Comparative study of NOTES rectosigmoidectomy in a swine model: E-NOTES vs. P-NOTES

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.

No inflammatory benefit obtained by single-incision laparoscopic surgery for right hemicolectomy compared with conventional laparoscopy

PURPOSE

We evaluated the perioperative inflammatory mediators in a right hemicolectomy performed with single-incision laparoscopic surgery (SILS) and traditional multi-port laparoscopic surgery (MLS) to compare the postoperative inflammatory response and feasibility of SILS with that of MLS.

METHODS

In this retrospective study, we enrolled 56 consecutive colorectal cancer patients who underwent right hemicolectomy prospectively. Twenty patients underwent SILS, and 36 underwent MLS. The preoperative and postoperative levels of plasma vascular endothelial growth factor (VEGF), serum interleukin-6 (IL-6), and C-reactive protein (CRP) as well as the number of platelet cells were measured in all patients. The operation duration, number of harvested lymph nodes, length of the resected bowel, blood loss, and duration of hospital stay were also compared between the two groups.

RESULTS

Neither SILS nor MLS had any conversion cases. The operation duration was longer for MLS than for SILS. Blood loss tended to be lower among patients who underwent SILS than among those who underwent MLS. However, the number of harvested LNs was significantly lower with SILS than with MLS. In both pre- and postoperative blood examinations, there was no marked difference in inflammatory mediators between MLS and SILS.

CONCLUSION

There was no systemic inflammatory advantage associated with SILS compared with MLS.

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.

Phase II Clinical Trial to Evaluate the Efficacy of Transanal Endoscopic Total Mesorectal Excision for Rectal Cancer

BACKGROUND

Total mesorectal excision has become the standard treatment for rectal cancer, and several investigators have shown that a transanal approach is a feasible option.

OBJECTIVE

This study aimed to evaluate the efficacy of transanal endoscopic total mesorectal excision in patients with rectal cancer.

DESIGN

This study was a prospective, single-arm phase II trial. It was registered on clinicaltrials.gov under identifier NCT02406118.

SETTINGS

Inpatients at a hospital specializing in oncology were selected.

PATIENTS

This prospective study enrolled 49 patients with rectal cancer located 3 to 12 cm from the anal verge who were scheduled to undergo radical surgery.

INTERVENTIONS

Laparoscopy-assisted transanal total mesorectal excision was performed.

MAIN OUTCOME MEASURES

The primary end point was total mesorectal excision quality and circumferential resection margin. Secondary end points included the number of harvested lymph nodes, operation time, and 30-day postoperative complications.

RESULTS

From March 2015 to April 2016, 32 men and 17 women with rectal cancer were enrolled. The mean age was 61.2 years, and mean BMI was 23.3 kg/m. The mean operating time was 158 minutes, and the mean estimated blood loss was 89.3 mL. There were no intraoperative complications and no conversions to open surgery. Successful treatment based on total mesorectal excision quality and circumferential resection margin was achieved in 45 patients (91.8%). Fifteen patients (30.6%) had 30-day postoperative complications, including 7 (14.3%) with anastomotic dehiscence, 5 (10.2%) with urinary retention, 2 (4.1%) with abdominal wound complications, and 1 (2.0%) with ileus. There was no postoperative mortality.

LIMITATIONS

This was a noncomparative single-arm trial conducted at a single institution.

CONCLUSIONS

Transanal endoscopic total mesorectal excision showed acceptable results based on perioperative and short-term oncologic outcomes. Further investigations are necessary to show the benefits and long-term outcomes of this procedure. See Video Abstract at http://links.lww.com/DCR/A563.

Feasibility of transanal total mesorectal excision in cases with challenging patient and tumor characteristics

Purpose

To assess the feasibility of transanal total mesorectal excision in difficult cases including obese patients or patients with bulky tumors or threatened mesorectal fascias.

Methods

We performed laparoscopy-assisted transanal total mesorectal excision in patients with biopsy-proven rectal adenocarcinoma located 3–12 cm from the anal verge as part of a prospective, single arm, pilot trial. The primary endpoint was resection quality and circumferential resection margin involvement. Secondary endpoints included the number of harvested lymph nodes and 30-day postoperative complications.

Results

A total of 12 patients (9 men and 3 women) were enrolled: one obese patient, 7 with large tumors and 8 with threatened mesorectal fascias (4 patients had multiple indications). Tumors were located a median of 5.5 cm from the anal verge, and all patients received preoperative chemoradiotherapy. Median operating time was 191 minutes, and there were no intraoperative complications. One patient needed conversion to open surgery for ureterocystostomy after en bloc resection. Complete or near-complete excision and negative circumferential resection margins were achieved in all cases. The median number of harvested lymph nodes was 15.5. There was no postoperative mortality and 3 cases of postoperative morbidity (1 postoperative ileus, 1 wound problem near the stoma site, and 1 anastomotic dehiscence).

Conclusion

This pilot study showed that transanal total mesorectal excision is also feasible in difficult laparoscopic cases such as in obese patients or those with bulky tumors or tumors threatening the mesorectal fascia. Additional larger studies are needed.

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.

Comparison of Inflammatory Response to Transgastric and Transcolonic NOTES

Aims. The aim of our study was to determine the physiologic impact of NOTES and to compare the transgastric and transcolonic approaches. Methods. Thirty pigs were randomized to transgastric, transcolonic, or laparoscopic peritoneoscopy. Blood was drawn and analyzed for C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1β, IL-6, WBCs, and platelets. Results. Endoscopic closure with an OTSC was successful in all 20 animals. The postoperative course was uneventful in all animals. CRP values rose on day 1 in all animals and slowly declined to baseline levels on day 14 with no differences between the groups (P > 0.05, NS). The levels of TNF-α were significantly increased in the transcolonic group (P < 0.01); however this difference was already present prior to the procedure and remained unchanged. No differences were observed in IL1-β and IL-6 values. There was a temporary rise of WBC on day 1 and of platelets on day 7 in all groups (P > 0.05, NS). Conclusions. Transgastric, transcolonic, and laparoscopic peritoneoscopy resulted in similar changes in systemic inflammatory markers. Our findings do not support the assumption that NOTES is less invasive than laparoscopy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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.

Transvaginal cholecystectomy vs conventional laparoscopic cholecystectomy for gallbladder disease: A meta-analysis

AIM: To compare the results of transvaginal cholecystectomy (TVC) and conventional laparoscopic cholecystectomy (CLC) for gallbladder disease.

METHODS: We performed a literature search of PubMed, EMBASE, Ovid, Web of Science, Cochrane Library, Google Scholar, MetaRegister of Controlled Trials, Chinese Medical Journal database and Wanfang Data for trials comparing outcomes between TVC and CLC. Data were extracted by two authors. Mean difference (MD), standardized mean difference (SMD), odds ratios and risk rate with 95%CIs were calculated using fixed- or random-effects models. Statistical heterogeneity was evaluated with the χ² test. The fixed-effects model was used in the absence of statistically significant heterogeneity. The random-effects model was chosen when heterogeneity was found.

RESULTS: There were 730 patients in nine controlled clinical trials. No significant difference was found regarding demographic characteristics (P > 0.5), including anesthetic risk score, age, body mass index, and abdominal surgical history between the TVC and CLC groups. Both groups had similar mortality, morbidity, and return to work after surgery. Patients in the TVC group had a lower pain score on postoperative day 1 (SMD: -0.957, 95%CI: -1.488 to -0.426, P < 0.001), needed less postoperative analgesic medication (SMD: -0.574, 95%CI: -0.807 to -0.341, P < 0.001) and stayed for a shorter time in hospital (MD: -1.004 d, 95%CI: -1.779 to 0.228, P = 0.011), but had longer operative time (MD: 17.307 min, 95%CI: 6.789 to 27.826, P = 0.001). TVC had no significant influence on postoperative sexual function and quality of life. Better cosmetic results and satisfaction were achieved in the TVC group.

CONCLUSION: TVC is safe and effective for gallbladder disease. However, vaginal injury might occur, and further trials are needed to compare TVC with CLC.

Transanal endoscopic microsurgery (TEM) facilitated by video-assistance and anal insertion of a single-incision laparoscopic surgery (SILS(®))-port: preliminary experience

OBJECTIVE

Transanal endoscopic microsurgery (TEM) is an established method for the resection of benign and early malignant rectal lesions. Very recently, TEM via an anally inserted single incision laparoscopic surgery (SILS(®))-port has been proposed to overcome remaining obstacles of the classical TEM equipment.

METHODS

Nine patients with a total of 12 benign or early stage malignant rectal polyps were operated using the SILS(®)-port for TEM. Patients' and polyps' characteristics, perioperative and postoperative complications, as well as operating and hospitalization time were recorded.

RESULTS

All 12 polyps (ten low-grade adenoma, one high-grade adenoma, one pT2 carcinoma [preoperatively staged as T1]) were resected. Local full-thickness bowel wall resection was performed for three lesions and submucosal resection for nine lesions. Median operating time was 64 (range 30-180) min. No conversion to laparoscopic or open techniques was necessary. The median maximum diameter of the specimen was 25 (range 3-60) mm, fragmentation of polyps was avoidable in 11 of 12 (92 %) lesions, and resection margins were histologically clear in 11 of 12 (92 %) polyps. Only one patient, in whom three lesions were resected, experienced a complication as postoperative hemorrhage. No mortality occurred. Median hospitalization time was four (range 1-14) days.

CONCLUSIONS

SILS(®)-TEM is a feasible and safe method, providing numerous advantages in application, handling, and economy compared with the classical TEM technique. SILS(®)-TEM might become a promising alternative to classical TEM. Randomized, controlled trials comparing safety and efficacy of both instrumental settings will be needed in the future.

Transanal natural orifice transluminal endoscopic surgery total mesorectal excision in animal models: endoscopic inferior mesenteric artery dissection made easier by a retroperitoneal approach

Purpose

We report the performance of natural orifice transluminal endoscopic surgery (NOTES) low anterior resection in animals using transanal total mesorectal excision (TME) with laparoscopic assistance and endoscopic inferior mesenteric artery (IMA) dissection.

Methods

Four pigs weighing 45 kg each, and one dog weighing 25 kg, underwent surgery via a transanal approach. The rectum was occluded transanally using a purse-string suture, approximately 3-4 cm from the anal verge. The rectal mucosa was incised circumferentially just distal to the purse-string. A SILS or GelPOINT port was inserted transanally. Transanal TME was assisted by laparoscopy and proceeded up to the peritoneal reflection. More proximal dissection, including IMA dissection, was performed along the retroperitoneal avascular plane by endoscopy alone and facilitated by CO₂ insufflation. The IMA was clipped and divided endoscopically. The mobilized rectosigmoid were exteriorized transanally and transected. A colorectal anastomosis was performed using a circular stapler with a single stapling technique.

Results

Endoscopic dissection of the IMA was successful in all five animals. The mean operation time was 125 minutes (range, 90-170 minutes). There were no intraoperative complications or hemodynamic instability. The mean length of the resected specimen was 14.4 cm (range, 12-16 cm).

Conclusion

A NOTES retroperitoneal approach to the IMA with CO₂ insufflation and intact peritoneal covering overcame the difficulties of retraction and exposure of endoscopic dissection in animals.

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.

Prolonged capnoperitoneum does not cause postoperative ileus in pigs: safety of prolonged capnoperitoneum

INTRODUCTION

Operative time is an accepted risk factor for the development of postoperative ileus (POI). Innovative surgical procedures such as robotic surgery and natural orifice transluminal endoscopic surgery (NOTES) will be associated with longer operative times. Although intraabdominal manipulation is a major factor for POI the impact of prolonged capnoperitoneum on postoperative gastrointestinal transit time (GIT-TT) has rarely been studied.

MATERIAL AND METHODS

IRB approved survival pilot study to assess postoperative GIT-TT using fecal collection and chromium-oxide (Cr2O3) labeling in pigs. Twelve female pigs were randomly assigned to three groups of four animals each. Group A received eight hours anesthesia and pressure-controlled high flow capnoperitoneum (15 mmHg), group B eight hours of anesthesia only and group C no intervention. No intraoperative manipulation. The pilot study was terminated after eight days.

RESULTS

None of the animals developed POI. In Group A one animal died after eight hours of general anesthesia. No differences in postoperative fecal output, Cr2O3 excretion rate or weight gain were found.

CONCLUSION

This study is the first to investigate eight hours of capnoperitoneum in a survival model. GIT-TT is not affected by prolonged capnoperitoneum in pigs. No POI occurred with prolonged capnoperitoneum. Prolonged capnoperitoneum is safe regarding postoperative gastrointestinal function in innovative surgical procedures.

Transanal minimally invasive surgery for total mesorectal excision

Transanal TME is a new and important application for TAMIS. It allows for resection and mobilization of the rectum while preserving the quality of the mesorectal envelop. This new approach has gained considerable interest not only because of its minimally invasive nature, but because TAMIS-TME offers a solution to one of the most difficult problems in rectal cancer surgery: Specifically, access to the distal rectum in obese male patients with a narrow pelvis. Recently, transanal TME has become one of the most rapidly expanding areas in rectal cancer surgery. Interestingly, the origin and inception of this approach began decades ago. The evolution of transanal TME with a historical perspective is described.

Pure NOTES rectosigmoid resection: transgastric endoscopic IMA dissection and transanal rectal mobilization in animal models

BACKGROUND

We report a pure natural orifice translumenal endoscopic surgery (NOTES(®); American Society for Gastrointestinal Endoscopy [Oak Brook, IL] and the Society of American Gastrointestinal and Endoscopic Surgeons [Los Angeles, CA]) rectosigmoidectomy in animal models using transgastric endoscopic inferior mesenteric artery (IMA) dissection and transanal rectal mobilization.

MATERIALS AND METHODS

Ten live animals (2 pigs weighing 35-40 kg each and 8 dogs weighing 25-30 kg each) were used. A gastrotomy was made using a needle-knife puncture and the balloon dilatation technique or following the creation of a submucosal tunnel. A circular stapler shaft was transanally inserted up to the sigmoid colon for spatial orientation and traction of the mesocolon. The IMA was endoscopically dissected using a Coagrasper™ (Olympus, Tokyo, Japan) and then clipped. Endoscopic division of the sigmoid mesocolon was conducted laterally toward the marginal artery. Transanal full-thickness circumferential rectal and mesorectal dissections were performed, and a colorectal anastomosis was performed using a circular stapler with a single stapling technique. During the transanal approach, the gastrotomy was closed using four endoscopic clips.

RESULTS

Endoscopic dissection of the IMA was successful in all cases, but minor bleedings occurred in 3 cases. The mean time from dissection and clipping to division of the IMA was 36.7 minutes (range, 25-45 minutes). The mean operation time was 180.5 minutes (range, 145-210 minutes). There were no intraoperative complications or hemodynamic instability. The mean length of the resected specimen was 11.2 cm (range, 9-17 cm).

CONCLUSIONS

A pure NOTES approach to rectosigmoid resection using transgastric endoscopic IMA dissection is technically feasible in animal models.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Transanal rectosigmoidectomy using a single port in a Swine model

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) and single access surgery are emerging techniques that reduce surgical invasiveness. This study was performed to evaluate the feasibility of NOTES transanal rectosigmoidectomy using a single port in a swine model.

METHODS

Ten male pigs were used to conduct 2 studies, 4 for a nonsurvival study and 6 for a survival study. After anesthesia, the rectum was occluded transanally with a purse-string suture, and then a single port was placed. CO(2) gas was insufflated, and full-thickness rectal dissection was extended using laparoscopic instruments as far cephalad as possible. A 5-mm trocar was placed on the abdominal wall for transabdominal laparoscopic view, and then further colonic mobilization was performed using the endoscope through the anus. When the dissection was completed, the specimen was exteriorized and colorectal anastomosis was performed using a circular stapler. In the survival study, necropsies were performed on postoperative day 7.

RESULTS

Full-thickness circumferential rectosigmoid mobilization was achieved in all cases. The mean length of resected colon was 10 cm (range = 8-15 cm). No anastomotic defects were noted. All resected rectosigmoid specimens were grossly intact. No mortality or significant postoperative complications was observed in the survival group. On necropsy, a small abscess in the pelvic cavity was noted in 1 case and bladder distention was noted in 3 cases.

CONCLUSIONS

NOTES transanal rectosigmoidectomy using the single port is feasible and safe. Further experimental studies are warranted, especially in human cadaver model.

Analysis of the Anatomical Characteristics of the Pelvis in Koreans to Aid in Development of a NOTES Platform

Transanal endoscopic microsurgery (TEM) is a minimally invasive technique affording full-thickness resection of rectal tumors and can also be used as a platform for transrectal access to the peritoneal cavity for NOTES (natural orifice transluminal endoscopic surgery) procedures. The authors investigated the anatomical characteristics of the pelvis in Koreans to develop an ergonomically designed NOTES platform. A total of 256 patients (156 men and 100 women) who underwent pelvic magnetic resonance imaging for evaluating rectal neoplasms were enrolled for analysis. The authors retrospectively reviewed and calculated anatomical lengths and angles on pelvic magnetic resonance images and analyzed differences in pelvic anatomy in terms of patient gender, age, and body mass index. Various angulations were noted from the anal canal to the sacral promontory, attributable to the shape of the sacral bone. Minimal difference in pelvic anatomy was evident between men and women. In conclusions, the authors expect that their data will be useful in the development of ergonomic TEM-NOTES platforms.