Ventricular shunt complications in patients undergoing posterior vault distraction osteogenesis

Craniocerebral Disproportion Corrected With Biparietal Distraction Osteogenesis

Ventriculoperitoneal shunt therapy represents a lifesaving neurosurgical intervention in pediatric patients with hydrocephalus. Although necessary, research indicates that shunting may be associated with a spectrum of craniocerebral disproportion from frank craniosynostosis to later presenting neurofunctional symptoms and headaches. The surgical management of craniosynostosis is generally treated according to provider and institutional preference; however, shunt therapy presents difficulties for typical vault remodeling procedures. In this report, we describe the utility of a biparietal distraction osteogenesis configuration for the treatment of craniocerebral disproportion in 2 patients. A parallel arrangement of an anterior and a posterior set of 2 distractors allows for a doubling of the typical expansion of the parietal diameter. This method effectively alleviates the scaphocephaly without disruption of the shunt site. We propose our repair for the indication of sagittal craniosynostosis in the shunted patient.

Prevalence and treatment outcomes of hydrocephalus among children with craniofacial syndromes

INTRODUCTION

Hydrocephalus is more common in patients with craniofacial syndromes (CS) relative to non-syndromic craniosynostosis, and the optimal management is challenging. This study examined the prevalence and treatment outcomes of hydrocephalus among children with CS.

MATERIALS AND METHODS

We performed a retrospective review of medical records for all children with established CS and registered in the Gothenburg Craniofacial Registry between 1975 and 2022. This review included analyses of data regarding patient demographics, radiological imaging, hydrocephalus treatment modalities, and shunt revisions.

RESULTS

Eligible patients (n = 193) included those with CS, including Pfeiffer (n = 13), Crouzon (n = 57), Apert (n = 49), Muenke (n = 25), and Saethre-Chotzen (n = 49) syndromes. A total of 22 patients (11.4%) presented hydrocephalus requiring treatment [Pfeiffer, n = 8 (61.5%); Crouzon, n = 13 (22.8%); and Apert, n = 1 (2.0%)]. Nineteen (9.8%) patients underwent ventricular shunt insertion, and three (1.6%) underwent endoscopic third ventriculostomy as a first procedure. None of the Muenke or Saethre-Chotzen patients required hydrocephalus treatment. Seventeen (85%) patients with shunts required revision mainly due to shunt obstruction. Pfeiffer patients had the highest risk of both developing hydrocephalus requiring treatment and needing shunt revision (p < 0.001 and p = 0.004, respectively). Approximately 40% of patients with Pfeiffer, Crouzon, or Apert presented ventriculomegaly not requiring treatment.

CONCLUSIONS

Hydrocephalus requiring treatment is common in Pfeiffer and Crouzon patients but rare in Apert, Muenke, or Saethre-Chotzen syndrome. Shunt treatment is often associated with complications that require revisions, emphasizing the importance of distinguishing non-progressive ventriculomegaly from hydrocephalus requiring treatment.

Free-floating bone flap posterior cranial vault release in syndromic craniosynostosis

The aim of this study was to investigate the efficacy of non-detachable free-floating bone flap posterior cranial vault release (FFBF-PCVR) in syndromic craniosynostosis. A retrospective review was completed of subjects who underwent FFBF-PCVR at 4 time-points: within 3 months preoperatively, 7 days postoperatively, 3 months postoperatively and at the last follow-up postoperatively. Volumetric and craniometric data, the ratio of ventricular diameter, and the cerebellar tonsillar descent were measured after FFBF-PCVR by using computed tomographic and magnetic resonance imaging. A total of 19 patients underwent FFBF-PCVR. The mean age was 11.7 months (range 4-36 months). The mid cranial height, posterior cranial height, and anterior posterior diameter length significantly increased from preoperative to postoperative 7 days, from postoperative 7 days to postoperative3 months, and from postoperative 3 months to the last follow-up. There was a significant increase in pre- to 7 days postoperative intracranial volume (1195.21 ± 246.56 cm³, p < 0.001; respectively), 3 months postoperative intracranial volume (1228.03 ± 249.61 cm³, p < 0.001; respectively), and intracranial volume at last follow-up (1390.25 ± 219.99 cm³, p < 0.001; respectively). There was a significant increase in 7 days' postoperative to 3 months' postoperative intracranial volume (p < 0.001; respectively), and intracranial volume at last follow-up (p < 0.001; respectively). There was a significant increase in 3 months postoperative to intracranial volume at last follow-up (p < 0.001). The mean intracranial volume increased by an average of 36.6 percent (range, 18.1 to 79.2 percent) at last follow-up. The degree of hydrocephalus in the preoperative child was (45.77% ± 9.17%), and at the last follow-up after surgery, the degree of hydrocephalus was (35.02 ± 9.50%), p < 0.01). Preoperatively, 14 patients (73.7 percent) had radiographic evidence of Chiari malformation type I. The cerebellar tonsillar descent, measured using pre- and postoperative MRI, decreased in all patients after FFBF-PCVR (preoperative: 7.5 ± 1.4 mm, postoperative: 5.3 ± 1.7 mm; p = 0.001). FFBF-PCVR can efficiently expand the posterior cranial vault with only one surgical procedure. Moreover, it helps to relieve hydrocephalus and cerebellar tonsillar herniation.

Vaulting further: cranial vault expansion for craniocerebral disproportion without primary craniosynostosis

PURPOSE

Treatment of subjects with refractory idiopathic intracranial hypertension (IIH) or shunted hydrocephalus with chronic shunt complications is challenging. What is the role for cranial vault expansion, particularly utilizing posterior vault distraction osteogenesis (PVDO), in these cases? This study assesses medium-term efficacy of cranial vault expansion in this unique patient population.

METHODS

A retrospective review was conducted of patients who underwent cranial vault expansion from 2008 to 2023 at the Children's Hospital of Philadelphia. Subjects who did not have a diagnosis of primary craniosynostosis were included in the study. Demographic information, medical history, and perioperative details were collected from medical records. Primary outcomes were the rate of CSF diversion procedures and resolution of presenting signs and symptoms. Secondary outcomes were perioperative and 90-day complications and reoperation requirement.

RESULTS

Among 13 included subjects, nine (69.2%) patients had a primary diagnosis of shunted hydrocephalus and 4 (30.8%) patients had IIH. Twelve (92.3%) subjects underwent posterior vault distraction osteogenesis (PVDO) and one (7.7%) underwent posterior vault remodeling (PVR). All 4 patients with IIH demonstrated symptomatic improvement following PVDO, including resolution of headaches, vomiting, and/or papilledema. Among 9 patients with shunted hydrocephalus, CSF diversion requirement decreased from 2.7 ± 1.6 procedures per year preoperatively to 1.2 ± 1.8 per year following cranial vault expansion (p = 0.030). The mean postoperative follow-up was 4.1 ± 2.1 years and four (30.8%) patients experienced complications within 90 days of surgery, including infection (n = 2), CSF leak (n = 1), and elevated ICP requiring lumbar puncture (n = 1). Four (30.8%) patients underwent repeat cranial vault expansion for recurrence of ICP-related symptoms. At most recent follow-up, 7 of 9 patients with shunted hydrocephalus demonstrated symptomatic improvement.

CONCLUSION

Cranial vault expansion reduced intracranial hypertension-related symptomology as well as the rate of CSF diversion-related procedures in patients with refractory IIH and shunted hydrocephalus without craniosynostosis, and should be considered in those who have significant shunt morbidity.

Early posterior vault distraction osteogenesis changes the syndromic craniosynostosis treatment paradigm: long-term outcomes of a 23-year cohort study

BACKGROUND

Early surgical management of syndromic craniosynostosis varies widely between centers, with patients typically undergoing multiple intracranial procedures through childhood. This study evaluates the long-term impact of early posterior vault distraction osteogenesis (PVDO) versus conventional treatment paradigms on the number and timing of subsequent craniofacial procedures.

METHODS

We retrospectively analyzed the longitudinal operative patterns of patients with syndromic craniosynostosis treated from 2000 to 2023 with greater than five years of follow-up. Outcomes of patients who underwent early PVDO and conventional vault reconstruction were compared.

RESULTS

Fifty-five patients met the inclusion criteria (30 PVDO and 25 conventional). Age at initial vault surgery was similar between the PVDO and conventional cohorts (7.6 vs. 8.8 months), as were baseline craniometrics (p > 0.05). Multiple fronto-orbital advancement (FOA) procedures were performed in only 1/30 (3%) PVDO-treated patient versus 12/25 (48%) conventionally-treated patients (p < 0.001). Twelve (40%) PVDO-treated patients did not undergo FOA at all. Among patients with Apert and Crouzon syndromes, fewer PVDO-treated patients required FOA prior to midface surgery (33% vs. 92%, p = 0.004) or repeat FOA (6% vs. 50%, p = 0.005) compared to conventionally-treated patients. Among patients with Muenke and Saethre-Chotzen syndromes, a similar proportion of patients required FOA in the PVDO and conventional cohorts (91% vs. 100%, p = 0.353), though no PVDO-treated patients required repeat FOA (0% vs. 44%, p = 0.018).

CONCLUSIONS

Early PVDO is associated with a reduction in the high burden of both FOA and, critically, revisionary frontal procedures which are commonly seen in conventionally-treated patients with syndromic craniosynostosis.

Craniosynostosis and hydrocephalus: relevance and treatment modalities

INTRODUCTION

Hydrocephalus is variously associated to syndromic craniosynostosis (CS), while it is randomly encountered in monosutural CS. Pathogenesis is still debated and reliable criteria for the diagnosis of overt hydrocephalus are lacking. Additionally, optimal treatment is controversial since it should balance the need to relieve intracranial hypertension and the risk of recurrence favored by lowering intracranial pressure.

METHODS

A thorough review of the literature has been performed. Accordingly, pathogenic theories, diagnostic issues, and treatment options on hydrocephalus presenting in the context of CS are discussed.

RESULTS

The association of hydrocephalus to simple CS is considered a fortuitous event. Its treatment is usually driven by the etiology and clinical relevance of hydrocephalus, favoring treatment before surgical correction to reduce CSF-related complications. On the other side, pathogenesis of hydrocephalus in the context of syndromic CS has been mainly related to factors that are secondary to the synostostic process, such as craniocerebral disproportion and venous hypertension. Hydrocephalus complicates 12-15% of syndromic CS, though its incidence is more relevant in FGFR2-related CS and raises up to 88% in Pfeiffer syndrome. Overt hydrocephalus should be properly differentiated by non-tense ventriculomegaly that is more frequent in Apert syndrome. Since intracranial hypertension is constant in syndromic CS even in the absence of active hydrocephalus, radiological monitoring of ventricular size along with intracranial pressure monitoring is essential. Active hydrocephalus occurs more frequently in infants, though stable ventriculomegaly may evolve into overt hydrocephalus after cranial expansion. If hydrocephalus is not clinically prominent, cranial expansion should be favored as first surgical step. Although posterior cranial expansion may address posterior cranial fossa constriction and stabilize ventricular dilation, effectiveness in long-term control of hydrocephalus is not clear. ETV is an effective treatment option, though success rate is affected by the presence of brain malformations and patient age. Extrathecal CSF shunting should be used as last resource due to the increased risk of complications in this context.

CONCLUSIONS

The pathogenesis of hydrocephalus complicating syndromic CS should be further investigated. Concomitantly, the definition of reliable diagnostic criteria is advocated in order to promptly and properly identify active hydrocephalus. Finally, treatment algorithm should refine the best timing and treatment options aiming to relieve intracranial hypertension on one side and reduce the risk of restenosis on the other side.

Posterior vault distraction osteogenesis: indications and expectations

Cranial vault remodeling (CVR) in patients with craniosynostosis serves to correct abnormal skull morphology and increase intracranial volume to prevent or treat pathologic increases in intracranial pressure (Taylor and Bartlett, Plast Reconstr Surg 140: 82e-93e, 2017). Distraction osteogenesis is a well-established technique for bony repositioning and growth stimulation in the facial and long bones, in which the gradual separation of bony segments at an osteotomy site results in generation of new bone and subsequent bone lengthening (Greene, 2018). While initially described in the orthopedic literature, the relevance and applicability of distraction osteogenesis to craniofacial surgery has been well-studied and is now well-established (Steinbacher et al., Plast Reconstr Surg 127: 792-801, 2011). Posterior cranial vault distraction osteogenesis (PVDO) was introduced as a treatment option for cranial vault expansion in patients with craniosynostosis in 2009 by White et al., based upon the premise that posterior vault distraction could provide greater intracranial volume expansion than fronto-orbital advancement and remodeling (FOAR), but that acute posterior cranial vault expansions were limited by the soft tissue envelope of the infant scalp and prone to relapse related to the supine positioning typical of infants (White et al., Childs Nerv Syst 25: 231-236, 2009). Since this introduction, significant evidence has accrued regarding the safety of, and outcomes after, PVDO. PVDO is now known to provide larger increases in intracranial volume in comparison to anterior cranial vault remodeling procedures (Derderian et al., Plast Reconstr Surg 135:1665-1672, 2015) and to provide morphologic improvements in both the posterior and anterior cranial vaults (Goldstein et al., Plast Reconstr Surg 131:1367-1375, 2013). Perioperative major morbidity is comparable to conventional vault remodeling (Taylor et al., Plast Reconstr Surg 129:674e-680e, 2012) and the procedure has been safely applied to patients of various ages with syndromic and non-syndromic craniosynostosis (Zhang et al., J Craniofac Surg 29:566-571, 2018; Li et al., J Craniofac Surg 27:1165-1169, 2016). Many high-volume craniofacial centers now consider PVDO the preferred first operation in infants with syndromic craniosynostosis, and indications for this procedure continue to expand as evidence accrues regarding its utility and safety (Steinbacher et al., Plast Reconstr Surg 127: 792-801, 2011; Swanson et al., Plast Reconstr Surg 137:829e-841e, 2016).

The Expanding Role of Posterior Vault Distraction Osteogenesis in Idiopathic Intracranial Hypertension and Slit Ventricle Syndrome

ABSTRACT

The purpose of this study was to compare perioperative safety and efficacy of posterior vault distraction osteogenesis (PVDO) in patients with primary nonsynostotic cephalo-cranial disproportion, namely slit ventricle syndrome and idiopathic intracranial hypertension (IIH), to a cohort of patients with craniosynostosis (CS). A retrospective review of patients undergoing PVDO from 2009 to 2019 at our institution was performed. Craniosynostosis patients were matched by sex and age at PVDO to the nonsynostotic cohort. Operative details, perioperative outcomes, and distraction patterns were analyzed with appropriate statistics. Nine patients met inclusion criteria for the non-CS cohort. Six patients (67%) underwent PVDO for slit ventricle and the remaining 3 patients (33%) underwent PVDO for IIH. The majority of CS patients were syndromic (n = 6, 67%) and had multisuture synostosis (n = 7, 78%). The non-CS cohort underwent PVDO at a median 56.1 months old [Q1 41.1, Q3 86.6] versus the CS cohort at 55.7 months [Q1 39.6, Q3 76.0] (P = 0.931). Total hospital length of stay was longer in the non-CS patients (median days 5 [Q1 4, Q3 6] versus 3 [Q1 3, Q3 4], P = 0.021). Non-CS patients with ventriculoperitoneal shunts had significantly less shunt operations for ICP concerns post-PVDO (median rate: 1.74/year [Q1 1.30, Q3 3.00] versus median: 0.18/year [Q1 0.0, Q3 0.7]; P = 0.046). In this pilot study using PVDO to treat slit ventricle syndrome and IIH, safety appears similar to PVDO in the synostotic setting. The cohort lacks adequate follow-up to assess long term efficacy, although short-midterm follow-up demonstrates promising results with less need for shunt revision and symptomatic relief. Future studies are warranted to identify the preferred surgical approach in these complex patients.

Craniometric and Volumetric Analysis of Posterior Vault Distraction Osteogenesis: 10 Year Update

PURPOSE

The purpose of this study is to quantitatively establish the volumetric changes observed with posterior vault distraction osteogenesis in the anterior, middle, and posterior thirds of the cranial vault; characterize change in cranial length, width, and height, correlating these changes to demographic variables that may help identify why younger kids gain more volume; and describe the short-term position of the transport segment.

METHODS

Multisuture craniosynostosis patients who underwent posterior vault distraction osteogenesis were retrospectively reviewed. Pediatric, dose-reduced, thin cut helically acquired head computed tomography scans were analyzed on Materialise Mimics v22 (Materialise, Ghent, Belgium). Pre and post-PVDO and "old" and "young" cohort were compared.

RESULTS

Twenty-one patients met inclusion criteria. The change in cranial length was significantly less at a median of 14.9 mm [Interquartile range (IQR) 11.8, 31.6] compared to the X-ray measured AP distraction distance (30 mm [IQR 24, 33]; P < 0.001) and significantly less than the theoretically calculated distance (23 mm [IQR 19, 31]; P = 0.012). Median anterior cranial height was shorter post PVDO (82.9 mm, [IQR 64.8, 92.6] versus 78.7 mm [IQR 57.0, 88.7]; P = 0.030). The younger cohort saw a greater increase in total intracranial volume (median 335.1 mL [IQR 163.2, 452.3, median 37.1%] versus 144.6 mL [IQR 119.0, 184.8, median 12.0%]; P = 0.011).

CONCLUSIONS

This is the first study to quantify volumetric changes to the anterior, middle, and posterior cranial vaults and demonstrates benefits of preforming PVDO at a younger age to help control turricephaly and produce greater percentage volumetric increases.

Craniosynostosis: Posterior Cranial Vault Remodeling

Posterior cranial vault distraction osteogenesis is a powerful, reliable, low-morbidity method to achieve intracranial expansion. It is particularly useful in treating turribrachycephaly seen in syndromic craniosynostosis, allowing for gradual expansion of the bone while stretching the soft tissues over several weeks allowing greater volumetric expansion than conventional techniques. Posterior cranial vault distraction osteogenesis constitutes a more gradual remodeling modality, with infrequent complications. As a first step in intracranial expansion, it preserves the frontal cranium for future frontofacial procedures. A drawback is the need for a second surgery to remove the device, and this must be taken into account during counseling.