Is Continuous Flow Superior to Pulsatile Flow in Single Ventricle Mechanical Support? Results from a Large Animal Pilot Study.
ASAIO journal (American Society for Artificial Internal Organs : 1992)
Fujii, Y., Ferro, G., Kagawa, H., Centola, L., Zhu, L., Ferrier, W. T., Talken, L., Riemer, R. K., Maeda, K., Nasirov, T., Hodges, B., Amirriazi, S., Lee, E., Sheff, D., May, J., May, R., Reinhartz, O.
; 61 (4): 443–47
Abstract
Durable mechanical support in situations of physiologic single ventricle has been met with little success so far, particularly in small children. We created an animal model to investigate whether pulsatile or continuous flow would be superior. Three 1 month old sheep (10-16 kg) were instrumented. Via sternotomy and with cardiopulmonary bypass, a large ventricular septal defect and atrial septal defect were created. The left ventricle was cannulated using a Berlin Heart inflow cannula. This was connected sequentially to a continuous flow device (Thoratec HeartMate X, Pleasanton, CA) and to a pulsatile device (Berlin Heart Excor, The Woodlands, TX). Outflow was via a Y-graft to both aorta and pulmonary artery, striving for equal flow to both. Atrial filling pressures were controlled with volume infusions over a wide range. Under comparable loading conditions, significantly higher maximum flow was obtained by HeartMate X than by Excor (4.95 ± 1.27 L/min [range, 3.84-6.34 L/min] for HeartMate X vs. 1.80 ± 0.85 L/min [range, 1.01-2.7 L/min] for Excor; p < 0.05). Judging from this limited animal study, in single ventricle scenarios, continuous flow devices may achieve higher pump flows than pulsatile devices when provided with similar filling pressures. Their clinical use should be investigated. More extensive experimental studies are needed.
View details for PubMedID 25794246
Abstract
BACKGROUND: Several modifications of the Norwood procedure utilizing valved right ventricle to pulmonary artery conduits have recently been reported. Our group has been using aortic or pulmonary valved homografts combined with PTFE tube grafts for now 16 years.METHODS: In this report, we review our technique in detail and describe any changes that have occurred over the years. We provide detailed illustrations of our preferred surgical technique, report outcome data, and compare it to the other conduit options available.RESULTS: Between 2006 and 2015, 130 stage I Norwood procedures were performed at our institution, 100 of them using valved conduits. Our technique is described and illustrated in detail. Early mortality was 15%. Postoperative percutaneous intervention on the conduit was required in 29% of cases.CONCLUSIONS: While a randomized trial comparing different valved conduits is lacking, we believe a composite conduit made from homograft aortic or pulmonary valves and PTFE tube grafts is an excellent choice in stage I Norwood procedure.
View details for DOI 10.1177/2150135119842865
View details for PubMedID 31307304
Abstract
OBJECTIVE: Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries is a complex form of congenital heart disease. Midline unifocalization has been developed for the surgical treatment of this condition. There are 3 outcome measures that determine long-term success: patients are alive, patients have achieved complete repair (i.e. ventricular septal defect closure), and patients have a relatively low right ventricle-to-aortic pressure ratio (<0.45). However, to date, no studies have combined these 3 outcome measures to analyze the likelihood of achieving an ideal outcome.METHODS: This was a retrospective review of 255 patients who underwent midline unifocalization for pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. The median age at unifocalization was 4.5 months.RESULTS: Two hundred thirty-five (92%) patients were alive at a mean follow-up of 5.3 years. Two hundred and seventeen (85%) patients underwent single-stage complete repair, and 38 (15%) had an initial unifocalization and shunt. Twenty-four of the 38 palliated patients have subsequently undergone repair. Thus 241 (94%) patients ultimately achieved complete repair. Of the 241 patients who were repaired, 219 (86%) had a right ventricle-to-aortic peak systolic pressure ratio <0.45. Combining these outcome measures, 77% of patients achieved an ideal outcome at one month, 73% at 6 months, 76% at one year, and 80% at 4 years.CONCLUSIONS: Most (80%) patients can achieve all 3 measures of favorable outcome at 4 years following midline unifocalization. We speculate that this will be a favorable portend for the future of these patients.
View details for DOI 10.1177/0218492318814079
View details for PubMedID 30417684
Abstract
Hypertrophic cardiomyopathy is known to be difficult to support by left ventricular assist device due to the small ventricular cavity and inadequate drainage. Therefore, instead of cannulating on the left ventricular apex, Heartware HVAD ventricular device was connected to the left atrium through right atrium onto atrial septum using ringed Goretex interposition graft. The patient has been discharged home after VAD implant and underwent successful heart transplant after 111 days of support without any complications including any thromboembolic events. This new trans-atrial left atrial cannulation technique can be an alternative approach for VAD cannulation in hypertrophic cardiomyopathy. It can be safely performed with the Heartware HVAD.
View details for PubMedID 29807009
Abstract
We describe an extremely rare case of partial anomalous pulmonary venous return in a 3-year-old boy with an abnormal connection between the right upper pulmonary vein and the right middle pulmonary vein, which created biatrial communication hemodynamically. Patch closure on the orifice of the right upper pulmonary vein was performed to avoid distortion or kinking of the right pulmonary veins and the connection.
View details for DOI 10.1177/0218492317704526
View details for PubMedID 28361581
Abstract
Durable mechanical support in situations of physiologic single ventricle has been met with little success so far, particularly in small children. We created an animal model to investigate whether pulsatile or continuous flow would be superior. Three 1 month old sheep (10-16 kg) were instrumented. Via sternotomy and with cardiopulmonary bypass, a large ventricular septal defect and atrial septal defect were created. The left ventricle was cannulated using a Berlin Heart inflow cannula. This was connected sequentially to a continuous flow device (Thoratec HeartMate X, Pleasanton, CA) and to a pulsatile device (Berlin Heart Excor, The Woodlands, TX). Outflow was via a Y-graft to both aorta and pulmonary artery, striving for equal flow to both. Atrial filling pressures were controlled with volume infusions over a wide range. Under comparable loading conditions, significantly higher maximum flow was obtained by HeartMate X than by Excor (4.95 ± 1.27 L/min [range, 3.84-6.34 L/min] for HeartMate X vs. 1.80 ± 0.85 L/min [range, 1.01-2.7 L/min] for Excor; p < 0.05). Judging from this limited animal study, in single ventricle scenarios, continuous flow devices may achieve higher pump flows than pulsatile devices when provided with similar filling pressures. Their clinical use should be investigated. More extensive experimental studies are needed.
View details for DOI 10.1097/MAT.0000000000000220
View details for Web of Science ID 000358285100013
Abstract
Telemetric physiological monitoring systems (TPMS) have enabled accurate continuous measurement of animal blood pressures and flows. However, few studies describe approaches for use of TPMS in the great vessels or inside the heart. We describe our initial experiences using two types of TPMSs. Twelve lambs (20-37 kg) underwent sternotomy. Two lambs were not instrumented and were killed at 14 days to confirm normal sternal wound healing (sham group, n = 2). Ten lambs underwent placement of either standard indwelling pressure-monitoring catheter and perivascular-flow-probe (CFP group, n = 3) or TPMS implantation (TPMS group, n = 7). The TPMS used were EG1-V3S2T-M2 (EG1, n = 5; Transonic Endogear Inc.) and Physio Tel Digital L21 (PTD, n = 2; Data Sciences Inc.). Two deaths because of respiratory problems occurred in TPMS group, attributed to lung compression by the implanted device. In TPMS group, more consistent trends of blood pressures and flows were recorded, and management of animals was easier and less labor-intensive. Comparing the two TPMSs, the initiation and renewal costs for each case was $28 K vs. $20 K and $1,700 vs. $0, (PTD versus EG1, respectively). In conclusion, TPMS implantation was feasible via median sternotomy in lambs. Telemetric physiological monitoring systems significantly improve reliability of hemodynamic monitoring in chronic survival animal study. EG1 was less costly than PTD.
View details for DOI 10.1097/MAT.0000000000000202
View details for Web of Science ID 000353811800018
View details for PubMedID 25635937
Abstract
Innominate artery cannulation has been widely adopted as a means to perform aortic arch reconstruction with continuous cerebral perfusion in the newborn. Although this technique has been subsequently utilized in infants and children, there is currently no data regarding the safety or efficacy in these older children. The purpose of this study was to review our experience with innominate artery cannulation for aortic arch reconstruction in patients beyond the neonatal period.This was a retrospective review of 42 infants and children who underwent aortic arch reconstruction using the technique of innominate artery cannulation with continuous cerebral perfusion. Of these procedures, 29 (69%) were primary arch reconstructions, while 13 (31%) were aortic arch reoperations. The median age at surgery was 8 months, and 22 patients underwent concomitant intracardiac repairs.There was no operative mortality in this cohort of 42 patients undergoing aortic arch reconstruction. There was also no overt evidence of neurologic injury. Specifically, none of the patients demonstrated a neurologic deficit, clinical seizure, or unexpected delay in regaining a normal state of consciousness. The median duration of antegrade cerebral perfusion was 34 minutes. The median duration of hospital stay was 11 days. No patient required reoperation on the aortic arch with a median of 45-month follow-up.Innominate artery cannulation is a safe and effective technique for aortic arch reconstruction in nonneonates. We conclude that antegrade cerebral perfusion is a useful technique for aortic arch reconstruction in this patient population.
View details for DOI 10.1177/2150135113497767
View details for PubMedID 24327627
Abstract
Fetal cardiac surgery is a potential innovative treatment for certain congenital heart defects that have significant mortality and morbidity in utero or after birth, but it has been limited by placental dysfunction after fetal cardiac bypass. We have used the TinyPump device for fetal cardiac bypass in sheep fetuses at 90 to 110 days gestation.Ten mixed-breed pregnant ewes were used over a period of 6 months, and 10 fetuses were placed on bypass for 30 minutes. Five fetuses with a mean gestational age of 104 ± 4.5 days and mean weight of 1.4 ± 0.4 kg were placed on bypass using the TinyPump device, and 5 fetuses with a mean gestational age of 119 ± 4.5 days and mean weight of 3.4 ± 0.4 kg were placed on bypass using the roller head pump. The fetuses were monitored for up to 3 hours after bypass or until earlier demise.Progressive respiratory and metabolic acidosis developed in all fetuses. The TinyPump group had a lower gestational age and weight compared with the roller head pump group. However, the rate of postbypass deterioration in the TinyPump group, as measured with blood gases, was noted to be significantly slower compared with the roller head pump group.We demonstrate the feasibility of the TinyPump device for fetal cardiac bypass in a fetal sheep model. The TinyPump group showed improved results compared with the roller head group despite more immature fetuses. The TinyPump device seems to be a promising device for future studies of fetal cardiac bypass in immature fetal sheep and in primates.
View details for DOI 10.1016/j.jtcvs.2012.08.014
View details for PubMedID 22944083
Abstract
Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital heart defect that has been associated with myocardial ischemia and sudden death. Controversies exist regarding the diagnosis, treatment, and long-term recommendations for patients with AAOCA. The purpose of this study is to evaluate the medium-term results of surgical repair for AAOCA.From January 1999 through August 2010, 50 patients underwent surgical repair of AAOCA. The median age at surgery was 14 years (range, 5 days to 47 years). Thirty-one patients had the right coronary originate from the left sinus of Valsalva, 17 had the left coronary originate from the right sinus, and 2 had an eccentric single coronary ostium. Twenty six of the 50 patients had symptoms of myocardial ischemia preoperatively, and 14 patients had associated congenital heart defects. Repair was accomplished by unroofing in 35, reimplantation in 6, and pulmonary artery translocation in 9.There was no operative mortality. The median time of follow-up has been 5.7 years. Two patients were lost to follow-up, and 1 patient required heart transplantation 1 year after AAOCA repair. In the remaining 47 postoperative patients, all have remained free of cardiac symptoms and no one has experienced a sudden death event.The surgical treatment of AAOCA is safe and appears to be highly effective in eliminating ischemic symptoms. These medium-term results are encouraging and suggest that many patients may be able to resume normal activities.
View details for DOI 10.1016/j.athoracsur.2011.03.127
View details for Web of Science ID 000293221000050
View details for PubMedID 21718962
