title: Direct comparison of postoperative monitoring of free flaps with microdialysis, implantable cook-swartz Doppler probe, and clinical monitoring in 20 consecutive patients.
abstract: BACKGROUND
  There is an increasing demand for successful free tissue transfer, with postoperative monitoring of flaps a key to early salvage. Monitoring methods have ranged from clinical techniques to invasive options, of which two are particularly applicable to buried flaps (Cook-Swartz Doppler probe and microdialysis). The evidence for these options has been represented largely in separate cohort studies, with no single study comparing these three techniques. We aim to perform this comparison in a single cohort of patients.
  
  
  METHODS
  A prospective, consecutive cohort study comparing clinical monitoring, microdialysis and the implantable Doppler probe was undertaken. In 20 patients receiving 22 flaps, 21 flaps were monitored with microdialysis, 18 flaps with clinical observation, and 21 flaps with the Cook-Swartz Implantable Doppler probe. Exclusion was based on applicability and availability intra-operatively. Efficacy was assessed through sensitivity, specificity, positive, and negative predictive values.
  
  
  RESULTS
  Nineteen of 22 flaps had no suspected anastomotic problems; 3 of 22 flaps were explored for anastomotic problems, with two salvaged and one lost. The implantable Doppler and microdialysis were found to detect flap statistically earlier than clinical assessment, with microdialysis better at detecting flap compromise: 100% specificity (confidence interval 31-100%) when compared to the implantable probe and clinical assessment (67%: 13-98% and 33%: 2-87%, respectively).
  
  
  CONCLUSIONS
  Each of the Cook-Swartz Doppler probe, microdialysis and clinical assessment was found suitable for monitoring in free tissue transfer. The implantable Doppler and microdialysis offer the potential for earlier detection of flap compromise.
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic Surgery, Aarhus University Hospital, 44 Noerrebrogade, 8000 Aarhus C, Denmark.
authors.forename: Markus Winther
authors.initials: MW
authors.lastname: Frost
authors.affiliation: Department of Surgery, Monash University, Level 5, E Block, Monash Medical Centre, Clayton, Vic, Australia.
authors.forename: Vachara
authors.initials: V
authors.lastname: Niumsawatt
authors.affiliation: Department of Surgery, Monash University, Level 5, E Block, Monash Medical Centre, Clayton, Vic, Australia.
authors.forename: Warren Matthew
authors.initials: WM
authors.lastname: Rozen
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic Surgery, Aarhus University Hospital, 44 Noerrebrogade, 8000 Aarhus C, Denmark.
authors.forename: Gete Ester Toft
authors.initials: GE
authors.lastname: Eschen
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic Surgery, Aarhus University Hospital, 44 Noerrebrogade, 8000 Aarhus C, Denmark.
authors.forename: Tine Engberg
authors.initials: TE
authors.lastname: Damsgaard
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic Surgery, Aarhus University Hospital, 44 Noerrebrogade, 8000 Aarhus C, Denmark.
authors.forename: Birgitte Jul
authors.initials: BJ
authors.lastname: Kiil
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D058752:Free Tissue Flaps / Q000098:blood supply* / Q000637:transplantation; D006801:Humans; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D010865:Pilot Projects; D011182:Postoperative Care / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000295:instrumentation / Q000379:methods