Postintervention Primary Patency Research Articles

Risk factors associated with arteriovenous fistula failure after first radiologic intervention.

Improving arteriovenous fistula (AVF) patency is an integral part of the care of hemodialysis patients, often requiring procedures such as percutaneous transluminal angioplasty (PTA). However, these interventions may fail to reduce AVF dysfunction and failure. The purpose of this study was to determine predictive factors for subsequent AVF failure post-PTA. Data from 155 consecutive AVFs in 155 patients at a single institution who had undergone a first PTA and had at least 1 year of follow-up data were analyzed. Using survival analysis, we assessed primary and secondary patency, and identified predictive factors taking into account competing risks. Of the 155 patients, 52% required multiple subsequent PTAs; 32% of the AVFs were not in use prior to the first PTA. At first PTA, 83% had outflow vein stenosis (OVS), 26% had multiple stenoses and 43% of stenoses were longer than 2 cm. During follow-up, 1-, 2-, 3-year postintervention primary patency was 41%, 32%, 32% and secondary patency was 80%, 71% and 68%. AVFs with stenoses greater than 2 cm or OVS were at higher risk of requiring multiple PTAs (p = 0.04, 0.006). Factors associated with requiring a second PTA included stenosis greater than 2 cm (hazard ratio (HR) = 1.8, 95% confidence interval (CI) = 1.2-2.9), OVS (HR = 2.5, 95% CI = 1.1-5.4) and primary renal diagnosis of diabetes or renal vascular diseases (HR = 1.8, 95% CI = 1.1-2.9); after adjustments for competing risks, OVS and stenosis length remained associated with requiring subsequent PTAs. The location and size of the AVF stenosis at first PTA appear to be consistent factors associated with worse postintervention primary patency.

Abstract No. 18 - Bare metal versus covered stents for treatment of intragraft stenosis within prosthetic hemodialysis arteriovenous grafts

Angioplasty is the standard method for treatment of intragraft stenosis within prosthetic hemodialysis grafts. While stenting can be performed, there are no comparative data in the literature on various stent types at this location. Therefore, the purpose of this study was to compare post-intervention access patency rates after deployment of bare metal versus covered stents for the treatment of intragraft stenoses. Our procedural database was retrospectively reviewed for all percutaneous interventions on prosthetic hemodialysis grafts over a 7-year period in which a stent was deployed at the site of an intragraft stenosis. 31 stent deployments within 22 patients were identified (15 males, 7 females, mean age 57.4 years). All stents were deployed due to suboptimal results with angioplasty (“bail-out”). Intragraft stents deployed for the treatment of anastomotic stenosis, pseudoaneurysms, or bleeding were excluded. Post-intervention access patencies were calculated using Kaplan-Meier analysis and compared using the logrank test. 21 covered stents and 10 bare metal stents were deployed for the treatment of intragraft stenoses. 90% of the grafts were thrombosed at presentation. The 3 and 6 month post-intervention primary access patency rates for bare metal stents were not significantly different from covered stents: 44% and 22% compared to 45% and 25%, respectively (p=0.92). The 6 and 12 month post-intervention secondary access patency rates were also not significantly different: 50% and 30% for bare metal stents and 80% and 55% for covered stents (p=0.28). The 6 month lesion patency rate was 56% and 70%, respectively (p=0.45). In this retrospective study with limited sample size, bare metal and covered stents deployed to treat intragraft stenosis resistant to angioplasty demonstrated similar primary, secondary, and lesion patency rates.

Percutaneous Creation of Bare Intervascular Tunnels for Salvage of Thrombosed Hemodialysis Fistulas Without Recanalizable Outflow.

This study aimed to retrospectively assess the efficacy of a bare intervascular tunnel for salvage of a thrombosed hemodialysis fistula. We examined the clinical outcomes and provided follow-up images of the bare intervascular tunnel. Eight thrombosed fistulas lacked available recanalizable outflow veins were included in this study. These fistulas were salvaged by re-directing access site flow to a new outflow vein through a percutaneously created intervascular tunnel without stent graft placement. The post-intervention primary and secondary access patency rates were calculated using the Kaplan-Meier method. The procedural and clinical success rates were 100%. Post-intervention primary and secondary access patency at 300 days were 18.7 ± 15.8 and 87.5 ± 11.7%, respectively. The mean follow-up period was 218.7 days (range 10-368 days). One patient died of acute myocardial infarction 10 days after the procedure. No other major complications were observed. Minor complications, such as swelling, ecchymosis, and pain around the tunnel, occurred in all of the patients. Percutaneous creation of a bare intervascular tunnel is a treatment option for thrombosed hemodialysis fistulas without recanalizable outflow in selected patients.

Clinical outcome of percutaneous thrombectomy of dialysis access thrombosis by an interventional nephrologist

BackgroundTraditionally, the treatment of a thrombosed dialysis access in hemodialysis patients in Korea has been primarily performed by vascular surgeons and interventional radiologists. The objective of this study was to evaluate the outcome of percutaneous thrombectomy procedures performed by an interventional nephrologist. MethodsFrom October 2010 to May 2014, 75 consecutive percutaneous thrombectomies were performed on 42 patients treated with maintenance hemodialysis. All percutaneous thrombectomy procedures were performed by an interventional nephrologist in a single hospital in Jeju, Korea. The thrombosed arteriovenous graft and arteriovenous fistula were declotted by thromboaspiration mechanical thrombectomy or pharmacomechanical thrombolysis. Kaplan–Meier survival analysis was performed to analyze the primary and secondary patency after the initial successful thrombectomy. Success and complication rates were identified and compared with the recommendations of the Kidney Disease Dialysis Outcomes Quality Initiative (KDOQI) guideline. ResultsThe overall clinical success rate was 89.3% (67/75). In the successful cases, the postintervention primary (unassisted) patency rates at 30 days, 90 days, and 180 days were 79.9%, 56.6%, and 25.6%, respectively. The secondary patency rates at 30 days, 90 days, and 180 days were 92.2%, 85.7%, and 83.7%, respectively. There were no major complications, and all complications were treated successfully during the procedure. ConclusionThe clinical success rate and primary patency rate at 3 months exceeded the recommendations of the KDOQI guideline, and were comparable to that of other reports. Percutaneous thrombectomy by an interventional nephrologist was safe and effective.

Transradial approach for challenging vascular access interventions.

Percutaneous interventional procedures for vascular access are usually performed using the draining cephalic or basilic vein. The transradial approach, which has been extensively investigated for coronary angiography and intervention, could be an attractive new technique for peri-anastomotic arteriovenous fistula stenosis. From June 2012 to February 2013, 30 patients with end-stage renal failure were evaluated for transradial vascular access intervention. A 4-French (Fr) micropuncture kit was used to access the radial artery and then subsequently upgraded to a 5-Fr sheath. Fourteen patients required an upgrade to a 6-Fr sheath for the final intervention. Primary technical success (residual stenosis <30%) was achieved in all cases where angioplasty was performed. Technical success regarding access was achieved in all patients. There were no peri-procedural complications. The post-interventional primary patency was calculated as 100%, 100%, 88.4% and 32.8% at 1, 6, 9 and 12 months, respectively. The post-interventional primary assisted patency was calculated as 100%, 100%, 100% and 63.3% at 1, 6, 9 and 12 months, respectively. Based on colour-coded Duplex scan and/or photoelectric plethysmography, all access-site arteries showed normal perfusion; however, the freedom from significant radial artery restenosis was 92.4% at 12-month follow-up. The transradial approach for vascular access endovascular interventions is technically feasible and safe. It allows simultaneous treatment of peri-anastomotic lesions in fistulas with complex venous anatomy as well as lesions in the arterial inflow and central outflow.

Factors Associated with Patency Following Angioplasty of Hemodialysis Fistulae

PurposePatency after percutaneous transluminal angioplasty of native hemodialysis arteriovenous fistulae (AVFs) is highly variable. This study aimed to identify predictors of patency following angioplasty in native AVFs. Materials and MethodsAll endovascular procedures performed in native AVFs between 2005 and 2013 at two institutions were retrospectively reviewed. Clinical, anatomic, biochemical, and medication variables were subjected to univariate and multivariate Cox regression analysis to identify predictors of postintervention primary and secondary patency. ResultsDuring the study period, 207 patients underwent first angioplasty of their AVF. Follow-up ranged from 14 days to 8 years, during which another 247 endovascular interventions were performed to maintain patency. Postintervention primary patency rates at 6, 12, and 24 months were 66%, 49%, and 29%, respectively. Postintervention secondary patency rates at 6, 12, and 24 months were 94%, 84%, and 79%, respectively. On multivariate adjusted Cox regression analysis, upper-arm AVFs (P = .00072), AVFs less than 6 months of age (P = .0014), presence of multiple stenoses (P = .019), and degree of initial stenosis (P = .016) were significantly associated with shorter postintervention primary patency. A previously failed AVF was the only significant predictor of postintervention secondary patency loss (P = .0053). ConclusionsAnatomic factors related to the AVF location, AVF age, and the extent of the lesion are important predictors of restenosis after balloon angioplasty. Traditional cardiovascular risk factors, metabolic and inflammatory markers, and medications were not associated with postintervention patency.

Should All Inflow Stenoses Be Treated in Failing Autogenous Hemodialysis Fistulae?

PurposeTo determine whether angioplasty of inflow stenosis in malfunctioning but patent autogenous hemodialysis fistulae has an impact on postintervention primary patency in patients without a clinical indicator of inflow-related access malfunction. Materials and MethodsMedical records for 76 procedures in 62 patients with inflow stenoses undergoing fistulography in nonthrombosed mature autogenous fistulae without an inflow-related indication of access malfunction over a 5-year period were reviewed retrospectively. Control and treatment arms were defined as patients with untreated (26 procedures in 23 patients) and treated (50 procedures in 39 patients) inflow stenoses, respectively. All patients in both arms of the study had concurrent intrafistula and/or venous outflow stenosis, which were treated successfully with angioplasty. The clinical endpoint was defined as return for a failing or thrombosed access (ie, primary patency). A two-tailed unpaired Student t test was performed to compare primary patency and percent inflow stenosis in treatment (angioplasty) and control (untreated inflow stenoses) groups, with significance defined at P < .05. Kaplan–Meier analysis was performed. ResultsThere was no significant difference in percent inflow stenosis between control and treatment arms (P = .95). There was no significant difference in access patency between the two groups (139 and 124 d for control and treated groups, respectively; P = .95). No procedural complications occurred in either arm of the study. ConclusionsAngioplasty of inflow stenosis in failing autogenous fistulae without an appropriate clinical indicator of an inflow pathologic process does not improve postintervention primary patency.

Outcomes of Percutaneous Interventions in Transposed Hemodialysis Fistulas Compared with Nontransposed Fistulas and Grafts

To compare postpercutaneous intervention outcomes of autogenous venous-transposition arteriovenous fistulas (AVFs) versus those of autogenous nontransposed AVFs (nAVFs) and prosthetic arteriovenous grafts (AVGs). A total of 591 hemodialysis accesses (195 transposed AVFs [tAVFs], 205 nAVFs, 191 AVGs) in 522 patients (278 male; mean age, 57 y; range, 15–91 y) underwent percutaneous transluminal angioplasty (PTA) and/or mechanical thrombectomy (ie, declotting). Access characteristics, surgical history, percutaneous interventions, postinterventional primary and secondary access patency, and follow-up data were collected. Cox proportional-hazards regression analyses, Fisher exact tests, and χ2 tests were performed. Mean follow-up period was 32 months. Mean access ages at initial percutaneous intervention were 260 days (tAVF), 206 days (nAVF), and 176 days (AVG; P < .01). One-year postinterventional primary patency (PIPP) rates were 25% (tAVF), 24% (nAVF), and 14% (AVG). One-year postinterventional secondary patency (PISP) rates were 77% (tAVF), 61% (nAVF), and 63% (AVG). Median PIPP durations were 138 days (tAVF), 121 days (nAVF), and 79 days (AVG; P = .0001). Median PISP durations were 1,076 days (tAVF), 783 days (nAVF), and 750 days (AVG; P = .019). Total interventions needed to maintain PISP were 2.4 (tAVF), 1.3 (nAVF), and 3.2 (AVG) per patient-year (P < .001), which included 1.9, 1.2, and 1.4 PTAs (P < .01) and 0.45, 0.15, and 1.8 declotting procedures, respectively (P < .001). Based on the number of percutaneous interventions needed to maintain PISP, these results confirm the current Dialysis Outcomes Quality Initiative access preference of nAVFs before tAVFs before AVGs. tAVFs offered superior postinterventional outcomes than AVGs. With additional interventions, tAVFs could even outperform nAVFs in terms of PISP.

Abstract No. 331 - Outcomes of interventions in hybrid hemodialysis access

Purpose Fistulae and grafts respond differently to percutaneous interventions, with fistulae generally yielding longer patency. Failing fistulae, whether due to aneurysm or refractory stenosis, may be treated surgically with interposition grafting, creating a “hybrid” access. The purpose of this study was to determine the outcomes of percutaneous interventions in hybrid accesses. Materials and Methods We retrospectively reviewed patient records from a prospectively collected database containing more than 6,000 hemodialysis interventions conducted over a 10-year period. From this database, patients identified as having hybrid access were included; those without follow-up were excluded. The main outcomes investigated were the intervals of primary and secondary patency after percutaneous interventions to maintain or restore function, as defined by SIR guidelines. A sample of synthetic and native hemodialysis access interventions from the same database served as control. Results Of 40 patients with hybrid access, 29 met inclusion criteria. Mean access age for fistulae, grafts, and hybrids was 232±257, 176±232, and 918±953 days respectively. 77 interventions were performed in this group, 737 in the fistula control group, and 603 in the graft control group. Median post intervention primary patency in hybrids was similar to fistulae (166 vs 133 days, P=0.7) and longer than grafts (79 days, P Conclusion Our data suggest that interposition grafting in fistulae to form a hybrid access does not compromise post-intervention patency.

Comparisons of clinical outcomes for thrombectomy devices with different mechanisms in hemodialysis arteriovenous fistulas

To compare clinical outcomes between mechanical thrombectomy devices with hydrodynamic mechanism and rotational mechanism. A number of advantages and concerns have been raised for different mechanical devices but the comparisons of clinical outcomes are absent, especially for the treatment of autogenous hemodialysis arteriovenous (AV) fistulas. The authors retrospectively reviewed 275 percutaneous thrombectomy procedures in AV fistulas. Procedures included were thrombectomy using devices with hydrodynamic mechanism, the AngioJet rheolytic catheter (AngioJet) (n = 134) or devices with rotational mechanism, the Arrow-Trerotola percutaneous thrombectomy device (PTD) (n = 141). Measured outcomes included clinical success, complications and patency rates. Clinical success was achieved in 76% (102 of 134) of the AngioJet procedures and in 91% (128 of 141) of the PTD procedures (P = 0.002). The procedure time for the PTD method was significantly shorter than that of the AngioJet method (52 vs. 88 min, P < 0.001). Complications occurred in 14% of the AngioJet procedures and 11% of the PTD procedures. The post-intervention primary patency rates at 6 months were 45% for the AngioJet group and 43% for the PTD group (P = 0.70). The postintervention secondary patency rates at 1 year were 74% for the AngioJet group and 87% for the PTD group (P = 0.01). For the salvage of thrombosed AV fistulas, a device using rotational mechanism is more time-saving with a higher immediate success rate and secondary patency rate. However, the long-term patency results were not different.

Salvage of Angioplasty Failures and Complications in Hemodialysis Arteriovenous Access Using the FLUENCY Plus Stent Graft: Technical and 180-Day Patency Results

PurposeTo review technical and 180-day clinical outcomes when stent grafts were used to treat dysfunctional arteriovenous (AV) hemodialysis access circuits. Materials and MethodsThe FLUENCY Plus Stent Graft (Bard Peripheral Vascular, Tempe, Arizona) was used to salvage percutaneous transluminal angioplasty (PTA) technical failures and complications in AV access circuits over 2 years. There were 106 patients treated with 138 stent grafts. Indications for stent graft use included residual stenosis after PTA (n = 81), extravasation after PTA (n = 22), early recurrent stenosis (n = 14), pseudoaneurysms (n = 4), and “other” (n = 4). Data were retrospectively analyzed for complications and outcomes. ResultsTechnical success was achieved in all patients, and clinical success was achieved in 104 (98%) of 106 patients. At 180 days, postintervention primary patency (PIPP) was 47%, and postintervention secondary patency (PISP) was 79%. PIPP was 62% for autogenous fistulas (AVFs) and 35% for prosthetic grafts (AVGs) (P = .010). The 180-day PIPP for stent grafts 9–10 mm in diameter was 63% versus 38% for stent grafts 6–8 mm in diameter (P = .012). Implants that did not cross the elbow had a 180-day PIPP of 47% compared with 25% for implants across the elbow (P = .032). Technical complications were periprocedure AVG thromboses (n = 2), intraprocedural stent graft dislodgment (n = 1), venospasm (n = 2), and contrast agent–related hives (n = 1). One patient returned at 2 months with an infected AVG and stent graft in the outflow vein. ConclusionsThe FLUENCY Plus Stent Graft was effective for maintenance of hemodialysis access circuit patency and was comparable or better than historical outcomes for PTA and bare stents. Factors that favored improved patency included larger diameter devices, use in AVFs, and avoiding placement across the elbow joint.

Efficacy of a Modified Pharmacomechanical Thrombolysis Technique for Endovascular Treatment of Thrombosed Prosthetic Arteriovenous Grafts

ObjectiveWe applied a modified pharmacomechanical thrombolysis (PMT) technique to endovascular treatment of thrombosed arteriovenous (AV) grafts without the use of any mechanical thrombectomy devices. The aim of this study was to evaluate the efficacy of the PMT technique in the treatment of thrombosed AV grafts by analyzing the long-term patency.Materials and MethodsEighty-two patients with thrombosed AV grafts were treated with the PMT technique. AV graft surveillance to detect failing/failed access was followed by endovascular treatment.ResultsThe technical and clinical success rates were 95% and 95%, respectively. The total number of thrombolysis sessions was 279. A post-intervention primary patency rate was 45% and 22% at 12 and 24 months, respectively. The secondary patency rate was 96% and 91% at 12 and 24 months, respectively. No major complications were noticed.ConclusionThe modified PMT technique is effective in endovascular treatment of thrombosed AV grafts.

Management of perianastomotic stenosis of direct wrist autogenous radial-cephalic arteriovenous accesses for dialysis

Radial-cephalic fistulas (RCFs) perianastomotic stenoses (PASs) are on and around the fistula anastomosis. This group of lesions encompasses juxta-anastomotic stenosis (stenosis located on the venous side within 3 cm away from the anastomosis), anastomotic, and arterial stenosis. The purpose of our study was to assess the postintervention primary patency and assisted postintervention primary patency (APP) rates for surgery and angioplasty when treating these stenoses. The secondary endpoint was to identify factors that might influence the procedure's patency rates. This retrospective study included 73 consecutive patients treated for lack of maturation PASs between January 1999 and December 2005 in two interventional centers. Patients' mean age was 65 years old. Stenoses were treated by surgery (n = 21) or percutaneous transluminal angioplasty (PTA; n = 52). Surgery meant creation of a new anastomosis excluding the area of stenosis. Preoperative characteristics including the patient's age, gender, comorbidities, stenosis location, and length were not statistically different between the two groups. The mean follow-up was 39 months for PTA and 49 months for surgery. Anatomical and clinical success rates were 86% and 90% for surgery, and 75% and 92% for PTA. At 1 year, the primary patency rates were 71 ± 10% for surgery and 41 ± 6% for PTA, respectively (P < .02). There was no significant difference between the two groups with respect to assisted primary patency (95% vs 92%). In the PTA group, stenosis location at the anastomosis itself was a risk factor of early recurrence (P = .047). The complication rate was similar between surgery and PTA. Our results suggest that the treatment of anastomotic stenoses should be surgical rather than endovascular. Angioplasty and surgery have shown similar results when used to treat other perianastomotic stenoses, but repeat procedures were more frequent with angioplasty.

Endovascular Revascularization of Chronically Thrombosed Arteriovenous Fistulas and Grafts for Hemodialysis: A Retrospective Study in 15 Patients With 18 Access Sites

The current study retrospectively evaluated whether endovascular revascularization of chronically thrombosed and long-discarded vascular access sites for hemodialysis was feasible. Technical and clinical success rates, postintervention primary and secondary patency rates, and complications were reported. During a 1-year period, we reviewed a total of 924 interventions performed for dysfunction and/or failed hemodialysis vascular access sites and permanent catheters in 881 patients. In patients whose vascular access-site problems were considered untreatable or were considered treatable with a high risk of failure and access-site abandonment, we attempted to revascularize (resurrect) the chronically occluded and long-discarded (mummy) vascular access sites. We attempted to resurrect a total of 18 mummy access sites (mean age 46.6 ± 38.7 months; range 5-144) in 15 patients (8 women and 7 men; mean age 66.2 ± 11.5 years; age range 50-85) and had an overall technical success rate of 77.8%. Resurrection failure occurred in 3 fistulas and in 1 straight graft. The clinical success rate was 100% at 2 months after resurrection. In the 14 resurrected vascular access sites, 6 balloon-assisted maturation procedures were required in 5 fistulas; after access-site maturation, a total of 22 interventions were performed to maintain access-site patency. The mean go-through time for successful resurrection procedures was 146.6 ± 34.3 min (range 74-193). Postmaturation primary patency rates were 71.4 ± 12.1% at 30 days, 57.1 ± 13.2% at 60 days, 28.6 ± 13.4% at 90 days, and 19 ± 11.8% at 180 days. Postmaturation secondary patency rates were 100% at 30, 60, and 90 days and 81.8 ± 11.6% at 180 days. There were 2 major complications consisting of massive venous ruptures in 2 mummy access sites during balloon dilation; in both cases, prolonged balloon inflation failed to achieve hemostasis, but percutaneous N-butyl cyanoacrylate glue seal-off was performed successfully. Percutaneous resurrection of mummy vascular access sites for hemodialysis is technically feasible with high clinical success rates. In selected patients, resurrection of mummy access sites provides long-discarded access sites one more chance to be used for hemodialysis in an effort to preserve potential extremity sites for future access-site placement and to prevent long-term catheter indwelling.

Comparison of Post-surgical Patency Rates between Failing and Failed Arterio-venous Graft for Hemodialysis with Venous Anastomosis Stenosis

Purpose: The most frequent complication in vascular access for hemodialysis is the stenosis of venous anastomosis site and resultant thrombosis. And it has been suggested that the correction of stenosis before thrombosis can prolong graft survival. We compared the outcomes of surgical repair between stenosed group and thrombosed group. Methods: From March 2003 to July 2007, 155 cases of stenosed graft-venous anastomosis (GVA) of arteriovenous graft (AVG) underwent salvage operation; 53 elective revisions for stenosis (group A), and 102 emergency open thrombectomies with jump grafts (group B). Outcomes were compared by post-intervention primary patency (PIPP) and post-intervention secondary patency (PISP). Results: The mean follow-up duration was 24.8±15.2 months. Surgical success rate was 100% for elective revision group and 98% for emergency operation group. Elective revision of symptomatic GVA stenosis improved PIPP compared to emergency operation of thrombosed graft (mean 13.0 vs. 8.6 months, P=0.018). But PISP was not extended (mean 24.2 vs. 23.2 months, P=0.359). The electively revised GVA stenosed graft had fewer subsequent thrombotic events (0.3 vs 0.7 thrombosis/patient year, P=0.027) and fewer interventions (0.6 vs. 1.2 interventions/patient year, P=0.06). The proportion of other stenoses for group A and group B was 35.8% and 38.2%, respectively. Conclusion: The frequency of subsequent thrombotic events and total number of postoperative interventions decreased significantly after elective revision. Elective revision of GVA stenosis in PTFE graft prolongs PIPP, and should be considered before the occurrence of thrombosis.

Percutaneous Intervention in Axillary Loop-Configured Arteriovenous Grafts for Chronic Hemodialysis Patients

ObjectiveThe purpose of this study was to evaluate the fistulographic features of malfunctioning axillary loop-configured arteriovenous grafts and the efficacy of percutaneous interventions in failed axillary loop-configured arteriovenous grafts.Materials and MethodsTen patients with axillary loop-configured arteriovenous grafts were referred for evaluation of graft patency or upper arm swelling. Fistulography and percutaneous intervention, including thrombolysis, percutaneous transluminal angioplasty and stent placement, were performed. Statistical analysis of the procedure success rate and the primary and secondary patency rates was done.ResultsFour patients had graft related and subclavian venous stenosis, two patients had graft related stenosis and another four patients had subclavian venous stenosis only. Sixteen sessions of interventional procedures were performed in eight patients (average: 2 sessions / patient) until the end of follow-up. An interventional procedure was not done in two patients with central venous stenosis. The overall procedure success rate was 69% (11 of 16 sessions). The post-intervention primary and secondary patency rates were 50% and 63% at three months, 38% and 63% at six months and 25% and 63% at one year, respectively.ConclusionDysfunctional axillary loop-configured arteriovenous grafts almost always had subclavian venous and graft-related stenosis. Interventional treatments are helpful to overcome this and these treatments are expected to play a major role in restoring and maintaining the axillary loop-configured arteriovenous loop grafts.

Radial Arterial Approach with Adjunctive Urokinase for Treating Occluded Autogenous Radial-Cephalic Fistulas

There are no data regarding the feasibility and safety of a radial arterial approach with adjunctive urokinase for treating occluded autogenous radial-cephalic fistulas. We retrospectively examined 54 transradial interventions performed to treat occluded autogenous radial-cephalic fistulas within 72 h of occurrence. Urokinase was used in patients with a large thrombus burden. A total of 92 lesions in 54 consecutive patients (27 males, 27 females; mean age, 61.8+/-12.3 years) were treated via radial access. All radial punctures were successful except in one patient. Most thrombotic lesions were located within 1 cm of the radiocephalic anastomosis (79.6%). The mean length of treated thrombotic lesions was 10.3+/-5.4 cm (range, 4-32 cm). Twenty-five patients (46.3%) received urokinase (mean dose, 96,000+/-30,000 U). After transradial intervention, systolic, diastolic, and mean pressures in the radial artery decreased from 179+/-41, 77+/-17, and 111+/-22 mm Hg to 71+/-29, 36+/-15, and 48+/-19 mm Hg (all p's\0.001), respectively. Four radial interventions were unsuccessful. The anatomic and clinical success rates of the radial approach were both 92.6%; postinterventional primary patency rates were 65% at 6 months and 40% at 12 months. Two minor vascular complications were noted, one caused by guidewire-induced contrast extravasation and the other by balloon-induced contrast extravasation. No patient developed clinical signs of pulmonary embolism. In conclusion, the radial approach with adjunctive urokinase is an effective and safe approach to treat occluded autogenous radial-cephalic fistulas.

Endovascular Treatment of Autogenous Radiocephalic Fistulas with the “Eighth Note” Deformity for Hemodialysis

The purpose of this paper is to describe a unique "eighth note" deformity of the autogenous radiocephalic fistula for hemodialysis and to retrospectively evaluate the efficacy and safety of its endovascular treatment. Over 3 years, a total of 808 patients and 558 autogenous radiocephalic fistulas were treated for vascular access dysfunction or thrombosis. These included 14 fistulas in 14 patients (9 men, 5 women; mean age, 58.2 +/- 2.8 years; range 27-79 years) whose fistulograms before treatment resembled a musical note, the eighth note. Endovascular treatment sought to remodel the deformed vascular access to a classic radiocephalic fistula and increase the number of cannulation sites available for hemodialysis. The technical and clinical success rates were each 92.8% (13/14). Fistula remodeling was successful in 13 patients. The postintervention primary patency was 100% at 90 days, 91.7 +/- 0.8% at 120 days, 78.6 +/- 13.9% at 180 days, 62.9 +/- 17.9% at 360 days, 31.4 +/- 24.0% at 540 days, and 0% at 720 days. The postintervention secondary patency was 100% at 90 days, 100% at 120 days, 100% at 180 days, 85.7 +/- 13.2% at 360 days, and 85.7 +/- 13.2% at 720 days. No major complications were noted. Minor complications were found in 71.4% of patients, all of which resolved spontaneously. In conclusion, endovascular treatment of fistulas with the eighth note deformity can effectively increase the number of available cannulation sites, facilitate fistula maturation, and facilitate thromboaspiration after fistula thrombosis.

Radial artery approach for endovascular salvage of occluded autogenous radial-cephalic fistulae

The endovascular salvage of occluded autogenous radial-cephalic fistulae is a more challenging procedure than that for stenotic fistulae. To obtain an access to the fistula is one of the keys to success. Both retrograde venous approach and brachial artery approach have some disadvantages. The radial artery approach has been used in the endovascular therapy of fistula dysfunction, but few data focused on their feasibility and safety for the totally occluded fistulae. We retrospectively reviewed the patients with occluded autogenous radial-cephalic fistulae receiving endovascular salvage via the radial artery approach in our institution. From January 2004 to July 2007, 48 patients fulfilling the above criteria were enrolled. Balloon maceration was used for patients with small clots. Mechanical thrombectomy with an Arrow-Trerotola percutaneous thrombolytic device or an AngioJet rheolytic catheter was used for patients with large clot burden. Outcome variables included anatomic and clinical success, complications and primary and secondary patency. All the transradial punctures were successful. Anatomic and clinical success was achieved in 96% of the cases. The post-interventional primary patency rates were 92%, 77%, 55% and 44% at 1, 3, 6 and 12 months, respectively. The post-interventional secondary patency rates were 96%, 93%, 89% and 89% at 1, 3, 6 and 12 months, respectively. The 12-month primary patency of the short-segment thrombus group was better than that of the long-segment thrombus group (57% versus 19%, P = 0.005). The complication rate was 4%. No puncture-site-related complications were noted, and all the radial arteries were palpable at follow-up. An endovascular intervention through the radial artery approach is a safe and feasible strategy choice for restoring occluded autogenous radial-cephalic fistulae.

Dialysis Access Venous Stenoses: Treatment with Balloon Angioplasty—1- versus 3-minute Inflation Times

To examine prospectively the effects of balloon inflation time on the technical success of balloon angioplasty in dialysis access venous stenosis and on postintervention primary patency. The study design was approved by the institution's Committee for the Protection of Human Subjects, and informed consent was obtained. Demographic information and access-specific data were collected. Patients with thrombosis, prior stent placement within the access circuit, and allergy to heparin were excluded. Patients were randomly assigned to a balloon inflation time of either 1 or 3 minutes. Balloon sizing, inflation pressure, balloon type, and heparin administration were controlled variables. The technical success of the angioplasty, defined as less than 30% residual stenosis, was evaluated for each lesion. A total of 48 patients were enrolled: 27 patients (40 stenoses) randomly assigned to the 1-minute group and 21 (36 stenoses) to the 3-minute group. There were no significant demographic differences between the two inflation groups. Technical success rates in the 1- and 3-minute inflation groups were 75% and 89%, respectively. Logistic regression analysis, which controlled for patient age, sex, and age of the access, demonstrated that technical success was 4.7 times more likely in the 3- versus the 1-minute inflation group (95% confidence interval: 1.1, 20.1). The 1-, 3-, and 6-month postintervention patencies were not significantly different between the two groups. Although a 3-minute inflation time significantly improved the likelihood of technical success for percutaneous transluminal angioplasty of dialysis access venous stenoses, there was no significant difference in postintervention access patency.