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In a side-to-side fistula between femoral artery and vein, an external “shunt” was created that simultaneously connected the distal femoral vein and the proximal femoral vein in 14 normal dogs with weight ranging from 14 to 28 kg. Blood flow and pressure alterations of different sites of this experimental model of vascular access were studied. The results showed that the degree of blood flow on these two vascular communications depends on the structural integrity of the femoral artery with adequate blood flow and blood pressure. Also, the correct connection of external shunt with the fistula is of equal importance. It is suggested that the blood pressure as well as the blood flow rate of these two vascular communications were adequate to allow performance of acute and chronic hemodialysis.

Twenty-five brachial-basilic arteriovenous (AV) fistulas with transposed basilic vein for alternative vascular access were created in 22 chronic hemodialysis patients. This surgical procedure was performed under brachial block or general anesthesia. After a longitudinal skin incision that was made in the inner side of the arm, the basilic vein was exposed, transposed subcutaneously, and anastomosed end-to-side to the brachial artery. The follow-up was between 7 and 24 months. Early complications were hemorrhage, thrombosis, steal syndrome, and swelling of the arm. Among the late complications were failure of the fistula because of thrombosis and multiple stenosis at the site of venipuncture. The accumulated one-year patency rate of fistulas was 81%. The complications of high-output cardiac failure or local infection were not seen in our study. On the basis of our results, the brachial-basilic AV fistula with transposed basilic vein is a useful and safe second- or third-choice vascular procedure for hemodialysis patients, in particular for women without good quality of vessels.

Twelve patients, 8 male and 4 female, aged from 26 to 70 years were studied. They were on hemodialysis (HD) 4 h three times weekly with cuprophan hollow fiber dialyzers (Gambro 120M) and dialysate containing 35 mEq/L of acetate. The study compares two random HD sessions on each patient. Sixty minutes prior to one random session a placebo was administered orally, and prior to another random session piracetam was given at a dose of 8 g. Heparin dosage was not reduced during HD using QB 200 ml, QD 500 ml, and no ultrafiltration. Blood samples for leukocyte and platelet counts, serum C3, arterial paO2 and paCO2, thromboxane-B2 (TxB2), and β-thromboglobulin (β-TG) were taken from the arterial line before and at 15, 60, and 240 min during HD. Leu-kopenia at 15 min of HD was found to be less severe (p < 0.01) in the piracetam study than in the placebo, whereas platelet count did not change. Serum C3 was slightly increased in both studies. Arterial oxygen was preserved close to the initial levels by piracetam (91.66 mm Hg versus 81.08, p < 0.01 at 60 min, and 93.08 versus 80.17 mm Hg, p < 0.01 at 240 min of HD sessions) but paCO2 did not change significantly. TxB2 increased less with piracetam in comparison to placebo (p < 0.01 or p < 0.001), but (J-TG was reduced significantly by piracetam at any time during HD (p < 0.001). The above statistical analysis was done by paired t-test. Using the ANOVA test, significance was found only in plasma TxB2 levels between the two groups (p < 0.001). It is suggested that piracetam is a potent inhibitor of some HD-associated bioincompat-ibility parameters.