ASDIN Original Investigations: Venous Mapping Using Venography and the Risk of Radiocontrast-Induced Nephropathy

Initiation of hemodialysis at one month following fistulogram in patients with advanced kidney disease

OBJECTIVE

Previous studies have demonstrated that low contrast volume used in access-related interventions had limited effects on the progression of chronic kidney disease (CKD) after fistulography, but studies are limited and heterogeneous. We sought to evaluate the rate of and factors associated with progression to dialysis (HD) within 1 month after fistulography for patients with advanced CKD.

METHODS

A single-institution retrospective cohort analysis of patients with CKD stage IV and V, not yet on HD, undergoing fistulography from 1 January 2014 to 31 December 2018 was performed. The primary outcome was progression to HD within 1 month. Additional variables and the association with the primary outcome such as medical comorbidities, contrast type or volume were assessed.

RESULTS

A total of 34 patients underwent 41 fistulograms prior to HD initiation. Progression to HD within 1 month of fistulogram occurred in seven patients (all CKD V). The mean time between fistulogram and HD was 271 days for 31 of 34 patients who ultimately progressed to HD. Those with CKD IV began HD in 549 days on average, while those with CKD V began HD in 190 days on average. Three patients had not initiated HD at a mean of 539 days of follow-up. The only factors associated with progression to HD within 1 month included use of isovue (p = .005) and elevated contrast volume, with a mean of 40 mL (p = .027).

CONCLUSION

Although none of the patients with CKD IV required HD within 1 month after fistulogram, the use of larger iodinated contrast volume was associated with progression to HD within 1 month of fistulography for patients with CKD V. Further studies should investigate the safety of iodinated and alternative (e.g., carbon dioxide) contrast media in fistulography or duplex-based HD access procedures for CKD patients, especially CKD V, not yet on HD.

Anatomical variants of upper arm veins on preoperative mapping venography for hemodialysis access in Korean adults

INTRODUCTION

The number of elderly patients requiring hemodialysis has increased, along with the need for multiple vascular access placements. Thus, the frequency of access creation using the upper arm veins, including transposed basilic arteriovenous fistula, has also increased. The purpose of this study was to identify the prevalence of anatomical variations in the upper arm veins on preoperative mapping venography and to investigate the implications of such variants on access creation.

METHODS

A total of 494 venograms were performed on 251 patients for primary access creation from June 2014 to June 2017 in this single-center, retrospective study. The venograms were classified into eight subtypes, based on the anatomical relationship between the basilic and brachial veins. The presence of bifid cephalic arches and brachial-basilic ladders was also examined.

RESULTS

The presence of bifid cephalic arches and brachial-basilic ladders was identified in 8.7% and 14.0% of cases, respectively. Paired brachial veins joined separately with the basilic vein in 67.4% of venograms, whereas these veins merged into a common brachial vein before connecting to the basilic vein in 13.1% of cases. A single brachial vein was present in 19.3% of cases. 15.7% of cases were considered unsuitable for basilic vein transposition due to the early confluence of the brachial-basilic vein, posing a risk of obliterating the deep venous drainage if transposed.

CONCLUSION

There are significant anatomical variations of upper arm veins, and the recognition of certain variants can affect surgical planning and outcomes of access placement. It is important to identify anatomical variants of the upper arm veins during preoperative vein mapping.

Improving haemodialysis fistula maturation following early ultrasound vascular mapping: 'The Venous Preservation Scan'

AIM

Formation of autogenous arteriovenous fistula (AVF) in patients with chronic kidney disease (CKD) is complicated by a high primary failure rate. We hypothesized that early (months to years before AVF creation) Venous Preservation Scan (VPS) followed by vasculature preservation is effective in protecting the patient's best 'for fistula' vasculature. This study was performed to evaluate the impact of VPS on AVF outcomes.

METHODS

The case records of 123 patients who underwent ultrasound mapping for AVF creation in a district hospital were reviewed. Ninety-seven were VPS and 26 were Routine Pre-Operative Planning Scan (RPOPS) performed immediately prior to surgery. Outcomes of 21 patients who went onto AVF creation in the VPS group were compared to 23 patients in the RPOPS group.

RESULTS

Success and complication rates for AVF placement in patients who underwent VPS versus RPOPS were 100% versus 91.3% (P = 0.27) and 0 versus 8.7% (P = 0.23). A greater proportion of AVF created following RPOPS required intervention before maturation (47.6% vs 19%, P = 0.05). The median primary patency of AVF created following VPS versus RPOPS was 492 (IQR 222, 1219) versus 169 (IQR 116, 414) days (P = 0.02). The cumulative patency did not differ between the two groups (median = 807 (IQR 499, 1308) versus 1059 (IQR 331, 1263) days, P = 0.26).

CONCLUSIONS

This small study suggests that VPS may favourably influence the survival of primary AVF and reduce the need for assisted interventions. However, confirmation with larger randomized controlled trial is warranted.

Vascular Access Practice Patterns in Canada: A National Survey

Background:

One of the mandates of the Canadian Society of Nephrology’s (CSN) Vascular Access Working Group (VAWG) is to inform the nephrology community of the current status of vascular access (VA) practice within Canada. To better understand VA practice patterns across Canada, the CSN VAWG conducted a national survey.

Objectives:

(1) To inform on VA practice patterns, including fistula creation and maintenance, within Canada. (2) To determine the degree of consensus among Canadian clinicians regarding patient suitability for fistula creation and to assess barriers to and facilitators of fistula creation in Canada.

Design:

Development and implementation of a survey.

Setting:

Community and academic VA programs.

Participants:

Nephrologists, surgeons, and nurses who are involved in VA programs across Canada.

Measurements:

Practice patterns regarding access creation and maintenance, including indications and contraindications to fistula creation, as well as program-wide facilitators of and barriers to VA.

Methods:

A small group of CSN VAWG members determined the scope and created several VA questions which were then reviewed by 5 additional VAWG members (4 nephrologists and 1 VA nurse) to ensure that questions were clear and relevant. The survey was then tested by the remaining members of the VAWG and refinements were made. The final survey version was submitted electronically to relevant clinicians (nephrologists, surgeons, and nurses) involved or interested in VA across Canada. Questions centered around 4 major themes: (1) Practice patterns regarding access creation (preoperative assessment and maturation assessment), (2) Practice patterns regarding access maintenance (surveillance and salvage), (3) Indications and contraindications for arteriovenous (AV) access creation, and (4) Facilitators of and barriers to fistula creation and utilization.

Results:

Eighty-two percent (84 of 102) of invited participants completed the survey; the majority were nurses or VA coordinators (55%) with the remainder consisting of nephrologists (21%) and surgeons (20%). Variation in practice was noted in utility of preoperative Doppler ultrasound, interventions to assist nonmaturing fistulas, and procedures to salvage failing or thrombosed AV-access. Little consensus was seen regarding potential contraindications to AV-access creation (with the exception of limited life expectancy and poor vasculature on preoperative imaging, which had high agreement). Frequent barriers to fistula utilization were primary failure (77% of respondents) and long maturation times (73%). Respondents from centers with low fistula prevalence also cited long surgical wait times as an important barrier to fistula creation, whereas those from centers with high fistula prevalence cited access to multidisciplinary teams and interventional radiology as keys to successful fistula creation and utilization.

Conclusions:

There is significant variation in VA practice across Canada and little consensus among Canadian clinicians regarding contraindications to fistula creation. Further high-quality studies are needed with regard to appropriate fistula placement to help guide clinical practice.

Impact of pre-operative venography on the planning and outcome of vascular access for hemodialysis patients

Objective

Pre-operative venous mapping has increased dramatically in most dialysis units since the Dialysis Outcome Quality Initiative (DOQI) guidelines recommended a native arteriovenous venous fistula (AVF) rather than a graft for hemodialysis (HD) access procedures. However, there are conflicting consequences as a result of this policy. Some studies have showed that routine mapping has resulted in a marked increase in maturation rate while others have observed the reverse. This study aimed to evaluate the impact of pre-operative venography on the planning and outcome of AVF for our HD patients.

Patients and methods

A prospective study was performed on all patients with end-stage renal disease (ESRD) who had HD access procedures and pre-operative venography between October 2003 and November 2005. Upper limb venography was done for all patients except those that required primary access and had visible veins. All patients had HD immediately after the venography. Access procedure selection was based on the result of the venography. The complications of venography, the surgical procedure and the outcome were recorded.

Results

One hundred and twenty-nine patients with ESRD who had pre-operative venography were included in this study. They were mostly middle age (mean age ± SD = 41 ± 15.5 yrs) with a high rate of diabetes mellitus (53%). No single complication was reported. A graft was placed in six patients (5%) only. Unsuccessful surgical exploration was 0%. Early failure was in 10 patients (8%).

Conclusion

Pre-operative venography resulted in an increase in the number of AVFs. It can improve the results of HD access procedures by selecting the most suitable veins.

Preoperative management of arteriovenous fistula (AVF) for hemodialysis

Native arteriovenous fistula (AVF) is the favorite access for hemodialysis (HD). The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) recommends its creation in most patients with renal failure. Unfortunately, intensive efforts to promote native AVF in patients with marginal vessels have increased the rate of primary fistula failure. A non-functioning fistula prompts the use of central venous catheter (CVC) that, unlike AVF, has been associated with an increased risk of morbidity and mortality among patients receiving HD. We believe that successful and timely AVF placement relies on the development of a multidisciplinary integrated preoperative program divided into five stages: (i) management of patients with advanced chronic kidney disease (CKD), (ii) management of preoperative risk factors for AVF failure, (iii) planning of native AVF, (iv) assessment of patient eligibility and (v) preoperative vascular mapping. Focusing specifically on native AVF, we review scientific evidence regarding preoperative management of this vascular access in order to favor construction of long-term functioning fistula minimizing development of severe complications.

Estimating the Risk of Radiocontrast-Associated Nephropathy

Estimates of the incidence of radiocontrast-associated nephropathy vary widely and suffer from misclassification of the cause of AKI and confounding. Using the Nationwide Inpatient Sample, we created multiple estimates of the risk of radiocontrast-associated nephropathy among adult patients hospitalized in the United States in 2009. First, we stratified patients according to the presence or absence of 12 relatively common diagnoses associated with AKI and evaluated the rate of AKI between strata. Next, we created a logistic regression model, controlling for comorbidity and acuity of illness, to estimate the risk of AKI associated with radiocontrast administration within each stratum. Finally, we performed an analysis stratified by the degree of preexisting comorbidity. In general, patients who received radiocontrast did not develop AKI at a clinically significant higher rate. Adjusted only for the complex survey design, patients to whom radiocontrast was and was not administered developed AKI at rates of 5.5% and 5.6%, respectively. After controlling for comorbidity and acuity of illness, radiocontrast administration associated with an odds ratio for AKI of 0.93 (95% confidence interval, 0.88 to 0.97). In conclusion, the risk of radiocontrast-associated nephropathy may be overstated in the literature and overestimated by clinicians. More accurate AKI risk estimates may improve clinical decision-making when attempting to balance the potential benefits of radiocontrast-enhanced imaging and the risk of AKI.

Pre-Access Creation Evaluation--Is Vein Mapping Enough?

The changing demographic of the hemodialysis population in the United States is posing significant challenge for selection and creation of an optimal vascular access. An arteriovenous fistula (AVF) is by far the most reliable access provided it matures and functions successfully. System-wide changes implemented by Fistula First Breakthrough Initiative and Kidney Disease Outcomes Quality Initiative guidelines have increased the awareness and incidence of AVF in the prevalent dialysis population; however, achieving the current goal of 68% AVF rate continues to remain elusive. The present article reviews the evidence in literature in support of and against using vessel mapping alone as a strategy to improve AVF rate. The current strategy of evaluating the vessels before an access is created seems to be inadequate. A patient-centered approach for an optimal vascular access needs to be considered to improve the AVF rate.

Radiological Assessment of Vascular access in Haemodialysis Patients

Clinical examination is still the most important diagnostic tool and duplex ultrasonography is the imaging method of first choice. Radiological assessment of vascular access for haemodialysis includes preoperative analysis of vessel anatomy and postoperative surveillance for access maturation as well as diagnosis in vascular access insufficiency. Compared to ultrasonography digital subtraction angiography is superior for the evaluation of the central veins and allows diagnosis and treatment in one session. Computed tomography should only be used in patients with inconclusive ultrasonography results, for example, for the assessment of the central veins and visualization of the vascular tree. Gadolinium-enhanced magnetic resonance imaging is no longer recommended in dialysis patients, because it may trigger nephrogenic systemic fibrosis. In patients with a history of previous central venous catheters additional preoperative imaging of the central veins should be performed. In this article we review the different radiological imaging methods for preoperative assessment and suspected vascular access dysfunction.

Retrospective review of angiography before cannulation of newly created vascular accesses in hemodialysis patients

PURPOSE

To investigate vascular access status before first cannulation and the clinical implications of angiography performed before cannulation.

MATERIALS AND METHODS

A retrospective review of 300 consecutive patients who underwent angiography after vascular access surgery and before cannulation between August 2004 and April 2010 was performed. Angiography was performed 4-6 weeks after the surgery but before the first cannulation.

RESULTS

Angiography revealed 94 (31.3%) cases of severe stenosis (≥ 50% luminal narrowing) that required percutaneous transluminal angioplasty (PTA) or a second operation. No stenosis was observed in 122 (40.7%) cases, and mild stenosis (< 50% luminal narrowing) was observed in 84 (28%) cases. For the 94 cases with severe stenosis, PTA was performed in 66, and a second operation was performed in 16. In the other cases (n = 12), HD was maintained by a permanent catheter, or the patients were transferred to another institution. PTA was an immediate success in all patients who underwent the procedure except two. Of 84 patients with mild stenosis, 70 were followed for 1 year; vascular access dysfunction occurred in 15, and 11 of these underwent successful PTA. Of the 122 patients with normal angiographic findings, 102 were followed for 1 year, and vascular access dysfunction did not occur in any of these patients.

CONCLUSIONS

Early postoperative angiography before the first hemodialysis is helpful for the early detection and treatment of vascular access dysfunction.

Clinical significance of upper-arm cephalic vein patency in autogenous radial-cephalic wrist fistulas for hemodialysis

OBJECTIVES

To investigate the significance of upper-arm cephalic veins (UACVs) in radial-cephalic arteriovenous fistulas (RCAVFs), the medical records of 183 patients who had undergone RCAVF creation were reviewed retrospectively.

METHODS

The patients were divided into two groups according to the status of the UACV upon preoperative venography: group A of 153 cases (83.6%) with a patent UACV and group B of 30 cases (16.3%) with a stenosed or occluded UACV. The clinical outcomes were compared.

RESULT

RCAVFs in group B had a significantly higher maturation failure rate (26.7% vs. 9.8%, p = 0.009) and lower primary/secondary patency rates (log-rank test, p < 0.0001) than those in the group A. The patients in group B required more frequent endovascular intervention to maintain access function (p = 0.002). The most common stenosis site was a draining vein in group B, in comparison to juxta-anastomosis in group A. In the multivariate analyses, the status of the UACV was an independent predictor of the primary and secondary patency rates of RCAVFs (p < 0.005).

CONCLUSION

UACV patency has a significant impact on clinical outcome for RCAVFs. When planning an RCAVF placement, venous status including the UACV should be considered.

Meta-analysis: serum creatinine changes following contrast enhanced CT imaging

PURPOSE

Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN.

MATERIALS AND METHODS

A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach.

RESULTS

Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0-8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01-0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6-2.1%). Patients with chronic kidney disease (odds ratio 2.26, p<0.001) or diabetes mellitus (odds ratio 3.10, p<0.001) were at increased risk for the development of CIN.

CONCLUSION

CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

Low volume contrast CTPA in patients with renal dysfunction

INTRODUCTION

The study aims to evaluate a method for and technical feasibility of performing CT pulmonary angiography (CTPA) with just 30 mL of contrast.

METHODS

Twenty-four patients with renal dysfunction suspected of having pulmonary embolus underwent CTPA using 30 mL of contrast. A modified acquisition protocol was employed where sequential monitoring of the central superior vena cava (SVC) was performed following injection of contrast. Scanning was triggered at the first visualised arrival of contrast within the SVC. Hounsfield unit (HU) measurements were performed at the main pulmonary artery to the subsegmental branches to determine the adequacy of each study.

RESULTS

The level of pulmonary arterial enhancement achieved was high, averaging 247 HU across all measured arteries. Average enhancement within more peripheral lobar, segmental and subsegmental arteries was also greater than 200. Only one study was considered non-diagnostic.

CONCLUSION

Low-volume CTPA is technically feasible and provides excellent enhancement of the pulmonary arterial tree.

Standardized definitions for hemodialysis vascular access

Vascular access dysfunction is one of the leading causes of morbidity and mortality among end-stage renal disease patients. Vascular access dysfunction exists in all three types of available accesses: arteriovenous fistulas, arteriovenous grafts, and tunneled catheters. To improve clinical research and outcomes in hemodialysis (HD) access dysfunction, the development of a multidisciplinary network of collaborative investigators with various areas of expertise, and common standards for terminology and classification in all vascular access types, is required. The North American Vascular Access Consortium (NAVAC) is a newly formed multidisciplinary and multicenter network of experts in the area of HD vascular access, who include nephrologists and interventional nephrologists from the United States and Canada with: (1) a primary clinical and research focus in HD vascular access dysfunction, (2) national and internationally recognized experts in vascular access, and (3) a history of productivity measured by peer-reviewed publications and funding among members of this consortium. The consortium's mission is to improve the quality and efficiency in vascular access research, and impact the research in the area of HD vascular access by conducting observational studies and randomized controlled trials. The purpose of the consortium's initial manuscript is to provide working and standard vascular access definitions relating to (1) epidemiology, (2) vascular access function, (3) vascular access patency, and (4) complications in vascular accesses relating to each of the vascular access types.

Management Of The Immature Autogenous Arteriovenous Fistula

A high-quality autogenous arteriovenous fistula provides the optimal access for hemodialysis. Following initial surgical construction of a fistula, the maturation process is driven by hemodynamic, cellular, and humoral factors that must result in increased blood flow, vessel dilation, and thickening of the vessel wall before the fistula can be successfully used for dialysis needle access. Different demands are placed on each fistula depending on the individual patient's hemodialysis requirements, which must be clearly understood to properly assess and treat the immature fistula. When spontaneous maturation fails to achieve a functional fistula, additional surgical or minimally invasive interventional procedures may be necessary to enhance the maturation process. Various techniques have been reported to achieve successful fistula maturation. The purpose of this article is to review the concepts of fistula maturation and the interventions that may be performed in cases where there is failure to mature spontaneously.

Small dose contrast venography as venous mapping in predialysis patients

PURPOSE

This study was designed to evaluate radiocontrast-induced nephrotoxicity (RIN), and the image quality and findings of venography using small doses of radiocontrast as a venous mapping method in pre-dialysis patients.

METHODS

Twenty-eight patients with stage 4 and 5 chronic kidney disease underwent arm venography with 10-15 ml of dilute contrast medium. Image quality, venographic findings and glomerular filtration rate (GFR) before and after the procedure were evaluated.

RESULTS

Mean GFR was 19.3+/-5.8 ml/min/1.73 m2 (7-30 ml/min/1.73 m2). Image quality of venography in the forearm and upper arm veins was good in all patients. Central veins were visualized well in 26 (92.8%) patients. Eight (28.5%) patients showed cephalic veins inadequate for creation of radiocephalic arteriovenous fistula (AVF) because of occlusion or small diameter veins. There was no significant difference in GFR between the pre- and post-study (19.3+/-5.8 vs. 19.2+/-6.2 ml/min/1.73 m2, p=0.693). RIN developed (GFR: 17 to 13 ml/min/1.73 m2) in only one patient but without sequelae, and the GFR completely recovered to baseline level 7 days after the study.

CONCLUSION

Small dose venography is safe and effective for venous mapping in pre-dialysis patients.

Preoperative mapping for haemodialysis access surgery with CO(2) venography of the upper limb

OBJECTIVE

This study aims to evaluate the impact of CO(2) venography on the planning and outcome of native arteriovenous fistula (AVF) creation.

METHODS

Records of patients who underwent CO(2) venography prior to access surgery between January 2000 and December 2008 were reviewed. CO(2) venography was performed selectively in chronic kidney disease (CKD) in stage IV-V patients without suitable veins on clinical examination. Findings at surgery were compared to CO(2) venography images. Patency of AVFs was analysed by the Kaplan-Meier method. Differences in outcome of maturation were compared using a chi(2) test.

RESULTS

A total of 209 CO(2) venograms were obtained in 116 patients. In 89 patients (77%), 101 AVFs (21 forearm AVF (21%) and 80 elbow AVF (79%) were created. Surgical findings corresponded with CO(2) venography findings in 90% of patients. In 10 cases (10%), access was created at the elbow despite a patent forearm cephalic vein on CO(2) venography (n = 2) or access was attempted with a vein which was thought to be unsuitable on CO(2) venography (n = 8). Maturation rate of the latter was 50% (4/8) vs. 88% (80/91) for AVFs created with veins considered usable (P = 0.004). The overall maturation rate was 84% with 1-year primary, assisted primary and secondary patency rates of 63%, 70% and 71%, respectively.

CONCLUSION

CO(2) venography is a useful tool for venous mapping prior to vascular access surgery, resulting in an overall maturation rate of 84% and good patency rates.

Fistula salvage by endovascular therapy

Fistulas are considered superior to synthetic grafts as a hemodialysis vascular access; however, fistulas are not without problems. To maximize the number of fistulas being used in prevalent patients, it is important to have a program designed to salvage early failures or fistulas that fail to mature and those that become dysfunctional during the course of usage. Endovascular techniques have proven to be very effective in the management of both of these problems. These fistulas should be aggressively evaluated and treated because treatment carries with it a high expectation of successful salvage of what would have otherwise been an abandoned access.

Vascular mapping: does it help to maximize fistulae placement?

The population of patients with ESRD in the United States is progressively increasing, with hemodialysis (HD) as the major mode of renal replacement therapy. The National Kidney Foundation's Dialysis Outcomes and Quality Initiative and the Fistula First Initiative recommend increasing the use of arteriovenous fistulae (AVF) in both incident and prevalent hemodialysis patients. One measure proposed is the use of pre-operative vascular mapping to assess the upper extremities for the presence of suitable vessels prior to the surgical creation of an AVF among both pre-dialysis CKD and ESRD patients on HD. This article aims to review the literature on vascular mapping, including the various techniques; their advantages and disadvantages; and whether they help to maximize the AVF creation rate as well as increase the use of AVF in the HD population.

Interventional nephrology in Puerto Rico

Vascular access is emerging as a critical issue for hemodialysis patients in Puerto Rico. In more than 50% of the hemodialysis patients, tunneled hemodialysis catheters are the sole access for providing dialysis therapy. Most disturbing is the fact that a significant number of these catheters are nontunneled temporary catheters, sometimes placed in the subclavian vein. These facts have contributed significantly to the morbidity and mortality seen in chronic dialysis patients. In addition, many cases of early or late dysfunction of arteriovenous access are not detected and treated in a timely manner due to the lack of a comprehensive vascular access program for end-stage renal disease (ESRD) patients. In fact, monitoring programs to identify and detect vascular access dysfunction are virtually nonexistent in many chronic dialysis units. Even when diagnosed, it is not treated in a timely fashion. Recently literature has shown that procedure-related delays in the treatment of patients with renal disease can be minimized and nephrology care more efficiently delivered by a nephrologist trained in nephrology-related procedures. In an effort to optimize the care of our ESRD patients, we took the initiative to develop an interventional nephrology program that effectively deals with vascular access-related procedures in a timely manner. This approach has minimized delays, decreased hospitalizations and the use of temporary catheters, and improved the medical care of our chronic dialysis patients. So far we have performed more than 400 procedures in the 6 months since the initiation of the program. In this article we describe our initial experience with interventional nephrology in Puerto Rico.

Safety of low-dose radiocontrast for interventional AV fistula salvage in stage 4 chronic kidney disease patients

The Dialysis Outcomes Quality Initiative emphasizes increasing arteriovenous fistula prevalence, by promoting referral for fistula creation in patients with stage 4 chronic kidney disease (CKD). The aim is to provide an optimal access for initiation of dialysis, thus avoiding central venous catheter use. The endovascular management of nonmaturing fistulas is more complicated in these patients, where the expected benefit of catheter avoidance must be weighed against the risk of contrast induced nephropathy (CIN). This study reports on the safety of a low-dose radiocontrast regimen, used in performing endovascular fistula salvage procedures in patients with stage 4 CKD. All consecutive endovascular procedures performed over a 2-year period in patients with stage 4 CKD and nonmaturing access were identified. Data collected included the type of procedure, contrast volume per procedure, pre, 2- and 7-day creatinine, need for acute dialysis, and the type of access used to initiate dialysis. Total of 65 procedures were performed in 34 patients. The mean contrast volume was 7.8 ml per procedure. The incidence of CIN (25% increase in serum creatinine) was 4% at 2 days and 4.6% at 1 week. All values returned to baseline within 2 weeks, and no patient required acute dialysis. Among the 33 patients with nonmaturing fistulas, 20 initiated dialysis during the follow-up period, 15 (75%) using their fistula, and five (25%) using a catheter. This study demonstrates that in patients with advanced CKD, fistulas can be successfully salvaged using small contrast volumes with a low incidence of CIN.