A three-year follow-up on standard versus thin wall ePTFE grafts for hemodialysis.

PURPOSE: Expanded polytetraflouroethylene (ePTFE) grafts are the most popular prosthetic grafts for hemodialysis patients in whom autogenous fistulas cannot be constructed. Long-term studies to study the durability and complication rate of the different wall configurations of ePTFE grafts have not been carried out. The primary, secondary, and cumulative patency and other complications between standard thickness (STD) and thin wall (THN) 6 mm stretch ePTFE grafts (WL Gore & Assoc, Flagstaff, AZ) was prospectively evaluated. METHODS: From September 1993 to August 1995, 108 patients receiving new grafts were randomized into 2 groups: those receiving STD grafts (n = 56) or those receiving THN (n = 52) grafts. Data prospectively collected included day of first access, primary patency, interventions required, and long-term results. Infections, pseudoaneurysms, and mortality were also documented. Student's unpaired t-test was used to compare the 2 groups, and log-rank life tables were constructed and compared. RESULTS: Mean follow-up examination time was 38.1 +/- 0.8 months for STD grafts and 35.1 +/- 1.0 months for THN grafts (P<.03). Longer patency was noted in the STD group of grafts (18.2 months for STD vs. 12.1 months for THN). Biographical data and complications, including pseudoaneurysm (6% vs. 5%), infection (2% vs. 3%), and mortality (22% vs. 19%), between STD and THN groups were not different statistically. Mean primary (18.2 months vs. 12.1 months), secondary (20.9 months vs. 13.7 months), and cumulative patency times (22.2 months vs. 15.2 months) for the STD group were significantly more than those for the THN group (P<.000 by log rank of life tables). Other complications were not different between groups. CONCLUSION: Standard thickness ePTFE is the graft of choice when placing ePTFE arteriovenous grafts for hemodialysis.

Prophylactic Greenfield filter placement in selected high-risk trauma patients.

PURPOSE: Pulmonary embolus (PE) remains a major factor in morbidity and death in severely injured patients, especially those in specific high-risk groups. PEs have been documented to occur despite routine deep venous thrombosis prophylaxis. The purpose of this study was to evaluate the safety and efficacy of prophylactic Greenfield filter (PGF) placement in patients who have multiple trauma with known high-risk injuries for PE. METHODS: From January 1992 to June 1994, PGF were prospectively placed in 108 patients who had an injury severity score greater than 9 and met one of the following criteria: (1) severe head injury with prolonged ventilator dependence, (2) severe head injury with multiple lower extremity fractures, (3) spinal cord injury with or without paralysis, (4) major abdominal or pelvic penetrating venous injury, (5) pelvic fracture with lower extremity fractures. These patients were compared with 216 patients, historically matched for age, sex, mechanism of injury, injury severity score, and days in the intensive care unit. Data analysis was done with chi-squared and Student's t testing. RESULT: There were no statistical differences between the PGF and control group with regard to age (35.9 +/- 1.5 vs 38.3 +/- 1.4), sex (male 76% vs 75.5%), days in the intensive care unit (21.2 +/- 1.4 vs 18.1 +/- 1.5), ISS (28.0 +/- 1.0 vs 25.4 +/- 0.8) and mechanism of injury (blunt 85% vs 81%). None of the patients in the PGF group had a PE. In the control group, however, 13 patients had a PE, nine of which were fatal. These differences were statistically significant for both PE (p < 0.009) and PE-related death (p < 0.03). The overall mortality rate was reduced in the PGF group (18 of 108, 16%) versus the control group (47 of 216, 22%); however, this did not achieve statistical significance. CONCLUSION: PGF insertion in selected patients at high risk who had trauma effectively prevented both fatal and nonfatal PE. The lower incidence of fatal PE in the PGF group may have contributed to a reduction in the overall mortality rate. Patients who have trauma with high risk for PE should be considered for PGF placement.

Delayed emergence of striatal dopaminergic hyperactivity after anterolateral ischemic cortical lesions in humans; evidence from turning behavior.

To test the hypothesis that striatal dopaminergic hyperactivity in humans may be an aftermath of anterior cortical ischemic insults, we utilized earlier observations that in several species, including humans with hemiparkinson's disease, asymmetric striatal dopaminergic activity results in spontaneous asymmetric turning away from the hemisphere with higher dopaminergic activity. In this study, electronic monitoring showed that, compared to normal controls, outpatients with old frontal and inferior-parietal cortical strokes exhibit a marked tendency to turn away from the side of the lesion. This delayed ipsilateral neglect suggests a delayed emergence of lasting ipsilateral striatal dopaminergic hyperactivity after unilateral anterolateral cortical insult in humans. Old ischemic insults to anterolateral cortical areas could be one etiological mechanism in human brain disorders that are associated with cortical dysfunction and delayed subcortical dopamine hyperactivity.