Impact of stent implantation on pulmonary artery growth.

BACKGROUND: Goals of stent implantation (SI) in children with pulmonary artery (PA) stenosis are to relieve obstruction and improve flow to the distal vasculature. We evaluated stent impact on distal PA growth. METHODS: We compared data of children who underwent unilateral SI using the nonstenotic contralateral PA (CPA) as a control (1998-2005; f/u data through 2009). Main/lobar diameters measured at initial and f/u catheterizations were analyzed. RESULTS: For single ventricle (SV) patients (N = 18), the stented PA diameter (SPA D) increased 118%. At initial f/u catheterization (14 ± 9.6 months), both upper lobe (UL) and lower lobe (LL) growth of SPA was comparable to those of the CPA (UL:7% vs. 7%; P = 0.97); (LL:5% vs. 10%; P = 0.33). Subsequent f/u in 11/18 patients (mean 26 ± 20 months) revealed similar results: both UL and LL growth of SPA were comparable to those of the CPA (UL:51% vs. 27%; P = 0.3); (LL:18% vs. 21%; P = 0.62). For two-ventricle (2V) patients (N = 21), the SPAD increased 100%. At f/u, UL, and LL growth on SPA was similar to those of the CPA (UL: 32% vs. 21%; P = 0.37); (LL: 17% vs. 18%; P = 0.88). Subsequent f/u in 10/21 patients (mean 34 ± 14 months) showed UL growth of SPA was significantly greater than that of the CPA (44% vs. 21%; P = 0.05). LL growth of SPA was similar to that of the CPA (19% vs. 14%; P = 0.56). CONCLUSION: SI for PA stenosis is effective in promoting normal lobar growth in SV and 2V patients. Greater lobar growth was seen in 2V compared to SV pts at first f/u. Early, aggressive PA stenting is beneficial in promoting lobar branch growth.

Left main coronary artery compression from right pulmonary artery stenting.

Complications related to pulmonary artery stenting include stent migration, jailing of vessels, vessel rupture, and compression of surrounding structures. Compression of the left main coronary artery (LMCA) as a result of stent placement in the right pulmonary artery (RPA) is extremely rare. We present two patients post repair of congenital heart disease who suffered LMCA compression following RPA stenting. The first patient experienced acute coronary insufficiency in the cardiac catheterization laboratory, whereas the second patient had a more chronic course. We also present a third patient who had a CT angiogram that demonstrated a close spatial relationship between the RPA and the LMCA. Based on our previous experiences, we felt that this patient was at significant risk for LMCA compression if the RPA were stented. Coronary compression is rare complication of pulmonary artery stenting but should be considered in cases with history of repaired congenital heart disease.

Myocardial Performance Index in Childhood Onset Essential Hypertension and White Coat Hypertension.

BACKGROUND: As a global measure of ventricular systolic and diastolic function, the myocardial performance index (MPI) can be an early indicator of hypertensive cardiomyopathy in children with essential hypertension (EH). METHODS: Children with untreated newly diagnosed EH and white coat hypertension (WCH) by a 24-hour ambulatory blood pressure monitoring (ABPM), both groups without any identifiable etiology for the hypertension, were enrolled for the study. Echocardiograms and vascular ultrasounds for carotid artery intimal medial thickness were performed on all children prior to therapy. Diastolic function (peak E and A velocities, E/A ratio, isovolumic relaxation time, and deceleration times) and MPI were evaluated by simultaneous transmitral and transaortic spectral Doppler flow velocities. Systolic function was evaluated by shortening fraction and ejection fraction. RESULTS: A cohort of 66 children (24 with EH, 42 with WCH, males 61%, median age of 13 years, range 10-17 years) were enrolled in the study. The demographic, anthropometric, laboratory tests, vascular ultrasound, and conventional echocardiographic parameters were similar between the 2 groups. There was a very small difference in MPI between the EH and WCH children (0.28 SD: 0.07 vs. 0.31 SD: 0.08, P = 0.045). However, in EH children, MPI increased by 0.14 units for every 10 unit increase in mean ABPM systolic BP (95% confidence interval: 0.03-0.25). CONCLUSIONS: We found the increasing MPI was associated with increasing 24-hour mean systolic BP in children with EH. Therefore, MPI may have utility as a single, quick, noninvasive method of detection and tracking of subclinical hypertensive heart disease.

"Wire-target" technique for precise vascular access.

Herein, we describe a technique that facilitates percutaneous vascular access when the traditional method of achieving access is unsuccessful. For multiple reasons, gaining access to small vessels in pediatric patients is sometimes difficult. In instances of atrial, ventricular, or great arterial communications, a wire can be positioned from a vein or artery across the communications into an artery or vein to which access needs to be gained. This wire then serves as a target for vascular access. All pediatric patients who underwent cardiac catheterization at Mattel Children's Hospital from July 2003 through June 2006, and at Rady Children's Hospital from July through December 2006, were considered for the wire-target technique when access could not be achieved in vessels of interest via traditional methods. Fifteen wire-target procedures were undertaken in 14 patients (ages, 4 d-11 yr). By use of a directional catheter, a Wholey or 0.014-inch coronary wire was positioned in a vessel to which access was desired. Anterior-posterior and lateral fluoroscopic views were used to target the wire and attain vascular access. The patients' diagnoses, ages, vessels to which access was gained via traditional methods and via the wire-target technique, and wire routes were retrospectively recorded, and outcomes were noted. In all instances, the technique was performed successfully and without complications. In selected pediatric patients in whom percutaneous vascular access is difficult, the wire-target technique may be used safely and effectively to establish arterial, venous, or transhepatic access.