Distal Revascularization and Interval Ligation for the Management of Dialysis Access Steal Syndrome.

BACKGROUND: Treatment options for dialysis access steal syndrome (DASS) include distal revascularization with interval ligation (DRIL), proximalization of arterial inflow (PAI), access banding, and access ligation. This study examines the efficacy of DRIL in treating DASS and reports short-term bypass patency, access patency, and wound infection rates. METHODS: A retrospective analysis was performed on adults diagnosed with DASS following hemo-dialysis access creation who underwent DRIL procedures between January 1, 2009 and May 11, 2017. Patients <18 years and those with lower extremity accesses or HeRO grafts that developed DASS were excluded. Data was obtained using electronic medical records and analyzed using SPSS software. Residual steal was defined as reintervention for DASS within 60 days of DRIL. Recurrent steal was defined as reintervention beyond 60 days. RESULTS: Eighty-nine DRIL procedures were performed for correction of DASS. Population included 59.6% female (n = 53), 47.2% current/former smokers (n = 42), 76.4% diabetic (n = 68), and 79.8% AVF (n = 71). Symptom resolution was complete for 69.7% (n = 62), and partial for 25.8% (n = 23), with no improvement in 4.5% (n = 4). Following DRIL, mean DBI improved from 0.43 to 0.67 (P= 0.002). Mean steal classification improved from 3.04 to 0.64 (P< 0.001). Five patients required a subsequent procedure for DASS symptoms - 3 for residual steal and 2 for recurrent steal. Bypass patency at 6 months post DRIL was 93.3% (n = 83) primary, 97.8% (n = 87) primary-assisted, and 100% (n = 89) secondary patency. Access patency at 6 months post DRIL was 78.7% (n = 70) primary, 91% (n = 81) primary-assisted, and 94.4% (n = 84) secondary. Twenty-one patients (23.5%) had 24 cases of surgical site infections, with 70.8% (n = 17) occurring at the saphenectomy site. Wound infections re-solved within 60 days postoperatively in 23 out of 24 patients. CONCLUSIONS: DRIL is highly effective in relieving symptoms of DASS and has excellent rates of short-term access and bypass patency. However, consideration must be given to the high wound infection rate and the potential need for subsequent procedures.

A comparison of stenting versus hemodialysis reliable outflow graft for hemodialysis patients with recurrent central venous obstructions.

BACKGROUND: Central venous occlusive disease is a common cause of upper extremity arteriovenous access dysfunction in hemodialysis patients. When refractory to balloon angioplasty, the treatment options include central venous stenting and hemodialysis reliable outflow (HeRO; Merit Medical, South Jordan, Utah) graft. The purpose of the present study was to evaluate the outcomes of these options. METHODS: A retrospective review was performed of patients who had undergone central venous stenting or HeRO placement for central venous obstruction from December 2008 to March 2018. The primary outcomes were the reintervention rates, patency, and mortality. RESULTS: A total of 75 hemodialysis patients were identified after failed balloon angioplasty for central venous obstruction. Of the 75 patients, 44 underwent central venous stenting comprising coverage of the subclavian vein (n = 27), innominate vein (n = 18), and/or superior vena cava (n = 5). Six stent patients later underwent HeRO placement. The stents used were stent grafts in 65% (Viabahn, n = 9; Fluency/Flair, n = 19; iCast, n = 2; and other, n = 1) and bare metal stents in 35% (Wall-stent, n = 6; Protégé, n = 1; Cobalt, n = 1; and other, n = 9). The remaining 31 patients underwent HeRO graft placement. The venous outflow component insertion sites were the internal jugular (n = 20), external jugular (n = 1), subclavian (n = 6), axillary (n = 2), and other (n = 2). The stent and HeRO groups were similar in the previous central venous intervention rates (median, 0.6 [interquartile range (IQR), 0-3.0]; vs median, 3.5 [IQR, 0-10.1] annually; P = .679). After the index procedure, no difference was found between the two groups in the frequency of dialysis circuit interventions annually (median, 2.0 [IQR, 0-6.0]; vs median, 2.0 [IQR, 0-7.0]; P = .291) nor central venous interventions (ie, angioplasty of the central veins or within the portion of the HeRO inside the central veins) annually (median, 2.0 [IQR, 0-4.1]; vs median, 0 [IQR, 0-2.4]; P = .419). The 1-year access circuit primary patency was 8.1% for stenting and 22.2% for HeRO (P = .109). The 2-year access circuit secondary patency was 40.0% for stenting and 52.4% for HeRO (P = .401). The all-cause mortality was similar at 1 year (3.7% vs 4.8%; P = .856) and 2 years (11.8% vs 23.5%; P = .368). CONCLUSIONS: Central venous stenting and HeRO were shown to have similar rates of reintervention and patency. The results from the present study suggest that the multiple treatment options available for this problematic disease process can yield similar results when careful patient selection is applied.

A Novel Iliac Morphology Score Predicts Procedural Mortality and Major Vascular Complications in Transfemoral Aortic Valve Replacement.

BACKGROUND: Vascular complications remain a significant technical challenge for transfemoral TAVR (transcatheter aortic valve replacement). The goal of this study is to develop a preoperative tool for prediction of major vascular complications of TAVR. METHODS: A retrospective review was performed of all patients who underwent transfemoral TAVR at a tertiary medical center from 2011 to 2015. Iliofemoral arterial measurements were obtained with computed tomography angiography three-dimensional reconstruction images and an Iliac Morphology Score (IMS) was created from these measurements. Vascular complications were defined by Valve Academic Research Consortium (VARC-2) criteria. Statistical analyses were performed utilizing chi-squared test, Student's t-test, and binomial regression. RESULTS: We analyzed the data of 198 transfemoral TAVR patients. VARC-2 vascular complications were seen in 25 patients (13%). Major and minor vascular complication rates in the entire cohort were 4% (n = 7) and 9% (n = 18), respectively. Thirty-one patients (15.6%) required vascular surgery consultation. A total of 24 patients (12%) required surgical or percutaneous vascular interventions. Univariate analysis identified gender, iliac diameter, iliac calcification, and access type (open versus percutaneous) as predictors of major complications. The IMS was composed of ipsilateral minimum iliac diameter and iliac calcifications based on area under the receiver operator curve (AUROC) analysis (P < 0.05, AUROC = 0.82). Arterial size and calcification were classified with a value of 0-3 based on severity. Multivariate analysis identified gender and IMS as independent predictors of major complications. The mean IMS for the cohort was 3.4 (range 0-6). Patients were divided into high (IMS ≥ 5, n = 55) and low risk (IMS<5, n = 143) groups based on the inflection point for specificity (73%) and sensitivity (83%). The high-risk group had smaller iliac diameters, areas, luminal volumes, and a higher rate of major vascular complications (9% vs. 1%, P = 0.001). The 30-day mortality rate in the high score group was 9% and 1.4% in low score group (P = 0.02, AUROC = 0.72). CONCLUSIONS: An IMS composed of ipsilateral minimum iliac diameter plus iliac calcification is an excellent predictor of major vascular complications and mortality. Alternative access in patients with high IMS may reduce major vascular complications and 30-day mortality.

Analysis of vascular closure devices after transbrachial artery access.

INTRODUCTION: We seek to determine whether vascular closure devices (VCDs) are safe and effective for brachial artery access. METHODS: A retrospective review of brachial artery access using either manual compression (MC) or a VCD for hemostasis from November 2005 to February 2011 was performed. RESULTS: Brachial artery access was performed on 154 limbs: MC on 134 limbs and VCD on 20 limbs. The incidence of thrombotic (VCD n = 0 [0%] vs MC n = 7 [5.2%], P = .37), hemorrhagic complications (VCD n = 1 [5%] vs MC n = 7 [5.2%], P = .72), or major adverse events (VCD n = 1 [5%] vs MC n = 16 [12%], P = .32) was not significantly different between the techniques. After univariate and multivariate analysis, female sex (P = .07, relative risk [RR] = 5.7), sheath size > 6F (P = .008, RR = 14.6), and diagnostic versus interventional procedure (P = .04, RR = 0.4) all impacted the occurrence of thrombosis. CONCLUSIONS: Use of VCD in the brachial artery following an endovascular procedure showed equivalence to MC.

Grayscale median analysis of primary stenosis and restenosis after carotid endarterectomy.

BACKGROUND: Several studies have reported that echolucent carotid lesions, as determined by grayscale median (GSM) analysis, are associated with increased perioperative embolic complications during carotid artery stenting (CAS). However, there is limited research of the predictive value of GSM analysis comparing values for primary atherosclerotic lesions in the carotid artery with those for recurrent lesions after carotid endarterectomy (CEA). METHODS: Retrospective data were collected and analyzed from all patients undergoing CAS from November 2005 to August 2010. Available preoperative images amenable to GSM analysis were processed in Adobe Photoshop (version CS4; San Jose, Calif). Statistical analysis included t-test, Fischer exact test, and generation of a receiver operating characteristic curve. RESULTS: With at least 29 days of follow-up, 212 patients underwent 228 CAS procedures. There were 189 stents placed for primary lesions (CAS for primary stenosis group) and 39 stents placed for restenosis after CEA (CAS for restenosis group). GSM analysis was feasible for 47 patients, and the mean GSM was 45.6 (n = 34; 95% confidence interval, ± 8.3) for the primary stenosis group and 20.5 (n = 13; 95% confidence interval, ±9.6) for the restenosis group (P < .01). The mean time from CEA to CAS intervention for the restenosis group was 8.6 years. There was no statistical difference in procedural individual and combined complications of ipsilateral stroke, 30-day stroke, or 30-day mortality between the CAS for primary stenosis group and the CAS for restenosis group. In the primary stenosis group, the mean GSM was lower in those with procedural complications compared with those without complications (15 ± 22 vs 49 ± 8; P = .02). CONCLUSIONS: A low GSM value was associated with increased perioperative risk when CAS was performed for native carotid lesions, but a low GSM value was not associated with higher procedural risk when carotid stenting was performed for carotid stenosis after CEA (restenosis). GSM analysis for restenosis may be altered by the time interval from CEA to restenosis.

Outcomes comparison of HeRO and lower extremity arteriovenous grafts in patients with long-standing renal failure.

OBJECTIVE: The Hemodialysis Reliable Outflow (HeRO) graft is becoming a recognized alternative to lower extremity arteriovenous grafts (LEAVGs) as an option for patients who have exhausted traditional upper extremity access; however, which should be applied preferentially is unclear. METHODS: A retrospective review of LEAVG and HeRO implants from January 2004 to August 2010 was performed. Patient demographics, medical history, procedural data, and outcomes were evaluated. RESULTS: Within the time periods, 60 HeROs were placed in 59 patients and 22 LEAVGs were placed in 21 patients. Demographics were similar between the two groups for many factors; however, the patients who underwent HeRO placement had significantly higher body mass index compared with the LEAVG group. Mean follow-up was 13.9 months for the HeRO group and 11.9 months for the LEAVG group. The HeRO patients underwent a mean of 6.3 previous tunneled dialysis catheter insertions and 3.1 previous AVG/arteriovenous fistula placements. The LEAVG patients underwent placement of a mean of 4.1 previous tunneled dialysis catheters and 2.6 previous AVG/arteriovenous fistulas. The principal difference was the number of interventions to maintain patency, which was 2.21 per year in the HeRO group and 1.17 per year in the AVG group (P = .003) Secondary patency at 6 months was 77% for the HeRO patients and 83% for the LEAVG patients (P = .14). The HeRO and LEAVG groups had no difference in infection rate per 1000 days (0.61 vs 0.71; P = .77) or mortality rate (22% vs 19% respectively; P = .22) at 6 months. CONCLUSIONS: In access challenged patients, LEAVG and HeRO offer similar rates of secondary patency, infection, and all-cause mortality. The LEAVG required fewer interventions to maintain patency, and the HeRO maintains the benefit of utilizing the upper extremity site of venous drainage. In our practice, we prefer the HeRO to LEAVG, especially in patients with peripheral arterial disease and in the obese population, because it preserves lower extremity access options.

Pharmacokinetics & drug resistance of melphalan in regional chemotherapy: ILP versus ILI.

Two forms of regional chemotherapy for the treatment of advanced melanoma or sarcoma of the extremity are isolated limb perfusion (ILP) and the more recently described isolated limb infusion (ILI). Melphalan is the most commonly employed agent in both ILP and ILI, although it is often used in conjunction with other cytotoxic and/or biologic therapies. While ILP and ILI are far more effective for the treatment of extremity disease than is systemic therapy, there is still significant room for improvement in outcomes, from the standpoint of both response rate and toxicity. An understanding of the pharmacokinetics of regional chemotherapy would allow for the prediction of tumor response and toxicity and therefore patient outcomes. In addition, elucidating the mechanisms of drug resistance would lead to opportunities to develop effective chemo-modulators that enhance the effectiveness of ILP and ILI. This paper reviews progress in these two key areas of active investigation.