Partial cardiopulmonary bypass through left thoracotomy for coarctation repair in children.

BACKGROUND: A left thoracotomy approach is anatomically appropriate for childhood aortic coarctation; however, the pediatric femoral arteriovenous diameters are too small for cardiopulmonary bypass cannulation. We aimed to determine the safety of a partial cardiopulmonary bypass through the main pulmonary artery and the descending aorta in pediatric aortic coarctation repair. METHODS: We retrospectively reviewed 10 patients who underwent coarctation repair under partial main pulmonary artery-to-descending aorta cardiopulmonary bypass with a left thoracotomy as the CPB group. During the same period, 16 cases of simple coarctation of the aorta repair, with end-to-end anastomosis through a left thoracotomy without partial CPB assistance, were included as the non-CPB group to evaluate the impact of partial CPB. RESULTS: The median age and weight at surgery of the CPB group were 3.1 years (range, 9 days to 17.9 years) and 14.0 (range, 2.8-40.7) kg, respectively. Indications for the partial cardiopulmonary bypass with overlap were as follows: age > 1 year (n = 7), mild aortic coarctation (n = 3), and predicted ischemic time > 30 min (n = 5). Coarctation repair using autologous tissue was performed in seven cases and graft replacement in three. The mean partial cardiopulmonary bypass time, descending aortic clamp time, and cardiopulmonary bypass flow rate were 73 ± 37 min, 57 ± 27 min, and 1.6 ± 0.2 L/min/m2, respectively. Urine output during descending aortic clamping was observed in most cases in the CPB group (mean: 9.1 ± 7.9 mL/kg/h), and the total intraoperative urine output was 3.2 ± 2.7 mL/kg/h and 1.2 ± 1.5 mL/kg/h in the CPB and non-CPB group, respectively (p = 0.020). The median ventilation time was 1 day (range, 0-15), and the intensive care unit stay duration was 4 days (range, 1-16) with no surgical deaths. No major complications, including paraplegia or recurrent coarctation, occurred postoperatively during a median observation period of 8.1 (range, 3.4-17.5) years in the CPB group. In contrast, reoperation with recurrent coarctation was observed in 2 cases in the non-CPB group (p = 0.37). CONCLUSIONS: Partial cardiopulmonary bypass through the main pulmonary artery and descending aorta via a left thoracotomy is a safe and useful option for aortic coarctation repair in children.

Hypothermia Inhibits the Expression of Receptor Interacting Protein Kinases 1 and 3 After Transient Spinal Cord Ischaemia in Rabbits.

OBJECTIVES: Necroptosis, a form of regulated necrosis, might be a potential mechanism of delayed paraplegia; therefore, its role in transient spinal cord ischaemia was investigated by immunohistochemical analysis of necroptosis related protein receptor interacting protein kinase (RIP) 1, RIP3, and cellular inhibitor of apoptosis protein (cIAP) 1/2. METHODS: This study used rabbit normothermic (n = 24) and hypothermic (n = 24) transient spinal cord ischaemia models and sham controls (n = 6). Neurological function was assessed according to a modified Tarlov score at 8 h, 1, 2, and 7 days after reperfusion (n = 6 each). Morphological changes in the spinal cord were examined using haematoxylin and eosin staining in the sham, 2, and 7 day groups. Western blot and histochemical analyses of RIP1, RIP3, and cIAP1/2, and double label fluorescent immunocytochemical studies of RIP3 and cIAP1/2 were performed at 8 h, 1, and 2 days after reperfusion (n = 6 each). RESULTS: There were significant differences in neurological function between the normothermic and hypothermic groups (median scores 0 and 5 at 7 days, p = .023). In the normothermic group, most motor neurons were lost seven days after reperfusion (p = .046 compared with sham), but they were preserved in the hypothermic group. Western blot analysis revealed the upregulation of RIP1, RIP3, and cIAP1/2 at 8 h in the normothermic group (RIP1, p = .032; RIP3, p < .001; cIAP1/2, p = .041 compared with sham), and the overexpression of RIP3 was prolonged for two days. In the hypothermic group, the expression of these proteins was not observed. The double label fluorescent immunocytochemical study revealed the induction of RIP3 and cIAP1/2 in the same motor neurons. CONCLUSIONS: These data suggest that transient normothermic ischaemia induces necroptosis, a potential factor in delayed motor neuron death, and that hypothermia may inhibit necroptosis.

Thoracic endografting increases cardiac afterload and leads to left ventricular hypertrophy in dogs.

OBJECTIVES: Aortic endografting can cause aortic stiffening. We aimed to determine the chronic effect of thoracic endografting on cardiac afterload, function and remodelling. METHODS: Eleven dogs were included, and all except 1 was successfully assessed [endograft, n = 5; sham operation (control), n = 5]. We deployed a stent graft in the descending aorta. The ascending aortic pressure and flow were measured, and aortic input impedance was obtained by frequency analysis to determine characteristic impedance and arterial compliance. Left ventricular pressure-volume relations were measured with an admittance catheter. Measurements were performed before, 10 min after and 3 months after endografting. Following euthanasia, we weighed the left ventricle of each dog and measured the cardiomyocyte cell size. RESULTS: Arterial compliance decreased from 0.47 ± 0.07 to 0.36 ± 0.06 and to 0.31 ± 0.05 ml/mmHg (both P < 0.01 versus baseline), and characteristic impedance increased from 0.11 ± 0.04 to 0.19 ± 0.05 and to 0.21 ± 0.04 mmHg/ml/s (both P < 0.01 versus baseline) 10 min and 3 months after endografting, respectively. Pressure-volume relation analysis showed that arterial elastance increased from 5.3 ± 1.0 to 6.7 ± 1.6 (at 10 min) and to 6.8 ± 1.0 mmHg/ml (at 3 months) (both P < 0.05 versus baseline), but end-systolic elastance and ventriculo-arterial coupling remained unchanged. Left ventricular weight to body weight ratio and left ventricular cardiomyocyte cell width in the endograft group were larger compared with the control's results (5.06 ± 0.27 g/kg vs 4.20 ± 0.49 g/kg, P = 0.009, 15.1 ± 1.7 µm vs 13.9 ± 1.5 µm, P = 0.02, respectively). CONCLUSIONS: The mid-term effect of the descending aortic endografting on left ventricular contractility and efficiency in canine normal hearts was minimal. However, endografting resulted in increased cardiac afterload and left ventricular hypertrophy.

Primary Cardiac T-Cell Lymphoma Localized in the Mitral Valve.

Primary cardiac lymphoma is a rare cardiac tumor, and usually originates from B cells and involves the right side of the heart. We present an extremely rare case of primary cardiac T-cell lymphoma involving the mitral valve alone. A 58-year-old woman who was positive for human T-cell leukemia virus 1 underwent mitral valve replacement because of severe mitral regurgitation. The postoperative pathologic diagnosis of the mitral valve was T-cell lymphoma. Further evaluation revealed no malignancy, except for the mitral valve. To the best of our knowledge, this is the first case of primary cardiac T-cell lymphoma localized in the mitral valve.

Midterm Results of Sternal Band Closure in Open Heart Surgery and Risk Analysis of Sternal Band Removal.

Sternal dehiscence, which is responsible for the development of mediastinitis, is a serious complication after cardiothoracic surgery. We retrospectively compared the results of two methods for sternal closure after cardiothoracic surgery performed during January 2009 to May 2012. The methods comprised closure with sternal bands and steel wires (group A, n = 92) versus conventional closure using steel wires alone (group B, n = 442). Although not significantly different between the two groups, no patients undergoing sternal band closure experienced dehiscence or mediastinitis. The incidence of having to remove materials used for sternal closure was significantly higher in group A than in group B. In each case of removal in group A, the materials removed were sternal bands whose tips had caused direct cutaneous irritation. Thus, although sternal bands may be effective for rigid sternal closure, they must sometimes be removed because of chest discomfort caused by the tip of the band.

Ventricular energetics early after surgery for chronic mitral regurgitation: repair versus replacement.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare the effects of mitral valve (MV) repair and replacement with partial (posterior leaflet only) chordal preservation on left ventricular (LV) performance in chronic degenerative mitral regurgitation (MR) by assessing ventricular energetics. METHODS: Contractility (end-systolic elastance), afterload (effective arterial elastance), and ventricular efficiency (ventriculoarterial coupling and the ratio of stroke work to pressure-volume area were determined using transthoracic echocardiography data obtained before and at one month after surgery in 29 patients undergoing MV repair, and in 12 patients undergoing partial chordal-sparing MV replacement. A two-way analysis of variance with repeated measures was used for comparisons among patients who underwent MV surgery (valve repair versus valve replacement). RESULTS: The LV diastolic volume index was decreased significantly in both groups (p<0.0001), whereas the LV systolic volume index did not change significantly (p=0.956). Despite the similar remarkable decrease in ejection fraction (p<0.0001) in both groups, end-systolic elastance remained unchanged (p=0.312). Effective arterial elastance was increased significantly in both groups (p<0.0001). Ventriculoarterial coupling and the ratio of stroke work to pressure-volume area deteriorated similarly in both groups (p<0.0001 and p<0.0001). CONCLUSION: Compensation of LV geometry after correction of chronic MR preserved ventricular contractility. Furthermore, the results of MV repair were not superior to those of MV replacement with partial chordal preservation in the early postoperative period. This suggested that partial chordal-sparing MV replacement is an effective method for the treatment of chronic MR in selected patients.

Repair of acute aortic dissection in an octogenarian with prior thoracoplasty.

Cardiovascular surgery is challenging in patients who have previously undergone thoracoplasty because of severe chest deformity and impaired pulmonary function. We report a case of an octogenarian with prior left thoracoplasty, who successfully underwent surgical repair of an acute aortic dissection through a standard median sternotomy. We suggest that prior thoracoplasty might not necessarily be an exclusion criterion for aortic surgery in cases with adequate pulmonary function.