Prognosis for recovery of bladder function following lumbar central disc prolapse

From a retrospective review of 932 patients undergoing surgery for prolapsed lumbar intervertebral disc a group of 33 cases with acute urinary retention was studied. There was no identifiable factor which predisposed this subgroup of patients to cauda equina compression. The mean duration of bladder paralysis prior to operation was 3.6 days. Ultimately almost 79% of patients claimed full recovery of bladder function, but only 22% were left without sensory deficit in the limbs or perineum. There was no correlation between recovery and the duration of bladder paralysis before surgery, except in three patients in whom there was no sciatica and where the correct diagnosis was delayed for many days. Retention developing less than 48 h after an acute prolapse was associated with a poorer prognosis. Despite claims that bladder paralysis should be treated with the same urgency as an extradural haematoma, there is no evidence in this study or in the literature to support the view that emergency surgery has any bearing upon the degree of clinical recovery. The exception may be if decompression can be undertaken within 6 h, the time estimated for axonal ischaemia to become irreversible. This should not however engender complacency in the management of this condition, which still requires prompt treatment. Whilst any apparent delay to surgery may have medicolegal implications should the patient fail to recover completely, in the majority of cases the die is cast at the time the prolapse occurs.