Use of the novel curved GOKU balloon catheter for acute-angled lesions in palliative surgery for congenital heart disease: comparison with a conventional straight balloon.

Obstruction develops commonly at the acute-angled portion of the vessels following palliative surgery, such as systemic-pulmonary shunt (SP shunt), right ventricle-to-pulmonary artery shunt (RV-PA shunt) in the Norwood-Sano procedure for hypoplastic left heart syndrome, and cavopulmonary (Glenn) anastomosis. Although balloon angioplasty is a treatment option, dilation with existing straight balloons is sometimes ineffective and technically complicated because of balloon slippage and target vessel distortion. In this study, we investigated the effectiveness of a curved GOKU balloon catheter for balloon angioplasty in postoperative acute-angled lesions associated with palliative surgery for congenital heart disease. We reviewed patients who underwent balloon angioplasty for angled lesions complicated by SP shunt, RV-PA shunt, or Glenn anastomosis, using the novel curved GOKU or a conventional balloon catheter, such as a Sterling balloon catheter. We evaluated patients' backgrounds, balloon specifications, target lesion anatomical features and angles, and short-term outcomes. We evaluated 45 procedures in 18 patients. A curved GOKU was used in 20 procedures, and a Sterling balloon in 25 procedures. The angulation of the lesions at maximum balloon inflation was significantly smaller using a curved GOKU vs a Sterling balloon [70-120 (mean ± standard deviation, 97 ± 40) degrees vs 110-180 (149 ± 46) degrees, respectively; p < 0.001], while the original angle was similar between the groups. Patients' short-term outcomes with the curved GOKU were excellent, with a significantly better percent increase in minimum lumen diameter of 0-220% (92% ± 66%) vs 0-46% (18% ± 15%) with the Sterling balloon (p < 00.1) and with less frequent balloon slippage. The curved GOKU was more effective in balloon angioplasty for acute-angled lesions compared with a conventional straight balloon, likely because of better conformability to the lesion angle and slip resistance.

Stent unzipping using an ultra-high-pressure balloon: in vitro and animal experiments.

As a child grows, limitations to the maximum dilatable stent diameter (MDD) will result in stenosis associated with size mismatch. If an implanted stent can be intentionally fractured along its length, a process called "unzipping," it may eventually be redilated to adult vessel size. Few studies have addressed how a stent can be unzipped using an ultra-high-pressure balloon (UHB) with the smallest balloon diameter. Eleven commercially available stents, three Liberté stents (LS), six genesis renal stents (GS), and two express vascular SD stents (ES), were tested for in vitro unzipping. In addition, using eight stents, we investigated whether a balloon that had unzipped the stent in vitro would work similarly in the vessel of a pig. Finally, we assessed the histological influence of the unzipped stent on the surrounding tissue. In a bench test, LS, GS, and ES were consistently unzipped by a balloon whose diameter was ≥ 1.5, 2.18, and 1.66 times that of MDD, respectively. In animal experiments, LS, GS, and ES were predictably unzipped with balloons of 1.50, 1.81, and 1.66 times the MDD, respectively. After unzipping, the unzipped strut did not damage the surrounding tissue histologically. Use of a UHB enabled unzipping of the stent with a balloon diameter less than two times the MDD enables implantation of a larger stent in the unzipped small stent by incremental steps.

Static balloon atrial septostomy for the purpose of left heart intervention in postoperative adult CHD.

Background and purposeStatic balloon atrial septostomy is a widely accepted intervention for children with CHD. Successful surgical palliation is creating increasing numbers of adult CHD patients who need subsequent left heart intervention requiring transseptal access. In these patients, the interatrial septum is usually thick and fibrotic because of a previous open heart surgery or catheter intervention, and conventional transseptal puncture may be unsuccessful. Static balloon atrial septostomy to access the left atrium may facilitate intervention via the interatrial septum in such situations. The purpose of this study was to investigate the usefulness and the safety of static balloon atrial septostomy, and the evolution of an iatrogenic atrial septal defect post procedure in adult CHD. METHODS: We retrospectively reviewed six procedures in five adults with CHD and collected demographic characteristics, details of the procedures, clinical outcome, and size changes of the iatrogenic atrial septal defect. RESULTS: The mean age at the time of the procedure was 35 years. The intended primary interventions were pulmonary vein isolation, stenting for pulmonary vein obstruction, and catheter ablation for focal atrial tachycardia. All static balloon atrial septostomies were effective, and the left heart interventions were successfully achieved via transseptal sheaths. There were no major complications associated with the static balloon atrial septostomy. There were no adverse clinical outcomes related to iatrogenic atrial septal defect, and the size of the defects regressed over time in all cases. CONCLUSIONS: Static balloon atrial septostomy can be a safe and useful technique in adult CHD patients needing left heart procedures. The thick interatrial septum found in postoperative patients may reduce the risk of persistent iatrogenic atrial septal defect.

Novel curved balloon catheter for dilating postoperative angled lesions associated with congenital heart disease.

OBJECTIVES: This study aimed to analyze the surface stress generated by a novel curved balloon and assess its efficacy for treating angular lesions associated with congenital heart disease. BACKGROUND: Obstructions at the anastomosis of aortopulmonary shunts and cavopulmonary connections may occur postoperatively. Catheter interventions are often performed for such lesions; however, acute angulation may cause balloon slippage or inappropriate stress on the vessel wall. METHODS: We dilated the curved balloon in a curved vessel model and measured the resultant wall stress and its distribution. Clinical evaluations were performed using this balloon in angled lesions. RESULTS: In the curved vessel model, curved balloons generated uniform stress on the lesser and greater curvatures (curved type, lesser/greater = 0.343 MPa/0.327 MPa; P = 0.61), whereas straight balloons caused disproportionate stress (straight type, lesser/greater = 0.358 MPa/0.254 MPa; P = 0.19). However, the difference in average stress was not statistically significant. Furthermore, the stress was uniform along the entire length of the curved balloon, but differed between the mid and end portions of the straight balloon. Curved balloon dilations were performed for 10 lesions in 7 patients. The curved balloon conformed well to the angulated lesion without slipping. The median percent change in the minimal lumen diameter (MLD) was 64% (range, 0-206%). In 5 lesions, MLD increased by ≥50%. Oxygen saturation increased by 5% (0-9%). CONCLUSIONS: Although further clinical evaluation is necessary, this novel curved balloon may be a reasonable alternative in angled lesions, providing better conformability and preventing excessive stress to the vessel wall adjacent to the stenosis.

Monolayered mesenchymal stem cells repair scarred myocardium after myocardial infarction.

Mesenchymal stem cells are multipotent cells that can differentiate into cardiomyocytes and vascular endothelial cells. Here we show, using cell sheet technology, that monolayered mesenchymal stem cells have multipotent and self-propagating properties after transplantation into infarcted rat hearts. We cultured adipose tissue-derived mesenchymal stem cells characterized by flow cytometry using temperature-responsive culture dishes. Four weeks after coronary ligation, we transplanted the monolayered mesenchymal stem cells onto the scarred myocardium. After transplantation, the engrafted sheet gradually grew to form a thick stratum that included newly formed vessels, undifferentiated cells and few cardiomyocytes. The mesenchymal stem cell sheet also acted through paracrine pathways to trigger angiogenesis. Unlike a fibroblast cell sheet, the monolayered mesenchymal stem cells reversed wall thinning in the scar area and improved cardiac function in rats with myocardial infarction. Thus, transplantation of monolayered mesenchymal stem cells may be a new therapeutic strategy for cardiac tissue regeneration.

Atrionatriuretic peptide improves left ventricular function after myocardial global ischemia-reperfusion in hypoxic hearts.

Atrionatriuretic peptide (ANP) is reported to be useful for attenuating myocardial ischemia-reperfusion injury and improving left ventricular function after reperfusion. However, ANP may be either ineffectual or harmful in cases where the myocardium has been chronically hypoxic since birth. This can be a result of the concomitant high levels of cyclic guanosine monophosphate (cGMP) produced within the myocardium. This study aimed to verify the validity of using ANP to improve left ventricular function after myocardial ischemia-reperfusion injury. For this purpose, a cyanotic congenital disease model that was developed using isolated rat hearts was used. Hearts were obtained from Sprague-Dawley rats that were housed from birth until 6 weeks of age either in a hypoxic environment with 13-14% FiO(2) (hypoxic group) or in ambient air (normoxic group). These hearts were subjected to 30min of normothermic global ischemia followed by 30min of reperfusion using the Langendorff technique. Left ventricular functional recovery in hearts administered ANP (0.1µM) into the reperfusion solution was compared with those hearts that were not administered ANP in both hypoxic (without ANP: n=6, with ANP: n=6, with ANP and HS-142-1[an antagonist of ANP]: n=6) and normoxic hearts (without ANP: n =6, with ANP: n=6). In the hypoxic hearts, ANP administration improved the percent recovery of the left ventricular developed pressure (76.3±9.2% without ANP vs. 86.9±6.7% with ANP), maximum first derivative of the left ventricular pressure (82.4±1.1% without ANP vs. 95.8±6.5% with ANP), and heart rate (85.6±4.7% without ANP vs. 96.1±5.2% with ANP) after reperfusion. The improvement and recovery of these cardiac functions were closely related to significantly increased levels of postischemic cGMP release after ANP administration. The effect of ANP was blocked by HS-142-1. The improvements observed in the hypoxic group were similar to those found in the normoxic group. ANP administration during reperfusion improved left ventricular function after myocardial acute global ischemia-reperfusion equally in both the chronically hypoxic and age-matched normoxic groups.

Percutaneous pulmonary artery debanding.

BACKGROUND: There is a paucity of data on palliative or total percutaneous pulmonary artery debanding (p-debanding), particularly with use of a stent. METHODS: Twelve p-debandings in eight patients were included in this study. Age at pulmonary artery banding (PAB) ranged from 3 days to 1 year (median, 13 days), while p-debanding was performed at 2-157 (7) months. The body weight at the p-debanding ranged from 3.2 to 22.2 (7.3) kg. We chose the balloon diameter of 30-50% to the circumference of the band for palliative, and larger than 50% for total p-debanding, respectively. In either way, the balloon diameter did not exceed 1.5 times the reference vessel diameter. Stent was implanted for palliative p-debanding in 2 patients. RESULTS: 1. The circumference of the band ranged from 16 to 23 (20) mm, while the balloon diameter ranged from 20-60 (40)% to that, where larger than 50% was used for 2 procedures intended total p-debanding. 2. PAB diameter increased from 2.5-4.7 (3.0) mm to 2.8-9.5 (4.5) mm (p<0.01), however, there was no significant change in the diameter in 2 procedures. In one patient, p-debanding was the definitive treatment associated with spontaneous near closure of muscular ventricular septal defect, in another patient of congenitally corrected transposition of the great arteries, severely depressed left ventricular ejection fraction was recovered following p-debanding. 3. Arterial oxygen saturation (SaO2) increased from 64-97 (80)% to 66-95 (90)% (p<0.01), while in 10 procedures of 6 patients where the indication of p-debanding was hypoxia, SaO2 increased in 8 procedures. There was no significant pulmonary hypertension following p-debanding. CONCLUSION: Palliative or total p-debanding using balloon and/or stenting is generally feasible and effective. A balloon diameter 35-50% to the band circumference in palliative, and more than 50% in total p-debanding, while in either way less than 1.5 times the reference vessel diameter, is safe.

Evaluation of the appropriate root pressure for maintaining heartbeat during an aortic cross-clamp for primary repair of the aortic arch in premature infants with associated cardiac anomalies.

We developed a new cardiopulmonary bypass (CPB) method to minimize myocardial damage during aortic arch reconstruction. In this method, coronary flow and heartbeat were stabilized by maintaining the aortic root pressure with an adjusted preload of the ventricle during aortic cross-clamping. This study was performed to determine the appropriate root pressure to maintain the heartbeat without causing deterioration of ventricular function. Study 1. Under partial CPB, the ascending aorta was cross-clamped in 6 pigs (group 1). Experimental data at various systolic aortic root pressures was analysed to determine the appropriate root pressure. Study 2. In group 2 (control, n＝6), the aorta was not clamped, while in group 3 (n＝6), the aorta was cross-clamped for 60 min and the systolic aortic root pressure was maintained at the pressure determined in study 1. Study 1. The diastolic coronary flow was stabilized at values comparable to that before initiation of CPB (6.6±1.4 ml/beat) when the systolic aortic root pressure was above 80 mmHg. Intracardiac pressure and the myocardial oxygen consumption (MvO2) seemed to be acceptable when the systolic aortic root pressure was below 100 mmHg. Therefore, 90 mmHg was selected for study 2. Study 2. Perioperative cardiac function did not differ between the groups. We concluded that 90 mmHg was the systolic aortic root pressure appropriate for this method.

Effect of a miniaturized cardiopulmonary bypass system on the inflammatory response and cardiac function in neonatal piglets.

The cognitive impairment and hemodynamic instability after neonatal cardiac surgery with cardiopulmonary bypass (CPB) might be exacerbated by hemodilution. Therefore, this study investigated the impact of different bloodless prime volumes on the hemodynamics and the inflammatory response by a miniaturized CPB system in neonatal piglets. The bypass circuit consisted of a Capiox RX05 (Capiox Baby RX, Terumo Corp., Tokyo, Japan) oxygenator and 3/16 internal diameter arterial and venous polyvinyl chloride tubing lines, with a minimum 75 mL prime volume. Twelve 1-week-old piglets were placed on a mild hypothermic CPB (32 degrees C) at 120 mL/kg/min for 2 h. The animals were divided into two groups, based on the volume of the prime solution. The priming volume was 75 mL in Group I and 175 mL in Group II. No blood transfusions were performed, and no inotropic or vasoactive drugs were used. The interleukin-6 (IL-6) and thrombin-antithrombin (TAT) complex levels, as well as right ventricular and pulmonary functions, were measured before and after CPB. Group I had low levels of IL-6 and TAT immediately after CPB (4370 +/- 2346 vs. 9058 +/- 2307 pg/mL, P < 0.01 and 9.9 +/- 7.7 vs. 25.1 +/- 8.8 ng/mL, P < 0.01, respectively). Group I had significantly improved cardiopulmonary function, cardiac index (0.22 +/- 0.03 vs. 0.11 +/- 0.05 L/kg/min, P < 0.001), and pulmonary vascular resistance index (7366 +/- 2860 vs. 28 620 +/- 15 552 dynes/cm(5)/kg, P < 0.01) compared with Group II. The miniaturized bloodless prime circuit for neonatal CPB demonstrated that the influence of hemodilution can reduce the subsequent inflammatory response. In addition, a low prime volume could therefore be particularly effective for attenuating pulmonary vascular resistance and right ventricular dysfunction in neonates.

Age-dependent vulnerability to ischemia-reperfusion injury of cyanotic myocardium in a chronic hypoxic rat model.

This study evaluated the effects of chronic hypoxia from birth on the resistance of rat hearts to global ischemia, with special emphasis on the duration of hypoxia. Male Wistar rats were housed from birth for 4 weeks or 8 weeks either in a hypoxic environment (FiO2 = 0.12) or in ambient air (8 animals for each group). Isolated rat hearts were perfused for 40 min with oxygenated Krebs-Henseleit buffer, subjected to 20 min global no-flow ischemia at 37, and then underwent 40 min of reperfusion. A non-elastic balloon was inserted into the left ventricle and inflated until the pre-ischemic LVEDP rose to 8 mmHg. Cardiac function was measured before and after ischemia. The post-ischemic percent recovery of LVDP in hypoxic hearts was worse than in normoxic hearts (4 weeks:55+/-7 vs. 96+/-3%, p0.01;8 weeks:40+/-5 vs. 92+/-4%, p0.01), and was worst in the 8-week-hypoxic hearts. Similarly, the percent recovery of dP/dt in the hypoxic hearts was lower than in the normoxic hearts (4 weeks:51+/-5 vs. 96+/-7%, p0.01;8 weeks:31+/-6 vs. 92+/-7%, p0.01), and was lowest in the 8-week-hypoxic hearts. In conclusion, cyanotic myocardium revealed an age-dependent vulnerability to ischemia-reperfusion injury in a chronic hypoxic rat model.

Transcatheter closure of perimembranous ventricular septal defects with Amplatzer® duct occluder I; The first case report in Japan.

We report the first case of transcatheter perimembranous ventricular septal defect (pmVSD) closure in Japan where none of existing devices for VSD closure has been approved. The pmVSD was successfully closed with first generation Amplatzer® duct occluder (ADO-I; St Jude Medical, St Paul, MN, USA). The procedure was performed under general anesthesia with transesophageal echocardiographic and fluoroscopic guidance. The left ventricular volume overload after the procedure was remarkably improved and no major complications occurred. ADO-I can be a safe and effective option for transcatheter pmVSD closure. The incidence of heart block may be less than reported with the original device. .

Cardiac epinephrine synthesis and ischemia-induced myocardial epinephrine release.

OBJECTIVE: Phenylethanolamine-N-methyltransferase (PNMT), the enzyme that synthesizes epinephrine (EPI) from norepinephrine (NE) in the adrenal gland, is present in extra-adrenal tissues including heart. Ischemia evokes an excessive NE accumulation in the myocardial interstitial spaces. Therefore, cardiac PNMT activity with high NE levels may contribute to cardiac EPI synthesis and release evoked by ischemia. METHODS: We measured dialysate EPI levels in the left ventricle of anesthetized rabbits using a cardiac microdialysis technique. The dialysate EPI level served as an index of the myocardial interstitial EPI level. Locally administered NE-induced dialysate EPI responses were measured. The left circumflex coronary artery was occluded for 60 min and the dialysate EPI and NE levels in the ischemic region were measured. Coronary occlusion-induced EPI responses were compared with and without administration of a PNMT inhibitor (SKF29661) in the presence and absence of desipramine (catecholamine transport blocker). RESULTS: Local administration of NE (250, 2500 ng/ml) increased the EPI levels to 734+/-125 and 2088+/-367 pg/ml respectively. These increases in dialysate EPI were suppressed by the PNMT inhibitor. Acute myocardial ischemia significantly increased the EPI levels to 3607+/-1069 pg/ml in the ischemic region, and these were suppressed by the PNMT inhibitor (1417+/-581 pg/ml). The pretreatment with desipramine suppressed ischemia-induced EPI release, which did not differ with (725+/-155 pg/ml) and without administration of a PNMT inhibitor (743+/-172 pg/ml). CONCLUSION: The cardiac PNMT in the left ventricle is capable of synthesizing EPI with markedly elevated NE levels in the myocardial interstitial space.

Percutaneous pulmonary debanding for an infant complicated by spontaneously closing muscular ventricular septal defect: A case report and in vitro study.

Pulmonary artery banding (PAB) is a standard operation for various congenital heart defects complicated by pulmonary hypertension (PH) and judged unsuitable for primary intracardiac repair. We report successful percutaneous pulmonary artery debanding in a baby complicated by muscular ventricular septal defect (VSD), that was initially large and multiple, but closed spontaneously later. The 5-month-old boy was referred to our hospital on day 3, diagnosed as having aortic coarctation (CoA), with multiple muscular VSDs and severe PH. On day 6, he underwent CoA repair and PAB using expanded polytetrafluoroethylene (ePTFE), while the muscular VSDs were left open. We planned percutaneous pulmonary debanding at the age of 5 months, as the muscular VSDs had become small. After dilation with a Mustang® (Boston Scientific, Marlborough, Massachusetts, United State) balloon (12 mm diameter) there was a persistent waist indicating a residual narrowing. Use of an extra-high pressure balloon, Conquest® (Medicon, Osaka, Japan) balloon of the same size, completely eliminated the waist. In in vitro experiments, the Mustang® partially tore the ePTFE, while a Conquest® of the same diameter completely opened the band. The mechanism of debanding was tearing of the ePTFE by the knot of the suture thread. Percutaneous pulmonary debanding to avoid unnecessary surgery is feasible in such a patient if the VSD becomes small. .

Successful intra-postoperative extracorporeal circulatory support with atrial communication for treatment of anomalous left coronary artery from the pulmonary artery: a case report.

We describe a successful case of surgical treatment for anomalous left coronary artery from the pulmonary artery (ALCAPA) syndrome with severe left ventricular dysfunction. Because of the severe left ventricular dysfunction, we planned to use an extracorporeal membrane oxygenation for heart support until a satisfactory recovery had been established. The left ventricular function significantly recovered in a few days, and the patient could be discharged without any complications.

Effect of sustained limb ischemia on norepinephrine release from skeletal muscle sympathetic nerve endings.

Acute ischemia has been reported to impair sympathetic outflow distal to the ischemic area in various organs, whereas relatively little is known about this phenomenon in skeletal muscle. We examined how acute ischemia affects norepinephrine (NE) release at skeletal muscle sympathetic nerve endings. We implanted a dialysis probe into the adductor muscle in anesthetized rabbits and measured dialysate NE levels as an index of skeletal muscle interstitial NE levels. Regional ischemia was introduced by microsphere injection and ligation of the common iliac artery. The time courses of dialysate NE levels were examined during prolonged ischemia. Ischemia induced a decrease in the dialysate NE level (from 19+/-4 to 2.0+/-0 pg/ml, mean+/-S.E.), and then a progressive increase in the dialysate NE level. The increment in the dialysate NE level was examined with local administration of desipramine (DMI, a membrane NE transport inhibitor), omega-conotoxin GVIA (CTX, an N-type Ca(2+) channel blocker), or TMB-8 (an intracellular Ca(2+) antagonist). At 4h ischemia, the increment in the dialysate NE level (vehicle group, 143+/-30 pg/ml) was suppressed by TMB-8 (25+/-5 pg/ml) but not by DMI (128+/-10 pg/ml) or CTX (122+/-18 pg/ml). At 6h ischemia, the increment in the dialysate NE level was not suppressed by the pretreatment. Ischemia induced biphasic responses in the skeletal muscle. Initial reduction of NE release may be mediated by an impairment of axonal conduction and/or NE release function, while in the later phase, the skeletal muscle ischemia-induced NE release was partly attributable to exocytosis via intracellular Ca(2+) overload rather than opening of calcium channels or carrier mediated outward transport of NE.

Repair of a dysplastic tricuspid valve using artificial chordae: case report.

Atrioventricular valve repair with artificial chordal replacement has been widely used for congenital and acquired mitral valve abnormalities, but not for tricuspid valve abnormalities. A case is presented of dysplastic tricuspid valve that was successfully repaired using artificial chordae. A 2-year-old female presented with poor weight gain. Echocardiography revealed severe tricuspid regurgitation due to dysplastic tricuspid valve, poor coaptation by prolapse of the anterior leaflet, and tethering of the septal leaflet by short chordae. The prolapsed anterior leaflet was repaired with three pairs of 6-0 expanded polytetrafluoroethylene sutures. The short chordae of the septal leaflet were detached, and the septal and posterior leaflets were sutured together. Trivial tricuspid regurgitation was noted postoperatively. There was no tricuspid regurgitation during the follow up period of three years. The present case provides further evidence that artificial chordal replacement is a useful technique even for small children with congenitally abnormal tricuspid valves.

Continuous cerebral and myocardial perfusion during aortic arch repair in neonates and infants.

To minimize myocardial ischemia, we repaired aortic arch obstruction with ventricular septal defect, using two different techniques of cerebral and myocardial perfusion. Seventy-one infants, ages 3 to 137 days, underwent primary repair of coarctation of the aorta (n = 49)/interruption of the aortic arch (n = 22) with ventricular septal defect. In 65 patients, an end-to-end arch anastomosis was performed with cerebral and myocardial perfusion through the innominate or the ascending arterial cannula (non-working beating heart: NWBH). In the remaining 6 patients, an arterial cannula was placed into the innominate artery. With partial cardiopulmonary bypass, the innominate artery was snared proximal to the cannulation site and the ascending aorta was cross-clamped. An extended arch anastomosis was carried out with cerebral perfusion and a working beating heart (WBH). Ten patients (15%) undergoing aortic arch repair with the NWBH technique required cardioplegic arrest to complete a proximal anastomosis, whereas in all 6 repairs with the WBH technique, the extended anastomoses were completed without myocardial ischemia. One hospital death and late death occurred, with an overall survival of 98%. End-to-end arch reconstruction is feasible without myocardial ischemia, using the NWBH technique in patients without hypoplastic arch and using the WBH technique in patients with hypoplastic arch.

Advantages of temporary venoatrial shunt using centrifugal pump during bidirectional cavopulmonary shunt.

Single-ventricle palliation without the use of cardiopulmonary bypass carries advantages that reduce systemic edema and inflammatory responses; however, simple clamping of the superior vena cava (SVC) without a temporary shunt leads to increase in cerebral venous pressure and subsequent decrease in cerebral blood flow during bidirectional cavopulmonary shunt (BCPS). We report our experience of BCPS, using a centrifugal pump-assisted temporary shunt. The criteria included an unrestrictive interatrial communication, the absence of atrioventricular valve regurgitation, and the existence of an antegrade pulmonary blood flow. From August 2000, 14 children with single-ventricle physiology met the criteria. The mean age was 1.0 +/- 0.9 years, and the mean weight was 8.4 +/- 2.6 kg. A temporary shunt was established between the SVC and the right atrium with right-angle cannulae, which were connected to a centrifugal pump to accelerate the blood flow from the SVC to the right atrium. All patients tolerated the procedure. Mean central venous pressure was 17 +/- 4 mm Hg, and transcutaneous oxygen saturation was maintained at 77 +/- 8% during anastomosis. No patients required blood transfusion. There were no postoperative neurological complications. The centrifugal pump-assisted temporary shunt offered safer and more effective circulatory support than other shunt systems, with excellent venous drainage in pediatric patients undergoing BCPS.

Efficacy of an endothelin-A receptor antagonist in heart transplantation from asphyxiated canine non-heart-beating donors.

OBJECTIVE: Hypoxic perfusion before arrest, an indeterminate period of warm ischemia, and subsequent reperfusion are major causes of cardiac allograft dysfunction in non-heart-beating donors (NHBDs). The present study was undertaken to elucidate the cardioprotective effects of ET(A) receptor antagonist FR139317 for hearts obtained from asphyxiated NHBDs in a canine transplantation model. METHODS: Hypoxic cardiac arrest was induced in 17 donor dogs. FR139317 (10 mg/kg) was given to 7 of the dogs over a period of 10 min before disconnecting the ventilator. The hearts were preserved with FR 139317-supplemented cardioplegic solution (FR group). The remaining 10 did not receive FR 139317 at any time during the experiment (control group). Orthotopic transplantation was performed after a mean myocardial ischemic time of 4h. RESULTS: During the agonal period, the highest systolic pulmonary artery pressure in the FR group was lower than that in the control group (47 +/- 14 vs. 58 +/- 27 mmHg). All animals in the FR group were weaned from cardiopulmonary bypass, whereas only five of the controls were weaned, two of which were identified to have dominant right ventricular failure. After transplantation, recovery rates of the left ventricular end-systolic pressure-volume ratio (E(max)) and the maximum first derivative of pressure measured over time (max dP/dt) were not significantly different between the groups, but recovery rates of the cardiac index, left ventricular minimum dP/dt and exponential time constant of LV relaxation (tau) in the FR group were higher than those in the control group. CONCLUSIONS: The ET(A) receptor antagonist FR 139317 reduced pressure overload on the right ventricle by decreasing the peak pulmonary artery pressure before donor arrest. Cardioprotective effects of this agent for heart transplantation from NHBDs are manifested by preserved diastolic properties of the left ventricle.

Total right ventricular exclusion improves left ventricular function in patients with end-stage congestive right ventricular failure.

BACKGROUND: We developed a total right ventricular (RV) exclusion procedure for the treatment of isolated congestive RV failure. The objective of the present study was to elucidate the effects of a complete removal of RV volume overload (RVVO) on the surgically created single left ventricle (LV). METHODS AND RESULTS: Three adults (2 arrhythmogenic RV dysplasia, 1 Ebstein) and 5 children (all Ebstein) in NYHA class IV underwent the procedure. The RV free wall was resected from the heart, and the tricuspid orifice was closed. Pulmonary blood supply was obtained by a cavopulmonary connection in 6 patients and a systemic-pulmonary shunt in 2. The LV function was evaluated by 2-dimensional echocardiography 1 month after the surgery. All patients are alive. The paradoxical movement of the interventricular septum and geometry of the LV expressed by its eccentricity (2.1 to 1.2, P<0.01) were normalized after the operation in all 8 patients. LV end-diastolic volumes (59% to 109% of normal value, P<0.01), indexed maximal left atrial area (6.5 to 10.5 cm2/m2, P<0.01), LV ejection fraction (27% to 62%, P<0.01), and cardiac index (2.1 to 3.3 L/min/m2, P<0.05) all significantly increased. CONCLUSIONS: Removal of the RVVO by means of the total RV exclusion procedure provides effective volume loading, restores a cylindrical shape, and improves contractile function of the LV, thus leading to increased systemic output.