Anatomical variations of the thoracic duct: a preliminary report in adults and fetal specimens

Abstract

The study aim is to evaluate anatomical variations of the thoracic duct using a specialized sequential injection procedure. The different types, frequencies, and anatomical topography were recorded and evaluated using 12 adult and 16 fetus specimens. By employing a perfusion pump device, cadavers were sequentially perfused with acrylic colored latex first through the internal marginal vein, then the thoracic duct at the interazygous-aortic recess, and finally through the posterior tibial artery. After perfusion, thoracic ducts were identified, partially dissected, and cadavers fixed by soaking in an aqueous solution of 5% formalin (v/v). Finally, further dissection and detailed photography were performed. Plexus shapes at different levels were clearly evident in 80% of the adult specimens. Whereas the presence of the cisterna chyli was detected in 100% of fetuses as an ampule dilatation at the beginning of the thoracic duct, in only one adult specimen was a dilatation found at the lumbar lymphatic trunk level. Functionally it is not known whether these modified anatomical features (plexus shapes) have served to compensate (as a derivative pathway) for lymphatic hypertension in life as a reflection of lymphatic system challenges and subsequent growth in the adult specimens.