title: Anterior thoracolumbar spine exposure: critical review and analysis.
abstract: BACKGROUND
  Indications for anterior thoracolumbar spine interbody fusion have expanded because of safe and expeditious surgical exposure that can be provided by the approach surgeon. In our practice, previous anterior interbody instrumentation, multiple disc level exposure, patient age, and body habitus are not surgical deterrents despite the potential for increased complications. The arterial and venous complications of anterior spine exposure have been well documented; however, the purpose of this study is to document the incidence of other complications, such as deep vein thrombosis (DVT), lymphedema, seroma/hematoma, wound infection, and hospital readmission and to determine whether outcome is influenced by the factors mentioned above.
  
  
  METHODS
  Six hundred seventeen consecutive patients had anterior thoracolumbar spine exposure performed by a single vascular surgeon between January 2007 and June 2012. Office and hospital records were reviewed with institutional review board approval.
  
  
  RESULTS
  The mean patient age was 56 years, and 16% were >69 years of age. The mean body mass index (BMI) was 29.27 kg/m(2) (range: 16-53 kg/m(2)); 39% were considered obese, with BMI measurements of >30 kg/m(2). The overwhelming majority of cases were performed for varying grades of spondylolisthesis and/or degenerative disc disease; in 8 cases (1.3%), the indication for disc exposure was diskitis/osteomyelitis. One disc level was exposed in 36% of cases, 2 in 43%, and ≥3 in 21%. Six percent of patients had previous anterior spine exposure, 42% had previous posterior laminectomy and/or diskectomy, and 3% required anterior disc reexposure to remove hardware or an artificial disc. There was 1 major arterial dissection and 3 major venous injuries. Other complications included extensive DVT (2%), debilitating lymphedema (0.5%), wound seroma/hematoma requiring treatment (2%), wound infection (3%), and readmission within 60 days (8%). Multilevel (>2 levels) disc exposure was associated with an increased rate of lymphedema, posterior lumbar wound infection, and hospital readmission (all P values ≤ 0.01; chi-squared analysis). A BMI >30 kg/m(2) was associated with an increased rate of DVT, posterior lumbar wound infection, and hospital readmission (all P values ≤ 0.018; chi-squared analysis). Age >69 years was associated with an increased rate of wound hematoma (P = 0.002; chi-squared analysis). Logistic regression analysis revealed that BMI >30, multilevel disc exposure, and removal of an artificial disc or hardware were all associated with an increased rate of any nonvessel complication (P values < 0.001); however, no specific variable was associated with an increased rate of a major vessel complication, including those cases where the surgical indication was diskitis/osteomyelitis.
  
  
  CONCLUSIONS
  The overall incidence of nonvessel injury complications after anterior thoracolumbar spine exposure is low. Redo anterior spine exposure and redo disc exposure cases, including those that require hardware or artificial disc removal, can be performed safely. Multidisc level exposure is, however, associated with an increased incidence of lymphedema, wound infection, and hospital readmission. Patients with BMI >30 kg/m(2) should be approached with caution because there is a significantly increased rate of DVT, wound infection, and hospital readmission.
authors.affiliation: Department of Vascular Surgery, Saint Joseph Hospital, Orange, CA. Electronic address: jeffreyballard@visoc.org.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Ballard
authors.affiliation: Department of Orthopedic Surgery, Saint Joseph Hospital, Orange, CA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Carlson
authors.affiliation: Department of Orthopedic Surgery, Saint Joseph Hospital, Orange, CA.
authors.forename: Jack
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Orthopedic Surgery, Saint Joseph Hospital, Orange, CA.
authors.forename: Jon
authors.initials: J
authors.lastname: White
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002140:California / Q000453:epidemiology; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010359:Patient Readmission; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods; D013904:Thoracic Vertebrae / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult