Vasodilatory efficacy and impact of papaverine on endothelium in radial artery predilatation for cabg surgery: in search for optimal concentration

Abstract Objective: The aim of this study was to compare the efficacy of two different papaverine concentrations (0.5 mg/ml and 2 mg/ml) for vasospasm prevention and their impact on endothelium integrity. Methods: We have studied distal segments of radial arteries obtained by no-touch technique from coronary artery bypass graft (CABG) patients (n=10). The vasodilatory effect of papaverine (concentrations of 0.5 mg/ml and 2 mg/ml) was assessed in vitro, in isometric tension studies using ex vivo myography (organ bath technique) and arterial rings precontracted with potassium chloride (KCl) and phenylephrine. The impact of papaverine on endothelial integrity was studied by measurement of the percentage of vessel's circumference revealing CD34 endothelial marker. Results: 2 mg/ml papaverine concentration showed stronger vasodilatatory effect than 0.5 mg/ml, but it caused significantly higher endothelial damage. Response to KCl was 7.35±3.33 mN for vessels protected with papaverine 0.5 mg/ml and 2.66±1.96 mN when papaverine in concentration of 2 mg/ml was used. The histological examination revealed a significant difference in the presence of undamaged endothelium between vessels incubated in papaverine 0.5 mg/ml (72.86±9.3%) and 2 mg/ml (50.23±13.42%), P=0.002. Conclusion: Papaverine 2 mg/ml caused the higher endothelial damage. Concentration of 0.5 mg/ml caused better preservation of the endothelial lining.

Effects of arterial balloon dilatation papaverine administration and arterial clamping on internal mammary artery endothelial cells morphology: a scanning electron microscopic study

The internal mammary artery has become the conduit of choice for coronary artery bypass grafting. Harvesting of the internal mammary artery [IMA] for use in myocardial revascularization may result in spasm, which can impair early graft flow. Hydrostatic and mechanical dilatation can exert an lntraluminal shear force causing denudation of the IMA endothelium. Performance of a vascular anastomosis or repair requires meticulous, gentle technique and a bloodless operative field. Many vascular surgeons rely on commercial [atrauniatic] vascular clamps for the latter; however, most experimental evidence incriminates clamps as agents of moderate to severe endothelial and medial layer injury. Moreover, Intraluminal papaverine treatment during operation is said to reduce vasospasm and facilitates anastomosis. However, it has been suggested that papaverine may cause intimal damage and accordingly this work investigated endothelial architectural alterations by comparing the effect of balloon dilation, papaverine administration and vascular clamp at 10 and 30 minutes clamping in the internal mammary arteries segments using the scanning electron microscopy. In the present study, the balloon angioplasty was found to be the most detrimental procedure on endoihelial integrity [40% endothelial loss], while the papaverine was the safest procedure during IMA grafting [5% loss]. Endothelial damage following clamping for 10 min was significantly less [mild] 10% loss than that produced by 30 min clamping [moderate] 30% loss

Tratamiento de la erección prolongada secundaria a inyección intracavernosa de medicamentos / Treatment of the prolonged erection induced by an intracavernous drug injection

La erección prolongada es la principal complicación de la inyección intracavernosa de papaverina y/o phentolamina. En 1700 inyecciones tuvimos esta complicación en un 3,06%(52/1700). Cuando se usa papaverina mezclada con Phentolamina sube a 19%. Se tratan a las 6 horas con medicamentos simpaticomiméticos con excelente rendimiento. 5 de ellas se trataron con Ketamina 30 mg en IIC con resultados espectaculares y sin complicaciones secundarias.