Tsukasa Ozawa

Improved Left Ventricular Aneurysm Repair With Bioengineered Vascular Smooth Muscle Grafts

Background—Recurrent ventricular dilatation can occur after surgical repair of a left ventricular (LV) aneurysm. Use of an autologous bioengineered muscle graft to replace resected scar tissue may prevent recurrent dilatation and improve cardiac function. Methods—Vascular smooth muscle cells (SMCs, 5×106 cells) from rat aortas were seeded onto synthetic PCLA (sponge polymer of &egr;-caprolactone-co-L-lactide reinforced with knitted poly-L-lactide fabric) patches and cultured for 2 weeks to allow tissue formation. Syngenic rats underwent proximal left coronary artery ligation to create a transmural myocardial scar. Four weeks after coronary ligation, cell-seeded patches (n=15) or unseeded patches (n=12) were used for a modified endoventricular circular patch plasty (EVCPP) repair of the infarct area. Ligated controls (n=14) and nonligated normal rats (n=10) had sham surgeries without EVCPP. Cardiac function was assessed by echocardiography and isolated Langendorff heart perfusion. Graft histology and morphology was also assessed. Results—After 8 weeks in vivo, seeded patches were thicker (P <0.05) and smaller in area (P <0.003) than unseeded patches. Only seeded patches had prominent elastic tissue formation (P <0.001) in association with SMCs. LV systolic function by echocardiography was improved in the seeded group compared with both unseeded (P <0.002) and control groups (P <0.0001). LV volumes in both patch repair groups were comparable but were significantly smaller (P <0.05) than controls. LV distensibility tended toward improvement in the seeded group as compared with unseeded hearts, but the difference did not achieve statistical significance (P =0.06). Conclusions—Surgical repair with muscle-cell seeded grafts reduced abnormal chamber distensibility and improved LV function after myocardial infarction as compared with unseeded grafts. Bioengineered muscle grafts may be superior to synthetic materials for the surgical repair of LV scar.

Clinical efficacy of heparin-bonded bypass circuits related to cytokine responses in children.

BACKGROUND Cardiopulmonary bypass (CPB) induces numerous systemic reactions. This study examined the efficacy of heparin-bonded CPB circuits on inflammatory responses and postoperative status in children. METHODS Thirty-four infants undergoing elective cardiac surgery were randomly divided into two groups: a heparin-bonded CPB group (n = 17) and a non-heparin-bonded group (n = 17). Plasma levels of the inflammatory cytokines were measured before, during, and after CPB, and postoperative status was determined by examining the respiratory index, blood loss, and the post- and preoperative body weight percent ratio. RESULTS Significant differences in tumor necrosis factor-alpha, interleukin-6, and interleukin-8 patterns were observed during and after CPB between the two groups (p < 0.01, p < 0.01, p < 0.05, respectively). All cytokines measured were significantly lower in the heparin-bonded group just after CPB (p < 0.05). There were no differences in duration of intubation, intensive care unit or hospital stay, or postoperative blood loss, but the respiratory index 3 hours after CPB and body weight percent ratio 24 and 48 hours after CPB were significantly reduced in the bonded group (p < 0.05, p < 0.01, p < 0.05, respectively). CONCLUSIONS Our findings suggest that heparin bonding of the bypass circuits affects early postoperative status and reduces cytokine responses in pediatric cardiac surgery.

Tuberculous abdominal aortic pseudoaneurysm penetrating the left psoas muscle after BCG therapy for bladder cancer

We describe a case of a 75-year-old man with abdominal aortic and right femoral tuberculous pseudoaneurysms 32 months after intravesical bacillus Calmette-Guerin therapy for bladder cancer. These aneurysms were probably brought on by systemic infection by Mycobacterium bovis. The infrarenal aorta and right common femoral artery were successfully replaced with an in situ expanded polytetrafluoroethylene graft. Tuberculous pseudoaneurysm after bacillus Calmette-Guerin therapy for malignancy is very rare, and we review the related literature.

Literature survey on epidemiology and pathology of cardiac fibroma

BackgroundAlthough cardiac fibroma has been regarded as benign tumor, it presents various symptoms and may lead to death. Unfortunately, only a few studies have reported the epidemiology, embryology, and histopathology of the tumor, and the factors predicting poorer outcome are still obscured.MethodsIn July 2011 we searched for English and Japanese cases of cardiac fibroma using the PubMed and IgakuChuoZasshi databases. We then extracted and sampled raw data from the selected publications in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) style as much as was possible.ResultsDetails of a total of 178 patients with cardiac fibroma were retrieved. The mean age was 11.4 years (median: 2.8 years). Tumor sizes ranged from 8.0 to 150.0 mm (mean 53.1 mm). The left ventricle was found to be the most common site associated with the tumor at a rate of 57.3%, followed by the right ventricle, and interventricular septum. The highest mortality was found in patients with septal involvement (58.6%). In all, 111 patients survived among the 160 patients with a recorded outcome. A younger age of the patient at the time of diagnosis was associated with a decreased survival rate. In addition, a significant positive association was found between ages for patients younger than 17 years of age and the diameter of the tumor at the time of diagnosis (r = 0.341, P = 0.006).ConclusionsBoth the younger age of patients at the time of diagnosis and septal involvement can be regarded as factors significantly indicating a poor prognosis. Furthermore, our statistical analyses support the following hypotheses. First, the high ratio of tumor-to-heart size may generate low cardiac output and therefore lead to poor outcome. Second, the ratio of the sites where cardiac fibroma occurred corresponds with the ratio of the muscular weight of the cardiac chamber. Third, cardiac fibroma involving the interventricular septum more frequently induces conduction system disease.

Superior biocompatibility of heparin-bonded circuits in pediatric cardiopulmonary bypass.

BACKGROUND Heparin bonding of pediatric cardiopulmonary bypass circuits may decrease activation of blood compartments as inflammatory responses. We studied the biocompatibility of heparin-bonded circuits in infant cardiac surgery. METHODS Twenty-four infants undergoing elective cardiac surgery were randomly assigned to either a nonheparin-bonded control circuit (n = 12) or a fully heparin-bonded circuit (n = 12) including membrane oxygenator, reservoir, and all tubing. Blood samples were used to identify differences in complement activation and cytokine release between groups during and after cardiopulmonary bypass. The postbypass oxygenation index was also compared. RESULTS The C3 activation product in the heparin-bonded group was significantly lower during (p < 0.01) and just after (p < 0.05) cardiopulmonary bypass. No statistically significant difference in C4 activation products was observed. Lower interleukin-6 and tumor necrosis factor-alpha were found immediately after cardiopulmonary bypass (p < 0.05) and a higher mean postbypass oxygenation index was also seen (p < 0.05) in the heparin-bonded group. CONCLUSION We found that a heparin-bonded cardiopulmonary bypass circuit reduced inflammatory response and improved oxygenation in pediatric cardiac surgery. These results suggest that the superior biocompatibility of the bonded circuit may reduce pulmonary complications.

Ventricular septal defect repair in an infant with severe pulmonary hypertension and preoperatively diagnosed left ventricular noncompaction

There are several options to address RV failure in patients after atrial switch operations. Some groups advocate the conversion from the atrial to an arterial switch operation, and others support orthotopic HTx. Although we are generally in favor of HTx, we also face the general problem of a lack of donors for patients awaiting HTx. A bridge to transplantation with different VADs has been one answer for patients whose condition deteriorates while on the waiting list, but using VADs in patients with ‘‘abnormal’’ anatomy presents a surgical challenge, especially after the Senning operation. As patients with TGA rarely show left ventricular (LV) dysfunction, the use of a univentricular VAD should be adequate for most, if not all, patients. To the best of our knowledge, there is no single report in the literature describing biventricular mechanical circulatory support in patients with ventricular failure after atrial switch operation. Installing an RV assist device is easy, because the enlarged and thickened left atrium is an optimal structure for the inflow conduit. The right ventricle may be another option for the LV assist device inflow conduit, but it requires dissection and exposure of the right ventricle and ventricular fibrillation, or even cardioplegic cardiac arrest as described by George and colleagues. However, if biventricular support should be required, installing an LV assist device might be done by cannulating the superior vena cava as the right atrium, which is ‘‘in the middle’’ of the heart and

Study of coronary artery bypass using the PAS-Port device: assessment by multidetector computed tomography.

ObjectiveThe use of automatic anastomotic devices in coronary artery bypass grafting surgery is associated with lower patency rates in comparison to conventional anastomosis methods. This is thought to be caused by graft curvature occurring after closing of the chest wall.MethodsWe evaluated 39 grafts in 28 patients who underwent off-pump coronary artery bypass surgery using the PAS-Port. After surgery, the proximal anastomotic angle of each stent, graft morphology, and patency were evaluated with axial and sagittal views.ResultsThe angle for the left anterior descending coronary artery segment was relatively obtuse on the left side of the ascending aorta, and the graft loop formation was not necessary. The angle for the left circumflex coronary artery segment was significantly acute for anastomosis from the upper left side of the ascending aorta. Because grafts are under the constraints of a large loop, graft length tended to become easily excessive or deficient. The angle for the right coronary artery segment was relatively obtuse. The space on the right side of the heart was so narrow that in some cases we had difficulty setting out the appropriate graft location to prevent graft curvature. No bending or stenosis was present in any graft, showing a patency rate of 100%.ConclusionThe short-term results of coronary bypass grafting using PAS-Port are satisfactory.

Bidirectional Glenn procedure for an infected modified Blalock–Taussig shunt

A 1-month-old girl underwent right modified Blalock–Taussig shunt (mBTS) for pulmonary atresia with hypoplastic right ventricle. Five months after palliation, she suffered from sepsis and progressive desaturation following otitis media. Computed tomography and angiography revealed a pseudoaneurysm surrounding the mBTS graft. After stabilization of the infection, we performed pseudoaneurysm resection, shunt-graft removal, and the bidirectional Glenn (BDG) procedure under cardiopulmonary bypass. Her condition improved, and she was discharged on the 17th day after surgery. When parameters for the partial right heart bypass should permit, the BDG procedure can be a beneficial recovery procedure for the cases of infected pseudoaneurysm after mBTS in Fontan candidates.

Fontan conversion with novel direct ablation after childbirth: Report of a case

A 38-year-old woman underwent atriopulmonary Fontan surgery at age 18 years and subsequently successfully delivered a girl by cesarean section at age 34. Her condition later deteriorated due to atrial tachyarrhythmia and progressed to New York Heart Association (NYHA) class IV heart failure. Her treatment, at age 36, comprised total cavopulmonary connection conversion, direct right atrial ablation with bipolar radiofrequency devices, the creation of an atrial septal defect, and placement of a dual-chamber permanent pacemaker. Three years after the conversion, her condition has improved to NYHA class I.

Stent graft implantation combined with coil embolization and external-internal iliac artery bypass surgery: Report of a case

A 73-year-old male patient was found to have an abdominal aortic aneurysm complicated with bilateral common iliac artery aneurysms. He also had hepatitis C, chronic liver cirrhosis (Child-Pugh class B), a rupture of esophageal varices, hepatocellular carcinoma, and intractable ascites. The functions of other systemic organs were also impaired. We first performed a right internal iliac artery coil embolization prior to stent graft implantation combined with a left external-internal iliac artery bypass. These additional procedures allowed for safe treatment with stent graft implantation, without any serious complications.