Comparison of the inter-laminar approach and laminotomy open approach for filum terminale lipoma: A retrospective analysis

Filum terminale lipoma (FTL) causes spinal-cord tethering and is associated with tethered-cord syndrome, which is treated by dissection of the entrapment. The conventional treatment for FTL involves dissection of the spinal cord through a laminotomy open approach (LOA). However, in recent years, the interlaminar approach (ILA) has gained popularity as a minimally invasive surgery. This study compares the effectiveness of the minimally invasive ILA with the conventional LOA in treating FTL.

We retrospectively evaluated data on the ILA and LOA for FTL at our center. In total, 103 participants were enrolled, including 55 in the ILA group and 48 in the LOA group.

The ILA required significantly less surgical time and resulted in less blood loss. The improvement rate of symptoms in symptomatic patients was 84%, and for urinary symptoms and abnormal urodynamic study findings, it was 77%. The postoperative maintenance rate for asymptomatic patients was 100%. Postoperative complications of ILA included delayed wound healing in two patients (3.6%).

Compared with LOA, ILA offers advantages in terms of shorter operative time and less blood loss, with no significant difference in long-term symptom-improvement rates between the groups.