Central Pulmonary Artery Research Articles

Congenital central pulmonary artery anomalies: Part 1.

There is a broad spectrum of congenital anomalies of the central pulmonary arteries including abnormalities of development, origin, course and caliber. These anomalies incorporate simple lesions such as isolated pulmonary valve stenosis to very complex anomalies with many associated abnormalities. Part 1 and Part 2 of this review describe the range of anatomical variations that are encountered as well as important aspects of anatomy, physiology and surgical correction. The authors summarize and illustrate well-recognized as well as more complex anomalies to provide a broad and comprehensive understanding of these lesions and their appearances on CT and MR imaging. Part 1 covers anomalous development or origin of the main pulmonary artery.

Impact of ductal stenting on pulmonary artery reconstruction in patients with duct-dependent congenital heart diseases-an institutional experience.

This study aims to review our institutional experience of ductal stenting (DS) on the growth of pulmonary arteries (PAs) and surgical outcomes of PA reconstruction in this subset of patients. This is a retrospective study done in neonates and infants up to 3 months of age with duct-dependent pulmonary circulation who underwent DS from January 2014 to December 2015. Post-stenting PA growth, surgical outcomes of PA reconstruction, post-surgical re-interventions, morbidity and mortality were analysed. During the study period, 46 patients underwent successful DS, of whom 38 underwent presurgery catheterization and definite surgery. There was significant growth of PAs in these patients. Biventricular repair was done in 31 patients while 7 had univentricular palliation. Left PA augmentation was required in 13 patients, and 10 required central PA augmentation during surgery. The mean follow-up period post-surgery was 4.5 ± 1.5 years. No significant postoperative complications were seen. No early or follow-up post-surgery mortality was seen. Four patients required re-interventions in the form of left PA stenting based on the echocardiography or computed tomography evidence of significant stenosis. DS provides good short-term palliation and the growth of PAs. However, a significant number of stented patients require reparative procedure on PAs at the time of surgical intervention. Acquired changes in the PAs following DS may be the reason for reintervention following PA reconstruction.

Contrast media volume is significantly related to patient lung volume during CT pulmonary angiography when employing a patient-specific contrast protocol

Aim: The purpose of this study is to investigate the relationship between contrast media volume and patient lung volume when employing a patient-specific contrast media formula during pulmonary computed tomography angiography (CTA).
 Materials and methods: IRB approved this retrospective study. CTA of the pulmonary arteries was performed on 200 patients with suspected pulmonary embolism (PE). The contrast media volume (CMV) was calculted by employing a patient-specific contrast formula. Lung volume was quantified employing semi-automated lung software that calculated lung volumes (intellispace -Philips). The mean cross-sectional opacification profile of central and peripheral pulmonary arteries and veins were measured for each patient and arteriovenous contrast ratio (AVCR) calculated for each lung segment. Mean body mass index (BMI) and lung volume were quantified. Receiver operating (ROC) and visual grading characteristics (VGC) measured reader confidence in emboli detection and image quality respectively. Inter and intra-observer variations were investigated employing Cohen’s kappa methodology.
 Results: Results showed that the mean pulmonary arterial opacification of the main pulmonary circulation (343.88±73HU), right lung; upper (316.51±23HU), middle (312.5±39HU) and lower (315.23±65HU) lobes and left; upper (318.76±83HU), and lower (321.91±12HU) lobes. The mean venous opacification of all pulmonary veins was below 182±72HU. AVCR was observed at all anatomic locations (p<0.0002) where this ratio was calculated. Moreover, larger volumes of contrast significantly correlated with larger lung volumes (r=0.89, p<0.03) and radiation dose (p<0.03). VGC and ROC analysis demonstrated increased area under the curve: 0.831 and 0.99 respectively (p<0.02). Inter-observer variation was observed as excellent (κ = 0.71).
 Conclusion: We conclude that increased CMV is significantly correlated to increased patient lung volume and radiation dose when employing a patient-specific contrast formula. The effects patient habitus is highlighted.

Flow Dynamics of Bilateral Superior Cavopulomonary Shunts Influence Outcomes After Fontan Completion

Bilateral superior vena cava (SVC), which occurs following bilateral bidirectional cavopulmonary shunt (BCPS), is an anomaly marked by unique hemodynamics. This study aimed to determine its effects on outcomes after Fontan completion. Among 405 patients who underwent BCPS and total cavopulmonary connection (TCPC) between 1997 and 2017, 40 required a bilateral-BCPS. The dominant SVC prior to TCPC was identified according to the direction of blood flow in the central pulmonary artery, and its relationship to the inferior vena cava (IVC) was classified as a concordant or discordant relationship. Preoperative factors were analyzed to identify the risk factors for specific adverse outcomes. The length of intensive care unit (ICU) stay after TCPC was longer in the 40 patients who underwent bilateral-BCPS than in those who underwent unilateral BCPS (p = 0.024), and the survival rate was lower in the former group than in the latter group (p = 0.004). In the patients who underwent bilateral-BCPS, the dominant SVC was concordant with the IVC in 30 patients and discordant in 10 patients. With regard to whether certain morphological, hemodynamic, and flow dynamics-related variables were risk factors for adverse outcomes following TCPC, a discordant relationship between dominant SVC and IVC was identified as an independent risk factor for both a longer ICU stay (p = 0.037, HR 2.370) and worse survival (p = 0.019, HR 13.880). Therefore, in patients with a bilateral SVC who have previously undergone bilateral-BCPS, a discordant relationship between dominant SVC and IVC might contribute to worse outcomes following TCPC.

Chronic Thromboembolic Pulmonary Hypertension Perioperative Monitoring Using Phase-Resolved Functional Lung (PREFUL)-MRI.

The translation of phase-resolved functional lung (PREFUL)-MRI to routine practice in monitoring chronic thromboembolic pulmonary hypertension (CTEPH) still requires clinical corresponding imaging biomarkers of pulmonary vascular disease. To evaluate successful pulmonary endarterectomy (PEA) via PREFUL-MRI with pulmonary pulse wave transit time (pPTT). Retrospective. Thirty CTEPH patients and 12 healthy controls were included. For PREFUL-MRI a 2D spoiled gradient echo sequence and for DCE-MRI a 3D time-resolved angiography with stochastic trajectories (TWIST) sequence were performed on 1.5T. Eight coronal slices of PREFUL-MRI were obtained on consecutive 13 days before and 14 days after PEA. PREFUL quantitative lung perfusion (PREFULQ ) phases over the whole cardiac cycle were calculated to quantify pPTT, the time the pulmonary pulse wave travels from the central pulmonary arteries to the pulmonary capillaries. Also, perfusion defect percentage based on pPTT (QDPpPTT ), PREFULQ (QDPPREFUL ), and V/Q match were calculated. For DCE-MRI, pulmonary blood flow (PBF) and QDPPBF were computed as reference. For clinical correlation, mean pulmonary arterial pressure (mPAP) and 6-minute walking distance were evaluated preoperatively and after PEA. The Shapiro-Wilk test, paired two-sided Wilcoxon rank sum test, Dice coefficient, and Spearman's correlation coefficient (ρ) were applied. Median pPTT was significantly lower post PEA (139 msec) compared to pre PEA (193 msec), P = 0.0002. Median pPTT correlated significantly with the mPAP post PEA (r = 0.52, P < 0.008). Median pPTT was distributed more homogeneously after PEA: IQR pPTT decreased from 336 to 281 msec (P < 0.004). Median PREFULQ (P < 0.0002), QDPpPTT (P < 0.0478), QDPPREFUL (P < 0.0001) and V/Q match (P < 0.0001) improved significantly after PEA. Percentage change of PREFULQ correlated significantly with percentage change of 6-minute walking distance (ρ = 0.61; P = 0.0031) 5 months post PEA. Perioperative perfusion changes in CTEPH can be detected and quantified by PREFUL-MRI. Normalization of pPTT reflects surgical success and improvement of PREFULQ predicts 6-minute walking distance changes. 3 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:610-619.

Geometry of the pulmonary arteries before the Fontan operation: can we influence it during the Norwood procedure?

The right ventricle-to-pulmonary artery (RV-PA) shunt provides stable haemodynamics after the Norwood procedure but can influence development of the central pulmonary arteries (PAs). The goal of this study was to analyse the geometry of the central PAs in children with hypoplastic left heart syndrome before the Fontan operation with respect to the RV-PA shunt site and the type of the second-stage operation. A total of 161 children with hypoplastic left heart syndrome, median age 2.7 (range 1.3-9.8) years and median weight 12.7 (range 7.6-26.1) kg, underwent the Fontan operation after having had the Norwood procedure with an RV-PA shunt. The patients were divided into 2 groups: left-sided RV-PA (L-RV-PA) (n = 129) with the shunt on the left and right-sided RV-PA (n = 32) with the shunt on the right side of the neoaorta. Angiographic data obtained before the Fontan and all cardiac catheterization interventions were analysed retrospectively. Between the second and third stages, as well as directly before the Fontan operation, the L-RV-PA group required more PA catheter interventions (P = 0.001 and P = 0.03). In this group, the minimal left PA diameter was smaller than that in the R-RV-PA group (P = 0.021). Leaving the shunt open until the Fontan operation increased the rate of PA interventions in the L-RV-PA group (P = 0.001), but there is no evidence of the impact on the development of the left PAs (P = 0.075). There is also no evidence that the type of the second-stage procedure influences the intervention rate before the Fontan procedure (P = 0.14). Children who have the L-RV-PA shunt require more PA catheter interventions. The right-sided RV-PA shunt and the subsequent Glenn anastomosis in the place of the shunt are associated with distortion-free and more symmetrical development of the central PAs.

Improving Contrast Enhancement in Pulmonary CTA: The value of breathing maneuvers

PurposeTo investigate contrast dynamics and artifacts associated with different breathing maneuvers during pulmonary computed tomography angiography (pCTA) in a prospective randomized clinical trial. MethodThree different breathing maneuvers (inspiration, expiration, Mueller) were randomly assigned to 146 patients receiving pCTA for suspected pulmonary embolism (PE). Contrast enhancement of central and peripheral arteries and imaging quality of lung parenchyma were compared and analyzed. Results were compared by using the analysis of variances (ANOVA) and Kruskal-Wallis-Test. ResultsMean enhancement in the pulmonary trunk was highest during breath-hold in inspiration (293 HU, range 195–460 HU) compared to Mueller (259 HU, range 136–429 HU, p = 0022) and expiration (267 HU, range 115–376 HU). This was similar for the right pulmonary artery (inspiration 289 HU, range 173–454 HU; Mueller 250 HU, range 119–378 HU; p = 0.007; expiration 257 HU, range 114–366 HU; p = 0.032) and left pulmonary artery (inspiration 280.3 HU, range 170–462 HU; Mueller 245 HU, range 111–371 HU; p = 0.016; expiration 252 HU, range 110–371 HU).Delineation of peripheral arteries was significantly better in inspiration vs Mueller (p = 0.006) and expiration (p = 0.049). Assessment of the lung parenchyma was significantly better in inspiration vs Mueller (p = 0.013) or expiration (p < 0.001). ConclusionsResting inspiratory position achieved the highest enhancement levels in central and peripheral pulmonary arteries and best image quality of the pulmonary parenchyma in comparison to other breathing maneuvers. It is necessary to train the maneuver prior to the examination in order to avoid deep inspiration with the risk of suboptimal opacification of the pulmonary arteries.

P1701 Biatrial thrombus detection in a patient with atrial paroxysmal fibrillation and asymptomatic massive pulmonary embolism

Abstract Introduction Computed tomography (CT) is a noninvasive test for detection of LA and LAA thrombus.Although the transesophageal echocardiogram is the gold standart method, it can have rare but potential life threatening complications.Case report:A 62 y.o woman presented to the ER complaining of palpitations started less then 12h ago with no chest pain or dispnea.She was diagnosed with high rate paroxysmal atrial fibrillation (HR∼120/min).The ECG showed AF with no specific changes,the troponin I (TPI) level was negative and a TTE revealed a dilated left atria.The other lab results were within normal range(TBC and blood chemistry).Her past medical history included hypertension and diabetes type 2 for 10 years and 6 months respectively both on regular treatment and obesity.Also 2 months ago she was diagnosed with Hashimoto thyroiditis and close monitoring of TSH was recommended but no treatment.Subsequently,LMWH (enoxaparin) and amiodarone loading dose for cardioversion were started.After 24h the pt was still in AF,with a controlled heart rate and no complains.However ECG changes were noticed (evolutive T negative waves in leads D1,D2,aVL,V3-V6).A D-Dimer was requested and came back negative,O2 saturation was 97%.The asymptomatic pt was transferred to the Cardiology ward for further evaluation.TPI remained negative.Due to the cardiac risk factors and the ECG changes it was decided to perfom a coronary angiography which resulted normal.An electrical cardioversion was considered.Both TEE and pulmonary angio CT were requested prior.Because of the ECG changes the CT was performed first and showed central and peripheric bilateral pulmonary artery clots present also in both the left and right atrial auricles.Due to the massive thromboembolism(PE) unfractioned heparin was immediately started (aPTT 50-70s).A new TTE showed a PAP of 50 mmHg.Approximately 10h after the heparin infusion,the pt became hypotensive and started complaining of dyspnea,tachypnea,cough,pleuritic pain and fever(high temperature 39.5-40ᵒC).Considering the deteriorating conditions she was consulted by a cardiac surgery team and it was decided to perform an emergency surgical pulmonary embolectomy despite the high risk.Within 24h,the pt underwent a surgical embolectomy of the right and left pulmonary branches after incision of the pulmonary artery, as well as a clot embolectomy of the right and left atria auricles (confirmed by intraoperatory TEE).She was put on an iv heparin regimen and recovered well.She was discharged 2 weeks later in good condition,with a PAP of 40 mmHg,on acenocoumarol with persistent AF.1.5 years later she is in NYHA class I,in sinus rhythm taking rivaroxaban 20 mg/d.Discussion: Biatrial thrombus detection in both atrial auricles is rare as well as in this case a massive PE without a stroke.CT can be used as an alternative modality for detecting thrombus in selected high risk patients because it shows a good diagnostic accuracy with high sensitivity and specificity. Abstract P1701 Figure. Biatrial clots on CT and removed ones

Primary Central Pulmonary Artery Plasty for Ductal-Associated Pulmonary Artery Coarctation

Infants with functionally single ventricle who require a modified Blalock-Taussig shunt can have stenosis at the ductal insertion site on the pulmonary artery (PA), the so-called ductal-associated PA coarctation. We hypothesized that central PA plasty with resection of the ductal tissue on the PA during the first palliation would prevent PA coarctation and obtain well-balanced PA for Fontan operation. We performed this strategy on 40 consecutive patients (from 1998 to 2012, Age 38.4 ± 24.7 day [17 neonates], body weight 3.5 ± 0.8 kg, heterotaxy n = 27). The mean Nakata index (mm2/m2) before bidirectional cavopulmonary shunt was 230.7 ± 101.7 without pulmonary stenosis. The PA diameter ratio and lung perfusion ratio (nonshunt side and/or shunt side) were 0.93 ± 0.25 and 0.9 ± 0.2, respectively. This strategy may improve clinical outcomes on functional single ventricle patients with increased risk of stenosis from pulmonary coarctation, with avoidance of an unbalanced pulmonary vascular bed.

Valve-Sparing Neoaortic Root Replacement Post Norwood

Progressive aortic root dilatation following palliation for hypoplastic left heart syndrome has become increasingly recognized and constitutes a significant issue with potential morbidity. Although little is known about the natural history and the optimal management strategy, currently the indications and optimal timing for surgical intervention are undefined and largely due to significant associated issues, most commonly important semilunar valve regurgitation and/or compromise of the Fontan circulation due to central pulmonary artery obstruction secondary to extrinsic compression by the aneurysm. A description of the technical aspect of this procedure is provided.

Inositol 1,4,5-trisphosphate receptor 2 as a novel marker of vasculature to delineate processes of cardiopulmonary development

Congenital heart diseases (CHDs) involving the outflow tract (OFT), such as persistent truncus arteriosus (PTA), lead to mortality and morbidity with implications not only in the heart, but also in the pulmonary vasculature. The mechanisms of pulmonary artery (PA) development and the etiologies underlying PA disorders associated with CHD remain poorly understood partly because of a specific marker for PA development is nonexistent. The three subtypes of inositol 1,4,5-trisphosphate receptors (IP3R1, 2, and 3) are intracellular Ca2+ channels that are essential for many tissues and organs. We discovered that IP3R2 was expressed in the vasculature and heart during development using transgenic mice, in which a LacZ marker gene was knocked into the IP3R2 locus. Whole-mount and section LacZ staining showed that IP3R2-LacZ-positive cells were detectable exclusively in the smooth muscle cells, or tunica media, of PA, merging into αSMA-positive cells during development. Furthermore, our analyses suggested that IP3R2-LacZ positive PA smooth muscle layers gradually elongate from the central PA to the peripheral PAs from E13.5 to E18.5, supporting the distal angiogenesis theory for the development of PA, whereas IP3R2-LacZ was rarely expressed in smooth muscle cells in the pulmonary trunk. Crossing IP3R-LacZ mice with mice hypomorphic for Tbx1 alleles revealed that PTA of Tbx1 mutants may result from agenesis or hypoplasia of the pulmonary trunk; thus, the left and right central to peripheral PAs connect directly to the dorsal side of the truncus arteriosus in these mutants. Additionally, we found hypercellular interstitial mesenchyme and delayed maturation of the lung endoderm in the Tbx1 mutant lungs. Our study identifies IP3R2 as a novel marker for clear visualization of PA during development and can be utilized for studying cardiopulmonary development and disease.

Tailored approach to trans-catheter palliation of critically reduced pulmonary blood supply. Data on long term follow up

The most appropriate treatment of duct dependent pulmonary circulation is still a matter of debate. In particular data on long term results of trans-catheter palliation are still inconclusive. We present the long term outcome of trans-catheter palliation in this group of patients according to the anatomy and to a prespecified algorithm, with particular focus on development of pulmonary tree.We retrospectively analyzed data on patients who had undergone trans-catheter palliation of duct dependant congenital heart disease between 2005 and 2017 in our institution. Arterial duct or right ventricular outflow tract (RVOT) percutaneous transluminal angioplasty (PTA)/stenting were performed according a pre-specified algorithm.47 patients underwent either arterial duct stenting (n = 42) or RVOT PTA/Stenting (n = 5). Median age at catheterization was 13 days (IQR 3–686). Median weight was 3 kg (1.5–4.3). Median follow up was 1127 (6–4396) days. 11 patients out of 47 died (23%). One year, five year and ten year survival were respectively: 82% (95% CI 68–90), 75% (95% CI 60–85) and 60% (95% CI 27–81). At Cox regression analysis, weight at the initial Trans-catheter palliation and univentricular physiology remained independently associated with long term mortality, respectively Hazard ratio 0.3 (95% CI 0.12–0.88, p = 0.03) and Hazard ratio 5 (95% CI 1.3–20.2, p = 0.02). In the overall study cohort 36 patients (76%) needed further intervention, either surgical or trans-catheter, before surgical repair or definitive palliation. Overall, median time to re-intervention was 107 days (2–750). Central pulmonary arteries grew in all patients. Tailored trans-catheter management of congenital heart disease associated with critically reduced pulmonary flow resulted in proper maturation of pulmonary tree allowing surgical repair or definite palliation despite the need for repeated procedures.

Hepatopulmonary syndrome has low prevalence of pulmonary vascular abnormalities on chest computed tomography.

Hepatopulmonary syndrome (HPS) is defined as an arterial oxygenation defect induced by intrapulmonary vascular dilatations associated with hepatic disease. This study aimed to assess the prevalence of type 1 and 2 pulmonary vascular abnormalities on chest computed tomography (CT) in patients with cirrhosis and HPS and to characterize intra- and interobserver reliability. Two thoracic radiologists retrospectively evaluated chest CT scans from 38 cirrhosis patients with HPS. They classified the pulmonary vascular abnormalities as type 1 (multiple dilated distal pulmonary arteries), type 2(nodular dilatation or individual pulmonary arterial malformation), or absence of abnormality. Furthermore, they measured the diameters of the central pulmonary arteries and subsegmental pulmonary arteries and bronchi. We analyzed the prevalence, intraobserver reliability, and interobserver reliability of abnormal CT findings related to HPS, and the correlation of these findings with partial arterial oxygen pressure (PaO2). The overall prevalence of pulmonary vascular abnormalities was 28.9% (95% confidence intervals: 15.4%, 45.9%). Moreover, 26.3% of patients had type 1 abnormality (13.4%, 43.1%) and 2.6% of patients had type 2 abnormality (0.0%, 13.8%). The intraobserver reliability kappa value was 0.666 (0.40, 0.91) and the interobserver kappa value was 0.443 (0.12, 0.77). There was no correlation between pulmonary vascular abnormalities on CT and PaO2 values. The prevalence of pulmonary vascular abnormalities on chest CT of patients with cirrhosis and HPS is low and not correlated with PaO2. These findings question the usefulness of chest CT for the evaluation of patients with cirrhosis and HPS.

P2742Right ventricular stroke volume during dobutamine stress magnetic resonance compared to lung perfusion and peak oxygen uptake after arterial switch operation for transposition of the great arteries

Abstract Objectives Abnormal pulmonary perfusion due to stenosis of the central pulmonary arteries is common after neonatal arterial switch operation (ASO) for transposition of the great arteries (TGA). We conducted a monocentric prospective study in young adults after neonatal ASO for TGA to evaluate the effects of abnormal pulmonary perfusion on the increase of the right ventricular stroke volume (RVSV) during dobutamine stress magnetic resonance (DSMR) and on cardiopulmonary exercise capacity. Methods 68 unselected patients (age 18–29 years) underwent CMR at rest and under dobutamine stress (10 to 40 μg/kg/min). RVSV, pulmonary blood flow distribution (PBFD) and peak flow velocity were derived from phase contrast mapping in the main, right and left pulmonary artery (PA) at rest and each stress level. A cardiopulmonary exercise test (CPET) was performed at the same day. All patients reached maximal exercise effort according to heart rate and respiratory exchange rate. Results PBFD at rest: 9/68 patients (13%, ASO-S) had abnormal pulmonary perfusion at rest, defined as PBFD &gt;2:1 (right/left or left/right) and/or relevant stenosis of the main PA (Vmax &gt;2.5 m/s). 59/68 patients (87%, ASO-N) had normal pulmonary perfusion. PBFD under DSMR: (1) In the whole patient group, there was no increase of PBFD under stress compared to PBFD at rest. On an individual patient level, no relevant worsening of abnormal PBFD was found. (2) Under low dose dobutamine, ASO-S had a significantly lower RVSV-increase (RVSVstress/RVSVrest) compared to ASO-N (see figure). However, under high dose dobutamine, this effect was no longer significant (see figure). (3) The RVSV-increase under low and high dose dobutamine did not correlate with peak oxygen uptake during CPET, neither in the total group nor in the subgroups (see table). Peak oxygen uptake was not significantly different between ASO-N and ASO-S (p=0,72). RVSV-increase compared to CPET peak VO2% ASO-total ASO-S ASO-N RVSV-increase/peak VO2% RVSV-increase/peak VO2% RVSV-increase/peak VO2% low dose dobu high dose dobu low dose dobu high dose dobu low dose dobu high dose dobu Pearson correlation coefficient −0.02 −0.05 0.01 −0.22 −0.05 −0.04 p-value 0.90 0.71 0.98 0.56 0.71 0.78 Figure 1 Conclusion (1) Patients with relevant stenosis of main PA and/or abnormal peripheral blood flow distribution (ASO-S) exhibit a reduced RVSV-increase under low dose dobutamine compared to patients without stenosis (ASO-N). This effect was not present under high dose dobutamine stress. (2) These findings did not correlate with peak oxygen uptake during CPET, an objective parameter of cardiopulmonary exercise capacity. (3) Therefore, a conservative proceeding rather than surgery or catheter intervention should be considered, especially in asymptomatic adult patients. Acknowledgement/Funding Supported by Kinderherzen, Fördergemeinschaft Deutsche Kinderherzzentren e.V.

A decision tree built with parameters obtained by computed tomographic pulmonary angiography is useful for predicting adverse outcomes in non-high-risk acute pulmonary embolism patients

BackgroundAcute pulmonary embolism (APE) is one of the leading causes of death in cardiovascular disease. The 30-day mortality can still be 1.7–15% in non-high-risk APE patients. Some non-high-risk patients can progress into the high-risk group and even die, which is referred to as an adverse outcome. Promoting the diagnosis and predictive ability of adverse short-term prognosis was still a problem that needed to be solved. Computed tomography pulmonary angiography (CTPA) may be a way to promote the predictive ability. Our aim to develop predictive tools based on parameters obtained by computed tomographic pulmonary angiography (CTPA) in the form of a decision tree for use in non-high-risk acute pulmonary embolism (APE) patients.MethodsAdverse outcome was defined within 30 days after admission to the hospital. A decision tree was built to predict adverse outcomes based on discriminating factors screened from cardiac volume and clot characteristics from recursive partitioning analysis and compared with simplified pulmonary embolism severity index (sPESI), Bova scores and risk stratification. The area under the receiver operating characteristic curve (ROC-AUC) was used to confirm the predictive ability.ResultsA total of 38 patients with and 303 patients without adverse outcomes were enrolled. Right ventricular/left ventricular (RV/LV) volume ratio, central pulmonary artery (CPA) embolism and right atria/left atria (RA/LA) volume ratio were used as splits in the decision tree to predict adverse outcomes in all patients. The ROC-AUC was 0.858. In CPA embolism patients, a recursive partitioning analysis was performed with cardiac volume and novel clot burden, but only the obstructing area (OA) ratio was included as a discriminating factor to build a second decision tree. The ROC-AUC for the second decision tree was 0.810. The decision trees were superior to those of sPESI, Bova scores and risk stratification, and there were no significant differences between the two decision trees.ConclusionsA decision tree built by CTPA parameters can predict adverse outcomes in non-high-risk APE patients.

Septal bowing and pulmonary artery diameter on computed tomography pulmonary angiography are associated with short-term outcomes in patients with acute pulmonary embolism.

Patients with acute pulmonary embolism (PE) can quickly deteriorate and the condition has high mortality due to right ventricular (RV) failure. Immediately available predictors of adverse outcome are of major interest to the treating physician in the acute setting. The purpose of the present study was to evaluate if easily attainable measurements of RV function from the diagnostic computed tomography pulmonary angiography (CTPA) provide information for fast risk stratification in patients with acute PE. We retrospectively evaluated images from CTPA in 261 patients (age median 60years, 50% females) enrolled in a prospective study. RV and left ventricular (LV) diameters and their ratio, the presence of septal bowing, contrast reflux in the inferior vena cava, and the diameter of the central pulmonary arteries (PA) were measured. The composite outcome was 5-day severe adverse events including death, acute decompensation, or need for emergent treatment. We used Wilcoxon rank sum test and Fischer's exact test to test between groups and multivariate logistic regression for prediction. In multivariate analysis, increased diameter of the main PA (OR = 1.08 per 1mm increase, p = 0.047) and the presence of septal bowing (OR = 2.23, p = 0.055) were associated with severe adverse events. RV/LV > 1 did not predict severe outcomes (OR = 0.73, p = 0.541). Two easily attainable parameters of RV function on CTPA, septal bowing and main PA diameter, are associated with short-term adverse outcomes in patients with acute PE. Further study is required to determine whether these findings can be incorporated into clinical treatment algorithms.

The validity of central venous to arterial carbon dioxide difference to predict adequate fluid management during living donor liver transplantation. A prospective observational study

BackgroundTo assess the validity of central and pulmonary veno-arterial CO2 gradients to predict fluid responsiveness and to guide fluid management during liver transplantation.MethodsIn adult recipients (ASA III to IV) scheduled for liver transplantation, intraoperative fluid management was guided by pulse pressure variations (PPV). PPV of ≥15% (Fluid Responding Status-FRS) indicated fluid resuscitation with 250 ml albumin 5% boluses repeated as required to restore PPV to < 15% (Fluid non-Responding Status-FnRS). Simultaneous blood samples from central venous and pulmonary artery catheters (PAC) were sent to calculate central venous to arterial CO2 gap [C(v-a) CO2 gap] and pulmonary venous to arterial CO2 gap [Pulm(p-a) CO2 gap]. CO and lactate were also measured.ResultsSixty seven data points were recorded (20 FRS and 47 FnRS). The discriminative ability of central and pulmonary CO2 gaps between the two states (FRS and FnRS) was poor with AUC of ROC of 0.698 and 0.570 respectively. Central CO2 gap was significantly higher in FRS than FnRS (P = 0.016), with no difference in the pulmonary CO2 gap between both states. The central and Pulmonary CO2 gaps are weakly correlated to PPV [r = 0.291, (P = 0.017) and r = 0.367, (P = 0.002) respectively]. There was no correlation between both CO2 gaps and both CO and lactate.ConclusionCentral and the Pulmonary CO2 gaps cannot be used as valid tools to predict fluid responsiveness or to guide fluid management during liver transplantation. CO2 gaps also do not correlate well with the changes in PPV or CO.Trial registrationClinicaltrials.gov Identifier: NCT03123172. Registered on 31-march-2017.

Is it safe to embolize a central pulmonary artery?—a case report

Pulmonary arterial embolization is a common and accepted treatment for a somewhat rare group of lesions that involve the pulmonary arterial tree such as pseudoaneurysms, aneurysms, and arteriovenous fistulae. Therapeutic intervention is localized to the lesion and rarely used for en bloc embolization of large lung territories. Embolization of a central right or left pulmonary artery to cut off blood supply to an entire lung has not been reported. We present a case in which embolization of the left main pulmonary artery was performed and was well tolerated by the patient. The purpose of our case report is to share our experience of the efficacy and safety of this procedure.

Outcomes After Aortopulmonary Window for Hypoplastic Pulmonary Arteries and Dual-Supply Collaterals

Our institutional approach to tetralogy of Fallot with major aortopulmonary collateral arteries (MAPCAs) emphasizes early unifocalization and complete repair (CR). In the small subset of patients with dual-supply MAPCAs and confluent but hypoplastic central pulmonary arteries (PAs), our surgical approach is early creation of an aortopulmonary window (APW) to promote PA growth. Factors associated with successful progression to CR and mid-term outcomes have not been assessed. Clinical data were reviewed. PA diameters were measured offline from angiograms prior to APW and on follow-up catheterization >1 month after APW but prior to any additional surgical interventions. From November 2001 to March 2018, 352 patients with tetralogy of Fallot/MAPCAs underwent initial surgery at our center, 40 of whom had a simple APW with or without ligation of MAPCAs as the first procedure (median age, 1.4 months). All PA diameters increased significantly on follow-up angiography. Ultimately, 35 patients underwent CR after APW. Nine of these patients (26%) underwent intermediate palliative operation between 5 and 39 months (median, 8 months) after APW. There were no early deaths. The cumulative incidence of CR was 65% 1 year post-APW and 87% at 3 years. Repaired patients were followed for a median of 4.2 years after repair; the median PA:aortic pressure ratio was 0.39 (range, 0.22 to 0.74). Most patients with tetralogy of Fallot/MAPCAs and hypoplastic but normally arborizing PAs and dual-supply MAPCAs are able to undergo CR with low right ventricular pressure after APW early in life. Long-term outcomes were good, with acceptable PA pressures in most patients.

Combined automated 3D volumetry by pulmonary CT angiography and echocardiography for detection of pulmonary hypertension.

To assess the diagnostic accuracy of automated 3D volumetry of central pulmonary arteries using computed tomography pulmonary angiography (CTPA) for suspected pulmonary hypertension alone and in combination with echocardiography. This retrospective diagnostic accuracy study included 70 patients (mean age 66.7, 48 female) assessed for pulmonary hypertension by CTPA and transthoracic echocardiography with estimation of the pulmonary arterial systolic pressure (PASP). Gold standard right heart catheterisation with measurement of the invasive mean pulmonary arterial pressure (invasive mPAP) served as the reference. Volumes of the main, right and left pulmonary arteries (MPA, RPA and LPA) were computed using automated 3D segmentation. For comparison, axial dimensions were manually measured. A linear regression model was established for prediction of mPAP (predicted mPAP). MPA, RPA and LPA volumes were significantly increased in patients with vs. without pulmonary hypertension (all p < 0.001). Of all measures, MPA volume demonstrated the strongest correlation with invasive mPAP (r = 0.76, p < 0.001). Predicted mPAP using MPA volume and echocardiographic PASP as covariates showed excellent correlation with invasive mPAP (r= 0.89, p < 0.001). Area under the curves for predicting pulmonary hypertension were 0.94 for predicted mPAP, compared to 0.90 for MPA volume and 0.92 for echocardiographic PASP alone. A predicted mPAP > 25.8mmHg identified pulmonary hypertension with sensitivity, specificity, positive and negative predictive values of 86%, 93%, 95% and 81%, respectively. Automated 3D volumetry of central pulmonary arteries based on CTPA may be used in conjunction with echocardiographic pressure estimates to noninvasively predict mPAP and pulmonary hypertension as confirmed by gold standard right heart catheterisation with higher diagnostic accuracy than either test alone. • This diagnostic accuracy study derived a regression model for noninvasive prediction of invasively measured mean pulmonary arterial pressure as assessed by gold standard right heart catheterisation. • This regression model using automated 3D volumetry of the central pulmonary arteries based on CT pulmonary angiography in conjunction with the echocardiographic pressure estimate predicted pulmonary arterial pressure and the presence of pulmonary hypertension with good diagnostic accuracy. • The combination of automated 3D volumetry and echocardiographic pressure estimate in the regression model provided superior diagnostic accuracy compared to each parameter alone.