Changes in Internal Thoracic Artery Blood Flow According to the Degree of Stenosis of the Anterior Descending Branch of the Left Coronary Artery.

PURPOSE: Computational fluid dynamics has enabled the evaluation of coronary flow reserve. The purpose of this study was to clarify the hemodynamic variation and reserve potential of the left internal thoracic artery (LITA). METHODS: Four patients were selected on the basis of various native coronary stenosis patterns and graft design. The wall shear stress and oscillatory shear index were measured, and one patient was selected. Next, we created three hypothetical lesions with 75%, 90%, and 99% stenosis in front of the graft anastomosis, and compared the changes in LITA blood flow and coronary flow distribution. RESULTS: In the 75% to 90% stenosis model, blood flow was significantly higher in the native coronary flow proximal to the coronary artery bypass anastomosis regardless of time phase. In the 99% stenosis model, blood flow from the LITA was significantly dominant compared to native coronary flow at the proximal site of anastomosis. The range of LITA flow variability was the largest at 99% stenosis, with a difference of 70 ml/min. CONCLUSION: The 99% stenosis model showed the highest LITA flow. The range of LITA flow variability is large, suggesting that it may vary according to the rate of native coronary stenosis.

Superior restoration of left ventricular performance after prolonged single-dose del Nido cardioplegia in conjunction with terminal warm blood cardioplegic reperfusion.

OBJECTIVES: An incomplete restoration of left ventricular contractility after del Nido cardioplegia was noted in our recent study. This study tested the hypothesis that terminal warm blood cardioplegia promotes a prompt restoration of left ventricular performance after a prolonged single-dose del Nido cardioplegia. METHODS: Fourteen piglets were subjected to 120 minutes of arrest by del Nido cardioplegia without terminal warm blood cardioplegia (del Nido cardioplegia group; n = 7) or with terminal warm blood cardioplegia before reperfusion (terminal warm blood cardioplegia group; n = 7). The other 7 piglets underwent total cardiopulmonary bypass without ischemia/reperfusion for 150 minutes (control group). Left ventricular function was assessed by percent recovery of end-systolic elastance as the contractility and percent end-diastolic pressure-volume relationship as the compliance using a conductance catheter. Troponin T and the mitochondrial score were also measured. RESULTS: Depressed percent recovery of end-systolic elastance was sustained in the del Nido cardioplegia group, and a prompt restoration of end-systolic elastance was achieved using terminal warm blood cardioplegia (57.9 ± 17.8 vs 94.7 ± 13.1, P < .028). Percent end-diastolic pressure-volume relationship at the early phase was better in the terminal warm blood cardioplegia compared with the del Nido group (88.5 ± 24.0 vs 101.4 ± 16.8, P = .050). Troponin T was higher in the terminal warm blood cardioplegia compared with the control group (0.80% ± 0.21% and 1.49% ± 0.31%, respectively, P = .002). The mitochondrial score was equivalent in all groups. Spontaneous restoration to sinus rhythm was more frequent in the terminal warm blood cardioplegia group than in the del Nido cardioplegia group (6/7 vs 1/7, P < .028). CONCLUSIONS: The supplementary use of terminal warm blood cardioplegia achieved prolongation of the safe ischemic time up to 120 minutes for a single-dose application.

Modified Del Nido Cardioplegia and Its Evaluation in a Piglet Model.

Del Nido cardioplegia (DN) is not available worldwide as the required solution is made from a commercial base (PlasmaLyte) that is not approved in all countries. We report our own modified DN solution and confirm its safety and effectiveness. Fourteen piglets were subjected to 90 minutes of global ischemia on cardiopulmonary bypass induced by original DN (n = 7) or NS (normal saline)-based DN (n = 7). Our DN solution begins with a base of NS (800 mL) and distilled water (200 mL), to which are added 15 mL KCl (2 mEq/mL), 17 mL NaHCO3 (1 mEq/mL), 10 mL MgSO4 (0.2 g/mL), 13 mL lidocaine 1%, and 13 mL mannitol 25%. LV function recovery was assessed in end-systolic elastance (EES) as systolic function and end-diastolic pressure-volume relationship (EDPVR) as diastolic function using a conductance catheter. Creatine kinase-MB (CK-MB) and mitochondrial score were also measured. Left ventricular (LV) contractility after ischemia (%EES ± SD) was not significantly different between the group induced by original DN (89.3 ± 20.6%) and the group induced by NS-based DN (99.3 ± 18.4%). LV compliance (%EDPVR ± SD) was likewise not significantly different between these groups (102.7 ± 28.2% vs 94.4 ± 22.8%, PL vs NS, respectively). CK-MB was equivalent between the groups. Mitochondrial scores were not significantly different between the groups, and this difference did not cause severe damage. NS-based DN preserves LV function recovery after prolonged global ischemia as effectively and as safely as original DN does. NS-based modified DN can be substituted for original DN.

Aortic root destruction after aortic valvuloplasty for bicuspid aortic valve.

Ultrasound cardiography showed severe aortic regurgitation (AR) due to bicuspid aortic valve with dilatation of the aortic annulus and sinotubular junction in a 27-year-old man hospitalized with loss of consciousness. He underwent aortic valvuloplasty combined with external suture annuloplasty using an expanded polytetrafluoroethylene (ePTFE) suture. Intraoperative findings revealed thickening and adhesion of the aortic root despite the first surgery. He developed recurrent AR 7 months later and underwent redo surgery. An ePTFE suture was found inside the aorta. Aortic root replacement with a mechanical composite graft was performed, as reconstruction appeared difficult because the aortic annulus was damaged and there were multiple holes on all cusps. Here, we report a rare case of aortic root destruction after external suture annuloplasty.

Excellent Restoration of Left Ventricular Compliance After Prolonged Del Nido Single-Dose Cardioplegia in an In Vivo Piglet Model.

Del Nido cardioplegia (DN) is used in congenital heart surgery and recently in adults, a single dose has been administered. However, the tolerable ischemic time has not been established. The objective is to evaluate the left ventricular (LV) function recovery and accompanying biochemical and histologic markers to clarify the tolerable ischemic time in an in vivo cardiopulmonary bypass (CPB) piglet model. Twenty-one piglets were subjected to either 90 minutes (with or without topical cooling; TC) or 120 minutes (with TC) of global ischemia induced by single-dose DN, while the other 7 served as the control group (CPB only). The CPB temperature was established with a perfusion temperature of 30°C. The LV function recovery was assessed by the percent change in end-systolic elastance (Ees) and the end-diastolic pressure-volume relationship (EDPVR). Creatine kinase-MB (CK-MB) levels and the mitochondrial score were also assessed. LV contractility assessed by %Ees after 90 and 120 minutes of ischemia (89.3 ± 20.6% and 57.9 ± 17.8%) was lower compared with the control group (122.6 ± 35.8%, P = 0.001). Conversely, LV compliance assessed by %EDPVR was preserved in both groups (102.7 ± 28.2% and 88.5 ± 24.0%), which was comparable to the control group (105.8 ± 36.9%, P = 0.531). There was no change in LV contractility after 90 minutes of ischemia with or without TC (89.3 ± 20.6% or 84.8 ± 16.2%, P = 0.657), whereas LV compliance was lower but not statistically different without TC (102.7 ± 28.2% vs 78.0 ± 38.9%). CK-MB and the mitochondrial score were equivalent between all groups. The proposed single-dose ischemic time for redosing is 90 minutes using TC.

[A New-born Case of Total Conus Defect and Single Coronary Artery with Situs Inversus Totalis Suspected Kartagener Syndrome].

We report a new-born case of total conus defect type ventricular septal defect (VSD) and single coronary artery with situs inversus totalis, suspected Kartagener syndrome clinically. After the birth, as the patient had suffered from respiratory distress due to high pulmonary blood flow through the large defect, surgery was planned at age of 14-days after birth. Under median sternotomy and cardiac arrest, patch closure of VSD was performed as ordinary fashion. In spite of the situs inversus totalis and single coronary artery arose from right coronary sinus, operator could have completed all of surgical procedure at the right side of patient as usual. No remarkable respiratory complication was seen postoperatively and she was discharged from hospital 18th day in a good condition.

Aortic root replacement for annuloaortic ectasia with a single coronary artery.

A single coronary artery, arising from the left sinus of Valsalva, associated with a bicuspid aortic valve and annuloaortic ectasia, is very rare. We report on a surgical case of bicuspid aortic valve regurgitation, annuloaortic ectasia, and dilation of the ascending aorta to the aortic arch in a patient with a single coronary artery. We successfully performed aortic root replacement with reimplantation of the single coronary artery and total arch replacement. The reimplantation of the coronary orifice required particular attention. Postoperative CT demonstrated the expected contours from the aortic annulus to the aortic arch with a patent implanted coronary artery.

[A 28-Week-Pregnant Woman at Twenty Years of Age, Who Had Been Hospitalized with Jaundice].

The Reversed Clinicopathological Conference (R-CPC) is a useful tool to analyze a patient's condition us- ing only laboratory data. An R-CPC was held at the 59th Regional Congress. One case presenter, two dis- cussers, and one commenter participated in this R-CPC. We report a 28-week-pregnant woman at twenty years of age, who had been hospitalized with jaundice. In laboratory data, AST, ALT, and bilirubin were ele- vated and the prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged. Although the liver failure was improved after she delivered a baby by Caesarean section, postoperative intra- peritoneal bleeding persisted. The diagnosis based on liver biopsy was autoimmune hepatitis. Although the bleeding was stopped on the seventh postoperative day, the prolongation of PT and APTT remained. LA was positive in the diluted Russell's viper venom time. Anti-cardiolipin and anti-beta-2-glycoprotein anti- bodies were also positive. The prothrombin activity was reduced. A high titer of phosphatidylserine- dependent anti-prothrombin antibody (aPS/PT), which causes bleeding, was observed. Based on these data, she was diagnosed with lupus anticoagulant-hypothrombinemia syndrome (LAHS). The 2 discussers care- fully analyzed the laboratory data and the commenter gave appropriate opinions. [Review].

Variability of Pulmonary Regurgitation in Proportion to Pulmonary Vascular Resistance in a Porcine Model of Total Resection of the Pulmonary Valve: Implications for Early- and Long-Term Postoperative Management of Right Ventricular Outflow Tract Reconstruction With Resulting Pulmonary Valve Incompetence.

INTRODUCTION: Pulmonary regurgitation (PR) is a major concern after right ventricular (RV) outflow tract surgery. We assessed the impact of physiological changes in pulmonary vasculature on hemodynamic severity of PR and RV function and their potential clinical implications for postoperative management using a porcine model with severe PR. MATERIALS AND METHODS: Eight porcine models of acute PR were established by means of resection of pulmonary valve on cardiopulmonary bypass. After separation from bypass and stabilization, blood flow in the main pulmonary artery was measured by a pulsed Doppler flowmeter, and RV systolic function was assessed on the basis of RV segment shortening (RVSS), which was analyzed by sonomicrometry. In the acute PR model, we verified the impact of pulmonary vascular resistance (Rp) on pulmonary regurgitant fraction (PRF) and RV function. Pulmonary vascular resistance was changed by manipulating the level of PaCo 2 and by inhalation of nitric oxide (NO). RESULTS: After bypass, the mean PRF was 40% ± 5%, and there was a deterioration of RV function. Under each ventilation condition (high CO2, low CO2, and NO 20 ppm), Rp was 836 ± 207 dyne × s × cm(-5), 499 ± 125 dyne × s × cm(-5), and 340 ± 102 dyne × s × cm(-5), respectively, and PRF was 60% ± 10%, 37% ± 5%, and 24% ± 4%, respectively, under each condition. They also showed a positive correlation in all animals. Cardiac output and RVSS were decreased by hypercapnia, while they were significantly improved after NO inhalation. CONCLUSIONS: This study indicates that low Rp after right ventricular outflow tract reconstruction (RVOTR) resulting in acute PR is advantageous in reducing the severity of PR and RV volume load. These findings may have clinical implications for early and long-term postoperative management of patients subjected to RVOTR with resulting pulmonary valve incompetence.

Distal aortic arch aneurysm associated with persistent fifth aortic arch.

Persistent fifth aortic arch (PFAA) associated with interruption of the fourth aortic arch is a rare malformation, usually requiring surgical intervention in childhood. A 51-year-old woman developed a distal aortic arch aneurysm associated with PFAA after patch aortoplasty for coarctation of the aorta at the age of 18. To our knowledge, this is the first reported case of a distal aortic arch aneurysm associated with PFAA. Residual tissues of the ductus and PFAA, which is not a definitive aortic arch, and the implanted synthetic patch may have been related to the development of the aneurysm. Graft interposition between the proximal border of PFAA and the descending aorta was performed because severe adhesions impeded the application of the fourth aortic arch as a proximal anastomotic site of the graft. Accurate diagnosis and sufficient understanding of PFAA allow an appropriate surgical treatment in childhood with a good result over the long term.

[Lower body ischemia due to bending of the stent after hybrid treatment for chronic stanford type B aortic dissection].

Lower body ischemia due to bending of a stented graft at the thoracic aorta was rare, particularly when it occurred in several days after surgery. We experienced this complication and performed the 3rd-time thoracic endovascular repair( TEVAR).A 49-year-old man with a chronic aortic dissection of Stanford type B underwent TEVER;however we failed to close the entry because of the tortuously bended distal arch of the aorta. Then it was decided the patient undergo a hybrid treatment with arch replacement and frozen elephant trunk. Seventeen days after the surgery, the blood pressure of the patient's lower limb was reduced rapidly and his renal function deteriorated. Bending of the stent was revealed by computed tomography( CT). The patient underwent the 3rd-time emergency TEVAR, and his symptoms improved.