Transrectal Natural Orifice Transluminal Endoscopic Surgery Research Articles

Transgastric versus transrectal: Which access route is the best for NOTES gallbladder-preserving gallstone therapy?

To compare the effectiveness and safety of transgastric and transrectal pure natural orifice transluminal endoscopic surgery (NOTES) for cholecystolithotomy. This was a single-center retrospective comparative study of consecutive patients who underwent pure NOTES for eithertransrectal or transgastric gallbladder-preserving cholecystolithotomy between September 2017 and April 2020. Patients with symptomatic cholelithiasis were assigned for transrectal or transgastric NOTES based on the patients' choice. Treatment success, postoperative pain, peritonitis, time to resume normal diet, and duration of hospitalization were compared. The technical success rate was 100%. Forty-eight patients underwent successful NOTES cholecystolithotomy via the transrectal (n = 26) or transgastric route (n = 22). One (3.8%) patient in the transrectal NOTES group experienced postoperative abdominal pain compared to 6 (27.3%) in the transgastric NOTES group (P = 0.04). Fever and bile peritonitis developed in one (3.8%) patient in the transrectal NOTES group versus 8 (36.4%) in the transgastric NOTES group (P = 0.005). A postoperative fluid diet was commenced at 6 h with the transrectal approach versus on day 3 for the transgastric NOTES group. The mean postoperative hospitalization for transrectal and transgastric NOTES groups was 4.5 days versus 7 days (P = 0.001). Three patients in the transgastric NOTES group developed postoperative gastric fistula. Transrectal NOTES has advantages over transgastric NOTES, including preserved spatial orientation, relatively easier removal of specimens, early food intake, shorter hospitalization, fewer postoperative complications and less pain. Multicenter clinical trials with long-term follow-up are needed to confirm the safety and efficacy of both approaches.

Are laparoscopic cholecystectomy and natural orifice transluminal endoscopic surgery gallbladder preserving cholecystolithotomy truly comparable? A propensity matched study.

BACKGROUNDCholecystectomy is the preferred treatment option for symptomatic gallstones. However, another option is gallbladder-preserving cholecystolithotomy which preserves the normal physiological functions of the gallbladder in patients desiring to avoid surgical resection.AIMTo compare the feasibility, safety and effectiveness of pure natural orifice transluminal endoscopic surgery (NOTES) gallbladder-preserving cholecystolithotomy vs laparoscopic cholecystectomy (LC) for symptomatic gallstones.METHODSWe adopted propensity score matching (1:1) to compare trans-rectal NOTES cholecystolithotomy and LC patients with symptomatic gallstones. We reviewed 2511 patients with symptomatic gallstones from December 2017 to December 2020; 517 patients met the matching criteria (NOTES, 110; LC, 407), yielding 86 pairs.RESULTSThe technical success rate for the NOTES group was 98.9% vs 100% for the LC group. The median procedure time was 119 min [interquartile ranges (IQRs), 95-175] with NOTES vs 60 min (IQRs, 48-90) with LC (P < 0.001). The frequency of post-operative pain was similar between NOTES and LC: 4.7% (4/85) vs 5.8% (5/95) (P = 0.740). The median duration of post-procedure fasting with NOTES was 1 d (IQRs, 1-2) vs 2 d with LC (IQRs, 1-3) (P < 0.001). The median post-operative hospital stay for NOTES was 4 d (IQRs, 3-6) vs 4 d for LC (IQRs, 3-5), (P = 0.092). During follow-up, diarrhea was significantly less with NOTES (5.8%) compared to LC (18.6%) (P = 0.011). Gallstones and cholecystitis recurrence within a median of 12 mo (range: 6-40 mo) following NOTES was 10.5% and 3.5%, respectively. Concerns regarding the presence of abdominal wall scars were present in 17.4% (n = 15/86) of patients following LC (mainly women).CONCLUSIONNOTES provides a feasible new alternative scar-free treatment for patients who are unwilling or unable to undergo cholecystectomy. This minimally invasive organ-sparing procedure both removes the gallstones and preserves the physiological function of the gallbladder. Reducing gallstone recurrence is essential to achieving widespread clinical adoption of NOTES.

A reliable detachable balloon that prevents abdominal cavity contamination during transrectal natural orifice transluminal endoscopic surgery.

To evaluate the efficacy and safety of a detachable endoluminal balloon in the prevention of abdominal cavity contamination during transrectal natural orifice transluminal endoscopic surgery (NOTES). The efficacy and safety of a detachable endoluminal balloon to maintain disinfection in the distal colon of the pigs were evaluated. The bacterial loads and colonic cleanliness were monitored. Additionally, the device was applied to another nine pigs that underwent a cholecystotomy by transrectal NOTES. Necropsy and pathological examination were performed after 28-day follow-up. All animals exposed to the device and one of the seven pigs not exposed to the device scored three points on the bowel cleanliness scale (P < 0.001). After 30 min bacterial loads of the test (with balloon occlusion) and control (without balloon occlusion) groups showed a significant difference (0.8 × 103 CFU/mL vs 186.8 × 103 CFU/mL, P < 0.01). Cholecystotomy by transrectal NOTES with the device was successfully performed. The mean intraperitoneal procedure time was 102.9 ± 37.7 min. There were no procedure-related adverse events. During the follow-up, all animals presented normal behavior and appetite. No peritoneal infection or adhesion was detected at autopsy. Cholecystotomy and rectal incision were histologically healed and no histological abnormalities were detected in the colon related to balloon placement. The detachable balloon provides a reliable solution for preventing peritoneal contamination during transluminal operations. The technique may assist in future transrectal NOTES.

Contamination After Disinfectant Rectal Washout in Left Colectomy as a Model for Transrectal NOTES: A Randomized Controlled Trial

BackgroundIn natural orifice transluminal endoscopic surgery (NOTES) with transrectal (TR) access the intraoperative opening of the rectal wall poses a risk of intraperitoneal contamination and subsequent infectious complications. A rectal washout with a disinfectant may reduce this risk. The aim of the study was to assess the intraoperative contamination on the circular stapler pin when a rectal washout with povidone-iodine (RW-PI) or Ringer solution was performed in patients undergoing left-sided colectomy. Furthermore, the additional effect of an irrigation instrument on the contamination was evaluated. MethodsIn a patient and assessor blinded randomized controlled trial, patients undergoing left-sided colectomy were assigned to rectal washout with PI with an irrigation instrument (RW-PI; n = 23), rectal washout with Ringer solution with an irrigation instrument (RW-R; n = 21) or rectal washout with Ringer solution without an irrigation instrument (RW; n = 25). An end-to-end anastomosis with a circular stapler was performed. The contamination on the pin of the circular stapler was chosen as primary endpoint in order to simulate the intraabdominal contamination risk during TR NOTES. Secondary endpoints were contamination of the rectal mucosa, peritoneal contamination and postoperative morbidity. ResultsThe contamination rate of the pin of the circular stapler did not differ (RW-PI 39.1%, RW-R 33.3%, RW 52.0%; P = 0.421), but contamination of the rectal mucosa was reduced (47.8% versus 95.2% versus 100%; P < 0.001) and peritoneal contamination tended to be reduced (39.1% versus 71.4% versus 60.0%; P = 0.09) when a rectal washout with PI was performed. The rates of infectious complications (17.4% versus 9.5% versus 12.0%; P = 0.821) and of overall complications (30.4% versus 28.6% versus 44.0%; P = 0.476) did not differ. ConclusionsDespite an intense rectal washout with PI, contamination of the stapler pin did not differ. Intraabdominal bacterial translocation was frequently encountered even after disinfectant rectal washout with PI. Further studies might focus on the clinical impact of intraabdominal contamination in TR NOTES.

The transrectal single-port laparoscopic radical prostatectomy in a cadaver model.

Radical prostatectomy is the most commonly used and most effective treatment for localized prostate cancer; however, this treatment modality is not without disadvantages. After describing the first technique of radical perineal prostatectomy, several techniques, including open, laparoscopic, and robotic retropubic radical prostatectomy were developed and preferred in the treatment of patients. The desire for reproducible, minimally invasive surgery, which reduces complication rates and maximizes cosmetic outcomes, is met by natural orifice transluminal endoscopic surgery (NOTES).[1] Akca et al.[2] revealed that radical prostatectomy may be performed using a transrectal NOTES route. The authors state that transrectal radical prostatectomy is technically feasible in the cadaver model and the transrectal NOTES route provides good exposure and easy access to the posterior surface of the prostate. Anatomy dissection studies using human cadavers are valuable to show surgeons exactly what is intended for them to see without the risk of disrupting the integrity of the cadaver.[3] We would like to congratulate the authors for an ethical cadaver study of a new treatment modality and for finding a cost-effective model to explore the feasibility of the technique. Rectal injury or rectal perforation is one of the most important complications in radical prostatectomy, and the frequency of this complication varies from 0% to 11% in the literature.[4] Additionally, a recent study showed that rectal perforation is an important cause of litigation in cases of radical prostatectomy in the United States of America, and this complication represents 40 % of all cases of negligence in the performance of radical prostatectomy surgery.[5] Even though the authors state that a meticulous repair of rectal mucosa makes this procedure less morbid than an inadvertent unrecognized rectal injury, a living human study may show that prolonged retraction on the rectal wall in the single port procedures can damage the viability of rectal tissue. Opening the gastrointestinal system can cause several complications, including sepsis and even death. Thus, concerning the motto ‘primum nil nocere’, an innovative technique should be experienced by using fundamental anatomical principles. Humphreys et al.[6] introduced another innovative surgical technique called NOTES radical prostatectomy for localized prostate cancer via a transurethral approach. This technique has the same advantages as transrectal NOTES radical prostatectomy, such as minimal invasiviness and improved cosmetic outcomes, with the lack of potential risks seen rectal injury. Nevertheless, the study by Akca et al.[2] is noteworthy, important, and will guide researchers in finding the best type of approach for radical prostatectomy surgery.

The transrectal single port laparoscopic radical prostatectomy in a cadaver model.

To explore the feasibility of laparoscopic trans-rectal Natural Orifice Transluminal Endoscopic Surgery (NOTES) radical prostatectomy in a cadaveric model and to define anatomical landmarks of this surgical route. After the ethical clearance, the study was conducted in Turkish Council of Forensic Medicine. With the cadaver in an exaggerated lithotomy position, a full thickness incision was made on the anterior wall of the rectum. The anteriorly visible Denonvilliers' fascia was incised sharply, exposing the posterior surface of the prostate. A single-port device (GelPOINT(®)Path) was inserted transanally passing the incision on the anterior wall of the rectum, into the bluntly created space between rectum and prostate. Three, 10 mm ports were placed through the GelPOINT(®)Path, at 3, 6, and 9 o'clock positions. A 5 mm, 0° degree lens was introduced at 6 o'clock position; followed by laparoscopic scissors and laparoscopic grasper. Prostatic and periprostatic anatomy was defined as encountered during each step of the procedure. Exposure of the posterior surface of the prostate and seminal vesicles was easily achieved. No additional openings of the rectal wall were made. Surgical specimen was extracted keeping its integrity. Transrectal radical prostatectomy is technically feasible in the cadaver model, being facilitated by previous experience with perineal surgery. Anatomical observations during the present experimental study suggest that the transrectal NOTES route provides good exposure of the operative field and easy access to the posterior surface of prostate, Future experimental endeavors should focus on reproducibility of this approach and feasibility of lymph node dissection using trans-rectal route.

Comparison of Transrectal and Transvaginal Hybrid Natural Orifice Transluminal Endoscopic Surgery Partial Nephrectomy in the Porcine Model

To compare the feasibility of porcine transrectal (TR) and transvaginal (TV) hybrid natural orifice transluminal endoscopic surgery (NOTES) partial nephrectomy (PN), as NOTES nephrectomy has recently been performed in the porcine model. A total of 10 female pigs (weight 45 kg) underwent TR (n= 5) or TV (n= 5) NOTES PN. The pneumoperitoneum was created by a periumbilical 12-mm trocar, through which a laparoscope was advanced for intra-abdominal visualization. For TV-NOTES PN, a gastroscope was used to obtain TV peritoneal access. For TR-NOTES PN, a horizontal incision was made 2 cm above the dentate line, and a submucosal tunnel was created in the posterior rectal wall. The gastroscope was advanced through the submucosal tunnel and retroperitoneum to the kidney, and a peritoneal window was created. For both TR- and TV-NOTES PN, the gastroscope was exchanged for the SPIDER Surgical System. Flexible dissecting instruments and hook cautery introduced through the SPIDER Surgical System were used to mobilize the kidney. A harmonic scalpel introduced periumbilically was used to excise a portion of the lower pole. LAPRA-TY-secured sutured renorrhaphy was performed, followed by TR or TV specimen extraction. TR- and TV-NOTES PN was successfully performed in all 10 pigs. A comparison of TR- and TV-NOTES PN revealed no significant differences in the mean access time (29.2 vs 29.6 minutes, P= .944), operative time (196.0 vs 183.0 minutes, P= .631), and estimated blood loss (59.0 vs 54.0 mL, P= .861). Necropsy did not demonstrate abdominal injuries. We have demonstrated proof-of-principle for TR and TV-NOTES PN in swine, with comparable perioperative parameters. Preclinical survival studies are requisite to assess the potential of TR-NOTES as an alternative to TV-NOTES.

Duhamel pull-through assisted by transrectal port: a hybrid natural orifice transluminal endoscopic surgery approach

One of the latest surgical innovations is natural orifice transluminal endoscopic surgery (NOTES). We hypothesize that the principles of NOTES could be applied to the laparoscopic Duhamel procedure. Between March 2008 and May 2010, 3 children underwent the laparoscopic Duhamel procedure assisted by transrectal NOTES. Three 5-mm transabdominal trocars were combined with a 12-mm transrectal trocar. We were able to safely apply the principles of NOTES, improving the performance of laparoscopic Duhamel pull-through using current instruments and technology. This new approach avoids the need of an extra transabdominal 12-mm trocar for the endoscopic stapler, allows an easier creation of a smaller rectal stump, and offers the possibility of an extra working port. This hybrid concept can be seen as a transition into the emerging field of NOTES in colorectal surgery.

Feasibility of Transrectal Hybrid Natural Orifice Transluminal Endoscopic Surgery (NOTES) Nephrectomy in the Cadaveric Model

To examine feasibility of transrectal hybrid natural orifice transluminal endoscopic surgery (NOTES) nephrectomy in human cadavers in the evolution of this technique, as transrectal hybrid NOTES nephrectomy has been demonstrated in the porcine model. Four hybrid transrectal NOTES nephrectomies were performed on 4 cadavers (3 female/1 male, 2 right/2 left). Pneumoperitoneum was created by periumbilical 12-mm trocar, through which a laparoscope was advanced to obtain intra-abdominal visualization. A 4-cm horizontal incision was made 2-cm above the dentate line and a submucosal tunnel was created in the posterior rectal wall/presacral space. A dual-channel gastroscope was advanced through the submucosal tunnel and retroperitoneum to the level of the kidney using air insufflation. A peritoneal window was created and renal mobilization was completed. A transumbilically applied laparoscopic 45-mm stapler was used to transect the ureter and renal hilum. A specimen entrapment bag was deployed transrectally for specimen extraction, followed by transrectal incision closure. Transrectal NOTES nephrectomy was successfully performed in all cases, with intact specimen extraction. Median weight was 77 kg (range 74-85 kg); median body mass index (BMI) was 30.1 kg/m(2) (range 25.6-31.2 kg/m(2)). Mean operative time was 175 minutes (range 150-210 minutes). Median transrectal access time was 36 minutes (range 24-47 minutes). Median dimensions of removed kidneys were length 11.2 cm (range 10-12 cm), width 5 cm (range 4.5-6 cm), and thickness 3.8 cm (range 3-4.5 cm). Transrectal hybrid NOTES nephrectomy in the cadaver model is feasible with intact specimen extraction and acceptable operative times. Preclinical survival studies are requisite to assess sterility and complications. This approach may be an alternative to transvaginal access.

Prospective experimental study of transrectal viscerotomy closure using transanal endoscopic suture vs. circular stapler: a step toward NOTES

Endoluminal full-thickness closure of the rectal wall is critical in emerging procedures including endoscopic submucosal dissection and transrectal natural orifice transluminal endoscopic surgery (NOTES). This study aimed to compare manual suture using the transanal endoscopic operation platform (TEO; Karl Storz, Tüttlingen, Germany) with the end-to-end anastomosis hemorrhoid circular stapler (EEA; Covidien, Dublin, Ireland) for closure of the rectal viscerotomy during transrectal NOTES segmental colectomy. A total of 12 swine underwent transrectal hybrid NOTES partial colectomies. Animals were divided into two groups according to the viscerotomy closure technique: 1) TEO manual suture; 2) EEA circular stapler closure. Mean (± SD) viscerotomy closure time was 67.5 ± 59.5 minutes and 31.5 ± 19.6 minutes for TEO and EEA, respectively. There was one conversion to laparoscopy in the TEO group and a misfiring in the EEA group that required a TEO salvage suture. There was one positive air-leak test in each group. Peritoneal fluid collected at the end of the procedure tested positive for bacterial contamination in all cases. A mild stenosis was present in 4 /6 viscerotomies (67 %) in the TEO group and in 1/6 (17 %) in the EEA group on endoscopic control. Inflammatory changes were mild in 3/5 (60 %) and 4/5 (80 %) viscerotomies in the TEO and EEA groups, respectively, whereas severe inflammation was found in 2/5 (TEO) and 1 /5 (EEA). Transrectal viscerotomy closure using the EEA circular stapler technique is feasible, easy to perform, and histologically comparable to suture closure through a TEO platform. It may offer an attractive alternative for NOTES segmental colectomies and endoscopic resections.

852 COMPARISON OF TRANSRECTAL AND TRANSVAGINAL HYBRID NATURAL ORIFICE TRANSLUMINAL ENDOSCOPIC SURGERY (NOTES) PARTIAL NEPHRECTOMY IN THE PORCINE MODEL

You have accessJournal of UrologyTechnology & Instruments: Laparoscopy - Malignant Disease1 Apr 2012852 COMPARISON OF TRANSRECTAL AND TRANSVAGINAL HYBRID NATURAL ORIFICE TRANSLUMINAL ENDOSCOPIC SURGERY (NOTES) PARTIAL NEPHRECTOMY IN THE PORCINE MODEL Wassim M. Bazzi, Sean P. Stroup, Takayuki Dotai, Seth A. Cohen, Ryan P. Kopp, Omer Raheem, James Masterson, Suzanne Gudeman, Caroline Colangelo, Santiago Horgan, Christopher J. Kane, and Ithaar H. Derweesh Wassim M. BazziWassim M. Bazzi San Diego, CA More articles by this author , Sean P. StroupSean P. Stroup San Diego, CA More articles by this author , Takayuki DotaiTakayuki Dotai San Diego, CA More articles by this author , Seth A. CohenSeth A. Cohen San Diego, CA More articles by this author , Ryan P. KoppRyan P. Kopp San Diego, CA More articles by this author , Omer RaheemOmer Raheem San Diego, CA More articles by this author , James MastersonJames Masterson San Diego, CA More articles by this author , Suzanne GudemanSuzanne Gudeman San Diego, CA More articles by this author , Caroline ColangeloCaroline Colangelo San Diego, CA More articles by this author , Santiago HorganSantiago Horgan San Diego, CA More articles by this author , Christopher J. KaneChristopher J. Kane San Diego, CA More articles by this author , and Ithaar H. DerweeshIthaar H. Derweesh San Diego, CA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.944AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Transrectal Natural Orifice Transluminal Endoscopic Surgery (NOTES) nephrectomy has recently been performed in the porcine model. We compared feasibility of porcine Transrectal (TR) and Transvaginal (TV) hybrid NOTES partial nephrectomy (NOTES-PN). METHODS 8 female pigs (45 kg) underwent TR (n=4) or TV (n=4) NOTES-PN. In both pneumoperitoneum was created by periumbilical 12-mm trocar, through which a laparoscope was advanced for intra-abdominal visualization. For TV-NOTES-PN: A gastroscope (Olympus, Center Valley, PA) was used to obtain transvaginal peritoneal access. For TR-NOTES-PN: horizontal incision was made 2-cm above the dentate line and a submucosal tunnel was created in the posterior rectal wall. Gastroscope was advanced through the submucosal tunnel and retroperitoneum to the kidney. A peritoneal window was created. For both TR- and TV-NOTES-PN, the gastroscope was exchanged for the SPIDER System (TransEnterix, Morrisville, NC) TR, Figure 1). Flexible dissecting instruments and hook cautery introduced through the SPIDER arms were used to mobilize kidney (TR, Figure 2) and hilum. Periumbilical-introduced harmonic scalpel (Ethicon, Cincinnati, OH) and scissors were used to excise a portion of the lower pole. Lapra-Ty secured (Ethicon) sutured renorrhaphy was performed, followed by completion nephrectomy, TR or TV specimen extraction and rectotomy/vaginotomy closure. RESULTS TR-and TV-NOTES-PN was successfully performed in all 8 pigs. Comparison of TR and TV approaches revealed no significant difference in mean: access time (33.5 vs. 30.8 min, p=0.626), operative time (212.5 vs. 197.5 min, p=0.561), estimated blood loss (68.8 vs. 66.3 mL, p=0.943), and volume of resected specimen (p=0.763). Necropsy did not demonstrate abdominal injuries. CONCLUSIONS We demonstrate proof-of-principle for TR and TV-NOTES-PN in swine, with comparable perioperative parameters. Preclinical survival studies are requisite to assess potential of TR NOTES to be an alternative to TV. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e347 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wassim M. Bazzi San Diego, CA More articles by this author Sean P. Stroup San Diego, CA More articles by this author Takayuki Dotai San Diego, CA More articles by this author Seth A. Cohen San Diego, CA More articles by this author Ryan P. Kopp San Diego, CA More articles by this author Omer Raheem San Diego, CA More articles by this author James Masterson San Diego, CA More articles by this author Suzanne Gudeman San Diego, CA More articles by this author Caroline Colangelo San Diego, CA More articles by this author Santiago Horgan San Diego, CA More articles by this author Christopher J. Kane San Diego, CA More articles by this author Ithaar H. Derweesh San Diego, CA More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Development of a feasible transrectal natural orifice transluminal endoscopic surgery (NOTES®) approach in a cadaveric appendectomy model: anterior is better

The transrectal natural orifice transluminal endoscopic surgery (NOTES) approach is a potentially promising alternative to transgastric or transvaginal approaches for intraperitoneal procedures. However, whether the optimal transrectal approach for intraperitoneal surgery is anterior or posterior remains unknown. To evaluate this, a prospective comparison of anterior and posterior transrectal NOTES approaches in a cadaveric appendectomy model was performed. Operations were performed on human cadavers using a transanal endoscopic microsurgery (TEM) scope to assist with access and closure. Posterior access was achieved by tunneling cephalad through the retrorectal space into the peritoneal cavity. Anterior transrectal access was established through the rectal wall just above the peritoneal reflection. A dual-channel flexible endoscope was used to perform appendectomies. Rectotomies were closed using sutures or staples. Operative time, degree of laparoscopic assistance, complications, and leak-testing results were recorded. This study investigated 10 cadavers with access and closure attempted using both anterior (n = 10) and posterior (n = 5) approaches, whereas appendectomies were performed using either an anterior (n = 8) or a posterior (n = 2) approach. The anterior approach required less time than the posterior approach for peritoneal access (4 ± 1 vs. 61 ± 14 min; p < 0.001), specimen extraction (2 ± 1 vs. 5 ± 1 min; p < 0.01), and the total operation (99 ± 35 vs. 176 ± 26 min; p = 0.02). A "pure" NOTES dissection was possible with the anterior approach using rigid transanal instruments for assistance. Dissection time, closure time, and the incidence of complications were similar between the two approaches. Leak testing of closures showed significant variability for all closure types. Transrectal NOTES appendectomy is feasible in a cadaveric model using an anterior transrectal approach. This approach is technically easier, results in shorter operative times, and allows for a "pure" NOTES dissection compared with a posterior transrectal approach. Leak pressure testing of NOTES closures is unreliable in the cadaveric model.

Transanal endoscopic microsurgical platform for natural orifice surgery

The excitement surrounding natural orifice transluminal endoscopic surgery (NOTES) remains tempered by concerns over safe access and closure of transvisceral enterotomies. Research in NOTES has commonly been described as using an oral transgastric access point. Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for a full-thickness resection of rectal tumors and with suture closure of the resultant defect with highly specialized instruments. This technique has been used clinically in human beings for more than 2 decades. Entry into the peritoneal cavity during a resection of rectosigmoid lesions has been described, and safe closure can be obtained. To assess the feasibility of transrectal NOTES procedures by using TEM instrumentation. Three porcine and 3 human cadaver models were studied by using standard TEM instrumentation and flexible endoscopes. NOTES peritoneal access, a peritoneoscopy, a liver biopsy, and colorectal resections were performed. True NOTES procedures facilitated with TEM instrumentation were successfully completed. This was a preclinical study, and several challenges to bridging to human clinical use exist: TEM instruments are currently designed for intraluminal tasks low in the pelvis, with 5-mm to 10-mm port sizes; the cost of the TEM instruments and insufflation system; and the learning curve to perform TEM closure. Our preclinical study demonstrated the feasibility of several transrectal NOTES procedures, colorectal resection, and anastomosis when using TEM instrumentation. We, therefore, suggest TEM as a portal for NOTES.