Venous Stenosis Research Articles

Editorial

Editorial

Repeated failure of arterio-venous haemodialysis access

Background: The subsequent development of vascular access techniques and devices now permits patients to be maintained on dialysis for decades. Aim of study: To evaluate the most possible causes behind repeated arteriovenous (AV) access failure in ESRD patients and finding the relationship between those causes and the timing of access failure, and putting the possible solutions in the form of interventions and guidelines for those patients. Patients and methods: This retrospective non-randomized study was conducted in department of vascular surgery, Al-Azhar University Hospitals – Cairo (Al-Hussein and Sayed Glal Hospitals). This study was conducted on 100 ESRD patients on regular hemodialysis and with repeated AV access failure; at least two failed accesses for each patient. The total number of failed accesses was 245 where 230 accesses were autogenous AV fistulae and 15 were synthetic bridge grafts in upper limb. Results: Among the cases of access thrombosis 25.5% were associated with access stenosis, 10.5% with hypotension, and 2.5% with external compression. Among the cases of failure of maturation 16% were due to small vein diameter (less than 2.5 mm), 9% associated with hypotension, and 7% with hypotension together with central venous stenosis.

Pathologic characteristics of human venous in-stent stenosis and stent occlusion

ObjectiveThe objective of this study was to determine the pathologic features of venous in-stent stenosis over time occurring in bare metal stents. MethodsEndovascular biopsy samples were obtained prospectively from venous bare metal stents implanted in 2009 through 2018. All samples were formalin-fixed, paraffin-embedded and stained with hematoxylin and eosin. Samples were examined by a cardiovascular pathologist to estimate the amount of its constituent components, which included fresh thrombus, organizing thrombus, old thrombus, or diffuse intimal thickening (DIT), and pathologic features including calcification, neovascularization, and hemosiderin deposition. This pathologic characterization was correlated with time following stent implantation to discern time-dependence of pathologic evolution of in-stent stenosis using both descriptive statistics and binary logistic regression. ResultsA total of 254 post-stent venograms with biopsies of in-stent contents from 148 unique patients were studied. Fresh thrombus and organizing thrombus were both present across all studied time intervals. Old thrombus was seen beginning at approximately 2 weeks and DIT at approximately 4 weeks. Calcification was a rare finding encountered at later time intervals. The prevalence of each component varied with time: the probability of encountering fresh thrombus (P = .010) and organizing thrombus (P = .008) decreased over time. By contrast, the probability of finding DIT (P = .002) and calcifications (P < .001) increased over time. The presence of old thrombus, neovascularization, or hemosiderin did not demonstrate time dependence. Diffuse intimal thickening was frequently seen along with organizing thrombus as well as independently, and in many instances, these two features were directly merged. ConclusionsThe evolution of human venous in-stent restenosis appears to follow a time-dependent course, suggesting a possible progressive evolution from fresh and organizing thrombus to DIT. Contrasted with the literature on arterial in-stent restenosis, vein in-stent restenosis may have an increased thrombus prevalence (both organizing and old thrombus). DIT is a primary feature of late in-stent stenosis and may explain in part why many of these lesions may not respond to thrombolytic or anticoagulant treatment alone.

Overview of hemodialysis access and assessment.

To provide family physicians with an evidence-based overview on the various methods of vascular access for hemodialysis (HD) and to provide a framework for the clinical assessment of HD access. A MEDLINE literature search was conducted using the MeSH terms arteriovenous fistula, arteriovenous graft, central venous catheter, and hemodialysis (or haemodialysis), including all relevant English-language articles published between January 1995 and September 2021. The main types of permanent vascular access for HD are arteriovenous fistulas, arteriovenous grafts, and central venous catheters. A pragmatic, patient-centred approach is required when choosing the type of access for an individual. Common complications of vascular access creation include thrombosis, central venous stenosis, dialysis access steal syndrome, and arteriovenous fistula aneurysms. Family physicians play an important role in the clinical assessment and monitoring of HD vascular access. A thorough clinical assessment can detect a failing arteriovenous fistula and any associated complications, which can allow for prompt investigation and intervention to restore functionality, maintain access longevity, and improve patient quality of life.

Bindarit encapsulated nanoparticles prevent venous neointimal hyperplasia and restenosis in a murine angioplasty model

Monocyte and macrophage recruitment occur to the injured vessel wall after percutaneous transluminal angioplasty (PTA) of stenotic arteriovenous fistulas (AVF) through increased expression of MCP-1 leading to venous neointimal hyperplasia (VNH) and venous stenosis (VS). We hypothesized that adventitial delivery of Bindarit, an oral selective inhibitor of MCP-1, -2, and -3 encapsulated in poly lactic-co-glycolic acid (PLGA) nanoparticles embedded in a thermosensitive Pluronic F127 hydrogel (BN NP) could prevent VNH/VS formation in a murine model of PTA with AVF. Scanning electron microscope and dynamic light scattering were used to characterize the BN NP and control nanoparticles (NP C). Liquid chromatography with tandem mass spectrometry (LC-MS/MS) was used to study drug release kinetics. Immediately after PTA, in a murine model of AVF stenosis, BN NP or NP C was administrated to the adventitia of outflow veins. Animals were sacrificed 3 and 21 days later for gene expression, histomorphometric, and immunohistochemical analyses. Doppler ultrasound was performed weekly. There was no difference in the size and storage modulus of BN NP compared to controls. The pharmacokinetic analysis demonstrated increased drug release from BN NP when compared to controls. BN NP-treated vessels had reduced MCP-1, MCP-2, and MCP-3 gene, and protein levels, reduced macrophage/monocyte abundance, proinflammatory cytokines, and venous fibrosis resulting in positive vascular remodeling and improved patency with reduced VNH/VS. There was increased peak velocity 21 days after PTA in the BN NP group. Adventitial administration of BN NP to the outflow vein after PTA results in decreased VNH/VS.

Establishment and Evaluation of a Porcine Vein Graft Disease Model.

Venous graft disease (VGD) is the leading cause of coronary artery bypass graft (CABG) failure. Large animal models of CABG-VGD are needed for the investigation of disease mechanisms and the development of therapeutic strategies. To perform the surgery, we enter the cardiac chamber through the third intercostal space and carefully dissect the internal mammary vein and immerse it in normal saline. The right main coronary artery is then treated for ischemia. The target vessel is incised, a shunt plug is placed, and the distal end of the graft vein is anastomosed. The ascending aorta is partially blocked, and the proximal end of the graft vein is anastomosed after perforation. The graft vein is checked for patency, and the proximal right coronary artery is ligated. CABG surgery is performed in minipigs to harvest the left internal mammary vein for its use as a vascular graft. Serum biochemical tests are used to evaluate the physiological status of the animals after surgery. Ultrasound examination shows that the proximal, middle, and distal end of the graft vessel are unobstructed. In the surgical model, turbulent blood flow in the graft is observed upon histological examination after the CABG surgery, and venous graft stenosis associated with intimal hyperplasia is observed in the graft. The study here provides detailed surgical procedures for the establishment of a repeatable CABG-induced VGD model.

O079 Predictive value for elevated platelet-derived SGPVI in venous in-stent stenosis in patients with post-thrombotic syndrome

Abstract Introduction In-stent stenosis following intervention for post-thrombotic syndrome (PTS) occurs in ∼30% of cases, despite therapeutic anticoagulation. Our aim was to investigate whether platelets are involved. Methods Blood was taken from case-matched patients before and after venous stenting. Flow-cytometry was used to assess platelet activation (P-selectin and/or phosphatidylserine exposure) while= functional activity was measured by plate-based aggregation and through a flow-cell model of thrombus formation. Soluble glycoprotein VI (sGPVI) was measured in plasma. Patients with in-stent stenosis requiring reintervention (&amp;gt;50% diameter reduction) were compared with those who did not. Results Forty-five patients were recruited (median age: 43yrs (33–55yrs); 65% female), and 19/45 (42%) required reintervention (median time: 3wks (1day-3mths)). There was no difference in platelet activation or reactivity after stenting, but P-selectin exposure pre-stent was significantly higher in patients who developed in-stent stenosis (2.7%±0.4 vs 1.7%±0.2; P&amp;lt;0.05). Pre-stent sGPVI levels were increased in patients who developed in-stent stenosis (18.9±3.6ng/mL vs. 7.4±0.9ng/mL; P&amp;lt;0.01). Platelet reactivity to collagen-related peptide, a GPVI-specific platelet agonist, was reduced in patients who developed in-stent stenosis (logEC50 = -6.5M±0.3 vs -7.2M±0.2; P&amp;lt;0.05; n=33). Pre-stent platelet accumulation (26.6AU±0.5 vs 19.0AU±8.1; P=0.04) was significantly increased in PTS patients compared with healthy controls. Conclusion Venous stenting does not activate platelets, but patients who developed in-stent stenosis exhibited greater levels of pre-stent platelet activation, greater loss of platelet surface GPVI in the form of sGPVI and reduction in reactivity to GPVI activation. sGPVI may have potential to risk stratify patients undergoing venous stenting and predict who requires closer surveillance. Take-home message Soluble GPVI may have potential to risk-stratify patients undergoing deep venous reconstruction and predict who requires closer surveillance.

Analysis of Revision Surgery Following Surgical Reconstruction of the Sigmoid Sinus Wall in Patients with Pulsatile Tinnitus.

Background:To explore potential causes leading to the failure of the surgical reconstruction of sigmoid sinus wall in patients with pulsatile tinnitus.Methods:This study retrospectively analyzed pulsatile tinnitus patients with sigmoid sinus wall dehiscence and/or sigmoid sinus diverticulum, who underwent revision surgeries following the surgical reconstruction of the sigmoid sinus wall.Results:A total of 7 pulsatile tinnitus patients were included. After the first surgery, 5 of 7 patients showed varying degrees of remission in pulsatile tinnitus, but pulsatile tinnitus gradually recurred. The other 2 patients experienced no change in pulsatile tinnitus. Images after the first surgeries revealed that the surgical failure of Patients 1-5 was caused by incompleted elimination of sigmoid sinus wall dehiscence and sigmoid sinus diverticulum. Following revision surgeries, they all acquired great or complete resolution of pulsatile tinnitus. In Patient 6, an abnormal diploic vein entering the sigmoid sinus was overlooked during the first surgery for repairing sigmoid sinus wall dehiscence. As soon as the diploic vein was blocked during the revision surgery, the patient’s pulsatile tinnitus was alleviated significantly. Patient 7 had a recurrence of pulsatile tinnitus after transient improvement following the first surgery, and still experienced no change in pulsatile tinnitus after the revision surgery. However, after venous sinus stenting in the stenosis of transverse-sigmoid sinus junction, she got complete resolution of pulsatile tinnitus. It suggested that the unresolved stenosis of the venous sinus was the cause of the surgical failure.Conclusions:Both sigmoid sinus diverticulum and sigmoid sinus wall dehiscence are recommended to be resolved during surgery. Abnormal diploic veins and venous sinus stenosis are potential causes of pulsatile tinnitus.

Idiopathic intracranial hypertension imaging approaches and the implications in patient management.

Idiopathic intracranial hypertension (IIH) represents a clinical disease entity without a clear etiology, that if left untreated, can result in severe outcomes, including permanent vision loss. For this reason, early diagnosis and treatment is necessary. Historically, the role of cross-sectional imaging has been to rule out secondary or emergent causes of increased intracranial pressure, including tumor, infection, hydrocephalus, or venous thrombosis. MRI and MRV, however, can serve as valuable imaging tools to not only rule out causes for secondary intracranial hypertension but can also detect indirect signs of IIH resultant from increased intracranial pressure, and demonstrate potentially treatable sinus venous stenosis. Digital subtraction venographic imaging also plays a central role in both diagnosis and treatment, providing enhanced anatomic delineation and temporal flow evaluation, quantitative assessment of the pressure gradient across a venous stenosis, treatment guidance, and immediate opportunity for endovascular therapy. In this review, we discuss the multiple modalities for imaging IIH, their limitations, and their contributions to the management of IIH.

Results of endovascular treatment of venous anastomotic stenosis in prosthetic arteriovenous for hemodialysis PTFE grafts. Comparative analysis between patent and occluded grafts

ObjectiveTo analyze the results of endovascular treatment of venous anastomotic stenosis (VAS) in humero-axillary arteriovenous grafts (HAG), comparing outcomes between patent and thrombosed HAG. Material and methodsA retrospective cohort study was made of endovascular treated patients because of a VAS in a HAG between January 2009 and December 2019. Group A: Thrombosed HAG secondary to a VAS. Group B: Patent HAG with a VAS detected during follow-up. Technical success was defined as residual stenosis after treatment <30%, and clinical success as satisfactory immediate dialysis after surgery. After ET a biannual clinical and ultrasound follow-up was performed. Statistical analysis: Survival analysis was performed for time-to-event data to assess patency. ResultsGroup A: 55 patients. Group B: 22. There were no significative differences in demographic and anatomical factors between groups.Technical and clinical success were 100% in group B and 94.5% and 91% respectively in group A.Primary patency at 1, 6 and 12 months was: Group A: 81.8%, 22.4% y 15.7% respectively. Group B: 100%, 85.9%, 76,4% (p < 0.001). Secondary patency at 1, 6 and 12 months was: Group A: 85.2%, 45.8% y 31.3% respectively. Group B 100%, 95.3%, 95.2% (p < 0.001). Use of non-covered stents was associated with an increased risk of occlusion (HR 2.669 IC 95% 1.146–6.216, p = 0.010). ConclusionA higher patency of EV performed on a patent HAG is expected. It is therefore advisable to develop surveillance programs that are capable to detect VAS before its occlusion.

不同引流静脉类型对支架治疗特发性颅内高压合并静脉窦狭窄疗效的影响 Effect of Different Intracranial Venous Drainage Patterns on Stenting for Idiopathic Intracranial Hypertension with Venous Sinus Stenosis

不同引流静脉类型对支架治疗特发性颅内高压合并静脉窦狭窄疗效的影响 Effect of Different Intracranial Venous Drainage Patterns on Stenting for Idiopathic Intracranial Hypertension with Venous Sinus Stenosis

Central Vein Stenosis in Hemodialysis Patients During COVID Pandemic

End-stage kidney disease (ESKD) patients who were on maintenance hemodialysis require a stable, permanent vascular access as a lifeline. Venous mapping during prearteriovenous fistula (AVF) construction does not include central vein assessment. The guidelines on angiographic assessment of central veins during pre-AVF construction are yet to be streamlined. Moreover, during COVID pandemic, assess difficulty in catheterization laboratory and interventional radiology created devastating situation. We report 15 ESKD cases of central venous stenosis presented during the COVID pandemic time from February 2020 to July 2021. Patients' basic details were collected and initial clinical examination findings were recorded; they were subjected to Doppler and fistulogram. After the combined decision of nephrologist, interventional cardiologist, and vascular surgeon, the management (fistula closure/repair) was planned. Of 15 patients, 13 were males. Basic disease is chronic glomerulonephritis in 9, diabetic nephropathy in 4, and chronic interstitial nephritis in 2. Average number of central vein cannulation prior to AVF creation was 2.6. The median time to the development of symptoms after fistula creation was 13 months. Major initial symptoms were swelling of the upper limb in 4, dilatation of outflow veins in 5, swelling and dilatation in 2, poor flow during dialysis in 3, and dilatation of neck and chest vein in 1. Arm elevation test was positive in most of the cases. On Doppler assessment, dilated veins (&gt;12 mm) with high outflow (&gt;2000 ml/min) in 5, 4 patients showed low flow (&lt;400 ml/min), and six patients showed normal findings. In fistulogram, the common location of stenosis/thrombosis was brachiocephalic vein (BV) in 5 and subclavian vein (SC) in 3, BV vein + SC vein in 4, and superior vena cava in 3. Out of 15, 3 underwent balloon dilatation, 7 underwent fistula closure, 1 no intervention done, 3 lost to follow-up, and 1 expired. This is the first case series of central vein stenosis (CVS) brought in light during COVID pandemic. CVS is a serious issue, which might result in permanent vascular access failure. Further study is needed on impact of previous central vein catheterization leading to stenosis and role of pre-AVF creation angiographic assessment to avoid this type of devastating AVF complication.

The first years of liver transplantation: experiences at a single center.

BackgroundThe aim of this study was to analyze the first stages of progress in liver transplantation (LT) at a single center in Vietnam.MethodsThis study analyzed data from patients and donors who participated in the LT program between August 2018 and December 2021 at University Medical Center, Ho Chi Minh City. Study measures included any difficulties encountered, as well as the post-LT outcomes for living donor LT (LDLT) and deceased donor LT (DDLT). The chi-square test and Kaplan Meier survival analysis were used to test the factors that influenced the outcomes.ResultsA total of 18 adult recipients with LT (LDLT, n=16; DDLT, n=2) were included (mean age, 55.2±2.6 years; male, 88.9%). The most common post-LT complications were middle hepatic venous stenosis (20%) and graft rejection (22.2%). These complications were observed in LDLT patients. For DDLT, graft rejection (50%) was the only complication recorded. The survival rates for recipients at 3 months, 6 months, and 1 year were 100%, 88.9%, and 88.9%, respectively. The LDs had their right livers without the middle hepatic veins harvested, and biliary leakage (6.25%) was the only complication observed. There were no deaths among recipients or LDs during the operations or hospital stays.ConclusionsThis study provides key details about the process of LT, and these positive outcomes support LT as an important therapy for end-stage liver disease and early hepatocellular carcinomas.

Impact of allograft types on outcomes after pediatric liver transplantation due to biliary atresia.

Several surgical strategies, including split donor transplantation and living donor transplantation, have been used to increase the donor liver pool. This report focuses on the effects of whole, split, and LDLT on recipient outcomes. We retrospectively analyzed the records of all patients with biliary atresia at Tianjin First Central Hospital between April 2013 and December 2019. A total of 882 patients were included and divided into three groups by graft type, with 198 in the whole-liver-transplantation group, 78 in the split liver transplantation group, and 606 in the LDLT group. The median follow-up time was 39months, patient survival rates of three groups were 94.4%, 88.5%, and 95.0%, respectively, and graft survival rates were 90.2%, 83.3%, and 94.7%, respectively. We divided the split liver transplantation group into two subgroups according to the donor's age, and patient survival rates exhibited a significant difference only in the group whose donor age was over 45 years. The postoperative complication rates were significantly higher with respect to hepatic artery thrombosis, portal stenosis, and AR; and lower in hepatic venous stenosis, PTLDs, CMV virus, and EBV infection in the WLT group. Our multivariate model showed that donor age ≥45 years, RBC transfusion, pneumonia, and HAT were the independent predictors of allograft loss. The survival of split liver transplantation group was slightly lower. The types of complications are different from different graft types. Therefore, postoperative monitoring and treatment need to be adjusted according to the different graft types used.

Clinical Implications of Phenotypes of Hemodialysis Patients With Central Venous Occlusion or Central Venous Stenosis Defined by Cluster Analysis.

ObjectiveThis study aims to investigate the association between clinical factors of patients with central (superior vena cava, brachiocephalic, or subclavian) venous occlusion or central venous stenosis (CVO/CVS) and the difficulty of interventional recanalization as well as the duration of postoperative patency.MethodsA total of 103 hemodialysis patients with CVO/CVS treated with endovascular treatment were enrolled. The two-step cluster analysis was selected to differentiate the cases into distinct phenotypes automatically. Differences in characteristics, the difficulty of interventional recanalization, and the duration of postoperative primary patency time between the two clusters were statistically compared.ResultsThe 103 cases were divided into distinct two clusters by the two-step cluster analysis with 48 (46.6%) in cluster 1 and 55 (53.4%) in cluster 2. Compared to cluster 2, patients in cluster 1 have a higher proportion of blunt stump, side branches, occlusion lesions >2 cm, calcification, or organization. Moreover, the above four factors were, in turn, the most critical four predictors distinguishing 103 patients into two clusters. The remaining six factors were, in turn, occlusion located in the superior vena cava (SVC), duration of central venous catheterization (CVC), lesion location, vessel diameter, number of CVC, and previously failed lesion. Of the four most important factors, with the exception of occlusion lesions exceeding 2 cm, there were significant differences in the length of procedure time between the groups grouped by the remaining three factors. And there was a significant difference in the primary patency rate between the group with blunt stump and the group without blunt stump and also between the group with occlusion lesions ≥ 2 cm and the group with occlusion lesions <2 cm. The operation time of cluster 1 was longer than that of cluster 2. In terms of postoperative patency time, the primary patency time was significantly longer in the patients of cluster 2 compared with cluster 1 (P = 0.025).ConclusionPatients were divided into distinct two clusters. CVO/CVS of patients in cluster 1 was more challenging to be recanalized than that in cluster 2, and the primary patency time was significantly longer in the patients of cluster 2 compared with cluster 1. Blunt stump, side branches, occlusion lesions exceeding 2 cm, and calcification or organization are the four most critical predictors distinguishing 103 patients into two clusters.

Functional analysis of arteriovenous fistulae in non-contrast magnetic resonance images

Background and ObjectiveArteriovenous fistulae (AVF) are the preferred mode of hemodialysis vascular access and their successful maturation is critical to reduce patient morbidity, mortality, cost, and improve quality of life. Peri-anastomotic venous segment stenosis is the primary cause of AVF maturation failure. The objective is to develop a software protocol for the functional analysis of arteriovenous fistula. MethodWe have developed a standard protocol for the anatomical analysis of the AVF to better understand the mechanisms involved in AVF stenosis and to identify future imaging biomarkers for AVF success or failure using non-contrast magnetic resonance imaging (MRI). The 3D model of the AVF is created using a polar dynamic programming technique. Analysis has been performed on six Yorkshire cross domestic swine, but techniques can be applied into clinical settings. ResultsDifferences in AVF angles and vein curvature are associated with significant variability of venous cross-sectional area. This suggests that the pattern of stenosis is likely to be dependent upon hemodynamic profiles which are largely determined by AVF anatomical features and could play an important role in AVF maturation. ConclusionsThis protocol enables us to visualize and study the hemodynamic profiles indirectly allowing early stratification of patients into high and low risk groups for AVF maturation failure. High risk patients could then be targeted with an enhanced process of care or future maturation enhancing therapies resulting in a much-needed precision-medicine approach to dialysis vascular access.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension-From Physiopathology to Treatment.

In this review, we provide an update on the pathogenesis, diagnosis, and management of adults with idiopathic intracranial hypertension (IIH) and implications of the cerebral venous system, highlighting the progress made during the past decade with regard to mechanisms of the venous outflow pathway and its connection with the cerebral glymphatic and lymphatic network in genesis of IIH. Early diagnosis and treatment are crucial for favorable visual outcomes and to avoid vision loss, but there is also a risk of overdiagnosis and misdiagnosis in many patients with IIH. We also present details about treatment of intracranial hypertension, which is possible in most cases with a combination of weight loss and drug treatments, but also in selected cases with surgical interventions such as optic nerve sheath fenestration, cerebral spinal fluid (CSF) diversion, or dural venous sinus stenting for some patients with cerebral venous sinus stenosis, after careful analysis of mechanisms of intracranial hypertension, patient clinical profile, and method risks.

Safety and efficacy comparison between OACs plus single antiplatelet and dual antiplatelet therapy in patients with cerebral venous sinus stenosis poststenting

Background and purposeThe present strategies regarding poststent management for cerebral venous sinus stenosis (CVSS) are inconsistent. Herein, we compared the safety and efficacy of oral anticoagulants (OACs) plus single antiplatelet therapy and dual antiplatelet therapy for CVSS poststenting.MethodsA real-world observational study conducted from January 2009 through October 2019 enrolled patients who were diagnosed with CVSS and received stenting. Patients were divided into two groups according to the management they received poststenting. Group 1: OACs plus a single antiplatelet agent (clopidogrel 75 mg or aspirin 100 mg) and Group 2: dual antiplatelet therapy (clopidogrel 75 mg plus aspirin 100 mg). The safety (such as major or minor bleeding or venous thrombosis) and efficacy (the incidences of cerebral venous sinus restenosis, intrastent thrombosis, or stent displacement) of the two groups were compared.ResultsThere were a total of 110 eligible patients in the final analysis, including 79 females and 31 males with a mean age of 43.42 ± 13.23 years. No major bleeding or venous thrombosis occurred in either of the two groups. Two minor bleeding events occurred in group 2 (one with subcutaneous bleeding points in both lower limbs, another with submucosal bleeding in the mouth), whereas no bleeding events occurred in Group 1. In addition, at the 1-year follow-up, one case of intraluminal restenosis and two cases of in-stent thrombi occurred in Group 2, while none occurred in Group 1. Neither stenosis at stent-adjacent segments nor stent migration was detected in either group during the 1-year following stent placement.ConclusionOACs plus single antiplatelet therapy and dual antiplatelet therapy alone are both safe and efficacious management strategies after CVSS stent placement. The former may have more advantages than the latter for inhibiting intrastent thrombosis. However, further research by larger, multicenter clinical trials is needed.

Clinical implications of airway anomalies and stenosis in patients with heterotaxy syndrome.

In heterotaxy syndrome, bronchopulmonary situs usually reflects atrial situs, resulting in either right (RAI) or left atrial isomerism (LAI). This study determines airway anomalies and its implications in patients with heterotaxy. This retrospective study included 223 patients with heterotaxy syndrome who received an integrated cardiac computed tomography evaluation. Patient database from 1995 to 2020 was reviewed. The patients were examined by a congenital heart disease team comprising pediatric cardiologists, radiologists, pulmonologists, and cardiovascular surgeons. Among the 223 patients, 189 (84.8%, M/F = 1.66) had RAI and 29 had LAI (13.0%, M/F = 0.71). Five patients had indeterminate isomerism (2.2%, M/F = 1.5). Discordant bronchopulmonary and atrial situs occurred in 4% patients, while discordant bronchopulmonary, atrial, and splenic situs occurred in 23.2% patients. Lower airway stenosis was observed in 61 patients (27.4%), including 27.5%, 20.7%, and 60% RAI, LAI, and indeterminate isomerism patients, respectively (p = 0.189). One patient had an intrinsic long segment lower tracheal stenosis and received slide tracheoplasty. Initial cardiac operation was performed in 213 patients. Higher surgical mortality occurred in patients with RAI (19.5% vs. none for LAI and indeterminate isomerism, p = 0.038). In patients with RAI, lower airway anomaly/stenosis increased the duration of ventilator usage (p = 0.030) but did not affect surgical mortality. Total anomalous pulmonary venous return to systemic veins and pulmonary venous stenosis were major surgical risk factors. Bronchopulmonary isomerism shares a similar isomeric pattern to cardiac atrial appendage. Lower airway anomalies/stenosis was common in patients with heterotaxy, resulting in prolonged ventilator therapy in patients with RAI.

Korean Experience of Venovo Stent in Central Venous Stenosis of Hemodialysis Patients

Korean Experience of Venovo Stent in Central Venous Stenosis of Hemodialysis Patients