Mitsuru Nakaya

Simultaneous graft replacement of the ascending aorta and total aortic arch for type A aortic dissection

We performed simultaneous graft replacement of the total aortic arch and ascending aorta for type A aortic dissection with a patent false lumen extending through the arch into the descending or abdominal aorta. During the past 7 years, this procedure was performed in 42 patients (28 men and 14 women), aged 20 to 72 years (mean age, 50 years). Nineteen patients underwent the procedure during the acute period, and 23 during the chronic period. The site of the initial intimal tear was the ascending aorta in 17 patients and the transverse aortic arch in 25 patients. Artificial graft replacement was initially accomplished by proximal anastomosis, followed by open distal anastomosis, and finally by anastomosis of each of the three arch vessels. There were 3 hospital deaths (7.1%), 1 resulting from acute dissection (5.3%) and 2 from chronic dissection (8.7%). Among the type A dissections, total arch graft replacement has been indicated in the setting of rupture of the aortic arch, arch dissection, and Marfans syndrome. However, with increasing experience in arch reconstructions and improvement in outcome, the indications could be expanded to include all type A aortic dissections with a patent false lumen in the descending aorta.

Surgical Treatment for Chronic Pulmonary Thromboembolism Under Cardiopulmonary Bypass with Selective Cerebral Perfusion

Abstract The median sternotomy approach for the treatment of chronic pulmonary thromboembolism was recently improved by Daily, Jamieson, and coworkers who adopted it for use under cardiopulmonary bypass with intermittent circulatory arrest; however, we have sometimes found that the circulatory arrest time was too short to complete thromboendarterectomy. Therefore, we attempted to perform a selective cerebral perfusion technique to extend the endarterectomy time. Although we noted slight back-bleeding from the bronchial arteries, we were able to extend the endarterectomy time without causing any postoperative delirium. We conclude that the median sternotomy approach using cardiopulmonary bypass with selective cerebral perfusion may be the best option for extending the thromboendarterectomy time.

Nonanastomotic rupture of thoracic aortic Dacron graft treated by endovascular stent graft placement

A 61-year-old man had a Stanford type A acute aortic dissection, and the total aortic arch was replaced with 22-mm knitted Dacron graft in 1996. In 2006, he underwent mitral valve replacement and tricuspid valve repair due to severe mitral and tricuspid valve regurgitation. Although preoperative computed tomography (CT) scan suggested pseudoaneurysm around the Dacron graft replaced with aortic arch, it could not be repaired concomitantly. Four months later, in view of the technical difficulties of an open surgical procedure, the prosthetic graft failure was repaired by endovascular stent graft consisting of a Gianturco Z stent covered with an UBE woven Dacron graft. However, during a follow-up, aneurysm sac diameter increased without any sings of endoleak in follow-up CT scans. Redo endovascular stent graft placement using a Gore-TAG device was performed. Subsequently, shrinkage of the pseudoaneurysmal sac could be observed.

A Successful Case of Pulmonary Thromboendarterectomy for Chronic Thromboembolic Pulmonary Hypertension with a Thrombus in the Right Ventricle

Chronic thromboembolism is a frequent cause of progressive hypertension and carries a poor prognosis. Medical treatment is not effective and surgery provides the only potential for a cure at present. We herein report a successful case of thromboendarterectomy treated via a median sternotomy with intermittent circulatory arrest. A 43-year-old man was admitted to our hospital complaining of progressive dyspnea, edema of the lower extremities, and a fever with an unknown origin. A subsequent definitive evaluation showed him to be suffering from surgically accessible chronic thromboembolic pulmonary hypertension with a thrombus in the right ventricle. He underwent a pulmonary thromboen-darterectomy and thrombectomy via a median sternotomy with intermittent circulatory arrest on November 24, 1994. Postoperatively he showed a marked improvement in his hemodynamic status and blood gas analysis. He has also returned to work with no trouble. Deep vein thrombosis appeared to be the pathogenesis of this case, but we could not find the origin of his unknown fever. He is currently being controlled by treatment with methylprednisolone as before.

A mital valve reconstruction of infective endocarditis with brain abscess and intracranial mycotic aneurysm

A case is reported of a brain abscess and an intracranial mycotic aneurysm associated with infective endocarditis caused by streptococcus intermedius. A 60-year-old man with a history of fever presented aphasia and right hemiparesis. A computed tomographic scan of the head revealed a low-density area with ring enhancement in the left parietal lobe consistent with a brain abscess. An angiography demonstrated an aneurysm on the distal branch of the middle cerebral artery compatible with a mycotic aneurysm. Doppler echo cardiography showed severe mitral regurgitation by chordal ruptures. The brain abscess and intracranial mycotic aneurysm were resolved under appropriate antibiotic therapy for eight weeks. Then, the mitral valve was reconstructed by replacement of the chordae tendineae with expanded polytetrafloroethylene suture and annuloplasty. The patient had no neurologic deficit except for paresthesia in the right hand, and had no mitral regurgitation at discharge.

Surgical Treatment for Chronic Pulmonary Thromboembolism: Results from the Chiba University School of Medicine

Chronic pulmonary thromboembolism is a frequent cause of progressive pulmonary hypertension and carries a poor prognosis. Medical treatment is not particularly effective, and surgery provides the only possibility of a cure at present. We report our experiences of surgical treatment for chronic pulmonary thromboembolism. Between June 1986 and February 1998, 35 patients underwent pulmonary surgical treatment at our hospital. Twelve patients (37.5%) had deep vein thrombosis. Our surgical indications were based on the San Diego group criteria. We have adopted two surgical approaches to pulmonary thromboendarterectomy. The preoperative mean pulmonary pressure was 46.7 ± 7.5 mmHg, the cardiac index was 2.41 ± 0.51/min per m2, and the PVR was 901.3 ± 305.0 dyn∙s∙cm-5. The PaO2 (FiO2 = 0.21) was 58.1 ± 8.5 mmHg. The number of operative deaths was six (17.1%). Twenty-nine patients survived, and the declines in their pulmonary arterial pressures and pulmonary vascular resistance, and the increases in their cardiac indices, were significant postoperatively. Their Pa02 improved significantly after 6 months. We conclude that surgical treatment can improve the prognosis of patients with chronic pulmonary thromboembolism.

Autologous Pericardial Patch Repair for Papillary Fibroelastoma on an Aortic Valve Leaflet

A 50-year-old man with no history of cardiovascular disease was referred to our hospital because of an abnormal electrocardiogram. Echocardiograms and computed tomograms revealed a 9-mm mass on the underside of an aortic valve leaflet. We chose surgical treatment, to prevent embolic events. The tumors appearance and intraoperative frozen section were consistent with myxoma. We resected the tumor and its attachment, including the free margin of the aortic valve leaflet, and repaired the defect with use of a glutaraldehyde-treated autologous pericardial patch. The postoperative histopathologic diagnosis was papillary fibroelastoma. Six months later, echocardiograms showed mild aortic regurgitation and no recurrence of the aortic valve mass. Papillary fibroelastoma and myxoma can be difficult to distinguish intraoperatively, yet the diagnosis has considerable influence on the surgical strategy, including whether valve-sparing excision is an option. Therefore, it is necessary to at least suspect both entities if the tumor characteristics are unusual. This case is instructive for surgeons and pathologists.

A Successful Case of Mitral Valve Repair after Percutaneous Transluminal Carotid Angioplasty with Stenting.

症例は75歳,男性.僧帽弁閉鎖不全に対する手術目的で当科を紹介された.2年4ヵ月前に脳血栓の既往があり,右内頸動脈起始部に80%狭窄を認めた.まず頸動脈病変に対し,PTAとステント留置を行った.60%狭窄が残存したが心不全症状が増悪したため,2ヵ月後に僧帽弁形成術を行った.IABPを用いて体外循環中の灌流圧を高く維持し脳合併症を回避できたので報告した.

Graft Infection After Aortic Surgery: Strategy and Outcome

Graft infection is the most serious complication associated with aortic surgery. It is difficult to treat, and as a consequence mortality and morbidity are high. The conventional treatment when dealing with this complication is resection of the infected graft and creation of an extraanatomical bypass. We have introduced a new treatment strategy that aims to preserve the original graft by a disinfection procedure of the wound. This procedure consists of two stages. The first stage is an extended disinfection maneuver that includes reexploration, debridement of infected tissue, irrigation, and soaking with iodine solution. The second stage is vital tissue transposition around the graft and to the wound, with primary closure. Nine patients with graft infection (five at the ascending + aortic arch segment, two at the descending segment, and one each at the thoracoabdominal and infrarenal segments) were treated with this procedure. Infection could not controlled in two patients, who died of sepsis; it was controlled in seven patients, although one died in hospital from an unrelated cause. Six patients were discharged without signs of infection recurrence. A 78% infection control rate was achieved using this new treatment strategy.

Brain Protection with the Use of Antegrade Selective Cerebral Perfusion and Aortic Surgery

Selective cerebral perfusion (SCP) has been employed since 1979. High mortality and cerebral complication rates were encountered during the initial period, but with modification of the perfusion condition, the development of a monitoring system, and more experience, these rates were markedly reduced. SCP is most frequently applied for surgery on aortic arch aneurysms, and a standard surgical approach to this lesion has been firmly established since 1986. Recently a more aggressive approach, the “extended application of SCP,” was introduced for the purpose of minimizing cerebral complications caused by intraoperative atheromatous embolization. With induction of this new technique in accordance with the present surgical procedure, the cerebral complication rate is now further reduced to the point of being acceptable.