The cleft palate is one of the most common craniofacial anomalies which requires a multidisciplinary treatment approach. Physiotherapy, nutrition, orthodontic management, and speech therapy can improve the quality of life of patients with cleft palate. Primary palatoplasty is usually recommended at early ages which ultimately leads to the return of the natural speech production mechanism. In palatoplasty, tension-free two-layer closure of oral cavities without penetration of water and fluids reduces the risk of the oronasal fistula. The repair will be effective when less tension is exerted on the oral layers (24). The success criteria of primary palatoplasty are the rate of oronasal fistula, Velopharyngeal insufficiency (VPI), and achievement of natural speech. In present study, we achieved the success criteria of the primary palatoplasty with intravelar veloplasty. Because the incidence of infection and wound dehiscence in each group was zero. In addition no fistula was reported in 63 of our patients after surgery.
Epidemiological studies of the cleft palate prevalence found that boys more than girls are likely to have this disorder (26). In the present study, fistula was observed in five boys and three girls' patients with a cleft greater than 15 mm.
Clark et al. in 2003 reported the use of ADM in primary palatoplasty. In a retrospective study, they investigated patients with a cleft palate greater than 15 mm who were candidates for palatoplasty and were subjected to two-flaps intravelar veloplasty using ADM. The result was completely successful in all patients. In two patients ADM was exposed but fistula was not formed (27). In our current study, out of 35 patients with a cleft palate greater than 15 mm who received ADM, twenty six had successful treatment.
In recent years, improvements have been made in the management of palatoplasty techniques and the timing to do a surgery leading to a decrease in the incidence of oronasal fistulas after primary palatoplasty. One of the studies that investigated the use of ADM in plastic surgeries was the 2012 retrospective case-series study by Aldekhayel et al. fistula incidence using ADM was estimated 7.1%. While recurrence of oronasal fistula using ADM was reported 11% (28). In our study recurrence of oronasal fistula was 8.3%.
When the use of ADM was first proposed for cleft palate surgery, successful results were observed in a small group of patients. A few years later, Kirschner in an empirical study in 2006 presented the results of using ADM to repair cleft palate fistulas. Four other studies assessed the applicability and utility of using ADM to prevent the occurrence of fistula in the primary palatoplasty (29).
Helling et al. described 32 surgeries for primary closure of cleft using the Furlow technique. In these surgeries, ADM was placed in junction between hard and soft palate. In 97% of cases the cleft was successfully closed. Only one of the patients had an oronasal fistula (30). Our therapeutic research team achieved similar results. The closure success rate was about 92%, and only three ADM recipient who had a cleft more than 15 mm in size and engagement of both soft and hard palate developed fistula after six months.
The largest collection of information about the use of ADM in the primary palatoplasty was published by Losee et al. in 2008. In order to close the cleft in these patients, Furlow palatoplasty with ADM and an algorithmic approach that would provide proper stable repair and also close the nasal cavity was used. The size of the cleft was not mentioned in this study; however, the closure of the cleft was achieved in 92.2% of the patients, and in only 4 (7.8%) cases, failure to close the cleft and occurrence of fistula was observed. The use of ADM in tenuous repair and the closure of the cleft and nasal defect resulted in satisfactory results (31). Although the evidence presented in this study confirms the results of our study, the differences in the type of palatoplasty technique in these two studies can be controversial. Govshievich et al. in 2015 reported using ADM in the Furlow selective surgical procedure reduces fistula. In contrast, in a group of patients who were candidates for receiving ADM based on the size of the cleft (patients who had a cleft less than 15 mm had surgeries without ADM use) have more fistulas (32).
Aziz et al. in 2011 published the results of their study in which 3 patients were treated with intravelar veloplasty using ADM. This bond was placed between the muscle and the oral mucosa. The overall width of the cleft was 13.3 mm, and all patients improved without fistula formation (33). The success rate of cleft repair using ADM in our 12 patients with a cleft less than 15 mm was 100%. Our results are consistent with the aziz’s study.
Gilardino et al. in 2018 in a prospective study conducted on 130 patients undergoing primary palatoplasty stated that the incidence of fistula in the study group using ADM was 1.5% versus 12.3% in the control group. The results of this study showed strong evidence of the positive effect of using ADM in the development of fistula following primary palatoplasty (25) .
Agir et al. in 2015, described the different methods of palatoplasty which were improved using ADM in 35 different patients. The average size of the cleft was 15 mm and in the subsequent examination 3 patients had fistulas. Although there was no strong evidence of routine use of ADM as primary palatoplasty; however, retrospective studies shows the advantage of using this method and other methods (26).
Hudson et al. in 2015, in a five year retrospective study assessed 6 patients who had a 10 mm cleft palate in average and had the primary palatoplasty with ADM. After one year of surgery, no fistula was seen in patients (34).
Winter et al. Performed 34 cleft reconstruction surgeries using ADM. Furlow palatoplasty was used for 5 patients and for other patients the intravelar veloplasty was used. Finally, the fistula formation was 6% (35).
Although the results of studies are not in favor of ADM, its use is increasing in recent years  the type and degree of the initial cleft palate seems to lead to the fistula reoccurrence. Since the results of this study showed a significant difference in the success of patients’ treatment using ADM, it is suggested that further studies will be carried out in the future. In addition, because the incidence of the fistula has been observed in patients with a cleft palate greater than 15 mm, this group of patients should be selected for future studies. If a similar type of surgical technique to previous studies is selected, the confounding factors of the study will be less and a better explanation for the results can be provided.