Abstract
Amniotic band syndrome (ABS) is a congenital disorder characterized by limb constrictions. The disorder lacks precise definition, and its exact pathogenesis is unknown. Though theories have been advanced to explain the condition’s origin, none have been scientifically validated. The “exogenous” theory, popularized by Torpin, is the most widely accepted. It suggests that early amniotic rupture leads to formation of amniotic strands, which by means of progressive compression induce formation of extremity bands. In this disorder, histological examination of the excised bands demonstrates them to be composed of fibrous tissue. Multiple clinical and experimental data reveal this theory has only low plausibility. Our purpose is to assess whether annular external compression of a fetal rabbit limb will produce a band of subcutaneous fibrous tissue characteristic of amniotic band syndrome.
We operated on one limb of 10 different rabbit fetuses, each at 21 days of gestation. The extremity was ligated with a nylon suture at the infracondylar level. At 30 days gestation, each fetus was delivered by caesarean section. Limbs were analyzed histologically using different techniques. Histological analysis did not show subcutaneous fibrous tissue in the mechanically constricted zone. The distal segment showed dilatation of lymphatic vessels and edema of soft tissue.
Annular external compression of a fetal rabbit limb does not induce development of new fibrous tissue; therefore this experimental study does not support the theory of a mechanical exogenous pathogenesis in amniotic band syndrome.
Correspondence should be addressed to EORS Secretariat Mag. Gerlinde M. Jahn, c/o Vienna Medical Academy, Alserstrasse 4, 1090 Vienna, Austria. Fax: +43-1-4078274. Email: eors@medacad.org
