Invasive Strategies for the Treatment of Pulmonary Embolism. Where Are We in 2020?

Pulmonary arteries segmentation from CT images using PA-Net with attention module and contour loss

BACKGROUND

Pulmonary embolism is a kind of cardiovascular disease that threatens human life and health. Since pulmonary embolism exists in the pulmonary artery, improving the segmentation accuracy of pulmonary artery is the key to the diagnosis of pulmonary embolism. Traditional medical image segmentation methods have limited effectiveness in pulmonary artery segmentation. In recent years, deep learning methods have been gradually adopted to solve complex problems in the field of medical image segmentation.

PURPOSE

Due to the irregular shape of the pulmonary artery and the adjacent-complex tissues, the accuracy of the existing pulmonary artery segmentation methods based on deep learning needs to be improved. Therefore, the purpose of this paper is to develop a segmentation network, which can obtain higher segmentation accuracy and further improve the diagnosis effect.

METHODS

In this study, the pulmonary artery segmentation performance from the network model and loss function is improved, proposing a pulmonary artery segmentation network (PA-Net) to segment the pulmonary artery region from 2D CT images. Reverse Attention and edge attention are used to enhance the expression ability of the boundary. In addition, to better use feature information, the channel attention module is introduced in the decoder to highlight the important channel features and suppress the unimportant channels. Due to blurred boundaries, pixels near the boundaries of the pulmonary artery may be difficult to segment. Therefore, a new contour loss function based on the active contour model is proposed in this study to segment the target region by assigning dynamic weights to false positive and false negative regions and accurately predict the boundary structure.

RESULTS

The experimental results show that the segmentation accuracy of this proposed method is significantly improved in comparison with state-of-the-art segmentation methods, and the Dice coefficient is 0.938 ± 0.035, which is also confirmed from the 3D reconstruction results.

CONCLUSIONS

Our proposed method can accurately segment pulmonary artery structure. This new development will provide the possibility for further rapid diagnosis of pulmonary artery diseases such as pulmonary embolism. Code is available at https://github.com/Yuanyan19/PA-Net.

Ultrasound-Accelerated Catheter-Directed Thrombolysis

Venous thromboembolism is a very common presentation in the hospital setting. In patients with high-risk pulmonary embolism (PE) or PE and hemodynamic instability, systemic thrombolytic treatment is generally indicated. In those with contraindications to systemic thrombolysis, catheter-directed local thrombolytic therapy and surgical embolectomy are currently considered. In particular, catheter-directed thrombolysis (CDT) is a drug delivery system coupling the endovascular drug administration nearby in the thrombus and the local facilitating effect of ultrasounds. The applications of CDT are currently debated. Here we provide a systematic review of the clinical utilization of CDT.

Clinical Profile, Immediate- and Short-term Outcome of Patients with Intermediate-risk Acute Pulmonary Thromboembolism

Background

Long-term outcomes of acute pulmonary thromboembolism (PTE) have been reported. However, the immediate- and short-term outcomes have not been reported adequately.

Objectives

Primary objective was to determine the patient characteristics, and immediate- and short-term outcomes of intermediate-risk PTE, and the secondary objective was to evaluate the benefit of thrombolysis in normotensive PTE patients.

Material and methods

This study included patients diagnosed with acute intermediate PTE. Patient's electrocardiography (ECG) parameters along with echocardiography (echo), etc., conducted at the time of admission, during their stay in hospital, at the time of discharge, and during follow-up were recorded. The patients were treated using thrombolysis or anticoagulants depending on hemodynamic decompensation. During follow-up, they were reassessed for echo parameters-right ventricular (RV) function and pulmonary arterial hypertension (PAH).

Results

Among 55 patients, 29 (52.73%) were diagnosed with intermediate high-risk PTE and 26 (47.27%) with intermediate low-risk PTE. They were normotensive and most of them had a simplified pulmonary embolism severity index (sPESI) score <2. Typical ECG pattern S1Q3T3 along with echo patterns and elevated cardiac troponin levels were observed in most of the patients. Patients treated with thrombolytic agents showed a reduction in hemodynamic decompensation as opposed to patients treated with anticoagulants who had clinical signs of right heart failure (RHF) on follow-up after 3 months.

Conclusion

This study contributes to the existing literature on outcomes of intermediate-risk PTE and the effect of thrombolysis on patients with hemodynamic stability. Thrombolysis reduced the incidence and progression of RHF in patients with hemodynamic instability.

How to cite this article

Mathiyalagan P, Rajangam T, Bhargavi K, Gnanaraj R, Sundaram S. Clinical Profile, Immediate- and Short-term Outcome of Patients with Intermediate-risk Acute Pulmonary Thromboembolism. Indian J Crit Care Med 2022;26(11):1192-1197.

How we dealt with the double whammy! Acute pulmonary embolism with abdominal aortic clot and renal infarcts

Pulmonary embolism (PE) is the third most common cause of cardiovascular mortality in the United States, and the submassive PE accounts for 20%-25% of all acute PE. In the last decade, endovascular therapy with catheter-directed thrombolysis (CDT) intervention has shown great success in the treatment of submassive PE. There is limited data regarding using these devices to treat patients with concomitant abdominal aortic and renal vessel clots. Herein, we present a case of a 23-year-old male who presented with submassive PE associated with abdominal aortic thrombosis and renal infarcts. The patient was successfully treated with CDT with complete resolution of pulmonary and bilateral renal artery clots.

Contemporary management of acute pulmonary embolism

This review examines the recent progress in the initial management of pulmonary embolism (PE). Diagnostic strategies allowing the safe decrease of imaging testing have been proposed. New modalities of catheter-based interventions have emerged for hemodynamically unstable PE patients. For normotensive PE patients, direct oral anticoagulant treatment has become the new norm and a large proportion of patients are eligible for home treatment.