Sergey V. Kantsevoy

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

BACKGROUNDnMultiple studies have demonstrated the feasibility of natural orifice transluminal endoscopic surgery in animal models.nnnOBJECTIVEnTo determine the feasibility of transgastric peritoneoscopy and liver biopsy in human beings.nnnSETTINGnOur institutional review board approved the procedures in the operating room with the patients under general anesthesia.nnnDESIGN AND INTERVENTIONSnDuring 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 A peritoneoscopy with a liver biopsy was performed, then the flexible endoscope was withdrawn into the stomach, and gastric bypass surgery was completed laparoscopically.nnnPATIENTSnThree patients who were morbidly obese (mean weight 115.22 +/- 9.07 kg [254 +/- 20 lb]).nnnMAIN OUTCOME MEASUREMENTSnThe 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.nnnRESULTSnIt 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.nnnLIMITATIONnThis was a pilot feasibility study.nnnCONCLUSIONSnTransgastric 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.

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

BackgroundReliable 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.MethodsA 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.ResultsFour 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.ConclusionsThe 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.

Performance Characteristics of the Suspected Blood Indicator Feature in Capsule Endoscopy According to Indication for Study

BACKGROUND & AIMSnThe suspected blood indicator (SBI) feature of wireless capsule endoscopy (WCE) was developed for rapid screening of intestinal lesions with bleeding potential. Our aim was to assess the accuracy and performance characteristics of the SBI according to the indications for study in a large cohort of patients.nnnMETHODSnWe reviewed collected data on all WCE studies performed at Johns Hopkins Hospital from January 2006 to June 2007. Study indications were as follows: anemia of unknown origin (n = 53), obscure gastrointestinal bleeding (n = 112), suspected Crohns disease (n = 122), and other (n = 4). Concordant and discordant findings between gastroenterologists readings and SBI were recorded for each patient.nnnRESULTSnA total of 221 lesions with bleeding potential was detected. The overall sensitivity, specificity, positive predictive value, and negative predictive value for the SBI were 56.4%, 33.5%, 24.0%, and 67.3%, respectively. For actively bleeding lesions, the SBI sensitivity and positive predictive value were only 58.3% and 70%, respectively. The sensitivity was highest (64%) in patients undergoing WCE for suspected Crohns disease, with a negative predictive value of 80.4%. The sensitivity was only 58.3% and 41.3%, respectively, in studies performed for obscure gastrointestinal bleeding and anemia.nnnCONCLUSIONSnPerformance characteristics of the currently available SBI feature in WCE are suboptimal and insufficient to screen for lesions with bleeding potential. Even in patients with active intestinal bleeding, the sensitivity of SBI was less than 60%, which is lower than previously reported. However, in patients with suspected Crohns disease, the high sensitivity and negative predictive value of SBI may make it a useful tool for the detection of large areas of abnormal mucosa.

Hybrid minimally invasive surgery—a bridge between laparoscopic and translumenal surgery

BackgroundThe peroral transluminal approach to the peritoneal cavity appears safe, feasible, and may further reduce the invasiveness of surgery. However, flexible endoscopes have multiple limitations inside the peritoneal cavity, which can potentially be overcome by blending the use of both a laparoscope and a flexible upper endoscope—a hybrid approach. The goal of the present study was to evaluate a hybrid minimally invasive technique for cholecystectomy in a porcine model.MethodsHybrid cholecystectomies were performed in acute experiments on 50-kg pigs under general anesthesia. Pneumoperitoneum was created with a Veress needle, and a laparoscopic 10-mm port was inserted. Under laparoscopic observation, the gastric wall incision was done with an endoscopic needle-knife and sphincterotome, and the upper endoscope was advanced into the peritoneal cavity. A laparoscopic 10-mm port was inserted into the right upper quadrant of the abdomen for gallbladder traction to facilitate exposure of the cystic duct and artery. Via the biopsy channel of the flexible endoscope, and using a knife with an isolated tip, a needle knife, and clips, both the cystic duct and artery were identified, clipped, and transected. The gallbladder itself was then dissected and retracted through the mouth, and the gastric wall incision was closed with endoscopic clips.ResultsFive hybrid cholecystectomies were performed without complications. The laparoscopic port enabled a stable pneumoperitoneum, good traction and counter-traction, and improved spatial orientation and visualization. Necropsy did not reveal any intraperitoneal complications.ConclusionsThe hybrid approach increases safety of initial gastric puncture and gastric wall incision, improves orientation and navigation of the flexible endoscope inside the peritoneal cavity, simplifies peroral transgastric cholecystectomy, and could be used to decrease invasiveness of laparoscopic surgery and to facilitate development and clinical introduction of transgastric endoscopic procedures.

Comparison of intraabdominal pressures using the gastroscope and laparoscope for transgastric surgery

BackgroundThe peroral transgastric endoscopic approach for intraabdominal procedures appears to be feasible, although multiple aspects of this approach remain unclear. This study aimed to measure intraperitoneal pressure in a porcine model during the peroral transgastric endoscopic approach, comparing an endoscopic on-demand insufflator/light source with a standard autoregulated laparoscopic insufflator.MethodsAll experiments were performed with 50-kg female pigs under general anesthesia. A standard upper endoscope was advanced perorally through a gastric wall incision into the peritoneal cavity. The peritoneal cavity was insufflated with operating room air from an endoscopic light source/insufflator. Intraperitoneal pressure was measured by three routes: (1) through the endoscope biopsy channel, (2) through a 5-mm transabdominal laparoscopic port, and (3) through a 16-gauge Veress needle inserted into the peritoneal cavity through the anterior abdominal wall. The source of insufflation alternated between on-demand manual insufflation through the endoscopic light source/insufflator using room air and a standard autoregulated laparoscopic insufflator using carbon dioxide (CO2).ResultsSix acute experiments were performed. Intraperitoneal pressure measurements showed good correlation regardless of measurement route and were independent of the type of insufflation gas, whether room air or CO2. On-demand insufflation with the endoscopic light source/insufflator resulted in a wide variation in pressures (range, 4–32 mmHg; mean, 16.0 ± 11.7). Intraabdominal pressures using a standard autoregulated laparoscopic insufflator demonstrated minimal fluctuation (range, 8–15 mmHg; mean, 11.0 ± 2.2 mmHg) around a predetermined value.ConclusionUse of an on-demand unregulated endoscopic light source/insufflator for translumenal surgery can cause large variation in intraperitoneal pressures and intraabdominal hypertension, leading to the risk of hemodynamic and respiratory compromise. Safety may favor well-controlled intraabdominal pressures achieved with a standard autoregulated laparoscopic insufflator.

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) ≥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 ≥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.

Gallstones and biliary diseases

Gallstones are common in the US and western countries. This article describes the pathogenesis of gallstone formation and the clinical manifestations and current approaches to diagnosis and treatment of the most common clinical conditions caused by gallstones: biliary colic, acute cholecystitis, choledocholithiasis, and acute gallstone pancreatitis. The role of widely used imaging techniques (transabdominal ultrasound, CT scan, MR imaging, and MRCP) and diagnostic and therapeutic endoscopy (endoscopic ultrasound, ERCP) is emphasized. This article is intended mainly for general practitioners, primary care physicians, and other specialists providing medical care to patients with gallstones and their complications.

Accuracy and reliability of the endoscopic classification of portal hypertensive gastropathy

BACKGROUNDnThere is no consensus regarding the endoscopic classification of the severity of portal hypertensive gastropathy. This study compared the accuracy and reproducibility of the 2-category classification system (2-CCS) with the 3-category classification system (3-CCS).nnnMETHODSnNinety-eight endoscopic pictures of portal hypertensive gastropathy and 22 of nonspecific gastritis were selected. Eight duplicate sets were generated, each in a different random order. These were shown to 6 experienced endoscopists during 2 sessions 1 week apart with 4 slide sets at each session. Each picture was scored by using either the 2-CCS or 3-CCS. Kappa statistics and percent agreement were used to estimate the reproducibility and agreement.nnnRESULTSnThe mean percentage agreement among the 4 separate readings for each observer was significantly lower for the 3-CCS compared with the 2-CCS (mean [standard deviation] = 33.5% [8.9%] vs. 64.9% [9.1%]; p = 0.0001). The mean (SD) interobserver kappa values were 0.44 (0.03) for the 3-CCS and 0.52 (0.04) for the 2-CCS (p = 0.02), and the respective intraobserver kappa values were 0.43 (0.1) and 0.63 (0.06) (p = 0.002).nnnCONCLUSIONSnEven though both the 2-CCS and 3-CCS have substantial limitations with regard to specificity and reliability, there were better agreement and reproducibility with the simpler classification system for portal hypertensive gastropathy.

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

BACKGROUNDnVentral hernia repair is currently performed via open surgery or laparoscopic approach.nnnOBJECTIVEnTo develop an alternative ventral hernia repair technique.nnnSETTINGnAcute and survival experiments on twelve 50-kg pigs.nnnDESIGN AND INTERVENTIONSnAn 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.nnnMAIN OUTCOME MEASUREMENTnThe presence of ventral hernia on necropsy.nnnRESULTSnIn 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.nnnLIMITATIONnThe study was performed in a porcine model.nnnCONCLUSIONSnTransgastric 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.

Performance Characteristics and Comparison of Two Fecal Occult Blood Tests in Patients Undergoing Colonoscopy

We investigated the use of a new type of FOBT (EZ-Detect) that uses the bloods pseudo-peroxidase activity as an enzymatic catalyst, in a one-step chromogen-substrate system performed by the patient. Asymptomatic patients ≥50 years old received three Hemoccult II (HO) cards and three EZ-Detect (EZ) packages to be used in three consecutive bowel movements. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of colorectal neoplasia was calculated. The study included 207 patients, with a mean age of 58.9 years. Diagnostic accuracy for detection of adenomas was similar for the EZ and HO tests (66.7% vs. 71.0%; P=0.48), while for advanced adenomas diagnostic accuracy for the EZ and HO tests was 86.0% vs. 94.2% (P=0.01), respectively. Most patients preferred the EZ test (92% vs. 8%). We conclude that the EZ test has a diagnostic profile similar to that of the HO test for identification of adenomas; however, for advanced adenomas the diagnostic accuracy was slightly better for the HO. The EZ test was preferred by most patients, which may increase colorectal cancer screening compliance.