As with any operation, complications can and do happen. Being aware of their potential allows us to establish safety nets and thereby diminish their occurrence to an acceptable level. Fasano noted a 5 percent incidence of sensory disorder (small area of numbness), half being temporary and half permanent. One of his patients had transient difficulty with bladder control. Laitinen reported that two of nine patients experienced a decrease in pinprick sensation of a slight but permanent nature, although one had a bladder dysfunction lasting three months. Peacock's patients had no early surgical complications, but one female experienced spondylolisthesis (a slippage of one level of the spine over another resulting in focal pain). None had post-operative decrease in sensation, but he did find that an "occasional patient could complain of increased cutaneous sensitivity during the first few post-operative weeks."
We have reviewed the outcome in 350 of our patients who have undergone this surgery and found the following problems after their surgery. Eight percent experienced intraoperative asthma attacks. Common to these patients was a history of asthma, bronchitis or a recent upper respiratory tract infection. We have avoided this complication by using asthma inhalers in children at risk. Of 350, 5 percent had intraoperative vomiting into the lungs resulting in pneumonia. This is no longer a problem because we use protective measures for children at risk for this complication. Post-operatively, 40 percent of our patients experienced a trunk weakness, and 3 percent a transient increase in muscle tone associated with incisional pain and spasms lasting for 48 hours. Both of these problems last a limited amount of time. We have observed a 12 percent incidence of transient urinary retention (an inability to void urine) requiring intermittent catheterization of the bladder for up to three weeks. There are also scattered reports from centers in North America of permanent urinary problems in children who have undergone this procedure.
Long-term complications are beginning to be recognized. There have been recent reports of children suffering a progressive hip dislocation post-operatively. We have seen this with 11 patients. Typically, it occurs in those who were not ambulatory pre-operatively, and who had a great deal of hip and pelvic instability due to weakness of hip musculature. We are exploring use of long leg bracing (ankle-foot orthosis with single upright, hinged support attached to a pelvic band) for controlling the available planes of movement in the hip joint. Many of our children experienced loss of available range in their knee and ankle joints after initial improvement. They exhibit no change in tone, but a deterioration in the range of movement of a muscle. When questioned, parents almost uniformly report a growth spurt since the previous examination. We feel that this deterioration in range reflects inadequate stretching of the muscle groups during the growth period. That this can occur in spite of the decrease in muscle tone after the operation is a testament to the ongoing therapy needs of these children. Surgery does not supplant the need for physical therapy, and may actually increase it to the degree that the child's potential functional abilities increase.
Of theoretical concern is the possibility of late-onset scoliosis (lateral spine curvature) due to the extensive laminectomy/laminotomy being performed. There have been no reports, however, of scoliosis in these cases, and this may be related to the site of surgery. Yasuoka reports that the development of post-laminectomy scoliosis seems to be a function of the level of the spine at which the procedure is performed; scoliosis did not occur after lumbar laminectomy in the three patients whose post-operative X-rays he reviewed.