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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.

Leak-resistant closure of transluminal access is a major challenge facing natural orifice transluminal endoscopic surgery (NOTES).To evaluate a hydrogen (H(2))-based leak test for assessment of transluminal-access closure integrity after NOTES procedures.Nine acute porcine experiments.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.Intraperitoneal H(2) concentration after gastric insufflation with H(2).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.Nonsurvival animal experiments.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.

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. Setting: 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.

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.

Introduction L’acces transgastrique a la cavite peritoneale en chirurgie endoscopique transviscerale par les orifices naturels (NOTES) doit etre sur et rapide. Materiels et Methodes Modele porcin vivant. Comparaisons randomisees de 3 modalites de ponction de la paroi anterieure de l’estomac puis de 2 techniques d’extension du site de ponction (ballon vs sphincterotome), pour abord endoscopique de la cavite peritoneale. Comparaison des techniques de ponction. 30 animaux etaient repartis aleatoirement dans 3 groupes : 1) Ponction directe de la paroi gastrique a l’aiguille de coupe (n = 5). 2) Ponction directe de la paroi gastrique a l’aiguille de coupe apres creation d’un pneumoperitoine (n = 13). 3) Ponction transcutanee de la paroi gastrique anterieure (n = 12), selon des modalites proches de la pull technique de pose de gastrostomie. Dans les 3 groupes, le site de ponction initiale etait dilate a l’aide d’un ballon a extension radiale controlee de 18 mm de diametre (Boston Scientific, Natick, MA) puis l’endoscope etait avance dans la cavite peritoneale. Comparaison des techniques d’extension du site de ponction. Apres pneumoperitoine et ponction directe de la paroi gastrique a l’aiguille de coupe, 32 animaux etaient repartis aleatoirement dans 2 groupes. A) Dilatation par ballon a extension radiale controlee de 18 mm (n = 16). B) Incision par sphincterotome (n = 16). L’endoscope etait ensuite avance dans la cavite peritoneale. Criteres de jugement : complications observees en peritoneoscopie endoscopique transgastrique ou a l’autopsie ; duree de la procedure (comparaison par test non-parametrique). Resultats L’abord endoscopique transgastrique de la cavite peritoneale etait realise avec succes chez tous les animaux. Comparaison des techniques de ponction : 3 complications etaient observees apres ponction directe de la paroi gastrique (groupe 1), aboutissant a l’arret premature de l’inclusion dans ce groupe. Aucune complication n’etait observee dans les groupes 2 et 3. L’acces peritoneal transgastrique etait realise en 9,7 ± 4,7 minutes dans le groupe 2 (pneumoperitoine puis ponction directe) vs 14,7 ± 3,1 minutes dans le groupe 3 (pull technique) (p Comparaison des techniques d’extension du site de ponction. Aucune complication n’etait observee apres dilatation au ballon. Deux complications (une laceration du bord libre du foie, une hemorragie gastrique massive) etaient observees apres incision au sphincterotome. L’acces peritoneal transgastrique etait realise en 9,3 ± 4,9 minutes au ballon vs 7,4 ± 1,9 minutes au sphincterotome (p = 0,37). Conclusion La ponction directe de la paroi anterieure de l’estomac est source de complications en l’absence de pneumoperitoine prealable. A durees egales, la ponction directe apres pneumperitoine autorise plus de liberte dans le choix du site de gastrotomie que la pull technique (ou le choix du site est restreint par la necessite d’une transillumination). La dilatation au ballon est aussi efficace, plus rapide, et source de moins de complications que l’incision au sphincterotome. Remerciements, financements, autres Xavier Dray remercie la SNFGE, l’AGA et l’AP-HP.

Introduction L’etancheite d’une suture doit pouvoir etre appreciee apres chirurgie endoscopique transviscerale (NOTES) afin de prevenir la contamination postoperatoire de la cavite peritoneale. L’hydrogene (H 2 ) est un gaz non toxique, non inflammable a basse concentration, volatile et detectable. Objectif Evaluer un test d’etancheite a l’H 2 pour la NOTES transgastrique. Materiels et Methodes Une NOTES transgastrique standardisee (creation d’un pneumoperitoine au CO 2 a travers une aiguille minilaparoscopique, ponction transgastrique a l’aiguille de coupe, dilation au ballonnet de 20 mm, peritoneoscopie souple, suture endoscopique) etait realisee chez 21 porcs. Le test d’etancheite consistait a 1) insuffler endoscopiquement l’estomac a l’H 2 (dilution a 4 %, volume 1 000 ml, pression 30 mmHg) ; 2) prelever un echantillon de 20 ml de pneumoperitoine a travers l’aiguille minilaparoscopique ; 3) analyser la concentration intraperitoneale en H 2 (CIPH 2 ) ; 4) exsuffler le pneumoperitoine. Dans une serie d’experiences sans survie (9 animaux), des tests a l’H 2 etaient repetes aux differentes etapes de l’intervention (basal, post-ponction, avant fermeture) et apres suture de l’abord transgastrique. La suture etait realisee par 2 paires de points en T de facon aleatoirement complete (2 points serres) ou incomplete (1 point serre, 1 lâche). Une necropsie avec test au bleu de methylene (BM) etait realisee. Dans une serie d’experiences avec survie (12 animaux), l’abord transgastrique etait ferme par clips ou points serres, puis un test a l’H 2 realise. Les resultats du test a l’H 2 etaient compares a l’evaluation endoscopique et necropsique a 15 jours. Resultats Les peritoneoscopies et sutures endoscopiques etaient realisees avec succes chez les 21 animaux. Les echantillonages et mesures de CIPH 2 (donnees en ppm) etaient realisees en moins de 2 minutes. Experiences sans survie : les CIPH 2 etaient similaires entre les 2 groupes avant ponction (0,18 ± 0,29 vs 0,22 ± 0,35, p = 0,97) et avant suture (414,8 ± 198,5 vs 601,3 ± 116,1, p > 0,99). Apres suture complete, la CIPH 2 etait significativement plus basse qu’en cas de suture complete incomplete (0,01 ± 0,77 vs 162,0 ± 83,0, p 2 a 25 ppm determinait une correlation parfaite avec les resultats du test au BM. Experiences avec survie : Le test a l’H 2 etait negatif chez 11 animaux (moyenne 4,3 ± 8,1), positif chez 1 animal (106,7 ppm). Aucun animal ne developpait de complication postoperatoire. L’endoscopie et la necropsie confirmaient l’integrite de la fermeture de la gastrotomie chez les 12 animaux. La specificite et la valeur predictive negative du test etaient de 100 % et 95 %, respectivement. Conclusion Le test d’etancheite a l’H 2 est un outil non-invasif, rapide, quantitatif et specifique, adapte a la NOTES. Remerciements, financements, autres Xavier Dray remercie la SNFGE, l’AGA et l’AP-HP.