Sagittal synostosis: II. Cranial morphology and growth after the modified pi-plasty

The value of three-dimensional photogrammetry in isolated sagittal synostosis: Impact of age and surgical technique on intracranial volume and cephalic index─a retrospective cohort study

PURPOSE

The aim of this study was to compare the outcome of intracranial volume (ICV) and cephalic index (CI) between two different techniques for surgical therapy of sagittal synostosis.

MATERIAL AND METHODS

Between 2011 and 2015, all patients scheduled for surgical therapy of sagittal synostosis were consecutively enrolled. All patients younger than 6 months underwent early extended strip craniectomy (ESC group), and patients older than 6 months underwent late modified pi-procedure (MPP group). To measure ICV and CI, data acquisition was performed via three-dimensional photogrammetry, 1 day before (T0) and between 10 and 12 weeks after surgery (T1). Results were compared with an age-matched reference group of healthy children. Perioperative parameters, as duration of surgery and the amount of blood loss of both surgical procedures were analyzed.

RESULTS

A total of 85 patients were enrolled. Of the patients, 48 underwent an extended strip craniotomy with parietal osteotomies and biparietal widening and 37 patients underwent a late modified pi-procedure. There was no significant difference between the ESC group and the MPP group regarding the efficacy of improving CI (p > 0.05). Both techniques were able to normalize CI and to improve head shape. ICV was normal compared to age-matched norm-groups with both techniques, pre- and postoperatively. However, duration of the surgical procedure and calculated blood loss were significantly lower in the ESC group (p < 0.05).

CONCLUSION

ESC and MPP were effective techniques to normalize cephalic index (CI) and improve head shape at their recommended time of surgery. Measurement of ICV and CI with 3D photogrammetry is a valid method to objectively evaluate patients before and after surgery without exposing pediatric patients to ionizing radiation.

The Management of Nonsyndromic, Isolated Sagittal Synostosis

AIM

Isolated sagittal synostosis is the commonest form of craniosynostosis. The reasons for surgery are to normalize the head shape and to increase the cranial volume, thus reducing the risk of raised intracranial pressure and allowing for normal brain development. It has been suggested that sagittal synostosis may impair neuropsychological development. This systematic review appraised the literature on the management of sagittal synostosis.

METHODS

A literature search was performed with the assistance of a professional librarian. Studies selected had to satisfy the criteria set by PICO (patients, intervention, comparison, and outcome). Cranial index and neuropsychological outcome were used as outcome measures. MINORS was used to assess the methodological quality of the selected articles. A score of 75% was deemed to be of satisfactory quality, and the quality of the evidence from the selected studies was graded using the GRADE system.

RESULTS

One hundred forty-eight articles were initially identified. Only 6 articles fulfilled the PICO criteria and scored a minimum of 75% on MINORS. Four studies compared 1 technique to another with documented cranial indices. Two studies compared 1 group to another and assessed the neuropsychological development. According to GRADE, the quality of evidence was deemed to be very low.

CONCLUSIONS

This systematic review assessed cranial index and neuropsychological outcome following surgery for isolated, nonsyndromic sagittal synostosis. The quality of the evidence in the published literature was noted to be of very low quality. There is a need for better-designed, prospective studies to guide surgeons involved in management of sagittal synostosis.

Expansion and compression distraction osteogenesis based on volumetric and neurodevelopmental analysis in sagittal craniosynostosis

PURPOSE

Distraction osteogenesis (DO) is a less daunting procedure than extensive cranial vault remodeling and has been used to correct sagittal craniosynostosis. The purposes of this study are to describe DO in combination with expansion and compression procedures and to report analytic results based on the cranial index (CI), volumetric measurement, and neurodevelopmental tests.

METHODS

Between June 2002 and May 2013, 32 patients with non-syndromic sagittal synostosis who had undergone antero-posterior compression with bitemporal expansion were recruited. Circumferential baseline, mid-sagittal, and bicoronal craniotomies were performed in addition to four-quadrant bone flap procedures via distraction with dural attachment. CI, intracranial volume (ICV), head circumference (HC), and neurodevelopmental outcomes using the Bayley Scales of Infant Development-II (BSID-II) scoring system were analyzed.

RESULTS

Dolichocephalic CI (68.85 ± 3.61) was altered to mesocephalic CI (78.28 ± 3.74) postoperatively. Preoperative ICV and HC determinations were within the normal range for the majority of participants (normal ICV 87.5%, n = 28; normal HC 75%, n = 24). ICV and HC did not show significant changes with postoperative measurements and were maintained within normal ranges. Regarding neurodevelopment, both the mental and psychomotor developmental indices (MDI, PDI) demonstrated significant improvement (MDI, 88.69 ± 17.38 to 96.23 ± 21.05; PDI, 91.38 ± 16.31 to 100 ± 11.51; p < 0.05).

CONCLUSIONS

Symmetric sagittal synostosis can be treated comprehensively through DO in combination with expansion and compression procedures. ICV and HC measurements were useful for designing surgical and postoperative distraction strategies. Achievement of mesocephalic CI and neurodevelopmental improvement validated morphological and functional effectiveness.

Craniofacial cephalometric morphology in 8-year-old children with operated sagittal synostosis

OBJECTIVES

To evaluate cephalometrically craniofacial morphology in children with operated sagittal synostosis and to compare the findings with age- and sex-matched controls.

SETTING AND SAMPLE POPULATION

Forty-two children (37 boys) with operated primary sagittal synostosis were compared retrospectively with age- and sex-matched controls from lateral cephalograms taken at a mean age of 8.1 (range 7.0-8.9) years.

MATERIAL AND METHODS

The operations had been performed between the ages of 2 months and 6.3 years at three Finnish hospitals. The surgical methods included strip craniectomy, pi-plasty and cranial vault expansion. A paired Student's t-test and Pearson's correlation analysis were used in the statistical analyses.

RESULTS

Children with operated sagittal synostosis had wide cranial base angles and their mandibles were retrognathic with labially inclined lower incisors relative to the controls. Age at craniosynostosis operation did not correlate with the cranial base angle.

CONCLUSION

This study suggests that children with operated sagittal synostosis have minor distinctive morphological features in the cranial base and mandible. Orthodontic evaluation of craniofacial growth is recommended.

Surgical treatment of sagittal synostosis by extended strip craniectomy: cranial index, nasofrontal angle, reoperation rate, and a review of the literature

BACKGROUND

Sagittal synostosis is the most common non-syndromic single suture craniosynostosis. Different techniques of surgical correction, including extended strip craniectomy (ESC), have been used to treat this condition. The aim of this study is to evaluate radiologic changes and rate of symptomatic restenosis after ESC in a large group of patients less than 12 months of age with non-syndromic sagittal synostosis.

METHODS

A retrospective study of patients from 1990 to 2012 was performed comparing cranial index (CI) and nasofrontal angle (NFA) before and after surgical correction by ESC. Also, the frequency of subsequent reoperations for symptomatic restricted head growth was determined.

RESULTS

A total of 238 patients underwent ESC. Follow-up information was available for 182 patients. The average age at the time of the operation was 4.5 months and the mean duration of follow-up was 49.6 months. The average post procedure radiologic follow-up (22 patients) was 40.7 months.

CONCLUSIONS

The mean CI increased from 0.68 to 0.75 (p < 0.001) after ESC. Also, mean NFA increased from 127 to 133° (p < 0.001). Five patients (2.7%) required a second operation due to symptomatic cranial growth restriction. Reoperation occurred at an average of 26.5 months after the initial procedure. The most common symptom reported was headache. ESC is effective in treating non-syndromic sagittal synostosis. It significantly improved NFA without the need for direct frontal bone resection or frontal orbital osteotomy and significantly increased CI without adjunctive helmet treatment. Patients should be followed for at least 5 years after surgical correction as symptomatic restenosis, although rare, can occur.

Anesthesia for craniofacial surgery in infancy

Anesthetic management of infants undergoing craniofacial surgery can be challenging. Primary concerns for the anesthesiologist include blood loss and its management. The evolution of procedures to treat craniosynostosis has resulted in improvements in perioperative morbidity, including decreased blood loss and transfusion, shorter operations, and shorter hospital stays. An understanding of the procedures performed to treat craniosynostosis is necessary to provide optimal anesthetic management. Descriptions of current surgical techniques and approaches to anesthetic care are presented in this review.

Intracranial compartment volume changes in sagittal craniosynostosis patients: influence of comprehensive cranioplasty

BACKGROUND

A retrospective analysis of intracranial compartment volume changes in children with sagittal craniosynostosis was performed to clarify the therapeutic objectives of corrective surgery.

METHODS

Chart and computed tomographic review of 53 consecutive children with previously unoperated sagittal synostosis was performed, and preoperative and postoperative computed tomographic scans were examined and compared with 143 age- and gender-matched controls.

RESULTS

Preoperative mean intracranial compartment volume and mean brain tissue volume of each subgroup were age dependent. Brain volume was less in unoperated male sagittal synostosis patients (<6 months old) compared with controls (672.63 ml versus 716.14 ml). Brain tissue volume was approximately the same as controls for the 7- to 12-month and 12- to 30-month age groups. Long-term brain volume, however, again became less than controls with longer periods without treatment (31 to 60 months, 1050.6 versus 1291.51 ml, respectively). Intracranial compartment volume was less in unoperated male sagittal synostosis patients (<6 months old) compared with controls (706.6 ml versus 757.76 ml). Preoperative mean intracranial compartment volume, however, was greater than in controls in the 7- to 12-month (979.78 versus 970.34 ml) and 13- to 30-month age groups (1108.23 versus 1177.52 ml). Long term (31 to 60 months), however, intracranial compartment volume was less in untreated sagittal synostosis patients (1206.3 ml versus 1311.37 ml). Comparing day-1 postoperative sagittal synostosis patient data to age- and gender-matched controls to 1 year postoperatively, the operated patients develop an equivalent increase in skull growth compared with normals.

CONCLUSIONS

Intracranial compartment volume is increased preoperatively in untreated sagittal synostosis patients older than 6 months. Intracranial compartment volume enlargement is largely attributable to an increase in brain volume. Comprehensive cranioplasty before 12 months of age increases intracranial compartment volume over normal growth.