Reformation of suture following surgery for isolated sagittal craniosynostosis

Reformation of Suture Following Surgery for Isolated Sagittal

Craniosynostosis

Deepak Agrawal, Paul Steinbok, D CochraneDivision of Pediatric Neurosurgery, UBC and BC Children’s

Hospital, Vancouver, BC

ISOLATED SAGITTAL CRANIOSYNOSTOSIS

BASIS FOR MANAGEMENT

• Isolated entity in a normal child

• Operative Intervention-Improve cosmesis

ETIOLOGY

Moss’s Hypothesis

• Abnormality at cranial baseMoss, M. L. (1959). "The pathogenesis of premature cranial synostosis in man." Acta Anat (Basel) 37: 351-70.

• Proven for syndromic craniosynostosis

ETIOLOGY

Babler’s Hypothesis

• Abnormality is in the affected calvarial sutures Babler, W. J., J. A. Persing, et al. (1982). "Compensatory growth following premature closure of the coronal suture in rabbits." J Neurosurg 57(4): 535-42.

• Support from animal experimentsMabbutt, L. W. and V. G. Kokich (1979). "Calvarial and sutural re-development following craniectomy in the neonatal rabbit." J Anat 129(2): 413-22.

Reformation of sagittal suture should similarly be expected in children with isolated sagittal synostosis

OBJECTIVE

• To determine the incidence of reformation of the sagittal suture following surgical procedures for sagittal synostosis that involved a minimum of sagittal strip craniectomy

MATERIALS AND METHODS

• Retrospective study 1987-2000

• Children with isolated sagittal craniosynostosis

Operative Procedure

Minimum of vertex and parietal craniectomies(removal of the sagittal suture + 1.5 - 2.5 cm piece of adjacent parietal bone with the attached pericranium)

Children who had the bone flap replaced were excluded from the study

Assessment of resynostosis

POST-OP SKULL RADIOGRAPHS

• Suture morphology

• Patency of coronal and lambdoid sutures

RESULTS

• 114 children operated for isolated sagittal craniosynostosis in the above period.

• 42 children composed the study group.

RESULTS

• Median age at surgery- 3.9 months

(1.9 to 7.6 months)

• Mean follow up - 32.2 months

(6 to 144 months)

RESULTS

• Only 7/42 (16.7%) reformed the suture

• 35/42 (83.3%) had resynostosis of the sagittal suture

These findings are contrary to the results from animal experiments

WHY THE DISCREPANCY?

DISCUSSION

• Both dura mater and pericranium have osteogenic properties

• Dura-source of central new bone

• Pericranium- enhances peripheral new bone formation

Gosain AK, Santoro TD, Song LS, et al: Osteogenesis in calvarial defects: contribution of the dura, the pericranium, and the surrounding bone in adult versus infant animals. Plast Reconstr Surg 112:515-527, 2003

DISCUSSION

• In Sag synostosis surgery-central strip of bone with the attached pericranium removed

• Removal of this pericranium could potentially impair bony regeneration as well as suture reformation

DISCUSSION

• Common practice to coagulate the bleeding points on the dura

• This again could impair the osteogenic capacity of the dura

DISCUSSION

• Primary aim of surgery is cosmetic

• Persistence of bony defects and uneven contour of the bony regrowth may result in patient dissatisfaction, rarely culminating in repeat surgery

OUR HYPOTHESIS

Limiting coagulation on the dura & replacing pericranium could potentially result in consistent bone regeneration with smooth contour and reformation of a normal suture.

Further prospective studies would be required to prove this hypothesis

OTHER POTENTIAL FACTORS

GENETIC BASIS

• Inclusion of undiagnosed syndromic patients

• Genetic predisposition to synostosis

CONCLUSIONS

• We found a very high incidence of resynostosis following surgery for sagittal craniosynostosis

• The variability in reformation of the suture after surgery suggests a heterogeneous etiology and pathogenesis of isolated sagittal synostosis.

THANK YOU