The effect of modified paramedian and median approaches of spinal anesthesia on postspinal acute low back pain in patients undergoing urological surgery: a prospective cohort study

Background: Low back pain after spinal anesthesia may be a complicated issue for many patients. We aimed to evaluate the incidence of postspinal low back pain in the modified paramedian approach of spinal anesthesia compared to the classical median approach.Materials and Method: The study is a prospective non-randomized observational trial. We included 297 patients aged 20 to 80 years who underwent urological surgery under spinal anesthesia. Patients were allocated into two groups: In Group P, patients underwent spinal anesthesia by using a modified paramedian approach and in Group M, the classical median approach was used. Primary outcome was the incidence of postoperative low back pain. Secondary outcomes were number of needle insertion attempts, needle bone contacts and patient satisfaction.Results: The incidence of low back pain in Group M was 70.3% on the first day, 39.5% on the 7th day and 5.9% at the end of one month after surgery. In Group P, the incidence of low back pain was 30.7% on the first day, 12.4% on the 7th day and 0.7% at the end of one month after surgery. The low back pain scores were significantly lower in group P at all-time points. Patient satisfaction was significantly higher in group P (p=0.038). The number of needle interventions (p=0.001) and bone contact (p=0.000) were significantly lower in group P.Conclusions: Low back pain was less common with the modified paramedian approach compared to the classical median spinal approach. We found lower number of needle insertion attempts and bone contacts in the modified paramedian technique. Patient satisfaction was also higher in the paramedian technique.