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.

A 2-microm continuous-wave laser system for safe and high-precision dissection during NOTES procedures.

INTRODUCTION: Lasers 2-microm in wavelength offer efficient tissue cutting with limited thermal damage in biological tissue. OBJECTIVE: To evaluate the dissection capabilities of a 2-microm continuous-wave laser for NOTES procedures. METHODS AND PROCEDURES: We conducted 18 acute animal experiments. Group 1 (three animals): transcolonic access to the peritoneal cavity (15-W transcolonic laser puncture, balloon dilation over the laser probe). Group 2 (six animals): transcolonic access with needle-knife puncture and balloon dilation. Group 3 (three animals): transgastric access to the peritoneal cavity (similar technique as group 1) followed by laser-assisted dissection of the kidney. In one animal of group 3, a therapeutic target (hematoma) was created by percutaneous puncture of the kidney. Group 4 (six animals): transgastric access (similar to the technique of group 2). RESULTS: Translumenal access to the peritoneal cavity was achieved in 2-3 min in group 1 (significantly shorter than with the needle-knife-assisted technique, 4-5 min, p=0.02) and in 7-10 min in group 3 (compared to 6-17 min in group 4, p=0.88). In group 3, laser dissection of the parietal peritoneum and of perinephric connective tissue allowed access to the retroperitoneum with complete removal of a blood collection in the animal with puncture trauma. Laser dissection demonstrated good maneuverability, clean and rapid cutting, and excellent hemostasis. Peritoneoscopy and necropsy showed no damage of targeted tissue and surrounding organs. CONCLUSIONS: The 2-microm continuous-wave laser system showed promising capabilities for highly precise and safe dissection during NOTES procedures.

Successful diagnostic and therapeutic intrauterine fetal interventions by natural orifice transluminal endoscopic surgery (with videos).

BACKGROUND: Despite advances in the development of fetal surgery, morbidity and mortality are substantial. A natural orifice transluminal endoscopic surgery (NOTES)-guided approach to the gravid uterus may offer a less-invasive technique. OBJECTIVE: To assess the feasibility of NOTES for diagnostic and therapeutic intrauterine fetal interventions. SETTING: Survival and nonsurvival experiments on pregnant sheep. DESIGN AND INTERVENTION: Nonsurvival experiments performed in 2 pregnant sheep (80-110 days' gestation). A third ewe underwent NOTES and survived for 4 weeks. Transgastric (nonsurvival ewes) and transvaginal (1 nonsurvival and the survived ewe) peritoneoscopy was performed after standard needle-knife entry into the peritoneal cavity. Endoscopic access to the gravid uterus was assessed. EUS-guided, transuterine injection of saline solution into the fetal cardiac ventricle and vessels was attempted in all. MAIN OUTCOME MEASUREMENTS: Feasibility of NOTES- and EUS-guided intervention in a pregnant animal model, visibility of fetal parts via EUS compared with transabdominal US. RESULTS: Entry into the peritoneal cavity was achieved in each ewe. Access to and complete visualization of the gravid uterus were successful once within the abdominal cavity. Visualization of the fetal parts and the placental cotyledons by EUS was achieved in all animals. EUS-guided amniocenteses and transuterine intracardiac and intravascular injection of saline were successful. There were no complications or preterm delivery after the procedures. LIMITATIONS: Animal model. CONCLUSIONS: NOTES is technically feasible in the pregnant ewe. Intraperitoneal EUS via a NOTES approach provides excellent access and visualization of the intrauterine cavity and fetal parts.

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).

BACKGROUND: Leak-resistant closure of transluminal access is a major challenge facing natural orifice transluminal endoscopic surgery (NOTES). OBJECTIVE: To evaluate a hydrogen (H(2))-based leak test for assessment of transluminal-access closure integrity after NOTES procedures. SETTING: Nine acute porcine experiments. DESIGN AND INTERVENTION: After gastric-wall puncture and balloon dilation, peritoneoscopy was performed, followed by transmural closure of the gastric opening. The animals were randomly assigned to complete or incomplete closure groups. The H(2) leak test was performed by using 1000 mL of 4% H(2) gas mixture and the Hydrogen Leak Detector H2000+. The animals were then euthanized for a methylene blue (MB) test of gastric closure integrity. MAIN OUTCOME MEASUREMENT: Intraperitoneal H(2) concentration after gastric insufflation with H(2). RESULTS: The H(2) leak test was quick and easy. Intraperitoneal H(2) concentrations in parts per million in both groups were similar at baseline (mean +/- SD, 0.18 +/- 0.29 parts per million [ppm] vs 0.22 +/- 0.35 ppm, P = .97) and after balloon dilation (414.8 +/- 198.5 ppm vs 601.3 +/- 116.1 ppm, P > .99). Postclosure intraperitoneal H(2) concentrations dropped to 0.01 +/- 0.77 ppm in the complete-closure group, similar (P = .81) to matched-pairs preopening levels and significantly lower than in the incomplete-closure group (162.0 +/- 83.0 ppm, P < .02). On necropsy, the MB test was negative in all 5 animals of the complete-closure group and positive in all 4 animals of the incomplete-closure group. A cutoff of 25 ppm in intraperitoneal H(2) concentration after closure gave 100% sensitivity, specificity, and positive and negative predictive values for MB leakage. LIMITATIONS: Nonsurvival animal experiments. CONCLUSIONS: The H(2) leak test is highly accurate for detection of leakage after NOTES procedures and could become a substitute for currently used MB leak tests.