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Brachiocephalic arteriovenous fistulas (AVF) makeup approximately one third of prevalent dialysis vascular accesses. The most common cause of malfunction with this access is cephalic arch stenosis (CAS). The accepted requirement for treatment of a venous stenosis lesion is ⩾50% stenosis associated with hemodynamically abnormalities. However, the correlation between percentage stenosis and a clinically significant decrease in access blood flow (Qa) is low. The critical parameter is the absolute minimal luminal diameter (MLD) of the lesion. This is the parameter that exerts the key restrictive effect on Qa and results in hemodynamic and functional implications for the access. CAS is the result of low wall shear stress (WSS) resulting from the effects of increased blood flow and the unique anatomical configuration of the CAS. Decrease in WSS has a linear relationship to increased blood flow velocity and neointimal hyperplasia exhibits an inverse relationship with WSS. The result is a stenotic lesion. The presence of downstream venous stenosis causes an inflow-outflow mismatch resulting in increased pressure within the access. Qa in this situation may be decreased, increased, or within a normal range. Over time, the increased intraluminal pressure can result in marked aneurysmal changes within the AVF, difficulties with cannulation and the dialysis treatment, and ultimately, increasing risk of access thrombosis. Complete characterization of the lesion both hemodynamically and anatomically should be the first step in developing a strategy for management. This requires both access flow measurement and angiographic imaging. Patients with CAS present a relatively broad spectrum as relates to both of these parameters. These data should be used to determine whether primary treatment of CAS should be directed toward the anatomical lesion (small MLD and low Qa) or the pathophysiology (large MLD and high Qa).

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PURPOSE: To assess the safety and efficacy of an expanded polytetrafluoroethylene stent graft versus balloon angioplasty for the treatment of in-stent restenosis in the venous outflow of hemodialysis access grafts and fistulae. MATERIALS AND METHODS: Two hundred seventy-five patients were randomized at 23 US sites to stent-graft placement or percutaneous transluminal angioplasty (PTA). Primary study endpoints were access circuit primary patency (ACPP) at 6 months and safety through 30 days; secondary endpoints were evaluated through 24 months. RESULTS: ACPP at 6 months was significantly higher in the stent-graft group (18.6%) versus the PTA group (4.5%; P < .001), and freedom from safety events (30 days) was comparable (stent graft, 96.9%; PTA, 96.4%; P = .003 for noninferiority). The separation in ACPP survival curves remained through 12 months (stent graft, 6.2%; PTA, 1.5%). Treatment area primary patency (TAPP) was superior for the stent-graft group (66.4%) versus the PTA group (12.3%) at 6 months (P < .001), with a survivorship difference in favor of stent-graft placement maintained through 24 months (stent graft, 15.6%; PTA, 2.2%). ACPP and TAPP for the stent-graft group were better than those for the PTA group when compared within central and peripheral vein subgroups (P < .001). In central veins, TAPP was 13.6% in the stent-graft group versus 4.3% in the PTA group at 24 months (P < .001). CONCLUSIONS: Stent-graft use provided better ACPP and TAPP than PTA when treating in-stent restenosis in patients receiving dialysis with arteriovenous grafts and fistulae.

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PURPOSE: To determine if postintervention cephalic arch stenosis (CAS) primary patency and access circuit patency are superior with the VIABAHN stent graft compared with angioplasty at 3, 6, and 12 months. MATERIALS AND METHODS: All patients presenting with dysfunctional hemodialysis accesses with CAS over a 4-year period were assessed for inclusion in a randomized prospective study. A total of 14 patients were recruited across three centers. All patients had mature brachiocephalic fistulae. Five were randomized to undergo percutaneous transluminal angioplasty and nine to undergo stent-graft placement. Patency of the treated cephalic arch was assessed with transonic flow and/or follow-up fistulography. Variables assessed were diabetes, previous interventions performed on the access, access age and side, and sex. Patency was determined with Kaplan-Meier estimation. RESULTS: Anatomic and clinical success was obtained in all interventions. Mean patency intervals were 100 days in the PTA group and 300 days in the stent-graft group. Primary access circuit patency rates at 3, 6, and 12 months were significantly different: 20%, 0%, and 0% for PTA and 100%, 67%, and 22% for stent grafts (P < .01). Primacy target lesion patency rates at 3, 6, and 12 months were also significantly different: 60%, 0%, and 0% for PTA and 100%, 100%, and 29% for stent grafts (P < .01). No complications or adverse events were observed. CONCLUSIONS: Treatment of CAS with the VIABAHN stent graft appears to provide statistically superior primary patency rates compared with balloon angioplasty.

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Maintenance of hemodialysis vascular access is increasingly performed on an outpatient basis by physicians trained in interventional techniques. The adoption of guidelines by national reputable organizations will help identify patients eligible for such outpatient treatments and help optimize the safety and efficacy of their procedures in the outpatient setting.

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PURPOSE: To review why hemodialysis fistulas fail to mature and how percutaneous techniques can salvage them. METHODS: A review of the medical literature was performed, with specific attention to the location of the lesions, the types and the numbers of procedures performed, salvage and patency rates. RESULTS: Using balloon angioplasty of the arteries and/or veins with sequential dilation if needed and ligation or embolization of collateral side branches the fistula that has failed to mature can be salvaged. Usually, more than one procedure is required to salvage a fistula; however, salvage rates of 75-95% are achieved with 1 yr primary patency rates of 30-60%. With repeat percutaneous interventions, 1 yr secondary patency rates are 75-90%. CONCLUSIONS: With surveillance and aggressive follow-up after placement, early intervention (primarily dilation in the access circuit) can yield high salvage rates in fistulas that fail to mature.

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Autogenous arteriovenous fistulas are the preferred vascular access in patients undergoing hemodialysis. Increasing fistula prevalence depends on increasing fistula placement, improving the maturation of fistula that fail to mature and enhancing the long-term patency of mature fistula. Percutaneous methods for optimizing arteriovenous fistula maturation will be reviewed.

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PURPOSE: To determine the outcome of tunneled hemodialysis catheters inserted through the common femoral vein. MATERIALS AND METHODS: From April 2000 to June 2003, 33 consecutive patients had 86 tunneled hemodialysis catheters inserted through the femoral vein. There were 14 male and 19 female patients with a mean age of 56 years. Seventeen patients had bilateral central venous and/or superior vena cava (SVC) occlusions, 12 patients had unilateral central venous occlusions and were to receive contralateral arteriovenous fistulas or arteriovenous polytetrafluoroethylene grafts, and 4 patients received femoral catheters for other reasons. The technical success, complications, and clinical outcomes of these procedures were retrospectively evaluated. RESULTS: All procedures were technically successful. Fifty-seven catheters were inserted into the right femoral vein and 29 into the left femoral vein. This included 25 catheter exchanges in 13 patients. Two patients developed thigh hematomas. Follow-up data were available for 68 catheters; mean follow-up period was 51 days with a total of 3,484 catheter days. The catheter-related infection rate was 6.3 per 1,000 catheter days; 22 catheters were removed for infection. Eighteen catheters were removed because of poor blood flows (<200 mL/min). Thirteen catheters were removed because they had become retracted. Primary catheter patency was 44% at 1 month. CONCLUSIONS: The femoral vein provides an alternative access site for insertion of tunneled hemodialysis catheters when conventional sites are not available. However, tunneled femoral hemodialysis catheters have low primary patency rates and significant complications. Catheter retraction is a unique and common problem.

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PURPOSE: To track the natural history of tunneled hemodialysis catheters requiring removal or exchange at a single institution. MATERIALS AND METHODS: Over a 2-year period, tunneled hemodialysis catheters that presented to interventional radiology for removal or exchange were entered into this retrospective study. Patient demographics, catheter location, dwell time, and indication for removal were recorded. Pull-back contrast venography was performed with imaging over the chest. Catheters were then removed or exchanged. RESULTS: Three hundred thirty-four tunneled dialysis catheters were removed or exchanged in 207 patients; 108 male, median age 53 years. Dwell time, available from 296 catheters, ranged from 1 to 114 days (median, 66 days) for a total of 32,847 catheter days. One hundred three catheters were removed for infection, yielding a rate of infection requiring catheter removal of 3.0 per 1,000 catheter days. One hundred catheters were removed for other working access, and 96 catheters were exchanged for poor function. Two hundred sixty-five were removed or exchanged from the internal jugular vein, 22 from the subclavian vein, and 24 from the femoral vein. One hundred seventy-two (76%) of the 226 catheters studied with contrast had fibrin sheaths; of which 42 had thrombus identified along the catheter tract. One hundred ninety-three catheters were removed, and 141 catheters were exchanged for new catheters with 82 catheters receiving balloon disruption of the fibrin sheath. CONCLUSIONS: Approximately one third of tunneled dialysis catheters are removed for infection, one third for other working access, and one third for poor function. Catheters usually remain in the patient for a median of 2 months. Fibrin sheaths associated with hemodialysis catheters are very common. Thrombus formation around the sheath is frequent.

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OBJECTIVE: The purpose of this study was to evaluate the use of the brachiocephalic vein as an alternative access site for the insertion of tunneled hemodialysis catheters in patients with occluded jugular veins. CONCLUSION: Placement of brachiocephalic catheters for central venous access is safe and provides an alternative access in patients with internal and external jugular vein occlusion.

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PURPOSE: To describe the number and type of percutaneous interventions required to promote maturation and maintain patency of hemodialysis fistulas. MATERIALS AND METHODS: One hundred fifty-four hemodialysis fistulas were created in 146 patients by a single surgeon between August 2001 and March 2005. There were 88 male patients (60%), and the median age of the group was 66 years. The records of all percutaneous procedures performed on these patients were retrospectively reviewed. The medical records from the hemodialysis treatment centers were also reviewed to assess fistula patency during the follow-up period. RESULTS: Of the initial 154 fistulas created, 112 (73%) were successfully used for hemodialysis. One hundred thirteen procedures were performed to promote maturation of 65 fistulas (1.7 procedures per fistula), including 66 venous angioplasty procedures, 16 arterial angioplasty procedures, ligation of 21 venous side branches, five thrombectomy procedures, three banding procedures, and two other procedures. Only 48 of these nonmaturing fistulas (74%) became functional. Sixty-three mature fistulas required 209 procedures (3.3 procedures per fistula, 1.75 procedures per access-year) to maintain vascular access patency. These included 174 venous angioplasty procedures, 18 arterial angioplasty procedures, 14 thrombectomy procedures, ligation of three venous side branches, and two stent placement procedures. The mean follow-up period for all 154 fistulas was 317 days (range, 12-1,138 days). Primary patency rates at 90, 180, and 360 days were 71%, 69%, and 64%, respectively, and secondary patency rates were 73%, 72%, and 68%, respectively. CONCLUSIONS: Percutaneous procedures can promote maturation and maintain patency of arteriovenous fistulas. However, despite numerous procedures to promote maturation, only 74% of nonmaturing fistulas became functional.

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Many clinicians believe that de novo access is required when converting temporary hemodialysis (HD) catheters to long-term or permanent catheters. However, since vascular access sites are at a premium in the dialysis patient, it is important to preserve existing central venous catheters and conserve future access sites. In this retrospective study, data from 94 patients referred to interventional radiology for placement of long-term, tunneled HD catheters between July 2001 and September 2002 were reviewed. The study group consisted of 42 patients in whom the temporary catheter was exchanged for a peel-away sheath and a tunneled catheter inserted using the existing venous access site. The control group included 52 patients who received traditional de novo placement of permanent catheters. Based on available follow-up data, we report a 100% technical success rate, with 72% patency at 30 days in the study group (n = 32; mean age 58 years). By comparison, de novo catheter placement (n = 35; mean age 59 years) yielded a 100% technical success rate, with 83% patency at 30 days. The overall infection rate was 0.30 per 100 catheter-days (total 3036 catheter-days) and 0.36 per 100 catheter-days (total 3295 catheter-days), respectively (chi2 = 0.64, p > or = 0.05). There was no incidence of exit site infection, tunnel infection, or florid sepsis in either group. Likewise, no stenosis or bleeding complication was noted. Thus conversion of a temporary HD catheter to a tunneled catheter using the same venous insertion site is safe, does not increase the risk of infection, and allows conservation of other central venous access sites.

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A pilot study was carried out to prospectively evaluate the efficacy and safety of Tenecteplase (TNKase) using a modified 'lyse and wait" technique with percutaneous transluminal angioplasty (PTA) to treat thrombosed hemodialysis arteriovenous grafts (AVG)s. Seven patients with eight hemodialysis AVGs were treated and followed up to 1 year. Dosing included 1 mg TNKase and 3,000-4,000 U of heparin. Technical and clinical success rates were 100% and 88%, respectively. No major complications occurred. Primary patency rates at 30, 90, and 180 days were 62%, 50%, and 33%, respectively. TNKase, used in this fashion, may be comparable to alteplase and reteplase for safe and effective thrombolysis of PTFE dialysis grafts.

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A majority of the quarter of a million end-stage renal disease patients nationwide are treated with hemodialysis. Important and frequent causes of morbidity and mortality, when they undergo this procedure, include vascular access infection and thrombosis associated with the use of catheters and, to a lesser extent, grafts. Therefore, an arteriovenous (AV) fistula is the preferred hemodialysis access. A multidisciplinary approach, including nephrologists, vascular surgeons, interventional radiologists, nurses, nephrology fellows, and nephrology physician assistants, meeting together weekly, should improve hemodialysis outcomes by promoting the use of AV fistulas. The specific roles of the interventional radiologist, vascular surgeon, nephrologist and other members of the multidisciplinary team are reviewed. Important additional components of this program are Doppler ultrasound for preoperative hemodialysis access vein mapping and screening techniques for early detection of arteriovenous graft stenosis. The use of arteriovenous fistulas in the Mount Sinai outpatient hemodialysis program has increased from 15% to 43% (p<0.001) and substantially limited catheter use since 1998, when the multidisciplinary program began.

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Minimally invasive techniques as the first line of management in vascular reconstruction are beginning to replace older surgical techniques. General and specific approaches in the endovascular reconstruction of branches off the aortic arch (innominate and subclavian arteries) and the visceral branches off the abdominal aorta (renal and mesenteric arteries) are described. The branches of the aortic arch and the visceral arteries are discussed together because of the similarity in the interventional techniques used for revascularization. Patient selection, endoluminal techniques, complications, and patient management will also be discussed.

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BACKGROUND: Arteriovenous fistulae (AVFs) are the preferred method of vascular access for hemodialysis patients; however, the current rate of AVF placement is only 25% to 30% in the United States. This prevalence is even smaller among women and attributed to their perceived inadequate vasculature. This commonly held view that women have less adequate vasculature for AVF placement than men has not been shown objectively in the literature. METHODS: To determine a difference in vasculature between the sexes, we retrospectively analyzed data on preoperative vascular mapping in 192 patients. During a 2-year period, vascular mapping of the upper extremities was routinely performed using duplex ultrasound in all patients requiring vascular access in our institution. RESULTS: One hundred six of these 192 patients were women, and 86 were men. There was no significant difference in vein size between men and women at any of the sites measured. A total of 87 fistulae were placed in 140 patients, 49% in women and 51% in men (P = 0.16). Prevalences of AVFs were 57% and 68% (P = 0.2) in women and men, respectively. Percentages of fistulae used at the initiation of hemodialysis therapy were 72% in women and 77% in men (P = 0.57). CONCLUSION: These data support the view that women have adequate vasculature for the placement of AVFs compared with men. We cannot explain the different outcomes found in other studies; however, we suggest that the differences are caused by physician practice patterns, not anatomic differences between men and women.

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Ultrasound (US)-guided cannulation of the internal jugular vein (IJV) has become the preferred approach for venous access as a result of its higher success rate and lower incidence of complications. This report describes a case of thoracic duct injury during US-guided left IJV catheterization. The normal and variant anatomy of the thoracic duct in the neck is illustrated.

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