Cardiac MRI for Fontan candidates after intrapulmonary-artery septation

Intrapulmonary-artery septoplasty may be effective for establishing two-lung Fontan circulation in patients with unilateral pulmonary circulation. However, evaluation of the function of each lung by conventional modalities can be challenging in these patients due to differing sources of blood flow to the left and right lungs following intrapulmonary-artery septation. Herein, we report a case in which two-lung Fontan circulation was successfully achieved after using cardiac MRI along with conventional modalities to evaluate pulmonary circulation.

Management of failing bidirectional cavopulmonary shunt: Influence of additional systemic-to-pulmonary-artery shunt with classic Glenn physiology

Objectives

Methods

Results

Conclusions

Role of intrapulmonary artery septation in univentricular hearts

The optimal management of functionally univentricular hearts with a significant unbalanced pulmonary blood flow is unclear. The role of cavopulmonary shunt in the rehabilitation of hypoplastic pulmonary arteries is limited. Intrapulmonary artery septation is a technique, wherein a systemic-to-pulmonary artery shunt provides an additional source of blood flow to rehabilitate the hypoplastic pulmonary artery. We report a case of functionally univentricular heart with hypoplastic left pulmonary artery following a cavopulmonary shunt in whom intrapulmonary artery septation resulted in adequate growth of the left pulmonary artery.

Intrapulmonary artery septation for pulmonary artery growth in functionally univentricular hearts

The pulmonary artery anatomy is one of the important determinants of Fontan completion and its outcomes in patients with functionally univentricular hearts. Despite several modifications to Fontan operation, unbalanced pulmonary arteries pose a significant challenge in this subset of patients. Intrapulmonary artery septation is a technique, developed to rehabilitate the unilateral hypoplastic pulmonary artery following various initial palliative procedures in functionally univentricular hearts. Literature is sparse on this technique. This article reviews the basic concepts and literature on intrapulmonary artery septation. We also describe our experience with modified intrapulmonary artery septation.

Primary pulmonary artery reconstruction for functional single ventricle with absent central pulmonary artery and bilateral patent ductus arteriosus

OBJECTIVE

This study aimed to evaluate and discuss the outcomes of creating a single systemic-pulmonary shunt and reconstruction of the pulmonary artery continuity in patients with a single functional ventricle, absent central pulmonary artery, and bilateral patent ductus arteriosus.

METHODS

Six infants diagnosed with a functional single ventricle, absent central pulmonary artery, and bilateral patent ductus arteriosus were treated by creating a single systemic-pulmonary shunt and reconstructing the pulmonary artery continuity (primary operation) between January 2010 and September 2020. Pulmonary artery continuity was ensured using the remnant pulmonary artery and an autologous pericardial patch in five patients and a rolled autologous pericardium in one patient.

RESULTS

All patients eventually underwent total cavopulmonary connection. Two patients underwent intrapulmonary artery septation before Glenn or total cavopulmonary connection procedure. The median follow-up period was 9.02 years (interquartile range, 3.90-9.53). No late deaths were observed.

CONCLUSIONS

Our strategy of establishing a single systemic-pulmonary shunt with reconstruction of the pulmonary artery continuity was useful for treating patients with a functional single ventricle with absent central pulmonary artery and bilateral patent ductus arteriosus. This procedure helped accomplish pulmonary artery growth and ensured an appropriate volume load after total cavopulmonary connection.

Augmentation of Pulmonary Arterial Growth in Single Ventricle Patients by Interim Selective Shunts

Stenosis or diffuse hypoplasia of central pulmonary arteries (PA) is common in patients with single ventricle physiology, often requiring surgical patching. Such repairs are prone to failure, particularly with low pressure venous flow (bidirectional cavopulmonary connection or Fontan). We describe our experience of disconnection of central PA and selective systemic-PA shunt to the hypoplastic vessel. Single ventricle patients (n = 12) with diffuse left pulmonary artery (LPA) hypoplasia (LPA:right pulmonary artery diameter <0.7) underwent PA disconnection (ligation clip) and selective arterial shunt to the LPA. Patients with ≤mild atrioventricular valve regurgitation, and no more than mild systolic dysfunction on echocardiogram were considered. Following systemic-LPA shunt, patients were reassessed by cardiac catheterization prior to further surgery, with follow-up catheterization later performed and description of changes observed. Increased volume loading was well tolerated with no greater than mild atrioventricular valve regurgitation and preserved systolic function (normal or mildly reduced). Selective arterial shunting increased the caliber of the LPA from 4.1 mm (1.2-5.6) to 6.5 mm (1.7-11.9) and this increase was preserved post-Fontan (6.7 mm [1.3-8.0]) (median [range]). Ventricular end diastolic pressure increased with arterial shunting but resolved after shunt takedown and Fontan completion (median +3 and -4 mm Hg respectively). Post-Fontan hospital length of stay was not prolonged (median 11 days, range 7-14). No deaths occurred. In univentricular hearts and PA hypoplasia, selective systemic-PA shunting physiologically increases the caliber of the distal vessels. In selected patients this can be done safely with maintenance of PA growth and resolution of the elevated end diastolic pressure with Fontan completion.

Impact of intrapulmonary-artery septation to pulmonary vein obstruction for two-lung Fontan

OBJECTIVES

Patients with unbalanced pulmonary artery (PA) growth and decreased unilateral pulmonary circulation are considered unsuitable candidates for the Fontan procedure. Following our previous study on the utility of intrapulmonary-artery septation for patients with PA hypoplasia, we investigated its use in patients with pulmonary venous obstruction (PVO).

METHODS

We recruited 42 patients who underwent intrapulmonary-artery septation for unilateral PA hypoplasia and/or PVO between 1998 and 2018 and classified them into no PVO or PVO group. We analysed overall survival, success of the Fontan procedure and data from catheterization and echocardiography. In PVO, we evaluated the functional lung area before the Fontan procedure and the relevance of this parameter to operative outcomes.

RESULTS

The PVO and no-PVO group included 24 and 18 patients, respectively. One patient in the no-PVO and 6 patients in the PVO group died during follow-up; this difference was statistically significant (log-rank P = 0.040). In the no-PVO group, 15 (83%) patients achieved two-lung Fontan circulation. In the PVO group, 12 (50%) patients achieved two-lung Fontan circulation. Multivariate analysis revealed that functional lung area and shunt size [significantly larger in patients with functional lung area ≥50% in affected lung (P = 0.040)] were significant factors for successful two-lung Fontan procedure (P = 0.030).

CONCLUSIONS

Intrapulmonary-artery septation may contribute to increase functional lung area after PVO release to establish two-lung Fontan circulation in patients with PVO who have unbalanced PA growth and/or decreased unilateral pulmonary circulation.

Rapid growth of pulmonary artery after intrapulmonary artery septation

Intrapulmonary artery septation is employed in patients with unbalanced pulmonary artery growth. A baby girl received a systemic pulmonary shunt in the neonatal period and bilateral Glenn shunts in early infancy. Once the Glenn shunts were established, the right pulmonary artery became hypoplastic. We performed intrapulmonary artery septation involving the Glenn shunts to the left pulmonary artery and the systemic pulmonary shunt to the right pulmonary artery. As early as 3 months after intrapulmonary artery septation, right pulmonary artery growth was observed. Eventually, Fontan circulation was achieved with fenestration.

Modification of hemi-Fontan operation for patients with functional single ventricle and anomalous pulmonary venous connection to the superior vena cava: mid-term results

OBJECTIVES

Fontan candidates with mixed totally anomalous pulmonary venous connection often have postoperative pulmonary venous obstruction after cavopulmonary anastomosis. Because some pulmonary venous obstructions have no intimal hypertrophy at reoperation, we considered such pulmonary venous obstructions to be caused by 3D deformities arising from dissection or mobilization of the vessels, and hypothesized that keeping the pulmonary venous branches in a natural position could avoid such obstruction. Here, we evaluated a modified hemi-Fontan strategy consisting of minimal dissection with no division of vessels and patch separation between systemic and pulmonary venous flow.

METHODS

We retrospectively reviewed clinical records of infants with a functional single ventricle and supracardiac anomalous pulmonary venous connection who had undergone this procedure between 2002 and 2012.

RESULTS

Nine infants underwent this procedure (median age, 5.6 months; range 3.2-30), all with right atrial isomerism and several pulmonary venous branches directly and separately connecting to the superior vena cava. In 5 patients, all pulmonary veins drained into the superior vena cava; in 1, the right pulmonary veins drained into the superior vena cava and in 3, a pulmonary venous branch drained into the superior vena cava. The median follow-up was 6.9 years (0.8-13 years). Three patients underwent reoperation for postoperative pulmonary venous obstruction caused by intimal hypertrophy; however, we confirmed no pulmonary venous obstruction caused by 3D deformities on the pulmonary venous branches connecting separately to the superior vena cava. Although 2 patients were effectively relieved from pulmonary venous obstruction, 1 died due to recurrent pulmonary venous obstruction. There was no late death and no sinus-node dysfunction. Eight patients underwent successful Fontan operation and catheterization. The median interval from the Fontan operation to the latest catheterization was 3.7 years (0.9-3.7 years). The median arterial oxygen saturation was 94% (91-97%) and the central venous pressure was 12 mmHg (8-14 mmHg); no deficiency of pulmonary arteries and veins was noted.

CONCLUSIONS

For patients with functional single ventricle and anomalous pulmonary venous connections to the superior vena cava, our novel strategy of second-stage palliation could avoid postoperative pulmonary venous obstruction caused by 3D deformities, but may not eliminate pulmonary venous obstruction caused by intimal hypertrophy.