Abstract
Parotid fistula represents an uncommon complication in parotid surgery. Its early recognition contributes to successful management. The condition is distressing for both the patient and the surgeon, since conservative and operative treatment frequently fail. There is no consensus on the optimal management of parotid gland fistula. The aim of this study is to describe a new, simple procedure in the treatment of this condition using transdermal scopolamine. We report 3 cases of salivary fistulae occurring after parotidectomy. The patients were admitted to our department with swelling in the parotid region and an output of clear drainage from the drain site during oral intake. The patients were treated with a scopolamine transdermal release system applied to hairless skin overlying the parotid region. A prompt and remarkable decrease in daily salivary output was observed. Fistulae healed completely within 3 days. No collateral effects were observed. Parotid fistulae do not generally occur as a complication of parotidectomies. Their management can be difficult, and several methods of treatment have been attempted. We believe that the use of transdermal scopolamine is a valid option in the treatment of parotid fistulae without causing collateral effects.
Introduction
Parotid fistulae are connections between the skin and salivary ducts or glands, through which saliva is discharged.1–3 Fistulae of the parotid gland are rather uncommon and result either from ductal or parenchymal injury. While in the preantibiotic era parotid gland fistulae were frequently the consequence of parotid abscess drainage or suppuration associated with sialolithiasis, today the most frequent causes are gland injury during parotid surgery and penetrating trauma.4,5 Parotid fistulae could also be a rare complication of rhytidectomy, mastoidectomy, dental extraction, temporomandibular joint surgery, and mandibular osteotomy.6–8
Early detection of injury and prompt treatment are important, since fistulae may cause embarrassment as well as wound dehiscence and infection. 8 Although numerous methods have been advocated in the treatment of salivary fistulae, none of these has proven to be totally satisfactory.1,2,5,9–12
We report 3 cases of salivary fistulae occurring after superficial parotidectomy that were successfully treated with transdermal scopolamine.
Case Reports
Patient 1
A 62-year-old man was admitted to our department complaining of unilateral swelling in the right parotid gland region. The swelling was firm, nonindurated, and not painful on palpation. The size of the mass was approximately 4 × 4 cm. A fine-needle aspiration biopsy (FNAB) was suggestive of Warthin tumor.
The patient underwent a superficial parotidectomy with facial nerve preservation. Intraoperative findings confirmed a large, firm parotid mass. The main facial nerve trunk was identified, and the tumor was removed en bloc. A suction drain was placed and a pressure dressing applied.
The patient did very well after surgery. Facial nerve function was intact in all divisions. The pressure dressing was removed 48 hours later, and the drain was removed 72 hours later; this was possible because the amount of drainage was less than 15 ml in a 24-hour period.
The day after drain removal, the patient discharged clear drainage from the drain site, which increased with mastication and oral intake. This drainage caused embarrassment, thus preventing participation in social activities. The patient was examined, and a diagnosis of parotid fistula was made. SteriStrips were placed to close the fistula but without success. In order to limit saliva production, a scopolamine transdermal release system was applied to the hairless skin overlying the parotid region. This system is a circular, film-like patch with a drug reservoir containing 1.5 mg of scopolamine that is delivered into the bloodstream.
Approximately 0.5 mg of scopolamine was delivered every day for 3 days. A few hours after patch application, the patient noticed a prompt and remarkable decrease in the fistula output, allowing him to appear in public that same evening. The following day the fistula did not drain, but a limited sialocele appeared in the area of the residual deep parotid gland. The fistula healed completely after 3 days of scopolamine treatment. On the third day, the patch and the SteriStrips were removed. The sialocele progressively shrank and was completely reabsorbed within 10 days from initial treatment. The treatment was well tolerated; the patient only complained of slight xerostomia without any other side effects. He had no recurrence of the fistula during 5 months of follow-up.
Patient 2
A 60-year-old woman was admitted to our department because of a nodule in the right parotid gland that had appeared 4 months earlier. The size of the nodule was approximately 3 × 4 cm. FNAB revealed a mixed tumor. The patient underwent a right parotidectomy with facial nerve monitoring. The main facial nerve trunk was identified, and the tumor was removed en bloc.
A small drain was placed and a mastoid dressing applied. The dressing and drain were removed 3 days after surgery. The postoperative course was uneventful except for the formation of a small fistula that secreted saliva while the patient was eating. SteriStrips were placed to close the fistula, and oral intake was limited to reduce salivary output, but without success.
Because of severe discomfort caused by a large amount of secretion, a system of transdermal-release scopolamine was applied to the hairless skin overlying the parotid region. A prompt and remarkable decrease in the daily salivary output was observed. The fistula healed completely after 2 days of scopolamine treatment. After 3 days the patch was removed. Treatment was well tolerated without any side effects. No recurrence of the fistula was observed.
Patient 3
A 58-year-old man was admitted to our department with chronic salivary drainage in the left preauricular region. Superficial parotidectomy for Warthin tumor had been performed elsewhere 1 year earlier. Because of persistent sialorrhea in the preauricular region, revision surgery had been performed twice under local anesthesia without success.
On physical examination, permanent preauricular sialorrhea from the incision site that increased with mastication and oral intake was noted. A diagnosis of salivary fistula was made. Placement of a scopolamine transdermal delivery system in the preauricular area relieved the patient's symptoms within a day. After 3 days, the patch was removed and the fistula healed completely. Treatment was well tolerated, and the patient only complained of slight xerostomia without other side effects. No recurrence of the fistula was observed.
Discussion
Although parotid parenchymal injury is part and parcel of every superficial parotidectomy, the reasons for the rare occurrence of postoperative salivary fistulae remain unclear. Postparotidectomy fistulae occur when the resected edge of the remaining gland leaks saliva, which drains through the surgical wound. Saliva secretion, particularly during meals, counteracts the healing process. Moreover, the fistulous opening usually becomes coated with epithelium, thus further preventing fistula closure. 2
After superficial parotidectomy, the placement of an acellular human dermal matrix graft to cover the entire parotid bed has been successfully used to prevent Frey syndrome and to obtain a better cosmesis of the surgical site. 13,14 It could be hypothesized that this physical interpositional barrier, separating the skin flap from the remaining gland, may also play a role in preventing the formation of salivary fistulae.
In spite of a number of procedures advocated for the management of this condition, none of the methods is satisfactory, and there is no standard approach. Since saliva coming out through the fistula impairs wound healing, the reduction of salivary flow plays a major role in the management of this complication.
Since the main stimulus for parotid secretion is the gustatory reflex, a method to reduce salivary secretion is to reduce oral intake. Parekh et al obtained acceptable results in the treatment of parotid fistulae by suspending oral intake, but their patients required intravenous feeding for a mean period of 15 days. 3
Some authors recommend that compressive dressing alone be used to close fistulae after parotidectomies. 4 However, some patients require long-lasting treatment (up to 1 month) and have difficulty maintaining the compression dressing for more than a few days. Other authors have proposed more aggressive approaches when conservative treatment fails. Total parotidectomies and tympanic neurectomies are disadvantageous, since they represent additional and dangerous surgical procedures.1,2,4,5,9 Radiotherapy has been used but is no longer popular. Doses required for healing are high and may cause secondary malignancies.1,3,10
Since the work of Bushara, reporting on the ability of botulinum toxin type A (BoNT/A) to block the cholinergic secretions in the head and neck area, many authors have experimented with this toxin in the treatment of salivary disorders. 15 Vargas et al 16 first performed percutaneous local injections of the residual parotid gland using BoNT/A for the treatment of postparotidectomy sialoceles, while Guntinas-Lichius and Sittel 17 proposed botulinum toxin to treat postparotidectomy fistulae. Although local injections of botulinum toxin, as described by several researchers, appear to be an effective and noninvasive strategy in the management of postparotidectomy fistulae, this approach is burdened with rare side effects.17-20 However, many authors perform BoNT/A injections under electromyographic control to prevent facial nerve damage. Other authors suggest the use of ultrasonographic assistance during the injections to avoid blood vessel puncturing, thus preventing systemic diffusion of the toxin. 20
The use of anticholinergics as antisialogogues, alone or in combination with pressure dressings, has been reported in the treatment of parotid gland fistulae. 5 However, the undesirable side effects—such as drowsiness, blurred vision, sedation, nausea and vomiting, urinary retention, and mouth dryness—associated with high peak serum levels after oral or parenteral administration of anticholinergics have precluded their utilization.
Scopolamine is an antimuscarinic agent with a potent action on salivary glands; it can reduce the volume of salivary secretion in human beings. The availability of scopolamine in a transdermal delivery system provides an alternative method for the administration of antisialogogues and avoids collateral effects. 21 The system is a circular, film-like patch with a drug reservoir containing 1.5 mg of scopolamine. When the patch is applied to the skin, the scopolamine is released at a constant rate to maintain a steady plasma level for at least 72 hours. Absorption occurs when the patch is applied to the hairless skin behind the ear. The application of the patch in this region may have a direct effect on the residual parotid tissue, thus causing a reduction in salivary secretion.
Transdermal scopolamine has been described in the management of drooling in neurologically damaged patients, in the prevention of nausea and vomiting associated with motion sickness, and in the prevention of postoperative nausea and vomiting.21,22 Mouth dryness, which occurs in as many as two-thirds of patients, is the only relevant side effect in the use of transdermal scopolamine. 21 However, other side effects such as somnolence and transient disorders of ocular accommodation can occasionally occur, even with the transdermal system.
In 2007, the first report of transdermal scopolamine in the treatment of salivary fistulae was published. 23 In this study, Dessy et al first described a case of parotid fistula after a face-lift that was treated successfully using a transdermal scopolamine patch combined with BoNT/A. Previously, a case of post-rhytidectomy sialocele was reported to have resolved in 6 days when a transdermal scopolamine patch alone was used. 24 These cases are, to the best of our knowledge, the only two descriptions of the use of transdermal scopolamine in the management of salivary disorders after surgery.
Salivary fistulae after a face-lift are caused by parotid injury due to the deeper dissection of the superficial musculoaponeurotic system. The pathogenesis of post-rhytidectomy salivary fistulae is therefore similar to that of postparotidectomy fistulae.
In the present case series, our patients were initially treated with direct closure of the fistulae using Steri-Strips and with reduction of oral intake. After a few days, transdermal scopolamine was applied to the region of the residual parotid gland. A prompt and remarkable decrease in the fistula output was observed. The salivary fistulae healed completely in 2 to 3 days. The patch was kept in place for 3 days and then replaced by a new one to maintain an adequate scopolamine plasma level for at least 3 more days after the resolution of salivary discharge. The only adverse effect that 2 of our 3 patients experienced was xerostomia, which resolved after the end of treatment. No recurrence of the fistula was observed during follow-up.
Although our case records are limited, our experience shows that transdermal scopolamine could be a minimally invasive and effective therapy in cases of parotid fistulae. In consideration of the cost and safety of transdermal scopolamine, this treatment could be a valid alternative to BoNT/A as primary treatment in the management of postparotidectomy fistulae.
In conclusion, postparotidectomy fistulae are uncommon. Their management can be difficult, and several methods of treatment have been used. Because of our encouraging experience, we believe that the use of transdermal scopolamine is a valid and simple option in the treatment of parotid fistulae. It is possible that the application of the patch on the preauricular region may have a direct effect on the residual parotid tissue by reducing salivary secretion and rapidly healing the fistula.