1. 2019;22;E133-E138Risk Factors for Early Recurrence After Transforaminal Endoscopic Lumbar Disc Decompression
   Observational Study
   Chan Hong Park, MD, PhD, Eun Soo Park, MD, Sang Ho Lee, MD, PhD, Kyung Kyu Lee, MD, Yoon Kwang Kwon, MD, Min Soo Kang, MD, Shin Young Lee, MD, and Young Hwan Shin, MD, PhD.

BACKGROUND: Transforaminal endoscopic lumbar disc decompression (TELD) has emerged as a treatment alternative to open lumbar discectomy, but rates of herniated lumbar disc (HLD) recurrence after TELD are higher by comparison.

OBJECTIVES: We conducted this study to identify factors correlating with early HLD recurrence after TELD.

STUDY DESIGN: Retrospective study.

SETTING: The Department of Anesthesiology and Pain Medicine, Neurosurgery at Spine Health Wooridul Hospital.

METHODS: As a retrospective review, we examined all patients undergoing TELD between 2012 and 2017, analyzing the following in terms of time to recurrence: age, gender, body mass index (BMI), comorbid conditions (diabetes mellitus [DM], hypertension [HTN]), smoking status, nature of disc herniation (central, paramedian, or foraminal), Modic changes, migration grade (rostral vs. caudal track + degree), herniated disc height (Dht) and base size (Dbase), and the presence of spondylolisthesis on magnetic resonance imaging.

RESULTS: During the 5-year study period, 1,900 patients underwent TELD procedures, resulting in 209 recurrences (11.0%). In 27 of these patients (12.9%), herniation recurred within 24 hours after surgery. Recurrences most often developed within 2-30 days (n = 76). The smaller the size of a herniated disc, the earlier it recurred. Recurrences were unrelated to gender, BMI, DM or HTN, smoking status, migration grade, nature (Dht or Dbase of herniated disc), or the presence of spondylolisthesis.

LIMITATIONS: In addition to variables assessed herein, other clinical and radiologic parameters that may be important in recurrent disc herniation should be included. Furthermore, only univariate analyses were performed, making no adjustments for potential confounders, therefore, independent risk factors could not be assessed. A prospective study would likely generate more precise results, especially in terms of standardized sampling and data classification. Finally, multiple causes for primary discectomy failures may have rendered our patient groups nonhomogeneous, and inequalities in surgical options or physician-dictated surgical choices may have had an effect.

CONCLUSIONS: In patients undergoing TELD procedures, smaller-sized herniated discs are linked to early recurrences.

KEY WORDS: Disc herniation, lumbar, endoscopic, recurrence, early