OBJECTIVETo assess the impact of delayed decompression on long-term neurological and bladder function recovery in patients with cauda equina syndrome (CES) secondary to lumbar disc herniation (LDH).

METHODSThe clinical data of 35 patients receiving delayed decompression surgery for CES secondary to LDH were reviewed. The bladder empty function, bowel control, sexual ability and neurological functions of the lower limbs were evaluated after the operation, and the urodynamic changes were assessed in 6 patients with urodynamic data before and after the operation.

RESULTSSurgical decompression was performed at 4.1∓3.9 weeks in 12 patients with complete CES and at 5.5∓7.6 weeks in 23 patients with incomplete CES after the onset of symptoms. The patients were followed up for a mean of 43.0∓28.9 months (3-110 months). In the 23 patients with incomplete CES, 19 obtained full recovery, 4 had slight sensory alterations in the saddle area or the lower limbs. In the 12 patients with complete CES, 2 had full recovery, 4 reported slight sensory alterations in the saddle area or the lower limbs (including 2 with occasional constipation); 6 still had sense deficit in the saddle area and difficulties in bladder or bowl emptying, but they all reported significant improvements compared to the condition before operation. Urodynamic analysis in the 6 patients with pre- and postoperative urodynamic data showed increased abdominal pressure when voiding with significantly reduced residual urine in all the 6 patients; 4 patients with abnormal first desire volume before operation reported recovery after the operation.

CONCLUSIONPatients with LDH-induced CES who missed the chance of early decompression can still expect favorable functional recovery in the long term. The improvement of bladder function following decompression is probably a result of recovery of bladder sensation and the compensation by increased intra-abdominal pressure. The key strategy to promote bladder function recovery in these patients is to promote the detrusor recovery.