Abstract
PURPOSE:
The goal of this retrospective chart review study was to explore factors that contributed to consideration of or actual pump explantation in pediatric patients with intrathecal baclofen (ITB) pumps.
METHODS:
Medical records of 30 patients with ITB pumps were reviewed. Quantitative data, including demographic, clinical, psychosocial, and service utilization variables were culled from the records. Qualitative data were collected from clinic visit notes, pump-related follow-up phone calls, and any pump-related emergency room visits.
RESULTS:
Of those reviewed, six underwent ITB pump explantation, and two considered explantation. Factors contributing to pump explantation or consideration of explantation included the following: postoperative infection, pump malfunction, non-adherence, anxiety/behavioral factors impacting the patient’s tolerance of the pump, distance to the medical provider, frequency of required pump refill appointments, lack or perceived lack of intrathecal baclofen effect, and difficulty transitioning to adult care providers.
CONCLUSION:
Due to the complex care regimen associated with ITB pumps and various psychosocial and logistical factors that impact treatment success, a standardized multidisciplinary pre-implantation education, screening, and assessment process should be developed. Such a process would ensure that patients/families receive appropriate education, including proactively identifying treatment barriers and potential complications, possibly minimizing dissatisfaction with treatment and the need for explantation.
Introduction
Intrathecal baclofen (ITB) therapy can be an effective treatment of spasticity [1], dystonia [2], and other dyskinesias [3] in children.Cerebral palsy (CP) is a condition that affects tone and movement due to non-progressive lesions of the brain acquired in infancy and is the most common cause of disability in children [4, 5]. ITB therapy, therefore, is most often used to treat spasticity and dystonia due to CP, but it can also be used to treat spasticity and dystonia in other conditions such as hereditary spastic paraplegia (HSP), spinal cord injury, and traumatic brain injury.
Gamma-aminobutyric acid (GABA) is an amino acid that serves as the primary inhibitory neurotransmitter in the brain and a major inhibitory neurotransmitter in the spinal cord [6]. Baclofen is a centrally-acting skeletal muscle relaxant that acts on the GABAB receptors in the spinal cord [7]. The route of administration can be either oral or intrathecal. Because the intrathecal route does not have to cross the blood-brain barrier, lower doses of intrathecal baclofen are required to treat tone with potentially fewer systemic side effects.
While ITB therapy has the potential to decrease systemic side effects, it is also associated with important risks and care considerations. ITB pumps must be refilled regularly and consistently (e.g., every three to six months) to prevent baclofen withdrawal. Similarly, pump malfunction can lead to baclofen withdrawal. Symptoms of withdrawal may include increased spasticity, muscle breakdown, fever, high blood pressure, seizures, organ failure, and even death [8, 9]. As such, ITB pump management can be burdensome and stressful on the patient and their caregiver(s). This may be especially true for those with logistical or financial challenges (e.g., patients who live a significant distance from their medical provider, patients with inconsistent transportation access), emotional concerns (e.g., anxiety, needle phobia), or behavioral symptoms (e.g., self-harm behavior). In turn, these factors can lead to dissatisfaction with the pump and requests to abort ITB therapy.
Given that pump explantation may significantly impact a pediatric patient’s overall tone management and quality of life, it is essential to understand the factors that may lead patients and families to decide to abort ITB therapy and to address them before the pump is implanted. Although extant literature refers to the consideration of psychosocial, logistical, and financial variables before implantation [10], a standardized psychosocial assessment and pre-implantation education process in the pediatric population has yet to be identified within the literature. Thus, the aim of this study was to explore, via retrospective chart review of individual cases, the role that psychosocial barriers, expectations of treatment, and anticipatory guidance played in the decision to explant the ITB pump. It is the ultimate intention of this work to delineate best practices regarding multidisciplinary ITB pump pre-implantation assessments, education and goal setting.
Materials and methods
This Institutional Review Board (IRB)-approved study retrospectively assessed a series of patients at a single pediatric institution, who were treated with intrathecal baclofen between September 1, 2009, and October 1, 2020, and subsequently had the pump removed or attempted its removal. Participants met the following inclusion criteria for this study: between age 1 month to 26 years at the time of establishing care with the ITB team and must have been treated with an ITB pump.
All data collected as part of this study were recorded in the patient’s medical record. As such, there were no study-specific procedures performed on participants. Quantitative data were culled from patient medical records. A comprehensive list of collected variables is provided below. Additionally, qualitative data were collected from patient clinic visit notes, follow-up phone calls regarding the patient’s ITB pump, and any emergency room visits associated with the ITB pump.
Data were collected from the medical records of 30 participants who had been treated with intrathecal baclofen between September 1, 2009, and October 1, 2020. The participants were then divided into those who had pump removals and those who attempted pump removal. Specific variables were collected to further characterize those individuals.
Comparison between the groups showed no differences in the variables culled. A subsequent power analysis conducted using an unbalanced design of 1:2, chosen because ITB pumps are not frequently explanted once placed, demonstrated that for all the variables to achieve at least 80% power at 5% significance, a group size of between 56–204 and 112–408 would be needed to compare all the variables between cohorts that considered/underwent pump removal and those that did not consider pump removal, respectively. Given the limitation in sample size, a descriptive study using case studies was conducted.
Results
Thirty participants were identified who had ITB pumps. Participants ranged in age from 6 to 18 years old (average 11.8 years based on participant age at ITB pump implant). The sample was fairly evenly divided by sex (53% female assigned at birth; 47% male assigned at birth). Participants’ racial and ethnic breakdown was as follows: 87% White, 13% Black; 70% non-Hispanic White, 26% Hispanic/Latino, 3% Middle Eastern/North African. None of the subjects had a documented psychological assessment in their medical record.
Of the 30 participants with ITB pumps, six had them removed, and two had attempted pump removal. The majority of patients who had or attempted pump removal were diagnosed with CP (75%; N = 6). For the reviewed patients, the documented GMFCS ratings ranged from III to V, with 67% meeting criteria for GMFCS V (Table 1). Most patients were insured (87.5%) through private or public insurance plans (Table 1).
Demographic Variables
Demographic Variables
In this case series, patients attempted and/or completed the removal of the ITB pump for numerous reasons. The most frequent reason for explantation was postoperative infection (Table 3), which often required significant medical intervention in the form of workup and revision surgeries (Table 2). Of those with infection, only one pursued pump reimplantation. Pump malfunction as well as perceived or actual lack of ITB pump effect were other important factors leading to attempt of/or completed explantation (Table 3), even in cases where available documentation noted positive response after a test dose (Cases 1–6). One patient (Patient 4) missed multiple appointments, causing their pump to run dry. However, this particular patient did not experience any negative effects of their pump running dry. Given the lack of withdrawal symptoms, which would be expected to occur if the pump was delivering medication as intended, the pump likely had malfunctioned (Table 3).
Factors Associated with Explant/Attempt to Explant
‡: Selective Serotonin Receptor Inhibitor.
Healthcare Utilization Variables
*ITB titration appointments.
Patient 1
Patient 1 is a female with spastic quadriplegic cerebral palsy. Her motor function was described as GMFCS V. She was first referred to the ITB team and established a relationship at age 10 years, 5 months. She had been on oral baclofen, but the family continued to report difficulty with dressing, positioning, hygiene, and physical therapy stretching exercises despite 30 mg-30 mg-30 mg-20 mg of enteral baclofen daily via g-tube. Goals of ITB therapy included reducing dependence on oral baclofen, preparing for spinal surgery, improving ease of hygiene care, and improving positioning/sitting. The patient’s ITB test dose trial was done at age 10 years, 7 months. She underwent physical and occupational therapy assessments as part of the trial, but records of other psychosocial assessments were not available in the chart. Social work was consulted for referral to a neurosurgical specialist for pump implantation. The pump was subsequently implanted at age 11 years, 4 months. During the titration phase, she experienced fever, erythema, and swelling over the pump, and the pump pocket was found to be infected. It was explanted three months after implant at age 11 years, 7 months. Oral baclofen treatment resumed.
Patient 2
Patient 2 is a male with mixed tone (dystonia and spasticity) quadriparesis of unknown etiology. His GMFCS functional equivalent was V. The first documented encounter with the ITB team was at age 11 years, 4 months. His ITB team managed enteral baclofen 25 mg-20 mg-25 mg daily via g-tube with noted sedation. He also continued to have significant tone, making positioning and hygiene difficult. At age 12 years, 2 months, he had an ITB trial with physical therapy and occupational therapy assessments. Goals of ITB therapy were to improve ease of hygiene and comfort. At age 12 years, 4 months, a family conference was conducted to reiterate goals. No psychology assessments were noted in the chart. Social work was consulted for referrals to neurosurgery. The pump was implanted approximately two months later. Three months after pump placement, the patient had symptoms of baclofen withdrawal, with workup showing interruption in the intrathecal baclofen flow, necessitating that the pump be revised. The pump remained in place through the last encounter with the ITB team, at age 16 years, 1 month. Due to a report of increased tone at night, dosing was changed from continuous to flex dosing at that visit. He then reported signs of withdrawal, and the pump was revised for a second time for the interruption in flow at age 16 years, 3 months. Shortly after the pump was revised, the family requested a transfer of care. A year and 3 months later, the patient underwent spinal fusion surgery, at which time the pump tubing was dislodged. The pump was removed during the surgery, and the patient was started on oral medications to prevent withdrawal. The pump was not replaced.
Patient 3
Patient 3 is a female with mixed tone (spastic and dystonic) cerebral palsy, GMFCS level V. She established care with the ITB team at age 7 years, 10 months. She was previously prescribed lorazepam and diazepam for tone; however, this was changed to baclofen when care was established. By age 16 years, 5 months, the patient was on 20 mg of baclofen four times daily by mouth. During that visit, it was noted that she had pain in her back and legs thought to be associated with positioning while seated and when lying down. Given her discomfort, the decision was made for a baclofen trial to improve positioning in her chair, ease of transfers, and to decrease muscle spasms. During that time, the family and the patient also talked to psychology and social work to emphasize goals and commitment associated with the pump. An adult provider was also identified who could take over pump management once the patient transitioned out of the pediatric setting. Since a solid bony fusion mass in the lumbar region related to a prior spinal fusion procedure was preventing access via routine lumbar puncture, the ITB test dose trial was conducted by neurosurgery. At 16 years, 8 months, the neurosurgical team drilled through the mass to place a catheter in the intrathecal space and deliver an intrathecal baclofen test dose. The patient responded to the procedure well, and an ITB pump was placed the day after the trial. Five months later, there was noted ITB pump wound dehiscence and drainage, and the pump pocket was found to be infected. This was treated with a washout and IV antibiotics. The patient’s maximum ITB dose at that time was 225.22 mcg/day, which she was on for two months. The pump then became re-infected, and the pump was explanted two months later at age 17 years, 4 months. The patient was restarted on oral baclofen at the dose of 20 mg four times daily.
Patient 4
Patient 4 is a male with mixed tone (spastic and dystonic) triplegic cerebral palsy. GMFCS level was noted to be III. He was first seen by the ITB team at age 6 years, 9 months. Throughout childhood, the patient received multiple rounds of botulinum toxin injections in addition to being placed on oral baclofen and titrated to 10 mg three times daily. At age 18 years, 11 months, he had been noted to have significant tone after orthopedic surgery, and an ITB trial was conducted with the goal to reduce spasticity in the lower extremities. He was assessed by physical therapy, but no social work or psychology assessments were found in the medical record. An ITB pump was implanted one month later; total dosing was increased to 811 mcg daily and remained at that dose for 9 months. Two years after the pump was implanted, the patient did not show up for two ITB refill appointments, and the pump ran out of medication. He and his mother denied any signs or symptoms of withdrawal. The patient also noted no changes in tone after the pump ran out of medication. The pump was subsequently tapped to ensure that it was indeed dry and oral baclofen, 10 mg three times daily, was prescribed. The pump was subsequently explanted three months later at age 20 years, 11 months.
Patient 5
Patient 5 is a female with a history of spastic quadriparesis of unknown etiology. She was first referred to the neurology/ITB team at 5 weeks of age. She continued to follow with the ITB team, and at age 12 years, 5 months, she was noted to have increased tone in the lower extremities, leading to difficulty in diapering and stretching with physical therapy. She was trialed on trihexyphenidyl, which led to behavior changes and was discontinued. She was also trialed on baclofen, up to 10 mg twice daily. With little improvement in tone, it was discontinued. At age 14, difficulties with positioning and standing were also reported, and an ITB test dose trial was performed by her neurosurgeon at age 14 years, 11 months. No records were noted in the chart of any physical therapy, social work, or psychology assessments before the trial. The pump was titrated up to 109 mcg daily after the implant. One month after her implant, the patient was noted to have fevers, nausea and vomiting, headache, and increased tone. She was treated for a urinary tract infection. Her symptoms recurred two months after the pump implant, and she was found to have meningitis. The pump was subsequently explanted three months after implantation. The patient was thereafter restarted on oral baclofen 10 mg three times daily.
Patient 6
Patient 6 is a female with a history of mixed tone (spastic and dystonic) diplegic cerebral palsy with watershed ischemia seen on MRI related to complications of premature birth. Her GMFCS level at the time of pump consideration was III. She also had a concomitant medical history of chronic pain and mood disorder. At age 13 years, 7 months, she reported significant pain and associated muscle spasms in her back and thighs. At that time, she was taking oral baclofen at 30 mg-20 mg-30 mg daily. She was considered for an ITB pump with the goal of addressing the spasms. She underwent an ITB test dose trial two months later and was evaluated by PT and OT at that time. Social work was involved in the process to help with referrals to the implanting neurosurgeon, and the pump was implanted at 13 years, 9 months. There is no documentation in the chart of psychology involvement before the pump was placed. Her ITB dose was titrated up to 611 mcg and set to flex mode dosing. During titration, the subject continued to take oral baclofen for breakthrough spams. At age 15 years, 4 months, fluoroscopy and oral diazepam were used to facilitate pump refill due to the increased amount of soft tissue related to rapid weight gain and anxiety. Subsequent pump refills were done using fluoroscopy given difficulty accessing the pump and severe anxiety related to refills. At age 17 years, 6 months, the patient was referred to the neurosurgeon who implanted the pump to assess pump pocket revision. The subject decided to proceed with a pump explant at that time, citing concerns about transitioning to an adult provider and anxiety related to pump refills. The ITB dose was subsequently titrated down and the pump was explanted at 18 years of age. The patient transitioned back to oral baclofen.
Patient 7
Patient 7 is a female who first established care with the ITB team at age 8 years, 11 months. She is a female with mixed tone (spastic and dystonic) CP associated with perinatal strokes and hypoxic brain injury. She was referred for management of the ITB pump as her pump was implanted at an outside institution before the patient’s family moved across the country. The pump was implanted at age 8 years, 4 months, with the goal of reducing hip pain and improving ease of diaper changes and hygiene. The family reported that other tone interventions trialed included botulinum toxin injections, phenol injections, enteric baclofen, and enteric carbidopa-levodopa. There were no records available describing PT, OT, social work, or psychology evaluations. The new ITB team titrated the ITB dose up slowly from 177 mcg daily to 683 mcg daily, and a flex dosing schedule was set. The family was concerned that the increases in intrathecal baclofen were not providing adequate tone relief, which was noted to be worse when the patient was excited or upset. Given her fluctuations in mood, she was started on a selective serotonin inhibitor. Enteric baclofen was also added, which appeared to improve her tone. The family reported concerns about the integrity of the pump and the increased burden of having to travel approximately 35 miles to refill the pump frequently, given that the patient had a 20 mL pump. At age 12 years, 10 months, they asked for the pump to be weaned with the plan to explant during an upcoming spine surgery to address scoliosis. During the weaning process, the patient did not tolerate the decrease in dose, with significant dystonia and spasticity returning. The family then decided to keep the pump, and a plan was made to quickly uptitrate the ITB pump in the inpatient setting. Rapid titration demonstrated the efficacy of the pump, as the patient did not tolerate 20% increases daily and experienced classic signs of baclofen overdose. The pump was then titrated more slowly in the outpatient setting and she remained on 474 mcg daily, with the plan to exchange the pump to a 40 mL volume reservoir pump after the estimated replacement interval is reached.
Patient 8
Patient 8 is a female with a history of mixed tone (dystonic and spastic) quadriplegic cerebral palsy associated with non-accidental trauma at 3 months of age. Her motor function was classified as GMFCS V. She first presented to the ITB team at age 15 years, 9 months, for transfer of care of ITB pump management. At that time, the patient was on enteric diazepam 3 mg three times daily. Her pump was placed at age 8 years, 4 months, at an outside institution. There was documentation that referenced an ITB test dose trial, but no documentation was available in the chart regarding goals, physical therapy, occupational therapy, psychology or social work assessments before the pump was implanted. One month after implantation, migration of the distal catheter was noted and resulted in a catheter revision. The pump was subsequently replaced at age 14 years, 6 months at the recommended replacement interval. Two years after the pump was replaced, there was a concern for a catheter leak, and the patient’s mother asked for the pump to be explanted. A wean of ITB was started, but after a 5% decrease, tone was noted to be worse, and the patient’s mother requested to keep the pump. Her ITB dose remained stable at 988.8 mcg daily, with a flex dosing mode, and she continued on that dose until she was transitioned to an adult provider at 19 years of age.
Discussion
In carefully selected patients, ITB therapy has the potential to make a meaningful difference in quality of life. While etiology, characterization, and distribution of tone should be considered when evaluating candidacy for ITB therapy, psychosocial and logistical considerations can be just as or even more important than clinical considerations [8, 10]. Proactively identifying barriers and complications is especially critical, as suboptimal ITB pump management is likely to lead to poor results and patient dissatisfaction with the therapy which may even lead to life-threatening complications [11].
Based on observations regarding the reasons patients in this series considered or had their pump removed, the following should be considered in the pre-implantation assessment and education process: risks and complications associated with ITB implantation, level of understanding of collaboratively created and realistic goals, level of understanding of the ongoing refill expectations, geographic availability of resources that may be needed in case complications or pump malfunctions arise, history of patient/family non-adherence, as well as logistical barriers such as transportation and work schedules that may preclude frequent follow-up. In addition, special considerations for maturing children should be addressed, including stability of family home/structure and the psychological and emotional changes that can accompany adolescence; this is particularly important as psychological distress may worsen the appearance of tone. Further, potential body habitus changes should be considered, as these may also lead to difficulties with refills. Finally, ensuring that families know that providers and plans may have to change when the child transitions out of the pediatric care setting should also be emphasized.
Standardizing the multidisciplinary preoperative psychosocial assessment and education process is a way to ensure a full and comprehensive evaluation of goals, expectations for treatment, and potential psychosocial barriers to successful treatment. Including a multidisciplinary team with various areas of expertise, such as physicians, advance practice providers, therapists, psychologists, social workers, and nurses allows for psychosocial considerations and families’ knowledge of goals and complications to be assessed from multiple points of view.
Goal setting should occur collaboratively between the patient, the patient’s family, and the medical team within the context of the preoperative assessment and should be tailored to the level of patient function. Care and comfort should be the goal setting focus for children who do not ambulate, while gait-associated activity goals should be targeted in the ambulatory population [10, 12]. Having the opportunity to assess patient/family understanding of treatment goals and limitations of treatment within the context of a child’s function is of utmost importance. Assessment of patient and family expectations and how these expectations have been formed is especially relevant as children with complex medical needs are more likely to receive care from multidisciplinary teams that may have variable familiarity with ITB therapy.
Given that ITB complications can arise throughout the course of the ITB life span [13], as was evident in the case series, education, anticipatory guidance, and contingency planning should also be conducted within the preoperative assessment setting. Families and caregivers should, therefore, be proactively aware of the potential problems that can arise, such as postoperative infections, programming errors, and mechanical dysfunction of the pump or catheter/tubing. The fact that these potential complications may also affect work attendance for caregivers, transportation logistics, and financial security should also be addressed. Additionally, a preoperative evaluation can help contextualize ITB therapy as a lifelong commitment with relation to insurance changes as well as adult treatment accessibility (e.g., distance between home and tertiary centers that are appropriately staffed to deal with ITB pumps; availability of adult providers), possibly minimizing the risk for explantation at the time of transition.
Furthermore, pediatric ITB pump management needs assessments should be ongoing, as the social and psychological environment can be dynamic throughout childhood. For example, family structure can change with divorce, marriage, the addition of family members with unique care needs, changes in parent/caregiver employment, and even caregiver turnover if the primary caregiver is hired through a nursing or caregiver agency. Insurance is also likely to change throughout a pediatric patient’s life, especially during transitions from pediatric age to adulthood. Patients may struggle to identify adult care providers who are willing to manage ITB pumps locally. If an adult care provider cannot be identified, patients may face pump explantation and an overall reduction in the quality of their symptom management. Finally, psychological well-being can also be dynamic, particularly during puberty and major school transitions. The care team should be aware that medications used for mood and psychiatric symptoms may also affect movement disorders [14] and body habitus [15].
Certain study limitations merit review. First, due to the small sample size, results may be incomplete, and there may be additional important variables that contribute to a patient’s risk for explantation. Second, and relatedly, this retrospective case series relied in part on patients’/families’ self-report of ITB challenges. As patients are sometimes motivated to try and ‘please’ their doctors, their self-report of relevant difficulties may not have been comprehensive.
It is hoped that the data from this study will be used to justify the benefit of establishing a formalized, multidisciplinary assessment and educational process before pediatric ITB pump implantation. Delineating best practice guidelines for the field will ideally improve treatment adherence and outcomes for those who do receive a pump while optimizing hospital service utilization.
Conclusions
This retrospective review cohort study indicated that, of 30 pediatric patients with ITB pumps reviewed, eight attempted and/or underwent pump explantation. Medical, psychosocial, and logistical factors contributed to a patient’s risk for explantation. Recognizing the critical importance of expectation and goal setting, proactive identification of barriers to treatment, contingency planning for medical complications, and transitional care variables, establishing a formalized, multidisciplinary assessment and education process before pediatric ITB pump implantation is indicated.
Footnotes
Acknowledgments
The authors have no acknowledgements.
Conflict of interest
The authors have no conflicts of interest to report.
Ethical considerations
This study, as a case series, was reviewed by an Institutional Review Board and deemed exempt.
Funding
No funding was received.