Transcatheter balloon angioplasty of internal pulmonary artery bands to improve pulmonary blood flow: a case series

Pulmonary artery banding (PAB) is used to restrict pulmonary blood flow in select patients with large left-to-right intracardiac shunts or unrestrictive pulmonary blood flow prior to eventual surgical repair or palliation. More recently, surgical placement of an internal or intraluminal PAB (IPAB) has been used to restrict pulmonary circulation. Here we present two patients who underwent balloon angioplasty of the IPAB to treat cyanosis and improve pulmonary blood flow.

Pulmonary artery debanding in the cath lab: Lessons learned!

Background

Although primary definitive repair of congenital heart disease has become the preferred management approach, pulmonary artery banding (PAB) remains a valuable palliative procedure used to restrict pulmonary blood flow in certain conditions. However, when the band is to be removed, another surgical intervention is usually required.

Methods

To describe percutaneous removal of pulmonary artery band, the medical records of patients who underwent this procedure were reviewed.

Results

Between 2000 and 2020, 143 patients underwent PAB. Of these, we attempted balloon debanding of the pulmonary artery in four patients. At the time of the procedure, the average age of patients was 36 ± 6.24 months, and their average weight was 12.37 kg. Band removal via catheter was successful in three cases and was associated with an adequate reduction in pressure gradient across the pulmonary artery band site (average of 71.67 ± 12.58 to 23.67 ± 2.89 mm Hg). None of the patients experienced complications during or after the procedure. Follow-up data after discharge (3-10 years) provides reassuring and satisfactory results.

Conclusion

Based on our findings, we suggest that percutaneous removal of the pulmonary artery band might be a safe and effective alternative to surgical debanding. However, studies with a larger sample are required for further clinical implementation of the technique.

Percutaneous pulmonary artery debanding

BACKGROUND

There is a paucity of data on palliative or total percutaneous pulmonary artery debanding (p-debanding), particularly with use of a stent.

METHODS

Twelve p-debandings in eight patients were included in this study. Age at pulmonary artery banding (PAB) ranged from 3 days to 1 year (median, 13 days), while p-debanding was performed at 2-157 (7) months. The body weight at the p-debanding ranged from 3.2 to 22.2 (7.3) kg. We chose the balloon diameter of 30-50% to the circumference of the band for palliative, and larger than 50% for total p-debanding, respectively. In either way, the balloon diameter did not exceed 1.5 times the reference vessel diameter. Stent was implanted for palliative p-debanding in 2 patients.

RESULTS

1. The circumference of the band ranged from 16 to 23 (20) mm, while the balloon diameter ranged from 20-60 (40)% to that, where larger than 50% was used for 2 procedures intended total p-debanding. 2. PAB diameter increased from 2.5-4.7 (3.0) mm to 2.8-9.5 (4.5) mm (p<0.01), however, there was no significant change in the diameter in 2 procedures. In one patient, p-debanding was the definitive treatment associated with spontaneous near closure of muscular ventricular septal defect, in another patient of congenitally corrected transposition of the great arteries, severely depressed left ventricular ejection fraction was recovered following p-debanding. 3. Arterial oxygen saturation (SaO₂) increased from 64-97 (80)% to 66-95 (90)% (p<0.01), while in 10 procedures of 6 patients where the indication of p-debanding was hypoxia, SaO₂ increased in 8 procedures. There was no significant pulmonary hypertension following p-debanding.

CONCLUSION

Palliative or total p-debanding using balloon and/or stenting is generally feasible and effective. A balloon diameter 35-50% to the band circumference in palliative, and more than 50% in total p-debanding, while in either way less than 1.5 times the reference vessel diameter, is safe.

Atrial Fibrillation Screen, Management And Guideline Recommended Therapy (AF SMART II) in the rural primary care setting: an implementation study protocol

INTRODUCTION

Screening for atrial fibrillation (AF) in people ≥65 years is now recommended by guidelines and expert consensus. While AF is often asymptomatic, it is the most common heart arrhythmia and is associated with increased risk of stroke. Early identification and treatment with oral anticoagulants can substantially reduce stroke risk. The general practice setting is ideal for opportunistic screening and provides a natural pathway for treatment for those identified.This study aims to investigate the feasibility of implementing screening for AF in rural general practice using novel electronic tools. It will assess whether screening will fit within an existing workflow to quickly and accurately identify AF, and will potentially inform a generalisable, scalable approach.

METHODS AND ANALYSIS

Screening with a smartphone ECG will be conducted by general practitioners and practice nurses in rural general practices in New South Wales, Australia for 3-4 months during 2018-2019. Up to 10 practices will be recruited, and we aim to screen 2000 patients aged ≥65 years. Practices will be given an electronic screening prompt and electronic decision support to guide evidence-based treatment for those with AF. De-identified data will be collected using a clinical audit tool and qualitative interviews will be conducted with selected practice staff. A process evaluation and cost-effectiveness analysis will also be undertaken. Outcomes include implementation success (proportion of eligible patients screened, fidelity to protocol), proportion of people screened identified with new AF and rates of treatment with anticoagulants and antiplatelets at baseline and completion. Results will be compared against an earlier metropolitan study and a 'control' dataset of practices.

ETHICS AND DISSEMINATION

Ethics approval was received from the University of Sydney Human Research Ethics Committee on 27 February 2018 (Project no.: 2017/1017). Results will be disseminated through various forums, including peer-reviewed publication and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12618000004268; Pre-results.

Percutaneous pulmonary debanding for an infant complicated by spontaneously closing muscular ventricular septal defect: A case report and in vitro study

Pulmonary artery banding (PAB) is a standard operation for various congenital heart defects complicated by pulmonary hypertension (PH) and judged unsuitable for primary intracardiac repair. We report successful percutaneous pulmonary artery debanding in a baby complicated by muscular ventricular septal defect (VSD), that was initially large and multiple, but closed spontaneously later. The 5-month-old boy was referred to our hospital on day 3, diagnosed as having aortic coarctation (CoA), with multiple muscular VSDs and severe PH. On day 6, he underwent CoA repair and PAB using expanded polytetrafluoroethylene (ePTFE), while the muscular VSDs were left open. We planned percutaneous pulmonary debanding at the age of 5 months, as the muscular VSDs had become small. After dilation with a Mustang^® (Boston Scientific, Marlborough, Massachusetts, United State) balloon (12 mm diameter) there was a persistent waist indicating a residual narrowing. Use of an extra-high pressure balloon, Conquest^® (Medicon, Osaka, Japan) balloon of the same size, completely eliminated the waist. In in vitro experiments, the Mustang^® partially tore the ePTFE, while a Conquest^® of the same diameter completely opened the band. The mechanism of debanding was tearing of the ePTFE by the knot of the suture thread. Percutaneous pulmonary debanding to avoid unnecessary surgery is feasible in such a patient if the VSD becomes small. <Learning objective: Use of an extra-high pressure balloon, Conquest^® (Medicon, Osaka, Japan) balloon could open the pulmonary artery banding made of expanded polytetrafluoroethylene (ePTFE). The mechanism of debanding was tearing of the ePTFE by the knot of the suture thread. Percutaneous pulmonary debanding to avoid unnecessary surgery is feasible in such a patient if the ventricular septal defect (VSD) becomes small.>.

Validation and clinical use of a novel diagnostic device for screening of atrial fibrillation

AIMS

Patients with asymptomatic and undiagnosed atrial fibrillation (AF) are at increased risk of heart failure and ischaemic stroke. In this study, we validated a new diagnostic device, the MyDiagnostick, for detection of AF by general practitioners and patients. It records and stores a Lead I electrocardiogram (ECG) which is automatically analysed for the presence of AF.

METHODS AND RESULTS

In total, 192 patients (age 69.4 ± 12.6 years) were asked to hold the MyDiagnostick for 1 min, immediately before a routine 12-lead ECG was recorded. Atrial fibrillation detection and ECGs stored by the MyDiagnostick were compared with the cardiac rhythm on the 12-lead ECG. In a second part of the study, the MyDiagnostick was used to screen for AF during influenza vaccination in the general practitioner's office. Atrial fibrillation was present in 53 out of the 192 patients (27.6%). All AF patients were correctly detected by the MyDiagnostick (sensitivity 100%; 95% confidence interval 93-100%). MyDiagnostick AF classification in 6 out of 139 patients in sinus rhythm was considered false positive (specificity 95.9%; 95% confidence interval 91.3-98.1%). During 4 h of influenza vaccination in 676 patients (age 74 ± 7.1 years), the MyDiagnostick correctly diagnosed AF in all 55 patients (prevalence 8.1%). In 11 patients (1.6%), AF was not diagnosed before, all with a CHA2DS2VASc score of >1.

CONCLUSION

The high AF detection performance of the MyDiagnostick, combined with the ease of use of the device, enables large screening programmes for detection of undiagnosed AF.

Pulmonary artery debanding

Pulmonary artery banding is a simple palliative surgical procedure for congenital heart defects with left-to-right shunt or complete mixing and pulmonary over-circulation. Even though indication for pulmonary artery banding has been sensibly reduced, since early reparative surgery has been proved superior to palliation and a staged approach, an increasing support for pulmonary banding has been raised in the last two decades by new indications such as left ventricular retraining, in the late arterial switch operation for complete transposition of the great arteries or before the double-switch operation in congenitally corrected transposition. Along with the increasing interest raised by the new indications and the consequently more diffuse use of banding, debanding has become an important surgical issue. Debanding is usually performed several months after palliation along with the repair of the cardiac malformations; otherwise, it can be done progressively or partially to further delay surgery and let the patient grow. Occasionally, after pulmonary artery banding, a spontaneous resolution of the underlying cardiac malformation can occur; however, a debanding procedure is in any case necessary.

Pulmonary artery banding

Pulmonary artery banding (PAB) is a simple surgical technique to reduce pulmonary overcirculation in some congenital heart disease. In the beginning, when the use of cardiopulmonary bypass was affected by many deleterious effects, this technique played a fundamental role in the treatment of patients with congenital heart defects and an intracardiac left-to-right shunt. The use of PAB has decreased during the last two decades, due to the increasing popularity of early complete intracardiac repair, which results have shown to be superior to staged repair, even in low body weight patients. Moreover, several authors have emphasized the negative effects of PAB such as pulmonary arterial branch distortion, abnormal right ventricular hypertrophy, pulmonary valve insufficiency, sub-aortic obstruction and decreased ventricular compliance in patients with univentricular heart. For all these reasons, this procedure has been placed in the dark corner of surgery, representing, between 2002 and 2005, ∼2% of the total amount of cardiac surgery procedures. In a more recent era, PAB has been performed in instances other than classic univentricular heart, as palliation in small infants with cardiac defects with a left-to-right shunt and pulmonary overcirculation, thus gaining some time prior to a planned staged repair. Recently, the role of PAB is becoming more important in selected subsets of congenital cardiac defects: L-transposition of the great arteries, D-transposition of the great arteries, hypoplastic left heart syndrome, moderately hypoplastic left ventricle (congenitally corrected transposition of the great arteries). This renewed interest in the banding procedure is spurring all surgeons and cardiologists to find new solutions for an easier banding procedure while making debanding less traumatic.

Vascular histopathologic reaction to pulmonary artery banding in an in vivo growing porcine model

Pulmonary artery banding (PAB) is used as a surgical palliation to reduce excessive pulmonary blood flow caused by congenital heart defects. Due to the lack of microscopic studies dealing with the tissue remodeling caused by contemporary PAB materials, this study aimed to assess histologic changes associated with PAB surgery by analyzing local tissue reaction to the presence of Gore-Tex strips fixed around the pulmonary artery. Gore-Tex strips were used for PAB in a growing porcine model. After 5 weeks, histologic samples with PAB (n = 5) were compared with healthy pulmonary arterial segments distal to the PAB or from a sham-treated animal (n = 1). Stereology was used to quantify the density of the vasa vasorum and the area fraction of elastin, smooth muscle actin, macrophages, and nervi vasorum within the pulmonary arterial wall. The null hypothesis stated that samples did not differ histopathologically from adjacent vascular segments or sham-treated samples. The PAB samples had a greater area fraction of macrophages, a lower amount of nervi vasorum, and a tendency toward decreased smooth muscle content compared with samples that had no PAB strips. There was no destruction of elastic membranes, no medionecrosis, no pronounced inflammatory infiltration or foreign body reaction, and no vasa vasorum deficiency after the PAB. All the histopathologic changes were limited to the banded vascular segment and did not affect distal parts of the pulmonary artery. The study results show the tissue reaction of palliative PAB and suggest that Gore-Tex strips used contemporarily for PAB do not cause severe local histologic damage to the banded segment of the pulmonary arterial wall after 5 weeks in a porcine PAB model.