Injectable, Drug-Eluting Nanocrystals Prevent Fibrosis and Stricture Formation In Vivo.

BACKGROUND & AIMS: Tissue fibrosis results from uncontrolled healing responses leading to excessive mesenchymal cell activation and collagen and other extracellular matrix deposition. In the gastrointestinal tract, fibrosis leads to narrowing of the lumen and stricture formation. A drug treatment to prevent fibrosis and strictures in the gastrointestinal tract would be transformational for patient care. We aimed to develop a stricture treatment with the following characteristics and components: a small molecule with strong antifibrotic effects that is delivered locally at the site of the stricture to ensure correct lesional targeting while protecting the systemic circulation, and that is formulated with sustained-release properties to act throughout the wound healing processes. METHODS: A high-throughput drug screening was performed to identify small molecules with antifibrotic properties. Next, we formulated an antifibrotic small molecule for sustained release and tested its antifibrotic potential in 3 animal models of fibrosis. RESULTS: Sulconazole, a US Food and Drug Administration-approved drug for fungal infections, was found to have strong antifibrotic properties. Sulconazole was formulated as sulconazole nanocrystals for sustained release. We found that sulconazole nanocrystals provided superior or equivalent fibrosis prevention with less frequent dosing in mouse models of skin and intestinal tissue fibrosis. In a patient-like swine model of bowel stricture, a single injection of sulconazole nanocrystals prevented stricture formation. CONCLUSIONS: The current data lay the foundation for further studies to improve the management of a range of diseases and conditions characterized by tissue fibrosis.

A patient-like swine model of gastrointestinal fibrotic strictures for advancing therapeutics.

Gastrointestinal (GI) strictures are difficult to treat in a variety of disease processes. Currently, there are no Food and Drug Administration (FDA) approved drugs for fibrosis in the GI tract. One of the limitations to developing anti-fibrotic drugs has been the lack of a reproducible, relatively inexpensive, large animal model of fibrosis-driven luminal stricture. This study aimed to evaluate the feasibility of creating a model of luminal GI tract strictures. Argon plasma coagulation (APC) was applied circumferentially in porcine esophagi in vivo. Follow-up endoscopy (EGD) was performed at day 14 after the APC procedure. We noted high grade, benign esophageal strictures (n = 8). All 8 strictures resembled luminal GI fibrotic strictures in humans. These strictures were characterized, and then successfully dilated. A repeat EGD was performed at day 28 after the APC procedure and found evidence of recurrent, high grade, fibrotic, strictures at all 8 locations in all pigs. Pigs were sacrificed and gross and histologic analyses performed. Histologic examination showed extensive fibrosis, with significant collagen deposition in the lamina propria and submucosa, as well as extensive inflammatory infiltrates within the strictures. In conclusion, we report a porcine model of luminal GI fibrotic stricture that has the potential to assist with developing novel anti-fibrotic therapies as well as endoscopic techniques to address recurring fibrotic strictures in humans.

Lumen apposing metal stents are superior to plastic stents in pancreatic walled-off necrosis: a large international multicenter study.

Background and study aims The use of lumen apposing metal stents (LAMS) during EUS-guided transmural drainage (EUS-TD) of pancreatic walled-off necrosis (WON) has gained popularity. Data supporting their use in WON over plastic stents (PS), however, remain scarce. The aim of this study was to compare the clinical efficacy of LAMS (Axios, Boston Scientific) with PS in WON. Patients and methods This was a multicenter, retrospective study involving 14 centers. Consecutive patients who underwent EUS-TD of WON (2012 - 2016) were included. The primary end point was clinical success defined as WON size ≤ 3 cm within a 6-month period without need for percutaneous drainage (PCD) or surgery. Results A total of 189 patients (mean age 55.2 ±â€Š15.6 years, 34.9 % female) were included (102 LAMS and 87 PS). Technical success rates were similar: 100 % in LAMS and 98.9 % in PS ( P  = 0.28). Clinical success was attained in 80.4 % of LAMS and 57.5 % of PS ( P  = 0.001). Rate of PCD was similar (13.7 % LAMS vs. 16.3 % PS, P  = 0.62), while PS was associated with a greater need for surgery (16.1 % PS vs. 5.6 % LAMS, P  = 0.02). Adverse events (AEs) were observed in 9.8 % of LAMS and 10.3 % of PS ( P  = 0.90) and were rated as severe in 2.0 % and 6.9 %, respectively ( P  = 0.93). After excluding patients with < 6 months follow-up, the rate of WON recurrence following initial clinical success was greater with PS (22.9 % PS vs. 5.6 % LAMS, P  = 0.04). Conclusions When compared to PS, LAMS in WON is associated with higher clinical success, shorter procedure time, lower need for surgery, and lower rate of recurrence.

Erratum: EUS-guided gastroenterostomy in management of benign gastric outlet obstruction.

[This corrects the article DOI: 10.1055/s-0043-123468.].

Cost-effectiveness analysis comparing lumen-apposing metal stents with plastic stents in the management of pancreatic walled-off necrosis.

BACKGROUND AND AIMS: EUS-guided transmural drainage is effective in the management of pancreatic walled-off necrosis (WON). A lumen-apposing metal stent (LAMS) has recently been developed specifically for the drainage of pancreatic fluid collections that shows promising results. However, no cost-effectiveness data have been published in comparison with endoscopic drainage with traditional plastic stents (PSs). Our aim here was to compare the cost-effectiveness of LAMSs to PSs in the management of WON. METHODS: A decision tree was developed to assess both LAMSs and PSs over a 6-month time horizon. For each strategy, after the insertion of the respective stents, patients were followed for subsequent need for direct endoscopic necrosectomy, adverse events requiring unplanned endoscopy, percutaneous drainage (PCD), or surgery using probabilities obtained from the literature. The unit of effectiveness was defined as successful endoscopic drainage without the need for PCD or surgery. Costs in 2016 U.S.$ were based on inpatient institutional costs. Sensitivity analyses were performed. An a priori willingness-to-pay threshold of U.S.$50,000 was established. RESULTS: LAMSs were found to be more efficacious than PSs, with 92% and 84%, respectively, of the patients achieving successful endoscopic drainage of WON. LAMSs, however, were more costly: the average cost per patient of U.S.$20,029 compared with U.S.$15,941 for PSs. The incremental cost-effectiveness ratio favored LAMSs at U.S.$49,214 per additional patient successfully treated. Sensitivity analyses confirmed the robustness of the results. CONCLUSION: LAMSs are more effective but also more costly than PSs in managing WON. Data from high-quality, adequately controlled, prospective, randomized trials are needed to confirm our findings.

EUS-guided gastroenterostomy in management of benign gastric outlet obstruction.

Background and study aims: Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) in malignant gastric outlet obstruction (GOO) appears to be promising; however, its role in benign GOO is unclear. The aim of this study was to ascertain the clinical efficacy and safety of EUS-GE in benign GOO. Patients and methods: This was an international retrospective series involving 5 tertiary centers. Consecutive patients who underwent EUS-GE between 1/2013 - 10/2016 for benign GOO were included. The primary endpoint was the rate of clinical success defined as ability to tolerate oral intake without vomiting. Secondary endpoints included technical success and rate of adverse events (AE). Results: Overall, 26 patients (46.2 % female; mean age 57.7 ±â€Š13.9 years) underwent EUS-GE for benign GOO due to strictures from chronic pancreatitis (n = 11), surgical anastomosis (n = 6), peptic ulcer disease (n = 5), acute pancreatitis (n = 1), superior mesentery artery syndrome (n = 1), caustic injury (n = 1), and hematoma (n = 1). Technical success was achieved in 96.2 %. Dilation of the lumen apposing metal stent was performed in 13/25 (52 %) with a mean maximum diameter of 14.6 ±â€Š1.0 mm. Mean procedure time was 44.6 ±â€Š26.1 min. Clinical success was observed in 84.0 % with a mean time to oral intake of 1.4 ±â€Š1.9 days and a median follow-up of 176.5 (IQR: 47 - 445.75) days. Rate of unplanned re-intervention was 4.8 %. 3 AE were noted including 2 misdeployed stents and 1 gastric leak needing surgical intervention following elective GE stent removal. Conclusions: EUS-GE is a promising treatment for benign GOO. Larger and prospective data are needed to further validate this novel endoscopic technique in treating benign GOO of various etiologies.

EUS-guided gastroenterostomy: a multicenter study comparing the direct and balloon-assisted techniques.

BACKGROUND: EUS-guided gastroenterostomy (EUS-GE) is a developing modality in the management of gastric outlet obstruction (GOO) with several technical approaches, including the direct and balloon-assisted techniques. The aim of this study was to compare the direct with the balloon-assisted modality while further defining the role of EUS-GE in GOO. METHODS: This multicenter, retrospective study involved consecutive patients who underwent EUS-GE with the direct or balloon-assisted technique for GOO (January 2014 to October 2016). The primary outcome was technical success. Secondary outcomes were success (ability to tolerate at least a full fluid diet), procedure time, and rate/severity of adverse events (AEs). RESULTS: A total of 74 patients (44.6% women; mean age 63.0 ± 11.7 years) underwent EUS-GE for GOO (direct gastroenterostomy, n = 52; balloon-assisted gastroenterostomy, n = 22). GOO was of malignant and benign etiology in 66.2% and 33.8% of patients, respectively. Technical success was achieved in 94.2% of the direct and 90.9% of the balloon-assisted approach (P = .63). Mean procedure time was shorter with the direct technique (35.7 ± 32.1 minutes vs 89.9 ± 33.3 minutes, P < .001). The clinical success rate was 92.3% for the direct technique and 90.9% for the balloon-assisted modality (P = 1.00), with a mean time to oral intake of 1.32 ± 2.76 days. The AE rate was 6.8% with only 1 severe AE noted. Rate of AEs, postprocedure length of stay, need for reintervention, and survival were similar between the 2 groups. CONCLUSIONS: EUS-GE is effective and safe in the management of GOO. The direct technique may be the preferred method given its shorter procedure time when compared with the balloon-assisted approach. Prospective trials are needed to confirm these findings.