Central venous stenosis in the hemodialysis patient: incidence and efficacy of endovascular treatment

Endovascular treatment for symptomatic iliac vein compression syndrome: a prospective consecutive series of 48 patients

BACKGROUND

We sought to assess the prevalence of iliac vein compression syndrome (IVCS) in patients with unilateral left lower limb chronic venous disease and evaluate the feasibility and effectiveness of endovascular treatment for IVCS.

METHODS

We conducted a prospective cohort study of 48 consecutive patients diagnosed with IVCS between December 2008 and May 2012. We divided the patients into 2 groups: thrombotic IVCS (n = 12) and nonthrombotic IVCS (n = 36). We evaluated the perioperative, 30-day, and 1-year outcomes of endovascular treatment. We estimated the stent patency rate using the Kaplan-Meier method.

RESULTS

The prevalence of IVCS within our cohort was 14.8% (48/324). The technical success rate of the endovascular treatment was 95.8%. There was no death, pulmonary embolism, or contrast-induced nephropathy among the patients. The 1-year primary patency rate was 93.0%. There was no significant difference between the thrombotic and nonthrombotic IVCS groups (P = 0.156). Perioperative complications were minor and improved quickly. The median pain level recorded on a visual analogue scale declined from 4.5 to 1.2 (P < 0.05) in the thrombotic ICVS group and from 3.3 to 0.3 (P < 0.05) in the nonthrombotic ICVS group. The edema relief rates in the thrombotic and nonthrombotic ICVS groups were 81.8% and 58.5%, respectively. The cumulative recurrence free ulcer healing rate was 71.4% 12 months after treatment.

CONCLUSIONS

IVCS is more common than previously thought among patients with unilateral left lower limb chronic venous disease. Endovascular therapy, a minimally invasive approach to treating venous lesions, is a feasible and effective treatment for left-sided IVCS and has a high technical success rate and an acceptable complication profile.

Fibrin sheath angioplasty: a technique to prevent superior vena cava stenosis secondary to dialysis catheters

Fibrin sheaths are a heterogeneous matrix of cells and debris that form around catheters and are a known cause of central venous stenosis and catheter failure. A total of 50 cases of central venous catheter fibrin sheath angioplasty (FSA) after catheter removal or exchange are presented. A retrospective review of an outpatient office database identified 70 eligible patients over a 19-month period. After informed consent was obtained, the dialysis catheter exiting the skin was clamped, amputated, and a wire was inserted. The catheter was then removed and a 9-French sheath was inserted into the superior vena cava, a venogram was performed. If a fibrin sheath was present, angioplasty was performed using an 8 × 4 or 10 × 4 balloon along the entire length of the fibrin sheath. A completion venogram was performed to document obliteration of the sheath. During the study, 50 patients were diagnosed with a fibrin sheath, and 43 had no pre-existing central venous stenosis. After FSA, 39 of the 43 patient's (91%) central systems remained patent without the need for subsequent interventions; 3 patients (7%) developed subclavian stenoses requiring repeat angioplasty and stenting; 1 patent (2.3%) developed an occlusion requiring a reintervention. Seven patients with prior central stenosis required multiple angioplasties; five required stenting of their central lesions. Every patient had follow-up fistulograms to document long-term patency. We propose that FSA is a prudent and safe procedure that may help reduce the risk of central venous stenosis from fibrin sheaths due to central venous catheters.

Stent grafts for central venous occlusive disease in patients with ipsilateral hemodialysis access

PURPOSE

To assess long-term outcomes of stent grafts in patients with symptomatic central venous stenoses and occlusions ipsilateral to hemodialysis grafts or fistulas.

MATERIALS AND METHODS

The study included 52 of 55 consecutive patients with symptomatic stenoses of the central veins draining upper limb dialysis access grafts or fistulas treated with stent grafts. Indications for stent grafts were poor angioplasty results, rapid recurrence, or total occlusion. Endpoints were lesion patency and access patency following intervention. Mean follow-up was 25 months with a median of 24 months and 1.25 additional procedures per patient year. Patency rates were calculated using Kaplan-Meier analysis.

RESULTS

All stent grafts were successfully deployed. The lesion patency rates at 6, 12, 24, and 36 months after intervention were 60%, 40%, 28%, and 28%. The access patency rates at 6, 12, 24, and 36 months after intervention were 96%, 94%, 85%, and 72%. There was one major complication and no minor complications. In 40 patients (77%), the internal jugular vein confluence was covered by the stent graft. In five patients, the dialysis circuits became occluded, with no clinical sequelae in four; one patient was lost to follow-up. The contralateral brachiocephalic vein was covered in three patients (6%), preventing contralateral access construction in one patient.

CONCLUSIONS

Central vein stent graft placement in patients with hemodialysis access is associated with prolonged access patency. Coverage of major vein confluences, which occurred in 83% of the patients in this series, can compromise future access and should be avoided whenever possible by careful technique.

Neurological sequelae from brachiocephalic vein stenosis

Stenosis of central veins (brachiocephalic vein [BCV] and superior vena cava) occurs in 30% of hemodialysis patients, rarely producing intracranial pathology. The authors present the first cases of BCV stenosis causing perimesencephalic subarachnoid hemorrhage and myoclonic epilepsy.

In the first case, a 73-year-old man on hemodialysis presented with headache and blurry vision, and was admitted with presumed idiopathic intracranial hypertension after negative CT studies and confirmatory lumbar puncture. The patient mildly improved until hospital Day 3, when he experienced a seizure; emergency CT scans showed perimesencephalic subarachnoid hemorrhage. Cerebral angiography failed to find any vascular abnormality, but demonstrated venous congestion. A fistulogram found left BCV occlusion with jugular reflux. The occlusion could not be reopened percutaneously and required open fistula ligation. Postoperatively, symptoms resolved and the patient remained intact at 7-month follow-up.

In the second case, a 67-year-old woman on hemodialysis presented with right arm weakness and myoclonic jerks. Admission MRI revealed subcortical edema and a possible dural arteriovenous fistula. Cerebral angiography showed venous engorgement, but no vascular malformation. A fistulogram found left BCV stenosis with jugular reflux, which was immediately reversed with angioplasty and stent placement. Postprocedure the patient was seizure free, and her strength improved. Seven months later the patient presented in myoclonic status epilepticus, and a fistulogram revealed stent occlusion. Angioplasty successfully reopened the stent and she returned to baseline; she was seizure free at 4-month follow-up.

Central venous stenosis is common with hemodialysis, but rarely presents with neurological findings. Prompt recognition and endovascular intervention can restore normal venous drainage and resolve symptoms.

Prophylactic distal revascularization and interval ligation procedure during femoral vein transposition fistula creation in patients at high risk for ischemic complications

Femoral vein transposition arteriovenous fistula (FVt AVF) is a viable autologous option when upper extremity dialysis access sites have become compromised. High volume flow through the AVF can lead to ischemic complications, including steal syndrome (SS), and may threaten access and limb viability. Risk factors for SS include: age >60 years, female sex, diabetes, atherosclerosis, hypertension, and previous limb procedures. Two dialysis patients, who were at high risk for SS in their lower extremities as assessed during the preoperative evaluation for an elective FVt AVF, had a distal revascularization and interval ligation (DRIL) procedure concurrently performed. At 42 and 24 months from their respective surgeries, both patients are reliably using their lower extremity autologous access sites and have not developed any signs or symptoms of ischemia. DRIL may represent an effective surgical strategy that can prophylactically be used to minimize the incidence of ischemic complications during FVt AVF in carefully selected, high-risk patients.

Central vein stenosis

Central vein stenosis (CVS) is commonly seen in patients receiving hemodialysis through an arteriovenous access, threatening the usability of arteriovenous access for dialysis. Subclavian and internal jugular catheters are prime reasons for the development of CVS, especially in the setting of long-term use of multiple catheters. CVS related to cardiac rhythm devices also is seen frequently. Idiopathic CVS can be encountered, although it is less common. Clinical features ultimately become sufficiently prominent to prompt angiographic evaluation. CVS should be evaluated carefully because management must be individualized. The primary method for treatment of CVS is endovascular intervention, including angioplasty and stent placement, whereas surgical options should be pursued in only refractory cases due to the invasiveness of the intervention. Early referral of patients for chronic kidney disease care; timely discussion of kidney replacement modality choices, including nonhemodialysis options such as peritoneal dialysis and kidney transplantation; placement of arteriovenous access prior to the onset of dialysis; and avoidance of catheters and other central vein instrumentation will prevent the development of CVS in most patients with kidney disease.

Central venous disease in hemodialysis patients: an update

Central venous occlusive disease (CVD) is a common concern among the hemodialysis patient population, with the potential to cause significant morbidity. Endovascular management of CVD, comprising percutaneous balloon angioplasty and bare-metal stenting, has been established as a safe alternative to open surgical treatment. However, these available treatments have poor long-term patency, requiring close surveillance and multiple repeat interventions. Recently, covered stents have been proposed and their efficacy assessed for the treatment of recalcitrant central venous stenosis and obstruction. Moreover, newly proposed algorithms for the surgical management of CVD warrant consideration. Here, we seek to provide an updated review of the current literature on the various treatment modalities for CVD.

Utilização da técnica do varal para angioplastia de estenose de veia central com stent-graft

A estenose de veia central é uma das situações mais frequentes em pacientes com insuficiência renal crônica em hemodiálise. A angioplastia com o uso de stent-graft tem obtido bons resultados nestes casos. O sistema de liberação dos stents é de calibre maior, podendo dificultar sua navegabilidade em áreas de estenose ou tortuosidade acentuadas. A técnica do varal é comumente utilizada para o tratamento endovascular do aneurisma de aorta, permitindo atingir bom mecanismo de estiramento e facilitando a navegação do sistema de entrega da endoprótese. Descrevemos o caso de uma angioplastia de veia central com stent-graft na qual foi utilizada a técnica do varal para permitir a transposição da área de estenose.

Recanalization of Chronic Refractory Central Venous Occlusions Utilizing a Radiofrequency Guidewire Perforation Technique

Purpose

To assess the technical success rate and safety of radiofrequency perforation guidewire (RF) technology for the recanalization of refractory chronic central venous occlusions in symptomatic hemodialysis patients with failed conventional endovascular methods.

Methods

This single center retrospective cohort of hemodialysis patients comprised of six men (mean age 67 years, range 55 to 80) with autogenous fistulae, who had already undergone failed conventional endovascular methods. These patients underwent the RF perforation technique from December 2006 to January 2010.

Results

Three patients were successfully treated using the RF perforation technique, after which they had PTFE stent grafts placed at the site of occlusion. There was no recurrence of clinical symptoms. In the remaining three patients, the procedure was terminated after multiple unsuccessful attempts. There were no complications.

Conclusions

The RF perforation technique is a potential alternative technology for recanalization of refractory chronic central venous occlusions in hemodialysis patients in the setting of failed conventional endovascular recanalization techniques.

Use of covered stents in the central vein: a feasibility study in a canine model

PURPOSE

To evaluate the feasibility of using covered stents vs. bare stents in a model of central vein stenosis with an arteriovenous graft created to mimic the conditions in hemodialysis patients.

METHODS

In 7 mongrel dogs, an expanded polytetrafluoroethylene-covered nitinol stent was placed in one common iliac vein and a bare stent was placed in the contralateral vein. Arteriovenous grafts were created bilaterally between the common femoral artery and vein to induce endothelial damage. Neointima formation in the covered stents was compared to the bare stents at 12 weeks using microscopy and histochemical staining.

RESULTS

Two dogs were excluded due to thrombosis and infection of the arteriovenous grafts, but all stents in the remaining 5 dogs were patent. Smooth, complete neointimal coverage was observed on the inner surface of all the covered stents without intraluminal thrombus. In contrast, incomplete neointimal coverage was seen in all bare stents, with small focal thrombi adhering to the neointima on 3 bare stents. Focal nodular neointimal hyperplasia with denudation of the endothelium was observed in only 2 bare stents. Mean neointimal thickening was significantly greater in the covered stents. Eccentric neointimal thickening was observed at the inflow and outflow segments of both types of stents.

CONCLUSION

Covered stents are technically feasible for the treatment of central vein stenosis, and they demonstrate complete, smooth neointimal coverage in normal central veins, but they also display greater neointimal thickening than bare stents.

Long-term results of stent-graft placement to treat central venous stenosis and occlusion in hemodialysis patients with arteriovenous fistulas

PURPOSE

To determine the effectiveness of stent-grafts for the treatment of central venous disease in hemodialysis patients with functioning arteriovenous (AV) fistulas.

MATERIALS AND METHODS

Between October 2004 and March 2010, 42 VIABAHN stent-grafts were deployed in central veins of 30 patients (16 men, 14 women; mean age 60 y) with functioning AV fistulas and central venous disease that did not respond to percutaneous transluminal angioplasty (PTA). Eighteen patients had central vein stenosis and 12 had occlusion. Previous PTA and/or bare metal stent placement had been performed in 23 patients (77%). Surveillance was carried out at 3, 6, 9, 12, 18, and 24 months with diagnostic fistulography. The mean follow-up was 705 days (range, 66-1,645 d). Statistical analysis included Kaplan-Meier and log-rank studies.

RESULTS

Technical success rate was 100%. Primary patency rates were 97%, 81%, 67%, and 45% at 3, 6, 12, and 24 months, respectively. Primary assisted patency rates were 100%, 100%, 80%, and 75% at 3, 6, 12, and 24 months, respectively. Patients without previous procedures had significantly shorter times to repeat intervention (P = .018) than those who had undergone PTA or bare metal stent placement previously. Patients with occlusive lesions had a significantly shorter primary patency interval (P = .05) than patients with stenoses. Occluded veins were more likely to require further stent-grafts (P = .02). Twelve patients required further stent-grafts to maintain patency. There was one minor complication.

CONCLUSIONS

Stent-graft placement to treat central venous disease in hemodialysis patients with autogenous AV fistulas is safe and effective if PTA fails to maintain luminal patency.

Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients

OBJECTIVES

Covered stents have been proposed as an endovascular option for recalcitrant cases of hemodialysis-related central venous occlusive disease (CVOD). This study evaluated the efficacy and durability of covered stents in treating CVOD to preserve a functional dialysis access circuit.

METHODS

A retrospective review was performed of all patients with clinically significant CVOD who were treated by placement of covered stents from April 2007 to September 2010. Demographics, lesion locations and anatomic characteristics, stent graft, and access patency rates were determined. Complications, reinterventions, and factors influencing their outcomes were examined.

RESULTS

In 25 patients (56% men; mean age, 57 ± 29 years) with CVOD, covered stents were used in 20 to treat symptomatic venous hypertension or in 5 at the time of access creation to enable functionality. The target lesion was accessed via the dialysis access site or the common femoral vein. The Viabahn endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz) was used in 24 patients (average size and length, 11 mm × 5 cm) and a 13-mm × 5-cm Fluency covered stent (Bard Peripheral Vascular, Tempe, Ariz) was implanted in 1 patient. Technical success was 100%, and resolution of arm edema occurred after covered stent deployment in symptomatic patients. Two postprocedural cases (8%) of thrombosis occurred, one within 30 days and another at 3 months. Both required percutaneous thrombectomy and percutaneous transluminal angioplasty (PTA). Three additional patients (12%) required PTA due to restenosis in one of the ends of the device. Covered stent primary patency (PP), assisted primary patency (APP), and secondary patency (SP) were 56%, 86%, and 100% at 12 months, respectively. Access patency rates at 12 months were 29%, 85%, and 94% for PP, APP, and SP, respectively, in patients that received a covered stent for access salvage; patency rates were 74%, 85%, and 94% for PP, APP, and SP, respectively, in patients in whom the access was created after the venous outflow restoration.

CONCLUSIONS

Placement of covered stents for hemodialysis-related CVOD is safe, effective in relieving symptoms, and enabled functionality of new dialysis access circuits. Further prospective and randomized studies are necessary to determine whether covered stents provide superior long-term results to those achieved with PTA and bare metal stents.

Revascularization of a central vein total occlusion via antegrade and retrograde approach in a patient with hemodialysis access

The occurrence of central vein total occlusion results in upper arm edema, pain, and hemodialysis access failure in uremic patient. Previous studies have proven the effectiveness of percutaneous balloon angioplasty for central vein total occlusion. Here, we report a rare case of successful revascularization of central vein total occlusion via antegrade and retrograde approach.

Review of central venous disease in hemodialysis patients

A common problem in the management of patients who are undergoing hemodialysis is central venous occlusive disease. There has been extensive literature on the treatment of this important and prevalent problem. Treatment options to date include percutaneous balloon angioplasty, bare metal stents, and surgical bypass. Unfortunately, all the available treatment options have poor long-term patency, requiring repeated interventions. More recently, covered stents have been mentioned in the literature for the treatment of central venous stenosis and obstruction. There are very few data to date on this technology, and further randomized controlled trials will be needed to compare the efficacy of percutaneous balloon angioplasty, bare metal stents, and covered stents. It appears that it is of paramount importance to prevent this difficult problem by limiting access to, or intervention in, the central venous system.

Central vein stenosis: current concepts

Central vein stenosis (CVS) is a common complication of the central venous catheter (CVC) placement. The prevalence of CVS has mostly been studied in those who present with symptoms such as swelling of the extremity, neck and breast. CVS compromises arteriovenous access and can be resistant to treatment. A previous history of CVC placement is the most important risk factor for the development of CVS later. Pacemaker and defibrillator wires are associated with a high incidence of CVS. Increasingly liberal use of peripherally inserted central catheters (PICC) is likely to increase the incidence of CVS. The trauma and inflammation related to the catheter placement is thought to result in microthrombi formation, intimal hyperplasia and fibrotic response, with development of CVS. Treatment of CVS by endovascular procedures involves angioplasty of the stenosis. An elastic or recurrent stenosis may require a stent placement. The long-term benefits of the endovascular procedures, although improved with newer technology, remain modest. Surgical options are usually limited. Future studies to explore the pathogenesis and the use of novel therapies to prevent and treat CVS are needed. The key to reducing the prevalence of CVS is in reducing CVC placement and placement of arteriovenous accesses prior to initiating dialysis. Early referral of the patients to the nephrologists by the primary care physicians is important. Timely vein mapping and referral to the surgeon for fistula creation can obviate the need for a CVC and decrease incidence of CVS.

Central venous obstruction management

A major challenge in the management of hemodialysis patients is central venous stenosis and obstruction. Placement of central venous catheters has been shown to result in a high incidence of central venous stenosis or obstruction. There has been extensive literature on the treatment of this important and prevalent problem. Treatment options include percutaneous balloon angioplasty and bare metal stents. Unfortunately, all the available treatment options have variable rates of patency, requiring repeated intervention. More recently, covered stents have been mentioned in the literature for the treatment of central venous stenosis and obstruction. There is very little data to date, and further randomized controlled trials will be needed to compare the efficacy of percutaneous balloon angioplasty, bare metal stents, and covered stents. It appears prevention of this difficult problem is paramount, by limiting use of central venous catheters.

Reversed internal jugular vein flow as a sign of brachiocephalic vein obstruction

The value of colour Doppler sonography is well known in the assessment of venous disease, including obstruction/occlusion from thrombosis. Central venous disease, however, can be more difficult to directly assess than disease in peripheral veins. Accordingly, there is significant value not only in the direct signs of venous disease, but also in the indirect signs. We report a case of reversed internal jugular vein flow in a patient with left arm swelling as a sign of brachiocephalic vein obstruction.

Stent placement in hemodialysis access: historical lessons, the state of the art and future directions

Vascular access stenosis in patients undergoing chronic hemodialysis is a major issue that is associated with increased morbidity, mortality, and cost of medical care. Recent data have emphasized that endovascular stents could be used in the treatment of central as well as peripheral stenotic lesions. In general, a peripheral or central vein lesion that is elastic or recurs within a three-month period after an initially successful balloon angioplasty or a stenosis where surgical revision is not possible are some indications for intravascular stent placement. Recent reports have expanded the role of stents in the management of pseudoaneurysms associated with dialysis access. In this context, the utilization of these devices must take into account a fair comparison with the traditional (surgical) approaches regarding effectiveness as well as costs. This report describes the role of stents in arteriovenous dialysis access. In addition, some of the recent advances in the structure and complicating issues such as stent fracture, migration, and infection, as well cannulation through the stent, are discussed.

Percutaneous treatment of central venous stenosis in hemodialysis patients: long-term outcomes

The purpose of this study was to evaluate the long-term outcomes of endovascular treatment of central venous stenosis in patients with arteriovenous fistulas (AVFs) for hemodialysis. Five hundred sixty-three patients with AVFs who were referred for a fistulogram were enrolled in this study. Among them, 44 patients showed stenosis (n = 35) or occlusions (n = 9) in the central vein. For the initial treatment, 26 patients underwent percutaneous transluminal angioplasty (PTA) and 15 patients underwent stent placements. Periods between AVF formation and first intervention ranged from 3 to 144 months. Each patient was followed for 14 to 60 months. Procedures were successful in 41 of 44 patients (93.2%). Primary patency rates for PTA at 12 and 36 months were 52.1% and 20.0%, and assisted primary patency rates were 77.8% and 33.3%, respectively. Primary patency rates for stent at 12 and 36 months were 46.7% and 6.7%, and assisted primary patency rates were 60.0% and 20.0%, respectively. Fifteen of 26 patients with PTAs underwent repeated interventions because of restenosis. Fourteen of 15 patients with a stent underwent repeated interventions because of restenosis and combined migration (n = 1) and shortening (n = 6) of the first stent. There was no significant difference in patency between PTAs and stent placement (p > 0.05). Average AVF patency duration was 61.8 months and average number of endovascular treatments was 2.12. In conclusion, endovascular treatments of central venous stenosis could lengthen the available period of AVFs. There was no significant difference in patency between PTAs and stent placement.

Complications of arteriovenous hemodialysis access: recognition and management

English language citations reporting complications of arteriovenous access for hemodialysis are critically reviewed and discussed. Venous hypertension, arterial steal syndrome, and high-output cardiac failure occur as a result of hemodynamic alterations potentiated by access flow. Uremic and diabetic neuropathies are common but may obfuscate recognition of potentially correctable problems such as compression or ischemic neuropathy. Mechanical complications include pseudoaneurysm, which may develop from a puncture hematoma, degeneration of the wall, or infection. Dysfunctional hemostasis, hemorrhage, noninfectious fluid collections, and access-related infections are, in part, manifestations of the adverse effects of uremia on the function of circulating hematologic elements. Impaired erythropoiesis is successfully managed with hormonal stimulation; perhaps, similar therapies can be devised to reverse platelet and leukocyte dysfunction and reduce bleeding and infectious complications.

Intravascular ultrasound-guided central vein angioplasty and stenting without the use of radiographic contrast agents

Patients with contraindications to iodinated radiographic contrast agents present a significant challenge during endovascular intervention. A 46-year-old man with end-stage renal disease and a normally functioning left upper extremity arteriovenous fistula presented with severe left arm edema. The patient's history included repeated severe anaphylactoid reactions with severe respiratory distress upon exposure to iodinated contrast. In an attempt to avoid the use of iodinated contrast, angioplasty and stent placement of a severe central venous stenosis were performed using only fluoroscopy and intravascular sonography. In patients unable to receive iodinated contrast secondary to anaphylactoid reactions, intravascular sonography can be used to guide angioplasty and stenting of central venous stenosis.

Use of nitinol stents following recanalization of central venous occlusions in hemodialysis patients

PURPOSE

To retrospectively review the patency of endovascular interventions with nitinol stent placement for symptomatic central venous occlusions in hemodialysis patients.

METHODS

A retrospective review of all patients who underwent endovascular interventions for dysfunctional hemodialysis grafts and fistulas was performed from April 2004 to August 2006. A total of 6 patients presented with arm and/or neck and facial swelling and left brachiocephalic vein occlusion. The study group consisted of 3 men and 3 women with a mean age of 79.5 years (SD 11.2 years). Of these 6 patients, 1 had a graft and 5 had fistulas in the left arm. The primary indication for nitinol stent placement was technical failure of angioplasty following successful traversal of occluded central venous segments. Patency was assessed from repeat fistulograms and central venograms performed when patients redeveloped symptoms or were referred for access dysfunction determined by the ultrasound dilution technique. No patients were lost to follow-up.

RESULTS

Nitinol stent placement to obtain technically successful recanalization of occluded venous segments was initially successful in 5 of 6 patients (83%). In 1 patient, incorrect stent positioning resulted in partial migration to the superior vena cava requiring restenting to prevent further migration. Clinical success was observed in all patients (100%). Over the follow-up period, 2 patients underwent repeat intervention with angioplasty alone. Primary patency was 83.3% (95% CI 0.5-1.2) at 3 months, and 66.7% at 6 and 12 months (0.2-1.1, 0.1-1.2). Secondary patency was 100% at 12 months with 3 patients censored over that time period. Mean primary patency was 10.4 months with a mean follow-up of 12.4 months. No complications related to recanalization of the occluded central venous segments were observed.

CONCLUSION

Our initial experience has demonstrated that use of nitinol stents for central venous occlusion in hemodialysis patients is associated with good mid-term patency and may exceed historical observations with prior use of Wallstents.

Successful angioaccess

Surgery for hemodialysis access is the most commonly performed vascular surgical operation in the United States, predominantly because of a steady increase in the prevalence of end-stage renal disease. Multiple studies have confirmed the improved patency rate and lower infection rates for native arteriovenous fistulae compared with prosthetic arteriovenous grafts. In formulating a strategy for successful dialysis access a comprehensive approach should be undertaken. The preoperative planning, as with any surgical procedure, is the most important aspect, followed by the postoperative maintenance of the access.

A Practical Approach for Diagnosis and Treatment of Central Venous Stenosis and Occlusion

Treating symptomatic central venous stenosis and occlusion is a challenge for those caring for patients with end stage renal disease. With the increase incidence and decrease mortality of end stage renal disease, there are more patients presenting for vascular access procedures. Although there has been a significant increase in the prevalence of fistulae in the United States over the last several years, many of these patients require central venous catheters during the fistula maturation process. The use of these catheters, along with the increase in the diameters of many of these catheters over the last several years, has likely played a significant role in the development of symptomatic central venous stenosis and occlusion. In this article the origin or central venous stenosis and occlusion will be reviewed along with a practical approach on how to best manage this disease process.

The Value of Preoperative Vascular Imaging in the Selection and Success of Hemodialysis Access

The purpose of this study was to determine the value of preoperative vascular imaging (PVI) in the selection of an arteriovenous fistula (AVF) for hemodialysis with respect to site selection, maturation, patency, and functionality. We retrospectively evaluated 482 AVFs and arteriovenous grafts (AVGs) created in 321 patients who were regularly undergoing hemodialysis at our university's hemodialysis centers. The patients were divided into two groups according to PVI status. The patients in group 1 (n = 260) underwent Doppler ultrasonographic evaluation and venographic studies as well as physical examination before operation. The patients in group 2 (n = 222) underwent only physical examination before operation. Both groups were compared with respect to vascular access type, access maturation rate, and duration of access patency. In group 1, central veins were also evaluated for possible stenosis, and significant asymptomatic stenosis was treated with interventional techniques. The patients in group 1 were significantly older than those in group 2 and had a significantly higher mean number of previous central venous catheterizations and vascular access sites. At the initiation of the study, 234 of the vascular access sites had matured with a success rate of 90% in group 1. In group 2, however, 152 (68.5%) of the vascular access sites had matured. AVGs of the vascular access type were created in 31.5% of patients in group 1 and in 12.6% of patients in group 2. The mean duration of primary patency in group 1 overall (i.e., AVFs and AVGs) was 14.7 +/- 16.8 months, and the 6-month and 12-month patency rates were 72% and 46%, respectively. The mean duration of primary patency in group 2 overall was 11.9 +/- 9.4 months, and the 6-month and 12-month patency rates were 71% and 41%, respectively. Patients in group 1 had a significantly longer mean primary patency time than did those in group 2 (P = 0.024). Sixty-six cases of central vein stenosis were detected during PVI studies and treated interventionally. After those interventions, 38 AVFs and 28 AVGs were created, and all matured sufficiently without exception. As an adjunct to physical examination, PVI evaluations (venography, Doppler ultrasonography) can be used to determine the likelihood of the maturation of vascular access sites and can reveal problems such as central vein stenosis, which can then be treated promptly with percutaneous intervention. In patients with end-stage renal disease, these interventions should lead to a decrease in morbidity and mortality and improved quality of life.

Current management of vascular access

Optimizing vascular access outcomes remains an ongoing challenge for clinical nephrologists. All other things being equal, fistulas are preferred over grafts, and grafts are preferred over catheters. Mature fistulas have better longevity and require fewer interventions, as compared with mature grafts. The major hurdle to increasing fistula use is the high rate of failure to mature of newly created fistulas. There is a desperate need for enhanced understanding of the mechanisms of failure to mature and the optimal type and timing of interventions to promote maturity. Grafts are prone to frequent stenosis and thrombosis. Surveillance for graft stenosis with preemptive angioplasty may reduce graft thrombosis, but recent randomized clinical trials have questioned the efficacy of this approach. Graft stenosis results from aggressive neointimal hyperplasia, and pharmacologic approaches to slowing this process are being investigated in clinical trials. Catheters are prone to frequent thrombosis and infection. The optimal management of catheter-related bacteremia is a subject of ongoing debate. Prophylaxis of catheter-related bacteremia continues to generate important clinical research. Close collaboration among nephrologists, surgeons, radiologists, and the dialysis staff is required to optimize vascular access outcomes and can be expedited by having a dedicated access coordinator to streamline the process. The goal of this review is to provide an update on the current status of vascular access management.

Long-term outcomes of primary angioplasty and primary stenting of central venous stenosis in hemodialysis patients

INTRODUCTION

Central (superior vena cava, brachiocephalic, or subclavian) venous stenoses are a major impediment to long-term arteriovenous access in the upper extremities. The optimal management of these stenoses is still undecided. The purpose of this study was to determine the outcomes of primary angioplasty (PTA) vs primary stenting (PTS) in a dialysis access population at a tertiary referral academic medical center.

METHODS

A database of consecutive hemodialysis patients undergoing endovascular treatment for central venous stenosis was developed for the period 1995 through 2003. This database was retrospectively reviewed. Vessels exposed to either primary high-pressure balloon angioplasty or primary stenting were examined. Vessels undergoing stenting after failed or suboptimal angioplasty were defined as failures at the time of stenting despite the potential continued patency upon completion of stenting. Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Cox proportional hazards analysis was performed for time-dependent variables. Data are presented as mean +/- standard deviation where appropriate.

RESULTS

PTS was used to treat 26 patients (35% male; average age, 57 +/- 15 years) with 26 central venous stenoses, and 47 patients (45% male; average age, 57 +/- 18 years) with 49 central venous stenoses were treated with PTA. The PTS group underwent 71 percutaneous interventions per stenosis (average, 2.7 +/- 2.4 interventions), and the PTA group underwent 98 interventions per stenosis (average, 2.0 +/- 1.6 interventions). The PTS group hemodialysis access site was an average of 1.0 +/- 1.3 years old at the time of the initial intervention, and the hemodialysis access in the PTA group was an average of 1.1 +/- 1.2 years old. Primary patency was equivalent between groups by Kaplan-Meier analysis, with 30-day rates of 76% for both groups and 12-month rates of 29% for PTA and 21% for PTS (P = .48). Assisted primary patency was also equivalent (P = .08), with a 30-day patency rate of 81% and 12-month rate of 73% for the PTA group, vs PTS assisted patency rates of 84% at 30 days, and 46% at 12 months. Ipsilateral hemodialysis access survival was equivalent between groups.

CONCLUSIONS

Endovascular therapy with PTA or PTS for central venous stenosis is safe, with low rates of technical failure. Multiple additional interventions are the rule with both treatments. Although neither offers truly durable outcomes, PTS does not improve on the patency rates more than PTA and does not add to the longevity of ipsilateral hemodialysis access sites.

Treatment of refractory central vein stenosis in hemodialysis patients with stents

Central venous stenosis is a frequent complication in hemodialysis patients, which can manifest clinically with ipsilateral upper extremity edema. When symptomatic, it is usually treated by percutaneous transluminal angioplasty. When angioplasty is unsuccessful, stent deployment is a therapeutic option. The goal of the present study was to evaluate the primary and secondary patency of refractory central vein stenosis after treatment with a stent. Using a prospective vascular access database we retrospectively identified 23 patients presenting with unilateral upper extremity edema and a significant (> 50%) central vein stenosis, who underwent stent placement due to refractory stenosis following angioplasty. The primary (unassisted) central vein patency was determined from the initial intervention to the next angioplasty for recurrent central vein stenosis, and the secondary (assisted) patency from the initial intervention to permanent central vein occlusion. An immediate technical success was achieved in all patients after the stent deployment. However, the median primary central vein patency was only 138 days, with a 19% patency at 1 year. Recurrence of ipsilateral edema was always due to in-stent restenosis. The median secondary central vein patency was 1036 days, with a 64% patency at 1 year. In patients with symptomatic central vein stenosis that is refractory to percutaneous transluminal angioplasty, stent deployment provides short-term relief of the stenosis and ipsilateral upper extremity edema. However, long-term symptomatic relief can be achieved with multiple subsequent interventions in many patients.

Central vein stenosis: a nephrologist's perspective

Central vein stenosis is commonly associated with placement of central venous catheters and devices. Central vein stenosis can jeopardize the future of arteriovenous fistula and arteriovenous graft in the ipsilateral extremity. Occurrence of central vein stenosis in association with indwelling intravascular devices including short-term, small-diameter catheters such as peripherally inserted central catheters, long-term hemodialysis catheters, as well as pacemaker wires, has been recognized for over two decades. Placement of multiple catheters, longer duration, location in subclavian vein, and placement on the left-hand side of neck seem to predispose to the development of central vein stenosis. Endothelial injury with subsequent changes in the vessel wall results in development of microthrombi, smooth muscle proliferation, and central vein stenosis. Central vein stenosis is often asymptomatic in nondialysis patients, but can result in edema of ipsilateral extremity and breast when challenged by increased flow from an arteriovenous fistula or arteriovenous graft. Bilateral central vein stenosis or superior vena cava stenosis can produce a clinical picture of superior vena cava syndrome, associated with engorgement of face and neck. Endovascular interventions are the mainstay of management of central vein stenosis. Percutaneous angioplasty and stent placement for elastic and recurring lesions can restore the functionality of the vascular access, at least temporarily. Frequent or multiple interventions are usually required. In recalcitrant cases, surgical bypass of the obstruction is an option. In resistant cases with severe symptoms, occlusion of the functioning vascular access will usually provide relief of symptoms. Further study of mechanisms of development of central vein stenosis and search for a targeted therapy is likely to lead to better ways of managing central vein stenosis. Prevention of central vein stenosis is the key to avoid access failure and other complications from central vein stenosis and relies upon avoidance of central vein stenosis placement and timely placement of arteriovenous fistula in prospective dialysis patient.

Prevalence of optic nerve edema in patients on peripheral hemodialysis

PURPOSE

Cerebral venous hypertension with optic nerve edema has been reported in patients with peripheral arteriovenous hemodialysis shunts. This study aimed to estimate the prevalence of optic nerve edema in patients with peripheral arteriovenous accesses and to evaluate the value of ophthalmic examination and surveillance in this study population.

DESIGN

Cross-sectional observation case series.

PARTICIPANTS

Forty-four patients with peripheral arteriovenous shunts for hemodialysis.

METHODS

A cross-sectional observation was done of all patients with peripheral arteriovenous shunts presenting to our outpatient hemodialysis unit on 2 consecutive days. Using indirect ophthalmoscopy, the presence or absence of optic nerve edema was recorded. Patients also were asked to record any symptoms suggestive of intracranial hypertension and/or papilledema such as headache, decreased visual acuity, or an abnormal visual phenomenon. The 95% confidence interval (CI) was calculated to estimate the prevalence of optic nerve edema in patients with peripheral arteriovenous accesses. A literature search also was conducted to obtain prior reports of optic nerve edema and ophthalmic complications in patients with peripheral arteriovenous accesses.

MAIN OUTCOME MEASURES

Presence or absence of optic nerve edema.

RESULTS

Among our series of 44 patients with peripheral arteriovenous shunts for hemodialysis, no case of optic nerve edema was observed and no patient reported any headache, decrease in vision, or visual phenomenon. The 95% CI for the estimated prevalence of optic nerve edema was 0% to 8.0%. A literature review revealed 7 reports of symptomatic ophthalmic complications in patients with peripheral arteriovenous accesses.

CONCLUSIONS

Although cases of papilledema in patients with peripheral arteriovenous shunts have been reported in the literature, the occurrence appears to be low, and routine ophthalmic surveillance is probably unnecessary in asymptomatic patients.

Patency of Endovascular Treatment for Central Venous Stenosis: Is There a Difference Between Dialysis Fistulas and Grafts?

PURPOSE

To determine if there is a difference in intervention patency for central venous stenosis (CVS) and occlusion between patients with autogenous hemodialysis fistulas and those with grafts.

MATERIAL AND METHODS

A retrospective study was performed from March 1998 to September 2005 identifying all patients with autogenous fistulas and synthetic grafts who underwent percutaneous angioplasty and/or stent placement for CVS. This study cohort consisted of 38 patients (22 with fistulas and 16 with grafts). Age, sex, type of access, location and side of the access, location and side of the CVS, presence of diabetes, previous hemodialysis catheter placement, date and type of interventions, and outcomes were recorded. The patency of each intervention was estimated by using the Kaplan-Meier survival curves. Univariate and multivariate analysis of the variables were performed.

RESULTS

Eighty-nine interventions were performed; 83 were angioplasties and six were stent placements. Previous catheter placement on the side of the CVS occurred in 29 of the 38 patients (76%). Technical and clinical success of the interventions were 93.3% and 94.4% respectively. The intervention or primary patency rates +/- standard errors at 3, 6, and 9 months in the fistula group were 88.5% +/- 4.8, 59.4% +/- 7.6, and 46% +/- 7.9, respectively. In the graft group, the rates were 78.1% +/- 7.3, 40.7% +/- 9, and 16% +/- 7.3, respectively. With multivariate analysis, intervention patency remained significantly longer for fistulas (P .014) and in patients who did not have a previous catheter (P .001).

CONCLUSION

Longer intervention-free survival for CVS was observed in patients with autogenous fistulas compared with grafts and in patients who did not previously undergo hemodialysis catheter insertion.

Tunnelled Catheters for the Haemodialysis Patient

Haemodialysis depends upon the establishment of a durable means of vascular access. Although the creation of a successful arterio-venous Fistulae (AVF) is the ideal, this is not always possible or practical. Tunnelled catheters play an important role as an interim/bridge technique for emergency access or while an AVF matures, but may be associated with significant morbidity. The aim of this review is to highlight recent evidence based developments in tunnelled catheters, including methods of placement, complications and possible management strategies.

Effect of Secondary Interventions on Patency of Vascular Access Sites for Hemodialysis

PURPOSE

To determine the impact of secondary procedures performed to maintain arteriovenous fistula (AVF) and arteriovenous graft (AVG) patency.

METHODS

There hundred and eighty six vascular access procedures were retrospectively evaluated. 156 (40.4%) patients required radiological interventions to treat acute thrombosis, swelling of the extremity with the access site, insufficient hemodialysis, or stenosis at an anastomotic site.

RESULTS

The 386 cases comprised 106 AVGs and 280 AVFs. In 138 of the 156 cases, which required a radiological intervention, the treatment was successful and saved the vascular access site. The unassisted post-intervention patency time for these 138 successful cases was 13.1 +/- 12 months (range, 1-65 months). Twenty-nine (63%) of the 46 access sites treated with surgical thrombectomy were saved.

CONCLUSIONS

Frequent, regular follow-up of hemodialysis patients with vascular access sites is the best way to diagnose problems early and allow the best chance of long-term function.

Central vein obstruction in vascular access

Central venous obstruction has become a major problem because of the frequent need for central venous catheters in haemodialysis patients. This article discusses the epidemiology and clinical features of central venous obstruction and the different surgical and interventional alternatives for its treatment.

Arterioarterial prosthetic loop: A new approach for hemodialysis access

OBJECTIVES

In this report we present a novel procedure that uses an arterioarterial prosthetic loop (AAPL) with the proximal axillary or the femoral artery as a vascular access for hemodialysis in patients who have inadequate vascular conditions for creating an arteriovenous fistula or graft.

METHODS

Between April 1996 and September 2004, 34 patients received 36 AAPLs as vascular access, either as an axillary chest loop (n = 31) or as a femoral loop (n = 5). In this procedure the artery is ligated between the anastomoses to direct flow through the AAPL. Data from all patients undergoing the procedure were prospectively collected.

RESULTS

The indication for an AAPL was the unsuitability of large deep veins in 64%, steal syndrome in 11%, the combination of only a suitable femoral vein and severe peripheral arterial disease in 22%, and congestive heart failure in 3%. All AAPLs were cannulated 18 +/- 4 days postoperatively. Mean follow-up was 31 months (range, 1 to 83). Primary patency was 73% and secondary patency was 96% at 1 year; these rates at 3 years were 54% and 87%, respectively. The rate of all interventions for the maintenance of AAPL function was 0.47 procedures per patient year. Four grafts were abandoned. More than 11,000 hemodialyses with proven efficiency were performed.

CONCLUSIONS

The AAPL is an unusual but useful and easy-to-perform alternative procedure to create vascular access for hemodialysis. It can provide survival for strictly selected patients in whom conventional vascular access is not possible. The axillary chest AAPL is preferred.

Combination treatment of venous thoracic outlet syndrome: Open surgical decompression and intraoperative angioplasty

OBJECTIVE

Residual subclavian vein stenosis after thoracic outlet decompression in patients with venous thoracic outlet syndrome is often treated with postoperative percutaneous angioplasty (PTA). However, interval recurrent thrombosis before postoperative angioplasty is performed can be a vexing problem. Therefore we initiated a prospective trial at 2 referral institutions to evaluate the safety and efficacy of combined thoracic outlet decompression with intraoperative PTA performed in 1 stage.

METHODS

Over 3 years 25 consecutive patients (16 women, 9 men; median age, 30 years) underwent treatment for venous thoracic outlet syndrome with a standard protocol at 2 institutions. Twenty-one patients (84%) underwent preoperative thrombolysis to treat axillosubclavian vein thrombosis. First-rib resection was performed through combined supraclavicular and infraclavicular incisions. Intraoperative venography and subclavian vein PTA were performed through a percutaneous basilic vein approach. Postoperative anticoagulation therapy was not used routinely. Venous duplex ultrasound scanning was performed postoperatively and at 1, 6, and 12 months.

RESULTS

Intraoperative venography enabled identification of residual subclavian vein stenosis in 16 patients (64%), and all underwent intraoperative PTA with 100% technical success. Postoperative duplex scans documented subclavian vein patency in 23 patients (92%). Complications included subclavian vein recurrent thrombosis in 2 patients (8%), and both underwent percutaneous mechanical thrombectomy, with restoration of patency in 1 patient. One-year primary and secondary patency rates were 92% and 96%, respectively, at life-table analysis.

CONCLUSIONS

Residual subclavian vein stenosis after operative thoracic outlet decompression is common in patients with venous thoracic outlet syndrome. Combination treatment with surgical thoracic outlet decompression and intraoperative PTA is a safe and effective means for identifying and treating residual subclavian vein stenosis. Moreover, intraoperative PTA may reduce the incidence of postoperative recurrent thrombosis and eliminate the need for venous stent placement or open venous repair.

Percutaneous treatment of symptomatic central venous stenosis angioplasty

OBJECTIVES

The increased use of central venous access primarily for hemodialysis has led to a significant increase in clinically relevant central venous occlusive disease (CVOD). The magnitude of and the optimal therapy for CVOD are not clearly established. The purpose of this study is to define the problem of CVOD and determine the success of percutaneous therapy for relieving symptoms and maintaining central venous patency.

METHODS

Patients presenting with disabling upper-extremity edema suggestive of central venous stenosis or occlusion during a 3-year period were evaluated by venography of the upper extremity and central veins. Percutaneous venous angioplasty (PTA) and/or stent placement was performed as clinically indicated. The success of therapy was assessed, and the patients were observed to determine the incidence of recurrence and additional procedures. Recurrent lesions underwent similar evaluation and treatment.

RESULTS

A total of 32 sides were treated in 29 patients with a mean of 1.9 interventions per side treated. Hemodialysis-related lesions were the underlying cause in 87% with the remaining 13% related to previous central venous catheterization. The lesions involved the axillary, subclavian, and innominate veins with complete venous occlusion in six (19%) cases. Percutaneous angioplasty was followed by stent placement in six (19%) cases. The procedure was a technical success and was performed without complications in all cases (100%). Mean follow-up was 16.5 months (range, 4-36 months). On average, patient symptoms were controlled for 6.5 months after the initial intervention. Recurrent edema led to additional PTA in 20 (63%) cases. Fifty percent (n = 14) of patients with an arteriovenous fistula (AVF) experienced recurrent symptoms after initial and/or repeat PTA and required AVF ligation. Complete resolution after the initial PTA was predictive of long-term success.

CONCLUSIONS

Central venous occlusive disease has emerged as a significant clinical problem. Percutaneous venous angioplasty can provide temporary symptomatic relief; however, multiple procedures are often required and long-term relief is rarely achieved.

Endovascular treatment of central venous stenoses in patients with dialysis shunts

OBJECTIVE

Evaluation of long-term results of percutaneous treatment of central vein stenoses or occlusions in patients with haemodialysis shunt.

MATERIALS AND METHODS

In 26 patients with haemodialysis shunts and confirmed central vein stenosis or occlusion, 28 primary percutaneous transluminal angioplasties (PTA) and 5 repeated PTAs (re-PTA) were performed; in three patients a stent was implanted - primary in one patient and due to early restenosis after PTA in two patients. To maintain stent patency, 10 re-PTA were performed.

RESULTS

The technical success rate of primary interventions was 96 % (100 % in stenoses and 50 % in occlusions). Primary post-PTA patency rate was 70 % at 3 months, 60 % at 6 months and 30 % at 12 months.

CONCLUSION

PTA with possible stent implantation is a first-choice method in the treatment of stenoses and occlusions of the central venous system. Despite the relatively frequent re-interventions, endovascular treatment is capable to preserve long-term function of the dialysis shunt.

Central vein obstruction in hemodialysis patients: Results of radiological and surgical intervention

BACKGROUND/AIMS

Symptomatic central venosus obstruction (CVO) in dialysis patients with arteriovenous fistulas (AVFs) leads to significant morbidity and patient inconvenience. We evaluated the results of surgical and radiological interventional treatment of symptomatic central venous obstruction.

METHODS

Clinical data, site and length of vein obstruction, type and outcome of intervention were obtained from patient records. Patency rates of radiological and surgical treatment were calculated using Life Table survival analysis.

RESULTS

In 28 patients with VH, 45 interventions (percutaneous intervention 30; surgical reconstruction 10; AVF closure five) were performed. Mean vessel obstruction length was 4.9 cm, mainly localized in the subclavian vein (55%). Initial clinical success rate of PTA and surgery was 92%, with complications after percutaneous transluminal angioplasty (PTA) on six occasions. Restenosis after PTA was observed in 39%. One-year primary and secondary patency after PTA was 50 and 63%, respectively. One-year primary patency after surgical reconstruction was 75%.

CONCLUSION

Symptomatic CVO in dialysis patients with AVFs can be treated with a high success rate through radiological intervention. Surgical reconstruction is an appropriate alternative method in case of failed PTA.