Central Pulmonary Artery Research Articles

Assessment of fluid responsiveness as a component of hemodynamic monitoring in the operating room and intensive care unit

Fluid therapy is a critical, and often primary treatment modality in the management of various critical conditions. Like any therapeutic intervention, intravenous fluids require precise indications, contraindications, and dosing, all determined through the assessment of a patient’s volume status. Hemodynamic assessment plays a pivotal role in the treatment of critically ill patients, enabling clinicians to administer appropriate fluid therapy and cardiovascular support to optimize tissue perfusion and oxygenation. Traditional methods of assessing fluid responsiveness, which are predominantly static such as central venous pressure and pulmonary artery occlusion pressure, often fall short in their predictive accuracy under dynamic clinical conditions. Consequently, there is a growing interest in dynamic methods of fluid responsiveness assessment, which analyze cardiovascular response to specific preload changes. This literature review aims to explore various dynamic methods of hemodynamic assessment, discussing their advantages and limitations based on sources from databases like PubMed and MEDLINE.

Haemodynamic effects of intra-aortic balloon pumps stratified by baseline pulmonary artery pulsatility index.

Intra-aortic balloon pump (IABP) devices are commonly used in patients with heart failure related cardiogenic shock (HF-CS), including those with out-of-proportion right ventricular (RV) dysfunction. Pulmonary artery pulsatility index (PAPi) is a haemodynamic surrogate for RV performance. We aimed to assess short-term haemodynamic changes in patients with HF-CS following IABP support stratified by baseline PAPi. This is a single-centre study of 67 consecutive patients with HF-CS who underwent IABP placement between 2020 and 2022. The primary aim was haemodynamic changes of specific variables on pulmonary artery catheter monitoring over 72h following IABP placement. Secondary aims were clinically significant changes in diuretic regimens, changes in inotropes or vasopressors at 72h following IABP, along with clinical outcomes. Prior to IABP placement, 57% of the total cohort (median age 59years [48, 69], 31% female) had Society of Cardiovascular Angiography and Interventions Stage C HF-CS. Thirty-eight (56%) patients had a PAPi <2.0. Following 72h of IABP support, the PAPi <2.0 group had an observed significant decrease in central venous pressure (CVP; 20 to 12mmHg, P<0.001) and mean pulmonary artery pressure (mPAP; 37.5 to 28.5mmHg, P=0.001), and an increase in PAPi (1 to 1.6, P=0.001). No significant change in cardiac index (CI; 2 to 2.1L/min/m2, P=0.31) was observed. The PAPi ≥2.0 group (N=29) had no observed significant change in CVP (10 to 8mmHg, P=0.47), or PAPi (2.6 to 2.8, P=0.92), but there was a significant improvement in CI (1.9 to 2.5L/min/m2, P=0.004) along with reduction in mPA (37 to 29mmHg, P=0.03). The PAPi <2.0 group had a significant increase in diuretic requirement (52.6% vs. 20.7%, P=0.01) and numerically greater addition of inotropes/vasopressors (47.3% vs. 34.4%, P=0.07) compared with the PAPi ≥2.0 group at 72h following IABP placement. Significantly more patients in the PAPi ≥2.0 group underwent left ventricular assist device (55.2% vs. 26.3%, P=0.02), with no overall significant differences observed in escalation to veno-arterial extracorporeal membrane oxygenation, 30-day mortality, renal replacement therapy post-IABP, or rates of heart transplantation. IABP devices in those with HF-CS and low or abnormal PAPi may provide modest short-term haemodynamic benefits without significant improvement in CI, along with greater need for adjustment in medical therapeutics to achieve haemodynamic optimization.

Donor great vessel free arterial grafts for complex reconstruction during pediatric heart transplantation

ObjectivePrior studies suggest that prolonged donor heart warm ischemia time increases heart transplant mortality. Patients with single-ventricle heart disease requiring transplant with concomitant aortic arch or central pulmonary artery reconstruction present technical challenges that extend donor warm ischemia time using conventional techniques. Studies in larger pediatric and adult patients with single-ventricle anatomy have described the use of prosthetic material for concomitant great vessel reconstruction. We have used donor free arterial grafts to simplify concomitant great vessel reconstructions and reduce warm donor ischemia time in small patients with single-ventricle physiology undergoing heart transplant. The purpose of this study is to review our results in these patients. MethodsChildren with single-ventricle heart disease who underwent free donor arterial graft great vessel reconstruction at heart transplant were identified, divided into aortic arch and central pulmonary artery groups, and retrospectively reviewed. Warm and total ischemia times were recorded contemporaneously at transplant. ResultsFifteen pediatric patients with single-ventricle physiology underwent donor free arterial graft great vessel reconstructions (9 aortic arch, 6 pulmonary artery). Mean donor warm and total ischemia times for the entire cohort were 52.8 ± 10.7 and 341.7 ± 41.2 minutes. Two patients required postoperative extracorporeal membrane oxygenation. Hospital survival was 94% (1 death). There were no late deaths, and 2 patients had late retransplant. There were no early or late aortic or pulmonary artery obstructions, reinterventions, or complications at median follow-up of 14.2 years (interquartile range, 4.2-16.3 years). ConclusionsDonor free arterial grafts for concomitant great vessel reconstruction during heart transplant in small, single-ventricle patients reduces warm ischemia time, simplifies technical demands, and preserves growth potential.

Simultaneous stent implantation for pulmonary artery bifurcation stenosis in infants.

Pulmonary artery (PA) bifurcation stenosis often requires simultaneous stent placement, which may be technically challenging. Limited data exist regarding this practice in infants. We aim to report the procedural outcomes and safety of bifurcation stent placement in infants. We performed a single-center retrospective review of infants younger than 12 months who underwent simultaneous stent placement for PA bifurcation stenosis from January 1, 2001 through December 31, 2019. Seventeen infants underwent simultaneous PA bifurcation stent placement. The median age was 6.4 months (1.1-10.1 months), and weight was 5.8 kg (3-10.6 kg). Nine (52.9%) patients had had prior PA intervention. Most stents were placed in central PAs (28, 82.4%), followed by lobar branches (6, 17.6%). All patients received pre-mounted stents. The peak gradient across each branch decreased from 47.4 ± 16 to 18.7 ± 13 mm Hg (P less than .0001). The right ventricle to systemic systolic pressure ratio decreased from systemic (1.0 ± 0.3) to just over half systemic (0.58 ± 0.2) (P = .0001). The minimum vessel diameter increased from 3.6 ± 1.5 to 6.0 ± 1.9 mm (P less than .0001). There were 4 (23.5%) patients with high severity adverse events. There were no procedure-related deaths. The median follow-up period was 83.8 months (5.3 months-19.4 years). All patients had subsequent PA re-intervention at a median time of 8.1 months (2.9 months-8.8 years), and median time to re-operation was 19.1 months (2.9 months-7.5 years). Simultaneous PA stent placement is an effective strategy for relief of bifurcation stenosis in infants. Future transcatheter interventions are necessary to account for patient growth, but may delay the need for re-operation.

Stereotactic body radiotherapy in ultracentrally located lung tumors

Stereotactic body radiotherapy (SBRT) is a highly conformal radiotherapy technique that delivers high doses of radiation per fraction, typically in 1 &amp;ndash; 5 fractions. It is a standard treatment option for patients with early-stage non-small cell lung cancer that is peripherally located, for those who are medically inoperable, or for patients who do not opt for surgery. Similarly, SBRT is considered an effective treatment option for oligometastatic lung tumors. However, in the case of ultracentrally located lung tumors&amp;mdash;tumors situated close to the central airway and mediastinal region&amp;mdash;there is an increased risk of severe toxicities (grade 4 &amp;ndash; 5) due to the dose tolerances of the surrounding organs at risk. The definition of ultracentrally located lung tumors remains unclear. Some studies define an ultracentral lung tumor as one in which the gross tumor volume directly involves the proximal bronchial tree or trachea, while others define it as the planning target volume (PTV) that includes the trachea or main bronchial system. In addition, some studies consider tumors whose PTV touches or overlaps with the central bronchial tree, esophagus, pulmonary vein, or pulmonary artery as ultracentral. In addition, the optimal SBRT regime and organ-at-risk dose limitations for ultracentral tumors have yet to be clearly established. The aim of this review is to explore and discuss the role of SBRT in the treatment of ultracentrally located lung tumors.

Living-donor lobar lung transplantation for pulmonary Langerhans cell histiocytosis complicated by extensive thrombi in central pulmonary arteries

BackgroundPulmonary Langerhans cell histiocytosis (PLCH) is a rare disorder characterized by the proliferation of Langerhans cells along the small airways, which causes nodular and cystic changes in the lung parenchyma. Lung transplantation can be a life-saving option for patients with severe respiratory failure or pulmonary hypertension. Herein, we present a case of successful lung transplantation in a patient with PLCH who developed unusually large thrombi in the central pulmonary artery.Case presentationA 47-year-old woman with 16-year history of PLCH with rapidly developing respiratory failure was admitted to our hospital for the evaluation of a lung transplant. Enhanced computed tomography revealed large thrombi in dilated central pulmonary arteries. Right heart catheterization revealed severe pulmonary hypertension, with a mean pulmonary artery pressure of 48 mmHg. The thrombi shrank markedly after 3 months of anticoagulation therapy. However, the respiratory status of the patient did not improve. We performed bilateral living-donor lobar lung transplantation with thrombectomy under extracorporeal membrane oxygenation for the remaining thrombi in the main pulmonary arteries. The dilated main pulmonary arteries of the recipient required direct plication for size mismatch. The patient survived in good condition for more than 2 years with no recurrence of thrombosis.ConclusionPreoperative anticoagulation therapy for massive thrombi in the pulmonary arteries was effective and led to safe lung transplantation.

Central Venopulmonary Extracorporeal Membrane Oxygenation: Background and Standardized Nomenclature.

This review highlights advancements in extracorporeal life support (ECLS), emphasizing the critical role of standardized terminology, particularly for extracorporeal membrane oxygenation (ECMO) in treating right ventricular and respiratory failure. Advocating for the adoption of the Extracorporeal Life Support Organization (ELSO) Maastricht Treaty for ECLS Nomenclature guidelines, it aims to resolve communication barriers in the ECMO field. Focusing on venopulmonary (VP) ECMO utilizing central pulmonary artery (PA) access, this review details surgical approaches and introduces a terminology guide to support effective knowledge exchange and advancements in patient care.

Relationship of Aortopulmonary Collaterals and Pulmonary Artery Development During Staged Single Ventricle Reconstruction.

To evaluate the relationship of aortopulmonary collaterals and the development of central pulmonary arteries during staged palliation. A total of 287 patients, who underwent staged palliation with bidirectional cavopulmonary shunt and total cavopulmonary connection between 2008 and 2019, had available angiography. Pulmonary artery index was calculated using pulmonary angiography as described by Nakata and colleagues. Aortopulmonary collaterals were observed in 47 (16%) patients at stage II palliation, in 131 (46%) at total cavopulmonary connection, and afterwards in 49 (7%). The interventional closure of aortopulmonary collaterals was performed before stage II in 12 (4%) patients, before Fontan completion in 38 (13%), and afterwards in 39 (14%). Presence of aortopulmonary collaterals before stage II was not associated with the pulmonary artery index (129 vs. 150 mm2/m2, p = 0.176) at stage II. In contrast, aortopulmonary collaterals before the Fontan completion were associated with lower pulmonary artery index (154 vs. 172 mm2/m2, p = 0.005), and right pulmonary artery index (99 vs. 106 mm2/m2, p = 0.006). Patients who underwent interventional closure of aortopulmonary collaterals before total cavopulmonary connection had lower pulmonary artery index (141 vs. 169 mm2/m2, p < 0.001), lower right pulmonary artery index (93 vs. 106 mm2/m2, p = 0.007), and left pulmonary artery index (54 vs. 60 mm2/m2, p = 0.013) at Fontan completion. The presence of aortopulmonary collaterals did not influence pulmonary artery size by the time of stage II. However, presence of aortopulmonary collaterals was associated with under-developed pulmonary arteries at Fontan completion, especially in patients who needed interventional closure of aortopulmonary collaterals.

Evaluation of the Pulmonary Arteries on CTPA With Dual Energy CT: Objective Analysis and Subjective Preferences in a Multireader Study.

To perform qualitative and quantitative evaluation of low-monoenergetic images (50KeV) compared with conventional images (120kVp) in pulmonary embolism (PE) studies and to determine the extent and clinical relevance of these differences as well as radiologists' preferences. One hundred fifty CT examinations for PE detection conducted on a single-source dual-energy CT were retrospectively evaluated. Attenuation, contrast-to-noise-ratio, and signal-to-noise-ratio were obtained in a total of 8 individual pulmonary arteries on each exam-including both central (450/1200=37.5%) and peripheral (750/1200=62.5%) locations. Results were compared between the conventional and low-monoenergetic images. For quality assessment, 41 images containing PE were presented side-by-side as pairs of slices in both conventional and monoenergetic modes and evaluated for ease in embolus detection by 9 radiologists: cardiothoracic specialists (3), noncardiothoracic specialists (3), and residents (3). Paired samples t tests, a-parametric Wilcoxon test, McNemar test, and kappa statistics were performed. Monoenergetic images had an overall statistically significant increased average ratio of 2.09 to 2.26 ( P <0.05) for each measured vessel attenuation, with an increase in signal-to-noise ratio (23.82±9.29 vs. 11.39±3.2) and contrast-to-noise ratio (17.17±6.7 vs 7.27±2.52) ( P <0.05). Moreover, 10/150 (6%) of central pulmonary artery measurements considered suboptimal on conventional mode were considered diagnostic on the monoenergetic images (181±14.6 vs. 387.7±72.4 HU respectively, P <0.05). In the subjective evaluation, noncardiothoracic radiologists showed a preference towards low-monoenergetic images, whereas cardiothoracic radiologists did not (74.4% vs. 57.7%, respectively, P <0.05). The SNR and CNR increase on monoenergetic images may have clinical significance particularly in the setting of sub-optimal PE studies. Noncardiothoracic radiologists and residents prefer low monoenergetic images.

Bridge to transplant in single-ventricle anatomy: subpulmonary support with EXCOR ventricular assist device associated with pulmonary artery reconstruction.

Patients with a single ventricle circulation continue to be a challenge for a heart transplant. The patients in this cohort, often in poor clinical condition with frequent hepatic and renal impairment having undergone previous multiple surgical procedures, are often allosensitive and consequently have an increased risk of post-transplant complications. Although the most recently published series results are improved, this group of patients, with preserved ventricular function, continues to have a higher mortality rate. Moreover, the operation can be complicated by anatomical differences among the pulmonary arteries. This case report presents a child with tricuspid atresia and pulmonary vascular resistance contraindicating Fontan surgery, unfavourable anatomy of the central pulmonary arteries and in poor clinical condition. An EXCOR ventricular assist device (Berlin Heart) was used for sub- pulmonary mechanical circulatory support and pulmonary bifurcation reconstruction, as a bridge to a transplant.

Diagnostic value of 3D volume measurement of central pulmonary artery based on CTPA images in the pulmonary hypertension

BackgroundThis retrospective study aims to evaluate the diagnostic value of volume measurement of central pulmonary arteries using computer tomography pulmonary angiography (CTPA) for predicting pulmonary hypertension (PH).MethodsA total of 59 patients in our hospital from November 2013 to April 2021 who underwent both right cardiac catheterization (RHC) and CTPA examination were included. Systolic pulmonary artery pressure (SPAP), mean PAP (mPAP), and diastolic PAP (DPAP) were acquired from RHC testing. Patients were divided into the non-PH group (18 cases) and the PH group (41 cases). The diameters of the main pulmonary artery (DMPA), right pulmonary artery (DRPA), and left pulmonary artery (DLPA) were measured manually. A 3D model software was used for the segmentation of central pulmonary arteries. The cross-sectional areas (AMPA, ARPA, ALPA) and the volumes (VMPA, VRPA, VLPA) were calculated. Measurements of the pulmonary arteries derived from CTPA images were compared between the two groups, and correlated with the parameters of RHC testing. ROC curves and decision curve analysis (DCA) were used to evaluate the benefit of the three-dimensional CTPA parameters for predicting PH. A multiple linear regression model with a forward-step approach was adopted to integrate all statistically significant CTPA parameters for PH prediction.ResultsAll parameters (DMPA, DRPA, DLPA, AMPA, ARPA, ALPA, VMPA, VRPA, and VLPA) of CTPA images exhibited significantly elevated in the PH group in contrast to the non-PH group (P < 0.05), and showed positive correlations with the parameters of RHC testing (mPAP, DPAP, SPAP) (r ranged 0.586~0.752 for MPA, 0.527~0.640 for RPA, and 0.302~0.495 for LPA, all with P < 0.05). For the MPA and RPA, 3D parameters showed higher correlation coefficients compared to their one-dimensional and two-dimensional counterparts. The ROC analysis indicated that the VMPA showed higher area under the curves (AUC) than the DMPA and AMPA without significance, and the VRPA showed higher AUC than the DRPA and ARPA significantly (DRPA vs. VRPA, Z = 2.029, P = 0.042; ARPA vs. VRPA, Z = 2.119, P = 0.034). The DCA demonstrated that the three-dimensional parameters could provide great net benefit for MPA and RPA. The predictive equations for mPAP, DPAP, and SPAP were formulated as [8.178 + 0.0006 * VMPA], [1.418 + 0.0005 * VMPA], and [-11.137 + 0.0006*VRPA + 1.259 * DMPA], respectively.ConclusionThe 3D volume measurement of the MPA and RPA based on CTPA images maybe more informative than the traditional diameter and cross-sectional area in predicting PH.

Are dynamic measurements of central venous pressure in Fontan circulation during exercise or volume loading superior to resting measurements?

The main objective measure to assess the health of the Fontan circulation is the pressure measurement of the superior vena cava or pulmonary arteries. We reviewed the literature for benefits of measuring resting pressure in the Fontan circuit and explored whether dynamic measurement by volume loading or exercise has the potential to refine this diagnostic tool. PubMed was searched for articles showing a relationship between resting post-operative central venous pressure or pulmonary artery pressure and Fontan failure. Relationships between post-operative central venous pressure or pulmonary artery pressure and volume loading changes, such as during exercise or volume loading during cardiac catheterization, were also queried. A total of 44 articles mentioned relationships between resting central venous pressure or pulmonary artery pressure and Fontan failure. Only 26 included an analysis between the variables and only seven of those articles found pressure to be predictive of Fontan failure. Ten articles examined the relationship between exercise or volume loading and outcomes and demonstrated a large individual variation of pressures under these dynamic conditions. Based on current literature, there is not a lot of strong evidence to show that elevated resting central venous pressure or pulmonary artery pressure is predictive of Fontan failure. Some individuals experience dramatic increases in central venous pressure or pulmonary artery pressure under increased loading conditions with exercise or bolus fluid infusion, while others experience increases closer to that of a healthy control population. Further studies are needed to examine whether more dynamic and continuous monitoring of systemic venous pressures might better predict outcomes in patients with Fontan circulation.

Abstract 17842: 3D Visualization and Quantitative Assessment of the Pulmonary Arteries on CT Using Deep Learning Segmentation

Introduction: Assessment of the pulmonary arteries (PA) on CT scan is typically qualitative and requires review of hundreds of images. PA segmentation would enable creation of 3D reconstructions that visualize the entire pulmonary arterial tree in a single image, similar to catheter angiography, and also enable quantification of pathophysiologic changes. Manual segmentation is very time-consuming, but deep-learning (DL) can automate the process. Hypothesis: A DL segmentation algorithm can be used to automatically generate 3D reconstructions of the PAs and quantify morphologic changes seen in Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Pulmonary Arterial Hypertension (PAH). Methods: A DL algorithm based on a 3D U-Net architecture which segments PAs larger than 2 mm was trained and validated on a total of 250 contrast-enhanced CT chest. The study group included 15 CTEPH and 15 PAH patients seen consecutively in pulmonary hypertension (PH) clinic in 2022 with prior CT chest and right heart catheterization, and 10 additional patients with prior CT chest and no evidence of PH on same day echo (normal). After running the DL algorithm on CTs, 3D renderings were created from segmentations and the relative volume of the central, interlobar, and segmental/subsegmental PAs was derived. Results: 3D renderings of PAH and CTEPH patients showed larger central and interlobar PAs compared with those of normal patients, whereas segmental and subsegmental PAs were smaller and pruned in CTEPH patients (Figure). Quantitatively, the volume of the central and interlobar PAs was higher in CTEPH and PAH compared to normal (p &lt; 0.05). The combined volume of segmental/subsegmental PAs was smaller in CTEPH patients relative to normal and PAH patients (p &lt; 0.005). Conclusions: DL segmentation enables intuitive visualization and quantification of the morphologic changes to the PAs seen in conditions causing PH. This method may improve diagnosis and assessment of PH on CT.

T-Remodeling of the Pulmonary Artery Bifurcation for Pulmonary Artery Origin Stenosis.

Various surgical techniques are utilized for reconstructing hypoplastic pulmonary arteries (PAs) in patients with conotruncal anomalies and at times, may be susceptible to restenosis and reoperation. We reviewed our experience with a simple technique of T-shaped remodeling of the PA bifurcation. Between 2005 and 2019, 31 patients underwent T-remodeling of central PAs by a single cardiac surgeon. The PA bifurcation was opened cranially, and the opening was augmented with an oval-shaped patch effectively transforming the V-shaped bifurcation into a T-shaped bifurcation. Both origins of the PAs were enlarged, even in the instance of single PA origin stenosis. Median age at time of T-remodeling was 17 months (range: 7 weeks to 14 years). The following cardiac morphologies were observed: tetralogy of Fallot (n = 12, 39%), pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (n = 8, 26%), truncus arteriosus (n = 6, 19%), pulmonary atresia with VSD (n = 3, 9.7%), and transposition of the great arteries (n = 2, 6.5%). Thirteen patients (42%) had previous central shunt, and eight patients (26%) had previous modified Blalock-Taussig shunt. There were no operative mortalities. Immediately after T-remodeling, echocardiographic estimates of right ventricle to PA gradient decreased from 42 [interquartile range 28-58] mm Hg to 20 [12-36] mm Hg (P = .03). Freedom from reoperation on the PA bifurcation for the entire cohort was 100% at one year, 88% (95% CI 68%-96%) at five years and 82% (57%-93%) at ten years. T-remodeling for PA origin stenosis is a safe procedure with excellent freedom from reoperation that is easily reproducible and applicable to patients with all cardiac morphologies.

Central Lung Tumors Eligible for Stereotactic Ablative Radiotherapy (SABR) Trials: Analysis of a Cohort Treated Using MR-Guided SABR

SABR for central and ultracentral lung tumors results in increased toxicity. We implemented MR-guided SABR in patients meeting the IASLC classification for central tumors, namely a Gross Tumor Volume (GTV) ≤2cm from trachea, main bronchi, esophagus, heart, brachial plexus, main mediastinal vessels, phrenic or laryngeal nerves and spinal cord. As patient inclusion criteria for ongoing clinical trials varies, we studied the eligibility of MR-SABR patients for inclusion into 3 clinical trials for central tumors. An Ethics approved institutional database was accessed for details of patients treated using multifractionated lung MR-SABR between 2016 and 2022. GTV and Planning Target Volumes (PTV) had been delineated on a breath-hold planning MRI and CT scans. For each tumor meeting the IASLC classification, patient eligibility for HILUS (NCT04917224), STRICT/STARLUNG (NCT05354596) and SUNSET (NCT03306680) trials were examined. Multifraction MR-SABR was performed in 97 central lung lesions meeting IASLC criteria. Of these, 73 patients (75.3%) fulfilled inclusion criteria for at least 1 trial, but inclusion in all 3 trials was possible in just 18.6% of treated lesions. Inclusion in the HILUS, STRICT/STARLUNG and SUNSET trials were possible in 33.0%, 73.2% and 25.8% of MR-SABR patients, respectively. For HILUS-eligible patients, 11 met the HILUS group A classification (GTV ≤1cm from the trachea and main bronchi), and 21 in group B (GTV >1cm from the trachea and main bronchi but ≤1cm from the intermediate and lobar bronchi). Use of STRICT/STARLUNG trial criteria would have defined 13 tumors as ultracentral (GTV ≤0.5cm from the trachea, main bronchi or intermediary bronchus or esophagus), and 58 as central (GTV 0.5cm-2.5cm from previously described structures or ≤0.5cm from the heart, aorta, spinal cord or lobar bronchi). For the SUNSET study, 25 tumors fulfilled criteria for ultracentral location (PTV touching or overlapping the central bronchial tree, esophagus, pulmonary vein or pulmonary artery). Ongoing clinical trials in central or ultracentral lung SABR enroll considerably different patient populations than those selected using the IASLC definition of central tumors. Due to steep dose-fall off in SABR plans, detailed descriptions of the location of tumor and organs-at-risk, as well as dose-distributions achieved, are necessary in order to allow study results to be uniformly extrapolated to clinical practice.

Risk Factors and Outcome of Pulmonary Artery Stenting After Bidirectional Cavopulmonary Connection (BDCPC) in Single Ventricle Circulation.

After bidirectional cavopulmonary connection (BDCPC) central pulmonary arteries (PAs) of single ventricle (SV) patients can be affected by stenosis or even closure. Aim of this study is to compare SV patients with and without PA-stent implantation post-BDCPC regarding risk factors for stent implantation and outcome. Single center, retrospective (2006-2021) study of 136 SV consecutive patients with and without PA-stent implantation post-BDCPC. Patient characteristics, risk factors for PA-stent implantation and PA growth were assessed comparing angiographic data pre-BDCPC and pre-TCPC. A total of 40/136 (29%) patients underwent PA-stent implantation at median (IQR) 14 (1.1-39.0) days post-BDCPC. 37/40 (92.5%) underwent LPA-stenting. Multiple regression analysis showed single LV patients to receive less likely PA-stents than single RV patients (OR 0.41; p = 0.05). Reduced LPA/BSA (mm/m2) and larger diameter of neo-ascending aorta pre-BDCPC were associated with an increased likelihood of PA-stent implantation post-BDCPC (OR 0.89, p = 0.03; OR 1.05, p = 0.001). Stent re-dilatation was performed in 36/40 (89%) after 1 (0.8-1.5) year. Pulmonary artery diameters pre-BDCPC were lower in the PA-stent group: McGoon (p < 0.001), Nakata (p < 0.001). Indexed pulmonary artery diameters increased equally in both groups but remained lower pre-TCPC in the PA-stent group: McGoon (p < 0.001), Nakata (p = 0.009), and Lower Lobe Index (p = 0.003). LPA and RPA grew symmetrically in both groups. Single RV, larger neo-ascending aorta, and small LPA pre- BDCPC are independent risk factors for PA-stent implantation post-BDCPC. Pulmonary artery diameters after PA-stent implantation and stent re-dilatation showed significant growth together with the contralateral side, but the PA-system remained symmetrically smaller in the stent group.

Retroaortic Innominate Vein in Association With Pulmonary Atresia/Major Aortopulmonary Collaterals

BackgroundRetroaortic innominate vein (RAIV) is an extremely rare anomaly of systemic venous return. The prevalence of RAIV has been estimated to be 0.02% in individuals without congenital heart disease and 0.5% in those with congenital heart disease. Previous studies have demonstrated an association between RAIV and both conotruncal abnormalities and right aortic arch. Our center specializes in surgical procedures for patients with pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs), and we have frequently observed the presence of RAIV in these patients. The purpose of this study was to evaluate the prevalence and anatomic characteristics of RAIV. MethodsThis was a single-center retrospective review of medical records to identify patients with an RAIV. The study period was 2002 through 2022, with approximately 20,000 patients evaluated during this time frame. ResultsA total of 99 patients were identified with an RAIV. Of the 99 patients, 64 (65%) had PA/VSD/MAPCAs. Other diagnoses included tetralogy of Fallot (n = 16), tetralogy of Fallot with pulmonary atresia (n = 3), double outlet right ventricle (n = 4), peripheral pulmonary artery stenosis (n = 3), and other (n = 9). In the cohort of patients with PA/VSD/MAPCAs, 69% had a right aortic arch and 30% had completely absent central pulmonary arteries. ConclusionsThe overwhelming majority (90%) of patients with RAIV had conotruncal abnormalities, with PA/VSD/MAPCAs accounting for the preponderance of cases in our center.

Revisiting the central aortopulmonary shunt procedure.

In this study, we present our experience with the central aortopulmonary shunt technique with interposing a polytetrafluoroethylene graft between main pulmonary artery (end-to-end) and the ascending aorta (side-to-side) in a variety of cyanotic congenital heart defects. Between January 2019 and June 2022, a total of 10 patients (6 males, 4 females; mean age: 4.3±2.8 months; range, 5 days to 10 months) with hypoplastic central pulmonary arteries who underwent central aortopulmonary shunt procedure were retrospectively analyzed. Demographic characteristics, preoperative, operative, and postoperative data of the patients were recorded. The Nakata indices of the patients were also noted before the procedure, as well as before the second stage of palliation or definitive repair. Four (40%) patients were operated as the first-step palliation for univentricular circulation. Six (60%) patients had well-developed ventricles and were palliated to be treated with total correction. The median follow-up after the procedure was 12 (range, 8 to 16) months. The mean systemic arterial saturation level at room air was 89.3±2.9% during follow-up. No mortality was observed in any patient. A central aortopulmonary shunt procedure provides a reliable antegrade blood flow with a relatively non-challenging surgical technique that offers sufficient growth for the hypoplastic and confluent central pulmonary arteries with a very low risk of shunt thrombosis and overflow.

Antiproliferative effect of selexipag active metabolite MRE-269 on pulmonary arterial smooth muscle cells from patients with chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a group 4 pulmonary hypertension (PH) characterized by nonresolving thromboembolism in the central pulmonary artery and vascular occlusion in the proximal and distal pulmonary artery. Medical therapy is chosen for patients who are ineligible for pulmonary endarterectomy or balloon pulmonary angioplasty or who have symptomatic residual PH after surgery or intervention. Selexipag, an oral prostacyclin receptor agonist and potent vasodilator, was approved for CTEPH in Japan in 2021. To evaluate the pharmacological effect of selexipag on vascular occlusion in CTEPH, we examined how its active metabolite MRE-269 affects platelet-derived growth factor-stimulated pulmonary arterial smooth muscle cells (PASMCs) from CTEPH patients. MRE-269 showed a more potent antiproliferative effect on PASMCs from CTEPH patients than on those from normal subjects. DNA-binding protein inhibitor (ID) genes ID1 and ID3 were found by RNA sequencing and real-time quantitative polymerase chain reaction to be expressed at lower levels in PASMCs from CTEPH patients than in those from normal subjects and were upregulated by MRE-269 treatment. ID1 and ID3 upregulation by MRE-269 was blocked by co-incubation with a prostacyclin receptor antagonist, and ID1 knockdown by small interfering RNA transfection attenuated the antiproliferative effect of MRE-269. ID signaling may be involved in the antiproliferative effect of MRE-269 on PASMCs. This is the first study to demonstrate the pharmacological effects on PASMCs from CTEPH patients of a drug approved for the treatment of CTEPH. Both the vasodilatory and the antiproliferative effect of MRE-269 may contribute to the efficacy of selexipag in CTEPH.

Prognostic role of pulmonary impedance estimation to predict right ventricular dysfunction in pulmonary hypertension.

The effect of pulmonary hypertension (PH) on right ventricular (RV) afterload is commonly defined by elevation of pulmonary artery (PA) pressure or pulmonary vascular resistance (PVR). In humans however, one-third to half of the hydraulic power in the PA is contained in pulsatile components of flow. Pulmonary impedance (Zc) expresses opposition of the PA to pulsatile blood flow. We evaluate pulmonary Zc relationships according to PH classification using a cardiac magnetic resonance (CMR)/right heart catheterization (RHC) method. Prospective study of 70 clinically indicated patients referred for same-day CMR and RHC [60±16years; 77% females, 16 mPAP <25mmHg (PVR <240dynes.s.cm-5 /mPCWP <15mmHg), 24 pre-capillary (PrecPH), 15 isolated post-capillary (IpcPH), 15 combined pre-capillary/post-capillary (CpcPH)]. CMR provided assessment of PA flow, and RHC, central PA pressure. Pulmonary Zc was expressed as the relationship of PA pressure to flow in the frequency domain (dynes.s.cm-5 ). Baseline demographic characteristics were well matched. There was a significant difference in mPAP (P<0.001), PVR (P=0.001), and pulmonary Zc between mPAP<25mmHg patients and those with PH (mPAP <25mmHg: 47±19 dynes.s.cm-5 ; PrecPH 86±20dynes.s.cm-5 ; IpcPH 66±30dynes.s.cm-5 ; CpcPH 86±39dynes.s.cm-5 ; P=0.05). For all patients with PH, elevated mPAP was found to be associated with raised PVR (P<0.001) but not with pulmonary Zc (P=0.87), except for those with PrecPH (P<0.001). Elevated pulmonary Zc was associated with reduced RVSWI, RVEF, and CO (all P<0.05), whereas PVR and mPAP were not. Raised pulmonary Zc was independent of elevated mPAP in patients with PH and more strongly predictive of maladaptive RV remodelling than PVR and mPAP. Use of this straightforward method to determine pulmonary Zc may help to better characterize pulsatile components of RV afterload in patients with PH than mPAP or PVR alone.