Correlation analysis between the changes in the root canal area and the intervertebral foramen cross-sectional area and the relevant scores of clinical symptom improvement in patients with unilateral L4-L5 spinal stenosis after MIS-TLIF

Abstract

Objective This study aimed to investigate changes in the root canal area and the cross-sectional area of the intervertebral foramen in patients with unilateral L4-L5 spinal stenosis who underwent Minimally Invasive Surgery-Transforaminal Lumbar Interbody Fusion (MIS-TLIF) and their correlation with clinical symptom improvement. Methods We selected 35 patients diagnosed and treated for unilateral L4-L5 spinal stenosis at our hospital from June 2020 to February 2022. We recorded intraoperative blood loss, operation time, and postoperative complications. The study compared changes in nerve root canal area observed in CT scans before and after MIS-TLIF surgery in spinal stenosis patients. We also assessed the nerve root canal area at different heights and the L4-L5 intervertebral foramen area. Preoperative and postoperative scores were collected for ODI (Oswestry Disability Index), NRS (Numeric Rating Scale), EQ-5D (EuroQol-5D), and GPE (Global Perceived Effect) to evaluate clinical symptoms. Correlation analyses were conducted between changes in clinical scores and changes in the above-mentioned anatomical areas. Results All patients underwent successful surgeries with an average operation time of 122.2 ± 20.33 minutes and an average intraoperative blood loss of 231.43 ± 129.53 ml. Five cases required blood transfusions, and three cases experienced postoperative cerebrospinal fluid leakage, which resolved with bed rest and fluid infusion. There were no infections, but eight cases had postoperative anemia, and no other complications, such as pulmonary embolism, occurred. Postoperative ODI and EQ-5D scores at 3 months, 6 months, and 12 months showed significant improvement compared to preoperative scores. Linear correlation analysis revealed that the cross-sectional area of the lumbar root canal was negatively correlated with ODI scores (r=-0.45, P < 0.01), positively correlated with EQ-5D scores (r = 0.46, P < 0.01), and negatively correlated with NRS-leg scores (r=-0.47, P < 0.01). Moreover, the L4-L5 intervertebral foramen area was significantly negatively correlated with ODI scores (r=-0.80, P < 0.01) and positively correlated with EQ-5D scores (r = 0.517, P < 0.01). Conclusion Identifying lumbar spinal stenosis preoperatively provides valuable guidance for effective decompression during minimally invasive surgery. However, this study has limitations, primarily due to the small sample size of patients with unilateral single-level L4-L5 symptoms. Further research with a larger sample size is warranted.