title: Lateralising paraumbilical medial row perforators: dangers and pitfalls in DIEP FLAP planning: a systematic review of 1116 DIEP flaps.
abstract: BACKGROUND
  The DIEP flap remains the gold standard for autologous breast reconstruction. Recently, the 'perforasome concept' has advanced our understanding of DIEP flap physiology and planning. This study highlights a patient sub-population that produces anomalies to the perforasome hypothesis: those with paramedian, paraumbilical perforators.
  
  
  METHODS
  Operation notes and pre-operative CT angiograms from 1116 consecutive DIEP flaps were reviewed retrospectively. Patients with paramedian, paraumbilical perforators (n = 153) were contrasted against a control group whose perforators were not paraumbilical (n = 963). Further sub-group analysis was performed within the study group, comparing paraumbilical perforators that held a lateral course within the flap (n = 25) versus those that held a medial course (n = 128).
  
  
  RESULTS
  Rates of post-operative DIEP flap partial necrosis was greater in the study population compared with the control group (6.54% vs. 3% p = 0.032). When analysis was made contrasting paraumbilical perforators that held a lateral course in the flap versus perforators that held a median course, flap necrosis was significantly greater in those with a lateral course (24% vs. 3.13%).
  
  
  CONCLUSIONS
  The perforasome concept has improved our understanding of perfusion from perforators in DIEP flaps. However when the umbilicus presents a physical barrier to blood vessel passage resulting in lateralizing paraumbilical medial row perforators it appears an exception to the "perforasome" rule. Our experience suggests that when a paraumbilical perforator is harvested, a hemi-flap is safe but caution should be exercised when further volume is needed from the contralateral side.
authors.affiliation: East Grinstead, United Kingdom. Electronic address: jambokelly@gmail.com.
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Kelly
authors.affiliation: East Grinstead, United Kingdom.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Pacifico
mesh_terms: D000792:Angiography; D005260:Female; D006801:Humans; D016462:Mammaplasty / Q000379:methods*; D008875:Middle Aged; D009336:Necrosis; D061525:Perforator Flap / Q000009:adverse effects / Q000098:blood supply* / Q000473:pathology*; D012189:Retrospective Studies; D020858:Tissue and Organ Harvesting / Q000379:methods*
keywords: Angiosome; Breast; Breast reconstruction; Deep inferior epigastic artery; Free-flap; Necrosis; Perforasome; Perforator; Periumbilical; Surgery; Zones of perfusion