Stent Obstruction Research Articles

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

Infection of (Peri-)Pancreatic Necrosis Is Associated with Increased Rates of Adverse Events during Endoscopic Drainage: A Retrospective Study.

Pancreatic necroses are a major challenge in the treatment of patients with pancreatitis, causing high morbidity. When indicated, these lesions are usually drained endoscopically using plastic or metal stents. However, data on factors associated with the occurrence of failure or adverse events during stent therapy are scarce. We retrospectively analyzed all adverse events and their associated features which occurred in patients who underwent a first-time endoscopic drainage of pancreatic necrosis from 2009 to 2019. During the observation period, a total of 89 eligible cases were identified. Adverse events occurred in 58.4% of the cases, of which 76.9% were minor (e.g., stent dislocation, residual lesions, or stent obstruction). However, these events triggered repeated interventions (63.5% vs. 0%, p < 0.001) and prolonged hospital stays (21.0 [11.8–63.0] vs. 14.0 [7.0–31.0], p = 0.003) compared to controls without any adverse event. Important factors associated with the occurrence of adverse events during endoscopic drainage therapy were positive necrosis cultures (6.1 [2.3–16.1], OR [95% CI], p < 0.001) and a larger diameter of the treated lesion (1.3 [1.1–1.5], p < 0.001). Superinfection of pancreatic necrosis is the most significant factor increasing the likelihood of adverse events during endoscopic drainage. Therefore, control of infection is crucial for successful drainage therapy, and future studies need to consider superinfection of pancreatic necrosis as a possible confounding factor when comparing different therapeutic modalities.

S83 Fully Covered vs Uncovered Self-Expanding Metal Stents for the Treatment of Distal Malignant Biliary Obstruction in the Setting of Locally Advanced Pancreatic Cancer

Introduction: Self-expanding metal stents (SEMS) are preferred for the treatment of distal biliary obstruction (dMBO) caused by pancreatic cancer. Optimizing biliary drainage in the neoadjuvant period while patients await definitive surgical treatment is essential. The aim of this study is to compare clinical outcomes of patients who underwent fully covered (FCSEMS) versus uncovered (UCSEMS) placement for the treatment of dMBO due to locally advanced pancreatic cancer (LAPC). Methods: Consecutive patients who underwent biliary SEMS placement for treatment of dMBO in the setting of LAPC were identified from a single, tertiary care center between May 2017 and May 2021. Patients were categorized into FCSEMS or UCSEMS cohorts based on the type of stent placed during index ERCP. UCSEMS included WallFlex (Boston Scientific,Boston,MA) and Flexxus (ConMed,Utica,NY). Primary outcomes were clinical success, overall incidence of adverse events (AEs), and need for unplanned endoscopic reintervention. Secondary outcomes included stent patency, type of AEs, and overall survival. Results: 817 cases of ERCP with SEMS placement were reviewed to identify 187 patients with dMBO due to LAPC. 35 (18.7%) patients underwent FCSEMS placement and 152 (81.3%) UCSEMS (49 WallFlex, 103 Flexxus). High rates of clinical success were seen in both cohorts (92.1% UCSEMS vs. 97.1% FCSEMS, p = 0.29). (Table) Stent patency was significantly longer in patients who underwent FCSEMS placement (Figure 1A). There was no difference in rates of occlusion or time to occlusion between the two UCSEMS models. AE rates were significantly higher after UCSEMS placement (32.9% vs. 14.3%, p = 0.03) as was need for unplanned reintervention (29.0% vs. 5.7%, p = 0.004), largely driven by SEMS occlusion (28.9% vs. 2.9%, P = 0.001) in the setting of tissue ingrowth (42/44 cases). A similar number of patients underwent surgical resection (UCSEMS 55.9% vs. FCSEMS 65.7%, p = 0.29) at similar interval after stent placement (UCSEMS 7.0 vs. FCSEMS 6.0 months, p=0.57). All-cause mortality and duration of survival was not different between the two groups (Figure 1B). Conclusion: FCSEMS were associated with longer patency times and fewer interventions in a cohort of patients with LAPC that otherwise exhibited similar survival and rates of surgical intervention. Additional studies are needed to evaluate cost implications, but this data suggests placement of a FCSEMS may be preferred to UCSEMS in the palliation of dMBO in anatomically amenable patients with LAPC.Figure 1.: Cumulative patency time. Stent patency was defined as the interval between the time of stent insertion and the time of biliary reintervention because of stent dysfunction or the end of the follow-up. Patients without stent obstruction were censored at the time of surgery, last follow-up or death. 1B: Overall survival Table 1. - Clinical outcomes of patients who underwent metal biliary stent placement for the management of locally advanced pancreatic cancer UCSEMS n=152 FCSEMS n=35 P Value Clinical Success 140 (92.1) 34 (97.1) 0.29 Adverse Events 50 (32.9) 5 (14.3) 0.03 Stent Occlusion 44 (28.9) 1 (2.9) 0.001 PEP 8 (5.3) 2 (5.7) 1.00 Stent Migration 3 (2.0) 2 (5.7) 0.24 Cholecystitis 1 (0.7) 0 (0.0) 1.00 Unplanned reintervention 44 (29.0) 2 (5.7) 0.004 Median time to unplanned reintervention (months) 4.4 (3.0-5.6) 4.3 (3.6-5.1) 0.81 Median time to stent occlusion (months) 4.4 (3.0-5.6) 5.9 (5.9-5.9) 0.73 Median stent dwell time (months) 7.0 (5.0-8.7) 6.0 (3.5-8.5) 0.16 Median follow up time (months) 15.6 (8.8-24.6) 22.4 (8.3-27.9) 0.23 Surgical resection 85 (55.9) 23 (65.7) 0.29 Median time to surgical resection (months) 7.0 (5.0-8.9) 6.0 (4.4-8.2) 0.57 Death 84 (55.3) 22 (62.9) 0.41 Values are presented as median (IQR) or n (%). UCSEMS uncovered self-expandable metal stent FCSEMS fully covered self-expandable metal stent PEP post-ERCP pancreatitis.

Anti-reflux versus conventional self-expanding metal stents in the palliation of esophageal cancer: A systematic review and meta-analysis.

Background and study aims Self-expanding metal stents (SEMS) are an effective palliative endoscopic therapy to reduce dysphagia in esophageal cancer. Gastroesophageal reflux disease (GERD) is a relatively common complaint after non-valved conventional SEMS placement. Therefore, valved self-expanding metal stents (SEMS-V) were designed to reduce the rate of GERD symptoms. We aimed to perform a systematic review and meta-analysis comparing the two stents. Material and methods This was a systematic review and meta-analysis including only randomized clinical trials (RCT) comparing the outcomes between SEMS-V and non-valved self-expanding metal stents (SEMS-NV) following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Data were analyzed with Review Manager Software. Quality of evidence was evaluated using Grading of Recommendations Assessment, Development, and Evaluation guidelines. Results Ten randomized clinical trials including a total of 467 patients, 234 in the SEMS-V group and 233 in the SEMS-NV group, were included. There were no statistically significant differences regarding GERD qualitative analysis (RD –0.17; 95 % CI –0.67, 0.33; P = 0.5) and quantitative analysis (SMD –0.22; 95 % CI –0.53, 0.08; P = 0.15) technical success (RD –0.03; 95 % CI –0.07, 0.01; P = 0.16), dysphagia improvement (RD –0.07; 95 % CI –0.19, 0.06; P = 0.30), and adverse events (RD 0.07; 95 % CI –0.07, 0.20; P = 0.32). Conclusions Both SEMS-V and SEMS-NV are safe and effective in the palliation of esophageal cancer with similar rates of GERD, dysphagia relief, technical success, adverse events, stent migration, stent obstruction, bleeding, and improvement of the quality of life.

Differences in the management of patients requiring an emergency resection for colonic cancer in two European populations.

BackgroundPatients with colonic cancer who require emergency colonic cancer surgery often experience poorer outcomes compared with their elective counterparts. In this setting, several treatments approaches are available. In 2009, Danish guidelines recommended treatment with stent for obstruction in left-sided tumours as a bridge to surgery, if expertise is accessible. The aim of this study was to compare the use of elective and emergency resections for colonic cancer and postoperative mortality in two similar demographic populations.MethodsAll patients who underwent a major resection for colonic cancer, between 2005 and 2016 in Denmark and Yorkshire (UK) were identified. The proportion undergoing emergency surgery, the proportion receiving a stent procedure before their resection, and 30-day postoperative mortality were compared between the populations. Logistic regression was used to determine changes in the proportion of those undergoing emergency surgery and 30-day postoperative mortality.ResultsOut of 45 397 patients treated during the study interval, 41 880 were selected. Emergency surgery decreased in Denmark from 16.6 per cent in 2005–07 to 12.9 per cent in 2014–16, but increased in Yorkshire (13.5 per cent to 16.8 per cent). Danish patients with left-sided tumours were less likely to undergo emergency surgery (risk ratio 0.90, 95 per cent c.i. 0.82 to 0.99) and an increase in stent use coincided with a statistically significant decrease in emergency surgery in these patients. Thirty-day postoperative mortality in all resections (elective and emergency) decreased in both populations, but a larger decrease was observed in Denmark (7.7 per cent to 3.0 per cent in Denmark and 7.1 per cent to 3.3 per cent in Yorkshire).ConclusionPatients in Denmark experienced a reduction in the use of emergency resection and increase in stenting procedures, following the policy implemented in some departments of converting potential emergency resections into elective resections.

TH3.8 Retrospective study on the use of colonic stents in malignancy; a bridge to surgery or the end of the line?

Abstract Aim Colonic stenting is a management option for obstructed left sided colorectal malignancy in the emergency and elective setting. Stenting can provide a bridge to curative surgery or to adjuvant treatment. The aim of this study was to assess the role of colonic stenting in management of obstructed colorectal cancer. Methods This retrospective cohort study analyses prospectively collected data from two centres within one Health Board in Wales. Patients were recorded in a cancer database, who underwent colonic stenting for left sided colonic malignancy between January 2008 and December 2021. Patient demographics, treatment pathways, length of admission, stoma formation rates and morbidity were recorded. Results In total, 98 patients, with a mean age of 73.5 years (range 37–97) underwent a colonic stent. The majority were elective 55% (n=54). The sigmoid colon was the commonest site of tumour in 33 patients, with metastatic disease in 82% (n=80). The study found 86% (n=84) of patients were successfully stented. The mean length of admission was 13 days. The complication rate was 23% (n=23), most commonly stent obstruction (n=6). Stenting was a bridge to curative surgery for 3 patients, and 47% (n=46) received adjuvant treatment. Five-year survival was 19.3% (n=19). The overall stoma rate was 10.2% (10 patients). Conclusion This study shows colonic stenting is a viable alternative in surgical management for advanced obstructing colorectal malignancy but not as a bridge to surgery. The majority of this cohort returned home following stenting, had a low overall stoma rate and 19% survival at 5 years.

How to successfully administer palliative treatment with a stent for malignant gastric outlet obstruction?

Although endoscopic stenting (ES) has been widely used as a less-invasive palliation method for malignant gastric outlet obstruction (GOO), recent reports have highlighted issues related to the procedure. For successful treatment, various aspects must be assessed before considering the practices. First, it is necessary to eliminate cases with contraindications such as coexistence of distal small-bowel obstruction or perforation. Other factors potentially related to clinical failure (i.e., peritoneal carcinomatosis) may require consideration but remain controversial. ES has better short-term outcomes than surgical gastrojejunostomy (GJ). GJ has recently been considered preferable in cases with longer life expectancy because of superior sustainability. Various types of stents are now commercially available, but their ideal structure and mechanical properties have not yet been clarified. Covered metal stent may reduce stent obstruction but is prone to increase stent migration, and its significance remains uncertain. Subsequent chemotherapy after stenting should be considered, as it is expected to prolong patient survival without increasing the risk of adverse events. Furthermore, it may be helpful in preventing tumor ingrowth. In cases with GOO combined with biliary obstruction, biliary intervention is often difficult. Recently, endoscopic ultrasound-guided biliary drainage (EUS-BD) has been widely used as an alternative procedure for endoscopic transpapillary biliary drainage (ETBD). Despite the lack of consensus as to whether ETBD or EUS-BD is preferred, EUS-BD is useful as a salvage technique for cases where ETBD is difficult. To perform stent placement successfully, it is important to pay attention to the above points; however, many remaining issues need to be clarified in the future.

Balloon passage method to avoid stent maldeployment during the stent-in-stent technique for a colonic metallic stent obstruction.

Balloon passage method to avoid stent maldeployment during the stent-in-stent technique for a colonic metallic stent obstruction.

Challenges in Diagnosis of Uretero-Arterial Fistulas after Complex Pelvic Oncological Procedures-Single Center Experience and Review of the Literature.

Introduction: Uretero–arterial fistula (UAF) represents a rare condition that manifests as massive or intermittent hematuria and requires collaboration between a urologist, vascular surgeon and interventional radiologist. In this article, we present our experience with UAF diagnosis, treatment pathways and the results of a nonsystematic review of the literature published in the last decade regarding modern diagnostic procedures. Material and method: We analyzed the clinical data of nine consecutive patients from our institution diagnosed with UAF in the interval of 2012–2022 who underwent open or endovascular surgical treatment. We reviewed patient characteristics, diagnoses and treatment pathways. The literature search resulted in 14 case series, published from 2012 to 2022, describing a total of 670 cases of UAF. Results: The mean age of patients in our cohort was 65.3 years (IQR: 51–79). UAFs were more common in women (77.7%). All patients presented a history of surgical intervention and ir-radiation for pelvic malignancy with permanent ureteric stenting. Overall, 88.8% of patients had urinary diversion, either via ileal conduit or cutaneous ureterostomy. The most common clinical manifestation of UAF was gross hematuria with or without clots accompanied by flank pain due to stent obstruction, while three patients presented with hypovolemic shock. Angiography represents the best option for diagnosis, followed by angioCT, with a sensitivity of 59.83% and 47.01%, respectively. There is no definitive imaging modality associated with high accuracy in detecting UAF and negative findings do not exclude the disease. In emergency cases with massive bleeding, surgical exploration remains the most appropriate management option for both diagnosis and treatment. Endovascular stent graft placement is preferred over open surgery in stable hemodynamic patients. Conclusions: Uretero–arterial fistulas represent a life-threatening complication and must be treated with great awareness. Angiography represents the best modality for diagnosis, followed by computed tomography. However, there is no definitive imaging modality and, in some cases, open approach remains the only option for diagnosis and treatment.

Effectiveness of the Rotarex Excisional Atherectomy System in Both Subacute and Chronic Aortoiliac Endograft Thrombosis: An Innovative Option for the Modern Endovascular Surgeon Toolkit.

To report a successful revascularization case using the Rotarex™S atherothrombectomy system in a recent iliac limb thrombosis, and chronic hypogastric stent obstruction after previous aortoiliac aneurysm endovascular repair (EVAR). A 72-year-old patient was treated for recent right iliac limb thrombosis and left iliac branch chronic hypogastric stent occlusion, 5 years after EVAR. A total endovascular approach, using both upper extremity and femoral vascular access, was settled with 2 Rotarex™S (6Fr and 10Fr) devices. The Rotarex™S catheters removed most of the intraluminal material, allowing additional endografts and bare metal stents to be deployed to support a new healthy lumen surface. The total endovascular approach provided by the Rotarex™S device appears to be safe and effective in treating aortoiliac endografts occlusions, both in subacute and chronic phases. Larger studies could highlight differences and eventual advantages compared with more traditional solutions.

Recurrent Cholecystitis Due to Gallstone Obstruction of a Lumen-Apposing Metal Stent

An 86-year-old man with limited performance and substantial comorbidity presented to the emergency department with fever, upper abdominal discomfort, and confusion. His medical history noted an endoscopic ultrasound-guided gallbladder drainage for acute cholecystitis with a lumen-apposing metal stent 22 days prior. On admission, his hematology tests were unremarkable except for elevated C-reactive protein (125 mg/L [reference range, <10 mg/L]). Computed tomography revealed a recurrent cholecystitis with a gallstone obstructing the lumen-apposing metal stent (orange arrow, Figure A), with 2 larger stones in the gallbladder (red arrow, Figure A).

Usefulness of duckbill-type anti-reflux self-expandable metal stents for distal malignant biliary obstruction with duodenal invasion: A pilot study.

ObjectivesEarly obstruction of a self‐expandable metal stent placed for distal malignant biliary obstruction is more likely to occur in the presence of duodenal invasion. An anti‐reflux self‐expandable metal stent (ARMS) has been developed for the purpose of preventing duodenal fluid reflux into the bile duct. In this study, we evaluated the usefulness and safety of a duckbill‐type ARMS (D‐ARMS) in the situation of duodenal invasion.MethodsWe retrospectively analyzed 10 consecutive patients who received D‐ARMS for distal malignant biliary obstruction with duodenal invasion. We evaluated non‐occlusion cholangitis, recurrent biliary obstruction (RBO), and adverse events after D‐ARMS placement.ResultsThere were no cases of non‐occlusion cholangitis. RBO was observed in 2 patients (20%), and time to RBO was 236 days and 117 days, respectively. The causes of RBO were overgrowth and sludge formation. The median time to RBO was 382 days (range, 117–382 days). Only one adverse event was observed (cholecystitis).ConclusionsD‐ARMS shows potential as an optimal ARMS.

Synchronous resection of primary colorectal cancer with liver metastases: two birds with one stone?

About one in every five patients with colorectal cancer presents with liver metastases at the time of diagnosis1. Logically, the mode of presentation drives the sequence of intervention. In patients with an urgent presentation and complications from the primary tumour, the management of intestinal obstruction, perforation or bleeding dictates treatment. Even if the acute episode is managed non-surgically, for example with use of a colonic stent for obstruction, the likelihood of advanced T category or node positivity of the primary tumour suggests that systemic chemotherapy should be the preferred treatment after resolution of the urgent issue2. Contrast-enhanced MRI of the liver and contrast-enhanced CT of the thorax after treatment of the emergency situation should be considered to document the extent of disease at baseline and before commencement of systemic chemotherapy. Patients with colorectal cancer and synchronous liver metastases may also present with either an asymptomatic or minimally/moderately symptomatic primary tumour. Should staging show metastases in more than one organ (in the context of liver metastases, this typically represents additional lung metastases), both North American and European oncology guidelines2,3 advocate systemic chemotherapy as first-line treatment. Thus, it is in the subset of patients with colorectal cancer and synchronous liver-limited metastatic disease with an asymptomatic presentation that synchronous surgery (resection of primary and liver metastases at a single operative procedure) is an option. In this setting, the practical management question of how to select patients for synchronous rather than staged surgery (resection of bowel tumour followed by hepatic resection) is an active issue (Fig. 1).

Use of magnetic double J stents in pediatric patients.

Traditionally, double J stent removal in pediatric patients has required cystoscopy under general anesthesia. Magnetic stents allow for double J stent removal without the need for anesthesia. This work describes our initial experience with these stents. A prospective cohort study of patients under 14 years of age carrying magnetic double J stents from 2018 to 2021 was performed. Variables assessed included baseline diagnosis, surgical procedure, placement success rate, complications associated with use, and need for general anesthesia at removal. 23 stents (4.8 Fr, 15 cm-20 cm) were placed in 21 patients, 62% of whom were male. Mean age was 5.01 years (3 months-13 years). Indications for placement included Anderson-Hynes dismembered pyeloplasty (34.8%), endoscopic dilatation of the ureteropelvic junction (UPJ) (21.8%), cystoscopic dilatation of the ureterovesical junction (UVJ) (17.4%), endoscopic lithotripsy (13.1%), renal trauma (4.3%), suspected retroiliac ureter (4.3%), and cystoscopic drainage of pyonephrosis (4.3%). Mean time of stent use was 4.2 weeks. 3 complications (13%) associated with the double J stent - 1 urinary tract infection (UTI), 1 stent obstruction, and 1 distal stent migration - were recorded. 95.5% of magnetic stents were successfully removed without anesthesia. Magnetic double J stents can be regarded as an effective alternative to conventional double J stents, since they avoid an additional surgical procedure with general anesthesia in pediatric patients.

EUS-guided drainage of the pancreatic duct for the treatment of postoperative stenosis of pancreatico-digestive anastomosis or pancreatic duct stenosis complicating chronic pancreatitis: Experience at a tertiary care center.

Background and Objectives:For the treatment of pancreatic duct stenosis due to chronic pancreatitis (CP) or postoperative (PO) stenosis, endoscopic procedures are usually the first choice. In cases of failure of the recommended treatment by ERCP, anastomosis between the Wirsung duct and the stomach or duodenum can be performed under EUS guidance. The objective of this retrospective study was to compare the outcomes of pancreatico-gastric or pancreaticoduodenal anastomosis under EUS for PO stenosis versus CP stenosis.Subjects and Methods:This was a retrospective, single-center, consecutive case study of patients who underwent EUS-guided Wirsungo-gastric/bulbar anastomosis.Results:Forty-three patients were included. Twenty-one patients underwent treatment for PO stenosis, and 22 patients underwent treatment for CP stenosis. The technical success rate was 95.3% (41/43), with 100% in cases of PO stenosis and 90.9% in cases of CP stenosis. The clinical success rate was 72.5% (29/40): 75% (15/20) in cases of PO stenosis and 70% (14/20) in cases of CP stenosis. The overall morbidity rate was 34.9% (15/43). The main complication was postprocedural pain, occurring in 20.9% (9/443) of patients. The rate of stent migration or obstruction was 27.9% (12/43). There was no difference in patient outcomes or morbidity according to the etiology of the stenosis. The median follow-up duration in this study was 14 months.Conclusions:EUS-guided Wirsungo-gastric/duodenal anastomosis is a feasible, minimally invasive, safe, and relatively effective procedure. The rates of technical success, clinical success, and complications were not different between patients with PO and CP stenosis. However, the follow-up period was too short to assess recurrent symptoms in these patients.

Studying in vivo and in vitro effects of a novel polyvinyl benzyl chloride-D-glucaro-1, 4-lactonate polymer-coated bile duct stent for anti-biliary mud deposition.

We aim to coat a novel polyvinyl benzyl chloride-D-glucaro-1, 4-lactonate polymer-coated bile duct stent for anti-biliary mud deposition and investigate its in vivo and in vitro impacts. Biliary mud deposition is a leading cause of plastic biliary stent obstruction after its placement. Orally administrated D-glucaro-1, 4-lactonate is a specific competitive inhibitor of β-glucuronidase that causes biliary mud deposition. In this study, the stents coated with polyvinyl benzyl chloride-D-glucaro-1,4-lactonate polymer (PVBC-DGL) were placed in an ex vivo bile duct model perfused with porcine bile and observed every week until completely blocked. Post establishing the model of bile duct stenosis in piglets, stents are observed through endoscopy, hematology, patency time, and pathological changes within 6 months. The 70% PVBC-DGL stents achieved the highest percentage of the inhibitory effect when the drugs were completely released in vitro. Results were obtained from 14 pigs (5: no coating (original), 4: 0% coating, and 5: 70% coating). The overall patency time of the stents was prolonged in all groups; however, the group with 70% coated stents showed a significantly prolonged patency time as compared to no coating (original) and the 0% coating groups in pigs (23.4 ± 1.8 vs 11.2 ± 2.1 w (p = 0.05); 23.4 ± 1.8 vs 10.5 ± 2.5 w (p = 0.05), respectively). The stents with 70% PVBC-DGL better prevent and control the deposition of bile mud and prolong the patency time of stent placement in the subject animals and may be proposed for further clinical trials in patients.

Hemodialysis Reliable Outflow (HeRO) graft creation in upper extremities abandoned due to stent obstruction via recanalization and HeRO outflow component insertion across stent interstices.

The purpose of this study was to assess the feasibility and outcomes of recanalization and subsequent HeRO graft outflow component insertion across stent interstices in patients with an otherwise abandoned upper extremity. Over a 10-year period, 15 patients underwent central venous recanalization by interventional radiology across the interstices of one or more occluded stents for the purpose of subsequent HeRO graft creation. A tunneled central venous catheter was left across the stent and occlusions with tip in right atrium. On a later date, the catheter was used for rapid guidewire access for HeRO graft implantation in the OR by vascular surgery. Procedural and clinical outcomes were determined by retrospective review. Primary and secondary HeRO graft patency rates were estimated with the Kaplan-Meier technique. The technical success rates of recanalization across stent interstices was 100% (15/15). Between one and four overlapping stent walls were traversed. The technical success of the patients who underwent attempted HeRO graft implantation with outflow component traversing across stent interstices was 91% (11/12). No major complications were encountered with either recanalization or HeRO graft implantation. The primary and secondary HeRO patency rates at 12 months were 64% and 80%, respectively. HeRO graft insertion across stent interstices is feasible and can provide effective permanent AV access; thus, the presence of stents across the subclavian and brachiocephalic veins should not be considered a contraindication.

Current Status and Prospect of Stent Placement for May-Thurner Syndrome.

Stent implantation has been proven to be safe and has become the first-line intervention for May-Thurner syndrome (MTS), with satisfactory mid-term patency rates and clinical outcomes. Recent research has demonstrated that catheter-directed thrombolysis is the preferred strategy when MTS is combined with deep vein thrombosis after self-expanding stent placement. However, the stent used for the venous system was developed based on the experience obtained in the treatment of arterial disease. Consequently, relatively common corresponding complications may come along later, which include stent displacement, deformation, and obstruction. Different measures such as adopting a stent with a larger diameter, improving stent flexibility, and increasing stent strength have been employed in order to prevent these complications. The ideal venous stent is presently being evaluated and will be introduced in detail in this review.

Diagnostic performance of digital tomosynthesis to evaluate silicone airway stents and related complications.

BackgroundDigital tomosynthesis (DTS) is an imaging technique with benefits in reconstructing sequential cross-sectional images. We evaluated the diagnostic performance of DTS for silicone airway stents and stent-related complications in patients who underwent bronchoscopic intervention.MethodsThis retrospective study included patients who underwent bronchoscopic intervention after chest radiography (CXR) and DTS examinations from September 2013 to August 2020. The interval between CXR, DTS, and bronchoscopic intervention was a maximum of 10 days. CXR and DTS images were evaluated using a bronchoscopic view as a reference. We calculated the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for assessing the diagnostic performance.ResultsThe total CXR, DTS, and bronchoscopic intervention-matching datasets comprised 213 cases from 119 patients and, silicone stents were present in 167 of them. The ability of DTS to detect silicone stents was better than that of CXR (sensitivity, 92.8% vs. 71.3%, P<0.001). Of the 167 cases with silicone stents, 53 experienced stent migration and 121 experienced stent obstructions due to granulation tissue or fibrosis. The sensitivity for detecting stent migration was also higher with DTS than with CXR (45.3% vs. 24.5%, P=0.025). The sensitivity for detecting the stent obstruction was better with DTS than with CXR (64.5% vs. 19.0%, P<0.001).ConclusionsDTS was more sensitive and accurate in revealing silicone airway stents and silicone stent-related complications than CXR. However, there were limitations in confirming stent migration and obstruction with DTS due to granulation tissue growth and fibrosis.

URINOTHORAX FOLLOWING THE FORMATION OF A NEPHROPLEUROCUTANEOUS FISTULA AFTER PERCUTANEOUS NEPHROLITHOTOMY TO REMOVE STAGHORN CALCULI

TOPIC: Disorders of the Pleura TYPE: Medical Student/Resident Case Reports INTRODUCTION: Urinothorax is a rare cause of pleural effusion secondary to obstructive uropathy or a complication of a post urological procedure. Patients may present with respiratory and urinary symptoms. Pleural fluid analysis is traditionally transudative and the pleural fluid to serum (PF/S) creatinine ratio is greater than 1. Imaging can also be done to find the etiology while treatment of the underlying pathophysiology typically results in its resolution. CASE PRESENTATION: A 27-year-old female with history of nephrolithiasis secondary to proteus mirabilis infection presented to the emergency room with SOB and CP six days after undergoing a left ureteral stent placement alongside a left percutaneous nephrolithotomy (PCNL) in order to remove a staghorn calculi measuring 9.2cm x 3.2cm.Initial chest x-rays revealed a large, left-sided pleural effusion. A diagnostic thoracentesis was performed and 800cc of cloudy, yellow fluid was removed. Pleural fluid analysis revealed a PF/S creatinine ratio of 2.7 and pleural LDH of 208. Since these findings were consistent with an LDH-discordant urinothorax, a Foley catheter was placed; however, the patient began to develop fevers and left flank pain. A CT scan revealed left upper pole hydronephrosis, a newly-formed left renal pelvis stone causing stent obstruction, and the presence of a nephropleurocutaneous tract likely secondary to the PCNL. The patient was then taken to the OR for stent revision and chest tube placement. Within the next few days, her respiratory status improved and she was discharged home with close follow-up. DISCUSSION: Urine translocation into the pleural space occurs in two ways. The first comes from the lymphatic drainage of urine that has been extravasated into the retroperitoneal space because of increased pressure gradients from obstructive uropathy. The second, which is what our patient had, comes from the urine entering into the pleura through a fistula or an anatomical defect. A diagnostic thoracentesis of a urinothorax will reveal a cloudy, yellow fluid with the smell of urine, a PF/S creatinine ratio greater than 1, and a transudate. However, studies have shown that concomitant infections, such as our patient's proteus mirabilis infection, can cause the fluid to be exudative. Imaging can also be used to further identify the pleural effusion as well as any pathological or structural abnormalities. Treatment of a urinothorax depends on the underlying etiology. For obstructive cases, stents, nephrostomy tubes, and Foley catheters are utilized. For iatrogenic cases like our patient's, repairing the defect yields the best results. CONCLUSIONS: The identification of a urinothorax following a post urological procedure requires a high level of clinical suspicion in the correct clinical context. As such, it is important for clinicians to learn more about this rare cause of pleural effusions, its pathophysiology, and its treatment options. REFERENCE #1: Toubes, M., Lama, A., Ferreiro, L., Golpe, A., Álvarez-Dobaño, J., & González-Barcala, F. et al. (2017). Urinothorax: a systematic review. Journal Of Thoracic Disease, 9(5), 1209-1218. https://doi.org/10.21037/jtd.2017.04.22 REFERENCE #2: Austin, A., Jogani, S., Brasher, P., Argula, R., Huggins, J., & Chopra, A. (2017). The Urinothorax: A Comprehensive Review With Case Series. The American Journal Of The Medical Sciences, 354(1), 44-53. https://doi.org/10.1016/j.amjms.2017.03.034 REFERENCE #3: Ramahi, A., Aburayyan, K., Alqahtani, A., Said Ahmed, T., & Taleb, M. (2019). Shortness of Breath: An Unusual Presentation of Bladder Injury. A Case Report and Literature Review of Urinothorax. Cureus. https://doi.org/10.7759/cureus.4559 DISCLOSURES: No relevant relationships by Sanford Church, source=Web Response No relevant relationships by Timothy Vu, source=Web Response No relevant relationships by Bassam Yaghmour, source=Web Response, value=Honoraria Removed 04/30/2021 by Bassam Yaghmour, source=Web Response