Hajime Kumagai

High-Output Heart Failure Caused by a Huge Renal Arteriovenous Fistula After Nephrectomy: Report of a Case

Abstract Postnephrectomy renal arteriovenous fistula (AVF) with an aneurysmal lesion is a rare clinical entity that may cause high-output heart failure. In this report, we describe the case of a 68-year-old man who had undergone nephrectomy for renal tuberculosis 43 years previously, in whom an acquired large renal AVF presenting as an aneurysm caused congestive cardiac failure. We also discuss the hemodynamic, hormonogenic (human arterial natriuretic polypeptide; hANP), and radiographic findings before and after surgery for the AVF. The AVF with an aneurysmal lesion was clearly visualized by three-dimensional-computerized tomographic (CT) scanning, and proximal ligation of the renal artery was followed by an uneventful recovery. This procedure can produce good results when a fistula is too large to allow safe embolization and when excision would be hazardous due to inflammation surrounding the fistula.

Low-Dose Edaravone Injection into the Clamped Aorta Prevents Ischemic Spinal Cord Injury

Previous studies have indicated that high-dose intravenous edaravone (3-10mg/kg) protects against ischemic spinal cord injury. This study examined whether direct injection of low-dose edaravone into the clamped segment of the aorta prevents ischemic spinal cord injury. Spinal cord ischemia was induced in rabbits by aortic clamping below the renal artery and above the aortic bifurcation for 15min at normothermia. In groups A and B, 3 and 1mg/kg of edaravone, respectively, was injected into the clamped segment of the aorta immediately following aortic clamping. In group C, saline was injected. Neurological function was assessed at 8, 24, and 48hr and 7 days after reperfusion with Tarlov criteria. The spinal cord was histologically examined at 7 days with hematoxylin-eosin staining and in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. The Tarlov score remained grade 4 throughout the period in groups A and B, whereas it dropped to grade 0 or 1 at 7 days in group C, significantly higher in the former two groups. The number of intact motor neurons was significantly greater in groups A and B with less necrotic motor neurons than in group C. There was no significant difference in terms of spinal cord protection between groups A and B. There was no TUNEL-positive neuron in any group, indicating the absence of apoptosis. Low-dose intra-aortic edaravone injection prevents immediate neuronal injury by reducing neuronal cell damage in the early stage as well as delayed neuronal injury at 7 days.

Thymic carcinoids in multiple endocrine neoplasia-type 1

We report a case of a 45-year-old man with thymic carcinoids in multiple endocrine neoplasm-type 1. Extended total thymectomy was performed through a median sternotomy, and the mediastinal regional lymph nodes and fibroadipose tissue were dissected. Multiple endocrine neoplasm-type 1 related thymic carcinoids are rare and have a poor prognosis. The efficacy of radiotherapy and chemotherapy for prolonging survival is limited, and an aggressive surgical approach with complete excision of the tumor with resection of the peripheral tissues and dissection of the mediastinal lymph nodes seems to be the best available treatment today. We have found that this practice of thymectomy at an early stage in combination with genetic and effective radiological treatment can be effective for multiple endocrine neoplasm-type 1 patients.

A novel canine model of spinal cord ischemia with reproducible neurologic outcomes.

PurposeTo develop a canine model of spinal cord ischemia (SCI) with highly reproducible neurologic outcomes.MethodsSpinal cord ischemia was induced by cross-clamping the proximal descending aorta. To produce substantial ischemia in the critical lumbar region, the proximal aortic blood pressure (PAP) was reduced to 80u2009mmHg by withdrawing blood into a reservoir connected to the left subclavian artery. We conducted an intraischemia spinal cord electrophysiologic study and a postischemia assessment of hindlimb motor function in six animals subjected to this procedure with an aortic occlusion time of 40u2009min, and in six animals subjected only to aortic occlusion for 60u2009min.ResultsAll the animals subjected to this procedure exhibited a significant decrease in motor-evoked spinal cord potentials to transcranial electric stimulation (MEPs) during the acute ischemic phase, and they were paraplegic 48u2009h after ischemia. In contrast, two of the animals not subjected to PAP reduction showed complete functional recovery with intact MEP findings.ConclusionThis model is feasible for experimental SCI studies because it can reliably and easily reproduce substantial ischemia.