Prosthetic Arteriovenous Access Research Articles

Recent evaluation by nephrologists is associated with decreased incidence of tunneled dialysis catheter being used at the time of first arteriovenous access creation

ObjectiveLate primary care provider (PCP) or nephrologist evaluation of patients with progressive kidney disease may be associated with increased morbidity and mortality. Among patients undergoing initial arteriovenous (AV) access creation, we aimed to study the relationship of recent PCP and nephrologist evaluations with perioperative morbidity and mortality. MethodsWe performed a retrospective review of patients from 2014 to 2022 who underwent initial AV access creation at an urban, safety-net hospital. Univariable and multivariable analyses identified associations of PCP and nephrologist evaluations <1 year and <3 months before surgery, respectively, with hemodialysis initiation via tunneled dialysis catheters (TDCs), 90-day readmission, and 90-day mortality. ResultsAmong 558 patients receiving initial AV access, mean age was 59.7 ± 14 years, 59% were female gender, and 60.6% were Black race. Recent PCP and nephrology evaluations occurred in 386 (69%) and 362 (65%) patients, respectively. On multivariable analysis, unemployed and uninsured statuses were associated with decreased likelihood of PCP evaluation (unemployment: odds ratio [OR], 0.51; 95% confidence interval [CI], 0.34-0.77; uninsured status: OR, 0.05; 95% CI, 0.01-0.45) and nephrologist evaluation (unemployment: OR, 0.63; 95% CI, 0.43-0.91; uninsured status: OR, 0.22; 95% CI, 0.06-0.83) (all P < .05). Social support was associated with increased likelihood of PCP evaluation (OR, 1.81; 95% CI, 1.07-3.08) (all P < .05). Hemodialysis was initiated with TDCs in 304 patients (55%). Older age (OR, 0.98; 95% CI, 0.96-0.99), obesity (OR, 0.38; 95% CI, 0.25-0.58), and nephrologist evaluation (OR, 0.12; 95% CI, 0.08-0.19) were independently associated with decreased hemodialysis initiation with TDCs in patients receiving an initial AV access (all P < .05). Ninety-day readmission occurred in 270 cases (48%). Cirrhosis (OR, 2.5; 95% CI, 1.03-6.03; P = .04), coronary artery disease (OR, 2.31; 95% CI, 1.5-3.57), prosthetic AV access (OR, 1.84; 95% CI, 1.04-3.26), and impaired ambulation (OR, 1.75; 95% CI, 1.15-2.66) were independently associated with increased readmission (all P < .05). Older age (OR, 0.98; 95% CI, 0.97-0.99), prior TDC (OR, 0.65; 95% CI, 0.45-0.94), and unemployment (OR, 0.58; 95% CI, 0.39-0.86) were associated with decreased readmission (all P < .05). Ninety-day mortality occurred in 1.6% of patients. Neither PCP nor nephrologist evaluation was associated with readmission or mortality. ConclusionsRecent nephrology evaluation was associated with reduced hemodialysis initiation with TDCs among patients undergoing initial AV access creation. Unemployed and uninsured statuses posed barriers to accessing nephrology care.

The Impact of Seasonality on Prosthetic Arteriovenous Vascular Access Graft Thrombosis

Highlights Abstract Introduction: Arteriovenous prosthetic grafts are susceptible to recurrent thrombotic occlusions mainly due to venous outflow disease secondary to neointimal hyperplasia. Maintenance of vascular access for dialysis is a perpetual challenge for both patients and health care systems. In regions with hotter climates, there is a clinical impression that episodes of prosthetic arteriovenous vascular access graft thrombosis are more frequent during hot dry summers secondary to dehydration and increased blood viscosity. Seasonality of thrombotic events has been observed in multiple vascular beds. However, a seasonal pattern or any association of arteriovenous graft thrombosis with temperature and relative humidity levels has never been fully demonstrated. Methods: Data were collected prospectively from January 2014 until December 2020 but analyzed retrospectively. In this 7-year timeframe, 289 episodes of arteriovenous graft thrombosis were identified from 142 grafts fashioned. Results: No monthly variation (P = 0.35) or seasonal variation (P = 0.91) was identified. No statistically significant correlation between episodes of thrombosis and mean monthly temperature and mean relative humidity was noted. Conclusion: No evidence was identified to support this theory. However, multiple issues with assessments of events must be conceded. Graft thrombosis is multifactorial in nature, and venous outflow disease contributes toward a significant number of these events. Within our local cohort, a low primary patency rate was identified, which further contributes to graft interventions. Relatively small numbers were recruited, and therefore, potential correlations could have been missed.

Strategies of Hemodialysis Access

Chronic kidney disease and end-stage renal disease (ESRD) have become common diagnoses in the United States; in response, several clinical practice guidelines for the surgical placement and maintenance of arteriovenous (AV) hemodialysis access have been published. This review examines temporary hemodialysis access, permanent hemodialysis accesses, and the Hemodialysis Reliable Outflow (HeRO) graft. Figures show trends in the number of incident cases of ESRD, in thousands, by modality, in the US population, 1980 to 2012, Medicare ESRD expenditures, algorithm for access location selection, autogenous posterior radial branch-cephalic wrist direct access (snuff-box fistula), autogenous radial-cephalic wrist direct access (Brescia-Cimino-Appel fistula), autogenous radial-basilic forearm transposition, prosthetic radial-antecubital forearm straight access, prosthetic brachial (or proximal radial) antecubital forearm looped access, autogenous brachial (or proximal radial) cephalic upper arm direct access, autogenous brachial (or proximal radial) basilic upper arm transposition, prosthetic brachial (or proximal radial) axillary (or brachial) upper arm straight access, prosthetic superficial femoral-femoral (vein) lower extremity straight access and looped access, prosthetic axillary-axillary (vein) chest looped access, straight access, and body wall straight access, HeRO graft, banding of the outflow access tract, distal revascularization with interval ligation, upper extremity edema and varicosities associated with venous hypertension, internal jugular to subclavian venous bypass, and puncture-site pseudoaneurysms of an AV access. Tables list AV access configuration, autogenous AV access patency rates, and prosthetic AV access patency rates. This review contains 20 figures, 3 tables, and 76 references. Keywords: Chronic Kidney Disease, End-stage renal disease, Short- and Long-term dialysis catheters, Autogenous AV access, Prosthetic AV access, HeRO graft, Arterial Steal, Venous hypertension, Pseudoaneurysm, Megafistula

Strategies of Hemodialysis Access

Chronic kidney disease and end-stage renal disease (ESRD) have become common diagnoses in the United States; in response, several clinical practice guidelines for the surgical placement and maintenance of arteriovenous (AV) hemodialysis access have been published. This review examines temporary hemodialysis access, permanent hemodialysis accesses, and the Hemodialysis Reliable Outflow (HeRO) graft. Figures show trends in the number of incident cases of ESRD, in thousands, by modality, in the US population, 1980 to 2012, Medicare ESRD expenditures, algorithm for access location selection, autogenous posterior radial branch-cephalic wrist direct access (snuff-box fistula), autogenous radial-cephalic wrist direct access (Brescia-Cimino-Appel fistula), autogenous radial-basilic forearm transposition, prosthetic radial-antecubital forearm straight access, prosthetic brachial (or proximal radial) antecubital forearm looped access, autogenous brachial (or proximal radial) cephalic upper arm direct access, autogenous brachial (or proximal radial) basilic upper arm transposition, prosthetic brachial (or proximal radial) axillary (or brachial) upper arm straight access, prosthetic superficial femoral-femoral (vein) lower extremity straight access and looped access, prosthetic axillary-axillary (vein) chest looped access, straight access, and body wall straight access, HeRO graft, banding of the outflow access tract, distal revascularization with interval ligation, upper extremity edema and varicosities associated with venous hypertension, internal jugular to subclavian venous bypass, and puncture-site pseudoaneurysms of an AV access. Tables list AV access configuration, autogenous AV access patency rates, and prosthetic AV access patency rates. This review contains 20 figures, 3 tables, and 76 references. Keywords: Chronic Kidney Disease, End-stage renal disease, Short- and Long-term dialysis catheters, Autogenous AV access, Prosthetic AV access, HeRO graft, Arterial Steal, Venous hypertension, Pseudoaneurysm, Megafistula

Strategies of Hemodialysis Access

Chronic kidney disease and end-stage renal disease (ESRD) have become common diagnoses in the United States; in response, several clinical practice guidelines for the surgical placement and maintenance of arteriovenous (AV) hemodialysis access have been published. This review examines temporary hemodialysis access, permanent hemodialysis accesses, and the Hemodialysis Reliable Outflow (HeRO) graft. Figures show trends in the number of incident cases of ESRD, in thousands, by modality, in the US population, 1980 to 2012, Medicare ESRD expenditures, algorithm for access location selection, autogenous posterior radial branch-cephalic wrist direct access (snuff-box fistula), autogenous radial-cephalic wrist direct access (Brescia-Cimino-Appel fistula), autogenous radial-basilic forearm transposition, prosthetic radial-antecubital forearm straight access, prosthetic brachial (or proximal radial) antecubital forearm looped access, autogenous brachial (or proximal radial) cephalic upper arm direct access, autogenous brachial (or proximal radial) basilic upper arm transposition, prosthetic brachial (or proximal radial) axillary (or brachial) upper arm straight access, prosthetic superficial femoral-femoral (vein) lower extremity straight access and looped access, prosthetic axillary-axillary (vein) chest looped access, straight access, and body wall straight access, HeRO graft, banding of the outflow access tract, distal revascularization with interval ligation, upper extremity edema and varicosities associated with venous hypertension, internal jugular to subclavian venous bypass, and puncture-site pseudoaneurysms of an AV access. Tables list AV access configuration, autogenous AV access patency rates, and prosthetic AV access patency rates. This review contains 20 figures, 3 tables, and 76 references. Keywords: Chronic Kidney Disease, End-stage renal disease, Short- and Long-term dialysis catheters, Autogenous AV access, Prosthetic AV access, HeRO graft, Arterial Steal, Venous hypertension, Pseudoaneurysm, Megafistula

Strategies of Hemodialysis Access

Chronic kidney disease and end-stage renal disease (ESRD) have become common diagnoses in the United States; in response, several clinical practice guidelines for the surgical placement and maintenance of arteriovenous (AV) hemodialysis access have been published. This review examines temporary hemodialysis access, permanent hemodialysis accesses, and the Hemodialysis Reliable Outflow (HeRO) graft. Figures show trends in the number of incident cases of ESRD, in thousands, by modality, in the US population, 1980 to 2012, Medicare ESRD expenditures, algorithm for access location selection, autogenous posterior radial branch-cephalic wrist direct access (snuff-box fistula), autogenous radial-cephalic wrist direct access (Brescia-Cimino-Appel fistula), autogenous radial-basilic forearm transposition, prosthetic radial-antecubital forearm straight access, prosthetic brachial (or proximal radial) antecubital forearm looped access, autogenous brachial (or proximal radial) cephalic upper arm direct access, autogenous brachial (or proximal radial) basilic upper arm transposition, prosthetic brachial (or proximal radial) axillary (or brachial) upper arm straight access, prosthetic superficial femoral-femoral (vein) lower extremity straight access and looped access, prosthetic axillary-axillary (vein) chest looped access, straight access, and body wall straight access, HeRO graft, banding of the outflow access tract, distal revascularization with interval ligation, upper extremity edema and varicosities associated with venous hypertension, internal jugular to subclavian venous bypass, and puncture-site pseudoaneurysms of an AV access. Tables list AV access configuration, autogenous AV access patency rates, and prosthetic AV access patency rates. This review contains 20 figures, 3 tables, and 76 references. Keywords: Chronic Kidney Disease, End-stage renal disease, Short- and Long-term dialysis catheters, Autogenous AV access, Prosthetic AV access, HeRO graft, Arterial Steal, Venous hypertension, Pseudoaneurysm, Megafistula

Ultrasound-Guided Pharmacomechanical Thrombolysis and Angioplasty for Treatment of Acute Thrombotic Prosthetic Arteriovenous Access: 5-Year Experience with 154 Procedures in a Single Center

Pharmacomechanical thrombolysis (PMT) and percutaneous transluminal angioplasty (PTA) for the treatment of acute thrombotic prosthetic arteriovenous access (PAVA) are conventionally guided by radiography, which may cause radiation injury and requires the use of radiographic contrast media. The aim of the present study was to summarize our experience with ultrasound-guided PMT and PTA as an alternative to radiographic guidance. Between December 2012 and October 2016, 114 patients with acute thrombosis of PAVA were treated urgently with ultrasound-guided PMT and PTA to restore blood flow. The patients were followed up every 3 mo postoperatively. The 114 included patients underwent 154 episodes of ultrasound-guided PMT and PTA and were followed up for a mean of 20.7 ± 9.1 mo. The technical success rate was 91.6%, and the clinical success rate was 97.4%. Post-intervention-assisted primary patency rates at 3, 6, 12 and 24 mo were 90.8%, 78.8%, 66.3% and 50.9%, respectively. Post-intervention secondary patency rates at 3, 6, 12 and 24 months were 96.3%, 94.5%, 90.6% and 85.4%, respectively. PMT and PTA for the treatment of PAVA were performed successfully under the guidance of ultrasound with a success rate similar to that under radiographic guidance, thus avoiding radiation injury and contrast medium use, although close surveillance and timely intervention are imperative to ensure long-term patency.

Endovascular Salvage Procedures in Increasing the Longevity of Hemodialysis Access

Introduction: The leading cause of failure for an autogenous or prosthetic arteriovenous hemodialysis access is venous anastomotic stenosis & central venous stenosis. Endovascular procedures have come a long way in treating such lesions without significant postoperative morbidity and reliable technical success rates.This study aims at studying the long term results of such central venous and anastomotic site stenosis treated with endovascular approach in our centre. Materials and Methods: A total of 26 patients were treated, for a duration of 33 months between March 2012 to November 2014 with central venous, anastomotic site angioplasty ± stenting. Patients were followed up for 9 months. We had re-intervention in 3 cases. Results: Inadequate dialysis, thrombosed graft were the commonest presenting symptoms. Primary patency at the end of 15 months was 34.6% (9 patients), & at the end of 20 months was 11.5 %( 3 patients). Conclusion: Endovascular treatment with angioplasty or stenting for central venous stenosis & access salvage is safe, with low rates of technical failure. Only angioplasty without stenting seems by far the preferred approach, since it is less invasive, highly repeatable.

Midterm Results Following Percutaneous Rotational Thrombectomy for Acute Thrombotic Occlusions of Prosthetic Arteriovenous Access Grafts.

Patent vascular access is critical for patients on regular hemodialysis. Prosthetic grafts are good alternatives when the superficial venous system is of poor quality. However, thrombosis is one of the main drawbacks of synthetic grafts, with reports of 59% to 90% patency rates for 1 year. In cases of thrombotic occlusion of prosthetic arteriovenous fistula grafts, percutaneous mechanical thrombectomy has recently gained clinical popularity as a potential alternative to surgical thrombectomy or pharmacologic thrombolysis. We reviewed our preliminary results from 30 percutaneous rotational thrombectomies performed in a total of 22 patients in the setting of acute dialysis-access prosthetic graft occlusion of the upper extremity. Among the 30 cases of acute occlusion of the arteriovenous graft, immediate success with angiographic flow restoration was observed in all patients except for 2 patients (both females; 6%), with de novo occlusion where reocclusion occurred within 12 hours despite apparent immediate angiographic patency. The mean duration between the initial presentation with acute arteriovenous graft occlusion and the thrombectomy procedure was 27.4 ± 12.4 hours. The mean duration of graft patency was 10.45 ± 0.6 months. A total of 75% of the arteriovenous grafts were patent at the end of 12 months of follow-up. Female gender, diabetes mellitus, and diagnosis to intervention interval were reviewed for midterm graft failure, and the presence of diabetes mellitus yielded significance (P < 0.05). Percutaneous techniques play important roles in the treatment of failed or failing arteriovenous fistulae and grafts. Ongoing analysis of outcomes of both percutaneous and surgical intervention is necessary to continue to identify optimum treatment algorithms.

True aneurysm in autologous hemodialysis fistulae: definitions, classification and indications for treatment.

Definition, etiology, classification and indication for treatment of the arteriovenous access (AVA) aneurysm are poorly described in medical literature. The objectives of the paper are to complete this information gap according to the extensive review of the literature. A literature search was performed of the articles published between April 1, 1967, and March 1, 2014. The databases searched included Medline and the Cochrane Database of Systematic Reviews. The eligibility criteria in this review studies the need to assess the association of aneurysms and pseudoaneurysms with autologous AVA. Aneurysms and pseudoaneurysms involving prosthetic AVA were not included in this literature review. From a total of 327 papers, 54 non-English papers, 40 case reports and 167 papers which did not meet the eligibility criteria were removed. The remaining 66 papers were reviewed. Based on the literature the indication for the treatment of an AVA aneurysm is its clinical presentation related to the patient's discomfort, bleeding prevention and inadequate access flow. A new classification system of AVA aneurysm, which divides it into the four types, was also suggested. AVA aneurysm is characterized by an enlargement of all three vessel layers with a diameter of more than 18 mm and can be presented in four types according to the presence of stenosis and/or thrombosis. The management of an AVA aneurysm depends on several factors including skin condition, clinical symptoms, ease of cannulation and access flow. The diameter of the AVA aneurysm as a solo parameter is not an indication for the treatment.

A call to action for pre-end-stage renal disease care.

Malas and colleagues1haveused theUSRenal Data System to analyze the impact of the incident hemodialysis access type on long-term survival as a follow-up to the original Dialysis Outcome Quality Initiative (DOQI) that set a 50% incident goal for autogenous arteriovenoushemodialysis access (arteriovenous fistula [AVF]).2 Unfortunately, there has been little improvement in the incident AVF rate (14%) since the publication of these guidelines in 1997, despite the consistent observation that initiatingdialysiswith anAVFwas associated with improved long-term survival. In the current study,1 the use of an AVF at the initiation of dialysis was associated with a 35% lower mortality when compared with hemodialysis catheters (HCs), with similar benefits for patients dialyzing with a catheter while waiting for their AVF to mature (23%mortality decrease) and those with a prosthetic arteriovenous access (arteriovenous graft [AVG], 18%mortality decrease).Not surprisingly, theuseof anAVForAVGat theonset of dialysis was associated with a lower hazard of cardiovascularand sepsis-related mortality. Indeed, these known survival benefits provided some of the impetus for the originalDOQIguidelinesalongwith their successor, theKidneyDisease Outcome Quality Initiative3 and the Fistula First Breakthrough Initiative.4 These findings are very sobering and suggest that our health care system has woefully underperformed, particularly given the fact that mortality is only one of several important outcome measures (ie, morbidity, quality of life, and cost) for patients with end-stage renal disease (ESRD). The potential impact on health care costs of the incident access choicewas addressed byMalas and colleagues1 in their Discussion section and, predictably, their estimates on the additional cost (or potential savings) were staggering. The authors’ findingsmust be interpretedwith some cautionbecause it isworth emphasizing that startingdialysiswith functional AVF truly represents the best case scenario that reflects a tremendous amount of selection bias at each stage of thecareprocess includinganinvolvedpatient,earlyreferral from theprimarycarephysician toanephrologist, early referral from a nephrologist to a committed access surgeon, arterial/venous anatomy suitable for an AVF, access construction well in advance of the anticipated dialysis date, and an AVF that matures suitable for cannulation. Indeed, it is not surprising that patients with this level of pre-ESRD care (and favorable outcome in termsof a functionalAVF)haveabetter long-termoutcome. Iwould contend it is notpossible to construct anAVFon everypatientgiventheiranatomyandcomorbiditiesandwould echo the findings of the current study that AVGs are far better thanHCs and the sentiment that “fistula first” should really be “catheter last.” Interestingly, the authors’ sophisticated statistical analyses did not support the hypotheses that the low incidence of AVF was owing to poor pre-ESRD care or the patients being poor surgical candidates for an AVF. The outstanding question remains as to how these powerful data can be used to improve the incident AVF rates and, more importantly, patient outcomes. The authors have proposed changes inhealth care policy and reimbursement,with the hope of extending coverage to uninsured patients preESRD and rewarding quality care (eg, early referral to a nephrologist).Althoughsoundrecommendations, I remainskeptical that these proposed changes are practical in our rapidly shifting health care landscape. The authors have also proposed developing multidisciplinary teams that include all of the stakeholders detailed in the best-case scenario outlined here and the various hospital systems. This seems like amore realistic approach, although the challenge remains to developeffectivestrategies that leadto thedesiredoutcomewithout reproducing the failed efforts from the past decade. It is worth emphasizing that the DOQI, Kidney Disease Outcome Quality Initiative, andFistulaFirstBreakthrough Initiativehad a collective dramatic impact on the prevalence ofAVF (23% in 2003 vs 60% in 2011)5 and it has always struck me that most of these efforts were largely directed at access surgeons. Perhapsweneed to redefine the expectations andprovide gentle pressure to the nonsurgeonmembers of the pre-ESRD health care team.

Alternative prosthetic vascular access creation using subscapular artery as inflow to prevent dialysis access related steal syndrome

In patients highly suspected of developing steal syndrome, the subscapular artery may be a good supplier for functional prosthetic arteriovenous access, as well as a good solution for the prevention of steal syndrome. A 51-year-old woman was preparing to have a loop shaped polytetrafluoroethylene (PTFE) graft placed at the left upper extremity. The diameter of subscapular the artery was 3 mm. Arterial calcification was not evident. The diameter of the basilic vein was 6 mm. A 50-cm long 4-7 mm tapered PTFE graft was placed in a loop shape between both skin incisions. The patient was uneventfully discharged at postoperative day 4 without any remaining steal syndrome. The PTFE graft was well-functioning during the follow-up period. The patient did not experience symptoms of steal syndrome any longer.

Analysis of Infection Risk Following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts

Purpose: To determine whether exclusion of pseudoaneurysms with the use of a covered stent in prosthetic arteriovenous (AV) hemodialysis access grafts impacts the incidence of eventual AV graft infection. Materials and Methods: Review of an interventional radiology database for prosthetic AV graft interventions involving stent deployment anywhere within the AV graft circuit revealed 235 interventions in 174 patients between November 2004 and December 2008. Incidence of AV graft infection was analyzed based on stent type (bare metal vs covered), location, and indication for stent deployment on a per-stent, per-procedure, and per-graft basis. Results: A total of 16.3% of the stent-implanted AV grafts were eventually surgically excised as a result of graft infection. Covered stents used to treat an intragraft pseudoaneurysm were more commonly associated with subsequent graft infection compared with bare or covered stents deployed within the graft for other reasons: 42.1% versus 18.2% (P .011). Stents deployed in an intragraft location were also associated with a higher incidence of graft infection compared with those deployed at the venous anastomosis or outflow vein: 26.9% versus 6.9% (P .001). No significant difference was identified in infection rates between bare and covered stents. Conclusions: Covered stent exclusion of intragraft pseudoaneurysms demonstrated a significant correlation with eventual prosthetic AV graft infection.

Treating thrombotic prosthetic arteriovenous access with cross-balloon occlusive thrombolysis and angioplasty

Clot embolism remains a concern due to flushing of clot and thrombolytic agent centrally in the process of percutaneous pharmacomechanical thrombolysis (PMT) for a thrombosed prosthetic arteriovenous access (PAVA), which might be reduced by a modified technique. We retrospectively review this modified technique that uses two balloon-catheters in crisscross fashion and occludes both ends of PAVA during thrombolysis. Underlying stenotic lesions were dilated simultaneously with balloon angioplasty when needed. Among the 23 patients treated, 21 (91.3%), 10 (43.5%), and seven (30.4%) presented significant stenosis at the outflow, intragraft, and inflow segments of PAVA, respectively. The median duration of follow-up was 310.0 (range, 288.0-327.0) days. Anatomic success was achieved in 12 out of 23 (52.2%). Clinical success for successful dialysis was achieved in all patients. The median primary patency and secondary patency were 126.0 days (range, 7.0-316.0) days and 308.0 days (range, 84.0-327.0), respectively. We believe this method is safe and effective in dissolving PAVA thrombus as well as treating culprit stenosis. It may reduce concerns of flushing of clot and thrombolytic agent into the central circulation in the process of PMT.

Analysis of Infection Risk following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts

Analysis of Infection Risk following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts

Guidelines are Local, Commentary on “Analysis of Infection Risk following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts”

Guidelines are Local, Commentary on “Analysis of Infection Risk following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts”

Analysis of Infection Risk following Covered Stent Exclusion of Pseudoaneurysms in Prosthetic Arteriovenous Hemodialysis Access Grafts

Purpose To determine whether exclusion of pseudoaneurysms with the use of a covered stent in prosthetic arteriovenous (AV) hemodialysis access grafts impacts the incidence of eventual AV graft infection. Materials and Methods Review of an interventional radiology database for prosthetic AV graft interventions involving stent deployment anywhere within the AV graft circuit revealed 235 interventions in 174 patients between November 2004 and December 2008. Incidence of AV graft infection was analyzed based on stent type (bare metal vs covered), location, and indication for stent deployment on a per-stent, per-procedure, and per-graft basis. Results A total of 16.3% of the stent-implanted AV grafts were eventually surgically excised as a result of graft infection. Covered stents used to treat an intragraft pseudoaneurysm were more commonly associated with subsequent graft infection compared with bare or covered stents deployed within the graft for other reasons: 42.1% versus 18.2% ( P = .011). Stents deployed in an intragraft location were also associated with a higher incidence of graft infection compared with those deployed at the venous anastomosis or outflow vein: 26.9% versus 6.9% ( P < .001). No significant difference was identified in infection rates between bare and covered stents. Conclusions Covered stent exclusion of intragraft pseudoaneurysms demonstrated a significant correlation with eventual prosthetic AV graft infection.

Management of Central Vein Stenoses and Occlusions: The Critical Importance of the Costoclavicular Junction

The failure of an autogenous or prosthetic arteriovenous hemodialysis access is usually related to the failure of the venous outflow resulting from a stenosis somewhere in the venous system, commonly at the venous anastomosis for a prosthetic access or within the central veins. The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative guidelines state that percutaneous transluminal venoplasty with or without stenting is the preferred initial treatment for a central venous stenosis, but the results of these therapies have been have relatively disappointing when analyzed as a whole. Although endoluminal intervention works well (and is, indeed, the primary option) for treating areas of stenosis surrounded by soft tissue, we believe stenoses occurring at the costoclavicular junction are caused by extrinsic bony compression and, therefore, should be considered dialysis-associated venous thoracic outlet syndrome. The treatment of venous thoracic outlet syndrome, based on decades of experience, generally requires bony decompression for long-term patency. In the last 2 years, we have treated 12 patients with dialysis-associated venous thoracic outlet syndrome with surgical decompression of the thoracic outlet. Functional patency was achieved in 75% of patients at a mean follow-up of 8 months. We would contend that not all central vein stenoses are equivalent and that an individualized approach is most appropriate based on the extent and anatomic location of the lesion.

Role of Access Surveillance and Preemptive Intervention

Vascular access dysfunction continues to be a major cause of morbidity and mortality in the end-stage renal patient. Thrombosis is the primary cause of prosthetic arteriovenous access (ie, graft) failure caused by the progressive development of neointimal hyperplasia, which eventually leads to a stenosis, usually at the venous anastomosis. More than 20 years ago, observational studies using a variety of surveillance techniques, coupled with preemptive angioplasty, convincingly demonstrated the ability to detect venous stenosis, and elective treatment of stenoses significantly decreased both thrombosis and access loss. Although multiple observational studies have shown a benefit from surveillance, these studies generally had no control population, used historical controls, or used incorrect statistical analysis. However, five randomized controlled trials that evaluated the effect of graft surveillance coupled with preemptive angioplasty have failed to demonstrate a benefit on graft outcomes, including prolongation of graft survival. This review will examine the role of access surveillance and preemptive angioplasty in achieving the goal of reducing vascular access thrombosis and prolonging access survival.

Lower-extremity Arteriovenous Access for Haemodialysis: A Systematic Review

The lower extremity is increasingly used as an access site in end-stage renal disease patients. However, reports present conflicting results, creating confusion regarding the feasibility and outcomes. Our objective is to review the available literature and analyse the patency rates and complications of various types of lower-extremity arteriovenous access. An Internet-based literature search was performed using MEDLINE to identify all published reports on lower-extremity vascular access. The analysis involved studies comprising at least 10 arteriovenous accesses with both inflow and outflow vessels in the lower extremity, and reporting on patency rates and access-related complications. The weighted mean patency rates were calculated, and the chi-square (chi(2)) test was used to evaluate the differences in the complication rates in the subgroups of patients identified. Three main types of lower-extremity vascular access were identified: the upper thigh prosthetic, the mid-thigh prosthetic and the femoral vein transposition arteriovenous access. There are limited data on saphenous vein loop grafts, which report poor results. The weighted mean primary patency rates at 12 months were 48%, 43% and 83%, respectively. The weighted mean secondary patency rates at 12 months were 69%, 67% and 93%, respectively. Access loss as a result of infection was more common in upper thigh and mid-thigh grafts than femoral vein transposition arteriovenous access (18.40%, 18.33% vs. 1.61%; P<0.05). Ischaemic complications rates were higher in autologous than prosthetic arteriovenous access (20.97% vs. 7.18%, P<0.05). Lower-extremity vascular access has acceptable results in terms of patency, with femoral vein transposition having better patency rates than femoral grafts. Autologous access is associated with less infective complications, however, at the expense of increased ischaemic complications rates. Further research with randomised trials is required to assess the outcomes of lower-extremity vascular access.