title: Unilateral approach for bilateral foramen decompression in minimally invasive transforaminal interbody fusion.
abstract: OBJECTIVE
  To evaluate the efficiency and safety of a unilateral approach for bilateral foramen decompression in minimally invasive transforaminal lumbar interbody fusion (miTLIF) for the treatment of bilateral foraminal stenosis.
  
  
  METHODS
  Treatment of 52 levels of bilateral foraminal stenosis in 48 patients was performed using a unilateral approach for bilateral foramen decompression in miTLIF. The foramen areas on bilateral sides, the cross-sectional areas of the dura mater, and the structural preservation of the multifidus muscle on bilateral sides were compared preoperatively and 1 year postoperatively. Visual analog scale scores of pain, 36-item short form health survey results, and complications were recorded after reviewing patient charts. Fusion rates were evaluated 1 year postoperatively.
  
  
  RESULTS
  The average age of patients was 62.48 years. The mean follow-up period was 12.78 months. The foramen areas on bilateral sides and the cross-sectional area of the dura mater increased significantly postoperatively (P < 0.05). Structural preservation of the multifidus muscle was observed in 20 of 54 levels (37%) on ipsilateral sides and in 48 of 54 levels (89%) on contralateral sides. No major complications were observed, and the incidences of minor complications and incidental durotomy were 28% and 4%, respectively. Improvements in average visual analog scale pain and 36-item short form health survey 6 (preoperative to 1 year postoperatively) scores were from 5.9 to 1.8 (P < 0.05) and from 51.3 to 71.3 (P < 0.01), respectively. The radiologic criteria of bony fusion were met by 40 patients (83%).
  
  
  CONCLUSIONS
  A unilateral approach for bilateral foramen decompression in miTLIF provides a safe and efficient method for the treatment of bilateral foramen stenosis in patients with degenerative spinal disorders.
authors.affiliation: Department of Neurosurgery, Taipei Medical University Hospital, Taipei, Taiwan; Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
authors.forename: Jiann-Her
authors.initials: JH
authors.lastname: Lin
authors.affiliation: Department of Neurosurgery, Taipei Medical University Hospital, Taipei, Taiwan; Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan. Electronic address: jiannherlin@gmail.com.
authors.forename: Yung-Hsiao
authors.initials: YH
authors.lastname: Chiang
mesh_terms: D001416:Back Pain / Q000473:pathology / Q000601:surgery; D019299:Decompression, Surgical / Q000379:methods*; D004388:Dura Mater / Q000473:pathology / Q000601:surgery; D005260:Female; D006306:Health Surveys; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D010147:Pain Measurement; D064170:Paraspinal Muscles / Q000601:surgery; D013123:Spinal Fusion / Q000379:methods*; D013130:Spinal Stenosis / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D021801:Zygapophyseal Joint / Q000473:pathology / Q000601:surgery
keywords: Foramen stenosis; Minimally invasive; Transforaminal interbody fusion; Unilateral approach