A Prospective Multicenter Randomized Controlled Trial for Comparing Drug-Coated and Conventional Balloon Angioplasty in Venous Anastomotic Stenosis of Hemodialysis Arteriovenous Grafts.

PURPOSE: To evaluate the efficacy and safety of drug-coated balloon angioplasty compared to conventional balloon angioplasty in the treatment of dysfunctional arteriovenous grafts. MATERIALS AND METHODS: This prospective, multicenter, randomized clinical trial enrolled 190 patients with venous anastomotic stenosis in arteriovenous grafts at five participating hospitals. During pre-dilation, 4 patients dropped out due to ruptures requiring further treatment (n = 2) and residual stenosis of > 30% (n = 2). On successful pre-dilation with a 7 mm conventional balloon, patients were randomized to undergo either a 7 mm drug-coated balloon (n = 94) or conventional balloon angioplasty (n = 92). The primary out-come measure was target lesion primary patency at 3 and 6 months. The secondary out-come measures included target lesion primary patency at 12 months and access circuit primary patency at 6 and 12 months, clinical and technical success rates, and 12-month mortality differences between the groups. RESULTS: The target lesion primary patency and access circuit patency rates at 3 and 6 months were significantly higher in drug-coated balloon angioplasty group as compared to conventional balloon angioplasty group. The technical and clinical success rates were 100% for both the groups. As a procedure-related complication, anastomotic site rupture occurred during pre-dilation in 4 cases. The number of deaths during the 12-month follow-up was one for each group. The number of early thrombotic events (at < 3 months) was significantly higher in the drug-coated balloon group (p = 0.002). CONCLUSION: Drug-coated balloon angioplasty was more effective and safer for the treatment of dysfunctional arteriovenous grafts compared to conventional balloon angioplasty.

Patency and Durability of Stent Grafts Placed in the Dialysis Circuit Cannulation Zone.

PURPOSE: To investigate the safety, durability, and patency rates of stent grafts (SGs) placed in the cannulation zone of hemodialysis access circuits. MATERIALS AND METHODS: From April 2020 to April 2023, all procedures with SGs placed in the cannulation zone were retrospectively analyzed. A total of 40 patients (25 men and 15 women) with SGs placed in the cannulation zone were included in the study. Mean age of the patients was 70 years. The Covera covered stent (BD, Franklin Lakes, New Jersey) was used in all cases. Of these, 26 were arteriovenous (AV) fistulae and 14 were AV grafts. SGs were placed for residual stenosis, perforation, aneurysm, and thrombosis. Follow-up outcomes were determined using follow-up angiographic images and included primary patency, primary-assisted patency, and secondary patency. RESULTS: The primary patency of the target lesion was 89% (SD ± 5) and 74% (SD ± 8.4) at 6 and 12 months, respectively. The primary-assisted patency was 89% (SD ± 5.2) and 78% (SD ± 7.6) at 6 and 12 months, respectively. Secondary patency of the access circuit was 97% (SD ± 2.5) at both 6 and 12 months. Mean follow-up was 332 days (range, 28-661 days). All SGs were successfully cannulated for hemodialysis. No cases of stent fracture or stent infection were observed during follow-up. CONCLUSIONS: SGs placed for cannulation zone pathologies can be safely cannulated for dialysis and have adequate short- and mid-term patency rates.

Rotational Mechanical Thrombectomy to Treat Iliac Limb Occlusion after Endovascular Aortic Aneurysm Repair: The Rotational Mechanical Thrombectomy Italian Study.

PURPOSE: To assess the safety and effectiveness of a rotational mechanical atherothrombectomy device in patients with symptomatic iliac limb occlusion after abdominal endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: A retrospective analysis was conducted on patients who underwent rotational mechanical thrombectomy using the Rotarex S device for symptomatic acute, subacute, or chronic graft limb thrombosis at 5 vascular centers between 2017 and 2021. This study comprised 23 male patients with a mean age of 74.5 years (SD ± 7.2) at the time of the procedure. The clinical presentation of the patients varied, with 1 patient experiencing acute limb ischemia and 11 patients (47.8%) experiencing disabling intermittent claudication. The remaining patients developed chronic limb-threatening ischemia after iliac limb occlusion. Early outcomes included technical success, postprocedural complications, and periprocedural mortality. Follow-up evaluations encompassed primary patency, patient survival, freedom from reintervention, and the need for surgical conversion. RESULTS: Technical success was achieved in all cases, with no occurrences of distal embolization during or after the procedure, and no periprocedural deaths were reported. Endograft relining was performed in 82.6% of patients to establish a new, nonthrombogenic surface within the graft. Over a median follow-up period of 8 months (interquartile range, 3-16 months), 2 patients experienced iliac limb reocclusion. No deaths or other reinterventions occurred during the observational follow-up period. CONCLUSIONS: Rotational mechanical thrombectomy for iliac limb occlusion after EVAR appears to be both safe and effective. This technique may uncover intraluminal defects contributing to graft occlusion and enable their resolution within the same procedure.

Association between heart failure and arteriovenous access patency in patients with end-stage renal disease on hemodialysis.

BACKGROUND: Heart disease and chronic kidney disease are often comorbid conditions owing to shared risk factors, including diabetes and hypertension. However, the effect of congestive heart failure (CHF) on arteriovenous fistula (AVF) and AV graft (AVG) patency rates is poorly understood. We hypothesize preexisting HF may diminish blood flow to the developing AVF and worsen patency. METHODS: We conducted a single-institution retrospective review of 412 patients with end-stage renal disease who underwent hemodialysis access creation from 2015 to 2021. Patients were stratified based on presence of preexisting CHF, defined as clinical symptoms plus evidence of reduced left ventricular ejection fraction (EF) (<50%) or diastolic dysfunction on preoperative echocardiography. Baseline demographics, preoperative measures of cardiac function, and dialysis access-related surgical history were collected. Kaplan-Meier time-to-event analyses were performed for primary patency, primary-assisted patency, and secondary patency using standard definitions for patency from the literature. We assessed differences in patency for patients with CHF vs patients without CHF, patients with a reduced vs a normal EF, and AVG vs AVF in patients with CHF. RESULTS: We included 204 patients (50%) with preexisting CHF with confirmatory echocardiography. Patients with CHF were more likely to be male and have comorbidities including, diabetes, chronic obstructive pulmonary disease, hypertension, and a history of cerebrovascular accident. The groups were not significantly different in terms of prior fistula history (P = .99), body mass index (P = .74), or type of hemodialysis access created (P = .54). There was no statistically significant difference in primary patency, primary-assisted patency, or secondary patency over time in the CHF vs non-CHF group (log-rank P > .05 for all three patency measures). When stratified by preoperative left ventricular EF, patients with an EF of <50% had lower primary (38% vs 51% at 1 year), primary-assisted (76% vs 82% at 1 year), and secondary patency (86% vs 93% at 1 year) rates than those with a normal EF. Difference reached significance for secondary patency only (log-rank P = .029). AVG patency was compared against AVF patency within the CHF subgroup, with significantly lower primary-assisted (39% vs 87% at 1 year) and secondary (62% vs 95%) patency rates for AVG (P < .0001 for both). CONCLUSIONS: In this 7-year experience of hemodialysis access creation, reduced EF is associated with lower secondary patency. Preoperative CHF (including HF with reduced EF and HF with preserved EF together) is not associated with significant differences in overall hemodialysis access patency rates over time, but patients with CHF who receive AVG have markedly worse patency than those who receive AVF. For patients with end-stage renal disease and CHF, the risks and benefits must be carefully weighed, particularly for those with low EF or lack of a suitable vein for fistula creation.

Non-contrast computed tomography findings for identification of chronically occluded coronary artery bypass grafts.

BACKGROUND: Detecting occlusions of coronary artery bypass grafts using non-contrast computed tomography (CT) series is understudied and underestimated. PURPOSE: To evaluate morphological findings for the diagnosis of chronic coronary artery bypass graft occlusion on non-contrast CT and investigate performance statistics for potential use cases. MATERIAL AND METHODS: Seventy-three patients with coronary artery bypass grafts who had CT angiography of the chest (non-contrast and arterial phases) were retrospectively included. Two readers applied pre-set morphologic findings to assess the patency of a bypass graft on non-contrast series. These findings included vessel shape (linear-band like), collapsed lumen and surgical graft marker without a visible vessel. Performance was tested using the simultaneously acquired arterial phase series as the ground truth. RESULTS: The per-patient diagnostic accuracy for occlusion was 0.890 (95% confidence interval = 0.795-0.951). Venous grafts overall had an 88% accuracy. None of the left internal mammary artery to left anterior descending artery arterial graft occlusions were detected. The negative likelihood ratio for an occluded graft that is truly patent was 0.121, demonstrating a true post-test probability of 97% for identifying a patent graft as truly patent given a prevalence of 20% occlusion at a median 8.4 years post-surgery. Neither years post-surgery, nor number of vessels was associated with a significant decrease in reader accuracy. CONCLUSION: Evaluation of coronary bypass grafts for chronic occlusion on non-contrast CT based off vessel morphology is feasible and accurate for venous grafts. Potential use cases include low-intermediate risk patients with chest pain or shortness of breath for whom non-contrast CT was ordered, or administration of iodine-based contrast is contraindicated.

The Role of Drug-Coated Balloon in Haemodialysis Arteriovenous Fistula Stenosis Management.

Arteriovenous fistula (AVF) stenosis is a common problem leading to dialysis access dysfunction. The conventional balloon (CB) is the most commonly used device during angioplasty but suffers from poor durability of results due to neointimal hyperplasia-mediated recurrence. The drug-coated balloon (DCB) is an adjunct to balloon angioplasty that reduces neointimal hyperplasia, thereby improving post-angioplasty patency. Despite the heterogeneity of DCB clinical trials to date, the evidence suggests that DCBs of different brands are not necessarily equal, and that patient selection, adequate lesion preparation and proper DCB procedural technique are important to realize the benefit of DCB angioplasty.

Factors affecting the primary patency of native arteriovenous fistulas after ultrasound-guided percutaneous transluminal angioplasty.

OBJECTIVE: By analyzing the clinical history, laboratory test indexes, and intraoperative ultrasound imaging data of patients receiving ultrasound-guided percutaneous transluminal angioplasty (UG-PTA) for the first time, the application value of UG-PTA in the treatment of peripheral stenosis of autogenous arteriovenous fistula (AVF) and the related factors affecting postoperative patency were investigated. METHODS: A total of 381 patients with dysfunction of radio-cephalic AVF were treated with UG-PTA from June 2017 to September 2019. According to the inclusion and exclusion criteria, 199 patients were included in this study. Baseline characteristics of patients, including demographic, clinical, and laboratory data, were collected. Kaplan-Meier's survival curve was used to demonstrate the cumulative primary patency rate of UG-PTA. Univariate and multivariate Cox regression analysis was performed on clinical, anatomic, biochemical, and medication variables to identify the predictors of postintervention primary patency. RESULTS: The early technical success rate of UG-PTA was 98.4% (375/381). One hundred and ninety-nine patients, with an average age of 52.9 years, were analyzed, 97 of whom were males (48.7%). The median follow-up duration was 21 months. No major complication was observed. Postintervention primary patency rates were 87.7%, 75.8%, and 60.0% at 6, 12, and 24 months, respectively. A previously failed AVF (HR, 1.935, 95% CI 1.071-3.494; p = .029) and an increased level of parathyroid hormone (HR per 100 pg/mL increase, 1.105; 95% CI 1.014-1.203; p = .004) were identified as independent negative predictors of primary patency of UG-PTA. CONCLUSIONS: UG-PTA is a safe and effective method for the treatment of peripheral stenosis of AVF. Previously failed AVF and elevated parathyroid hormone levels are associated with lower primary patency rate.

A Retrospective Evaluation of Intra-Prosthetic Thrombus Formation After Endovascular Aortic Repair in Cook Zenith Alpha and Medtronic Endurant II Patients.

OBJECTIVE: To investigate the occurrence of limb graft occlusion (LGO) and intra-prosthetic thrombus (IPT) formation in Zenith Alpha and Endurant II stent graft limbs. METHODS: A single centre retrospective study was conducted on patients treated with the Zenith Alpha and Endurant II stent grafts between 2017 and 2019. All post-operative computed tomography angiography images were re-investigated for thrombus formation. Demographic, aneurysm, and stent graft data were collected and compared. LGO was defined as complete occlusion or significant stenosis (≥ 50% lumen diameter reduction). Logistic regression on pro-thrombotic risk factors was conducted. Freedom from LGO and overall limb IPT were compared using Kaplan-Meier analyses. RESULTS: Seventy-eight Zenith Alpha and eighty-six Endurant II patients were studied. The median follow up was 33 (IQR 25, 44) months for Zenith Alpha patients and 36 (IQR 22, 46) months for Endurant II patients (p = .53). LGO was seen in 15% (n = 12) of Zenith Alpha patients and 5% (n = 4) of Endurant II patients (p = .032), and freedom from LGO was significantly higher among Endurant II patients (p = .024). The Zenith Alpha stent graft was an independent risk factor for LGO (OR 3.9, 95% CI 1.1 - 13.4; p = .032). Among Zenith Alpha patients, limb flare compression within the main body gate was over represented in LGO patients (p = .011). There was no difference in freedom from overall limb IPT between the stent graft systems. For Endurant II limbs, IPT was significantly less common in the integrated ipsilateral limbs (without ETLW/ETEW stent graft limbs) (p = .044). Main endograft body IPT was correlated with overall limb IPT (p = .035). CONCLUSION: LGO was significantly more common among Zenith Alpha than Endurant II patients. Zenith Alpha limbs was an independent risk factor for LGO. There was no difference between stent grafts in overall limb IPT formation.

Feasibility of Percutaneous Ultrasound Guided Intervention with Direct Access in Failing Infrainguinal Vein Bypass Grafts.

BACKGROUND: Patients with infrainguinal venous bypass grafts are at risk of graft stenosis leading to thrombosis and failure of the graft conduit. When primary assisted reintervention is needed, a common first choice of treatment is percutaneous angioplasty using fluoroscopy and digital subtraction angiography (DSA). We investigated whether percutaneous ultrasound-guided intervention (PUSGI) is feasible for such endovascular reinterventions. METHODS: In this retrospective observational study (feasibility study), we included patients with ultrasound evidence of significant stenosis in below-the-knee vein grafts in the lower extremities. Inclusion period was 18 months. Reinterventions were disrupted by performing PUSGI in between traditional DSA. Perioperative success was defined as no sign of residual stenosis, stenosis at the access point in the vein, or need for further fluoroscopy guided intervention. Patient follow-up was conducted 6 weeks after the intervention. Patency of the procedure was defined as no disease recurrence or signs of ultrasonographic restenosis at follow-up. RESULTS: PUSGI was performed in 17 patients referred for reintervention with imminent failing grafts (12 men, 5 women, age range 52-82 years). PUSGI alone was performed successfully in 10 out of 17 patients (59%). The remaining 7 patients underwent successful revascularization with PUSGI in combination with DSA-guided angioplasty. Periprocedural complications occurred in 4 patients. Two of 17 patients had occluded grafts at 6 weeks of follow-up. No PUSGI access site stenoses in grafts were observed. CONCLUSIONS: Percutaneous ultrasound-guided reintervention in peripheral vein bypass disease is feasible for selected patients. The study provides insight to qualitative criteria of eligibility for PUSGI in such reinterventions with direct conduit access.

Dialysis Access Maintenance: Plain Balloon Angioplasty.

Plain balloon angioplasty remains the first-line treatment for dialysis access stenosis. This chapter reviews the outcomes of plain balloon angioplasty from cohort studies and comparative studies. Angioplasty outcomes are more favourable in arteriovenous fistulae (AVF) compared to arteriovenous grafts (AVG) with primary patency at 6 months ranging from 42-63% compared to 27-61%, respectively, and improved for forearm fistulae compared with upper arm fistulae. Higher pressures are required to treat stenoses in AVFs compared to AVGs. Outcomes are worse in more severe stenoses, increased patient age, previous interventions and fistulae that develop early stenoses. Major complication rates following angioplasty in dialysis access are between 3 and 5%. Repeat treatments and the use of adjuncts such as drug-coated balloons and stents can prolong the patency of dialysis access. Level of Evidence No level of evidence (Review paper).

Antecubital perforating vein stent-grafting for radiocephalic arteriovenous fistula recovery: A case report.

Stent-grafts have been increasingly used in hemodialysis arteriovenous accesses, particularly in recurrent stenosis or in cases of vein rupture after percutaneous transluminal angioplasty (PTA). Although they limit neointimal hyperplasia, stenosis development at stent edges remains a concern. Despite their advantages, they are seldom used on the forearm veins due to fracture risk associated with elbow motion and the potential to limit cannulation sites. This report presents a novel application of stent-grafts in salvaging a radio-cephalic arteriovenous fistula in an 84-year-old male to treat a single outflow path at the elbow through a stenosed antecubital perforating vein, after failed PTA. The vascular access remained patent 18 months after the procedure, with no need for additional treatments at this target lesion, even though a PTA was required for juxta-anastomotic stenosis. This report highlights a possible further use of covered stents in arteriovenous vascular accesses.

A Multicenter Analysis of Revision of Aneurysmal Dialysis Access Using Bovine Carotid Artery Conduit.

BACKGROUND: Dialysis access complications and failure requiring revision are common. Understanding which methods of revision yield the optimal patency rates and lowest complications remain in evolution. Revision of native vessels is preferred, with revision using expanded polytetrafluoroethylene (ePTFE) graft as an alternative. Revision with Bovine Carotid Artery Graft (Artegraft) has historically been indicated when other options have been exhausted. While earlier studies demonstrated lower patency and higher infection rates compared to ePTFE, more recent studies have suggested otherwise. We describe our experience with patients who underwent arteriovenous access revision with Artegraft, and present this as a viable alternative. METHODS: A multicenter analysis was conducted over 6 years of 25 patients with arteriovenous access complications requiring revision. Complications included aneurysmal degeneration, bleeding, recurrent thrombosis, and sclerotic outflow. Patients were grouped into 2 groups based on the complication. The first group included aneurysm-only complication and the second group included aneurysm and all other complications. All patients underwent revision of their arteriovenous fistula with excision of diseased segment of the arteriovenous fistula and interposition placement of Artegraft. All patients were followed long term and assessed for postop complications, patency, and any reintervention. RESULTS: Of 25 patients, 13 were male and 12 female. Average age was 57 (range 27-83). Sixteen of the 25 patients had follow-up. Of the 16, 10 patients had primary patency (62.5%), 3 with primary-assisted patency (18.75%), and 3 with failure of grafts (18.75%). Ten of the 16 had at least 1 year or greater follow-up (5 with primary patency, 3 primary-assisted patency, and 2 with failure both of which failed after 1 year). Those that required intervention to maintain patency were from thrombosis requiring declot or anastomotic stenosis requiring angioplasty. None of the followed patients were found to have neither postoperative surgical site nor graft infections. CONCLUSIONS: This case series supports that arteriovenous access revision with Artegraft is a viable option that has acceptable patency rates (81% overall functional patency rate at 1.5 years), with an observed 0% infection rate, and is comparable to ePTFE. With more recent studies suggesting Artegraft may have superior outcomes, further study and consideration should be given to using Artegraft as a conduit for arteriovenous fistula revision.

Routine Completion Angiography for Infrainguinal Bypasses Using Prosthetic Conduit: No Effect on Postoperative Patency.

BACKGROUND: Recent studies have demonstrated increased postoperative patency with the use of routine completion angiography for bypass using venous conduit. Compared to vein conduits, however, prosthetic conduits are less plagued by technical issues such as unlysed valves or arteriovenous fistulae. The effect of routine completion angiography on bypass patency in prosthetic bypasses has yet to be compared to the more traditional selective use of completion imaging. METHODS: A retrospective review of all infrainguinal bypass procedures using prosthetic conduit completed at a single hospital system from 2001 to 2018 was performed. Demographics, comorbidities, intraoperative reintervention rates, and 30-day rates of graft thrombosis were analyzed. Statistical analysis included t-tests, chi-square tests, and cox regression. RESULTS: Four hundred and ninety-eight bypasses that were performed in 426 patients met inclusion criteria. Fifty-six (11.2%) bypasses were classified into the routine completion angiogram group compared to 442 (88.8%) into the no completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 21.4%. When comparing bypasses that underwent routine completion angiography versus no completion angiography, there were no significant differences in rates of reintervention (3.5% vs. 4.5%, P = 0.74) or graft occlusion (3.5% vs. 4.7%, P = 0.69) at 30-days postoperatively. CONCLUSIONS: Almost one-quarter of lower extremity bypasses using prosthetic conduit that undergo routine completion angiography undergo postangiogram bypass revision; however, this is not associated with an increased graft patency at 30 days postoperatively.

Prospective, randomized, multicenter clinical study comparing a self-expanding covered stent to percutaneous transluminal angioplasty for treatment of upper extremity hemodialysis arteriovenous fistula stenosis.

Use of a covered stent after percutaneous transluminal angioplasty (PTA) was compared to PTA alone for treatment of upper extremity hemodialysis patients with arteriovenous fistula (AVF) stenoses. Patients with AVF stenosis of 50% or more and evidence of AVF dysfunction underwent treatment with PTA followed by randomization of 142 patients to include a covered stent or 138 patients with PTA alone. Primary outcomes were 30-day safety, powered for noninferiority, and six-month target lesion primary patency (TLPP), powered to test whether TLPP after covered-stent placement was superior to PTA alone. Twelve-month TLPP and six-month access circuit primary patency (ACPP) were also hypothesis tested while additional clinical outcomes were observed through two years. Safety was significantly non-inferior while six- and 12-month TLPP were each superior for the covered stent group compared to PTA alone (six months: 78.7% versus 55.8%; 12 months: 47.9% versus 21.2%, respectively). ACPP was not statistically different between groups at six-months. Observed differences at 24 months favored the covered-stent group: 28.4% better TLPP, fewer target-lesion reinterventions (1.6 ± 1.6 versus 2.8 ± 2.0), and a longer mean time between target-lesion reinterventions (380.4 ± 249.5 versus 217.6 ± 158.4 days). Thus, our multicenter, prospective, randomized study of a covered stent used to treat AVF stenosis demonstrated noninferior safety with better TLPP and fewer target-lesion reinterventions than PTA alone through 24 months.

Impact of Revascularization Technique on the Outcomes of Peripheral Graft Revision Procedures.

BACKGROUND: The acute occlusion of a peripheral bypass graft leads to acute limb ischemia (ALI) and threatens the viability of the limb if left untreated. The aim of the present study was to analyze the results of surgical and hybrid revascularization techniques for patients with ALI due to peripheral graft occlusions. METHODS: A retrospective analysis of 102 patients undergoing treatment for ALI due to peripheral graft occlusion between 2002 and 2021 was carried out at a tertiary vascular center. Procedures were classified as surgical when only surgical techniques were used and as hybrid when surgical procedures were combined with endovascular techniques such as balloon or stent angioplasty or thrombolysis. Endpoints were primary and secondary patency and amputation-free survival after 1 and 3 years. RESULTS: Of all patients, 67 met the inclusion criteria, 41 were treated surgically and 26 by hybrid procedures. There were no significant differences in the 30-day patency rate, 30-day amputation rate, and 30-day mortality. The 1- and 3-year primary patency rates were 41.4% and 29.2% overall, respectively; 45% and 32.1% in the surgical group, respectively; and 33.2% and 26.6% in the hybrid group, respectively. The 1- and 3-year secondary patency rates were 54.1% and 35.8% overall, respectively; 52.5% and 34.2% in the surgical group, respectively; and 54.4% and 43.5% in the hybrid group, respectively. The 1- and 3-year amputation-free survival rates were 67.5% and 59.2%, overall, respectively; 67.3% and 67.3% in the surgical group, respectively; and 68.5% and 48.2% in the hybrid group, respectively. There were no significant differences between the surgical and the hybrid groups. CONCLUSIONS: The results of surgical and hybrid procedures after bypass thrombectomy for ALI to eliminate the cause of infrainguinal bypass occlusion are comparable with good midterm results in terms of amputation-free survival. New endovascular techniques and devices need to be established in comparison to the results of these proven surgical revascularization methods.

Outflow Rescue of Elbow-Blockade Forearm Arteriovenous Fistulas: Outcomes of Open Surgical Techniques.

BACKGROUND: Venous scarring at the elbow is a common problem that can cause early and late forearm arteriovenous fistula (AVF) dysfunction in hemodialysis patients. However, any effort to prolong the long-term patency of distal vascular accesses could benefit the patient's survival, maximizing the use of restricted venous patrimony. This study aims to report a single-center experience in the recovery of distal autologous AVF with venous outflow obstruction at the elbow using different surgical techniques. METHODS: Retrospective observational study of all patients treated at a single vascular access center from January 2011 to March 2022, with dysfunctional forearm AVFs presenting with outflow stenosis or occlusions at the elbow treated by open surgery, using 3 different surgical techniques. Demographics and clinically relevant data were collected. Evaluated endpoints included primary, assisted primary, and secondary patency rates at 1 and 2 years. RESULTS: Twenty-three patients with elbow-blocked outflow forearm AVFs have been treated with a mean age of 64 ± 15 years. The majority (96%) had a radiocephalic fistula. The median time from vascular access creation to intervention was 34.5 months (12-216 months). A total of 24 procedures have been performed using 3 different surgical techniques for bypassing the obstructed venous outflow at the elbow. Technical success was achieved in 96% of the surgically treated patients. Primary and secondary patency rates at 1 year were 67.4% and 89.4%, respectively, and 52.9% and 82.0% at 2 years, with a median follow-up of 19 months (6-92 months). CONCLUSIONS: AVFs outflow stenosis or occlusions at the elbow not amenable to endovascular therapy could lead to vascular access abandonment. Our study demonstrates multiple surgical solutions to avoid this adverse outcome. Elbow venous outflow surgical reconstruction seems effective for distal vascular access preservation. Close surveillance is essential for timely endovascular treatment of newly developed stenosis at the venous drainage.

The Effects of Protrusion into the Outflow Vein on Outcomes of Stent Grafts Used to Treat Cephalic Arch Stenoses in Dysfunctional Brachiocephalic Fistulae.

PURPOSE: To assess long-term patency rates of cephalic arch stent grafts in brachiocephalic fistulae and the importance of device position. MATERIALS AND METHODS: This retrospective study reviewed 152 patients with dysfunctional brachiocephalic fistulae and cephalic arch stenosis treated with stent grafts (Viabahn; W. L. Gore) at a single tertiary center between 2012 and 2021. The median age was 67.5 years (range, 25-91 years), and the median follow-up period was 637 days (range, 3-3,368 days). A grading system of protrusion was applied: (a) Grade 0, no protrusion; (b) Grade 1, perpendicular; and (c) Grade 2, in-line protrusion. Subsequent fistulograms were available in 133 (88%) of the 152 patients and were assessed for central vein stenosis within 10 mm of the stent graft. Clinical records were assessed for sequelae of stent graft protrusion. Stent graft primary and cumulative circuit patencies were calculated using the Kaplan-Meier method. RESULTS: Protrusion was documented in 106 (70%) stent grafts-56 Grade 1 and 50 Grade 2. Central vein stenosis was seen in 1 (2%) case of no protrusion (Grade 0) and 38 (40%) cases of protrusion (P < .0001). There was no significant difference in stenosis between Grade 1 and 2 protrusion (P = .15). No adverse clinical sequelae occurred in 147 (97%) patients. Eight patients had a new access subsequently formed in the same arm, and 3 of these 8 patients developed symptoms due to the previous stent graft protrusion (all Grade 2). The primary patency rates of the stent-grafts at 6 and 12 months were 73% and 50%, respectively. The cumulative access circuit patency rates at 1, 2, and 5 years were 84%, 72%, and 54%, respectively. CONCLUSIONS: This study demonstrated that protrusion of a cephalic arch stent graft into the central vein is safe and only clinically relevant when a subsequent ipsilateral access is created.