome. There was a clear selection bias related to the study cohort exclusively composed of high-risk patients, but we need to be cautious before generalizing this technique.

CONCLUSION

The transanal endoscopic proctectomy is a feasible alternative surgical option to conventional laparoscopy for radical rectal resection in selected cases with unfavorable characteristics. Further investigations with larger cohorts are required to validate its safety and to clarify its best indication.

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.

Transanal endoscopic total mesorectal excision combined with single-port laparoscopy

BACKGROUND

Rectal dissection using a conventional multiport laparoscopic approach involves risks due to technical difficulties, particularly in patients with a low tumor, a narrow pelvis, or obesity.

OBJECTIVE

We describe a technique of transanal endoscopic low and middle rectal dissection with subsequent coloanal anastomosis via single-port laparoscopy, with the aim of reducing technical problems, increasing safety, and improving cosmesis after resection of rectal cancer.

DESIGN AND SETTING

This was an observational study conducted in a large, tertiary care cancer center in France.

PATIENTS

Consecutive patients with rectal adenocarcinoma requiring total mesorectal excision with a coloanal anastomosis were evaluated for eligibility to undergo the procedure. Patients were selected if they had 1 or more of the following risk factors: narrow pelvis, a voluminous prostate, or obesity.

INTERVENTION

After an anal mucosectomy, the rectal wall was circumferentially transected above the external sphincter and a transanal trocar was introduced. The dissection of the mesorectum was completely performed via endoscopy up to the Douglas rectovesical pouch. A single port was inserted at the future site of the transient ileostomy, and a left colectomy and a lymphadenectomy were performed. The upper rectum dissection enabled joining the transanal rectal plane of dissection. Then the splenic flexure was completely mobilized and the specimen was extracted through the site of the future ileostomy.

OUTCOME MEASURES

Operative time, blood loss, duration of hospital stay, and histopathologic variables (margins, number of harvested lymph nodes, grade of the mesorectal fascia dissection) were recorded, and the quality of the surgical plane was assessed. The Cleveland Clinic Florida (Wexner) fecal incontinence questionnaire was administered after ileostomy closure.

RESULTS

Four consecutive male patients with rectal cancer in a narrow pelvis were treated with this new approach. No conversion (by laparotomy or multiport laparoscopy) was necessary. The pathologic variables were satisfactory and the Wexner scores indicated no severe incontinence after ileostomy closure. The postoperative follow-up was uneventful except for an anastomotic fistula which developed in 1 patient and was treated without reoperation.

LIMITATIONS

The study was limited by the small number of patients and the fact that no women and no obese patients were included.

CONCLUSIONS

Rectal resection via the transanal approach combined with single-port laparoscopic assistance may be easier and safer than the traditional approach, especially in male patients who have a narrow pelvis. More data are needed in order to draw conclusions concerning oncologic results and before selecting the most appropriate indications for this technique.

Transvaginal sigmoid cancer resection: first case with 12 months of follow-up--technique description

OBJECTIVE

Several minimally invasive techniques using natural orifices as an entrance site to the peritoneal cavity have been described recently. Pure natural orifice translumenal endoscopic surgery (NOTES) techniques have been mainly implemented to perform cholecystectomies and appendectomies, while more complex operations like colon resections have been described in a hybrid setting and with the use of the transumbilical approach. Here we describe the technique of transvaginal sigmoid colon resection for cancer with standard laparoscopy equipment.

MATERIALS AND METHODS

After developing the transvaginal technique of sigmoid colon resection in an experimental sheep model, we have performed this operation in a human patient for cancer. Twelve months of follow-up is reported.

RESULTS

A totally transvaginal R0 resection of the sigmoid colon for adenocarcinoma has been successfully performed in a female patient with laparoscopy equipment. The specimen included 13 lymph nodes, all of which were free of metastasis. Twelve months after surgery the patient is alive with no evidence of disease.

CONCLUSION

A pure transvaginal NOTES approach to sigmoid colon cancer is feasible in human patients.

Transanal single port access to facilitate distal rectal mobilization in laparoscopic rectal sleeve resection with hand-sewn coloanal anastomosis

BACKGROUND

Laparoscopic rectal sleeve resection is challenging and technically demanding. Exposure and mobilization of the most distal part of the rectum can be especially hazardous. We propose the use of a single port access device, placed in the anal canal after incision of the sleeve at the appropriate level, to facilitate dissection without sphincter damage. The case of a 51-year-old woman suffering from a recurrent supralevator abscess is presented to illustrate the technique.

METHODS

The procedure consisted of laparoscopic rectal pull-through with rectal sleeve resection and coloanal anastomosis. Incision of the endopelvic fascia and mobilization of the distal mesorectum was performed via the single port device under direct control. Medial-to-lateral mobilization of the colon was performed with a 3-port technique.

RESULTS

Total operating time was 122 min: 50 min for rectal mobilization, 42 min for the laparoscopic part of the procedure and 30 min for the coloanal anastomosis. The patient's recovery was uneventful, and at 1-month follow-up, she was asymptomatic.

CONCLUSIONS

Laparoscopic-assisted transanal single port rectal mobilization seems to be a promising addition to the armamentarium of minimally invasive surgery.

Transrectal natural orifice translumenal endoscopic surgery (NOTES) for colorectal resection

Natural orifice translumenal endoscopic surgery (NOTES) is a new surgical paradigm involving performance of intra-abdominal surgery via a natural orifice and thereafter peritoneal access through an intentionally created hole in a hollow viscus. The vast majority of research in this rapidly evolving field had involved access via an oral or vaginal route. Access via a transanal route, other than the obvious concern over contamination, has many appealing attributes. In addition, transanal surgery has long been a common procedure lending a valuable clinical experience to the foundation of this field of research. Examples of preclinical and clinical research on transanal NOTES colorectal resections are here presented and discussed.

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

Transanal endoscopic microsurgery (TEM) was described in 1983 for local excision of rectal tumors. In the context of natural orifice translumenal endoscopic surgery, we have modified the original TEM system and developed a new set of instruments. These are more curved and, in addition, steerable. After extensive studies in an ex-vivo model, we developed a novel technique for transanal rectosigmoid resection and colorectal anastomosis. The technique comprises closure of the rectal lumen by purse-string suture, transection of the rectal wall distal to the closure, circumferential mobilization of rectum and mesorectal tissue in the anatomical plane from below upward, control of the inferior mesenteric vessel, removal of mobilized colorectum through the anus, and, finally, the colorectal anastomosis by either stapled or hand-sutured technique. This procedure was performed on three alcohol-glycerol preserved well-built human cadavers (M:F=2:1). The average operating time was 190 minutes. The average length of the resected specimen was 23 cm. There was no fecal contamination or injury to the resected specimen. Postprocedure laparotomy revealed adequate mesorectal resection and no inadvertent injury to other viscera. During dissection in the pelvis, as the resected rectum was pushed upward, an unobstructed "empty pelvis" situation was developed in the operating site, thus facilitating the mesorectal resection. Transanal access for colorectal surgery seems feasible. It provides a precise definition of the distal safety margin, good view of the pelvis for meticulous mesorectal resection, and reduces the abdominal wall trauma. These may enhance the outcome of colorectal resection. However, further clinical studies can only substantiate these findings.

A natural orifice transrectal approach for oncologic resection of the rectosigmoid: an experimental study and comparison with conventional laparoscopy

BACKGROUND

A transrectal (TR) approach for natural orifice translumenal endoscopic surgery (NOTES) makes sense for colorectal surgery because the colotomy can be incorporated into subsequent anastomosis. Because cancer is a primary indication for left-sided colon resection, oncologic standards will have to be met by a NOTES procedure. This study aimed to assess whether pure TR rectosigmoidectomy can be performed with strict adherence to oncologic principles compared with a conventional laparoscopically assisted approach (LAP).

METHODS

Human male cadavers were allocated to either TR (n = 4) or LAP (n = 2). A simulated sigmoid lesion was created at 25 cm. Transrectal retrograde mobilization of the rectosigmoid was performed using conventional transanal endoscopic microsurgery (TEM) instrumentation. After ligation of the superior hemorrhoidal artery and further mobilization, the specimen was delivered transanally and divided extracorporeally. Using a circular stapler, NOTES colorectal anastomosis was performed. Lymph node yield, adequate resection margins, and operative time were compared with LAP.

RESULTS

Transrectal retrograde rectosigmoid dissection was achieved in all attempts (4/4) and showed numbers of lymph nodes (median, 5; range, 3-6) similar to the LAP group (median, 4.5; range, 2-7). One pure TR approach failed to resect the lesion. Three TR procedures required additional mobilization via an abdominal approach to provide adequate margins. The mean length of TR specimens was 16 ± 4 cm compared with 31 ± 9 cm achieved by LAP (p < 0.01). The TR operative time was significantly longer (247 ± 15 vs 110 ± 14 min).

CONCLUSION

Lymph node yield during TR rectosigmoidectomy was similar to that achieved by the LAP approach. However, conventional TEM instrumentation alone did not permit adequate colon mobilization. This indicates a need for flexible instrumentation or other technical solutions to perform true NOTES colectomies.