Perioperative implications of retrograde flow in both the subclavian arteries in an adult undergoing surgical repair of coarctation of aorta.

During surgical repair of coarctation of aorta (CoA), management of spinal cord ischemia and prevention of paraplegia is an important issue. The risk factors for paraplegia include level and duration of aortic-clamping, clamping of left subclavian artery (SCA), intraoperative temperature, variability of collateral circulation to the spinal cord, cerebrospinal fluid pressure, upper body arterial pressure, and aortic pressure beyond the aortic clamp. A short clamp time (<30 min), and distal aortic pressure>60 mmHg, minimizes the risks of spinal cord injury. In an adult patient during surgical repair of CoA, the arterial pressure in the femoral artery remained around 45 mmHg and repair took 83 min of aortic-clamping. Neurological assessment on regaining consciousness showed no deficit of lower limbs. Aortic root angiogram had shown retrograde filling of both SCAs. A unique situation in which clamping of SCAs would increase flow to the spinal cord as their clamping would stop stealing of blood and aortic-clamping proximal to CoA will further increase collateral flow; because of these reasons, the patient tolerated prolonged aortic-clamping despite low distal aortic pressure without neurological deficit. However, aortic-clamping increased left ventricular after-load and the patient developed worsening of mitral regurgitation and pulmonary hypertension during aortic clamping.