Superficial parotidectomy for chronic parotid sialadenitis

Abstract

Chronic sialadenitis (CS) of the parotid gland is an insidious inflammatory disorder which tends to progress and may lead to the formation of a fibrous mass. This is a review of the author’s experience of superficial parotidectomy (SP) with duct ligation for non-specific CS of the parotid gland not responding to conservative management. 21 patients (11 females; 10 males) with intractable non specific CS underwent SP with duct ligation. The mean duration of symptoms was 1.93 years (SD 0.48). Fine needle aspiration cytology and magnetic resonance imaging were carried out prior to SP to rule out benign or malignant tumours. The mean duration of observation was 1.71 years (SD 0.39). Six patients (28.57%) developed temporary facial nerve palsy. Three (14.28%) patients developed Frey’s syndrome. Paresthesia of the ear lobe was found in all cases. One case (4.76%) each of sialocoele and hypertrophic scar was found. There was complete resolution of symptoms in all the cases. The histopathological report confirmed three cases (14.28%) of mild CS and 18 cases (85.72%) of CS of greater degree. SP along with ligation of the duct is a safe and effective treatment for non-specific CS of the parotid gland.

Disorders of the salivary glands are uncommon. When they do occur, experience in managing the process is diluted over a range of disciplines. The result is that traditional views go unchallenged and are recast, unchanged, from one text book to another. Non-specific chronic sialadenitis (CS) of the parotid gland is an insidious inflammatory disorder characterized by intermittent, often painful swelling of the gland. The disease tends to progress and if left untreated may lead to the formation of a fibrous mass in the gland. CS of the parotid gland is most commonly seen in middle age. The definitive aetiology and pathogenesis of the disease remains obscure but reduced salivary flow is considered the most important factor in its multifactorial aetiology. The normal flow of saliva prevents inspissation of secretions and helps to remove microorganisms from the duct system. The reduction of salivary flow either by decrease in acinar tissue or duct obstruction, facilitates ascending infection. Two theories have been put forward to explain the origin of CS. One postulates that retrograde infection by low grade opportunistic oral flora can result directly in recurrent CS. The other proposes that repeated episodes of acute infection may lead to mucous metaplasia of ductal epithelium, resulting in increased mucus content of secretions, stasis and further episodes of inflammation. Secretory disorders of the parotid gland may also play an important role in the pathogenesis of CS. The aggregated crystalloid, derived from these secretions has been implicated in calculus formation in the gland. The chronic enlargement of the salivary glands with recurring infection has been a dilemma for professionals for more than a century. Transient and chronic episodes of parotid gland swelling may occur in patients treated with radioactive iodine injections for management of thyroid malignancies. Juvenile recurrent parotitis, which continues into adulthood, can also manifest as recurrent CS. CS can cause considerable morbidity and requires careful assessment to provide appropriate treatment. The parotid gland is more often affected than the submandibular gland, probably because of its lower rate of secretion.

Most patients initially respond to conservative management with systemic antibiotics, intraductal methyl violet (1%) injections, intraductal tetracycline therapy, parasympathectomy, kallikerine inhibitor (aprotonin) therapy, ductal ligation, sialogogues, gland massage, and oral hygiene measures. The intraductal instillation of penicillin or saline is a simple and surprisingly successful technique for the initial stages of CS. Various surgical treatments have been proposed. When there are local factors such as a stone or stricture in the anterior portion of the duct, these may be treated with some success by conventional surgery, lithotripsy or endoscopic techniques. Most patients need radical excision of parenchymal tissue for complete cure with least morbidity. There has been reluctance to advocate superficial parotidectomy (SP) because of the perceived risk to the facial nerve. SP is now widely recognized as the treatment of choice for recurrent CS not responding to conservative management, but the extent of parenchymal resection required and whether to ligate the duct is controversial. Post SP and duct ligation the deep lobe is expected to become fibrosed and atrophied with time. There is little evidence that isolated procedures such as ligation of the parotid duct and tympanic neurectomy are of any significant advantage.

Conventional radiographs and sialography forms the basis of radiological investigations during the initial phases of CS. In long standing cases the focus is mainly on diagnostic ultrasound and resonance methods because, with their aid, the investigation of almost all the inflammatory diseases of salivary glands can be performed accurately, without exposing the patient to radiation.

The purpose of this article is to review the author’s experience of SP with duct ligation for non-specific CS of the parotid gland not responding to conservative management.

Materials and method

21 patients with non-specific CS intractable to conservative and non-surgical treatment (including multiple courses of antibiotics, oral hygiene measures and duct exploration and dilatation) who underwent SP along with duct ligation, with a minimum of 1 year of follow up, were selected for the study. Three patients had undergone sialendoscopic treatment at different centres with no relief. Approval of the institutional ethical committee was obtained before proceeding with the study. All the selected cases were subjected to fine needle aspiration cytology (FNAC) and magnetic resonance imaging (MRI) to confirm the diagnosis and to exclude benign or malignant tumours. There were 11 females (52.4%) and 10 males (47.6%). The mean age was 48.74 years (SD 2.53) and the mean duration of symptoms was 1.93 years (SD 0.48) [ Fig. 1 ]. Routine investigations for pre-anaesthetic checkup were carried out. A single surgeon (R.S.) performed all the superficial parotidectomies under general anaesthesia (endotracheal tube intubation/oral). In all the cases the duct was tied as far forward as possible. The superficial lobe was sent for histopathological examination. Postoperatively, all the patients received prophylactic antibiotics and analgesics. The drain was left in place until there was complete cessation of blood and serous secretions. Sutures were removed after 7 days.

Fig. 1
Duration of symptoms and follow up.

Results

According to the House-Brackmann classification, 5 cases (23.81%) had grade II involvement of the facial nerve and 1 case (4.76%) had grade III involvement. The temporary facial palsy resolved within 6 months in all cases. There was no case of permanent facial palsy. Three (14.25%) patients developed Frey’s syndrome. Paresthesia of the ear lobe was found in all the cases but was of less concern to the patients. One case (4.76%) each of sialocoele and hypertrophic scar was found [ Fig. 2 ]. Histopathology revealed 18 cases (86%) with widespread involvement of the gland while 3 (14%) had mild evidence of CS [ Fig. 3 ]. All the patients were observed for a mean duration of 1.71 years (SD 0.39) [ Fig. 1 ]. There was complete resolution of symptoms in all the cases.

Fig. 2
Complications post SP for CS.

Fig. 3
Histopathology report of CS following SP.

Results

According to the House-Brackmann classification, 5 cases (23.81%) had grade II involvement of the facial nerve and 1 case (4.76%) had grade III involvement. The temporary facial palsy resolved within 6 months in all cases. There was no case of permanent facial palsy. Three (14.25%) patients developed Frey’s syndrome. Paresthesia of the ear lobe was found in all the cases but was of less concern to the patients. One case (4.76%) each of sialocoele and hypertrophic scar was found [ Fig. 2 ]. Histopathology revealed 18 cases (86%) with widespread involvement of the gland while 3 (14%) had mild evidence of CS [ Fig. 3 ]. All the patients were observed for a mean duration of 1.71 years (SD 0.39) [ Fig. 1 ]. There was complete resolution of symptoms in all the cases.

Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Superficial parotidectomy for chronic parotid sialadenitis

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