Dermal Sinus Tracts of the Spine

Scott Elton, M.D., and W. Jerry Oakes, M.D, Departments of Neurosurgery and Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama

Neurosurg Focus. 2001;10(1) 

In This Article


There were 12 men and 22 women in the group. The patients' ages ranged from 18 to 70 years; the median and mean ages at surgery were both 34 years. Although the majority of patients had the cutaneous stigmata of dysraphism (21 patients with cutaneous anomalies and two patients with sacral agenesis or hypogenesis), these were either disregarded or had been treated surgically in the past without attention to the underlying spinal cord malformation (Figures 1 and 2). Instead, the presenting complaints included pain in 27 patients, motor or sensory symptoms or signs in 27, and bowel and bladder dysfunction in 18. Vertebral anomalies were present in 30 patients. Although strongly suspected, no documentation of the presence or absence of such bone anomalies was found in the records of the other four patients.

. Upper: Bar graph depicting the percentages of patients with associated anomalies. Lower: Bar graph showing the percentages of patients with cutaneous anomalies. The term "previous superficial surgery" is used to describe a number of patients who underwent previous operations for cutaneous deformities. These earlier operations did not include an intraspinal exploration.

. Left: Intraoperative photograph showing a flat faint skin hemangioma and dermal sinus opening, two typical stigmata of OSD. Right: Magnetic resonance image revealing a conus medullaris at L-3, a thick and fatty filum terminale, and evidence of a mass or fluid of the sacral spinal canal.

Intraoperative findings (Figures 3 and 4) included a thick and/or fatty filum terminale in 19 patients, a spinal cord lipoma or lipomyelomeningocele in 15, a split cord malformation in 13, meningocele manqué in eight, terminal syringohydromyelia in two, a dermoid cyst in two, and ventral bands, a neurenteric cyst, an atretic meningocele, an epithelialized myelomeningocele, and an arachnoid cyst in one patient each. Some of these lesions were diagnosed preoperatively by using myelograms and postmyelogram computerized tomography scans and/or magnetic resonance images.

. Bar graph displaying the percentages of patients with the various aspects of OSD. LMM = lipomyelo-meningocele.

. Upper: Intraoperatively it was noted that the sinus tract led to a cauda equina dermoid that was severely calcified and adherent to the nerve roots. Lower: Photograph of a "hair ball" that accompanied the dermoid.

Surgical results that had been recorded by the physician in the clinic notes were collected for all 34 patients (Figure 5). Of the 27 patients with pain, 22 improved, one worsened, and four were unchanged. Of the 27 patients with motor or sensory complaints, 13 improved, two worsened, and 12 were unchanged. Of the 18 patients with bowel and bladder dysfunction, 11 improved, one worsened, and six were unchanged. Deteriorations were generally mild and did not affect the patient's functional level.

. Bar graph showing the results of surgery on different presenting symptoms and signs: pain, neurological problems (NEURO), and bowel and bladder dysfunction (B & B). The mean follow-up duration was 4 years.

Long-term results recorded during telephone interviews were collected for 28 of the 34 patients. When asked if the operation was a success, 22 patients responded yes and six said no. When asked if there was improvement in the presenting symptomatology, 21 responded in the affirmative. Thirteen of the patients described complete resolution of their symptoms; five patients stated that, although some symptoms had improved or resolved, others remained unchanged; another four patients reported improvement in some symptoms and deterioration in others; two patients said that their symptoms had worsened postoperatively; and four others detected no change. According to the majority of patients who reported postoperative symptomatic deteriorations, these were of minor functional significance. One particular patient with terminal syringohydromyelia as well as other spinal defects underwent several surgical procedures on the syrinx. Improvement or resolution of the symptoms and signs, as well as radiographic improvement in the size of the syrinx, lasted several months to 2 years after each operation.

Long-term work history was also established by telephone interview. Of 22 patients who had worked preoperatively, 19 returned to their jobs after surgery. The other three patients stopped working within months of surgery due to circumstances unrelated to the surgery. One underwent a coronary artery bypass operation shortly after his spinal operation; another obtained the disability status that he had decided to seek preoperatively; and the third retired from her job in anesthesiology, a decision that she had also made preoperatively. Of six patients who did not work preoperatively, two had full-time jobs after surgery. One of these patients had just turned 18 years of age; therefore, the surgery may have been inconsequential to her obtaining a job postoperatively. When asked, only two of the 28 patients stated that they had sought Workers' Compensation benefits preoperatively. Both of these patients returned to work after surgery.

Nonneurological surgical complications consisted of one spinal fluid leak and five pseudomeningoceles, all of which were successfully treated either conservatively or surgically.