A reappraisal of adult thoracic surface anatomy

Abstract

Accurate surface anatomy is essential for safe clinical practice. Numerous inconsistencies in clinically important surface markings exist between and within anatomical reference texts. The aim of this study was to investigate key thoracic surface anatomical landmarks in vivo using computed tomographic (CT) imaging. High-resolution thoracic CT scans from 153 supine adults (mean age 63, range 19-89 years; 53% female) taken at end tidal inspiration were analyzed by dual consensus reporting to determine the surface anatomy of the sternal angle, central veins, heart, lungs, and diaphragm. Patients with kyphosis/scoliosis, distorting space-occupying lesions, or visceromegaly were excluded. The position of the cardiac apex, formation of the brachiocephalic veins, and vertebral levels of the sternal angle, xiphisternal joint, and aortic hiatus were consistent with commonly accepted surface markings although there was a wide range of normal variation. In contrast, common surface markings were markedly inaccurate for the following: the position of the tracheal bifurcation, aortic arch, and azygos vein termination (below the plane of the sternal angle at T5-T6 vertebral level in most individuals); the superior vena cava/right atrial junction (most often behind the fourth costal cartilage); the lower border of the lung (adjacent to T12 vertebra posteriorly); and the level at which the inferior vena cava and esophagus traverse the diaphragm (T11 in most). Surface anatomy must be reappraised using modern imaging in vivo if it is to be evidence based and fit for purpose. The effects of gender, age, posture, respiration, build, and ethnicity also deserve greater emphasis.

Revisiting thoracic surface anatomy in an adult population: A computed tomography evaluation of vertebral level

“…Clearly, surface anatomy needs to be accurate to ensure safe clinical patient assessment (Hale et al, 2010). Modern imaging techniques provide an opportunity to determine the accuracy of surface anatomy in living individuals (Mirjalili et al, 2012a). Indeed, modern imaging studies such as computed tomography (CT) have been used during the last two decades to assess traditional surface anatomical landmarks (Chukwuemeka et Mirjalili et al, 2012a), and (ii) to educate medical students for future clinical practice.…”

“…Modern imaging techniques provide an opportunity to determine the accuracy of surface anatomy in living individuals (Mirjalili et al, 2012a). Indeed, modern imaging studies such as computed tomography (CT) have been used during the last two decades to assess traditional surface anatomical landmarks (Chukwuemeka et Mirjalili et al, 2012a), and (ii) to educate medical students for future clinical practice. Surgeons must be familiar with relevant surface markings as a prerequisite for donor site reconstruction (Cunningham et al, 2004).…”

Would you prefer to use surface anatomy based on living persons or cadavers?

“…We note his concern about the potential variability of surface anatomical features caused by different degrees of inspiration. We agree that deep inspiration or expiration will affect the position of some viscera in relation to bony landmarks and we have repeatedly acknowledged this in several of our publications (Mirjalili et al, 2012a(Mirjalili et al, ,2012b(Mirjalili et al, ,2012c. However, we wish to make several points:…”

Perhaps we don’t know what we thought we knew: Why clinicians need to re-visit and re-engage with clinical anatomy

“…1 The topic of surface landmarks, popular with clinicians, have been given a special section in a recent edition of the journal Clinical Anatomy. [2][3][4][5][6][7][8] This section was dedicated to recent findings that challenge the existing anatomical dogma and guidelines by examining the evidence for the current data. Many original research articles in this issue provide evidence that is contrary to the commonly held beliefs that have been passed from generation to generation of both textbook and clinician.…”