Supplementary decompression and extended surgical time contribute to hidden blood loss In percutaneous endoscopic lumbar discectomy

Background: It is widely believed that the Percutaneous endoscopic lumbar discectomy (PELD) is associated with minimal blood loss. However, significant perioperative hidden blood loss (HBL) is frequently unaccounted for. This study aimed to investigate HBL and peri-operative factors contributing to HBL in a series of individuals undergoing PELD.

Method: ology: A total of 156 consecutive patients with a mean age of 43.6 years (ranging from 18 to 80 years) who underwent PELD at our department from May 2019 to November 2020, were included in the study. Factors including gender, age, body mass index, symptom duration, operation approach/technique, operation duration, the presence of associated chronic diseases, and improvements in the Visual Analog Scale (VAS) score, Japanese Orthopaedic Association (JOA) score and the Oswestry Disability Index (ODI) were analyzed, and Gross's formula was applied to calculate blood loss, which was used to determine HBL.

Results: The average total blood loss (TBL) was 221.0 ± 126.2 mL, while the average HBL was 181.7 ± 119.0 mL (82.2 % of TBL). There was no statistically significant difference in HBL between the transverse surgical approach and the interlayer approach. Additionally, no significant differences were observed in improvements in VAS, JOA, and ODI scores between the two surgical approaches. However, the multivariate linear regression analysis revealed that longer surgical time and foraminal decompression were factors contributing to the increase in HBL, which subsequently led to the occurrence of post-operative anemia.

Conclusion: HBL is significant in PELD cases with long surgical time and lumbar foraminal decompression.