Central Vein Stenosis Research Articles

Cardiac implantable electronic device and vascular access: Strategies to overcome problems.

For arrhythmia treatment or sudden cardiac death prevention in hemodialysis patients, there is a frequent need for placement of a cardiac implantable electronic device (pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization device). Leads from a cardiac implantable electronic device can cause central vein stenosis and carry the risk of tricuspid regurgitation or contribute to infective endocarditis. In patients with end-stage kidney disease requiring vascular access and cardiac implantable electronic device, the best strategy is to create an arteriovenous fistula on the contralateral upper limb for a cardiac implantable electronic device and avoidance of central vein catheter. Fortunately, cardiac electrotherapy is moving toward miniaturization and less transvenous wires. Whenever feasible, one should avoid transvenous leads and choose alternative options such as subcutaneous implantable cardioverter defibrillator, epicardial leads, and leadless pacemaker. Based on recent reports on the leadless pacemaker/implantable cardioverter defibrillator effectiveness, in patients with rapid progression of chronic kidney disease (high risk of renal failure) or glomerular filtration rate <20 mL/min/1.73 m2, this option should be considered by the implanting cardiologist for future access protection.

Ultrasound-guided direct basilic-axillary approach in preoperative venography for hemodialysis access.

Hemodialysis patients with suspected central vein stenosis or occlusion require venographic assessment before access surgery. Conventional venography may be unsatisfactory because of the limited ability to image central veins via peripheral arm veins that are inadequate or that have been damaged by multiple cannulations. Imaging of the central veins requires high flow contrast injection, which may be unattainable through small peripheral veins. We suggest a simple technique to improve central vein imaging by ultrasound-guided direct puncture of the basilic vein at its entry to the axilla. We studied 20 patients in whom upper limb venography via peripheral veins was inadequate for the satisfactory demonstration of central vein anatomy and they underwent direct basilic-axillary vein puncture with Doppler ultrasound guidance. A 4Fr micropuncture catheter was used for manual injection of the contrast agent to image the central veins. All patients had inadequate upper limb venography via peripheral vein cannulation, and stenosis could not be ruled out due to poor visualization of the central veins. In all cases, venography by Doppler ultrasound-guided direct basilic-axillary vein puncture was very easy for both the radiologist and the patient, consistently providing high quality imaging without the need for repeated attempts at cannulation and without the need for infusion pumps. No complications were noted during or after the procedure. Venography by Doppler ultrasound-guided direct basilic-axillary vein puncture is a simple and rapidly performed technique that improves the visualization of the central veins.

3:20 PM Abstract No. 233 Severe arm swelling in hemodialysis patients with an arteriovenous access and ipsilateral central vein stenosis: comparison of stent deployment versus conversion to a HeRO graft

In ESRD patients with indwelling arteriovenous (AV) fistulas or grafts, central venous stenosis can result in massive arm swelling. For angioplasty-resistant lesions, treatment options include stent deployment, conversion to HeRO graft, and access ligation. While stent deployment is the least invasive option, stents have the potential to limit access options on the ipsilateral or contralateral side. The purpose of this study was to compare clinical outcomes in patients with severe arm swelling due to a central vein stenosis ipsilateral to AV fistula or graft treated with stent deployment versus access conversion to a HeRO graft. This retrospective study was performed on 52 patients (19 males, 32 females, mean age 56.6) with severe arm swelling ipsilateral to an AV access and a central vein stenosis. Of these, 29 patients underwent central venous stent deployment and 23 underwent placement of a HeRO graft with anastomosis directly to the existing graft or fistula. Symptomatic improvement in arm swelling, and primary and secondary access patency were ascertained from medical records. Categorical and continuous variables were compared with the chi square and t-test respectively. Patency rates were calculated with the Kaplan-Meier technique and compared with the log rank test. The two groups were not significantly different with regard to gender (p = 0.78), age (p = 0.61), side of AV access (p = 1.0), fistula versus graft (p = 0.56), or age of access (p = 0.45). Improvement in swelling was found in 86% and 95% after stent deployment or HeRO conversion within 1 month, respectively (p = 0.55). The median primary patency was significantly longer for HeRO conversions than stent deployments (18.9 vs 5.4 months, p<0.001). HeRO conversions also resulted in longer secondary patency (105.2 vs 29.4 months, p = 0.005). The mean number of interventions to maintain secondary patency was 2.7 per 1000 access days for HeRO conversions and 6.3 per 1000 access days for stent deployments. In patients with severe arm swelling due to a central venous stenosis ipsilateral to an AV access, conversion of the access to a HeRO graft resulted in significantly longer primary and secondary patency rates than stent deployment.

Percutaneous intervention for symptomatic central vein stenosis in patients with upper limb arteriovenous dialysis access

Central venous stenosis is an important hindrance to long-term maintenance of arteriovenous access in the upper extremities in dialysis patients. AimThe present study was done to determine feasibility and clinical success of endovascular approach for the treatment of symptomatic central venous stenosis associated with significant ipsilateral limb edema in dialysis patients with vascular access in the upper limb. MethodsA database of hemodialysis patients who underwent endovascular treatment for central venous stenosis from January 2014 to January 2017 at our institute was retrospectively reviewed. Follow-up was variable. ResultsThe study included ten patients (6 men and 4 women) with a mean age of 45.2 years, who underwent thirteen interventions during a period of 3 years. The technical success rate for endovascular treatment was 100%. One patient underwent primary PTA (percutaneous transluminal angioplasty). Seven patients underwent primary PTA and stenting. Three patients underwent secondary PTA. One among these patients underwent secondary PTA twice along with fistuloplasty. One patient underwent secondary PTA with stenting. No immediate complications were encountered during the procedure. Our study shows a primary patency rate of 67% and 33% at 6 months and 12 months for PTA with stenting. Our study also shows secondary or assisted primary patency of 75% at 6 months of follow-up. ConclusionsEndovascular therapy (PTA) with or without stenting for central venous stenosis is safe, with low rates of technical failure. Multiple additional interventions are the rule and long-term patency rate is not very good.

Paclitaxel-Coated Balloon Angioplasty for Early Restenosis of Central Veins in Hemodialysis Patients: A Single Center Initial Experience.

ObjectiveTo report the results of angioplasty with paclitaxel-coated balloons for the treatment of early restenosis of central veins in hemodialysis patients.Materials and MethodsSixteen patients (9 men and 7 women; mean age 65.8 ± 14.4 years; range, 40–82 years) with 16 episodes of early restenoses of central veins within 3 months (median patency duration 2.5 months) were enrolled from January 2014 to June 2015. Ten native central veins and 6 intra-stent central veins were treated with double paclitaxel-coated balloons (diameter 6–7 mm) plus a high pressure balloon (diameter 12–14 mm). The study outcomes included procedural success (< 30% residual stenosis) and primary patency of the treated lesion (< 50% angiographic stenosis without re-intervention).Results Procedural success was achieved in all 16 cases of central vein stenoses. The mean diameter of the central vein was 3.7 ± 2.4 mm before the procedure vs. 11.4 ± 1.8 mm after the initial procedure. There were no procedure-related complications. The mean diameters of the central veins at 6 months and 12 months were 7.8 ± 1.3 mm and 6.9 ± 2.7 mm, respectively. The primary patency rates at 6 months and 12 months were 93.8% and 31.2%, respectively. One patient had significant restenosis of the central vein at 3 months. The median primary patency period was 9 months for paclitaxel-coated balloons and 2.5 months for the last previous procedure with conventional balloons (p < 0.001).ConclusionIn our limited study, paclitaxel-coated balloons seem to improve the patency rate in cases of early restenosis of central veins. However, a further randomized control trial is necessary.

Central vein rupture during percutaneous transluminal angioplasty for central vein stenosis or occlusion in haemodialysis patients

Background: Endovascular treatments such as percutaneous transluminal angioplasty (PTA) and stent placements are becoming the standard method in managing haemodialysis access failure. Venous rupture is the most common complication during endovascular procedures. Complications during endovascular treatments of central venous stenosis or occlusion have been rarely reported.Objectives: To investigate the incidence and management of central vein rupture while performing PTA for central vein stenosis or occlusion in haemodialysis patients.Method: Between 1998 and 2013, PTA was performed using various techniques in haemodialysis patients for central vein stenoses (n = 2437) and occlusions (n = 666). When the guide wire passed through the stenosis or the occlusion, PTA was performed regardless of the presence of a venous rupture. The incidence of central vein rupture was analysed using the chi-square test according to the gender, location, right versus left, presence of thrombosis and stenosis versus occlusion. Percutaneous management of central vein rupture was also evaluated.Results: Central vein rupture occurred in 12 cases (0.39%). All ruptures occurred in the cases with occlusion. Only stenosis versus occlusion reflected a significant correlation (p &lt; 0.001) with central vein rupture. Central vein ruptures were managed by low-pressure balloon tamponade (n = 2), stent/stent-graft (n = 5) and balloon-mediated haemostasis blocking venous inflow followed by the observation (n = 5).Conclusion: Central vein rupture is a rarely occurring complication while performing PTA for central vein stenosis and occlusion, and the majority can be successfully managed by percutaneous techniques.

Doing Less rather than More in Asymptomatic Central Vein Stenosis: The Debate Continues

Doing Less rather than More in Asymptomatic Central Vein Stenosis: The Debate Continues

HEAMODIALYSIS PATIENTS;

Background: Internal jugular vein is considered the preferred site of insertion.Prevalence of central vein stenosis following temporary double lumen catheterization at differentsites seems to be different in Asian countries. Objectives: To evaluate the number of cases havingcatheterization and stenosis after being subjected to central vein catheterization (CVC) amongPakistani population. Study Design: Cross sectional study. Period: 6 months period. Setting:Admitted in the Department of Nephrology or already undergoing maintenance hemodialysisfulfilling the inclusion criteria were included in the study. Material and Method: The samplewhich was considered suitable for this study was 150 cases after checking the inclusion criteriacarefully. The patients were advised to undergo color Doppler ultrasonography of IJV and SCVof both sides. Demographics and outcome variables were noted and recorded for the analysispurposes. Data was analyzed used SPSS 20.inc Results: The frequency of catheterization ofcatherization at IJV was found to be 128(85.3%) and frequency of catheterization at SCV was22(14.7%). The frequency of CVS at IJV was found to be 43(29.68%) and the frequency of CVSat SCV was 81(54.54%). The frequency of stenosis at SCV was found to be significantly higherwith a p value of 0.029 (&lt;0.05). Conclusion: Internal jugular vein is the most frequent andpreferred site of temporary double lumen catheterization for haemodialysis as it is associatedwith significantly lower rate of stenosis as compared to subclavian vein.

Brachial vein transposition is a promising ultimate upper limb autologous arteriovenous angioaccess despite its many pitfalls

ObjectiveThe objective of this study was to retrospectively evaluate the possibility of using the brachial veins despite their deep location, small caliber, and thin wall. MethodsThere were 64 patients without superficial veins who were eligible for two-stage brachial vein transposition (BrVT); 54 patients were on hemodialysis, 9 patients had sickle cell disease, and 1 patient had long-term parenteral nutrition. Preoperative imaging was performed with color duplex ultrasound as well as venography for suspected central vein stenosis. A surgical microscope was used to create an end-to-side anastomosis between the brachial vein (medial, if possible) and artery. No minimum vein diameter was required. Postoperative color duplex ultrasound imaging was scheduled at 1 month. Second-stage superficialization was performed 2 to 3 months later with tunnelization and a new arteriovenous anastomosis. ResultsFor the 64 patients, cumulative primary patency rates (± standard deviation [SD]) at 1 year, 2 years, 3 years, and 4 years were 50% (±7%), 42% (±7%), 37% (±8%), and 27% (±11%), respectively. Primary assisted patency rates (±SD) at 1 year, 2 years, 3 years, and 4 years were 60% (±6%), 51% (±7%), 45% (±7%), and 37% (±9%), respectively. Secondary patency rates (±SD) at 1 year, 2 years, 3 years, and 4 years were 60% (±6%), 53% (±7%), 53% (±7%), and 45% (±8%), respectively. Early complications included thrombosis, nonmaturation, and upper arm edema. At the second stage (n = 50), four patients presented with unexplained major fibrosis extending cephalad from the first surgical site and preventing any dissection of the vein. Four patients had more usual complications (one nonmaturation, two occlusions of the brachial vein at the previous arteriovenous graft-vein anastomosis), and two were lost to follow-up. Vein transposition in a subcutaneous tunnel was technically unfeasible in eight patients. Of the 64 patients, 40 (62%) had a functional BrVT that was cannulated for effective dialysis after a median interval of 72 days (15-420 days) from the first stage. Mean cumulative secondary patency rates (from first cannulation) at 1 year, 2 years, and 3 years were 91% ± 5%, 72% ± 8%, and 62% ± 10%, respectively. Overall, 13 patients were lost to follow-up. Secondary complications were low flow and central vein occlusion. Long-term complications were related to stenosis and thrombosis, aneurysms, and puncture site necrosis. Median follow-up from the first stage was 1.62 years (0.02-11.3 years). ConclusionsDespite many pitfalls for the surgeon, BrVT offers promising long-term patency.

Treatment of central venous in-stent restenosis with repeat stent deployment in hemodialysis patients.

To report patency rates for stent deployment for treatment of in-stent stenosis of the central veins of the chest in hemodialysis patients. A retrospective analysis was performed on 29 patients who underwent 35 secondary percutaneous transluminal stent (PTS) deployments for in-stent stenosis within the central veins that were refractory to angioplasty and ipsilateral to a functioning hemodialysis access (in-stent PTS group). For comparison, patency data were acquired for 47 patients who underwent 78 successful percutaneous transluminal angioplasty (PTA) procedures for in-stent stenosis (in-stent PTA group) and 55 patients who underwent 55 stent deployments within native central vein stenosis refractory to angioplasty (native vein PTS group). The 3-, 6-, and 12-month primary lesion patency for the in-stent PTS group was 73%, 57%, and 32%, respectively. The 3-, 6-, and 12-month primary patency for the in-stent PTA group was 70%, 38%, and 17% and for the native vein PTS group was 78%, 57%, and 26%, which were similar to the in-stent PTS group (p = 0.20 and 0.41, respectively). The 3-, 6-, and 12-month secondary access patency was 91%, 73%, and 65% for the in-stent PTS group. Sub-analysis of the in-stent PTS group revealed no difference in primary (p = 0.93) or secondary patency rates (p = 0.27) of bare metal stents (n = 23) compared with stent grafts (n = 12). Stent deployment for central vein in-stent stenosis refractory to angioplasty was associated with reasonable patency rates, which were similar to in-stent PTA and native vein PTS.

Clinical experience with ultrasound guided angioplasty for vascular access.

BackgroundThe use of ultrasound guided percutaneous transluminal angioplasty (UG-PTA), which use ultrasound as an imaging modality, is an evolving strategy. But, in Korea, this method is rarely used. We report our experiences with UG-PTA with respect to technical success rates and complication rates compared to conventional PTA (C-PTA), performed between 2010 and 2015 at Samsung Changwon Hospital, Korea.MethodsIn our series, 53 cases of UG-PTA and 90 cases of C-PTA were reviewed, respectively. Cases of central vein stenosis, cephalic arch stenosis, arterial stenosis and thrombosis were excluded. However, cases of juxta-anastomotic stenosis and outflow vein stenosis were included.ResultsTechnical success was achieved in 96.2% (51 of 53) of cases in the UG-PTA group and in 93.3% (84 of 90) of cases in the C-PTA group, respectively (P = 0.710). Technical failure was experienced in a total 8 cases (UG-PTA group: 2/53, 3.8%; C-PTA group: 6/90, 6.7%). No differences were observed in complications.ConclusionDuplex ultrasound-guided angioplasty for dialysis access in the outpatient setting is feasible, safe, and effective for peripheral venous stenotic lesions. It offers many advantages over conventional angiographic procedures, and, in the future, it has great potential to play a significant role in the management of these challenging patients.

Significance of Blunted Venous Waveforms Seen on Upper Extremity Ultrasound

Current guidelines recommend vascular mapping ultrasound (US) prior to arteriovenous fistula creation. Blunted venous waveforms (BVWs) suggest central venous stenosis; however, this relationship and one between BVWs and the presence of a central venous catheter (CVC) remain unclear. All patients who received upper extremity vascular mapping US between January 2013 and October 2014 at a single institution were retrospectively reviewed. Patient demographics, comorbidities, US results, pacemaker history, and CVC status were collected. Waveforms were assessed at the proximal subclavian vein/distal axillary vein and interpreted by radiologists. Patients were determined to have central venous stenosis (CVS) if detected by venography within 6months of US. There were 342 patients, of which 165 (48%) had a current CVC and 29 (8.5%) had BVW of at least 1 arm. Right-sided BVW were associated with a history of a prior ipsilateral CVC (odds ratio [OR]=4.5, 95% confidence interval [CI]=1.6-12.6, P=0.009). Of the 342 patients, 69 (20%) had a venogram within 6months. Seventeen (25%) of the 69 patients had CVS, with 7 involving the left subclavian vein, 8 the right subclavian vein, and 3 the superior vena cava (one patient had tandem stenoses). A BVW on the left side was not associated with any CVS. A BVW on the right side was associated with an ipsilateral CVS (OR=5.8, 95% CI=1.2-27.4, P=0.04). This association persisted in the setting of a prior CVC (relative risk = 1.3, 95% CI=0.9-2, P=0.01). There are associations between right-sided BVW and an ipsilateral subclavian vein stenosis. We recommend that hemodialysis access planning includes venography to rule out central vein stenosis in patients with BVW, especially if right-sided and in the setting of a prior CVC.

Dialysis Access Hemorrhage: Access Rescue from a Surgical Emergency

Hemorrhage from a dialysis access can be a life-threatening condition. Thisstudy details our experience using access rescue strategies, including in situ graft replacement, primary repair, or conversion to an autogenous fistula, coupled with treatment of central vein occlusion to maintain access usage in patients presenting with conduit hemorrhage. During a 3-year period (2012-2014), 26 patients (14 women, 12 men) on chronic hemodialysis were treated for access conduit bleeding (n=18) or life-threatening hemorrhage (n=8), located in the upper extremity (n=23) or thigh (n=3). All patients had developed bleeding from a skin eschar/ulcer over a bovine (n=9) or polytetrafluoroethylene (n=9) bridge graft, or aneurysmal autogenous fistula (n=8). A retrospective review of outcome relative to clinical signs, etiology of conduit bleeding (infection, wall erosion), and the type of rescue procedure(s) was performed. Duplex ultrasound testing was used to guide therapy based on the presence of aneurysmal degeneration, perigraft fluid, or access flow pattern indicative of venous outflow obstruction. One-half of the patients were taken emergently to the operating room for hemorrhage control or impending rupture of an infected false aneurysm, the remaining repaired on an urgent basis. In 18 patients, emergency room personnel attempted control of access site bleeding by suturing (n=14) or tourniquet (n=4). Dialysis access salvage was achieved in 22 (85%) of 26 patients by in situ conduit replacement using a rifampin-soaked polytetrafluoroethylene conduit (n=19) or primary repair (n=3). Two patients with sepsis and ruptured, infected false aneurysm were treated by ligation, and 2 patients with nonsalvable access had conversion to an autogenous fistula. One-third of rescued accesses (n=7) had staged endovascular treatment of central vein stenosis. One patient died within 30days. All dialysis access revisions remained patent and used for immediate dialysis (n=5), within 4-5weeks (n=19), or after vein maturation (n=2). One replaced graft was revised for infection. Positive blood or bleeding site cultures were obtained from 9 (45%) of 20 patients tested. Salvage of a functional dialysis access is possible in the majority of patients presenting with conduit hemorrhage. Loss of wall integrity, infection, and venous hypertension were etiologic factors. Application of in situ graft replacement strategies known to be effective in the treatment of graft infection should be considered in the management of this surgical emergency.

Ultrasound-guided fistuloplasty: A novel office-based technique for arteriovenous fistula salvage

Introduction: Alongwith the increasing awareness of fistula for dialysis, there has been an increasing utilization of endovascular interventions to create and maintain native Arterovenous fistulas. So far the widely practiced corrective endovascular options are fistulogram and plasty. However with most target segments being superficial veins of the outflow channel with juxta anastomotic lesions, ultrasound guided fistuloplasty is a promising answer to such a clinical scenario. Methods: All patients with diagnosed outflow vein obstruction with dialysis disturbance and no evidence of central vein stenosis were subjected to the procedure. Results: Satisfactory dialatation was achieved in 84% of patients at the end of one month. Only four patients required adjunctive procedure prior to dialysis. The most common procedure related side effect was hematoma- in 08 ( 19%) of patients, however they were non expanding and self resolving- limited to the area around the plasty site. Conclusion: The procedure can be accomplished in office setting avoiding the exposure of dye and radiation. It also decreases the burden on health care in operating theatres and decreases cost and time of hospitalization. However central vein stenosis and cephalic arch stenosis are definitely limitations of the procedure.

Long Term Outcomes of Arteriovenous Grafts for Hemodialysis in Lower Extremities.

Purpose:The lower extremity has received its fair share of attention as a vascular access site in patients who have exhausted their upper arm vessels. However, experiences with lower extremity arteriovenous grafts (AVGs) have so far been disappointing because of high infection rates and severe limb ischemia. We report our experience with hemodialysis access from the lower extremity.Materials and Methods:A retrospective review of 60 lower extremity AVGs created between January 2003 and December 2011 was performed. Age, sex, etiology of end-stage renal disease and complications were tabulated. Primary and secondary patency rates were determined.Results:The average age of the study population was 56 years and 38 patients were female. Renal failure was associated with hypertension in 40 (66.7%) patients, diabetes in 28 (46.7%) patients and cardiovascular disease in 9 (15.0%) patients. The follow-up period was 8–108 months. Fifty-four patients had bilateral central vein stenosis. Seven (11.7%) patients had primary failure of their AVG. There was no operation-related death. Primary and secondary patency rates were: 66% and 90% at 1 year, 40% and 90% at 2 years, 27% and 87% at 3 years, and 18% and 87% at 5 years, respectively. There were 105 postoperative complications that developed in 67 patients. Postoperative complications were: thrombosis (30), proximal vein stenosis (56), infection (9), bleeding with hematoma (1), perigraft seroma (3), steal syndrome (2), and pseudoaneurysm (4).Conclusion:A lower extremity AVG seems to be a viable option in patients with unusable upper extremity veins.

Symptomatic superior vena cava syndrome in hemodialysis patients: mid-term results of primary stenting

This clinical report details the results of endovascular treatment of symptomatic superior vena cava syndrome due to central vein stenosis or obstruction (CVSO) by stent angioplasty in patients with dialysis-dependent end-stage renal disease. A 3-year retrospective review of two institutional registries identified 25 chronic hemodialysis patients (17 men, 8 women) affected by CVSO who received endovascular treatment. The majority of the patients (n = 19) presented with symptomatic arm, breast, and facial swelling; and 6 patients presented with dialysis-access dysfunction and venous-line hypertension. The etiology of CVSO was before central venous catheter in all but 2 patients. Venography showed 19 cases of stenosis (4 stenoses of superior vena cava, 3 brachiocephalic, 10 subclavian, and 2 axillary veins) and 6 occlusions of the superior vena cava. After percutaneous transluminal angioplasty and primary stent angioplasty, there was an immediate regression of symptoms and arteriovenous fistula preservation in 21 cases; 4 patients received a new arteriovenous fistula after interventional treatment. No procedural major complications or patient deaths occurred. During the follow-up period, we recorded a primary patency rate of 95%, 80%, and 70%, respectively, at 6, 12, and 18 months; and a secondary patency rate of 100%, 95%, and 90%, respectively, at 6, 12, and 18 months. In conclusion, endovascular treatment with primary stenting has proven to be a durable treatment option for hemodialysis patients with CVSO, and this treatment should be considered before dialysis access placement in patients with catheter-induced central vein obstruction.

Complications of Vascular Access: Superior Vena Cava Syndrome

Stenosis or occlusion of central veins in hemodialysis patients is common, especially with previous intravascular catheter or device use. Superior vena cava (SVC) obstruction is emerging as a frequent chronic complication of central vein cannulation that not only jeopardizes the availability of vascular access for hemodialysis, but can become a life-threatening emergency. Clinical features of SVC syndrome can be subtle or dramatic, including facial swelling and shortness of breath, which require expeditious attention and intervention. The approach to SVC syndrome involves judicious use of imaging techniques to define the cause and location. Early management with endovascular intervention with angioplasty and stent placement is the usual first choice. The occlusion can often be recanalized using new techniques such as radiofrequency wire and then salvaged with stents, providing prompt resolution of symptoms. Limitations to interventions include requirement of cutting-edge equipment, expertise, expense, and the usually temporary nature of the resolution. Surgery is considered the treatment of last resort for refractory cases. SVC syndrome can be prevented by minimizing catheter and intravascular device use through early recognition of patients with chronic kidney disease, early referral for education about all choices for kidney replacement modalities, and early placement of arteriovenous access prior to the onset of dialysis therapy.

Comparison of Open-Cell Stent and Closed-Cell Stent for Treatment of Central Vein Stenosis or Occlusion in Hemodialysis Patients.

BackgroundCentral vein stenosis or occlusion is a common complication that can lead to significant morbidity and dysfunction of access in the hemodialysis patient. More lesions can develop over time, and preserving access becomes a challenge as life expectancy of the hemodialysis patient increases.ObjectivesThe goal was to compare long-term results and determine the outcomes of open-cell stent versus closed-cell stent for central vein stenosis or occlusion in hemodialysis patients.Patients and MethodsFrom 1997 to 2015, in 401 hemodialysis patients, stent placement for central vein stenosis or occlusion was performed if balloon angioplasty was unsatisfactory, due to elastic recoil or occurrence of restenosis within 3 months. When thrombus was present, primary stenting was performed. A total of 257 open-cell stents and 144 closed-cell stents were used. Angiographic findings including lesion site, central vein stenosis or occlusion, and presence of thrombosis and complication were evaluated. Primary patency rate and mean patency rate of the stent were compared between two stent groups by Kaplan-Meier survival analysis.ResultsFor the open-cell stent group, 159 patients were diagnosed as central vein stenosis and 98 were occlusion. For the closed-cell stent group, 78 were stenosis and 66 were occlusion. There were two complications for central migration and two for procedure-related vein rupture. Open-cell stents and closed-cell stents had mean patency rates of 10.9 ± 0.80 months and 8.5 ± 10.87 months, respectively (P = 0.002).ConclusionThe open-cell stent is effective and its performance is higher than that obtained with the closed-cell stent for treating central vein stenosis or occlusion in hemodialysis patients.

Placement of Tunneled Dialysis Catheters at or Just Before Autogenous Fistula Creation Does Not Increase the Risk of Central Vein Stenosis

Placement of Tunneled Dialysis Catheters at or Just Before Autogenous Fistula Creation Does Not Increase the Risk of Central Vein Stenosis

136-40: Successful retrieval of a Micra™ leadless pacemaker after 3 months

Introduction: Single chamber leadless pacemakers (PM) are a new alternative to conventional VVI PM eliminating the risk of pocket or lead problems. Currently available systems use either a helical wire screw (Nanostim™, St. Jude Medical) or nitinol tines (Micra™, Medtronic) for endocardial fixation. There is some concern that device retrieval in case of infection or battery depletion may be a problem with these new PM. Data on extraction of leadless PM beyond the immediate postoperative phase are very limited. Methods: Since European market release in June 2015 we successfully implanted Micra PM in 8 pts. (mean age 75.5 yrs. (20 – 92 yrs.); 5 females). Indications for implantation of Micra where bilateral PM pocket infection (n = 1), central vein occlusion or stenosis (n = 3), severe pocket problems (n = 1) or other reasons (n = 3). There were no acute complications in any patient; in 2 pts. up to 3 positions had to be tested to reach adequate sensing and/or pacing threshold. Mean radiation duration was 7,56 + 7,37 min. In one of these pts. the Micra device was explanted after 12 weeks. He received the system due to symptomatic bradyarrhythmia and permanent atrial fibrillation with moderately reduced left ventricular function (LVEF 45%) and planned implant of a phrenic nerve stimulator to treat his central sleep apnea which was successfully performed 3 weeks after the Micra implant. Nine weeks later the pt. was successfully resuscitated from ventricular fibrillation. The patient recovered well and a coronary angiogram after the event showed no new coronary stenoses. The decision was made to extract the leadless VVI PM and exchange it for an implantable defibrillator for secondary prevention of sudden death, combined with cardiac resynchronization therapy (CRT-D) to prevent left ventricular desynchronisation by right ventricular apical pacing. After placement of the ICD lead, a left femoral venous access was used to place a new 23 French (F) introducer system into the right atrium. Using a 8.5 F steerable catheter and a 25 mm snare the Micra pacemaker could be fixed in the neck section of the device and retrieved from endocardial fixation with permanent traction for 18 seconds without any hemodynamic compromise. The whole system could then be retracted into the 23 F sheath and removed without problems. Conclusion: This case report illustrates that retrieval of the Micra leadless PM is possible beyond the immediate postoperative phase by using a femoral approach with a large introducer sheath and a snare catheter, capturing the neck of the PM and using gentle traction (as opposed to “screwing off” with the Nanostim device). It cannot be excluded that retrieval may be more difficult by strong fixation of the Micra nitinol tines and tissue overgrowth years after implant. In this situation, the implantation of an additional leadless PM while leaving the first device in place may be an alternative.