Hydrogen leak test is minimally invasive and highly specific for assessment of the integrity of the luminal closure after natural orifice transluminal endoscopic surgery procedures (with video)

Endoscopic clip closure of gastrointestinal perforations, fistulae, and leaks

Development of endoscopic devices to close perforations has certainly revolutionized endoscopy. Immediate closure of perforations eliminates the need for surgery, which allows us to push the limits of endoscopic surgery from the mucosal plane to deep submucosal layers and eventually transmurally. The present article focuses on endoscopic closure devices, closure techniques, followed by a review of animal and clinical studies on endoscopic closure of perforations.

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.

Pure natural orifice transluminal endoscopic surgery (NOTES) with ultrasonography-guided transgastric access and over-the-scope-clip closure: a porcine feasibility and survival study

BACKGROUND

Most natural orifice transluminal endoscopic surgery (NOTES) procedures to date rely on the hybrid technique with simultaneous laparoscopic access to protect against access-related complications and to achieve adequate triangulation for dissection. This is done at the cost of the potential benefits of this new minimally invasive technique. This study aimed to evaluate the feasibility and safety of a transgastric (TG) pure-NOTES procedure in a diagnostic setting.

METHODS

A TG pure-NOTES procedure with endoscopic ultrasonograpy (EUS)-guided access and over-the-scope-clip (OTSC) closure was performed for 10 pigs in a survival and feasibility study. A full macroscopic necropsy with subsequent histologic evaluation was performed on postoperative day (POD) 14. The outcome parameters were uncomplicated follow-up assessment, survival, intraoperative complications, intraabdominal pathology, macroscopic full-thickness closure, and histology-proven full-thickness healing of the gastrotomy.

RESULTS

An uncomplicated postoperative course was reported for 9 of the 10 pigs, and survival was reported for all 10 pigs. For all the pigs, EUS-guided access was performed successfully with a median duration of 25 min (range, 12-62 min) and without intraoperative complications or access-related lesions at necropsy. An OTSC closure was achieved with a median duration of 11 min (range, 3-28 min). The OTSC provided immediate closure, but according to the authors' definition of a full-thickness healing evaluated by histologic examination, this was not achieved in any of the cases. Although all the animals survived until POD 14, intraabdominal chronic abscesses were present in 3 of the 10 pigs at necropsy.

CONCLUSIONS

The EUS-guided TG access proved to be feasible without access-related complications. Although OTSC provided an immediate closure, the histopathology raised concerns regarding the risk of perforation. Together with the high risk of intraabdominal infection, TG pure-NOTES is not yet ready for routine clinical practice.

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.

Gastric wall healing after NOTES procedures: closure with endoscopic clips provides superior histological outcome compared with threaded tags closure

BACKGROUND

Closure of the transgastric access to the peritoneal cavity is a critical step in natural orifice transluminal endoscopic surgery (NOTES).

OBJECTIVE

To perform a direct comparison of the histological healing post clips and threaded tags (T-tags) closure after transgastric NOTES procedures.

DESIGN AND INTERVENTION

Twelve survival porcine experiments. After standardized endoscopic gastric wall puncture, balloon-dilation, and transgastric peritoneoscopy, closure of the gastric wall was performed with either clips or T-tags. Necropsy at 14 days was performed for histological evaluation of 2-mm interval transversal cross sections of the gastrotomy site.

MAIN OUTCOME MEASUREMENTS

Histological healing of the gastric wall opening.

RESULTS

Endoscopic closure of the gastrotomy was successfully achieved in all 12 animals, followed by an uneventful 2-week clinical follow-up. Transmural healing was seen in 3 (75%) animals after clip closure compared with only 1 (12.5%) in the group with T-tag closure (P = .06). Gastric wall muscular bridging was observed in 4 (100%) animals with clip closure compared with only 1 (12.5%) in the group with T-tag closure (P = .01).

LIMITATIONS

Animal model with short-term follow-up.

CONCLUSIONS

Endoscopic clip closure results in a layer-to-layer transmural healing of the gastric wall. In contrast, T-tag gastric wall plication impairs gastric layer bridging. These findings might guide the future design of new endoscopic devices and techniques for gastrotomy closure after NOTES procedures.

Leaks and endoscopic assessment of break of integrity after NOTES gastrotomy: the LEAKING study, a prospective, randomized, controlled trial

BACKGROUND

Gastric leak testing after natural orifice transluminal endoscopic surgery (NOTES) gastrotomy closure may help reduce the risk of leaks after transgastric procedures.

OBJECTIVE

To develop a novel endoscopy-based system to determine the presence of a leak after NOTES gastrotomy and to compare this system prospectively with radiographic leak testing.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Academic Medical Center laboratory.

SUBJECTS

Fifty swine.

INTERVENTION

During the pretrial phase, an endoscopic system for the measurement of intragastric pressure was developed. In the trial phase, swine with a NOTES gastrotomy were randomized to endoscopic versus radiographic leak testing. If a leak was demonstrated, the gastrotomy was reclosed by using a second-generation prototype T-anchor system. The primary outcome was leak detection after gastrotomy closure. The secondary outcome variables included necropsy findings, peritoneal fluid analysis, histologic examination, and clinical outcome.

RESULTS

Fourteen swine were included in the pretrial phase and 36 in the randomized trial. Swine were survived for a mean of 9 days postoperatively. Endoscopic pressure monitoring demonstrated a reproducible change in intragastric pressure with insufflation; r = 0.735, P = .001 and r = 0.769, P < or = .000 for the total and maximum pressures, respectively. Post-peritoneoscopy, there was a detectable and significant decrease in the mean total and mean maximum pressures versus baseline (P = .006 and P = .009). There was no significant difference between the radiologic and endoscopic arms in leak detection rate (4/18 vs 3/18, respectively, P = .500). Clinical outcomes and mean weight gain were equivalent. There was 1 operative abdominal wall injury and no deaths.

LIMITATIONS

Animal study.

CONCLUSION

Endoscopic pressure monitoring was reproducible, demonstrated the presence of gastric leak, and was as reliable as contrast-based radiographic leak testing.