Conjoined Epigastric Heteropagus Twins: Excision of a Parasitic Twin from the Anterior Abdominal Wall of Her Sibling

Abstract

Epigastric heteropagus twins (EHT) are an exceedingly rare form of asymmetric conjoined twins in whom the dependent twin (parasite) is attached to the right or left upper abdomen of the dominant part (autosite). Such a case observed at our institution with 34 month follow-up is presented here and the surgical technique described. A magnetic resonance imaging (MRI)-supported surgical separation of the parasite with successful closure of the abdominal wall defect of the autosite was performed. Follow-up studies showed an autosite which was alive and in optimal health. A comprehensive review including data from English and non-English literature is presented.

Heteropagus (parasitic) twins: a review

“…In all 3 cases, combined weight of parasite and autosite were more than 3000 ggreater than the median 2795 g calculated on review of 23 articles reporting birth weight of heteropagus twins from 1986 to 2007. Size and weight of the isolated parasite is not noted in any of the three, but in 2 cases, photographs reveal large parasites with pelvises, as well as lower, and upper limbs [40,51]. In the third case, the parasite was composed of 2 small, discontinuous cranial and epigastric segments.…”

“…Although 11 cases (28%) noted the presence of some portion of parasite bowel, communication with autosite bowel was only found in one set of twins [62]. Bony connection between autosite xiphisternal region and parasite upper extremity was noted in 2 cases [23,51]. Two cases of urinary tract communication were reported [24,62].…”

“…Most parasitic twins are acephalic. Yet, ischemia in other settings, such as uteroplacental insufficiency, shows brainsparing growth restriction [51,52]. A role for Pax1, Wnt-8c, as well as other homeobox, homeobox-like, and WNT superfamily proteins involved in induction and differentiation has been suggested [18,51,53,54].…”

“…At least 3 examples exist in which the authors explicitly note the failure of prenatal sonographic assessment to detect heteropagus twins [40,51,61]. In all 3 cases, combined weight of parasite and autosite were more than 3000 ggreater than the median 2795 g calculated on review of 23 articles reporting birth weight of heteropagus twins from 1986 to 2007.…”

“…This may be a result of less complexity in vascular communications observed between autosite and parasite, in contrast to those between diplopagus twins. Several groups have used Doppler ultrasound [20,51,56,72] or magnetic resonance angiography [40,57] to identify the vascular pedicle sustaining the parasite before surgical separation. Vascular connections are often determined intraoperatively.…”