title: Postoperative monitoring of free flap reconstruction: A comparison of external Doppler ultrasonography and the implantable Doppler probe.
abstract: OBJECTIVE
  The time to detection of vascular compromise and the postoperative time to re-exploration are shorter using the implantable Doppler (ID) probe, thereby resulting in earlier surgical re-exploration 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 re-exploration for the ID group, from 48 h to one week after initial surgery (ID 74.5 h, ED 136.8 h; P=0.05).
  
  
  CONCLUSIONS
  The present analysis revealed a potential benefit for the ID probe in the postoperative monitoring of free tissue transfers.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Rayaad C
authors.initials: RC
authors.lastname: Hosein
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Agustin
authors.initials: A
authors.lastname: Cornejo
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Howard T
authors.initials: HT
authors.lastname: Wang
keywords: Complications; Doppler; External; Free flap; Handheld; Implantable; Internal; Monitoring; Reconstruction