Surgical correction of lambdoid synostosis - New technique and first results.

OBJECTIVE: Premature craniosynostosis of the lambdoid suture is rare. The use of differential diagnosis to rule out positional occipital plagiocephaly is crucial. Nevertheless, once diagnosed, lambdoid craniosynostosis requires corrective surgery to prevent intracranial harm and aesthetic stigma by significant dyscrania. Operative correction of the lambdoid fusion is often performed by suturectomy and helmet therapy, total occipital remodeling interventions, transposition of occipital bone flaps, or occipital advancement procedures either with or without distraction osteogenesis. We present a simple surgical maneuver to potentially correct the occipital and suboccipital constriction caused by unilateral lambdoid craniosynostosis.

MATERIALS AND METHODS: Three patients with true unilateral lambdoid synostosis underwent surgery. A straight-line skin incision was created, beginning at the caudal pole of the ipsilateral mastoideal bulge. The incision ran cranially and corresponded to the course of the lambdoid suture up to the posterior fontanel. The periosteum was incised and the contralateral (potent) lambdoid suture was identified at its origin. One burr-hole was created to separate the dura from the intern tabula. Afterwards, a square meander-shaped craniotomy was performed along the assumed course of the lambdoid suture. The squares were then forced apart to form the occipital and suboccipital area into a more rounded shape. The squares were fixed in those positions with resorbable plates or sutures. Pre- and postoperative three-dimensional (3D) photoscans were performed and analyzed with special software to follow the perioperative course of the cranial shape.

RESULTS: This new approach minimized the operative time and degree of blood-loss, and rounding of the occipital area was accomplished with only one unilateral intervention. In terms of the available photogrammetric data of two of the patients, the cranial vault asymmetry index, posterior symmetry ratio, and posterior/anterior skull volume ratio were improved but not normalized completely. The measurement outcome, as determined by an automated analysis of the photoscans, however, indicated clear flaws with regard to repeatability.

CONCLUSION: A unilateral approach using a square meander-shaped craniotomy and subsequent inclination may be a suitable surgical method for correcting assorted cases of lambdoid craniosynostosis. Transposition of the occipital bone flaps, subtotal craniectomies of the occipital area, and occipital advancements with or without distraction devices may not be essential in all cases of lambdoid synostosis. However, the reliability of the automated analysis of three-dimensional photoscans must be determined.