Dilation of synthetic grafts and junctional aneurysms.

Dilation of prosthetic graft has been noted by authors in association with junctional aneurysm between the synthetic graft and host arteries. Dilation of graft materials was suspected as one of the etiologic factors of the junctional aneurysm. Increase in transverse diameter was observed as early as a few minutes to five years postimplantation in clinical cases. The phenomenon of dilation was studied experimentally. Nine different types of graft materials were tested using intraluminal pulse pressure of 100/60 mm Hg, and the transverse diameters were measured at various time intervals. Knitted grafts showed the more pronounced changes compared with the woven. Degree of dilation differed considerably among the different types of knitted grafts.