The management of oronasal fistulas in the cleft palate patient

An oronasal fistula is an abnormal communication between the oral cavity and the nose that occurs after surgical repair of a cleft palate. After the primary repair of a cleft palate, oronasal fistulas develop in a certain number of patients; this is the most common defect in the hard palate after the primary surgical repair [1]. These fistulas are sometimes located in the soft palate but occur more frequently in the hard palate. They typically occur at the junction of the primary and secondary palate or at the junction of the hard and soft palate. It is difficult to determine the true incidence of fistula formation after primary repair of a cleft palate because the reports in the literature vary widely, and the centers that generate the reports seem to have a significant influence on the rate of fistula development. The severity (width) of the original cleft, however, shows a direct correlation with the risk of fistula formation [2], and the incidence of fistulas is higher after palatoplasty for complete clefts of the primary and secondary palates than after closure of an isolated secondary palatal cleft [3]. The technique used to close the palate and the experience and skill of the surgeon affect the occurrence rate [4]. Reported incidences over the years have ranged from a low of 5% [5] to between 9% and 50% with one-stage closures in a review article by Shultz [6]. In 1960, Musgrave and Bremner [5] reported the incidence of fistula formation in the palate to be 12.5% for bilateral clefts, 7.7% for unilateral clefts, and 4.6% for isolated clefts of the secondary palate. These numbers seem to be low compared to rates published more recently in which the mean for isolated cleft palate was reported at 15% [6]. Lilja et al [7] reported an 8% fistula formation rate with their older use of the Wardill-Killner technique, and in the author’s experience this technique produces fewer fistulas in the hard palate than other techniques that close the hard and soft palate in a one-stage procedure. The defect (often referred to as a ‘‘fistula’’) in the anterior alveolar palate (Fig. 1) must be considered a residual cleft rather than a fistula, because this area is usually not repaired as a part of the primary closure of the cleft palate defect in cleft lip and cleft palate patients but is intentionally left opened. The management of this defect is presented elsewhere in this issue and is not discussed in this article. Some of the causes of oronasal fistulas include excessive tension on the primary repair site because of inadequate medial mobilization of the flaps, excessive trauma to the margins of the palatal flaps by instruments during surgery, faulty suturing, traumatic disruption of the healing wound, infections, inadequate attachment of the palatal tissue to the nasal mucosa, hematoma formation between the oral and nasal layers, and flap necrosis. The development of the fistula may be noted in the immediate postoperative period or may not become evident for a few weeks. Surgery to close the fistula should not be attempted too early, and the surgeon should wait until the area is fully healed and the inflammation has subsided completely (4–6 months). Attempting to close the defect in the presence of inflammation only makes the fistula worse because sutures do not hold in the inflamed palate and ‘‘walk through’’ the tissue in a few days. The presence of excess foreign body material de-