Naoto Morimoto

Inferior mesenteric artery aneurysm in Behcet syndrome

We present a case report of an aneurysm of the inferior mesenteric artery, associated with occlusion of the celiac, superior mesenteric, and left renal arteries and severe stenosis in the right renal artery, in a 48-year-old patient with Behçet syndrome. The meandering inferior mesenteric artery, with an aneurysm 28 mm in greatest dimension, was the blood supply source for the intraperitoneal viscera. Aneurysm resection and reimplantation of the inferior mesenteric artery, and right renal artery bypass grafting with saphenous vein was performed. To our knowledge, this is the first reported case of inferior mesenteric artery aneurysm caused by Behçet syndrome.

Free-radical scavenger edaravone inhibits both formation and development of abdominal aortic aneurysm in rats

OBJECTIVE An ideal pharmaceutical treatment for abdominal aortic aneurysm (AAA) is to prevent aneurysm formation and development (further dilatation of pre-existing aneurysm). Recent studies have reported that oxidative stress with reactive oxygen species (ROS) is crucial in aneurysm formation. We hypothesized that edaravone, a free-radical scavenger, would attenuate vascular oxidative stress and inhibit AAA formation and development. METHODS An AAA model induced with intraluminal elastase and extraluminal calcium chloride was created in 42 rats. Thirty-six rats were divided three groups: a low-dose (group LD; 1 mg/kg/d), high-dose (group HD; 5 mg/kg/d), and control (group C, saline). Edaravone or saline was intraperitoneally injected twice daily, starting 30 minutes before aneurysm preparation. The remaining six rats (group DA) received a delayed edaravone injection (5 mg/kg/d) intraperitoneally, starting 7 days after aneurysm preparation to 28 days. AAA dilatation ratio was calculated. Pathologic examination was performed. ROS expression was semi-quantified by dihydroethidium staining and the oxidative product of DNA induced by ROS, 8-hydroxydeoxyguanosine (8-OHdG), by immunohistochemical staining. RESULTS At day 7, ROS expression and 8-OHdG-positive cells in aneurysm walls were decreased by edaravone treatment (ROS expression: 3.0 ± 0.5 in group LD, 1.7 ± 0.3 in group HD, and 4.8 ± 0.7 in group C; 8-OHdG-positive cells: 106.2 ± 7.8 cells in group LD, 64.5 ± 7.7 cells in group HD, and 136.6 ± 7.4 cells in group C; P < .0001), compared with group C. Edaravone treatment significantly reduced messenger RNA expressions of cytokines and matrix metalloproteinases (MMPs) in aneurysm walls (MMP-2: 1.1 ± 0.5 in group LD, 0.6 ± 0.1 in group HD, and 2.3 ± 0.4 in group C; P < .001; MMP-9: 1.2 ± 0.1 in group LD, 0.2 ± 0.6 in group HD, and 2.4 ± 0.2 in group C; P < .001). At day 28, aortic walls in groups LD and HD were less dilated, with increased wall thickness and elastin content than those in group C (dilatation ratio: 204.7% ± 16.0% in group C, 156.5% ± 6.6% in group LD, 136.7% ± 2.0% in group HD; P < .0001). Delayed edaravone administration significantly prevented further aneurysm dilatation, with increased elastin content (155.2% ± 2.9% at day 7, 153.1% ± 11.6% at day 28; not significant). CONCLUSIONS Edaravone inhibition of ROS can prevent aneurysm formation and expansion in the rat AAA model. Free-radical scavenger edaravone might be an effective pharmaceutical agent for AAA in clinical practice.

The Model for End-Stage Liver Disease (MELD) Predicts Early and Late Outcomes of Cardiovascular Operations in Patients With Liver Cirrhosis

BACKGROUND We aimed to evaluate the severity of cirrhosis as a predictor of early and late outcomes after cardiovascular operations. METHODS We retrospectively reviewed patients who underwent cardiovascular operations in our institute between October 1999 and April 2009. The severity of liver cirrhosis was assessed using the Child-Pugh classification and the Model for End-stage Liver Disease (MELD) score. RESULTS Liver cirrhosis was identified in 32 consecutive patients. Averages of Child-Pugh and MELD scores were 7.2 ± 1.9 and 11.5 ± 5.1, respectively: 14 patients were classified as Child-Pugh class A, 14 as class B, and 4 as class C. The MELD score was less than 10 (category 1) in 10 patients, between 10 and 14.9 (category 2) in 14, and 15 or higher (category 3) in 8. The hospital mortality rate was 16% (5 of 32). Hospital mortality increased significantly as the MELD score category increased: category 1, 0%; category 2, 7%; and category 3, 50% (p = 0.005). There was no significant association between hospital mortality and Child-Pugh classification: class A, 7%; class B, 21%; and class C, 0% (p = 0.60). Overall survival was 72% ± 8% at 5 years and 47% ± 13% at 10 years. The survival rate decreased significantly as the MELD score category increased (p = 0.004). No relationship was found between the Child-Pugh classification and long-term survival. CONCLUSIONS Our results suggest that the MELD score is useful to predict hospital death and long-term survival after cardiac operations for patients with liver cirrhosis.

Leukoaraiosis and hippocampal atrophy predict neurologic outcome in patients who undergo total aortic arch replacement.

BACKGROUND This retrospective study determined whether leukoaraiosis and hippocampal atrophy seen in preoperative magnetic resonance imaging (MRI) predict neurologic outcome after total aortic arch replacement. METHODS From August 2001 to November 2007, 131 consecutive patients (22% women) who underwent elective total arch replacement with selective cerebral perfusion were enrolled. Mean patient age was 71 +/- 17 years (range, 27 to 88 years). On preoperative MRI, mean leukoaraiosis score and hippocampal atrophy score, rated according to the Scheltens scale, were 11.0 +/- 9.2 and 1.5 +/- 1.9, respectively. Forty-three patients (32.8%) had carotid or basilica arterial stenosis, 18 (12.6%) had a stroke, and 6 (4.2%) had a transient ischemic attack. RESULTS One hospital death (0.8%) occurred. Adverse perioperative neurologic events included intraoperative stroke in 8 (6.1%), postoperative stroke in 2 (1.5%), and temporary neurologic dysfunction (TND) in 11 (8.4%). On multivariate logistic regression, significant predictors of postoperative intraoperative stroke were leukoaraiosis (odds ratio [OR], 1.1, p = 0.02) and aortic arch atheroma (OR, 2.4; p = 0.001). TND was significantly associated with leukoaraiosis (OR, 1.1, p = 0.03) and hippocampal atrophy (OR, 1.6, p = 0.01). The best cutoff value for predicting intraoperative stroke was a leukoaraiosis score exceeding 16 (sensitivity, 70%; specificity, 70%); that for predicting TND was a leukoaraiosis score exceeding 18 (sensitivity, 82%; specificity, 77%) and a hippocampal atrophy score exceeding 2 (sensitivity, 82%; specificity, 76%). CONCLUSIONS Leukoaraiosis and hippocampal atrophy are significant independent factors for adverse neurologic outcome after total arch replacement.

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.

Mid-Term Results of Valve-Sparing Aortic Root Replacement in Patients With Expanded Indications

BACKGROUND The mid-term results of valve-sparing aortic root reimplantation (VSRR) for various indications were investigated. METHODS From 2000 to 2013, 183 consecutive patients undergoing VSRR were enrolled. Expanded indications, defined as a patient on the marginal operative indication, included age 65 years or older (n = 33), age 15 years or younger (n = 4), acute type A aortic dissection (AAAD) (n = 21), aortitis (n = 8), reoperative root replacement (n = 11), cusp prolapse (n = 67), large aortoventricular junction of greater than 28 mm (AVJ) (n = 42), preoperative severe aortic regurgitation (AR) (n = 89), left ventricular ejection fraction 0.40 or less (n = 12), LV dilation (n = 66), New York Heart Association class III or greater (n = 5), need for total arch replacement (n = 29), and concomitant mitral valve repair (n = 12). RESULTS The overall survival at 5 years was 96.6%. Freedom from greater than mild AR and reoperation at 5 years was 85.8% and 92.9%, respectively. Cox proportional hazard model revealed that AAAD, cusp prolapse, AVJ 28 mm or greater, and operation before 2009 were at risk for late AR recurrence (p = 0.015, p = 0.0041, p = 0.032, and p = 0.014, respectively). After 2009, freedom from late AR in the cusp prolapse group improved (p = 0.055, versus control). Both freedom from recurrent AR and reoperation were worse as the number of expanded indications increased (log-rank trend p = 0.00017 and p = 0.00067, respectively). CONCLUSIONS Surgical outcomes of VSRR in these patient cohorts were satisfactory with some room for improvement in patients with cusp prolapse. Although the indications for VSRR are being expanded, a larger number of expanded indications were associated with poor outcomes in terms of longevity of valve function.

Sivelestat attenuates postoperative pulmonary dysfunction after total arch replacement under deep hypothermia

BACKGROUND Total arch replacement necessitating deep hypothermia with circulatory arrest has a greater effect on pulmonary function than other cardiac surgery using cardiopulmonary bypass (CPB). Since April 2004, 100mg of sivelestat sodium hydrate was administrated by bolus injection into pulp circuit at the initiation of CPB in every case performed total arch replacement. We investigated the hypothesis that prophylactic use of the drug attenuates post-pump pulmonary dysfunction. METHODS A retrospective analysis of 120 consecutive patients who underwent total arch replacement from August 2001 to December 2006 was conducted. Patients were divided into two groups according to the date of surgery, April 2004, when we started sivelestat administration. Group A (n=60), operated after April 2004, was administrated sivelestat at the initiation of CPB. Group B (n=60), before April 2004, was not administrated. Time courses of hemodynamic variables were evaluated until 24h after surgery and those of respiratory variables and inflammatory markers until 48 h after surgery. RESULTS There were no significant differences in patient age, sex, prevalence of chronic obstructive lung disease, preoperative lung function, time of operation and CPB, minimum temperature, and aprotinin usage. Hospital mortality occurred in two patients in the group B (3.3%) and no patient in group A (0%). Postoperative hemodynamic variables were not different between the two groups. Respiratory index, oxygenation index were significantly better in patients pretreated with sivelestat (respiratory index; p<0.001, oxygenation index; p<0.001, respectively). CRP was significantly lower in patients pretreated with sivelestat (p=0.022). Except for patients who required tracheostomy or re-exploration for bleeding, patients pretreated with sivelestat were extubated significantly shorter (group A: 12.6+/-10.8h, group B: 25.5+/-12.9h, p=0.033). No patient with postoperative respiratory failure requiring tracheostomy was noted in sivelestat group. CONCLUSION Prophylactic administration of sivelestat at the initiation of CPB results in better postoperative pulmonary function, leading to earlier extubation time. Our study suggests that sivelestat was effective in facilitating postoperative respiratory management in total arch replacement.

Aortic Root Reimplantation for Isolated Sinus of Valsalva Aneurysm in the Patient With Marfan's Syndrome

We describe an isolated extracardiac unruptured acquired aneurysm in the right coronary sinus of Valsalva, which was seen in a 55-year-old woman with Marfans syndrome. The patient underwent aortic root replacement using a reimplantation technique. Pathologic examination revealed absence of the medial elastic fiber of the aortic wall of the normal sinus of Valsalva. This result supports the preference of entire root replacement instead of patch repair of the affected sinus for the isolated aneurysm in 1 sinus of Valsalva in a patient with Marfans syndrome.

Adjustment of Sinotubular Junction for Aortic Insufficiency Secondary to Ascending Aortic Aneurysm

BACKGROUND Dilatation of the sinotubular junction (STJ) causes aortic regurgitation (AR) in patients with ascending aneurysm. These patients can regain valve competence by simple reduction of the diameter of STJ. Results of this technique were investigated clinically and echocardiographically. METHODS Replacement of the ascending aorta with reduction of the diameter of the STJ to correct AR (mean grade, 2.7 +/- 0.7) was performed in 29 consecutive patients (mean age, 73.2 +/- 6.2). Two required repair of cusp prolapse. All underwent ascending aortic aneurysm replacement. Echocardiographic studies were performed at discharge and during latest clinical follow-up (mean follow-up, 3.8 +/- 2.5 years). RESULTS No hospital deaths occurred. The AR grade at discharge was 0.7 +/- 0.5. No valve related-deaths occurred. Actual survival at 8 years was 91% +/- 9%. Failure occurred 4.1 years postoperatively in a patient with bicuspid valve. Three patients had late recurrence of AR that was caused by aortic root dilatation in bicuspid valves in 2. Multivariate analysis showed bicuspid aortic valve was the predictor of late progression of AR. The freedom from more than grade II AR at 8 years was 79.5% +/- 10.7%. CONCLUSIONS Adjustment of the diameter of STJ could treat AR secondary to ascending aortic aneurysm with nearly normal aortic cusps. Midterm results of this procedure were acceptable. Although bicuspid aortic valve is the risk factor for late AR due to dilation of remaining aortic root, this procedure provides satisfactory long-term outcomes among the patients with tricuspid valve.

Reverse diastolic flow in the common carotid artery in severe aortic regurgitation, causing brain ischemia

Diastolic reverse flow in the common carotid artery (CCA) at duplex sonography can be seen in patients with severe aortic regurgitation (AR). We report a patient with severe AR whose diastolic reverse flow in the right CCA caused transient brain ischemia. To our knowledge, there are no descriptions of diastolic steal volume by AR causing cerebral ischemia. This is the first description of this rare pathophysiologic form of cerebral ischemia.