Short interposition with a small-diameter prosthetic graft for flow reduction of a high-flow arteriovenous fistula.

OBJECTIVE: The objective of this study was to evaluate the outcome of a short interposition using a small-diameter prosthetic graft as a flow-limiting procedure to manage symptomatic high-flow arteriovenous fistula (AVF). METHODS: A retrospective review of medical records on a case series was conducted. From June 2004 to April 2017, there were 25 patients with clinical symptoms of high output cardiac failure and progressive dilation of aneurysmal fistula vein due to high-flow AVF (≥1.5 L/min) who underwent short interposition with a 5-mm prosthetic graft at Saitama Medical Center. The primary outcome was the relief of clinical symptoms; other outcome measures included technical success, surgical complications, patency of vascular access, and postoperative changes in local and systemic hemodynamics as assessed by Doppler ultrasound. RESULTS: Twenty-five patients underwent short interposition for cardiac indications (n = 16) and aneurysmal dilation (n = 9). The technical success rate was 100%. The clinical symptoms were relieved in 24 patients (96.0%). Mean reduction in access blood flow was 52.4%. Cumulative primary unassisted patency rates (± standard error) at 1 year, 2 years, and 3 years were 76.2% ± 9.3%, 70.4% ± 10.3%, and 58.1% ± 11.6%, respectively. Secondary patency rates (± standard error) at 1 year, 2 years, and 3 years were 81.8% ± 8.2%, 71.5% ± 9.9%, and 71.5% ± 9.9%, respectively. Complications included access occlusion due to late thrombosis (n = 5 [21.7%]) and graft infection (n = 1 [4.3%]) in the median follow-up period of 3.9 years. CONCLUSIONS: Short interposition with a prosthetic graft is a simple, effective, and durable treatment option for end-stage renal disease patients with cardiac symptoms and progressive dilation of the fistula vein due to high-flow AVF, offering clinical symptom resolution while preserving the autologous behavior of the initial access.

Novel Reconstruction of Complex Central Venous Occlusion Using Supraclavicular Stent Graft in Hemodialysis Patients.

BACKGROUND: Subclavian vein and brachiocephalic vein occlusions are challenging problems in dialysis patients with ipsilateral upper extremity (UE) vascular access or in need of one. HeRO grafts (Hemodialysis Reliable Outflow, Merit Medical Systems, Inc, South Jordan, UT) have been used to manage such occlusions but patients with chronic hypotension treated with HeRO graft may have threatened patency. We describe an alternative technique using a supraclavicular stent graft to reconstruct the venous outflow, evaluate outcomes of this procedure, and discuss its role in complex hemodialysis patients. METHODS: From January 2019 to January 2020, we performed open surgical and endovascular dialysis access procedures in 297 patients. Eight patients (2.7%) with failing or failed access and subclavian and or brachiocephalic vein occlusion were treated with supraclavicular stent graft placement. Mean age was 52 years, ranging from 32 to 70. Five patients had failed access and were dialyzed using catheters (two femoral). Three patients with failing fistulas had severe arm edema. Two patients had recurrent HeRO graft thrombosis. We performed a retrospective review of these 8 patients and evaluated access patency and complications. RESULTS: Technical success and access function were 100% in all patients. One patient developed ischemic neuropathy and underwent proximalization of the arterial inflow with improvement. Already-existing fistulas were used for dialysis the day after the procedure and new grafts within 2-4 weeks. Arm edema resolved within one week after the procedure. Median follow-up was 254.5 days, range 24-408 days, with primary patency rate of 87.5% and secondary patency rate of 100%. Only one patient has required reintervention. Postoperative evaluation with ultrasound has revealed patent stent graft in the area of the subcutaneous cervical tunnel over the clavicle. CONCLUSIONS: Supraclavicular stent graft placement to a central vein can be used successfully to reconstruct venous outflow in hemodialysis patients with complex central vein occlusions. A supraclavicular extra-anatomic path can be used safely and effectively to place new UE vascular access or salvage threatened access in this challenging patient population.

Fontan venovenous collaterals and hepatic fibrosis.

OBJECTIVE: We hypothesized that a relationship might exist between angiographically demonstrable, post-Fontan venovenous collaterals, and hepatic fibrosis. METHODS: We analyzed data from post-Fontan patients that underwent cardiac catheterization and transvenous-hepatic biopsy procedures between March 2012 and March 2020. From innominate vein angiography, we determined those that either had or lacked venovenous collaterals. Additionally, we examined data from post-Fontan patients that underwent hepatic ultrasound, shear-wave elastography between January 2017 and March 2020. RESULTS: We identified 164 patients that met inclusion criteria. Of the 164, 101 (62%) had venovenous collaterals. Of the 101 with collaterals, average total fibrosis score (TFS) was 3.2 and the average rate of fibrosis progression was 0.28 vs an average TFS of 2.1 and an average fibrosis progression rate of 0.22 for those without collaterals (P = .00001 and P = .01, respectively). Of the 101 with collaterals, oxygen saturation was 91% ± 4% vs 93% ± 3% (P = .048) without collaterals. Of the 164, 86 (52%) underwent ultrasound shear-wave elastography. Of the 86 patients undergoing elastography, 50 (58%) were performed in those with collaterals, and 36 (42%) in those without collaterals. For the 50 with collaterals, average elastography values were 13.3 vs 11.2 kPa for the 36 without collaterals (P = .006). We found no statistically significant differences for age at biopsy, Fontan duration, Fontan-type, type of functional univentricle, laboratory, clinical, or hemodynamic values between those with or without collaterals. CONCLUSIONS: The presence of angiographically demonstrated venovenous collaterals was associated with statistically, significantly more advanced liver fibrosis than those without collaterals.

Stent-retriever thrombectomy in the treatment of infants with acute thrombosis of the superior vena cava and innominate vein.

OBJECTIVES: To describe the efficacy and safety of stent-retriever thrombectomy in infants with thrombosis of the superior vena cava (SVC) and innominate vein. BACKGROUND: Thrombosis of the SVC and of the innominate vein is a potentially life threatening complication in infants during intensive care treatment following major surgical procedures. To avoid reoperations, we evaluated interventional revascularization by stent-retriever thrombectomy. METHODS: From 2015 to 2017, five infants were diagnosed with acute thrombosis of the SVC and innominate vein following major cardiac or pediatric surgery. Using a femoral venous access and 4 or 5 French guiding catheters stent-retriever systems (4/20 mm or 6/30 mm) were placed into the thrombus and retrieved under suction. We aimed to revascularize not only the SVC but also the innominate, jugular, and subclavian veins. RESULTS: Following repeated stent retrieving manoeuvers, we were able to reestablish flow in the major veins of all patients. Due to significant residual thrombotic material, we decided to perform additional balloon dilatation of the SVC and innominate vein in 3/5 patients. There were no complications related to the procedure and none of our patients required blood transfusion. Following the intervention, the patients received treatment with low-molecular-weight heparin. Interventional treatment achieved persistent patency of the SVC and innominate vein in all patients. CONCLUSION: Stent-retriever thrombectomy is a safe and effective method for interventional treatment of acute thrombosis of the central veins in infants. Due to the large amount of thrombotic material, it is frequently required to combine this method with balloon compression of residual thrombotic material.

Surgical Treatment of Cephalic Arch Stenosis through Rotation of the External Jugular Vein.

The percutaneous transluminal balloon angioplasty or cephalic vein transposition is the treatment for cephalic arch stenosis. In some cases, rotation of the external jugular vein may be a good option for the cephalic arch problems. We describe a new technique to treat cephalic arch stenosis. The technique enables the cephalic arch and subclavian vein to be bypassed altogether through the rotation of the external jugular vein. It consists of 3 small incisions, thus causing minimal surgical damage.

Laser Recanalization of Central Venous Occlusion to Salvage a Threatened Arteriovenous Fistula.

Central venous occlusion is conventionally managed with balloon angioplasty, stent extension, or sharp recanalization. Here, we describe recanalization of a chronically occluded innominate vein using excimer laser after conventional techniques were unsuccessful. Patient clinical improvement and fistula patency have been sustained 2 years postintervention. This technique may provide new hemodialysis access options for patients who would not otherwise be candidates for hemodialysis access on the ipsilateral side of a central venous occlusion.

Surgical Treatment of Cephalic Arch Problems in Arteriovenous Fistulas: A Center Experience.

BACKGROUND: Cephalic arch problems, mainly stenosis, are a common cause of arteriovenous fistulas (AVFs) failure, and the most effective treatment is yet to be clearly defined. Restenosis usually occurs soon, and multiple interventions become necessary to maintain patency and functionality. The authors present the experience of their center with cephalic vein transposition in a group of patients with different problems involving the cephalic arch. METHODS: After consultation of the medical records, an observational retrospective analysis was performed to evaluate the outcomes of surgical treatment in cephalic arch problems of AVFs treated at the author's center between January 2013 and December 2015. The considered outcomes were endovascular intervention rate, thrombosis rate, and primary and secondary patencies. RESULTS: Seven patients were treated by venovenostomy with transposition of the cephalic arch and anastomosis to the axillary vein. The average patient age was 72 years (59-81), and most patients were female (71%) and diabetic (71%). All accesses were brachiocephalic AVFs with a mean duration of 4 years (1-7). The underlying problems were intrinsic cephalic arch stenosis (n = 5), entrapment of the cephalic vein (n = 1), and clinically significant vein tortuosity at the cephalic arch (n = 1). These last 2 problems conducted to a surgical approach as first-line therapy instead of endovascular intervention, the initial treatment in the other 5 cases (all with high-pressure balloons, with cutting balloon in one case). Previous thrombotic episodes were reported in 57% of the patients. The mean access flow before surgical intervention was 425 mL/min (350-1,500). No complications related with the surgical procedure were reported. One patient underwent surgical thrombectomy after AVF thrombosis, followed by transposition of the vein. In another case, a simultaneous flow reduction was performed. Most of the patients on dialysis (5/6) used the AVF after surgery. After a mean follow-up period of 9 months (1-22), surgical treatment was associated with a reduction in endovascular intervention rate (1.9 interventions per patient-year presurgery versus 0.4 postsurgery; P < 0.05) and thrombosis rate (0.93 thrombotic episodes per patient-year presurgery versus 0.17 postsurgery; P < 0.05). The problems leading to endovascular reintervention were as follows: new venous anastomosis stenosis (57%), axillary vein stenosis (29%), and swing-point stenosis (14%). Primary and secondary patencies at 6 months were 57% and 71%, respectively. CONCLUSIONS: In this group of patients with cephalic arch problems and multiple previous procedures, surgical treatment was associated with a reduction in endovascular intervention and thrombosis rate but did not avoid reintervention. Facing the complexity and multiplicity of the cephalic arch complications, treatment should be individually decided.

Outcomes of intervention for cephalic arch stenosis in brachiocephalic arteriovenous fistulas.

BACKGROUND: Development of recalcitrant stenotic lesions of the cephalic arch is a significant cause of dysfunction of brachiocephalic access arteriovenous fistulas (AVFs). Endovascular and surgical therapy can be used to treat cephalic arch stenosis. The aim of this study was to evaluate the outcomes of endovascular and surgical interventions for cephalic arch stenosis. METHODS: A retrospective review of all patients during a 16-year period with a compromised but not occluded brachiocephalic AVF due to cephalic arch stenosis was undertaken. Patency, reintervention, infection, and functional dialysis rates were examined. RESULTS: From January 2000 to December 2015, 219 patients (67% female; mean age, 58 ± 20 years) with a failing brachiocephalic AVF underwent intervention at the cephalic arch. These interventions included angioplasty, primary stent placement, transposition, and bypass. The average time to intervention for cephalic arch stenosis was 1.7 years after primary access placement. The average number of percutaneous interventions before the decision to intervene surgically on the cephalic arch was three (range, two to six). Technical success was superior in the surgical groups (70% and 80% compared with 96% and 100% for balloon angioplasty, stenting, transposition, and bypass, respectively; P = .02). Major adverse cardiovascular events were overall low but significantly higher in the surgical groups (1%, 1%, 0.3%, and 0.3% for transposition, bypass, balloon angioplasty, and stenting, respectively; P = .02). Both surgical options carried significantly superior patency rates at 2 years for transposition, bypass, balloon angioplasty, and stenting, respectively (63%, 59%, 90%, and 92%; P = .04). There was a lower rate of interventions per person-year of follow-up in the surgical groups compared with the endovascular groups (1.9, 1.4, 3.5, and 3.1 for transposition, bypass, balloon angioplasty, and stenting, respectively; P = .04). Functional dialysis durations were significantly superior in the surgical groups compared with the endovascular group (P = .03). CONCLUSIONS: Cephalic arch stenosis is a significant cause of brachiocephalic AVF malfunction. Surgical options offer superior long-term patency and functional results and should be considered earlier in the treatment of this disease.

Radiologists need to be aware of secondary central venous stenosis in patients with SAPHO syndrome.

OBJECTIVES: We aimed to define central venous stenosis (CVS) caused by sternocostoclavicular hyperostosis as a feature of synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome on routine contrast-enhanced computed tomography (CT) images. The relationship between SAPHO syndrome and CVS without venous thrombosis caused by anterior chest wall compression has not been investigated. Therefore, the present study evaluated CVS in patients with SAPHO syndrome at our hospital. METHODS: We retrospectively reviewed contrast-enhanced CT images of ten patients with suspected or diagnosed SAPHO syndrome between January 2007 and November 2015. The patients were assessed by contrast-enhanced CT using 16-, 64- or 128-detector row scanners. Two radiologists independently assessed the presence of CVS or obstruction and SAPHO syndrome in a retrospective review of CT images. RESULTS: Six of the ten patients had findings of CVS with SAPHO syndrome. The mean diameter and patency rate at the site of CVS were 1.88 mm and 27.2%, respectively. Stenosis was more significant in terms of the mean diameter of CVS sites than of stenotic sites that crossed the anteroposterior vein (p < 0.05). CONCLUSIONS: Radiologists who routinely assess contrast-enhanced CT images should be aware that sternocostoclavicular hyperostosis with SAPHO syndrome could cause secondary CVS. KEY POINTS: • SAPHO syndrome can cause central venous stenosis. • Radiologists should consider central venous stenosis in patients with SAPHO syndrome. • Early diagnosis of central venous stenosis due to SAPHO syndrome is challenging.

Imaging topography and morphometry of persistent left superior caval vein and its variations, detected on cardiac implantable electronic device implantation.

BACKGROUND: Persistent left superior caval vein (PLSCV) is a rare, anatomically diverse developmental anomaly of systemic veins. Clinically asymptomatic PLSCVs are detected incidentally during medical procedures that utilise systemic veins, such as cardiac implantable electronic device (CIED) placement, and whose successful completion depends on favourable morphometric parameters of these vessels. The aim of this paper was to present topography and morphometry of PLSCV variations encountered during CIED implantation procedures. MATERIALS AND METHODS: We analysed a group of 5,010 patients for detection of PLSCV during de-novo CIED implantation procedures with transvenous lead placement in the years 2003-2015. PLSCVs were detected intraprocedurally based on venographic images illustrating the venous anomaly and its morphometric parameters, and were subsequently confirmed via postoperative diagnostics. RESULTS: PLSCVs were detected in 10 patients (mean age 66.0 ± 14.0 years; 5 females and 5 males), who constituted 0.2% of the analysed group. There were 6 cases of double superior vena cava (DSVC), 3 of which had a brachiocephalic vein (BCV) connection and did not have BCV bridging. Four patients with a PLSCV had right superior vena cava agenesis; this very rare variation is known as 'single PLSCV'. All of the detected PLSCV variations drained into the right atrium via the coronary sinus. CONCLUSIONS: Our data from a period of 13 years illustrate how rare the PLSCV-type venous anomaly is. The three distinct anatomical PLSCV types showed inter-individual morphometric variations. Due to asymptomatic nature of this anomaly, all cases were detected incidentally, during CIED implantation procedures.

Recurrent Brachiocephalic Vein Stenosis as a Cause for Persistent Left-sided Transudative Pleural Effusion in a Hemodialysis Patient.

BACKGROUND: Effusion is common in dialysis patients. The most common causes include fluid overload due to renal failure and nonrenal causes like congestive heart failure and infection. We here report a case of left side transudative effusion due to brachiocephalic venous stenosis. METHODS: A 34-year-old female who had chronic kidney disease V during transplant work-up was found to be having left arm swelling and left transudative effusion. Work-up for transudative effusion did not show any cardiac cause or liver problem. Her dialysis duration was optimized from 2 times a week to 3 times a week for 4 hr and her dry weight was adjusted. Despite adequate dialysis for 1 month, effusion on the left side persisted. She had a previous venoplasty for a stenosis in brachiocephalic vein but restenosis occurred again. RESULTS: Brachiocephalic vein stenting was performed which successfully lead to resolution of left arm swelling and left effusion. She was later on successfully transplanted. CONCLUSIONS: Brachiocephalic stenosis can cause ipsilateral transudative effusion. Venoplasty and stenting of the brachiocephalic vein lead to complete resolution of effusion.

Creation of a Successful Transposed Antecubital Radiocephalic Arteriovenous Fistula in Patient with Known Ipsilateral Modified Radical Mastectomy, Postoperative Radiation, and Proximal Central Venous Occlusion.

Native arteriovenous fistula (AVF) placement in patients with ipsilateral mastectomy and radiation has been avoided because of concerns regarding central venous outflow obstruction. To our knowledge, only 3 such cases have been reported. We present a patient with bilateral mastectomies and right-sided radiation therapy presenting for vascular access in the setting of multiple failed AVF in her left upper extremity and infected-groin catheter, central catheters, and axillary loop graft. We created and superficialized a radiocephalic AVF in her right upper extremity in the setting of central vein occlusion and robust collaterals which remains patent and has been cannulated successfully.

Increased minimum vein diameter on preoperative mapping with duplex ultrasound is associated with arteriovenous fistula maturation and secondary patency.

OBJECTIVE: Autogenous arteriovenous hemodialysis accesses (arteriovenous fistulas [AVFs]) are preferred for chronic hemodialysis access. Preoperative vein mapping by duplex ultrasound is recommended before AVF creation, but there are few data correlating vein diameter with postoperative outcomes. Also, vein diameter has not been included in prior predictive models of fistula maturation. This study aims to test whether preoperative vein diameter is associated with failure of AVF maturation and long-term (secondary) patency. METHODS: We performed a retrospective analysis of clinical variables of patients undergoing brachiobasilic or brachiocephalic AVF creation. Kaplan-Meier and multivariate Cox regression models tested whether preoperative minimum vein diameter (MVD) and clinical covariates were associated with failure of AVF maturation and secondary patency. RESULTS: The sample included 158 adults (54 ± 14 years; 45% male; 61% white; 56% diabetes; body mass index, 32 ± 8; MVD, 3.4 ± 1.1 mm; follow-up, 12 ± 9 months [range, <1-40 months]). Increased MVD was associated with decreased risk of AVF failure. More than one third of AVFs with MVD <2.7 mm failed to mature within 6 months. Multivariate models that adjusted for age, diabetes, race, gender, body mass index, and preoperative dialysis status demonstrated that increased MVD was associated with decreased risk of failure of maturation and better long-term patency overall (P = .005 and P = .001, respectively). CONCLUSIONS: Patients with a larger MVD on preoperative vein mapping are at lower risk for failure of fistula maturation and have increased long-term AVF patency. MVD is the only clinical or demographic factor associated with both AVF maturation and long-term patency. MVD is an important preoperative indicator of fistula success in assessment of potential AVF sites. Future predictive models of fistula maturation and patency should include MVD.

Sheep Model of Hemodialysis Arteriovenous Fistula Using Superficial Veins.

Current models of animal arteriovenous fistula (AVF) are swine models of femoral vein terminolaterally anastomosed to femoral artery, creating a deep AVF. This feature sets it aside from human AVFs using superficial veins. Our AVF model uses sheep superficial veins to create an AVF almost identical to human model. AVFs were created in six sheep using basilic veins sutured terminolaterally to brachial artery. Presurgery vein and artery diameters were measured. We measured AVFs and feeding arteries blood flows and diameters at 1, 3, and 5 weeks postsurgery. At 5 weeks we performed angiograms, euthanized animals, and harvested AVFs. Four animals completed the study. Three AVFs developed and were patent at 5 weeks; one thrombosed. Animal weight and presurgery vessels diameters predicted AVFs blood flows and diameters. Despite using vessels with diameters smaller than the ones recommended for human AVF, the Fistulas developed. Two animals died before the study conclusion for causes unrelated to surgery. This AVF model is anatomically almost identical to the human AVF and has a good maturation rate. It is a viable model for studying AVF maturation, devices intended to improve AVF maturation, AVF related procedures and can even support hemodialysis needles.

Clinical Importance of Intraoperative Cephalic Vein Distensibility as a Predictor of Radiocephalic Arteriovenous Fistula Maturation.

Radiocephalic arteriovenous fistula (RCAVF) is the preferred vascular access, but the maturation failure rate is high. Poor vein distensibility is the main cause of maturation failure. There have been several studies regarding vein distensibility, but vein dilation protocol and the cut-off value predicting maturation failure were inconsistent. We were doubtful that the vein distensibility had been appropriately evaluated, and sought to determine a more clinically applicable parameter. The cephalic vein was dilated via intraluminal hydrostatic pressure during the surgery and the vein size was measured. Maturation failure occurred in 30 patients (22.4%) and was more common in females and in patients who had a previous history of arteriovenous access formation (p = 0.0095 and p = 0.014). The intraoperative postdilation diameter, and the difference between pre and postdilation diameters differed between the two groups (p = 0.0004 and p = 0.0004). The cut-off value of the postdilation diameter, which indicated a high probability of maturation success, was >4 mm, and the cut-off value which indicated a higher probability of maturation failure; that is, the difference between the pre and postdilation diameter, was ≤2.2 mm. The degree of distensibility of the cephalic vein may be an important determinant of RCAVF maturation.

Left brachiocephalic vein stenosis and infectious aortitis: two unusual causes of Ortner's syndrome.

Ortner's syndrome (also known as cardiovocal syndrome) is defined as hoarseness due to compression of the left recurrent laryngeal nerve by an enlarged left atrium or enlarged thoracic vessels. We describe two cases of Ortner's syndrome with an unusual underlying vascular pathology. In the first patient, Ortner's syndrome was a consequence of left brachiocephalic vein stenosis resulting in collateral circulation filling the aorto-pulmonary window. The second patient developed a thoracic aortic aneurysm due infectious aortitis. Both patients required careful scrutiny in differential diagnosis because of their complex past medical history and concomitant diseases.

Outcomes of single-stage compared to two-stage basilic vein transposition fistulae.

Basilic vein transposition (BVT) fistulae are increasing in prevalence in the United States. We examined outcomes of BVT fistulae created in a single stage compared to those created in two stages. Prospective QA databases identified a consecutive cohort of 144 patients with BVT fistulae. Of these, 42% were created in one stage and 58% in two stages. Fistula maturation rates, mean time to fistula use and intensity of percutaneous interventions were compared; patency rates were compared from time of first intervention. Maturation rates (including assisted maturation) were 90% among 1-stage and 75% among 2-stage BVT (p = 0.02). Mean time to initiation of fistula use was 142 days (1-stage) and 146 days (2-stage) (p = 0.92). Intensity of percutaneous interventions was 1.84/patient-year of dialysis (PYD) (1-stage) and 2.15/PYD (2-stage) (p = 0.57). Secondary patency at 1, 2, 3, and 4 years for 1-stage BVT was 86%, 75%, 69%, and 57%; secondary patency at 1, 2, 3, and 4 years for 2-stage BVT was 76%, 71%, 49%, and 25%, respectively (p = 0.12). BVT creation in two stages confers only a modest reduction in maturation rates and secondary patency and therefore should be considered over a synthetic graft in patients with basilic veins deemed inadequate for 1-stage BVT.

Do blood pressure levels and other patient characteristics influence native fistula patency?

Arteriovenous fistulas (AVFs) play an important role in access for hemodialysis, yet premature thrombosis is a challenge. This study identifies factors influencing primary patency in a series of AVF creations. Postoperative systolic blood pressure (BP) was of principal interest; demographical information, comorbidities, smoking status, warfarin, aspirin, clopidogrel, and statins were considered. A retrospective review of AVF creations performed by one surgeon between January 2008 and September 2010 was conducted. Fistula patency was denoted by a bruit and measured at 3 weeks and 12 months after surgery. One hundred and fifty-one AVF creations were studied; 134 fistulas (88.7%) were patent at 3 weeks and 85 (56.3%) at 12 months. The odds ratio (OR) for thrombosis at 12 months was 0.16 (95% CI: 0.04, 0.62; p = 0.008) among patients with a postoperative systolic BP of 120-139 mmHg compared with those with a BP of ≤ 119 mmHg. Patients taking warfarin yielded an OR of 5.71 at 3 weeks (95% CI: 1.20, 27.11; p = 0.028), and 3.33 at 12 months (95% CI: 1.01, 10.99; p = 0.048). No other variables were statistically significant. Patients with postoperative systolic BP of 120-139 mmHg showed a reduction in fistula thromboses compared with patients with a systolic BP of ≤ 119 mmHg. Patients on warfarin were less likely to maintain a patent fistula.