Assessment of collateral blood flow and exclusion criteria
Adequacy of collateral ulnar circulation in the non-dominant hand was preoperatively assessed with a modified Allen’s test and a Doppler study (17-19). Those found to have incomplete palmar arch or inadequate collateral blood flow were not enrolled. Additional assessment of collateral flow was also done intraoperatively using a digital oxygen saturation probe. Excluded were from the study patients with chronic renal failure already on dialysis or likely to require dialysis in the future. Patients in whom the RA of the non-dominant has been used for coronary angiography or other transradial catheterization procedure were not included in order to avoid the risk of endothelial damage and RA occlusion (20-21).