Laparoscopic right colectomy vs laparoscopic-assisted colonoscopic polypectomy for endoscopically unresectable polyps: a randomized controlled trial.

AIM: A randomized controlled trial (RCT) was conducted to test the null hypothesis that there is no difference in complication rates and length of stay (LOS) between laparoscopic right colectomy (LRC) and laparoscopic-assisted colonoscopic polypectomy (LACP) for endoscopically unresectable polyps of the right colon. METHOD: A single-centre RCT (NCT01986699) was conducted on patients with polyps of the right colon deemed by the gastroenterologist to be unresectable. Patients underwent a repeat colonoscopy with biopsy by an interventional endoscopist and were allocated to LRC or LACP. Patients with a nonlift sign, dysplasia, adenocarcinoma, inflammatory bowel disease or familial adenomatous polyposis were excluded from the trial. The study was powered to detect a 73% difference in the LOS which required 17 patients in each arm with an α error of 0.05 and a power of 95%. RESULTS: Thirty-four patients were comparable for age (P = 0.919), gender (P = 0.364), body mass index (P = 0.634), American Society of Anesthesiologists class (P = 0.388) and previous abdominal surgery (P = 0.366). There was no significant difference in the preoperative morphology (P = 0.485), location (P = 0.297), size (P = 0.690) or histology of the polyps (P = 0.779). LRC patients experienced a longer operating time (180 vs 90 min; P = 0.001), required more intravenous infusion (3.1 vs 2.0 l; P = 0.025), took significantly longer to pass flatus (2.88 vs 1.44 days; P < 0.001), resumed solid food later (3.94 vs 1.69 days; P < 0.001) and had a longer postoperative LOS (4.94 vs 2.63 days; P < 0.001). Postoperative complications (P = 0.656), readmissions (P = 0.5) and reoperations (P = 0.5) did not differ. Final size (P = 0.339) and histology (P = 0.104) of the polyps did not differ. There were four cancers in the LRC arm. At follow-up colonoscopy with biopsy of the scar in 10 patients at 15.3 months, one patient had recurrence of the polyp at the site of the previous LACP. CONCLUSION: LACP and LRC had similar complication rates, but LOS was shorter after LACP.

Simulated colonoscopy training using a low-cost physical model improves responsiveness of surgery interns.

AIM: Surgery residents are required to become proficient in colonoscopy before completing training. The aim of this study was to evaluate the responsiveness of surgery interns to simulated colonoscopy training. METHOD: Interns, defined as postgraduate year 1 residents without exposure to endoscopy, underwent training in a physical model including colonoscopy, synthetic anatomy trays with luminal tattoos and a hybrid simulator. After baseline testing and mentored training, final testing was performed using five predetermined proficiency criteria. Content-valid metrics defined by the extent of departure from clinical reality were evaluated by two blinded assessors. Responsiveness was defined as change in performance over time and assessed comparing baseline testing with nonmentored final testing. RESULTS: Twelve interns (eight male, mean age 26, 80% right-handed) performed 48 colonoscopies each over 1 year. Improvement was seen in the overall procedure time (24 min 46 s vs 20 min 54 s; P = 0.03), passing the splenic flexure (20 min 33 s vs 10 min 45 s; P = 0.007), passing the hepatic flexure (23 min 31 s vs 12 min 45 s; P = 0.003), caecal intubation time (23 min 38 s vs 13 min 26 s; P = 0.008), the duration of loss of view of the lumen (75% vs 8.3%; P = 0.023), incomplete colonoscopy (100% vs 33.3%; P = 0.042), colonoscope withdrawal < 6 min (16.7% vs 8.3%; P = 0.052). Tattoo identification time (9 min 16 s vs 12 min 25 s; P = 0.50), colon looped time (2 min 12 s vs 1 min 45 s; P = 0.50) and rate of colon perforation (8.3% vs 8.3%; P = 1) remained unchanged. Interrater reliability was 1.0 for all measures. CONCLUSION: Simulated colonoscopy training in a low-cost physical model improved the performance of surgery interns with decreased procedure time, increased rates of complete colonoscopy and appropriate scope withdrawal.

The spiral enteroscopy training initiative: results of a prospective study evaluating the Discovery SB overtube device during small bowel enteroscopy (with video).

BACKGROUND AND AIM: Indications for small-bowel enteroscopy are increasing, but advancing the endoscope to the ileum remains challenging, especially for less experienced operators. The aim was to evaluate the ease of use, safety, and efficacy of the Discovery SB overtube (Spirus Medical, Stoughton, Massachusetts, USA) during SB enteroscopy by physicians with no experience of the device. PATIENTS AND METHODS: Thirty-three "untrained" endoscopists performed spiral enteroscopy during one of four 2-day training modules. Data were prospectively collected. Patient demographics, depth and time to maximal insertion, total procedure time, and findings were recorded. Trauma was documented during scope withdrawal. Day 1 and day 2 results were compared. RESULTS: Ninety procedures were successfully performed in 95 patients (72.6 % women, age = 48.8 +/- 14.2 years). Endoscopists each performed a mean of five procedures. Mean time to maximal insertion was 20.9 +/- 6.4 minutes. Mean depth achieved was 262.0 +/- 57.4 cm. Total procedure time was 33.6 +/- 8.0 minutes. In 90.3 %, 94.6 %, and 83.9 % of patients, respectively, a trauma score less than 3 was recorded in the esophagus, stomach, and intestine (scale = 0 - 5). There were no perforations, nor significant associations between trauma score and patient age, body mass index, depth of insertion, time to maximal insertion, total procedure time, or day 1 vs. day 2 procedures. Depth of insertion was greater on day 2 than on day 1 (276.9 +/- 53.7 cm vs. 252.0 +/- 58.0 cm, P = 0.043). CONCLUSIONS: Discovery SB provides safe advancement of the enteroscope into the distal small bowel. Maximum depth of insertion appears comparable to that of balloon enteroscopy while taking less time. The device is easy to use and may be effectively operated in as few as five training cases.

Endoscopic retrograde cholangiopancreatography, but not esophagogastroduodenoscopy or colonoscopy, significantly increases portal venous pressure: direct portal pressure measurements through endoscopic ultrasound-guided cannulation.

BACKGROUND AND STUDY AIMS: Changes in portal pressure during endoscopy have not been previously evaluated. The aims of this study were to assess the effect of esophagogastroduodenoscopy (EGD), colonoscopy, and endoscopic retrograde cholangiopancreatography (ERCP) on portal vein, inferior vena cava (IVC), and systemic pressures. PATIENTS AND METHODS: Five acute experiments were performed on 50-kg pigs utilizing endoscopic ultrasound (EUS)-guided catheterization of the portal vein and IVC. Systemic, intra-abdominal, IVC, and portal vein pressures were monitored during colonoscopy, EGD, and ERCP with endoscopic sphincterotomy. After endoscopy the animals were sacrificed for necropsy. The main outcome measure was pressure change during each type of endoscopic procedure. RESULTS: There were no significant changes in heart rate or systemic pressure during all endoscopic procedures. Intra-abdominal pressure increased during colonoscopy ( P = 0.02) and ERCP ( P = 0.007). However, mean portal venous pressure was significantly elevated only after the injection of contrast into the common bile duct, reaching its peak value at the time of biliary sphincterotomy (39.0 +/- 15.2 mm Hg vs. 13.4 +/- 3.6 mm Hg at baseline, P = 0.006). Mean peak IVC pressure was also elevated during ERCP, but it did not reach statistical significance (24.0 +/- 10.7 mm Hg vs. 12.6 +/- 4.1 mm Hg at baseline, P = 0.06). CONCLUSION: EGD and colonoscopy did not cause significant changes in portal vein, IVC, or systemic pressures. ERCP with biliary sphincterotomy increased portal pressure with only limited effect on IVC and systemic pressures. These new data indicate a possible connection between ERCP with sphincterotomy and portal pressure, and may be clinically important for patients with liver disease and other causes of portal hypertension who undergo this procedure.

Severity of post-ERCP pancreatitis directly proportional to the invasiveness of endoscopic intervention: a pilot study in a canine model.

BACKGROUND AND STUDY AIMS: Pancreatitis complicates 1% - 22% of endoscopic retrograde cholangiopancreatography procedures. The study aims were to develop a reproducible animal model of post-ERCP pancreatitis (PEP), and investigate the impact of endoscopic technique on severity of PEP. PATIENTS AND METHODS: ERCP was carried out in six male hound dogs. Pancreatitis was induced by one of three escalating methods: 1) pancreatic acinarization with 20 - 30 mL of contrast; 2) acinarization + ductal balloon occlusion + sphincterotomy; 3) acinarization + intraductal synthetic bile injection + ductal balloon occlusion + sphincterotomy. Dogs 5 and 6 received a pancreatic stent. Necropsy was performed on postoperative day 5. All pancreatic specimens were graded by two blinded pathologists according to a validated scoring system. All dogs were compared with three control dogs. RESULTS: Dogs 1 - 4 developed clinical pancreatitis and hyperamylasemia (11 736 vs. 722 U/L, P = 0.02). Total injury scores were significantly elevated compared with controls (6.85 vs. 1.06, P = 0.004). There was significant increase in acinar cell necrosis (0.86 vs. 0.06, P = < 0.001), and all other categories (except fibrosis) demonstrated elevated injury scores . Dogs 5 and 6 developed clinical pancreatitis without significant hyperamylasemia; total injury scores were elevated compared with controls (4.83 vs. 1.06, P = 0.01), but lower than in Dogs 1 - 4 (4.83 vs. 6.85, P = 0.25). There was escalating severity of pancreatic injury from Dogs 1 to 4 correlating with the method of endoscopic injury used. CONCLUSION: Severity of PEP is directly proportional to invasiveness of endoscopic intervention. Pancreatic acinarization, even without balloon occlusion and sphincterotomy, can be used as a reliable animal model for future studies investigating therapy and prevention of disease.

Preliminary pneumoperitoneum facilitates transgastric access into the peritoneal cavity for natural orifice transluminal endoscopic surgery: a pilot study in a live porcine model.

BACKGROUND AND STUDY AIMS: Safe entrance into the peritoneal cavity through the gastric wall is paramount for the successful clinical introduction of natural orifice transluminal endoscopic surgery (NOTES). The aim of the study was to develop alternative safe transgastric access to the peritoneal cavity. PATIENTS AND METHODS: We performed 11 survival experiments on 50-kg pigs. In sterile conditions, the abdominal wall was punctured with a Veress needle. The peritoneal cavity was insufflated with 2 L carbon dioxide (CO (2)). A sterile endoscope was introduced into the stomach through a sterile overtube; the gastric wall was punctured with a needle-knife; after balloon dilation of the puncture site, the endoscope was advanced into the peritoneal cavity. Peritoneoscopy with biopsies from abdominal wall, liver and omentum, was performed. The endoscope was withdrawn into the stomach. The animals were kept alive for 2 weeks and repeat endoscopy was followed by necropsy. RESULTS: The pneumoperitoneum, easily created with the Veress needle, lifted the abdominal wall and made a CO (2)-filled space between the stomach and adjacent organs, facilitating gastric wall puncture and advancement of the endoscope into the peritoneal cavity. There were no hemodynamic changes or immediate or delayed complications related to pneumoperitoneum, transgastric access, or intraperitoneal manipulations. Follow-up endoscopy and necropsy revealed no problems or complications inside the stomach or peritoneal cavity. CONCLUSIONS: Creation of a preliminary pneumoperitoneum with a Veress needle facilitates gastric wall puncture and entrance into the peritoneal cavity without injury to adjacent organs, and can improve the safety of NOTES.

The utility of contrast-enhanced endoscopic ultrasound in monitoring ethanol-induced pancreatic tissue ablation: a pilot study in a porcine model.

BACKGROUND AND STUDY AIMS: Pancreatic ablation is gaining popularity for the treatment of focal pancreatic lesions. The aim of our study was to evaluate local effects of intrapancreatic alcohol injection and the utility of contrast-enhanced endoscopic ultrasound (EUS) for its monitoring in a porcine model. METHODS: We performed four survival experiments on 50-kg pigs. Under linear EUS guidance, 0.5 mL of 50% ethanol plus purified carbon particle solution (GI Spot) was injected into the pancreatic body to create a focal area of pancreatic necrosis. The animals survived for 24-48 hours (pigs # 1, # 2, and # 3) and 7 days (pig # 4). EUS was then repeated with and without perflutren lipid microspheres (Definity) administration through the peripheral vein. Standard and microsphere-enhanced images of the pancreas were compared. Afterwards the animals were euthanized for necropsy. RESULTS: Alcohol injection caused focal pancreatic necrosis, which was barely seen by standard EUS as a subtle hypoechoic lesion 1 cm in diameter. Color and power Doppler EUS of this region did not reveal any blood flow. After intravenous injection of microspheres, color Doppler EUS revealed marked contrast enhancement of normal pancreatic parenchyma with a clearly delineated avascular alcohol-treated area, which on postmortem examination corresponded to the discrete necrotic area marked with carbon particles. CONCLUSIONS: EUS-guided alcohol injection consistently causes focal areas of pancreatic necrosis. Contrast-enhanced EUS with microspheres improves visualization of altered pancreatic vascular perfusion and can be used to facilitate detection of small pancreatic lesions and its follow-up post-ablation.

Is blood the ideal submucosal cushioning agent? A comparative study in a porcine model.

BACKGROUND AND STUDY AIMS: Creation of a submucosal cushion before endoscopic mucosal resection (EMR) significantly reduces perforation risk. We evaluated six solutions as cushioning agents in live pigs. MATERIAL AND METHODS: 5 ml of normal saline, normal saline plus epinephrine, albumin 12.5 %, albumin 25 %, hydroxypropyl methylcellulose, and the pig's own whole blood were endoscopically injected into the porcine esophageal submucosa. Blood was obtained from a peripheral vein immediately before injection. Injections were made every 4 cm from the gastroesophageal junction. The time from completion of the injection to disappearance of the cushion was recorded. Endoscopy was repeated at 48 hours post injection. Two EMRs were performed after blood injection. Statistical analysis employed one-way analysis of variance followed by pairwise T test comparisons using the Bonferroni correction. RESULTS: Five animal experiments were completed. The mean time to dissipation of the submucosal cushion was shortest for saline plus epinephrine sites (2.87 minutes, SD 2.21) followed by the saline (4.8 minutes, SD 1.56), albumin 12.5 % (5.68 minutes, SD 3.48), albumin 25 % (7.83 minutes, SD 2.02), hydroxypropyl methylcellulose (9.77 minutes, SD 1.55), and blood sites (38.6 minutes, SD 6.07). Injection of blood resulted in significantly longer mucosal elevation than any other solution ( P < 0.0007). Blood from the cushion did not hamper visualization and facilitated EMR. CONCLUSION: Blood produces the most durable cushion compared with standard agents, also having the advantages of being readily available and without cost. Albumin 25 % provides as durable a cushion as hydroxypropyl methylcellulose.