3D-printed, patient-specific DIEP flap templates for preoperative planning in breast reconstruction: a prospective case series

Abstract

Background: Modern imaging technologies, such as computed tomographic angiography (CTA), can be useful for preoperative assessment in deep inferior epigastric artery perforator (DIEP) flap surgery. Planning perforator flap design can lead to improved surgical efficiency. However, current imaging modalities are limited by being displayed on a two-dimensional (2D) surface. In contrast, a 3D-printed model provides tactile feedback that facilitates superior understanding. Hence, we have 3D-printed patient-specific deep inferior epigastric artery perforator (DIEP) templates, in an affordable and convenient manner, for preoperative planning.

Methods: Twenty consecutive patients undergoing 25 immediate or delayed post-mastectomy autologous breast reconstruction with DIEP or muscle-sparing transverse rectus abdominis (MS-TRAM) flaps are recruited prospectively. Using free, open-source softwares (3D Slicer, Autodesk MeshMixer, and Cura) and desktop 3D printers (Ultimaker 3E and Moment), we created a template based on a patient's abdominal wall anatomy from CTA, with holes and lines indicating the position of perforators, their intramuscular course and the DIEA pedicle.

Results: The mean age of patients was 52 [38-67]. There were 15 immediate and 10 delayed reconstructions. 3D printing time took mean 18 hours and 123.7 g of plastic filament, which calculates to a mean material cost of AUD 8.25. DIEP templates accurately identified the perforators and reduced intraoperative perforator identification by 7.29 minutes (P=0.02). However, the intramuscular dissection time was not affected (P=0.34). Surgeons found the template useful for preoperative marking (8.6/10) and planning (7.9/10), but not for intramuscular dissection (5.9/10). There were no immediate flap-related complications.

Conclusions: Our 3D-printed, patient-specific DIEP template is accurate, significantly reduces intraoperative perforator identification time and, hence, may be a useful tool for preoperative planning in autologous breast reconstruction.

Keywords: 3D printing; autologous breast reconstruction; deep inferior epigastric artery perforator (DIEP); preoperative planning; surgical template.

Figure 1

3D printing software. (A) Using 3D Slicer software (Surgical Planning Laboratory, Boston, MA USA), CTA scan data is converted into a 3D image of the abdominal wall and holes and lines are placed appropriately to indicate the location of DIEA perforators, their intramuscular course and the DIEA pedicle. (B) Using Autodesk MeshMixer software (Autodesk, Inc., San Rafael, CA USA), the 3D image is cropped into appropriate size and the holes/lines are enlarged to fit marking pens. (C) Using Cura software (Ultimaker, Geldermalsen, Netherlands), the final file is converted to a 3D printer-friendly file. CTA, computed tomographic angiography; DIEA, deep inferior epigastric artery.

Figure 2

Clinical application of the 3D-printed DIEP template in use. The template was orientated on the abdomen by the umbilicus, notch at the pubic symphysis and the abdominal skin crease (A). Markings from the template were used for flap design and the skin island (B). DIEP, deep inferior epigastric artery perforator.