Management of Sialocele Secondary to Iatrogenic Parotid Duct Injury: A Case Report

Introduction

Sialocoele is understood as the extra glandular subcutaneous collection of saliva. Sialocoele presents as soft, fluctuant, non-tender, diffused swelling involving the ipsilateral cheek region, and further histopathological and radiological investigations which comprises of ultrasonography, sialolithography and amylase estimation of the fluid aspirated are done. A clear serous type aspirate can be suggestive of saliva which is confirmed by amylase estimation and if amylase is more than 10,000U/L, it is indicative of a salivary secretion.¹

If left untreated, the sialocoele can develop into a massive facial swelling and eventually into an extra-oral fistula with a facial scar. This paper makes an attempt to provide clarity for the management of sialocoele and reduce the incidence of faulty diagnosis.

The parotid gland is the largest contributor of saliva with an approximate production of 90% total saliva produced.² Being located inferior to the external acoustic meatus, sandwiched between the mandible and sternocleidomastoid, protected under the parotid fascia, the gland delivers mostly serous saliva through the Stenson’s duct. The duct runs out of the anterior aspect of the gland with masseter muscle as its bed and the (SMAS), subcutaneous tissue, and skin lying superficial to it (Figure 1).

In its course to the oral cavity, it pierces the buccal fat pad, buccinator and the buccal mucosa to drain the saliva through the parotid papilla, in the mucosa adjacent to the upper second molar tooth. The parotid or stenson’s duct has a total length of 5cm and a diameter of 3mm.²

Any assault in the cheek region, if deep enough, has the potential to traumatize the duct. Thus, the saliva, unable to reach its destined site, may pool at a subcutaneous level and is termed as a ‘Sialocoele’.

Case Presentation

Case One

A 40-year-old male patient reported with a soft fluctuant swelling in the left cheek region which according to him increased while eating and subsided on compression. There was a linear vertical scar across the swelling pertaining to history of attempted incision and drainage twice done elsewhere. He had a reduced mouth opening due to bilateral buccal submucosal fibrosis which restricted intraoral examination. The ipsilateral stenson’s duct orifice was seen to be inflamed.

The overlying swelling presented no bruit nor raised temperature. Thus, an aspiration of the fluid was done yielding ~2ml of straw-colored fluid with bubbles, suggestive of saliva. The aspirated content was sent for amylase estimation. The stenson’s duct orifice was enlarged intraorally and the distal parotid ductal patency was confirmed with a round-tipped periodontal marked probe. An 18-gauge gauge IV canula was adjusted according to the size and introduced into it. (Figure 2) The patient was advised to chew on vitamin C lozenges to encourage catheter patency.

On confirming the aspirate to be saliva (amylase level of 10000U/L), in the operative day, under local anesthesia the extra-oral scar was excised and explored surgically through layers of skin, subcutaneous tissue and the Superficial Musculo Aponeurotic System (SMAS), with the expectation of locating the proximal severed ductal end. Due to difficulty in the latter, direct end-to-end anastomosis could not be carried out. Instead after confirming the severed distal end of the duct in the surgical field, a pediatric feeding tube was inserted intra-orally through the orifice and IV canula was removed. One end of the tube was sutured intra-orally with approximation to distal defect, while the other end was at the site of previous saliva accumulation. The overlying tissues were closed esthetically in layers.

Case Two (Figure 3)

An eighteen-year-old male patient presented with a soft, fluctuant swelling measuring approximately 6x5x5cm in the right cheek region, just one week after the first patient’s report. This patient had two horizontal scar marks at the level of lip commissure and upper lip vermillion level. He gave a history of incision and drainage done twice elsewhere for the swelling. As per his previous reports, pus drainage was noted in the first episode and in the second, a chocolate brown serosanguinous fluid was drained (Figure 3).

The swelling was soft, fluctuant, non-tender with no bruit and normal overlying temperature. The patient had an adequate mouth opening with no obvious carious teeth. On aspiration, the swelling yielded ~70ml of straw-colored fluid with bubbling, suggestive of saliva. Following aspiration a decrease in size was noted. An 18-gauge green IV canula was placed intraorally through the ipsilateral stenson’s duct orifice after enlarging it. The patient was sent for USG of the swelling and parotid region and aspirated fluid was sent for amylase estimation.

In both cases, an unaesthetic fibrotic scar was present on the cheek. Hence, as per the patient’s preference, scar revision was carried out and the same incision was used to surgically explore for proximal part of the duct. (Figure 4) In case II, the cystic lining was clearly identified, removed and sent for histopathological examination. We then used a pediatric Ryle’s Tube (RT) as a stent for the formation of a new duct. This pediatric RT was introduced intra-orally through the stenson’s duct orifice and it emerged through the other end of the duct into the extra-oral surgical site.

Discussion

Parotid duct injury can be attributed to any sort of facial trauma or any iatrogenic cause following surgery of any proximal structure.² A common manifestation of this injury results in complete or partial obstruction of duct due to severing leading to pooling of saliva in periductal region.² In our study, both the cases gave the history of a prior attempt of incision and drainage of the cheek swelling, extra-orally. Conventional radiological tools such as USG, OPG, etc., were used keeping in mind the socioeconomic status of the patient. After complete examination, the treatment protocol was devised revolving around these objectives (Figure 5):

1. Removal of cystic lining, if present.

2. Formation of a new duct with patent drainage of saliva.

3. Removal of the fibrotic scar (esthetic correction).

A pediatric ryle’s tube is made up of polyvinyl chloride and is available in different sizes. For an infant, the size of ryle’s tube ranges from 3.0-4.0 mm similar to that of parotid duct which ranges from 0 to 2.9mm.² Literature contains evidence of several other stenting material such as double J urine catheter, IV canula, cuff tube of Endo Tracheal tube, etc.^3,6 However, pediatric Ryle’s tube was considered to be more readily available and a costeffective option. It provides a non-collapsible structure to drain the salivary collection.

Asha’ari et al advocated the use of frequent aspirations and compression dressings as the first line of treatment. However, persistent swelling may warrant the use of some intervention. Peroral catheter drainage gives a good success rate in drainage of salivary collection and resolving the swelling.² As compared to surgical reapproximation of the parotid duct, cannulation provides the advantage of being less invasive and spares the suturing of duct which may cause obstruction.⁶

One needs to be vigilant while performing procedures on face due to the dense networking of nerves subcutaneously, presence of parotid duct and other nerves and vessels. Iatrogenic causes for any trauma to the stenson’s duct can thereby be avoided. It is crucial to be well versed with the anatomy as well as the pathologies maxillofacial region before taking up any invasive procedure. A case of sialocoele can be managed well even with limited resources if the practitioner has made the correct diagnosis. Peroral parotid cannulation proves to be a minimally invasive technique with much fewer complications.

Conclusion

Knowledge of anatomy and its surgical correlation proves paramount importance in placing a skin incision in the cheek region. Treatment spectrum ranges from conservative medicinal treatment, anticholinergic drugs administration, and surgical intervention. Patient compliance and frequent follow-ups decide the completeness of a treatment. Enucleation and Catheterization is predictable treatment modality.

Sources of Support

Nil

Conflict of Interest

No conflict of interest.