This study examined whether the high sensitivity of plasma free metanephrines for diagnosis of pheochromocytoma may result from production of free metanephrines within tumors. Presence in pheochromocytomas of catechol-O-methyltransferase (COMT), the enzyme responsible for conversion of catecholamines to metanephrines, was confirmed by Western blot analysis, enzyme assay, and immunohistochemistry. Western blot analysis and enzyme assay indicated that membrane-bound and not soluble COMT was the predominant form of the enzyme in pheochromocytoma. Immunohistochemistry revealed colocalization of COMT in the same chromaffin cells where catecholamines are translocated into storage vesicles by the vesicular monoamine transporter. Levels of free metanephrines in pheochromocytoma over 10,000 times higher than plasma concentrations in the same patients before removal of tumors indicated production of metanephrines within tumors. Comparisons of the production of metanephrines in patients with pheochromocytoma with production from catecholamines released or infused into the circulation indicated that more than 93% of the consistently elevated levels of circulating free metanephrines in patients with pheochromocytoma are derived from metabolism before and not after release of catecholamines into the circulation. The data indicate that the elevated plasma levels of free metanephrines in patients with pheochromocytoma are derived from catecholamines produced and metabolized within tumors. Some tumors do not secrete catecholamines, but all appear to metabolize catecholamines to free metanephrines, thus explaining the better sensitivity of plasma free metanephrines over other tests for diagnosis of pheochromocytoma.

Pancreatic fluid collections (PFCs) have conventionally been treated with surgery, percutaneous drainage, or with the more recently established endoscopic ultrasound (EUS)-guided drainage modality. Currently, endoscopic plastic or metallic stents are used for PFC drainage. Plastic stents present issues with stent migration and premature occlusion requiring frequent stent exchanges or placement of additional stents. Metallic stents are tubular and may migrate, resulting in inefficient drainage, content leakage, retrieval and replacement, and possible mucosal injury. The aim of this review was to summarize and evaluate the clinical and technical effectiveness of EUS-guided placement of the recently developed AXIOS stent, a lumen-apposing self-expandable metallic stent (LASEMS)for PFC drainage. A literature review was performed to identify the studies describing this technique. In this review article we have summarized case series or reports describing EUS-guided LASEMS placement. The indications, techniques, limitations and complications reported are discussed. A total of 298 patients were included across all studies described thus far in the literature. Overall, a 97% technical success rate and a 96% clinical success rate have been reported. Early and late complications related to the placement or removal of LASEMS have been reported, however few cases have presented life-threatening results. EUS-guided PFC drainage and LASEMS placement can be a safe and effective alternative approach in the management of selected patients.

Gastrointestinal bleeding is a leading cause of morbidity and mortality in the United States. The management of gastrointestinal bleeding is often challenging, depending on its location and severity. To date, widely accepted hemostatic treatment options include injection of epinephrine and tissue adhesives such as cyanoacrylate, ablative therapy with contact modalities such as thermal coagulation with heater probe and bipolar hemostatic forceps, noncontact modalities such as photodynamic therapy and argon plasma coagulation, and mechanical hemostasis with band ligation, endoscopic hemoclips, and over-the-scope clips. These approaches, albeit effective in achieving hemostasis, are associated with a 5-10% rebleeding risk. New simple, effective, universal, and safe methods are needed to address some of the challenges posed by the current endoscopic hemostatic techniques. The use of a novel hemostatic powder spray appears to be effective and safe in controlling upper and lower gastrointestinal bleeding. Although initial reports of hemostatic powder spray as an innovative approach to manage gastrointestinal bleeding are promising, further studies are needed to support and confirm its efficacy and safety. The aim of this study was to evaluate the technical feasibility, clinical efficacy, and safety of hemostatic powder spray (Hemospray, Cook Medical, Winston-Salem, North Carolina, USA) as a new method for managing gastrointestinal bleeding. In this review article, we performed an extensive literature search summarizing case reports and case series of Hemospray for the management of gastrointestinal bleeding. Indications, features, technique, deployment, success rate, complications, and limitations are discussed. The combined technical and clinical success rate of Hemospray was 88.5% (207/234) among the human subjects and 81.8% (9/11) among the porcine models studied. Rebleeding occurred within 72 hours post-treatment in 38 patients (38/234; 16.2%) and in three porcine models (3/11; 27.3%). No procedure-related adverse events were associated with the use of Hemospray. Hemospray appears to be a safe and effective approach in the management of gastrointestinal bleeding.

No abstract

The use of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) appears to be a safe and feasible means of confirming or excluding malignancy in the adrenal glands. EUS-FNA with biopsy of suspicious masses in either adrenal gland allows for assessment of these lesions while keeping complications relatively rare. The main advantages of EUS-FNA are that it can be done as an outpatient procedure, with good results, minimal morbidity, and a short hospital stay. Nevertheless, EUS-FNA of adrenal masses should be indicated only in selected cases, in which there is potential to either decrease unnecessary treatment or guide therapy in cancer patients by aiding in either staging of malignancy or treatment of recurrence.v

Colon capsule endoscopy (CCE) is being actively evaluated as an emerging complementary or alternative procedure for evaluation of the colon. The yield of CCE is significantly dependent on the quality of bowel preparation. In addition to achieving a stool-free colon the bowel preparation protocols need to decrease bubble effect and aid propulsion of the capsule. An extensive English literature search was done using PubMed with search terms of colon capsule endoscopy, PillCam and bowel preparation. Full-length articles which met the criteria were included for review. A total of 12 studies including 1149 patients were reviewed. There was significant variability in the type of bowel preparation regimens. Large-volume (3-4 liters) polyethylene glycol (PEG) was the most widely used laxative. Lower volumes of PEG showed comparable results but larger studies are needed to determine efficacy. Sodium phosphate was used as an effective booster in most studies. Magnesium citrate and ascorbic acid are emerging as promising boosters to replace sodium phosphate when it is contraindicated. The potential benefit of prokinetics needs further evaluation. Over the past decade there has been significant improvement in the bowel preparation regimens for CCE. Further experience and studies are likely to standardize the bowel preparation regimens before CCE is adopted into routine clinical practice.

Objectives:The Over-The-Scope-Clip (OTSC) has had an evolving role in endoscopic closure of gastrointestinal wall defects, in hemostasis of primary or postinterventional bleeding, and approximation of postbariatric surgery defects. Rapid and effective closure of gastrocutaneous (GC) fistulae using this device has been recently described in the literature. The aim of this study was to evaluate the technical feasibility, efficacy and safety of OTSC as an effective tool in the management of persistent GC fistulae secondary to a complication of percutaneous endoscopic gastrostomy (PEG) tube placement. Method: In this multicenter prospective observational study, we describe our experience with OTSC in the closure of persistent GC fistulas secondary to PEG tube placement. Patients with GC fistulas were sequentially enrolled with a mean age of 84 years. Primary treatment outcome was the immediate successful closure of GC fistula and resolution of leak. Secondary outcome was no recurrence of the fistula and leaks on follow up. Results: A total of 10 patients were enrolled over the study period. Mean age was 84.4 ± 8.75 years. The primary treatment outcome was achieved in all the patients undergoing this intervention. Secondary outcome was observed in 9/10 (90%) subjects. No procedural complications were reported. Larger fistulae (>2.5 cm) and those with significant fibrosis were more difficult to close with the OTSC system. The mean follow-up time after OTSC application was 43.7 ± 20.57 days. A limitation of this study was that there was no control group. Conclusions: OTSC application is a safe and effective endoscopic approach for the closure of persistent GC fistulae secondary to a complication of PEG tube placement.

Acute cholecystitis and other clinical problems requiring gallbladder removal or drainage have conventionally been treated with surgery, endoscopic retrograde cholangiopancreatography or percutaneous transhepatic drainage of the gallbladder and/or extrahepatic bile duct. Patients unable to undergo these procedures due to functional status or anatomical anomalies are candidates for endoscopic ultrasound (EUS)-guided gallbladder drainage with stent placement. The aim of this review was to evaluate the technical feasibility and efficacy of EUS-guided placement of the recently developed lumen-apposing self-expandable metallic stent (LASEMS). A literature review was performed to identify the studies describing this technique. In this review article we have summarized case series or reports describing EUS-guided LASEMS placement. The indications, techniques, limitations and complications reported are discussed. A total of 78 patients were included across all studies described thus far in the literature. Studies have reported near 100% technical and clinical success rates in selected cases. No major complications were reported. EUS-guided gallbladder drainage and LASEMS placement can be a safe and effective alternative approach in the management of selected patients.