Piezosurgical Suturectomy and Sutural Distraction Osteogenesis for the Treatment of Unilateral Coronal Synostosis.

Different surgical procedures are used for the treatment of synostosis. Among them, suturectomy and sutural distraction osteogenesis (SDO) are suitable for young infant patients. In this report, we present the case of a young infant patient with a clear synostosis of the left coronal suture, which was treated by piezoelectric suturectomy combined with SDO and 2 internal distractors. One-year follow-up showed good results. Thirty-six months after surgery, normal skull growth and shape were observed by 3D computed tomographic examination. No infection, bleeding, fistula, and other complications were observed. The results suggested that the treatment of unilateral coronal synostosis in young infant patient by piezosurgical suturectomy and SDO is to be preferred because of its simplicity and relatively minimal invasiveness.

Craniosynostosis is a relatively rare congenital deformity in which one or more of the cranial sutures have closed prematurely. Premature fusion of one of the coronal sutures results in plagiocephaly, which is a common deformity in craniomaxillofacial surgery that can be associated with many complications affecting sensory, respiratory, and neurological function.[1]

Different surgical procedures have been considered in the treatment of synostosis. Suturectomy (strip craniectomy) and sutural distraction osteogenesis (SDO) are widely used.[2-5] In particular, during suturectomy, the prematurely fused suture line is reopened, permitting brain growth and cerebral decompression but not the reshaping of the dysmorphic skull; on the other hand, gradual SDO helps in reshaping the skull without leaving any subcranial dead space.[5]

Distraction methods include both external and internal devices. The external devices require a frame that is attached to the skull and permit to control and modify the vectors and forces during activation. They are easier to apply and simpler to remove, but its bulk can result in physical and psychosocial discomfort for the patient. On the contrary, internal devices are smaller with better patient acceptance but require an additional surgical access for removal. So, internal devices have a specific indication in patients under school age, whereas external devices should probably be preferred in adolescents and adult patients because they offer easier implantation and better control of the vectors and assure more predictable and effective results.[3,6,7]

Here, we present the case of a young infant patient with a clear synostosis of the left coronal suture, which was treated by piezoelectric suturectomy combined with SDO.

CASE REPORT

A 6-month-old male infant was referred to Nanjing Children’s Hospital with deformities of the skull and face. Clinical examination revealed left frontal flattening, slight nasal tip deviation toward the flattening, and depression at the frontotemporal junction; Harlequin eye was not observed. Cranial perimeter was normal (Table 1).

Table 1.

Measurement of Preoperation and Postoperation

Three-dimensional computed tomography (3D CT, Philips, the Netherlands) scans showed a slightly smaller size of the left orbit and a thickening of the pterion with a retrusion of the greater sphenoid wing; moreover, synostosis of the left coronal suture was evident (Fig. 1).

Fig. 1.

A, Preoperative frontal view by 3D CT. B, Preoperative oblique view by 3D CT showing a clear synostosis of the left coronal suture.

The parents were informed about the cosmetic aspect of the surgery and the progressive deformations and their informed consent was obtained. Suturectomy and SDO were planned. Surgery was performed with the patient in a supine position. A half coronal incision was made and the scalp was dissected. The dissection plane was extended subperiosteally to expose the frontal bone, the superior part of the orbit, the left fused coronal suture, and the temporal fossa behind the zygomatic process of the left frontal bone. Piezoelectric suturectomy (2-cm strip of bone) of the left coronal suture was performed without dura mater dissection by piezoelectric surgery (Surgybone, Silfradent Srl, Italy). Two internal distraction devices (Ningbo Cibei Medical Treatment Appliance, Ningbo, China) were applied across the osteotomized fused coronal suture (Fig. 2). From the second day after surgery, distraction was started at 1.2 mm per day for 15 days. The postoperative clinical course was uneventful. Three months after surgery, 3D CT scan was performed (Fig. 3). The internal device was removed, and the distraction-resulted skull defect was filled with Medpor (Porex, Atlanta, Ga.) to prevent skull growth and craniosynostosis again. One-year follow-up showed good results (Table 1), even if the left orbit was smaller. Thirty-six months after surgery, normal skull growth and shape were observed by 3D CT examination (Fig. 4). No infection, bleeding, fistula, and other complications were observed.

Fig. 2.

Intraoperative view of 2 internal distraction devices.

Fig. 3.

Postoperative view 3 months after surgery. A, Frontal view by 3D CT. B, Lateral view by 3D CT.

Fig. 4.

Postoperative view 36 months after surgery. A, Frontal view by 3D CT. B, Vertex view by 3D CT.

DISCUSSION

Unilateral coronal synostosis is a premature fusion of one of the coronal sutures occurring in 1 in 10,000 live births.[8] Multiple procedures have been described for its treatment, highlighting the fact that no single approach seems to alleviate all functional and aesthetic problems. Among them, craniotomy and SDO are used for the treatment of cranial synostosis.[4,8-14]

McCarthy et al[15] first introduced distractors for lengthening the mandible. In 1998, Sugawara et al[12] pioneered the use of distractors for the treatment of cranial synostosis and, in particular, to expand gradually vascularized cranial bone together with the intracranial content, keeping the dura-cranium connection intact. Then, the use of distractors has been widely employed, allowing safer and more controlled advancement of the midface, without the need for internal plating and graft site morbidity.[3] Nevertheless, one difficulty with the distractor frame is the need to anchor it securely to the cranium. In very young patients, the bone may be too thin for its safe application; consequently, the timing of surgical intervention has to be considered. Some authors believed that it should be as early as 6 months of age because it takes advantage of rapid brain growth that occurs within first years. Other authors believe in delaying until ninth or 12th month because the bones are better developed and the surgical results are better maintained.[3,8,16]

Here, we presented a surgical approach for the treatment of unilateral coronal synostosis in young infant patient: piezosurgical suturectomy combined with SDO.

Piezosurgery is mainly used in oral surgery[17,18]; however, it has been used for osteotomies in cranial vault and orbital walls with minimal undermining of the dura mater and periorbital soft tissue, reducing the postoperative swelling.[19] In particular, it is adequate in the case of osteotomies involving thin bone (eg, infant skull), whereas in the case of osteotomies involving thick bone, the procedure requires more time and could be performed initially with the drill and eventually completed with the piezoelectric device. Furthermore, with piezoelectric surgery, it has been possible to perform precise osteotomy in close proximity of vessels, nerves, and other important structures, such as dura mater, with minimal bleeding.[17,18,20]

The pro-osteogenic properties of the dura are well known and are thought to result from the production of osteoinductive factors.[14,21] Therefore, in our surgical design, the intact dura mater permitted bone regeneration from islands of bone within the dura mater, as suggested by other authors.[21,22]

Here, we decided to combine piezosurgical suturectomy with SDO. SDO technique, in fact, is suitable for young infant patients (under 6 months), with several advantages. In particular, bone is expanded gradually without subcranial dead space postoperatively, and the cranial bone remains vascularized.[12] However, some disadvantages include the limited possibility of initial reshaping and the necessity of one more operation for distractor removal.[16]

Our experience of combining piezosurgical suturectomy with SDO for the management of unilateral coronal synostosis in a young infant patient is promising. In particular, this surgical approach permitted to obtain both the correction of the underlying bony deformity associated with the synostotic suture and the management of the overlying soft-tissue envelope, avoiding long-term surgical relapse.[23]

CONCLUSION

Treatment of unilateral coronal synostosis by piezosurgical suturectomy combined with SDO permitted the expansion of cranial bone with overlying skin and underlying dura mater. A long-term follow-up in more cases will be required to validate our results.

PATIENT CONSENT

Parents provided written consent for the use of the patient’s image.