Advances in self-expandable metal stents for endoscopic ultrasound-guided interventions.

Endoscopic ultrasound (EUS)-guided interventions have evolved rapidly in recent years, with dedicated metal stents playing a crucial role in this process. Specifically, the invention of biflanged short metal-covered stents, including lumen-apposing metal stents (LAMS), and modifications in a variety of tubular self-expandable metal stents (SEMS), have led to innovations in EUS-guided interventions. LAMS or non-LAMS stents are commonly used in the EUS-guided drainage of pancreatic fluid collections, especially in cases of walled-off necrosis. Additionally, LAMS is commonly considered for drainage of the EUS-guided gallbladder or dilated common bile duct and EUS-guided gastroenterostomy. Fully or partially covered tubular SEMS with several new designs are being considered for EUS-guided biliary drainage. This review focuses on advances in SEMS for EUS-guided interventions and discusses related research results.

Polymer-free stents for percutaneous coronary intervention in diabetic patients: a systematic review and meta-analysis.

Aim: To compare the efficacy of polymer-free drug-eluting stents (PF-DES) versus other stents in diabetic patients with coronary artery disease undergoing percutaneous coronary interventions. Materials & methods: A systematic review and meta-analysis were performed to identify pertinent randomized controlled trials. The primary end point was the occurrence of target lesion failure. Results: Eight randomized controlled trials were included for a total of 4854 subjects. The PF-DES group experienced a trend in favor of a lower rate of target lesion failure (Incidence rate ratio = 0.91; p = 0.11) and a significantly lower rate of cardiac mortality, as compared with the control group (Incidence rate ratio = 0.82; p = 0.04). However, statistical significance was lost if bare-metal stent patients were excluded and a trend in favor of the PF-DES strategy was reported only for cardiac mortality. Conclusion: PF-DES could be a valuable strategy in diabetic patients with coronary artery disease undergoing percutaneous coronary interventions.

What is this summary about? Polymer-free drug-eluting stents (PF-DES) are a novel type of coronary stent with potential benefits in terms of chronic coronary inflammation. This is a comprehensive, up-to-date, systematic review and meta-analysis of randomized controlled trials comparing the efficacy of PF-DES versus other stents in diabetic patients with coronary artery disease undergoing percutaneous coronary intervention.What were the results? Patients treated with PF-DES experienced similar prognosis, with a trend toward better outcomes, as compared with conventional stents.What do the results mean? PF-DES could represent a novel and effective strategy for treating coronary artery disease in diabetic patients.

Comparison of Drug-Coated Balloon to Drug Eluting Stent in Patients with In-Stent Restenosis: A Systematic Review and Meta-Analysis.

In-stent restenosis (ISR) is the gradual narrowing of the stented coronary segment, presenting as angina or leading to an acute myocardial infarction. Although the incidence has decreased with the use of newer drug-eluting stents (DES), it still carries significant mortality & morbidity. We compared the two most common interventions, i.e. drug-coated balloons (DCB) vs drug-eluting stents (DES) for managing DES-related ISR. Electronic databases were searched to identify all randomized controlled trials (RCTs) comparing DCB to DES in patients with DES-ISR. The Mantel-Haenszel method with a random effects model was used to calculate pooled risk ratios (RR). Five trials comprising 1,100 patients (577 in DCB and 523 in DES group) were included in the final study. The mean follow-up was 42 months. DCB was found to have a higher risk for target lesion revascularization (TLR) (RR: 1.41, p: 0.02) compared to DES. No difference was observed in all-cause mortality, target vessel revascularization (TVR), myocardial infarction, or stroke between the two intervention arms. In conclusion, management of DES-ISR with DCB has a higher risk of TLR as compared to re-stenting with DES. Both therapeutic interventions are comparable in other terms of efficacy and safety profile.

Selective iliofemoral stent placement for complex pediatric cases: a decade of institutional experience.

BACKGROUND: Pediatric iliofemoral venous thromboembolism that is resistant to conventional treatments poses significant management challenges. Stent placement represents a potentially underutilized strategy in children when stenosis or thrombosis persists intraprocedurally or recurs postoperatively, despite treatments such as venoplasty, lysis, and thrombectomy. OBJECTIVE: This study aims to report our institutional experience with iliofemoral stenting in 17 pediatric patients with recurrent iliofemoral venous thromboembolism or stenosis. MATERIALS AND METHODS: We performed an IRB-approved retrospective review of pediatric patients (<18 years of age) who underwent iliofemoral venous stenting for recurrent stenosis or thrombosis between January 2012 and December 2022 at a single tertiary care institution. Patient demographics, risk factors for venous thromboembolism, presenting symptoms, and procedural characteristics were recorded. The primary outcome was stent patency rates at interval imaging follow-up. RESULTS: Seventeen patients with mean age of 14.6 years (range 7-17) and mean BMI of 27.7 were stented during the study period. Sixteen of 17 patients presented with evidence of May-Thurner anatomy. 14/17 patients presented with acute iliofemoral venous thromboembolism, 2/17 with chronic venous thromboembolism, and 1/17 with left lower extremity swelling without thrombosis. Seventy-three total angiographic procedures were performed, which included angioplasty, lysis, and thrombectomy, and 23 stent placements. Patients underwent an average of 3 procedures (range 1-9) over a mean of 2.8 months (range 0-17 months) prior to undergoing stent placement. Stents were deployed successfully in all patients. The median follow-up was 18 months (range, 1-77 months). Primary and secondary patency rates were 13/17 (76%) and 14/14 (100%) at 12 months and 12/17 (71%) and 14/14 (100%) at 24 months, respectively. CONCLUSION: In our experience of 17 patients, stent placement appears to be a durable option for children with iliofemoral venous thromboembolism following failure to establish vessel patency or development of recurrent thrombosis/stenosis postoperatively.

A novel lumen-apposing metal stent for endoscopic drainage of symptomatic pancreatic fluid collections: a retrospective study.

Background and Objectives: Previous studies showed that lumen-apposing metal stent (LAMS) provides a feasible route to perform direct endoscopic necrosectomy. However, the high risk of bleeding and migration induced by the placement of LAMS attracted attention. The aim of this study was to evaluate the safety and effectiveness of a novel LAMS. Methods: In this retrospective study, we enrolled patients with symptomatic pancreatic fluid collections (PFCs) to perform EUS-guided drainage with a LAMS in our hospital. Evaluation variables included technical success rate, clinical success rate, and adverse events. Results: Thirty-two patients with a mean age of 41.38 ± 10.72 years (53.1% males) were included in our study, and the mean size of PFC was 10.06 ± 3.03 cm. Technical success rate and clinical success rate reached 96.9% and 93.8%, respectively. Stent migration occurred in 1 patient (3.1%), and no stent-induced bleeding occurred. The outcomes of using LAMS in 10 patients with pancreatic pseudocyst and 22 patients with walled-off necrosis were comparable. Compared with pancreatic pseudocyst, walled-off necrosis needed more direct endoscopic necrosectomy times to achieve resolution (P = 0.024). Conclusions: Our study showed that the novel LAMS is effective and safe for endoscopic drainage of PFCs with a relatively low rate of adverse events. Further large-scale multicenter studies are needed to confirm the present findings.

Percutaneous Coronary Revascularization Strategies After Myocardial Infarction: A Systematic Review and Network Meta-Analysis.

BACKGROUND: Complete revascularization with percutaneous coronary intervention improves outcomes compared with culprit revascularization following myocardial infarction (MI) with multivessel coronary artery disease. An all-cause mortality reduction has never been demonstrated. Debate also remains regarding the optimal timing of complete revascularization (immediate or staged), and method of evaluation of nonculprit lesions (physiology or angiography). OBJECTIVES: This study aims to perform an updated systematic review with frequentist and Bayesian network meta-analyses including the totality of randomized data investigating revascularization strategies in patients presenting with MI and multivessel coronary artery disease. METHODS: The primary comparison tested complete vs culprit revascularization. Timing and methods of achieving complete revascularization were assessed. The prespecified primary outcome was all-cause mortality. Outcomes were expressed as relative risk (RR) (95% CI). RESULTS: Twenty-four eligible trials randomized 16,371 patients (weighted mean follow-up: 26.4 months). Compared with culprit revascularization, complete revascularization reduced all-cause mortality in patients with any MI (RR: 0.85; 95% CI: 0.74-0.99; P = 0.04). Cardiovascular mortality, MI, major adverse cardiac events and repeat revascularization were also significantly reduced. In patients presenting with ST-segment elevation myocardial infarction, the point estimate for all-cause mortality with complete revascularization was RR: 0.91 (95% CI: 0.78-1.05; P = 0.18). Rates of stent thrombosis, major bleeding, and acute kidney injury were similar. Immediate complete revascularization ranked higher than staged complete revascularization for all endpoints. CONCLUSIONS: Complete revascularization following MI reduces all-cause mortality, cardiovascular mortality, MI, major adverse cardiac events, and repeat revascularization. There may be benefits to immediate complete revascularization, but additional head-to-head trials are needed.

Sustained Intraprocedural Cardiac Arrest During BASILICA TAVR.

The bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) procedure allows patients with severe aortic stenosis and anatomical challenges from aortic leaflet orientation, positioning of coronary ostia, and height of sinuses of Valsalva to undergo TAVR. We present a case of intraprocedural cardiac arrest secondary to iatrogenic left main coronary artery obstruction following a successful BASILICA procedure.

Obstructing colorectal cancer: a population-based review of colonic stenting in Queensland, Australia.

PURPOSE: Stenting is a useful treatment option for malignant colonic obstruction, but its role remains unclear. This study was designed to establish how stents have been used in Queensland, Australia, and to review outcomes. METHODS: Patients diagnosed with colorectal cancer in Queensland from January 1, 2008, to December 31, 2014, who underwent colonic stent insertion were reviewed. Primary outcomes of 5-year survival, 30-day mortality, and overall length of survival were calculated. The secondary outcomes included patient and tumor factors, and stoma rates. RESULTS: In total, 319 patients were included, and distant metastases were identified in 183 patients (57.4%). The 30-day mortality rate was 6.6% (n=21), and the 5-year survival was 11.9% (n=38). Median survival was 11 months (interquartile range, 4-27 months). A further operation (hazard ratio [HR], 0.19; P<0.001) and chemotherapy and/or radiotherapy (HR, 0.718; P=0.046) reduced the risk of 5-year mortality. The presence of distant metastases (HR, 2.052; P<0.001) and a comorbidity score of 3 or more (HR, 1.572; P=0.20) increased mortality. Surgery was associated with a reduced risk of mortality even in patients with metastatic disease (HR, 0.14; P<0.001). Twenty-two patients (6.9%) ended the study period with a stoma. CONCLUSION: Colorectal stenting was used in Queensland in several diverse scenarios, in both localized and metastatic disease. Surgery had a survival advantage, even in patients with metastatic disease. There was no survival difference according to whether patients were socioeconomically disadvantaged, diagnosed in a major city or not, or treated at private or public hospitals. Stenting proved a valid treatment option with low stoma rates.

Efficacy of different stent types in post-liver-transplant anastomotic biliary strictures: a systematic review and meta-analysis.

Background: Stent selection in the endoscopic management of post-liver-transplant anastomotic biliary strictures remains controversial. This systematic review and meta-analysis aimed to evaluate the potential differences between available stents. Methods: MEDLINE, Cochrane, and Scopus databases were searched until April 2023 for comparative studies evaluating stricture management using multiple plastic stents (MPS) and self-expandable metal stents (SEMS), including fully-covered (FC)- and intraductal (ID)-SEMS. The primary outcome was stricture resolution, while secondary outcomes included stricture recurrence, stent migration and adverse events. Meta-analyses were based on a random-effects model and the results were reported as odds ratios (OR) with 95% confidence intervals (CI). Subgroup analyses by type of metal stent and a cost-effectiveness analysis were also performed. Results: Nine studies (687 patients) were finally included. Considering stricture resolution, SEMS and MPS did not differ significantly (OR 0.99, 95%CI 0.48-2.01; I 2=35%). Stricture recurrence, migration rates and adverse events were also comparable (OR 1.71, 95%CI 0.87-3.38; I 2=55%, OR 0.73, 95%CI 0.32-1.68; I 2=56%, and OR 1.47, 95%CI 0.89-2.43; I 2=24%, respectively). In the subgroup analysis, stricture resolution and recurrence rates did not differ for ID-SEMS vs. MPS or FC-SEMS vs. MPS. Migration rates were lower for ID-SEMS compared to MPS (OR 0.28, 95%CI 0.11-0.70; I 2=0%), and complication rates were higher after FC-SEMS compared to MPS (OR 1.76, 95%CI 1.06-2.93; I 2=0%). Finally, ID-SEMS were the most cost-effective approach, with the lowest incremental cost-effectiveness ratio: 3447.6 £/QALY. Conclusion: Stent type did not affect stricture resolution and recurrence; however, ID-SEMS placement was the most cost-effective approach compared to the alternatives.

Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures.

BACKGROUND: Endoscopic management is the first-line therapy for post-liver-transplant anastomotic strictures. Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months, data on safety and duration for metal stents in this setting is scarce. Due to limited access to endoscopic retrograde cholangiopancreatography (ERCP) during the coronavirus disease 2019 pandemic in our centre, there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy. This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents. AIM: To compare the safety and efficacy profile of different stenting durations using Kaffes stents. METHODS: Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query. Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records. The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months. Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for ≤ 120 d or > 120 d. RESULTS: During the study period, a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course. In 33 ERCPs, the stent was removed or exchanged on a 3-month interval. No pancreatitis, perforations or deaths occurred. Minor post-ERCP complications were similar between the 3-month (abdominal pain and intraductal migration) and 6-month (abdominal pain, septic shower and embedded stent) groups - 6.1% vs 9.1% respectively, P = 0.40. All strictures resolved at the end of the stenting course, but the stenting course was variable from 3 to 22 months. The recurrence rate for stenting courses lasting for up to 120 d was 71.4% and 21.4% for stenting courses of 121 d or over (P = 0.03). There were 28 patients that were treated with a single ERCP with Kaffes, 21 with removal after 120 d and 7 within 120 d. There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course (71.0% vs 10.0%, P = 0.01). CONCLUSION: Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.

Dosimetric characteristics of self-expandable metallic and plastic stents for transpapillary biliary decompression in external beam radiotherapy.

There is little evidence regarding radiation dose perturbation caused by the self-expandable metallic stents (SEMSs) used for transpapillary biliary decompression. We aimed to compare SEMSs with plastic stents (PSs) and clarify their dosimetric characteristics. Fifteen SEMSs (10 braided and 5 lasercut type) and six PSs (diameter: 2.3-3.3 mm) were inserted into a water-equivalent solid phantom. In total, 13 SEMSs had radiopaque markers, whereas the other two did not. Using radiochromic films, the dose difference adjacent to the stents at locations proximal, distal, and arc delivery to the radiation source was evaluated based on comparison to measurement of the dose delivery in phantom without any stent in place. The median values of the dose difference for each stent were used to compare the SEMS and PS groups.Results: The dose difference (median (minimum/maximum)) was as follows: proximal, SEMSs + 2.1% (1.8 / 4.7) / PSs + 5.4% (4.1 / 6.3) (p < 0.001); distal, SEMSs -1.0% (-1.6 /-0.4) / PSs -8.9% (-11.7 / -7.4) (p < 0.001); arc delivery, SEMSs 1.2% (0.9 / 2.3) / PSs 2.2% (1.6 / 3.6) (p = 0.005). These results demonstrated that the dose differences of SEMSs were significantly smaller than those of PSs. On the other hand, the dose difference was large at surface of the radiopaque markers for SEMSs: proximal, 10.3% (7.2 / 20.9); distal, -8.4% (-16.3 / -4.2); arc delivery, 5.5% (4.2 / 9.2). SEMSs for biliary decompression can be safely used in patients undergoing radiotherapy, by focusing on the dose distribution around the stents and by paying attention to local changes in the dose distribution of radiopaque markers.

The Impact of Centralized Procurement on Treatment Patterns for Myocardial Infarction and More Principled Utilization of Coronary Stents.

Reducing the price of expensive medical products through centralized procurement is generally considered an effective way to save public medical resources. Against this background, this paper presents an analysis of the impact of centralized procurement in China by comparing the treatment costs and patterns for acute myocardial infarction (AMI) patients before and after the introduction of this method of purchasing, with specific reference to the use of coronary stents. We found that, after the implementation of centralized procurement for coronary stents, the total expenditure of AMI cases receiving percutaneous coronary interventions with stent implantation (PCI with stents) dropped by 23.4%. The use rate of PCI with stents decreased by 32.5%, with the most significant decrease being evident in cases in which two stents were used simultaneously (32.9%). Meanwhile, percutaneous coronary interventions with balloon implantation (PCI with balloons) increased by 31.5% and coronary artery bypass grafting (CABG) increased by 80.3%. Based on these patterns, it can be observed that the use of centralized procurement significantly reduced the profits of the relevant medical manufacturers, forcing them to decrease their marketing investments, weakening their influence on providers, and ultimately resulting in a more principled use of coronary stents. We therefore conclude that, with reference to the data cited, the centralized procurement program led not only to a reduction in procurement prices but also to decreased overuse of these expensive medical products.

Coronary stent implantation links to the occurrence of eosinophilia and interstitial pneumonia: a case report and systematic review.

BACKGROUND: Rapamycin has been extensively utilized for coating coronary artery stents to reduce the occurrence of restenosis, yet there has been limited research on the potential harms of rapamycin-eluting stents. Herein, We report a case of eosinophilia and interstitial pneumonia caused by a cobalt-based alloy stent eluted with rapamycin. CASE PRESENTATION: The patient was admitted due to fever, cough, and expectoration symptoms. Previously, the patient had undergone a procedure of percutaneous coronary stent implantation in our hospital's cardiology department, which led to a gradual rise in blood eosinophil count. This time, the eosinophil count was higher than the previous admission. A chest CT scan revealed multiple flocculent density increases in both lungs and bronchiectasis. The rapamycin-eluting stents may have caused eosinophilia and interstitial pneumonia, which improved after administering corticosteroids. A systematic review of relevant literature was conducted to summarize the characteristics of interstitial pneumonia caused by drug-eluting stents. CONCLUSION: Paclitaxel, everolimus, zotarolimus, and rapamycin are the types of drugs that can lead to drug-eluting stents, and because of the rarity of their onset, clinical doctors must be precise and prompt in diagnosing suspected cases to avoid misdiagnosis and delayed treatment.

Midterm Clinical Outcomes of Endovascular Treatment for Acute Aortic Dissection with Malperfusion Syndrome.

Purpose: There is limited data on the midterm results of endovascular treatment for acute type B aortic dissection (TBAD) with malperfusion syndrome (MS), particularly in Asia. This study aimed to investigate the clinical outcomes of endovascular treatment of acute TBAD with MS. Materials and Methods: We retrospectively analyzed 27 patients who underwent endovascular treatment for acute TBAD with MS. Results: Among the 27 patients with TBAD and MS, malperfusion was observed in the isolated renal (44.4%), visceral (7.4%) and iliofemoral (25.9%) arteries, as well as their combinations (22.2%). The patients underwent thoracic endovascular aortic repair (TEVAR) only (25.9%), selective stenting only in arteries affected by malperfusion (22.2%), or combined treatment with TEVAR and selective stenting (51.9%). Primary technical success was achieved in all the patients. No inhospital mortality or early death within 30 days after operation occurred. The rates of stroke, limb ischemia, acute kidney injury, and reintervention at 30 days were 7.4%, 3.7%, 25.9%, and 3.7%, respectively. The mean follow-up period was 4.3±3.1 years. During the follow-up, the rates of death, stroke, maintenance hemodialysis, aneurysmal change, and reintervention were 0%, 3.7%, 7.4%, 7.4%, and 7.4%, respectively. Two patients required reintervention due to limb ischemia and aneurysmal changes in the distal portion of the stent graft. Computed tomography scans revealed a significant increase in aortic diameters in patients who underwent selective stenting compared to those who underwent TEVAR over a 3-year period, with changes in aortic area measuring 878.9 mm2 vs. 188.4 mm2 at the middle of the lesion (P=0.037), 303.7 mm2 vs. 22.8 mm2 at the level of the celiac trunk (P=0.025), and 442.9 mm2 vs. 37.3 mm2 at the level of the renal artery (P=0.019). Conclusion: The endovascular treatment of acute TBAD with MS demonstrated a high primary technical success rate and promising short- and midterm clinical outcomes.

One-Year Outcomes of Long Coronary Drug-Eluting Stents (≥40 MM) in Patients With Diffuse Coronary Artery Disease: Findings From a Tertiary Care Hospital in North India.

Background and objective Diffuse coronary artery disease (CAD) is associated with extensive involvement of coronary arteries, necessitating the use of long (≥40 mm) drug-eluting stents (DES) based on the lesion length. However, these long DES can lead to complications such as in-stent restenosis (ISR) and stent thrombosis. This study aimed to assess the safety, efficacy, and one-year clinical outcomes of using long DES in patients with diffuse CAD undergoing PCI at a tertiary care hospital in north India. Methodology Patients with diffuse CAD undergoing PCI with long DES between January 2017 and June 2022 were included in the study. Baseline characteristics were recorded, and patients were followed up telephonically or in the outpatient department (OPD) at one, three, six, and 12 months following the PCI. The primary endpoint was the target lesion failure (TLF) rate, with secondary endpoints constituting all-cause mortality, major adverse cardiovascular events (MACE), subacute stent thrombosis, and ISR. Results A total of 200 patients were recruited and followed up for one year. The median age of the patients was 58 years (range: 48.25-63 years), and 82% were men. The most frequently stented artery was the left anterior descending (LAD, 48%), followed by the right coronary artery (RCA, 36%). A total of 388 stents (mean: 1.94 ±0.79) were implanted, including both long and short stents. The mean length and diameter of long stents were 43.64 ±3.58 mm and 3 ±0.37 mm, respectively. At the one-year follow-up, patients undergoing PCI with long DES ≥40 mm had an overall TLF rate of 5%, all-cause mortality of 6% (12 patients), MACE of 6% (12 patients), subacute stent thrombosis of 4% (eight patients), and ISR of 1% (two patients). A large proportion of patients (90%) had an uneventful follow-up of up to a year. At the one-year follow-up, all 10 (5%) patients with a primary outcome had a smaller stent diameter than those without a primary outcome (2.5 ±0.25 mm vs. 3.03 ±0.35 mm, p=0.015). Conclusions Our results suggest that using extremely long stents (>40 mm) for diffuse coronary lesions is safe, efficacious, and associated with relatively low event rates. In addition, the stent diameter has a substantial correlation with the primary outcome. Further studies with larger sample sizes as well as longer follow-up periods are required to validate our findings.

Degrees of Inflammation in the Treatment of Subglottic Stenosis in a Rabbit Model: Histopathological Assessment of a Novel Bioabsorbable Ultra-high Ductility Magnesium Alloy Stent.

OBJECTIVE: Utilizing a novel histopathological scoring system and subglottic stenosis (SGS) rabbit model, we aimed to compare degrees of inflammation and severity of narrowing in the subglottis between two minimally invasive therapeutic modalities: endoscopic balloon dilation (EBD) alone versus EBD with placement of a bioabsorbable ultra-high ductility magnesium (UHD-Mg) alloy stent. METHODS: SGS was induced endoscopically via microsuspension laryngoscopy in 23 New Zealand white rabbits. The control group (n = 11) underwent EBD alone, the study arm (n = 12) underwent EBD with implantation of bioabsorbable UHD-Mg alloy stents. Rabbits were euthanized at 2-, 3-, and 6-weeks after SGS induction, coinciding with wound healing stages. Using Optical Coherence Tomography (OCT), cross-sectional areas of airways were compared to calculate the mean percentage of intraluminal area at sequential time points. A novel histopathological scoring system was used to analyze frozen sections of laryngotracheal complexes. The degree of inflammation was quantified by scoring changes in inflammatory cell infiltration, epithelial ulceration/metaplasia, subepithelial edema/fibrosis, and capillary number/dilation. Univariate analysis was utilized to analyze these markers. RESULTS: We found rabbits implanted with the bioabsorbable UHD-Mg alloy stent had statistically significantly higher scores in categories of hyperplastic change (stents vs controls: 1.48 vs 0.46 p < 0.001), squamous metaplasia (22 vs 5 p < 0.001), and neutrophils/fibrin in lumen (31 vs 8, p < 0.001). Rabbits who received EBD alone had higher scores of subepithelial edema and fibrosis (2.70 vs 3.49, p < 0.0256). The stented rabbits demonstrated significantly increased mean percent stenosis by intraluminal mean area compared to controls at 2 weeks (88.56 vs 58.98, p = 0.032), however at all other time points there was no significant difference between intraluminal subglottic stenosis by mean percent stenosis area. DISCUSSION: Rabbits with SGS treated with UHD-Mg alloy stents demonstrated histopathologic findings suggestive of lower levels of tracheal fibrosis. This could indicate a reduced tendency towards the development of stenosis when compared to EBD alone. There was not a difference in luminal size between stent and non-stented rabbits at the six-week end point. Histologically, however, overall the use of bioabsorbable UHD-Mg alloy stenting elicited a greater tissue response at the level of the superficial mucosa rather than fibrosis of the lamina propria seen in the stented rabbits. This suggests more favorable healing and less of a tendency towards fibrosis and stenosis even though there may not be a benefit from a luminal size standpoint during this early healing period. Compared to known complications of currently available non-bioabsorbable metal or silicone-based stents, this proof-of-concept investigation highlights the potential use of a novel biodegradable UHD-Mg stent as a therapeutic modality for pediatric SGS.

Transcatheter Correction of Superior Venacaval Form of Sinus Venosus Defects Using Balloon-Mounted Covered STENTS.

Superior sinus venosus defects (SVD) are interatrial communications located above the confines of the oval fossa, where unroofing of the right upper pulmonary vein leads to its anomalous drainage to the superior venacava. Recent emergence of transcatheter closure of these defects using covered stents is an attractive alternative option especially in adults with additional comorbidities. This article focuses on various aspects of non-surgical closure of SVD, including patient selection, appropriate hardware options, step-by-step procedural details, evolution and modifications in the techniques over the last decade, protocols for follow-up evaluation, and potential complications associated with this intervention.