A scoping review on surgical reduction of high flow arteriovenous haemodialysis access.

Volume flow (Qa) > 1.5-2 l /minQa in arteriovenous accesses may be associated with high flow related systemic or locoregional complications. A variety of surgical techniques are advocated for Qa reduction. Aim of this scoping review is to provide an overview of available evidence regarding the efficacy of this broad spectrum of interventions for Qa reduction in patients with a high flow haemodialysis access. PubMed and Embase were searched according to PRISMA-guidelines. Studies on invasive management of HFA were selected. Inclusion required an English description of surgical techniques in human HFAs including pre- and postoperative access flow-values. Sixty-six studies on 940 patients (mean age 56 years (3-90 years), male 62%, diabetes mellitus 26%, brachial artery-based arteriovenous access 65%) fulfilled inclusion criteria. Performed techniques were banding (58%), revision using distal inflow (12%), plication/anastomoplasty (10%), graft interposition (5%), proximal radial artery ligation (3%), aneurysm repair (4%), or miscellaneous other techniques (8%). Definition of HFA, work-up, indication for surgery and intraoperative monitoring were diverse. All techniques reduced Qa on the short term (mean drop 0.9-1.7 l/min). Secondary access patency rates varied between 70% and 93% (mean follow-up 15 (0-189) months). Definitions of success and recurrence varied widely precluding a comparison of efficacy of techniques. Patient specific factors legitimizing invasive treatment for HFA are discussed. Recommendations on reporting standards when dealing with HFA surgery are provided. In conclusion, the present report on the current management of high flow access does not allow for drawing any definite conclusions due to a lack of standardization in definition, indications for surgical intervention and techniques. Randomized trials comparing different Qa reducing techniques in symptomatic patients are warranted, as are trials comparing a wait-and-see approach versus Qa reduction in asymptomatic patients. As an overview of the variety of techniques was lacking, this scoping review might serve as a map for future researchers.

Access flow volume (Qa) and survival in a haemodialysis population: an analysis of 5208 Qa measurements over a 9-year period.

BACKGROUND: The aim of this study was to determine associations between characteristics of arteriovenous access (AVA) flow volume (Qa; mL/min) and 4-year freedom from cardiovascular mortality (CVM) in haemodialysis (HD) patients. METHODS: HD patients who received a primary AVA between January 2010 and December 2017 in one centre were analysed. Initial Qa was defined as the first Qa value obtained in a well-functioning AVA by a two-needle dilution technique. Actual Qa was defined as access flow at a random point in time. Changes in actual Qa were expressed per 3-month period. CVM was assessed according to the European Renal Association-European Dialysis and Transplant Association classification. The optimal cut-off point for initial Qa was identified by a receiver operating characteristics curve. A joint modelling statistical technique determined longitudinal associations between Qa characteristics and 4-year CVM. RESULTS: A total of 5208 Qa measurements (165 patients; 103 male, age 70 ± 12 years, autologous AVA n = 146, graft n = 19) were analysed. During follow-up (December 2010-January 2018, median 36 months), 79 patients (48%) died. An initial Qa <900 mL/min was associated with an increased 4-y CVM risk {hazard ratio [HR] 4.05 [95% confidence interval (CI) 1.94-8.43], P < 0.001}. After 4 years, freedom from CVM was 34% lower in patients with a Qa <900 mL/min (53 ± 7%) versus a Qa ≥900 mL/min (87 ± 4%; P < 0.001). An association between increases in actual Qa per 3-month period and mortality was found [HR 4.48/100 mL/min (95% CI 1.44-13.97), P = 0.010], indicating that patients demonstrating increasing Qa were more likely to die. In contrast, actual Qa per se was not related to survival. CONCLUSIONS: Studying novel AVA Qa characteristics may contribute to understanding excess CVM in HD patients.

A preoperative modified Allen test result may be associated with long term mortality after hemodialysis access construction.

BACKGROUND: The modified Allen test (MAT) is a simple bedside method determining collateral hand circulation prior to hemodialysis (HD) access surgery. Hand ischemia as reflected by low systolic finger pressures (Pdig) is associated with high mortality rates in severe kidney disease (CKD) patients. Aim of the present study was to assess a possible relation between absolute finger pressure drop (∂Pdig) during a preoperative MAT and mortality after a first HD access construction. METHODS: Pdig (systolic pressure, mmHg) was measured using digital plethysmography following compression of radial and ulnar arteries in CKD patients just before access surgery between January 2009 and December 2018 in one center. The greatest ∂Pdig of both index fingers was used for analysis. Cardiovascular and overall mortality were assessed during the following 4 years using the ERA-EDTA classification system (codes 11, 14-16, 18, 22-26, 29). Cox regression analysis determined possible associations between ∂Pdig and mortality. RESULTS: Complete data sets were available in 108 patients (male n = 71; age 70 years ±12; mean follow up (FU) 1.6 years ±0.1; FU index 99% ±1). Median ∂Pdig was 31 mmHg (range 0-167 mmHg). Patients having cardiovascular disease (CV+) demonstrated higher ∂Pdig values (CV+ 44 ± 5 mmHg vs CV- 29 ± 3 mmHg, p = 0.012). A total of 26 patients (24%) died during FU (CV+ death, n = 16; 62%). For each 10 mmHg ∂Pdig increase, overall mortality increased by 10%, and CV+ mortality by 15% (overall mortality: HR 1.10 [1.01-1.22], p = 0.048; CV+ mortality: 1.15 [1.03-1.29], p = 0.017). Following correction for age, ∂Pdig remained associated with CV+ mortality (HR 1.13 [1.00-1.26], p = 0.043). CONCLUSIONS: A large drop in systolic finger pressure during a preoperative MAT is related to mortality after primary HD access surgery. The role of this potential novel risk parameter requires confirmation in a larger population.

Systolic finger pressures during an Allen test before hemodialysis access construction predict severe postoperative hand ischemia.

OBJECTIVE: The Allen test is a simple bedside method for determining hand perfusion. Earlier studies in patients on hemodialysis (HD) found that an Allen test before access construction did not predict hand ischemia later on. The study aimed to assess whether an Allen test combined with finger plethysmography before access surgery has a potential to predict the onset of severe HD access induced distal ischemia (HAIDI). METHODS: Before the first access construction in patients with chronic kidney disease, systolic finger pressures (Pdig, in millimeters of mercury) were obtained using plethysmography at rest and after serial compression of the radial and ulnar artery. A decrease in Pdig (∂Pdig) was calculated as the difference between Pdig-rest and Pdig-compression. The severity of postoperative HAIDI was graded as suggested by a 2016 consensus meeting. Patients with a severe type of HAIDI (grade 2b-4, intolerable pain, invasive treatment required) were compared with controls not having HAIDI. RESULTS: A total of 105 patients with chronic kidney disease (mean age 70 ± 13 years; 65% males) receiving their first access between January 2009 and December 2018 in one center fulfilled study criteria. Ten patients (10%) developed severe HAIDI at 14 ± 5 months after access construction. Before access creation, all patients with HAIDI demonstrated a radial or ulnar dominant hand perfusion pattern compared with just 57% in controls (P = .010). Compression resulted in an almost two-fold greater ∂Pdig in patients with severe HAIDI (51 ± 8 mm Hg vs 27 ± 3 mm Hg; P = .005). A 40-mm Hg ∂Pdig cut-off value demonstrated optimal tests characteristics (sensitivity of 80%, specificity of 77%, positive predictive value of 27%, negative predictive value of 97%) indicating a 10 times greater risk of developing severe HAIDI. CONCLUSIONS: Finger plethysmography quantifying ∂Pdig during an Allen test before access creation may identify patients who have a substantially increased risk of developing severe hand ischemia after HD access surgery.

Abnormal preoperative digital brachial index is associated with lower 2-year arteriovenous fistula access patency.

OBJECTIVE: The aim of the present study was to assess whether a single measurement of the digital brachial index (DBI; systolic finger pressure/systemic pressure ratio), reflecting the arm's circulation, was associated with access patency in patients with severe chronic kidney disease scheduled for arteriovenous fistula (AVF) creation. METHODS: A bilateral DBI was obtained using digital plethysmography just before construction of the patient's first AVF from January 2009 to December 2017 at one center. A DBI of 80% to 99% was considered normal, and a DBI of <80% (low) or DBI of ≥100% (high) were considered abnormal. DBI values ipsilateral to the AVF were used for analysis. The primary and secondary access patency rates were calculated using reported standards and compared using standard statistical techniques. RESULTS: Data sets of 163 patients were obtained (69 women; age, 71 ± 12 years). The median follow-up was 40 weeks (range, 0-104 weeks; follow-up index, 99% ± 1%). Patients with abnormal preoperative DBI values had lower 2-year primary patency rates (low DBI, 25% ± 11%; high DBI, 28% ± 6%; normal DBI, 49% ± 8%; P = .018). After correction for age, sex, hypertension, diabetes mellitus, cardiovascular disease, smoking status, and a history of ipsilateral central venous catheter use, an adjusted model demonstrated that abnormal DBI values conferred an increased risk of primary patency failure (low DBI [<80%]: hazard ratio [HR], 2.25; 95% confidence interval [CI], 1.13-4.48; high DBI [≥100%]: HR, 1.74; 95% CI, 1.06-2.85; P < .030 for both). Patients with a low preoperative DBI had also had diminished secondary patency (HR, 2.86; 95% CI, 1.08-7.59; P = .035). In contrast, the diameters of the outflow veins did not determine access patency. CONCLUSIONS: Patients with abnormal DBI values before AVF construction for hemodialysis had lower 2-year access patency rates compared with patients with a normal DBI. Plethysmographic finger measurements might have a role in the preoperative counseling of patients with severe chronic kidney disease requiring an AVF.

Severe hemodialysis access-induced distal ischemia may be associated with poor survival.

BACKGROUND: Some hemodialysis patients develop hemodialysis access-induced distal ischemia due to insufficient loco-regional perfusion pressure and consequent poor arterial flow. We hypothesized that patients with severe hemodialysis access-induced distal ischemia had worse survival compared with patients with mild or no hemodialysis access-induced distal ischemia. METHODS: This single-center retrospective observational cohort study included three groups of prevalent hemodialysis patients with an upper extremity vascular access between 2006 and 2018. Symptomatic patients had signs and symptoms of hemodialysis access-induced distal ischemia and low digital brachial indices (<60%) and were divided into a mild (Grade I-IIa) and a severe hemodialysis access-induced distal ischemia (IIb-IV) group. The control group consisted of hemodialysis patients without signs of hemodialysis access-induced distal ischemia with digital brachial indices ≥60%. Factors potentially related to 4-year survival were analyzed. RESULTS: Mild hemodialysis access-induced distal ischemia-patients displayed higher digital brachial indices (n = 23, 41%, ±3) compared with severe hemodialysis access-induced distal ischemia-patients (n = 28, 24%, ±4), whereas controls had the highest values (n = 48, 80%, ±2; p < .001). A total of 44 patients (44%) died during follow-up. Digital brachial index (hazards ratio 0.989 [0.979-1.000] p = .046) was related to overall mortality following correction for presence of arterial occlusive disease (hazards ratio 2.28 [1.22-4.29], diabetes (hazards ratio 2.00 [1.07-3.72], and increasing age (hazards ratio 1.03 [1.01-1.06] as was digital pressure (hazards ratio 0.990 [0.983-0.998], p = .011). Overall survival was similar in mild hemodialysis access-induced distal ischemia and controls (2-year, 79% ±5; 4-year, 57% ±6, p = .818). In contrast, 4-year survival was >20% lower in patients with severe hemodialysis access-induced distal ischemia (2-year 62%± 10; 4-year 34% ± 10; p = .026). CONCLUSION: Presence of severe hemodialysis access-induced distal ischemia may be associated with poorer survival in hemodialysis patients. Lower digital brachial index values are associated with higher overall mortality, even following correction for other known risk factors.

Abnormal digital brachial index prior to hemodialysis access construction and cardiovascular mortality.

INTRODUCTION: An abnormal ankle-brachial index indicating presence of peripheral arterial disease (PAD) is known to predict mortality in end-stage renal disease (ESRD). Hand ischemia, reflected by low finger pressures, is also a factor associated with increased mortality in patients undergoing hemodialysis (HD). The Aim of the present study is to determine whether an abnormal digital brachial index in ESRD patients prior to HD access surgery is related to lower survival rates. METHODS: A digital brachial index (DBI, systolic finger pressure/systolic brachial arterial pressure) was obtained using digital plethysmography in ESRD patients before construction of a primary HD access between January 2009 and December 2018 in a single center. Patients were grouped based on categories of DBI (low <80%, normal 80-99%, high ≥100%). Overall and cardiovascular mortality were assessed with the ERA-EDTA classification system (ERA-EDTA codes 11, 14-16, 18, and 22-26, 29). Factors potentially influencing survival rates were analyzed using standard statistics. FINDINGS: Follow-up was available in 199 patients (female n = 80; age 70 years ±12; follow-up index 99% ±1). Overall, 2 and 4 years survival were similar among DBI groups Moreover, 2 and 4 years freedom from cardiovascular death were also not different (low DBI 80% ±8 and 58% ±11; normal DBI 86% ±4 and 75% ±6; high DBI 74% ±6 and 61% ±7). Following correction for age, diabetes mellitus, cardiovascular disease and smoking, a high DBI conferred a significantly increased risk of cardiovascular mortality (HR 2.09 [1.06-4.13], P = 0.03) and a trend toward higher overall mortality (HR 1.69 [0.98-2.93], P = 0.06). DISCUSSION: ESRD patients with an abnormally elevated DBI before HD access creation have an increased risk of cardiovascular mortality in the first four postoperative years.