Keitarou Nakagiri

Open Distal Anastomosis in Retrograde Cerebral Perfusion for Repair of Ascending Aortic Dissection

BACKGROUND In patients with aortic dissection, a patent distal false lumen at long-term follow-up leads to complications. We investigated the feasibility of performing an open distal anastomosis using retrograde cerebral perfusion. METHODS Over a 10-year period, 41 patients with acute type A aortic dissection underwent 43 surgical repairs. In 1991, an open distal anastomosis using retrograde cerebral perfusion (group 2) was introduced to replace the standard aortic cross-clamp method (group 1). The mean retrograde cerebral perfusion time was 47.3 minutes (range, 22 to 67 minutes), and there were no neurologic sequelae in surviving patients. RESULTS The operative mortality rate was 18.5% in group 1 and 18.7% in group 2. At long-term follow-up, dilatation of the false lumen (more than 50 mm in diameter) occurred in 9 of 18 patients (50%) in group 1, and 2 patients died of aortic rupture. There were no deaths in group 2, and dilatation of the distal false lumen occurred in only 15.4% of patients (p < 0.05). CONCLUSIONS The use of retrograde cerebral perfusion in patients with acute aortic dissection provides adequate time to perform a safe, open, distal anastomosis, and could decrease significantly the rate of enlarged, patent, false lumina.

Impact of retrograde cerebral perfusion with posterolateral thoracotomy on distal arch aneurysm repair.

BACKGROUND Repair of distal aortic arch aneurysms is difficult to accomplish through a median sternotomy or left thoracotomy, and stroke and respiratory disorders often become lethal complications with the use of circulatory arrest. We investigated the use of retrograde cerebral perfusion with a posterolateral thoracotomy in the repair of distal arch aneurysms. METHODS Thirty-eight patients underwent repair of a distal arch aneurysm. They were divided into three groups according to the method of surgical repair used. Sixteen patients (group I) underwent proximal anastomosis of the graft with the use of an aortic cross-clamp. Eight patients (group II) underwent open proximal anastomosis with the use of retrograde cerebral perfusion (oxygenated blood perfusion through a superior vena cava cannula) and a median sternotomy and anterolateral thoracotomy. Fourteen patients (group III) also underwent open anastomosis with the use of retrograde cerebral perfusion (cerebral perfusion through blood returned to the right atrium with the patient in the Trendelenburg position) and a posterolateral thoracotomy. RESULTS The operative mortality rate in group I was 25.0%; 4 of 16 patients died of stroke, myocardial infarction, and intestinal necrosis. In group II, 3 of 8 patients (37.5%) died of respiratory failure and aortic dissection. In group III, only 1 of 14 patients (7.1%) died, as a result of heart failure. CONCLUSIONS The use of retrograde cerebral perfusion with a posterolateral thoracotomy is an alternative method that minimizes the risk of stroke and respiratory failure during distal aortic arch operations.

Evaluation of local platelet deposition during laser thermal angioplasty.

Laser thermal angioplasty is one of the brand-new transluminal interventions for arterial occlusive disease. And one of the most important prognostic factors of this intervention is the degree of local platelet deposition which causes the acute platelet thrombus and increases the proliferation of smooth muscle cells. The purpose of this study is to assess the degree of platelet deposition on the laser ablated area and to investigate the optimal conditions of laser ablation from the point of thrombogenesis. First of all, the laser ablations of various delivered energy were carried out on canine femoral arteries, then thrombus formation after laser ablation was evaluated with angioscopy. No thrombus was recognized on all ablated areas in the cases with a laser energy of 16 Joule (J) and 20 J. On the other hand, small thrombus on the ablated area was observed in 1 of 4 cases (25%) with that of 24 J, and in 2 of 4 cases (50%) with that of 30 J. Then, the degree of platelet deposition on the laser ablated area was evaluated with platelet labeled radioimmunoassay. Laser ablations were employed in canine femoral arteries varying delivered laser energy. There were no differences in the numbers of platelet deposition when the laser energy for one shot was within 24 J. The numbers of platelet deposition with a laser energy of 30 J and 45 J were significantly (p < 0.05) higher than those with a laser energy within 24 J. The numbers of platelet deposition were gradually increased related to the frequency of laser ablations, and the numbers of platelet depositions in 10 repeated laser ablations of 16 J and 20 J were significantly (p < 0.05) higher than that in single laser ablation of 16 J and 20 J. From the aspect of local platelet deposition, the optimal laser energy for one shot should be restricted within 24 J and the repeated ablation was the most appropriate method of laser thermal ablation.