Pharmacological control of intimal hyperplasia in small diameter polytetrafluoroethylene grafts. An experimental study.

OBJECTIVE: The efficacy of a postoperative treatment with Low molecular weight heparin (LMWH) vs Ticlopidine in controlling early thrombosis, intimal hyperplasia and growth of true endothelial cells in small prosthetic expanded polytetrafluoroethylene (ePTFE) grafts (4 mm) interposed in the carotid artery of sheep has been evaluated. EXPERIMENTAL DESIGN: Thirty animals were randomized into three different groups: control group (CTRL); ticlopidine hydrochloride (TICL) 250 mg/b.d. by month for 4 weeks from day 1; LMWH 3,085 IU AXa s.c. preoperatively and once a day for the same period. RESULTS: Complete thrombosis of the graft occurred in 7 sheep in the CTRL group and 5 in the TICL group while 2 partial thrombosis were observed in the LMWH group (n.s.). In all the evaluable cases, hyperplasia was observed in both anastomotic areas and did not involve the middle portion of the graft. The mean +/- SD intimal thickness was 603 +/- 20 micron in the CTRL group, 356 +/- 10 in the TICL group and 152 +/- 17 in the LMWH group (p < 0.001) compared to the 60 +/- 12 of the normal intima. True endothlial cells were found mainly in the LMWH group close to the arterial anastomosis. CONCLUSIONS: The postoperative use of LMWH seems to inhibit intimal hyperplasia, with interesting results also on patency and cellular coverage. Further studies are necessary to support this promising trend.

[Prevention of vascular intimal hyperplasia in small caliber prostheses. Preliminary results]. / Controllo dell'iperplasia intimale in protesi di piccolo calibro. Risultati preliminari.

Intimal hyperplasia is one of the main risk factors for the patency of small diameter bypass grafts. The standard unfractioned heparin (UH) is able to control this phenomenon but the clinical use is not fit for long term treatment; on the other hand the antiplatelet drugs have an anti-thrombotic effect but they seem to be unable to control intimal hyperplasia. Low molecular weight heparins (LMWH) have an anti-thrombotic effect superimposable to that of UH with minimal side-effects and might inhibit intimal hyperplasia too. Based on these criteria, we carried out an experimental study on sheep with the aim of evaluating the efficacy of postoperative treatment with LMWH versus an anti-platelet drug in controlling intimal hyperplasia and growth of true endothelial cells in small prosthetic ePTFE grafts (4 mm) interposed in the carotid artery. At the operation, 30 sheep were randomly located in 3 groups: A = control group, no treatment; B = Ticlopidine hydrochloride 250 mg/bid by mouth for 4 weeks; C = LMWH 3.075 IU AXa (0.3 ml) sc preoperatively and then once a day for the same period. Complete thrombosis of the graft occurred in 7 sheep of group A, 5 in B and 2 partial in group C. The intimal hyperplasia was moderate-severe in group A, mild-moderate in group B and no-mild in group C. True endothelial cells were found mainly in the LMWH group; in the other groups and in other portions of the grafts the cellular coverage was accomplished almost completely by fibroblasts. The study is still in progress with 6 further sheep treated with LMWH.

The impact of consumer health information provided by libraries: the Delaware experience.

In the past two decades, consumer health libraries have proliferated in response to the changing health care environment and consumer demand. While this growth of consumer health resources and services has been extensively described in the literature, there is little documentation about the impact and value of providing consumer health information. This paper explores the issues of impact and value as examined in a retrospective study of consumers who received health information from the Delaware Academy of Medicine's Consumer Health Library during 1995. In this study, 270 adults were mailed a questionnaire that focused on whether the information influenced decisions, actions, anxiety levels, and patient-provider communication. The questionnaire also addressed the value of such library service in terms of likelihood of repeat use, recommendation to others, and willingness to pay. The results, based on a return rate of 86.7%, identified effects of library-supplied consumer health information that extend beyond the anticipated acquisition of knowledge to specific actions and effects on anxiety. The value of consumer health library information service was shown by the extremely high percentage of probable repeat use and recommendation to others, the willingness of 83.8% of the respondents to pay for such service, and the copious comments volunteered by the respondents.