Yujiro Kawanishi

Transcranial myogenic motor-evoked potentials after transient spinal cord ischemia predicts neurologic outcome in rabbits

OBJECTIVE Myogenic transcranial motor-evoked potentials (tc-MEPs) were applied to monitor spinal cord ischemia in the repairs of thoracoabdominal aortic aneurysms. We investigated whether tc-MEPs after spinal cord ischemia/reperfusion could be used to predict neurologic outcome in leporine model. METHODS Tc-MEPs were measured at 30-second intervals before, during, and after spinal cord ischemia (SCI) induced by balloon occlusion of the infrarenal aorta. Twenty rabbits were divided into five groups. Four groups (n = 4 animals in each group) had transient ischemia induced for 10, 15, 20, or 30 minutes. In fifth group, the terminal aorta at the aortic bifurcation was occluded for 30 minutes. All animals were evaluated neurologically 48 hours later, and their spinal cords were removed for histologic examination. RESULTS The tc-MEPs in each SCI group rapidly disappeared after SCI. After reperfusion, the recovery of tc-MEPs amplitude was inversely correlated to duration of SCI. Tc-MEPs amplitude at one hour after reperfusion was correlated with both neurologic score and number of neuron cells in the spinal cord 48 hours later. Logistic regression analysis demonstrated that the neurologic deficits differed significantly between animals with tc-MEPs amplitude of less than 75% of the baseline and those with an amplitude of more than 75%. CONCLUSIONS The amplitude of tc-MEPs after ischemia /reperfusion of the spinal cord showed a high correlation with durations of SCI, with neurologic deficits, and with pathologic findings of the spinal cord. Tc-MEPs, therefore, could be used to predict neurologic outcome. In particular, tc-MEPs whose amplitude recovered by less than 75% indicated a risk of paraplegia.

Aortic Root Replacement for Destructive Aortic Valve Endocarditis with Left Ventricular–Aortic Discontinuity

BACKGROUND Destructive aortic valve endocarditis causes the development of left ventricular-aortic discontinuity. Our experience of aortic root replacement in patients with the left ventricular-aortic discontinuity is presented. METHODS Between 1999 and 2006, 8 patients (7 men, 1 woman) with left ventricular-aortic discontinuity underwent aortic root replacement in our institute. Their mean age was 56 years. Six patients were in New York Heart Association functional class III or higher. Four patients were diagnosed to have native valve endocarditis, and 4 had prosthetic valve endocarditis (previous aortic valve replacements in 2 patients, aortic root replacements in 2). Radical débridement of the aortic root abscess was performed in all patients, followed by reconstruction of the aortic annulus using autologous or xenogenic pericardium in 2 patients. Fibrin glue saturated with antibiotics was applied into the cavity in 5 patients. Aortic root replacement was achieved with pulmonary autograft (Ross procedure) in 4 patients and stentless aortic root xenograft in 3. One patient who had advanced liver cirrhosis underwent aortic valve replacement with a stentless xenograft by subcoronary fashion. RESULTS No patients died during hospitalization or follow-up. Freedom from major adverse cardiac events was noted in 67% of the patients at 5 years. CONCLUSIONS An excellent outcome can be achieved by radical exclusion of abscess in the cavity, followed by root replacement with viable pulmonary autograft or flexible stentless aortic root xenograft in patients with left ventricular-aortic discontinuity.

Primary osteosarcoma of heart with severe congestive heart failure

We present a case report on a 54-year-old woman with extraskeletal osteosarcoma of the left atrium featuring severe congestive heart failure. We resected the tumor, which occupied the left atrium and had widely infiltrated the atrial wall, but the patients died of the tumor 9 months after surgery. This is to our knowledge the 32nd case of cardiac osteosarcoma ever reported.

Congenital quadricuspid aortic valve associated with severe regurgitation.

A 56-year-old man was referred because of severe aortic regurgitation. He had a quadricuspid aortic valve with a small accessory cusp between the right coronary and noncoronary cusps. The ostium of the right coronary artery was deviated toward the accessory cusp commissure. Aortic valve replacement was performed with a bioprosthesis. The resected cusps showed fibrotic thickening with calcification and fenestration.

Aortic aneurysm and aortic regurgitation following aortic valve replacement due to Takayasu's arteritis

A 26-year-old man who underwent aortic valve replacement for aortic regurgitation due to Takayasus arteritis 2 years earlier experienced left amaurosis persisting for some minutes. Computed tomography showed aneurysmal dilation of the ascending aorta to a diameter of 60 mm and occlusion of the left carotid artery. Cardiac echography showed perivalvular leakage. Following administration of a calcium antagonist, the patients amaurosis subsided and brain bloodstream scintigraphy showed no abnormalities. We resected the aneurysm instead of using Bentalls operation. Following an uncomplicated postoperative course, the patient was discharged 21 days after surgery and echocardiography has shown no perivalvular leakage to date.

Impending rupture in an aortic arch aneurysm by Candida infection

A 68-year-old man was hospitalized with the complaints of left back pain and fever. He had a history of using steroids to treat uveitis for about thirty years. Computed tomography on the chest demonstrated an impending rupture in an aortic arch aneurysm, which was consequently surgically excised. Candida albicans was identified in the wall of the aneurysm, so fluconazole and itraconazole were administered. The patient was discharged at 120 days after surgery without recrudescence of the candida. To our knowledge, this is the fifteenth case of a successfully treated aneurysm caused by candida infection.

Abdominal aortic aneurysm associated with horseshoe kidney.

The optimal approach to abdominal aortic aneurysm with horseshoe kidney is still debated. We describe a successful abdominal aortic aneurysm repair through a left retroperitoneal approach in a 77-year-old woman with a horseshoe kidney.