Bidirectional Cavopulmonary Connections Research Articles

Effects of oral sildenafil after palliative procedures to increase pulmonary blood flow in cyanotic heart diseases

BackgroundContinuing efforts have been exerted to improve the outcome of palliative procedures for cyanotic congenital heart diseases. Sildenafil is known for the management of erectile dysfunction and pulmonary hypertension, but the cardiac benefits of this drug showed its impacts in the hemodynamic profile of cardiac patients.AimTo evaluate the effect of oral sildenafil on man-made shunts and vascular connection of cyanotic heart diseases.Patients and methodsThis comparative study was conducted from 2013 to 2017 on patients who had congenital cyanotic heart disease and who underwent acquired palliative procedure to increase the pulmonary blood flow. Procedures included: modified Blalock and Taussig shunts (MBTS), bidirectional cavopulmonary connections (BDCPC) or Glenn, and Fontan procedures. The pulse oximetry readings were obtained at three different stages and the results were compared with data obtained from similar procedures under the standard management regimen.ResultsTwenty-seven patients were enrolled in the case group (group 1) who received oral sildenafil compared with the control group (group 2) of patients who received the standard management which included 31 patients. The oxygen saturations showed significant difference between group 1 and group 2 in patients who had MBTS and BDCPC, while the difference was not significant in the group of patients who had Fontan procedure.ConclusionSildenafil showed significant improvement in oxygen saturation in patients with complex cyanotic heart disease who have undergone palliative surgery to increase pulmonary blood flow as MBTS and BDCPC in contrast to the patients who get Fontan procedure.

Aortopulmonary Collaterals After Bidirectional Cavopulmonary Connection or Fontan Completion

Background— Aortopulmonary collaterals (APCs) have been associated with increased morbidity after the Fontan operation. We aimed to quantify APC flow after bidirectional cavopulmonary connections and Fontan completions, using phase-contrast MRI, and to identify risk factors for the development of APCs. Methods and Results— APC blood flow was quantifiable in 24 of 36 retrospectively analyzed MRI studies. Sixteen studies were performed after the bidirectional cavopulmonary connections (group A) and 8 after the Fontan operation (group B). APC blood flow was calculated by subtracting the blood flow volume through the pulmonary arteries from that through the pulmonary veins. The ratio of pulmonary to systemic blood flow (Qp/Qs) was 0.93�0.26 in group A and 1.27�0.16 in group B. APC flow was 1.42 (0.58 to 3.83) L/min/m 2 and 0.82 (0.50 to 1.81) L/min/m 2 in groups A and B, respectively. The mean inaccuracies corresponded to 7.9�14.5% and 7.1�13.6% of ascending aortic flow in groups A and B, respectively. Qp/Qs was negatively correlated with a younger age at the time of the bidirectional cavopulmonary connections operation ( r =0.62, P =0.01) and positively correlated with the age at the time of the Fontan completion ( r =0.81, P =0.01). Patients with a previous right-sided modified Blalock-Taussig shunt had more collateral flow to the right lung than those without. Conclusions— APC blood flow can be noninvasively measured in bidirectional cavopulmonary connections and Fontan patients, using MRI in the majority of patients and results in a significant left-to-right shunt.

Heart Transplantation After Fontan's Procedure with Bilateral Cavopulmonary Connections

We present a young female patient with three caval drainages after complete Fontan's procedure and with bilateral bidirectional cavopulmonary connections who underwent orthotopic heart transplantation. Instead of reconstructing the hypoplastic innominate vein the persistent left superior caval vein was reanastomosed via the recipient's coronary sinus into the right atrium.

Invited commentary

Suda and colleagues have produced an intriguing investigation of the relationship of vascular endothelial growth factor (VEGF) in patients with cyanosis and the palliative or reparative operations that these patients receive. The topic is an important one, in that VEGF has been hypothesized to play at least a contributory role in the pathophysiology of pulmonary arteriovenous malformations (PAVM). Because PAVM are known to regress in many, if not all, patients who undergo Fontan procedures, the failure of VEGF levels to normalize after the Fontan may at first be taken to undermine the theory that VEGF is a causative factor in PAVM formation and persistence. Although that may indeed be the case, it would be premature to exclude VEGF as an actor in this process. It is known that PAVM occur in a significant proportion of patients with unidirectional or bidirectional cavopulmonary connections over a sufficient period of time; however PAVM do not occur in all such patients. It is much more likely that it is a combination of hemodynamic and humoral factors that determine the presence of PAVM and their likelihood of dilatation (which may in fact be a greater variable than their presence). Accordingly, it is possible that elevation of serum VEGF is a necessary but not sufficient condition for PAVM that attain a clinical degree of significance. Likewise, it is a fascinating observation that VEGF levels normalize after biventricular repairs. Here, as well, caution should be exercised in interpreting these data. The underlying anatomy is so profoundly different in hearts for which biventricular repair is possible as opposed to those for which Fontan palliation remains the best acceptable option that comparisons of vascular derived growth factors may be of little relevance. Furthermore, the observations are at relatively few points in time, thus opening a very narrow window on a process that evolves over many years. Despite these reservations, Suda and colleagues have explored an important avenue that improves our understanding of a poorly understood clinical problem.

Effectiveness of shielding for patients during cardiac catheterization or electrophysiologic testing

1. Magee AG, McCrindle BW, Mawson J, Benson LN, Williams WG, Freedom RM. Systemic venous collateral development after the bidirectional cavopulmonary anastomosis. Prevalence and predictors. J Am Coll Cardiol 1998;32:502– 508. 2. McElhinney DB, Reddy VM, Hanley FL, Moore P. Systemic venous collateral channels causing desaturation after bidirectional cavopulmonary anastomosis: evaluation and management. J Am Coll Cardiol 1997;30:817–824. 3. Gatzoulis MA, Shinebourne EA, Redington AN, Rigby ML, Ho SY, Shore DF. Increasing cyanosis early after cavopulmonary connection caused by abnormal systemic venous channels. Br Heart J 1995;73:182–186. 4. Filippini LH, Ovaert C, Nykanen DG, Freedom RM. Reopening of persistent left superior caval vein after bidirectional cavopulmonary connections. Heart 1998;79:509–512. 5. Yoshimura N, Yamaguchi M, Oshima Y, Tei T, Ogawa K. Intrahepatic venovenous shunting to an accessory hepatic vein after Fontan type operation. Ann Thorac Surg 1999;67:1494–1496. 6. Fernandez-Martorell P, Sklansky MS, Lucas VW, Kashani IA, Cocalis MW, Jamieson SW, Rothman A. Accessory hepatic vein to pulmonary venous atrium as a cause of cyanosis after the Fontan operation. Am J Cardiol 1996;77:1386– 1387.

Intravascular and intracardiac stents used in congenital heart disease.

Intravascular or intracardiac stenoses occur in many forms of congenital heart disease or after attempted surgical repair. Although balloon dilation is one option for management, restenosis can occur due to elastic recoil immediately after the procedure. To address to such stenotic lesions, many reports support implanting endovascular stents to provide a framework for vessel expansion. Both balloon-expandable fixed tubular mesh stainless steel devices, and self-expandable stents have had an extensive clinical application. In pediatric patients, stents are used for a variety of stenoses, such as systemic venous obstruction pathways (eg, Mustard, Fontan baffle, or bidirectional cavopulmonary connections), pulmonary artery, right ventricular to pulmonary conduits, aortic coarctation, the arterial duct, aorticopulmonary collaterals, or postoperative systemic to pulmonary shunts. Because of improvements in device profile, implantation rates have increased. Complications such as stent fracture, migration, aneurysm formation, and in-stent restenosis occur but only rarely. This latter event may be because of intimal hyperplasia and/or continued vessel (and patient) growth related to the stent diameter. As such, some instances require redilation to manage the acquired lesion. Stent application has importantly altered management algorithms in congenital heart disease.

'You didn't see them, but now you do!': use of balloon occlusion angiography in the identification of systemic venous anomalies before and after cavopulmonary procedures.

We describe the importance of angiographic identification of collateral venous channels by balloon occlusion venography after bidirectional cavopulmonary connections. Use of the balloon occlusion technique is essential for identification of these vessels, as they can easily be missed by standard venous angiography, with possible clinical consequences for postoperative management.