Letter to the Editor: ‘The Safety of Spinal Surgery in Patients Over 80 Years of Age: Propensity Score Matching Study’ by Bang C et al

To the Editor,

Recently, we read with great interest the article titled “The Safety of Spinal Surgery in Patients over 80 years of Age: Propensity Score Matching Study” written by Bang C et al. ¹ The authors conducted a commendable retrospective cohort study, gathering data on patients aged 65 to 89 who underwent lumbosacral fusion surgery at their institution between 2016 and 2021. The patient population was stratified into 2 distinct groups: an octogenarian group (ages 80 to 89) and an elderly group (ages 65 to 79). To mitigate confounding variables, the authors utilized propensity score matching (PSM) analysis and subsequently compared the clinical outcomes and perioperative complications between the 2 cohorts following spinal surgery. Results showed no significant differences in most hospital-related factors, but the octogenarians had more medical complications, especially delirium. While the study is valuable, some issues need further discussion.

Firstly, the authors used propensity score matching (PSM) to reduce confounding variables but overlooked the impact of anesthetic techniques on outcomes in elderly spinal surgery, where different anesthesia methods can significantly affect recovery and complication rates. For instance, one study suggests that spinal anesthesia may offer improved blood pressure stability and facilitate enhanced postoperative recovery in elderly individuals. Furthermore, spinal anesthesia has been associated with reduced intraoperative blood loss compared to general anesthesia, which also demonstrates efficacy in providing postoperative analgesia. ² Research conducted by Ellger Bjorn et al ³ indicates that spinal anesthesia can attenuate the postoperative hyperglycemic response in elderly patients, a finding of particular importance for those with diabetes.

Secondly, the selection of anesthetic agents significantly influences postoperative cognitive outcomes. The study by Chang Jee-Eun et al ⁴ examined the differential effects of intravenous anesthesia, primarily using propofol, vs inhalation anesthesia, primarily using sevoflurane, in elderly patients undergoing spinal surgery. They found that propofol was associated with a lower incidence of postoperative delirium, while sevoflurane increased the risk. Additional research has identified dexmedetomidine as a superior sedative for mitigating postoperative delirium when compared to midazolam, propofol, desflurane, and sevoflurane. ⁵ Nevertheless, the study did not account for the influence of various anesthesia techniques and agents on postoperative complications in elderly spinal surgery patients, particularly the potential for delirium associated with different anesthetic drugs, which may compromise the validity of the experimental conclusions. Consequently, we recommend incorporating anesthesiology considerations into future research designs.

Furthermore, a study examining elderly patients undergoing spinal surgery identified a history of stroke, the use of non-benzodiazepine hypnotics, preoperative hyponatremia, and the prognostic nutritional index (PNI) as independent preoperative predictors of delirium. ⁶ However, it is noteworthy that this article did not exclude participants with a history of stroke or those utilizing hypnotic medications in the 2 experimental groups, which may potentially compromise the study’s accuracy.

In conclusion, we wish to convey our sincere appreciation to the authors for their invaluable contributions to this research. It is our hope that the insights presented herein will prove advantageous for their future scholarly pursuits. Additionally, we look forward to their response.