"Ten Years of Posterior Cranial Vault Expansion via Distraction Osteogenesis: An Update and Critical Evaluation"

Long-term sequelae of normocephalic pansynostosis: a rare but insidious entity

OBJECTIVE

Patients with normocephalic pansynostosis, who have a grossly normal head shape, are often overlooked early in life and present late with elevated intracranial pressure (ICP) requiring timely cranial vault expansion. This study evaluates the long-term clinical outcomes of patients with normocephalic pansynostosis.

METHODS

We retrospectively reviewed patients with a clinical and radiographic diagnosis of primary pansynostosis who underwent vault reconstruction between 2000 and 2023. Clinical and treatment course after craniofacial interventions was followed in patients with normocephaly to assess outcomes.

RESULTS

Thirty-five patients with primary pansynostosis were identified, of which eight (23.5%) had normocephaly and underwent initial vault expansion at a mean age of 5.0 ± 2.4 years. All eight patients (50.0% male) presented with symptoms of elevated ICP including headaches (50.0%), nausea and vomiting (50.0%), and developmental delay (62.5%) and/or signs of elevated ICP including papilledema (75.0%) and radiologic thumbprinting on head computed tomography scan (87.5%). Three of the four normocephalic patients who had over 7 years of postoperative follow-up developed subjective headaches, vision changes, or learning and behavioral issues in the long-term despite successful vault reconstruction.

CONCLUSIONS

Our longitudinal experience with this rare but insidious entity demonstrates the importance of timely intervention and frequent postoperative monitoring, which are critical to limiting long-term neurological sequelae. Multidisciplinary care by craniofacial surgery, neurosurgery, ophthalmology, and neuropsychology with follow-up into adolescence are recommended to assess for possible recurrence of elevated ICP secondary to cranio-cerebral disproportion.

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.

Craniofacial Distraction Osteogenesis

Distraction osteogenesis (DO) of the craniofacial skeleton has become an effective technique for the treatment of both nonsyndromic and syndromic conditions. The advent of craniofacial DO has allowed for earlier intervention in pediatric patients with less complication risk and morbidity compared to traditional techniques. In this review, we will discuss current application and technique for craniofacial DO by anatomical region and explore future applications in craniofacial surgery.

Oxycephaly-systematic review, case presentation, and diagnostic clarification

PURPOSE

Oxycephaly is a specific phenotype of multi-suture craniosynostosis that is often misrepresented. This study aims to review the relevant literature, clarify the diagnostic criteria, and present an alternate approach to its management.

METHODS

Published literature regarding oxycephaly was reviewed from 1997, when the largest series was published, until 2022. All cases at a single institution were then retrospectively reviewed.

RESULTS

Over the last 25 years, four studies met the inclusion criteria, none of which specifically defined oxycephaly. One case, in one study, was potentially consistent with the phenotype. An institutional review yielded two patients who met the original diagnostic criteria set forth by Renier and Marchac. Both patients had unexplained speech delays, mild retinal nerve fiber layer thickening, and diffuse inner table scalloping, along with the characteristic oxycephalic phenotype. One patient also had a direct intracranial pressure (ICP) measurement of 25 mmHg, and the other had a Chiari I malformation. Both were treated with posterior vault distraction osteogenesis (PVDO) to alleviate the cephalo-cranial disproportion while simultaneously allowing for turricephaly correction.

CONCLUSIONS

Oxycephaly presents with late onset multi-suture fusion. Patients have patent sutures at birth. Midface hypoplasia and known syndromic associations are absent. Patients demonstrate supraorbital recession, an obtuse fronto-nasal angle, and turricephaly without substantial brachycephaly. Over 60% of patients have symptomatic ICP elevation, the presentation of which ranges from headaches to rapidly progressive blindness. This rare form of craniosynostosis is particularly virulent and likely often missed due to diagnostic ambiguity and its relatively mild phenotype.

A Rare Case of Sagittal Sinus Obstruction Following Posterior Cranial Vault Distraction Osteogenesis

Posterior cranial vault distraction osteogenesis (PCVDO) is a relatively new paradigm in the treatment of syndromic craniosynostosis, having first been introduced in 2009. PCVDO directly addresses the underdeveloped cranial vault and appears to allow for a larger increase in intracranial volume when compared to traditional techniques. Although reported as safe in the literature, critical appraisal is still required as PCVDO is a relatively uncommon procedure that may require greater numbers to detect true complication rates. The overall reported incidence of serious complications in PCVDO to date is low. This presentation highlights a rare case of sagittal sinus obstruction following posterior cranial vault distraction and raises questions as to the safest technical considerations when planning the operation.

Posterior Cranial Distraction in Craniosynostosis: A Systematic Review of the Literature

OBJECTIVE

Posterior cranial distraction (PCD) is a surgical technique to address craniosynostosis, especially in syndromic patients. The technique has the ability to significantly expand the cranium, while requiring minimal dural dissection, compared to cranial remodeling. Our goals were to determine the patient characteristics and surgical outcomes of PCD. The two questions that we sought to answer were: 1) What is the average published complication rate and the most common complications of PCD? and 2) How much intracranial volume expansion can one expect with PCD?

DESIGN

A PubMed database search of articles on PCD was performed. Case reports and articles with overlapping patients were excluded. A systematic review was performed using the remaining articles.

MAIN OUTCOME MEASURES

Patient data were extracted in order to determine the total number of patients, patients with a syndrome, types of syndromes, mean age at surgery, mean distraction distance, mean increase in intracranial volume, and complications.

RESULTS

18 articles representing 325 patients were analyzed. A syndrome was present in 68.6% of patients. The mean age at time of surgery was 22.1 months. Mean distraction amount was 24.7 mm. Mean increase in intracranial volume was 253.2 cm³. The overall complication rate was 32.2%, with the most common complications being surgical-site infection, hardware-related complications and delayed wound healing.

CONCLUSIONS

PCD is a powerful technique in the management of syndromic craniosynostosis, although complication rates are significantly higher than traditional remodeling techniques. Future studies should compare the effects of supratorcular and infratorcular osteotomies on intracranial volume, cosmesis and complications.