Pediatric neurosurgery perspective

Prolonged continuity of care coupled with the characteristic personality and communicative practices embraced by many pediatric neurosurgeons help forge strong bonds with patients and their families. Pediatric neurosurgery teams (including attendings, physician assistants, and nurse practitioners) often care for a child from birth to adolescence given the chronicity of their disease and need for long-term follow-up [1]. However, given the constant influx of new patients, transitioning care of young adults to general neurosurgeons helps provide outflow to balance pediatric practices and help prevent over-saturation. Furthermore, children’s hospitals employing pediatric neurosurgeons may discourage care of patients reaching adulthood at their facility [1].

Many general hospitals offer support for patients over a wide age range. Large academic hospitals often house facilities for both children and adults, lowering barriers for pediatric neurosurgeons to continue caring for young adults. This dual-role model allows pediatric and congenital neurosurgeons to care for children and adults with developmental or childhood disorders [1]. Furthermore, certain units primarily accommodate young adults with SHCN diagnosed during infancy or childhood [1]. These hybrid models provide adolescents with established, continuous medical care into middle-age [1]. However, they do not represent a universal approach to providing continuous care for young adults. Consequently, many pediatric neurosurgeons routinely face the issue of transitioning patients with congenital hydrocephalus from pediatric to adult-oriented care.

Adults with congenital hydrocephalus who lack cognitive or physical deficits may progress smoothly through the transition process. When only adult neurosurgical follow-up is required, pediatric neurosurgeons may serve primary roles in the transfer of care [3]. In contrast, adults with congenital hydrocephalus and SHCN, cognitive impairment, or related comorbidities may require a collaborative approach. Multidisciplinary strategies especially benefit spina bifida patients who have intricate medical profiles [3]. More complex adult patients with congenital hydrocephalus and profound developmental delay may fail to transition care. Their degree of cognitive impairment may prevent independent functional living or participation in medical decision-making. These patients may remain under the care of a willing pediatric neurosurgeon into adulthood, given their medical and social complexity [4]. Even following successful transfer of care, pediatric neurosurgeons should remain available for discussion or consult with prior patients or new healthcare providers [1].

Adult neurosurgery perspective

Given their training and style of practice, adult neurosurgeons may not be equipped optimally to handle patients transitioning from pediatric-oriented care. Staff members within adult-oriented practices often lack experience with developmentally delayed patients or child-onset diseases [4]. Furthermore, the subset of neurological disorders handled by pediatric neurosurgeons differs considerably from the range of pathologies familiar to adult or general neurosurgeons [1]. The lack of familiarity with these patients from both the medical staff and general neurosurgeon may lead to suboptimal care. Beyond general characteristics of the patient population with congenital hydrocephalus, idiosyncrasies of individual patients unbeknownst to the newly accepting adult neurosurgeon may impact care. For instance, the previously treating pediatric attending may have become familiar with a certain patient’s pattern of presentation during shunt malfunction [1]. Much of this information about a patient and their neurologic profile must be relearned by the adult practitioner.

Congenital hydrocephalus differs considerably from adult-onset hydrocephalus regarding etiology and natural history. Hydrocephalus diagnosed at birth or in infancy can result from developmental malformations, myelomeningocele, hemorrhage, meningitis, tumor, or other type of obstruction. While adult neurosurgeons may have experience with obstructive, normal pressure, or tumor-related hydrocephalus, they may lack perspective on the management of a chronically shunted patient treated since birth or childhood [1]. Furthermore, patients shunted during infancy may not exhibit expected ventricular enlargement during shunt malfunction. Despite increased ICP and shunt failure, the ventricles within these children or adults may exhibit little response and misguide radiographic or clinical interpretation. This condition, referred to as normal volume hydrocephalus (NVH) or nonresponding ventricles, may affect up to 25% of patients shunted during infancy [1]. Accustomed to ventricular enlargement during shunt malfunction, general neurosurgeons may fail to recognize shunt failure in an adult with congenital hydrocephalus.

Despite the presence of guidelines, few health systems employ standard practices regarding transition of care for young adults, especially those with SHCN or cognitive impairment [4]. Without standardized practices, adult or general neurosurgeons may face a complicated task during the first consultation involving laborious review of prior medical files and operative reports. Furthermore, guidelines do not exist regarding the follow-up of adults with congenital hydrocephalus beyond the transition period [3]. Patients without significant comorbidities or cognitive impairment may simply require regularly scheduled neurosurgery clinic visits. However, adults with congenital hydrocephalus and SHCN or cognitive impairment likely require continued follow-up with rehabilitation specialists and other medical professionals [3].

Patient and family perspective

An adolescent’s intellectual and behavioral development and their ability to function independently represent critical factors impacting their transition to adult care [4]. The presence of family or caretaker support also affects this process. Congenital hydrocephalus, representing both a chronic illness and potential cause of cognitive impairment or developmental delay, deserves special attention regarding the transition process from pediatric to adult-oriented care.

Adolescents may face several stressors upon transitioning care. Timing of the transition represents an important component, especially concerning other major life events (issues with school, family, friends, etc.). Additionally, patients often experience distress upon breaking the relationship with a familiar pediatric physician and visiting new, unfamiliar adult practitioners [4]. In addition to personnel changes, physical settings differ between typical children’s hospitals and most general neurosurgery practices [1].

Young adults with congenital hydrocephalus may exhibit cognitive impairment, further complicating the transition process. Intellectual impairment may limit independent functioning, decision-making, executive function, and organizational skills [4]. These limitations impair the patient’s ability to assume an active, independent role in their care, forcing more responsibility onto family members, caretakers, or healthcare professionals [1]. The presence of SHCN may also delay or prolong the transition process from pediatric to adult-oriented care [1]. Patients with developmental delay may require longer durations of time to feel prepared for the transfer [4]. Nevertheless, the coexistence of SHCN in a young adult with congenital hydrocephalus should not preclude that individual’s contribution to medical decision-making as they reach maturity [1].

Recommendations

Most sets of recommendations regarding transition from pediatric to adult-oriented care champion standardized and collaborative approaches. General pediatric guidelines suggest having appropriately trained healthcare providers facilitate the transition process. This may help ensure that the transition occurs without lapses in medical coverage [4]. Furthermore, healthcare professionals should document the transition plan in consultation with the patient and family. Patients and caretakers should maintain accurate, updated medical summaries that are readily available [4]. In addition to this formalized approach, the transition process should be flexible and individualized based on patient needs. Relevant patient factors include chronologic and developmental age, neurocognitive function, and family dynamics and resources [4]. The healthcare providers responsible for facilitating the transfer process must consider these factors when determining an individual patient’s readiness and role in the transition [4].

Adolescents with SHCN or cognitive deficits, including those with congenital hydrocephalus, may benefit from a multidisciplinary approach to transferring care. Parents or other caretakers, social workers, pediatricians, adult healthcare providers, pediatric and adult neurosurgeons, and pediatric psychologists may all provide integral roles in the successful transition to adult-oriented care [4]. Depending on their cognitive function, adults with congenital hydrocephalus may still rely upon parents or other family members for medical decision-making and coordination of care. Therefore, transfer of care into adult-oriented practices may still require the designation of a caretaker intimately involved in the process [4]. Additionally, adult neurosurgeons newly seeing a patient with congenital hydrocephalus should communicate openly with pediatricians and pediatric neurosurgeons previously responsible for that individual’s care [1]. This would benefit those adults with congenital hydrocephalus and complex medical profiles due to spina bifida, cerebral palsy, or orthopedic deformities. Social workers represent integral components of the transition process as well. Their assistance may be required for case management, coordination of care, and facilitation of vocational services for patients with developmental delay [4].

For adolescents with congenital hydrocephalus and cognitive impairment, pediatric psychologists may also serve an important role in the transfer from pediatric to adult-oriented care. While neuropsychologists may help assess a patient’s cognitive and adaptive skills, pediatric psychologists can translate these results into clinical practice [4]. For instance, these professionals can implement a variety of strategies (multisensory communication, frequent review and repetition, language adjustment) when communicating with and teaching cognitively impaired adolescents [4]. These tactics may assist pediatric healthcare providers, including pediatric neurosurgeons, to prepare a young adult for transition. Pediatric psychologists can assist in educating patients about their illness, reinforcing disease management and coping skills, and fostering greater independence and a stronger sense of responsibility within the patient. Finally, pediatric psychologists can assess an adolescent’s readiness for transfer and whether they require longer transition periods [4].

Based on AAP guidelines, discussions regarding transition of care for adolescents should commence at age 14, with the knowledge that most children’s hospitals discourage admissions beyond age 18 or 21 [1]. However, this process must be modified according to the individual needs of an adolescent with SHCN. Early initiation of the transition process at age 14 allows greater time intervals for young adults requiring more support. The transition process may begin with education and encouraging the patient to learn more about their conditions [1]. Beyond knowledge of their medical history, adolescents should become familiar with a plan of action in the setting of emergencies and understand who to contact with questions. Additionally, the designation of an individual to make medical decisions as necessary and serve as a power-of-attorney is recommended [1]. The creation of a written, stored, accessible document with this and other pertinent information may help clarify and demystify an individual’s medical profile for both patient and provider [1]. These steps may also help a young adult feel more comfortable and empowered to embrace a proactive role in their care. These patient and provider efforts, along with a multidisciplinary approach, help tailor transition planning to the individual needs of a young adult with congenital hydrocephalus [3,4].

Endoscopic third ventriculostomy (ETV)

Endoscopic third ventriculostomy can be used to functionally convert appropriately selected hydrocephalic patients to shunt independence. Individuals with noncommunicating hydrocephalus classically represent the best candidates for ETV. Additionally, ETV has been applied to chronically shunted patients presenting with recurrent shunt malfunction [6–9]. Given the variability of and difficulty to predict outcomes in such patients, especially those with communicating hydrocephalus, considerable controversy exists regarding this treatment strategy [5]. Several case series report successful conversion of patients with chronic hydrocephalus to shunt independence via ETV. Many of these patients underwent ETV as an alternative approach to treating shunt complications like slit ventricle syndrome, mechanical obstruction, or infection. With study sizes ranging between 4 and 88 patients, including children and adults with shunted hydrocephalus, various research groups have reported rates of shunt independence following ETV between 38% and 84% [5–9].

In a large series of 88 pediatric and adult patients with hydrocephalus and shunt complications, 61% of patients responded favorably to ETV (after first or second attempts) [9]. Patients with noncommunicating hydrocephalus exhibited higher rates of shunt independence (73%) than those with communicating hydrocephalus (46%) following ETV [5,8,9]. Additionally, 73% of patients failing ETV in the setting of shunt malfunction suffered from post-hemorrhagic hydrocephalus [9]. Notably, congenital hydrocephalus represented a risk factor for ETV failure in this study. Of those patients failing ETV, 88% underwent shunt placement early during infancy [5,9].

A retrospective review of 63 patients (pediatric and adult) with shunted hydrocephalus undergoing secondary ETV for shunt malfunction showed a 70% ETV success rate [6]. Statistical analysis showed similar trends of success irrespective of the type of shunt malfunction, including mechanical obstruction and infection [6]. Regarding the original etiology of hydrocephalus, patients with spina bifida exhibited a 55% ETV success rate, while those with aqueductal stenosis displayed a 68% success rate [6]. Clinical evidence of ETV failure occurred within 1 month following neuroendoscopy in 95% of patients; however, one patient expired acutely 5 months postoperatively [6]. Patients presenting with ETV failure may undergo a repeat trial of ventriculostomy or ventricular shunt reinsertion.

In another large series of adult patients with shunt malfunction (without stratification by type of hydrocephalus), Jenkinson et al. reported an ETV success rate of 67% [7]. The authors explained the relatively high success rate of secondary ETV in the setting of shunt infection as compared to primary ETV for neonatal post-meningitic hydrocephalus based on differing pathophysiology. Meningitis frequently results in development of subarachnoid membranes and adhesions that may not be visualized during endoscopy or re-form following fenestration [7]. These obstructions to CSF flow can result in ETV failure rates of up to 45% [7]. In contrast, shunt infections do not typically propagate formation of subarachnoid adhesions, leading to higher success rates with secondary ETV. Similarly, primary ETV for post-hemorrhagic hydrocephalus may exhibit high failure rates due to blockage of CSF flow through subarachnoid spaces and arachnoid granulations by debris [6]. CSF flow diversion via shunting may alter intracranial anatomy, allowing subarachnoid CSF spaces to re-expand and the sylvian aqueduct to stenose. Such factors favor the success of secondary ETV in communicating hydrocephalus (infective or post-hemorrhagic) after shunt malfunction [6].

ETV failure and complications

In the same study by Jenkinson et al., ETV failure in adult patients with shunt malfunction occurred at a median duration of 2 weeks postoperatively [7]. While ETV success plateaued by 3 months postoperatively on Kaplan–Meier survival analysis, delayed ETV failure still occurred with potentially devastating consequences, stressing the importance of prolonged long-term follow-up [7]. Adults with congenital hydrocephalus who undergo ETV to achieve shunt independence should be educated and counseled thoroughly about the risks of acute intracranial hypertension [6].

Despite the potential benefits of shunt independence, many patients fail or are not candidates for ETV. Relative contraindications of ETV include slit ventricles or aberrant anatomy that would complicate visualization or perforation of the third ventricular floor. Other factors that increase the risk of ETV failure include subarachnoid membranes deep to the third ventricular floor, prior subarachnoid hemorrhage or intracranial infection, and narrowing of the ventriculostomy stoma [5]. Furthermore, patients with multiple shunt revisions prior to ETV in the setting of shunt malfunction exhibit higher risk of shunt reinsertion [8]. Retrospective series have reported median times to failure within 4–6 weeks following ETV for shunt malfunction [7,9]. However, case reports describing remote sudden death in the setting of acute obstructive hydrocephalus following ETV and shunt removal illustrate the importance of vigilant follow-up [6,9,10].

In addition to ETV failure requiring shunt reinsertion, several complications exist with ETV. These risks include CSF leakage, intracranial infections or hemorrhage, hypothalamic-pituitary axis abnormalities, cranial nerve palsies, transient memory or cognitive disturbances, and thalamic or anterior spinal infarcts [8,11]. A case series by Hader et al. reported elevated frequency of serious complications with ETV at the time of shunt malfunction (31%) as opposed to primary intervention for hydrocephalus (8%) [8]. In contrast, other series have reported lower serious complication rates of 1.6–5.6% for ETV in the setting of shunt malfunction [8,9]. Rates of infection following ETV (1–2%) typically fall below those of ventriculoperitoneal (VP) shunt insertion (5–10%) [6].

Complications may occur more frequently in secondary ETV due to the increased difficulty of performing neuroendoscopy in the context of chronic shunting. Distorted anatomy, lower degrees of ventricular enlargement, and thickened third ventricular floors enhance the complexity of ETV in shunted patients [8]. Furthermore, the practice of external ventricular drain (EVD) insertion following ETV in chronically shunted patients leads to higher risk of CSF leaks and infections [8]. However, this strategy also helps protect patients against temporary intracranial hypertension following ETV during adjustment to shunt independence [8]. The potential complications and risks of ETV failure necessitate careful patient selection when considering ETV in the setting of shunt malfunction.