The Journal of Vascular Access

Central vein thrombosis or obstruction is a common complication associated with central venous catheters placed for intermittent hemodialysis. The reported outcomes of percutaneous catheter-based interventions reveal high rates of lesion recurrence with varying and frequently limited patency intervals. We present the case of open venous bypass in the treatment of catheter-associated chronic central vein occlusion.

We report a case of symptomatic arm swelling secondary to central vein stenosis and failed endovascular venous intervention treated by central vein bypass with prosthetic graft through median sternotomy.

Patient had an open axillary to innominate venous bypass via median sternotomy incision, which resulted in resolution of patient's symptoms and uninterrupted patency of the pre-existing vascular access.

Open venous bypass is a reliable alternative to endovascular intervention in the symptomatic patient with extensive central vein occlusion as a primary intervention or in whom prior endovascular therapy has failed.

The central venous pressure (CVP) is the most commonly used static marker of preload for guiding fluid therapy in critically ill patients, though its usefulness remains controversial. Centrally inserted central catheters (CICCs) are the gold-standard devices for CVP monitoring but peripherally inserted central catheters (PICCs) may represent a valid alternative. We undertook a systematic review and meta-analysis with the aim to investigate whether the difference between PICC- and CICC-measured CVP is not significant.

We searched for clinical studies published in PubMed and EMBASE databases from inception until December 21^st 2016. We included studies providing data on paired and simultaneous CVP measurement from PICCs and CICCs. We conducted two analyses on the values of CVP, the first one according to the total number of CVP assessments, the second one considering the number of patients recruited.

Four studies matched the inclusion criteria, but only three of them provided data for the meta-analyses. Both analyses showed non-significant differences between PICC-measured and CICC-measured CVP: 1489 paired simultaneous CVP assessments (MD 0.16, 95%CI −0.14, 0.45, p = 0.30) on a total of 57 patients (MD 0.22, 95%CI −1.46, 1.91, p = 0.80). Both analyses showed no heterogeneity (I² = 0%).

Available evidence supports that CVP monitoring with PICCs is accurate and reproduces similar values to those obtained from CICCs. The possibility to monitor CVP should not be used among clinical criteria for preferring a CICC over a PICC line.

All patients who underwent TDC insertion by nephrologists from October 2013 to June 2016 were included. TDC survival was calculated using Kaplan-Meier survival method. Impact of variables was assessed using Cox proportional hazards model.

A total of 344 TDCs were inserted in 274 patients. The most common indication was haemodialysis initiation (60.2%) followed by existing catheter dysfunction (CD) (12.2%), failed vascular access (10.2%) and catheter-related bacteraemia (CRB) (9.9%). Insertion was successful in 97% patients. The most common location was the right internal jugular vein (87%). The cumulative survival for all TDCs inserted, as defined by the time to non-elective removal of a TDC, at 3, 6 and 9 months was 83%, 61%, and 44%, respectively. Median catheter survival was 231 days. Common indications for removal were CD (13.4%) and CRB or suspected infection (12.5%). Common complications were bleeding (8.72%), infection (13.7%) and CD (16.5%). Median time to infection was 103 days. In multivariate analysis, male gender was associated with poor catheter survival, for primary insertions (p = 0.015, HR 0.62) and diabetes was associated with TDC infection (p = 0.024, OR 1.1).

This is one of the first reports of TDC insertion by nephrologists from SEA. Our outcomes compare favourably with those reported in the literature.

We report the use of a new ultrasound technique to evaluate the axial and lateral components of a complex flow in the arteriovenous fistula (AVF). Vector Flow Imaging (VFI) allows to identify different components of the flow in every direction, even orthogonal to the flow streamline, represented by many single vectors. VFI could help to identify flow alterations in AVF, probably responsible for its malfunction.

From February to June 2016, 14 consecutive patients with upper-limb AVF were examined with a Resona 7 (Mindray, Shenzhen, China) ultrasound scanner equipped with VFI. An analysis of mean velocity, angular direction and mean number of vectors impacting the vessel wall was carried out. We also identified main flow patterns present in the arterial side, into the venous aneurysm and in correspondence of significant stenosis.

A disturbed flow with the presence of vectors directed against the vessel walls was found in 9/14 patients (64.28%): in correspondence of the iuxta-anastomotic venous side (4/9; 44.4%), into the venous aneurysmal tracts (3/9; 33.3%) and in concomitance of stenosis (2/9; 22.2%). The mean velocity of the vectors was around 20-25 cm/s, except in presence of stenosis, where the velocities were much higher (45-50 cm/s). The vectors directed against the vessel walls presented high angle attack (from 45° to 90°, with a median angular deviation 65°).

VFI was confirmed to be an innovative and intuitive imaging technology to study the flow complexity in the arteriovenous fistulas.

Ipsilateral arteriovenous fistula (AVF) may cause symptoms of coronary steal in patients who had undergone coronary artery bypass graft (CABG) using internal thoracic artery. The purpose of this study was to evaluate the adverse effects of ipsilateral AVF to CABG, including the incidence of coronary steal, and to analyze the risk factors for coronary steal.

Between 2000 and 2013, a total of 25 patients undergoing hemodialysis via upper extremity AVF, ipsilateral to the preexisting CABG, were reviewed retrospectively. Clinical assessment related to coronary steal, echocardiography before AVF, and coronary angiography after symptoms were assessed. The definition of coronary steal was the new development of one or more of the following symptoms within 12 weeks after AVF creation: chest pain, chest discomfort, and dyspnea.

Three patients were clinically diagnosed as coronary steal. Left ventricular ejection fraction (LVEF) was statistically lower in coronary steal group compared to no-steal group (41.7% vs. 50.9%; p = 0.036). Patients with coronary steal were older at the age of CABG surgery and showed a higher incidence of regional wall motion abnormality.

Coronary steal after ipsilateral AVF creation in patients with CABG using in situ internal thoracic artery (ITA) developed in 12%, which can be related to low LVEF. In patients with CABG requiring AVF for hemodialysis, the ipsilateral fistula to the grafted ITA should be carefully selected and performed.

An effective approach to prevent hemodialysis vascular access dysfunction is still unclear despite previous studies, which have shown conflicting results of several drugs on vascular access outcomes. In this study, we focused on diabetic hemodialysis patients with native arteriovenous fistula and evaluated the impact of statin treatment on vascular access patency.

A retrospective cohort study of 268 consecutive patients who newly started hemodialysis due to diabetic nephropathy between January 2011 and December 2013 at Japan Community Health Care Organization Sendai Hospital was performed and the patients were followed for two years. The primary outcome was vascular access dysfunction. Effect of statin treatment was examined using Kaplan Meier analysis and Cox proportional hazard, after adjusting for covariates.

The mean follow-up period was 426.7 days, and 117 (52.2%) patients developed vascular access dysfunction. The two-year patency rate was 55.0% among statin users and 36.1% in non-users. Vascular access survival period was significantly longer among statin users (log-rank test, p = 0.004). In multivariable analysis, statin treatment is significantly associated with better vascular access outcomes, in which the hazard ratio was 0.71 (95% CI, 0.52 to 0.97; p = 0.028) in the unadjusted model and 0.63 (95% CI, 0.45 to 0.88; p = 0.007) after adjustment for covariates.

Statin treatment could be associated with improved vascular access dysfunction among diabetic hemodialysis patients.

The possibility of coronary steal through an arteriovenous fistula (AVF) in hemodialysis (HD) patients with coronary artery bypass grafts (CABGs) using an ipsilateral internal thoracic artery (ITA) has been suggested. In order to define the significance of such a possibility, we analyzed cardiac events and mortality risk in patients in relation to AVF flow.

A retrospective cohort study was performed on prevalent HD patients from a single center. The outcomes included a first cardiac event, cardiac death and death from any cause.

The group consisted of 23 chronic HD patients having ITA CABG and upper extremity AV access, 12 patients had an ipsilateral and 11 patients had a contralateral location of ITA CABG and an upper extremity AV access. The mean follow-up period was for 37.0 months.

Multivariable Cox proportional-hazards regression analysis of risk of death from any cause in relation to AV access flow showed no increased risk, neither in the group with ipsilateral location of ITA grafts and dialysis accesses (adjusted HR, 3.047 [95% CI, 0.996 to 1.000], p = 0.081), nor in the group with contralateral location of both shunts (adjusted HR, 0.173 [95% CI, 0.997 to 1.002], p = 0.678). There was no significant correlation between AV access blood flow and the risk of first cardiac event as well as cardiac death in either study group.

In this study on HD patients having ipsilateral ITA CABG and AVF, fistula flow rate was not found to be associated with mortality or cardiac risk.

Arteriovenous fistulas (AVFs) are the recommended form of vascular access for hemodialysis. However, controversy exists regarding whether AVFs are suitable for elderly patients.

Single-center retrospective review to investigate the impact of age on AVF outcomes. Five hundred and twenty-five patients with AVF creation were stratified based on age <65, 65-75, and >75 years. AVF outcomes including primary failure, AVF patency (primary, secondary, and functional), and AVF complications were studied for 3 years following AVF creation.

The cohort was 63% male, 44% Caucasian, and 55% had diabetes or cardiovascular disease. 39% were aged <65 years, 33% 65-75 years, and 28% were aged >75 years. No differences in rates of primary failure, loss of primary patency, complications, or need for intervention were observed between age groups. There was a significant association of age with secondary patency and functional patency, with age >75 being an independent risk factor for shortened lifespan of the fistula. For patients aged >75 years, secondary patency at 3 years was 64% compared to 75%-78% for younger patients. Functional patency at 2 years was 69% for those aged >75 years compared to 78%-81% for younger patients.

We found no difference in AVF maturation, primary patency, complications, or interventions in those over the age of 75 compared to younger counterparts. While secondary and functional patency rates were significantly lower in those aged >75 years, the magnitude of difference is likely not clinically relevant. Therefore, we recommend that advanced age alone should not preclude patients from AVF creation.

The arteriovenous fistula (AVF) is the preferred method of long-term haemodialysis. However, it has been shown to have a substantial rate of maturation failure. The formation of an AVF creates haemodynamic changes to blood flow in the arm with diversion of blood away from the distal circulation into the low pressure venous system, in turn, leading to thermal changes distally. In this study, we aimed to assess the novel use of infrared thermal imaging as a predictor of arteriovenous maturation.

A prospective cohort study was conducted on 100 consecutive patients who had AVF formation from December 2015 to June 2016. Infrared thermal imaging was undertaken pre- and post-operatively on the day of surgery to assess thermal changes to the arms and to assess them as predictors of clinical patency and functional maturation.

For clinical patency, infrared thermal imaging was found to have a positive predictive value of 88% and a negative predictive value of 86%. For functional maturation, it was found to have a positive predictive value of 84%, a negative predictive value of 95%. In addition, it was shown to have superiority to the commonly used intra-operative predictor of thrill as well as other independent pre-operative patient factors.

Infrared thermal imaging has been found to be a very useful tool in accurately predicting fistula patency and maturation.

Cephalic arch stenosis is one of the most common reasons for repeated endovascular intervention and eventual abandonment of access in hemodialysis patients. There is no prediction model to identify risk factors for recurrent cephalic arch stenosis. We have developed a mathematical model to predict the need for reintervention in brachiocephalic (BC) fistulas with recurrent cephalic arch stenosis.

Single-center retrospective analysis of 143 patients with a BC fistula referred to the vascular clinic for access dysfunction who underwent cephalic arch angioplasty were included for the analysis. Twelve-month post-index angioplasty data were analyzed using parametric, non-parametric and multiple regression models using SPSS software.

The mean need for re-intervention in 1 year since first index visit was 2.46 ± 1.404. Statistically significant correlation (p≤0.001) for re-intervention was observed with the severity of stenosis at index visit, access flow, vessel wall diameter proximal to the stenosis, average venous pressure >50% of the delivered blood flow rate and prolonged bleeding for >30 minutes as a reason for referral. Three equations have been derived for calculating the need for re-intervention based on the diameter of the vessel wall proximal to the stenosis.

Risk stratification of BC fistulas utilizing the above parameters could enable clinicians to identify accesses that are at risk for multiple re-interventions. Early identification of accesses that are at high risk for re-interventions at the cephalic arch might prolong access survival and reduce the cost for intervention by utilizing alternate strategies.

Patients with cancer need stable venous access using central vascular devices like central venous ports and peripherally inserted central catheters that can be used for a wide range of indications. Numerous flushing protocols exist including different frequencies for catheter locking to maintain catheter patency. The aim of this retrospective study was to evaluate the incidence of lumen occlusion of central venous ports in a group of adult cancer patients, adopting a policy of locking with normal saline every three months.

This is a single-center retrospective observational study. During follow-up, we analyzed adult cancer patients who had undergone port insertion from January 1^st, 2007 to August 31^st, 2014. Flushing and locking were performed every three months with a syringe containing normal saline.

We collected data from 381 patients with ports inserted in subclavian vein (379 patients) and in the right jugular vein (2 patients). Locking was performed during 3-monthly follow-up visits. Median follow-up was 810 days (90-2700 days). Among 381 ports, 59 were removed; the reasons for removal were: end of use (45 cases), catheter rupture (9 cases), dislocation (3 cases) and catheter-related bloodstream infection (2 cases). We had no reports of lumen occlusion.

Our data suggest that locking ports with normal saline every three months is not associated with an increased risk of lumen occlusion.

Centrally inserted central catheter (CICC) insertion is a commonly performed procedure that may give rise to different complications. Despite the suggestion of guidelines to use ultrasound guidance (USG) for vascular access, not all centers use it systematically. The aim of this study is to illustrate the experience with ultrasound in CICC placement at a high-volume oncological center, in a country where the landmark technique is standard.

Retrospective analysis of a prospective database was performed on CICC placement under USG in the Central Venous Catheter Unit of Instituto Português de Oncologia de Lisboa Francisco Gentil, from 2012 to 2015.

Three thousand five hundred and seventy-two procedures were recorded. From 2728 CICC placements, 1187 (43.5%) were done using USG. The majority of CICC placements were successful without immediate complications (96.1%). In 55 cases (4.6%), more than three attempts were necessary to puncture the vein. Pneumothorax occurred in 5 cases (0.4%) and arterial puncture was registered in 41 cases (3.5%). An increasing use of USG for placing CICCs was planned and observed over the years and, in the last year of the study, 67.3% of the CICC placements were with USG.

CICC placement with USG is a safe and effective technique. Despite some resistance that is observed, these results support that it is worth following the guidelines that advocate the use of the USG in the placement of CICC.

Despite their well-recognised shortcomings, haemodialysis catheters (HDCs) remain an important form of haemodialysis access for many patients. There are several HDCs commercially available, each differing considerably in design, which is known to significantly influence performance and survival. We sought to determine which of two tunnelled HDCs, DuraMax^® (Angiodynamics, NY, USA) or SplitCath^® (MedComp, PA, USA) delivers the best performance, safety and reliability for dialysis patients.

Eighty-six patients were prospectively randomised to receive either DuraMax^® (DM) or SplitCath^® (SC). Outcomes included: (i) mean flow rates (mL/min) averaged over the first 10 weeks of dialysis, and urea reduction ratio (URR); and (ii) long-term catheter survival with appraisal of any events leading to catheter dysfunction and early removal.

Median flow rates (interquartile range) in the DM and SC groups were 321 (309-343) and 309 (294-322) mL/min, respectively (p = 0.002). URR values for the DM and SC groups were 71 (65-76) and 74 (70-78), respectively, (p = 0.094). There was no significant difference in long-term survival or frequency of incidents that required early HDC removal (9/43 in the DM group, 5/43 patients SC). A slightly higher incidence of HDC dislodgement was noted in the DM group, although this study was not statistically powered to determine its significance.

We conclude that DM yields slightly higher flow rates in the first 10 weeks of dialysis, and a similar low incidence of complications and long-term survival for both DM and SC HDCs.

Vascular closure devices (VCDs) are commonly used to achieve hemostasis of arterial access sites, but there is little comparative data on the variety of VCDs currently in clinical use. We reviewed the VCD experience at our institution to determine the safest and most effective VCD.

Retrospective analysis of 907 consecutive arterial procedures in interventional radiology from June 2012 to June 2014 was performed. Five VCDs were used: Angio-Seal (n = 478), FISH (n = 56), Mynx (n = 56), Perclose (n = 61), and Starclose (n = 68). Patients who underwent manual compression (n = 188) without use of VCDs were also studied as a comparison group. Patient demographics and pre-procedural laboratory parameters were recorded. The technical success rate for achievement of hemostasis and complication rates were noted.

Complete hemostasis rate (aka technical success rate) was 93.5% for Angio-Seal, 83.9% for FISH, 53.6% for Mynx, 73.7% for Perclose, 76.5% for Starclose, and 91.5% for manual compression. The differences among the devices were statistically significant (p<0.001). Fourteen major complications (1.5%) were encountered: nine with Angio-Seal (1.9%), one with Mynx (1.8%), one with Starclose (1.5%), and three with manual compression (1.6%); these differences were not statistically significant. Of the demographic and laboratory parameters studied, none were significantly correlated with hemostasis failure or development of complications.

In our single-center institutional experience, Angio-Seal is the device with the best technical success rate. Major complications of VCDs were rare, with no statistically significant difference between devices.

To evaluate long-term clinical outcomes and complications of the single-incision technique for implantation of totally implantable venous access ports (TIVAPs) via the axillary vein.

A total of 932 TIVAPs were placed in 927 patients between May 2012 and October 2014 using a single-incision technique. Patients included 620 men and 307 women with a mean age of 60.0 years. TIVAPs were placed via the left (n = 475) and right (n = 457) axillary veins after making a single oblique vertical incision and medial side pocket without subcutaneous tunneling. We retrospectively reviewed medical records to evaluate status of the patients and TIVAPs, complications, and reasons for explantation. In patients who still had a TIVAP in place, we calculated the duration of TIVAP use from the cut-off day of November 1, 2015.

Clinical follow-up was obtained for a total device service period of 311,069 days with a median indwelling time of 467 days (range: 3-1097 days). A total of 37 (4.0%) complications developed. Early complications (n = 4) were one case each of stenosis of the brachiocephalic vein by tumor growth, thrombosis of axillary vein, intravascular migration, and malfunction depending on patient's position. Late complications (n = 33) were suspected catheter-related blood stream infection (n = 23), local infection of the pocket (n = 4), symptomatic stenosis and thrombosis of central vein (n = 4), malfunction by fibrin sleeve (n = 1), and intravascular migration (n = 1).

A single-incision technique for TIVAP implantation via the axillary vein seems to be safe with a low risk of complication.

Stenosis is the main cause of arteriovenous fistula (AVF) failure. It is still unclear whether surveillance based on vascular access blood flow (Q_A) enhances AVF function and longevity.

We conducted a three-year follow-up randomized, controlled, multicenter, open-label trial to compare Q_A-based surveillance and pre-emptive repair of subclinical stenosis with standard monitoring/surveillance techniques in prevalent mature AVFs. AVFs were randomized to either the control group (surveillance based on classic alarm criteria; n = 104) or to the Q_A group (Q_A measured quarterly using Doppler ultrasound [M-Turbo^®] and ultrasound dilution [Transonic^®] added to classic surveillance; n = 103).

The criteria for intervention in the Q_A group were: 25% reduction in Q_A, Q_A<500 mL/min or significant stenosis with hemodynamic repercussion (peak systolic velocity [PSV] more than 400 cm/sc or PSV pre-stenosis/stenosis higher than 3).

At the end of follow-up we observed a significant reduction in the thrombosis rate in the Q_A group (0.025 thrombosis/patient/year in the Q_A group vs. 0.086 thrombosis/patient/year in the control group [p = 0.007]). There was a significant improvement in the thrombosis-free patency rate (HR, 0.30; 95% CI, 0.11-0.82; p = 0.011) and in the secondary patency rate in the Q_A group (HR, 0.49; 95% CI, 0.26-0.93; p = 0.030), with no differences in the primary patency rate between the groups (HR, 0.98; 95% CI, 0.57-1.61; p = 0.935).

There was greater need for a central venous catheter and more hospitalizations associated with vascular access in the control group (p = 0.034/p = 0.029).

Total vascular access-related costs were higher in the control group (€227.194 vs. €133.807; p = 0.029).

Q_A-based surveillance combining Doppler ultrasound and ultrasound dilution reduces the frequency of thrombosis, is cost effective, and improves thrombosis free and secondary patency in autologous AVF.

Perioperative ultrasound performed by the operative surgeon can improve outcomes of vascular access surgery. We present the case of a patient referred for dysfunctional vascular access with two separate and patent right arm arteriovenous fistulas (AVF). Pre-operative ultrasound vessel mapping defined the complex anatomy and intraoperative ultrasound allowed the optimal surgical approach for access salvage while avoiding the need for catheter placement.

A 45-year-old male patient of African descent presented with a malfunctioning right forearm AVF and aneurysm formation in the arm. Clinical examination revealed a soft, low-flow forearm fistula merging into a high-flow and pulsatile AVF outflow aneurysm in the arm. Multiple well healed surgical incisions were present. Ultrasound examination revealed two separate AVFs. One was a low-flow radiocephalic AVF at the wrist that was used routinely for cannulation in the forearm, although with some difficulty due to low inflow pressure. The second AVF, a brachiocephalic anastomosis, was pulsatile, aneurysmal, and not in use. Blood flow in the proximal brachial artery was 3.0 L/min. Surgeon-performed ultrasound (SP-US) was used perioperatively to plan the surgical approach and incision, closing the existing brachial anastomosis and creating a veno-venous anastomosis between both outflow veins, establishing a mature and undisturbed cannulation conduit from the wrist through the arm. The revised AVF was immediately usable for hemodialysis with restored normal AVF flow in the forearm and appropriately reduced flow in the arm. Importantly, dialysis catheter placement was avoided.