Evaluation of Tethered Cord Syndrome Associated with Anorectal Malformations:

Outcome of anorectal malformations and Hirschsprung's disease beyond childhood

Anorectal malformations (ARMs) and Hirschsprung disease (HD) are the most common congenital colorectal defects in the newborn. The outcomes of HD and ARMs have improved significantly because of improved understanding of the pathologic anatomy and physiology of these defects and of the modern surgical techniques. Still, many patients suffer from defective bowel control even as adults. Some of these also have problems with urinary control and sexual functions. The functional problems are more pronounced in patients with ARMs. Compared with healthy people, both patients with ARMs and those with HD have limitations in their quality of life. Inferior quality of life is more common in patients with ARMs. There are very few published data on long-term outcome of adults with ARMs and HD. The effect of aging on the functional outcome and quality of life remains unclear, although some preliminary data suggest that the bowel function and quality of life may deteriorate with aging.

Imperforate anus: long- and short-term outcome

Anorectal malformations are common anomalies observed in neonates. Survival of these babies is currently achieved in most cases and improvements in operative technique, patient care, and better follow-up have led to improved functional results. A new, simplified classification system (Krickenbeck classification) and method of functional assessment has led to an improved understanding of these anomalies and has allowed for a better comparison of outcomes. Following successful anatomical repair and appropriate programs of bowel care, socially acceptable continence can be achieved in a majority of patients, especially those with an intact sacrum.

Spinal lipomas: clinical spectrum, embryology, and treatment

✓Spinal lipomas, particularly lipomas of the conus medullaris and terminal filum, are the most common form of occult spinal dysraphism and represent a wide spectrum of disease with regard to anatomy, clinical presentation, and treatment options. These lesions, however, are united by a similar embryology and pathological mechanism by which symptoms arise.

Recently, the treatment of these lesions has generated much controversy, with some physicians advocating surgical treatment for all patients regardless of symptoms and others proposing that surgery be withheld until symptoms develop. The authors discuss lumbosacral spinal lipomas, with particular attention to the theories of their origin, anatomical and pathological features, and treatment options, including a review of current controversies.

Tethered spinal cord and VACTERL association

OBJECT

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).

METHODS

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 lipo-meningomyelocele in another patient.

CONCLUSIONS

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.

Spinal lipomas

Lipomas of the spinal cord are among the most fascinating lesions encountered by the pediatric neurosurgeon. An understanding of spinal lipomas may, however, be difficult because the terminology used to describe the accumulations of spinal fat is confusing, inconsistently applied, and at times contradictory. An anatomical characterization of lipomas may assist in understanding these lesions. Lipomas of the spinal cord are very rare and cause symptoms related to mass effect and secondary compressive myelopathy. Lipomas of the conus medullaris (or lipomyelomeningocele) are the most common form of fatty masses in the spine and can be divided into dorsal, caudal, and transitional forms. These lesions are a manifestation of occult spinal dysraphism and a common cause of the tethered cord syndrome (TCS). The natural history of untreated lipomyelomeningocele, although incompletely understood, appears to be progressive neurological deterioration with loss of bladder control. Timely, careful surgical intervention may prevent significant neurological deterioration and progressive disability in the majority of children harboring these lesions. In surgical intervention the surgeon seeks to disrupt the connection between the fibrofatty mass and underlying cord as well as to reestablish normal anatomical planes. Several intraoperative video segments illustrating lipomyelomeningocele resection are included in this paper. Lipomas of the terminal filum (fatty filum) are truly occult and are also associated with TCS. Surgical treatment of filum lipomas carries significantly lower risk than that for lipomas of the conus medullaris. Again, the goal of surgery is to disrupt the connection between the abnormal fibrofatty tissue and the underlying spinal cord.