title: Outcome Measures of an Intracanal, Endoscopic Transforaminal Decompression Technique: Initial Findings from the MIS Prospective Registry.
abstract: BACKGROUND
  Minimally invasive transforaminal endoscopic procedures can achieve spinal decompression through either direct or indirect techniques. Subtle variations in trajectory of the surgical corridor can dictate access to the pathologic tissue. Two general strategies exist: the intradiscal "inside-out" technique and the extradiscal, intracanal (IC) technique. The IC technique utilizes a more lateral transforaminal approach than the intradiscal technique, which allows for a more direct decompression of the spinal canal.
  
  
  OBJECTIVE
  This study is an assessment of IC patient outcome data obtained through analysis of a previously validated MIS Prospective Registry.
  
  
  METHODS
  Post-hoc analysis was performed on the MIS Prospective Registry database containing 1032 patients. A subgroup of patients treated with the endoscopic IC technique was identified. Patient outcome measures after treatment of symptomatic disk herniation and neuroforaminal stenosis were evaluated.
  
  
  RESULTS
  A total of 86 IC patients were analyzed. Overall, there was significant improvement in employment and walking tolerance as soon as 6 weeks post-op as well as significant one year VAS and ODI score improvement. Subanalysis of IC patients with two distinct primary diagnoses was performed. Group IC-1 (disc herniation) showed improvement in ODI and VAS back and leg outcomes at 1 year post-op. Group IC-2 (foraminal stenosis) showed VAS back and leg score improvement at one year post-op but did not demonstrate significant improvement in overall ODI outcome at any time point. The one year re-operation rate was 2% (1/40) for group IC-1 and 28% (5/18) for group IC-2.
  
  
  CONCLUSIONS
  The initial results of the MIS Registry IC subgroup show a significant clinical improvement when the technique is employed to treat patients with lumbar disc herniation. The treatment of foraminal stenosis can lead to improved short-term clinical outcome but is associated with a high re-operation rate at 1 year post-op.
authors.affiliation: Spine Institute of San Diego, San Diego, CA; Milestone Research Organization, San Diego, CA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sclafani
authors.affiliation: Spine Institute of San Diego, San Diego, CA.
authors.forename: Kamshad
authors.initials: K
authors.lastname: Raiszadeh
authors.affiliation: Swedish Covenant Hospital, Chicago, IL.
authors.forename: Dan
authors.initials: D
authors.lastname: Laich
authors.affiliation: Mohawk Valley Orthopedics, Amsterdam, NY.
authors.forename: Jian
authors.initials: J
authors.lastname: Shen
authors.affiliation: Tier Orthopedic Associates, Johnson, NY.
authors.forename: Matthew
authors.initials: M
authors.lastname: Bennett
authors.affiliation: Clark Memorial Medical Center, Clarksville, IN.
authors.forename: Robert
authors.initials: R
authors.lastname: Blok
authors.affiliation: Milestone Research Organization, San Diego, CA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Liang
authors.affiliation: Spine Institute of San Diego, San Diego, CA.
authors.forename: Choll W
authors.initials: CW
authors.lastname: Kim
keywords: clinical outcome; disc herniation; endoscopic decompression; minimally invasive spine surgery; stenosis