Neal Mehta

Magnetic anchor guidance for endoscopic submucosal dissection and other endoscopic procedures

Endoscopic submucosal dissection (ESD) is a well-established, minimally invasive treatment for superficial neoplasms of the gastrointestinal tract. The universal adoption of ESD has been limited by its slow learning curve, long procedure times, and high risk of complications. One technical challenge is the lack of a second hand that can provide traction, as in conventional surgery. Reliable tissue retraction that exposes the submucosal plane of dissection would allow for safer and more efficient dissection. Magnetic anchor guided endoscopic submucosal dissection (MAG-ESD) has potential benefits compared to other current traction methods. MAG-ESD offers dynamic tissue retraction independent of the endoscope mimicking a surgeon’s “second hand”. Two types of magnets can be used: electromagnets and permanent magnets. In this article we review the MAG-ESD technology, published work and studies of magnets in ESD. We also review the use of magnetic anchor guidance systems in natural orifice transluminal endoscopic surgery and the idea of magnetic non-contact retraction using surface ferromagentization. We discuss the current limitations, the future potential of MAG-ESD and the developments needed for adoption of this technology.

The Heart Age Is Increased in Patients With Nonalcoholic Fatty Liver Disease and Correlates With Fibrosis and Hepatocyte Ballooning

The Heart Age Is Increased in Patients With Nonalcoholic Fatty Liver Disease and Correlates With Fibrosis and Hepatocyte Ballooning

Patients with clinically metabolically healthy obesity are not necessarily healthy subclinically: further support for bariatric surgery in patients without metabolic disease?

BACKGROUND Nonalcoholic fatty liver disease (NAFLD) increases the risk of liver cirrhosis and hepatocellular carcinoma and is also strongly correlated with extrahepatic diseases, including cardiovascular disease and type 2 diabetes. This risk of NAFLD among obese individuals who are otherwise metabolically healthy is not well characterized. OBJECTIVES To determine the prevalence and characteristics of NAFLD in individuals with metabolically healthy obesity. SETTING A tertiary, academic, referral hospital. METHODS All patients who underwent bariatric surgery with intraoperative liver biopsy from 2008 to 2015 were identified. Patients with preoperative hypertension, dyslipidemia, or prediabetes/diabetes were excluded to identify a cohort of metabolically healthy obesity patients. Liver biopsy reports were reviewed to determine the prevalence of NAFLD. RESULTS A total of 270 patients (7.0% of the total bariatric surgery patients) met the strict inclusion criteria for metabolically healthy obesity. The average age was 38 ± 10 years and the average body mass index was 47 ± 7 kg/m2. Abnormal alanine aminotransferase (>45 U/L) and asparate aminotransferase levels (>40 U/L) were observed in 28 (10.4%) and 18 (6.7%) patients, respectively. A total of 96 (35.5%) patients had NAFLD with NALFD Activity Scores 0 to 2 (n = 61), 3 to 4 (n = 25), and 5 to 8 (n = 10). A total of 62 (23%) patients had lobular inflammation, 23 (8.5%) had hepatocyte ballooning, 22 (8.2%) had steatohepatitis, and 12 (4.4%) had liver fibrosis. CONCLUSION Even with the use of strict criteria to eliminate all patients with any metabolic problems, a significant proportion of metabolically healthy patients had unsuspected NAFLD. The need and clinical utility of routine screening of obese patients for fatty liver disease and the role of bariatric surgery in the management of NAFLD warrants further investigation.

Common Bile Duct Dilation after Bariatric Surgery

Background Biliary dilation suggests obstruction and prompts further work up. Our experience with endoscopic ultrasound and endoscopic retrograde cholangiopancreatography in the symptomatic post-bariatric surgery population revealed many patients with radiographically dilated bile ducts, but endoscopically normal studies. It is unclear if this finding is phenomenological or an effect of surgery. Additionally, it is unknown whether the type of bariatric surgery alters biliary pathophysiology. Thus, we studied whether a change occurs in biliary diameter following Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

The EMALT Score: An Improved Model for Prediction of Early Mortality in Liver Transplant Recipients:

Purpose: Needs, risks, and outcomes of patients admitted to a post liver transplant intensive care unit (POLTICU) differ in important ways from those admitted to pretransplant intensive care units (ICUs). The aim of this study was to create the optimal model to risk stratify POLTICU patients. Methods: Consecutive patients who underwent first deceased donor liver transplantation (LT) at a large United States center between 2008 and 2014 were followed from admission to LT and to discharge or death. Receiver–operating characteristic analysis was performed to assess the value of various scores in predicting in-hospital mortality. A predictive model was developed using logistic regression analysis. Results: A total of 697 patients underwent LT, and 3.2% died without leaving the hospital. A model for in-hospital mortality was derived from variables available within 24 hours of admission to the POLTICU. Key variables best predicting survival were white blood cell count, 24-hour urine output, and serum glucose. A model using these variables performed with an area under the curve (AUC) of 0.88, compared to the Acute Physiology and Chronic Health Evaluation III and Model for End-Stage Liver Disease, which performed with AUCs of 0.74 and 0.60, respectively. Conclusion: An improved model, the early mortality after LT (EMALT) score, performs better than conventional models in predicting in-hospital mortality after LT.

Endoscopic retrieval of a lumen-apposing metal stent complicated by inward migration after cystogastrostomy

Endoscopic ultrasound (EUS)-guided drainage is well known as an established technique for the treatment of pancreatic pseudocysts [1, 2]. New covered metal stents, known as lumen-apposing metal stents (LAMS), have been designed. Despite their superior antimigration features, these LAMS can migrate inwardly [3, 4]. We report a case of successful endoscopic retrieval of a LAMS with inward migration after cystogastrostomy. A 50-year-old man with a history of alcohol-induced chronic pancreatitis complicated by a large pancreatic pseudocysts at the head of the pancreas (▶Fig. 1), presented with severe abdominal pain and gastric outlet obstruction. EUS-guided cystogastrostomy was successfully performed with a 15-mm LAMS (▶Fig. 2). The patient returned for stent removal 2 months later, and the follow-up computed tomography (CT) scan revealed resolution of the cyst. However, during the esophagogastroduodenoscopy to remove the stent, we observed a small orifice at the location of the previously applied stent (▶Fig. 3 a). Fluoroscopic images confirmed stent migration into the fistulous lumen of the remaining pseudocyst (▶Fig. 3 b). We proceeded with endoscopic retrieval of LAMS (▶Video1). The retrieval procedure was performed under general anesthesia. Carbon diox▶ Fig. 1 Computed tomography scan demonstrating a large pancreatic pseudocyst (circled) at the head of the pancreas, requiring endoscopic ultrasound-guided drainage.

Optimal injection solution for endoscopic submucosal dissection: A randomized controlled trial of Western solutions in a porcine model

When carrying out endoscopic submucosal dissection (ESD), procedural safety increases with greater tissue elevation and efficiency increases with longer‐lasting submucosal cushion. Fluids specifically developed for ESD in Asia are not commercially available in the West, leaving endoscopists to use a variety of injectable fluids off‐label. To determine the optimal fluid available in the West, we compared commonly used fluids for Western ESD.

Gastric Antral Pseudomelanosis

A 47-year-old man with history of cadaveric liver transplant on tacrolimus was admitted for his second living nonrelated liver transplant due to recurrent hepatitis C. His postoperative course was complicated by encephalopathy, hypotension, and atrial fibrillation. On posttransplant day 12, a targetoid, purpuric lesion was noted on his anterior left thigh (a). Within 24 hours, the lesion rapidly expanded, and numerous similar lesions were observed extensively on his face, chest, abdomen, arms, legs, hands, and feet. Biopsy of the lesions revealed dense growth of angioinvasive fungi of the Zygomycota phylum in the vasculature and surrounding tissue. The patient was started on liposomal amphotericin B but died shortly afterward. Autopsy revealed adherent endocardial thrombi (b) composed largely of fungi on histology and cerebral hemorrhages (c) with fungi in vasculature invading surrounding tissue on histology. (Significant efforts were made to obtain informed consent for these images, but the patient’s next of kin could not be reached.)

Gastric Perforation Caused by a Left Ventricular Assist Device.

A 52-year-old man with a history of necrotizing pancreatitis complicated by walled-off necrosis requiring cystogastrostomy drainage five years previously was referred for evaluation of subacute malnourishment, early satiety, and abdominal pain. Computed tomography of the abdomen and endoscopic ultrasound showed a mature, 13-cm walled-off complex collection in the region of the pancreatic body (a). Initially, given the history and available imaging, there was no suspicion of malignancy, and the collection was drained by cystogastrostomy with deployment of a lumen-apposing metal stent. Thick, mucinous drainage was expressed (b) without overt release of necrotic or thin liquid content. Subsequent identification of suspicious hepatic lesions—thought initially to be abscesses—prompted percutaneous biopsy confirming metastatic pancreatic adenocarcinoma. At follow-up drainage two weeks later, the patient noted decreased pain and improved oral tolerance. Interval transcystogastrostomy endoscopic imaging demonstrated retained thick mucinous material that when suctioned revealed an adenomatous patterned wall with a central solid component consistent with primary mucinous adenocarcinoma (c). (Informed consent was obtained from the patient to publish these images.)

Migration and Erosion of Cervical Spine Hardware into the Esophageal Lumen Causing Odynophagia and Dysphagia

A 41-year-old man with a history of metastatic medullary thyroid cancer presented with stridor, odynophagia, and dysphagia, worsening abruptly over the past 2 days. He had a moderate degree of dysphagia even at baseline secondary to a radiation-induced esophageal stricture, and previously had multiple esophagogastroduodenoscopies (EGDs) with dilation, most recently a year prior to presentation. He had also undergone a complete thyroidectomy and received radioactive iodine and radiation therapy. His clinical course had been complicated by cervical and thoracic cord compression from bone metastases requiring corpectomy, laminectomy, and instrumented vertebral fusion.