Diminutive Pulmonary Arteries Research Articles

Modified Transannular Patching Palliation versus Modified Blalock-Taussig-Thomas Shunt in Infants with Severe Tetralogy of Fallot with Diminutive Pulmonary Arteries

Objective: The purpose of this study was to compare pulmonary arterial (PA) growth and morbidity, mortality, reintervention and complete repair rates after modified transannular patching palliation (mTAP) versus modified Blalock-Taussig-Thomas shunt (mBTS) for palliation in infants with severe tetralogy of Fallot (TOF) with diminutive pulmonary arteries. Methods: This was a retrospective case review study of 107 patients (64 males) with severe TOF who underwent staged repair with either mTAP (n = 55) or mBTS (n = 52) over an 8-year period. Procedure-related PA growth and morbidity, mortality, reintervention and complete repair rates were compared. Results: Two deaths occurred in the mBTS group due to sudden cardiac arrest, and five patients needed reintervention after the mBTS procedure because of shunt thrombosis or stenosis. Postoperative complications of mBTS included sudden cardiac arrest, shunt thrombosis/stenosis, vocal cord palsy and diaphragmatic palsy. Unlike in the mBTS group, no death, severe complications or reintervention occurred in the mTAP group. Oxygen saturations post mTAP and mBTS were significantly higher, which improved from 67.73 ± 4.36% to 94.33 ± 2.19% in the mTAP group and from 68.24 ± 3.87% to 86.87 ± 3.38% in the mBTS group. The increase in oxygen saturation and pulmonary artery growth (from pre- to post palliation) was significantly better with mTAP than with mBTS palliation (p < 0.01). All 55 patients showed complete repair after mTAP, and the time from palliation to complete repair was significantly shorter in the mTAP group. Conclusions: In a severe form of TOF with the hypoplastic PA tree, mTAP seems to be a better strategy that is safe and better facilitates satisfactory pulmonary arterial growth until complete repair than the mBTS procedure.

Modified central shunt in pulmonary atresia with diminutive pulmonary arteries.

The commonly used central shunt (i.e. direct connection of the divided main pulmonary artery to the ascending aorta) to facilitate the growth of the diminutive branch pulmonary artery in patients with pulmonary atresia with major aortopulmonary collateral arteries can cause main pulmonary artery distortion, and subsequent disproportional branch pulmonary artery flow and growth. This report describes a novel technique of shunt construction to minimize pulmonary artery torque and tension by using a modified central shunt constructed from autologous pericardium that is anastomosed in an end-to-side fashion to the lateral aspect of the ascending aorta. This shunt will serve as an intermediary conduit to facilitate the main pulmonary artery anastomosis while minimizing torque and tension on the main pulmonary artery. The tension-free connection between the main pulmonary artery and the aorta enabled by the modified central shunt supports proportional pulmonary artery flow and growth in patients with pulmonary atresia, ventricular septal defect, or multiple aortopulmonary collateral arteries and concomitant diminutive native pulmonary arteries.

Hidden pulmonary arteries in tetralogy of Fallot and pulmonary artery pressure in patients operated with a pulmonary artery

IntroductionThe absence of a pulmonary artery is a rare congenital anomaly that occurs isolated or with other congenital cardiac disorders, particularly tetralogy of Fallot (TOF); meanwhile, a hidden pulmonary artery might exist and originate from a closed ductus arteriosus (DA), which can be stented to reach the artery.Material and methodsThis prospective study describes cardiac catheterization of nine TOF patients diagnosed with the absence of the left pulmonary artery before the operation. The patients were stratified into three groups: group one, whose closed DA was found and connected to the hidden pulmonary artery with a stent; group two, whose hidden pulmonary arteries were found via the pulmonary vein angiography; and group three, for whom we could not find the remnant of the DA, or our attempt to stent the DA to the hidden pulmonary artery was not successful. We also evaluated outcomes of six other surgically-corrected TOF patients who were operated with the absent left pulmonary artery.ResultsThe first group included the patients aged 1, 24, and 30 months, whose CT angiography 6–9 months after stenting showed acceptable left pulmonary artery diameter for surgical correction, and the pulmonary vein angiography of the second group showed a hidden left pulmonary artery with a suitable diameter for surgical correction. However, we were unable to find or stent the DA of group three patients, aged 12, 38, 60, and 63 months. Earlier Angiography might have increased the chance of access to the hidden vessel. Apart from these three groups, follow-ups of six other patients previously corrected with only the right pulmonary artery revealed pulmonary artery hypertension in all patients.ConclusionThe concealed pulmonary artery might be found, and stenting of the closed DA to it might be performed to improve the diameter of the diminutive pulmonary artery. This procedure may allow TOF total surgical correction with two pulmonary arteries. Besides, pulmonary vein angiography can reveal the hidden pulmonary artery.

A road map for collaterals: Use of 3-dimensional techniques in tetralogy of Fallot pulmonary atresia with major aortopulmonary collateral arteries.

Treatment of tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries (MAPCA) remains challenging.1,2 Surgical repair involves unifocalization and arterioplasty of collaterals and frequently diminutive pulmonary arteries (PAs).2 These vessels are frequently torturous and complex, limiting the utility of traditional imaging modalities (eg, echocardiography and angiography).3 We present images from a novel visualization strategy to enhance preoperative understanding of the anatomy.

Long-term results after palliative intra-cardiac repair for tetralogy of Fallot and diminutive pulmonary arteries.

In patients with tetralogy of Fallot with the diminutive pulmonary arteries, we sometimes have to give up the complete intra-cardiac repair due to insufficient growth of the pulmonary arteries. We have carried out palliative intra-cardiac repair using a fenestrated patch. Of all 202 patients with tetralogy of Fallot in our centre since 1996, five patients (2.5%) with the diminutive pulmonary arteries underwent palliative intra-cardiac repair using a fenestrated patch. Mean operative age was 1.8 years. Previous operation was Blalock-Taussig shunt in 4. At operation, the ventricular septal defect was closed using a fenestrated patch and the right ventricular outflow tract was enlarged. Follow-up period was 9.8 ± 2.6 years. There were no operative and late deaths. Fenestration closed spontaneously on its own in four patients 2.7 ± 2.1 years after the intra-cardiac repair with a stable haemodynamics; however, the last patient with the smallest pulmonary artery index had supra-systemic pressure of the right ventricle post-operatively. The fenestration was emergently enlarged. Systemic arterial oxygen saturation was significantly and dramatically increased from 83.5 to 94% after the palliative intra-cardiac repair, and to 98% at the long term. A ratio of systolic pressure of the right ventricle to the left was significantly decreased to 0.76 ± 0.12 at the long term. Now all five patients were Ross classification class I. Although frequent catheter and surgical interventions were needed after the palliative intra-cardiac repair, this repair might be a choice improving quality of life with good results in patients with tetralogy of Fallot associated with the diminutive pulmonary arteries.

Hybrid procedure of right ventricle outflow tract stenting in small infants with pulmonary atresia and ventricular septal defect: early and mid-term results from a single centre.

We retrospectively reviewed the cardiovascular database of our centre in order to analyse our experience in hybrid procedure. We detected six patients who underwent hybrid first approach between November 2007 and December 2015. We report our early results and mid-term outcomes. Median age at the procedure was 26 days, median weight was 3150 g, and median Nakata index was 52 mm2/m2. All procedures were successful except for one: this patient underwent a surgical shunt. No immediate and early deaths or major complications occurred and oxygen saturation levels increased in all the patients. Patients were followed up for a period of 12-103 months, and four of them underwent a procedure of unifocalisation at the mean age of 12.5 months. We reported data from the largest series of patients who underwent this hybrid procedure. Our experience demonstrated encouraging results to expand the use of this approach to bridge high-risk patients with diminutive pulmonary arteries to a second step of surgical repair.

A central shunt to rehabilitate diminutive pulmonary arteries in patients with pulmonary atresia with ventricular septal defect

We evaluated our clinical experiences on rehabilitation of native pulmonary arteries (PAs) with a central shunt using an expanded polytetrafluoroethylene (ePTFE) tube graft in management of pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (MAPCAs) with diminutive PAs. From March 1993 to June 2013, a total of 28 consecutive patients underwent surgery for pulmonary atresia with VSD and MAPCAs. We identified 15 patients who underwent a central shunt procedure using an ePTFE tube graft. Median age and weight at the initial operation were 1.91 months and 5.22 kg, respectively. Ligation of MAPCAs was performed in 3 patients concomitantly. The techniques used were a U-shaped central shunt in 13 patients, and a side-to-side aorto-ePTFE tube graft anastomosis in 2 patients. There was no surgical mortality, and no shunt occlusion. The mean follow-up duration was 70.7 ± 67.1 months. Complete repair was achieved in 13 patients (13 of 14 of the follow-up patients; 92.9%), and the remaining patient is waiting for complete repair. The median age at complete repair was 19.4 months. The mean PA index before the initial central shunt procedure was 22.7 ± 13.2 mm(2)/m(2), which increased to 149.4 ± 86.6 mm(2)/m(2) at the final recordings before shunt division, and 185.9 ± 84.0 mm(2)/m(2) before complete repair. There were 2 late mortality cases. The overall survival rates were 92.9%, 82.5%, and 82.5%, at 1, 5, and 10 years, respectively. A central shunt, using an ePTFE tube graft, is an effective initial palliative procedure for rehabilitation of the diminutive PAs in patients with pulmonary atresia with VSD and MAPCAs.

Development of Pulmonary Arteries after a Central End-to-Side Shunt in Patients with Pulmonary Atresia, Ventricular Septal Defect, and Diminutive Pulmonary Arteries

To evaluate the development of pulmonary arteries (PAs) in patients with pulmonary atresia, ventricular septal defect, and diminutive PAs by using a central end-to-side shunt. A total of 103 consecutive patients (71 male and 32 female) with pulmonary atresia, ventricular septal defect, and diminutive PAs received a central end-to-side shunt between PA and aorta from May 2004 to December 2010. The age and weight ranged between 2 to 86 months and 2.5 to 21.5 kg, respectively. Overall 79 patients with main PA diameters less than 4 mm received a central end-to-side shunt between PA and aorta, and 24 patients with main PAs absence received a modified central shunt between PA branches and aorta. There were no deaths during operation and follow-up. Compared with preoperative measures, total PA index increased from mean value 68.8 ± 11.4 mm2/m2 to 129.1 ± 24.9 mm2/m2 (p < 0.001). The increased PA index change at the time of 6 months or final repair after shunt completion was 87.7 ± 27.4% (27-150%). By multivariate regression analysis, age at shunt, shunt procedure, and number of major aortopulmonary collateral arteries were correlated with increasing PA index change. The central end-to-side shunt promoted sufficient growth of the diminutive central PAs, especially in infant patients. Due to the risk of a distortion of pulmonary branches, the authors interposed a modified procedure for patients with main PAs absence by anastomosis of left PA and right PA directly in an end-to-side fashion to the both lateral wall of ascending aorta. It is technically easy to perform, warrants low risk of shunt thrombosis, and flow restriction in the early postoperative period.

Double outlet right ventricle with single coronary artery

A 27-year-old lady underwent surgery for double outlet right ventricle (DORV) and left ventricular hypoplasia. The patient had malposed great vessels with an aorta (Ao) levo-anterior to a diminutive pulmonary artery (PA), a left superior vena cava (LSVC) in addition to the right superior vena cava (RSVC), and atrial and subpulmonary ventricular septal defects (Fig. 1). A single right coronary artery (RCA) bifurcated to supply the entire heart with tortuous, dilated branches (Fig. 1). No left coronary system was present. Although DORV is a well-known entity, an associated single coronary system is relatively uncommon, found in only 11% of patients [1]. The patient underwent total cavopulmonary correction and is doing well at 2-month follow-up.

Sutureless rescue of a severely hypoplastic pulmonary artery

The management of severely hypoplastic pulmonary arteries in the adolescent or adult with congenital heart disease is challenging. A patient with pulmonary atresia and ventricular septal defect (PA-VSD) presented with severe cyanosis due to a kinked and thrombosed right ventricle to pulmonary artery conduit. Retrograde wedge angiography showed a patent right and a diminutive left pulmonary artery deep in the lung hilus. Treatment options were limited and therefore a different strategy had to be considered to rescue the lung segments. This case report describes the novel use of a covered stent to successfully obtain a sutureless connection between a vascular graft and a diminutive pulmonary artery during a hybrid procedure.

Transannular Pulmonary Enlargement and Bioprostheses for Carcinoid Disease

A diminutive pulmonary artery and right ventricular outflow tract in a 46-year-old woman with a 10-year history of carcinoid syndrome required transannular pulmonary patch enlargement to allow replacement of the pulmonary and tricuspid valves with bioprostheses. The avoidance of anticoagulation permitted further hepatic arterial embolization without an increased risk of bleeding.

Extracardiac Fontan with T-shape conduit in non-confluent pulmonary arteries

A 34 months-old male patient with double inlet right ventricle with nonconfluent pulmonary arteries who underwent successful extracardiac fenestarated Fontan procedure using pre-designed T-shaped PTFE vascular graft after multi-step rehabilitation of the diminutive hilar pulmonary arteries. At first we performed 6 mm confluent pulmonary artery vascular graft implantation with 4 mm BT shunt at patient's 4 weeks old. At 9 months of patient, we upsized the confluent pulmonary arterial graft to 8 mm with bidirectional cavopulmonary connection, and, at 34 months, we performed extracardiac conduit Fontan procedure with pre-designed T-shape conduit including the confluent pulmonary arterial portion at last. Patient shows excellent functional status and development.

Protocols associated with no mortality in 100 consecutive Fontan procedures☆

Results of Fontan's procedure have improved considerably, but perioperative mortality still occurs, attributed to ventricular dysfunction, stroke, arrhythmia, thromboembolism, and multi-organ dysfunction. Our protocols of operative and intensive care unit management address these potential issues, and have been associated with zero mortality, even with many high-risk candidates. From 1996 to 2006, all Fontan patients were managed as follows: operative strategy based on aortic and single atrial cannulation, cooling on full-flow bypass, and hypothermic circulatory arrest to create the Fontan pathway. No direct caval cannulation. Use of central venous lines was completely avoided. Fresh whole blood was used for pump prime and for volume restoration. Inotropic and vasodilator therapy was continued for at least 48 h. Aspirin was used exclusively as anti-thrombotic therapy. Postoperative pleural drainage was accomplished with small pigtail catheters. The usual Fontan pathway was by lateral atrial tunnel (84), with extra-cardiac conduit when dictated by anatomy (16). One hundred Fontan operations were performed with no mortality. All patients were extubated by postoperative day 1. Hospital stay was 10+/-5 days. Complications were: bleeding (1), reintubation (1), emergent fenestration closure (1), pericardial effusion (4), and seizures (1). Risk factors included Fontan connection to one lung (3), diminutive pulmonary arteries (PAs) and unifocalized major aortopulmonary collateral arteries (MAPCAs) (1), discontinuous PAs (3), right ventricle dependent coronaries (3), neonatal pulmonary venous obstruction (3), Trisomy 21 (1), preoperative pacemaker dependence (2), and heterotaxy (10). No candidate was excluded. While many surgeons try to avoid bypass or aortic clamping when performing Fontan operations, the strategies we have employed facilitate safe accomplishment of Fontan's operation in diverse anatomic groups with multiple risk factors, with avoidance of operative mortality in 100 consecutive cases.

Systemic venous segments interposition for pulmonary artery to aorta connection

Two patients with pulmonary atresia and ventricular septal defect underwent implantation of the diminutive pulmonary arteries on the ascending aorta by interposition of short segment of azygos and innominate veins. The very thin structure of the systemic veins' wall matched perfectly the fragile pulmonary arterial wall. The anastomosis were perfectly patent and no aneurism dilatation was evident after three and four months, respectively.

Pulmonary Atresia, VSD in Association with Coronary-Pulmonary Artery Fistula

Congenital coronary-pulmonary artery fistula is rare in patients with pulmonary atresia and ventricular septal defect. The nomenclature, physiological, clinical, and surgical implications of these fistulas are yet to be defined. We report a one-year-old child with pulmonary atresia, ventricular septal defect, and a right coronary-pulmonary artery fistula who also had a diminutive, disconnected left pulmonary artery in addition to aortopulmonary collaterals. The patient underwent corrective surgery. However, the fate of diminutive pulmonary arteries is unknown. The literature was reviewed to explore the clinical or surgical implications of such fistulas for improved understanding and management in the future.

Staged repair of tetralogy of Fallot and diminutive pulmonary arteries with a fenestrated ventricular septal defect patch

Objectives Patients with tetralogy of Fallot and diminutive pulmonary arteries are at risk for suprasystemic right ventricular pressure and right ventricular failure after complete repair. We report the short-term outcome and medium-term follow-up after using a fenestrated ventricular septal defect patch as a component of staged repair in selected patients. Methods We reviewed 47 patients with tetralogy of Fallot and diminutive pulmonary arteries whose ventricular septal defect patch was fenestrated, either electively or as a rescue technique, at a single institution between 1984 and 2001. Results Early mortality was 10.6% and occurred only in patients who underwent rescue fenestration. Review of medium-term follow-up (median, 39 months) revealed 4 late deaths; an additional 4 patients experienced right ventricular failure despite fenestration. Most (7/8) of these late events occurred in patients who underwent planned fenestration. Excessive left-to-right shunt through the fenestration developed in only 2 patients. Conclusions Fenestrated patch closure of the ventricular septal defect in patients with tetralogy of Fallot and diminutive pulmonary arteries resulted in 10.6% early mortality. Used preemptively in selected patients, this technique is associated with no surgical mortality and a low incidence of excessive left-to-right shunt (4%). Early survivors remain at risk for late death and right ventricular failure despite fenestration.

Antegrade palliation for diminutive pulmonary arteries in Tetralogy of Fallot1

The purpose of this study was to evaluate the outcome following palliative reconstruction of right ventricular outflow tract in Tetralogy of Fallot (TOF) with diminutive pulmonary arteries with central and peripheral stenosis. Between 1986 and 1999 in 15 children with the diagnosis of TOF palliative reconstruction of the right ventricular outflow tract without closure of the ventricular septal defect (VSD) was performed. All patients were not suitable for an AP-Shunt because of a diminutive pulmonary vascular bed. Six patients were younger than 1 year at operation. There was one hospital death (6.7%) in a child with additional aortic valve insufficiency in multi-organ failure. Although the postoperative course was prolonged (median duration on ICU: 8 days) and complicated by congestive heart failure, clinically the 14 patients discharged improved significantly. The arterial oxygen saturation increased from 67 to 93% (P<0.001), the hemoglobin decreased from 16.1 to 13.3g/l (P=0.02) and hematocrit from 0.52 to 0.40 (P=0.06). In control angiography, the McGoon Index increased in the average from 1.01 to 1.95 (P<0.001). VSD closure was performed in 12 patients (median: 2.5 years after initial operation) with one perioperative death. A homograft had to be implanted in seven patients and a mechanical prosthesis in the right ventricular outflow tract in one. One late death occurred due to ventricular arrhythmia 12 years after antegrade palliation (11 years after corrective operation). The antegrade palliation seems to be an adequate strategy for the treatment of selected children with diminutive pulmonary arteries in TOF, who were not candidates for primary correction or an AP-Shunt.

INTERVENTIONAL CARDIAC CATHETERIZATION

Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

CYANOTIC CONGENITAL HEART DISEASE WITH DECREASED PULMONARY BLOOD FLOW IN CHILDREN

Of the "five T's" of cyanotic congenital heart disease--tetralogy of Fallot, TGA, TAPVC, truncus, and tricuspid valve abnormalities (tricuspid atresia, stenosis, and displacement)--the first and last are commonly associated with diminished PBF. The four features that comprise tetralogy of Fallot--right ventricular hypertrophy, VSD, overriding aorta, and subpulmonary stenosis--are all secondary to a single morphogenetic defect: failure of expansion of the subpulmonary conus. This also explains the variability in clinical presentation. When neonates need intervention, shunts are usually performed. Coronary arterial anatomy must be defined before repair, which is usually done after these infants are 3 months of age. Although children with repaired tetralogy of Fallot are not completely "normal," markedly increased longevity and improvement in quality of life can be achieved. When major associated defects are present, such as atrioventricular canal defect, diminutive pulmonary arteries or collateral vessels, or left heart lesions, the prognosis changes from excellent to merely good. Tetralogy of Fallot with absent pulmonary valve syndrome is physiologically different from other tetralogy of Fallot conditions and characterized primarily by airway obstruction from massive dilatation of the central and perihilar pulmonary arteries; repair with pulmonary artery reduction is necessary. Tricuspid valve abnormalities include atresia, hypoplasia (i.e., pulmonary atresia with intact ventricular septum), and displacement (i.e., Ebstein anomaly). The pathophysiology that dictates these children's clinical condition (and prognosis) relates to three factors: (1) status of the tricuspid valve, (2) presence and size of a VSD, and (3) TGA or normally related great arteries. Virtually all children with tricuspid valve abnormalities can be palliated; reparative options include repair using two-ventricle, one-ventricle, or 1-1/2 ventricle repair. Children with critical pulmonary stenosis generally have a normal tricuspid valve and right ventricle. Balloon dilation is usually the only therapy necessary.

Magnetic resonance imaging of complex congenital heart disease.

Current MR techniques enable both anatomical and functional evaluations of the heart. Although it is rarely used as a primary diagnostic tool in pediatric cardiology, it can be used as a valuable adjunct to echocardiography and angiography. MRI is particularly useful in clarification of morphology of complex congenital heart diseases. It is the most accurate method of determination of visceral and atrial situs. It is easy to evaluate the systemic and pulmonary venous connections that are very important for the Fontan type of operation, especially in patients with visceral heterotaxy. It facilitates demonstration of diminutive pulmonary arteries in patients with pulmonary atresia. It clearly demonstrates juxtaposition of the atrial appendages that is often missed by echocardiography. The anatomy of the twisted atrioventricular connections is much more clear in MRI than in echocardiography. It enables en face imaging of ventricular septal defect that provides a surgical view. We find en face imaging particularly helpful in patients with double inlet left ventricle and transposition of the great arteries where the size of the ventricular septal defect governs the blood flow into the aorta. It is often advantageous to echocardiography in defining the type of univentricular atrioventricular connections by demonstrating the position and topology of the rudimentary chamber in difficult cases. In double outlet right ventricle, the spatial relationship of the ventricular septal defect to the great arterial valves can be clearly defined by visualizing the ventricular septal defect and the outlet septum in the same imaging plane.