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

Endoscopic ultrasound-assisted direct peritoneal visualization with a small-caliber scope: A proof of concept study in a swine model

BACKGROUND

Laparoscopic and natural orifice transluminal endoscopic surgery techniques can diagnose peritoneal findings that suggest tumor cell dissemination. However, they have not been incorporated into routine practice, mainly owing to their complexity. To develop a minimally invasive endoscopic technique for the diagnosis of peritoneal findings, we conducted feasibility study using an acute swine model.

MATERIALS AND METHODS

This study involved six domestic pigs. Trans-gastric access to the peritoneal cavity was performed utilizing an endoscopic ultrasound fine needle aspiration (EUS-FNA) technique. After dilation of the needle hole with a biliary dilatation catheter and balloon, a small-caliber scope was inserted into the peritoneal cavity. Peritoneal images were obtained with the scope and a high-resolution microendoscope (HRME). Main outcome measurements were technical feasibility and time needed to access the peritoneal cavity.

RESULTS

Direct visualization of the peritoneum was successful in all six pigs and gained access to the gross appearance of the peritoneal cavity. HRME imaging with topical contrast agent also obtained reasonable quality images representing nuclei of the peritoneal mesothelium. Average operation time from the initiation of EUS-FNA to acquiring peritoneal images was 26.5 min (range 15-40 min). Autopsy found no damage to the adjacent organs, and stomach wall defects were tightly closed with hemostasis clips.

CONCLUSION

EUS-assisted direct peritoneal visualization with small-caliber scope is technically feasible. HRME may assist in the diagnosis of findings on the peritoneum.

EUS assisted transmural cholecystogastrostomy fistula creation as a bridge for endoscopic internal gallbladder therapy using a novel fully covered metal stent

BACKGROUND

Laparoscopic cholecystectomy (LC) has become the "gold standard" for treating symptomatic gallstones. Innovative methods, such as a scarless therapeutic procedure through a natural orifice are being introduced, and include transgastric or transcolonic endoscopic cholecystectomy. However, before clinical implementation, instruments still need modification, and a more convenient treatment is still needed. The aim of this study was to evaluate the feasibility of endoscopic internal gallbladder therapy such as cholecystolithotomy in an animal survival model.

METHODS

Four pigs underwent endoscopic-ultrasound (EUS)-guided cholecystogastrostomy and the placement of a novel covered mental stent. Four weeks later the stents were removed and an endoscope was advanced into the gallbladder via the fistula, and cholecystolithotomy was performed. Two weeks later the pigs were sacrificed, and the healing of the fistulas was assessed.

RESULTS

EUS-guided cholecystogastrostomy with mental stent deployment was successfully performed in all the animals. Four weeks after the procedure, the fistulas had formed and all the stents were removed. Endoscopic cholecystolithotomy was performed through each fistula. All the animals survived until they were sacrificed 2 weeks later. The fistulas were found to be completely healed.

CONCLUSIONS

This study reports the first endoscopic transmural cholecystolithotomy after placement of a novel mental stent in an animal survival model.

Forward-viewing endoscopic ultrasound-guided NOTES interventions: A study on peritoneoscopic potential

AIM: To evaluate the feasibility of diagnostic and therapeutic transgastric (TG) peritoneoscopic interventions with a forward-viewing endoscopic ultrasound (FV-EUS).

METHODS: This prospective endoscopic experimental study used an animal model. Combined TG peritoneoscopic interventions and EUS examination of the intra-abdominal organs were performed using an FV-EUS on 10 animal models (1 porcine and 9 canine). The procedures carried out include EUS evaluation and endoscopic biopsy of intraperitoneal organs, EUS-guided fine needle aspiration (EUS-FNA), EUS-guided radiofrequency ablation (EUS-RFA), and argon plasma coagulation (APC) for hemostatic control. The animals were kept alive for 7 d, and then necropsy was performed to evaluate results and complications.

RESULTS: In all 10 animals, TG peritoneoscopy, followed by endoscopic biopsy for the liver, spleen, abdominal wall, and omentum, was performed successfully. APC helped control minor bleeding. Visualization of intra-abdominal solid organs with real-time EUS was accomplished with ease. Intraperitoneal EUS-FNA was successfully performed on the liver, spleen, and kidney. Similarly, a successful outcome was achieved with EUS-RFA of the hepatic parenchyma. No adverse events were recorded during the study.

CONCLUSION: Peritoneoscopic natural orifice transluminal endoscopic surgery (NOTES) interventions through FV-EUS were feasible in providing evaluation and performing endoscopic procedures. It promises potential as a platform for future EUS-based NOTES.

Natural orifice transluminal endoscopic surgery (NOTES) for clinical management of intra-abdominal diseases

Clinical research on natural orifice transluminal endoscopic surgery (NOTES) has been increasingly reported over the past 5 years and more than 1200 patients have received various NOTES procedures. The present article reviews the clinical practice of NOTES for the treatment of intra-abdominal diseases, and was carried out through systematic search with specific keywords in major databases for NOTES-related clinical literature. The last date of the search was 15 August, 2012. Transvaginal cholecystectomy is the commonest NOTES procedure reported, and its clinical feasibility and safety was established through prospective case series and randomized trials. There is a regional difference in NOTES development with the majority of NOTES fromCaucasian countries being transvaginal cholecystectomy and most reports from Asian countries being NOTES-related procedures. Safe closure of gastrointestinal access remains challenging, and novel endoscopic instruments are essential to enhance future development of NOTES.

NOTES for the management of an intra-abdominal abscess: transcolonic peritonoscopy and abscess drainage in a canine model

BACKGROUND

We studied natural orifice transcolonic drainage of intra-abdominal abscesses in a canine survival model to evaluate the difficulty of peritonoscopy and abscess drainage and the reliability of endoluminal colotomy closure.

METHODS

We placed a 7 cm nonsterile saline-filled latex balloon intra-abdominally to mimic or induce an abscess or inflammatory mass. Seven days later, we advanced a single-channel endoscope transanally into the sigmoid colon of the animal, made a colotomy and then advanced the endoscope intraperitoneally. We evacuated the identified abscess and placed a drain transabdominally. We closed the colotomy endoluminally with a tissue approximation system using 2 polypropylene sutures attached to metal T-bars. Two weeks later, we evaluated the colotomy closure at laparotomy.

RESULTS

We studied 12 dogs: 8 had subphrenic balloon implants and 4 had interbowel loop implants. Eleven survived and underwent transcolonic peritonoscopy; we identified the "abscess" in 9. The colotomy was successfully closed in 10 of 11 dogs. Although abscesses were easily identified, the overall difficulty of the peritonoscopy was moderate to severe. One dog required colotomy closure via laparotomy, while 9 had successful endoluminal closure. After colotomy closure, 8 animals survived for 2 weeks (study end point) without surgical complications, sepsis or localized abdominal infections. On postmortem examination, all closures were intact without any adjacent organ damage or procedure-related complications.

CONCLUSION

Natural orifice transluminal endoscopic surgery provides a novel alternative to treating intra-abdominal pathology. It is technically feasible to perform endoscopic transcolonic peritonoscopy and drainage of an intra-abdominal abscess with reliable closure of the colotomy in a canine experimental model.

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

AIM

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Intraoperative NOTES endosonography and identification of mock hepatic lesions

PURPOSE

Intraoperative ultrasound is commonly used during standard transabdominal surgery. The feasibility of endoscopic ultrasound (EUS) through Natural Orifice Translumenal Endoscopic Surgery (NOTES) for identification of abdominal lesions with a flexible echoendoscope has not been studied.

AIM

To test the feasibility of NOTES-EUS for abdominal exploration and identification of mock hepatic lesions.

METHODS

Five pigs underwent transvaginal or transcolonic NOTES and endosonographic exploration. In 3 anesthetized pigs, mock hepatic lesions were created and NOTES-EUS was then performed to identify these mock lesions. Necropsy was performed in all cases.

RESULTS

All target organs were consistently identified by NOTES-EUS in all animals. Mock hepatic lesions were successfully created in 3 animals and were able to be located by NOTES-EUS. No complications were observed at necropsy.

CONCLUSIONS

Abdominal exploration and localization of mock lesions by NOTES-EUS is technically feasible. As natural orifice surgery evolves, intraoperative NOTES-EUS would be an essential addition to the NOTES armamentarium.

Transgastric pure-NOTES peritoneoscopy and endoscopic ultrasonography for staging of gastrointestinal cancers: a survival and feasibility study

BACKGROUND

Human natural orifice transluminal endoscopic surgery (NOTES) has mainly been based on simultaneous laparoscopic assistance (hybrid NOTES), forgoing the theoretical benefits of the NOTES technique. This is due to a lack of NOTES-specific instruments and endoscopes, making pure-NOTES procedures difficult and time consuming. An area where pure NOTES could be adopted at its present stage of development is minimally invasive staging of gastrointestinal (GI) cancer. The aim of this study is to evaluate the feasibility of combining transgastric (TG) pure-NOTES peritoneoscopy and intraperitoneal endoscopic ultrasonography (ip-EUS) with intraluminal EUS (il-EUS) for peritoneal evaluation.

METHODS

This was a feasibility and survival study where il-EUS followed by ip-EUS and peritoneoscopy was performed in 10 pigs subjected to TG pure NOTES. A score was given with regard to achieved visualisation of predefined anatomical structures. Survival was assessed at postoperative day (POD) 14.

RESULTS

All animals survived until POD 14. Median total procedural time was 94 min (range 74-130 min). Median time for il-EUS, ip-EUS and peritoneoscopy was 11 min (range 7-14 min), 13 min (range 8-20 min) and 10 min (range 6-23 min). Il-EUS, ip-EUS and peritoneoscopy resulted in a score of 15/15 points (range 14-15 points), 6/9 points (range 1-8 points) and 12/13 points (range 8-13 points).

CONCLUSIONS

TG pure-NOTES peritoneoscopy and ip-EUS combined with il-EUS is feasible and provides sufficient peritoneal evaluation. The technique could have potential for minimally invasive staging of GI cancers.

Natural orifice transluminal endoscopic surgery: New minimally invasive surgery come of age

Although in the past two decades, laparoscopic surgery, considered as a great revolution in the minimally invasive surgery field, has undergone major development worldwide, another dramatic surgical revolution has quietly appeared in recent years. Ever since Kalloo’s first report on transgastric peritoneoscopy in a porcine model in 2004, interest in a new surgical procedure named natural orifice transluminal endoscopic surgery (NOTES) has blossomed worldwide. Considering that a NOTES procedure could theoretically avoid any abdominal incision, operation-related pain and scarring, many surgeons and endoscopists have been enthusiastic in their study of this new technique. In recent years, several NOTES studies have been carried out on porcine models and even on humans, including transvaginal cholecystectomy, transgastric appendectomy, transvaginal appendectomy, and transvesical peritoneoscopy. So what is the current situation of NOTES and how many challenges do we still face? This review discusses the current research progress in NOTES.

Critical analysis of hot topics in NOTES

Natural orifice transluminal endoscopic surgery (NOTES) has gained a great deal of attention from gastroenterologists and surgeons all over the world since its introduction in 2000. The field of NOTES has advanced tremendously since that time and exciting and well-designed research has been reported. Both randomized controlled trials and results from large national and international registries have been published. Many experimental and clinical studies have discussed transesophageal, transgastric, transvaginal and transrectal access for a variety of NOTES procedures. Transvaginal access has been the most frequently reported NOTES access route in clinical trials. When suitable instruments become available, a true comparison of NOTES with current laparoscopic approaches can be realized.

Transgastric endoscopic fenestration of a hepatic cyst: a report of one case

We present a case of transgastric endoscopic fenestration of a symptomatic simple hepatic cyst in the left lobe. After per-oral intubation, the anterior wall of the stomach was punctured with a needle. After the anatomic location was defined by intraperitoneal endoscopic ultrasound, fenestration was performed by gastric endoscopy. The procedure was successfully performed without any difficulties. The patient had an uncomplicated postoperative course. This method is technically feasible and represents a potential new approach to the treatment of simple hepatic cysts.

Transumbilical single-port laparoscopic-assisted vaginal hysterectomy via 12-mm trocar incision site

BACKGROUND

Single-port laparoscopic-assisted vaginal hysterectomy (S-LAVH) uses only one transumbilical incision site and has better cosmetic result than conventional multiport LAVH. This study aimed to evaluate our initial experience with S-LAVH compared with the more conventional three-port LAVH in women with benign uterine diseases.

METHODS

Between April 2009 and April 2010, S-LAVH was attempted on 183 patients with benign uterine diseases through a transumbilical incision for a 12-mm trocar, and conventional LAVH was performed on 275 patients by the same surgeon. The medical records of patients were reviewed. The age, body mass index, operative time, blood loss, and uterine weight on pathologic report were compared.

RESULTS

Two of 183 patients in the S-LAVH group were converted to two- or three-port surgery, compared with none in the conventional group. Data analysis was done for 181 patients in the S-LAVH group and 275 patients in the conventional LAVH group. No major complications, including ureteral or bladder injuries, occurred in any of the patients. No statistically significant differences were found in mean age, mean body mass index, mean operative time, mean anesthesia time, mean estimated blood loss, or mean postoperative days to passage of flatus, but the mean uterine weights on the pathologic reports were significantly reduced in the S-LAVH group.

CONCLUSION

S-LAVH could be a feasible alternative method for removal of the uterus with a better cosmetic outcome resulting from single wound in selected patients. For patients with large-sized uterus, more surgical experience and improvement in instruments suitable for S-LAVH are needed.

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.

Randomized, blinded comparison of transgastric, transcolonic, and laparoscopic peritoneoscopy for the detection of peritoneal metastases in a human cadaver model

BACKGROUND

Natural orifice transluminal endoscopic surgery peritoneoscopy may be able to replace laparoscopic peritoneoscopy (LAP) for staging of GI malignancies if it is proven to be equally accurate and safe.

OBJECTIVE

To compare transgastric peritoneoscopy (TGP) and transcolonic peritoneoscopy (TCP) to LAP, pairwise, in a randomized, blinded (to location and number of beads) human cadaver model with simulated peritoneal metastases.

DESIGN

Metastases were simulated by 2.5-mm, color-coded beads, which were placed into the peritoneal cavity via an open approach. In previous porcine experiments, LAP resulted in a yield of 95%. By using a noninferiority design with a margin of equivalence of 15%, we needed a sample size of 34 beads for 80% power. Randomization was performed for number and location of beads. Eighteen experiments were performed on 6 fresh-frozen human cadavers.

SETTING

Experimental surgical laboratory.

INTERVENTION

LAP, TGP, and TCP were performed in randomized order by one of two surgeons/endoscopists blinded for location and number of beads.

MAIN OUTCOME MEASUREMENTS

Number of beads detected and touched.

RESULTS

LAP found and touched 33 beads (yield 97%), TGP 26 beads (76%; difference in yield vs LAP was -20.5 [95% CI, -26.3 to -9.27]), and TCP 29 beads (85%; difference in yield vs LAP was -11.8 [95% CI, -14.6 to 4.98]). Beads that were missed were mostly located at the inferior liver surface: TGP missed 6 of 9 of these beads (67%), TCP 4 of 9 (44%).

LIMITATIONS

Cadaver model.

CONCLUSION

In this prospective, blinded, comparative trial in a human cadaver model, TCP was comparable to LAP in detecting simulated metastases. TGP was inferior to LAP. Future development should focus on improved visualization of the inferior surface of the liver.

Current developments in natural orifices transluminal endoscopic surgery: An evidence-based review

Tremendous advances have been made in recent years addressing the key obstacles to safe performance and introduction of human natural orifice transluminal endoscopic surgery (NOTES). Animal studies have focused on identifying optimal solutions to these obstacles, in particular methods of creating transluminal access, safe closure of the point of access, and development of a multitasking platform with dedicated instruments. Whether the performance data generated from these animal studies can be reproduced in humans has yet to be determined. Reports of human NOTES procedures are emerging, and the possibility of accomplishing human NOTES based on existing technology has been demonstrated. However, dedicated platforms and devices are still lacking to allow for pure NOTES procedures, and whether NOTES can deliver the postulated benefits of earlier recovery and improved cosmesis remains uncertain.

Natural orifice translumenal endoscopic surgery

PURPOSE OF REVIEW

Since its introduction in 2000, natural orifice translumenal endoscopic surgery (NOTES) has gained a great deal of attention from gastroenterologists and surgeons all over the world. In this article, we will review the progress in the field of NOTES and present the latest publications that provide some answers and solutions to the barriers suggested by the Natural Orifice Surgery Consortium for Assessment and Research white paper.

RECENT FINDINGS

Because of the first human NOTES procedure by Rao and Reddy, more pioneering procedures, including transgastric and transvaginal cholecystectomies, appendectomies, and hernia repairs, have been performed. Although NOTES researchers continue to experiment with new innovative equipment and procedures in the lab, more structured work, including randomized controlled trials, has been published.

SUMMARY

In the last several years, there has been growing interest in NOTES, which has translated into exciting animal research work and publication of randomized controlled trials. Additionally, preliminary NOTES human procedures have been successfully performed. When suitable instruments become available, the subsequent step should be comparing NOTES with current laparoscopic approaches. Superiority or even equality of NOTES to laparoscopic surgery would be the best argument for advancing and integrating implementation into clinical practice.

Hybrid NOTES transgastric cholecystectomy with reliable gastric closure: an animal survival study

Background

Secure transluminal closure remains the most fundamental barrier to safe translation of transgastric natural orifice transluminal endoscopic surgery (NOTES) procedures to humans. Obtaining optimal critical view of safety (CVS) is a prerequisite to performing cholecystectomy avoiding common bile duct injury.

Objectives

(1) To evaluate feasibility and safety of hybrid transgastric NOTES cholecystectomy. (2) To evaluate feasibility and reliability of gastrotomy closure using a novel Over-The-Scope-Clip (OTSC; Ovesco) in survival porcine experiments.

Methods

Laparoscopic access to the abdominal cavity was obtained by two 2-mm and one umbilical optical trocar(s). Gastric access was created by balloon dilatation of a needle knife puncture up to 18 mm. Exposure of CVS was obtained and evaluated by aid of a 2-mm device. Subsequently the cystic duct and artery were clipped endoscopically. After laparoscopic dissection the specimen was extracted via the stomach. The gastrotomy was closed endoscopically using the OTSC. Necropsy was performed after 10 days with inspection of gastrotomy and peritoneal cavity for complications. Experiments were planned in 3 acute and 16 survival pigs. Main outcome parameters were documented exposure of CVS, successful cholecystectomy and closure, uncomplicated survival and histology-confirmed full-thickness closure.

Results

In all 16 survival experiments CVS was obtained satisfactorily and hybrid cholecystectomy was successfully performed [100%; 95% confidence interval (CI): 81–100%]. Transgastric closure was endoscopically successful in all experiments in mean time of 7 min [standard deviation (SD) 3 min]. At necropsy 10 days after surgery there were no signs of (infectious) complications. Histology confirmed full-thickness healing with 100% success (95% CI: 81–100%).

Conclusion

Hybrid transgastric NOTES cholecystectomy is feasible, safe and results in optimal CVS. Use of OTSC for gastrotomy closure is feasible, reliable and results in histology-proven full-thickness closure in survival porcine experiments.

Electronic supplementary material

The online version of this article (doi:10.1007/s00464-010-1242-4) contains supplementary material, which is available to authorized users.

Role of endosonography in drainage of fluid collections and other NOTES procedures

Endosonography (EUS) has become the accepted procedure for drainage of pancreatic fluid collections in the past decade. EUS was shown to be safe and effective and it has been the first-line therapy for uncomplicated pseudocysts. Where walled-off pancreatic necrosis was originally thought to be a contraindication for endoscopic treatment, multiple case series have now shown that these fluid collections also can be treated endoscopically with low morbidity and mortality. Analogous to the treatment of pancreatic fluid collections, others, such as abscesses in the lower and upper abdomen, have also been treated successfully, although there is limited literature in this regard, EUS appears to be a useful technique in natural orifice transluminal endoscopic surgery (NOTES) procedures as well.

Comparison of Transgastric NOTES and laparoscopic peritoneoscopy for detection of peritoneal metastases

BACKGROUND

Transgastric peritoneoscopy (TGP) may be a future alternative to the diagnostic laparoscopy (LAP).

OBJECTIVE

To create a model of peritoneal metastases for development of TGP and to employ this model to compare TGP to LAP.

METHODS

Small beads were stapled in porcine peritoneal cavities to simulate metastases. Using a noninferiority design a sample size of 64 beads was determined, which were divided over 12 animals. Randomization was performed for number and location of beads. LAP was performed by one of 2 blinded surgeons. TGP was then performed in the same pig using either standard endoscopic accessories (TGP-s) or a specially designed toolkit (TGP-t) in randomized order by 1 of 2 blinded endoscopists. Primary outcome was number of beads found and touched during peritoneoscopy.

RESULTS

Locations of beads included: abdominal peritoneum (14 beads), diaphragm (11), surface of liver and hepatoduodenal ligament (32), and miscellaneous sites (7). LAP detected 61 beads (yield = 95%), TGP-s 40 beads (63%), and TGP-t 40 beads (63%). TGP-s and TGP-t were both inferior in comparison with LAP (P = 0.8465 and P = 0.7440 respectively). TGP-s and TGP-t were similar in number, distribution and time to detect beads. TGP was superior for detecting beads on the abdominal and diaphragmatic peritoneum than for the liver, namely TGP-s: 23/25 (92%) versus 12/32 (38%) (P < 0.001); TGP-t: 25/25 (100%) versus 11/32 (34%) (P < 0.001).

CONCLUSION

In this first prospective, blinded, comparative trial TGP was inferior to LAP for the detection of simulated metastases. Future development for NOTES peritoneoscopy should focus on improved access to the region of the liver and enhanced endoscopic optics and performance.