Pulmonary Artery Banding for Functionally Single Ventricles: Impact of Tighter Banding in Staged Fontan Era

Reintervention Before Bidirectional Cavopulmonary Shunt and Intermediate Outcomes in Children with Single Ventricle Who Underwent Main Pulmonary Artery Banding

Unplanned reinterventions following pulmonary artery banding (PAB) in single ventricle patients are common before stage 2 palliation (S2P) but associated risk factors are unknown. We hypothesized that reintervention is more common when PAB is placed at younger age and with a looser band, reflected by lower PAB pressure gradient. Retrospective single center study of single ventricle patients undergoing PAB between Jan 2000 and Dec 2020. The association with reintervention and successful S2P was modeled using exploratory cause-specific hazard regression. A multivariable model was developed adjusting for clinical and statistically relevant predictors. The cumulative proportion of patients undergoing reintervention were summarized using a competing risk model. 77 patients underwent PAB at median (IQR) 47 (24-66) days and 3.73 (3.2-4.5) kg. Within18 months of PAB, 60 (78%) reached S2P, 9 (12%) died, 1 (1%) transplanted and 7 (9%) were alive without S2P. Within 18 months of PAB 10 (13%) patients underwent reintervention related to pulmonary blood flow modification: PAB adjustment (n = 6) and conversion to Damus-Kaye-Stansel/Blalock-Taussig-Thomas shunt (n = 4). 6/10 (60%) reached S2P following reintervention. A trend toward higher intervention in patients with a genetic syndrome (p-0.06) and weight < 3 kg (p-0.057) at time of PAB was noted. Only genetic syndrome was a risk factor associated with poor outcome (p-0.025). PAB has a reasonable outcome in SV patients with unobstructed systemic and pulmonary blood flow, but with a high reintervention rate. Only a quarter of patients with genetic syndromes reach S2P and further study is required to explore the benefits from an alternative palliative strategy.

Univentricular Pulmonary Artery Banding: How Tight is Tight Enough for Successful Progress?

We investigated the effects of intraoperative parameters measured during pulmonary artery banding operations and pre-discharge parameters on the completion of Fontan procedures. Fifty consecutive patients with single-ventricle anomalies and unrestricted pulmonary blood flow who underwent a PAB operation in and were discharged from our hospital were retrospectively analyzed. Patients who underwent a Fontan operation, a Glenn shunt operation, or who were eligible for a Fontan procedure were defined as the "successful group." Patients who needed rebanding prior to a bidirectional Glenn shunt, patients who were not eligible for a Glenn shunt, and those underwent a takedown due to high pulmonary arterial pressure after implantation of a Glenn shunt were defined as the "failure-to-progress group." The successful group included 34 (68%) patients and the failure-to-progress group included 16 (32%) patients. The median age was 2 months (IQR 1-4 months). There was a statistically significant difference between the groups in terms of systolic pulmonary arterial pressure, mean pulmonary arterial pressure, and pulmonary arterial pressure/systemic arterial pressure after PAB (P = 0.01, 0.03, and 0.03, respectively). While the median gradient before discharge was 60 mm Hg (IQR 50-70 mm Hg) in the successful group, it was 47.5 mm Hg (IQR 45-63.7 mm Hg) in the failure-to-progress group (P = 0.05). Mortality was observed in one (2.9%) patient in the successful group and five (31.2%) patients in the failure-to-progress group (P = 0.04). Successful pulmonary arterial banding increases long-term survival. Adequate targets should be determined, efforts should be made to achieve these targets, and patients should be followed up closely in terms of rebanding when the targets are not reached.

Pulmonary artery banding in patients with functional single ventricle associated with pulmonary hypertension

Background: To assess the impact of our surgical strategy for the treatment of patients with functional single ventricle and pulmonary hypertension, especially in patients>24 months old.Methods We retrospectively analyzed the clinical data of 97 patients with functional single ventricle and pulmonary hypertension undergoing pulmonary artery banding (PAB) in our hospital between April 2010 and December 2018. The surgical results, transition to Glenn operation and subsequent transition to Fontan operation were analyzed.Results: The 97 patients underwent PAB included 34 patients>24 months old, hospital mortality was 2.1% (2/97). 62 patients underwent the second-stage Glenn operation, and 21 patients underwent third-stage Fontan operation. On competing risk analysis, at 80 months after PAB, 81% had undergone the Glenn operation, and 13% were awaiting the Glenn operation. At 35 months after the Glenn operation, 2% of patients had died, 63% had undergone the Fontan operation, and 36% were awaiting the Fontan operation.Conclusion: PAB is an acceptable strategy for patients with functional single ventricle associated with pulmonary hypertension. Outcomes and results of subsequent Glenn and Fontan procedures are generally good included patients>24 months. Accompanied with unbalanced atrioventricular septal defect for lower ratio of transition to Glenn and Fontan operation.

Case report: duct dependency in hypoplastic left heart complex can be reversible without surgery

We describe an infant with duct-dependent hypoplastic left heart complex with moderate hypoplasia of the left ventricle and aortic arch who was not operated due to resource limitations. The left-sided structures grew remarkably due to favourable loading condition changes of the left ventricle, allowing weaning from prostaglandin at the age of 3 months and discharging the patient without intervention.

Reverse Remodeling of Pulmonary Arterioles After Pulmonary Artery Banding in Patients ≥ 2 Years Old with Severe Pulmonary Arterial Hypertension and Congenital Heart Disease

The purpose of this study was to evaluate the pathological changes of the pulmonary arterioles in patients ≥ 2 years of age who first underwent a pulmonary artery banding (PAB) procedure, followed by bidirectional Glenn or Fontan according to their specific conditions. This was a prospective study of 15 children diagnosed and treated with PAB at the Department of Cardiothoracic Surgery of Anzhen Hospital between January 2009 and December 2012. The percentage of media area (%MS) of pulmonary arteriole, the percentage of media thickness (%MT), and pulmonary arterial density (APSC) were calculated from lung tissue sections. Pulmonary artery pressure decreased significantly after PAB surgery (P < 0.01). Postoperative mean pulmonary artery pressure declined significantly (P < 0.01), the cardiothoracic ratio was reduced (P < 0.05), and percutaneous oxygen saturation (inhaled air) decreased to 80-85% (P < 0.01). %MT (from 35.1 ± 5.6% to 26.9 ± 4.3%, P < 0.01), %MS (from 51.4 ± 6.7% to 32.2 ± 7.4%, P < 0.01), and APSC (from 108.3 ± 38.5 to 83.6 ± 19.6, P < 0.01) were decreased significantly after PAB. Five patients underwent the bidirectional Glenn procedure and four underwent Fontan. In conclusion, the results suggest that PAB can reduce pulmonary artery pressure and that pulmonary arterial lesions can be reversed after PAB.

Successful Palliation via Kawashima Procedure of an Infant With Heterotaxy Syndrome and Left-Atrial Isomerism

Background

Heterotaxy is a condition of abnormal lateralization of organs across the body's left-right axis, causing multiple congenital malformations. The anatomic manifestations of heterotaxy syndrome generally follow one of two patterns, referred to as right atrial isomerism (with two similar right atria and duplication of right-sided features of multiple organs) and left atrial isomerism (with two similar left atria and duplication of left-sided features of multiple organs). Cardiac surgical intervention for patients with heterotaxy syndrome depends on ventricular physiology and circulatory balance. For patients with single-ventricle physiology, a Fontan operation, which directs systemic venous return to the pulmonary arteries, is the definitive intervention. Prior to a Fontan operation, many patients require one or more palliative surgeries (eg, a Blalock-Taussig-Thomas shunt or bidirectional Glenn/Kawashima procedure) to prepare them for definitive correction.

Case Report

We present the case of a term female neonate who was transferred to our pediatric cardiovascular intensive care unit for management of suspected congenital cardiac disease. Echocardiography confirmed the diagnosis of heterotaxy syndrome with left atrial isomerism, an interrupted inferior vena cava with azygos continuation, and a hypoplastic left ventricle with single-ventricle physiology. At 11 months of age, she underwent a Kawashima procedure with subtotal pulmonary artery ligation. She tolerated the procedure well and is anticipated to remain stable for the near future, possibly without the need for further cardiac surgery.

Conclusion

Patients with heterotaxy syndrome have congenital malformations in several organ systems, requiring lifelong coordination of care among health providers across multiple disciplines.

Decision-Making for Surgery in the Management of Patients with Univentricular Heart

A series of technical refinements over the past 30 years, in combination with advances in perioperative management, have resulted in dramatic improvements in the survival of patients with univentricular heart. While the goal of single-ventricle palliation remains unchanged - normalization of the pressure and volume loads on the systemic ventricle, the strategies to achieve that goal have become more diverse. Optimal palliation relies on a thorough understanding of the changing physiology over the first years of life and the risks and consequences of each palliative strategy. This review describes how to optimize surgical decision-making in univentricular patients based on a current understanding of anatomy, physiology, and surgical palliation.

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.

Pulmonary artery banding for univentricular heart beyond the neonatal period

Background

It is standard practice to band the pulmonary artery at 2 to 4 weeks of age in patients with univentricular hearts with increased pulmonary blood flow. The behavior of patients banded beyond the neonatal period has not been well elucidated.

Patients and methods

This was a retrospective chart review of 32 consecutive patients (one neonate) who underwent pulmonary artery banding for functionally univentricular heart. The mean age at banding was 5.7 ± 6.0 months, and 34.4% were over 6-months old.

Results

Mortality was 15.6%. The mean systolic pulmonary artery pressure decreased from 43.6 ± 9.7 to 29.6 ± 7.0 mm Hg. The mean pre-discharge echocardiographic band gradient was 60.6 ± 13.6 mm Hg (mean systemic systolic pressure 73.7 ± 11.0 mm Hg) and systemic oxygen saturation was 81.7% ± 5.8%. At a mean follow-up period of 44.9 ± 30.0 months, 6 patients were lost to follow-up, 13 had undergone bidirectional Glenn shunt, and 7 had Fontan operations. Pulmonary artery mean pressure was 17.2 ± 4.6 mm Hg at pre-Glenn catheterization. Of the 5 patients who had not undergone further surgery, only one was inoperable. All were in functional class I or II.

Conclusion

Pulmonary artery banding beyond the neonatal period in suitable patients with univentricular hearts provides reasonable palliation in the intermediate term, with a significant number successfully undergoing Fontan stages.

Extracorporeal life support after cardiac surgery in children: outcomes from a single institution

Extracorporeal life support (ECLS) is used after congenital heart surgery for several indications, including failure to separate from cardiopulmonary bypass, postoperative low cardiac output syndrome, and extracorporeal cardiopulmonary resuscitation. Here, we assessed the outcomes of ECLS in children after cardiac surgery at our institution. Medical records of all children who required postoperative ECLS at our institution were reviewed. Between 2003 and 2011, 36 (1.4%) of 2541 pediatric cardiac surgical cases required postoperative ECLS. Median age of patients was 64 days (range: 0 days-4.1 years). ECLS was in the form of either extracorporeal membrane oxygenation (ECMO; n = 24) or ventricular assist system (VAS; n = 12). Mean duration of ECLS was 4.9 ± 4.2 days. Overall, 21 patients (58%) were weaned off ECLS, and 17 patients (47%) were successfully discharged from the hospital. Patients with biventricular heart (BVH) had higher survival-to-hospital discharge rates compared with those with univentricular heart (UVH) (P = 0.019). Regarding ECLS type, UVH patients who received VAS showed higher rates of device discontinuation than UVH patients who received ECMO (P = 0.012). However, rates of hospital discharge were not significantly different between UVH patients who received VAS or ECMO. Surgical interventions, such as banding of Blalock-Taussig shunt to reduce pulmonary blood flow or placing bidirectional cavopulmonary shunt to minimize ventricular volume overload, were effective for weaning off ECLS in patients with UVH. ECLS is beneficial to children with low cardiac output after cardiac surgery. Rates of survival-to-hospital discharge were higher in BVH patients than UVH patients. Additional interventions to reduce ventricular volume load may be effective for discontinuing ECLS in patients with UVH.

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.

Pulmonary artery banding in the current era: Is it still useful?

Background:

The objective of this study was to assess the results of the pulmonary artery (PA) banding in patients with congenital heart defects (CHD) and pulmonary hypertension (PH) in the current era.

Methods:

We analyzed data from 305 patients who underwent PA banding between April 2005 and April 2010 at our centre. All patients were approached through a left thoracotomy. Twenty percent of patients underwent PA banding based on Trusler's rule (Group 1), 55% of them underwent PA banding based on PA pressure measurement (Group 2), and the rest of them (25%) based on surgeon experience (Group 3). The follow-up period was 39 ± 20 month and 75% of patients (230 cases) had definitive repair at mean interval 23 ± 10 months.

Results:

The rate of anatomically and functionally effectiveness of PA banding in all groups was high (97% and 92%, respectively). There were no significant differences in anatomically and functionally efficacy rate between all groups (P=0.77, P=0.728, respectively). There was PA bifurcation stenosis in six cases (2%), and pulmonary valve injury in one case (0.3%). The mortality rate in PA banding was 2% and in definitive repair was 3%.

Conclusions:

We believe that PA banding still plays a role in management of patients with CHD, particularly for infants with medical problems such as sepsis, low body weight, intracranial hemorrhage and associated non cardiac anomalies. PA banding can be done safely with low morbidity and mortality.

Effect of ventricular volume before unloading in a systemic ventricle supporting the Fontan circulation

The influence of volume overload on ventricular performance has been previously investigated but primarily with respect to the duration of overload. The aim of the present study was to elucidate whether the magnitude of the preoperative volume overload, represented by the ventricular volume, has any effect on ventricular performance long after the Fontan operation in patients with tricuspid atresia. We evaluated consecutive changes in hemodynamic catheterization data obtained at 1, 5, and 10 years after primary Fontan repair. The variables were compared between patients with larger (n = 20) and smaller (n = 21) ventricles (preoperative end-diastolic volume [percentage of predicted] 262 ± 33%, maximum 320% vs 182 ± 22%, minimum 133%, respectively). In a subgroup of patients (n = 33) who underwent symptom-limited exercise at 10.7 ± 3.0 postoperative years, the peak oxygen uptake was measured, and the potential predictors were interrogated. The difference in ventricular contractility between the groups tended to increase with time, with those with a larger ventricle showing poorer contraction, irrespective of whether it was assessed in a load-dependent (ejection fraction) or load-independent (end-systolic elastance) manner. The differences in these variables reached statistical significance at 10 years (p = 0.028 and p = 0.032). Multivariate analysis indicated a larger ventricle was an independent risk factor of poorer aerobic capacity (p = 0.047). In conclusion, ventricular performance was less preserved in those with a larger ventricle, which might result in suboptimal aerobic capacity. Our findings suggest not only early unloading, but also avoidance of excessive volume overload is of importance to minimize the deleterious effect of volume overload on an inherently susceptible ventricle.