title: Surgical outcomes of 156 spinal accessory nerve injuries caused by lymph node biopsy procedures.
abstract: OBJECTIVE
  Iatrogenic injuries to the spinal accessory nerve (SAN) are not uncommon during lymph node biopsy of the posterior cervical triangle (PCT). In this study, the authors review the operative techniques and surgical outcomes of 156 surgical repairs of the SAN following iatrogenic injury during lymph node biopsy procedures.
  
  
  METHODS
  This retrospective study examines the authors' clinical and surgical experience with 156 patients with SAN injury between 1980 and 2012. All patients suffered iatrogenic SAN injuries during lymph node biopsy, with the vast majority (154/156, 98.7%) occurring in Zone I of the PCT. Surgery was performed on the basis of anatomical and electro-physiological findings at the time of the operation. The mean follow-up period was 24 months (range 8-44 months).
  
  
  RESULTS
  Of the 123 patients who underwent graft or suture repair, 107 patients (87%) improved to Grade 3 functionality or higher using the Louisiana State University Health Science Center (LSUHSC) grading system. Neurolysis was performed in 29 patients (19%) when the nerve was found in continuity with recordable nerve action potential (NAP) across the lesion. More than 95% of patients treated by neurolysis with positive NAP recordings recovered to LSUHSC Grade 3 or higher. Forty-one patients (26%) underwent end-to-end repair, while 82 patients (53%) underwent graft repair, and Grade 3 or higher recovery was assessed for 90% and 85% of these patients, respectively. The average graft length used was 3.81 cm. Neurotization was performed in 4 patients, 2 of whom recovered to Grade 2 and 3, respectively.
  
  
  CONCLUSIONS
  SAN injuries present challenges for surgical exploration and repair because of the nerve's size and location in the PCT. However, through proper and timely intervention, patients with diminished or absent function achieved favorable functional outcomes. Surgeons performing lymph node biopsy procedures in Zone I of the PCT should be aware of the potential risk of injury to the SAN.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Jeju National University Medical School, Jeju, Korea;
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, The University of Texas Health Science Center at Houston Medical School, Houston, Texas; and.
authors.forename: Yoshua
authors.initials: Y
authors.lastname: Esquenazi
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, New Orleans, Louisiana.
authors.forename: David G
authors.initials: DG
authors.lastname: Kline
authors.affiliation: Department of Neurosurgery, The University of Texas Health Science Center at Houston Medical School, Houston, Texas; and.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Kim
mesh_terms: D061227:Accessory Nerve Injuries / Q000209:etiology* / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D007049:Iatrogenic Disease; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy / Q000009:adverse effects*
keywords: LSUHSC = Louisiana State University Health Science Center; NAP = nerve action potential; PCT = posterior cervical triangle; SAN = spinal accessory nerve; SCM = sternocleidomastoid muscle; iatrogenic injury; lymph node biopsy; nerve action potential; nerve injury; nerve repair; spinal accessory nerve