Left Pulmonary Artery Stenosis Research Articles

Estimating pulmonary arterial remodeling via an animal-specific computational model of pulmonary artery stenosis.

Pulmonary artery stenosis (PAS) often presents in children with congenital heart disease, altering blood flow and pressure during critical periods of growth and development. Variability in stenosis onset, duration, and severity result in variable growth and remodeling of the pulmonary vasculature. Computational fluid dynamics (CFD) models enable investigation into the hemodynamic impact and altered mechanics associated with PAS. In this study, a one-dimensional (1D) fluid dynamics model was used to simulate hemodynamics throughout the pulmonary arteries of individual animals. The geometry of the large pulmonary arteries was prescribed by animal-specific imaging, whereas the distal vasculature was simulated by a three-element Windkessel model at each terminal vessel outlet. Remodeling of the pulmonary vasculature, which cannot be measured in vivo, was estimated via model-fitted parameters. The large artery stiffness was significantly higher on the left side of the vasculature in the left pulmonary artery (LPA) stenosis group, but neither side differed from the sham group. The sham group exhibited a balanced distribution of total distal vascular resistance, whereas the left side was generally larger in the LPA stenosis group, with no significant differences between groups. In contrast, the peripheral compliance on the right side of the LPA stenosis group was significantly greater than the corresponding side of the sham group. Further analysis indicated the underperfused distal vasculature likely moderately decreased in radius with little change in stiffness given the increase in thickness observed with histology. Ultimately, our model enables greater understanding of pulmonary arterial adaptation due to LPA stenosis and has potential for use as a tool to noninvasively estimate remodeling of the pulmonary vasculature.

Complex Pulmonary Artery Rehabilitation in Children with Alagille Syndrome: An Early Single-Center Experience of a Successful Collaborative Work.

Objective: In this paper, we share our single-center experience of successful multidisciplinary management of patients with Alagille syndrome. In addition, we aim to highlight the need for an Alagille program for effectively managing these patients, in general, and particularly peripheral pulmonary artery stenosis associated with this syndrome. Study Design: This is a retrospective review of six children with Alagille syndrome and advanced liver involvement who underwent pulmonary artery reconstruction between 2021 and 2022. Cardiac diagnosis, co-existing liver disease burdens, management approach, and short-term outcomes were analyzed. Results: All the patients underwent one-stage extensive bilateral branch pulmonary rehabilitation. Concomitant procedures included repair of tetralogy of Fallot in one patient and repair of supravalvar pulmonary artery stenosis in two. One patient had balloon pulmonary branch angioplasty before surgery. In all patients, there was a decrease in right ventricular systolic pressure post-operatively. Three patients underwent liver transplantation for pre-existing liver dysfunction. At a median 3-year follow-up, all the patients were alive with their right ventricular systolic pressure less than half of their systemic systolic pressure. One patient underwent balloon angioplasty due to new and recurrent left pulmonary artery stenosis 13 months after surgery. Conclusion: Pulmonary arteries can be successfully rehabilitated surgically in the presence of complex branch disease. Patients with advanced liver disease can undergo successful complex pulmonary artery reconstruction, which can facilitate their future liver transplantation course. A multidisciplinary team approach is a key for successful management of Alagille patients.

Surgical Management of Norwood Procedure for Atypical Aortic Arch.

Background: Postoperative restenosis of the aortic arch after the Norwood procedure is still an important complication that significantly affects surgical outcomes. The rarity of the Norwood procedure for atypical aortic morphology means appropriate arch reconstruction methods and postoperative complications are still unknown. This study aimed to assess the rate of arch reintervention and clinical outcomes after the Norwood procedure for atypical aortic arch. Methods: This retrospective single-center study was conducted between 2001 and 2022. Sixteen patients were identified, eight with a right aortic arch, five with transposition of the great arteries, one with a right aortic arch and transposition of the great arteries, and two with a large tortuous patent ductus arteriosus connected to the opposite side of the descending aorta. We selected and performed four different surgical techniques depending on each aortic arch morphology. Results: Except for one case, autologous tissue-only arch reconstruction was possible. There was one operative death and four late deaths. Overall, no patients required any surgical or catheter-based reintervention for the aortic arch. On the other hand, left pulmonary artery stenosis due to a narrow subaortic space was found in two patients. Conclusions: The Norwood procedure for atypical aortic arch was performed with good results by choosing the appropriate technique for each morphology. On the other hand, pulmonary artery stenosis is likely to occur especially in the transposition of the great arteries group. Therefore, careful surgical method selection or further improvement of the technique that allows retroaortic space should be considered.

May 2024 Medical Image of the Month: Hereditary Hemorrhagic Telangiectasia in a Patient on Veno-Arterial Extra-Corporeal Membrane Oxygenation

No abstract available. Manuscript truncated after 150 words. A 54-year-old man with a complex cardiac history, including Tetralogy of Fallot requiring Blalock-Taussig shunt in infancy, infundibular patch repair at age 7, and bioprosthetic tricuspid valve replacement at age 52, had ongoing frequent hospitalizations with decompensated right ventricular heart failure secondary to native pulmonary valve mixed stenosis plus regurgitation and left pulmonary artery stenosis. His case was further complicated by his history of hereditary hemorrhagic telangiectasia (HHT) with recurrent epistaxis and recent GI bleeds with multiple angiodysplastic lesions throughout the stomach, duodenum, and descending colon which were previously treated with argon plasma coagulation. The patient was admitted to our hospital in NYHA class IV heart failure receiving a continuous dopamine infusion and aggressive diuresis. Upon admission, a right heart catheterization demonstrated severe pulmonary valve regurgitation, left pulmonary artery stenosis, and systemic hypoxemia suggestive of an intrapulmonary shunt. Admission transthoracic echocardiogram demonstrated normal left ventricular ejection fraction of 55-60%, a …

Short-and-medium term outcomes of Piccolo Device closure of patent ductus arteriosus in premature infants: A single center review

Introduction: Obstruction of the left pulmonary artery (LPA) or descending aorta requiring late intervention is a rare complication after transcatheter closure with Piccolo device, but a multidisciplinary approach is often needed to discover and manage the patient when it does occur. We report our center’s experience with the Piccolo device, including 3 cases of late LPA stenosis requiring surgical debridement and pulmonary artery plasty. Methods: Retrospective chart review of 60 patent ductus arteriosus closures using Amplatzer Piccolo device in premature infants. Results: 60 cases of device closure in premature infants. Transient LPA stenosis was noted in 8% of patients, LPA stenosis requiring surgical intervention in 5% of patients. LPA velocity of 2.7 m/s at any point following device placement by echocardiogram, and right pulmonary artery (RPA) to LPA ratio of 1.5 to 1 by 2D echo are predictive indicators of need for surgical intervention. Differential lung perfusion scans may also provide important prognostic and follow-up data after intervention. Conclusion: Transient LPA stenosis is expected after device closure of a patent ductus arteriosus in premature infants. A multidisciplinary approach and vigilant follow-up are required to discover late complications including LPA occlusion and manage the patient when it does occur.

Pulmonary Artery Angioplasty for Improving Ipsilateral Lung Perfusion in Adolescent and Adult Patients: An Analysis Based on Cardiac Magnetic Resonance Imaging and Lung Perfusion Scanning.

The left pulmonary artery (LPA) may be kinked and stenotic, especially in tetralogy of Fallot, because of ductal tissue and anterior deviation of the conal septum. If LPA stenosis is not effectively treated during total correction, surgical angioplasty is occasionally performed. However, whether pulmonary artery (PA) angioplasty in adolescents or adults improves perfusion in the ipsilateral lung remains unclear. This retrospective review enrolled patients who underwent PA angioplasty for LPA stenosis between 2004 and 2019. Among patients who underwent a lung perfusion scan (LPS) or cardiac magnetic resonance imaging (cMRI) pre- and post-pulmonary angioplasty, those aged >13 years with <40% left lung perfusion (p-left) in the pre-angioplasty study were included. Preoperative and postoperative computed tomography, LPS, and cMRI data were collected. The perfusion ratio was analyzed according to the LPA's anatomical characteristics. Seventeen adolescents and 16 adults (≥18 years old) were finally included (median age, 17 years). The most common primary diagnosis was tetralogy of Fallot (87.9%). In all patients, LPA angioplasty was performed concomitantly with right ventricular outflow tract reconstruction. No patients died. Preoperative p-left was not significantly different between adolescents and adults; however, adolescents had significantly higher postoperative p-left than adults. P-left significantly increased in adolescents, but not in adults. Seven patients had significant stenosis (z-score <-2.0) confined only to the proximal LPA and demonstrated significantly increased p-left. PA angioplasty significantly increased ipsilateral lung perfusion in adolescents. If focal stenosis is confined to the proximal LPA, PA angioplasty may improve ipsilateral lung perfusion, regardless of age.

Impact of preoperative left pulmonary artery stenting on the Fontan procedure: a retrospective multicentre study.

Left pulmonary artery (LPA) or bifurcation stenoses at Fontan palliation can be very challenging to treat and may also require cardioplegia and aortic transection. Moreover, the low pressure of Fontan circulation and the bulkiness of the aorta increase the risk of a patch angioplasty collapse. Pre-Fontan LPA stenting of stenotic LPAs overcomes those drawbacks therefore the present study aimed to evaluate its advantageous impact on Fontan surgery. A multicentre retrospective analysis was performed on 304 consecutive Fontan patients. The study population was divided into 2 groups (LPA stented, n = 62 vs not stented, n = 242); pre-and postoperative data were compared. LPA-stented patients had a higher prevalence of systemic right ventricle (P = 0.01), hypoplastic left heart syndrome (P = 0.042), complex neonatal palliations (Norwood/Damus-Kaye-Stansel) and surgical LPA patch repair at Glenn (P < 0.001). No differences were found in cross-clamp rates, early (P = 0.29) and late survival (94.6% vs 98.4, P = 0.2) or complications (P = 0.14). Complex palliations on ascending aorta/aortic arch (P = 0.013) and surgical LPA repair at Glenn (P < 0.001) proved to be risk factors for LPA stenting before Fontan at multivariable analysis. The LPA-stented group showed similar outcomes in terms of survival and complications rate compared to patients without LPA stenosis; however, they significantly differ in their higher preoperative risk profile and in their more complex anatomy. Complex neonatal palliations involving ascending aorta or aortic arch may increase the risk of pulmonary branches stenosis requiring stenting; therefore, preoperative stenting of LPA stenoses could help to reduce the surgical risk of complex Fontan procedure by avoiding the need for cross-clamp or complex mediastinal dissections to perform a high-risk surgical repair.

Hemodynamic-based virtual surgery design of double-patch repair for pulmonary arterioplasty in tetralogy of Fallot

Background and objectiveSurgical correction of pulmonary artery stenosis (PAS) is essential to the prognosis of patients with tetralogy of Fallot (TOF). The double-patch method of pulmonary arterioplasty is usually applied in case of multiple stenosis in TOF patients’ pulmonary artery (PA) and when PAS cannot be relieved by the single-patch method. The surgical planning for the double-patch design remains challenging. The purpose of this study is to investigate the double-patch design with different angulations between the left pulmonary artery (LPA) and the right pulmonary artery (RPA), and to understand postoperative hemodynamic alterations by the application of computer-aided design (CAD) and computational fluid dynamics (CFD) techniques. MethodsThe three-dimensional model of the PA was reconstructed based on preoperative computed tomography imaging data obtained from the patient with TOF. Three postoperative models with different designs of double-patch were created by “virtual surgery” using the CAD technique. Double-Patch 120 Model was created with double patches implanted in the main pulmonary artery (MPA) and the PA bifurcation and without changing the spatial position of PA. The angulation between the LPA and the RPA was defined as θ, which equaled to 120° in Pre-Operative Model and Double-Patch 120 Model. Based on Double-Patch 120 Model, Double-Patch 110 Model and Double-Patch 130 Model were generated with θ equaled to 110° and 130°, respectively. Combined with CFD, the differences of velocity streamlines, wall shear stress (WSS), flow distribution ratio (FDR), and energy loss (EL) were compared to analyze postoperative pulmonary flow characteristics. ResultsThe values of velocity and WSS decreased significantly after virtual surgery. Obvious vortices and swirling flows were observed downstream of the stenosis of RPA and LPA in Pre-Operative Model, while fewer vortices developed along the anterior wall of the expanded lumens of RPA, especially in Double-Patch 110 Model. With the relief of PAS, two relatively higher WSS regions were observed at the posterior walls of RPA and LPA. The maximum WSS values in these regions of Double-Patch 110 Model were lower than those in Double-Patch 120 Model and Double-Patch 130 Model. Furthermore, the FDRs were elevated and the ELs were greatly reduced. It was found that Double-Patch 110 Model with the angulation between the LPA and the RPA equaled to 110° showed relatively better properties of hemodynamics than other models. ConclusionsThe angulation between the LPA and the RPA is an important factor that should be integrated in the double-patch design for TOF repair. Virtual surgery based on patient-specific vascular model and computational hemodynamics can be used to provide assistance for individualized surgical planning of double-patch arterioplasty.

Left Pulmonary Artery Stenting for Left Pulmonary Artery Stenosis Following Patent Ductus Arteriosus Device Closure: Case Series and Review of the Literature

Percutaneous device occlusion is currently the standard of care for most cases of patent ductus arteriosus (PDA). Albeit infrequent, device‐related left pulmonary artery (LPA) stenosis is a known complication of this procedure, occasionally requiring stent placement to relieve the obstruction. We present a series of four patients who required left pulmonary stenting after ductus arteriosus device closure. A review of the current evidence is presented.

Polymer Coating Embolism: Cause of Left Pulmonary Artery Stenosis in an Infant

Polymer Coating Embolism: Cause of Left Pulmonary Artery Stenosis in an Infant

A Challenging Interventional Procedure: Transcatheter Closure of Tubular Patent Ductus Arteriosus in Patients with Pulmonary Hypertension.

Transcatheter closure of the tubular ducts remains the most challenging procedure, with higher complication rates than other types. This study evaluates the characteristics of transcatheter closure of tubular ducts with pulmonary hypertension. 73 patients with tubular ducts who underwent cardiac catheterization for transcatheter PDA closure were analyzed. The mean age and weight were 1.93 ± 2.68years and 8.83 ± 6.14kg, respectively. Transcatheter closure was attempted in 72 patients. Four cases (5.5%) were referred to surgery, while the procedure was completed in the remaining (94.5%). Amplatzer duct occluder (ADO) I or Cardiofix duct occluder (CDO) was the most commonly used devices. However, the use of Amplatzer vascular plug (AVP) II raised in recent years. The most common concern was aortic protrusion/stenosis in ADO I/CDO devices, but most regressed during follow-up. Iatrogenic coarctation of the aorta was observed in two with ADO I/CDO. Embolization of the device to the pulmonary artery was observed in three with CDO, AVP II, and AVP I. Significant left pulmonary artery stenosis requiring stenting developed in one after closure with an MVSDO device. Tubular ducts are highly associated with pulmonary arterial hypertension, and transcatheter closure of them is still challenging despite the developing device armamentarium. Although ADO I or similar devices are widely used, off-label devices are usually needed at increasing rates. The AVP II device is unsuitable for short tubular ducts but seems the best option for long ones.

A new predictor of the optimal pulmonary artery reconstruction method during the arterial switch operation.

To more accurately predict the optimal pulmonary artery (PA) reconstruction procedure (Lecompte manoeuvre or original Jatene procedure) during the arterial switch operation (ASO), we focused on the horizontal sectioning (HS) angle between the left hilum PA and the great arteries using preoperative computed tomography (CT) imaging. We defined the HS angle α (β) as the angle between the tangential line from the posterior (anterior) wall of the left PA at the hilum to the left anterior (right posterior) surface of the main PA and the tangential line from the left surface of the ascending aorta to the left anterior (right posterior) surface of the main PA. We identified 14 consecutive patients diagnosed with transposition of the great arteries (TGA) or TGA-type double-outlet right ventricle who underwent preoperative CT imaging. The original Jatene or Lecompte procedure was used for nine (OJ group) and five (L group) patients. Relationships of the great arteries of the OJ and L groups were side-by-side in eight and two patients, oblique in one and one patient, and anteroposterior in zero and two patients, respectively. In the OJ group, β was greater than α in all patients. The median α/β value was 0.618. In group L, α was greater than β in all patients. The median α/β was 1.307. Left PA stenosis caused by stretching was not observed in the L group. Coronary obstruction was not identified in the OJ group. Left PA stenosis behind the neo-ascending aorta was observed in one patient in the OJ group and required reoperation. The HS angle may be a useful predictor of optimal intraoperative PA reconstruction during ASO, especially for side-by-side or oblique relationships.

The Amplatzer duct occluder (ADOII) and Piccolo devices for patent ductus arteriosus closure: a large single institution series.

Evaluate Piccolo and ADOII devices for transcatheter patent ductus arteriosus (PDA) closure. Piccolo has smaller retention discs reducing risk of flow disturbance but residual leak and embolization risk may increase. Retrospective review of all patients undergoing PDA closure with an Amplatzer device between January 2008 and April 2022 in our institution. Data from the procedure and 6 months follow-up were collected. 762 patients, median age 2.6 years (range 0-46.7) years and median weight 13 kg (range 3.5-92) were referred for PDA closure. Overall, 758 (99.5%) had successful implantation: 296 (38.8%) with ADOII, 418 (54.8%) with Piccolo, and 44 (5.8%) with AVPII. The ADOII patients were smaller than the Piccolo patients (15.8 vs. 20.5 kg, p < 0.001) and with larger PDA diameters (2.3 vs. 1.9 mm, p < 0.001). Mean device diameter was similar for both groups. Closure rate at follow-up was similar for all devices ADOII 295/296 (99.6%), Piccolo 417/418 (99.7%), and AVPII 44/44 (100%). Four intraprocedural embolizations occurred during the study time period: two ADOII and two Piccolo. Following retrieval the PDA was closed with an AVPII in two cases, ADOI in one case and with surgery in the fourth case. Mild stenosis of the left pulmonary artery (LPA) occurred in three patients with ADOII devices (1%) and one patient with Piccolo device (0.2%). Severe LPA stenosis occurred in one patient with ADOII (0.3%) and one with AVPII device (2.2%). ADOII and Piccolo are safe and effective for PDA closure with a tendency to less LPA stenosis with Piccolo. There were no cases of aortic coarctation related to a PDA device in this study.

O-1 | 3D Printing of Patient-Specific Intravascular Stents for Congenital Heart Disease – Proof of Concept

Patients with congenital heart disease (CHD) may require stent placement for various vascular stenoses. Multiple stents are used “off-label” for patients with CHD. There is a need for accessible, modifiable and customizable stents for patients with CHD. This study aims to provide proof of concept for patient-specific 3D printed metal stents for CHD. Five hearts of patients with CHD and vascular stenoses were identified from our anonymized model database and 3D printed. Custom stents were designed using SolidWorks and Meshmixer and 3D printed with steel using the Ultimaker S5 Pro printer Metal Expansion Kit. The heart models were digitally reconstructed as if the stenosis was treated, 3D printed and the stents implanted by hand. Five stents were printed and implanted in the models. Diagnoses included: Scimitar syndrome with pulmonary vein baffle stenosis; proximal right pulmonary artery stenosis; left pulmonary artery arising from the aortic arch; left pulmonary artery stenosis; hypoplastic left heart syndrome after Norwood with recoarctation. Stent weight range 1-15g, print time 2-36 minutes, cost $0.13–1.94; these times do not account for the necessary post-processing, which is currently 10 business days. Examples of pre- and post-treated models are shown in the Figure. Utilizing the newest 3D metal printing technology, we were able to generate patient-specific stents and implant them in 3D printed models of CHD. The cost and print time are quite low, however the post-processing time is still quite long. As technology advances further, it may become possible to 3D print patient-specific stents in the cath lab.

The angiographic study of right ventricular outflow tract and pulmonary artery anatomy in tetralogy of Fallot

Objective: The objective of the study is to determine various anatomic variations in the pulmonary vasculature and associated cardiac defects in patients with tetralogy of Fallot (TOF). Methods: This was a cross-sectional descriptive study conducted at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore from January 2009 to December 2017. A total of 100 patients irrespective of age and gender, who were subjected to cardiac catheterization were enrolled in the study which included all age groups. Measurement of pulmonary valve annulus, main pulmonary artery, right pulmonary artery (RPA), left pulmonary artery (LPA), and descending aorta was taken and corresponding z scores were calculated. McGoon ratio and Nakata index were also calculated. Results: The age group in our study varied from 9 months to 49 years of age. Male-to-female gender ratio was 3:2. All patients had subvalvar (infundibular) stenosis and 82% of patients had stenosis at the valvar level. Seven patients had discrete stenosis, another seven patients had disconnection of RPA or LPA and six patients had supravalvar stenosis in the form of diffuse hypoplasia of one of the pulmonary arteries (PA). Significant communicating major aortopulmonary collaterals arteries (MAPCAs) were seen in 5% of patients and 16% of the patients had a persistent patent ductus arteriosus (PDA). Persistent left superior vena cava was present in 9 patients and 13% of the patients had coronary anomalies. Conclusion: Subvalvular stenosis, confluence of PA, discrete, disconnected, and diffuse stenosis of LPA and RPA were the most common PA abnormalities found in patients with TOF. Significant-associated cardiac lesions including communicating MAPCA, PDA, and coronary anomaly were more commonly observed in these patients.

Staged left ventricular recruitment facilitated by Sano conduit upsizing

Staged left ventricular recruitment facilitated by Sano conduit upsizing

Transcatheter closure of tubular patent ductus arteriosus using muscular ventricular septal defect devices in infants and small children with congestive heart failure

Transcatheter closure of a patent ductus arteriosus in children is widely performed to reduce symptoms and decrease the risk of endocarditis. Most arterial ducts are closed successfully with dedicated devices. However, in a tubular or "type C" patent ductus arteriosus with congestive heart failure, the occlusion is more challenging with these devices, with a higher risk of complications, such as aortic or left pulmonary stenosis and device embolization. To report our experience with muscular ventricular septal defect devices for patent ductus arteriosus occlusion in small children. Retrospective observational series of patients weighing<10kg, with a tubular patent ductus arteriosus (typeC) and congestive heart failure, who underwent transcatheter closure with a muscular ventricular septal defect device between 2017 and 2019. Eight patients were included. The mean age and weight at closure were 6.3 months (range 1-18 months) and 5.3kg (range 2.4-8.2kg), respectively. All patent ductus arteriosus were occluded successfully using Occlutech® (N=3) or Amplatzer® (N=5) muscular ventricular septal defect devices. In four cases, the muscular ventricular septal defect device was used after failure to close the patent ductus arteriosus with a dedicated patent ductus arteriosus device. Two patients had mild left pulmonary artery stenosis, with a maximum velocity on continuous Doppler of 3m/s and 2.7m/s, respectively. After a mean follow-up of 28 months (range 14-41 months), all patients were asymptomatic with excellent results. The mild pulmonary stenosis improved, with a maximum velocity of 2.3m/s in both patients. Closure of tubular patent ductus arteriosus in small children with congestive heart failure using a muscular ventricular septal defect device is safe in this preliminary experience. Further studies with more patients are warranted.

Use of the Medtronic Microvascular Plug 7Q for transcatheter closure of large patent ductus arteriosus in infants weighing less than 2.5 kg.

BackgroundThe sole Food and Drug Administration‐approved device for transcatheter closure of the patent arterial duct in premature infants is indicated for patent ductus arteriosus (PDAs) ≤ 4 mm in diameter. We report a two‐center experience with transcatheter closure of large PDAs (>4 mm) in infants weighing <2.5 kg using the Microvascular Plug 7Q (MVP‐7Q) device.MethodsThis is a retrospective review of departmental databases and medical charts to define patient cohort and report demographic, procedural, and follow‐up data.ResultsTwenty‐two patients (12 male) with a median gestational age and birthweight of 25.5 weeks (interquartile range [IQR] = 24–28) and 800 g (572–1075), respectively, underwent attempted PDA occlusion with the MVP‐7Q using a transvenous approach. The median age and weight at the time of PDA occlusion was 32 days (IQR = 24–28) and 1100 g (IQR = 960–1700), respectively. The median PDA length was 12 mm (IQR = 11–12.65). The median PDA diameters at the aortic and pulmonary ends were 5.1 (IQR = 4.9–5.5) and 4.8 mm (IQR = 4.6–5.3), respectively. Successful device occlusion was achieved in 20 patients (91%). There were two failed attempts: One due to inappropriate sizing, and the other secondary to left pulmonary artery stenosis. There were no procedural complications and no residual shunting on follow‐up.ConclusionsThe MVP‐7Q is safe and effective for transcatheter closure of large (>4 mm) PDAs in infants <2.5 kg. The lack of retention disks may help with avoiding impingement on surrounding vessels.

Ascending aortic extension to increase aortopulmonary space after comprehensive stage II palliation.

Aortic reconstruction at the time of the comprehensive stage II (CSII) procedure can be complicated by compression within the aortopulmonary space resulting in airway or pulmonary artery narrowing. We describe our experience with 2 patients with hypoplastic left heart syndrome and pulmonary artery stenosis after the CSII procedure. Both patients underwent an aortic extension with a Hemashield interposition graft to open up the aortopulmonary space. The patients were discharged from the hospital. In all cases the aortopulmonary space was enlarged, and the pulmonary arteries and airway were free from compression. Aortic extension is an option to be considered in children with pulmonary artery compression who previously had a CSII procedure.

Clinical Application of Individualized Pulmonary Bi-Orifice for the Reconstruction of Right Ventricular Outflow Tract in Tetralogy of Fallot.

Objective: The study aims to establish a new method in the Tetralogy of Fallot (ToF) called the pulmonary valve bi-orifice method (pulmonary annular sparing with an individualized autologous pericardial patch; thus, two orifices are formed at the level of the pulmonary valve annulus) to reconstruct the right ventricular outflow tract (RVOT).Methods: A retrospective analysis of 128 TOF patients from October 2009 to June 2018 with severe pulmonary valve dysplasia who underwent transvalvular annular patch (TAP) procedure (control group) or an individualized pulmonary valve bi-orifice procedure (observation group) were studied. The RVOT for each patient in the observation group was individually reconstructed per the patient's weight and the size of the autologous pulmonary valve using the bi-orifice method; however, increasing the cross-sectional area of the pulmonary valve annulus without destroying its integrity. The result was then compared to the control group, where TAP procedures were applied to evaluate the short to mid-term outcome(s). An in vitro simulation test was used to verify the anti-regurgitation mechanism of the new method.Results: The in vitro simulation test indicated that the anti-regurgitation mechanism was completed by the pericardial patch and the autologous pulmonary valve movement toward each other. Thus, for clinical applications, patients in both groups were compared. The results showed no significant differences in cardiopulmonary bypass and aortic cross-clamp time, mechanical ventilation, and ICU and post-operative residence between the two groups.During the follow-up period (3- to 12-years), 14 patients in the observation group had mild regurgitation after surgery (22.2%), while 10 patients had moderate pulmonary regurgitation (15.8%) with no right ventricular (RV) dilation. On the other hand, 22 patients (39.6%) had moderate to severe regurgitation in the control group, while left pulmonary artery stenosis occurred in one patient. In the control group, six patients (9.2%) with severe RV dilation were reoperated.Conclusion: Individualized pulmonary valve bi-orifice procedure is a safe and excellent method for reconstructing RVOT in ToF.