The iterative implementation of a comprehensive enhanced recovery after surgery protocol in all spinal surgery in Korea: a comparative analysis of clinical outcomes and medical costs between primary spinal tumors and degenerative spinal diseases
Authors: Yuh Woon Tak , Kim Jun-Hoe , Han Junghoon , Kim Tae-Shin , Won Young Il , Choi Yunhee , Noh Hyun Jung , Lee Chang-Hyun , Kim Chi Heon , Chung Chun Kee 
Published: December 2023

OBJECTIVE
Most studies on the enhanced recovery after surgery (ERAS) protocol in spine surgery have focused on patients with degenerative spinal diseases (DSDs), resulting in a lack of evidence for a comprehensive ERAS protocol applicable to patients with primary spine tumors (PSTs) and other spinal diseases. The authors had developed and gradually adopted components of the comprehensive ERAS protocol for all spine surgical procedures from 2003 to 2011, and then the current ERAS protocol was fully implemented in 2012. This study aimed to evaluate the impact and the applicability of the comprehensive ERAS protocol across all spine surgical procedures and to compare outcomes between the PST and DSD groups.

METHODS
Adult spine surgical procedures were conducted from 2003 to 2021 at the Seoul National University Hospital Spine Center and data were retrospectively reviewed. The author divided the study periods into the developing ERAS (2003–2011) and post-current ERAS (2012–2021) periods, and outcomes were compared between the two periods. Surgical procedures for metastatic cancer, infection, and trauma were excluded. Interrupted time series analysis (ITSA) was used to assess the impact of the ERAS protocol on medical costs and clinical outcomes, including length of stay (LOS) and rates of 30-day readmission, reoperation, and surgical site infection (SSI). Subgroup analyses were conducted on the PST and DSD groups in terms of LOS and medical costs.

RESULTS
The study included 7143 surgical procedures, comprising 1494 for PSTs, 5340 for DSDs, and 309 for other spinal diseases. After ERAS protocol implementation, spine surgical procedures showed significant reductions in LOS and medical costs by 22% (p = 0.008) and 22% (p < 0.001), respectively. The DSD group demonstrated a 16% (p < 0.001) reduction in LOS, whereas the PST group achieved a 28% (p < 0.001) reduction, noting a more pronounced LOS reduction in PST surgical procedures (p = 0.003). Medical costs decreased by 23% (p < 0.001) in the DSD group and 12% (p = 0.054) in the PST group, with a larger cost reduction for DSD surgical procedures (p = 0.021). No statistically significant differences were found in the rates of 30-day readmission, reoperation, and SSI between the developing and post-current ERAS implementation periods (p = 0.65, p = 0.59, and p = 0.52, respectively).

CONCLUSIONS
Comprehensive ERAS protocol implementation significantly reduced LOS and medical costs in all spine surgical procedures, while maintaining comparable 30-day readmission, reoperation, and SSI rates. These findings suggest that the ERAS protocol is equally applicable to all spine surgical procedures, with a more pronounced effect on reducing LOS in the PST group and on reducing medical costs in the DSD group.