A novel flexible endovascular stent for use in small and tortuous vessels.

We assessed in vivo the mode of delivery, short-term patency and cellular response to a prototype endovascular stent. The stent is designed for delivery through a modified microcatheter and is retrievable with detachment from a delivery wire effected by electrolysis. We successfully deployed 12 stents in a range of sizes from 3-4 mm in straight and angled arteries of pigs. At control angiography 3 and 6 weeks later, nine arteries were patent, two occluded and one narrowed; patency was not related to vessel or stent size. The device shows promise as a stent for intracranial arteries since it can be delivered through microcatheters small enough for intracranial navigation and provides the operator with greater control than currently available self- or balloon-expanded stents.

Aminoglycoside pharmacokinetics in African-Americans with normal renal function.

OBJECTIVE: To compare aminoglycoside pharmacokinetics in African-Americans with normal renal function with published adult population values. DESIGN: An Institutional Review Board approved concurrent study. SETTING: The study was conducted at Howard University Hospital, Washington DC. SUBJECTS: All subjects had serum creatinine levels of 1.5mg/dl or less and were receiving aminoglycoside for suspected or documented Gram-negative infection, had no obvious underlying disease condition that could influence aminoglycoside pharmacokinetics and were aged 18 years or older. MAIN OUTCOME MEASURES: Volume of distribution (Vd), half-life (t1/2), elimination rate constant (Ke) and total body clearance (Cl) were calculated using a one-compartment, open, linear pharmacokinetic model. Using an unpaired Student's t-test, the pharmacokinetic values of our patients were compared with general population values. INTERVENTIONS: Patients receiving aminoglycosides were identified by the pharmacist through the hospital's standard antibiotic order sheet. Twenty-five patients were enrolled after they met the inclusion criteria. Pharmacists made recommendations for dose change as part of standard of care when inappropriate doses were ordered. In collaboration with medical and nursing staff, the amount and time of dose administration, and steady-state peak and trough serum drug levels were stringently measured, documented on a data collection form and used to calculate pharmacokinetic values for our patients. The form was also used to document demographic information. RESULTS: The following values were obtained: Vd 0.27+/-0.15 litres/kg, t(1/2) 1.93+/-1.38h, Ke 0.31+/-0.134/h (gentamicin), Ke 0.22 +/- 0.10/h (tobramycin), Cl 103.95+/-62.98ml/kg/h (gentamicin) and Cl 118.96+/-84.83ml/kg/h (tobramycin). These values are not significantly different from general population values. Following a mean tobramycin or gentamicin dose of 1.32+/-0.32mg/kg ideal body weight (IBW)/ dose or 1.11+/-0.33 mg/kg actual body weight (ABW)/ dose every 8h, patients achieved a mean peak and trough serum drug levels of 6.6+/-3.86mg/litre and 1.03+/-0.68mg/litre, respectively. Wide interpatient pharmacokinetic variability was also observed. CONCLUSIONS: We conclude that aminoglycoside pharmacokinetics in African-Americans seem to be consistent with the published general population values. Thus, initiating aminoglycoside regimens using population dosing guidelines appears to be appropriate. However, due to the observed wide interpatient pharmacokinetic variability, individualized dosing is required with very close monitoring, to avoid or minimize toxicity.