Reverse-loop upper arm arteriovenous graft for chronic hemodialysis.

Options for an upper arm arteriovenous graft (AVG) commonly include the placement of a straight prosthetic graft connecting the brachial artery to the axillary vein. However, such configuration leads to underutilization of the upper arm veins, resulting in the loss of venous capital in the upper arm for future secondary fistula creation. In this retrospective analysis, we evaluated seven patients who had upper-arm AVGs created in a reverse-loop configuration. The prosthetic graft was created by connecting the brachial artery close to the cubital fossa and tunneled subcutaneously in a looped fashion distally thereby connecting the basilic or deep brachial vein just above the elbow. Endpoints were interventions, thrombosis, and loss of access at the last examination. The brachial vein was used in two patients and the basilic vein in the other five. The median duration of follow-up with 100% patency of the AVGs was 10.0 (range, 3.0-25.0) months. Patients were able to achieve a target hemodialysis dose with a (K(urea) x t(d))/V(urea) value of 1.4 (range, 1.2-1.5). The median flow rates achieved were 205.0 (range, 203.3-236.7) and 266.7 (range, 203.3-276.7) ml/minute at the first and 3-month dialysis sessions, respectively. The median dialysis venous pressures were 128.0 (range, 108.3-178.0) and 131.0 (range, 116.7-148.7) mmHg at the first and third month after operation, respectively. The median peak systolic velocity ratios of artery-graft and vein-graft junctions were 2.1 (range, 1.4-2.4) and 3.0 (range, 2.3-3.8) cm/second, respectively. In conclusion, this is a logical approach for patients who have exhausted their forearm vessels for AVG creation. In addition, it also provides a platform for future creation of a secondary fistula in the upper arm.

Albumin dialysis in critically ill patients: use versus omission of intradialytic heparin.

Albumin liver dialysis using the Molecular Adsorbent Recirculating System (MARS) (Teraklin AG, Rostock, Germany) is used in severe acute liver failure (ALF). We hypothesized that intradialytic heparin worsens preexisting hemostatic defects without enhancing system longevity or therapeutic efficacy. This was a retrospective, single center study of 10 critically ill patients (M : F = 8:2; mean age 58.5 +/- 16.5 years old; Acute Physiology and Chronic Health Evaluation II 25.0 +/- 3.5) treated with 31 MARS sessions (intradialytically heparinized : nonheparinized = 18:13). Mortality in this cohort was 80%. All MARS circuits were primed with dilute heparinized saline before commencement. However, intradialytic, intermittent, bolus heparin was administered on an ad hoc basis with circuit saline flush where indicated. Acute renal replacement therapy was instituted where indicated. Average total intradialytic heparin used was 757 +/- 389 IU. Circuit pressures were stable with or without intradialytic heparin. Significant reductions in serum urea, creatinine, ammonia, and total bilirubin were achieved using intradialytically heparinized and nonheparinized MARS. Thrombocytopenia and elevated activated partial thromboplastin time (aPTT) were further deranged post-MARS for both circuit types, but significantly so in intradialytically heparinized MARS: pre- versus post-MARS aPTT (s) 57.8 +/- 17.6 versus 88.7 +/- 48.0, P = 0.011, and platelet count (x 10(3)/L) 102.9 +/- 61.1 versus 84.4 +/- 50.5; P = 0.009. The use of low dose, intradialytic heparin during MARS exacerbates preexisting severe coagulopathy and thrombocytopenia in patients with severe ALF without enhancing circuit function and longevity. However, the role and safety of heparinized saline prime need further investigation.

Anticoagulation minimization is safe and effective in albumin liver dialysis using the molecular adsorbent recirculating system.

The molecular adsorbent recirculating system (MARS) is a blood purification device with renal and hepatic dialytic effects. This study examined the use of low-dose unfractionated heparin in MARS. This was a prospective, observational study of 15 MARS treatment sessions (mean duration per treatment cycle = 12.2 +/- 4.5 h) in four patients with severe acute decompensation of chronic liver disease (n = 3) and fulminant hepatic failure (n = 1) treated with intermittent MARS. All patients were critically ill (APACHE II 24.8 +/- 3.3). Renal dialysis was with continuous hemofiltration and/or slow low-efficiency dialysis. One MARS session was terminated because of vascular access occlusion (1/15; 6.7%). Bleeding was noted in two sessions (2/15; 13%). Twelve MARS sessions were heparin-free and three treatments were with mean heparin dose of 833 +/- 382 IU. Serum biochemical parameters pre- and post-MARS were total bilirubin (micromol/L): 409.4 +/- 141.6 versus 282.9 +/- 90, P < 0.05; plasma ammonia (micromol/L): 44.3 +/- 21.2 versus 28.8 +/- 20.2, P = 0.002; urea (mmol/L): 15.9 +/- 11.8 versus 7.9 +/- 6.6, P = 0.002; creatinine (micromol/L): 252.4 +/- 151.9 versus 150.1 +/- 96.6, P = 0.003. Pre-MARS versus post-MARS systolic (SBPs) and diastolic (DBPs) blood pressures (mm Hg) were SBP = 129.2 +/- 27.7 versus 124 +/- 25, P = 0.838; and DBP = 60.7 +/- 15.3 versus 56 +/- 13, P = 0.595. Prothrombin time (PT), activated partial thromboplastin time (aPTT) and platelet count (Plt) pre- and post-MARS were PT(s): 22 +/- 7.9 versus 23.8 +/- 10.2, P = 0.116; aPTT (s): 64.5 +/- 40.9 versus 85.5 +/- 50.6, P = 0.092; and Plt (x10(3)/mm(3)): 87 +/- 67.6 versus 68.8 +/- 39, P = 0.098. MARS priming with heparin saline was safe. Heparin-minimized MARS did not compromise circuit function and longevity in extended intermittent MARS.