Masaomi Fukuzumi

Hypothermic circulatory arrest: renal protection by atrial natriuretic peptide.

Moderate hypothermic circulatory arrest with selective cerebral perfusion has been developed for cerebral protection during thoracic aortic surgery. However, visceral organs, particularly the kidneys, suffer greater tissue damage under moderate hypothermic circulatory arrest, and acute renal failure after hypothermic circulatory arrest is an independent risk factor for early and late mortality. This study investigated whether atrial natriuretic peptide could prevent the reduction in renal perfusion and protect renal function after moderate hypothermic circulatory arrest. Twelve pigs cooled to 30°C during cardiopulmonary bypass were randomly assigned to a peptide-treated group of 6 and a control group of 6. Moderate hypothermic circulatory arrest was induced for 60 min. Systemic arterial mean pressure and renal artery flow did not differ between groups during the study. However, renal medullary blood flow increased significantly in the peptide-treated group after hypothermic circulatory arrest. Myeloperoxidase activity was significantly reduced in the medulla of the peptide-treated group. Renal medullary ischemia after hypothermic circulatory arrest was ameliorated by atrial natriuretic peptide which increased medullary blood flow and reduced sodium reabsorption in the medulla. Atrial natriuretic peptide also reduced the release of an inflammatory marker after ischemia in renal tissue.

Mitral valve repair for infective endocarditis

ObjectiveThis study investigated the feasibility of mitral valve (MV) repair in patients with active or healed infective endocarditis (IE) with mitral regurgitation and evaluated effects on left ventricular (LV) function and structure.MethodsSubjects comprised 19 patients who underwent MV operations for IE between December 2004 and September 2007. MV repair was performed for acute IE in 10 of 15 patients (67%) and for healed IE in 4 of 4 patients (100%).ResultsNo early or late postoperative deaths were encountered. One patient underwent redo MV repair owing to severe mitral regurgitation 1 month postoperatively. Postoperative echocardiography after MV repair demonstrated less than trivial (acute IE in seven, healed IE in three) or mild (acute IE in three, healed IE in one) mitral regurgitation. In patients with MV replacement, the postoperative left atrial dimension (LAD) was decreased (51.5 ± 39.2 vs. 39.2 ± 1.9 mm, P = 0.007); however LV end-diastolic dimension (LVDD) and LV end-systolic dimension were unchanged. In patients with MV repair, LVDD (57.5 ± 6.5 vs. 46.0 ± 5.6 mm, P < 0.001), LV end-systolic dimension (36.1 ± 5.2 vs. 32.4 ± 6.2 mm, P = 0.04), LAD (43.1 ± 8.1 vs. 33.6 ± 7.7 mm, P = 0.003) were reduced. Postoperative ejection fraction (55.3 ± 13.5% vs. 41.8% ± 10.0%, P = 0.03) and fraction shortening (30.1% ± 9.2% vs. 20.7% ± 5.5%, P = 0.03) were better in patients with MV repair than those with MV replacement.ConclusionsMV repair is feasible in patients with both active and healed IE. MV repair preserves better LV function and structure postoperatively.

Stanford Type A Acute Aortic Dissection With Intimal Intussusception

A70-year-old woman with a sudden onset of dizziness, disturbance of speech, and nausea was brought to our hospital. A contrast-enhanced computed tomography (CT) scan of the patient’s chest and abdomen showed no flaps in the ascending aorta (Fig 1A), but an intussuscepted flap appeared in the aortic arch, obstructing all arch vessels (Fig 1B). A three-dimensional CT scan providing an intravascular view from the proximal aortic arch revealed that the intimal flap was inverted and invaginated into the distal aortic arch (Fig 2). On the basis of these findings, we made a diagnosis of Stanford type A acute dissection of the aorta with intimal intussusception caused by a circumferential intimal tear. Emergency surgery was done, and revealed the circumferential intimal tear at the level of the sinotubular junction and the absence of an intimal layer in the ascending aorta. The dissected tubular intimal flap was inverted and invaginated into the aortic arch. The ascending aorta was replaced with a Dacron graft. The patient’s postoperative course was uneventful, without any neurologic complications, and she was discharged in good condition at 18 days after her operation. Complete circular dissection of the aorta was reported for the first time by Bostroem1) in 1887. Aortic dissection

Management for Active Infective Endocarditis with extensive aortic root abscess.

Active Aortic Valve Infective Endocarditis with root abscess has had high mortality and morbidity, especially the infective lesion extends deeply.

Minimally invasive mitral and tricuspid valve surgery using central arterial perfusion

Methods Our strategy for CPB management for MICS was as below: we evaluated atherosclerotic lesions in MICS candidates with CT examination in order to investigate condition of inner cavity of the aorta or arteries, especially the presence of intramural thrombus. In cases of no lesion of possible arteriosclerosis, we selected peripheral perfusion. Otherwise, we used central arterial perfusion with direct cannulation on the ascending aorta. For venous drainage, two-staged venous cannula via the femoral vein and additional SVC cannulation was applied. From November 2007 to April 2013, we had 81 (32 females, mean age of 68.3 +/11.8 y.o.) for MVP or MVR with/without TAP or Maze including 6 redo cases. After evaluation for atherosclerosis, we had applied peripheral perfusion in 9 cases (11%). The other cases were required the ascending aortic cannulation.