Editorial
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Respirol. Feb 20, 2019; 9(3): 30-34
Published online Feb 20, 2019. doi: 10.5320/wjr.v9.i3.30
Diagnosis and treatment of subsegmental pulmonary embolism
Michael Newnham, Alice M Turner
Michael Newnham, Alice M Turner, Institute of Applied Health Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
Author contributions: Newnham M and Turner AM wrote the editorial and both authors approved the final version of the article.
Conflict-of-interest statement: The authors have no conflict of interest to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Michael Newnham, MBChB, MRCP, MSc, Doctor, Lecturer, Institute of Applied Health Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. michaelnewnham@nhs.net
Telephone: +44-121-3713885
Received: December 3, 2018
Peer-review started: December 4, 2018
First decision: January 4, 2019
Revised: January 10, 2019
Accepted: January 28, 2019
Article in press: January 28, 2019
Published online: February 20, 2019
Abstract

Subsegmental pulmonary embolism (SSPE) affects the 4th division and more distal pulmonary arterial branches. SSPE can be isolated or affect multiple subsegments, be symptomatic or incidental (unsuspected) and may or may not be associated with deep vein thrombosis. Symptoms, clinical risk scores and biomarkers are less sensitive for diagnosing SSPE compared to more central pulmonary embolism. The diagnosis is confirmed using radiological imaging, predominately computed tomographic pulmonary angiogram (CTPA) or ventilation/perfusion scanning. The increasing utilization of CTPAs may have resulted in overdiagnosis driven by smaller pulmonary emboli. There is insufficient evidence of improved mortality or reduced venous thromboembolism recurrence with anticoagulation treatment for SSPE however, the major and clinically significant haemorrhage risks are well described. As the resolution of diagnostic imaging has improved, we may be viewing the natural physiological filtering process performed by the lungs that may not require treatment.

Keywords: Subsegmental pulmonary embolism, Venous thromboembolism, Incidence, Diagnosis, Treatment

Core tip: Current guidelines suggest that isolated subsegmental pulmonary embolism (SSPE) patients at low risk of venous thromboembolism (VTE) recurrence and without concurrent proximal VTE can be followed up with clinical surveillance in preference to anticoagulation. This is based on limited evidence and a randomised controlled trial is required to determine the risks and benefits of anticoagulation in SSPE.