Programs: Pediatric Neurosurgery
- Comprehensive Pediatric Epilepsy Surgery Program
- Spina Bifida Program
- Motor disorders/spasticity
- Rhizotomy Program
- Intrathecal Baclofen Program
- Pediatric Neurooncology
- Hydrocephalus
- Chiari malformation/syringomyelia
- Craniosynostosis
Comprehensive Pediatric Epilepsy Surgery Program
The Comprehensive Epilepsy Surgery Program was established in 1992 and is led by pediatric neurologist Dr. Mary Connolly. There is a large multidisciplinary team, including multiple neurologists, neuropsychologists, psychologists, radiologists, nurses, electrophysiologists and electrophysiology technologists, in addition to neurosurgeons. The neurosurgeons on the epilepsy surgical team comprise Dr. Steinbok and Dr. Singhal. From 1992 onwards, we have operated on over 200 children with intractable epilepsy, with the youngest patient being only 3 months old. The majority of patients have been from British Columbia, but we have also treated children from Manitoba, Saskatchewan and Nunavut.
Each individual patient is assessed by a team, which includes neurologists, neurosurgeons, radiologists, nurses, EEG technologists, radiology and nuclear medicine technologists and a neuropsychologist. Potential candidates for epilepsy surgery come to Children's for video-EEG monitoring over a period of days to capture and record typical seizures. This allows the neurologist to assess where the seizures begin within the brain. MR imaging provides a detailed look at the patient's brain structure to help identify the epileptic focus. Selected patients undergo SPECT and PET scanning which enable one to look at brain function if the MRI fails to show a structural lesion, and some patients have had magnetoencephalography (MEG).
A neuropsychologist with experience in epilepsy performs a detailed assessment of functions such as language, memory, attention and other tasks. A family-centered care approach helps the parents understand what the procedure looks like and its associated risks.
The procedures have included temporal lobectomies, extratemporal cortical resections, hemispherectomies or hemispherotomies, subpial transections, corpus callosotomies and implantation of vagal nerve stimulators. In approximately 15% of the children with epilepsy surgery we have made use of monitoring directly from the surface of the brain, using subdural grids and strips of electrodes.
Our results compare favorably with what has been reported from other major centers around the world. The most common epilepsy surgery procedure has been a temporal lobectomy, and of these children, over 80% are seizure free, 10% are significantly improved and fewer than 10% have not been improved. For extratemporal cortical resections, the results, as in other centers are not as good, with only 50% of patients, being seizure free. However, patients with frontal lobe epilepsy have done better as a group, with 69% being seizure free.
We have done over 20 hemispheric operations and over 80% are seizure free, many off medications. The neurosurgical team has moved away from hemispherectomy and hemidecortication procedures that were being done in the earlier years of the program to the more sophisticated and less invasive peri-insular hemispherotomy procedure. In our hands this procedure has proven to be as successful as a hemispherectomy with fewer complications, shorter hospital stays, and less need for blood transfusion or postoperative cerebrospinal fluid shunting.
Our program has inserted vagal nerve stimulators in over 30 children. Our results are similar to those reported from large centers in the United States and studies in adults, with 58% of the patients having a reduction of seizures of more than 50%.
The complications after all types of epilepsy surgery in our hands have been minimal. There have been no deaths. If one excludes the expected loss of function from removing a part of the brain (for example loss of peripheral vision on one side from doing a hemispheric operation) we have had only one patient who lost some neurologic function, and that child had a brain tumor that was more difficult to remove than usual. Blood transfusions for cortical resections have been unusual, and when necessary we have usually been able to give the child back his/her own blood (autologous blood transfusion). Even for hemispheric operations our transfusion rate is below 30% with the peri-insular hemispherotomy technique. There has been only one significant infection, and that was among the children who have had subdural grids inserted for monitoring.
The care of children with spina bifida remains one of the most challenging aspects of pediatric neurosurgery. The Spinal Cord Program at BCCH cares for over 350 children and families who have myelomeningocele, lipomyelomeningocele or meningocele, in addition to others with spinal cord injuries and tumours. The multidisciplinary team comprises physicians from the disciplines of pediatrics, neurosurgery, orthopedic surgery, urology, general surgery, psychiatry and other professionals from nursing, social work, physiotherapy, occupational therapy and psychology, nutrition services. The program is co-ordinated by a nurse clinicain, Bev Irwin (birwin@cw.bc.ca) and led by pediatrician, Dr. Paul Thiessen. The major representative from neurosurgery on the team is Dr Doug Cochrane.
Treatment for children with spina bifida begins in utero and is based on an excellent prenatal diagnosis program, which includes triple marker screening, high resolution ultrasonography and fetal MR imaging. Multidisciplinary consultation with the team and medical geneticists provides affected families with the likely outcome of current management based on the knowledge of their child's anomaly. Publications focusing on fetal hydrocephalus, postnatal treatment outcome, expected clinical outcome, and mode of delivery have been produced by the clinic team.
Post natal management is based on sound established principles for protection of neural tissue and the optimization of function. Regular follow-up visits are planned well in advance and are based on peer reviewed program evaluations. Patient satisfaction is part of these reviews and has been expanded to focus on the graduates of the clinic.
The cardinal principle of the management of children with Spina Bifida is the optimization of function. The multidisciplinary team of pediatricians, urologists, orthopedic surgeons, physiotherapists, occupational therapists, social workers and nutritionists provides this, using urodynamics, neuroimaging, electrophysiology and radiology to supplement clinical assessments.
While offering optimal treatment to patients with spina bifida, the clinic has also been active, in conjunction with the Department of Medical Genetics, in lobbying for folic acid fortification in flour and for aggressive pre-conception education regarding folic acid as a preventative agent at provincial and national levels.
The academic productivity of the clinic was established at its inception and continues through the regular publication and presentation of scientific works. Members of the clinic contribute to the Society for Research into Hydrocephalus and Spina Bifida and are supporters of the Spina Bifida Association of British Columbia and the Canada. Key academic works have included randomized trials of antibiotics for the control of urinary sepsis, basis science experiments to define methods for bladder augmentation, evaluation of the methods of delivery of patients with myelomeningocele and the definition of clinical significance for intrauterine treatment of myelomeningocele.
Children and Women's Health Center has developed over the years a comprehensive program for the management of children with motor disorders causing increased tone in the limbs. This program is recognized internationally as a center of excellence in the management of children with hypertonic cerebral palsy. Dr. Steinbok is the neurosurgeon in this program. There is a large team, comprising developmental pediatricians, orthopedic surgeons, a neurophysiologist, neurophysiology technologists, physiotherapists, occupational therapists, orthotists and nurses, who work together to optimize the management of these children. The program offers a variety of treatment modalities including botulinum toxin, intrathecal baclofen, selective dorsal rhizotomy, and orthopedic surgeries. A state of the art 3D gait laboratory is available for assessments. The management of the individual child is integrated within the program, but different aspects of the program are directed by different members of the team. For example, the rhizotomy program is directed by Dr. Steinbok, neurosurgeon, the intrathecal baclofen program by Dr. Maureen O'Donnell, developmental pediatrician, the botulinum toxin program and gait lab by Dr. Rick Beauchamp, orthopedic surgeon.. The most complex cases are assessed by multiple team members at a spasticity assessment clinic, whereas more straightforward cases may be directed to the subprogram most appropriate for that individual patient.
A more detailed description of the two major neurosurgical elements of the program, namely rhizotomy and intrathecal baclofen, is provided below.
Selective dorsal rhizotomies were first performed at BC Children's Hospital by Dr. Steinbok in February 1987, and we were the first center in Canada to do this procedure. Dr. Steinbok has performed over 200 rhizotomies. Most of the children have been from British Columbia, but patients have come from other provinces in Canada and from outside North America for this operation. From the onset, we have developed a team approach to the assessment and treatment of children, who are referred for consideration of selective dorsal rhizotomy. We have been very fortunate to have an orthopedic surgeon and neurosurgeon working together and not competing with each other. The program has made a point of assessing outcomes after rhizotomy, and indeed was the first group in the world to assess outcomes quantitatively after this procedure. There have been approximately 20 peer reviewed publications from our program on the subject of dorsal rhizotomies, and Dr. Steinbok, who does the surgery, is acknowledged to be one of the world's experts in this operation.
Our results with selective dorsal rhizotomy have been very gratifying. Over 90% of the children have had significant improvement as a result of the operation. More than 50% have improved in their level of ambulation, for example from walking with a walker to walking with crutches or independently. The reason the number is lower than the 90% who improve overall is as follows. Some children can walk independently even before their rhizotomy, so the most that can be expected is for the rhizotomy to improve their gait. Other children, who may be wheelchair bound, are operated on to make it easier for their care givers to look after, with no expectation that they will be able to get out of the wheelchair. Furthermore, other children may improve, and for example walk better with a walker, but never get to the next level of walking with crutches. The complications after selective dorsal rhizotomy have been reviewed in detail and have been published. Our complications have been few and have been as good as or better than any other series reported.
Our experience has been that the best candidates for selective dorsal rhizotomies are children with spastic diplegic cerebral palsy, with spasticity affecting many muscle groups in the lower limbs, between ages 3 and 8 years. All prospective patients are assessed by Dr. Steinbok, Dr. Beauchamp, orthopedic surgeon, a physiotherapist and an occupational therapist. The surgery is done with assistance of neurophysiology technologists and takes about 3-4 hours. The child is usually discharged after 5 days and usually returns to school after 1-2 weeks. There are no casts required, and the child can resume all activities after the incision has healed, which is usually by 2-3 weeks. Children receive physiotherapy in their home communities thereafter and return for reassessment at 3 and 12 months, if possible. We know that in other centers the surgery is longer and the hospital stay is longer, but our results and complication rate are among the best in the world.
The intrathecal baclofen program is directed by Dr. Maureen O'Donnell, developmental pediatrician and Medical Director of the Children's Rehabilitation Center at the Sunnyhill Hospital campus of Children's and Women's Health Center.
Intrathecal baclofen involves the implantation of a large pump into the abdomen, to allow continuous delivery of the drug, baclofen, with which the reservoir of the pump is filled. The pump is attached to a small catheter, the end of which is placed into the spinal fluid space in the back. The pump delivers the baclofen slowly, and after 2-3 months, when all the drug is gone, the pump can be refilled by injecting more baclofen into the pump reservoir using a small needle inserted into the pump through the skin. The pump is expensive and children are tested before implantation of the pump to determine if they respond to the baclofen. This is done by doing a spinal tap and injecting a test dose of baclofen. Alternatively, a small catheter may be inserted into the spinal fluid space in the back, with one end of the catheter coming to the outside through the skin. Baclofen can then be instilled into the spinal fluid space through this catheter over the next few days either as individual injections or continuously using an external pump.
Our center was one of the first to report on the use of intrathecal baclofen for treatment of spasticity secondary to disorders of the brain (spasticity of cerebral origin) in children. Our early results were positive, but there were many complications and the costs associated with this treatment were high. As a result this modality of treatment was used infrequently, and in highly selected children.
Brain tumors are the second most common neoplasm in children, second only to leukemia. We have in place at BCCH a formal Neurooncology program. This is led by Dr. Juliette Hukin, a pediatric neurologist with specific additional training in Pediatric Neurooncology. The program is multidisciplinary, with representation from neurosurgery, neurology, pathology, radiology, nursing, psychology, radiation oncology, oncology, endocrinology, nursing, physiotherapy, occupational therapy, and social services. BCCH has been involved for over 20 years with the Children's Cancer Group, and more recently with the Children's Oncology Group (COG), which have coordinated multiple disciplines and multiple centers to work together to advance the treatment of childhood cancers. As a result, we have provided the most modern treatments for tumors of the nervous system (brain and spinal cord), and are continually updating our treatment protocols as more information becomes available. Through our involvement in COG, we have access to and frequently obtain guidance from the best consultants in any discipline for any tumor type.
At BCCH, from 1984 to December 2001, we have treated over 450 children with newly diagnosed brain tumors and more than 75 children with intraspinal tumors. Each of the two senior neurosurgeons have done over 200 operations to remove brain tumors in children (some before BCCH opened in 1982). We are very conscious of the importance of resecting as much of the tumor as possible, while maintaining the function of the child. We have been able to resect tumors more radically than many, and still maintain acceptable neurologic function. Indeed, for cerebellar astrocytoma, one of the commoner tumors of childhood, and one which is potentially curable by total resection, our rates of total resection approach 100%. Our recurrence rate after surgery for this tumor is almost zero, which is significantly better than most reports in the medical literature. Another outcome measure that indirectly reflects expertise at radical tumor resection is the incidence of CSF shunting in children with brain tumors. Children with posterior fossa tumors commonly have associated hydrocephalus, secondary to blockage of CSF pathways by the tumor. Persistent hydrocephalus may require a shunt procedure or a third ventriculostomy. The incidence of shunting or third ventriculostomy for hydrocephalus in association with posterior fossa tumors in children is less than 20% at BCCH. This is at the low end of any reported series. This again reflects our ability to achieve radical resections of all types of posterior fossa tumors, thus opening up the CSF pathways that have may have been blocked by the tumor.
As mentioned above, the neurosurgeons at BCCH have developed a team approach to the management of these patients. All cases are routinely discussed among the three neurosurgeons and at a multidisciplinary conference. In many instances, the child receives the benefit of having two pediatric neurosurgeons working together for their surgical procedure. For some of the complex, but uncommon tumors, individual neurosurgeons have developed special expertise and the patients are directed to the neurosurgeon on the team with the appropriate expertise. For example, Dr. Steinbok offers expertise to patients with craniopharyngioma, and Dr. Cochrane for children with pineal region tumors.
Radical resections of tumor when appropriate are facilitated by the use of state of the art image guidance systems and intraoperative electrophysiologic monitoring, with the latter modalities being used particularly for spinal cord and brainstem tumors.
The development of neuroimaging techniques such as stereotactic guided techniques, 3D MRI, MR spectroscopy, and intraoperative ultrasound, allows accurate definition of the tumor and normal structures of the brain to help guide the neurosurgeons achieve a safe resection. New techniques such as functional MRI are being developed to assist us further in identifying whether essential structures are in close proximity to the tumor and if tumor can still be removed safely or whether these structures are enmeshed within the tumor thus rendering a complete resection impossible. CT PET is now availble to our patients to help us determine the extent of tumor affecting the brain in some more challenging cases.
We are fortunate to be have a dedicated neuropathologist to assist us in identifying the exact diagnosis and thus determining the most appropriate therapy.
Neuro-oncology is an integral part of the Division of Pediatric Hematology/Oncology/Bone marrow transplant (www.kidscancer.bc.ca). Some brain and spinal cord tumors are not cured by surgery alone. Through the pediatric radiotherapy program at the BC Cancer Agency, we are able to provide precise radiotherapy using photon beams in a conformal or stereotactic fashion. Some patients with small lesions may benefit from a stereotactic surgery approach available at the BC Cancer Agency. The present IMRT technology allows us to provide precise radiotherapy with minimal radiation to surrounding normal structures thus minimising long-term sequelae of therapy. We are presently developing the technology to provide stereotactic radiotherapy to children who require a general anaesthetic, in the mean time in situations where this is required we refer these patients to our colleagues with whom we collaborate.
In some situations chemotherapy is an essential component to therapy. Dr Hukin and the oncologists carefully determine the most appropriate medical therapy for any given brain tumor that is not cured by surgery alone. We direct the medical therapy, however some may be provided closer to home by our pediatric colleagues across the province. The more intensive chemotherapy including stem cell transplantation is provided at BC Children's Hospital. We provide the most up to date therapies for children with brain tumors and are constantly collaborating with our colleagues across the world, but particularly in the Children's Oncology Group to ensure that our patients receive the best treatment possible. Our oncology training program is the second largest in Canada and in the last ten years we have trained more Canadian graduates than any other program.
We believe in addressing the whole patient's needs from a multidisciplinary approach with the assistance of our nursing staff lead by our neuro-oncology RN, neuropsychologist to assist in reintegrating children back into school, dietician to optimize nutrition, physiotherapists and occupational therapists to maximize rehabilitation, and spiritual care. Patient and family counseling services are provided by social workers and psychologists to provide practical assistance related to travel, finances, and accommodation. Counseling is also available to individuals, parents and siblings. As well, programs such as Art Therapy, Music Therapy, Play Therapy and Relaxation Programs are available. In addition, Dan Mornar leads the parent group and explores novel ways to support parents and families through this difficult journey. Respite care is available through Canuck Place. Our provincial palliative care program provides palliative care to patients and their families in the home, local hospital or hospice setting.
The field of research into the causes of childhood cancer began to shift dramatically during the 1990's. This shift moved away from exploration of environmental causes, therapeutics and pharmacology and toward under-standing the underlying genetic and biologic bases of childhood cancer. The emergent consensus is that understanding the genetic changes inherent in childhood cancer will lead to new treatments that can be used in the fight against this disease. Future treatment will target tumor and related cells and avoid healthy ones undergoing normal development.
Hydrocephalus is the most common condition treated in pediatric neurosurgery. Most commonly this is done using ventricular shunts of various types, and in specific conditions, with endoscopic procedures. The indications for shunt insertion and revision are common to North American neurosurgical practice. However the results of shunting, measured as the time until the shunt fails or the infection rate vary considerably. A recent review demonstrated that in Canada for the period of 1989 to 2001, shunt insertions for hydrocephalus had longer duration of function and lower risk of infection if inserted by experienced surgeons. Even within the experienced surgical group, results varied, with BCCH surgeons having the longest duration of function and lowest infection rates in the high experience group.
In the situation where endoscopic procedures are suitable, the success rates for control of symptomatic hydrocephalus exceed 70% without the need for shunting.
Chiari malformation/syringomyelia
The Chiari malformation is a spectrum of disorders occurring in children with and without myelomeningocele. The Chiari II malformation is the form seen in association with myelomeningocele and is the result of differential growth patterns in the hindbrain (brainstem and cerebellum) and the bones of the posterior fossa presumed due to the loss of cerebrospinal fluid during embryonic life. All large series of myelomeningocele infants report a proportion of infants having brain stem dysfunction. This is presumed due to compression of the Chiari malformation. Work done by the Division has thrown this presumption into question in particular reference to expiratory apnea. For lesser degrees of medullary dysfunction, posterior fossa decompression is used following the establishment of optimal CSF drainage. Partial or complete recovery has been achieved in these patients. Of interest, long term craniocervical instability has not been a problem seen in these patients following decompressive laminectomy or expansion laminoplasty.
Older children with Chiari II malformation may require treatment for hydromyelia, hydrobulbia, progressive cranial nerve dysfunction or quadriparesis. Decompression of the hindbrain hernia and reconstitution of the "cisterna magna" has been used successfully in those children and teenagers who do not have arachnoiditis in the basal cisterns. Shunting of the fourth ventricle to the cervical subarachnoid space may or may not be necessary.
Chiari I malformation is usually found in children without myelomeningocele. This malformation is often associated with syringomyelia/hydromyelia (fluid within the spinal cord), or syringobulbia. Children typically present as teenagers, and the symptoms are variable. They include scoliosis, back pain, numbness in the chest or upper limbs, weakness in the upper and/or lower limbs, unsteadiness, occipital headache, and cranial nerve dysfunction, particularly swallowing difficulties and tongue weakness. The diagnosis is made readily by MR imaging . Sometimes the Chiari malformation is identified on a MR scan done for other reasons, and there are no symptoms related to the malformation.
In situations were the volume of the posterior fossa content can be changed, for example by treating a Vein of Galen arteriovenous malformation, Chiari I malformation may resolve. Other situations occur rarely and include cerebellar venous congestion following status epilepticus.
Not all children with Chiari I malformation require operative intervention. Where surgical intervention is recommended, the Division of Neurosurgery has a developed a consistent surgical approach to this problem based on experience over many years and the options that are reported in the literature. It is our goal to re-establish CSF flow from the fourth ventricle and reconstitute the cisterna magna based on the clinical and experimental evidence that either CSF outflow is impaired, as evidenced by an associated syrinx or that the posterior fossa is too small for the volume of the posterior fossa content. Intraoperative imaging is used to guide the extent of operation. The procedure begins with small posterior fossa bony decompression. Intraoperative ultrasound is used to assess the size of the cisterna magna and the compression on the hindbrain hernia. If, as the assessment is done, there is no dural relaxation and decompression of the neural structures, the dura is opened and plans made for dural patching with the patients own tissues. At this time, the arachnoid surrounding the brainstem and herniated cerebellar tonsils is inspected and the outlet of the fourth ventricle is assessed. If there is syringomyelia and if the outlet of the fourth ventricle is closed with arachnoid adhesions, the foramen is opened and one or more of the tonsils may be resected to achieve decompression of the neural structures, reconstitution of the cisterna magna and free CSF flow form the fourth ventricle.
Post operatively, children are placed in a collar when up, largely for comfort. Post operative evaluations are performed at 2-3 months, with repeat MR imaging . Re-operation is considered if the syrinx decompression is not demonstrated by 12 months.
Re-operation may be entail repeat posterior fossa exploration with or without fourth ventricle shunting or syringo-subarachnoid shunting. Syringo-pleural or syringo-peritoneal shunting has not been found to be necessary.
Over the past two decades, 50 patients with Chiari I malformation have been treated at BCCH. Resolution of clinical symptoms has been achieved in all patients. Only three patients have required repeat operation.
Craniosynostosis is a condition characterized by premature closure of one or more of the sutures of the cranial vault. The most common variety involves the sagittal suture (sagittal synostosis), and is characterized by a long, narrow head (scaphocephaly or dolichocephaly), with ridging over the sagittal suture. Less common are coronal synostosis, characterized by asymmetry of the forehead and orbits, and metopic synostosis, in which there is a triangular appearance to the forehead with ridging in the middle of the forehead over the metopic suture.
Craniosynostosis of all types is managed by the pediatric neurosurgeons at BC Children's Hospital. Since 1982, our group has operated on over 325 children with craniosynostosis, including 170 with sagittal synostosis, 140 with unilateral or bilateral craniosynostosis, and 20 with metopic synostosis. Children with coronal synostosis included those with Crouzon, Apert, Pfeiffer, Saethre Chotzen and other syndromes. The vast majority of these children have had their surgical procedures in the 1st year of life. Children with sagittal synostosis are operated on by a neurosurgeon alone, whereas those with coronal or metopic synostosis are operated on a s a team procedure with our plastic surgical craniofacial experts. There have been no mortalities or serious infections after surgical procedures for craniosynostosis, attesting not only to the expertise of the surgeons, but of the entire team, including the pediatric anesthesiologists. Except for the most complex craniofacial syndromic cases, children are not admitted to the ICU setting after surgery, and generally are discharged within 72 hours of surgery.
Over the years we have reduced the rate of blood transfusions during these procedures by meticulous attention to limiting intraoperative blood loss and by accepting a lower hemoglobin level in the postoperative period. The rate of blood transfusion in surgery for all types of craniosynostosis at . BCCH is now less than 20%, and this is lower than that in any reported series. We have recently reviewed in detail our series of 118 children having surgery for sagittal synostosis between January 1986 and December 1999, and have documented a reduction in the rate of transfusions from 42% before 1996 to 11% from 1997-1999.
The outcomes after surgery for craniosynostosis have been documented, where appropriate, using anthropometric measurements. We have also been interested in developing consistent 3D imaging paradigms as a tool in outcome assessment. We are currently studying the reproducibility of some of the anthropometric measurements that have been used in the assessment of children with asymmetric heads with positional occipital plagiocephaly. In the management of positional plagiocephaly, we have had a long interest in the concept of remodelling of the head shape using orthotic devices, and have been using either helmets or head bands for over 15 years.