Total Cavopulmonary Circulation Research Articles

2 Suitability of univentricular patients for cardiac resynchronisation therapy

Introduction In 2014 the Paediatric And Congenital Electrophysiology Society (PACES) and Heart Rhythm Society (HRS) published expert consensus statement regarding arrhythmia management in congenital heart disease, including Cardiac Resynchronisation Therapy (CRT) indications for adult congenital heart disease (ACHD) patients. These guidelines recommend CRT in univentricular hearts for those who have an impaired ventricle (EF ≤35%) with QRSd ≥150 ms, ventricular dilatation and NYHA II-IV[IIa, C]. Methods Retrospective analysis for EF, QRSd and NYHA status, from 211 patients with a Fontan circulation under specialist ACHD follow-up. Results Univentricular functional data was available for 94% (198, 84 CMR and 114 echo). 10 (5%) patients had EF ≤35%. QRSd was available for 91% (193). 5 (3%) had QRSd≥150 ms. 2 patients were identified with both EF ≤35% and QRSd ≥150 ms, fulfilling indications for CRT. One patient was NYHA IV, tricuspid atresia with an atriopulmonary fontan and subsequent conversion to total cavopulmonary circulation (TCPC). The second patient (NYHA II) had right atrial isomerism with pulmonary atresia and an unfenestrated TCPC. Conclusions If recent HRS CRT guidelines are applied to this large adult Fontan population there are very few candidates for CRT. Guidelines should be interpreted with caution. In virtually all cases, CRT device implantation in the adult Fontan will require a cardiac surgical approach associated with significant morbidity and mortality. The decision to implant CRT in Fontan patients is therefore complex and requires discussion in a combined ACHD electrophysiology MDT with careful consideration of patient anatomy and previous surgery

Pulmonary vasodilator therapy in the failing Fontan circulation: rationale and efficacy.

The Fontan operation is the final step of palliation for patients with a functionally single ventricle. Since its introduction in the 1970s, the Fontan surgery has become part of a successful surgical strategy that has improved single ventricle mortality. In recent years, we have become more aware of the limitations and long-term consequences of the Fontan physiology. Pulmonary vascular resistance plays an important role in total cavopulmonary circulation, and has been identified as a potential therapeutic target to mitigate Fontan sequelae. In this review, we will discuss the results of different pulmonary vasodilator trials and the use of pulmonary vasodilators as a treatment strategy for Fontan patients.

Experimental Measurements of Energy Augmentation for Mechanical Circulatory Assistance in a Patient-Specific Fontan Model

A mechanical blood pump specifically designed to increase pressure in the great veins would improve hemodynamic stability in adolescent and adult Fontan patients having dysfunctional cavopulmonary circulation. This study investigates the impact of axial-flow blood pumps on pressure, flow rate, and energy augmentation in the total cavopulmonary circulation (TCPC) using a patient-specific Fontan model. The experiments were conducted for three mechanical support configurations, which included an axial-flow impeller alone in the inferior vena cava (IVC) and an impeller with one of two different protective stent designs. All of the pump configurations led to an increase in pressure generation and flow in the Fontan circuit. The increase in IVC flow was found to augment pulmonary arterial flow, having only a small impact on the pressure and flow in the superior vena cava (SVC). Retrograde flow was neither observed nor measured from the TCPC junction into the SVC. All of the pump configurations enhanced the rate of power gain of the cavopulmonary circulation by adding energy and rotational force to the fluid flow. We measured an enhancement of forward flow into the TCPC junction, reduction in IVC pressure, and only minimally increased pulmonary arterial pressure under conditions of pump support.

Unilateral left lung agenesis with crossed-ectopic right lower lobe combined tricuspid atresia diagnosed by ECG gated computed tomography

Young in-fants with this condition may face a catastrophic clinicalcourse. We report an unusual case of lung agenesis withcomplexcardiacanomaliesand crossedectopiclungcompli-cating diagnosis in a 6-month-old child.CLINICAL SUMMARYAboywasbornuneventfullytoahealthymotheratagesta-tionalageof37weeks.Lowbirthweight(1700g)andmultiplecongenital anomalies were found at birth, including large an-terior fontanel and syndactyly over the second and third toes.Because tachypnea and heart murmur were heard 3 days afterbirth, serial workup was arranged. Chest radiography showedleft lung haziness (Figure 1), and echocardiography showedtricuspid atresia, small ventricular septal defect, atrial septaldefect, large patent ductus arteriosus, and suspected left pul-monary artery and pulmonary vein agenesis (Figure 2, A andB). Because ofthe suspected left lung agenesis, electrocardio-graphically gated chest computed tomography and 3-dimen-sional reconstruction were performed (Figure 2, C and D,andVideo1).Crossedectopicrightlowerlobeinthelefthemi-thoraxwasfoundincidentally,inadditiontoleftlungagenesisandtricuspidatresia.Thearteriesandveinssupplyingnotonlythislobebut alsothe bronchusofthislobewerefromthe rightlung.Thepatient’srespiratorydistressandheartfailuresymp-toms improved after anticongestive medication, and he wasthen discharged at 2 weeks old.When the boy was 5 months old, mean pulmonary arterypressure was measured as 10 mm Hg by cardiac catheteriza-tion. We then performed a staged operation including bidi-rectional Glenn shunt, atrial septal defect enlargement, andpatent ductus arteriosus ligation for his tricuspid atresia.The postoperative course was uneventful, and the patientwas discharged 10 days after the operation and followedup at our cardiology clinics. Total cavopulmonary circula-tion will be arranged in the future.DISCUSSIONLung agenesis is a rare congenital anomaly that may beassociated with multiple congenital anomalies.

Connection of Discontinuous Pulmonary Arteries in Patients With a Superior or Total Cavopulmonary Circulation

Connection of Discontinuous Pulmonary Arteries in Patients With a Superior or Total Cavopulmonary Circulation

Connection of Discontinuous Pulmonary Arteries in Patients With a Superior or Total Cavopulmonary Circulation

Discontinuous pulmonary arteries (PAs) may develop in patients with single-ventricle heart disease from a variety of causes. We investigated factors associated with successful connection of nonconfluent PAs in patients with a cavopulmonary circulation. We reviewed 49 patients who underwent connection of discontinuous PAs with or after a bidirectional Glenn (n = 29) or Fontan (n = 20) procedure at a median age of 7.9 years. PA continuity was established by direct anastomosis in 27, interposition graft in 19, and transcatheter recanalization in 3. Survival was 92% +/- 4% at 1 year and 89% +/- 5% at 5 years. Recurrent PA occlusion was documented in 7 patients, 5 within 10 days of PA connection. The only factor associated with shorter freedom from PA occlusion was sole supply of blood flow to 1 lung by systemic-to-PA collaterals before connection (66% +/- 14% vs 95% +/- 4% freedom from occlusion at 6 months, p = 0.03). Among the 45 early survivors, freedom from PA reintervention or occlusion was 83 +/- 6% at 1 year and 55 +/- 9% at 3 years. Discontinuous PAs can be successfully connected in most patients with a cavopulmonary circulation, although nonconfluent PAs appear to increase the risk of poor outcome after Fontan. Recurrent PA occlusion was usually diagnosed in the early postoperative period. In patients with sole supply to 1 lung through collaterals, shunt placement before PA connection may optimize outcome. A low threshold for investigation of the reconnected PA is warranted.

Efficiency differences in computational simulations of the total cavo-pulmonary circulation with and without compliant vessel walls

The Fontan operation is a palliative surgical procedure performed on children born with congenital defects of the heart that have yielded only a single functioning ventricle. The total cavo-pulmonary connection (TCPC) is the most popular variant of the Fontan procedure. The objective of the study was to quantify and compare the efficiency of numerical models of the TCPC with rigid versus elastic vessel wall models. The pressure drop and power loss through both type TCPC models was measured. Significant differences in efficiencies exist between rigid versus elastic numerical models. We have shown incorporating elasticity into numerical models of the total cavo-pulmonary connection is important when determining circuit efficiencies.

The partial cavo-pulmonary circulation with an additional source of pulmonary flow. an alternative to the total cavo-pulmonary circulation in patients with a functionally single ventricle

most paediatric cardiologists think that the optimal treatment for patients with functionally single ventricle is the relatively early construction, at from 2 to 7 years of age, of the total cavo-pulmonary circulation. this approach is based on the desire to produce an acyanotic child, such an outcome fostering the belief that the patient is cured. when using this therapeutic approach, the total connection is usually preceded by earlier creation of a partial connection, achieved by creating a bi-directional anastomosis between the superior caval vein and the right pulmonary artery at the age of from 3 to 9 months, without providing additional flow of blood to the lungs. this leads to severe cyanosis by the age of 3 years, when the flow increases in the inferior caval vein, and is the signal for early completion of the total connection. in this policy, the absence of additional flow to the lungs is justified by the fear of altering the ventricular function essential for the success of the total connection, because of the volume, and eventually the pressure, overload of the additional flow on the functionally single ventricle,which may impair its compliance and/or contractility, or be responsible for atrioventricular valvar regurgitation. these alterations in myocardial functions would then contraindicate, or increase, the mortality and morbidity of the total connection, producing deterioration in its long-term results.

Multiple small fenestrations created during construction of the total cavopulmonary circulation: Subsequent course and spontaneous closure

R E F E R E N C E S 1. Shahian DM, Labib SB, Chang G. Cardiac papillary fibroelastoma. Ann Thorac Surg 1995;59:538-41. 2. McAllister H, Fenoglio J Jr. Tumors of the cardiovascular system. Atlas of tumor pathology, 2rid series, Washington, DC: Armed Forces Institute of Pathology, 1978;15:20-5. 3. Edwards FH, Hale D, Cohen A, Thompson L, Pezzella T, Virmani R. Primary cardiac valve tumors. Ann Thorac Surg 1991;52:1127-31. 4. Wolfe JT III, Finck S J, Safford RE, Persellin ST. Tricuspid valve papillary fibroelastoma: echocardiographic characterization. Ann Thorac Surg 1991;51:116-8. 5. Frumin H, O'Donnell L, Kerin NZ, Levine F, Nathan LE Jr, Klein SP, Two-dimensional echocardiographic detection and diagnostic features of tricuspid papillary fibroelastoma. J Am Coll Cardiol 1983;2:1016-8. 6. Anderson KR, Fiddler FI, Lie JR. Congenital papillary tumor of the tricuspid valve: an unusual cause of right ventricular outflow obstruction in a neonate with trisomy E. Mayo Clin Proc 1977;52:665-9. 7. Neerukonda SK, Jantz RD, Vijay NK, Narrod JA, Schoonmaker FW. Pulmonary embolization of papillary fibroelastoma arising from the tricuspid valve. Tex Heart Inst J 1991;18:132-5. 8. Mohan JC, Goel PK, Gambhir DS, Khanna SK, Arora R. Calcified mobile papillary fibroelastoma of the tricuspid valve: a case report. Indian Heart J 1987;39:237-9.