Intraoperative intracranial pressure monitoring in the pediatric craniosynostosis population

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Evaluation of increased intracranial pressure (ICP) in the pediatric craniosynostosis population based solely on ophthalmological, clinical, and radiographic data is subjective, insensitive, and inconsistent. The aim of this study was to examine the intraoperative ICP before and after craniectomy in this patient population.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>The authors measured the ICP before and after craniectomy using a subdural ICP monitor in 45 children. They regulated end-tidal carbon dioxide and the monitoring site under general anesthesia to record consistent ICP readings.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The average age of the patient population was 29 months (range 3.8–180.5 months). Thirty-seven patients (82.2%) were undergoing initial craniosynostosis procedures. All craniosynostosis procedures were categorized as one of the following: frontoorbital advancement (n = 24), frontoorbital advancement with distraction osteogenesis (n = 1), posterior vault distraction osteogenesis (n = 10), and posterior vault reconstruction (n = 10). Nineteen of 45 patients (42.2%) had syndromic or multisuture craniosynostosis. The mean postcraniectomy ICP (8.8 mm Hg, range 2–18 mm Hg) was significantly lower than the precraniectomy ICP (16.5 mm Hg, range 6–35 mm Hg) (p &lt; 0.001). Twenty-four patients (53%) had elevated ICP prior to craniectomy, defined as ≥ 15 mm Hg. Only 4 (8.9%) children had papilledema on preoperative funduscopic examination (sensitivity 17%, specificity 100%, negative predictive value 51%, and positive predictive value 100%). There were no significant differences in elevated precraniectomy ICP based on type of craniosynostosis (syndromic/multisuture or nonsyndromic) or age at the time of surgery. Patients undergoing initial surgery in the first 12 months of life were significantly less likely to have elevated precraniectomy ICP compared with patients older than 12 months (26.3% vs 73.1%, p = 0.005).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>In this study, the authors report the largest cohort of syndromic and nonsyndromic craniosynostosis patients (n = 45) who underwent precraniectomy and postcraniectomy ICP evaluation. A craniectomy or completed craniotomy cuts for distractors effectively reduced ICP in 43/45 patients. The authors’ findings support the notion that papilledema on funduscopy is a highly specific, however poorly sensitive, indicator of increased ICP, and thus is not a reliable screening method. These findings indicate that even nonsyndromic patients with craniosynostosis are at risk for increased ICP. Furthermore, patients who present prior to 12 months of age appear less likely to have elevated ICP on presentation. Further studies with other noninvasive imaging of the retina may be useful as an adjunct tool for determining elevated ICP.</jats:p></jats:sec>

Neuro-Ophthalmological Manifestations of Craniosynostosis: Current Perspectives

“… 8 , 9 The highest risk of elevated ICP is seen in patients with multi-sutural involvement and in those with FGFR2 mutations (Apert, Crouzon, and Pfeiffer syndromes), with the overall risk of elevated ICP estimated to be around 30–40% in syndromic craniosynostosis and 15–20% in non-syndromic craniosynostosis (reflecting increased risk with multi-sutural involvement). 25 – 27 Papilledema is also more common in patients with a known causative genetic mutation, although it may still occur in cases where no mutation is identified; it is thought to be present in 10–15% of children with craniosynostosis. 12 , 13 , 28 Chronic compression or elongation of the optic nerve from synostosis-induced anomalies of the orbit or optic canal may also contribute to optic atrophy.…”

“…Another study of 37 craniosynostosis patients undergoing procedures found that preoperative finding of papilledema was only 17% sensitive for elevated ICP. 27 This is concerning given that papilledema has historically been considered a ubiquitous indicator for elevated ICP. The negative predictive value of absent papilledema is further diminished in cases where extensive optic atrophy has already occurred, as destroyed axons no longer swell and may fail to produce disc edema even with high pressures.…”

Epidemiology of craniosynostosis in Norway

“…2 Premature closure of one or more sutures often results in cranial deformity and compromised intracranial volume. [3][4][5][6] The latter may result in raised intracranial pressure and secondary brain injury. [6][7][8][9] Clinically, craniosynostosis is divided into syndromic and nonsyndromic craniosynostosis.…”

Identifying the Misshapen Head: Craniosynostosis and Related Disorders

“…To what extent, if any, treatable causes contribute to neurocognitive deficits in craniosynostosis, and whether prompt surgical treatment can improve neurobehavioral outcomes, is a matter of debate. Elevated ICP is present in 4% to 42% of children with single-suture craniosynostosis and approximately 50% to 68% with multisutural involvement [40][41][42][43][44] ; the incidence of intracranial hypertension is higher among older untreated individuals. 42,44 Elevated ICP correlates with developmental and cognitive outcomes in some studies 40 but not others.…”

“…Elevated ICP is present in 4% to 42% of children with single-suture craniosynostosis and approximately 50% to 68% with multisutural involvement [40][41][42][43][44] ; the incidence of intracranial hypertension is higher among older untreated individuals. 42,44 Elevated ICP correlates with developmental and cognitive outcomes in some studies 40 but not others. 39,45,46 Neither has the severity of the deformity correlated with the presence of neurocognitive deficits.…”