Using a customized GPT to provide guideline-based recommendations for management of pancreatic cystic lesions

Background and study aims Rising prevalence of pancreatic cysts and inconsistent management guidelines necessitate innovative approaches. New features of large language models (LLMs), namely custom GPT creation, provided by ChatGPT can be utilized to integrate multiple guidelines and settle inconsistencies. Methods A custom GPT was developed to provide guideline-based management advice for pancreatic cysts. Sixty clinical scenarios were evaluated by both the custom GPT and gastroenterology experts. A consensus was reached between experts and review of guidelines and the accuracy of recommendations provided by the custom GPT was evaluated and compared with experts. Results The custom GPT aligned with expert recommendations in 87% of scenarios. Initial expert recommendations were correct in 97% and 87% of cases, respectively. No significant difference was observed between the accuracy of custom GPT and the experts. Agreement analysis using Cohen's and Fleiss' Kappa coefficients indicated consistency among experts and the custom GPT. Conclusions This proof-of-concept study shows the custom GPT's potential to provide accurate, guideline-based recommendations for pancreatic cyst management, comparable to expert opinions. The study highlights the role of advanced features of LLMs in enhancing clinical decision-making in fields with significant practice variability.

Mechanical Perspective on Increasing Brush Cytology Yield

Brush cytology is a sampling technique extensively used for mucosal surfaces, particularly to identify malignancies. A sample is obtained by rubbing the brush bristles over the stricture or lesion several times until cells are trapped. Brush cytology detection rate varies, with malignancy confirmed in 15-65% of cases of adenocarcinoma-associated biliary strictures and 44-80% of cases of cholangiocarcinoma. Despite the widespread use of brush cytology, there is no consensus to date defining the optimal biliary brushing parameters for the collection of suspicious lesions, such as the number of passes, brushing rate, and force applied. The aim of this work is to increase the brush cytology diagnostic yield by elucidating the underlying mechanical phenomena. First, the mechanical interactions between the brush bristles and sampled tissue are analyzed. During brushing, mucus and detached cells are transferred to the space between the bristles through the capillary rise and flow eddies. These mass transfer mechanisms and their dependence on mucus rheology as a function of pH, brush displacement rate, and bristle geometry and configuration are examined. Lastly, results from ex vivo brushing experiments performed on porcine stomachs are presented. Clinical practitioners from a variety of disciplines can apply the findings of this study to outline clear procedures for cytological brushing to increase the sensitivity and specificity of the brushings.

Identification and control of two outbreaks of unrelated New Delhi metallo-β-lactamase-producing carbapenem-resistant Escherichia coli traced to the same endoscope defect

We report 2 outbreaks of genetically unrelated carbapenem-resistant New Delhi metallo-β-lactamase-producing Escherichia coli caused by contaminated duodenoscopes. Using endoscopes with disposable end caps, adherence to the manufacturer's reprocessing instructions, routine audits, and manufacturer evaluation are critical in preventing such outbreaks.

Pancreatic cyst dilemma: Between physical and biochemical markers

Physical analysis of the pancreatic cystic lesions (PCLs) fluid as expressed by the rheological behavior (“string sign”) can improve the diagnostic yield and should be integrated in every multimodal PCLs workup.

Heparanase as a potential player in SARS-CoV-2 infection and induced coagulopathy

During the current formidable COVID-19 pandemic, it is appealing to address ideas that may invoke therapeutic interventions. Clotting disorders are well recognized in patients infected with severe acute respiratory syndrome (SARS) caused by a novel coronavirus (SARS-CoV-2), which lead to severe complications that worsen the prognosis in these subjects. Increasing evidence implicate Heparan sulfate proteoglycans (HSPGs) and Heparanase in various diseases and pathologies, including hypercoagulability states. Moreover, HSPGs and Heparanase are involved in several viral infections, in which they enhance cell entry and release of the viruses. Herein we discuss the molecular involvement of HSPGs and heparanase in SARS-CoV-2 infection, namely cell entry and release, and the accompanied coagulopathy complications, which assumedly could be blocked by heparanase inhibitors such as Heparin and Pixatimod.

Primary synovial sarcoma of the mediastinum: a rare tumor diagnosed by endoscopic ultrasound-fine needle biopsy (EUS-FNB)-Cytomorphologic, immunohistochemical, and molecular analysis

Primary synovial sarcoma is exceedingly rare in the mediastinum. The differential diagnosis of this rare tumor is complex as a wide array of primary and metastatic tumors occur in this site.A definite diagnosis might be challenging even after tissue sampling. Immunohistochemistry can be very helpful and supportive for the diagnosis, but still inadequate in some cases as these tumors can mimic histopathologically other soft tissue tumors. Hence, in some case, an advanced pathological molecular analysis is needed.Endoscopic ultrasound (EUS) is an important diagnostic tool for mediastinal tumors. While EUS-fine needle aspiration (EUS-FNA) samples are usually inadequate for advanced pathological analysis, tissue acquisition by the newer generation of EUS-fine needle biopsy (EUS-FNB) needles might be sufficient.Here, we present the first report on primary mediastinal synovial sarcoma diagnosed by an immunohistochemical and FISH analysis performed on EUS-FNB tissue sample.

New technique: removal of embedded esophageal partially covered stent by endoscopic sub-stent space dissection

Both fully (FCSEMS) and partially (PCSEMS) covered self-expandable metal stents are used for the endoscopic management of leaks, perforations, and fistulas. PCSEMS have lower migration rates as their uncovered flanges allow for anchorage into the surrounding tissue, but this consequently makes them difficult to be removed, with reported cases of esophageal perforation during the removal of the embedded PCSEMS. Stent-in-stent technique is mostly used, where a FCSEMS is placed co-axially into an existing PCSEMS causing pressure necrosis and facilitating subsequent removal of both stents. This technique, although effective, is expensive, requiring the use of a second stent. In this report, we describe a series of 3 patients with embedded PCSEMS removed by a new endoscopic technique, i.e., endoscopic sub-stent space dissection, without using a second stent.

Endoscopic dilation of benign post-esophagectomy anastomotic strictures: long-term outcomes and risk of recurrence

Background

Benign esophageal anastomotic strictures often require repeat dilation to relieve dysphagia. Little is known about the factors that affect their remediation. The purpose of this article was to retrospectively evaluate the long-term clinical results of endoscopic dilation in the treatment of benign anastomotic strictures after esophagectomy, and to identify factors associated with stricture recurrence.

Methods

A single-center retrospective analysis (using electronic records) was performed on patients who underwent endoscopic dilation for esophageal anastomotic strictures. Long-term clinical effectiveness, including technical and clinical success, and complication rate were assessed. Factors independently related to recurrence were evaluated.

Results

Between January 2014 and December 2017, a total of 35 patients who had benign anastomotic strictures after esophagectomy underwent 182 endoscopic dilation procedures. Technical success was 100%. Thirty-two patients (91%) had initial relief of dysphagia. The clinical success, defined as resolution of dysphagia and achieving luminal patency of 13 mm or more, was achieved in 24 patients (69%). Strictures recurred in 43% of patients, and refractory strictures were identified in 10/35 (29%). Proximal anastomosis and the presence of anastomotic foreign bodies were found to be risk factors for refractory strictures. The complication rate was low (4%) and adverse events were mild. No major complications (perforations, severe bleeding) or treatment-related deaths occurred in this series.

Conclusions

Endoscopic dilation has a high technical and a good clinical success rate. However, anastomotic strictures are often refractory and frequently recur.

Rescuing the Rescuer: Fractured Dormia Basket and a Second Basket Rescue Technique

Mechanical lithotripsy is one of the well-known rescue methods for impacted common bile duct (CBD) stones. A fractured Dormia basket with a captured stone is an unusual complication and poses a special management problem. In the past, surgical intervention was the standard method. Various nonsurgical techniques have been reported. If the impaction is at the level of the papilla, extending the sphincterotomy might be sufficient. Stent insertion, endoscopic mechanical lithotripsy, extracorporeal shock wave lithotripsy, endoscopic laser lithotripsy, and transhepatic choledochoscopic lithotripsy have all been reported. In this case, we used a second basket, which is readily available and less expensive, as a rescue technique.

How to cite this article

Khamaysi I, Hajj E. Rescuing the Rescuer: Fractured Dormia Basket and a Second Basket Rescue Technique. Euroasian J Hepato-Gastroenterol 2020;10(1):45-46.

Heparanase in Acute Pancreatitis

Acute pancreatitis (AP) is one of the most common diseases in gastroenterology, affecting 2% of all hospitalized patients. Nevertheless, neither the etiology nor the pathophysiology of the disease is fully characterized, and no specific or effective treatment has been developed. Heparanase (Hpa) is an endoglycosidase that cleaves heparan sulfate (HS) side chains of heparan sulfate proteoglycans (HSPGs) into shorter oligosaccharides, activity that is highly implicated in cell invasion associated with cancer metastasis and inflammation. Given that AP is a typical inflammatory disease, we investigated whether Hpa plays a role in AP. Our results provide keen evidence that Hpa expression and activity are significantly increased following cerulein-induced AP in wild type mice. In parallel to the classic manifestations of AP, namely elevation of amylase and lipase levels, pancreas edema and inflammation as well as induction of cytokines and signaling molecules, have been detected in this experimental model of the disease. Noteworthy, these features were far more profound in transgenic mice overexpressing heparanase (Hpa-Tg), suggesting that these mice can be utilized as a model system to reveal the molecular mechanism by which Hpa functions in AP. Further support for the involvement of Hpa in the pathogenesis of AP emerged from our observation that treatment of experimental AP with PG545 or SST0001(= Ronepastat), two potent Hpa inhibitors, markedly attenuated the biochemical, histological and immunological manifestations of the disease. Hpa, therefore, emerges as a potential new target in AP, and Hpa inhibitors are hoped to prove beneficial in AP along with their promising efficacy as anti-cancer compounds.

Drug-induced Pancreatic Atrophy ("The Vanishing Pancreas")

Immune checkpoint inhibitors have become the therapeutic mainstay in a rapidly growing number of cancers. Immune checkpoint inhibitor-related diarrhea is attributed mainly to inflammatory colitis, with no other drug-related differential diagnosis. However, other causes of diarrhea should be considered. Pancreatic atrophy (and exocrine pancreatic insufficiency) is a relatively rare complication of immune checkpoint inhibitors. Herein we bring a set of striking computed tomography (CT) images that demonstrate a drug-related-progressive pancreatic atrophy until complete vanishing of pancreatic tissue. Exocrine pancreatic insufficiency (EPI) was diagnosed. Pancreatic enzyme replacement therapy was initiated with an excellent clinical response.

How to cite this article: Khamaysi I, Hajj E. Drug-induced Pancreatic Atrophy (“The Vanishing Pancreas”). Euroasian J Hepato-Gastroenterol 2020;10(2):101–102.

A phase II study of siG12D-LODER in combination with chemotherapy in patients with locally advanced pancreatic cancer (PROTACT)

TPS4672

Background: KRAS alterations are the most frequent driver alterations identified in pancreas cancer; however, KRAS has remained an elusive therapeutic target. siG12D-LODER is a novel, miniature bio-degradable polymeric matrix encompassing a novel small interfering RNA targeting KRAS G12D and all additional G12X mutations (G12C, G12V...). The siG12D-LODER is inserted directly into the pancreas tumor via endoscopic intervention. A Phase 1/2a dose escalation and expansion study of patients receiving a one-time dose of siG12D-LODER with ongoing chemotherapy demonstrated that the combination was well-tolerated and safe and exhibited promising potential efficacy with 10/12 patients achieving disease control and median overall survival 15.1 months (Golan, Oncotarget 2015). Methods: This phase 2 study was initially designed as a randomized, two arm, open label study of gemcitabine and nab-paclitaxel with or without siG12D-LODER for patients with locally advanced pancreas cancer with planned 40 patients in each arm and primary endpoint of progression-free survival. Eighteen patients were enrolled in the chemotherapy alone arm and 18 in the chemotherapy and siG12D-LODER arm. After an interim analysis, the study design has been amended and is now a single arm study in which patients (N=39) with both borderline resectable and locally advanced pancreas cancer will receive investigator’s choice of chemotherapy (the combination of gemcitabine/nab-paclitaxel or modified FOLFIRINOX) and all patients will receive up to three doses of the siG12D-LODER administered once every 12 weeks. Primary endpoint is overall response rate after final siG12D-LODER insertion. Secondary endpoints include duration of response, progression-free survival, overall survival, time to response, percentage of patients proceeding to surgical resection, and percentage of patients receiving radiation therapy. Exploratory analyses include evaluation of KRAS mutation status and monitoring of circulating free DNA and circulating tumor cells. The amended protocol is now open for accrual and four patients having been enrolled to date. Trial accrual is anticipated to be completed by December 2020. Clinical trial information: NCT01676259 .

Endoscopic treatment of post-cholecystectomy bile leaks: a tertiary center experience

BACKGROUND

Post-cholecystectomy bile leak is relatively a well-known surgical complication. Several potential treatment modalities for such leaks are used. The early use of ERCP to exclude significant bile duct injury and to treat the leak by various endoscopic means is supported by a large bulk of data. However, there is no consensus as to the optimal endoscopic intervention.

METHODS

A retrospective review of ERCP database was done to identify all cases of bile leak related to cholecystectomy. Patient records including surgical and endoscopic reports were reviewed, and telephone interviews were conducted to collect data.

RESULTS

During the period 2004-2016, 100 patients (53 men, 47 women; mean age, 55 years) with post-cholecystectomy bile leak were referred for ERCP. Cholecystectomy was done laparoscopically in 82 patients (with an open conversion rate of 13%). In the majority of cases (77%), the leak was diagnosed by ongoing bile flow from the drains. The most common symptoms were pain (17%) and fever (4%). The most common site of the leak was the cystic duct stump (79%) followed by subvesical ducts (7%). Low grade leaks were seen in 84% of cases. Treatment included stent insertion alone (9%), sphincterotomy alone (11%), combination stent/sphincterotomy (76%) and others (1%). Failed ERCP was encountered in 3%. Endoscopic therapy was successful in 90 patients (90%). In subgroup analysis, success rate of procedures with stent insertion (with or without sphincterotomy) is significantly higher compared to procedures without stent insertion (95.3% vs 72.7%, p < 0.05). The failure rate of sphincterotomy alone procedures (3/11, 27%) is much higher compared to procedures with stent insertion (4/85, 5%) with p < 0.05. Four patients (4%) developed post-ERCP pancreatitis (mild to moderate) and one patient (1%) suffered from retroperitoneal perforation.

CONCLUSION

The optimal endoscopic intervention for post-cholecystectomy bile leak should include temporary insertion of a biliary stent.

Physician adherence to societal guidelines following colonoscopy with polypectomy

Background

Colorectal cancer is a significant cause of mortality and morbidity in western countries. Polypectomy reduces the incidence and mortality of colorectal cancer. Following polypectomy, recommendations regarding the frequency and duration of surveillance rely mostly on features of the resected polyps and are summarized in various gastroenterological societal guidelines. In this study, we aimed to delineate the accuracy of current post-polypectomy surveillance recommendations and to check whether active intervention would lead to an improvement in accuracy and consistency with societal guidelines.

Methods

We prospectively collected polypectomy reports over a 3-month period in 2 tertiary medical centers. We then performed an intervention that included: 1) presentation of results from 1^st phase; 2) re-affirming the guidelines in a departmental meeting; 3) addition of a dedicated reporting form for post-polypectomy surveillance recommendations in the patients’ electronic medical file. Finally, we conducted a second prospective collection of post-polypectomy recommendations, over a second 3-month period.

Results

Prior to the intervention, 76% of the colonoscopies with polypectomy had a recommendation for surveillance, compared to 85% after the intervention (P=0.003). Prior to the intervention, 65% of patients received a recommendation consistent with societal guidelines, compared with 78% after the intervention (P=0.001).

Conclusion

Intervention, including re-affirmation of the current guidelines and creation of a dedicated reporting platform, significantly increases the number of follow-up recommendations after polypectomy and their consistency with societal guidelines.

Endoscopist-directed balanced propofol sedation is safe and effective in patients undergoing outpatient colonoscopy

Background and Aims: Propofol administered in combination with other moderate sedation medications (balanced propofol sedation [BPS]) is an appealing and effective sedation regimen for gastrointestinal (GI) endoscopy procedures. However, product labeling dictates propofol be administered only by anesthesiology personnel. We evaluated the safety of endoscopist-directed as well as anesthesiologist-administered BPS during outpatient colonoscopy. Methods: We performed a retrospective cohort study using prospectively collected endoscopy data where endoscopist-directed BPS is standard practice. Measured patient outcomes included: BPS drug dosages, postcolonoscopy oxygen saturation levels, pulse, and systolic/diastolic blood pressures, need for mask bag ventilation or endotracheal intubation, aborted colonoscopy due to sedation, hospital admission postcolonoscopy, and mortality. Results: From April 1 to November 30, 2013, 1036 patients undergoing outpatient colonoscopy (mean age 56.4 years, 55% males, 32% American Society of Anesthesiologists [ASA] I, 59% ASA II, 9% ASA III) received endoscopist-directed BPS. During the same time period, 40 patients (mean age 66.6 years, 55% males, 33% ASA II, 67% ASA III) received anesthesiologist-administered BPS. Indications for colonoscopy for the endoscopist-directed BPS included 352 (34%) colorectal cancer screening/surveillance, 404 (39%) evaluation of lower GI symptoms, 156 (15%) positive fecal occult blood, and 124 (12%) inflammatory bowel disease. BPS dosages (mean ± standard deviation) per patient were Fentanyl 0.05 mg (fixed dose), midazolam 1.6 mg ± 0.5 mg (range: 1-5 mg), and propofol 104 mg ± 62 mg (range: 10-460 mg). Propofol doses correlated inversely with patient age (r = −0.35; P < 0.001), and the mean Propofol dose was lower as ASA score increased: ASA I - 115 mg, ASA II - 103 mg, and ASA III - 75 mg (P < 0.01). No patient required bag mask ventilation, endotracheal intubation, or hospital admission. There were no aborted colonoscopies secondary to sedation and no mortality. All patients were discharged directly to home. Conclusions: Endoscopist-directed BPS appears safe and effective for low-, intermediate- and high-risk patients undergoing outpatient colonoscopy.

Safety and efficacy of endoscopist-directed balanced propofol sedation during endoscopic retrograde cholangiopancreatography

Background

Endoscopist-directed balanced propofol sedation (BPS) appears to be safe and effective for routine endoscopy. However, there are limited data on its use in endoscopic retrograde cholangiopancreatography (ERCP). We evaluated the safety and efficacy of endoscopist-directed BPS for ERCP, and compared patient outcomes with anesthesiologist-administered moderate sedation.

Methods

This was a retrospective cohort study, using prospectively collected endoscopy data from a tertiary care medical center where endoscopist-directed BPS during ERCP is routine practice. Adverse outcomes included need for bag-mask ventilation or intubation, aborted ERCP due to sedation, hospital admission post-ERCP (outpatients)/change in the level of care (inpatients), and death within 24 h.

Results

A total of 501 patients underwent ERCP with the use of endoscopist-directed BPS: Cohort 1 - 380 (76%) inpatients, mean age 64.1, 46% male, 24% American Society of Anesthesiologists physical status (ASA) score I, 65% ASA II, 11% ASA III. Concurrently, 24 patients received anesthesiologist-administered moderate sedation: Cohort 2 - 19 (79%) inpatients, mean age 65.0, 67% male, 12% ASA I, 25% ASA II, 38% ASA III, 25% ASA IV. In Cohort 1, none of the adverse outcomes were observed. Propofol dose was inversely correlated with age (r=-0.42, P<0.001), ASA score (r=-0.19, P<0.001), and Mallampati score (r=-0.24, P<0.001). One patient in Cohort 2 who received anesthesiologist-administered BPS required bag-mask ventilation and the ERCP was prematurely aborted because of the sedation. There were no deaths from any cause within 24 h of ERCP.

Conclusion

Endoscopist-directed BPS appears safe, efficacious, and feasible for ASA I-III patients undergoing inpatient or ambulatory ERCP.

Screening to Detect Precursor Lesions of Pancreatic Adenocarcinoma in High-risk Individuals: A Single-center Experience

OBJECTIVE OF THE WORK

Pancreatic cancer (PC) is a deadly disease that is most commonly diagnosed at an incurable stage. Early diagnosis is the most important factor for improving prognosis. Evidence is beginning to accumulate that screening and surveillance may lead to the early detection of precursor lesions and/or pancreatic cancer in asymptomatic individuals. Proper screening methods and identification of such precursor lesions may enable effective pre-emptive interventions to prevent further fatalities. The primary objective of this project was to examine the feasibility of identifying precursor or early cancerous lesions in high-risk individuals by endoscopic ultrasound (EUS) screening to prevent the deaths from pancreatic cancer.

RESEARCH AIM

Pancreatic cancer screening guidelines, based on consensus opinions, have been applied in various tertiary centers around the world; however, evidence for effectiveness is lacking. At Rambam Health Care Campus, we have established a cohort of high-risk individuals, and we report our local 10-year experience results of screening for pancreatic cancer.

METHODS

Between 2008 and 2018, a cohort of 123 asymptomatic high-risk individuals came for annual/biannual EUS screening for pancreatic cancer. Retrospective and prospectively collected data were obtained, analyzed, and compared on the basis of several variables. These variables include age at beginning of screening, gender, smoking, obesity, diabetes, and presence of tumor markers, as well as the patients' personal and family history of cancers. Findings on each EUS are described.

RESULTS

Three patients out of 123 underwent potentially life-saving surgery as a result of this screening program. All of these three had only one first-degree relative (FDR) with pancreatic cancer at the time of their first screenings, but two eventually had a second FDR with PC. Findings from 296 EUS exams regarding smoking, obesity, and other risk factors are presented. Minor, possibly trivial, EUS findings are found to be common. Detection of precursor pancreatic lesions is feasible with EUS screenings.

CONCLUSIONS

Adherence was an important limiting factor in screening. Better stratification of patients according to specific risk factors, including thorough genetics and family history, may direct when and how to initiate screening. International collaborations, such as the International Cancer of Pancreas Screening (CAPS) Consortium, of which Rambam is a collaborating partner, are needed to collate evidence for impact of screening to prevent pancreatic cancer morbidity and mortality, and are essential to achieve proof of concept. Different countries with varying health-care systems and budgets can find variance of appropriateness of screening procedures.

Large adrenal cyst masquerading as a pancreatic cystic tumor: a rare diagnosis based on endoscopic ultrasound

Adrenal cystic lesions constitute a rare finding and usually are diagnosed incidentally as retroperitoneal cysts during imaging studies. A major issue, especially for the large-sized ones, is their preoperative diagnosis and management, as imaging modalities often fail to detect their exact origin prior to surgery. We report a case of a big adrenal cyst that was mistakenly diagnosed and followed up as pancreatic cystic tail tumor. Our thorough workup, which included endoscopic ultrasound (EUS), managed to delineate an adrenal gland-originated cyst and altered further management of the patient. According to our knowledge, this is the first report in literature in which EUS proved its superiority over other imaging studies in clarifying the origin of an ambiguous big retroperitoneal cyst. We believe that for cases of large retroperitoneal cystic lesions, EUS consists the optimal diagnostic and sampling tool.

Management of gastric fistula complicating laparoscopic sleeve gastrectomy with biological glue in a combined percutaneous and endoscopic approach

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is considered as a first line treatment for morbid obesity around the globe. Leakage and subsequent gastric fistula is the most dreadful complication, which may lead to serious morbidity and even mortality.

OBJECTIVES

To assess the safety and efficacy of fibrin glue application in the setting of gastric fistula after LSG.

SETTING

University hospital, Israel.

METHODS

Twenty-four morbidly obese patients (mean age = 42.2 yr, mean body mass index = 42 kg/m²) developed gastric fistula after LSG. The fistula was acute in 10 patients, subacute in 9, and chronic in 5. Sixteen patients (67%) have had previous failed endoscopic interventions. Fibrin glue was applied percutaneously with fluoroscopic guidance, under endoscopic visualization. A pigtail drain was left in the distal tract to monitor and manage possible continuous leakage.

RESULTS

There were no complications except abdominal pain in 2 patients associated with fever in 1. Both resolved within 1 to 2 days. Fistula closure was achieved in all patients but 1 (95.8%). Closure was accomplished after a single application in 9 patients (39%), 2 applications in 8, 3 applications in 3, 5 applications in 2, and 6 applications in 1. All patients were followed with a mean time of 42.3 months (range, 20-46).

CONCLUSIONS

Although in most patients there was a need for multiple applications, our experience indicates that percutaneous fluoroscopic application of Fibrin glue under endoscopic visualization proved to be a simple, tolerable, and highly effective method for the treatment of selected patients with gastric fistula after LSG.

Involvement of heparanase in the pathogenesis of acute kidney injury: nephroprotective effect of PG545

Despite the high prevalence of acute kidney injury (AKI) and its association with increased morbidity and mortality, therapeutic approaches for AKI are disappointing. This is largely attributed to poor understanding of the pathogenesis of AKI. Heparanase, an endoglycosidase that cleaves heparan sulfate, is involved in extracellular matrix turnover, inflammation, kidney dysfunction, diabetes, fibrosis, angiogenesis and cancer progression. The current study examined the involvement of heparanase in the pathogenesis of ischemic reperfusion (I/R) AKI in a mouse model and the protective effect of PG545, a potent heparanase inhibitor. I/R induced tubular damage and elevation in serum creatinine and blood urea nitrogen to a higher extent in heparanase over-expressing transgenic mice vs. wild type mice. Moreover, TGF-β, vimentin, fibronectin and α-smooth muscle actin, biomarkers of fibrosis, and TNFα, IL6 and endothelin-1, biomarkers of inflammation, were upregulated in I/R induced AKI, primarily in heparanase transgenic mice, suggesting an adverse role of heparanase in the pathogenesis of AKI. Remarkably, pretreatment of mice with PG545 abolished kidney dysfunction and the up-regulation of heparanase, pro-inflammatory (i.e., IL-6) and pro-fibrotic (i.e., TGF-β) genes induced by I/R. The present study provides new insights into the involvement of heparanase in the pathogenesis of ischemic AKI. Our results demonstrate that heparanase plays a deleterious role in the development of renal injury and kidney dysfunction, attesting heparanase inhibition as a promising therapeutic approach for AKI.

Differentiation of Pancreatic Cyst Types by Analysis of Rheological Behavior of Pancreatic Cyst Fluid

Differentiation between mucinous and non-mucinous pancreatic cysts is exceedingly important and challenging, particularly as the former bears malignant transformation potential. Pancreatic cyst fluid (PCF)-based diagnostics, including analyses of biochemical markers, as well as cytology, has shown inadequate accuracy. Herein, a preliminary single-center study of 22 PCF samples, collected by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), assessed the rheological behavior of PCF and its correlation with lesion type. The dependence of PCF shear viscosity on shear rate was found to follow a power law and could be fitted using Ostwald-de Waele model. Three types of flow curves were identified, where two types correlated with non-mucinous cysts, differing by their power law exponent, and the third type corresponding to mucinous cysts. Viscosity measured at a high shear rate was shown to serve as an accurate and independent marker distinguishing between mucinous and non-mucinous cysts, with an optimal cutoff value of ηc = 1.3 cP The accuracy of this novel technique proved superior to string-sign, cytology, carcinoembryonic antigen, and amylase assessments. Moreover, the combined predictive value of ηc and patient age provided for sensitivity and specificity of 100% and 95.5%, respectively. This simple and rapid diagnostic tool can be immediately implemented after EUS-FNA sampling.

Heparanase: A Potential New Factor Involved in the Renal Epithelial Mesenchymal Transition (EMT) Induced by Ischemia/Reperfusion (I/R) Injury

BACKGROUND

Ischemia/reperfusion (I/R) is an important cause of acute renal failure and delayed graft function, and it may induce chronic renal damage by activating epithelial to mesenchymal transition (EMT) of renal tubular cells. Heparanase (HPSE), an endoglycosidase that regulates FGF-2 and TGFβ-induced EMT, may have an important role. Therefore, aim of this study was to evaluate its role in the I/R-induced renal pro-fibrotic machinery by employing in vitro and in vivo models.

METHODS

Wild type (WT) and HPSE-silenced renal tubular cells were subjected to hypoxia and reoxygenation in the presence or absence of SST0001, an inhibitor of HPSE. In vivo, I/R injury was induced by bilateral clamping of renal arteries for 30 min in transgenic mice over-expressing HPSE (HPA-tg) and in their WT littermates. Mice were sacrificed 48 and 72 h after I/R. Gene and protein EMT markers (α-SMA, VIM and FN) were evaluated by bio-molecular and histological methodologies.

RESULTS

In vitro: hypoxia/reoxygenation (H/R) significantly increased the expression of EMT-markers in WT, but not in HPSE-silenced tubular cells. Notably, EMT was prevented in WT cells by SST0001 treatment. In vivo: I/R induced a remarkable up-regulation of EMT markers in HPA-tg mice after 48-72 h. Noteworthy, these effects were absent in WT animals.

CONCLUSIONS

In conclusion, our results add new insights towards understanding the renal biological mechanisms activated by I/R and they demonstrate, for the first time, that HPSE is a pivotal factor involved in the onset and development of I/R-induced EMT. It is plausible that in future the inhibition of this endoglycosidase may represent a new therapeutic approach to minimize/prevent fibrosis and slow down chronic renal disease progression in native and transplanted kidneys.

Removal of a partially covered stent by endoscopic substent dissection

Herein we describe a new technical endoscopic removal of embedded partially covered esophageal stent that was inserted to treat a iatrogenic perforation of esophagus. Usually, partially covered stents can be removed by the stent-in-stent technique. In this case, the embedded stent could not be removed safely with this technique; so we performed a sub stent dissection to detach the stent from the esophageal wall.

Bowel preparation in "real-life" small bowel capsule endoscopy: a two-center experience

Background

Video capsule endoscopy (VCE) is an established diagnostic tool for the investigation of small bowel (SB) pathology. Bowel preparation prior to VCE may improve visualization, transit time, and diagnostic yield. We aimed to evaluate the “real-life” experience comparing two different preparation protocols in patients undergoing SB VCE.

Methods

We performed a retrospective analysis of prospectively collected data from SB VCE procedures, performed in two tertiary care medical centers in Israel. VCE procedures performed at “Sheba Medical Center” used a 2-L polyethylene glycol (PEG) bowel preparation (n=360) while VCEs performed at “Rambam Health Care campus” used a clear liquid diet plus 12-h fast protocol (n=500). A dichotomous preparation scale (adequate, inadequate) was used to classify cleansing quality. Data collection included patient and procedural details. The proportion of VCE procedures with adequate bowel preparation and the overall positive SB findings in the two different bowel preparation protocols were evaluated.

Results

SB completion rates were higher in the PEG protocol (96% vs. 83%, P<0.001) and SB passage time was significantly faster in the PEG protocol (mean 217±73 vs. 238±77 min, P<0.001). Bowel preparation quality was similar between groups (8% vs. 7% inadequate preparation, P=0.591). Overall positive SB findings were similar between the two groups (57% clear liquid fasting only vs. 51% PEG protocol, P=0.119).

Conclusion

In this large cohort, a 2-L PEG protocol had similar preparation quality and diagnostic yield compared with clear liquid fasting.

Nonvariceal Upper Gastrointestinal Bleeding: Timing of Endoscopy and Ways to Improve Endoscopic Visualization

Upper gastrointestinal (UGI) endoscopy is the cornerstone of diagnosis and management of patients presenting with acute UGI bleeding. Once hemodynamically resuscitated, early endoscopy (performed within 24 hours of patient presentation) ensures accurate identification of the bleeding source, facilitates risk stratification based on endoscopic stigmata, and allows endotherapy to be delivered where indicated. Moreover, the preendoscopy use of a prokinetic agent (eg, i.v. erythromycin), especially in patients with a suspected high probability of having blood or clots in the stomach before undergoing endoscopy, may result in improved endoscopic visualization, a higher diagnostic yield, and less need for repeat endoscopy.

Endoscopic removal of partially migrated intragastric bands following surgical gastroplasty: a prospective case series

BACKGROUND

The intragastric migration of a surgically placed adjustable gastric band is believed to occur slowly, over months to years. Band removal procedures necessitate surgical laparotomy, thus increasing the risk of complications.

METHODS

The endoscopic technique for band removal described in this case-series provides a minimally invasive approach.

RESULTS

Fifteen patients referred for endoscopic removal of a partially migrated intragastric band. The partially migrated intragastric bands were all successfully removed in a mean of 1.1 endoscopic sessions. No patient required subsequent surgical intervention, and there were no immediate or delayed adverse events including no infections, bleeding, or perforations.

CONCLUSIONS

Endoscopic removal of partially migrated intragastric bands appears feasible, effective, safe, and is a minimally invasive alternative to repeat surgery.

Acute upper gastrointestinal bleeding (UGIB) - initial evaluation and management

Acute upper gastrointestinal bleeding (UGIB) is the most common reason that the 'on-call' gastroenterologist is consulted. Despite the diagnostic and therapeutic capabilities of upper endoscopy, there is still significant associated morbidity and mortality in patients experiencing acute UGIB, thus this is a true GI emergency. Acute UGIB is divided into non-variceal and variceal causes. The most common type of acute UGIB is 'non-variceal' and includes diagnoses such as peptic ulcer (gastric and duodenal), gastroduodenal erosions, Mallory-Weiss tears, erosive oesophagitis, arterio-venous malformations, Dieulafoy's lesion, and upper GI tract tumours and malignancies. This article focuses exclusively on initial management strategies for acute upper GI bleeding. We discuss up to date and evidence-based strategies for patient risk stratification, initial patient management prior to endoscopy, potential causes of UGIB, role of proton pump inhibitors, prokinetic agents, prophylactic antibiotics, vasoactive pharmacotherapies, and timing of endoscopy.

Phosphodiesterase 5 inhibition protects against increased intra-abdominal pressure-induced renal dysfunction in experimental congestive heart failure

AIMS

Congestive heart failure (CHF) is associated with impaired renal function. Previously, we have demonstrated that rats with decompensated CHF exhibited exaggerated sensitivity to the adverse renal effects of increased increased intra-abdominal pressure (IAP) as compared with normal controls. This study tested whether phosphodiesterase 5 (PDE5) inhibition protects against the adverse renal effects of increased IAP in rats with CHF.

METHODS AND RESULTS

Following baseline periods, rats with compensated and decompensated CHF induced by the placement of an aorto-caval fistula (ACF), rats with myocardial infarction (MI) induced by left anterior descending (LAD) artery ligation, and sham controls were subjected to consecutive IAPs: 7, 10, or 14 mmHg. Urine flow (V), Na(+) excretion (U(Na)V), glomerular filtration rate (GFR), and renal plasma flow (RPF) were determined. The effects of pre-treatment with tadalafil on the adverse renal effects of IAP were examined in rats with decompensated CHF and MI. Elevation of IAP to 10 and 14 mmHg produced linear reductions in these parameters. Basal renal function and haemodynamics were lower in CHF rats. Decompensated CHF rats and MI rats that were subjected to 10 and 14 mmHg exhibited exaggerated declines in V, U(Na)V, GFR, and RPF. In contrast, no adverse renal effects were observed in rats with compensated CHF subjected to IAP. Pre-treatment of decompensated CHF rats and MI rats with tadalafil ameliorated the adverse renal effects of high IAP.

CONCLUSION

Decompensated CHF and MI rats are vulnerable to the adverse renal effects of IAP. Tadalafil abolishes IAP-induced renal dysfunction, supporting a therapeutic role for PDE5 inhibition in CHF associated with ascites.

Sub-clinical hepatic encephalopathy in cirrhotic patients is not aggravated by sedation with propofol compared to midazolam: a randomized controlled study

BACKGROUND & AIMS

The risk of exacerbating sub-clinical hepatic encephalopathy (HE) by propofol has not been established. The aim of this study is to determine whether the use of propofol, for upper endoscopy in patients with cirrhosis, precipitates sub-clinical HE.

METHODS

Sixty-one patients with compensated HCV and HBV cirrhosis (CP score 5-6) were randomly selected and divided into two groups (intent-to-treat population) matched for age, gender, and BMI. The first group received a single propofol sedation (N = 31, age 57 ± 12, dose range 70-100 mg/procedure) and the second group (N = 30, age 56 ± 12, dose 3-6 mg/procedure) received a single midazolam sedation, all done by an anesthesiologist. All patients completed number connection test (NCT), cognitive function score, time to recovery, time to discharge sheets, and hemodynamic parameters before sedation, and at discharge from the endoscopy unit, 1h post-procedure. Thirty control subjects without cirrhosis were matched to the cirrhotic patients who received sedation with regard to age, gender, BMI, and education level.

RESULTS

A total of 58/61 cirrhotic patients (95%) had sub-clinical encephalopathy before the endoscopy (mean NCT 84.7 ± 77 s, normal < 30 s). No patient developed overt HE after sedation. There were no differences between groups in the incidence of adverse effects, cognitive function, MELD score, CP score, oxygen saturation, or respiratory and heart rates before and after sedation. Propofol did not exacerbate minimal HE when compared to midazolam (NCT changed from 87.5 ± 62 s prior to sedation to 74.2 ± 58 s after sedation in the propofol group versus 72.8 ± 62 s before to 85.6 ± 72 s after sedation in the midazolam group; p < 0.01). Time to recovery (4.1 ± 1.9 min vs. 11.5 ± 5.0 min, p < 0.001), and time to discharge (38.0 ± 9 min vs. 110 ± 42 min, p < 0.001) were significantly shorter with propofol than midazolam. Pre- and post-procedure NCT (from 25 ± 20 s to 24 ± 20 s), cognitive function score (from 25 to 26), time to recovery (3.5 ± 1.0 min), and time to discharge (35 ± 10 min) did not change in the healthy controls.

CONCLUSIONS

Sedation with propofol has a shorter time recovery and a shorter time to discharge than midazolam and does not exacerbate sub-clinical hepatic encephalopathy in patients with compensated liver cirrhosis.

Difference of CBD width on US vs. ERCP

PURPOSE

To investigate the relationship between US and ERCP in the measurement of common bile duct (CBD) width after application of Compound and Harmonic imaging on ultrasound.

METHODS

We prospectively evaluated the CBD width as measured on endoscopic retrograde cholangiopancreatography (ERCP) and ultrasonography (US), applying Compound and Harmonic US techniques, on 100 patients. Furthermore, we retrospectively re-examined US and ERCP images of 48 patients who underwent ERCP and US during the same hospitalization period.

RESULTS

The average difference in measurements by US compared to ERCP was 2.3 mm (P < 0.01) in the retrospective and 1.9 mm in the prospective study (P < 0.001). The average difference in measurements between US and ERCP in post-cholecystectomy patients was 4.0 mm in the retrospective study (10 patients), and 3.8 in the prospective study (25 patients). The difference between the measurements on both examinations decreased with increasing CBD width. There was a good correlation between ERCP and US measurements of CBD width (r = 0.73 for all patients and r = 0.88 for patients with intact gallbladder, P < 0.001).

CONCLUSIONS

There is a gap between measurement of CBD width on US and ERCP of about 2 mm. The application of Compound and Harmonic techniques in the prospective study probably enabled a more accurate sonographic measurement.