Pulmonary artery banding: adequacy and long-term outcome

Transcatheter Palliation With Pulmonary Artery Flow Restrictors in Neonates With Congenital Heart Disease: Feasibility, Outcomes, and Comparison With a Historical Hybrid Stage 1 Cohort

BACKGROUND

Neonates with complex congenital heart disease and pulmonary overcirculation have been historically treated surgically. However, subcohorts may benefit from less invasive procedures. Data on transcatheter palliation are limited.

METHODS

We present our experience with pulmonary flow restrictors (PFRs) for palliation of neonates with congenital heart disease, including procedural feasibility, technical details, and outcomes. We then compared our subcohort of high-risk single ventricle neonates palliated with PFRs with a similar historical cohort who underwent a hybrid Stage 1. Cox regression was used to evaluate the association between palliation strategy and 6-month mortality.

RESULTS

From 2021 to 2023, 17 patients (median age, 4 days; interquartile range [IQR], 2-8; median weight, 2.5 kilograms [IQR, 2.1-3.3]) underwent a PFR procedure; 15 (88%) had single ventricle physiology; 15 (88%) were high-risk surgical candidates. All procedures were technically successful. At a median follow-up of 6.2 months (IQR, 4.0-10.8), 13 patients (76%) were successfully bridged to surgery (median time since PFR procedure, 2.6 months [IQR, 1.1-4.4]; median weight, 4.9 kilograms [IQR, 3.4-5.8]). Pulmonary arteries grew adequately for age, and devices were easily removed without complications. The all-cause mortality rate before target surgery was 24% (n=4). Compared with the historical hybrid stage 1 cohort (n=23), after adjustment for main confounding (age, weight, intact/severely restrictive atrial septum or left ventricle to coronary fistulae), the PFR procedure was associated with a significantly lower all-cause 6-month mortality risk (adjusted hazard ratio, 0.26 [95% CI, 0.08-0.82]).

CONCLUSIONS

Transcatheter palliation with PFR is feasible, safe, and represents an effective strategy for bridging high-risk neonates with congenital heart disease to surgical palliation, complete repair, or transplant while allowing for clinical stabilization and somatic growth.

Transcatheter Pulmonary Artery Banding in High-Risk Neonates: In-Vitro Study Provoked by Initial Clinical Experience

PURPOSE

Very high-risk, ductal-dependent or complex two-ventricle patients with associated comorbidities often require pulmonary blood flow restriction as bridge to a more definitive procedure, but current surgical options may not be well-tolerated. An evolving alternative utilizes a fenestrated Micro Vascular Plug (MVP) as a transcatheter, internal pulmonary artery band. In this study, we report a case series and an in-vitro evaluation of the MVP to elicit understanding of the challenges faced with device implantation.

METHODS

Following single-center, retrospective review of eight patients who underwent device placement, an in-vitro flow study was conducted on MVP devices to assess impact of device and fenestration sizing on pulmonary blood flow. A mathematical model was developed to relate migration risk to vessel size. Results of the engineering analysis were compared to the clinical series for validation.

RESULTS

At median follow-up of 8 months (range 1-15), survival was 63% (5/8), and 6 (75%) patients underwent subsequent target surgical intervention with relatively low mortality (1/6). Occluder-related challenges included migration (63%) and peri-device flow, which were evaluated in-vitro. The device demonstrated durability over normal and supraphysiologic conditions with minimal change in fenestration size. Smaller vessel size significantly increased pressure gradient due to reduced peri-device flow and smaller effective fenestration size.

CONCLUSION

Device oversizing, with appropriate adjustment to fenestration size, may reduce migration risk and provide a clinically appropriate balance between resulting pressure gradient and Qp:Qs. Our results can guide the interventionalist in appropriately selecting the device and fenestrations based on patient-specific anatomy and desired post-implantation flow characteristics.

Contemporary outcomes after pulmonary artery banding in complete atrioventricular septal defect

BACKGROUND

This study investigated the clinical outcomes and the effect of band tightness on outcome after pulmonary artery banding (PAB) in patients with complete atrioventricular septal defect (AVSD).

METHODS

From 2000 through 2019, among 133 patients with isolated complete AVSD pursuing biventricular repair, 34 patients (25.6%) who underwent PAB were included in this study. Factors associated with adverse outcome, which was defined as prolonged stay in the intensive care unit (ICU) (> 10 days), were analysed using multiple logistic regression model. Receiver operating characteristic (ROC) analysis was performed to identify a threshold band tightness for adverse outcome.

RESULTS

The median age and weight were 43 days and 3.6kg, respectively. There were 4 early deaths. The median ICU stay was 8 days. Twenty-eight patients (28/34, 82.4%) underwent corrective surgery 10 months (IQR 7∼12 months) after PAB. In multivariable analysis, indexed band diameter was identified as a factor associated with adverse outcome (odds ratio 1.60, 95% confidence interval 1.03-2.48; p=0.035). ROC analysis indicated 22.2 mm/m² of indexed PAB diameter measured at discharge as a threshold band tightness for adverse outcome (area under curve 0.871, p<0.001). The level of B-type natriuretic peptide similarly decreased after PAB regardless of band tightness, although the probability of worsening in atrioventricular valve regurgitation (AVVR) was significantly decreased in patients with tighter band (p=0.027).

CONCLUSIONS

PAB is a viable option for patients with early presenting complete AVSD. Tighter PAB might be beneficial for early postoperative outcomes and preventing progression of AVVR in complete AVSD.

Right Ventricular Function After Pulmonary Artery Banding: Adaptive Processes Assessed by CMR and Conductance Catheter Measurements in Sheep

This experimental study describes the adaptive processes of the right ventricular (RV) myocardium after pulmonary artery banding (PAB) evaluated by cine cardiac magnetic resonance (CMR), phase-contrast CMR (PC-CMR), and conductance catheter. Seven sheep were subjected to CMR 3 months after PAB. Conductance catheter measurements were performed before and 3 months after PAB. Four nonoperated, healthy, age-matched animals served as controls. Higher RV masses (p < 0.01), elevated RV end-systolic volumes (p < 0.05), and lower RV ejection fraction (p < 0.01) were observed in the operated group. The time-to-peak pulmonary artery flow was longer in the banding group (p < 0.01). RV maximal pressure and RV end-diastolic pressure correlated with the time-to-peak flow in the pulmonary artery (r = - 0.70 and - 0.69, respectively). In summary, PAB caused RV hypertrophy, increased myocardial contractility, and decreased RV-EF and cardiac output. The time-to-peak pulmonary artery flow correlated with RV pressures.

Modified Damus-Kaye-Stansel Procedure Subsequent to Pulmonary Artery Banding

Both the Damus-Kaye-Stansel procedure and pulmonary artery banding provide an effective palliative technique in certain subsets of patients, but this combination of procedures is potentially hazardous in pulmonary valve geometry. This is a matter of vital concern, especially in patients whose pulmonary arteries have to work after operations as the major systemic output routes. In this report, we present a novel surgical modification that builds a systemic output route without causing valve deformities.

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.

The challenges of cardiac surgery for African children

Abstract

In Africa the specific pattern of cardiovascular diseases and lack of adequate measures for disease prevention and control result in the frequent need for open-heart surgery for the management of complications of cardiomyopathies in children. Several strategies and innovative ways of providing cardiovascular surgical care in African countries have been used, from agreements to send patients overseas, to programmes for the creation of local services to provide comprehensive care locally.

This article attempts to outline the challenges faced by underdeveloped countries in Africa wanting to embark on programmes of cardiac surgery and the need for several sectors of society to play a role in the process. It discusses issues related to the establishment of centres performing cardiac surgery in Africa, describes the treatment of congenital heart disease, and reviews the aspects of management of conditions highly prevalent in or mostly confined to this continent, such as rheumatic heart valve disease and endomyocardial fibrosis.

Intraoperative hypercyanosis in a patient with pulmonary artery band: case report and review of the literature

A case of intraoperative cyanosis in a patient with a common atrioventricular canal palliated with a pulmonary artery (PA) band is presented. The patient's physiology was consistent with cyanosis due to inadequate pulmonary blood flow, and responded quickly to typical interventions used for a hypercyanotic episode in a patient with unrepaired Tetralogy of Fallot. Differences and similarities in the physiology of PA banding compared with Tetralogy of Fallot are presented, including a rationale for treatment options for hemodynamic decompensation occurring in the setting of anesthesia and surgery.

Endoluminal pulmonary artery banding: technique, applications and results

BACKGROUND

Occasionally pulmonary artery banding is necessary to reduce pulmonary arterial blood flow and pressure in patients who cannot be repaired in a single stage. Traditional extraluminal PAB can be associated with significant morbidity. We describe our technique, applications, and results of endoluminal pulmonary artery banding (EPAB) with and without creation of an aortopulmonary window (APW) for complex cardiac anomalies.

METHODS

Thirty-two patients underwent EPAB; 20 patients had simultaneous creation of an APW. Median patient age was 40 days (range, 2 to 3,210); median weight was 3.5 kg (range, 2.4 to 23 kg). Endoluminal pulmonary artery banding fenestrations of 2 to 8 mm were centrally placed in a Dacron patch that was attached circumferentially and intraluminally in the main pulmonary artery. Fenestrations were sized by presence of APW and patient weight. Thirty-one of 32 patients underwent associated cardiac procedures. The mean follow-up period was 2.6 years (range, 0 to 15.5).

RESULTS

Overall early mortality was 31% (10 of 32); 8% in EPAB alone (1 of 12) and 45% for EPAB+APW (9 of 20). Of the early deaths, 7 of 10 had severe, preoperative ventricular dysfunction. There was 1 early EPAB-related complication requiring band revision for relief of partial obstruction of the APW. At hospital dismissal, the mean pressure gradient after EPAB was 55.1 +/- 8.4 mm Hg as assessed by echocardiography. No patient experienced distal pulmonary hypertension, distortion, or band occlusion. There were 6 late deaths. At late follow-up, 5 patients underwent band revision, and complete repair was accomplished in 10 patients.

CONCLUSIONS

Endoluminal pulmonary artery banding provided a consistently effective and durable reduction in pulmonary arterial blood flow with no pulmonary artery distortion. Early mortality was low for EPAB alone. Endoluminal pulmonary artery banding alone is preferred when controlled pulmonary blood flow and cardiopulmonary bypass are required to address intracardiac abnormalities. The role of EPAB with APW needs to be defined.

Determinants of Left Ventricular Dysfunction After Anatomic Repair of Congenitally Corrected Transposition of the Great Arteries

BACKGROUND

Early results for anatomic repair of congenitally corrected transposition of the great arteries are excellent with respect to right ventricular and tricuspid valve function. However, development of left ventricular (systemic ventricle) dysfunction late after repair remains a concern. In this study we sought to determine factors leading to late impairment in left ventricular performance.

METHODS

From August 1992 to July 2005, 44 patients (median age at surgery, 1.6 years; range, 0.6 to 39.6 years) with congenitally corrected transposition of the great arteries had anatomic repair. Left ventricular function and mitral regurgitation were evaluated by echocardiography at follow-up. Twenty-three patients had a Rastelli procedure, and 21 underwent an arterial switch. Twelve patients (27%) were pacemaker dependent at latest follow-up.

RESULTS

Early mortality was 4.5% (n = 2) with 1 late death as a result of leukemia. Median follow-up was 3.0 years (range, 7 days to 12.4 years). Left ventricular function remained unchanged (normal) in 35 patients, improved in 1 patient, and deteriorated in 8 patients (18%). Mitral regurgitation was unchanged in 30 patients, improved in 6 patients, and worsened in 8 patients (18%). Development of left ventricular dysfunction was significantly associated with pacemaker implantation (p = 0.005) and a widened QRS (>20% > 98% percentile of normal; p = 0.03).

CONCLUSIONS

Anatomic repair of congenitally corrected transposition can be performed with low operative mortality. However, late left ventricular dysfunction is not uncommon, with higher incidence in those requiring pacing and with a prolonged QRS. Resynchronization may be of value in patients requiring a pacemaker.

Designing therapeutic strategies for patients with a dominant left ventricle, discordant ventriculo-arterial connections, and unobstructed flow of blood to the lungs

The palliation of the cyanotic child with a dominant morphologically left ventricle, discordant ventriculo-arterial connections, and obstruction to the pulmonary outflow tract has continued to evolve and mature. The evolution began in the early days of surgical palliation with the Blalock-Taussig shunt, extended to construction of cavopulmonary shunts, if required, and then to the Fontan procedure and its subsequent modifications. This journey took nearly 30 years to complete. There is increasing clinical data to document the beneficial effects of this approach, with ever-improving outcomes. Some aspects of the history of the cavopulmonary shunt have been previously reviewed in this journal and elsewhere, as have analysis of outcomes for some groups of patients considered for surgical completion of the Fontan circulation. While there has been some ongoing interest in ventricular septation since the early success of Sakakibara et al., this approach has largely been abandoned. Considerably more challenges and debate resonate in the surgical algorithms defined for patients whose hearts are characterized by a dominant left ventricle, discordant ventriculo-arterial connections, and unobstructed flow of blood to the lungs. This latter group will be the focus of this review, as will the aetiology of the myocardial hypertrophy that is particularly frequent in this group of patients, its clinical recognition, indeed its anticipation, and the multiple surgical strategies designed to prevent or treat it. All these manoeuvres are considered to optimise suitability for, and outcome from, creation of the Fontan circulation.

Doppler-guided regulation of a telemetrically operated adjustable pulmonary banding system

OBJECTIVES

We report on the Doppler-assessed regulation of an adjustable pulmonary artery band (PAB) in an animal model and in our first group of patients.

BACKGROUND

Indications for pulmonary artery banding have expanded to include patients requiring a late arterial switch. A telemetry-operated, fully implantable, adjustable PAB system (FloWatch- PAB, Endoart SA, Lausanne, Switzerland) has been developed to facilitate these operations.

METHODS

The device was implanted in 13 minipigs (age one to five months, weights 3.2 to 12.0 kg). The main study was performed on nine minipigs with adjustments of the PAB at implantation and at 1, 3, 5, 8, and 12 weeks after, assessed by Doppler pressure gradients. Explanation was performed 12 weeks after surgery. A long-term histology study (6 months and 14 months after surgery) was done on the other four minipigs. After approval by the ethics committee, the device was implanted in eight patients with weights between 2.8 and 9 kg to decrease pulmonary blood flow and pressure and to retrain the left ventricle before arterial switch. The device was progressively tightened, with increasing transband Doppler gradients. Follow-up was one to three months.

RESULTS

An excellent correlation between transbanding systolic pressure gradient and degree of PAB constriction was encountered in the minipig study as well as in the human setting. No early or late deaths or reoperations occurred. Malfunction of the device was noted in three of 21 implanted devices. Two were related to surgically inflicted damage at implantation and one to an electronic problem that was fixed by resetting the control device.

CONCLUSIONS

The device offers a Doppler-controllable adjustment of pulmonary blood flow. It permits controlled tightening and release of the band, which improves perioperative and postoperative courses and decreases surgical interventions to adjust tightness of the band. It allows a protracted occlusion protocol, which may provide the best effect on retraining the left ventricle.

Chronic and adjustable pulmonary artery banding

OBJECTIVE

Banding of the pulmonary artery might be required to prevent pulmonary vascular damage in patients with increased pulmonary artery flow and to retrain the left ventricle in preparation for an arterial switch operation in patients with congenitally corrected transposition of the great arteries. Readjustment of the pulmonary artery band might be required in the postoperative period. In this study we aimed to test the feasibility of a novel device for bidirectionally adjustable pulmonary artery constriction.

METHODS

A hydraulic main pulmonary artery occluder was implanted in lambs and gradually inflated to create right ventricular pressure overload at a systemic (aortic) level. During the following period (up to 12 weeks), this pressure overload was monitored by measuring aortic and right ventricular pressures by means of implanted subcutaneous reservoirs. If required to maintain the right ventricular pressure overload at a systemic level in the growing animals, the occluder was deflated through a third subcutaneous reservoir.

RESULTS

After the banding period (average of 64 +/- 8 days), the main pulmonary artery cuff could still be adjusted, and the animals showed no clinical signs of heart failure. Histologic analysis of the pulmonary artery showed extensive fibrosis, a giant cell response around the device, and small areas of tissue necrosis; complete transmural necrosis was not detected.

CONCLUSIONS

This device allows adjustment of the pulmonary artery cuff in a precise manner over a prolonged period of time without surgical reintervention. Potentially, the device might have applications for clinical use in children with congenital heart disease.

The challenge of pediatric cardiac services in the developing world

Pediatric cardiac services are too expensive for most developing nations. Problems other than cardiac disease take priority when it comes to budget allocations. Poor health infrastructure and referral systems, malnutrition, and the HIV/AIDS pandemic aggravate the situation, and the increasing economic divide is threatening what services do exist. We highlight how the practice of pediatric cardiac surgery in South Africa compares with first-world standards and outline some of the problems faced by pediatric cardiac services in developing nations.

Save a child's heart: we can and we should

BACKGROUND

Congenital heart disease (CHD) causes the death of thousands of children in developing countries. At the Wolfson Medical Center (WMC), a prototype program has been developed to address this issue.

METHODS

Since 1996, indigent children have been referred to the program, with the cooperation of partners in developing countries. The project's aims are to (a) train their medical personnel at WMC, (b) travel to participating countries to teach, evaluate patients, operate, and promote the development of local centers, and (c) treat children with CHD, at WMC, who lack a local option for care either due to prohibitive costs or unavailability. The project's personnel are state employees who volunteer to treat additional patients within the framework of their salaries, and community volunteers.

RESULTS

The program has seven partner sites in six countries, including two provinces in China (Hebei and Gansu), Ethiopia, Moldova, Nigeria, the Palestinian Authority, and Tanzania. Five physicians and 10 nurses have been trained from five participating countries. Over the past 4 years, 11 teaching trips have been made abroad, and operations have been performed at four partner sites. A total of 386 patients have been operated on-360 at WMC and 26 at other sites. There have been 17 (4.3%) acute deaths. Follow-up is 92% complete with 3 late deaths reported.

CONCLUSIONS

Hospital-based regional centers can be created to promote the care of children with CHD in developing countries. Good results and follow-up care can be provided with appropriate planning.

Multiple ventricular septal defects: how and when should they be repaired?

BACKGROUND

Congenital heart lesions with multiple ventricular septal defects remain a surgical challenge. Traditional approaches often rely on either ventriculotomy for exposure or palliation with pulmonary artery banding. However, indications for repair versus palliation and for various approaches to surgical exposure are not clearly defined.

METHODS

From July 1992 to January 1998, 45 patients with multiple (>/=2) ventricular septal defects (37 with associated lesions) underwent surgery. Median age was 86 days; all but 4 patients were infants. The mean number of defects was 3.7, and almost half of the patients had more than 3 defects. Apical muscular defects were present in 62% of patients. Thirty-one patients underwent primary complete repair through a right atriotomy or trans-semilunar valve approach (group 1), 8 had palliation (group 2), and 6 underwent complete repair after prior palliation elsewhere (group 3). No patient had a ventriculotomy.

RESULTS

One early death occurred in a group 1 patient. Four patients who had had palliation (50%) underwent early reoperation for pulmonary artery band revision because of failure to thrive or band removal after spontaneous closure of the defects. At follow-up (median 22 months), there was 1 death in a group 2 patient (palliation) and 1 other group 2 patient required cardiac transplantation. The only late reoperation was for removal of the pulmonary artery band and closure of multiple apical defects in a group 2 (palliation) patient. No patients who underwent repair have hemodynamically significant residual defects.

CONCLUSIONS

In our experience, palliation of multiple ventricular septal defects is associated with greater morbidity than primary repair. Multiple defects can almost always be repaired adequately in early infancy without ventriculotomy, although "Swiss-cheese" septum may be an indication for palliation.