Novel surgical approach 'intrapulmonary-artery septation' for Fontan candidates with unilateral pulmonary arterial hypoplasia or pulmonary venous obstruction

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.

Impact of Transcatheter Pulmonary Artery Intervention Following Superior Cavopulmonary Connection on Pulmonary Artery Growth

INTRODUCTION

Balloon and stent angioplasty of the pulmonary arteries (PAs) are frequently performed following superior cavopulmonary connection (SCPC), not only to normalize the caliber of the affected PA but also in hopes of maximizing downstream growth over time. There are limited data on the impact on subsequent PA growth prior to total cavopulmonary connection (TCPC).

METHODS

A single-center, retrospective cohort study was performed on children who underwent transcatheter (TC) PA intervention following SCPC between January 1, 2010, and December 31, 2018. Growth of treated and contralateral PAs was measured at the lobar bifurcation (distal branch PA [DBPA]) and in the proximal lower lobe (lower lobe branch [LLB]) on serial angiograms. Growth rate was evaluated using a mixed-effect model clustered by individual patient with an interaction term for treated PA and time to evaluate for differential growth rates between treated and contralateral PAs.

RESULTS

Thirty-five patients underwent TC PA intervention following SCPC, at a median of 70 days (interquartile range: 19-297 days) postoperatively. Significant growth was seen at both DBPA and LLB for raw (0.8 mm/year, 95% CI: 0.6-1.0, P < .001 for both) and body surface area (BSA) adjusted measures (8.4mm/m²/year, 95% CI: 5.6-11.2, P < .001; 7.9 mm/m²/year, 95% CI: 5.5-10.2, P < .001). The growth rate of the treated vessel was not significantly different from that of the contralateral vessel at the DBPA or LLB positions for raw (P = .71, .70) or BSA-adjusted measurements (P = .86, .64).

CONCLUSION

Transcatheter PA intervention was associated with normal distal PA growth rate relative to the untreated side.

Intrapulmonary artery septation for unilateral absence of the pulmonary artery

We describe a seven-month-old boy with tetralogy of Fallot and an absent left pulmonary artery. Due to the diminutive size of the left pulmonary artery, we performed a native tissue left pulmonary artery reconstruction and intrapulmonary artery septation procedure with a left modified Blalock-Taussig shunt. After confirming left pulmonary artery growth, the patient underwent tetralogy of Fallot repair, removal of septation patch, and division of the Blalock-Taussig shunt. Nine months post-surgery, we confirmed his balanced lung perfusion (R/L ratio 6:4). The intrapulmonary artery septation procedure would be suitable for both the resuscitation and reconstruction of the hypoplastic absent pulmonary artery.

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.

Palliative Operations for Cyanotic Congenital Heart Disease with Severely Asymmetrical Pulmonary Arteries

BACKGROUND

Surgically managing patients with complex congenital heart disease and severely asymmetrical pulmonary arteries is challenging. Here, we report our experience using combined palliative procedures.

METHOD

The medical records of 28 patients with complex congenital heart disease and severely asymmetrical pulmonary arteries who underwent combined palliative procedures between January 2004 and April 2013 were retrospectively reviewed until January 2018. The patients were divided into three groups according to shunt procedure timing: in group A (n = 15), cavopulmonary and systemic-pulmonary shunting were performed simultaneously; in group B (n = 11), systemic-pulmonary shunting was performed first; and in group C (n = 2), cavopulmonary shunt was performed first. Patients were followed for a mean ± standard deviation of 4.18 ± 2.22 years.

RESULTS

No operative deaths occurred. There were no postoperative complications in groups B or C, but there was one case of pulmonary effusion and one of chylothorax in group A. The superior vena cava pressures were higher in patients in groups A and B than in those in group C. The ventilatory support duration and intensive care unit stays were longer in group A than in groups B and C (p < 0.01). Hypoplastic pulmonary artery development significantly improved after the use of three systemic-pulmonary shunts (p < 0.05), while the peripheral oxygen saturation increased from 67%±17% preoperatively to 85%±8% postoperatively (p < 0.001). Haemoglobin concentration decreased from 190 ± 34 g/L preoperatively to 136 ± 26 g/L postoperatively (p < 0.001). Two patients underwent double ventricle correction. Two patients underwent Fontan procedure. One patient underwent one and a half ventricle correction. One patient underwent collateral occlusion.

CONCLUSIONS

Combined palliative procedures can achieve acceptable arterial oxygen saturation without extra volume loading and rescue the hypoplastic pulmonary artery.

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.

A Surgical Integration Technique for Right-Sided and Left-Sided Superior Venae Cavae

The treatment of some subsets of patients having both right-sided superior vena cava (SVC) and left-sided SVC may be very challenging. We performed the SVC integration (SVCI) technique with end-to-side anastomoses between the two SVCs on 4 such patients (age, 5 to 11 months; body weight, 5.4 to 10.2 kg) with excellent outcomes. In 2 patients, we performed intrapulmonary artery septation with SVCI; in 1 patient, pulmonary artery sling repair with SVCI; and in 1 patient with supramitral stenosis related to persistent left-sided SVC, repeated Blalock-Taussig shunt (BTS) with SVCI. Our SVCI technique is very useful in specific cases (eg, in candidates for the Fontan procedure.

Extra-aortic commissuroplasty concomitant with fenestrated Fontan operation for neoaortic valve regurgitation after Norwood reconstruction

We introduce a simple, less invasive surgical technique for treating neoaortic valve regurgitation (neoAR) after the Norwood procedure, with the aim of delaying reoperation for neoAR. A 31-month-old girl, with hypoplastic left heart syndrome, previously underwent 4 median sternotomies and was admitted to our hospital for a fenestrated Fontan operation. She presented with moderate neoAR, originating from a tricuspid neoaortic valve (neoAV), with the regurgitation oriented from the centre. Her neoAV annulus was dilated to twice its normal size. With the aim of delaying future neoAV intervention and minimizing the surgical invasiveness, we performed extra-aortic commissuroplasties on the 2 commissures that could be approached from the front during the Fontan operation, without inducing cardiac arrest. We used direct echocardiography and transoesophageal echocardiography to confirm the feasibility before applying this procedure. Her postoperative course was uneventful, and the postoperative echocardiography did not reveal any residual neoAR 5 months postoperatively. We believe that this technique is a useful surgical option for patients with moderate neoAR oriented from its centre and well-balanced tricuspid native pulmonary valves, and it might help to delay future neoAV interventions, with minimal surgical risk.

Fontan completion after external stenting of the left bronchus and intrapulmonary artery septation for left pulmonary artery hypoplasia

Tracheobronchial obstruction and unilateral hypoplasia of the pulmonary artery are serious barriers to successful Fontan completion. We describe a 5-year old girl with left bronchial obstruction, hypoplasia of the left pulmonary artery and a single ventricle (double inlet left ventricle). She had undergone external stenting to treat left bronchial stenosis at 3 years of age, bidirectional cavopulmonary anastomosis and Damus-Kaye-Stansel anastomosis at 4 years of age, intrapulmonary artery septation 1 year later and, finally, completion of the Fontan operation with excellent postoperative haemodynamics.

Connection of discontinuous pulmonary arteries in patients with a superior or total cavopulmonary circulation

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.