Overcoming perioperative spasm of the internal mammary artery: Which is the best vasodilator?

• Published in: The Journal of thoracic and cardiovascular surgery Vol. 104; no. 2; pp. 465 - 468
• Main Authors: Cooper, G.J., Wilkinson, G.A.L., Angelini, G.D.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Elsevier Inc 01.08.1992; AATS/WTSA; Elsevier
• Subjects: Administration, Topical; Biological and medical sciences; Cardiovascular system; Female; Humans; Internal Mammary-Coronary Artery Anastomosis; Intraoperative Care - methods; Intraoperative Complications - prevention & control; Male; Mammary Arteries - drug effects; Mammary Arteries - surgery; Medical sciences; Middle Aged; Nifedipine - pharmacology; Nitroglycerin - pharmacology; Nitroprusside - pharmacology; Papaverine - pharmacology; Pharmacology. Drug treatments; Sodium Chloride - pharmacology; Vasodilator Agents - therapeutic use; Human; In vivo; Chemotherapy; Treatment; Vasodilator agent; Bypass; Surgery; Spasm; Cardiovascular disease; Intraoperative; Internal mammary artery; Coronary heart disease
• ISSN: 0022-5223; 1097-685X
• DOI: 10.1016/S0022-5223(19)34805-6

After mobilization, vasospasm often reduces flow through the internal mammary artery. An established method of relaxing the artery and increasing flow is to wrap it in a papaverine-soaked swab. To our knowledge the ability of other topical vasodilators to overcome spasm of the internal mammary artery has not been studied clinically. In 50 patients in whom the left mammary artery was used for myocardial revascularization, we have investigated the effect of five agents on internal mammary artery free flow. The agents investigated were normal saline, papaverine, nifedipine, glyceryl trinitrate, and sodium nitroprusside. Under controlled hemodynamic conditions, free flow was measured before any pharmacologic intervention and a median of 18.5 minutes after the pedicle had been sprayed with one of the five agents. Normal saline produced a small increase in flow from a median of 23 ml/min (range 17 to 88) to 38 ml/min (20 to 84) (not significant), whereas a significant increase occurred with papaverine, from 25 (16 to 78) to 43 ml/min (34 to 112) (p < 0.01). Nifedipine and glyceryl trinitrate raised free flow by almost threefold, from 23 (14 to 66) to 71 ml/min (45 to 118) and from 23 (14 to 58) to 62 ml/min (46 to 126), respectively (both p < 0.001). Sodium nitroprusside, however, with an increase in flow from 26 (10 to 58) to 108 ml/min (46 to 196), 250% over control, proved to be more effective than nifedipine and glyceryl trinitrate (p < 0.05). We therefore recommend the topical use of sodium nitroprusside to relieve perioperative spasm of the internal mammary artery. (J Thorac Cardiovasc Surg 1992;104:465-8)