Postoperative monitoring of free flap reconstruction: A comparison of external Doppler ultrasonography and the implantable Doppler probe

Abstract

Hypothesis The time to detection of vascular compromise and the postoperative time to reexploration are shorter using the implantable Doppler (ID) probe, thereby resulting in earlier surgical reexploration and a higher flap salvage rate. Methods A single-centre experience with 176 consecutive free flap reconstructions in 167 patients from 2000 to 2008 in a university-based teaching hospital by retrospective chart review is presented. Results There was a significant difference in overall flap survival (ID 98.0%, external Doppler [ED] 89.3%) and total flap loss (ID 2.0%, ED 10.7%) between the two groups (P=0.03). The difference in flap salvage rate was not significant (ID 90.9%, ED 63.6%; P=0.068). The false-positive (ID 0%, ED 3%; P=0.18) and false-negative rates (ID 0.0%, ED 4.5%; P=1.0) were not significantly different. There was also a lower median postoperative time to reexploration for the ID group, from 48 h to one week after initial surgery (ID 74.5 h, ED 136.8 h; P=0.05). Conclusion The present analysis revealed a potential benefit for the ID probe in the postoperative monitoring of free tissue transfers.