Nafamostat Mesilate: Can It Be Used as a Conduit Preserving Agent in Coronary Artery Bypass Surgery?

BACKGROUND: Graft vessel preservation solution in coronary artery bypass surgery is used to maintain the graft conduit in optimal condition during the perioperative period. Nafamostat mesilate (NM) has anticoagulation and anti-inflammatory properties. Therefore, we investigated NM as a conduit preservative agent and compared it to papaverine. METHODS: Sprague-Dawley (SD) rat thoracic aortas were examined for their contraction-relaxation ability using phenylephrine (PE) and acetylcholine (ACh) following preincubation with papaverine and NM in standard classical organ baths. Human umbilical vein endothelial cells (HUVECs) were cultured to check for the endothelial cell viability. Histopathological examination and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were performed on the thoracic aortas of SD rats. RESULTS: The anti-contraction effects of papaverine were superior to those of NM at PE (p90% in various concentrations of both NM and papaverine. A histopathological study showed a protective effect against necrosis and apoptosis (p<0.05) in the NM group. CONCLUSION: NM exhibited good vascular relaxation and a reasonable anti-vasocontraction effect with a better cell protecting effect than papaverine; therefore, we concluded that NM is a good potential conduit preserving agent.

Histomorphological Comparison of the Coronary Artery and Available Graft Conduits / 대한흉부외과학회지

BACKGROUND: The histomorphological properties of the left anterior desecending artery (LAD), the left internal thoracic arteries (LITA), the radial arteries (RA) and the intercostal arteries (ICA) were studied for their use as a conduit for coronary artery bypass grafting (CABG), and we compared them with each other. MATERIAL AND METHOD: All the vessels were harvested from nineteen cadavers (17 males and 2 females). The mid-portion of the LAD, the mid-portion of the LITA, the distal RA and the mid-portion of the 5th ICA were obtained. All of them were stained with hematoxylin-eosin and with Van Gieson's elastin stain. The morphological characteristics were examined and the thicknesses of the intima and media (I/M ratio: the intima to media ratio) were compared using one-way ANOVA tests. RESULT: The mean age of the cadavers was 61.5+/-9.6 years. The LITA and ICA were elastic arteries, and the LAD and RA were muscular arteries. The I/M ratio showed statistically significant differences: 0.07+/-0.03 in the LITA, 0.16+/-0.11 in the ICA, 0.45+/-0.29 in the RA and 0.93+/-0.52 in the LAD, respectively. CONCLUSION: This study showed that the degrees of intimal hyperplasia of the CA and the various conduits for CABG were different significantly. The ICA was found to have relatively favorable characteristics as a coronary bypass conduit, but its suitability for clinical use is a challenging issue.

Angiographic Results of Radial Artery Grafts that are Used for Myocardial Revascularization / 대한흉부외과학회지

BACKGROUND: The radial artery is gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there have been limited reports about its angiographic patency compared with that of internal thoracic artery or saphenous vein. We tried to evaluate angiographic patency of radial artery graft and to compare that of radial artery and other grafts with retrospective manner. MATERIAL AND METHOD: From January 2001 to June 2006, totally 132 patients (male 92, female 40) who underwent coronary artery bypass graft using radial artery were re-admitted to our hospital for follow up angiographic examination. Mean age was 58.2+8.87 and mean follow up duration was 32 month (2~110 month). Off pump and on pump bypass surgery were performed 74 and 58 patients respectively. Along with radial artery, left internal thoracic arteries were used in 57 cases, concomitant left internal thoracic artery and saphenous veins were used in 47 cases and bilateral internal thoracic arteries were used in 20 cases. RESULT: Totally 412 distal anastomosis were performed and 376 anastomosis remained patent (91.2%). Left internal thoracic artery showed the most excellent patency in all of the conduits (98.5%). Radial artery graft patency was 90.8% (169/186). There was no statistical difference of the patency by conduit between on-pump and off-pump group. But radial artery showed more higher patency rate (98/110, 89%) in the severe stenotic lesion that preoperatively revealed more than 90% stenosis than in the lesser severe (<90%) stenotic lesion (60/76, 78%)(p<0.005). Radial artery conduit represented the worst result when it was grafted in the right coronary system. But when it was positioned in the left heart especially diagonal or obtuse marginal area, patency was comparable with left internal thoracic artery. CONCLUSION: Radial artery graft showed good midterm patency when it was used in the severe stenotic lesion more than 90% and left coronary system. But great notice should be taken when it is grafted in the right coronary system or less severe stenotic lesion.

Analysis of Postoperative Coronary Angiography in Symptomatic Patients / 대한흉부외과학회지

BACKGROUND: We analyzed post-operative angiography performed in symptomatic patients to evaluate the patency rates and the roles of grafts. MATERIAL AND METHOD: We reviewed 52 (15%) coronary angiograms performed for recurrent angina after prior coronary artery bypass surgery from January 1995 to June 2005. A total of 345 patients underwent coronary artery bypass surgery during this period. There were 41 men and 11 women and the mean age was 64.07+/-15.58 years. The median period from operation to re-angiogram was 68.5 months (range, 1 to 126 months). The numbers of grafts and peripheral anastomoses were 42 and 43 for internal thoracic artery (ITA), 14 and 20 for radial artery (RA), and 49 and 89 for saphenous vein. The mean number of anastomosis was 2.9 per patient. RESULT: The patency rates of ITA, RA and saphenous vein graft (SVG) were 37/43 (86%), 17/20 (85%) and 34/89 (38.2%). The patency rate of arterial grafts was significantly higher than that of SVG (p<0.001) and the patency rate of the RA was comparable to that of ITA (p=0.912). The patency rate of sequential SVGs was higher than that of single SVG (40.3% vs 31.8%, p=0.478) and the patency rate of proximal segments in sequential anastomosis was higher than that in single anastomsis (55.6% vs 31.8%, p=0.097), but statistically not significant. CONCLUSION: Arterial grafts have markedly superior patency rates than SVGs, so consideration should be given to the vigorous use of arterial grafts. The patency rate of the RA was comparable to that of ITA.