The Journal of Vascular Access

Peripherally inserted central catheters (PICC) are being increasingly used in critical care setting. However, PICCs are associated with a number of complications, particularly upper extremity venous thrombosis (UEVT), leading to post-thrombotic syndrome, pulmonary embolism and increased risk of catheter-related infection.

To review the literature surrounding PICCs and highlight the epidemiology, pathophysiology, diagnosis and management of PICC-related thrombosis in critically ill patients.

We performed an electronic literature search of the databases PubMed, EMBASE and Google scholar using set search terms, from their commencement date to the end of January 2014.

It has been shown that PICCs may double the risk of deep venous thrombosis compared with centrally inserted venous catheters, in critically ill patients. However, the incidence of PICC-related thrombosis in critically ill patients has not been quantified. Ultrasonography is the preferred diagnostic imaging modality. There are no randomized controlled trials (RCTs) on the best treatment of PICC-related thrombosis in the intensive care unit (ICU) setting and in most cohort studies, anticoagulation strategies with or without PICC removal have been used.

Decision to insert a PICC should be taken after careful risk stratification. There is lack of high-quality evidence assessing prevention strategies and management of PICC-related thrombosis in the ICU. Well-designed RCTs are required to estimate the prevalence of UEVT in ICU patients with PICCs and evaluate the efficacy and magnitude of clinical benefit and cost-effectiveness of therapeutic strategies.

The purpose of this article is to report our experience with drug-eluting balloons for the treatment of juxta-anastomotic stenoses of failing radiocephalic hemodialytic arteriovenous shunt and to evaluate the primary and secondary patency (PP and SP).

After approval by the local hospital's Ethical and Scientific Review Board, 26 consecutive patients with juxta-anastomotic stenosis of radiocephalic hemodialytic shunt were treated with angioplasty with drug-eluting balloon. The main objective was to evaluate PP defined, in accordance with the Kidney Disease Outcomes Quality Initiative recommendation, as the absence of dysfunction of the vascular access, patent lesion or residual stenosis <30% and no need for further reintervention of the target lesion (TL). PP and SP at 6, 12 and 24 months were evaluated, with echo color doppler and phlebography, for both arteriovenous fistulae, defined as absolute, and TL.

Immediate postprocedural technical and clinical success was 100% for all the patients; we had only one technical failure in repeated treatments. At 6 months the absolute and TL PP was 96.1%; at 12 months the absolute PP was 81.8%, TL PP 90.9%, absolute SP 95.4%, TL SP 100%; at 24 months the absolute and TL PP was 57.8%; absolute and TL SP 94.7%; only one arteriovenous fistula was lost during the period.

The use of drug-eluting balloons, after standard angioplasty, improves primary patency and decreases reinterventions of TL in juxta-anastomotic stenoses of failing native dialytic arteriovenous shunts.

To evaluate reasons for tunneled central venous catheter (TCVC) usage in our prevalent hemodialysis population and assess the impact of a surgically aggressive approach to definitive access creation.

Clinical review of all patients in the West of Scotland dialyzing via a TCVC in November 2010 was performed. Reasons for TCVC usage and TCVC complications were evaluated. Over the subsequent year, aggressive intervention was undertaken to achieve definitive access in all suitable patients and outcomes re-evaluated a year later (November 2011).

There was no significant difference in the proportion of patients dialyzing via a TCVC in 2010 compared to 2011 (30.3% (n=193) vs. 31.7% (n=201), respectively; p=0.56). All patients now have a “vascular access plan.” Of patients dialyzing via a TCVC in 2010, 37% had died by 2011, 22% remained on long-term line, 20% had successful arteriovenous fistula (AVF) creation, 1% had an arteriovenous graft and 2% were transplanted; 10.4% developed complications of vascular access and required ligation of a functioning AVF. A further 6.5% died within 28 days of surgery. The incidence of culture-positive Staphylococcus aureus bacteremia was 1.6 per 1,000 catheter days.

Aggressive strategies of AVF creation resulted in one-fifth of patients on a long-term TCVC having successful creation of an AVF. This was offset against high failure and significant complication rate from AVF creation in this population. One-third of patients dialyzing via a TCVC died in the subsequent year. Correct patient selection for AVF creation is essential and predialysis care must be optimized to avoid the need for TCVCs entirely.

This report presents a new animal model of arteriovenous fistula (AVF) with attention given to surgical techniques as well as hemodynamic and pathologic measurements. Of note, this model was created with a tunneled central catheter with the purpose of studying therapeutic interventions, including hemodialysis.

Side-common carotid artery to end-external jugular vein AVFs were created in eight minipigs. A tunneled central catheter was also placed in the internal jugular vein. After 28 days, hemodynamic measurements of AVF flow and stenosis were performed. The minipigs were then euthanized and the AVFs were harvested for pathologic measurements of neointimal hyperplasia and thrombus volumes. In order to account for variable size of the AVFs, percentage luminal stenosis and degree of intima–media thickening were calculated.

After 28 days, all eight AVFs remained patent. On average, 19% of arterial blood flow that approached the AVF traveled through the anastomosis. The average luminal stenosis by angiogram was 61.1%. The average neointimal hyperplasia and thrombus volumes were 1.4×10⁸ and 3.8×10⁸ μm³, respectively. The average luminal stenosis and intima–media thickening were 65.2% and 430.4 μm, respectively.

This AVF model is ideal because of the relative ease of surgery and husbandry, lack of complications, as well as consistent and rapid development of the neointimal lesion which underlies AVF failure.

Many individuals with end-stage renal disease (ESRD) have adequate arteries and veins for construction of an arteriovenous fistula (AVF) but the fistula may be too deep to cannulate because of overlying adipose tissue. This study evaluated the safety and efficacy of liposuction to superficialize deep AVFs.

Between September 2009 and January 2011, 13 patients participated in the study. Mean body mass index (BMI) was 39.1 kg/m². The study was limited to brachiocephalic and radiocephalic fistulas. Mean fistula depth was 8.1 mm. The primary endpoint was the date of the first successful cannulation with two 17-gauge needles. Patients were followed for 12 mo.

Eleven subjects (85%) underwent successful two-needle cannulation a mean of 33.7 days after the procedure. One patient died of endocarditis and one developed a hematoma and wound necrosis that required surgical elevation to enable cannulation. Projection and palpability of the fistulas tended to increase over time. Mean tissue removed was 243 mL and correlated positively with the number of days to cannulation (r=0.74, p=0.01). Greater BMI correlated positively with more surgical site complications and delays in cannulation. At 12 mo, primary patency after liposuction was 50% and secondary patency was 83%.

Most subjects had prompt, uncomplicated cannulation but a few had wound necrosis, large hematomas and prolonged time until cannulation. Liposuction is effective in enabling cannulation of deep vein fistulas but because of the substantial risk of serious surgical site complications, it may not be the ideal method.

Anesthetic options for arteriovenous fistula (AVF) creation include regional anesthesia (RA), general anesthesia (GA) and local anesthetic for select cases. In addition to the benefits of avoiding GA in high-risk patients, recent studies suggest that RA may increase perioperative venous dilation and improve maturation. Our objective was to assess perioperative outcomes of AVF creation with respect to anesthetic modality and identify patient-level factors associated with variation in contemporary anesthetic selection

National Surgical Quality Improvement Project (NSQIP) data (2007-2010) were accessed to identify patients undergoing AVF creation. Univariate analysis and multivariate logistic regression were performed to assess the relationships among patient characteristics, anesthesia modality and outcome.

Of 1,540 patients undergoing new upper extremity AVF creation, 52% were male and 81% were younger than 75 years. Anesthesia distribution was GA in 85.2%, local/monitored anesthetic care (MAC) in 2.9% and RA in 11.9% of cases. By multivariate analysis, independent predictors of RA were dyspnea at rest (hazard ratio [HR] 2.3, 95% confidence interval [CI] 1.1-4.9), age >75 (HR 1.6, 95% CI 1.1-2.3) and teaching hospital status as indicated by housestaff involvement (HR 3.7, 95% CI 2.5-5.5). RA was associated with higher total operative time, duration of anesthesia, length of time in operating room and duration of anesthesia start until surgery start (p<0.01). There were no differences between perioperative complications or mortality among anesthetic modalities, although all deaths occurred in the GA group.

Despite recent reports highlighting potential benefits of RA for AVF creation, GA was surprisingly used in the vast majority of cases in the United States. The only comorbidities associated with preferential RA use were advanced age and dyspnea at rest. Practice environment may influence anesthetic selection for these cases, as a nonteaching environment was associated with GA use. The trend seen here toward higher mortality in GA and the potential perioperative benefits of RA for the access should encourage more widespread use of RA in practice for this high-risk patient population.

Due to their relatively low complication rates autogenous arteriovenous fistulas (AVFs) are the preferred access for hemodialysis. In long-standing AVF, however, aneurysmatic degeneration of the fistula vein can develop. Several treatment options have been published. We evaluated our experience with autologous surgical reconstruction in patients with AVF aneurysms in order to assess complication and patency rates.

Demographics and comorbidities of all patients operated on for true AVF aneurysms in our institution, during a 7-year period, were reviewed. Access function and surgical outcomes were evaluated with pre- and postoperative Doppler ultrasonography. Patient survival, primary and secondary access patency rates are presented.

From April 2006 through March 2013, 31 patients presented with access-associated upper extremity venous aneurysms. The mean time from AVF creation to aneurysm formation was 4.9±3.6 years. The most frequent indication for surgery was aneurysm-associated stenosis (n=16) followed by high flow (n=9), complete thrombosis (n=3) and uncontrolled bleeding (n=3). All patients had autologous reconstructions: 5 resections with end-to-end anastomosis and 26 aneurysmorrhaphies. Overall patient survival at 1 and 2 years was 89% and 84%, respectively. The primary (secondary) patency rates at 6 mo, 1 and 2 years were 87%, 81% and 81% (96%, 96% and 90%), respectively.

Autologous surgical reconstruction is feasible in the majority of AVF aneurysms. It preserves fistula function and–-in contrast to graft interposition and endovascular repair–-keeps the advantages of an autogenous access: low complication and high patency rates.

To explore the safety and efficacy of PRT-201 applied to the outflow vein of a newly created arteriovenous graft (AVG).

Randomized, double-blind, placebo-controlled, single-dose escalation study of PRT-201 (0.01 to 9 mg) applied to the graft-vein anastomosis and adjacent outflow vein immediately after AVG placement. The primary outcome measure was safety. The efficacy measures were intraoperative increases in outflow vein diameter and blood flow rate, primary unassisted patency, and secondary patency by dose groups (placebo, low, medium, high and All PRT-201).

A total of 89 patients were treated (28 placebo and 61 PRT-201). There were no significant differences in the proportion of placebo and PRT-201 patients reporting adverse events. Intraoperative outflow vein diameter increased 5% (p=0.14) in the placebo group compared with 13% (p=0.01), 15% (p=0.07) and 12% (p<0.001), in the low, medium and high groups, respectively. The comparison between the high and placebo groups was marginally statistically significant (p=0.06). The intraoperative blood flow did not change in the placebo group, and increased in the low, medium and high groups by 19% (p=0.34), 36% (p=0.09) and 46% (p=0.02), respectively. The low group had the longest primary unassisted and secondary patency and the fewest procedures to restore or maintain patency; however, the differences between groups were not statistically significant.

PRT-201 was well tolerated and increased AVG intraoperative outflow vein diameter and blood flow. Low dose tended to increase secondary patency and decrease the rate of procedures to restore or maintain patency. Larger studies with these doses will be necessary to confirm these results.

The purpose of this study is to report the short-term results of the Gore^® Acuseal graft for prosthetic vascular access (pVA) in patients with end-stage renal disease on hemodialysis.

Between October 2011 and October 2013, all the consecutive patients who underwent implantation of a new expanded Polytetrafluoroethylene (ePTFE) tri-layer graft were included in the study. Primary and secondary patency rate, time to first cannulation, and complications were recorded. Follow-up was performed at 1, 3, 6, and 12 months after the intervention.

Thirty ePTFE tri-layer heparin bonded grafts were implanted in 18 males and 12 females. The graft configuration was radial-basilic (n=12, 40%), brachial-basilic (n=10, 33.3%), femoro-femoral (n=3, 10.0%), radial-cephalic (n=2, 6.7%), radial-antecubital forearm (n=2, 6.7%), and brachial-axillary (n=1, 3.3%). No patient was lost during a mean follow-up time of 6.3±5.9 months (range, 1-24; median, 5). Mean time to first cannulation was 2.4±1.2 days (range, 1-15). Primary functional patency rate was 68.0% ± 10 at 6 and 12 months. Secondary patency rate was 93.3% ± 6 at 6 and 12 months. Pseudoaneurysm, bleeding, seroma, or graft infection was never observed.

In our experience, the Gore^® Acuseal graft was useful and safe. Early cannulation was always performed, and structural complications did not occur. Primary functional and secondary patency rate are satisfactory in the short term.

Totally implantable venous access devices (Ports) represent the mainstay for infusion therapy in patients undergoing chemotherapy, total parenteral nutrition and/or long-term antibiotic treatment. Amongst mechanical complications, lesions of the catheter wall represent a rare but potentially severe condition. We report our experience with the accidental detection of catheter ruptures in a series of ports removed for complication or for end of use.

All ports removed from January 2011 to June 2013 were considered. All removed ports had been inserted according to a standardized protocol including ultrasound-guided percutaneous venipuncture (out-of-plane or in-plane approaches) and electrocardiogram-guided positioning of the tip. Once removed, each catheter was checked by inspection and saline instillation in order to evaluate the integrity of the device itself and rule out possible ruptures.

In over 338 removed ports, 12 Groshong catheters out of 65 (18.5%) had evidence of partial rupture of the catheter wall. Amongst considered variables, “out-of-plane” approach and type of port (silicon, closed tip with Groshong valve) were the only ones significantly associated with catheter ruptures (p=0.0003 and 0.0008, respectively). We could detect no evidence of rupture in any silicon open-ended catheter (Celsite ports) or in any catheter inserted by “in-plane” approach to the vein.

The actual advantage of using port connected with Groshong silicon catheters should be questioned, since apparently they are more fragile than standard catheters. Furthermore, ultrasound-guided “out-of-plane” puncture of the internal jugular vein should be discouraged.

The aim of the study was to evaluate our experience in the hybrid simultaneous treatment (open and endovascular) of acute thrombosis of prosthetic grafts for hemodialysis.

Between January 2011 and June 2013, 23 patients with acute thrombosis of a prosthetic graft for hemodialysis were urgently treated with a hybrid simultaneous treatment in order to obtain a prompt restoration of the flow. A new puncture of the graft was scheduled after 24 hours.

Intraoperative technical success was 100% with a completion angiography showing the restored patency of the graft. As adjunctive procedures, in 6 patients (26.1%) locoregional thrombolysis was necessary and in all cases further endovascular manoeuvres (angioplasty/stenting) were immediately performed to solve a significant stenosis of the venous anastomosis/first tract of the vein. At 24 hours when the first puncture was done, three grafts were occluded resulting in a primary patency of 87%. During the follow-up (mean duration 5.6 months) four reocclusions occurred. In-stent restenosis occurred in all patients undergone stenting. At 1 year the rates of primary patency, primary assisted patency and secondary patency were 58.7%, 78.3% and 87%, respectively.

In our series the combined simultaneous hybrid approach in urgency maximizes the use of different available techniques, which appeared to improve overall success rate to save a thrombosed graft for hemodialysis. The great difference showed between primary and primary assisted patency demonstrates the necessity of a close follow-up.

The purpose of this study was to evaluate the feasibility, efficacy and safety of percutaneous thromboaspiration with a 7F Desilets-Hoffman sheath compared with previously established percutaneous mechanical thrombectomy techniques in occluded hemodialysis grafts.

One thousand three hundred five patients (767 women, 538 men; mean age, 61.04±13.09 years; mean graft age, 36.64±30.80 mo) with 2,531 episodes of hemodialysis graft thrombosis underwent percutaneous thromboaspiration with a 7F Desilets-Hoffman sheath using criss-cross or apex puncture technique. Technical success rate, procedure time, complications and patency rates were analyzed.

Technical success was achieved in 2,426 of 2,531 procedures (95.9%). Average procedure time of the intervention was 42.87±22.77 minutes. Primary patency rate was 61.9% at 3 mo, 41.2% at 6 mo and 19.6% at 1 year. Major complications occurred in 4.1% of cases (23 graft outflow rupture; 68 arterial emboli; 1 arterial dissection; 3 symptomatic pulmonary embolism; 1 stent migration) and minor complications occurred in 7.7% of cases (196 cases). These results were comparable to previously reported mechanical thrombectomy techniques in occluded hemodialysis grafts.

Percutaneous thromboaspiration of occluded hemodialysis grafts with a Desilets-Hoffman Sheath is an effective and safe method.

Stenosis in a vascular access circuit is the predominant cause of access dysfunction. Hemodynamic significance of a stenosis identified by angiography in an access circuit is uncertain. This study utilizes computational fluid dynamics (CFD) to model flow through arteriovenous fistula to predict the functional significance of stenosis in vascular access circuits.

Three-dimensional models of fistulas were created with a range of clinically relevant stenoses using SolidWorks. Stenoses diameters ranged from 1.0 to 3.0 mm and lengths from 5 to 60 mm within a fistula diameter of 7 mm. CFD analyses were performed using a blood model over a range of blood pressures. Eight patient-specific stenoses were also modeled and analyzed with CFD and the resulting blood flow calculations were validated by comparison with brachial artery flow measured by duplex ultrasound.

Predicted flow rates were derived from CFD analysis of a range of stenoses. These stenoses were modeled by CFD and correlated with the ultrasound measured flow rate through the fistula of eight patients. The calculated flow rate using CFD correlated within 20% of ultrasound measured flow for five of eight patients. The mean difference was 17.2% (ranged from 1.3% to 30.1%).

CFD analysis-generated flow rate tables provide valuable information to assess the functional significance of stenosis detected during imaging studies. The CFD study can help in determining the clinical relevance of a stenosis in access dysfunction and guide the need for intervention.

Long intravenous catheters are an effective and economical choice of vascular access for intravenous antibiotic therapy in children with cystic fibrosis (CF). This prospective audit assesses the use of Vygon Leaderflex 22G × 8 cm catheters in an Australian tertiary centre. Key outcomes included catheter lifespan, ability to complete antibiotic therapy and complication rates.

All paediatric patients admitted with infective exacerbations of CF lung disease for 18 months between 2012 and 2013 were prospectively included. Data were analysed using t-tests and Fisher exact test.

A total of 40 successful catheter insertions for 20 patients during 32 admissions were identified. The mean duration of the catheters was 10.08 days (median 9.5, SD=5.0). Of the 32 admissions, antibiotic therapy was completed with long catheters in 78% of cases (n=25) and with a single catheter in 48% (n=19). Rates of local complications were high, but there were no serious adverse outcomes.

Although limited by a small sample size, the results from this study are promising and suggest that 8 cm long catheters are a safe, effective and economical alternative to peripherally inserted central catheters (PICCs) in treating pulmonary exacerbations in children with CF.

We report on the endovascular management of hemorrhage with stent-graft due to a misplaced central venous catheter in the vertebral artery (VA) during percutaneous internal jugular vein catheterization in a child.

A 16-year-old female was presented with the diagnosis of familial Mediterranean fever related chronic renal insufficiency. An attempt was made to place a central venous catheter via the right internal jugular vein without image guidance and the patient experienced dyspnea and pain at the catheter insertion site. Computerized tomography (CT) showed hemorrhage in the cervical region and upper mediastinum, also reformatted images showed that the catheter was passing through the proximal part of the VA and terminating in the right mediastinum. The catheter was removed during manual compression under angio-flouroscopic monitoring and ongoing extravasation was observed. A stent-graft was placed to the bleeding site of the VA.

Angiography immediately after the stent-graft placement revealed complete disappearance of extravasation and patency of vertebral and subclavian arteries.

Central venous catheterization (CVC) is not a risk-free procedure and arterial injuries are in a wide spectrum from a simple puncture to rupture of the artery. Inadvertent VA cannulation is a rare and serious complication necessitating prompt diagnosis and early treatment. If an arterial injury with a large-caliber catheter occurs, endovascular treatment with stent-graft seems to be a safe and effective option in terms of achieving hemostasis and preserving arterial patency. Recent findings suggest that endovascular management of inadvertent cervical arterial injury secondary to CVC seems to be the safest strategy.

A surveillance duplex scan detected a stenosis within a left groin hemodialysis loop graft in a 57-year-old woman who was allergic to both iohexol and gadolinium contrast agents. This precluded the use of standard angioplasty treatment techniques. Intravascular ultrasound (IVUS) uses a catheter mounted with a miniaturized ultrasound probe to produce detailed cross-sectional vessel images. Clinically, it has been used in the assessment of coronary artery disease but has also supplemented standard angiography techniques in the assessment of peripheral vascular and hemodialysis access lesions.

IVUS was utilized as the solitary imaging modality to identify the graft stenosis and guide the placement of a 6 mm diameter angioplasty balloon. Two areas of stenosis were successfully dilated and subsequent IVUS re-examination showed abolition of the stenosis.

Twelve-month follow-up surveillance scan showed that the graft remained functional with good flow rates.

In the setting of contrast allergy, IVUS may provide a valid and safe tool in the localization and treatment of peripheral vessel stenosis, including arteriovenous fistula angioplasty. To our knowledge this is the first reported use of IVUS for hemodialysis graft salvage adopting a completely ‘contrast-free’ technique. More studies are required to establish the true role of IVUS in the management of hemodialysis access angioplasty, but this successful case contributes valuable information to the literature on its clinical application.

True brachial artery aneurysms are rare, typically occurring secondary to trauma. In this report, we describe two recent cases of patients who presented acutely with upper limb ischaemia due to brachial artery aneurysms. Both patients presented many years after brachiocephalic arteriovenous (AV) fistula ligation in the ipsilateral limb.

Two male patients, aged 60 and 63 years, respectively, were seen acutely with symptoms of upper limb ischaemia. They had both undergone ligation of AV fistulae many years earlier having received functioning transplants. Subsequently, both patients were found to have true brachial artery aneurysms, which were bypassed in both instances using great saphenous vein grafts.

Patients undergoing ligation of AV fistulae should receive interval surveillance imaging to detect potential aneurysmal dilatation of upper limb vessels. Little is known about the incidence of aneurysm formation after AV fistula ligation; given the increasing number of patients undergoing dialysis, and hence the burgeoning number of patients who may receive transplants, it is important that upper limb ischaemia is pre-empted by appropriate follow-up.