Initial Outcomes Following Introduction of Percutaneous Arteriovenous Fistula Program with Comparison to Historical Surgically Created Fistulas.

BACKGROUND: Recently, there has been an abundance of encouraging data regarding the creation of percutaneous arteriovenous fistulas. Despite promising data regarding their clinical maturation, a paucity of data exists which provides direct comparison between percutaneously created AVFs (pAVF) and open surgically created AVFs (sAVF). This study has 2 primary objectives: First, to compare clinical outcomes of pAVFs to sAVFs, with emphasis on clinical maturation and frequency of postoperative interventions to facilitate maturation. Second, to contribute toward the evidence-based incorporation of the pAVF procedure into the hemodialysis access algorithm. METHODS: A single-center retrospective review was performed on all consecutive patients undergoing surgically created brachiocephalic arteriovenous fistula (BC-AVF, sAVF group) from January 1, 2018 to December 31, 2018 and Ellipsys-created percutaneous arteriovenous fistula (pAVF group) from January 1, 2019 to December 31, 2019. Comparative analysis between groups was performed. RESULTS: A total of 24 patients underwent Ellipsys-created pAVF with mean age of 56.7 ± 22.6 years (12 males [50%], 12 females [50%]) and 62 patients underwent surgically created BC-AVF with mean age of 62.5 ± 13.2 years (32 males [52%], 30 females [48%]). Both the pAVF and sAVF groups had comparable mean operating times (60 ± 40 vs. 56 ± 25 min, P = 0.67) and frequency of procedural technical success (23 [96%] vs. 62 [100%], P = 0.28), respectively. The pAVF group had a lower clinical maturation rate (12 [52%] vs. 54 [87%], P = 0.003) and a higher primary failure rate (9 [39%] vs. 6 [10%], P = 0.003) when compared to the sAVF group. The pAVF group had an increased overall rate of undergoing a postoperative intervention (18 [78%] vs. 13 [21%], P< 0.001), as well as an increased number of total postoperative interventions (1.1 ± 0.9 vs. 0.3 ± 0.6 interventions, P< 0.001) compared to the sAVF group. Percutaneous transluminal angioplasty of the juxta anastomotic segment was the most prevalent postoperative intervention performed in the pAVF group and occurred at a significantly increased frequency when compared to the sAVF group rate (13 [57%] vs. 5 [8%], P< 0.001). CONCLUSIONS: In our single-center retrospective review, patients undergoing Ellipsys-created pAVF in the first year following introduction of percutaneous endovascular had inferior rates of clinical maturation and underwent more postoperative interventions when compared to historical patients undergoing surgically created BC-AVF. Outcome discrepancies compared to previously reported Ellipsys data demonstrate a need for further studies examining the practical translatability of the pAVF.

Risk factors associated with the diagnosis of abdominal aortic aneurysm in patients screened at a regional Veterans Affairs health care system.

BACKGROUND: An active abdominal aortic aneurysm (AAA) screening program at a regional Veterans Affairs (VA) health system identifies patients at risk for AAA. The purpose of this study is to evaluate unique risk factors associated with the AAA diagnosis upon AAA screening examination to identify the most at risk patients for AAA. METHODS: Data were extracted from a regional VA health care system to identify patients who underwent AAA screening within a 3-year period. An aortic diameter ≥3.0 cm was defined as an AAA. Patient risk factors included age, body mass index, total cholesterol, estimated glomerular filtration rate (eGFR), statin use, and active smoking status; the presence of hypertension, diabetes, coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), or peripheral vascular disease (PVD) was also evaluated. Risk factors were compared in a multivariate analysis between patients with AAA and patients with a normal aorta. RESULTS: A total of 6,142 patients (mean ± SD age: 72.7 ± 5.3 years) were screened for AAA between January 2007 and December 2009. A total of 469 patients (7.6%) with AAA were identified. The following risk factors were significantly associated with a diagnosis of AAA: age >75 years (39.6% vs. 28.9%; P < 0.001), prevalence of CAD (43.1% vs. 28.5%; P < 0.001), COPD (26% vs. 11.4%; P < 0.001), PVD (37.3% vs. 7.7%; P < 0.001), eGFR <60 mL/min (36.7% vs. 24.3%; P < 0.001), and current smoking (23.2% vs. 15.3%; P < 0.001). The risk factors significantly associated with normal aortic size were the presence of diabetes (18.6% vs. 27.4%; P < 0.001) and total cholesterol ≥200 mg/dL (10.4% vs. 15%; P = 0.04). CONCLUSIONS: The diagnosis of AAA in a large screening study is typically identified in patients who are at high risk for cardiovascular disease. The presence of diabetes is a major cardiovascular risk factor that is more associated with normal aorta when compared to patients with the AAA diagnosis. Total cholesterol ≥200 mg/dL was associated with decreased AAA risk, and renal insufficiency was associated with increased AAA risk.

Initial 6-month quality review of a percutaneous endovascular arteriovenous fistula program.

BACKGROUND: Percutaneous arteriovenous fistulas have recently proven successful alternatives to surgical arteriovenous fistulas with encouraging initial results. The Ellipsys Endovascular Arteriovenous Fistula System utilizing ultrasound and thermal energy has recently received approval for use in the United States. At the University of New Mexico, we developed an integrated service between Vascular Surgery, Interventional Radiology, and Interventional Nephrology for percutaneous arteriovenous fistulas utilizing Ellipsys. METHODS: We performed a retrospective chart review of the initial 6 months (January 1st 2019 to July 1st 2019) of 18 percutaneous arteriovenous fistula placements to evaluate our initial technical success rate, the number of arteriovenous fistulas meeting maturation characteristics or use in dialysis, and to identify areas for quality improvement. RESULTS: Initial technical success was achieved in 17 out of 18 arteriovenous fistulas (94.4%). Three patients did not report for any follow-up at the end of the initial 6 months. Of the remaining patients, 7 out of 15 were using their arteriovenous fistulas or meeting maturation characteristics at the end of the study (46.7%). Patient loss to follow-up/no-show (16.7%), patient not yet requiring hemodialysis (27.8%), and poor post-surgical maturation and/or need for additional maturation procedures (55.6%) were the predominate reasons for non-use. We identified improved coordination of care, early intervention, and outpatient dialysis center education as the primary areas of focus for quality improvement. CONCLUSION: Initial technical success rate of percutaneous arteriovenous fistulas placement was comparable to published studies. Early and aggressive secondary angiographic interventions of arteriovenous fistulas failing to meet cannulation requirements, improved coordination of post-operative care, and outpatient dialysis center education appear to be the primary targets for quality improvement.

The effect of preoperative embolization on surgical outcomes for carotid body tumor resection.

OBJECTIVE: Compare the effects of preoperative embolization for carotid body tumor resection on surgical outcomes to carotid body tumor resections without preoperative embolization. METHODS: Single-center retrospective review of all consecutive patients who underwent carotid body tumor resection from 2001 to 2019. Surgical outcomes with emphasis on operative time (estimated blood loss and cranial nerve injury) of patients undergoing carotid body tumor resection following preoperative embolization were compared to those undergoing resection alone using unpaired Student's t-test and Fisher's exact test. RESULTS: Forty-six patients (15% male, mean age 50 ± 15 years) underwent resection of 49 carotid body tumors. Patients undergoing preoperative embolization (n = 20 (40%)) had larger mean tumor size (4.0 ± 0.7 vs 3.2 ± 1 cm, p = 0.006), increased Shamblin II/III tumor classification (18 (90%) vs 22 (76%), p < 0.001), operative time (337 ± 195 vs 199 ± 100 min, p = 0.004), and cranial nerve injuries overall (8 (40%) vs 2 (10%), p = 0.01) compared to patients undergoing resection without preoperative embolization (n = 29 (60%)). In subgroup analysis of Shamblin II/III classification tumors (n = 40), preoperative embolization (n = 18) was associated with increased tumor size (4.1 ± 0.6 vs 3.5 ± 0.9 cm, p = 0.01), operative time (351 ± 191 vs 244 ± 105 min, p = 0.02), and cranial nerve injury overall (8 (44%) vs 2 (9%), p = 0.03) compared to resections alone (n = 19). In further subgroup analysis of large (⩾ 3 cm) tumors (n = 37), preoperative embolization (n = 18) was associated with increased operative time (350 ± 191 vs 198 ± 99 min, p = 0.006) and cranial nerve injury overall (8 (44%) vs 2 (11%), p = 0.03) compared to resections alone (n = 19). There were no significant differences in estimated blood loss, transfusion requirement, or hematoma formation between any of the embolization and non-embolization subgroups. CONCLUSION: After controlling for tumor Shamblin classification and size, carotid body tumor resections following preoperative embolization were associated with increased operative time and inferior surgical outcomes compared to those tumors undergoing resection alone. Nonetheless, such results remain susceptible to the confounding effects of individual tumor characteristics often used in the decision to perform preoperative embolization, underscoring the need for prospective studies evaluating the utility of preoperative embolization for carotid body tumors.

Vein diameter is the major predictor of fistula maturation.

OBJECTIVES: Preoperative duplex ultrasound mapping of veins and arteries has been widely advocated to maximize the creation of native arteriovenous fistula (AVF) for hemodialysis access, but reliable diameter criteria have not been established. We sought to determine patient and anatomic variables predictive of fistula maturation in patients receiving their initial permanent hemodialysis access. METHODS: All patients undergoing dialysis access creation from January 2003 to June 2007 were retrospectively reviewed. We analyzed fistula type and functional maturation rates (Society for Vascular Surgery [SVS] reporting standards) based on patient characteristics and findings on physical examination, preoperative vein mapping studies, or venography. Maturation and patency rates were determined by Kaplan Meier analysis. The following factors were analyzed: age, race, gender, body-mass index (BMI), fistula site, preoperative duplex vein diameter, diabetes, hyperlipidemia, HTN, prior central catheter placement, HIV, and history of IV drug abuse. RESULTS: From January 2003 to June 2007, 298 vascular access procedures were performed. One hundred ninety-five (65%) were initial hemodialysis access procedures, among which a native AVF was created in 185 (95%); 158 patients with posterior radiocephalic AVF (PRCAVF, n = 24), wrist radiocephalic AVF (WRCAVF, n = 72), or brachiocephalic AVF (BCAVF, n = 62) had adequate follow-up and were included in the analysis. PRCAVF, WRCAVF, and BCAVF had 54%, 66%, and 81% maturation rates, respectively. Both the type of fistula type (P = .032) and vein size (P = .002) significantly affected maturation by univariate analysis. In contrast, by multivariate logistic regression analysis, vein diameter was the sole independent predictor of fistula functional maturation (P = .002). CONCLUSION: In this series of 158 patients undergoing initial hemodialysis access creation, native AVF creation was performed in 95%. In contrast to previous reports, age, gender, diabetes, and BMI had no significant effect on functional maturation. By multivariate logistic regression analysis, vein diameter was the sole independent predictor of functional fistula maturation.

Aneurysmal degeneration of deep lower extremity vein conduits used for vascular reconstruction.

BACKGROUND: Successful outcomes have been reported with the use of femoropopliteal vein (FPV) grafts as arterial conduits. We identified 2 patients with a rare complication, true, nonanastomotic aneurysmal degeneration. METHODS: Patients from 1997 through 2009 that utilized FPV grafts for revascularization were analyzed. We contacted survivors by phone and conducted a literature search of FPV aneurysms. RESULTS: Of the total of 14 patients in our practice whose FPV was used as a conduit during the study period, 2 developed nonanastomotic FPV graft aneurysms. The mean follow-up time was 33.44 months. Literature review uncovered only 1 previously published case of FPV aneurysmal degeneration. CONCLUSIONS: Our experience suggests that nonanastomotic aneurysms of FPV grafts may occur more often than those suspected previously. Our study represents the first reports of aneurysmal degeneration affecting FPV grafts when used for vascular reconstructions.