title: Vascular anatomy of the medial sural artery perforator flap: a new classification system of intra-muscular branching patterns.
abstract: BACKGROUND
  The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap. The main difficulty encountered when raising the MSAP flap is in obtaining adequate pedicle length during intra-muscular dissection. The objective of this study was to determine the pattern of intra-muscular course of the MSAP flap pedicle.
  
  
  METHODS
  14 cadaveric specimens were dissected and CT angiograms of 84 legs were examined. The intra-muscular branching pattern and depths of the medial sural artery branches were analyzed. The number of perforators, position of the dominant perforator and both intra-muscular and total pedicle length were also recorded and compared to existing anatomical data.
  
  
  RESULTS
  Three types of arterial branching pattern were identified within the medial gastrocnemius, demonstrating one (31%), two (59%) or three or more (10%) main branches. A dominant perforator from the medial sural artery was present in 92% of anatomical specimens (13/14). Vertically, the location of the perforator from the popliteal crease was on average 13 cm (±2 cm). Transversely, the perforator originated 2.5 cm (±1 cm) from the posterior midline. Using CT angiography it was possible in 10 consecutive patients to identify a more superficial intra-muscular branch and determine the leg with the optimal branching pattern type for flap harvest.
  
  
  CONCLUSIONS
  This study is the first to describe the variability of the intra-muscular arterial anatomy of the medial head of gastrocnemius muscle. Surgeons utilizing the MSAP flap option should be aware of the possible branching pattern types and consequently the differing perforator distribution and depths of intra-muscular branches. Routine use of pre-operative CT angiogram may help determine which leg has the most favorable branching pattern type and intra-muscular course for flap harvest.
authors: Department of Plastic and Reconstructive Surgery, Prince of Wales Hospital, Sydney, Australia. Electronic address: joeduss@hotmail.com.
authors: Joseph R
authors: JR
authors: Dusseldorp
authors: University of Sydney, Sydney, Australia.
authors: Quy J
authors: QJ
authors: Pham
authors: Department of Plastic and Reconstructive Surgery, Liverpool Hospital, Sydney, Australia.
authors: Quan
authors: Q
authors: Ngo
authors: Department of Plastic and Reconstructive Surgery, Prince of Wales Hospital, Sydney, Australia.
authors: Mark
authors: M
authors: Gianoutsos
authors: Department of Plastic and Reconstructive Surgery, Prince of Wales Hospital, Sydney, Australia.
authors: Pouria
authors: P
authors: Moradi
mesh_terms: D001158:Arteries / Q000033:anatomy & histology; D002102:Cadaver; D006801:Humans; D007866:Leg / Q000098:blood supply* / Q000000981:diagnostic imaging; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000000981:diagnostic imaging; D061525:Perforator Flap / Q000098:blood supply*; D014057:Tomography, X-Ray Computed
keywords: CT angiography; Free flap; Intra-muscular; Medial sural artery; Perforator