Ultrasound-Guided Cradle-Like Infiltrative Anesthesia for Percutaneous Transluminal Angioplasty of Stenotic Autogenous Arteriovenous Hemodialysis Access.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is an effective treatment for autogenous arteriovenous hemodialysis access (AAVA) stenosis; however, it causes pain in most cases. Therefore, safe and effective anesthesia for PTA is required. METHODS: We introduced a method of ultrasound-guided cradle-like infiltration anesthesia (UCIA) to administer analgesia during PTA. Using ultrasound guidance, 1% lidocaine was injected into the bilateral and inferior perivascular spaces of the stenosis to form a cradle-like region. In this study, 100 consecutive patients were divided into two groups, and the analgesic effect of UCIA was evaluated using a numerical rating scale with non-ultrasound-guided infiltration anesthesia as a control. Meanwhile, we compared the effect of PTA between the two groups with the postoperative internal diameter of the stenosis. RESULTS: The numerical rating scale score was 4.6 ± 1.9 and 2.0 ± 1.6 (P < 0.001) in UCIA group and non-ultrasound-guided infiltration anesthesia group, respectively. The postoperative internal diameter of stenosis was 3.9 ± 0.6 mm and 4.1 ± 0.7 mm (P = 0.113); the postoperative AAVA flow volume was 627 ± 176 mL/min and 644 ± 145 mL/min (P = 0.600). CONCLUSIONS: This study preliminarily showed that UCIA is effective and safe for the analgesia of AAVA PTA.

Medical Adjuvant Therapy in Reducing Thrombosis With Arteriovenous Grafts and Fistulae Use: A Meta-Analysis of Randomized Controlled Trials.

Hemodialysis is required for patients with end-stage renal disease (ESRD) that require arteriovenous (AV) grafts or fistulas for vascular access. These access points are prone to thrombosis. To determine the effect of medical adjuvant therapy on AV graft/fistula patency among patients with ESRD on hemodialysis. Adhering to the PRISMA 2020 statement, a systematic search was conducted until August 20, 2021, with keywords including arteriovenous graft, fistula, patency, thrombosis, hemodialysis, adjuvant treatment. The following databases were searched: PubMed, Scopus, Web of Science, CINAHL Plus, and Cochrane. A random-effects model was employed using Review Manager 5.4 for data analysis. The meta-analysis pooled in 1985 participants with 1000 (50.4%) in the medical adjuvant treatment group. At a snapshot, medical adjuvant therapy reduced the risk for graft thrombosis (RR = 0.64, P = .02). Notable medications included aspirin for graft thrombosis (RR = 0.36, P = .006) and ticlopidine for fistula thrombosis (RR = 0.53, P = .01). Certain antiplatelet therapies (aspirin and ticlopidine) reduced the number of patients with AV fistula/graft thrombosis among patients with high heterogeneity among the trials. Other therapies (fish oil, sulfinpyrazone, clopidogrel, and aspirin/dipyridamole) did not demonstrate significant improvement but may be promising once concrete evidence is available. Potential benefits of anti-platelet therapies may be explored to maintain the potency of AV grafts/fistulas through well-designed placebo-controlled trials and long-term follow-up.

General anesthesia is associated with reduced early failure among patients undergoing hemodialysis access.

BACKGROUND: Despite recent reports of improved patency with regional anesthesia (RA), general anesthesia (GA) remains the most common choice for anesthesia for patients undergoing arteriovenous fistula (AVF) or arteriovenous graft (AVG) creation, with nearly 85% utilization. Previous studies of the effect of anesthesia type on outcomes have been conducted through single institutions or a national database with poor granularity for vascular-specific data. Given the high variability of practice patterns and the high prevalence of end-stage renal disease requiring access creation, further study of the impact of anesthesia choice during AVF or AVG creation is warranted. METHODS: The Vascular Quality Initiative hemodialysis data set was queried to identify patients undergoing AVF or AVG creation between 2011 and 2017. Patients were grouped according to access type and anesthesia method (GA vs local anesthesia/RA). The primary outcome was early access failure within 120 days. Secondary outcomes were in-hospital and 30-day complications, including steal, swelling, hemorrhage, and wound infection. RESULTS: There were 31,028 patients undergoing AVG (6961) or AVF (24,067) identified. Compared with patients with GA, patients undergoing access creation with RA had higher early failure rates (AVG, 26.2% vs 23%; AVF, 22.3% vs 20.6%; both P = .04). However, in the GA group undergoing AVF creation, there was a 26% increase (adjusted odds ratio, 1.26 [1.06-1.55]) in bleeding complications and a 3.4-fold increase (adjusted odds ratio, 3.43 [1.38-8.51]) in wound infection rates. CONCLUSIONS: Whereas it is traditionally performed under GA, hemodialysis access with fistula or graft creation is increasingly being performed under RA. In our analysis, rates of perioperative complications, including infection and bleeding, may be lessened by using RA, especially among patients undergoing AVF creation. However, this was accompanied by a 3.2% absolute (21% relative) increased risk of early failure within the first 120 days after dialysis creation among patients undergoing AVG.

Intensive versus moderate atorvastatin therapy and one-year graft patency after CABG: Rationale and design of the ACTIVE (Aggressive Cholesterol Therapy to Inhibit Vein Graft Events) randomized controlled trial (NCT01528709).

RATIONALE: Saphenous vein graft disease remains a major limitation of coronary artery bypass graft surgery (CABG). Statin therapy inhibits the development of vein graft disease and improves outcomes after CABG. However, it is unclear whether treatment with high-dose statins will further slow the process of vein graft disease and improve graft patency, as compared to conventional moderate doses. Therefore, the goal of this study will be to evaluate the efficacy of high-dose statin therapy versus moderate-dose statin therapy for the prevention of saphenous vein graft occlusion following CABG. STUDY DESIGN: The Aggressive Cholesterol Therapy to Inhibit Vein Graft Events (ACTIVE) trial is a multi-center double-blind randomized controlled trial enrolling patients who have undergone multi-vessel CABG with at least one saphenous vein graft. Patients will be randomized to receive either atorvastatin 80mg daily or atorvastatin 10mg daily for one year starting within 5days after surgery. The target enrollment is 100 patients in each arm (200 patients total). Lipid levels will be assessed every 3months. After one year, patients will undergo computed tomography (CT) coronary angiography to assess the incidence of vein graft occlusion and stenosis. CONCLUSION: This trial is the first prospective study to evaluate the impact of early postoperative high-dose statin therapy on graft patency after CABG. Should high-dose statin therapy reduce the incidence of postoperative graft occlusion, the results will add to the growing evidence supporting the role of high-intensity statins for modern lipid management after coronary surgical revascularization (ClinicalTrials.govNCT01528709).

Regional versus local anesthesia for arteriovenous fistula creation in end-stage renal disease: a systematic review and meta-analysis.

There is a consensus in the literature that regional anesthesia (RA) improves local hemodynamic parameters in comparison to local anesthesia (LA) during arteriovenous fistula (AVF) surgical construction. However, the effects of both techniques on fistula patency and failure rates are still controversial. The aim of this meta-analysis is to synthesize evidence from published randomized trials and observational studies regarding the safety and efficacy of RA versus LA in AVF surgical construction. A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central retrieved six randomized trials (462 patients) and one retrospective study (408 patients). Pooling data using RevMan software (version 5.3) showed that RA was superior to LA in terms of primary fistula patency rate (RR = 1.22, 95% CI [1.08, 1.37], p = 0.0010); however, both types were comparable in terms of primary fistula failure rate (RR = 0.81, 95% CI [0.47, 1.40], p = 0.46). In comparison to LA, RA was associated with improved hemodynamic parameters including fistula blood flow (MD = 25.08, 95% CI [19.40, 30.76], p<0.00001), brachial artery diameter (SMD = 2.63, 95% CI [2.17, 3.08], p<0.00001), and outflow venous diameter (SMD = 0.93, 95% CI [0.30, 1.75], p = 0.004). Postoperative complications were comparable between both groups (OR = 0.23, 95% CI [0.05, 0.97], p = 0.05). In conclusion, RA was associated with higher primary patency rates of AVF and improved local blood flow in comparison to LA; however, both procedures were comparable in terms of primary failure rates and postoperative complications. Larger well-designed trials with longer follow-up periods should compare both techniques in terms of long-term patency rates and safety outcomes.

General, regional or local anesthesia for successful radial cephalic arteriovenous fistula.

Autogenous fistulas and in particular radiocephalic fistulas are recommended as the first vascular access for hemodialysis. Unfortunately, the rates of early failure and non-maturation are very high. For more than a decade, brachial plexus block has been proposed as the anesthesia of choice for fistula creation due to its beneficial sympathectomy-like effect, causing vasodilation and attenuation of spasm. Until recently, there was not a single randomized clinical study supporting this proposition. Because performing regional anesthesia is time-consuming and requires expertise, many surgeons prefer local or general anesthesia for vascular access surgery. However, in August 2016 a randomized clinical trial was published showing that regional anesthesia significantly reduces early failure and improves primary and functional patency at 3 months compared to local anesthesia. The aging of the dialysis population, with their attendant morbidity and increased risk for general anesthesia, makes it clear that regional anesthesia is the recommended approach for fistula creation. The excess time required for this approach will decrease with increasing expertise along the learning curve, and will be compensated by a reduction in time that would otherwise be needed for new access construction due to failure of fistulas constructed under local anesthesia.

Percutaneous Coronary Intervention in Native Coronary Arteries Versus Bypass Grafts in Patients With Prior Coronary Artery Bypass Graft Surgery: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

OBJECTIVES: The aim of this study was to examine the frequency, associations, and outcomes of native coronary artery versus bypass graft percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass grafting (CABG) in the Veterans Affairs (VA) integrated health care system. BACKGROUND: Patients with prior CABG surgery often undergo PCI, but the association between PCI target vessel and short- and long-term outcomes has received limited study. METHODS: A national cohort of 11,118 veterans with prior CABG who underwent PCI between October 2005 and September 2013 at 67 VA hospitals was examined, and the outcomes of patients who underwent native coronary versus bypass graft PCI were compared. Logistic regression with generalized estimating equations was used to adjust for correlation between patients within hospitals. Cox regressions were modeled for each outcome to determine the variables with significant hazard ratios (HRs). RESULTS: During the study period, patients with prior CABG represented 18.5% of all patients undergoing PCI (11,118 of 60,171). The PCI target vessel was a native coronary artery in 73.4% and a bypass graft in 26.6%: 25.0% in a saphenous vein graft and 1.5% in an arterial graft. Compared with patients undergoing native coronary artery PCI, those undergoing bypass graft PCI had higher risk characteristics and more procedure-related complications. During a median follow-up period of 3.11 years, bypass graft PCI was associated with significantly higher mortality (adjusted HR: 1.30; 95% confidence interval: 1.18 to 1.42), myocardial infarction (adjusted HR: 1.61; 95% confidence interval: 1.43 to 1.82), and repeat revascularization (adjusted HR: 1.60; 95% confidence interval: 1.50 to 1.71). CONCLUSIONS: In a national cohort of veterans, almost three-quarters of PCIs performed in patients with prior CABG involved native coronary artery lesions. Compared with native coronary PCI, bypass graft PCI was significantly associated with higher incidence of short- and long-term major adverse events, including more than double the rate of in-hospital mortality.

Assessment of Novel Anti-thrombotic Fusion Proteins for Inhibition of Stenosis in a Porcine Model of Arteriovenous Graft.

BACKGROUND: Hemodialysis arteriovenous synthetic grafts (AVG) provide high volumetric blood flow rates shortly after surgical placement. However, stenosis often develops at the vein-graft anastomosis contributing to thrombosis and early graft failure. Two novel fusion proteins, ANV-6L15 and TAP-ANV, inhibit the tissue factor/factor VIIa coagulation complex and the factor Xa/factor Va complex, respectively. Each inhibitor domain is fused to an annexin V domain that targets the inhibitor activity to sites of vascular injury to locally inhibit thrombosis. This study's objective was to determine if these antithrombotic proteins are safe and effective in inhibiting AVG stenosis. METHODS: A bolus of either TAP-ANV or ANV-6L15 fusion protein was administered intravenously immediately prior to surgical placement of a synthetic graft between the external jugular vein and common carotid artery in a porcine model. At surgery, the vein and artery were irrigated with the anti-thrombotic fusion protein. Control animals received intravenous heparin. At 4 weeks, MRI was performed to evaluate graft patency, the pigs were then euthanized and grafts and attached vessels were explanted for histomorphometric assessment of neointimal hyperplasia at the vein-graft anastomosis. Blood was collected at surgery, immediately after surgery and at euthanasia for serum metabolic panels and coagulation chemistries. RESULTS: No acute thrombosis occurred in the control group or in either experimental group. No abnormal serum chemistries, activated clotting times or PT, PTT values were observed after treatment in experimental or control animals. However, at the vein-graft anastomosis, there was no difference between the control and experimental groups in cross-sectional lumen areas, as measured on MRI, and no difference in hyperplasia areas as determined by histomorphometry. These results suggest that local irrigation of TAP-ANV or ANV-6L15 intra-operatively was as effective in inhibiting acute graft thrombosis as intravenous administration of heparin, but failed to inhibit hyperplasia development and stenosis in AVG.

Staple aneurysmorrhaphy to salvage autogenous arteriovenous fistulas with aneurysm-related complications.

OBJECTIVE: Aneurysm-related complications could lead to loss of a functioning arteriovenous fistula (AVF). We report our midterm and long-term results with the staple aneurysmorrhaphy technique to repair and preserve aneurysmal AVFs. METHODS: We retrospectively reviewed our surgical treatment of patients with aneurysmal autogenous AVF complicated by skin erosion, bleeding, infection, pain, and difficulty with needle access from 2007 through 2014. We identified 52 patients, 40 (77%) of whom underwent repair with the staple aneurysmorrhaphy technique. The operation involved mobilizing the entire aneurysmal segments. A TA (Covidien, Norwalk, Conn) or Endo GIA (Covidien, Mansfield, Mass) stapler was used to resect the redundant aneurysm wall to create a 6- to 8-mm-diameter conduit. A subcutaneous skin flap was created after excising compromised skin. The remodeled vein was repositioned underneath the subcutaneous flap, with the staple line rotated laterally to avoid needle puncture. RESULTS: We attempted staple aneurysmorrhaphy in 40 patients with complicated AVF aneurysms, of which 38 repairs (95%) were successful. Median patient age was 66 years (range, 29-88 years). Median AVF age was 63 months (range, 12-136 months). Median follow-up was 20 months (range, 5-81 months). At 1 year, primary patency was 67%, assisted primary patency was 88%, and secondary patency was 91%. At 2 years, primary patency was 59%, assisted primary patency was 84%, and secondary patency was 91%. At 3 years, primary patency was 46%, assisted primary patency was 69%, and secondary patency was 85%. Surgery was performed under local-regional anesthesia in 28 patients (70%) and under general anesthesia in the remaining 12 (30%). Proximal venous outflow stenoses were detected in 19 of 40 AVFs (48%) preoperatively and in 11 of 38 AVFs (29%) postoperatively. Aneurysm recurrence occurred in two repaired AVFs. CONCLUSIONS: Our experience with staple aneurysmorrhaphy shows that it is an effective, safe, and durable procedure to preserve a functioning autogenous AVF with complicated aneurysmal degeneration. Key principles are to reduce the vein to normal adjacent diameter and to provide healthy skin coverage. The remodeled AVF has a low aneurysm recurrence rate and maintains the beneficial properties of superior patency and low infection. It is important to aggressively monitor for and treat proximal outflow venous stenoses to prevent aneurysm recurrence. The surgery can be done safely under local anesthesia in selected patients.

Does regional compared to local anaesthesia influence outcome after arteriovenous fistula creation?

BACKGROUND: An arteriovenous fistula is the optimal form of vascular access in patients with end-stage renal failure requiring haemodialysis. Unfortunately, approximately one-third of fistulae fail at an early stage. Different anaesthetic techniques can influence factors associated with fistula success, such as intraoperative blood flow and venous diameter. A regional anaesthetic brachial plexus block results in vasodilatation and improved short- and long-term fistula flow compared to the infiltration of local anaesthetic alone. This, however, has not yet been shown in a large trial to influence long-term fistula patency, the ultimate clinical measure of success.The aim of this study is to compare whether a regional anaesthetic block, compared to local anaesthetic infiltration, can improve long-term fistula patency. METHODS: This study is an observer-blinded, randomised controlled trial. Patients scheduled to undergo creation of either brachial or radial arteriovenous fistulae will receive a study information sheet, and consent will be obtained in keeping with the Declaration of Helsinki. Patients will be randomised to receive either: (i) an ultrasound guided brachial plexus block using lignocaine with adrenaline and levobupivicaine, or (ii) local anaesthetic infiltration with lignocaine and levobupivicaine.A total of 126 patients will be recruited. The primary outcome is fistula primary patency at three months. Secondary outcomes include primary patency at 1 and 12 months, secondary patency and fistula flow at 1, 3 and 12 months, flow on first haemodialysis, procedural pain, patient satisfaction, change in cephalic vein diameter pre- and post-anaesthetic, change in radial or brachial artery flow pre- and post-anaesthetic, alteration of the surgical plan after anaesthesia as guided by vascular mapping with ultrasound, and fistula infection requiring antibiotics. CONCLUSIONS: No large randomised controlled trial has examined the influence of brachial plexus block compared with local anaesthetic infiltration on the long-term patency of arteriovenous fistulae. If the performance of brachial plexus block increases fistulae patency, this will have significant clinical and financial benefits as the number of patients able to commence haemodialysis when planned should increase, and the number of "redo" or revision procedures should be reduced. TRIAL REGISTRATION: This study has been approved by the West of Scotland Research Ethics Committee 5 (reference no. 12/WS/0199) and is registered with the ClinicalTrials.gov database (reference no. NCT01706354).

Treatment of hemodialysis vascular access rupture irresponsive to prolonged balloon tamponade: retrospective evaluation of the effectiveness of N-butyl cyanoacrylate seal-off technique.

OBJECTIVE: The current study retrospectively evaluated whether the percutaneous N-butyl cyanoacrylate (NBCA) seal-off technique is an effective treatment for controlling the angioplasty-related ruptures, which are irresponsive to prolonged balloon tamponade, during interventions for failed or failing hemodialysis vascular accesses. MATERIALS AND METHODS: We reviewed 1588 interventions performed during a 2-year period for dysfunction and/or failed hemodialysis vascular access sites in 1569 patients. For the angioplasty-related ruptures, which could not be controlled with repeated prolonged balloon tamponade, the rupture sites were sealed off with an injection of a glue mixture (NBCA and lipiodol), via a needle/needle sheath to the rupture site, under a sonographic guidance. Technical success rate, complications and clinical success rate were reported. The post-seal-off primary and secondary functional patency rates were calculated by a survival analysis with the Kaplan-Meier method. RESULTS: Twenty ruptures irresponsive to prolonged balloon tamponade occurred in 1588 interventions (1.3%). Two technical failures were noted; one was salvaged with a bailout stent-graft insertion and the other was lost after access embolization. Eighteen accesses (90.0%) were salvaged with the seal-off technique; of them, 16 ruptures were completely sealed off, and two lesions were controlled as acute pseudoaneurysms. Acute pseudoaneurysms were corrected with stentgraft insertion in one patient, and access ligation in the other. The most significant complication during the follow-up was delayed pseudoaneurysm, which occurred in 43.8% (7 of 16) of the completely sealed off accesses. Delayed pseudoaneurysms were treated with surgical revision (n = 2), access ligation (n = 2) and observation (n = 3). During the follow-up, despite the presence of pseudoaneurysms (acute = 1, delayed = 7), a high clinical success rate of 94.4% (17 of 18) was achieved, and they were utilized for hemodialysis at the mean of 411.0 days. The post-seal-off primary patency vs. secondary patency at 90, 180 and 360 days were 66.7 ± 11.1% vs. 94.4 ± 5.4%; 33.3 ± 11.1% vs. 83.3 ± 8.8%; and 13.3 ± 8.5% vs. 63.3 ± 12.1%, respectively. CONCLUSION: Our results suggest that the NBCA seal-off technique is effective for immediate control of a venous rupture irresponsive to prolonged balloon tamponade, during interventions for hemodialysis accesses. Both high technical and clinical success rates can be achieved. However, the treatment is not durable, and about 40% of the completely sealed off accesses are associated with developed delayed pseudoaneurysms in a 2-month of follow-up. Further repair of the vascular tear site, with surgery or stent-graft insertion, is often necessary.

Treatment of Hemodialysis Vascular Access Rupture Irresponsive to Prolonged Balloon Tamponade: Retrospective Evaluation of the Effectiveness of N-Butyl Cyanoacrylate Seal-Off Technique

OBJECTIVE: The current study retrospectively evaluated whether the percutaneous N-butyl cyanoacrylate (NBCA) seal-off technique is an effective treatment for controlling the angioplasty-related ruptures, which are irresponsive to prolonged balloon tamponade, during interventions for failed or failing hemodialysis vascular accesses. MATERIALS AND METHODS: We reviewed 1588 interventions performed during a 2-year period for dysfunction and/or failed hemodialysis vascular access sites in 1569 patients. For the angioplasty-related ruptures, which could not be controlled with repeated prolonged balloon tamponade, the rupture sites were sealed off with an injection of a glue mixture (NBCA and lipiodol), via a needle/needle sheath to the rupture site, under a sonographic guidance. Technical success rate, complications and clinical success rate were reported. The post-seal-off primary and secondary functional patency rates were calculated by a survival analysis with the Kaplan-Meier method. RESULTS: Twenty ruptures irresponsive to prolonged balloon tamponade occurred in 1588 interventions (1.3%). Two technical failures were noted; one was salvaged with a bailout stent-graft insertion and the other was lost after access embolization. Eighteen accesses (90.0%) were salvaged with the seal-off technique; of them, 16 ruptures were completely sealed off, and two lesions were controlled as acute pseudoaneurysms. Acute pseudoaneurysms were corrected with stentgraft insertion in one patient, and access ligation in the other. The most significant complication during the follow-up was delayed pseudoaneurysm, which occurred in 43.8% (7 of 16) of the completely sealed off accesses. Delayed pseudoaneurysms were treated with surgical revision (n = 2), access ligation (n = 2) and observation (n = 3). During the follow-up, despite the presence of pseudoaneurysms (acute = 1, delayed = 7), a high clinical success rate of 94.4% (17 of 18) was achieved, and they were utilized for hemodialysis at the mean of 411.0 days. The post-seal-off primary patency vs. secondary patency at 90, 180 and 360 days were 66.7 +/- 11.1% vs. 94.4 +/- 5.4%; 33.3 +/- 11.1% vs. 83.3 +/- 8.8%; and 13.3 +/- 8.5% vs. 63.3 +/- 12.1%, respectively. CONCLUSION: Our results suggest that the NBCA seal-off technique is effective for immediate control of a venous rupture irresponsive to prolonged balloon tamponade, during interventions for hemodialysis accesses. Both high technical and clinical success rates can be achieved. However, the treatment is not durable, and about 40% of the completely sealed off accesses are associated with developed delayed pseudoaneurysms in a 2-month of follow-up. Further repair of the vascular tear site, with surgery or stent-graft insertion, is often necessary.

Ultrasound-guided angioplasty of autogenous arteriovenous fistulas in the office setting.

OBJECTIVE: There has been an increasing awareness of the superiority of native arteriovenous fistulas (AVFs) over prosthetic grafts for dialysis access. Many AVFs fail to mature, however, and others develop stenosis while in use. There is growing experience in treating these patients in the interventional suite with percutaneous balloon angioplasty. These procedures, however, are expensive, uncomfortable, and inconvenient for patients and physicians, and involve exposure to radiation and intravenous contrast in patients who are often not on dialysis. This study reviews our experience with ultrasound-guided angioplasty of AVFs in the office setting. METHODS: A retrospective review was performed of all patients treated in our practice with ultrasound-guided AVF angioplasty, from May 2009 to April 2011. The need for intervention was determined by examination and duplex ultrasound. All patients referred to the practice with failing or nonmaturing AVFs were treated in the office under ultrasound guidance, unless a central venous stenosis was suspected. All procedures were performed with the patient under local anesthesia by a single surgeon, and preprocedure, periprocedure, and postprocedure ultrasounds were performed in a single vascular laboratory. RESULTS: There were 31 AVFs in 30 patients in the study. Fifty-five interventions were performed, 48 for AVFs failing to mature and seven for stenosis in functioning AFVs. The 90-day patency was 93%. The overall complication rate was 11%. Two patients had proximal stenosis that could not be crossed (one patient required surgical revision and one patient refused further treatment and thrombosed). There were four perifistular hematomas; three of these resulted in AFV thrombosis. No patients required hospitalization or urgent surgical intervention. Eighty-five percent of patients treated for AVF failing to mature achieved a functional fistula. CONCLUSIONS: AVF intervention can be performed safely and effectively under ultrasound guidance in the office setting and is a valuable tool in the management of dialysis access patients.

Bare-metal stent thrombosis after noncardiac surgery greater than 10 years after stent implantation.

We present a case of bare-metal stent thrombosis (ST) in a saphenous vein graft (SVG) after antiplatelet therapy cessation occurring in the setting of noncardiac surgery (NCS) greater than 10 years after stent implantation. This report represents the longest interval of ST in the setting of NCS and the longest interval between stent implantation and ST in a SVG.

Microsurgical complications in the upper extremity.

Although many advances have been made in microsurgery, it is not without complications. As microsurgeons continue to make advances in technology, technique, and applications that expand the utility of this field to more and more patients, they must be prepared to deal with the complications related to donor and recipient sites and the medical comorbidity that accompanies these large endeavors in the pre-, post-, and intraoperative periods.

Some old drugs improve late primary patency rate of native arteriovenous fistulas in hemodialysis patients.

Vascular access failure causes 20% of all hospitalizations of dialysis patients. Native arteriovenous fistulas, the best type of dialysis vascular access, have a 1-year primary patency rate that is extremely variable, ranging 40-80%. Neointimal hyperplasia is the most important cause of arteriovenous fistula late primary dysfunction. In recent years the arteriovenous fistula late primary patency rate has not improved because of the increase of old uremic patients with a high number of comorbidities and the lack of new therapeutic interventions. Therefore, we performed a long-term case-control study to analyze which factors or drugs may affect native arteriovenous fistula late primary patency rate in 60 incident hemodialysis patients. The arteriovenous fistula late primary patency rate was 75.1% after 12 months, 58.5% after 24 months, and 50% after 987 days. Homocysteine levels during follow-up had a significant direct association with vascular access failure (event vs. event-free 28.5+/-1.9 vs. 22.3+/-1.2 micromol/L, p<0.01). Folate values had a trend toward an inverse relationship with arteriovenous fistula failure (event vs. event-free 11.5+/-1.2 vs. 14.6 vs. 1.1 ng/mL, p=0.06). Patients treated with folic acid and/or statin had an arteriovenous fistula late primary patency rate significantly higher than patients without folic acid and statin therapy, respectively, 81.7% vs. 66% after 1 year and 71.5% vs. 39.1% after 2 years (p=0.02). Many other factors were not associated with vascular access failure. Statin and homocysteine-lowering folic acid therapy is associated with prolonged arteriovenous fistula survival. It is important to perform randomized trials to verify our observation.

Massaging thrombosed PTFE hemodialysis access graft - recipe for disaster.

Early thrombosis of a polytetrafluoroethylene (PTFE) graft used for hemodialysis vascular access can result from technical error or hypotension and hypovolaemia in the immediate postoperative period. Massaging a graft to dislodge a freshly formed thrombus with a view to restoring blood flow can lead to acute limb ischaemia from embolisation of the artery as a result of migration of the thrombus from the arterial end of the graft, hence massaging of thrombosed grafts should be avoided. This report describes the management of a 35-year-old diabetic male who developed acute ischaemia of hand due to embolisation of the radial artery following massage of a thrombosed brachio-basilic forearm PTFE loop graft.

Intravascular magnetic resonance/radiofrequency may enhance gene therapy for prevention of in-stent neointimal hyperplasia.

RATIONALE AND OBJECTIVES: We evaluated the potential of using intravascular magnetic resonance (MR)/radiofrequency (RF) to enhance vascular endothelial growth factor (VEGF) gene therapy of in-stent neointimal hyperplasia. MATERIALS AND METHODS: By using a catheter-based approach, VEGF/lentivirus was locally transferred into 10 (five paired) bilateral femoral-iliac arteries of five hypercholesterolemic pigs, whereas the right arteries were heated up to approximately 41 degrees C by using an intravascular MR/RF system. Then, identical stents were placed immediately into the bilateral VEGF-targeted arteries to create in-stent neointimal hyperplasia. At day 60 after gene/stent interventions, the targeted arteries were harvested for histological correlation. RESULTS: X-Ray angiography-detectable in-stent stenoses were found in three of the arteries treated with VEGF genes only, whereas there were no in-stent stenoses in arteries treated by using MR/RF-heated VEGF genes. Correlative histological examination confirmed a 138% reduction in average thickness of neointimal hyperplasia in VEGF/RF-treated arteries compared with VEGF-only-treated arteries (P < .01). CONCLUSION: We report a potential method of using an intravascular MR/RF heating technique to enhance gene therapy of in-stent restenosis.

Use of the implantable cardioverter-defibrillator in long-term survivors of orthotopic heart transplantation.

BACKGROUND: Orthotopic heart transplantation is considered an effective treatment for patients with refractory heart failure. The long-term survival of orthotopic heart transplantation recipients has increased over the last several decades, but many long-term survivors of orthotopic heart transplantation develop graft atherosclerosis and associated left ventricular dysfunction. The risk of sudden cardiac death in long-term survivors of orthotopic heart transplantation with these complications is believed to be high. There are no data on the usefulness of implantable cardioverter-defibrillators (ICDs) in this population; therefore, we report our early experience with ICD placement in such patients. OBJECTIVES: The purpose of this study was to examine the use of ICDs in adults who are long-term survivors of heart transplantation. METHODS: We retrospectively reviewed all adult patients who underwent orthotopic heart transplantation at Stanford University Hospital (Stanford, CA, USA) from 1980 to 2004. All patients who received an ICD after transplant were included in this study. We reviewed demographic data, medical history, ejection fraction, presence of graft atherosclerosis, indication for ICD placement, and any device therapy delivered. RESULTS: Of the 925 patients who had orthotopic heart transplantation during this time period, 493 patients were alive at the beginning of the year 2000. Of these patients, 10 ( approximately 2%) had subsequent placement of an ICD. All 10 patients were male. The average age at orthotopic heart transplantation was 37.8 years. The average age at ICD placement was 50.5 years. The average time from orthotopic heart transplantation to ICD placement was 14.6 years. The average ejection fraction at the time of implant was 46.5%. Five of the 10 patients had a low ejection fraction (within this subgroup, the average ejection fraction was 31%, range 15%-45%) and graft atherosclerosis. ICDs were placed because of symptomatic episodes of ventricular tachycardia (3 patients), low ejection fraction and severe graft atherosclerosis without symptoms (3 patients), and after thorough evaluation for otherwise unexplained syncope (4 patients). The average follow-up after device implantation was 13 months. Complications related to ICD placement were an infected ICD system requiring explant in one patient and a lead fracture in another patient. Three patients had subsequent appropriate shocks for ventricular arrhythmias, and one patient underwent a second orthotopic heart transplantation. One patient died of malignancy. CONCLUSION: Use of the ICD in long-term survivors of orthotopic heart transplantation should be considered in appropriately selected patients. Further data are needed regarding ICD use in this population.

Endarterectomia de carótida sob anestesia local: evolução de 104 pacientes / Carotid endarterectomy under regional anesthesia: follow-up of 104 patients

A estenose carotídea cervical é uma das causas mais freqüentes de acidente vascular cerebral isquêmico. A endarterectomia de carótida é um tratamento eficaz para lesões estenóticas moderadas e graves, tanto sintomáticas quanto assintomáticas. A endarterectomia realizada sob anestesia local permite a monitorização neurológica do paciente durante o ato cirúrgico. O objetivo deste trabalho foi avaliar as complicações cirúrgicas e acompanhar a evolução dos pacientes submetidos a endarterectomia sob anestesia local em nossa instituição, comparando os resultados com outras publicações. 104 pacientes foram submetidos a 110 procedimentos no período de abril de 1996 a maio de 2002. 64 pacientes eram sintomáticos (61,54 por cento) e 40 assintomáticos (38,46 por cento). Todos possuíam grau de estenose carotídea igual ou superior a 70 por cento. Os pacientes foram avaliados retrospectivamente. O tempo de evolução variou de um a 72 meses (média: 29,5). Três pacientes apresentaram hematoma cervical necessitando drenagem cirúrgica. Dois pacientes (1,92 por cento) tiveram acidente vascular cerebral do mesmo lado da endarterectomia no pós-operatório e outros dois durante o seguimento. Dois pacientes faleceram em decorrência da cirurgia (1,92 por cento). Os resultados desta série, comparados com a literatura, permitem concluir que a endarterectomia é uma forma segura de tratamento para as estenoses carotídeas moderadas e graves.