Ascending to Descending Aorta Bypass for Middle Aortic Syndrome

Abstract

iddle aortic syndrome is rare vascular anomaly, which involves long segment narrowing of the descending thoracic and abdominal aorta. The most common clinical manifestation is severe uncontrolled hypertension. We present a successful re-operation by the ascending to descending aorta bypass for middle aortic syndrome patient. Case ReportA 52-year-old woman complained of headache and easy fatigability of the lower extremities and had poorly controlled high blood pressure. Both femoral pulses were present but weak. Her blood pressure was 180/120 mmHg in the brachial artery and 108/76 mmHg in the thigh. Routine laboratory data were normal, with a blood urea nitrogen level of 12 mg/dl and a creatinine level of 0.6 mg/dl. C-reactive protein was negative. Twenty-seven years previously, she had undergone bypass grafting for Takayasu aortitis at another hospital. According to the operation record, an 8-mm-diameter prosthetic tube graft was bypassed from the descending thoracic aorta to the infrarenal abdominal aorta and it was passed through the aortic hiatus through a left thoracotomy and midline laparotomy.In the present admission computed tomography scanning showed marked diffuse narrowing of the descending thoracic aorta with severe calcification (Fig 1). The diameter of the aorta was 21 mm at the distal arch, 6 mm at the diaphragm level, 11 mm at the superior mesenteric artery level and 20 mm at the aortic bifurcation. The supradiaphragmatic descending aorta was completely occluded. The prosthetic graft was also severely atherosclerotic, but pseudoaneurysm formation was not detected on either the graft itself or at both anastomoses. The ascending aorta was normal and the both internal thoracic arteries were dilated. The right kidney was atrophic and non-functional. Preoperative angiography revealed total occlusion of the aorta from the mid-descending thorax to proximal to the celiac artery and multiple stenoses of the bypass graft. Blood flow to the celiac artery, the superior mesenteric artery, and the left renal artery was supplied retrogradely by the stenotic bypass graft. The right renal artery was occluded. No abnormality was detected in the ascending aorta, aortic arch, or supracervical branches. These findings indicated that her symptoms were related to the multiple stenoses of the graft, in addition to small size of the bypass graft itself. We decided to replace the graft.The operation was performed through a midline sternotomy and pararectal retroperitoneal approach. The ascending aorta was side-clamped and a 16-mm-diameter prosthetic tube graft was anastomosed in an end-to-side fashion. The graft was passed through a small incision in the left lateral portion of the diaphragm. Adhesion of the former anastomosis, just distal to the left renal artery, was so dense that the distal end of the new graft was anastomosed at the aortic bifurcation, which appeared to be a normal part of the aortic wall. The patient's postoperative course was uneventful. Her hypertension was controlled without antihypertensive agent...

A Case Report of Middle Aortic Syndrome: A Rare Vascular Disorder

“…Options include aorto-aortic bypass, patch aortoplasty, renal and mesenteric arterial reconstruction. 7 Results of surgery are good in most cases with improvement or normalization of blood pressure in 70% cases. 1 In our case we performed a patch aorto plasty of stenotic segment of the abdominal aorta.…”

“…Middle aortic syndrome (MAS) is a rare entity characterized by localized narrowing of abdominal or distal thoracic aorta. 1,7 It constitutes about 0.5-2% of all the cases of aortic coarctation. 7 MAS was first described by Sen et al, in 1963.…”

“…9,10 Another hypothesis implicates intra-uterine injury or infection, particularly rubella is the risk factor that precipitates aortic hypoplasia. 7 Acquired MAS is associated with neurofibromatosis, William's syndrome, Alagille syndrome, fibromuscular dysplasia, retroperitoneal fibrosis (Ormond disease), mucopolysaccharidosis, foetal alcohol syndrome and giant cell arteritides including temporal (cranial) and Takayasu arteritis. 1,11 It usually presents as hypertension in young age group which is typically unresponsive to medical therapy.…”

“…For patients with active vasculitides surgery is not recommended in active phase of disease. 1,6,7 For children best results are achieved if definitive treatment can be delayed till they have achieved full growth. 1 Aim of surgery is to control hypertension by improving tissue perfusion to renal, mesenteric vessels and lower limbs.…”

“…Indications of surgery therefore depend upon severity of hypertension, lower limb claudication, involvement of kidneys and mesenteric ischaemia. 1,7 Surgical repair depends upon anatomy of the lesion and involvement of visceral arteries. Options include aorto-aortic bypass, patch aortoplasty, renal and mesenteric arterial reconstruction.…”