[Impact of the number of pregnancies on the venous outflow of DIEP flap in breast reconstruction: A clinical and CT-scan study].

Introduction: The DIEP (deep inferior epigastric perforator) flap is the "gold standard" for breast reconstruction after cancer, giving better benefits on the quality of life. The most common complication is the venous congestion, because of the dominance of superficial venous outflow while the flap is drained by the deep epigastric vein. Pregnancy, by its physiological and vascular modifications, can reduce the risk of the venous congestion. Few studies explored the impact of pregnancy on the DIEP vascularization.

Material and methods: We studied the preoperative CT-scans of 104 patients who benefited reconstruction surgery by DIEP from January 2011 until March 2022. The patients were separated into 5 groups according to number of pregnancies. For each CT-scan, a concomitant vein of deep epigastric artery diameter/SIEV diameter ratio was performed on each side, to assess the relation between pregnancy and the reduction of venous complications.

Results: The results showed an increase of this ratio with the number of pregnancies. Patients with no pregnancy (G0) have the highest complication rate, with 41.7% of venous congestion case. On the other hand, in the group of four pregnancies or more (G4), the complication rate was significantly lower, at 10%, and none venous congestion was observed. These results suggest the beneficial effects of pregnancy on vascularization and especially on venous drainage in the DIEP flap.

Conclusion: This study highlights the benefit effect of the number of pregnancies on the DIEP vascularization, especially for the reduction of the venous congestion risk. The ratio DIEV/SIEV may be a useful help to predict the risk of venous complications in nullparous patients. These results open to new studies to deepen the understanding of the physiological effects of the pregnancy on the breast reconstruction surgery.