Determinants and clinical impact of ischemia time in microsurgical breast reconstruction: A multicenter registry analysis of 4209 flaps.

Background

Ischemia time is a key determinant of microsurgical free-flap survival and potentially modifiable risk factor in autologous breast reconstruction. However, factors influencing ischemia time within complex workflows are insufficiently understood. Existing evidence is largely limited to single-center, retrospective studies that focused predominantly on deep inferior epigastric perforator flaps.

Methods

Prospectively collected data from the German national registry, including 22 centers, for autologous breast reconstruction were analyzed. A subcohort of 4209 unilateral microsurgical breast reconstructions performed in 4113 patients between 2011 and 2018 was evaluated. Generalized linear models were used to assess the effects of flap type, intraoperative repositioning, anastomosis technique, surgeon-related factors, and recipient vessel choice on ischemia time. Associations with operative duration and clinical outcomes were examined using multivariable regression.

Results

Procedures that required intraoperative repositioning showed significantly longer ischemia times than non-repositioning procedures (mean difference 43 min, p <0.001). Hand-sewn venous anastomoses resulted in significantly longer ischemia times than did coupler-assisted anastomoses, with this difference increasing over time (mean difference 15 min, p =0.003). Prolonged ischemia time was associated with arterial revision and flap loss, whereas operative duration showed the strongest association with venous revision.

Conclusion

Ischemia time in microsurgical breast reconstruction is strongly influenced by technical and organizational factors. Coupler-assisted anastomoses shortened the ischemia time and appeared to be less influenced by surgeon-related variability and procedural complexity. Prolonged ischemia time continued to be associated after adjustment with arterial complications and flap loss, whereas operative duration showed its strongest and most robust association with venous anastomotic revision, thereby supporting ischemia time as a clinically relevant workflow-dependent quality metric.