How to assess a CTA of the abdomen to plan an autologous breast reconstruction
The deep inferior epigastric perforator (DIEP) flap is recognised as the most popular option for autologous breast reconstruction. Planning of the DIEP flap involves pre-operative assessment of abdominal vascular anatomy with imaging, of which computed tomographic angiography (CTA) has become the mainstay. CTA enables detailed planning of a range of surgical steps, leading to reduced operative times and improved surgical outcomes. The value of CTA is only demonstrated when the relevant vascular anatomy is able to be demonstrated and appraised. For optimal analysis, a 64-slice multi-detector row CT scanner and imaging software including OsiriX™, Siemens InSpace™ or Horos™ are required. The seven major steps to consider include: (I) perforator size; (II) perforator angiosome; (III) intramuscular course; (IV) deep inferior epigastric artery (DIEA) pedicle; (V) venous anatomy; (VI) superficial inferior epigastric artery (SIEA) and superficial inferior epigastric vein (SIEV); and (VII) abdominal wall structure. These steps should also be reviewed when marking the patient and planning the flap intra-operatively. While CTA has superior sensitivity and specificity in mapping perforator anatomy it also faces challenges due to ionising radiation exposure, contrast-induced allergy and potential nephrotoxicity. Despite these challenges, the benefits of CTA to the individual patient has maintained its role in pre-operative planning of the DIEP flap.