Mary A. Knipschield

A prospective comparison of capsule endoscopy and push enteroscopy in patients with GI bleeding of obscure origin.

BACKGROUND Capsule endoscopy is used to investigate the small bowel in patients with GI bleeding of obscure etiology. Capsule endoscopy was compared prospectively with push enteroscopy in 20 patients with GI hemorrhage. METHODS Twenty patients (8 men, 12 women; mean age 65.5 years, range 38-80 years) were enrolled in the study. All had undergone non-diagnostic EGD, colonoscopy, and barium contrast radiography of the small bowel. All patients underwent capsule endoscopy followed by push enteroscopy. The physician performing the enteroscopy (senior endoscopist) interpreted the capsule endoscopy in an unblinded manner, while a second blinded reviewer (endoscopy fellow) interpreted the capsule endoscopy to establish interinterpreter reliability. RESULTS There was complete agreement between the blinded and the unblinded physicians in 18 of 20 cases; minor disparities were noted in the remaining two cases. In the small bowel, capsule endoscopy identified positive findings in 14 (70%) patients, whereas, push enteroscopy identified positive findings in 5 (25%) patients. Despite these results, the findings were definitive in only 6 of the 20 patients by using capsule endoscopy, and in two of 20 patients with push enteroscopy. CONCLUSIONS When strict standards of interpretation were used, capsule endoscopy resulted in more positive findings than push enteroscopy, but the number of definitive findings for both imaging methods was low. There was a high degree of reliability between a novice and an experienced endoscopist with respect to the interpretation of capsule endoscopy.

Pilot study of transesophageal endoscopic epicardial coagulation by submucosal endoscopy with the mucosal flap safety valve technique (with videos)

BACKGROUND We previously demonstrated that the thoracic cavity could be safely accessed by submucosal endoscopy with the mucosal flap safety valve (SEMF) technique. OBJECTIVES To evaluate the technical feasibility of transesophageal access to the heart and epicardial ablation. DESIGN One-week survival study with 5 porcine models. SETTINGS Animal laboratory with general anesthesia. INTERVENTIONS High-pressure carbon dioxide injection and balloon dissection created a large submucosal working space for insertion of a cap-fitted endoscope. A myotomy was performed inside the submucosal space. The thoracic cavity was endoscopically accessed through the myotomy site. A pericardial window was created with a needle-knife. A spot coagulation of the epicardium was performed with a heat probe and a hook-knife. The myotomy site was sealed with the overlying mucosal flap, and the mucosal entry site was closed with clips. MAIN OUTCOME MEASUREMENTS An endoscopy and a necropsy were performed to study the esophagus, mediastinum, pericardial space, and cautery locations on the epicardium one week after the procedure. RESULTS Epicardial coagulation was successfully performed within 30 minutes in 4 of the 5 pigs. Follow-up endoscopy demonstrated completely sealed myotomy sites by the overlying mucosal flap. There was no gross contamination or signs of contamination in the thoracic cavity. The pericardial space was normal in appearance. The epicardial coagulation sites were healing, without exudative ulceration. CONCLUSIONS The SEMF technique allowed endoscopic access to the upper mediastinum, the pericardium, and the epicardium via the esophagus, along with a minimal intervention on the epicardium.

Cholangioscopy with narrow-band imaging in patients with primary sclerosing cholangitis undergoing ERCP

BACKGROUND Patients with primary sclerosing cholangitis (PSC) have an increased lifetime risk of cholangiocarcinoma (CCA). Detection of localized CCA in patients with PSC may result in curative liver transplantation. Recently, high-resolution per-oral video cholangioscopy (PVCS) has become available and may be useful for evaluating for biliary dysplasia. Narrow-band imaging (NBI) has shown promising results in detecting dysplasia in the esophagus and colon, but its utility in the bile duct is unproven. OBJECTIVE Evaluate NBI video PVCS in screening for dysplasia in patients with PSC. DESIGN Prospective case series. SETTING Tertiary-care referral center. PATIENTS Patients with PSC undergoing ERCP between December 2008 and July 2010. INTERVENTION ERCP with white-light and NBI PVCS and biopsy of suspicious lesions. MAIN OUTCOME MEASUREMENTS Dysplasia detection. RESULTS A total of 30 patients were enrolled. Median follow-up was 319.5 days. Four patients had a final diagnosis of CCA (2 extrahepatic, 2 intrahepatic). NBI visualized the 2 extrahepatic CCAs and allowed determination of tumor margins. The bile duct mucosa by NBI visual appearance in patients with PSC was variable. No correlation with CCA development could be determined. There was a 48% increase in suspicious lesions biopsied with NBI compared with white-light imaging, although NBI-directed biopsies did not improve the dysplasia detection rate. LIMITATIONS Small sample size, single center, referral bias. CONCLUSION NBI allowed visualization of tumor margins in CCA as compared with traditional fluoroscopy-based ERCP. An improvement in dysplasia detection in patients with PSC could not be demonstrated despite an increase in the biopsy rate. Additional experience is needed to assess the utility of NBI in screening for CCA in patients with PSC. ( CLINICAL TRIAL REGISTRATION NUMBER NCT00951327.).

Chemically assisted endoscopic mechanical submucosal dissection by using mesna.

BACKGROUND A class of thiol compounds, mesna (sodium-2-mercaptoethanesulfonate), has been used to facilitate tissue dissection in surgical fields. OBJECTIVES To evaluate the technical feasibility and efficacy of chemically assisted endoscopic mechanical submucosal dissection (CAEMSD) by using mesna. DESIGN An in vivo controlled blind trial by using porcine models. SETTINGS Nonsurvival study in an animal laboratory. INTERVENTIONS Six pigs were studied. Mucosal targets of about 2 cm (estimated) for treatment were created with a circle of cauterized spots along the greater curvature of the gastric body and the antrum. A mesna solution or the control hydroxypropyl methylcellulose solution was submucosally injected. The target mucosa was mechanically isolated with balloon dissection and removed by circumferential incision with a hook-knife inserted into the submucosal space. Necropsy and mucosal specimens from both groups were examined by histology. RESULTS En bloc resection of the target was achieved in all 8 attempts of the mesna group and in 7 of 8 attempts of the control group. Use of mesna significantly reduced tissue resistance to the initial balloon-catheter insertion into the submucosa and the technical difficulty of subsequent submucosal balloon dissection by using a subjective grading system (P < .05). There was no difference in histology between both groups. CONCLUSIONS CAEMSD is a unique methodology to facilitate mucosal resection.

Endoscopic full-thickness biopsy of the gastric wall with defect closure by using an endoscopic suturing device: survival porcine study

BACKGROUND The pathogenesis of several common gastric motility diseases and functional GI disorders remains essentially unexplained. Gastric wall biopsies that include the muscularis propria to evaluate the enteric nervous system, interstitial cells of Cajal, and immune cells can provide important insights for our understanding of the etiology of these disorders. OBJECTIVES To determine the technical feasibility, reproducibility, and safety of performing a full-thickness gastric biopsy (FTGB) by using a submucosal endoscopy with mucosal flap (SEMF) technique; the technical feasibility, reproducibility, and safety of tissue closure by using an endoscopic suturing device; the ability to identify myenteric ganglia in resected specimens; and the long-term safety. DESIGN Single center, preclinical survival study. SETTING Animal research laboratory, developmental endoscopy unit. SUBJECTS Twelve domestic pigs. INTERVENTIONS Animals underwent an SEMF procedure with gastric muscularis propria resection. The resultant offset mucosal entry site was closed by using an endoscopic suturing device. Animals were kept alive for 2 weeks. MAIN OUTCOME MEASUREMENTS The technical feasibility, reproducibility, and safety of the procedure; the clinical course of the animals; the histological and immunochemical evaluation of the resected specimen to determine whether myenteric ganglia were present in the sample. RESULTS FTGB was performed by using the SEMF technique in all 12 animals. The offset mucosal entry site was successfully closed by using the suturing device in all animals. The mean resected tissue specimen size was 11 mm. Mean total procedure time was 61 minutes with 2 to 4 interrupted sutures placed per animal. Histology showed muscularis propria and serosa, confirming full-thickness resections in all animals. Myenteric ganglia were visualized in 11 of 12 animals. The clinical course was uneventful. Repeat endoscopy and necropsy at 2 weeks showed absence of ulceration at both the mucosal entry sites and overlying the more distal muscularis propria resection sites. There was complete healing of the serosa in all animals with minimal single-band adhesions in 5 of 12 animals. Retained sutures were present in 10 of 12 animals. LIMITATIONS Animal experiment. CONCLUSIONS FTGB by using the SEMF technique and an endoscopic suturing device is technically feasible, reproducible, and safe. Larger tissue specimens will allow improved analysis of multiple cell types.

Omentum patch substitute for facilitating endoscopic repair of GI perforations: an early laparoscopic pilot study with a foam matrix plug (with video).

BACKGROUND Endoscopic perforations are surgically repaired by using an omentum patch. Omentum substitutes may have broader applications particularly in certain sites (eg, esophagus). OBJECTIVE Evaluate a self-expandable foam matrix plug as a synthetic omentum substitute for repairing iatrogenic gastric perforations in a 4-week survival pig model. DESIGN Experimental pilot study. SETTING Laboratory. INTERVENTION A laparoscopic plug repair of a 1-cm, full-thickness, gastric perforation was carried out by using either a polyurethane foam matrix plug (FMP, 8 animals) or an omentum plug (OP, 6 animals, control group). MAIN OUTCOME MEASUREMENTS Follow-up endoscopy was carried out at 1 and 4 weeks. At necropsy, the perforation site was evaluated for adhesions and histology by using hematoxylin and eosin analysis. A portion of the implant was sent for bacterial and fungal culture. RESULTS All procedures were technically simple and successful. Thirteen animals thrived well for 4 weeks. One animal from the FMP group died 3 days postoperatively from diffuse peritonitis because of a misplaced plug. All remaining FMPs were intact at 4 weeks and colonized with mixed bacteria, except one animal presenting with FMP migration after 1 week. Histologically, the FMP group had more prominent inflammation and suppuration as compared with the OP group, all limited to its adjacent tissue. LIMITATIONS Animal study. CONCLUSION The FMP offered a technically simple and feasible option for repairing iatrogenic gastric perforations. With effective sealing, the clinical outcome is similar to that of an omentum patch repair. Migration and inadequate sealing is a concern, which can lead to peritonitis and sepsis. Further development is needed to improve FMP performance.

Transcolonic peritoneoscopy by using submucosal endoscopy with mucosal flap for the detection of peritoneal bead targeting in the porcine survival model: a feasibility and effectiveness study

BACKGROUND Staging peritoneoscopy is typically done by laparoscopy in the operating room. Natural orifice transluminal endoscopic surgery peritoneoscopy is an appealing alternative to the current approach. Transcolonic submucosal endoscopy with mucosal flap (SEMF) may provide natural orifice transluminal endoscopic surgery peritoneoscopy. OBJECTIVE The aim was to verify the feasibility and safety of transcolonic peritoneoscopy with SEMF (TCPS) in a porcine survival model. DESIGN Survival study. SETTING Animal research unit. INTERVENTION Seven target beads were placed in the peritoneal cavity by laparoscopy in each of 6 animals, and TCPS was performed to identify and touch beads to simulate biopsy. Animals were euthanized after 1 week, at which time, laparotomy was performed and the SEMF site was resected for histological analysis. MAIN OUTCOME MEASUREMENTS The number of beads identified and touched during peritoneoscopy, rate of successful completion of TCPS, procedure time, mortality equivalent 1 week after TCPS, adverse event rate, histological assessment of SEMF site. RESULTS All 7 beads in all 6 pigs were identified and touched during TCPS. The success rate of TCP was 100%. No major adverse events occurred during the procedure. The median procedure times for the creation of a submucosal tunnel, peritoneoscopy, closure of mucosal incision, and entire procedure were 19.5, 17, 9.5, and 45 minutes, respectively. All pigs survived until euthanasia, and there was no evidence of peritonitis or severe infection. LIMITATIONS Animal study, single endoscopist, small sample size. CONCLUSION Results of this study indicate that TCPS is feasible and safe in a porcine survival model.

In Vivo Full-Thickness Endoluminal Gastroplication Using Tissue Anchors in a Live Pig Model

In Vivo Full-Thickness Endoluminal Gastroplication Using Tissue Anchors in a Live Pig Model Jose G. De la Mora, Elizabeth Rajan, David Rea, Thomas C. Smyrk, Lori J. Herman, Jodie L. Deters, Mary A. Knipschield, Christopher J. Gostout Background: Long-term success of gastric wall apposition performed by flexible endoscopy is dependent on fold permanence. Prior work by our group demonstrated that only full-thickness folds with serosal apposition are durable. Aim: To study feasibility of different tissue anchors to create a full thickness inverted fold and the durability of each single fold plication. Material & Methods: Four 35-45 Kg female pigs were used. Under anesthesia a midline abdominal incision was performed. A 5-cm incision parallel to the greater curvature of the stomach was made. The posterior wall was exposed and longitudinal folds were created by indenting the wall from the serosal side (inverted fold) 1.5 cm in height and 5 cm long. Anchors were deployed to traverse the inverted gastric wall, including apposing serosal surfaces within the fold. Anchors were 1 cm apart with 3-4 of the same type used per fold. 4-6 folds were made in each pig. Four types of paired anchors joined with suture (prolene 2-0) were used: T-bar (T); polypropylene mesh pledget (TM); plastic star-shaped buttons (S) and a self-expanding nitinol basket (B). Suture (vicryl 2-0) for incision closure was used to control for tissue reaction. Follow-up endoscopy was done at 15, 30 and 60 days. Two pigs were sacrificed each at 30 and 60 days. Macroscopic description of the folds was done and samples of the folds sent for histology. Results: Day 15: all folds were still present endoscopically. Day 30: S and B folds were unchanged, TM folds were reduced in height, and T folds had flattened. Day 60: only S & B folds remained. Histologically, all B folds included the muscle layer (30 & 60 day specimens) and one developed serosal fusion (30-day specimen). Only one S fold included the muscle layer with serosal fusion at 60 days. Conclusions: The durability of endoluminally placed full thickness inverted folds remains a challenge. Serosal apposition remains requisite for fold permanence. The use of tissue anchors such as the S and B designs may help achieve greater durability for endoscopic gastric remodeling by tissue apposition. Abstracts

Randomized controlled trial comparing submucosal endoscopy with mucosal resection and endoscopic submucosal dissection in the esophagus and stomach: Animal study

In Western countries, endoscopic submucosal dissection (ESD) has not prevailed as a result of training problems and a target patient population. We have previously reported a hybrid ESD technique, submucosal endoscopy with mucosal resection (SEMR), in which the submucosal dissection is carried out chiefly by blunt balloon dissection. We have also reported successful application in the porcine colon. In the present study, we compared the safety and efficacy of SEMR with ESD in the porcine esophagus and stomach.