Congenital spinal lipomatous malformations: part II--Clinical presentation, operative findings, and outcome.

BACKGROUND

To report this author's experience with patients with a congenital spinal lipomatous malformation with special emphasis on variations in clinical presentation, operative findings, and outcome based on the classification scheme proposed in the first part of this two part article.

METHODS

From January 1995 to July 2005, 80 patients with a congenital spinal lipomatous malformation were treated. All patients underwent routine neurological examination, plain radiographs of the spine and all but 10 patients underwent MRI. Ten patients underwent CT-myelography. Hoffman's functional grading scale was used for preoperative and postoperative clinical assessment. The operative findings, complications and outcome were assessed.

FINDINGS

Age ranged from 18 days to 19 years. The female: male ratio was 3:2. The malformations were divided into two groups: Group I: Lipomas without a dural defect and, Group II: Lipomas with a dural defect. Included in Group I were: 22 patients out of which there were Caudal lipomas: 10, Filum lipomas:11 and intramedullary lipoma: 1. In Group II there were 58 patients out of which there were Dorsal lipomas: 8, Caudal lipomas with dural defect: 8, Transitional lipomas: 10, lipomyelomeningoceles:28, lipomyeloceles: 4. Most of the group I patients were >5 years of age; cutaneous markers were absent in 60%, older children more often presented with sphincter disturbances. Surgery in group I was straight forward and consisted of sectioning of the filum in filum lipomas, debulking and untethering in caudal lipomas. Duroplasty was seldom required. CSF leak was rare. No patient deteriorated following surgery and no retethering was noted during follow-up. In Group II, all patients had cutaneous markers, most were <2 years of age, 19 were asymptomatic, older children had more severe neurological deficits. Duroplasty was required in most cases. A CSF leak occurred in 12%. Two patients deteriorated temporarily following surgery. Two patients presented with retethering 4 and 8 years after initial surgery. Improvement of more than one Hoffman's functional grade occurred when surgery was done <2 years of age.

CONCLUSIONS

Congenital spinal lipomatous malformations do not constitute a single homogenous entity. They can be broadly classified into two groups depending on the presence or absence of a dural defect. These two groups are different from one another embryologically, clinically, surgically and prognostically.