Usefulness of Contralateral Indirect Decompression through Minimally Invasive Unilateral Transforaminal Lumbar Interbody Fusion

STUDY DESIGN Retrospective study. PURPOSE This study aims to investigate the clinical and radiological results of contralateral indirect decompression through minimally invasive unilateral transforaminal lumbar interbody fusion (MI-TLIF). OVERVIEW OF LITERATURE Several studies have proposed that blood loss and operation time could be reduced through a unilateral approach, although many surgeons have forecast that satisfactory foraminal decompression is difficult to achieve through a unilateral approach. METHODS The study included 30 subjects who had undergone single-level MI-TLIF. Visual analogue scale (VAS) and Oswestry disability index (ODI) were analyzed for clinical assessment. Disc height, segmental lordosis, and lumbar lordosis angle were examined for radiological assessment. The degree of contralateral indirect decompression was evaluated through a comparative analysis, with a magnetic resonance imaging (MRI) performed preoperatively and at one year postoperatively. RESULTS Intraoperative blood loss volume was 308.75 mL in the unilateral approach group (UAP), and 575.00 mL in the bilateral approach group (BAP), showing a statistically significant difference. Operation time was 139.50 minutes in the UAP group, and 189.00 minutes in the BAP group, exhibiting a statistically significant difference (p<0.05). On the other hand, no significant difference was found in VAS, ODI, disc height, lordosis angles and the degree of nerve decompression in the vertebral foramen, using MRI, between the two groups (p>0.05). CONCLUSIONS Satisfactory results were acquired with MI-TLIF conducted through the unilateral approach of contralateral indirect decompression, in alignment with the bilateral approach. Therefore, contralateral indirect decompression is thought to be a useful procedure in reducing the operation time and volume of blood loss.