- Email: [email protected]
Subtotal cranial vault remodelling in anterior sagittal suture closure: impact of age on surgical outcome
Int. J. Oral Maxillofac. Surg. 2012; 41: 1232–1237 http://dx.doi.org/10.1016/j.ijom.2012.05.026, available online at http://www.sciencedirect.com
Leading Clinical Paper Craniofacial Anomalies
Subtotal cranial vault remodelling in anterior sagittal suture closure: impact of age on surgical outcome
M. Engel, J. Hoffmann, J. Mu¨hling, G. Castrillo´n-Oberndorfer, R. Seeberger, C. Freudlsperger Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
M. Engel, J. Hoffmann, J. Mu¨hling, G. Castrillo´n-Oberndorfer, R. Seeberger, C. Freudlsperger: Subtotal cranial vault remodelling in anterior sagittal suture closure: impact of age on surgical outcome. Int. J. Oral Maxillofac. Surg. 2012; 41: 1232– 1237. # 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Isolated fusion of the sagittal suture is usually treated before 1 year of age, but some patients present at a later age. The aim of this study was to evaluate the impact of children’s age on the surgical outcome. The authors investigated 46 patients with isolated nonsyndromic sagittal craniosynostosis limited to the anterior two-thirds of the cranial vault. All patients underwent subtotal cranial vault remodelling, 36 patients (78.3%) before the age of 12 months (mean 8.92 months) and 10 patients after the age of 12 months (mean 15.77 months). Perioperative parameters and measurements of the cephalic index, preoperatively and postoperatively, were evaluated. All 46 patients showed improved head shape independent of their age. In patients younger than 12 months, mean cephalic indices improved from 65.99 to 74.49 (p < 0.0001) and in patients older than 12 months from 66.38 to 74.38 (p < 0.0004). There were no statistical differences in perioperative parameters including length of surgery, intraoperative blood loss and duration of hospital stay. In this study, patients showed no significant differences in surgical outcome that could have been related to the age at surgery. Surgical treatment should be performed early enough to benefit from the remodelling potential of the skull.
Isolated synostosis of the sagittal suture is the most prevalent form of craniosynostosis with a frequency of one case per 2000–4000 live births.1,2 Children with sagittal craniosynostosis have an abnormal skull shape as a result of shortening of the transverse diameter and a compensatory increase in the antero-posterior 0901-5027/01001232 + 06 $36.00/0
diameter. The commonly used term, scaphocephaly, describes this anomaly with a long narrow skull in the antero-posterior plane accompanied by frontal and occipital bossing. Depending on the location of the premature fusion along the sagittal suture, sagittal synostosis is present in many different forms. In particular,
Key words: sagittal synostosis; scaphocephaly; cranial vault remodelling; posterior cranial remodelling technique; pi-procedure. Accepted for publication 24 May 2012 Available online 22 June 2012
anterior sagittal suture closure causes frontal bossing (Fig. 1), which requires extensive craniotomy to correct this compensatory growth of the frontal bone. Several surgical procedures have been described in the treatment of scaphocecraniectphaly including simple strip omy, H-procedure, pi-procedure, vertex
# 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Impact of age on subtotal cranial vault remodelling
1233
Fig. 1. Clinical manifestation of anterior fusion of the sagittal suture with typically shortening of the transverse diameter and a compensatory increase in the antero-posterior diameter with frontal bossing (A). Morphological outcome 2.9 years after surgery (B).
craniectomies and subtotal or total cranial vault remodelling.2–13 As diagnosis is commonly accomplished without difficulty during the first 12 months and surgery in younger children usually results in minimal impairment of brain development and shows optimal bone regeneration14,15 the preferred age for cranial vault expansion is before 1 year of age.16 Some children present at an older age with previously undiagnosed craniosynostosis. Few studies have focused on these older patients, who might be at a higher risk for elevated intracranial pressure or for developing non-healing cranial bone defects. Studies that have focused on the influence of the patient’s age on the surgical outcome have revealed conflicting results.17,18 In the present study, the authors investigated a homogenous study population consisting of 46 patients with isolated nonsyndromic anterior fusion of the sagittal suture. All patients received a standardized surgical procedure. Patients who underwent surgery before the age of 12 months were compared to patients older than 12 months at the time of surgery in terms of surgical outcome, perioperative parameters and postoperative complications.
Patients and methods
In this retrospective study, the authors reviewed 46 patients with a clinical and radiological diagnosis of isolated nonsyndromic sagittal craniosynostis who underwent subtotal cranial vault remodelling between January 2001 and December 2009 at the Department of Maxillofacial Surgery of the University Heidelberg. All review procedures were in strict accordance with general guidelines and an approved application on file at the authors’ institutional review board. Patients with multisuture or syndromic synostosis were excluded. Patients were only included with anterior fusion of the sagittal suture with frontal bossing to standardize the required surgical procedure. Patients were separated according to their age at surgery and patients who were younger than 12 months at the time of surgery (n = 36) were compared to patients who underwent surgery when they were older than 12 months (n = 10). The following data were collected: patient’s sex, age at primary surgery, length of operation, length of hospital stay, signs and symptoms of increased intracranial pressure, postoperative complications, incidence of residual cranial bone defects and preoperative and
postoperative head shape as measured by the cephalic index (CI). For the postoperative CI, the CI measured at the last clinical appointment (average follow-up of 54 months) was chosen, to provide information on the long term follow-up of the surgery performed. The CI was calculated from anthropomorphic measurements obtained in the clinic and is defined as the widest dimension of the cranium divided by the maximal length of the cranium multiplied by 100. The perioperative blood loss was calculated using the method previously described by Brecher et al.19 Aesthetic outcome was rated by the surgeon and the patient’s parents and rated as excellent if both parents and surgeon were satisfied, good if only the parents were satisfied and poor if both the parents and the physician were not satisfied. The Whitaker classification was used to evaluate the surgical results (Table 1).20 Neurodevelopmental delays were assessed preoperatively using the BSID II (Bayley Scales of Infant Developmental Second Edition), a tool to measure the infant cognitive and motor development standardized for ages from 1 to 42 months.21 Student’s t test was used to compare continuous variables and p-values < 0.05 were considered significant. All statistical
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Table 1. Whitaker classification of surgical results.20 Class 2 Soft-tissue or lesser bone-contouring revisions advisable apt to be performed on an outpatient basis or requiring a maximum 2 day hospitalization Class 3 Major alternative osteotomies or bone grafting procedure advisable (orbital repositions, onlay bone grafts are not as extensive as the original operations) Class 4 A major craniofacial procedure is advisable, duplicating or exceeding the original operation
analyses were performed using SPSS for Windows version 12.0 (SPSS, Chicago, USA). The operative procedures were undertaken in association with the neurosurgery team at the authors’ institution. Surgery was performed using a modified surgical procedure originally described by Jane et al.6 This method uses intraoperative longitudinal compression to shorten the skull dynamically. Of key importance is that the operation focuses more on the areas of compensatory growth than the excision of the pathological sagittal suture. All procedures were carried out through a coronal waveline incision to reduce scar visibility.
First, biparietal flaps were fashioned, which extended from the coronal sutures to the lambdoid sutures (Fig. 2A). Second, an osteotomy of the coronal suture is performed, leaving a craniotomy in the shape of the Greek letter pi (Fig. 2A). Before the remaining bone elements are brought together, the sagittal sinus must be separated from the overlying bone. As only cases with pronounced frontal bossing were included in this study, the frontal bone was removed after osteotomy approximately 10 mm above the N. supraorbitales and reshaped through radial osteotomies to harmonise the fronto-orbital region (Fig. 2B). When
the remaining bone elements were reapproximated, the skull length was shortened and actively widened and the frontal bossing was reduced. An even greater shortening of the skull length was achieved by excision of approximately 15 mm of the remaining sagittal bone element before re-approximation. In patients who were operated on between 2001 and 2007, bone elements were refixed with titanium plates, which were removed 6 months after surgery in a second operation. Since 2008, only resorbable mini- or microplates have been used, to avoid a second operation. Results
46 children with isolated nonsyndromic sagittal craniosynostosis underwent subtotal cranial vault remodelling; 37 were male (80.4%) and 9 female (19.6%). Follow-up after surgery ranged from 9.3 to 174.4 months, with an average follow-up of 54 months. Children were divided into
Fig. 2. Modified technique of the pi-procedure with osteotomy lines (A) and final vault remodelling (B).
Impact of age on subtotal cranial vault remodelling
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Table 2. Perioperative data. <12 months (n = 36)
p-Value Body weight [g] Age at surgery [months] Duration of operation [min] Intraoperative blood loss [% of estimated blood volume] Duration of postoperative hospital stay [days] Follow-up [month]
n.s. <0.0001 n.s. n.s. n.s. n.s.
two groups according to their age at surgery with 12 months being the cut off point. 36 patients underwent surgery before the age of 12 months (mean 8.9 months, range 3.1– 11.6 months), and 10 underwent surgery aged over 12 months (mean 15.8 months, range 12.3–19.4 months). Perioperative data for both groups are shown in
>12 months (n = 10)
Mean
Range
SD
Mean
Range
SD
8996 8.91 145 43.74
6000–11000 3.10–11.63 65–240 13.89–111.9
1226 1.86 41 23.03
8474 15.77 130 46.64
6220–11800 12.30–19.40 65–185 23.31–70.99
1865 2.73 34.64 14.22
6.28 54
4–10 9.33–174.37
1.23 36
Table 2. Intraoperative blood loss was calculated using the method described by Brecher et al.19 as percentage of the estimated blood volume. There was no statistical difference in blood loss as percentage of estimated blood volume in both groups (p = 0.708). The operation time for cranial remodelling did not differ statistically for
Fig. 3. Distribution of pre- and postoperative CI. In patients younger than 12 months at the time of surgery mean CI improved from 65.99 to 74.49 (p < 0.0001) (A) and in patients older than 12 months from 66.38 to 74.38 (p < 0.0004) (B). Postoperative CI was measured at the last clinical examination (average follow-up of 54 month).
7.2
5–12
1.93
62.82
22.83–120.70
30.12
both groups (p = 0.604) and there were no significant differences in hospital stay in both groups (p = 0.073). Preoperative and postoperative CI measurements were obtained by anthropomorphic measurements. In both groups, surgical intervention significantly improved the CI. In patients younger than 12 months, mean CI improved from 65.99 to 74.49 (p < 0.0001) (Fig. 3A) and in patients older than 12 month from 66.38 to 74.38 (p < 0.0004) (Fig. 3B). The difference between preoperative and postoperative CI in patients younger than 12 months (8.5%) did not differ statistically from the difference in CI in patients older than 12 months (8.0%). According to the Whitaker classification, in patients younger than 12 months, 27 patients had a Class 1 outcome, with excellent surgical results, 4 patients were defined as Class 2 and 1 patient as Class 3 (Table 3). Four patients were Class 4 which required a second operation because of a recurrence of scaphocephaly; they showed a good surgical result in their follow up. In patients who were older than 12 months at surgery, 8 patients showed a Class 1 outcome, 1 had Class 2 and 1 had Class 3. No patients were defined as Class 4 (Table 4). Regarding aesthetic outcome, in patients younger than 12 months, 32 showed an excellent (n = 27) or good (n = 5) aesthetic result. The four patients with Whitaker Class 4 had poor aesthetic results (Table 3). In the patients older than 12 months all 10 patients showed an excellent (n = 8) or good (n = 2) aesthetic result (Table 4). In both groups, no death, postoperative bleeding, cerebrospinal fluid leak or sagittal sinus injury were observed. In the patients younger than 12 months, 4 small dural tears were discovered and treated intraoperatively with primary closure. Using the BSID II,21 3 patients older than 12 months showed preoperative mental and/or motor developmental delays, compared to 5 patients younger than 12 months at the time of surgery. One patient in each group showed papilloedema indicating increased intracranial pressure. One
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Table 3. Results according to the Whitaker classification and cosmetic results judged by the families and the craniofacial team of patients younger than 12 months at the time of surgery (total number of patients = 36). n = 36 Whitaker Whitaker Whitaker Whitaker
1 2 3 4
(n = 27) (n = 4) (n = 1) (n = 4)
Excellent (n = 27)
Good (n = 5)
Poor (n = 4)
24 3 0 0
3 1 1 0
0 0 0 4
Table 4. Results according to the Whitaker classification and cosmetic results judged by the families and the craniofacial team for patients older than 12 months at the time of surgery (total number of patients = 10). n = 10 Whitaker Whitaker Whitaker Whitaker
Excellent (n = 8) 1 2 3 4
(n = 8) (n = 1) (n = 1) (n = 0)
8 0 0 0
patient who underwent surgery when over 12 months of age, developed a non-healing calvarial bone defect, which required a second operation. In the group that received surgery before the age of 12 months, two patients showed a bone defect, of which only one agreed to additional surgical treatment. In 4 patients who were operated on before the age of 12 months, a second operation had to be performed because of a recurrence of scaphocephaly, while there was no recurrence in the patients older than 12 months at the time of surgery. Discussion
Despite numerous studies, the surgical treatment of sagittal synostosis is still controversial.2–13 Regardless of the operative technique, most authors recommend, that surgery should be performed before patients reach 1 year of age, for presumed improved aesthetic and functional outcomes, due to the pliability of the infant skull.14 Although diagnosis of craniosynostosis is commonly accomplished without difficulty during the first 12 months, sometimes older patients are referred to craniofacial centres. Hence, the authors investigated the influence of children’s age on the surgical outcome in a homogenous study population consisting of only isolated non-syndromic fusion of the sagittal suture. They only included patients, in whom the fusion was located at the anterior part of the sagittal suture to standardize the operative technique used. All patients received subtotal cranial vault remodelling using a modified pi-procedure, originally described by Jane et al.6 and patients who were operated on before
Good (n = 2) 0 1 1 0
Poor (n = 0) 0 0 0 0
the age of 12 months were compared to patients who were operated on after the age of 12 months. Regardless of the age, the change of preoperative and postoperative CI was statistically significant in this study. The difference between preoperative and postoperative CI in patients younger than 12 months (8.5%) did not differ statistically from the difference in CI in patients older than 12 months (8.0%). The aesthetic outcome was comparable, as 88.9% of patients younger than 12 months and 100% of patients older than 12 months showed an excellent or good aesthetic outcome. As surgical treatment of craniosynostosis at older ages often requires more extensive cranial remodelling procedures,22 the authors investigated perioperative parameters indicative of the surgical extent. In this study, duration of operation, intraoperative blood loss or duration of hospital stay as indicators of the extent of surgery did not differ statistically in patients older or younger than 12 months (Table 2). Arnaud et al. have demonstrated that patients with craniosynostosis presenting after 1 year of age more often have increased intracranial pressure and inferior developmental outcomes23 and that patients presenting after 1 year of age showed a worse mental outcome when compared with patients who underwent surgery before 1 year of age.24 Rottgers et al. investigated intracranial hypertension in 60% of older patients with sagittal craniosynostosis with an average age of 1.75 years.25 In the present study, one patient with papilloedema as a clinical sign for increased intracranial pressure was found in each group. 3 patients (30%) older than 12 months showed
preoperative mental and/or motor developmental delays, compared to 5 patients (13.9%) younger than 12 months at the time of surgery. Although patients older than 12 months showed a higher percentage of papilloedema and developmental delays, with respect to the small sample size of the present study, the authors could not confirm, that delayed correction of craniosynostos increases the risk for raised intracranial pressure and developmental delays. As the ability to close large calvarial defects diminishes in the late first year of life, there is an increasingly lower probability of defect closure after 12 months.26 In this study, 1 patient (10%) who underwent surgery aged over 12 months developed a nonhealing calvarial bone defect. In the group that received surgery before the age of 12 months, 2 patients (5.5%) showed a bone defect. Children after the age of 11 months show an increasingly lower probability of closure compared to younger children.26 In the study by Rottgers et al., no patients had clinically significant or palpable bony defects after surgical treatment in older patients with sagittal craniosynostosis25; they used bone-grafting techniques. The incidence of resynostosis after surgical treatment of craniosynostosis is not well documented. Foster et al.17 found significantly lower resysnostosis rates in children who underwent surgery before the age of 12 months (2 of 79, 2.5%) compared to children who underwent surgery aged over 12 months (6 of 40, 15%). In the present study, 4 patients (11.1%) patients showed resynostosis when the primary operation occurred before the age of 12 months, compared to no resynostosis in patients who underwent surgery after the age of 12 months. Foster et al. included patients with both syndromic and non-syndromic craniosynostosis and only 2 patients with resynostosis had an isolated fusion of the sagittal suture. They suggested that with increasing age craniosynostosis presents greater inability to be corrected completely. Wall et al. demonstrated a higher rate of reoperation in children who underwent primary surgery before the age of 6 months18 as 11 of 56 (19.6%) of the children operated on before the age of 6 months needed reoperation compared to 6 of 163 (3.7%) when surgery was performed after 6 months of age. In conclusion, surgical treatment of sagittal craniosynostosis in patients after the age of 12 months is uncommon. According to others, children older than 12 months often require more extensive
Impact of age on subtotal cranial vault remodelling surgery to correct their deformity, which was not confirmed in the present study. All patients regardless of their age showed a significant improvement in head shape as evaluated by the change of the CI and in the majority of cases an excellent or good aesthetic result was achieved. Although this study does not provide enough evidence to determine the ideal timing for correction of sagittal suture closure, the authors recommend, that surgery should be performed early enough to benefit from the remodelling potential of the growing brain, but late enough to avoid resynostosis and unnecessary reoperation due to reysnostosis. Funding
5.
6.
7.
8.
9.
None. Competing interests
10.
None declared. Ethical approval
11.
Ethical approval was given by ‘EthikKommission der Medizinischen Fakulta¨t des Universita¨tsklinikums Heidelberg’. References 1. Fearon JA, Ruotolo RA, Kolar JC. Single sutural craniosynostoses: surgical outcomes and long-term growth. Plast Reconstr Surg 2009;123:635–42. 2. Moon SH, Paik HW, Byeon JH. Treatment of sagittal synostosis: subtotal cranial vault remodelling with right-angled Z-osteotomies. J Plast Reconstr Aesthet Surg 2010;63:1787–93. 3. Amm CA, Denny AD. Correction of sagittal synostosis using foreshortening and lateral expansion of the cranium activated by gravity: surgical technique and postoperative evolution. Plast Reconstr Surg 2005;116:723–35. 4. Antunez S, Arnaud E, Cruz A, Marchac D, Renier D. Scaphocephaly: Part I: Indices for scaphocephalic frontal and occipital morphology evaluation: long-term results.
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J Craniofac Surg 2009;20(Suppl. 2): 1837–42. Epstein N, Epstein F, Newman G. Total vertex craniectomy for the treatment of scaphocephaly. Childs Brain 1982;9:309–16. Jane JA, Edgerton MT, Futrell JW, Park TS. Immediate correction of sagittal synostosis, 1978. J Neurosurg 2007;107:427–32. Jimenez DF, Barone CM, McGee ME, Cartwright CC, Baker CL. Endoscopy-assisted wide-vertex craniectomy, barrel stave osteotomies, and postoperative helmet molding therapy in the management of sagittal suture craniosynostosis. J Neurosurg 2004;100: 407–17. Lane LC. Pioneer craniectomy for relief of mental imbecility due to premature sutural clo-sure and microcephalus. J Am Med Assoc 1892;XVIII:49–50. Lannelongue M. De la craniectomie dans la microce´phalie. Compt Rend Seances Acad Sci 1890:1382–5. Marchac D, Renier D. Les scaphocephalies. In: Marchac D, Renier D, editors. Chirurgie Craniofaciale des Craniostenoses. Paris: Medecine et Sciences Internationales; 1982. p. 79–82. Marsh JL, Jenny A, Galic M, Picker S, Vannier MW. Surgical management of sagittal synostosis. A quantitative evaluation of two techniques. Neurosurg Clin N Am 1991; 2:629–40. Venes JL, Sayers MP. Sagittal synostectomy. J Neurosurg 1976;44:390–2. [Technical note]. Vollmer DG, Jane JA, Park TS, Persing JA. Variants of sagittal synostosis: strategies for surgical correction. J Neurosurg 1984;61: 557–62. Jane Jr JA, Lin KY, Jane Sr JA. Sagittal synostosis. Neurosurg Focus 2000;9:e3. Jane Sr JA, Jane Jr JA. Treatment of craniosynostosis. Clin Neurosurg 1996;43:139–62. Hudgins RJ, Cohen SR, Burstein FD, Boydston WR. Multiple suture synostosis and increased intracranial pressure following repair of single suture, nonsyndromal craniosynostosis. Cleft Palate Craniofac J 1998;35:167–72. Foster T, Perinpanayagam H, Pfaffenbach A, Certo M. Recurrence of early childhood caries after comprehensive treatment with
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general anesthesia and follow-up. J Dent Child (Chicago) 2006;73:25–30. Wall SA, Goldin JH, Hockley AD, Wake MJ, Poole MD, Briggs M. Fronto-orbital reoperation in craniosynostosis. Br J Plast Surg 1994;47:180–4. Brecher ME, Monk T, Goodnough LT. A standardized method for calculating blood loss. Transfusion 1997;37:1070–4. Whitaker LA, Bartlett SP, Schut L, Bruce D. Craniosynostosis: an analysis of the timing, treatment, and complications in 164 consecutive patients. Plast Reconstr Surg 1987;80:195–212. Bayley N. Bayley scales of infant development: manual. 2nd ed. Orlando: Psychological Corporation; 1993. Weinzweig J, Baker SB, Whitaker LA, Sutton LN, Bartlett SP. Delayed cranial vault reconstruction for sagittal synostosis in older children: an algorithm for tailoring the reconstructive approach to the craniofacial deformity. Plast Reconstr Surg 2002;110: 397–408. Arnaud E, Renier D, Marchac D. Prognosis for mental function in scaphocephaly. J Neurosurg 1995;83:476–9. Arnaud E, Meneses P, Lajeunie E, Thorne JA, Marchac D, Renier D. Postoperative mental and morphological outcome for nonsyndromic brachycephaly. Plast Reconstr Surg 2002;110:6–12. [discussion 13]. Rottgers SA, Kim PD, Kumar AR, Cray JJ, Losee JE, Pollack IF. Cranial vault remodeling for sagittal craniosynostosis in older children. Neurosurg Focus 2011;31:E3. Paige KT, Vega SJ, Kelly CP, Bartlett SP, Zakai E, Jawad AF, et al. Age-dependent closure of bony defects after frontal orbital advancement. Plast Reconstr Surg 2006; 118:977–84.
Address: Michael Engel Department of Oral and Maxillofacial Surgery University Hospital Heidelberg Im Neuenheimer Feld 400 69120 Heidelberg Germany E-mail: [email protected]
Leading Clinical Paper Craniofacial Anomalies
Subtotal cranial vault remodelling in anterior sagittal suture closure: impact of age on surgical outcome
M. Engel, J. Hoffmann, J. Mu¨hling, G. Castrillo´n-Oberndorfer, R. Seeberger, C. Freudlsperger Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Germany
M. Engel, J. Hoffmann, J. Mu¨hling, G. Castrillo´n-Oberndorfer, R. Seeberger, C. Freudlsperger: Subtotal cranial vault remodelling in anterior sagittal suture closure: impact of age on surgical outcome. Int. J. Oral Maxillofac. Surg. 2012; 41: 1232– 1237. # 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Isolated fusion of the sagittal suture is usually treated before 1 year of age, but some patients present at a later age. The aim of this study was to evaluate the impact of children’s age on the surgical outcome. The authors investigated 46 patients with isolated nonsyndromic sagittal craniosynostosis limited to the anterior two-thirds of the cranial vault. All patients underwent subtotal cranial vault remodelling, 36 patients (78.3%) before the age of 12 months (mean 8.92 months) and 10 patients after the age of 12 months (mean 15.77 months). Perioperative parameters and measurements of the cephalic index, preoperatively and postoperatively, were evaluated. All 46 patients showed improved head shape independent of their age. In patients younger than 12 months, mean cephalic indices improved from 65.99 to 74.49 (p < 0.0001) and in patients older than 12 months from 66.38 to 74.38 (p < 0.0004). There were no statistical differences in perioperative parameters including length of surgery, intraoperative blood loss and duration of hospital stay. In this study, patients showed no significant differences in surgical outcome that could have been related to the age at surgery. Surgical treatment should be performed early enough to benefit from the remodelling potential of the skull.
Isolated synostosis of the sagittal suture is the most prevalent form of craniosynostosis with a frequency of one case per 2000–4000 live births.1,2 Children with sagittal craniosynostosis have an abnormal skull shape as a result of shortening of the transverse diameter and a compensatory increase in the antero-posterior 0901-5027/01001232 + 06 $36.00/0
diameter. The commonly used term, scaphocephaly, describes this anomaly with a long narrow skull in the antero-posterior plane accompanied by frontal and occipital bossing. Depending on the location of the premature fusion along the sagittal suture, sagittal synostosis is present in many different forms. In particular,
Key words: sagittal synostosis; scaphocephaly; cranial vault remodelling; posterior cranial remodelling technique; pi-procedure. Accepted for publication 24 May 2012 Available online 22 June 2012
anterior sagittal suture closure causes frontal bossing (Fig. 1), which requires extensive craniotomy to correct this compensatory growth of the frontal bone. Several surgical procedures have been described in the treatment of scaphocecraniectphaly including simple strip omy, H-procedure, pi-procedure, vertex
# 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Impact of age on subtotal cranial vault remodelling
1233
Fig. 1. Clinical manifestation of anterior fusion of the sagittal suture with typically shortening of the transverse diameter and a compensatory increase in the antero-posterior diameter with frontal bossing (A). Morphological outcome 2.9 years after surgery (B).
craniectomies and subtotal or total cranial vault remodelling.2–13 As diagnosis is commonly accomplished without difficulty during the first 12 months and surgery in younger children usually results in minimal impairment of brain development and shows optimal bone regeneration14,15 the preferred age for cranial vault expansion is before 1 year of age.16 Some children present at an older age with previously undiagnosed craniosynostosis. Few studies have focused on these older patients, who might be at a higher risk for elevated intracranial pressure or for developing non-healing cranial bone defects. Studies that have focused on the influence of the patient’s age on the surgical outcome have revealed conflicting results.17,18 In the present study, the authors investigated a homogenous study population consisting of 46 patients with isolated nonsyndromic anterior fusion of the sagittal suture. All patients received a standardized surgical procedure. Patients who underwent surgery before the age of 12 months were compared to patients older than 12 months at the time of surgery in terms of surgical outcome, perioperative parameters and postoperative complications.
Patients and methods
In this retrospective study, the authors reviewed 46 patients with a clinical and radiological diagnosis of isolated nonsyndromic sagittal craniosynostis who underwent subtotal cranial vault remodelling between January 2001 and December 2009 at the Department of Maxillofacial Surgery of the University Heidelberg. All review procedures were in strict accordance with general guidelines and an approved application on file at the authors’ institutional review board. Patients with multisuture or syndromic synostosis were excluded. Patients were only included with anterior fusion of the sagittal suture with frontal bossing to standardize the required surgical procedure. Patients were separated according to their age at surgery and patients who were younger than 12 months at the time of surgery (n = 36) were compared to patients who underwent surgery when they were older than 12 months (n = 10). The following data were collected: patient’s sex, age at primary surgery, length of operation, length of hospital stay, signs and symptoms of increased intracranial pressure, postoperative complications, incidence of residual cranial bone defects and preoperative and
postoperative head shape as measured by the cephalic index (CI). For the postoperative CI, the CI measured at the last clinical appointment (average follow-up of 54 months) was chosen, to provide information on the long term follow-up of the surgery performed. The CI was calculated from anthropomorphic measurements obtained in the clinic and is defined as the widest dimension of the cranium divided by the maximal length of the cranium multiplied by 100. The perioperative blood loss was calculated using the method previously described by Brecher et al.19 Aesthetic outcome was rated by the surgeon and the patient’s parents and rated as excellent if both parents and surgeon were satisfied, good if only the parents were satisfied and poor if both the parents and the physician were not satisfied. The Whitaker classification was used to evaluate the surgical results (Table 1).20 Neurodevelopmental delays were assessed preoperatively using the BSID II (Bayley Scales of Infant Developmental Second Edition), a tool to measure the infant cognitive and motor development standardized for ages from 1 to 42 months.21 Student’s t test was used to compare continuous variables and p-values < 0.05 were considered significant. All statistical
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Engel et al.
Table 1. Whitaker classification of surgical results.20 Class 2 Soft-tissue or lesser bone-contouring revisions advisable apt to be performed on an outpatient basis or requiring a maximum 2 day hospitalization Class 3 Major alternative osteotomies or bone grafting procedure advisable (orbital repositions, onlay bone grafts are not as extensive as the original operations) Class 4 A major craniofacial procedure is advisable, duplicating or exceeding the original operation
analyses were performed using SPSS for Windows version 12.0 (SPSS, Chicago, USA). The operative procedures were undertaken in association with the neurosurgery team at the authors’ institution. Surgery was performed using a modified surgical procedure originally described by Jane et al.6 This method uses intraoperative longitudinal compression to shorten the skull dynamically. Of key importance is that the operation focuses more on the areas of compensatory growth than the excision of the pathological sagittal suture. All procedures were carried out through a coronal waveline incision to reduce scar visibility.
First, biparietal flaps were fashioned, which extended from the coronal sutures to the lambdoid sutures (Fig. 2A). Second, an osteotomy of the coronal suture is performed, leaving a craniotomy in the shape of the Greek letter pi (Fig. 2A). Before the remaining bone elements are brought together, the sagittal sinus must be separated from the overlying bone. As only cases with pronounced frontal bossing were included in this study, the frontal bone was removed after osteotomy approximately 10 mm above the N. supraorbitales and reshaped through radial osteotomies to harmonise the fronto-orbital region (Fig. 2B). When
the remaining bone elements were reapproximated, the skull length was shortened and actively widened and the frontal bossing was reduced. An even greater shortening of the skull length was achieved by excision of approximately 15 mm of the remaining sagittal bone element before re-approximation. In patients who were operated on between 2001 and 2007, bone elements were refixed with titanium plates, which were removed 6 months after surgery in a second operation. Since 2008, only resorbable mini- or microplates have been used, to avoid a second operation. Results
46 children with isolated nonsyndromic sagittal craniosynostosis underwent subtotal cranial vault remodelling; 37 were male (80.4%) and 9 female (19.6%). Follow-up after surgery ranged from 9.3 to 174.4 months, with an average follow-up of 54 months. Children were divided into
Fig. 2. Modified technique of the pi-procedure with osteotomy lines (A) and final vault remodelling (B).
Impact of age on subtotal cranial vault remodelling
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Table 2. Perioperative data. <12 months (n = 36)
p-Value Body weight [g] Age at surgery [months] Duration of operation [min] Intraoperative blood loss [% of estimated blood volume] Duration of postoperative hospital stay [days] Follow-up [month]
n.s. <0.0001 n.s. n.s. n.s. n.s.
two groups according to their age at surgery with 12 months being the cut off point. 36 patients underwent surgery before the age of 12 months (mean 8.9 months, range 3.1– 11.6 months), and 10 underwent surgery aged over 12 months (mean 15.8 months, range 12.3–19.4 months). Perioperative data for both groups are shown in
>12 months (n = 10)
Mean
Range
SD
Mean
Range
SD
8996 8.91 145 43.74
6000–11000 3.10–11.63 65–240 13.89–111.9
1226 1.86 41 23.03
8474 15.77 130 46.64
6220–11800 12.30–19.40 65–185 23.31–70.99
1865 2.73 34.64 14.22
6.28 54
4–10 9.33–174.37
1.23 36
Table 2. Intraoperative blood loss was calculated using the method described by Brecher et al.19 as percentage of the estimated blood volume. There was no statistical difference in blood loss as percentage of estimated blood volume in both groups (p = 0.708). The operation time for cranial remodelling did not differ statistically for
Fig. 3. Distribution of pre- and postoperative CI. In patients younger than 12 months at the time of surgery mean CI improved from 65.99 to 74.49 (p < 0.0001) (A) and in patients older than 12 months from 66.38 to 74.38 (p < 0.0004) (B). Postoperative CI was measured at the last clinical examination (average follow-up of 54 month).
7.2
5–12
1.93
62.82
22.83–120.70
30.12
both groups (p = 0.604) and there were no significant differences in hospital stay in both groups (p = 0.073). Preoperative and postoperative CI measurements were obtained by anthropomorphic measurements. In both groups, surgical intervention significantly improved the CI. In patients younger than 12 months, mean CI improved from 65.99 to 74.49 (p < 0.0001) (Fig. 3A) and in patients older than 12 month from 66.38 to 74.38 (p < 0.0004) (Fig. 3B). The difference between preoperative and postoperative CI in patients younger than 12 months (8.5%) did not differ statistically from the difference in CI in patients older than 12 months (8.0%). According to the Whitaker classification, in patients younger than 12 months, 27 patients had a Class 1 outcome, with excellent surgical results, 4 patients were defined as Class 2 and 1 patient as Class 3 (Table 3). Four patients were Class 4 which required a second operation because of a recurrence of scaphocephaly; they showed a good surgical result in their follow up. In patients who were older than 12 months at surgery, 8 patients showed a Class 1 outcome, 1 had Class 2 and 1 had Class 3. No patients were defined as Class 4 (Table 4). Regarding aesthetic outcome, in patients younger than 12 months, 32 showed an excellent (n = 27) or good (n = 5) aesthetic result. The four patients with Whitaker Class 4 had poor aesthetic results (Table 3). In the patients older than 12 months all 10 patients showed an excellent (n = 8) or good (n = 2) aesthetic result (Table 4). In both groups, no death, postoperative bleeding, cerebrospinal fluid leak or sagittal sinus injury were observed. In the patients younger than 12 months, 4 small dural tears were discovered and treated intraoperatively with primary closure. Using the BSID II,21 3 patients older than 12 months showed preoperative mental and/or motor developmental delays, compared to 5 patients younger than 12 months at the time of surgery. One patient in each group showed papilloedema indicating increased intracranial pressure. One
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Engel et al.
Table 3. Results according to the Whitaker classification and cosmetic results judged by the families and the craniofacial team of patients younger than 12 months at the time of surgery (total number of patients = 36). n = 36 Whitaker Whitaker Whitaker Whitaker
1 2 3 4
(n = 27) (n = 4) (n = 1) (n = 4)
Excellent (n = 27)
Good (n = 5)
Poor (n = 4)
24 3 0 0
3 1 1 0
0 0 0 4
Table 4. Results according to the Whitaker classification and cosmetic results judged by the families and the craniofacial team for patients older than 12 months at the time of surgery (total number of patients = 10). n = 10 Whitaker Whitaker Whitaker Whitaker
Excellent (n = 8) 1 2 3 4
(n = 8) (n = 1) (n = 1) (n = 0)
8 0 0 0
patient who underwent surgery when over 12 months of age, developed a non-healing calvarial bone defect, which required a second operation. In the group that received surgery before the age of 12 months, two patients showed a bone defect, of which only one agreed to additional surgical treatment. In 4 patients who were operated on before the age of 12 months, a second operation had to be performed because of a recurrence of scaphocephaly, while there was no recurrence in the patients older than 12 months at the time of surgery. Discussion
Despite numerous studies, the surgical treatment of sagittal synostosis is still controversial.2–13 Regardless of the operative technique, most authors recommend, that surgery should be performed before patients reach 1 year of age, for presumed improved aesthetic and functional outcomes, due to the pliability of the infant skull.14 Although diagnosis of craniosynostosis is commonly accomplished without difficulty during the first 12 months, sometimes older patients are referred to craniofacial centres. Hence, the authors investigated the influence of children’s age on the surgical outcome in a homogenous study population consisting of only isolated non-syndromic fusion of the sagittal suture. They only included patients, in whom the fusion was located at the anterior part of the sagittal suture to standardize the operative technique used. All patients received subtotal cranial vault remodelling using a modified pi-procedure, originally described by Jane et al.6 and patients who were operated on before
Good (n = 2) 0 1 1 0
Poor (n = 0) 0 0 0 0
the age of 12 months were compared to patients who were operated on after the age of 12 months. Regardless of the age, the change of preoperative and postoperative CI was statistically significant in this study. The difference between preoperative and postoperative CI in patients younger than 12 months (8.5%) did not differ statistically from the difference in CI in patients older than 12 months (8.0%). The aesthetic outcome was comparable, as 88.9% of patients younger than 12 months and 100% of patients older than 12 months showed an excellent or good aesthetic outcome. As surgical treatment of craniosynostosis at older ages often requires more extensive cranial remodelling procedures,22 the authors investigated perioperative parameters indicative of the surgical extent. In this study, duration of operation, intraoperative blood loss or duration of hospital stay as indicators of the extent of surgery did not differ statistically in patients older or younger than 12 months (Table 2). Arnaud et al. have demonstrated that patients with craniosynostosis presenting after 1 year of age more often have increased intracranial pressure and inferior developmental outcomes23 and that patients presenting after 1 year of age showed a worse mental outcome when compared with patients who underwent surgery before 1 year of age.24 Rottgers et al. investigated intracranial hypertension in 60% of older patients with sagittal craniosynostosis with an average age of 1.75 years.25 In the present study, one patient with papilloedema as a clinical sign for increased intracranial pressure was found in each group. 3 patients (30%) older than 12 months showed
preoperative mental and/or motor developmental delays, compared to 5 patients (13.9%) younger than 12 months at the time of surgery. Although patients older than 12 months showed a higher percentage of papilloedema and developmental delays, with respect to the small sample size of the present study, the authors could not confirm, that delayed correction of craniosynostos increases the risk for raised intracranial pressure and developmental delays. As the ability to close large calvarial defects diminishes in the late first year of life, there is an increasingly lower probability of defect closure after 12 months.26 In this study, 1 patient (10%) who underwent surgery aged over 12 months developed a nonhealing calvarial bone defect. In the group that received surgery before the age of 12 months, 2 patients (5.5%) showed a bone defect. Children after the age of 11 months show an increasingly lower probability of closure compared to younger children.26 In the study by Rottgers et al., no patients had clinically significant or palpable bony defects after surgical treatment in older patients with sagittal craniosynostosis25; they used bone-grafting techniques. The incidence of resynostosis after surgical treatment of craniosynostosis is not well documented. Foster et al.17 found significantly lower resysnostosis rates in children who underwent surgery before the age of 12 months (2 of 79, 2.5%) compared to children who underwent surgery aged over 12 months (6 of 40, 15%). In the present study, 4 patients (11.1%) patients showed resynostosis when the primary operation occurred before the age of 12 months, compared to no resynostosis in patients who underwent surgery after the age of 12 months. Foster et al. included patients with both syndromic and non-syndromic craniosynostosis and only 2 patients with resynostosis had an isolated fusion of the sagittal suture. They suggested that with increasing age craniosynostosis presents greater inability to be corrected completely. Wall et al. demonstrated a higher rate of reoperation in children who underwent primary surgery before the age of 6 months18 as 11 of 56 (19.6%) of the children operated on before the age of 6 months needed reoperation compared to 6 of 163 (3.7%) when surgery was performed after 6 months of age. In conclusion, surgical treatment of sagittal craniosynostosis in patients after the age of 12 months is uncommon. According to others, children older than 12 months often require more extensive
Impact of age on subtotal cranial vault remodelling surgery to correct their deformity, which was not confirmed in the present study. All patients regardless of their age showed a significant improvement in head shape as evaluated by the change of the CI and in the majority of cases an excellent or good aesthetic result was achieved. Although this study does not provide enough evidence to determine the ideal timing for correction of sagittal suture closure, the authors recommend, that surgery should be performed early enough to benefit from the remodelling potential of the growing brain, but late enough to avoid resynostosis and unnecessary reoperation due to reysnostosis. Funding
5.
6.
7.
8.
9.
None. Competing interests
10.
None declared. Ethical approval
11.
Ethical approval was given by ‘EthikKommission der Medizinischen Fakulta¨t des Universita¨tsklinikums Heidelberg’. References 1. Fearon JA, Ruotolo RA, Kolar JC. Single sutural craniosynostoses: surgical outcomes and long-term growth. Plast Reconstr Surg 2009;123:635–42. 2. Moon SH, Paik HW, Byeon JH. Treatment of sagittal synostosis: subtotal cranial vault remodelling with right-angled Z-osteotomies. J Plast Reconstr Aesthet Surg 2010;63:1787–93. 3. Amm CA, Denny AD. Correction of sagittal synostosis using foreshortening and lateral expansion of the cranium activated by gravity: surgical technique and postoperative evolution. Plast Reconstr Surg 2005;116:723–35. 4. Antunez S, Arnaud E, Cruz A, Marchac D, Renier D. Scaphocephaly: Part I: Indices for scaphocephalic frontal and occipital morphology evaluation: long-term results.
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Address: Michael Engel Department of Oral and Maxillofacial Surgery University Hospital Heidelberg Im Neuenheimer Feld 400 69120 Heidelberg Germany E-mail: [email protected]