[Comparison of pulmonary vascular tortuosity and fractal dimension in patients with chronic thromboembolic pulmonary disease and chronic thromboembolic pulmonary hypertension].

Objective: To compare the differences in pulmonary vascular morphological parameters between patients with chronic thromboembolic pulmonary disease (CTEPD) and chronic thromboembolic pulmonary hypertension(CTEPH), and to explore the value of pulmonary artery morphology in the differential diagnosis of CTEPD and CTEPH. Methods: Thirty-nine patients with CTEPH [14 males, 25 females, mean age: (54.1±12.4) years] and 29 patients with CTEPD [10 males, 19 females, mean age: (51.4±18.0) years] from January 2018 to December 2020 were retrospectively included. The pulmonary artery and vein tree was segmented from the computed tomography pulmonary angiography (CTPA) images, and the morphological parameters of pulmonary vessels including the number of pulmonary arteries, pulmonary arterial tortuosity(distance metric, DM) and fractal dimension (FD), were calculated. The differences in pulmonary vascular morphological parameters between the two groups were compared, and the correlation between morphological parameters and hemodynamics was analyzed. Results: There was no significant difference in gender and age between CTEPH and CTEPD groups (χ2=0.015,P=0.904 & t=-0.729, P=0.469). The number of pulmonary arteries in CTEPH group (n=249.43±76.27) was significantly lower than that in CTEPF group (n=298.79±78.11, t=2.612, P=0.011). The pulmonary arterial tortuosity in CTEPH group (DM=1.26±0.17) was significantly higher than that in CTEPD group (DM=1.17±0.10, t=3.516, P=0.002). There was no significant difference in FD between CTEPH and CTEPD (FD=3.01±0.21 & 3.08±0.22, t=1.359, P=0.179). The number of pulmonary arteries was negatively correlated with pulmonary vascular resistance (r=-0.325, P=0.026). Pulmonary arterial tortuosity was positively correlated with mean pulmonary artery pressure (r=0.387,P=0.017), and was positively correlated with pulmonary vascular resistance (r=0.647, P<0.001). Conclusion: Pulmonary artery curvature is an important morphological parameter in differentiating CTEPH from CTEPD, and is related to mean pulmonary artery pressure and pulmonary vascular resistance.

[Rescue balloon pulmonary angioplasty for a patient with acute exacerbation of chronic thromboembolic pulmonary hypertension supported by extracorporeal membrane oxygenation: a case report].

A 33-year-old male patient was admitted to hospital because of "dyspnea after activity for 3 years and aggravation for 15 days". With a history of membranous nephropathy, irregular anticoagulation led to acute exacerbation of Chronic thromboembolic pulmonary hypertension(CTEPH) and acute respiratory failure, and endotracheal intubation and mechanical ventilation was given. Although treated with thrombolysis and adequate anticoagulation, the condition worsened and hemodynamics deteriorated, and then VA-ECMO was performed. Due to severe pulmonary hypertension and right heart failure,ECMO could not be weaned off, and the patient subsequently developed pulmonary infection, right lung hemorrhage, hyperbilirubinemia, coagulation dysfunction and other complications. Then the patient was transferred to our hospital by airplane, and multidisciplinary discussions were quickly arranged after admission. Considering that the patient was critically ill and complicated with multiple organ failure, pulmonary endarterectomy (PEA) could not be tolerated, rescue balloon pulmonary angioplasty (BPA) was recommended and performed on the second day after admission. The mean pulmonary artery pressure was 59 mmHg(1 mmHg=0.133 kPa) measured by right heart catheterization, and pulmonary angiography showed that the main pulmonary artery was dilated, while the right lower pulmonary artery was completely occluded, and there were multiple stenoses in the branches of the right upper lobe, middle lobe pulmonary artery and the left pulmonary artery. BPA was performed on a total of 9 pulmonary arteries. VA-ECMO was weaned off on day 6 after admission, and the mechanical ventilation was weaned off on day 41 after admission. The patient was successfully discharged on day 72 after admission. Rescue BPA was an effective treatment for severe CTEPH patients who could not be treated with PEA.

[Imaging findings of CT pulmonary angiography in patients with chronic thromboembolic pulmonary hypertension].

Objective: To investigate the imaging findings of CT pulmonary angiography (CTPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Methods: Consecutive CTEPH cases admitted to receive CTPA in China-Japan Friendship Hospital from December 2015 to December 2019 were enrolled with prospective data collected. The medical histories, imaging manifestation and hemodynamic parameters were analyzed. Patients were divided into proximal lesions group and distal lesions group according to the site of thrombus, and imaging findings were compared between these two groups. Results: In 135 cases of CTEPH, CTPA showed thrombus in both lungs in the majority of patients (133 cases, 98.5%) with location of thromboembolic disease in level Ⅰ, Ⅱ and Ⅲ for most patients, only 8 cases with level Ⅳ(7.3%) and no level 0 patients. The most common signs of chronic thrombus were vessel cutoffs (134 cases, 99.3%), eccentric wall-adherent filling defects (111 cases, 88.2%), web or bands (80 cases, 59.3%), stenosis (41 cases, 30.4%). Compared to patients with distal lesions, eccentric wall-adherent filling defects, irregular vessel wall were more common in patients with proximal lesions, stenosis was more common in distal lesions, all P<0.05. The most common lung parenchymal signs were mosaic attenuation (104 cases, 77.0%), and pulmonary infarction (79 cases, 58.5%). Pulmonary infarction included pleura-based consolidation opacity (35/79, 44.3%), linear opacities (23/79, 29.1%), or both (13/79, 16.5%). Pulmonary artery enlargement (132 cases, 97.8%) and right ventricular hypertrophy (130 cases, 96.3%) were common, other signs included contrast reflux into the inferior vena cava (70 cases, 51.9%), enlargement of bronchial arteries (68 cases, 50.3%). No differences were found for all the secondary signs between patients with proximal lesions and those with distal lesions, all P>0.05. Conclusions: Vessel cutoffs, eccentric wall-adherent filling defects, web or bands are the most common CTPA findings of chronic thrombus in CTEPH. Secondary signs include mosaic attenuation, pulmonary infarction, pulmonary artery enlargement, right ventricular hypertrophy and enlargement of bronchial arteries. Eccentric wall-adherent filling defects are more common in patients with proximal lesions than those with distal lesions.

[Efficacy and safety of Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension].

Objective: To study the efficacy and safety of Balloon pulmonary angioplasty (BPA) for chronic thromboembolic pulmonary hypertension (CTEPH). Methods: Patients who were diagnosed CTEPH in China-Japan Friendship Hospital from Feb 2018 to Sep 2019 were evaluated. The ineligibility for pulmonary endarterectomy (PEA) and the indication for BPA were decided on the basis of a consensus among the multidisciplinary team for all CTEPH patients. 6-min walk distance (6MWD), the plasma level of N-terminal pro-brain natriuretic peptide (NT-proBNP), mixed venous oxygen saturation, mean pulmonary artery pressure (mPAP), cardiac index (CI) and pulmonary vascular resistance (PVR) were collected and analyzed before the first and the last BPA session. Results: A total of 67 BPA sessions were performed for 302 subsegmental pulmonary arteries in 25 inoperable CTEPH patients. 10 males (40.0%) and 15 females (60.0%), with the age of (57.8±7.1) years old. The median interval between CTEPH diagnosis and first BPA was 20.0 (9.0, 48.5) months. 18 patients were received more than 2 BPA sessions, the median follow-up time was 5.0 (3.5, 8.3) months. 6MWD, CI and the mixed venous oxygen saturation were significant improved after BPA [(425±74) vs (345±109) m, (1.99±0.45) vs (1.62±0.35) L·min(-1)·m(-2), (68.1%±6.5%) vs (61.2%±6.3%)](all P<0.05). The plasma level of NT-proBNP, mPAP and PVR were significantly decreased after BPA [259 (93, 739) vs 806 (148, 2 159) ng/L, (40.6±8.3) vs (47.3±10.7) mmHg (1 mmHg=0.133 kPa), (11.9±4.9) vs (17.2±6.5) WU (1 WU=80 dyn·s·cm(-5))](all P<0.05). Hemoptysis occurred in 5 sessions (7.5%) and reperfusion pulmonary edema (RPE) occurred in 2 sessions (1.5%), 1 patient needed non-invasive mechanical ventilation because of RPE, 1 patient died from right heart failure caused by hemoptysis during perioperative period. Conclusions: BPA can significantly improve the exercise tolerance and hemodynamic parameters for inoperable CTEPH patients, the risks of BPA are acceptable. BPA is an effective and relatively safe treatment for inoperable CTEPH patients.

[Awareness and management of chronic thromboembolic pulmonary hypertension among respiratory physicians revealed by a questionnaire analysis].

Objective: To evaluate the awareness and management status of chronic thromboembolic pulmonary hypertension (CTEPH) among respiratory physicians and therefore to provide for establishing clinical guidelines on CTEPH. Methods: A questionnaire was designed to address the common questions in CTEPH management. The responses were collected online and the data were analyzed. Totally, 1 038 valid questionnaires were collected. Results: 74.1% of the responders were from tertiary hospitals and 88.5% were attending physicians. Only a few hospitals could carry out ventilation-perfusion scintigraphy (31.3%) and right heart catheterization (38.5%). For the treatment of CTEPH, pulmonary endarterectomy and balloon pulmonary angioplasty (BPA) were only performed in 8.0% and 10.4% of the hospitals respectively, and mostly in tertiary hospitals, P<0.01. 49.6% of the physicians were familiar with the interpretation of CTPA, while only 19.9% of V/Q scan. 88.5% of the physicians choose CTPA as the screening tool for CTEPH, but only 3.9% were consistent with the guidelines. 79% of the physicians agreed with lifelong anticoagulation for CTEPH, and 70.8% supported operability should be evaluated in all CTEPH patients. Conclusions: This questionnaire study showed that there was a gap between the guidelines and the real world practice in CTEPH management. Efforts should be made to improve the awareness and standardization of the management of CTEPH.

[Clinical characteristics of patients with chronic thromboembolic pulmonary hypertension].

Objective: To investigate the clinical characteristics of patients with chronic thromboembolic pulmonary hypertension (CTEPH). Methods: CTEPH cases consecutively admitted into China-Japan Friendship Hospital from September 2015 to June 2019 were enrolled with prospective data collection. The medical histories, clinical characteristics, laboratory tests, imaging manifestation and hemodynamic parameters were analyzed. Patients were divided into high pulmonary vascular resistance (PVR) group and low PVR group according to the PVR level>1 000 dyn·s·cm(-5) or not, and clinical characteristics were compared between these two groups. Results: In the 148 cases of CTEPH, right heart catheterization was performed in 103 cases with mPAP (45.1±11.0) mmHg and PVR of (992±430) dyn·s·cm(-5). At diagnosis, 88 (59.5%) cases were in WHO functional class Ⅲ and 27 (18.2%) in class Ⅳ. Most common presenting symptoms were dyspnea (147, 99.3%), chest tightness (68, 45.9%), hemoptysis (42, 28.3%), syncope (30, 20.3%), and most common signs were P2 accentuation (95, 64.9%), edema (65, 43.9%), cyanosis (47, 31.8%), systolic murmur (44, 29.7%) and jugular vein distention (35, 23.6%). In 103 cases with right heart catheterization, 52 were in the low PVR group and 51 in high PVR group. Compared to the low PVR group, high PVR group patients had higher WHO functional class and more jugular vein distention (both P<0.05). In all the 148 cases, previous venous thromboembolism (VTE) was confirmed in 105 (70.9%) patients, with a higher prevalence of previous VTE in low PVR group than that in high PVR group (P<0.001). 30 (20.3%) patients had varicose veins of the lower extremities, and 21 (14.2%) had other thrombophilic disorders including antiphospholipid syndrome, protein C and S deficiency and antithrombin Ⅲ deficiency. Conclusions: Dyspnea, P2 accentuation and edema are the most common clinical presentation of CTEPH. Previous history of VTE is common in CTEPH patients with thrombophilia in some cases.

[Brain protection strategy and effectivity in pulmonary thromboendarterectomy].

Objective: To summarize the experience and effectivity of brain protection in 25 patients who suffered from chronic thromboembolic pulmonary hypertension (CTEPH) and received pulmonary thromboendarterectomy (PTE) under deep hypothermic circulatory arrest. Methods: Retrospective analysis of 25 PTE surgeries in our center from December 2016 to August 2018. All cases were completed underdeep hypothermic circulatory arrest. Standard brain protections were strictly executed, including: balanced and controlled extracorporeal circulation cooling, cerebral oxygen saturation (rSO(2)) monitoring, strictly control of circulatory arrest time, and etc. The neurological adverse events during the perioperative period were recorded and statistically analyzed, and the intelligence level and cognitive function of the patients were evaluated by MMSE scale and MoCA scale before surgery and discharge. Results: All the 25 patients successfully completed the surgery, and 1 patient (4%) died of postoperative infection. The mean pulmonary arterial pressure decreased from (52.9±16.7) mmHg before surgery to (23.6±8.1) mmHg immediately after surgery (t=10.01, P<0.01), and(20.7±7.9) mmHg at 3 months follow-up (t=10.73, P<0.01). Pulmonary vascular resistance decreased from 975.4 (788.6-1 292.8) dyn·s·cm(-5) to 376.1 (283.6-565.5) dyn·s·cm(-5) (Z=5.34, P<0.01). Neurological complications occurred in 3 patients during the perioperative period, including 2 patients with hypoxic encephalopathy, and 1 patient with cerebral hemorrhage. All 3 patients fully recovered before discharge. Univariate analysis showed that the duration of rSO(2)<40% and the maximum decrease rate of rSO(2) from baseline were significantly correlated with postoperative neurological damage. Multivariate analysis showed only time of rSO(2)<40% was significantly correlated with postoperative neurological damage. There was no significant difference in MMSE and MoCA score before and after surgery (P>0.05). Conclusions: Adequate brain protection measures are essential to reduce the neurological complications of PTE surgery. Real-time intraoperative monitoring of rSO(2) and strict control of circulatory arrest time can further reduce the occurrence of neurological damage.

Aerobic microbial degradation of aromatic sulfur-containing compounds and effect of chemical structures.

Batch data of aerobic microbial degradation rate constants Kb of phenylthio, phenylsulfinyl and phenylsulfonyl acetates have been determined, and the qualitative relationships between their Kb and chemical structures were analyzed. The phenylthio acetates were most subject to microbial transformation, followed by the phenylsulfonyl acetates. The compounds with a methoxy group were easier degraded than those with a isopropoxy group. The nitro-group and chloro-group on benzene were shown to lower the biodegradability, while the nitro-group at the para-position had stronger side effect on degradation than at the ortho-position.