Conventional Versus Traction Endoscopic Submucosal Dissection for Colorectal Tumors: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Compared with conventional endoscopic submucosal dissection (C-ESD) for colorectal lesions, the traction method (T-ESD) allows the lesion to be stabilized with easier dissection. However, randomized controlled trials (RCTs) have reported conflicting results on the clinical outcomes of T-ESD as compared with C-ESD. We conducted a meta-analysis to compile the data.

METHODS

Multiple databases were searched for RCTs evaluating C-ESD versus T-ESD for colorectal tumors. The end points of interest were procedure time (min), resection speed (mm²/min), R0 resection, en bloc resection, delayed bleeding, and perforation. Standard meta-analysis methods were employed using the random-effects model.

RESULTS

Six RCTs with a total of 566 patients (C-ESD n=284, T-ESD n=282) were included. The mean age was 67±10 y and 60% were men. As compared with the T-ESD technique, the C-ESD group was associated with longer procedure time (SMD 0.91, 95% CI 0.58 to 1.23, P<0.00001) and lesser resection speed (SMD -1.03, 95% CI -2.01 to -0.06, P=0.04). No significant difference was found in the 2 groups with respect to R0 resection rate (RR 1.00, 95% CI 0.94 to 1.06, P=0.87), en bloc resection (RR 0.99, 95% CI 0.97 to 1.01, P=0.35), delayed bleeding (RR 0.66, 95% CI 0.17 to 2.59, P=0.55) and perforation (RR 2.16, 95% CI 0.75 to 6.27, P=0.16).

DISCUSSION

On meta-analysis, pooled procedure time was significantly faster with T-ESD compared with C-ESD. The clinical outcomes, however, were comparable.

The Development of the Overstitch System and Its Potentials

Endoscopic suturing device for flexible endoscopy was conceptualized by Apollo Group in collaboration with Olympus Optical Ltd. The first modification of suturing device for flexible endoscopy (Eagle Claw) was manufactured by Olympus engineers and extensively used by members of Apollo Group in numerous bench-top experiments on isolated pig stomachs and in live porcine model. The suturing system for flexible endoscopy in humans (Overstitch) was cleared for general clinical use in the United States in 2008. The latest model is compatible with more than 20 single-channel flexible endoscopes with diameters ranging from 8.8 mm to 9.8 mm made by major endoscope manufacturers.

Esophageal capsule endoscopy is not the optimal technique to determine the need for primary prophylaxis in patients with cirrhosis

INTRODUCTION

Capsule endoscopy has been suggested as a potential alternative to endoscopy for detection of esophagogastric varices and severe portal hypertensive gastropathy (PHG). The aim of the study was to determine whether PillCam esophageal capsule endoscopy could replace endoscopy for screening purposes.

MATERIAL AND METHODS

Sixty-two patients with cirrhosis with no previous variceal bleeding had PillCam capsule endoscopy and video endoscopy performed on the same day. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of capsule endoscopy were compared to endoscopy for the presence and severity of esophageal and gastric varices, PHG and the need for primary prophylaxis. Patients' preference was assessed by a questionnaire.

RESULTS

Four (6%) patients were unable to swallow the capsule. Sensitivity, specificity, PPV and NPV of capsule endoscopy for detecting any esophageal varices (92%, 50%, 92%, 50%), large varices (55%, 91%, 75%, 80%), variceal red signs (58%, 87%, 69%, 80%), PHG (95%, 50%, 95%, 50%), and the need for primary prophylaxis (91%, 57%, 78%, 80%) were not optimal, with only moderate agreement (κ) between capsule and upper GI endoscopy. Had only a capsule endoscopy been performed, 12 (21.4%) patients would have received inappropriate treatment. Capsule endoscopy also failed to detect (0/13) gastric varices. The majority of patients ranked capsule endoscopy as more convenient (69%) and their preferred (61%) method.

CONCLUSIONS

Despite the preference expressed by patients for capsule endoscopy, we believe that upper GI endoscopy should remain the preferred screening method for primary prophylaxis.

New endoscopic platform for endoluminal en bloc tissue resection in the gastrointestinal tract (with videos)

BACKGROUND

Endoscopic removal of gastrointestinal tract lesions is increasingly popular around the world. We evaluated feasibility, safety, effectiveness, and user learning curve of new endoscopic platform for complex intraluminal interventions.

METHODS

A novel system, consisting of expandable working chamber with two independent instrument guides (LIG), was inserted into colon. Simulated colonic lesions were removed with endoscopic submucosal (ESD) and submuscular (ESmD) dissection.

RESULTS

In all nine in vivo models, an intraluminal chamber and its dynamic tissue retractors (via LIG) provided a stable working space with excellent visualization and adequate access to target tissue. Endoscopic platform facilitated successful completion of 11 en bloc ESDs (mean size 43.0 ± 11.3 mm, mean time 46.3 ± 41.2 min) and eight ESmD (mean size 50.0 ± 14.1 mm, mean time 48.0 ± 21.2 min). The learning curve for ESD using this platform demonstrated three phases: rapid improvement in procedural skills took place during the first three procedures (mean ESD time 98.7 ± 40.0 min). A plateau phase then occurred (procedures 4-7) with mean procedure time 42.0 ± 13.4 min (p = 0.04), followed by another sharp improvement in procedural skills (procedures 8-11) requiring only 16.3 ± 11.4 min (p = 0.03) to complete ESD. Especially dramatic (p = 0.002) was the time difference between the first three procedures (mean time 98.7 ± 40.0 min) and subsequent eight procedures (mean time 29.1 ± 17.9 min).

CONCLUSIONS

A newly developed endoscopic platform provides stable intraluminal working space, dynamic tissue retraction, and instrument triangulation, improving visualization and access to the target tissue for safer and more effective en bloc endoscopic submucosal and submuscular dissection. The learning curve for ESD was markedly facilitated by this new endoscopic platform.

Nonsurgical treatment of actively bleeding internal hemorrhoids with a novel endoscopic device (with video)

BACKGROUND

Internal hemorrhoids often present with bleeding, prolapse, and other symptoms. Currently used nonsurgical treatment modalities have limited effectiveness and usually require several treatment sessions.

OBJECTIVE

To evaluate effectiveness and safety of a novel endoscopic device for nonsurgical treatment of internal hemorrhoids.

DESIGN

Retrospective study.

SETTING

Single center.

PATIENTS

This study involved 23 patients with actively bleeding internal hemorrhoids.

INTERVENTION

The HET Bipolar System is a modified anoscope, with a treatment window, light source, and tissue temperature monitor. The device is inserted into the rectum under direct observation. The tissue carrying superior hemorrhoidal branches and the apex of the internal hemorrhoid is positioned inside the treatment window, clamped with incorporated tissue forceps, and treated with bipolar energy to ligate hemorrhoidal feeding vessels.

MAIN OUTCOME MEASUREMENTS

Rate of hemorrhoidal bleeding after the treatment.

RESULTS

The mean age of the patients was 64.3 ± 9.9 years (range 44-79 years). Eleven patients (47.8%) had grade I hemorrhoids and 12 patients (52.2%) had grade II hemorrhoids. In 18 patients (78.3%), treatment with the HET System was performed with the patient under conscious sedation. Five patients (21.7%) were treated without sedation. All patients tolerated treatment without complaints. The average follow-up period was 11.2 ± 4.7 months. No bleeding or prolapse occurred after the procedure in any of the treated patients.

LIMITATIONS

Retrospective study.

CONCLUSION

The newly developed HET System is easy to use, safe, and highly effective in eliminating bleeding in grade I and II internal hemorrhoids and prolapse in grade II internal hemorrhoids.

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.

The role of the U.S. Food and Drug Administration in device evaluation and monitoring

The American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee provides reviews of existing, new, or emerging endoscopic technologies that have an impact on the practice of GI endoscopy. Evidence-based methodology is used by performing a MEDLINE literature search to identify pertinent clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Technology Status Evaluation Reports are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. When financial guidance is indicated, the most recent coding data and list prices at the time of publication are provided. For this review, the MEDLINE database was searched through October 2009 for articles and references related to devices and the U.S. Food and Drug Administration by using the keywords "FDA" and "devices." In addition, the Web was searched using the same keywords. The U.S. Food and Drug Administration website was also thoroughly reviewed. Practitioners should continue to monitor the medical literature for subsequent data about these issues. Technology Status Evaluation Reports are scientific reviews provided solely for educational and informational purposes. Technology Status Evaluation Reports are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Interventional EUS

The American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee provides reviews of new or emerging endoscopic technologies that have the potential to have an impact on the practice of GI endoscopy. Evidence-based methodology is used by performing a MEDLINE literature search to identify pertinent preclinical and clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but, in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. For this review, the MEDLINE database was searched through August 2009 by using the keywords "interventional endoscopic ultrasound," "EUS," and "interventional endoscopy." Reports on Emerging Technologies are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. These reports are scientific reviews provided solely for educational and informational purposes. Reports on Emerging Technologies are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Infection during natural orifice transluminal endoscopic surgery: a randomized, controlled study in a live porcine model

BACKGROUND

Currently reported natural orifice transluminal endoscopic surgery (NOTES) procedures in animals have been done in heterogeneous milieus ranging from nonsterile to sterile procedures, with mixed results, including no infection in those performed in nonsterile settings.

OBJECTIVE

To establish the potential frequency of infection during NOTES, comparing sterile to nonsterile approaches.

SETTING

Survival experiments on sixteen 50-kg pigs.

DESIGN AND INTERVENTIONS

From pilot data (100% infection frequency after nonsterile procedures), sample size (8 animals in each group) was calculated by using a power of 95% and an alpha risk of 0.05. The animals were randomly assigned to two groups: In the transgastric peritoneoscopy study group, liver and ovarian biopsies were performed with sterile overtubes, endoscopes, and accessories and the use of preoperative intravenous antibiotics and antiseptic gastric lavage. In the nonsterile (control) group, the same procedures were performed with nonsterile endoscopes and accessories without the use of gastric lavage and preoperative antibiotics. Complete transmural closure of the transgastric access site was made in all animals. After a 1-week survival time, all animals were killed for necropsy, which included Gram staining and peritoneal cultures.

MAIN OUTCOME MEASUREMENTS

Intraperitoneal infection on necropsy.

RESULTS

All necropsies revealed intraperitoneal infection (abscesses, fibrinopurulent exudates, and adhesions) in the control group (frequency of infection 100%). Peritoneal bacterial culture grew various aerobic and anaerobic organisms. No gross or bacteriological evidence of infection was seen in the sterile group (frequency of infection 0%, P value = <.0002).

LIMITATIONS

Animal experiments.

CONCLUSION

Nonsterile conditions invariably lead to intraperitoneal infection. Aseptic techniques during NOTES can prevent intra-abdominal infection. Future studies will determine which infection prevention steps are mandatory and which can be omitted during NOTES procedures.

Are large side holes associated with reduced rates of pancreatic stent occlusion? Results of a prospective study

CONTEXT

Pancreatic stents are frequently clogged at the time of removal. There is limited data regarding the factors associated with stent occlusion.

OBJECTIVES

To estimate the frequency of stent occlusion at the time of removal, to study the accuracy of endoscopic prediction of occlusion, and to determine the factors associated with clogged pancreatic stents.

SETTING

Consecutive patients at 4 academic medical centers undergoing removal of a previously placed pancreatic stent were prospectively enrolled.

PATIENTS

A total of 68 patients were enrolled between August 2007 and July 2008.

INTERVENTIONS

Following removal, stent occlusion was immediately assessed by complete lack of water flow from the duodenal end and side holes of the stent.

MAIN OUTCOME MEASURE

Survival analysis was performed using a Kaplan-Meier and Cox Regression model.

RESULTS

Indications for stent placement included chronic pancreatitis (n=23), pancreatic duct leak (n=7), prevention of post-ERCP pancreatitis (n=28), pseudocyst drainage (n=1), pancreas divisum (n=8), and pancreatic duct stricture without chronic pancreatitis (n=1). Standard Geenen (Cook Endoscopy, Winston-Salem, NC, USA) pancreatic stents were placed in 53 patients (77.9%). The majority of stents (42, 61.8%) were completely occluded at the time of removal. Median time to stent occlusion was 35 days (95% CI: 30-40 days). Stent type, diameter, length, number of small side holes, and indication for placement were not predictive of subsequent stent occlusion. However, stents with at least 4 large, flange-associated side holes were 54% less likely to be clogged upon removal (HR=0.46, P=0.029).

CONCLUSIONS

Pancreatic stents are mostly occluded as early as 1 month after insertion. Larger side holes may prevent stents within the pancreas from becoming clogged.

Patient- and cyst-related factors for improved prediction of malignancy within cystic lesions of the pancreas

BACKGROUND AND AIMS

Early diagnosis of cancer in pancreatic cysts is important for timely referral to surgery. The aim of this study was to develop a predictive model for pancreatic cyst malignancy to improve patient selection for surgical resection.

METHODS

We performed retrospective analyses of endoscopic ultrasound (EUS) and pathology databases identifying pancreatic cysts with available final pathological diagnoses. Main-duct intraductal papillary mucinous neoplasms (IPMNs) were excluded due to the clear indication for surgery. Patient demographics and symptoms, cyst morphology, and cyst fluid characteristics were studied as candidate risk factors for malignancy.

RESULTS

270 patients with pancreatic cysts were identified and analyzed (41% men, mean age 61.8 years). Final pathological diagnoses were branch-duct IPMN (n = 118, 50% malignant), serous cystadenoma (n = 71), pseudocyst (n = 37), mucinous cyst adenoma/adenocarcinoma (n = 36), islet cell tumor (n = 4), simple cyst (n = 3), and ductal adenocarcinoma with cystic degeneration (n = 1). Optimal cut-off points for surgical resection were cyst fluid carcinoembryonic antigen (CEA) > or =3,594 ng/ml, age >50, and cyst size >1.5 cm. Cyst malignancy was independently associated with white race (OR = 4.1, p = 0.002), weight loss (OR = 3.9, p = 0.001), cyst size >1.5 cm (OR = 2.4, p = 0.012), and high CEA > or =3,594 (OR = 5.3, p = 0.04). In white patients >50 years old presenting with weight loss and cyst size >1.5 cm, the likelihood of malignancy was nearly sixfold greater than in those patients who had none of these factors (OR = 5.8, 95% CI = 2.1-16.1, p = 0.004).

CONCLUSIONS

Risk factors other than cyst size are important for determination of malignancy in pancreatic cysts. Exceptionally high cyst fluid CEA levels and certain patient-related factors may help to better predict cyst malignancy and the need for surgical treatment.

Principle and history of Natural Orifice Translumenal Endoscopic Surgery (NOTES)

The field of gastrointestinal endoscopy has been witnessing major advances over the last five decades. Developing from flexible endoscopy to endoscopic retrograde cholangiopancreatography (ERCP) in the 1950's and 70's to endoscopic ultrasound in the 80's, endoscopic technology has been transformed from serving purely diagnostic purposes to therapeutic applications. One recent major advance is the notion of using the flexible endoscope, taking it beyond the gastrointestinal lumen into what lies beyond the confines of the gastrointestinal tract. Natural orifice translumenal surgery offers the exciting potential to be safer, less invasive and possibly more cost-effective than the traditional open surgical or laparoscopic approach. The history and principles of natural orifice translumenal endoscopic surgery (NOTES), along with future implications, are outlined in this article.

Omentoplasty for gastrotomy closure after natural orifice transluminal endoscopic surgery procedures (with video)

INTRODUCTION

The utility of the greater omentum has not been assessed in transluminal access closure after natural orifice transluminal endoscopic surgery (NOTES) procedures.

OBJECTIVE

Our purpose was to evaluate the feasibility, efficacy, and safety of omentoplasty for gastrotomy closure.

METHODS AND PROCEDURES

Survival experiments in 9 female 40-kg pigs were randomly assigned to 3 groups: group A, endoscopic full-thickness resection (EFTR) for transgastric access and peritoneoscopy without closure; group B, ETFR and peritoneoscopy with omentoplasty (flap of omentum is pulled into the stomach and attached to the gastric mucosa with clips but no clips are used for gastrotomy closure itself); group C, balloon dilation for opening and peritoneoscopy followed by omentoplasty for closure. The animals were observed for 2 weeks and then underwent endoscopy and necropsy with histologic evaluation.

RESULTS

Transgastric opening and peritoneoscopy were achieved in all pigs. In groups B and C, a flap of omentum was easily placed to seal the gastrotomy and then attached to the gastric mucosa with 2 to 5 clips (median 4) in 7 to 20 minutes (median 15 minutes). In group A, peritonitis developed in all animals. In both groups B and C, all animals survived 15 days with no peritonitis and minimal adhesions outside the gastrotomy site. In addition, all achieved complete healing (transmural, n = 4; mucosal ulceration, n = 2) of the gastrotomy site. One animal in group B had an 18-mm abscess in the omental flap.

LIMITATIONS

Animal model, small sample size, lack of appropriate controls for group C.

CONCLUSIONS

Omentoplasty of the gastrotomy site is a technically feasible method to seal balloon-created transgastric access to the peritoneal cavity after NOTES procedures.

A new alternative for a transjugular intrahepatic portosystemic shunt: EUS-guided creation of an intrahepatic portosystemic shunt (with video)

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPSS) is an effective treatment for portal hypertension and its associated complications. EUS-guided creation of an intrahepatic portosystemic shunt (IPSS) may become a useful alternative to conventional TIPSS.

OBJECTIVE

To assess the feasibility of EUS-guided IPSS creation in a live porcine model.

SETTING

Acute and survival experiments in 50-kg pigs.

DESIGN AND INTERVENTIONS

Under linear-array EUS guidance, the hepatic vein (HV) and then the portal vein (PV) were punctured with a 19-gauge FNA needle. A 0.035-inch guidewire was advanced through the needle into the PV lumen. The needle was exchanged over the wire, a metal stent was deployed under EUS and fluoroscopic guidance, and the distal end of the stent was positioned inside the PV and the proximal end within the HV. Eight animals were euthanized after the procedure, and 2 animals were kept alive for 2 weeks.

MAIN OUTCOME MEASUREMENTS

Successful EUS-guided IPSS creation.

RESULTS

Portosystemic shunt placement was successful in all animals. Intrahepatic vascular puncture and stent deployment were technically easy. Portosystemic flow through the shunt was documented by portal venogram and EUS Doppler. Necropsy performed after acute and survival experiments revealed no evidence of bleeding or damage to any intraperitoneal organs. There were no complications during the follow-up period in the 2 animals that were kept alive.

LIMITATION

Experiments were performed in healthy animals with normal PV pressure.

CONCLUSION

EUS-guided IPSS creation is technically feasible and may become an alternative to the currently used method of TIPSS placement.

Transgastric ventral hernia repair: a controlled study in a live porcine model (with videos)

BACKGROUND

Ventral hernia repair is currently performed via open surgery or laparoscopic approach.

OBJECTIVE

To develop an alternative ventral hernia repair technique.

SETTING

Acute and survival experiments on twelve 50-kg pigs.

DESIGN AND INTERVENTIONS

An endoscope was introduced transgastrically into the peritoneal cavity. An abdominal wall hernia was created through a 5-mm skin incision followed by a 5-cm-long incision of the abdominal wall muscles and aponeurosis. A hernia repair technique was developed in 3 acute experiments. Then animals were randomized into 2 groups. In the experimental group (5 animals) Gore-Tex mesh was transgastrically attached to the abdominal wall, repairing the previously created abdominal wall hernia. In the control group (4 animals), the hernia was not repaired. In both groups, the endoscope was then withdrawn into the stomach, and the gastric wall incision was closed with T-bars. The animals survived for 2 weeks and were then euthanized.

MAIN OUTCOME MEASUREMENT

The presence of ventral hernia on necropsy.

RESULTS

In the control group, the ventral hernia was present on necropsy in all animals. In the experimental group, the ventral hernia was easily repaired, with no evidence of hernia on necropsy. In the first animal in the experimental group, necropsy revealed infected mesh. After this discovery, we used sterilized cover for mesh delivery and did not find any signs of infection in 4 subsequent study animals.

LIMITATION

The study was performed in a porcine model.

CONCLUSIONS

Transgastric ventral hernia repair is feasible, technically easy, and effective. It can become a less invasive alternative to the currently used laparoscopic and surgical ventral hernia repair.

Air and fluid leak tests after NOTES procedures: a pilot study in a live porcine model (with videos)

BACKGROUND

Transluminal access site closure remains a major challenge in natural orifice transluminal endoscopic surgery (NOTES).

OBJECTIVE

Our purpose was to develop in vivo leak tests for evaluation of the integrity of transgastric access closure.

SETTINGS

Survival experiments on 12 50-kg pigs.

DESIGN AND INTERVENTIONS

After a standardized transgastric approach to the peritoneal cavity and peritoneoscopy, the gastric wall incision was closed with T-bars (Wilson-Cook Medical, Winston-Salem, NC) deployed on both sides of the incision and then cinched together. Gastrotomy closure was assessed with air and fluid leak tests. The animals were observed for 1 week and then underwent endoscopic evaluation and necropsy.

MAIN OUTCOME MEASUREMENTS

(1) Leak-proof closure of the gastric wall incision. (2) Gastric incision healing 1 week after the procedure.

RESULTS

The mean intraperitoneal pressure increased 10.7 +/- 3.7 mm Hg during gastric insufflation when the air leak test was performed before closure compared with 0.9 +/- 0.8 mm Hg after transmural closure of the transgastric access site with T-bars (P < .001). Fluid leak tests demonstrated no leakage of liquid contrast from the stomach into the peritoneal cavity after closure. Necropsy in 1 week confirmed completeness of the gastric closure in all animals with full-thickness healing and no spillage of the gastric contents into the peritoneal cavity.

LIMITATIONS

Leak tests were only evaluated on an animal model.

CONCLUSIONS

Fluid and air leak tests are simple techniques to evaluate in vivo the adequacy of the transluminal access site closure after NOTES procedures. Leak-proof gastric closure resulted in adequate tissue approximation and full-thickness healing of the gastric wall incision.

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.

Etanercept, a TNF-alpha binding agent, is ineffective in the prevention of post-ERCP pancreatitis in canines

CONTEXT

The incidence of post-ERCP pancreatitis is 1-22%. It continues to be a difficult problem for endoscopist and patient. Uncovering an agent that may be used to prevent its occurrence is critical.

OBJECTIVE

The aim of our study was to investigate the role of etanercept in the prevention of post-ERCP pancreatitis.

DESIGN

Endoscopic retrograde pancreatography (ERP)-induced injury was performed in dogs using a previously established endoscopic model of post-ERCP pancreatitis.

ANIMALS

Eight study dogs underwent ERP: 4 were pre-treated with etanercept one day before the procedure and 4 were untreated. In addition, three control dogs not undergoing ERP were also studied.

MAIN OUTCOME MEASURES

Serum levels of amylase, lipase, and TNF-alpha, as well as the ratio of urinary trypsinogen activation peptide (TAP) and urinary creatinine, were measured before and after ERP. Necropsy was performed on post-operative day 5. All pancreatic specimens were graded by two blinded pathologists according to a validated scoring system.

RESULTS

Eight study dogs developed mild to moderate clinical pancreatitis with hyperamylasemia (11,538+/-4,065 U/L vs. 701+/-157 U/L; post-ERP peak levels vs. baseline values: P<0.001) and hyperlipasemia (3,637+/-2,333 U/L vs. 246+/-125 U/L; P=0.003). Mean total injury score was significantly elevated in study dogs compared to control dogs (6.16+/-1.85 vs. 1.06+/-0.49; P=0.001). There were escalating total injury scores concordant with more elaborate methods of endoscopically-induced injury although the trend did not reach the statistical significance (P=0.223). When comparing untreated to etanercept-treated dogs, there were no significant differences in serum amylase levels (P=0.903), serum lipase levels (P=0.771), TAP/creatinine urinary ratio (P=0.912), and pancreatic injury score (P=0.324).

CONCLUSION

Etanercept is ineffective in prevention of mild to moderate post-ERCP pancreatitis in canines. ERP-induced pancreatic injury can be used as a reliable animal model for studies investigating therapy and prevention of post-ERCP pancreatitis.

Flexible transgastric peritoneoscopy and liver biopsy: a feasibility study in human beings (with videos)

BACKGROUND

Multiple studies have demonstrated the feasibility of natural orifice transluminal endoscopic surgery in animal models.

OBJECTIVE

To determine the feasibility of transgastric peritoneoscopy and liver biopsy in human beings.

SETTING

Our institutional review board approved the procedures in the operating room with the patients under general anesthesia.

DESIGN AND INTERVENTIONS

During laparoscopic gastric bypass surgery a flexible endoscope was introduced into the peritoneal cavity through the gastric-wall incision. A peritoneoscopy with a liver biopsy was performed, then the flexible endoscope was withdrawn into the stomach, and gastric bypass surgery was completed laparoscopically.

PATIENTS

Three patients who were morbidly obese (mean weight 115.22 +/- 9.07 kg [254 +/- 20 lb]).

MAIN OUTCOME MEASUREMENTS

The ability to navigate a flexible endoscope inside the peritoneal cavity, to visualize the intra-abdominal organs, and to perform a liver biopsy without laparoscopic assistance.

RESULTS

It was very easy to navigate the flexible endoscope inside the abdomen by using torque, advancement, and withdrawal of the endoscopic shaft, as well as by movement of the endoscope tip. The flexible endoscope provided an excellent view and adequate illumination of the peritoneal cavity. The orientation of the flexible endoscope inside the peritoneal cavity was technically easy, even in the retroflex position. Systematic visualization of the liver, the spleen, the omentum, and the small and large intestine was easily achieved through the flexible endoscope without laparoscopic assistance. A liver biopsy was successfully completed in all cases by obtaining adequate tissue samples for histologic examination.

LIMITATION

This was a pilot feasibility study.

CONCLUSIONS

Transgastric flexible endoscopic peritoneoscopy in human beings is technically feasible, simple, and can become a valuable tool that complements and facilitates laparoscopic interventions inside the peritoneal cavity.

EUS-guided submucosal implantation of a radiopaque marker: a simple and effective procedure to facilitate subsequent surgical and radiation therapy

BACKGROUND

Endosonography (EUS) is widely used for locoregional staging of malignant GI tumors. Delineation of a tumor's margins with a long-lasting fluoroscopically visible material will facilitate subsequent surgical and radiation therapy.

OBJECTIVE

To assess the feasibility of EUS-guided submucosal implantation of a radiopaque marker in a porcine model.

SETTING

Survival experiments on four 50-kg pigs.

METHODS

A linear array echoendoscope was introduced into the esophagus and advanced to the stomach. With a 19-gauge FNA needle, a submucosal bleb was created by injecting 3 mL of normal saline solution into the gastric and esophageal wall followed by injection of 1 mL of tantalum suspension under fluoroscopic observation. Fluoroscopy was repeated after 1, 2, and 4 weeks followed by euthanasia and necropsy.

MAIN OUTCOME MEASUREMENTS

Long-term depositions of the marker in the injection sites.

RESULTS

Submucosal injections of tantalum were easily performed through the 19-gauge FNA needle, resulting in good fluoroscopic opacification of injected material. Follow-up fluoroscopy in 1, 2, and 4 weeks demonstrated stable deposition of the tantalum at the sites of injection. There were no complications during and after the tantalum implantation. Histologic examination of the injection sites demonstrated submucosal tantalum depositions without signs of infection, inflammation, tissue damage, or necrosis.

LIMITATIONS

Animal experiments with 4 weeks' follow-up.

CONCLUSIONS

EUS-guided implantation of tantalum as a radiopaque marker into the submucosal layer of the GI tract in a porcine model is technically feasible and safe. Long-lasting fluoroscopically visible tantalum markings could facilitate subsequent surgical and radiation therapy.

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.

Reliable gastric closure after natural orifice translumenal endoscopic surgery (NOTES) using a novel automated flexible stapling device

BACKGROUND

Reliable closure of the translumenal incision is one of the main challenges facing natural orifice translumenal endoscopic surgery (NOTES). This study aimed to evaluate the use of an automated flexible stapling device (SurgASSIST) for closure of the gastrotomy incision in a porcine model.

METHODS

A double-channel gastroscope was advanced into the stomach. A gastric wall incision was made, and the endoscope was advanced into the peritoneal cavity. After peritoneoscopy, the endoscope was withdrawn into the stomach. The SurgASSIST stapler was advanced orally into the stomach. The gastrotomy edges were positioned between the opened stapler arms using two endoscopic grasping forceps. Stapler loads with and without a cutting blade were used for gastric closure. After firing of the stapler to close the gastric wall incision, x-ray with contrast was performed to assess for gastric leakage. At the end of the procedure, the animals were killed for a study of closure adequacy.

RESULTS

Four acute animal experiments were performed. The delivery and positioning of the stapler were achieved, with technical difficulties mostly due to a short working length (60 cm) of the device. Firing of the staple delivered four rows of staples. Postmortem examination of pig 1 (when a cutting blade was used) demonstrated full-thickness closure of the gastric wall incision, but the cutting blade caused a transmural hole right at the end of the staple line. For this reason, we stopped using stapler loads with a cutting blade. In the three remaining animals (pigs 2-4), we were able to achieve a full-thickness closure of the gastric wall incision without any complications.

CONCLUSIONS

The flexible stapling device may provide a simple and reliable technique for lumenal closure after NOTES procedures. Further survival studies are currently under way to evaluate the long-term efficacy of gastric closure with the stapler after intraperitoneal interventions.

[Combined transgastric and transcolonic endoscopic salpingectomy: experiment with pigs]

OBJECTIVE

To compare the feasibility and safety of combined transgastric and transcolonic dual approach and those of transgastric single approach in endoscopic salpingectomy.

METHODS

Two female Chinese Nongda miniature pigs underwent gastric and colonic lavage with tap water followed by disinfection of mucosa with 1:10 iodophor. An endoscope was inserted and the colonic wall was punctured with a needle knife, dilated with a balloon-dilator and a double-channel endoscope was advanced into the peritoneal cavity. Under direct observation through this endoscope, a trans-gastric entrance was made with the second double-channel endoscope. With the help of transcolonic endoscope, the left Fallopian tube was ligated and partially resected using the transgastric endoscope. With the help of transgastric endoscope, liver biopsy was performed using the transcolonic endoscope. Finally, the gastric incision was closed with 3 clips and the colonic incision was closed with a loop and a clip. Antibiotics were used for 3 days following the procedures. Seventeen days later laparotomy was performed to observe the infection, visceral damage and adhesion, healing of the incisions of gastrointestinal duct, etc.

RESULTS

Compared with the single route, the dual routes were more convenient to perform the liver biopsy and salpingectomy. The pigs drank and ate normally soon after the resuscitation. The pigs looked well and gained weight during 2 weeks after the operation. Repeat endoscopy in 2 weeks showed a well-healed gastric incision with 2 clips still in place and a healed colonic incision with 1 clip still attached. The necropsy revealed a complete transmural healing of the gastric incision with minimal adhesion and a complete healing of the colonic incision without any adhesion. Few adhesions were found around the liver biopsy site and the salpingectomy site without any intraperitoneal infection or organ damage.

CONCLUSION

Combined transgastric and transcolonic approach appears safe and feasible and facilitates translumenal intraperitoneal interventions.