T HERE is an unusual and interesting variety of craniosynostosis in

Transcription

1 SURGICAL TREATMENT OF CONGENITAL ANOMALIES OF THE CORONAL AND METOPIC SUTURES TECHNICAL NOTE DONALD D. MATSON, M.D. Neurosurgical Service, The Children's Medical Center, and Deparlment of Surgery, Itarvard Medical School, Boston, Massachusetts (Received for publication December 31, 1958) T HERE is an unusual and interesting variety of craniosynostosis in which prenatal closure of the coronal suture is accompanied by persistent separation of the normally fused metopic suture (Fig. 1A). This is usually associated with premature fusion of the sphenoid and orbital bones. There results a characteristic deformity marked by: (1) widening of the biparietal diameter of the head, anteriorly, (~) soft-tissue prominence in the midline of the forehead from the region of the anterior fontanel to the depressed bridge of the nose, (3) concavity of the lateral, supra-orbital, and anterior tempocal areas on both sides, (4) choanal atresia, and (5) protrusion of the eyes. This combination of cranial deformities may sometimes be accompanied 1)y syndactylism of the fingers and toes, or other congenital malformations. In spite of these various abnormalities, there may be no primary lesion of the central nervous system. The visible deformity is so striking and characteristic that these children should be recognized proml)tly at birth. Both cosmetic and functional results are best if operation is carried out during the first ~ or 3 months of life, preferably during the first month. 1 A plan of surgical correction which has evolved in this clinic is described in this brief technical note. Repair is ordinarily performed in one stage. If there is exophthahnos of sufficient degree to endanger the eyes it is perhaps wise to do the operation in ~ stages so that orbital decompressions may be carried out as well. 2 Among 3~5 patients with craniosynostosis operated upon in this clinic, this particular problem has arisen 4 times. OPERATIVE PROCEDURE The infant is placed on the operating table in the supine position under endotracheal, general anesthesia. Intubation should be performed with great care as there is usually narrowing of the nasopharyngeal airway. If, preoperatively, the baby is a mouth breather and it is impossible to pass a No. 8 French catheter through either nostril, indicating severe choanal atresia, it is wise previous to the cranial surgery to carry out elective tracheostomy and to give the anesthetic agent by this route. A long coronal incision is made from zygoma to zygoma, well back of the hairline (Fig. ~A). The anterior scalp flap is elevated down to the orbital ridges, exposing the entire forehead. Periosteum is first widely removed from the frontal 413

2 414 DONALD D. MATSON Fia. 1. (A) Anterior and lateral views of 4-month-old infant with coronal synostosis accompanied by widely patent metopic suture. (B) Postoperative appearance. bones and the area of the fused coronal suture (Fig. eb). The temporal muscle is detached from its insertion and split in the axis of its fibers so that bone is exposed well below the squamosal suture. A strip of bone 6 to 8 ram. in width is now removed bilaterally, extending from the open fontanel to the wing of the sphenoid and across the squamosal suture to the floor of the middle fossa (Fig. ~D). This craniectomy should curve well forward laterally because of the shallow triangular sh ape of the frontal fossa. The cranieetomy should be carried far enough forward and inferiorly to expose the orbital roof. The frontal bone is next cut across with a saw or stout scissors just above the orbital ridge so that each frontal bone is removed as a separate free bone flap (Fig. 3A). This allows the prominent midline metopic region of the intracranial contents to recede and the depressed anterior temporal areas to fill out bilaterally immediately. The fibrous-tissue layer continuous with periosteum which covers the anterior fontanel and separated metopie suture area is also removed (Fig. 3B). The frontal bones are brought together in the midline, reshaped as necessary, and held in close approximation by silk sutures through drill holes. The frontal bones are also secured to the orbital ridges medially in the same manner (Fig. 8C). This results in the lateral borders of the frontal bone flaps being rotated upward. These bone flaps may be bent or fractured laterally so that the scalp easily molds them to the new and normal contours of the underlying lobes of the brain. Polyethylene film is placed over the anterior margin of the

3 TREATMENT OF ANOMALIES OF CRANIAL SUTURES 415 parietal bones and the posterior margins of the replaced frontal bones so as to delay healing across the region of the coronal suture and thereby allow continued expansion of the frontal fossa with further growth of the brain (Fig. 3D). Because of the narrowed pharyngeal airway, these patients are placed in a humid atmosphere immediately after extubation until full recovery from anesthesia is achieved and normal respiratory exchange is assured. Instead of a soft-tissue swelling in the midline flanked by deep bony depressions in the anterior temporal regions, the baby now has a well-rounded, solid forehead (Fig. 1B). Improvement of contour of the anterior part of the head continues for many months after operation as further expansion of the brain occurs. The temporal bony defects fill in for the most part with new bone fornm(t from the dura mater by the end of the first year of life. FIG. ~. Plan of operative treatment (see text).

4 416 DONALD D. MATSON PREMATURE FUSION OF THE METOPIC SUTURE A modification of the operative procedure described above has been carried out on 6 occasions in very young babies with so-called trigonencephaly. That is, simple premature fusion of the metopic suture occurs so that there is: (1) a bony ridge down the midline of the forehead, (~) bilateral supra-orbital bony depression, and (3) normal patency of all the other sutures. In these circumstances, through the same type of incision and coronal scalp flap, the frontal bones are removed as ~ free bone flaps by cutting the bone from the anterior fontanel to the glabella and across the supra-orbital area from the midline to the lateral end of the coronal suture. FIG. 3. Plan of operative treatment (see text).

5 TREATMENT OF ANOMALIES OF CRANIAL SUTURES 417 FIG. 4. (A) Anteroposterior and lateral roentgenograms of same patient as in Fig. 1. (B) Postoperative roentgenograms. These bone flaps are then lined with polyethylene film along their opposing medial margins and inferiorly along the supra-orbital margins to delay bony union. This allows the frontal bones to be pushed forward and laterally as the brain grows, thereby permitting improvement in the contour of the forehead. Operative repair in trigonencephaly is probably purely a cosmetic procedure and is worth while only if carried out during the first few months of life. REFERENCES l. INGRAHAM,F. D., and MATSON,I). D. Neurosurgery of infancy and childhood. Springfield, Ill. : Charles C Thomas, 1954, xvii, 456 pp.!~. MC]~AURIN, R. L., and MATSON, D. D. Importance of early surgical treatment of craniosynostosis. Review of 36 cases treated during the first six months of life. Pediatrics, 195~, 10: ~.