Conventional CT versus Dedicated CT Angiography in DIEP Flap Planning: A Feasibility Study

Abstract

The deep inferior epigastric perforator (DIEP) flap is used with increasing frequency in post-mastectomy breast reconstruction. Preoperative mapping with CT angiography (CTa) is crucial in reducing surgical complications and optimizing surgical techniques. Our study's goal was to investigate the accuracy of conventional CT (cCT), performed during disease staging, compared to CTa in preoperative DIEP flap planning. In this retrospective, single-center study, we enrolled patients scheduled for mastectomy and DIEP flap breast reconstruction, subjected to cCT within 24 months after CTa. We included 35 patients in the study. cCT accuracy was 95% (CI 0.80-0.98) in assessing the three largest perforators, 100% (CI 0.89-100) in assessing the dominant perforator, 93% (CI 0.71-0.94) in assessing the perforator intramuscular course, and 90.6% (CI 0.79-0.98) in assessing superficial venous communications. Superficial inferior epigastric artery (SIEA) caliber was recognized in 90% of cases (CI 0.84-0.99), with an excellent assessment of superficial inferior epigastric vein (SIEV) integrity (96% of cases, CI 0.84-0.99), and a lower accuracy in the evaluation of deep inferior epigastric artery (DIEA) branching type (85% of cases, CI 0.69-0.93). The mean X-ray dose spared would have been 788 ± 255 mGy/cm. Our study shows that cCT is as accurate as CTa in DIEP flap surgery planning.

Keywords: DIEP flap planning; breast cancer; conventional CT and CT angiography.

Figure 1

Three-dimensional graphic illustration of a DIEP (deep inferior epigastric perforator) flap procedure (a). In 1, skin and fat, with the perforating vascular pedicle from the deep inferior epigastric artery, are dissected from the abdominal wall; in 2 the flap is sized to reconstruct the breast; in 3 the internal mammary vessels are anastomosed to the vascular pedicle of the flap. (b) A surgical view of a DIEP dissection. The rectus abdominis is dissected with its fascia to isolate the inferior epigastric pedicle with its dominant perforator (arrow). Microgrid was employed to measure perforator caliber.

Figure 2

Preoperative planning (a) of a DIEP flap reconstruction for right breast carcinoma, requiring nipple-sparing mastectomy. Eight-month postoperative result (b).

Figure 3

Dominant perforator’s emergence from the anterior rectus abdominis fascia (red arrows) in cCT (a) and CTa (b) axial sub-volume maximum intensity projection (MIP) reconstructions. Images (c,d) show mapping of the dominant perforator on a VR reconstruction of the abdominal surface via a virtual coordinate system centered on a zero point, corresponding to the umbilicus in cCT (c) and CTa (d).

Figure 4

Identification of the deep inferior epigastric artery branching according to Taylor’s classification. cCT (a) and CTa (b) oblique-coronal sub-volume maximum intensity projection reconstruction (MIP) of the superficial abdominal wall revealed a bifurcated artery on the right hemi-abdomen (red arrows) and a single on the left (white arrows).

Figure 5

Assessment of the SIEA caliber compared to the dominant perforator. cCT (a) and CTa (b) sub-volume sagittal MIP reconstructions show a SIEA (red arrows) with a 2 score (equal to the dominant perforator).

Figure 6

Assessment of superficial venous communications running between the right and left portion of the abdomen. Coronal sub-volume maximum intensity projection (MIP) reconstructions of the superficial abdominal wall for cCT (a) and CTa (b) show a large venous trunk on the right hemi-abdomen (red arrows), with a 3 score. Superficial inferior epigastric vein integrity was absent on the left (red circles).