Multi-perspective ultrasound evaluation of Carotid Intima-Media thickness in hemodialysis access patients and its possible use to predict clinical outcomes.

BACKGROUND: Hemodialysis (HD) patients present an increased carotid intima-media thickness (CIMT) and calcified plaques, and studies have demonstrated that CIMT is predictor for cardiovascular death in this patient population; hence, the importance of identifying early non-invasive markers of atherosclerosis. We aim to propose a new three-perspective CIMT measuring method in HD population, and to further investigate the possible use and value of this method to predict outcomes. METHODS: A cross-sectional study was conducted, the CIMT was measured with duplex ultrasound during the perioperative access planning. Software provided maximum CIMT in a 10 mm (mm) width of the common carotid artery. CIMT was measured in Right (R) and Left (L) carotid arteries, both in anterior (a), lateral (l), and posterior (p) view. The sum of these values (Ra+Rl+Rp+La+Ll+Lp) was completed and termed as Sixth Carotid Intimal (SCI) score. We stratified either in low (summation <4) or high (>=4) SCI score groups. Demographics, patency rates, complications, and mortality were collected; chi-square test was used for our analysis. RESULTS: A total of 30 patients (mean age 49 years and 56% females) that underwent access creation in the upper arm from 2010 to 2016 were selected and studied. A low SCI score was found 19 patients and 11 had high SCI, no significant difference was observed in demographics, history cardiovascular disease, and clinical outcomes as early thrombosis, and primary, primary-assisted patency at 12 months. Interestingly, during the follow up period of 36 months a significant higher difference in late thrombosis rates occurred (63.6% vs 26.3%, p = .044) and a higher all-cause mortality (54.4% vs 15.7%, p = .025) in patients with SCI score group above 4. CONCLUSIONS: The SCI score method, might offer a screening tool for traditional cardiovascular risk factors in HD patients. In this study, we demonstrate an increased rate in late thrombosis and mortality in those with high SCI. Further research is necessary to better define the role of CIMT in vascular surgical procedures.

A novel approach to autogenous hemodialysis access: paired brachial vein transposition in series.

Autogenous arteriovenous fistula (AVF) creation is the preferred method for long-term hemodialysis access. This report describes the novel use of paired brachial veins for the creation of an autogenous AVF in a patient without a traditional superficial venous conduit available. Application of this general concept might serve to expand the options for autogenous AVF creation.

Endovascular treatment of type 3 and 4 thoracic central vein obstruction in hemodialysis patients.

OBJECTIVE: Thoracic central vein (TCV) obstruction (TCVO) in the presence of upper extremity (UE) hemodialysis access can present as superior vena cava syndrome (SVCS) and cause vascular access dysfunction and failure. We report the techniques and results of endorevascularization of TCVO in hemodialysis patients, which allowed for long-term functioning vascular access in the UE. METHODS: From June 2009 to February 2020, 45 hemodialysis patients underwent TCV endorevascularization. The indications for surgery were TCVO or SVCS that threatened the function of a preexisting upper arm access or contraindicated placement of a new upper arm access. Conventional endovascular techniques were used when feasible. Patients with unfavorable anatomy were treated using a transseptal needle to cross difficult intrathoracic stenosis and occlusions or to facilitate an inside-out central venous access technique. The reestablishment of venous outflow was accomplished with angioplasty, stenting, and/or placement of HeRO conduits. Successful revascularization was followed by hemodialysis access revision or a new UE access placement. We recorded the risk factors and procedural outcomes, patency rates, complications, and mortality. RESULTS: The mean age was 53 ± 16.3 years, and 51% were women. The most common risk factors were diabetes mellitus (64.2%) and hypertension (56%). Twenty-five patients (55.5%) had symptoms of SVCS. These symptoms resolved after the TCV procedure in all cases. Crossing of the TCV lesion was successful using a conventional catheter and wire in 26 cases (57.8%) and transseptal needle in 17 cases (37.8%), including 12 using an inside-out central venous access technique. Treatment of the TCV lesion included a HeRO conduit in 20 cases (44.4%), stenting in 17 (37.7%), and transluminal balloon angioplasty alone in 7 (15.5%). Other veins were treated in 33 cases (73.3%). The overall technical success rate was 95.5%. Two intraoperative complications occurred, including one case of severe hypotension and one of fatal cardiac tamponade. Of the 16 patients with preexisting UE access, its function was preserved in all 16 (100%). In 24 of 27 patients (85.7%), new arm access was successfully created after the TCV procedure. The overall clinical success rate was 88.9%. The average follow-up was 663.4 days (median, 507 days; range, 0-2679 days). During follow-up, 26 patients had undergone 90 procedures to maintain access function, 21 had undergone repeat endovascular interventions, and 17 had undergone open procedures. Eight patients (17.8%) had developed infection, five involving HeRO conduits that required excision with loss of access. During the follow-up period, 14 patients (31%) had died of unrelated causes, and 34 patients (75.5%) maintained functional access. CONCLUSIONS: The results of the present study have shown that endorevascularization of TCVO reconstruction is effective in maintaining function or allowing the creation of UE hemodialysis access, with acceptable complication rates.

Comparison of axillary-atrial and axillary-iliac arteriovenous grafts for hemodialysis access creation.

OBJECTIVE: The aim of this study was to compare two complex vascular access techniques that utilize the axillary artery as inflow and accesses were created with early cannulation grafts: the axillary-atrial arteriovenous graft versus axillary-iliac arteriovenous graft. METHODS: This is a retrospective study of end-stage renal disease patients with occluded intrathoracic central veins that underwent complex hemodialysis access creation in our institution after failed endovascular recanalization attempts. Patients' demographics, comorbidities, number and types of previous accesses, intraoperative variables, and clinical outcomes were collected and compared. RESULTS: Four patients underwent axillary-atrial arteriovenous graft creation with Flixene™ (Atrium™, Hudson, NH, USA) grafts, through a midline sternotomy to expose the right atrium; all were successfully implanted and used for hemodialysis within the first 72 h; one patient developed a pseudoaneurysm in the mid-graft portion, requiring surgical repair, and it is currently functional. Eight axillary-iliac arteriovenous grafts were created; all grafts were patent and were utilized within 96 h after placement. At 6 months of follow-up period, five (62 %) of our patients underwent graft thrombectomy, one (12 %) balloon angioplasty at the vein anastomosis secondary to stenosis, and two (25 %) grafts were removed due to infectious complications. Axillary-atrial arteriovenous graft and axillary-iliac arteriovenous graft primary patency rates at 6 months were 75% and 48%, respectively; 6-month secondary patency of the axillary-atrial arteriovenous graft compares favorably against that of axillary-iliac arteriovenous graft (100% vs 75%, respectively). CONCLUSION: Despite the invasiveness, direct atrial outflow procedures remain a valid alternative in carefully selected patients with adequate cardiopulmonary reserve.

Brachial vein transposition: an alternative to hemodialysis arteriovenous graft.

BACKGROUND: There is currently a worldwide effort to increase the options for autogenous hemodialysis access. OBJECTIVES: To evaluate patency and complications of brachial vein transposition compared to other autogenous hemodialysis accesses. METHODS: A retrospective evaluation of 43 patients and 45 procedures. Patients who did not have adequate superficial veins according to duplex scanning were allocated to brachial vein transposition. The sample was thus divided in two groups, as follows: A: brachial vein transposition n=10 and B: other autogenous accesses n=35. RESULTS: There were no statistical differences between the two groups in terms of age diabetes, systemic arterial hypertension, dyslipidemias, arteriopathies, neoplasms, kidney disease stage, donor artery diameter, recipient vein diameter, systolic blood pressure in the operated limb, postoperative ischemia, hematoma, or infection. There were no statistical differences in terms of patency on day 7: A 80% vs. B 90% p=0.6, on day 30: A 80% vs. B 86% p=0.6, or on day 60: A 60% vs. B 80% p=0.22. There were statistical differences between the groups for number of previous fistulae A 1.0 ± 0.44 vs. B 0.6 ± 0.3 p = 0.04 and upper limb edema A: 20% x B 0% p = 0.04. A vein with diameter of less than 3 mm was associated with an increased risk of early occlusion (RR = 8 p = 0.0125). During the study period there were no procedures using grafts. CONCLUSIONS: Transposition of brachial vein is an alternative to arteriovenous graft.