Tibial artery elongation or redundancy stretch

Patient 1. A 69-year-old man, who is hyperstensive and a smoker, was found to have kinking or looping of both posterior tibial arteries on a lower limb duplex ultrasonography performed for mild lower limb swelling. (A-C). He gave a history bilateral of ankle sprain during child- hood with no major trauma and requiring no invasive or surgical treat- ment. No connective tissue disorder was detected in his family’s medical history. Patient 2. A 57-year-old woman with hypertension and hyperlipi- demia and who is also a smoker, underwent a supra-aortic vessels and lower limb duplex ultrasonography upon the request of her treating physi- cian. A coiling of the right anterior tibial artery was detected (D). She had no history of right ankle sprain with no family history of connective tissue disorders or major trauma. Structural remodeling of blood vessels continuously occurs in response to physical and biochemical stimuli. The structural adapta- tion of the vessel internal diameter and wall thickness caused by the circumferential stretch generated by the blood pressure and the wall shear stress generated by the flow are well known and docu- mented mechanisms. Moreover, axial stretch can also play an impor- tant role in arterial structural changes, so that circumferential, radial, and longitudinal wall adaptations usually occur under increased arte- rial pressure.1 However, the effect of sudden and abrupt arterial elongation or stretching that can lead to dissection or elongation in structurally predisposed arteries is less well known.1 The initial elongation and subsequent proliferation of endothelial cells in response to axial stretch have been well documented in an organ culture system by Lee et al.2 Elastic or collagen arterial components can vary in different arterial beds, and arterial elastin component loss could be responsible for fragmentation of elastomers and progressive vessel lengthening.3 Whereas arterial redundancy is well documented in experimental studies, it is difficult to follow the progressive elongation of arteries in pa- tients, given the long time required to identify such an occurrence. Furthermore, classification and grading of arterial kinking, coiling, or loop- ing have not been performed. Both patients consented to the publication of images and information included in this article.