Change in Pulmonary Arteries after Modified Blalock-Taussig Shunt Procedure: Analysis Based on Computed Tomography.

Background: Although the modified Blalock-Taussig shunt remains the mainstay method of palliation for augmenting pulmonary blood flow in various congenital heart diseases, the shunt must be carefully designed to achieve the best outcomes. This study investigated the effect of shunt configuration on pulmonary artery growth and growth discrepancy. Methods: Twenty patients with successful modified Blalock-Taussig shunt takedown were analyzed. Pulmonary artery and shunt characteristics were obtained using computed tomography scans. Differences in the baseline and follow-up diameter ratios and growth in the ipsilateral and contralateral arteries were calculated. The angle between the shunt and pulmonary artery, as well as the distance from the main pulmonary artery bifurcation, were measured. Correlations between pulmonary arteries and shunt configurations were analyzed. Results: The median interval time between shunt placement and takedown was 154.5 days (interquartile range, 113.25-276.25 days). Follow-up values of the ipsilateral-to-contralateral pulmonary artery diameter ratio showed no significant correlation with the shunt angle (ρ=0.429, p=0.126) or distance (ρ=0.110, p=0.645). The shunt angle and distance from the main pulmonary bifurcation showed no significant correlation (ρ=-0.373, p=0.189). Pulmonary artery growth was negatively correlated with shunt angle (ipsilateral, ρ=-0.565 and p=0.035; contralateral, ρ=-0.578 and p=0.030), but not with distance (ipsilateral, ρ=-0.065 and p=0.786; contralateral, ρ=-0.130 and p=0.586). Conclusion: Shunt configuration had no significant effect on growth imbalance. The angle and distance of the shunt showed no significant correlation with each other. A more vertical shunt was associated with significant pulmonary artery growth. We suggest a more vertical graft design for improved pulmonary artery growth.

Comparison between the modified Blalock-Taussig shunt and right ventricular outflow tract stent in the palliative treatment for tetralogy of Fallot. / 改良Blalock-Taussigåˆ†æµæœ¯ä¸Žå³å¿ƒå®¤æµå‡ºé“æ”¯æž¶æ¤å ¥æœ¯å§‘æ¯æ€§æ²»ç–—æ³•æ´›å››è”ç—‡çš„æ¯”è¾ƒ.

OBJECTIVES: For patients with tetralogy of Fallot (TOF) who are not suitable candidates for primary corrective surgery or have a high surgical risk, transcatheter right ventricular outflow tract (RVOT) stent implantation is considered a safe and effective palliative intervention. This study aims to investigate the therapeutic outcomes of RVOT stent implantation in neonates and infants with TOF in comparison with the modified Blalock-Taussig shunt (mBTS) and to compare the impact of the 2 palliative interventions on arterial oxygen saturation and pulmonary artery development in pediatric patients. METHODS: Clinical data of 32 patients with TOF admitted to the Second Xiangya Hospital of Central South University from March 2011 to March 2021 were retrospectively collected. The patients were divided into an mBTS group (undergoing mBTS, n=15) and a stent implantation group (undergoing RVOT stenting, n=17) according to the surgical procedures. The 2 groups were assessed and compared in the surgical-related arterial oxygen saturation, postoperative complication rate, mortality rate, and re-intervention rate. The development of the patients' main pulmonary artery, right pulmonary artery, and left pulmonary artery was assessed by z-scores according to echocardiographic results. RESULTS: The children in the stent implantation group were younger and less weighed compared with the mBTS group (both P<0.05). Compared with the preoperative period, children in the stent implantation group had significantly higher arterial oxygen saturation [(75±17)% vs (96±3)%, P=0.026]; z-scores of pulmonary trunk [(-2.82±1.27) points vs (0.86±0.77) points, P=0.014], right pulmonary artery [(-1.88±0.59) points vs (-0.28±0.71) points, P=0.011], and left pulmonary artery [(-2.34±0.36) points vs (-1.67±0.36) points, P=0.036] were significantly increased. However, there were no significant differences in arterial oxygen saturation and pulmonary artery z-scores between pre- and post-mBTS procedures (all P>0.05). CONCLUSIONS: RVOT stent would have good surgical outcomes used in TOF patients with low weight and severe comorbidities. It also leads to an higher postoperative oxygen saturation and better promotion of pulmonary artery growth with RVOT stent compared to mBTS.

Stent or Shunt, What Could be Better for Children with Duct Dependent Pulmonary Circulation?

BACKGROUND: Systemic to pulmonary shunt (Shunt) is offered for children with duct dependent pulmonary circulation to augment pulmonary flow. Recently patent ductus arteriosus (PDA) stent (Stent) is widely used as an alternative method. We aimed to compare post intervention outcomes in children underwent either procedure. METHODS: Infants under 3 months who had an initial palliation by Shunt or Stent were retrospectively reviewed between 2008 and 2016, then followed till the second intervention or 1 year whichever earlier. RESULTS: 187 patients (110 Shunt and 77 Stent) were included. Initial weight and pulmonary artery (PA) branches size were similar between the groups. Shunt patients had more shock preoperatively and required more emergency intervention. Stent group showed less ICU stay 4 (1-8) vs 13 (7-23) days, p < 0.0001 and less positive pressure ventilation days 1 (0-2) vs 5.5 (3-11), p < 0.0001. However, Stent group had more symptomatic arterial and deep venous thromboses. In Stent patients the branch PAs growth was better and more homogeneous. At follow-up, no difference between groups regarding cumulative readmission days to hospital, hemoglobin levels and the weight percentile for age. Mortality was not different with a tendency to be higher in the Shunt group (13%) compared to the Stent group (5%), p 0.1. CONCLUSIONS: The implantation of PDA stent in patients with duct dependent pulmonary circulation results in a smoother ICU course and a shorter hospital stay, with higher risk of vascular injury. Shunt and Stent procedures have a good outcome for PA growth, somatic growth and survival.

Evaluation of the Growth of Central Pulmonary Arteries Following Patent Ductus Arteriosus Stenting in Patients with Duct Dependent Pulmonary Circulation.

Pulmonary arteries' (PAs) growth can be promoted by stenting of patent ductus arteriosus (PDA). This may result in better angle between the PDA and the PAs, allowing improved growth. In this study, we sought to evaluate the effect of PDA stenting on the growth of the pulmonary arteries by comparing their dimensions pre-stenting to their dimensions in the pre-second stage operations in patients with congenital heart diseases-duct-dependent pulmonary (CHD-DDP) circulation. Between January 2015 and December 2016, 58 neonates with CHD-DDP circulation underwent transcatheter PDA stenting and had evaluation of PAs growth before the second stage. Various parameters [Pre-branching right and left pulmonary artery (RPA, LPA) diameters, their Z scores, LPA/RPA ratio, McGoon's ratio and Nakata index] were recorded and compared pre-stenting and pre-second stage. The evaluation was done using catheterization or multislice computed tomography (MSCT). PDA stenting was successful in 49 patients out of 58 (84.5%) patients with an age of 13.5 ± 10.4 days and a weight of 2.9 ± 0.5 kg. Twenty-two (44.9%) patients had complex CHD-DDP, 14 (28.6%) patients had PA/IVS and 13 (26.5%) patients had PA/VSD. Pre-second stage RPA, LPA diameters and their Z scores increased significantly (RPA increased from 0.36 ± 0.05 cm to 0.60 ± 0.11 cm, P < 0.001, RPA Z-score increased from - 1.29 ± 0.91 to 0.81 ± 0.18, P < 0.001; LPA increased from 0.34 ± 0.06 cm to 0.58 ± 0.10 cm, P < 0.001, LPA Z-score increased from - 1.17 ± 0.86 to 0.97 ± 0.48, P < 0.001). McGoon's ratio increased significantly from 1.20 ± 0.11 to 1.61 ± 0.15 (P < 0.001). Nakata index increased from 105.94 ± 33.53 to 183.48 ± 40.58 mm2/m2 (P < 0.001). However, LPA/RPA ratio did not change (0.96 ± 0.05 and 0.98 ± 0.16, P = 0.288). PDA stenting is effective in promoting the global and the individual pulmonary artery growth in congenital heart diseases with duct-dependent pulmonary circulation. In this study, we presented our experience with this approach in 2 tertiary care centers in the DELTA region of Egypt. PDA stenting, generally, showed symmetric growth of the pulmonary arteries with comparable results to the international figures.

Impact of ductal stenting on pulmonary artery reconstruction in patients with duct-dependent congenital heart diseases-an institutional experience.

OBJECTIVES: This study aims to review our institutional experience of ductal stenting (DS) on the growth of pulmonary arteries (PAs) and surgical outcomes of PA reconstruction in this subset of patients. METHODS: This is a retrospective study done in neonates and infants up to 3 months of age with duct-dependent pulmonary circulation who underwent DS from January 2014 to December 2015. Post-stenting PA growth, surgical outcomes of PA reconstruction, post-surgical re-interventions, morbidity and mortality were analysed. RESULTS: During the study period, 46 patients underwent successful DS, of whom 38 underwent presurgery catheterization and definite surgery. There was significant growth of PAs in these patients. Biventricular repair was done in 31 patients while 7 had univentricular palliation. Left PA augmentation was required in 13 patients, and 10 required central PA augmentation during surgery. The mean follow-up period post-surgery was 4.5 ± 1.5 years. No significant postoperative complications were seen. No early or follow-up post-surgery mortality was seen. Four patients required re-interventions in the form of left PA stenting based on the echocardiography or computed tomography evidence of significant stenosis. CONCLUSIONS: DS provides good short-term palliation and the growth of PAs. However, a significant number of stented patients require reparative procedure on PAs at the time of surgical intervention. Acquired changes in the PAs following DS may be the reason for reintervention following PA reconstruction.

Choice of shunt type for the Norwood I procedure: does it make a difference?

OBJECTIVES: This study aimed to compare pulmonary artery (PA) growth between patients who received a right ventricle-to-PA (RV-PA) shunt and those who received a modified Blalock-Taussig shunt (mBTS). METHODS: All consecutive patients with hypoplastic left heart syndrome who underwent the Norwood I procedure between 2001 and 2017 were included in the study. Pre-stage 2 angiograms were analysed to measure the size of the PA. The Nakata index was calculated to estimate PA growth. The ratio of the right PA to left PA cross-sectional area (RPA/LPA) was used to calculate the difference in growth between the 2 branches. Study end points were shunt failure, shunt-related mortality and growth of the PAs. RESULTS: A total of 223 patients with hypoplastic left heart syndrome (RV-PA group = 137, mBTS group = 86) underwent the Norwood I procedure, and 186 patients (RV-PA n = 116, mBTS n = 70) achieved the stage 2 procedure. PA growth was better in patients with mBTS (Nakata index: RV-PA = 282, mBTS = 315 mm2/m2, P = 0.021). LPA growth was worse compared to RPA growth in both groups (RPA/LPA: RV-PA = 1.21, mBTS = 1.29, P = 1.0). Patients with RV-PA shunts experienced more frequent shunt stenosis compared to patients with mBTS (26 vs 2, P < 0.010). Freedom from shunt failure was 83.3 ± 3.2% and 94 ± 2% at 6 months in the RV-PA and mBTS groups, respectively (P = 0.003). CONCLUSIONS: PA growth is significantly better in patients who received an mBTS. Moreover, patients with an RV-PA shunt more frequently experienced shunt failure due to shunt stenosis. However, survival after the NW procedure is not shunt dependent and growth of the LPA is less pronounced than RPA, regardless of the shunt type.

Pulmonary artery growth after Modified Blalock-Taussig shunt: A single center experience.

OBJECTIVE: This study evaluates growth of pulmonary artery (PA) between different age groups after Modified Blalock-Taussig shunt (MBTS) based on a single center experience. METHODS: We retrospective analyzed outcomes of 90 patients undergoing MBTS in our institute from January 1, 2010 to May 1, 2018. Patients were divided into three groups: Group 1, ≦2 months, Group 2, >2 months, ≦24 wmonths, Group 3, >24 months. The outcome included PA growth, overall survival rates and postoperative complications. RESULTS: 23 patients were involved in Group 1, while 49 in Group 2 and 18 in Group 3. The diameter of the PA, McGoon ratio, Nakata index and the oxygen saturation increased significantly after MBTS. Compared to pre-MBTS, there was no statistically significant increase of McGoon ratio in Group 3 after performing MBTS, but it witnessed less secondary cardiac surgery rate compared with Group 2 (11.11% vs. 48.98%, P = 0.005). Cumulative survival rates of three groups were 60.53%, 85.70%, 94.40% at 1 year; 60.53%, 78.30%, 87.75% at 3 years and 60.53%, 78.30%, 87.75% at 5 years. Multivariable analysis showed diastolic blood pressure <30 mmHg [OR 14.14 (1.92-104.32), P = 0.009], cardiopulmonary bypass use [OR 16.79 (2.05-137.67), P = 0.009] and single ventricle anomaly [OR 8.80 (1.18-65.54), P = 0.034] were predictors of perioperative mortality. CONCLUSION: MBTS in our institute is a conventional and effective procedure for growth of PA especially for patients younger than 24 months. Patients with biventricular anomaly, no cardiopulmonary bypass use in surgery and relatively high postoperative diastolic blood pressure will likely offer a good prognosis.

Femoral vein homograft as Sano shunt results in improved pulmonary artery growth after Norwood operation.

OBJECTIVE: To evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation. METHODS: A retrospective review of all patients who survived to the second stage following Norwood-Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation. RESULTS: A total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5-6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130-460) versus 165 (108-234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations. CONCLUSIONS: Utilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood-Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.

Stenting of the Right Ventricular Outflow Tract Promotes Better Pulmonary Arterial Growth Compared With Modified Blalock-Taussig Shunt Palliation in Tetralogy of Fallot-Type Lesions.

OBJECTIVES: This study sought to compare pulmonary arterial (PA) growth during palliation after right ventricular outflow tract (RVOT) stenting versus modified Blalock-Taussig shunt (mBTS) in patients coming forward for complete repair of tetralogy of Fallot-type lesions. BACKGROUND: RVOT stenting is a recent alternative to mBTS in the initial palliation of selected patients with Fallot-type lesions. METHODS: This was a retrospective, single-center study of nonrandomized, consecutive palliated Fallot patients over a 10-year period. Differential left PA (LPA) and right PA (RPA) growth was assessed by serial echocardiograms in 67 patients after mBTS (n = 28) or RVOT stent (n = 39). Statistical data analysis was performed using mixed model analysis. RESULTS: RPA z-scores in the mBTS group improved from median -2.41 (interquartile range [IQR]: -2.97 to -1.32) to -1.13 (IQR: -1.68 to -0.59). LPA z-scores improved from -1.89 (IQR: -2.33 to -1.12) to -0.32 (IQR: -0.88 to -0.05). In the RVOT stenting group RPA z-scores improved from -2.28 (IQR: -3.28 to -1.82) to -0.72 (IQR: -1.27 to +0.48), and LPA z-scores from -2.08 (IQR: -2.90 to -0.61) to -0.05 (IQR: -0.88 to +0.48). Mixed model analysis showed significantly better RPA and LPA growth after RVOT stenting. The benefit of RVOT stenting versus mBTS was 0.599 z-scores for the LPA and 0.749 z-scores for the RPA. Rise in oxygen saturations was greater with RVOT stenting (p = 0.012). Median time to complete repair was shorter in the RVOT stent group (227 [142 to 328] days) compared with the mBTS group (439 [300 to 529] days; p < 0.0003). CONCLUSIONS: RVOT stenting promotes better pulmonary arterial growth and oxygen saturations compared with mBTS in the initial palliation of Fallot-type lesions.

Fate of Duct-Dependent, Discontinuous Pulmonary Arteries After Arterial Duct Stenting.

Significant and balanced PA growth following arterial duct (AD) stenting has already been consistently reported in literature. However, to date, no data are available about the role of this approach as palliation of congenital heart disease with a duct-dependent discontinuous pulmonary artery (dPA). The aim of this study was to evaluate the fate of a dPA of ductal origin following trans-catheter AD stabilization. Angiographic PA evaluation was performed in seven patients submitted to neonatal AD stenting as palliative recruitment of dPA. Five patients showed discontinuity of one PA, while two patients had both PAs served by bilateral ducts. PA growth was evaluated as per the Nakata index, McGoon ratio as well as dPA (n = 9) versus heart-dependent PA (hPA; n = 5) size and z-score changes. AD stabilization was performed using coronary stents dilated to 3.2 ± 0.3 mm (median 3.4), with significant increase of O2 saturation (from 83 ± 11 to 95 ± 5%, p < 0.02). Control angiography was performed 5.1 ± 2.8 months (median 6 months) after duct stenting, showing significant growth of the dPA (from 3.7 ± 1.0 to 7.6 ± 2.7 mm, p < 0.001; z-score from -0.7 ± 1.4 to 1.7 ± 2.2, p < 0.01). A trend toward better growth of the dPA as compared with the hPA was found (117 ± 87 vs. 54 ± 34%, p = NS). The final vessel size was still significantly different between the groups (dPA 7.6 ± 2.7 vs. hPA 11.9 ± 3.4 mm, p = 0.02), although the final z-score value did not significantly differ (dPA 1.7 ± 2.2 vs. hPA 3.8 ± 0.9 mm, p = NS). In conclusion, percutaneous AD stenting is effective in promoting a significant catch-up growth of duct-dependent dPA, being, therefore, advisable as a reliable alternative to surgical palliation.

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

OBJECTIVES: 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). BACKGROUND: 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. METHODS: 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 <100 mm(2)/m(2), Group I [n = 15] vs. Nakata Index >100 mm(2)/m(2), Group II [n = 30]). RESULTS: 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 ± 105 mm(2)/m(2) vs. 282 ± 78 mm(2)/m(2), p = NS). CONCLUSIONS: 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.

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.