Potts Shunt Improves Right Ventricular Function and Coupling With Pulmonary Circulation in Children With Suprasystemic Pulmonary Arterial Hypertension

Lung Transplantation for Pulmonary Vascular Disease in Children: A United Network for Organ Sharing Analysis

Pulmonary vascular disease (PVD) represents an important clinical indication for lung transplant (LTx) in infants, children, and adolescents. There is limited information on LTx outcomes in these patients. We explored LTx volumes and post-LTx survival in children with PVD compared to other diagnoses. The UNOS Registry was queried from 1989 to 2020 to identify first-time pediatric LTx recipients (< 18 yo). PVD was categorized as idiopathic pulmonary arterial hypertension (IPAH) and non-idiopathic arterial hypertension (non-IPAH) and compared to all other patients as other diagnoses. Univariate and multivariate regression models were performed. 984 pediatric LTx patients (593 before 2010 and 391 during/after 2010) were identified, of which 145 (14.7%) had PVD. There has been no significant change in annual rate of all LTxs over comparative eras. However, there has been a decrease in rate of LTxs for PVD patients. Children with PVD had similar survival to other LTx groups in the early era (p = 0.2) and the latter era (p = 0.9). Univariate Cox models, showed that LTx in patients with PVD was associated with a significantly less risk of mortality for children aged 6-11 years compared to younger and older cohorts (HR = 0.4 [0.17-0.98]; p = 0.045), whereas multivariate analysis showed a trend toward higher mortality in 11-17-year-olds (HR = 1.54 [0.97-2.45]; p = 0.06). For PVD patients, oxygen supplementation and ventilator support at LTx were associated with worse post-transplant survival (p = 0.029 and p = 0.01). There has been a decrease in LTx volume for pediatric patients with PVD in the modern era. Post-LTx outcomes for children with PVD are similar to those of other diagnoses in both eras, with children aged 6-11 years having the best survival. Given these findings, LTx should be considered for this patient population.

Prostaglandin-E1 infusion in persistent pulmonary hypertension of the newborn

BACKGROUND

Neonates with persistent pulmonary hypertension of the newborn (PPHN) can present with hypoxia and right ventricular dysfunction with resultant inadequate oxygen delivery and end-organ damage. This study describes the use of prostaglandin-E1 (PGE) for ductal patency to preserve right ventricular systolic function and limit afterload in newborns with PPHN.

METHODS

This is a retrospective cohort study that follows the hemodynamics, markers of end-organ perfusion, length of therapeutics, and echocardiographic variables of 57 newborns who used prostglandin-E1 in the setting of PPHN.

RESULTS

Tachycardia, lactic acidosis, and supplemental oxygen use improved following PGE initiation. Fractional area change (FAC), to assess right ventricular systolic function, and pulmonary arterial acceleration time indexed to right ventricular ejection time (PAAT/RVET), to assess right ventricular afterload, also improved over three time points relative to PGE use (before, during, and after).

CONCLUSIONS

Overall, we described the safety and utility of PGE in newborns with severe PPHN for stabilization while allowing natural disease progression.

Inhaled iloprost as an add-on therapy for advanced pulmonary arterial hypertension: An Indian perspective

Background Pulmonary arterial hypertension (PAH) is a progressive disease with high morbidity and mortality. Risk stratification and initiation of dual or triple combination therapy has a better clinical response, especially in high-risk patients. Unfortunately, prostacyclin analogues are not marketed in India; hence, the use of these medications is limited. We report the benefits and difficulties of using iloprost inhalation in patients with advanced PAH in India. Methods In this prospective observational study, we included patients with group 1 PAH. Inhaled iloprost was initiated as an add-on therapy for patients who had clinical, echocardiographic or laboratory deterioration on dual oral medications. Patients with clinical instability were excluded. All patients underwent thorough clinical evaluation, detailed echocardiogram and laboratory investigations. Patients were started on inhaled iloprost 2.5 μg six times daily and closely followed up. The dose was escalated if necessary. On follow-up, clinical echocardiographic and laboratory evaluation was done on all patients. Results Fourteen patients (11 women) with a median age of 32 years (2-66 years) with group 1 PAH were started on inhaled iloprost as an add-on therapy. Improvement in clinical parameters, WHO functional class, echocardiographic-derived right ventricular function, and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels were observed in 10 of 14 patients. A median increase of 31% (4.2, 106%) in the distance travelled during 6-minute walk test, a median increase of 45% (-20, 120%) in right ventricular fractional area change, a median increase of 27% (-16.7, 60%) in tricuspid annular peak systolic excursion and a median decrease of 36.7% (-69.6, 17.2%) in NT-pro-BNP levels were observed after initiation of medication. Three patients had progression of symptoms and were then referred for lung/heart-lung transplant. One patient developed progression of symptoms after an excellent initial response and transitioned to subcutaneous treprostinil. Improvement in clinical, echocardiographic and laboratory features allowed us to successfully perform surgical Potts shunt in 2 patients. The medications were well tolerated with minimal and transient side-effects. There were no deaths. Conclusion Inhaled iloprost can be used with acceptable benefits and minimal side-effects in patients with PAH.

Lung Transplantation for Pulmonary Vascular Disease in Children: A United Network for Organ Sharing Analysis

Background

Pulmonary vascular disease (PVD) represents an important clinical indication for lung transplant (LTx) in infants, children, and adolescents. There is limited information on LTx outcomes in these patients. We explored LTx volumes and post-LTx survival in children with PVD compared to other diagnoses.

Methods

The UNOS Registry was queried from 1989-2020 to identify first-time pediatric LTx recipients (<18 yo). PVD was categorized as idiopathic pulmonary arterial hypertension (IPAH) and non-idiopathic arterial hypertension (non-IPAH) and compared to all other patients as other diagnoses. Univariate and multivariate regression models were performed.

Results

984 pediatric LTx patients (593 before 2010 and 391 during/after 2010) were identified, of which 145 (14.7%) had PVD. There has been no significant change in annual rate of all LTxs over comparative eras. However, there has been a decrease in rate of LTxs for PVD patients. Children with PVD had similar survival to other LTx groups in the early era (p=0.2) and the latter era (p=0.9). Univariate Cox models, showed that LTx in patients with PVD was associated with a significantly less risk of mortality for children aged 6-11 years compared to younger and older cohorts (HR=0.4 [0.17-0.98];p=0.045), whereas multivariate analysis showed a trend towards higher mortality in 11-17-year-olds (HR=1.54 [0.97-2.45];p=0.06). For PVD patients, oxygen supplementation and ventilator support at LTx were associated with worse post-transplant survival (p=0.029 and p=0.01).

Conclusions

There has been a decrease in LTx volume for pediatric patients with PVD in the modern era. Post-LTx outcomes for children with PVD are similar to those of other diagnoses in both eras, with children aged 6-11 years having the best survival. Given these findings, LTx should be considered for this patient population.

Treatment of pulmonary arterial hypertension: recent progress and a look to the future

Pulmonary arterial hypertension (PAH) is a severe but treatable form of pre-capillary pulmonary hypertension caused by pulmonary vascular remodelling. As a result of basic science discoveries, randomised controlled trials, studies of real-world data, and the development of clinical practice guidelines, considerable progress has been made in the treatment options and outcomes for patients with PAH, underscoring the importance of seamless translation of information from bench to bedside and, ultimately, to patients. However, PAH still carries a high mortality rate, which emphasises the urgent need for transformative innovations in the field. In this Series paper, written by a group of clinicians, researchers, and a patient with PAH, we review therapeutic approaches and treatment options for PAH. We summarise current knowledge of the cellular and molecular mechanisms of PAH, with an emphasis on emerging treatable pathways and optimisation of current management strategies. In considering future directions for the field, our ambition is to identify therapies with the potential to stall or reverse pulmonary vascular remodelling. We highlight novel therapeutic approaches, the important role of patients as partners in research, and innovative approaches to PAH clinical trials.

Bilateral lung transplantation for pediatric pulmonary arterial hypertension: perioperative management and one-year follow-up

Background

Bilateral lung transplantation (LuTx) remains the only established treatment for children with end-stage pulmonary arterial hypertension (PAH). Although PAH is the second most common indication for LuTx, little is known about optimal perioperative management and midterm clinical outcomes.

Methods

Prospective observational study on consecutive children with PAH who underwent LuTx with scheduled postoperative VA-ECMO support at Hannover Medical School from December 2013 to June 2020.

Results

Twelve patients with PAH underwent LuTx (mean age 11.9 years; age range 1.9-17.8). Underlying diagnoses included idiopathic (n = 4) or heritable PAH (n = 4), PAH associated with congenital heart disease (n = 2), pulmonary veno-occlusive disease (n = 1), and pulmonary capillary hemangiomatosis (n = 1). The mean waiting time was 58.5 days (range 1-220d). Three patients were bridged to LuTx on VA-ECMO. Intraoperative VA-ECMO/cardiopulmonary bypass was applied and VA-ECMO was continued postoperatively in all patients (mean ECMO-duration 185 h; range 73-363 h; early extubation). The median postoperative ventilation time was 28 h (range 17-145 h). Echocardiographic conventional and strain analysis showed that 12 months after LuTx, all patients had normal biventricular systolic function. All PAH patients are alive 2 years after LuTx (median follow-up 53 months, range 26-104 months).

Conclusion

LuTx in children with end-stage PAH resulted in excellent midterm outcomes (100% survival 2 years post-LuTx). Postoperative VA-ECMO facilitates early extubation with rapid gain of allograft function and sustained biventricular reverse-remodeling and systolic function after RV pressure unloading and LV volume loading.

Vanillic Acid Alleviates Right Ventricular Function in Rats With MCT-Induced Pulmonary Arterial Hypertension

This study examined the molecular processes behind the effects of vanillic acid (VA) on right ventricular (RV) hypertrophy and function in rats with monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). There were 40 male Sprague‒Dawley (SD) rats that were separated into 4 groups: Control, PAH, MCT + VA (50 mg/kg/d), and MCT + VA (100 mg/kg/d). Male SD rats were injected with MCT once under the skin to create the PAH model (40 mg/kg). RV morphological properties were evaluated using Masson and hematoxylin and eosin (H&E) staining. Echocardiography was used to evaluate RV functioning and right ventricle–pulmonary artery (RV-PA) coupling. In addition, Rho-associated protein kinase (ROCK) pathway-related factors were evaluated using Western blotting. Enzyme-linked immunosorbent assay (ELISA) was used to detect inflammatory markers as well as atrial natriuretic peptide (ANP) and brain-type natriuretic peptide (BNP) in the blood of PAH rats. As a result, VA effectively reduced the development of RV cardiomyocyte hypertrophy and fibrosis in PAH rats; levels of ANP, BNP, and inflammatory markers in the blood of PAH rats were also significantly decreased by VA intervention. Additionally, VA enhanced RV functioning and RV-PA coupling in PAH rats. In response to VA, the expression of proteins related to the ROCK pathway (ROCK1, ROCK2, NFATc3, P-STAT3, and Bax) was downregulated, whereas Bcl-2 expression was elevated. This study found that VA could attenuate RV remodeling and improve RV-PA coupling in PAH rats. RV remodeling and dysfunction may be linked to the dysregulation of the ROCK pathway, and the protective action of VA on RV function may be due to a block in the ROCK signaling pathway or its downstream signaling molecules.

Use of Prostaglandin E1 in the Management of Congenital Diaphragmatic Hernia-A Review

Congenital diaphragmatic hernia (CDH) is a rare congenital anomaly, whose presentation is complicated by pulmonary hypertension (PH), pulmonary hypoplasia, and myocardial dysfunction, each of which have significant impact on short-term clinical management and long-term outcomes. Despite many advances in therapy and surgical technique, optimal CDH management remains a topic of debate, due to the variable presentation, complex pathophysiology, and continued impact on morbidity and mortality. One of the more recent management strategies is the use of prostaglandin E1 (PGE1) infusion in the management of PH associated with CDH. PGE1 is widely used in the NICU in critical congenital cardiac disease to maintain ductal patency and facilitate pulmonary and systemic blood flow. In a related paradigm, PGE1 infusion has been used in situations of supra-systemic right ventricular pressures, including CDH, with the therapeutic intent to maintain ductal patency as a "pressure relief valve" to reduce the effective afterload on the right ventricle (RV), optimize cardiac function and support pulmonary and systemic blood flow. This paper reviews the current evidence for use of PGE1 in the CDH population and the opportunities for future investigations.

Reversed Potts Shunt Outcome in Suprasystemic Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Reversed Potts shunt has been a prospective approach to treat suprasystemic pulmonary hypertension, particularly when medication treatment fails to reduce right ventricular afterload.

OBJECTIVE

This meta-analysis aims to review the clinical, laboratory, and hemodynamic parameters after a reversed Potts shunt in suprasystemic pulmonary hypertension patients.

METHODS

Six electronic databases were searched from the date of inception to August 2021, where the obtained studies were evaluated according to the PRISMA statement. The effects of shunt creation were evaluated by comparing preprocedural to postprocedural or follow-up parameters, expressed as a mean difference of 99% confidence interval. Quality assessment was conducted using the STROBE statement.

RESULTS

Seven studies suited the inclusion criteria which were included in this article. A reduction in upper and lower limb oxygen saturation [Upper limb: St. Mean difference -0.55, 99% CI -1.25 to 0.15; P=0.04; I2=6%. Lower limb: St. Mean difference -4.45, 99% CI -7.37 to -1.52; P<0.00001; I2=65%]. Reversed Potts shunt was shown to improve WHO functional class, 6-minute walk distance, NTpro-BNP level, and hemodynamic parameters including tricuspid annular plane systolic excursion, interventricular septal curvature, and end-diastolic right ventricle/left ventricle ratio.

CONCLUSION

Reversed Potts shunt cannot be said to be relatively safe, although it allows improvement in the clinical and functional status in patients with suprasystemic PAH. Reversed Potts shunt procedure may be the last resort for drug-resistant pulmonary hypertension as it is considered a high-risk procedure performed on patients with extremely poor conditions.

Monitoring and evaluation of the surgical Potts shunt physiology using 4-dimensional flow magnetic resonance imaging

OBJECTIVE

The reversed Potts shunt is an increasingly applied mode of surgical palliation of severe pulmonary hypertension (PH). However, the long-term flow hemodynamic effect of the Potts shunt physiology and desirable long-term hemodynamic end points are not defined. The purpose of this descriptive study was to analyze a series of pediatric patients who underwent surgical Potts shunt as a part of end-stage PH palliation using 4-dimensional (4D)-flow magnetic resonance imaging (MRI) to (1) quantitate the flow through the anastomosis, (2) correlate the shunting pattern with phases of cardiac cycle and PH comorbidities, and (3) describe chronologic changes in shunting pattern.

METHODS

This was a 2-center study evaluating 4 patients seen in the Pulmonary Hypertension Clinic at Children's Hospital Colorado who were evaluated and selected to undergo surgical reverse Potts shunt at Washington University School of Medicine and were serially followed using comprehensive imaging including cardiac MRI and 4D-flow MRI.

RESULTS

After the procedure, each child underwent 2 4D-flow MRI evaluations. Pulmonary pressure offload was evident in all patients, as demonstrated by positive systolic right-to-left flow across the Potts shunt. All patients experienced some degree of the flow reversal, which occurs primarily in diastole. Interventricular dyssynchrony further contributed to flow reversal across the Potts shunt. Lastly, systemic and pulmonary blood mixing in the descending aorta results in secondary helical flow persisting throughout the diastole.

CONCLUSIONS

4D-flow MRI demonstrates that children who have undergone a Potts shunt for severe PH can experience shunt flow reversal. Cumulatively, this left-to-right pulmonary shunt adds to right ventricular volume overload. We speculate that a valved conduit may decrease the left to right shunting and improve overall cardiac output.

Improvement in exercise capacity after a modified Potts shunt in an adult patient with pulmonary arterial hypertension

For young adults with end-stage idiopathic pulmonary hypertension, a valved graft connecting the central pulmonary artery to the distal aortic arch can provide substantial palliation of symptoms and may defer lung transplantation https://bit.ly/2TvMFFC.

Role of cardiovascular magnetic resonance in pediatric pulmonary hypertension-novel concepts and imaging biomarkers

Pulmonary hypertension (PH) in children is a heterogenous disease of the small pulmonary arteries characterized by a progressive increase in pulmonary vascular resistance. Despite adequate medical therapy, long-term pressure overload is frequently associated with a progressive course leading to right ventricular failure and ultimately death. Invasive hemodynamic assessment by cardiac catheterization is crucial for initial diagnosis, risk stratification and therapeutic strategy. Although echocardiography remains the most important imaging modality for the assessment of right ventricular function and pulmonary hemodynamics, cardiovascular magnetic resonance (CMR) has emerged as a valuable non-invasive imaging technique that enables comprehensive evaluation of biventricular performance, blood flow, morphology and the myocardial tissue. In this review, we summarize the principles and applications of CMR in the evaluation of pediatric PH patients and present an update about novel CMR based concepts and imaging biomarkers that may provide further diagnostic, therapeutic and prognostic information.

Interventional and Surgical Treatments for Pulmonary Arterial Hypertension

Despite significant advancements in pharmacological treatment, interventional and surgical options are still viable treatments for patients with pulmonary arterial hypertension (PAH), particularly idiopathic PAH. Herein, we review the interventional and surgical treatments for PAH. Atrial septostomy and the Potts shunt can be useful bridging tools for lung transplantation (Ltx), which remains the final surgical treatment among patients who are refractory to any other kind of therapy. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) remains the ultimate bridging therapy for patients with severe PAH. More importantly, VA-ECMO plays a crucial role during Ltx and provides necessary left ventricular conditioning during the initial postoperative period. Pulmonary denervation may potentially be a new way to ensure better transplant-free survival among patients with the aforementioned disease. However, high-quality randomized controlled trials are needed. As established, obtaining the Eisenmenger physiology among patients with severe pulmonary hypertension by creating artificial defects is associated with improved survival. However, right-to-left shunting may be harmful after Ltx. Closure of the artificially created defects may carry some risk associated with cardiac surgery, especially among patients with Potts shunts. In conclusion, PAH requires an interdisciplinary approach using pharmacological, interventional, and surgical modalities.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

Tsantan Sumtang Restored Right Ventricular Function in Chronic Hypoxia-Induced Pulmonary Hypertension Rats

Background: Tsantan Sumtang originated from Four Tantras, which consisted of Choerospondias axillaris (Roxb.) B. L. Burtt and A. W. Hill, Santalum album L., and Myristica fragrans Houtt. The three herbs are in ratio 1:1:1. This medication is widely used for cardiovascular diseases.

Aims: The purpose of this study was to explore the effect of Tsantan Sumtang on right ventricular (RV) function in hypoxia-induced pulmonary hypertension (HPH) rats and investigate the underlying mechanism.

Methods: Sixty male Sprague-Dawley (SD) rats were divided into control, hypoxia, and hypoxia + Tsantan Sumtang (1.0, 1.25, and 1.5 g•kg⁻¹•d⁻¹) groups. Chronic hypoxia was induced by putting the rats inside a hypobaric chamber for four weeks and adjusting the inner pressure and oxygen content to match an altitude of 4500 m. Echocardiography was used to assess RV function and right ventricular-pulmonary arterial (RV-PA) coupling. The physiological parameters of the animals were also evaluated. Morphological characteristics of RV were assessed by hematoxylin and eosin (H&E) staining and TEM. Masson’s trichrome staining, immunohistochemical staining, western blotting, and TUNEL assay were used to assess fibrosis and apoptosis levels. The antioxidant and anti-apoptosis properties of Tsantan Sumtang were also evaluated. The effect of Tsantan Sumtang on ROCK signaling pathway was evaluated using real-time quantitative PCR and western blotting.

Results: We established an HPH rat model as indicated by the significant increases in the physiological parameters of the rats. Tsantan Sumtang showed a significant cardiac-protective function and an improved effect on RV-PA coupling. Moreover, Tsantan Sumtang treatment inhibited fibrosis and alleviated apoptosis and oxidative stress in RV. In terms of mechanism, Tsantan Sumtang reduced the expression of ROCK (ROCK1, ROCK2) in RV, inhibited cardiac remodeling-related transcription factors (NFATc3, P-STAT3), and regulated apoptosis-related proteins.

Conclusion: Tsantan Sumtang was able to restore RV function, improve RV-PA coupling, recover hemodynamic and hematological indexes, and protect RV against structural maladaptive remodeling in the HPH rats. These findings demonstrated that Tsantan Sumtang protects the function of RV in HPH rats. The antioxidant and anti-apoptosis properties of Tsantan Sumtang may be responsible for inhibiting the ROCK signaling pathway.

Potts shunt as an effective palliation for patients with end stage pulmonary arterial hypertension

BACKGROUND

Potts shunt has been suggested as an effective palliative therapy for patients with pulmonary artery hypertension (PAH) not associated with congenital heart disease.

MATERIALS AND METHODS

This is a prospective single-center study performed to assess outcomes of Potts shunt in patients with PAH who are in functional class III or IV.

RESULTS

52 patients in functional class III/IV with pulmonary arterial hypertension without significant intra or extracardiac shunt on maximal medical therapy were evaluated and counseled for undergoing Potts shunt/patent ductus arteriosus (PDA) stenting. 16/52 patients (13 females) consented for the procedure; 14 patients underwent surgical creation of Potts, and 2 underwent transcatheter stenting of PDA, which physiologically acted like a Potts shunt. Standard medical therapy was continued in patients who did not consent for the procedure. 12/16 patients survived the procedure. Patients who did not survive the procedure were older, with severe right ventricular systolic dysfunction, and functional class IV. Patients who survived the procedure were followed up in the pulmonary hypertension clinic. The Median follow-up was 17 months (1-40 months). 11/13 patients discharged after the operation showed sustained clinical, echocardiographic, and biochemical improvement, which reduced need for pulmonary vasodilator therapy in 10/13 patients. There was one death in the follow-up period 16 months post-surgery due to lower respiratory tract infection.

CONCLUSION

Potts shunt is feasible in patients with PAH without significant intra or extracardiac shunts. It can be done safely with an acceptable success rate. Patient selection, preoperative stabilization, and meticulous postoperative management are essential. It should be performed at the earliest sign of clinical, echocardiographic, or laboratory deterioation for optimal outcomes. Long-term follow-up is required to see a sustained improvement in functional class and the need for a lung transplant in the future.

Echocardiography for the Assessment of Pulmonary Hypertension and Congenital Heart Disease in the Young

While invasive assessment of hemodynamics and testing of acute vasoreactivity in the catheterization laboratory is the gold standard for diagnosing pulmonary hypertension (PH) and pulmonary vascular disease (PVD) in children, transthoracic echocardiography (TTE) serves as the initial diagnostic tool. International guidelines suggest several key echocardiographic variables and indices for the screening studies when PH is suspected. However, due to the complex anatomy and special physiological considerations, these may not apply to patients with congenital heart disease (CHD). Misinterpretation of TTE variables can lead to delayed diagnosis and therapy, with fatal consequences, or–on the other hand-unnecessary invasive diagnostic procedures that have relevant risks, especially in the pediatric age group. We herein provide an overview of the echocardiographic workup of children and adolescents with PH with a special focus on children with CHD, such as ventricular/atrial septal defects, tetralogy of Fallot or univentricular physiology. In addition, we address the use of echocardiography as a tool to assess eligibility for exercise and sports, a major determinant of quality of life and outcome in patients with PH associated with CHD.

Potts anastomosis in children with severe pulmonary arterial hypertension and atrial septal defect

Aims

Potts shunt has been proposed as a bridge or alternative to lung transplantation for children with severe and drug‐refractory suprasystemic pulmonary arterial hypertension (PAH). We describe the management of the atrial shunt when a Potts shunt is planned in refractory PAH.

Methods and results

We report a case series of children in whom a Potts shunt was done for severe PAH associated with an atrial septal defect to illustrate the different clinical and haemodynamic scenarios. Five children (2 to 13 years) underwent a Potts shunt: three surgical, one percutaneous Potts shunt, and one percutaneous stenting of a restrictive arterial duct. All had associated atrial septal defect. Those who had generalized cyanosis before the procedure had a complicated postoperative course and required longer ventilatory and inotropic support, except the one who had atrial septal defect closure before the Potts shunt. One of the three cyanotic patients died. Two patients with left‐to‐right shunt before the Potts shunt had an uncomplicated postoperative course.

Conclusions

Shunt physiology is only partially predictable after the Potts shunt in children with PAH and atrial septal defect. Abrupt drop in left ventricle preload while the right ventricle is decompressed can potentially be prevented by atrial septal defect closure prior to the Potts shunt.

Transcatheter creation of a Potts shunt with the Occlutech Atrial Flow Regulator: Feasibility in a pig model

BACKGROUND

Creation of a Potts shunt, a connection between the left pulmonary artery (LPA) and descending aorta (DAo), improves functional status and survival in drug-refractory suprasystemic pulmonary arterial hypertension. We investigated a new approach to transcatheter Potts shunt creation in pigs.

METHODS AND RESULTS

In six pigs, a steerable SureFlex sheath was used to optimize the trajectory of perforation from the DAo into LPA using a 0.035″ radiofrequency wire. The combination of a larger perforation, stiffer radiofrequency wire and smooth dilator-to-sheath transition allowed sheath entry into the LPA without requiring an arterio-venous wire circuit. The Occlutech Atrial Flow Regulator (AFR), a double-disc device with a central fenestration, was deployed through this sheath with apposition of the distal disc to the posterior LPA wall and the proximal disc to the anterior DAo wall. The AFR is compliant and crumpling of the central fenestration was resolved by balloon dilation. It was feasible to implant a stent within the fenestration (n = 3). Aortography confirmed a left-to-right shunt through the AFR without contrast extravasation. Autopsy demonstrated anchoring of both discs against the vessel walls, patency of the fenestration and secure placement of the stent with no intra-thoracic bleeding.

CONCLUSIONS

In an acute pig model, we have demonstrated the feasibility of creating a transcatheter Potts shunt with a simplified technique using a steerable sheath, a double-disc device with a central fenestration that acts as the shunt channel and optional stenting of the fenestration.

Upfront triple combination therapy in severe paediatric pulmonary arterial hypertension

Treatment strategies in paediatric pulmonary arterial hypertension (PAH) have evolved over the last years, but survival is still poor. Recently, in adults with severe PAH, upfront triple combination therapy (uTCT) from diagnosis has been reported to show significant clinical improvement and excellent long-term outcome. This retrospective, observational study aimed to assess the efficacy of uTCT in paediatric PAH.

Children diagnosed with PAH between 2010 and 2019 and started with uTCT were included. World Health Organization Functional Class (WHO-FC), haemodynamics, echocardiography, 6-min walking distance and serum level of N-terminal pro-brain-natriuretic-peptide were assessed at baseline, after 3 and 6 months and at last available follow-up. Events were defined as death, lung transplantation or Potts shunt.

21 children (median age 4.8 years (2.5–12.8), 57% females) were included. All children except one were in WHO-FC III or IV (28% and 67%, respectively). After 3 months, one child had died and one child had received a Potts shunt. The remaining 19 children showed clinical and echocardiographic improvement, which persisted at 6 months. Children with idiopathic and heritable PAH showed one-, two- and three-year transplant-free survival estimates of 100%, 94% and 87%, albeit 47% of them receiving a Potts shunt during follow-up.

Children with severe PAH, but not pulmonary veno-occlusive disease, improved significantly with uTCT and showed beneficial up to 3-year survival rates, albeit 47% of them receiving a Potts shunt during follow-up. The role of a Potts shunt in conjunction to uTCT in paediatric PAH needs to be further established.

Valved reverse Potts shunt in a case of pulmonary hypertension due to pulmonary veno-occlusive disease

Idiopathic pulmonary hypertension has a predictably morbid natural history with an absence of a uniformly successful treatment strategy. We describe our palliative surgical strategy in a symptomatic teenager. A 16-year-old girl, with a recent diagnosis of severe suprasystemic pulmonary hypertension, with severe right ventricular dysfunction, presented with syncope and World Health Organization functional class 4 symptoms. Blood and imaging work up revealed changes suggestive of pulmonary veno-occlusive disease. She failed to improve with oral pulmonary vasodilators and was listed for heart and lung transplant. Pending the transplant, a 10-mm handmade valved tube graft was placed between descending thoracic aorta and the proximal left pulmonary artery, on cardiopulmonary bypass. She had an uneventful recovery period with an early improvement in her symptoms. She was discharged home on aspirin and oral pulmonary vasodilators. At last follow up, 4 months post procedure, her functional capacity and right ventricular function had improved. The valved Potts shunt proved to be helpful in improving her symptomatology and as a bridge to transplant.

Palliative balloon atrial septostomy in two pediatric patients with severe pulmonary arterial hypertension requiring extracorporeal membrane oxygenation support

Pulmonary arterial hypertension is a pernicious disease with a diverse etiology in the pediatric population. Despite the increased availability of drug therapies, pulmonary arterial hypertension continues to cause significant morbidity and mortality. In pediatric patients with severe pulmonary arterial hypertension who have failed medical therapy, a few studies have demonstrated the role of balloon atrial septostomy as a bridge to lung transplantation or a means of improving symptomatology. However, no data exists on the utilization of balloon atrial septostomy as a palliative intervention to wean from extracorporeal membrane oxygenation (ECMO) when all other therapies are exhausted. Here we describe a case series of two pediatric patients with severe pulmonary arterial hypertension, requiring ECMO support, who were successfully weaned from ECMO following balloon atrial septostomy.

Shunts: When to Close Them and When to Create Them for Palliation

Pulmonary hypertension, despite specific therapies, remains an incurable disease with a dreadful prognosis. A systemic-to-pulmonary shunt, if left unrepaired, can cause pulmonary arterial hypertension. With time, pulmonary vascular disease develops, and closure of the shunt becomes contraindicated. Operability criteria are not well defined and rely mainly on hemodynamic values that fail to predict long-term survival. Shunts can also be created in selected cases of advanced pulmonary hyper-tension, in view of off-loading the right ventricle and improving cardiac output at the cost of cyanosis. Shunt creation is not without risks and remains indicated only in selected severe cases.