and Reinhart T. Grundmann2
(1)
Department of Vascular Medicine, University Heart and Vascular Center at University Clinics Hamburg–Eppendorf, Hamburg, Germany
(2)
Former Medical Director, Community Hospital Altoetting-Burghausen, Burghausen, Germany
12.1 Guidelines
12.1.1 UK Renal Association
Preferred type of vascular access (Kumwenda et al. 2015): We recommend that all patients with end stage kidney disease who commence haemodialysis or are on long-term haemodialysis should dialyse with an arteriovenous fistula (AVF) as first choice, an arteriovenous graft as second choice, a tunnelled venous catheter as third choice and a non-tunnelled temporary catheter as an option of necessity (1A).
We recommend that the AVF should be placed as distally as possible in the non-dominant arm. Radiocephalic and brachiocephalic AVF are preferred to brachiobasilic transposition AVF(2C).
Audit measures:
- (a)
60% of all incident patients with established end stage kidney disease commencing planned haemodialysis should receive dialysis via a functioning arteriovenous fistula (AVF) or arteriovenous graft (AVG).
- (b)
80% of all prevalent long term dialysis patients should receive dialysis treatment via definitive access: AVF or AVG or Tenckhoff catheter.
- (c)
The annual Staphylococcus aureus bacteraemia rate in the prevalent haemodialysis population should be less than 2.5 episodes per 100 HD patients and less than 1.0 for MRSA over 2 years.
- (a)
12.1.2 Society for Vascular Surgery
The Society for Vascular Surgery recommends the following operative strategies for the placement of autogenous accesses (Sidawy et al. 2008):
AV accesses are placed as far distally in the upper extremity as possible to preserve proximal sites for future accesses (GRADE 1 recommendation, very low-quality evidence).
When possible, autogenous AV accesses should be considered before prosthetic arteriovenous accesses are placed. These autogenous access configurations should include, in order of preference, the use of direct AV anastomosis, venous transpositions, and translocations (GRADE 1 recommendation, very low-quality evidence).
Upper extremity access sites are used first, with the non-dominant arm given preference over the dominant arm only when access opportunities are equal in both extremities (GRADE 1 recommendation, very low-quality evidence).
Lower extremity and body wall access sites are used only after all upper extremity access sites have been exhausted (GRADE 1 recommendation, very low-quality evidence).
We recommend the placement of forearm autogenous arteriovenous access as the first choice for primary access for hemodialysis (GRADE 1 recommendation, very low-quality evidence).
- A.
When arterial and venous anatomy is suitable, placement of autogenous radial–cephalic direct wrist access (Brescia-Cimino-Appel) or autogenous posterior radial branch–cephalic direct wrist access (snuffbox) is recommended.
- B.
In the case where arterial or venous anatomy does not allow placement of a direct access, forearm vein transposition or translocation are recommended. These procedures should use the maximal length of adequate vein and use arterial inflow from the forearm tailored to accommodate this length of vein.
- A.
For patients who have exhausted all forearm veins on both sides and, according to vein availability and surgical expertise, are suitable candidates for either forearm prosthetic access or upper arm access of any type, we suggest that the surgeon offer both alternatives to patients (GRADE 2, very low-quality evidence).
Management of non-functional or failed arteriovenous access: We suggest open surgery, endovascular means, or a combination of both to maintain or restore patency in AV access (GRADE 2, very low-quality evidence).
12.1.3 National Kidney Foundation (USA)
According to the clinical practice guidelines from the National Kidney Foundation (NKF) (2006) the order of preference for placement of fistulae in patients with kidney failure who choose hemodialysis as their initial mode of kidney replacement therapy should be (in descending order of preference):
Preferred: Fistulae. (B)
A wrist (radiocephalic) primary fistula. (A)
An elbow (brachiocephalic) primary fistula. (A)
A transposed brachial basilic vein fistula: (B)
Acceptable: arteriovenous grafts (AVG) of synthetic or biological material, such as: (B)
A forearm loop graft, preferable to a straight configuration.
Upper-arm graft.
Chest wall or “necklace” prosthetic graft or lower-extremity fistula or graft; all upper-arm sites should be exhausted.
12.1.4 German Task Force Clinical Nephrology
Interdisciplinary guidelines for monitoring arteriovenous access and management of complications have been compiled by a German task force (Hollenbeck et al. 2009). The recommendations:
A hemodynamically significant stenosis, suspected by clinical assessment and/or flow measurements, should be further verified as soon as possible by diagnostic imaging (evidence level III). A pre-emptive percutaneous or surgical intervention should be carried out without delay, and the imaging should occur shortly prior to the procedure (evidence level II).
Percutaneous transluminal angioplasty (PTA) is the therapy of choice for venous outflow stenosis (evidence level III).
Thrombosed AV fistulae or thrombosed AVG should be treated either by endovascular or surgical intervention. Clinical centres should review their results and choose the modality which provides the best outcome (evidence level III).
Localised widening of fistula veins with rapid progression and risk of perforation, parietal stenoses, and signs of infection should be surgically corrected. Clinicians must pay attention to the possibility of downstream stenosis.
Pseudoaneurysms from prosthetic grafts due to area puncture, which show progression, are an indication for partial graft replacement.
In the case of suspected central venous obstruction, an angiographic examination of AVF and complete venous outflow up to the right atrium should be accomplished (evidence level III). Treatment should be performed with percutaneous endovascular intervention (evidence level III).
Shunt-induced ischemia should be recognised through clinical examination. The cause should be identified, both through non-invasive imaging and angiography (evidence level III). Therapeutic options include the improvement of arterial inflow, restraining shunt-flow and/or the improvement of distal blood flow. When these techniques do not succeed, a shunt ligation should be considered (evidence level II).
Infected AV fistulae accompanied by fever and/or bacteraemia should be treated with intravenous antibiotics over at least 2 weeks. In the case of septic thrombi and/or septic emboli, an excision of the fistula is required (evidence level IV).
Locally infected prosthetic grafts can be preserved through segmental resection and circumvention of infected areas. A suitable, long-term antibiotic therapy (2 weeks intravenously and hereinafter orally over another 4 weeks) is recommended (evidence level III).
An infected anastomosis is an indication for the total removal of the graft (evidence level II).
12.2 Results
12.2.1 Meta-analyses/Systematic Reviews
12.2.1.1 Choice of Haemodialysis Access
Al-Jaishi et al. (2014) ascertained in a systematic review and meta-analysis outcomes of AVF. Fourty-six articles met eligibility criteria (62 unique cohorts; n = 12,383). They found that in recent years, AVF had a high rate of primary failure and low to moderate primary and secondary patency rates. The rate of primary failure was 23%. When primary failures were included, the primary patency rate was 60% at 1 year and 51% at 2 years. The secondary patency rate was 71% at 1 year and 64% at 2 years. In metaregression, there was a significant decrease in primary patency rate in studies that started recruitment in more recent years. Nonetheless, patients with usable fistulas have the lowest risk for death, infections, and cardiovascular events compared with other vascular access types. This was demonstrated by another systematic review of 62 cohort studies with 586,337 patients (Ravani et al. 2013). The risks of death from all causes, major cardiovascular events, and fatal infections associated with dialysis vascular access types are summarized in Table 12.1.
Table 12.1
Absolute risks of death from all causes, major cardiovascular events, and fatal infections associated with dialysis vascular access types
Vascular access comparison | Meta-analytic Relative Risk (RR) | Number of additional events per 1000 patients exposed per year |
|---|---|---|
All-cause mortality | ||
Catheter vs. AV fistula | 1.53 | 106 excess with catheter |
Catheter vs. graft | 1.38 | 91 excess with catheter |
Graft vs. AV fistula | 1.18 | 36 excess with graft |
Major cardiovascular events | ||
Catheter vs. AV fistula | 1.38 | 38 excess with catheter |
Catheter vs. graft | 1.26 | 28 excess with catheter |
Gaft vs. AV fistula | 1.07 | 7 excess with grafta |
Fatal infections | ||
Catheter vs. AV fistula | 2.12 | 28 excess with catheter |
Catheter vs. graft | 1.49 | 17 excess with catheter |
Graft vs. AV fistula | 1.36 | 9 excess with graft |
McGrogan et al. (2015) assessed outcomes of arteriovenous fistulas (AVF) in the elderly (anyone older than 60 years) and compared results of radiocephalic vs brachiocephalic AVF placements in a systematic review and meta-analysis. A total of 15 studies were included in the analysis of primary and secondary AVF patency rates. Pooled primary patency rates for radiocephalic and brachiocephalic AVFs were 49.7% and 58.5%, respectively. Pooled secondary AVF patency rates were 65.1% for radiocephalic and 72.7% for brachiocephalic AVFs. This meta-analysis confirmed that brachiocephalic AVFs have superior primary and secondary patency rates at 12 months compared with radiocephalic AVFs in the elderly.
The Fistula First Initiative has promoted AVFs as the vascular access of choice. Generally, snuff box and radio-cephalic are accepted and well described sites for AVFs, however, the forearm ulnar-basilic AVF is seldom used or recommended. Al Shakarchi, Khawaja et al. (2016b) systematically reviewed the evidence base for the creation of the ulnar-basilic fistula. Eight studies were included in the review. Weighted pooled data revealed 1-year primary patency rate for ulnar-basilic AVFs of 53.0% with a secondary patency rate of 72.0%. The review showed that the ulnar-basilic AVF may be a viable alternative when a radio-cephalic AVF is not possible and dialysis is not required urgently. It has adequate 1-year primary and secondary patency rates and extremely low risk of haemodialysis access induced distal ischaemia.
12.2.1.2 Treatment of Thrombosed Dialysis Shunts
Should occluded AV fistulas and grafts be managed by surgery or endovascular intervention? Kuhan et al. (2013) carried out a systematic review and meta-analysis to answer this question. There were no randomized trials comparing surgery vs. endovascular therapy for native fistulas and vein grafts. Six randomized studies reporting on 573 occluded grafts were identified. Technical success, 30-day morbidity and primary patency at 30 days were similar between the two groups. There was no statistical difference between the two groups for 1-year primary patency. In conclusion, comparable results to surgery have been achieved with endovascular techniques for occluded prosthetic grafts for dialysis access. Long-term data comparing the two groups were lacking.
12.2.1.3 Preemptive Correction of Arteriovenous Access Stenosis
In a systematic review and meta-analysis including 14 trials (1,390 participants) benefits and harms of preemptive versus deferred correction of AV access stenosis were evaluated (Ravani et al. 2016a). In this paper and in an additional Cochrane review Ravani et al. (2016b) concluded that pre-emptive correction of a newly identified or known stenosis in a functional AV access does not improve access longevity. Although pre-emptive stenosis correction may be promising in fistulas, existing evidence is insufficient to guide clinical practice. While pre-emptive stenosis correction may reduce the risk of hospitalisation, this benefit is uncertain whereas there may be a substantial increase (i.e. 80%) in the use of access-related procedures and procedure-related adverse events (e.g. infection, mortality). The net effects of pre-emptive correction on harms and resource use are thus unclear.
12.2.2 Registry Data
Malas et al. (2015) performed a retrospective analysis of the cohort of patients in the US Renal Data System (USRDS) database who initiated dialysis between January 1, 2006, and December 31, 2010. In the total study cohort of 510,000 patients, 71,452 (14.0%) initiated hemodialysis (HD) with AVF, 17,562 (3.4%) initiated with arteriovenous graft (AVG), and 420,986 (82.5%) initiated with hemodialysis catheter (HC). Survival at 1 year was 78% in the HC group compared with 84% for the AVG group and 89% for the AVF group. Five-year survival in the HC group was 45% compared with 48% in the AVG group and 55% in the AVF group. Initiating HD with an AVF provided a significant mortality benefit compared with initiating dialysis with an AVG or HC. Despite this, most patients in the United States initiate HD with HC, and incident AVF use falls markedly short of the initial Kidney Disease Outcomes Quality Initiative target of 50% that was established more than 15 years ago.
The type of vascular access at the start of HD (incidence) between 2005 and 2009 was reported for a total of 13,044 patients from five countries in the ERA-EDTA (European Renal Association − European Dialysis and Transplant Association) – registry (Noordzij et al. 2014). The majority of patients started HD using a CVC. This percentage showed an increasing tendency over time, from 58% in 2005 to 68% in 2009. Conversely, the use of AVFs as the first vascular access at the start of HD decreased from 42% in 2005 to 32% in 2009. AVGs were used infrequently (<1%) as the first vascular access. The prevalence of vascular access types based on the vascular access type reported once a year in nine countries (n = 75,715) showed a similar trend. The percentage of patients with an AVF decreased from 66 to 62% over time. In contrast, the use of CVC in the prevalent group increased from 28% in 2005 to 32% in 2009. Use of AVGs remained stable over time at 5–6%. Reasons behind these trends were not given.
The Dialysis Outcomes and Practice Patterns Study (DOPPS) Practice Monitor (DPM) refers to 3442 patients in the United States and 8478 patients in19 other nations. In the United States from August 2010 to August 2013, AVF use increased from 63 to 68%, while catheter use declined from 19 to 15%. Although AVF use did not differ greatly across age groups, AVG use was two-fold higher among black (26%) versus nonblack US patients (13%) in 2013. Across 20 countries in 2013, AVF use ranged from 49 to 92%, whereas catheter use ranged from 1 to 45% (Pisoni et al. 2015).
Using the USRDS database, Leake, Yuo et al. (2015b) identified incident HD patients in 2005 that started HD with a tunneled dialysis catheter (TDC) and survived at least 1 year. HD was initiated in 56,495 patients in 2005. Of those, 41,582 (74%) started with a TDC, 6368 (11%) with an AVF, and 2644 (5%) with an AVG. 10,966 (26.4%) patients of the TDC group died ≤ 1 year, and 16,461 (39.6%) never received a permanent access. A total of 6149 patients of the TDC group had an AVF (4524) or AVG (1625) procedure ≤3 months and had at least 1 year of follow-up available. In patients starting dialysis with a TDC, subsequent AVG placement was associated with earlier TDC removal along with fewer catheter days up to 6 months, compared with patients who underwent AVF placement. However, AVGs required more secondary procedures at all time points up to 1 year. The results suggest AVG placement may have an important role in decreasing TDC prevalence. In a further paper, Yuo et al. (2015) compared survival in patients with end-stage renal disease after creation of an AVF or AVG in patients starting HD with a TDC. The USRDS was used. A total of 138,245 patients were available for analysis who started HD with a TDC. In this group, 31,493 (22.8%) underwent AVF creation and 10,492 (7.6%) underwent AVG creation within 3 months of starting HD. After stratifying by age, in those younger than 65 years, AVF was superior to AVG (P = .031), but this was not evident in the elderly (65–79 years, P = .089; 80 years and older, P = .119). AVG and TDC appeared equivalent in patients younger than 65 years (P = .744), but AVG was associated with improved survival in the elderly (65–79 years and 80 years and older, both P < .001). After the 90-day mortality exclusion period, overall survival was short. For patients younger than 65 years, median survival was as follows: AVF, 3.02 years; AVG, 2.84 years; and TDC, 2.93 years. For patients between 65 and 80 years, median survival was as follows: AVF, 2.08 years; AVG, 2.03 years; and TDC, 1.23 years. For patients older than 80 years, median survival was as follows: AVF, 1.38 years; AVG, 1.58 years; and TDC, 0.83 years. In this retrospective review for patients who start HD through a TDC, placement of an AVF and AVG was associated with similar mortality hazard.
Hicks et al. (2015) analyzed the effects of age at hemodialysis initiation on mortality across different access types. The USRDS between the years 2006 and 2010 was used (507,791 patients ≥ 18 years). Increasing age was a significant predictor of overall mortality. Compared with patients with hemodialysis catheters (HCs), n = 418,932, overall risk-adjusted mortality was lowest in patients with AVFs (n = 71,316; adjusted hazard ratio [aHR] 0.63) followed by AVGs (n = 17,543; aHR, 0.83). AVF was superior to both HC and AVG for all age groups. However, there were no significant differences comparing adjusted mortality with AVG vs HC for patients aged 18–48 years or for patients >89 years, but AVG was superior to HC for patients 49–89 years of age. The mortality benefit of AVF was consistently superior to that of AVG and HC for patients of all ages. The authors concluded that all patients 18–48 years should receive AVF for dialysis access whenever possible.
12.2.3 Clinical Studies
12.2.3.1 Choice of Vascular Access
A total of 1206 AVF, 689 (57%) radiocephalic AVF (RCAVF), 383 (32%) brachiocephalic AVF (BCAVF), and 134 (11%) brachiobasilic AVF (BBAVF), were analysed by Wilmink et al. (2016). Primary failure (PF) occurred in 23% of the 1206 AVF. PF was lower for BCAVF (17%) than RCAVF (26%) and BBAVF (26%). The median maturation time was 10.3 weeks. Cumulative patency, including PF, of RCAVF was significantly better than BCAVF and BBAVF. RCAVFs resulted in 3% more dialysis-person-years (py) per 100 operations for all patients and in 15% more dialysis-py in the over 80s. It could be concluded that RCAVFs have higher PF, but better survival than other AVF, and result in more dialysis time. Vascular access planning should allow for a maturation time of 10 weeks, for a 50% probability, and 16 weeks for a 75% probability, that an AVF can be used. The study suggested that the best strategy in access planning is to create an RCAVF, irrespective of age, 4 months before the anticipated dialysis start. In contrast, in a population of predominantly diabetic patients, Kim et al. (2015) reduced the placement of radiocephalic AVFs and moved away from the wrist and toward the elbow. They suggested that the radiocephalic AVF is not the best option for hemodialysis access in diabetic patients. In their study with 191 AVFs increasing brachiocephalic AVF creation and reducing reliance on radiocephalic AVFs resulted in a significant increase in primary functional patency at 1 year. This was achieved while maintaining the same high percentage of fistulas, a lower rate of central catheter infections, and the same low incidence of steal syndrome.
The AVF is the preferred hemodialysis access, but AVF-failure rate is high. Schinstock et al. (2011) examined in a retrospective cohort study (317 AVFs in 293 patients) AVF failure rates and predictors of such failure. After excluding the AVFs unused because of death, no hemodialysis initiation during follow-up, kidney transplantation, or indeterminate outcome, 49.0% (103 of 210) of the remaining AVFs were unsuitable for hemodialysis within a reasonable time. The 3-, 6-, 12-, and 18-month primary patency rates were 67%, 50%, 41%, and 30%, respectively, and 92%, 86%, 77%, and 73%, respectively, for secondary patency. The risk for reduced patency was increased by diabetes (HR, 1.54), but decreased when larger arteries were employed (HR, 0.83). In this study, artery size was the main predictor of AVF patency.
Lok et al. (2013) compared retrospectively 1012 AV fistulas with 128 grafts (first accesses). The majority of first accesses were placed in the forearm (59.5% of fistulas and 74.2% of grafts) compared with the upper arm (40.5% of fistulas and 25.8% of grafts). Primary failure was twice as high for fistulas as for grafts (39.7% and 18.8%, respectively). When primary failures were included in the analysis, the proportion of first accesses that survived during follow-up did not differ between fistulas and grafts: 350 of 1012 (35%) versus 39 of 128 (31%), respectively. However, when 426 primary failures were excluded from the analysis, fistulas appeared significantly more likely to survive than grafts: 350 of 610 (57%) versus 39 of 104 (37%). In conclusion, fistulas in this study did not demonstrate better cumulative patency than grafts unless primary failures were excluded; however, grafts required more interventions to maintain patency.
Competing issues contribute to the decision about which hemodialysis vascular access strategy to pursue. Synthetic vascular accesses (SVA) can be cannulated and used for hemodialysis much sooner than AVFs, greatly reducing the exposure to central venous catheter complications. Conversely, SVAs have higher failure/complication rates than those associated with AVFs. Therefore, Rosas and Feldman (2012) determined the cost-effectiveness of two different vascular access strategies among incident dialysis patients. In their model, the AVF1st strategy had a better average cost-utility than SVA1st as long as the AVF maturation rate was greater than 69%. Further, the AVF1st strategy became less costly than SVA1st only if the AVF maturation rate was greater than or equal to 82%. The study demonstrated that the current emphasis of placing AVFs in all dialysis patients may not be optimal. AVF1st strategy may be most appropriate only for a subset of hemodialysis patients whose risk of AVF maturation failure is relatively low.
Olsha et al. (2015) examined the outcome of 146 new accesses in 134 patients aged 80 years and older. There were 128 autogenous accesses (30 forearm, 91 upper arm, and seven transposed basilic veins) and 18 prosthetic accesses. Overall primary patency was 39% and 23% at 12 and 36 months, respectively, while the secondary patency rate was 92% and 77%, respectively. There was no significant difference in patency between the different types of access. According to this data, age should not disqualify these patients from the Fistula First Initiative. However, Cui et al. (2016) came to the opposite conclusion. They assumed that grafts are a first-line hemodialysis access option in select elderly patients. In their series of 138 fistulas and 44 grafts in elderly patients (≥75 years old) the primary failure rate was higher for the fistulas compared with the grafts, and more fistulas required one or more interventions before their successful use compared with grafts (31% vs 10%). In addition, the time to catheter-free dialysis was longer for fistulas than for grafts. However, the primary and secondary patency rates were comparable between the fistulas and grafts.
12.2.3.2 Alternative Vascular Accesses
Bourquelot et al. (2012) reported on 70 patients (72 accesses) who underwent transposition of the superficial femoral vein to create an autogenous arteriovenous hemodialysis access. Two patients had bilateral procedures. All patients had exhausted upper arm veins or had central vein obstructions. The femoral vein in these patients was mobilised, transposed in a straight subcutaneous tunnel and anastomosed distally end-to-side to the superficial femoral artery. Thirteen patients (18%) experienced major complications necessitating fistula ligation (ischemic complications, five diabetic patients with peripheral arterial occlusive disease [one major amputation included]; lower leg compartment syndrome, one; acute venous hypertension, two; secondary major edema, two; high-output cardiac failure, one; bleeding, two). Finally, all the patent accesses (59/72) were utilized for dialysis after a mean interval of 2 ± 1 months resulting in an 82% success rate. According to life-table analysis, the primary patency rates at 1 and 9 years were 91% ± 4% and 45% ± 11%, respectively. Secondary patency rates at 2 and 9 years were 84% ± 5% and 56% ± 9%, respectively. Based on reasonable long-term patency and low rate of infection, the authors concluded that this method is a valuable alternative to arteriovenous grafts.
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