Sohail N. Shaikh

Smart Self-Assembling MagnetS for ENdoscopy (SAMSEN) for transoral endoscopic creation of immediate gastrojejunostomy (with video)

BACKGROUND Gastrojejunostomy is important for palliation of malignant gastric outlet obstruction and surgical obesity procedures. A less-invasive endoscopic technique for gastrojejunostomy creation is conceptually attractive. Our group has developed a compression anastomosis technology based on endoscopically delivered self-assembling magnets for endoscopy (SAMSEN) to create an instant, large-caliber gastrojejunostomy. OBJECTIVE To develop and evaluate an endoscopic means of gastrojejunostomy creation by using SAMSEN. SETTING Developmental laboratory and animal facility. DESIGN Animal study and human cadaveric study. SUBJECTS Yorkshire pigs (7 cadaver, 5 acute); human (1 cadaver). INTERVENTIONS A transoral procedure for SAMSEN delivery was developed in porcine and human cadaver models. Subsequently, gastrojejunostomy creation by using SAMSEN was performed in 5 acute pigs. The endoscope was advanced into the peritoneal cavity through the gastrotomy, and a segment of the small bowel was grasped and pulled closer to the stomach. An enterotomy was created, and a custom overtube was advanced into the small bowel for deployment of the first magnetic assembly. Next, a reciprocal magnetic assembly was deployed in the stomach. The 2 magnetic systems were mated under fluoroscopic and endoscopic guidance. Contrast studies assessed for gastrojejunostomy leak. Immediate necropsies were performed. MAIN OUTCOME MEASUREMENTS Technical feasibility and complications. RESULTS Gastrojejunostomy creation by using SAMSEN was successful in all 5 animals. Deep enteroscopy was performed through the stoma without difficulty. No leaks were identified on contrast evaluation. At necropsy, the magnets were properly deployed and robustly coupled together, resistant to vigorous tissue manipulation. LIMITATIONS Acute animal study. CONCLUSIONS Endoscopic creation of immediate gastrojejunostomy by using SAMSEN is technically feasible.

Natural orifice translumenal surgery: Flexible platform review

Natural orifice translumenal surgery (NOTES) has garnished significant attention from surgeons and gastroenterologists, due to the fusion of flexible endoscopy and operative technique. Preliminary efforts suggest that NOTES holds potential for a less invasive approach with certain surgical conditions. Many of the hurdles encountered during the shift from open to laparoscopic surgery are now being revisited in the development of NOTES. Physician directed efforts, coupled with industry support, have brought about several NOTES specific devices and platforms to help address limitations with current instrumentation. This review addresses current flexible platforms and their attributes, advantages, disadvantages and limitations.

Early Healing of Transcolonic and Transgastric Natural Orifice Transluminal Endoscopic Surgery Access Sites

BACKGROUND Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a developing, minimally invasive surgical approach whose potential benefits are being investigated. Little is known about secure access site closure and early healing kinetics of transvisceral access. STUDY DESIGN Transvisceral access incisions were created in the colon (C-NOTES, n = 8) and stomach (G-NOTES, n = 8) for peritoneal exploration. Incisions were closed primarily with endoloops, endoclips, or t-tags. Macroscopic and histologic analyses performed on postoperative day 7 assessed gross appearance, granulation tissue, inflammation, ulceration, and complications. RESULTS Macroscopically, incisions appeared closed without intraperitoneal spillage. Incisions closed by endoloop and t-tags showed intense granulation tissue fill of defect despite partial (G-NOTES, n = 3) and transmural ulceration (C-NOTES, n = 8; G-NOTES, n = 3). Of the 30 t-tags applied, 40% broke or deployed into the peritoneal cavity. Endoclip closures (C-NOTES, n = 1; G-NOTES, n = 1) did not show histologic mucosal continuity. Healing complications included transmural necrosis (C-NOTES, n = 1; G-NOTES, n = 1), foreign body material (C-NOTES, n = 3; G-NOTES, n = 2), and microabscesses (G-NOTES, n = 1). CONCLUSIONS This study provides a reproducible model to assess noninvasive repair of planned visceral perforations. Of investigated technologies, endoloop closure was favored for transcolonic incisions, and t-tags with omental patch for transgastric incisions, although these have significant limitations. Endoclips were inadequate for primary closure, but may be useful as an adjunctive closure modality. Additional studies are needed to examine visceral repair at later time points, as they will help determine the quality and kinetics of repair of a variety of incision closure strategies. This study demonstrates the need for improved technologies to more reliably close visceral transluminal defects.

Real-time computed tomography-based augmented reality for natural orifice transluminal endoscopic surgery navigation.

Natural orifice transluminal endoscopic surgery (NOTES) is technically challenging owing to endoscopic short‐sighted visualization, excessive scope flexibility and lack of adequate instrumentation. Augmented reality may overcome these difficulties. This study tested whether an image registration system for NOTES procedures (IR‐NOTES) can facilitate navigation.

Efficacy of a reverse-phase polymer as a submucosal injection solution for EMR: a comparative study (with video)

INTRODUCTION Reverse-phase polymers undergo a temperature-dependent liquid-to-gel transition that may provide a more durable cushion for EMR and could yield improvements in safety and efficacy. OBJECTIVE Our purpose was to assess the efficacy of poloxamer solution PS137-25 as a submucosal injection. DESIGN Comparative study among 3 different solutions for EMR using ex vivo and in vivo porcine models. INTERVENTIONS A total of 120 gastric submucosal cushions were performed in fresh ex vivo porcine stomachs with saline solution 0.9% (n = 40), hydroxypropyl methylcellulose (HPMC) (n = 40), and PS137-25 (n = 40). Five in vivo porcine colon EMRs were then performed. MAIN OUTCOME MEASUREMENTS Height and duration of submucosal cushions were measured in the ex vivo model, and the usefulness of reverse-phase polymers was assessed by in vivo en bloc resection. RESULTS Ex vivo: The height of mucosal elevation was greater with PS137-25 (10.3 +/- 2.2 mm) than with saline solution (8.3 +/- 2.6 mm) or HPMC (9.05 +/- 2.3 mm, not significant). All submucosal elevations with PS137-25 lasted longer (more than 20 minutes) than with saline solution (20.9 +/- 11 minutes, P < .01) or HPMC (89 +/- 32 minutes, P < .01). After 120 minutes, the elevations obtained with PS137-25 showed no differences in size, shape, or consistency from initial measurements. In vivo: All 5 EMRs were successfully performed after 1 injection of PS137-25. No repeat injections were needed. During resection, a large gel cushion was noted. CONCLUSIONS Mucosal elevation with PS137-25 is more durable than with other substances, with no changes in size or consistency observed over 120 minutes. Additionally, reverse-phase polymers performed well in in vivo colon EMRs. These results suggest that reverse-phase polymers may provide increased safety and efficacy for EMR procedures.

An implantable wireless biosensor for the immediate detection of upper GI bleeding: a new fluorescein-based tool for diagnosis and surveillance (with video)

BACKGROUND Early recurrent hemorrhage after endoscopic intervention for acute upper GI bleeding (UGIB) can approach 20% and leads to increased morbidity and mortality. Little has changed over the past several decades regarding immediate posthemorrhage surveillance, and there has likewise been no significant improvement in outcomes. OBJECTIVE To develop and test an endoscopically implantable wireless biosensor for real-time detection of fluorescein-labeled blood in ex vivo and in vivo porcine models of UGIB. SETTING Animal laboratory. DESIGN Benchtop and acute animal studies. SUBJECTS Five pigs. INTERVENTIONS UGIB models were surgically created in living pigs. Biosensors were endoscopically deployed in the stomach using standard endoscopic clips. The ability to detect acute UGIB and estimated blood loss leading to biosensor activation were recorded. Feasibility of wireless data transmission out of the body to an external computer and cell phone was assessed. MAIN OUTCOME MEASUREMENTS Technical feasibility and immediate complications. RESULTS A porcine UGIB model was successfully created. Biosensors were able to detect all acute bleeding events and wirelessly transmit out of the body, and successfully sent an emergency text message to the intended cell phone in all cases. Average estimated blood loss leading to biosensor activation was 30 mL (10-75 mL). LIMITATIONS Animal study; small numbers. CONCLUSIONS An endoscopically implantable wireless biosensor successfully detected acute hemorrhage in a porcine UGIB model and sent an emergency cell-phone alert in real time.

Magnetic pancreaticobiliary stents and retrieval system: obviating the need for repeat endoscopy (with video).

BACKGROUND Plastic stents are routinely placed in the pancreaticobiliary system to facilitate drainage. A second endoscopy is often required for stent removal. We have developed magnetic pancreaticobiliary stents that can be removed by using an external hand-held magnet, thereby obviating the need for a second endoscopy. OBJECTIVE To develop and test magnetic pancreaticobiliary stents and retrieval system in ex-vivo and in-vivo porcine models. SETTING Animal laboratory. DESIGN Benchtop and animal study. ANIMALS 5 pigs. INTERVENTIONS Design: Computer simulations determined both the optimal design of cylindrical magnets attached to the distal aspect of existing plastic stents and the optimal design of the external hand-held magnet. Benchtop ex-vivo experiments measured magnetic force to validate the design. In-vivo analysis: In 5 Yorkshire pigs, magnetic stents were deployed into the common bile duct by using a conventional duodenoscope. An external hand-held magnet was applied for stent removal. Stent insertion and removal times were recorded. MAIN OUTCOME MEASUREMENTS Technical feasibility. RESULTS Magnetic stents of varying lengths and calibers were successfully created. In ex-vivo testing, the capture distance was 10.0 cm. During in-vivo testing, the magnetic stents were inserted and removed easily. The mean insertion and removal times were 3.2 minutes and 33 seconds, respectively. LIMITATIONS Animal study, small numbers. CONCLUSIONS Magnetic pancreaticobiliary stents and associated retrieval system were successfully designed and tested in the acute porcine model. An external, noninvasive means of stent removal potentially obviates the need for a second endoscopy, which could represent a major gain both for patients and in health care savings.

Pancreaticoureteral Fistula: A Rare Complication of Chronic Pancreatitis.

Context: Chronic pancreatitis is an inflammatory condition that may result in progressive parenchymal damage and fibrosis which can ultimately lead to destruction of pancreatic tissue. Fistulas to the pleura, peritoneum, pericardium, and peripancreatic organs may form as a complications of pancreatitis. This case report describes an exceedingly rare complication, pancreaticoureteral fistula (PUF). Only two additional cases of PUF have been reported. However, they evolved following traumatic injury to the ureter or pancreatic duct. No published reports describe PUF as a complication of pancreatitis. Case Report: A 69-year-old Hispanic female with a past medical history of cholecystectomy, pancreatic pseudocyst, and recurrent episodes of pancreatitis presented with severe, sharp, and constant abdominal pain. Upon imaging, a fistulous tract was visualized between the left renal pelvis (at the level of an upper pole calyx) and the pancreatic duct and a ureteral stent was placed to facilitate fistula closure. Following the procedure, the patient attained symptomatic relief and oral intake was resumed. A left retrograde pyelogram was repeated 2 months after the initial stent placement and demonstrating no evidence of a persistent fistulous tract. Conclusion: Due to PUF′s unclear etiology and possible variance of presentation, it is important for physicians to keep this rare complication of pancreatitis in mind, especially, when evaluating a patient with recurrent pancreatitis, urinary symptoms and abnormal imaging within the urinary collecting system and pancreas.

Synchronous metastasis of prostate adenocarcinoma to the stomach and colon: A case report

Context: Prostate cancer is the leading cancer diagnosis in males. The most common metastatic site of metastases in patients with prostate cancer is the axial skeleton and local lymph nodes. Rarely has there been a description of metastatic prostate cancer to the stomach, esophagus, small bowel, and rectum. Case Report: We report an unusual case of a patient who was diagnosed with prostate cancer with synchronous metastasis to both the stomach and sigmoid colon. A 71-year-old African American man with a history of prostate cancer was admitted with a hemoglobin level of 6.1 g/dl, which had decreased from the baseline value of 8 g/dl. He underwent an esophagogastroduodenoscopy, which revealed a nodule in the fundus of stomach; a biopsy of the nodule was done. The patient also underwent a sigmoid polypectomy. Both surgical specimens were histopathologically consistent with metastatic adenocarcinoma of prostatic origin. Conclusion: To the best of our knowledge, this is the first case report in literature of synchronous metastasis of prostate cancer to both the stomach and sigmoid colon.

E. coli Sepsis: Red Flag for Colon Carcinoma—A Case Report and Review of the Literature

We present an atypical case of newly diagnosed colon cancer and provide insight into the infectious predispositions of E. coli bacteremia to the development of colon adenocarcinoma. A 66-year-old female was admitted to the hospital with one-week symptoms of subjective fevers, chills, and lower back pain. Upon initial evaluation, her temperature was 101 degrees Fahrenheit with a white count of 12,000 K/mm3. Initial septic workup was positive for E. coli bacteremia. The patient was started on Aztreonam. Repeat blood culture 48 hours later was negative for any growth. However, later during hospital stay blood culture was repeated due to SIRS, which was positive again for E. coli. CT scan of the chest/abdomen/pelvis with contrast revealed no signs of colitis. Without clear etiology for recurrent E. coli bacteremia ultimately colonoscopy was performed which showed an ulcerated mass in the cecum. Biopsy showed moderately differentiated adenocarcinoma. E. coli strains B2 and D produce cyclomodulin toxins as part of their virulence, which interferes with the cell cycle regulation, promoting chromosomal instability, and increasing susceptibility to cancer. In patients with recurrent E. coli bacteremia with an unknown source, colonoscopy should be done to look for colon cancer.