title: "In situ preparation": new surgical procedure indicated for soft-tissue sarcoma of a lower limb in close proximity to major neurovascular structures.
abstract: BACKGROUND
  When soft-tissue sarcomas occur near neurovascular structures, preoperative images cannot always reveal the accurate relationship between the tumor and these structures. Therefore, in some patients, neurovascular structures are sacrificed unnecessarily. In other patients, neurovascular structures are preserved with an inappropriate margin, followed by local recurrence. The objective of this study was to evaluate a new surgical method, "in situ preparation" (ISP), which enables the preparation of neurovascular bundles and the intraoperative evaluation of the surgical margin without contamination by tumor cells. With this method, additional procedures, including pasteurization, alcohol soaking, and distilled water soaking of the preserved neurovascular bundle can also be performed to preserve the continuity of vessels.
  
  
  METHODS
  Between April 1992 and December 1998, 18 patients with soft-tissue sarcoma were operated on using ISP. The tumor and neurovascular structure were lifted en bloc from the surgical bed and separated from the field by the use of a vinyl sheet. The consistency of the neurovascular structures was preserved. The tissue block could be freely turned around and the neurovascular structure was separated from the block through the nearest approach. The margin between the tumor and neurovascular structure was evaluated, and an additional procedure, such as pasteurization, alcohol soaking or distilled water soaking, was performed, according to the safety of the surgical margin.
  
  
  RESULTS
  Only one patient showed recurrence after ISP. Complications after ISP were arterial occlusion in two patients and nerve palsy in three patients. The main cause of these complications was the long period of pasteurization; modified additional procedures could prevent such complications.
  
  
  CONCLUSIONS
  ISP is a useful method with which to ensure a safe surgical margin and good functional results.
authors.affiliation: Cancer Institute Hospital, Department of Orthopedic Surgery, 1-37-1 Kami-ikebukuro, Toshima-ku, Tokyo 170-0012, Japan. smatsumoto@jfcr.or.jp
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Kawaguchi
authors.forename: Jun
authors.initials: J
authors.lastname: Manabe
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsushita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D005268:Femoral Vein / Q000601:surgery; D018219:Histiocytoma, Benign Fibrous / Q000601:surgery; D006801:Humans; D008080:Liposarcoma / Q000601:surgery; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery*; D012509:Sarcoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013584:Sarcoma, Synovial / Q000601:surgery; D012584:Sciatic Nerve / Q000601:surgery; D013514:Surgical Procedures, Operative / Q000379:methods; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome