Atypical scaphocephaly: a review

Atypical sagittal suture craniosynostosis: pathological considerations for early closure of the anterior part of the sagittal suture

Sagittal suture synostosis is one of the most common craniosynostoses and is often diagnosed by characteristic narrow and long skull shape, scaphocephaly. However, some patients with sagittal suture synostosis do not present with typical scaphocephaly, making early diagnosis difficult. In this study, five cases of characteristic skull deformity showing a narrowing of the cranium posterior to the coronal suture on computed tomography (CT) are presented. The three older children presented with papilledema and intellectual disability and a closed sagittal suture on CT. The two infant cases were diagnosed with the characteristic cranial deformities with aggravation of the deformity over time, but sagittal suture closure was not evident on CT. All patients underwent cranial remodeling surgery. In the two infant cases, the histopathological findings showed that the anterior part of the sagittal suture was firmly fused with fibrous tissue without bony fusion. These findings suggested that narrowing of the cranium posterior to the coronal suture might be due to functional fusion of the anterior portion of the sagittal suture prior to bony fusion. In an infant presenting with such a deformity that shows aggravation of the deformity over time, surgical treatment should be considered.

Single sagittal craniosynostosis surgical treatment with the "Peau d́ours" technique. Single-center experience in Mexico

Scaphocephaly (SC) is defined as an elongation of the anteroposterior axis of the skull resulting from the abnormal fusion of the sagittal suture. This study describes the "Peau d'ours" technique and results for correcting SC. We conducted a consecutive and retrospective analysis of patients treated from 2011 to 2016. We evaluated the gender, age, and surgical outcomes. A total of 53 patients were enrolled with a mean age of 19 months old. The advantages of this technique are healthy coronal and lambdoid suture preservation and symmetrical parietal bone flap opening. This technique is safe and simple to reproduce, allowing good surgical outcomes with a low incidence of secondary craniosynostosis. This technique is ideal for patients older than six months old.

Morphological and surgical results in sagittal synostosis: early craniectomy versus later cranioplasty

BACKGROUND AND PURPOSE

Morphological correction is one of the main aims of surgery for sagittal synostosis (SSO). Different surgical techniques have been developed; however, few studies have compared the different surgical protocols. The morphological outcome is poorly documented, because a consensual evaluation tool is lacking.

MATERIAL AND METHODS

We performed a prospective study of children operated for SSO in our institution. Children were operated whenever possible at 4 months for craniectomy; by default, children underwent cranioplasty at or after 9 months. The morphological outcome of all children was evaluated using traditional craniometry with head circumference (HC) and the cephalic index (CI), and with the Rotterdam scaphocephaly morphology score (RSMS), a total of semi-quantitative assessments of morphological hallmarks.

RESULTS

Craniectomy was significantly associated with a shorter operation time and hospital stay, and a better impact on HC and CI measurements, compared with cranioplasty. The RSMS was markedly improved after surgery in both groups; however, we found no significant difference in improvement between the two groups. Although the transfusion rate and the prevalence of developmental delay were lower in the craniectomy group, and reoperations for calvarial lacunae or complex craniosynostosis occurred only this group, these differences were not significant.

CONCLUSIONS

Our results support early surgery with craniectomy whenever possible; however, cranioplasty at a later age is a very acceptable by-default indication. In addition to classical craniometry, morphological evaluation using the RSMS or a similar quantitative scale appears highly desirable for future studies.

The metopic suture: Natural history

The metopic suture (MS) is one of the main sutures of the calvaria; premature closure is responsible for trigonocephaly, while persistence (metopism) is considered a normal variant. The ages of onset and completion of MS closure and prevalence of metopism in normal children are poorly documented. We studied the pattern of MS closure on 3D-CT scans of 477 children admitted for head trauma since 2012. We also studied the prevalence of trigonocephaly and the sex ratio in our clinical series of patients with all types of synostosis diagnosed during the last 4 decades. In the majority of children, MS closure started at 4 months and was complete at 9 months. The prevalence of metopism was stable after 1 year of age, at 5.1%; it was more than twice as frequent in girls (F/M ratio 2.1, non-significant). Our trigonocephaly series and the literature show a steady increase in prevalence over recent decades. During the same period, the prevalence of metopism decreased steadily. Data from comparative anatomy and paleoanthropology suggest that postnatal MS persistence in our species results from the risk of dystocia caused by the closed pelvis associated with bipedalism. The increasing incidence of trigonocephaly appears to parallel the fall in prevalence of metopism. The increasing use of cesarean section may have eliminated a potent selection factor in favor of postnatal persistence of the MS.

What remains of non-syndromic bicoronal synostosis?

More and more genetic syndromes are associated with bicoronal synostosis (BCS), making non-syndromic BCS (NSBCS) a shrinking entity. However, the numerical importance and clinical impact of syndromic BCS (SBCS) versus NSBCS have not been much studied. We retrospectively reviewed our experience with BCS over the last four decades in order to compare prevalence trends in SBCS and NSBCS. 195 patients were treated for BCS during the period 1978-2017: 104 (53.3%) were syndromic, 24 (12.3%) showed clinical and/or familial features suggesting a syndrome, although without final diagnostic confirmation, and 7 (3.5%) had associated extra-cranial malformations suggesting a syndromic context without identified genetic mutation; the remaining 61 (31.3%) were purely NSBCS. Surgery was required earlier in SBCS (21.7months, 95%CI 18.4-25.1) than in NSBCS (29.5months 95%CI 26.4-32.7). Prevalence of hydrocephalus and tonsillar herniation was significantly lower in NSBCS, and mortality concerned only SBCS. Prevalence of NSBC decreased significantly over the study period, likely because of more accurate testing, and decreased slightly over the last decade, possibly because of prenatal testing and abortion. NSBCS is now much less common than SBCS, and has a less aggressive clinical course, with lower rates of hydrocephalus, tonsillar herniation and mortality. This subgroup also deserves attention because it is likely that new discoveries are still to be made.

Case update on cranial osteopetrosis: which is the role of the neurosurgeon?

PURPOSE

Osteopetrosis (OP) is a rare skeletal disease, which can affect the skull base and calvaria. A multidisciplinary approach is mandatory and patient may need neurosurgical care. Few observations have been published, and optimal management of OP is not established yet.

METHOD

We report a case of an infant with OP diagnosed at 5 months, who presented signs of intracranial hypertension associated with unilateral blindness. Bone marrow allograft was performed at 6 months of age. At neurosurgical first examination at 11 months, the child was hypotonic, with severe amblyopia; features of bicoronal synostosis were appreciated, with tense anterior fontanel bulging indicating synostotic oxycephaly. Head circumference had decreased from +3 SD to +1SD. Cerebral CT scan showed reduction of intracranial volume, inward thickening of the calvaria, bilateral stenosis of optic canal, ventricular dilatation, enlarged arachnoid spaces, and tonsillar herniation. We performed cranial vault expansion with frontal advancement and bi parietal decompression, thinning of the inner table, unroofing of the left orbit and optic canal in order to obtain optic nerve decompression.

RESULTS

Postoperative course was uneventful, and the patient was discharged on day 8. Vision was unchanged but rapid improvement of axial tonus was noted. The CT scan showed satisfactory calvarial expansion with regression of tonsillar herniation.

CONCLUSIONS

Neurosurgical evaluation and care are necessary in the context of a multidisciplinary approach to the patient affected by osteopetrosis. Cranial vault remodeling and expansion should be considered in patients with sign of intracranial hypertension. Timing of optic canal decompression is to be defined.

Results of early surgery for sagittal suture synostosis: long-term follow-up and the occurrence of raised intracranial pressure

PURPOSE

Numerous techniques are used to correct sagittal synostosis. Although cosmetic results and operative complications are well documented, little is known about functional outcome. In our institution, the technique for extended strip craniectomy evolved over time. This study compares cosmetic results, complications, and signs of raised intracranial pressure (ICP) between the variants of the extended strip craniectomy.

METHODS

Seventy-nine consecutive patients undergoing early extended strip craniectomy for scaphocephaly (2002-2008) were included. Four techniques were used: A, a simple bilateral parietal flap with out-fracturing of the bone flap; B, C, and D included remodeling of the parietal flap by adding triangular cuts and bending or suturing the resulting fingers. In technique D, the sagittal strip was rotated and fixed between the parietal flaps. Data on head circumference (HC), skull X-ray, and fundoscopy were collected prospectively.

RESULTS

For all patients, the average cranial index (CI) was 74 after 3 months and 72 after 2 years. Although technique D resulted in the best initial improvement, there was no significant percentage increase in CI after 24 months between the four techniques. Postoperatively, 9 % of the patients developed papilledema, 42 % developed a fontanel bulge, and 57 % had diminished HC. Four patients were reoperated on because of raised ICP.

CONCLUSIONS

Postoperative CI is mainly determined by preoperative CI and hardly affected by type of extended strip craniectomy. Signs of raised ICP occurred more frequently than expected, therefore structural follow-up is required to detect such signs. Technique and timing of surgery should aim at creating sufficient intracranial volume.