Yoshiyuki Haga

Surgical reconstruction of an ascending aortic dissection in Takayasu's arteritis

A 45-year-old Japanese woman with Stanford type A dissecting aortic aneurysm underwent a reconstructive operation on the ascending aorta. Histopathological diagnosis was Takayasus arteritis in the chronic and inactive phase. It is very rare that a dissecting aortic aneurysm results from Takayasus arteritis. Long-standing hypertension and fragility of the aortic media due to disruption of elastic fibers were suspected to cause dissection in the entire aorta in this case.

Clinical application of intrathecal lidocaine administration in surgery of the descending thoracic aorta

We studied the protective effects of intrathecally administered lidocaine against ischemic spinal cord injury during surgery. Seven patients (mean age 63.7 years, male∶female=6∶1) with descending thoracic aortic aneurysms underwent reconstructive surgery. Following intrathecal lidocaine administration (10 ml), the operation was performed under femorofemoral bypass with an oxygenator. The aorta was cross-clamped at the distal end of the descending thoracic aorta and the proximal end of the lesions. The cross-clamping time was 47.1±23.3 minutes (mean ± SD). The operative procedure was total replacement of the descending thoracic aorta in five cases and patch closure in two. There were no operative deaths but paraparesis developed in two cases of total replacement. Neurological deficit was transient and disappeared in one case. In the other case, with 88 minutes of normothermic aortic cross-clamping, paraparesis gradually improved but was persistent after 7 months of follow-up. Graft anastomosis at the distal aortic arch was time consuming in this case and presumably caused prolonged spinal cord ischemia. Intrathecal administration of lidocaine was likely to reduce ischemic spinal cord injury and increase tolerance of the spinal cord to ischemia caused by prolonged aortic cross-clamping. This method was considered to provide a useful assistance to expand the safety limit of spinal cord ischemia in surgical reconstruction of the descending thoracic aorta requiring aortic occlusion. Tissue protective effects of intrathecal lidocaine administration may be further augmented by combining with deep hypothermia.

Evaluating Operative Techniques for Distal Aortic Arch Reconstruction

Twenty-three cases of aortic arch aneurysm, over the past 10 years, were divided into 3 groups of similar age and sex for comparison of operative technique. The aortic arch was reconstructed under normothermic femoral bypass via left posterolateral thoracotomy in 9 patients (group II), under hypothermic circulatory arrest via left posterolateral thoracotomy in 7patients (group II) and under hypothermic circulatory arrest with ascending aorta cannulation and brief retrograde systemic perfusion immediately after finishing reconstruction of the aortic arch via median sternotomy in 7 patients (group III). Surgical mortality in groups I, II and III was 33.3% (3/9), 14.3%(1/7)and14.3%(1/7), respectively. Cerebrovascular complications occurred in 1 of 8 patients (12.5%), excluding an intra-operative death, in group II, and in 4 of 7 cases (57%) in group II, of whom 2 were restored to consciousness. There were no cerebrovascular complications in group III (p< 0.005 v. group II). The patient in group III who died of a lung complication 11 days postoperatively was restored to consciousness. Circulatory arrest time was 30.7 ± 17 and 33 ± 17 minutes in groups II and III, respectively. This study demonstrated that normothermic bypass (group II) resulted in an unsatisfactory surgical outcome, and femoral artery cannulation (group II) caused increased cerebrovascular complications compared with ascending aortic cannulation (group III), suggesting that the retrograde aortic flow, but not circulatory arrest per se, predisposed cerebrovascular morbidity. Vascular embolism by debris could be prevented by normograde perfusion via the ascending aorta and brief retrograde systemic perfusion immediately after finishing reconstruction of the aortic arch.

Extra-Anatomical bypass for arteriosclerosis obliterans

Between April, 1981, and May, 1991, 40 patients underwent extra-anatomical bypass surgery for 49 lesions. Thirty-six men and 4 women with a mean age of 68 years (range 48–81) presented with symptoms of aortoiliac occlusive diseases caused by atherosclerosis. Patients were followed up for 44 months (range 1 to 121 months) after surgery. The operative mortality rate was 2.5% (1/40) and there were 4 late deaths. Hypertension, cardiac disease (history of ischemic heart disease and abnormal ECG), cerebrovascular disturbance, and diabetes mellitus were common concomitant preoperative diseases. Forty-nine percent of the limbs (24/49) were classified as Fontaine’s class II, 32.7% (16/49) as class III, and the remaining 18.4% (9/49) as class IV.Surgical procedures were axillofemoral bypasses on 53.1% of the lesions (26/49) and femorofemoral bypasses on the other 46.9% (23/49). Graft materials consisted of expanded polytetrafluoroethylene (EPTFE) (31/49), Dacron (13/49), and modified human umbilical veins (5/49).The ten-year cumulative patency rate was 95% in the femorofemoral bypass group and 88% in the axillofemoral bypass group.The anticoagulant (coumarin derivatives) was given at the first postoperative day, and it was continued as long as possible. No complications were recognized regarding this therapy. The value of the thrombo test was maintained between 20% and 40% during the follow-up period.The extra-anatomical bypass grafting was considered to be a beneficial alternative surgery to anatomical bypass in elderly and high-risk patients. Postoperative anticoagulant therapy may contribute to the patency of grafts.

A new bridging technique to heart transplantation in patients with ventricular septal perforation and mitral regurgitation after acute myocardial infarction — Feasibility of monoventricularization of bilateral ventricles with LVAD

Since the prognosis of ventricular septal perforation (VSP) and mitral regurgitation (MR) after acute myocardial infarction (MI) is remarkably poor, heart transplantation would be necessary for many of those patients. A new bridging technique was examined in canine models. The bilateral ventricles communicating throught a VSP were monoventricularized with mitral valve closure, and pulmonary circulation which had low vascular resistance was maintained. The systemic circulation was maintained by a left ventricular assist device (LVAD) placed between the left atrium and the aorta.