[Spinal cord tethering in myelomeningocele and lipomeningocele patients: the second operation]. / Reanclaje medular en pacientes con mielomeningocele y lipomeningocele: la segunda operación.

BACKGROUND: Spinal cord rethetering can occur after the primary surgical repair of myelomeningoceles (MMC) and lipomeningoceles (LMC) and produce devastating physical and psychological consequences. The inadvertent introduction of skin elements at the time of the initial surgery can lead to the growth of intraspinal epidermoid or dermoid cysts. OBJECTIVES: To review the incidence of spinal cord tethering following surgery for open and occult spinal dysraphism and to analyze factors that might influence the appearance of this complication. We also aimed to search technical measures at the time of the primary operation that might prevent the occurrence of symptomatic cord retethering. MATERIAL AND METHODS: We reviewed the medical records of patients submitted to surgical repair of MMC (n=162) or occult spinal dysraphism (n= 54) during the period 1975-2005 who developed symptomatic tethered cord syndrome. RESULTS: Eleven of 162 (6.79%) patients with MMC and 2 of 54 (3.7%) with LMC developed clinical symptoms and signs of spinal cord tethering after intervals ranging from 2 to 37 years after the initial surgical repair of their back lesions. Indications for surgical re-exploration were based mainly on clinical grounds. Postoperative fibrosis was a constant finding in all instances. Other surgical findings included inclusion tumors of cutaneous origin (n=3), lumbar canal stenosis (n= 2), foreign body reactions (n= 2), residual lipoma (n= 1), and a tight hyalinized filum (n=1). Interestingly, 3 of 162 (or 1.85%) myelomeningoceles were found to harbor an intradural epidermoid tumor at the time of spinal cord dethetering, accounting for an incidence of cutaneous inclusion tumors of 27% in cases of post- MMC repair tethering. After a mean follow-up time of 5.5 years, eight patients were improved, two were unchanged and one was worsened. CONCLUSIONS: Neurological deterioration is not a necessary consequence of the natural history of patients with MMC or LMC. Early or late clinical deterioration can be due to spinal cord re-tethering and deserves timely investigation and surgical exploration. Results of surgical intervention were rewarding as 92% of the patients showed improvement or stabilization in their otherwise deteriorating condition. We also report two infrequent causes of spinal cord deterioration: lumbar canal stenosis and intense foreign-body reactions to implanted materials.

Reanclaje medular en pacientes con mielomeningocele y lipomeningocele: la segunda operación / Spinal cord tethering in myelomeningocele and lipomeningocele patients: the second operation

Antecedentes. La médula espinal puede fijarse tras la reparación inicial en pacientes operados demielomeningocele (MMC) y lipomeningocele (LMC), produciendo graves lesiones físicas y psicológicas. Asimismo, la introducción accidental de restos cutáneos durante la reparación de estas lesiones puede dar lugar al desarrollo de tumores intraespinales de estirpe cutánea. Objetivos. Averiguar la incidencia del anclaje medular tras la cirugía de MMC y LMC y analizar los factores que puedan explicar su aparición. También, investigamos las maniobras técnicas durante la operación primaria susceptibles de evitar la aparición del síndrome de médula fijada. Pacientes y métodos. Revisión retrospectiva de las historias de los pacientes operados de MMC (n=162) y de espina bífida oculta (n=54) en el período 1975-2005 que desarrollaron cuadros de anclaje medular sintomático. Resultados. Once pacientes con MMC (6,79%) y dos con LMC (3,7%) presentaron manifestaciones de anclaje medular tras intervalos de 2 a 37 años después de la reparación primaria. Las indicaciones de reintervención se basaron fundamentalmente en criterios clínicos. Un hallazgo constante fue la fibrosiscicatricial que estuvo presente en todos los casos. Otros hallazgos operatorios causantes de la fijación medular consistieron en tumores cutáneos de inclusión (n=3),reacciones de cuerpo extraño (n=2), estenosis del canal lumbar (n=2), restos de lipoma (n=1), y filumhialinizado (n=1). En 3 casos de MMC se encontróademás un quiste epidermoide intradural (1,85% delos MMC), lo que supone una tasa de epidermoides en la reintervención de MMC de 27%. El periodo medio de seguimiento fue de 5,5 años y los resultados fueron: mejoría en 8, dos no experimentaron cambios, y uno sufrió empeoramiento. Conclusiones. El deterioro neurológico de los pacientes operados de MMC o LMC no constituye una consecuencia obligada o parte de la historia natural de estos procesos. El deterioro, precoz o tardío, puede estar motivado por el anclaje posquirúrgico de la médula espinal. Ello hace necesario realizar un seguimiento periódico de estos pacientes, acompañado de los oportunos estudios de neuroimagen y, en su caso, de exploración quirúrgica. Los resultados fueron satisfactorios, ya que el 92% de los pacientes reoperados experimentaron mejoría o estabilización de su enfermedad. Se describen además dos causas infrecuentemente descritas de deterioro tardío: la estenosis del canal y las reacciones fibrosas de cuerpo extraño a materiales implantados

Background. Spinal cord rethetering can occur after the primary surgical repair of myelomeningoceles (MMC) and lipomeningoceles (LMC) and produced evastating physical and psychological consequences.The inadvertent introduction of skin elements at the time of the initial surgery can lead to the growth of intraspinal epidermoid or dermoid cysts. Objectives. To review the incidence of spinal cord tethering following surgery for open and occult spinaldys raphism and to analyze factors that might influence the appearance of this complication. We also aimed to search technical measures at the time of the primary operation that might prevent the occurrence of symptomatic cord retethering. Material and methods. We reviewed the medical records of patients submitted to surgical repair of MMC (n=162) or occult spinal dysraphism (n= 54) during the period 1975-2005 who developed symptomatic tethered cord syndrome. Results. Eleven of 162 (6.79%) patients with MMCand 2 of 54 (3.7%) with LMC developed clinical symptoms and signs of spinal cord tethering after intervals ranging from 2 to 37 years after the initial surgical repair of their back lesions. Indications for surgical re-exploration were based mainly on clinical grounds. Postoperative fibrosis was a constant finding in all instances. Other surgical findings included inclusion tumors of cutaneous origin (n=3), lumbar canal stenosis(n= 2), foreign body reactions (n= 2), residual lipoma (n= 1), and a tight hyalinized filum (n=1). Interestingly,3 of 162 (or 1.85%) myelomeningoceles were found to harbor an intradural epidermoid tumor at the time of spinal cord dethetering, accounting for an incidence of cutaneous inclusion tumors of 27% in cases of post-MMC repair tethering. After a mean follow-up time of 5.5 years, eight patients were improved, two were unchanged and one was worsened. Conclusions. Neurological deterioration is not a necessary consequence of the natural history of patients with MMC or LMC. Early or late clinical deterioration can be due to spinal cord re-tethering and deserves timely investigation and surgical exploration. Results of surgical intervention were rewarding as 92% of the patients showed improvement or stabilization in their otherwise deteriorating condition. We also report two infrequent causes of spinal cord deterioration: lumbar canal stenosis and intense foreign-body reactions to implanted materials

Ventriculopleural shunting with new technology valves.

Ventriculoperitoneal shunting constitutes the standard procedure for draining cerebrospinal fluid (CSF) in children with hydrocephalus. Ventriculoatrial and ventriculopleural shunting are alternative methods of CSF drainage, which have gained less acceptance. Ventriculopleural shunts are seldom used owing to justified fears of pneumothorax and symptomatic effusions of CSF. The addition of an antisiphon device to standard shunt systems seems to have prevented CSF pleural effusion. From 1988 to 1998, we treated each of six hydrocephalic children with a ventriculopleural shunt. In five cases we used new-technology valves designed to prevent the effects of siphoning with current differential pressure valves. Peritoneal adhesions, recent peritonitis, ascites, and obstruction of a previous ventriculoatrial shunt were the indications for pleural shunting. After a mean follow-up period of 2.5 years all shunts were functioning adequately. Only one patient showed transient symptoms of CSF overdrainage, which were corrected by up-grading the valve setting with the magnet. A late death was unrelated to the pleural shunting procedure. The use of valves of a new design designed to prevent overdrainage seems to account for the satisfactory outcomes observed in this series. We suggest that ventriculopleural shunting should be considered as the preferred alternative to peritoneal drainage in children with intra-abdominal adhesions or with a history of recent peritoneal infection.