Azygos lobe in a South African cadaveric population

Abstract

3 D e p a r tm en t of A n a tom y , S ch ool of M e di ci n e , F a c ul ty of H eal th S ci en c es , U n i v e r si ty of Pretoria, Pretoria, 0001 4 Emergency Humanitarian Action, WHO Pakistan, PO Box 1013, Islamabad, 44000, Pakistan. ABSTRACTKnowledge of the prevalence, morphology and location of the azygos lobe is essential for diagnostic and surgical procedures of the lungs related to mediastinal pathologies, especially to minimize intraoperative vascular injuries, shock, possible thoracotomy and even the possibility of pulmonary torsion. Reports on the prevalence of the azygos lobe vary between 0.11% and 0.43%. The aim of the current study was to record the prevalence and morphological description of the azygos lobe in the South African cadaveric population. A total of 704 adult cadavers dissected over a ten-year period by students in the Department of Human Anatomy at the Medunsa Campus, University of Limpopo, were studied. The prevalence and dimensions of the azygos lobe were determined with a 95% confidence interval. Results indicate that an azygos lobe was present in the right lung in only four cases (prevalence 0.57%, 95% Confidence Interval[CI]: 0.2%-1.6%). The mean height and width were 6.7 cm (95% CI: 4.4-9.2) and 4.5 cm (95% CI: 3.7-5.2) respectively. Observations on the morphology of the azygos lobe showed that it was rectangular (n=3) and triangular (n=1) in shape with smooth margins. In conclusion, the azygos lobe is a rare anomaly in the South African cadaveric population. The present results are comparable with those reported in the literature for other populations. Future radiological studies on the azygos lobe on living subjects in South Africa will be useful for further understanding of this rare but significant anomaly.

Prevalence of an Azygos Lobe using Thoracic Computed Tomography

“…We did not detect a simultaneous pathology associated with the presence of an azygous lobe (5-7). Despite many published reports regarding an azygous lobe, a limited number of studies have examined its prevalence, which is reported to be 1% in cadaveric specimens, 0.4% on plain chest X-rays, and 1.2% on high-resolution CT images (8)(9)(10). A PubMed search on the prevalence of an azygous lobe detected using thoracic CT images yielded a limited number of studies (10,11).…”

Azygos lobe: A rare case

“…Although the azygos lobe can be detected in chest X-ray, CT can be used in some cases. Incidence is 1% in chest X-ray and 1.2% in CT. [2,7] Our case was detected incidentally in CT. Similar to our case, a convex line due to azygos fissure resembles a triangular-shaped area (trigon) attached to the extrapleural tissue on the fissure and the lower part of the azygos vein.…”

Video-assisted thoracoscopic surgery (VATS) right upper lobectomy for non-small-cell lung cancer with an azygos lobe

“…The mechanism of its development is that the azygos vein passes anteriorly to the lung; as a result, some segments of the right upper lobe remain in this structure [1, 3, 4]. It is a congenital variation seen in 0.11–1.06% of the population [3]. It has no serious consequences by itself, and there is no need for special treatment; however, accompanying conditions may warrant attention.…”