INTRODUCTION
The early surgical correction of cleft palate generally leads to favorable postoperative speech outcomes. However, submucous cleft palate (SMCP) is often asymptomatic and thus is characterized by delays in diagnosis. Once diagnosed, physicians typically keep patients with this condition under regular follow-up observation, often for long periods of time, before surgical treatment is needed, and thus SMCP tends to be treated surgically later than other types of cleft palate.
The surgical treatment of SMCP is not effective in improving speech performance. The reason for its poor effectiveness has not been conclusively determined, but is probably due to delays in surgical treatment.
In order to objectively evaluate speech performance outcomes and the incidence of complications after the surgical treatment of SMCP, we compared the outcomes of SMCP patients with those of incomplete cleft palate (ICP) patients.
RESULTS
While respiratory difficulty, bleeding, and wound disruption were not observed in any subjects, the SMCP group was slightly more likely to experience complications than the ICP group, with incidence rates of delayed wound healing of 18.9% and 14%, respectively, and incidence rates of fistula of 5.7% and 3.2%, respectively (
Table 3). However, these differences were not statistically significant.
Additional surgical correction was performed for VPD in nine SMCP patients (17%) and seven ICP patients (2.5%). The SMCP group was significantly more likely to require VPD correction than the ICP group (P<0.001).
On the postoperative speech evaluation, the 26 SMCP patients received scores ranging from 35 to 66 (median, 58.8), and the scores of the 62 ICP patients ranged from 27 to 66 (median, 66) (
Table 4). The SMCP group had poorer speech outcomes than the ICP group (P=0.002).
DISCUSSION
The incidence rate of postoperative palatal fistula has been reported to range from 0% to 45%. Emory et al. [
3] found that the rate depended on the experience of the surgeons, while Ahmed et al. [
4] found that it depended on the severity of the cleft, as classified by the Veau system: 0% (0/15) for Veau class I clefts, 12% (6/50) for class II clefts, 22.22% (12/54) for class III clefts, and 45.45% (5/11) for class IV clefts.
In patients with SMCP, Sullivan et al. [
5] reported that the incidence rate of postoperative fistula was 7% (1/15) for Z-plasty, Seagle et al. [
6] found that it was 6% (1/18) for Furlow palatoplasty, and Abyholm [
7] reported that it was 5% (1/19) for Von Langenbeck palatoplasty.
In this study, the incidence of postoperative fistula was found to be 3.2% in the ICP group and 5.7% in the SMCP group, which were similar to the incidence rates reported by previous studies. Although the incidence of fistula was higher in the SMCP group than in the ICP group, no statistically significant difference was observed between the two groups.
Kaplan [
8] suggested that the best time for palate repair is three to six months after birth, and Dorf and Curtin [
9] reported that surgery at approximately the age of one year can have a significant effect on speech abnormalities. Given these age-related outcomes, early palatal closure can lead to good postoperative results. Some researchers insist that similarly to overt cleft palate, SMCP should be surgically treated before the language development period. Pensler and Bauer [
10] argued that surgery should be performed before the age of two years. Chung et al. [
11] contended that early surgical treatment can correct and prevent VPD, because the skeletal structure, which determines the position of the nasopharynx as well as that of the soft tissues, can be an anatomical cause of VPD. In contrast, McWilliams [
12] reported that 44% of SMCP patients had no specific symptoms until they reached adulthood, and Weatherley-White et al. [
13] found that 90% of SMCP patients did not require early surgical treatment. Since some patients with SMCP may have no speech disorders, it is widely accepted that surgical correction should be considered when symptoms of velopharyngeal incompetence are found, during the period from the first diagnosis of VPD until the age of three or four years.
Although conditions such as muscular diastasis were taken into account, the SMCP patients received surgical treatment if they showed speech problems after a certain period of time. Consequently, in this study, the average age of the SMCP patients at the time of surgery was 3.9±1.9 years, which was older than the average age of the ICP patients (1.3±0.9 years). The median speech score value of the SMCP group after surgery was 58.8 (range, 35–66), which was lower than the score of 66 (range, 27–66) of the ICP group. Furthermore, 17% of the SMCP group received additional correction due to VPD sustained after surgery, which was overwhelmingly greater than the 2.5% of the ICP group; therefore, the delayed time of surgery may be considered to be the cause of the relatively poor language development observed in the SMCP group.
However, Park et al. [
14] reported that the postoperative results of SMCP repair were not significantly affected by age. In our experience, SMCP often manifests as extremely thin mucous membranes, scant submucosal tissue, and poor development of the levator muscle. Thus, in our study, differences in the anatomical structure between the groups can also be considered one of the causes of the poor speech performance observed in the SMCP group.
Ideally, further research should be conducted that strictly controls for the variables of age, surgical method, and operating surgeon in order to definitively identify the causes of poor speech performance in patients treated for SMCP. In Korea, a country with high accessibility to healthcare and a well-functioning system of prenatal diagnosis, the majority of cleft palate patients visit the hospital in the early stage of the condition. Currently, however, the generally accepted guideline is to decide upon surgery after follow-up observation of the occurrence of problems in feeding, otology, or speech, which might, on average, result in later treatment for SMCP patients than for ICP patients. Performing surgery in SMCP patients in the early stage of their condition simply in order to compare them with ICP patients would be ethically questionable. Given this reality, we conducted a study restricted to patients less than 10 years of age in order to overcome these limitations in the study design as much as possible.
The strengths of this study are also worth noting; namely, a single surgeon performed operations in two relatively large groups and reviewed the results using an objective metric.
In conclusion, although the incidence rate of complications was slightly higher in the SMCP group than in the ICP group, no statistically significant difference was observed. SMCP was more likely to require additional VPD correction and was associated with poorer postoperative speech outcomes than ICP.