Hemodialysis Access-induced Distal Ischemia Research Articles

Proximalization of arterial inflow for treatment of hemodialysis access-induced distal ischemia

ObjectiveHemodialysis access-induced distal ischemia (HAIDI) is a known complication of hemodialysis (HD) access. Distal revascularization and interval ligation (DRIL) is the preferred treatment for HAIDI by many surgeons. Proximalization of arterial inflow (PAI) is a promising alternative technique that, unlike DRIL, preserves the native arterial inflow. The purpose of this study is to report our experience with PAI on a series of 64 patients. MethodsThis is a single-center, retrospective cohort study of patients with both arteriovenous (AV) fistulas and grafts who underwent PAI for HAIDI from 2017 to 2023. A 4 × 7 tapered polytetrafluoroethylene (PTFE) graft was used to connect HD access inflow to the axillary artery in the majority of cases. The primary outcome of the study is resolution of HAIDI (complete, partial, or no resolution). Secondary outcomes include functional patency (primary and secondary) and 30-day complications following PAI. ResultsOf the 71 patients identified to have had PAI between May 2017 to August 2023, seven were lost to follow-up. In total, 64 patients were included, with an average age of 65 years (standard deviation, 15 years), 59.4% (38/64) female, and 37.5% (24/64) African American. The study population was notable for numerous comorbid conditions including 95.3% (61/64) hypertension; 50% (32/64) coronary artery disease; 79.7% (51/64) diabetes; and 43.8% (28/64) smoking history. Following PAI intervention for HAIDI, 55 of 64 patients (85.9%) experienced complete resolution of ischemic symptoms; five of 64 patients (7.8%) had partial resolution; two of 64 patients (3.1%) had no resolution, and two of 64 patients (3.1%) had unknown resolution. Primary patency at 1, 12, and 24 months was 94%, 81%, and 71%, respectively. Secondary patency at 1, 12, and 24 months was 97%, 87%, and 84%, respectively. The 30-day complication rate was 10.9% (7/64), with five of 64 (7.8%) thromboses, one of 64 (1.6%) thrombosis and infection, and one of 64 (1.6%) upper extremity swelling secondary to central venous stenosis (resolved with angioplasty of central venous system). Failure rate due to thrombosis at 12 and 24 months was 14% (9/64) and 15.6% (10/64), respectively. ConclusionsOur study, the largest case series of PAI to date, demonstrates that PAI is a reliable option for HAIDI intervention and has comparable safety and efficacy results to DRIL, despite the use of a synthetic graft. Furthermore, PAI has the added benefit of maintaining the native arterial pathway. Further investigation of PAI is warranted as a promising alternative to DRIL for HAIDI management.

Slowly moving the needle away from Fistula First

ObjectiveIn 2019, the management of end-stage kidney disease (ESKD) shifted away from “Fistula First” (FF) to “ESKD Life-Plan: Patient Life-Plan First then Access Needs.” Indeed, some patients exhibit such excessive comorbidity that even relatively minor vascular surgery may be complicated. The purpose of this study was to retrospectively assess complications and mortality (and delineate operative futility) in patients undergoing arteriovenous fistula (AVF) creation in the FF era. MethodsConsecutive AVFs created in a single institution before 2021 were retrospectively reviewed. Operative futility was defined as never-accessed fistula, no initiation of dialysis, failure of access maturation (despite secondary intervention), hemodialysis access-induced distal ischemia requiring ligation, early loss of secondary patency, and/or patient mortality within the first 6 postoperative months. ResultsA total of 401 AVFs were created including radial-cephalic (44%), brachial-cephalic (41%), and brachial-basilic (15%) constructions. Patients exhibited a mean age of 69 ± 15 years; 63% were male, and most (74%) were already being hemodialyzed at the time of fistula creation. Forty-five patients (11%) suffered a cardiac event, and five patients died (1%) within 90 days of their access surgery. Perioperative cardiac events were significantly more common after age 80 (19% vs 8%; P = .004); age >80 years was an independent predictor of major 90-day complications (odds ratio [OR], 1.88; 95% confidence interval [CI], 1.04-3.39; P = .036) and the sole independent predictor of major morbidity defined as cardiopulmonary complications, stroke, or death within the first year (OR, 2.01; 95% CI, 1.24-3.25; P = .004). Operative futility was encountered in 52% of the cohort (n = 208 patients): 40% (n = 160) of primary AVFs failed to mature despite assistance, 19% (n = 77) had lost secondary patency by 6 months, 13% of patients (n = 53) were never started on dialysis after access creation, 4% (n = 16) were dead by 6 months, 2% of AVFs (n = 10) matured but were never accessed, and 2% (n = 9) required ligation for hemodialysis access-induced distal ischemia. Not surprisingly, the sole independent protector against operative futility was that catheter-based dialysis had been established prior to AVF creation (OR, 0.36; 95% CI, 0.22-0.59; P < .01). ConclusionsApproximately 50% of primary AVF operations performed in the aggressive FF era were deemed futile. Octogenarians were particularly prone to futility and complications during this era. A paradigm shift, from FF to an “ESKD Life-Plan” will, hopefully, more thoughtfully match vascular access strategies to individual patient needs.

Potential Utility of Hand Acceleration Time in Quantifying the Degree of Malperfusion in Patients With Suspected Hemodialysis Access–Induced Distal Ischemia

Steal phenomenon after upper extremity hemodialysis access is a clinical diagnosis and consists of signs and symptoms ranging from pain during dialysis to tissue loss. Duplex ultrasonography of the access site and limb arterial perfusion often serves as an adjunct to the diagnosis but can have limitations and there is no specific duplex measurement that indicates that an intervention will be a success. We have used hand acceleration time (HAT) to assess perfusion in a number of trauma and shock cases and hypothesized that this approach could also be beneficial in assessing patients with hemodialysis access–induced distal ischemia (HAIDI), both for identifying patients who are candidates for intervention and to measure whether the intervention will be successful. Specifically, we hypothesized that a HAT &lt;100 ms is associated with normal hand perfusion. We performed a retrospective review of 4 patients with upper extremity arteriovenous fistulas who presented with pain and tissue loss involving the ipsilateral hand. In 2 cases, the tissue loss was not primarily due to steal (one due to skin slough from antibiotic reaction and the other due to focal calciphylaxis), and 2 patients had diffuse calcific disease of the forearm arteries. All 4 patients had antegrade flow in the forearm arteries and HAT &gt;100 ms. One patient with soft tissue sloughing was managed with banding of the proximal fistula, and 3 had proximalization of the fistula. All 4 achieved HAT &lt;100 ms and had resolution of symptoms. Hand acceleration time may be a valuable adjunct to determine whether intervention in the setting of hemodialysis access–induced distal ischemia HAIDI may assist with wound healing.

Extra-anatomical endo-bypass between left arm vascular access and superior vena cava

A 57-year-old male patient with a history of previous hemodialysis access-induced distal ischemia and known bilateral chronic venous outflow problems had a left arm axillary loop graft that was successfully used for a couple of months with minor-to-moderate left arm swelling. Although this was initially well tolerated and allowed the removal of the femoral catheter, the patient subsequently presented worsening swelling and eventually severely symptomatic superior vena cava (SVC) syndrome. A computed tomography angiography demonstrated bilateral innominate vein and SVC occlusion, and voluminous pseudoaneurysm was also observed at the level of the graft-vein anastomosis (A).

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

ObjectiveThe 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). MethodsBefore 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. ResultsA 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. ConclusionsFinger 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.

Arterial percutaneous angioplasty in hemodialysis access: Endovascular treatment of hand ischemia.

Hemodialysis access-induced distal ischemia consists of symptomatic extremity malperfusion after vascular access creation. It is usually caused by discordant vascular resistance, with arteriovenous shunting of a high blood volume from arterial into venous system and subsequent hand hypoperfusion. Less often, hemodialysis access-induced distal ischemia is caused by arterial stenosis. In these cases, access frequently has normal/low flow, radial pulse is usually absent and not recoverable with vascular access digital compression, diabetes is often present, and percutaneous transluminal angioplasty can be critical for access and limb salvage. Retrospective study conducted between June 2011 and February 2018 of patients with vascular access submitted to arterial percutaneous transluminal angioplasty for limb-threatening ischemia. Twenty-nine patients were referred for arterial angiography after hemodialysis access-induced distal ischemia diagnosis and physical examination or ultrasound findings suggestive of arterial disease. In 11 patients, percutaneous transluminal angioplasty was not technically feasible. Among 18 treated patients, 83.3% had diabetes and 60% had skin ulcerations. Target arteries were radial (11), brachial (7), axillar (2), ulnar (2), and subclavian (1). Clinical success, defined as arteriovenous maintenance and wound healing/pain resolution, was observed in 12 patients (66.7%). Concomitant procedures included adjuvant banding (n = 2) and finger amputation (n = 1), and one reintervention was performed. No intra- or postoperative complications were reported. Hemodialysis access-induced distal ischemia is a serious complication of hemodialysis vascular access, with multifactorial etiology. Correct and timely diagnosis is crucial for maintaining access and limb salvage. Percutaneous transluminal angioplasty is a minimally invasive procedure that may be effective and long-lasting in carefully selected patients with ischemic complaints.

Avoiding hemodialysis access-induced distal ischemia.

Timely creation and maintenance of a safe and reliable vascular access is essential for hemodialysis patients with end-stage renal disease. Hemodialysis access-induced distal ischemia (HAIDI) is a recognized complication of arteriovenous fistulas and grafts that may result in serious or even devastating consequences. Avoiding such complications is clearly preferred over treatment of HAIDI once established. Proper recognition of patients at increased risk of HAIDI includes careful pre-operative evaluation of the patient's medical and surgical history along with physical examination and imaging to determine a plan for creating a functional permanent access while minimizing the risk of distal ischemia. Our aim is to review identifying characteristics of individuals at risk of HAIDI and provide recommendations regarding pre-operative assessment. Vascular access options and techniques are suggested for establishing a functional vascular access without distal ischemia for such patients.

Revision using distal inflow for high flow hemodialysis access alters arterial flow characteristics in the dialysis arm

ObjectiveRevision using distal inflow (RUDI) is currently proposed in patients on hemodialysis having a high flow access (HFA; >2 L/min) or hemodialysis access-induced distal ischemia (HAIDI). However, a recurrence of high flow or hand ischemia is not unusual in the years after RUDI. The aim of the present study was to describe changes in flow characteristics and arterial diameters in the dialysis arm after RUDI for HFA. MethodsVolume flow, diameter, peak systolic velocity and end diastolic velocity of the brachial artery (BA) were studied 2 and 12 months after RUDI using duplex imaging. In a portion of patients, these characteristics were also assessed at proximal and distal portions of radial and ulnar arteries (proximal forearm radial artery, distal radial artery, ulnar artery, and distal ulnar artery), and in the greater saphenous venous interponate. HFA patients were grouped according to presence of concomitant hand ischemia (HFA-HAIDI) or absence (HFA). ResultsFifteen patients (54 ± 16 year old; 10 males; HFA-HAIDI, n = 6; HFA, n = 9) with a BA HFA (flow volume, 2740 ± 322 mL/min) undergoing RUDI were studied between March 2011 and October 2016 in two Dutch hospitals. After 2 months, flow volume had decreased (1180 ± 189 mL/min), but again increased at 12 months (1520 ± 217 mL/min; P < .001). BA diameters did not change (7.4 ± 0.5 mm), but proximal forearm radial diameters doubled (overall 2.6 ± 0.2 mm to 5.4 ±1.0 mm; P < .001), albeit less prominent in HFA-HAIDI (+80%) than in HFA (+130%; P = .019). During follow-up, the distal ulnar artery peak systolic velocity in HFA-HAIDI (83 ± 10 cm/s) was higher compared with the HFA group (54 ± 5 cm/s; P < .01). Dilatation was not present in the greater saphenous venous interponate. ConclusionsRUDI for HFA reduction does not reverse BA dilatation, suggesting irreversible structural arterial wall damage possibly contributing to recurrent high flow. Radial artery remodeling is attenuated in HFA patients previously reporting concurrent hand ischemia diminishing the likelihood of high flow recurrence in this subgroup.

Basilic vein transposition for unsuitable upper arm hemodialysis needle access segment may attenuate concurrent hand ischemia

Some hemodialysis patients with a brachial arteriovenous fistula (AVF) have an unsuitable upper arm needle access segment (NAS) necessitating basilic vein transposition (BVT). It was frequently observed that a portion of these patients spontaneously experienced a warmer and less painful dialysis hand after BVT. Aim of this study was to determine whether BVT for an inadequate NAS attenuated hemodialysis access-induced distal ischemia in patients with a brachial AVF. Patients with a brachial AVF and an unsuitable NAS also reporting hand ischemia and scheduled to undergo BVT between 2005 and 2016 in a single facility were studied. Hand ischemia was graded as proposed in a 2016 consensus meeting. Hand ischemic questionnaire (HIQ-) scores (0 points, no ischemia-500 points, maximal ischemia), digital brachial index (DBI, ischemia <0.6) and access flow (mL/min) before and after BVT were compared. The cephalic vein and all side branches of the basilic vein were ligated during the BVT. Ten patients were studied (8 males, 61 [54-75] years). BVT was performed 8 [4-10] months following the initial AVF construction. HIQ-scores dropped from 220 [71-285] to 9 [0-78] (P = 0.043) postoperatively, whereas DBI increased from 0.51 [0.39-0.67] to 0.85 [0.68-0.97] (P = 0.012). DBI and HIQ-scores were inversely correlated (R2 =71%, P = 0.001). Access flows dropped significantly (Flowpre 1120 mL/min [1100-2300] vs. Flowpost 700 mL/min [600-1760]; P = 0.018). Surgery-associated complications were absent and dialysis continued uninterruptedly. Eight patients reported total recovery from hand ischemia six weeks postoperatively. Basilic vein transposition for an unsuitable upper arm needle access segment may attenuate hand ischemia in patients with a brachial AVF previously reporting hemodialysis access-induced distal ischemia.

TCTAP C-254 Skin Ulcer Due to Hemodialysis Access-induced Distal Ischemia (HAIDI) in Patient with Giant Cell Arteritis Treated with Combination of Arteriovenous Fistula Banding and Endovascular Therapy

### Patient initials or identifier number O.M ### Relevant clinical history and physical exam A 58 years-old woman suffered from paleness on her left hand during hemodialysis for several years. She presented to our hospital with an intractable skin ulcer emerged on her left 3rd finger (Figure 1

Prosthetic Hemodialysis Access-induced Distal Hand Ischemia and its Contributors in Diabetics.

Avoidance of hand ischemia in the construction of prosthetic access for hemodialysis in diabetics that have no suitable vein for arteriovenous fistula is appreciated. Taper type may be an appropriately matched conduit to prevent its occurrence. This is a prospective controlled trial of 38 selected diabetics requiring hemodialysis, who were referred to our clinic during a period of 6 months. The aim of the study was to evaluate the efficacy of tapered grafts in preventing distal hand hypoperfusion and determining its most likely contributors. In 18 intervening cases, taper 4 mm × 7 mm and in twenty cases (control group), standard 6 mm polytetrafluoroethylene as straight Brachial-Axillary access was used. Graft flow rates, artery and vein diameters, and mean arterial pressure were included for evaluation. Within the control group, 11 patients (55%) (7 cases Grade 1, 3 Grade 2, 1 Grade 3) and in intervening group, 2 cases (11%) (Grade 1, Grade 3) developed Steal syndrome. There was no significant difference in the mean flow rates (P = 0.82). Increased risk of distal hypoperfusion was observed in the control group when flow rates were more than 1000 ml/min. Arterial diameters (P = 0.011) and mean arterial pressure (P = 0.05) were found to be important contributing factors. Taper grafts causes reduced incidence of distal hand hypoperfusion. When artery diameter was <6 mm and mean arterial pressure lower than 100 mmHg and the index (brachial artery diameter × mean arterial pressure) was under 500, distal hand ischemia occurred in standard and tapper type. We therefore recommend selective usage of taper grafts in diabetics with diminished distal hand pulses, considering the contributing factors when fistula first is not feasible.

Efficacy of the Ulnar-Basilic Arteriovenous Fistula for Hemodialysis: A Systematic Review

The fistula first initiative has promoted arteriovenous fistulas (AVFs) as the vascular access of choice. To preserve as many future access options as possible, multiple guidelines advocate that the most distal AVF possible should be created in the first place. Generally, snuff box and radiocephalic (RC) are accepted and well-described sites for AVFs; however, the forearm ulnar-basilic (UB) AVF is seldom used or recommended. The aim of this study is to assess and systematically review the evidence base for the creation of the UB fistula and to critically appraise whether more attention should be given to this site. Electronic databases were searched for studies involving the creation of UB fistulas for dialysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcomes for this study were 1-year primary and secondary patency rates. Secondary outcomes were rates of hemodialysis access-induced distal ischemia (HAIDI) and infection. After strict inclusion and/or exclusion criteria by 2 reviewers, 8 studies were included in our review. Weighted-pooled data reveal 1-year primary patency rate for UB AVFs of 53.0% (95% confidence interval [CI]: 40.1-65.8%) with a secondary patency rate of 72.0% (95% CI: 59.2-83.3). HAIDI and infection rates were low. Our review has shown that the UB AVF may be a viable alternative when a RC 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 HAIDI. While it may be more challenging for both surgeons and dialysis nurses to make it a successful vascular access it offers a further option of distal access which may be overlooked.

Digital pressure and oxygen saturation measurements in the diagnosis of chronic hemodialysis access-induced distal ischemia

Hemodialysis access-induced distal ischemia (HAIDI) can be classified as acute (on the first postoperative day), subacute (≤1 month), or chronic (>1 month), based on the time of onset after access creation. The diagnosis is mainly clinical. However, performing additional tests is beneficial in further assessment of patients. The purpose of this study was to evaluate the use of finger pressure and oxygen saturation measurements for the diagnosis of chronic HAIDI. A total of 20 patients with chronic HAIDI (cases) and 40 asymptomatic hemodialysis patients (controls) were matched for age, sex, etiology of end-stage renal disease, and type of arteriovenous access. Basal digital pressure (BDP), digital pressure during manual compression of access, digital brachial index (DBI), change in digital pressure with access compression (CDP), digital pressure of the contralateral side, and bilateral oxygen saturation (O2 Sat) were measured in all patients. In the case group, compression of the arteriovenous fistula (AVF) increased mean BDP from 61 ± 26 to 118 ± 28 mm Hg (P < .001), which failed to reach the non-AVF side mean digital pressure of 151 ± 25 mm Hg (P < .001). In addition, O2 Sat of the AVF side was significantly lower than the contralateral side (92.9% ± 2.1% vs 95.6% ± 1.4%; P = .001). Among the controls, manual AVF compression raised the mean BDP from 114 ± 36 mm Hg to 133 ± 29 mm Hg (P < .001), which was still significantly lower than the contralateral side mean digital pressure of 141 ± 30 mm Hg (P = .002). In addition, O2 Sat values of the two sides were different (96.7% ± 2.1% vs 97.1% ± 1.9%; P = .01). Comparing the cases and controls, the mean BDP (61 ± 26 mm Hg vs 114 ± 36 mm Hg; P < .001), DBI (0.44 ± 0.16 vs 0.82 ± 0.19; P < .001), and O2 Sat (92.9% ± 2.1% vs 96.7% ± 2.1%; P < .001) were significantly lower and CDP (57 ± 24 mm Hg vs 19 ± 17 mm Hg; P < .001) was significantly higher in the cases than in the controls. The optimal discriminatory thresholds of 80 mm Hg for BDP, 0.7 for DBI, 40 mm Hg for CDP, and 94% for O2 Sat were determined. Digital pressure and O2 Sat measurements are useful additional methods to assist in the clinical evaluation of hemodialysis patients with access-related hand ischemia. BDP <80 mm Hg, DBI <0.7, CDP >40 mm Hg, and O2 Sat <94% are associated with chronic HAIDI.

Hemodialysis Access-Induced Ischemia Is Not Related to Configuration and Access Flow Rates of Upper Arm Arteriovenous Fistulas at the Elbow

The purpose of the study was to find a relationship between the configuration of autogenous upper arm arteriovenous fistulas (AVFs) at the elbow and high access flow rates. Forty-seven patients with well-functioning autogenous upper arm AVFs at the elbow were included. The configuration of the AVF and access flow rate was determined by duplex scanning. Hemodialysis access-induced distal ischemia scores and access flow rates were comparable in AVFs with 1 or 2 efferent veins (1829.9±1121.3mL/min, range [400-5000] vs. 1988.5±1324.5mL/min, range [130-5000]; P=0.61). The basilic vein had statistically significant larger diameters than the cephalic vein (8.1±2.7mm, range [2.7-11.0] vs. 5.8±2.5mm, range [3.8-13.0]; P=0.02), but no statistically significant difference in flow rates were observed (1884.5±889.0mL/min, range [824-3600] vs. 1130.0±1258.4mL/min, range [400-5000]; P=0.53). Access flow rates were higher in AVFs with the brachial artery as afferent artery than when the radial artery was used (1909.5±1273.2mL/min, range [550-5000] vs. 1188.6±642.7mL/min, range [130-2800]; P=0.02). There is no difference in access flow rates in autogenous AVFs at the elbow with 1 or 2 efferent veins. Autogenous AVFs at the elbow on the radial artery have lower access flow rates than AVFs on the brachial artery.

Chronic hemodialysis access-induced distal ischemia (HAIDI): distinctive form of a major complication.

Hemodialysis access-induced distal ischemia (HAIDI) is an uncommon but potentially devastating complication. HAIDI is classified as acute, subacute and chronic based upon the time of onset. The aim of this study was to determine the prevalence, severity, patients' characteristics and the underlying etiologic mechanism of chronic HAIDI using color Doppler ultrasonography (CDUS). Between June and August 2010, 676 hemodialysis patients with arteriovenous access (AVA) were evaluated for clinical evidence of chronic HAIDI. In the case-control part of the study, CDUS findings were compared between ischemic patients and asymptomatic matched controls. Also, patients with chronic HAIDI were followed up until February 2014, access ligation, kidney transplantation or death. Eighteen chronic HAIDI patients were diagnosed (2.66%). Cold hand and cold sensation were the most common signs and symptoms of hand ischemia, respectively. Fifteen patients were classified in stage 1. Patients with proximal autogenous arteriovenous fistula, younger age, more previous AVAs and less access age were more likely to develop chronic HAIDI. Excessive fistula flow was found in the majority of ischemic patients (83.3%). The mean fistula flow was significantly higher in cases compared to controls (p=0.001). Eleven patients with chronic HAIDI were successfully treated by conservative measures alone until the end of follow-up (n=3), kidney transplantation (n=4) or death (n=4). CDUS is a useful adjunctive diagnostic tool to determine the etiology of chronic HAIDI. Conservative measures combined with close follow-up can be used as the first step in the management of chronic HAIDI patients with mild symptoms.

Systemic Effects of a High-Flow Arteriovenous Fistula for Hemodialysis

Absolute treatment criteria for reducing the access volume of a high-flow access (HFA, access flow>2 L/min) are absent. Previous studies suggested that a HFA may influence the systemic circulation including blood pressure (BP) and heart rate (HR). The aim of this study was to determine these parameters after access clamping in hemodialysis patients undergoing flow-reducing access surgery. Systolic BP (SBP), diastolic BP (DBP) and HR in HFA patients undergoing flow-reducing surgery were measured intraoperatively before and after access clamping. Data were compared to values obtained in patients receiving surgery for severe hand ischemia due to an access (HAIDI, hemodialysis access-induced distal ischemia). In 8 years, 34 patients underwent surgery for HFA (n=23) or HAIDI (n=11). Preoperative access flows in HFA were larger compared to HAIDI (3,026±147 vs 1,078±139 mL/min, respectively, p<0.001). Temporary clamping (15 sec) caused a 12±2 mm Hg increase in SBP (111±6 to 123±6 mm Hg, p<0.05) and a 6±1 mm Hg rise in DBP (57±4 to 63±5 mm Hg, p<0.05) in HFA patients. In contrast, SBP and DBP increases were not significant in HAIDI patients (+6±3 and +2±2 mm Hg, respectively, p=0.37). HR was modestly reduced in both groups following access clamping (-3±1 beats/min). The relationship between access flow volume and alterations in SBP best fitted a quadratic regression model, suggesting cardiovascular exhaustion with progressively higher access flows>2-2.5 L/min. HFA may influence systemic hemodynamics in some hemodialysis patients. The findings of this study may contribute to a tailored management of a high-flow fistula in this population.

Blood flow dynamics in patients with hemodialysis access-induced hand ischemia

Hand ischemia may occur in the presence of a hemodialysis arteriovenous fistula (AVF), but its pathophysiology is partly unclear. The aim of this observational study was to investigate flow characteristics of forearm arteries in patients with a brachial artery-based AVF suffering from hemodialysis access-induced distal ischemia (HAIDI). A questionnaire scored hand ischemia in patients with HAIDI scheduled for revisional surgery (no symptoms of ischemia, 0 points; maximal ischemia, 500 points). Systolic index finger pressures (Pdig) and digital brachial index (DBI) were determined with open and compressed AVF. Blood flow direction and peak systolic velocity (PSV) were measured in radial and ulnar arteries using Doppler ultrasonography. Age- and sex-matched hemodialysis patients without HAIDI served as controls (CONT). Questionnaire scores were 258 ± 30 in patients with HAIDI (n = 10) compared with 31 ± 16 in CONT (n = 10; P < .01). Pdig and DBI with open AVF were lower in the HAIDI group than the CONT group (Pdig 22 ± 10 vs 102 ± 10 mm Hg; DBI 0.18 ± 0.08 vs 0.70 ± 0.04; both P < .01). Ulnar artery PSV was lower in HAIDI compared with CONT patients (38 ± 4 vs 56 ± 3 cm/s; P < .01). Mean ulnar artery PSV was significantly correlated to Pdig (r = 0.87; P < .01) in contrast to mean radial artery PSV (r = 0.06; P = .81). Ulnar artery blood flow direction was always toward the ischemic hand (n = 20). However, blood flow was reversed in just a short segment of the proximal radial artery in one HAIDI patient but also in two CONT patients. Hand ischemia in hemodialysis patients with a brachial artery-based AVF is not caused by a reversed blood flow direction in forearm arteries. However, forearm blood flow is diminished in these patients leading to critically reduced arterial pressures in the hand.

ASDIN: Banding of Hemodialysis Access to Treat Hand Ischemia or Cardiac Overload

A hemodialysis access may lead to cardiac overload (CO) or hand ischemia [hemodialysis access induced distal ischemia (HAIDI). Surgical banding restricts access flow and promotes distal perfusion. Aim of the study was to investigate short- and long-term clinical success of banding in these patient groups. After evaluation using a standard protocol, banding procedures (n = 19) were performed in patients (n = 17) with a hemodialysis access flow > or =2 l/minute or with refractory HAIDI. Various parameters including access flow, digital brachial index (DBI), and symptomatology of hand ischemia using a standard scoring system were determined before and after the operation. Surgical banding in CO patients (n = 9) lowered access flows by 2 l (Flow(preop) 3.2 +/- 0.3 l/minute vs. Flow(postop) 1.2 +/- 0.1 l/minute, p < 0.001). Banding in HAIDI patients (n = 10) increased DBI from 0.52 +/- 0.08 to 0.65 +/- 0.08 (p = 0.05), whereas ischemic symptomatology was attenuated (153 +/- 33 to 42 +/- 15, p < 0.02). All patients successfully continued dialysis, and immediate access occlusions (<3 months) were not observed. Access flows remained at acceptable levels after a mean follow-up of 30 months in surviving patients (n = 11, flow: 1.0 +/- 0.1 l/min). Two patients were reoperated for recurrent CO (one and 28 months postoperatively). Surgical banding monitored by measurement of flow and finger pressures is an effective short- and long-term treatment modality for hemodialysis access related CO or distal ischemia.

Surgical Banding for Refractory Hemodialysis Access-Induced Distal Ischemia (HAIDI)

Hemodialysis patients may develop distal ischemia in an extremity harboring a functioning arteriovenous access (AVA). Surgery is indicated if conservative treatment including catheter-based therapies fails. The role of surgical banding for refractory hemodialysis access-induced distal ischemia (HAIDI) is systematically reviewed (n=39 articles). If banding is executed without an intraoperative monitoring tool ("blind"), or guided by finger pressures only, clinical success and access patency rates are low (<50%). In contrast, banding is clinically successful when access flow is monitored during the operative procedure, with excellent long-term patency of banded AVA's (97%, 17 +/- 3 months). Banding is the method of choice in HAIDI patients with a normal or high access flow (>1.2 l/min) provided that flow and distal perfusion are closely monitored intraoperatively.