Stent Obstruction Research Articles

Endoscopic treatment of chronic pancreatitis in children: a retrospective study

Background. Chronic pancreatitis (CP) in children is a relatively rare polyetiological disease of the pancreas, accompanied by progressive inflammation of the parenchyma with gradual loss of its function and/or the occurrence of specific complications. Indications for a particular treatment method for a specific patient with a specific etiology and stage of CP are not clearly defined and largely depend on the experience and technical capabilities of a specific clinic. In recent years, individual centers have accumulated experience in using endoscopic methods for the treatment of CP in children, which seems very promising. Aim. To analyze the results of our experience in endoscopic treatment of CP in children. Materials and methods. From 2018 to June 2023, endoscopic treatment methods were used in 31 children with CP. Indications for endoscopic treatment were frequent episodes of exacerbation of pancreatitis in combination with signs of ductal hypertension with or without Wirsungolithiasis. According to etiology, patients were divided into groups: pancreatic duct anomalies, abnormal pancreaticobiliary junction (APBJ), hereditary CP, acquired duct strictures and idiopathic pancreatitis. The results were assessed by the frequency of episodes of exacerbation of pancreatitis. Results. Endoscopic treatment failed in two patients due to: impossibility of cannulation of the main pancreatic duct in a child operated on for annular pancreas and impossibility of recanalization of posttraumatic duct stricture in the isthmus area. Early complications included post-manipulation pancreatitis (n=2; 6.4%), asymptomatic hyperenzymemia (n=5; 16.1%), stent loss (n=2; 6.4%), stent obstruction with pancreatic precipitates (n=2; 6.4%). The average follow-up period was 2.31±1.32 years. In all groups except APBJ, there was a significant decrease in exacerbation episodes with their complete absence in most patients. Ineffectiveness of endoscopic treatment was noted in one case of a combination of the complete type of divided pancreas and a pathogenic mutation of the gene SPINK1. Thus, endoscopic treatment was effective in 28 (90.3%) children in the early period and in 22 (71%) in the late period due to the return of symptoms in the APBJ group. Conclusion. Endoscopic treatment of chronic pancreatitis in children is effective and can be recommended as first-line therapy. Endoscopic treatment of symptomatic APBJ has a temporary clinical effect.

Homoeopathic Management of Acute Cholangitis in a Case of Adenocarcinoma of Gall Bladder with Metastasis: A Case Report

AbstractAcute cholangitis is a bacterial infection superimposed on an obstruction of biliary tree from a gall stone, neoplasm or stricture. The biliary obstruction is most commonly caused by choledocholithiasis benign or malignant stricture of the bile duct or hepatic ducts, pancreatic cancer, ampullary adenoma or cancer, porta hepatis tumour or metastasis, biliary stent obstruction (due to microbial biofilm formation, biliary sludge deposition and duodenal reflux of food content), primary sclerosing cholangitis and amyloid deposition in the biliary system. Classically, patients present with high fever persisting for more than 24 hours, abdominal pain and jaundice (Charcot's triad). The right upper quadrant abdominal (RUQ) pain is generally mild. When the cholangitis becomes more severe, patients become hypotensive and confused (Reynold's pentad). Charcot's triad has low sensitivity (26.4%) and high specificity (95.9%). Although the presence of Charcot's triad is suggestive of acute cholangitis, it is not diagnostic. Charcot's triad is present in 26.4 to 72% of patients with acute cholangitis. TG07 diagnostic criteria for acute cholangitis also do not have enough sensitivity and specificity and its severity criteria are also not suitable for clinical use. Antibiotics, intravenous fluid, Vitamin K supplementation and biliary drainage are the options available in conventional mode of treatment for acute cholangitis. Presented here is one case report of acute cholangitis in a patient of adenocarcinoma of gall bladder with metastasis. The case was treated using classical method of homoeopathy with complete improvement in clinical and laboratory parameters of acute cholangitis.

394. ESOPHAGEAL STENTING IN ESOPHAGEAL CANCER PATIENTS WITH PERFORATION AND FISTULA

Abstract Background Esophageal perforation and fistula to the respiratory system are serious problems in esophageal cancer patients. Esophageal self-expandable metal stent (SEMS) placement has become a popular treatment for this problem. This retrospective study aimed to evaluate the factors associated with clinical outcomes following the placement of a SEMS in esophageal cancer patients with perforation and fistula. Methods Data from 43 esophageal cancer patients with perforation and fistula who underwent esophageal SEMS placement at Prince of Songkla University Hospital between January 2008 and June 2023 were reviewed. Statistical analyses, including chi-square tests and Kaplan-Meier methods, were employed for comparisons and survival calculations. Results The SEMS location was the middle esophagus in 76.8% and 11.6% in each of the lower and upper esophagus. The disease was stage IV in 62.8% and stage III in 37.2%. 46.5% had a history of chemoradiotherapy. The perforation and fistula penetrated into the left bronchus in 39.5%, right bronchus 18.6%, trachea 16.3%, lung 14% and mediastinum 11.6%. The SEMS technique was successful in all patients. The median stent patency was 38.5 days. Tumor overgrowth was the major cause of stent obstruction. The median overall survival was 40 days. Initial success of the SEMS placement was the only predictor of better survival. Conclusion Esophageal SEMS placement in esophageal cancer perforation and fistula cases is technically uncomplicated. Although these advanced esophageal cancer patients had a poor prognosis, the esophageal SEMS provided symptom relief and improved quality of life for their remaining time.

Coaxial plastic stent placement within lumen-apposing metal stents for the management of pancreatic fluid collections: a systemic review and meta-analysis.

Coaxial placement of double pigtail plastic stents (DPPS) through lumen-apposing metal stents (LAMSs) is commonly performed to reduce the risk of LAMS obstruction, bleeding, and stent migration when used for the drainage of pancreatic fluid collections (PFCs). A systematic review and meta-analysis were performed to compare the outcomes of LAMS alone and LAMS with coaxial DPPS placement in the management of PFCs. A systematic review was conducted to identify studies comparing LAMS and LAMS/DPPS for PFC drainage. Primary outcomes included the rate of clinical success, overall adverse events (AEs), bleeding, infection, occlusion, and stent migration. The pooled effect size was summarized using a random-effects model and compared between LAMS and LAMS/DPPS by calculating odds ratios (ORs). Nine studies involving 709 patients were identified (338 on LAMS and 371 on LAMS/DPPS). LAMS/DPPS was associated with a reduced risk of stent obstruction (OR, 0.59; p=0.004) and infection (OR, 0.55; p=0.001). No significant differences were observed in clinical success (OR, 0.96; p=0.440), overall AEs (OR, 0.57; p=0.060), bleeding (OR, 0.61; p=0.120), or stent migration (OR, 1.03; p=0.480). Coaxial DPPS for LAMS drainage of PFCs is associated with a reduced risk of stent occlusion and infection; however, no difference was observed in the overall AE rates or bleeding.

Revolutionizing outcomes: endoscopic ultrasound-guided gallbladder drainage using innovative electrocautery enhanced-lumen apposing metal stents for high-risk surgical patients

This study retrospectively evaluated the outcomes of endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using novel electrocautery-enhanced lumen-apposing metal stents (LAMS) in high-risk patients with acute cholecystitis (AC). Between January 1, 2021, and November 30, 2022, 58 high-risk surgical patients with AC underwent EUS-GBD with the novel electrocautery-enhanced LAMS. The technical success rate was 94.8% (55/58), with one case of duodenal perforation requiring surgery with complete stent migration and two of partial stent migration into the gallbladder. However, the clinical success rate was 100% (55/55). Recurrent AC occurred in 3.6% of the cases (2/55), managed with double pigtail plastic stents through the LAMS. Early AEs observed in 1.8% (1/55) due to stent obstruction. Late AEs occurred in 5.4% (3/55), including two cases of cholangitis and one of stent obstruction. For 33 patients followed over 6 months, LAMS maintenance was sustained in 30 cases. Two patients underwent double-pigtail plastic stent replacement after LAMS removal, and one underwent LAMS removal during surgery following tumor stage regression after chemotherapy for cholangiocarcinoma. The novel electrocautery-enhanced LAMS demonstrated high technical and clinical success rates in high-risk surgical patients with AC, maintaining effective gallbladder drainage with minimal AEs during long-term follow-up, thus highlighting its efficacy and safety in challenging patients.

Clinical Outcomes of Secondary Duodenal Self-Expandable Metallic Stenting for Duodenal Stent Dysfunction in Patients with Malignant Duodenal Obstruction: A Retrospective Multicenter Study.

Malignant duodenal obstruction has become more common with the development of palliative therapies.The outcomes of endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) are comparable to those of surgical gastrojejunostomy or duodenal stenting. However, EUS-GJ is technically challenging. Duodenal self-expandable metallic stent (SEMS) placement is popular; however, obstructions are common. Duodenal SEMS obstruction can be managed with the insertion of a second SEMS in a stent-in-stent manner. Therefore, we aimed to analyze the clinical outcomes of secondary duodenal SEMS placement in patients with malignant duodenal obstruction. We retrospectively analyzed the data of patients who underwent secondary duodenal stent insertion for duodenal stent dysfunction between January 2016 and December 2021. The primary outcome was stent patency. The secondary outcomes were clinical success, factors associated with dysfunction, patient survival, and adverse events. A total of 109 patients were included. The mean age was 64.4±11.2 years, and 63 patients (57.8%) were male. Ninety-two patients (84.4%) had pancreaticobiliary cancer. Clinical success was achieved in 94 cases (86.2%). Twenty-three patients experienced stent dysfunction with 231 days of median stent patency (95% confidence interval [CI], 169 to not available). After a multivariable Cox hazard analysis of stent patency, the Eastern Cooperative Oncology Group performance status (hazard ratio [HR], 2.13; 95% CI, 1.20 to 3.81; p=0.010) and the first stent patency ≥6 months (HR, 0.33; 95% CI, 0.11 to 0.95; p=0.050) remained significant associated factors. Adverse events occurred in five patients (4.6%). Secondary duodenal stent insertion is a viable option for first duodenal stent obstruction. Further comparative studies involving surgery or EUS-GJ for obstructed duodenal stents are warranted.

Clinical impact of delayed plastic biliary stent removal because of the COVID-19 pandemic: the experience from a tertiary ERCP referral center

Background and AimsPlastic biliary endoprosthesis is widely used due to its high efficacy and low cost. Delays in the removal or exchange of plastic biliary stents may lead to stent occlusion and subsequent sepsis [1,2], with consensus recommendation of stent removal or exchange within three-months [3-7]. We postulated that Delayed Plastic Biliary Stent Removal (DPBSR) observed during the pandemic would increase stent-related adverse events. We aim to report our single-center experience with adverse events arising from DPBSR. MethodsAll subjects who had ERCP-guided plastic biliary stent placement in QEII hospital Halifax, Nova Scotia between Dec 2019 and March 2022 were included. Stent lifespan is defined as days between stent deployment and removal. Kaplan-Meier survival analysis was used to represent duration of stent patency. Only 10 French diameter stents were studied. Linear regression was used to analyze possible predictors of stent-related complications. ResultsIn total, 286 cases were analyzed, of which 187 had delayed stent removal. 216 stents were removed without complication, 21 required urgent reintervention for adverse events, 26 died due to non-stent related causes. 21 stents had fully migrated out without causing complications. There was no difference in overall adverse events between the non-delayed vs delayed groups (23.2% vs 21.4%, OR 0.899). Stent AE and emergent removal was marginally increased at OR 1.21 and OR 1.18 in indications related to stone disease. ConclusionsA significant increase was not observed in stent-related complications in subjects with stents removed after 90 days. Plastic biliary stent longevity may be longer than previously thought. Our findings suggest majority of inserted plastic biliary stents remain patent up to 6 months without adverse outcomes.Larger studies are required to better characterize other predictors of biliary stent obstruction.

EUS-guided pancreatic duct drainage: a single-center observational study

Background and aimsPancreatic duct obstruction can cause pain and atrophy of the pancreatic parenchyma. Endoscopic drainage is the first-line treatment, usually by endoscopic retrograde cholangiopancreatography. However, in some patients, the classic transpapillary approach cannot be performed because of anatomical inability to access the papilla, rupture of the main pancreatic duct, intracanal stones that cannot be crossed or tight stenosis of the main pancreatic duct due to extrinsic compression by parenchymal calcifications. Endoscopic ultrasound-guided pancreatic duct drainage is an efficient and minimally invasive therapeutic alternative for these patients. We aimed to evaluate clinical success of endoscopic ultrasound-guided pancreatic duct drainage in our center. MethodsData of patients who underwent endoscopic ultrasound-guided pancreatic duct drainage in our center between 2016 and 2022 were retrospectively reviewed. Clinical success was defined as pain ≤2 on the pain Visual Analog Scale (VAS, 0-10) and no recurrence of obstructive pancreatitis after successful stent placement. If the indication to the procedure was chronic pancreatitis with painless weight loss, then clinical success was defined as weight stabilization or weight regain after the procedure. Results46 patients (mean age 58 years old, 69.6% male) were included. Indications of endoscopic ultrasound-guided pancreatic duct drainage were chronic pancreatitis in 69.6% of patients (78.1% due to alcohol abuse). Other indications included post-operative complications, rupture of pancreatic duct and pancreatic cancer. Technical success was achieved in 93.5% of patients. 40 patients had pancreaticogastrostomy and 3 patients pancreaticoduodenostomy. The mean hospital stay was 2 days. Clinical success was 93% in patients who achieved technical success. Remaining pain on the VAS > 2 occurred in 9.3% of patients and obstructive pancreatitis recurrence in 6.9%. Adverse event occurred in 5 patients (11.6%). 18 stent dysfunctions were observed, 16 stent migrations and 2 stent obstructions. No patient died from the procedure. ConclusionEndoscopic ultrasound-guided pancreatic duct drainage showed a high clinical success rate. It is therefore a good minimally invasive alternative to avoid pancreatic surgery in patients with symptomatic pancreatic duct stenosis of benign or malignant etiology who failed endoscopic retrograde cholangiopancreatography.

The interplay between bacterial biofilms, encrustation, and wall shear stress in ureteral stents: a review across scales

Ureteral stents are hollow tubes that are inserted into the ureter to maintain the flow of urine from the kidney to the bladder. However, the use of these indwelling stents is associated with potential complications. Biofilm, an organized consortium of bacterial species embedded within a self-producing extracellular matrix, can attach to the outer and inner surfaces of ureteral stents. Furthermore, encrustation - defined as the buildup of mineral deposits on the stent surface - can occur independently or in parallel with biofilm formation. Both phenomena can cause stent obstruction, which can lead to obstructive pyelonephritis and make stent removal difficult. Understanding the influence of flow on the development of biofilm and encrustation and the impact of small mechanical environmental changes (e.g., wall shear stress distribution) is key to improve the long-term performance of stents. Identifying the optimal stent properties to prevent early bacterial attachment and/or crystal deposition and their growth, would represent a breakthrough in reducing biofilm-/encrustation-associated complications. This review identifies the most prevalent bacterial strains and crystal types associated with ureteral stents, and the process of their association with the stent surface, which often depends on patient comorbidities, stent material, and indwelling time. Furthermore, we focus on the often-overlooked role of fluid dynamics on biofilm and encrustation development in ureteral stents, across a range of physical scales (i.e., from micro- to macro-scale) with the aim of providing a knowledge base to inform the development of safer and more effective ureteral stents.

Esophageal stent dysfunction: unclogging the Red Sea.

Self-expandable metal stents (SEMS) have been widely used for the palliation of esophageal malignant dysphagia. Stent-related dysphagia is frequent and should raise the suspicion of stent migration, tumor ingrowth or overgrowth. In addition, bleeding has been reported in nearly 7% of patients. Nonetheless, this is the first case report of a complete stent obstruction by abundant blood clot formation. The authors present a 76-year-old male with severe ischemic heart disease and atrial fibrillation, requiring cardiac resynchronization therapy defibrillator and anticoagulation. After being diagnosed with metastasized squamous cell mid-esophageal cancer, he was proposed for chemotherapy and palliative esophageal stenting.

Five-Year Outcomes of Single Trabecular Microbypass Stent (iStent®) Implantation with Phacoemulsification in Korean Patients.

This study reports the long-term intraocular pressure (IOP)-lowering efficacy and safety of a singletrabecular microbypass stent(iStent®; Glaukos Corp., San Clemente, CA, USA) for medically controlled open-angleglaucoma in Korean patients. This retrospective observational study included 42 eyes of 35 patients with primary open-angle glaucoma (POAG). All subjects underwent single first-generation iStent® implantation with phacoemulsification by a single surgeon with 5years follow-up. The primary outcomes were changes in IOP and the number of antiglaucoma medications compared to the preoperative values. The secondary outcome was the proportion of eyes with IOP ≤ 18mmHg without medication, ≤ 15mmHg without medication, and ≤ 18mmHg with or without medication. Adverse events and need for secondary glaucoma surgery were also recorded. The mean IOP decreased from 15.8 ± 2.8 to 13.8 ± 1.7mmHg and the mean number of medications was reduced from 2.24 ± 1.18 to 0.83 ± 1.12, respectively, at year5. At 3 and 5years, 80.6% and 78.6% of eyes, respectively, were receiving fewer medications than preoperative numbers. In contrast, only 50% of eyes on four preoperative medications showed medication reductions at 5years. At years3 and 5, 61.3% and 53.5% of eyes achieved IOP ≤ 18mmHg without medication, whereas 90.3% and 89.3% of eyes achieved ≤ 18mmHg regardless of medication use, respectively. Four eyes required additional glaucoma surgery (two Ahmed glaucoma valve implantations, one trabeculectomy, and one XEN45 Gel Stent implantation), and all were receiving four preoperative antiglaucoma medications. Transient IOP elevation (14.3%) was the most common complication, followed by five hyphema, one stent obstruction, one stent malposition, and one severe anterior chamber reaction. This study demonstrated a good safety profile and sustained IOP reduction after the implantation of a single trabecular microbypass stent (iStent®) with phacoemulsification in Korean patients. The majority of subjects with POAG showed a relatively good response; however, eyes receiving a higher number of medications preoperatively (especially four medications) had difficulty achieving a low target IOP.

Preliminary results in tracheal replacement using stented aortic matrices for primary extensive tracheal cancer.

Recent studies have demonstrated the feasibility and favorable long-term results of tracheobronchial replacement using stented cryopreserved aortic allografts. We propose to investigate the outcomes of this emerging technique in the subgroup of patients with extensive tracheal cancer. This study was based on 13 patients with primary extensive tracheal cancer extracted from the prospective registry TRITON-01 (ClinicalTrials.gov Identifier: NCT04263129), which included 40 patients in total. We analyzed early and late outcomes in this subset of patients. From March 2019 to September 2022, 13 patients were included in the study. There were 9 female and 4 male patients, with a mean age of 53.9years [36-71 years]. They had tracheal replacement for extended adenoid cystic carcinoma (n=11), squamous cell carcinoma (n=1), and mucoepidermoid carcinoma (n=1). A venovenous extracorporeal membrane oxygenation was used in the 6 last cases. The mean length of resection was 81 mm [50-120 mm]. There was no 30-day postoperative mortality. A complete resection (R0) was achieved in 11 patients. The main late complications consisted of tracheal granulomas related to the stent and requiring repeated bronchoscopies (n=9), pneumonia (n=3), airway infection (n=1), bronchoesophageal fistula (n=1), mechanical stent obstruction requiring change (n=2), and mediastinitis treated by antibiotics, drainage, and omentoplasty (n=1). With a maximal follow-up of 3years and 7months, cancer recurrence was observed in 2 patients. All patients were alive at last follow-up except 2 (84.6%). Airway replacement using stented CAA represents a feasible and promising solution for extensive tracheal cancer.

Allium® ureteral stent, a new player in the treatment of ureteral stenosis: a prospective cohort study

Introduction and objectivesUreteral stricture is a chronic condition that can result in the obstruction of urinary drainage from the affected renal unit, leading to loss of renal function. Treatment methods can be categorized into two main headings: endourological and reconstructive procedures. We aimed to investigate the efficacy and safety of the self-expandable Allium® ureteral stent, which has been used in the minimally invasive treatment of ureteral stenosis in recent years. Materials and methodsTwenty patients who were applied Allium® ureteral stent between 2017 and 2021 included in the study. The demographic and clinical characteristics of the patients, the details of the treatments applied to the patients, the perioperative and postoperative complications, the treatments applied for the complications and the findings in the follow-up were recorded and evaluated prospectively. ResultsEtiology included urolithiasis in 16 patients (80%), malignancy in 3 patients (15%), and a previous gynecological operation in 1 patient (5%). Stent obstruction was found to be the most common complication in 3 patients (15%). Stent migration was the second most common complication in 2 patients (10%). Our follow-up continues with 15 patients without stent-related complications and stent obstruction. The mean follow-up period was 28 ± 15.7 months. ConclusionsAllium ureteral stent is an effective and reliable method in the minimally invasive treatment of ureteral stricture with complications seen at acceptable rates and ease of treatment in the management of complications.

Risk Factors for Early- and Late-Onset Cholecystitis after Y-Configured Metal Stent Placement in Patients with Malignant Hilar Biliary Obstruction: A Single-Center Study.

This study evaluated the prevalence and risk factors of early- (within 7 days of placement) and late-onset (after 7 days of placement) cholecystitis after Y-configured metal stent placement. Between June 2005 and August 2020, 109 patients who had been treated with Y-configured metal stents for malignant hilar obstruction were enrolled in the study. We retrospectively analyzed the potential risk factors for post-stent cholecystitis. The presence of diabetes (p = 0.042), the length of the common part of the Y-stent (p = 0.017), filling of the gallbladder with contrast medium during the procedure (p = 0.040), and tumor invasion of the cystic duct accompanied by filling the gallbladder with contrast medium during metal stent placement (p = 0.001) were identified as important risk factors. In cases of late-onset cholecystitis, stent obstruction (p = 0.004) and repeated endoscopic procedures due to stent malfunction (p = 0.024) were significant risk factors. In the multivariate logistic regression analysis, significant risk factors were the length of the common part of the Y-stent (p = 0.032) in early-onset cholecystitis and stent obstruction (p = 0.007) in late-onset cholecystitis. This study demonstrated that early-onset cholecystitis may occur in patients according to the length of the common portion of the Y-stent. In contrast, late-onset cholecystitis may occur in patients with stent obstruction.

Stent ureteral Allium®: una nueva alternativa para el tratamiento de estenosis ureterales. Estudio prospectivo de cohortes

Introduction and objectivesUreteral stricture is a chronic condition that can result in the obstruction of urinary drainage from the affected renal unit, leading to loss of renal function. reatment methods can be categorized into 2main headings: endourological and reconstructive procedures. We aimed to investigate the efficacy and safety of the self-expandable Allium® ureteral stent, which has been used in the minimally invasive treatment of ureteral stenosis in recent years. Materials and methodsTwenty patients who were applied Allium® ureteral stent between 2017-2021 included in the study. The demographic and clinical characteristics of the patients, the details of the treatments applied to the patients, the perioperative and postoperative complications, the treatments applied for the complications and the findings in the follow-up were recorded and evaluated prospectively. ResultsEtiology included urolithiasis in 16 patients (80%), malignancy in 3 patients (15%), and a previous gynecological operation in one patient (5%). Stent obstruction was found to be the most common complication in 3 patients (15%). Stent migration was the second most common complication in 2 patients (10%). Our follow-up continues with 15 patients without stent-related complications and stent obstruction. The mean follow-up period was 28±15.7 months. ConclusionsAllium ureteral stent is an effective and reliable method in the minimally invasive treatment of ureteral stricture with complications seen at acceptable rates and ease of treatment in the management of complications.

Recanalize ureteral stents with focused ultrasound.

Maintaining ureteral patency is imperative to preventing renal injury and systemic infection. Ureteral stents are small conduits connecting the kidney and the bladder. They have been widely used to treat ureteral obstructions and ureteral leaks. The most problematic and frequent stent-associated complication is stent encrustation. This occurs when mineral crystals (e.g. calcium, oxalate, phosphorus, struvite) are deposited onto the surface and internal lumen of the stent. Encrustation can lead to the obstruction of a stent and increases risk of systemic infection. As a result, ureteral stents need to be replaced typically every 2-3 months. In this study, we present a non-invasive, high-intensity focused ultrasound (HIFU)-based technique to recanalize obstructed stents. By taking advantage of the mechanical force produced by a HIFU beam, including acoustic radiation force, acoustic streaming, and cavitation, HIFU can break up encrustations, clearing the stent of obstruction. The ureteral stents for this study were obtained from patients undergoing ureteral stent removal. Under the guidance of ultrasound imaging, the encrustation in the stents were located, and then targeted by HIFU at frequencies of 0.25 and 1MHz. The duty cycle of HIFU was 10%, and the HIFU burst repetition rate was 1Hz, while the HIFU amplitude was varied to find the threshold pressure that would displace encrustations. The treatment duration was limited at 2 min (or 120 shots from HIFU). The treatments were carried out in two different orientations (parallel and perpendicular) of the ureteral stent with respect to the HIFU beam. For each setting, five treatments were conducted for a maximum duration of 2 min. During the entire treatment, an ultrasound imaging system was used to monitor the movement of encrustations inside the stent. The peak negative HIFU pressures needed to move the encrustations inside the stent was recorded for quantitative analysis. Our results demonstrated that at both 0.25 and 1MHz ultrasound frequencies, obstructed stents could be recanalized. At 0.25MHz, the needed average peak negative pressure was 0.52MPa in parallel orientation and 0.42MPa in perpendicular orientation. At 1MHz, the needed average peak negative pressure was 1.10MPa in parallel orientation and 1.15MPa in perpendicular orientation CONCLUSIONS: This first in-vitro study has demonstrated the feasibility of non-invasive HIFU to recanalize ureteral stents. This technology has a potential to reduce the need for ureteral stent exchange.

Clinical and cost effectiveness of endoscopic bipolar radiofrequency ablation for the treatment of malignant biliary obstruction: a systematic review.

Early evidence suggests that using radiofrequency ablation as an adjunct to standard care (i.e. endoscopic retrograde cholangiopancreatography with stenting) may improve outcomes in patients with malignant biliary obstruction. To assess the clinical effectiveness, cost-effectiveness and potential risks of endoscopic bipolar radiofrequency ablation for malignant biliary obstruction, and the value of future research. Seven bibliographic databases, three websites and seven trials registers were searched from 2008 until 21 January 2021. The study inclusion criteria were as follows: patients with biliary obstruction caused by any form of unresectable malignancy; the intervention was reported as an endoscopic biliary radiofrequency ablation to ablate malignant tissue that obstructs the bile or pancreatic ducts, either to fit a stent (primary radiofrequency ablation) or to clear an obstructed stent (secondary radiofrequency ablation); the primary outcomes were survival, quality of life or procedure-related adverse events; and the study design was a controlled study, an observational study or a case report. Risk of bias was assessed using Cochrane tools. The primary analysis was meta-analysis of the hazard ratio of mortality. Subgroup analyses were planned according to the type of probe, the type of stent (i.e. metal or plastic) and cancer type. A de novo Markov model was developed to model cost and quality-of-life outcomes associated with radiofrequency ablation in patients with primary advanced bile duct cancer. Insufficient data were available for pancreatic cancer and secondary bile duct cancer. An NHS and Personal Social Services perspective was adopted for the analysis. A probabilistic analysis was conducted to estimate the incremental cost-effectiveness ratio for radiofrequency ablation and the probability that radiofrequency ablation was cost-effective at different thresholds. The population expected value of perfect information was estimated in total and for the effectiveness parameters. Sixty-eight studies (1742 patients) were included in the systematic review. Four studies (336 participants) were combined in a meta-analysis, which showed that the pooled hazard ratio for mortality following primary radiofrequency ablation compared with a stent-only control was 0.34 (95% confidence interval 0.21 to 0.55). Little evidence relating to the impact on quality of life was found. There was no evidence to suggest an increased risk of cholangitis or pancreatitis, but radiofrequency ablation may be associated with an increase in cholecystitis. The results of the cost-effectiveness analysis were that the costs of radiofrequency ablation was £2659 and radiofrequency ablation produced 0.18 quality-adjusted life-years, which was more than no radiofrequency ablation on average. With an incremental cost-effectiveness ratio of £14,392 per quality-adjusted life-year, radiofrequency ablation was likely to be cost-effective at a threshold of £20,000 per quality-adjusted life-year across most scenario analyses, with moderate uncertainty. The source of the vast majority of decision uncertainty lay in the effect of radiofrequency ablation on stent patency. Only 6 of 18 comparative studies contributed to the survival meta-analysis, and few data were found concerning secondary radiofrequency ablation. The economic model and cost-effectiveness meta-analysis required simplification because of data limitations. Inconsistencies in standard reporting and study design were noted. Primary radiofrequency ablation increases survival and is likely to be cost-effective. The evidence for the impact of secondary radiofrequency ablation on survival and of quality of life is limited. There was a lack of robust clinical effectiveness data and, therefore, more information is needed for this indication. Future work investigating radiofrequency ablation must collect quality-of-life data. High-quality randomised controlled trials in secondary radiofrequency ablation are needed, with appropriate outcomes recorded. This study is registered as PROSPERO CRD42020170233. This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 7. See the NIHR Journals Library website for further project information.

Salvage endoscopic ultrasound-guided gastrojejunostomy as a bridge to definitive surgical therapy for duodenal adenocarcinoma presenting with duodenal stent obstruction

The utilization of endoscopic ultrasound-guided gastrojejunostomy (EUS-GJ) in the setting of an obstructed (ingrown) duodenal stent as a bridge to pancreaticoduodenectomy (PD) remains undescribed. Herein, we report a case study of a 51-year-old patient who underwent EUS-GJ using lumen apposing metal stent (LAMS) for an obstructed duodenal stent during neoadjuvant treatment for duodenal adenocarcinoma. The patient ultimately underwent surgical resection by a classic PD 14 weeks after LAMS placement. EUS-GJ using LAMS represents a potential option as a salvage bridge to surgery for duodenal obstruction in the setting of an obstructed duodenal stent.

OGC P13 Outcomes of Endoscopically Guided Stent Insertion in the Upper GI Tract in a Single Centre

Abstract Background Self-expanding metal stents (SEMS) are useful for palliation in patients suffering from dysphagia for malignant disease in the upper gi tract. Patients can resume oral intake, so improving nutrition and quality of life. Establishing the efficacy and complication rate of stents are important for informing patients to aid decision making when giving consent for SEMS insertion in the scenario of a short life expectancy. Methods A single centre's records were interrogated over a 10 year period for stents inserted in the upper gi tract. Data for stents inserted between 2011 and 2021 was retrospectively collected from electronic records for baseline demographics and outcomes in terms of complications and then subject to analysis. There was missing data in a number of domains and analysis was done on data available, no imputation of data was performed. Results Five hundred and sixty eight patient episodes were identified with a mean age of 73. There were 386 males and 170 females. Sites of obstruction were Lower Third of the oesophagus 279, mid-oesophagus 71, GOJ 37, upper oesophagus 15, unknown 9, duodenum 3, Cardia 1, and stomach other 1. Surgeons inserted 394 (70%) of stents and gastroenterologists 167 (30%). There were 212 covered stents, 248 not specified, 29 partially covered and 3 uncovered. When outcomes were measured, 276 had no complication (69%), 105 had a (any) complication (25%) and 32 had missing data (8%). There were 14 cases of bleeding (3%). There were 25 cases of stent migration (6%) and 54 cases of tumour overgrowth (13%). There were 43 cases of stent obstruction (10.4%), 3 cases of some stricturing (0.73%) and 366 with no blockage or stricture reported (88.6%), 1 case could not be determined. There were 2 cases of perforation (0.48%). Median survival was 105 days with IQR 44–210. Conclusions Our results for adverse events are not too dissimilar to the literature however there may be an under-reporting of some adverse events due to the terminal nature of the disease process the majority of the patients in this group have. Stents can relieve dysphagia and help regain quality of life. However there is a significant complication rate that should be taken into account. This information from a large dataset is useful to inform potential stent patients to aid decision-making. Data for significant known symptoms such as reflux and retrosternal chest pain were not reliably available and a prospectively kept database measuring PROMs information including relief of dysphagia will better inform patients.

Effect of intestinal obstruction stent combined with neoadjuvant chemotherapy on the pathological characteristics of surgical specimens in patients with complete obstructive colorectal cancer

Effect of intestinal obstruction stent combined with neoadjuvant chemotherapy on the pathological characteristics of surgical specimens in patients with complete obstructive colorectal cancer