Natural Orifice Transluminal Endoscopic Surgery Peritoneoscopy Research Articles

Transvaginal natural orifice transluminal endoscopic surgery in the diagnosis of ascites of unknown origin

Natural orifice transluminal endoscopic surgery (NOTES) has been established in animal models and human studies, but few clinical studies have investigated transvaginal NOTES in the diagnosis of unexplained refractory ascites. We aimed to assess the feasibility, efficacy, and safety of transvaginal NOTES for the diagnosis of unexplained ascites in female patients. A prospective study was done involving 3 female patients with unexplained ascites. After general anesthesia and disinfection, a 1.0-cm incision was made in the posterior fornix of the vagina. A gastroscope was inserted into the abdominal cavity through the transvaginal incision and an artificial pneumoperitoneum was created; NOTES peritoneoscopy was performed to scrutinize the pathologic changes. Endoscopic biopsy specimens were obtained for pathologic examination. The transvaginal incision was closed by direct suturing. Transvaginal NOTES for diagnostic peritoneoscopy was successfully performed in 3 patients. The mean operative time was 61 minutes. The estimated blood loss was 5 to 10 mL. The pathologic diagnoses were tuberculosis for all patients, and the symptoms and ascites disappeared after antituberculosis therapy. During the 4-year follow-up, no clinically significant adverse events occurred in any patient after NOTES. No patient experienced an annex inflammation, vaginitis, dyspareunia, or sexual dysfunction. All patients were comfortable and satisfied with the nonscarring surgical procedure. Transvaginal NOTES for the diagnosis of unexplained ascites is feasible, effective, and safe. This method had no long-term effect on female sexual function and is particularly suitable for women who have special aesthetic requirements. (Clinical trial registration number: ChiCTR-TRC-10001053.).

In vivo assessment of a biological occluder for NOTES gastrotomy closure.

The objective of this study is to evaluate the closure of a transgastric natural orifice transluminal endoscopic surgery (NOTES) access using a multilayer extracellular matrix (ECM) occluder in a canine model. Mongrel dogs (n = 4) underwent a transgastric NOTES peritoneoscopy and the gastrotomy was closed by deploying a 2-sided ECM occluder. Animals were killed at 7 days (n = 2) and 8 weeks (n = 2) for macroscopic and microscopic assessment. All procedures were completed without any complications. No air leaks were detected immediately after the procedure and at 48 hours postoperatively. At 7 days, ECM appeared to be resolved and mild mucosal inflammation was found at the site of gastrotomy. At 8 weeks, the gastrotomy site was macroscopically and microscopically covered with a normal-appearing gastric mucosa. There was an absence of inflammatory cells and no evidence of the ECM. The ECM occluder is safe and effective in this "proof-of-concept" preclinical model.

Direct incision versus submucosal tunneling as a method of creating transgastric accesses for natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy: Randomized controlled trial

The optimal approach for creating accesses for transgastric peritoneoscopy is still uncertain. The present study aims to assess the feasibility of carrying out transgastric submucosal tunnel (SMT) peritoneoscopy and to determine whether this approach improves or restricts access to various sectors within the peritoneal cavity. This was a randomized comparative study carried out in an in-vivo survival porcine model. Sixty-six beads in six swine were visualized and touched via gastrotomies created by either direct incision (DI) or SMT. The influence of the type of gastrotomy on improving or restricting access to particular sites within the peritoneal cavity for natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy was compared. The main outcome measurements were localization score of beads, overall procedural time, morbidities and mortalities. A significantly higher mean (SD) localization score was observed in peritoneoscopies carried out in the DI group (P < 0.001). Both the visualization and the touching scores were significantly better with the DI technique, and the overall yield of NOTES peritoneoscopy with DI and SMT were 72.73% and 60.6%, respectively (P = 0.043). Significantly more beads that were not touched in the SMT group were located in the sub-phrenic area (P = 0.013). The overall procedural time was significantly shorter in the DI group (P = 0.004). No major morbidities or mortalities occurred in any procedures. SMT resulted in lower visualization and touching scores for transgastric NOTES peritoneoscopy. Alternate methods to improve the diagnostic yield to the sub-phrenic area are required.

No-incision (NOTES) versus single-incision (single-port) surgery for access to sites of peritoneal carcinomatosis: a back-to-back animal study

Preoperative radiological diagnosis and evaluation of limited peritoneal carcinomatosis (PC) is suboptimal. Triangle laparoscopy is considered a noncarcinologic option due to the risk of tumoral spreading through the lateral ports into the abdominal wall muscles. Open surgery is therefore often needed to characterize PC. A minimally invasive approach would be progress. We aimed to compare access rates to elective sites of PC using natural orifice transluminal endoscopic surgery (NOTES) with those using single-port laparoscopic surgery (SPLS). Sixteen acute experiments were performed in a live porcine model. Back-to-back NOTES and SPLS standardized peritoneoscopy were conducted in a cross-over design. Access rates to 11 elective sites of PC were considered as end points based on operators' consensus and necropsy verification. Access to the targets was successful in 89 % with NOTES and 80 % with SPLS (p = 0.27). NOTES and SPLS achieved a 100 % access rate to the diaphragmatic domes and paracolic gutters, to the splenic area, to the pelvic floor, and to the trigonal bladder (p > 0.99). Access rates of NOTES versus SPLS to other elective sites of PC were the following: mesentery root (94 % vs. 0 %, p < 0.001), inferior mesenteric vein origin (88 % vs. 0 %, p < 0.001), inferior vena cava (88 % vs. 75 %, p = 0.85), and hepatic pedicle (8 % vs. 100 %, p < 0.001). Both transgastric NOTES and SPLS provided quick and easy access to most elective sites of PC, except for the mesenteric vessel root (better achieved by NOTES) and the hepatic pedicle (better achieved by SPLS). Both techniques could be improved or combined to overcome their specific drawbacks.

Infection during Natural Orifice Transluminal Endoscopic Surgery Peritoneoscopy: A Randomized Comparative Study in a Survival Porcine Model

Background Infection in natural orifice transluminal endoscopic surgery (NOTES) remains controversial. Objective To estimate the frequency of infection during NOTES peritoneoscopy with different routes of access and to compare with laparoscopy. Design Prospective randomized controlled study (Canadian Classification type I). Methods Forty female pigs were randomly assigned to 3 NOTES (transgastric, transrectal, and transvaginal) and laparoscopic groups. Antiseptic technique was used for NOTES, whereas laparoscopy was performed in a sterile environment. Preoperative and postoperative intravenous antibiotics were administered. Closure of the transluminal access site was performed in all animals. Peritoneal fluid was collected for culture at the end of surgery and at necropsy at day 14. Results Thirty-nine peritoneoscopies were successfully completed. Necropsy confirmed complete healing of NOTES incisions, but 2 animals in the laparoscopy group had small abscesses in the abdominal incisions. There were no statistical differences in the presence of peritoneal adhesions. Positive culture results were seen in all groups at the end of the procedure and in all animals at necropsy, but this did not lead to clinical signs of gross infection. The most common organisms that colonized the peritoneum were gram-positive cocci and gram-negative bacilli from the normal swine gastrointestinal flora. Limitations Animal model and small sample size. Conclusions In these small series of animals and with the careful lavage and preparation used, NOTES appeared to be comparable to laparoscopy in terms of peritoneal contamination and clinical infection. Despite the adherence to a strict antiseptic protocol, peritoneal contamination occurs but does not lead to septic complications in the swine.

Pulmonary and peritoneal inflammatory findings in transgastric NOTES compared with laparoscopy: pooled analysis from randomized porcine survival studies

Laparoscopy, which is a minimally invasive surgery, is associated with decreased peritoneal adhesions and inflammatory response compared with laparotomy. To evaluate whether natural orifice transluminal endoscopic surgery (NOTES) leads to an attenuated peritoneal response compared with laparoscopy. Pooled histologic analysis from 2 randomized porcine trials. Laboratory. Histologic analysis of swine undergoing diagnostic laparoscopy, diagnostic NOTES peritoneoscopy, NOTES with transgastric mesh placement, or diagnostic endoscopy (no gastrotomy) followed by laparoscopic mesh placement. The presence and grade of inflammation in necropsy specimens of lung, liver, and spleen as reviewed by a blinded veterinary pathologist. Four NOTES mesh animals exhibited mesh infections at necropsy. Tissue from 48 swine were available for analysis. Pulmonary inflammation, liver fibrosis, and spleen capsulitis were the primary findings. No difference was seen in the incidence of each finding among groups. The severity of the pulmonary inflammation in the laparoscopy group was significantly higher than in the NOTES groups. The NOTES mesh group exhibited significantly more severe liver fibrosis and spleen capsulitis. There was no difference between clinical behavior, serum white blood cell count, or peritoneal white blood cell count among groups in either study. Intra-abdominal pressures during NOTES were lower than during laparoscopy. Pooled analysis of 2 separate studies. More severe pulmonary inflammation was found in animals undergoing longer laparoscopic procedures with higher intra-abdominal pressures. Intraperitoneal inflammation was most significant with transgastric mesh placement, likely caused by infections.

State-of-the-art imaging techniques in endoscopic ultrasound

Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment, with a major clinical impact in digestive and mediastinal diseases. State-of-the-art EUS equipment now includes real-time sono-elastography, which might be useful for a better characterization of lesions and increased accuracy of differential diagnosis (for e.g. lymph nodes or focal pancreatic lesions). Contrast-enhanced EUS imaging is also available, and is already being used for the differential diagnosis of focal pancreatic masses. The recent development of low mechanical index contrast harmonic EUS imaging offers hope for improved diagnosis, staging and monitoring of anti-angiogenic treatment. Tridimensional EUS (3D-EUS) techniques can be applied to enhance the spatial understanding of EUS anatomy, especially for improved staging of tumors, obtained through a better assessment of the relationship with major surrounding vessels. Despite the progress gained through all these imaging techniques, they cannot replace cytological or histological diagnosis. However, real-time optical histological diagnosis can be achieved through the use of single-fiber confocal laser endomicroscopy techniques placed under real-time EUS-guidance through a 22G needle. Last, but not least, EUS-assisted natural orifice transluminal endoscopic surgery (NOTES) procedures offer a whole new area of imaging applications, used either for combination of NOTES peritoneoscopy and intraperitoneal EUS, but also for access of retroperitoneal organs through posterior EUS guidance.

Comparison of transcolonic NOTES and laparoscopic peritoneoscopy for the detection of peritoneal metastases

Peritoneoscopy by natural orifice transluminal endoscopic surgery (NOTES) could replace laparoscopic staging peritoneoscopy (LAP) if the yield were comparable to that from LAP. In previously performed porcine experiments, transgastric peritoneoscopy seemed inferior to LAP due to limited visualization of the liver. The aim of the present study was to improve liver visualization by using a colonic approach and to compare transcolonic peritoneoscopy (TCP) with the previously set LAP standard. Small beads were stapled into porcine peritoneal cavities to simulate metastases. Previously in the same model LAP had detected 95% of beads (95% CI 87% -98%). Using a non inferiority design, a sample size of 33 beads was determined; these were distributed among six animals with randomization for numbers and location. TCP was performed using either standard endoscopic accessories (TCP-s) or a specially designed toolkit (TCP-t) in randomized order by one of two blinded endoscopists. Primary outcome was number of beads found and touched during peritoneoscopy. Locations of beads included abdominal peritoneum (6 beads), diaphragm (8), liver (18), and miscellaneous sites (1). TCP-s found 25 beads (yield 76%, 95% CI 59% -87%). TCP-t found 19 beads (yield 58%, 95% CI 41%-71%). The majority of missed beads were located at the inferior liver surface: TCP-s detected 8/15 (53%) and TCP-t 5/15 (33%) of these simulated metastases. In this prospective, experimental trial, transcolonic NOTES peritoneoscopy was inferior in comparison with the diagnostic laparoscopy done previously in the same model.

Randomized study of natural orifice transluminal endoscopic surgery and endoscopy shows similar hemodynamic impact in a porcine model

A previous porcine study showed a significant difference in heart rate and diastolic blood pressure (DBP) between natural orifice transluminal endoscopic surgery (NOTES) and laparoscopy. This study evaluated the hemodynamics during endoscopy, laparoscopy, and transluminal access. For this study, 37 female swine were randomized and invasively monitored in terms of blood and abdominal pressure, heart rate, and arterial blood gas (ABG) during 90-min procedures. Group 1 (n = 11) underwent NOTES peritoneoscopy; group 2 (n = 14) underwent 45-min diagnostic endoscopy, a 10-min washout period, and 35-min laparoscopy with mesh placement; and group 3 (n = 12) NOTES had transgastric mesh placement. The groups were compared using a mixed model and a Spearman trend test. This study was approved by Institutional Animal Care and Use Committee (IACUC). No difference in the systolic blood pressure (SBP) was noted. During the initial 30 min, DBP increased significantly from baseline in groups 1 (p < 0.001) and 2 (p = 0.01), but not in group 3 (p = 0.08). The mean DBP did not differ between the groups. During laparoscopy, the average end-tidal carbon dioxide (CO(2)) level was 6.6 mmHg higher in group 2 than in group 1 (p = 0.01). The heart rate and ABG values did not differ between the groups (p ≥ 0.10). Heart rate and DBP were similar for NOTES and endoscopy. The differences seen in a previous trial comparing NOTES and laparoscopy were not duplicated. The initial DBP increased for the endoscopy and diagnostic NOTES animals. Differences in end-tidal CO(2) were encountered again during the shortened laparoscopy segment.

Confocal Laser Endomicroscopy: Technical Advances and Clinical Applications

Since its introduction in 2004, confocal laser endomicroscopy (CLE) has emerged as a valuable tool for gastrointestinal endoscopic imaging. Endomicroscopy enables the endoscopist to obtain real time in vivo histology during ongoing endoscopy thereby creating “optical biopsies.” To date, numerous studies have shown potential applications of endomicroscopy in the clinical setting, including in vivo diagnosis of esophageal squamous cell carcinoma, Barrett’s esophagus, celiac disease, and colonic polyps. Moreover, recent data suggest the potential application of endomicroscopy in the field of molecular imaging. Additionally, in recent months new applications and developments in the field of confocal imaging were introduced including endomicroscopy of the liver, pancreatic, and bile ducts. Furthermore, by introducing a new needle-based confocal imaging system, which is small enough to be introduced through a 22gauge puncture needle, a wide field for new applications of endomicroscopic imaging has been opened. Currently, 2 CE- and US Food and Drug Administration (FDA)approved devices for endomicroscopy are available (Figures 1 and 2; Supplementary Table 1). In this review, we introduce both systems and discuss new technical advances and clinical applications of CLE.

Transgastric natural-orifice transluminal endoscopic surgery peritoneoscopy in humans: a pilot study in efficacy and gastrotomy site selection by using a hybrid technique

Diagnostic natural-orifice transluminal endoscopic surgery (NOTES) peritoneoscopy can easily be performed with standard endoscopic equipment in animal studies. The efficacy and optimal transgastric site for NOTES access in humans, however, has not been determined. To characterize the efficacy of various anterior gastric access locations for diagnostic transgastric NOTES peritoneoscopy in humans. Prospective clinical study. Tertiary-care center with experience in NOTES peritoneoscopy. Patients undergoing planned laparoscopic gastrectomy or gastrotomy involving the anterior aspect of the stomach were eligible. An anterior gastric site for NOTES gastrotomy was chosen and transgastric NOTES access was independently established after laparoscopic abdominal exploration. Peritoneoscopy was then performed. The site of gastrotomy was closed as part of the intended laparoscopic procedure. The ability to visualize the abdominal and pelvic organs in all four quadrants was determined. Patients were evaluated postoperatively for complications. Eight patients requiring 9 procedures were studied. Gastrotomy sites were classified as body (n = 3), lesser curvature (n = 3), greater curvature (n = 1), fundus (n = 1), and antrum (n = 1). Satisfactory navigation could only be performed to the right upper and both lower quadrants. The left upper quadrant, specifically the spleen, was adequately visualized in only 1 case (11%), where the gastrotomy site was at the greater curvature. One patient developed a surgical site infection requiring oral antibiotic therapy. The median postoperative stay was 2 days (range, 0-3 days). Small number of patients. NOTES peritoneoscopy with a gastrotomy on the anterior stomach permits adequate visualization of organs in the right upper and both lower quadrants. Visualization of the left upper quadrant and spleen is, however, limited unless access is gained on the greater curvature of the stomach. The accuracy of NOTES in identifying intra-abdominal pathology compared with laparoscopy remains to be determined.

Needle-based confocal endomicroscopy for in vivo histology of intra-abdominal organs: first results in a porcine model (with )

Probe-based confocal laser scanning endomicroscopy enables in vivo real time histopathology of the mucosa layer. Recently, a prototype of a new confocal miniprobe has been developed that is small enough to be introduced through a 22-gauge puncture needle. The aim of this study was to evaluate the feasibility of such needle-based confocal laser scanning endomicroscopy (nCLE) for in vivo histology of various organs in a porcine model. Feasibility study. Nonsurvival animal experiments with the animals under general anesthesia at three academic centers. Ten pigs were examined while they were under general anesthesia. Either EUS-guided organ puncture or natural-orifice transluminal endoscopic surgery (NOTES) procedure was used. The confocal miniprobe was inserted through the 22-gauge needle, and puncture of various intra-abdominal structures and organs was performed (lymph nodes, diaphragm, ovaries, liver, spleen, and pancreas) after intravenous injection of fluorescein (5-10 mL 1% or 2 mL 10% solution). Real-time sequences were recorded. Biopsy specimens were taken for standard histopathology. It was technically feasible to introduce the needle-based confocal miniprobe into various organs at the time of EUS or NOTES procedures. The device enabled real-time in vivo collection of images at histologic resolutions and of acceptable image quality from several intra-abdominal organs interrogated. Data were assessed in an experimental animal setting and on healthy organs only. Needle-based confocal laser endomicroscopy (CLE) of intra-abdominal organs is feasible in a porcine model. This innovative, minimally invasive technique has the potential to facilitate in vivo histology during EUS punctures or NOTES peritoneoscopy.

Feasibility of transgastric and transcolonic natural orifice transluminal endoscopic surgery peritoneoscopy combined with intraperitoneal EUS

If natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy is to become an alternative to diagnostic laparoscopy, NOTES peritoneoscopy must be comparable to laparoscopy in its diagnostic accuracy. To assess the feasibility of transgastric (TG) and transcolonic (TC) NOTES peritoneoscopy combined with intraperitoneal EUS. Twelve nonsurvival experiments on 6 female pigs. Animal laboratory. Six 35- to 40-kg female pigs. Randomization was performed to determine the order of approach (TG or TC as first procedure). After peritoneal access, systematic peritoneoscopy was performed according to a preassessed list of 12 locations considered clinically important. For each visualized location, 1 point was scored and 1 point added if it was touched as well, leading to a maximum score of 24 points. Subsequently, the endoscope was exchanged for a linear EUS-scope. The percentage of visualization of the 4 sections of the liver was recorded (0, not visible; 1, 33%; 2, 66%; 3, 100%; maximum score, 12 points). After withdrawal, the protocol was repeated by using the second natural orifice (TG or TC). Extent of adequate visualization of diagnostic peritoneoscopy and intraperitoneal EUS measured by a preassessed record form. Access was achieved without difficulties at all 12 sites. TG peritoneoscopy resulted in a median of 23 points (range 20-24) via the TC approach. A maximum of 24 points was recorded in all pigs (P = .102). TG-EUS resulted in a median of 11 points (range 6-12) and TC-EUS in a median of 12 points (range 8-12) (P = .317). Lack of objective landmarks for EUS. TG and TC NOTES peritoneoscopy combined with intraperitoneal EUS is technically feasible. Furthermore, NOTES peritoneoscopy and intraperitoneal EUS seem to result in adequate visualization of the peritoneal cavity and liver, respectively.

Infectious implications in the porcine model of natural orifice transluminal endoscopic surgery (NOTES) with PEG-tube closure: a quantitative bacteriologic study

Obtaining reliable closure of transvisceral defects currently limits natural orifice transluminal endoscopic surgery (NOTES). PEG tubes are potential means of managing NOTES gastrotomies. To determine the efficacy of PEG closure after NOTES. An experimental animal study. A laboratory. The pigs received gastric lavage with saline solution, chloramphenicol, or no lavage, and then underwent transgastric NOTES peritoneoscopy. Cultures were obtained by endoscopy during the surgery. A sterile foreign body was left in the peritoneal cavity. The gastrotomy was closed with a 20F PEG tube. The animals were observed for 14 days and underwent sterile laparotomy. Cultures of the foreign body and the peritoneal cavity were obtained. Abscess rate, peritoneal quantitative cultures. After 1 exclusion for anesthetic complications, 19 animals underwent NOTES; 18 (94.7%) survived the entire postoperative period. One animal died on postoperative day 2 after the PEG tube dislodged. At 14 days, 5 animals (27.8%) had intra-abdominal abscesses, 8 (44.4%) had positive peritoneal cultures, and 9 (50%) foreign bodies were contaminated on culture. Infectious complications were not altered by the type of gastric lavage or peritoneal bacterial inoculum introduced at the time of surgery. An animal model. PEG closure of a NOTES gastrotomy is associated with subclinical intra-abdominal abscess formation and can result in death when the tube is dislodged during the early postoperative period. Preprocedural gastric lavage does not alter the intra-abdominal bacterial burden introduced at the time of surgery or subsequent infectious outcomes in the porcine model. These concerning findings necessitate additional studies to determine if porcine models are appropriate and applicable to human subjects in the NOTES setting.