Vertebral defects, anal atresia, cardiovascular anomalies, tracheoesophageal fistulas (TEFs), renal anomalies, and limb defects (most often of the radius) are commonly associated and known collectively by the acronym VACTERL. The authors studied these nonrandomly associated birth defects to determine if a further relationship exists between VACTERL association and the presence of a tethered spinal cord (TSC).
From 2001 to 2004, 12 patients with VACTERL association who were treated operatively by a single pediatric surgeon underwent magnetic resonance (MR) imaging to evaluate the intraspinal abnormalities that may cause tethering. Three patients were excluded from the study due to complications after surgery for TEF. Coincidentally, these three patients did not have imperforate ani. In the remaining nine patients, seven had associated urogenital anomalies, and six of these also had high-type imperforate ani. Five of the six patients and the one patient with low-type imperforate anus and a urogenital anomaly were found to have TSCs. In the remaining two patients without urogenital anomalies there was a high-type imperforate anus without a TSC in one patient and a low-type imperforate anus with a TSC in the other. All seven patients with TSCs underwent successful untethering. The lesions contributing to TSC included terminal filum lipomas (TFLs) in five patients, an intramedullary ependymal cyst in one patient, and a lipomeningomyelocele in another patient.
The authors found that in patients with VACTERL association there was a high incidence of TSC (seven of nine patients) if an imperforate anus was present as one of the anomalies. In patients with VACTERL association and urogenital anomalies, the incidence of TSC was even higher (86%). Five of the seven cases of TSC in the present study were caused by a TFL, a lesion that can be easily and safely managed surgically. The authors conclude that MR imaging is essential for ruling out the possibility of a TSC in patients with VACTERL association combined with urogenital anomalies or an imperforate anus.