Examples of synostoses include: craniosynostosis being an abnormal fusion of two or more cranial bones.
Craniosynostosis causes significant cranial deformity in the pediatric population.
In 1791, S. Soemmering, a German physiologist, anatomist, and anthropologist, admitted that premature fusion of the cranial suture played a significant role in pathogenesis of craniosynostosis.
Virchow R., (1859) defines the craniosynostoses as early closure of the sutures followed by secondary skull deformities that follow a law that says “the normal bone growth is inhibited on the orthogonal direction relative to the closed suture; a compensatory bone growth develops in parallel with the closed suture”.
Virchow’s law partly maintains its validity today. Virchow’s craniosynostose classification chart is still of reference today. However, the early closure of a suture may not always result in a compensatory bone growth. On this ground, the early closure of the sutures should not be defined by the secondary deformity but by the suture or the sutures that were affected 1).
Notably, craniosynostosis was earlier considered to be an incurable disease and was not of no interest for surgeons. Currently, taking into account the modern methods for diagnostics and treatment, the tactics for this pathology have been significantly changed. There is a clear trend for early diagnosis; earliest possible correction of craniosynostosis is considered to be crucial. Over than a century of surgical treatment of this pathology, multiple surgical techniques have been proposed for different types of craniosynostosis; some of them have been proposed by Russian surgeons. Several of these methods are still used in clinics.
Craniosynostosis has an incidence of 1 in 2000 to 2500 live births 2).
Craniosynostosis can occur as an isolated event resulting in nonsyndromic craniosynostosis, or it can occur in conjunction with other anomalies in well-defined patterns that make up clinically recognized syndromes.
Therefore, it is strongly desirable to use low-invasive techniques. The endoscopic method is a low-invasive technique used for surgical correction of craniosynostosis, which should be preferred for treating this pathology in children 5) 6).
Open and endoscopic-assisted surgeries have led to increasingly successful management of this condition. Following surgical reconstruction, subsequent development of postnatal synostosis of previously patent sutures have been described and noted to be most frequently associated with multisuture synostosis patients with syndromic diagnoses. Very rarely, postsurgical new sutural fusion has been identified in nonsyndromic patients who initially present with isolated single-suture synostosis.
Three (2.1%) of 145 patients undergoing open craniosynostosis surgery and 2 (1.7%) of 121 patients undergoing endoscopic surgery developed delayed fusion of an additional suture during follow-up. This was identified at a median of 16.4 months after initial surgery in the open group and 15.25 months after surgery in the endoscopic group. In patients undergoing open surgery, each patient developed new sagittal synostosis after initial presentation of coronal synostosis in 1 patient and metopic synostosis in 2 patients. In patients undergoing endoscopic surgery, each patient developed new coronal synostosis after sagittal repair.
Management of craniosynostosis has evolved over time with increasing availability of effective and safe treatments. During long-term follow-up, a small number of patients may develop premature closure of a different suture that did not undergo surgical manipulation.
This finding supports the necessity of long-term clinical follow-up and the utility of delayed imaging when clinical suspicion indicates 7).
A retrospective review was conducted on craniosynostosis patients who had invasive intracranial pressure measurement and at least one pattern visual evoked potentials test. Reversal pattern visual evoked potentials were performed with both eyes open. Thirteen patients met the inclusion criteria (mean age at intracranial pressure measurement, 5.7 years). Seven patients had raised intracranial pressure, and of these, five (71.4 percent) had abnormal or deteriorated pattern visual evoked potentials parameters on serial testing, whereas all patients (100 percent) with normal intracranial pressure had normal pattern visual evoked potentials amplitude and latency. Four of the five patients (80 percent) with raised intracranial pressure and abnormal pattern visual evoked potentials did not show evidence of papilledema. The mean latency in patients with raised intracranial pressure (118.7 msec) was longer than in those with normal intracranial pressure (108.1 msec), although it did not reach statistical significance (p = 0.09), whereas the mean amplitude in patients with raised intracranial pressure (12.4 µV) was significantly lower than in patients with normal intracranial pressure (23.3 µV) (p = 0.03). The authors' results showed that serial pattern visual evoked potentials testing was able to detect visual pathway dysfunction resulting from raised intracranial pressure in five of seven craniosynostosis patients, and of these five patients, 80 percent had no evidence of papilledema, demonstrating the utility of serial pattern visual evoked potentials in follow-up of the visual function in craniosynostosis patients. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Diagnostic, II 8).
Of 3415 patients, 65.8% were White, 21.4% were Hispanic, and 3.2% were Black. More than 96% were treated at urban teaching hospitals and 54.2% in southern or western regions. White patients were younger (mean 6.1 months) as compared with Blacks (mean 10.9 months) and Hispanics (mean 9.1 months; p < 0.0001) at the time of surgery. A higher fraction of Whites had private insurance (70.3%) compared with nonwhites (34.0%-41.6%; p < 0.001). Approximately 12.2% were nonelective admissions, more so among Blacks (16.9%). Mean hospital length of stay (LOS) was 3.5 days with no significant differences among races. Following surgical treatment, 12.1% of patients developed complications, most commonly pulmonary/respiratory (4.8%), wound infection (4.4%), and hydrocephalus (1.4%). The mean overall hospital charges were significantly lower for Whites than nonwhites ($34,527 vs $44,890-$48,543, respectively; p < 0.0001).
The findings of this national study suggest a higher prevalence of craniosynostosis in Hispanics. The higher predisposition among males was less evident in Hispanics and Blacks. There was a significant percentage of nonelective admissions, more commonly among Blacks. Additionally, Hispanics and Blacks were more likely to receive surgery at an older age, past the current recommendation of the optimum age for surgical intervention. These findings are likely associated with a lack of early detection. Although mean LOS and rate of complications did not significantly differ among different races, nonwhites had, on average, higher hospital charges of $10,000-$14,000. This discrepancy may be due to differences in type of insurance, craniosynostosis type, rates of comorbidities, and delay in treatment. Although there are several limitations to this analysis, the study reports on relevant disparities regarding a costly neurosurgical intervention, and ways to diminish these disparities should be further explored 9).