Amniotic band syndrome (ABS) is a rare condition that consists in the presence of fibrous bands within the amniotic cavity that may be attached to the fetus. The attachment may result in constriction of the involved part of the anatomy. The constriction may compromise the blood flow distally, which results in swelling (edema) before the constriction and restriction of the blood supply distal to the constriction. Untreated, the band may result in spontaneous amputation of the affected anatomy of the fetus distal to the constriction during the course of the pregnancy. Occasionally, constriction and amputations may be present without obvious bands. ABS may also be associated with other anatomical defects, including clefting and avulsion of organs, which are more difficult to understand as to how they could occur from the presence of bands.
ABS occurs in approximately 1:15000 live births. The cause of ABS is unknown. Although different theories have been proposed (rupture of the amnion and others), none can explain the spectrum of manifestations of ABS.
In 1997, Dr. Quintero and collaborators described for the first time the successful lysis (cutting) of amniotic bands in utero in a fetus at risk of losing an upper extremity. In that surgery, they used an endoscope to identify the location of the band and scissors to release the band from the upper extremity. This case also constituted the first successful surgery performed for a non-lethal fetal condition. Since then, the surgery has been successfully performed by Quintero's team and other fetal surgeons around the world. Surgery is indicated if there is suspicion of distal vascular compromise. During surgery, spontaneous amputations of other parts of the fetal anatomy may be found (e.g., digits), which may not be discernible preoperatively with ultrasound. Alternatively, the bands may only affect the part of the fetal anatomy that appears edematous on ultrasound without amputations. The antenatal release of amniotic bands may avoid spontaneous amputation of the affected anatomical segment. There may be functional deficits resulting from the constriction, which may or may not recover postnatally. Plastic surgery may be needed to repair the areas affected by the constriction. This may require the participation of several pediatric subspecialists to address all of the consequences of the constriction. Pediatric rehabilitation and physical therapy may also be required, depending on whether amputations or functional sequelae (consequences) resulted from the constrictions.