High-output cardiac failure secondary to a brachiocephalic arteriovenous hemodialysis fistula: two cases.

The use of native arteriovenous fistulas for hemodialysis access is important to the success of this form of treatment for patients with end-stage renal disease. Native fistulas have been shown to provide improved longevity and to have lower complication rates when compared to prosthetic graft fistulas. High-output cardiac failure related to hemodialysis fistulas is an uncommon complication of their usage. Two renal transplant patients who did develop this complication from large well-developed brachiocephalic arteriovenous hemodialysis fistulas are presented. Both patients underwent successful transplantation and have required fistula ligation, with subsequent resolution of their cardiac failure. Native fistulas remain the best choice for hemodialysis access, but the clinician should remain aware of the possible untoward hemodynamic effects of these fistulas.

Gastric bypass in morbidly obese kidney transplant recipients.

Severe post-transplant obesity has previously been shown to have a negative impact on graft survival following kidney transplantation. It also contributes to late patient mortality and is associated with hypertension, diabetes and hyperlipidemia. We undertook Roux-en-Y gastric bypass (GBP) in three morbidly obese (200-260% ideal body weight) (IBW) patients 6-8 yr following kidney transplantation. Roux-en-Y gastrojejunostomy to a 30 ml stapled gastric pouch was created with the jejunojejunostomy (both loops) 80-120 cm from the ligament of Treitz. By 12 months post-GBP, weight loss plateaued at 100-150% IBW. Both patients that had developed post-transplant diabetes mellitus (PTDM) had complete resolution within 9 months following GBP. On average the patients required 3 less hypertension (HTN) medications after GBP; 2 of the 3 patients are now normotensive off medication. Improvements in hyperlipidemia were also shown. The absolute cyclosporine (CsA) requirement (mg/d) increased by approximately 33% (p = NS), and there was also a significant increase in the weight adjusted CsA requirement from 1.8 to 3.5 mg/kg/d (p = 0.02, ANOVA) following GBP in order to maintain similar TDX trough CsA levels. GBP offers significant reduction in weight, HTN, PTDM and hyperlipidemia in morbidly obese kidney transplant recipients. However, CsA dose requirements may increase after GBP as a consequence of the defunctionalized intestine.

A percutaneous technique for venovenous bypass in orthotopic cadaver liver transplantation and comparison with the open technique.

Venovenous bypass minimizes the hemodynamic alterations during the anhepatic phase of liver transplantation. A new technique for the percutaneous placement of the bypass cannulae is described and compared to the cut-down ("open") technique. The records of 81 patients who underwent 94 liver transplants between August 1991 and April 1994 were reviewed for indications for transplant, United Network for Organ Sharing status, mean age, body surface area, bypass technique and time, flow rates, cardiac output, mean arterial pressure and central venous pressure during bypass, the development of deep venous thrombophlebitis, and lymphoceles. Femoral flow rates were higher in the open group (2054 +/- 74 mL/min), compared with the percutaneous group (1726 +/- 74 mL/min) (p = 0.003). Total flow rates in the open (2238 +/- 58 mL/min) and percutaneous (2197 +/- 67 mL/min) groups were not different. Maximum cardiac outputs (L/ min) were higher in the open (10.1 +/- 0.6) versus percutaneous group (7.0 +/- 0.5) (p < 0.0002). Similarly, minimum cardiac outputs (L/min) were higher in the open (8.9 +/- 0.7) versus percutaneous group (5.8 +/- 0.5) (p = 0.003). Other hemodynamic parameters (mean arterial pressure, central venous pressure) were not different between groups. Venous thrombosis occurred in 1/50 (2.0%) and 4/34 (11.8%) patients in the open and percutaneous groups, respectively (p = 0.153). Nineteen lymphoceles occurred in 102 (18.6%) at-risk sites in the open group, whereas no lymphoceles occurred in 66 at-risk sites in the percutaneous group (p < 0.001). Groin lymphoceles occurred in 7/50 (14%) and 0/34 at-risk sites in the open and percutaneous groups, respectively (p = 0.039). Axillary lymphoceles occurred in 12/52 (23.1%) and 0/32 at-risk sites in the open and percutaneous groups, respectively (p = 0.0031). Operative repair of a lymphocele was required in 11/16 (69%) patients. The percutaneous placement of catheters for venovenous bypass has the advantage of comparable flow rates with satisfactory hemodynamics without the lymphatic complications of the cut-down technique.

Small intestinal microcirculatory effects of octreotide.

Somatostatin and its analogue, octreotide acetate, are thought to decrease mesenteric blood flow; however, it is unknown whether the decrease occurs at the central, regional, or microvascular level. We hypothesized that the circulatory effects of octreotide are regulated at the microvascular level. Changes in superior mesentery artery (SMA) flow in response to octreotide were measured with a perivascular ultrasonic flow probe. In separate experiments, the jejunal microcirculatory effects of octreotide were studied using in vivo videomicroscopy. After accrual of baseline hemodynamic and microcirculatory data, animals were randomized to control or treatment (10 micrograms/kg octreotide) iv groups. Measurements were made every 15 min during the infusion and for 90 min after the completion of the infusion. Results are expressed as means +/- SEM. Intravenous infusion of octreotide caused no significant change in arterial pressure, cardiac index, or systemic vascular resistance index in either group in either set of experiments. A statistically significant decrease in heart rate (9%) occurred in the control group of animals undergoing SMA flow measurement. SMA flow did not change significantly with infusion of octreotide. In contrast, jejunal first-order arteriole flow increased to 117.9 +/- 9.7% of baseline (P < 0.05) in the absence of significant changes in microvessel diameters. This was due to an increase in centerline red cell velocity (116 +/- 5% of baseline, P < 0.05). We conclude that octreotide increases jejunal first order arteriole flow by mechanisms that are regulated at the microcirculatory level.

Locally invasive aspergillosis of the bowel.

Locally invasive aspergillosis of the bowel and peritoneal cavity is a rare complication of immunosuppression, broad-spectrum antibiotic therapy, and corticosteroid administration. We present the case of a 9-year-old boy with acute lymphocytic leukemia who presented with a small bowel obstruction. Surgical treatment of the aspergillosis required multiple aggressive resections of all involved bowel segments. Parenteral nutrition and intravenous Amphotericin B and 5-Fluorocytosine therapy were also instituted. Achievement of a hematologic remission is another prerequisite for cure.

Induction of the protooncogene c-fos and recovery of cytosolic adenosine triphosphate in reperfused liver after transient warm ischemia: effect of nitrone free-radical spin-trap agents.

Ischemia and reperfusion stimulate several adenosine triphosphate (ATP)-dependent processes involving release of substances including free radicals. This cellular response is mediated through receptors responsive to transcriptional products of gene expression; c-fos acts as a transcriptional factor involved in the regulation of genes associated with cellular proliferation and differentiation. We hypothesized that nitrone free-radical spin traps promote restoration of cytosolic ATP during reperfusion and prevent c-fos induction. Four control rats had no ischemia. Global hepatic ischemia was induced in 19 rats in four groups: saline solution, phenyl-N-tert-butyl nitrone (PBN), alpha 1-pyridyl-N-oxide N-tert-butyl nitrone (POBN), and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). ATP and intracellular pH were measured at intervals before, during, and after ischemia. At 90 minutes of reperfusion, liver c-fos mRNA was measured. A fourfold elevation of c-fos occurred in the saline-treated group (p less than 0.001). PBN and POBN groups did not differ from the saline group. DMPO resulted in significantly less induction of c-fos than did NS. ATP depletion and recovery in all treatment groups was similar to that of the saline group. We conclude that (1) nitrone spin traps do not prevent c-fos induction or alter the pattern of ATP recovery after hepatic ischemia and reperfusion and (2) c-fos induction is not necessary for restoration of ATP, but the rate of ATP restoration is inversely related to c-fos induction.