Biomedical subjects
T Campion
Publications and source records attributed to T Campion.
Effects of prostacyclin injections and infusions on canine femoral hemodynamics.
The use of prostacyclin (PGI2) infusions has been recommended in the management of patients with severe distal arteriopathy, who are not candidates for conventional bypass procedures. Further clarification regarding the route of administration and the optimal dose of this potent vasodilator, however, is needed before controlled clinical trials are initiated. We measured bilateral femoral arterial blood flow electromagnetically in seven anesthetized adult mongrel dogs. Systemic arterial pressure and cardiac output were also measured. Central venous and femoral arterial injections of PGI2 were administered in five doses ranging from 10(-4) to 10(0) micrograms X kg-1 to study the dose response. PGI2 was also infused intravenously and intra-arterially for 20 minutes at a dose of 10(-1) micrograms X kg-1 X min-1. Femoral arterial injections of PGI2 in doses from 10(-4) through 10(0) micrograms X kg-1 caused significant (p less than 0.05) and dose-dependent increases in ipsilateral femoral arterial blood flow. Intravenous injections of PGI2 caused no significant changes in the dose range from 10(-4) to 10(-2) micrograms X kg-1 but resulted in a significant (p less than 0.05) reduction in femoral arterial flow and systemic arterial pressure at doses of 10(-1) and 10(0) micrograms X kg-1. The femoral arterial infusion of PGI2 produced a significant and sustained increase in femoral arterial flow that was not observed during the intravenous infusion. Arterial pressure was unchanged with intra-arterial PGI2 but was significantly reduced during the intravenous infusion. The beneficial hemodynamic effects of intra-arterial PGI2 suggest that further clinical trials should employ this route of administration.(ABSTRACT TRUNCATED AT 250 WORDS)
Influence of prostacyclin on distribution of canine femoral blood flow.
Prostacyclin (PGI2) has been used clinically in the treatment of ischemic peripheral vascular disease. While intravenous infusions have been reported to be beneficial, the preferred route of administration (intravenous or intraarterial) and the influence of PGI2 on distribution of femoral blood flow have yet to be established. Bilateral femoral arterial blood flow was measured electromagnetically in 10 anesthetized adult mongrel dogs. The distribution of femoral arterial blood flow (FAQ) to skin, muscle, bone, and arteriovenous anastomoses (AVA) was determined by using femoral intraarterial injections of radioactively labeled microspheres before, during, and 30 min after 20-min intravenous (n = 5) and intraarterial (n = 5) infusions of PGI2 at 0.1 microgram kg-1 min-1. Control FAQ was 76 +/- 15 (mean +/- SEM) ml/min and its distribution to skin, muscle, bone, and AVA was 13 +/- 3%, 43 +/- 8%, 17 +/- 4%, and 26 +/- 7%, respectively. Arterial pressure was 127 +/- 7 mm Hg. Intraarterial infusions of PGI2 significantly (P less than 0.05) increased FAQ to 240 +/- 43 ml/min which was sustained throughout the infusion. Distribution of FAQ to skin increased significantly (P less than 0.05) to 47 +/- 8%, while that to the muscle of the thigh decreased to 17 +/- 4% (P less than 0.05). During intravenous infusion of PGI2 at the same concentration, FAQ did not change significantly and its distribution remained unchanged; however, there was a significant (P less than 0.05) reduction in arterial pressure to 78 +/- 6 mm Hg. No significant changes occurred in cardiac output, pulmonary arterial pressure, arterial blood gases, paw or core body temperatures.(ABSTRACT TRUNCATED AT 250 WORDS)
Reverse tapered vs. straight PTFE (Gore-Tex) grafts in dogs.
Reversed Autogenous Saphenous Vein (RASV) remains the material of choice in infrainguinal arterial bypass. A characteristic of RASV not seen in other grafts is its reverse tapered (RT) configuration. The purpose of this study was to investigate this geometric configuration. Straight 6 mm PTFE (gore-tex) grafts (SG) and 4-7 mm reverse tapered PTFE (gore-tex) grafts (RTG) were both implanted in the aorto-iliac position in 16 mongrel dogs. Specimens of surviving dogs were examined by the usual methods. In terms of absolute patency, 9 of 14 RTG (64%) and 5 of 14 SG (36%) P = 0.05, anastomotic thrombus formation 6 of 14 (43%) RTG vs. 10 of 14 (71%) SG P = 0.05 and in midgraft thrombus deposition P = 0.025 the RTG performed significantly better than the SG. In light of these results and other considerations, the reverse tapered configuration merits clinical investigation with other materials and in other species.