Erosion of inlet cannula of left ventricular assist device manifested as innocuous bleeding in stable patient: Lessons learned in prevention of catastrophic consequences

Abstract

commonly used as a diagnostic agent for the determination of plasma volume. 5 The reason for inhibition of the sodium nitroprusside response by gentian violet is unclear. Gentian violet is metabolized to a reactive intermediate or free radical that could act at the vascular smooth muscle to inhibit the response. However, this is unlikely inasmuch as this mechanism would also interfere with the acetylcholinemediated vasodilation. A more plausible explanation would be the formation of a reactive intermediate that interacts directly with the sodium nitroprusside molecule. In conclusion, although methylene blue has been used as a marker dye, our studies suggest that it is inappropriate for marking vascular grafts. Evans blue did not adversely affect vasodilation to any agent and thus could be used as an alternative to methylene blue without fear of affecting graft reactivity. Gentian violet also appears to be a better alternate to methylene blue. However, we did observe a decrease in endothelium-independent vasodilation, a factor that should be considered when this agent is used. R E F E R E N C E S 1. Barber DA, Rubin JW, Zumbro GL, Tackett RL. The use of methylene blue as an extravascular surgical marker impairs vascular responses of human saphenous veins. J Thorac Cardiovasc Surg 1995;109:21-9. 2. Ignarro LJ, Burke TM, Wood KS, Wolin MS, Kadowitz PJ. Association between cyclic GMP accumulation and acetylcholine-elicited relaxation in bovine intrapulmonary artery. J Pharmacol Exp Ther 1984;228:682-90. 3. Marshall JJ, Wei EP, Lontos HA. Independent blockade of cerebral vasodilation from acetylcholine and nitric oxide. Am J Physiol 1988;255:H847-55. 4. Wakelin LPG, Adams A, Hunter C, Waring MJ. Interactions of crystal violet with nucleic acids. Biochemistry 1981;20:577987. 5. Windholz M, Budavari S, Blumetti RF, Otterbein ES, editors. Evans blue. In The Merck index, 10th ed. Rahway (NJ): Merck & Co, 1983:3855.