Pulmonary Artery Z-scores Research Articles

Pulmonary artery growth after arterial duct stenting in completely duct-dependent pulmonary circulation

ObjectiveSignificant and balanced pulmonary artery (PA) growth following arterial duct (AD) stenting has already been reported in literature. However, no data are so far available about the role of this...

Fate of Hypoplastic Pulmonary Arteries After Arterial Duct Stenting in Congenital Heart Disease With Duct-Dependent Pulmonary Circulation.

This study sought to evaluate the impact of arterial duct (AD) stenting in promoting catch-up growth of hypoplastic pulmonary artery (PA) tree in congenital heart disease with duct-dependent pulmonary circulation (CHD-DPC). Significant and balanced PA growth following AD stenting has already been consistently reported in the literature. However, no data are so far available about the role of this approach in severe PA hypoplasia, which significantly impacts the risk of surgical repair. Pre-surgical angiographic PA evaluation was performed in 45 patients with confluent PAs submitted to neonatal AD stenting as palliation of CHD-DPC. PA growth was evaluated as Nakata Index and McGoon ratio as well as individual PA z-score changes, both in the whole population and according to the original vessel size (Nakata Index <100mm(2)/m(2), Group I [n= 15] vs. Nakata Index >100 mm(2)/m(2), Group II [n= 30]). Control angiography was performed 7.5 ± 6.5 months (median 6 months) after duct stenting, showing significant and balanced PA growth. The Nakata Index increased from 143 ± 73 mm(2)/m(2) to 270 ± 88 mm(2)/m(2) (124 ± 118%, p< 0.0001); left PA z-score from-0.7 ± 1.7 to 1.0 ± 1.4; right PA z-score from-0.6 ± 1.3 to 1.2 ± 1.3 (p< 0.0001 for both comparisons). Group I showed a greater increase of global PA growth (Nakata Index increase 227 ± 141% vs. 72±57%, p< 0.001) as compared with Group II. Final PA size did not significantly differ between the groups (246±105mm(2)/m(2) vs. 282 ± 78 mm(2)/m(2), p= NS). Percutaneous AD stenting is highly effective in promoting a significant and balanced catch-up growth of diminutive PAs, being therefore advisable in this subset of patients as a reliable alternative to surgical palliation.

Factors affecting perioperative mortality in tetralogy of Fallot.

We evaluated the preoperative, operative and postoperative risk factors affecting early mortality in patients who underwent total correction of tetralogy of Fallot (TOF). One hundred and twenty-two TOF patients who underwent reparative surgery between January 2010 and November 2013 were enrolled in the study. Mean patient age and weight was 2.3 ± 2.5 years and 11.3 ± 6.4 kg, respectively. Cardiac catheterization was performed in 101 patients (83%),and coronary anomalies were found in 11 patients. Mean McGoon index, pulmonary annulus z-score, main pulmonary artery z-score, left pulmonary artery z-score and right pulmonary artery z-score were 2.0 ± 0.4, -1.85 ± 1.54, -2.84 ± 2.06, 1.17 ± 1.73, and 0.74 ± 1.57, respectively. Total reparative surgery with a transannular patch was performed in 97 patients (79.6%); the rest underwent valve-sparing surgery. Median duration of postoperative mechanical ventilation, intensive care and hospital stay were 19 h, 3 days and 9 days, respectively. Extracorporeal membrane oxygenation (ECMO) was required in 10 patients in the postoperative early period. Arrhythmias occurring in the early postoperative period were junctional ectopic tachycardia (n = 13), complete atrioventricular block(n = 10; permanent epicardial pacemaker implanted in four) and ventricular tachycardia (n = 4). Nine patients died in the early postoperative period (7.3%). Parameters found to be associated with increased mortality were low preoperative oxygen saturation; high right ventricular/aortic pressure ratio immediately after surgery; presence of coronary anomaly; requirement of postoperative ECMO; and pacemaker (P = 0.02, P = 0.04, P = 0.01, P = 0.0001, P = 0.03, respectively). Poor preoperative oxygenation, presence of coronary anomaly, complete AV block in the early postoperative period, high RV pressure and requirement of ECMO appear to be the most significant factors that affect early mortality in the surgical treatment of TOF. Appropriate preoperative assessment, correct surgical strategies and attentive intensive care monitoring are required in order to reduce mortality.

Ten-years, single-center experience with arterial duct stenting in duct-dependent pulmonary circulation: early results, learning-curve changes, and mid-term outcome.

To evaluate early results, learning-curve changes, and mid-term outcome of arterial duct (AD) stenting in congenital heart disease with duct-dependent pulmonary circulation (CHD-DPC) in a high-volume, tertiary referral center. In spite of wide acceptance as cost-effective alternative to surgical palliation, AD stenting indications, results and mid-term outcome still largely depend on small series, experiences in particular subsets of patients or multicenter series with different approaches and interventional philosophy. Between April 2003 and December 2013, 119 patients underwent AD stenting as lower-risk palliation of CHD-DPC at our Institution. Procedural and mid-term follow-up data of these patients are reported. The procedure was successfully completed in 93.3% of cases, with a complication rate and in-hospital mortality of 17.6% and 3.6%, respectively. No patient underwent rescue surgical shunt but elective Blalock-Taussig shunt was needed in 15 patients (13.5%). Over time, favorable trends toward higher feasibility and efficacy in complex ductal anatomy as well as lower procedural risk were recorded. Presurgical cardiac catheterization (n = 36) showed significant and balanced pulmonary artery (PA) growth (Nakata Index +113 ± 101%; left PA z-score +87 ± 52%; right PA z-score +97 ± 53%, P < 0.001 for all comparisons), without significant changes of left-to-right PA diameter ratio. PA growth was significantly better in patients with severely hypoplastic PAs at the time of duct stabilization (Nakata Index increase 194 ± 115 vs. 75 ± 61%, P < 0.001). AD stenting is feasible and effective at low-risk in a high percentage of patients with CHD-DPC, promoting significant and balanced PA growth mainly in patients with hypoplastic main PAs at duct stabilization.

Pulmonary Artery Growth After Palliation of Congenital Heart Disease With Duct-Dependent Pulmonary Circulation: Arterial Duct Stenting Versus Surgical Shunt

The aim of this study was to compare the pulmonary artery (PA) growth after arterial duct (AD) stenting versus modified Blalock-Taussig shunt (MBTS) in neonates with congenital heart disease with duct-dependent pulmonary circulation (CHD-DPC). Arterial duct stenting is increasingly deemed a reliable alternative to surgical shunt in CHD-DPC. A stented duct might better adapt to the PA anatomy than a surgical conduit, thereby promoting a more uniform PA development. This study enrolled 27 patients with CHD-DPC submitted to AD stenting (n = 13, Group I) or MBTS (n = 14, Group II) at our institution. The PA growth was angiographically assessed with the Nakata and McGoon indexes as well as the individual PA z-scores. The right-to-left PA diameter ratio was considered as index of uniform growth. After 10 +/- 5 months, both options had promoted a significant increase of the Nakata index (from 136 +/- 72 mm/m(2) to 294 +/- 99 mm/m(2), p < 0.0001, Group I; from 151 +/- 74 mm/m(2) to 295 +/- 177 mm/m(2), p < 0.003, Group II) and McGoon ratio (from 1.5 +/- 0.3 to 2.1 +/- 0.3, p < 0.0001, Group I; from 1.6 +/- 0.3 to 2.0 +/- 0.5, p < 0.01, Group II). However, the surgical shunt had caused a worsening of the left-to-right PA diameter ratio compared with AD stenting (0.9 +/- 0.1 Group I vs. 1.6 +/- 0.9 Group II, p < 0.01), due to preferential growth of the PA contralateral to the shunt. Percutaneous AD stenting is as effective as MBTS in promoting a global PA growth in CHD-DPC. In addition, it ensures an even distribution of the pulmonary blood flow, thereby promoting a more balanced pulmonary vascular development than MBTS.

Pulmonary artery growth following arterial duct stenting in congenital heart disease with duct‐dependent pulmonary circulation

The aim of this study was to assess the pulmonary artery (PA) growth following arterial duct (AD) stenting in neonates with congenital heart disease (CHD) with duct-dependent pulmonary circulation. AD stenting is increasingly deemed as a reliable alternative to surgical shunt in CHD with duct-dependent pulmonary circulation. Allowing the stent to conform to the PA anatomy might avoid any unbalance of lung perfusion and promote a uniform growth of the main PAs. Of the 47 neonates and infants submitted to AD stenting as palliation of CHD with duct-dependent pulmonary circulation at our Institution, 15 underwent angiographic evaluation of the PA development before surgical repair due to progressive decrease of the systemic oxygen saturation. The Nakata and McGoon indexes as well as the left-to-right PA diameter ratio were considered as being indicative of global and balanced growth. Ductal stabilization was achieved with coronary stents dilated to 3.3 + or - 0.4 mm (range 2.5-4). The control angiography was performed 7 + or - 3 months (range 3-13) after the stenting procedure. At that time, the Nakata and McGoon indexes had significantly increased from 132 + or - 67 to 287 + or - 94 mm/m(2) and from 1.6 + or - 0.3 to 2.1 + or - 0.2 mm/m(2), respectively (P < 0.0001 for both comparisons), due to uniform vascular growth (left PA z-score from -0.7 + or - 1.6 to 1.4 + or - 1.2; right PA from -0.8 + or - 1.4 to 1.4 + or - 1.2, P < 0.0001 for both comparisons; final left-to-right PA ratio 0.9 + or - 0.1). Percutaneous AD stabilization with highly flexible coronary stents is effective in promoting a significant and balanced growth of the PAs in CHD with duct-dependent pulmonary circulation.

Invited Commentary

Invited Commentary

Surgery for bilateral outflow tract obstruction in elastin arteriopathy

Objective: A number of patients with Williams syndrome or other forms of elastin arteriopathy have stenoses of pulmonary arteries in addition to supravalvular aortic stenosis. We sought to investigate the effect of the degree of pulmonary arterial stenosis on the prognosis after an operation for supravalvular aortic stenosis to help define the optimal treatment strategy for patients with severe forms of elastin arteriopathy. Methods: Between 1960 and 1999, 33 patients underwent operations for supravalvular aortic stenosis while having significant stenoses of the pulmonary arteries. We retrospectively reviewed patient charts, obtained current follow-up information, and determined risk factors for survival and reoperation. Results: Fifteen patients with moderate right-sided obstructions (confirmed by pulmonary artery Z-scores and right ventricular/descending aortic pressure ratio) underwent operations for supravalvular aortic stenosis only. Eighteen patients had more severe right-sided obstructions and underwent surgical relief of pulmonary arterial stenoses or right ventricular outflow tract obstruction in addition to operations for supravalvular aortic stenosis. Eight patients had undergone preoperative balloon dilations of stenotic pulmonary arteries. There were 6 early deaths and 1 late death in our series. Survival at 10 and 20 years was 76% (70% confidence interval, 68%-84%) and freedom from reintervention was 59% (70% confidence interval, 46%-71%) at 10 years and 49% (70% confidence interval, 35%-62%) at 20 years. Multivariate analysis revealed that patients with a right ventricular/descending aortic pressure ratio of 1.0 or more were at higher risk for reintervention but not for death. Conclusions: Surgical treatment of pulmonary artery obstructions in elastin arteriopathy is palliative but, in conjunction with balloon dilation of peripheral pulmonary arteries, offers good long-term survival to patients with the severest form of elastin arteriopathy. (J Thorac Cardiovasc Surg 2000;120:755-63)

1002-83 In Utero Pulmonary Outflow Obstruction: Natural History and Predictors of Postnatal Severity

We reviewed prenatal and postnatal echocardiograms of fetuses with pulmonary stenosis (PS, n = 14) and pulmonary atresia (PAtr, n = 5), to elucidate the antenatal natural history of PS and PAtr and identify predictors of severe postnatal disease. Fifteen were serially studied in utero (age at first study 24 ± 4wks). Fetuses with PS were divided into severe and mild groups according to whether they were (9) or were not (4) ductus-dependent at birth, respectively. Measurements of RV short and long-axis, tricuspid valve, main and branch pulmonary artery (PA) and pulmonary valve dimensions were converted to Z-scores based on age-adjusted normal fetal data. At the initial exam, main and branch PA and pulmonary valve Z-scores were larger in fetuses with mild PS than in those with severe PS or PAtr (p ≤ 0.01). On serial followup, however, growth rates of right heart structures did not differ for mild PS versus severe PS and PAtr groups. Ductal flow in utero was antegrade in systole in all with mild PS, but was either bidirectional (5 severe PS) or retrograde only (4 severe PS, all PAtr) in the severe PS and PAtr groups. Initial RV outflow gradients by Doppler did not differ between the mild and severe PS groups with antegrade PA flow (mean 26 ± 12 mmHg). Pulmonary insufficiency was a consistent feature in fetuses with mild PS, but was not present in the severe PS or PAtr groups. By color Doppler, 3/4 with mild PS had mild tricuspid regurgitation, whereas mild or moderate tricuspid regurgitation was found in 9/9 with severe PS and 4/5 with PAtr. When severe PS and PAtr groups were compared, there was no significant difference in initial Z-scores or growth rates of right heart structures between the groups. Tricuspid regurgitation severity and initial RV pressure by the tricuspid regurgitation jet (mean 71 ± 21 mmHg) also did not differ between the severe PS and PAtr groups. On serial followup in 6/8 with severe RV outflow obstruction (1 PAtr, 7 severe PS), the RV pressure increased by 18–47 mmHg. In 3/6 serially studied fetuses with antegrade PA flow (2 severe PS, 1 mild PS), the RV outflow gradient increased later in gestation. There was no change in the severity of tricuspid or pulmonary regurgitation during followup in any fetus. The severity of PS may be differentiated in utero by the direction of ductal flow, the presence of pulmonary insufficiency, severity of tricuspid insufficiency and the size of the pulmonary valve and PAs. In the absence of antegrade PA flow, severe PS may be difficult to distinguish from PAtr antenatally.

985-54 Do Central Pulmonary Arteries Grow Following Bidirectional Superior Cavopulmonary Anastomosis?

The role of bidirectional superior cavopulmonary anastomosis (BCPA) in palliation of complex congenital heart defects is now established but little is known about the growth of pulmonary arteries following this operation. Between 1987 and 1993, 74 children underwent BCPA in 2 centres. Of these 21 were further studied by postoperative angiography and are the subject of this investigation. Their median age at BCPA was 23 months (range 1–108 months). BCPA was undertaken through a thoracotomy in 5 and through a midline sternotomy on cardiopulmonary bypass in 16. Competitive sources of pulmonary blood flow were left open in 9 patients. Follow-up angiograms were performed 1–65 months (median 11 months) postoperatively. Z-scores, which standardize pulmonary arteries to body surface area, were calculated from measurement of the diameter immediately prior to the first branching point of each pulmonary artery. The pre- and postoperative bodysurface areas increased from 0.46 m2 (SD 0.21) to 0.66 m2 (SD 0.22). The pre- and postoperative Z-scores of the right pulmonary artery were –1.77 (SO 2.63) and –0.38 (SD 1.69) respectively. The left pulmonary artery Z-scores were -0.08 (SD 2.14) and –0.17 (SD 1.31) pre- and post- operatively. In the subset of 13 patients with reduced pulmonary blood flow (O2 saturation &lt; 0.75) preoperatively, the right pulmonary artery grew in excess of somatic growth (mean Z-score –2.63 pre and –0.62 postoperatively; p = 0.003). There was no difference in growth of the pulmonary arteries in patients with and without competitive pulmonary blood flow. Our preliminary results demonstrate that adequate growth of the pulmonary arteries occurs following BCPA in short term follow-up.