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Biomedical subjects

F Castaneda

Publications and source records attributed to F Castaneda.

26 records · Page 2Linked to original sources
PubMed1983

Prostaglandins and angioplasty. An experimental study in canine arteries.

To prevent platelet aggregation following percutaneous transluminal angioplasty (PTA), cyclooxygenase inhibitors such as acetylsalicylic acid (ASA) and indomethacin are recommended. However, ASA blocks both the proaggregating effects of thromboxane (TXA2) and the antiaggregating and vasodilating effects of prostacyclin (PGI2). The authors measured the contractile response of dilated canine carotid arteries in situ and in vitro using an isometric force transducer. Following PTA, contraction of the arterial wall was significantly reduced (p less than 0.01). By blocking cyclooxygenase with indomethacin (3 micrograms/ml), contraction was greatly improved (p less than 0.001). These results suggest that PTA may result in marked release of prostacyclin by the damaged arterial wall, which could account for the decreased responsiveness of the artery to exogenous norepinephrine.

Angioplasty, Balloon↗
PubMed1983

Patency of the ductus arteriosus after balloon dilatation: an experimental study.

Balloon dilatation of the ductus arteriosus was carried out in vivo in newborn pigs and on postmortem specimens from humans and piglets. The ductus was functionally closed in all newborn animals but patency resulted in all animals after balloon dilatation. Left-to-right shunts of 50% to 70% were found with anatomic lumen sizes of 3 to 5 mm. Patency was demonstrated up to 6 weeks after dilatation. Histologic examination showed splitting of the internal elastic layer and media, areas of hemorrhage confined to the media, and preservation of the adventitia. Mediastinal hemorrhage did not occur. This new technique is useful as an animal model of patent ductus arteriosus and could theoretically be used for palliative treatment of ductus-dependent congenital heart disease.

Angioplasty, Balloon↗
PubMed1983

A new percutaneous vena cava filter.

A new, percutaneous vena cava filter was developed and tested in 11 dogs. Nitinol wire (0.045 cm diam) spirals were straightened and passed through an 8 French Teflon catheter into the inferior vena cava. The filter resumed its original spiral shape on warming to body temperature and was left in place up to 6 weeks. Long-term patency and capture of injected radiopaque clots were demonstrated. This new filter design may be a simple alternative to currently used implants.

Animals↗
PubMedDate not supplied

Percutaneous intravascular biopsy using a Simpson atherectomy catheter: technical note.

The design of the Simpson atherectomy catheter makes this device a potentially safe and technically easy tool to obtain adequate pathologic intravascular or intraluminal specimens. The risk of perforation should be low, but this use has to be further studied. We describe the first intravascular biopsy performed with the Simpson catheter.

Arteriosclerosis↗
PubMedDate not supplied

Reversible hepatic transplant ischemia: case report and review of literature.

We report the successful treatment of a hepatic arterial anastomotic stenosis by angioplasty in an orthotopic liver transplant recipient. The patient had already undergone hepatic infarction and compromised allograft function and sepsis. Baseline duplex ultrasound and angiographic studies showed obstruction of the transplant arterial anastomosis. Following angioplasty, allograft function, areas of infarction, and duplex ultrasound studies returned to normal. At 6-month follow-up the patient remains asymptomatic.

Adolescent↗
PubMedDate not supplied

A retrievable nitinol vena cava filter: experimental and initial clinical results.

PURPOSE: The authors describe the properties of a new retrievable nitinol vena cava filter and report experimental and initial clinical results. MATERIALS AND METHODS: The filters, made of nitinol monofilament wire that forms a spiral cone and retrieval wire, were introduced through an indwelling 5.5-F transfemoral sheath into the infrarenal portion of the inferior vena cava in 10 sheep. In seven animals, four 4 x 30-mm radiopaque clots were injected below the filter to test its thrombus-trapping efficacy. Aspiration thrombectomy was then attempted, and the filter was removed. Follow-up venography was performed 1 week after placement in three other animals. After successful preclinical testing, the filter was implanted and retrieved in two patients. RESULTS: All 10 filters were successfully and easily placed in sheep. All filters were thrombus-free at follow-up venography. All clots injected in the iliac veins were trapped by the filter and successfully removed by means of aspiration thrombectomy. All 10 filters were retrieved without difficulty. Temporary filter implantation and retrieval were accomplished in two patients for 5 and 7 days. In one patient, infrafilter thrombus was aspirated. Perisheath thrombosis occurred in both patients. One patient subsequently underwent permanent filter placement. CONCLUSION: Temporary vena cava filtration is feasible. Potential advantages include easy placement, surveillance, and retrieval. One current limitation is pericatheter thrombosis, which may be eliminated by a less thrombogenic sheath.

Alloys↗
PubMedDate not supplied

Percutaneous transthoracic needle biopsy of the lung: review of 612 lesions.

PURPOSE: The results and complications of 651 pulmonary fine-needle aspiration biopsies (FNABs) were reviewed. The number of needle passes and needle size were correlated to pneumothorax and chest tube placement rates. MATERIALS AND METHODS: FNAB of the lung was performed on 651 occasions in 612 patients with 18- to 22-gauge Franseen needles. Diagnostic rates were calculated. The number of needle passes performed and needle size used were evaluated for their association with pneumothorax and subsequent chest tube placement. RESULTS: Diagnostic accuracy was 94% with sensitivity for malignancy of 95%. Positive and negative predictive values were 99.5% and 90%, respectively. Pneumothorax occurred in 26.9% of patients with 9.2% requiring chest tube placement. Increasing numbers of needle passes and larger needle sizes did not increase the rates of pneumothorax or chest tube placement. CONCLUSIONS: FNAB of the lung has excellent diagnostic rates and remains the procedure of choice for diagnosing pulmonary lesions. This large study contradicts perceptions that pneumothorax and chest tube placement rates decrease with thinner needles and fewer passes.

Adult↗