|Year : 2016 | Volume
| Issue : 5 | Page : 600-604
Superficial parotidectomy an excellent procedure in the management of benign parotid tumors - outcome of various complications and tumor recurrence
Mervyn Correia, Francis Pantaliao Noronha, Pandarinath Audi
Department of General Surgery, Goa Medical College, Bambolim, Goa, India
|Date of Web Publication||13-Oct-2016|
Resicom Elite, Flat C-02, Of Kadamba Depot Road, Alto-Porvorim, Bardez - 403 521, Goa
Source of Support: None, Conflict of Interest: None
Background: The majority of parotid masses are benign pleomorphic adenomas that rarely recur, leaving a large group of patients healthy after their parotid surgery. Nearly, 80–90% of salivary gland tumors occur in the superficial lobe of the parotid gland, and the vast majority of them are benign. The optimal treatment for benign parotid tumors, of which pleomorphic adenomas is the most common is superficial parotidectomy with dissection and preservation of the facial nerve. Aims and Objectives: The aim of this study was to evaluate the postoperative complications and tumor recurrence following superficial parotidectomy for benign parotid tumors. Settings and Design: This was a retrospective study conducted of all patients who underwent superficial parotidectomy in a General Surgical Unit of the Goa Medical College, Bambolim, Goa, between December 2013 and December 2014. Materials and Methods: The records of 17 patients were analyzed in detail with regard to the complications and tumor recurrence that followed the operation of superficial parotidectomy. Data regarding age, gender and histology were also included in the study. Patients had all been chosen from the out-patient department on the basis of clinical presentation of swelling over the parotid region. The location of the tumor and diagnosis was confirmed in every case by advising ultrasound of the parotid region and/or computed tomography scan along with fine needle aspiration cytology of the swelling. All data were meticulously entered in a previously prepared proforma for this purpose. Patients were followed up for 1 year. Results: Twelve (70.5%) patients were male and 5 (29.5%) female, with ages ranging from 21 to 65 with a mean age of 38.2. There were 16 pleomorphic adenomas 94.1% and 1 adenolymphoma. Partial or temporary facial nerve damage was seen in six patients at 35.3%. At 6 months follow-up, however, recovery was complete, and we had no permanent facial nerve damage. Of 17 patients, 10 (58.9%) complained of numbness of the ear lobule which gradually improved with time. None of our patients had an infection, permanent facial weakness, or tumor recurrence. However, it should be stressed that Goa is a small state and due to the small number of cases in the study, it could be labeled more as a personal one. Conclusions: Superficial parotidectomy is a safe operation if performed with attention to detail, meticulous gentle dissection and avoidance of direct trauma or stretches to the nerve to prevent facial weakness.
Keywords: Facial nerve, pleomorphic adenoma, superficial parotidectomy
|How to cite this article:|
Correia M, Noronha FP, Audi P. Superficial parotidectomy an excellent procedure in the management of benign parotid tumors - outcome of various complications and tumor recurrence. Med J DY Patil Univ 2016;9:600-4
| Introduction|| |
The parotid gland is the most common site for salivary gland tumors. The majority of tumors arises in the superficial lobe and present as slowly growing masses below the ear, in front of the ear or sometimes in the upper aspect of the neck. Less commonly, they arise from accessory parotid tissue and then present as swellings in the cheek. Rarely tumors arise from the deep lobe and then present as parapharyngeal masses with a diffuse bulge in the soft palate and tonsillar region.
The superficial fascia of the face and neck overlying the parotid and cheek area is referred to as the superficial musculoaponeurotic system. This layer runs deep to the subcutaneous tissue and above the parotid capsule. It is continuous with the platysma inferiorly and inserts on the zygoma superiorly, with attachments to the temporoparietal fascia. It becomes attenuated medially, where it blends into the facial muscle investing fascia.
The facial nerve traverses through the parotid gland while dividing into various branches the pes anserinus. This result in the division of the parotid into a large superficial lobe and a smaller deep part. The primary duty of the surgeon is to identify and preserve the facial nerve trunk and its branches to prevent postoperative facial palsy.
The important pointers to the facial nerve are the mastoid process, the inferior portion of the cartilaginous canal, and the tragal pointer. This is termed Conley's pointer and indicates the position of the facial nerve, which lies 1 cm deep and inferior to its tip. The upper border of the posterior belly of the digastrics muscle is another very important landmark. The main trunk of the facial nerve is located at a point where the mastoid process, the cartilaginous portion of the auditory canal and the posterior belly of the digastrics muscle meet.
A thorough history and clinical examination are very important in the workup of parotid tumors. The major goal in the evaluation is to determine or exclude the diagnosis of malignancy. History often is the most useful tool in distinguishing inflammatory from neoplastic masses. Fine needle aspiration cytology (FNAC) is a very important investigation, and very rarely a computed tomography (CT) scan is required.
Important complications of parotid gland surgery are hematoma formation, flap necrosis, infection, temporary facial nerve weakness, the transaction of the nerve with permanent damage, sialocele, permanent numbness of the ear lobe due to transaction of the greater auricular nerve, Freys syndrome, facial asymmetry, and tumor recurrence.
Superficial parotidectomy is the most common procedure done for parotid pathology. Suprafacial parotidectomy also known as partial parotidectomy is especially useful for lesions in the lower pole of the gland. This involves not dissecting the upper division of the nerve with consequently, minimal of trauma to the facial nerve. Extracapsular dissection (ECD) may be considered an alternative surgical modality for select benign parotid neoplasms.
| Materials and Methods|| |
This was a retrospective study conducted of all patients who underwent superficial parotidectomy in a General Surgical Unit of the Goa Medical College, Bambolim, Goa, between December 2013 and December 2014. Patients had all been chosen from the out-patient department on the basis of clinical presentation of swelling over the parotid region. The location of the tumor and diagnosis was confirmed in every case by advising ultrasound of the parotid region and/or CT scan along with FNAC of the swelling.
The records of 17 patients were analyzed in detail with regard to the complications and tumor recurrence that followed the operation of superficial parotidectomy. Data regarding age, gender and histology were also studied. All patients were thoroughly counseled before surgery with special emphasis on facial nerve damage, and written informed consent was taken.
After surgery, patients were seen on day 7 for stitch removal. Follow-up was then done every month for 3 months and then every 3 months for a year and complications recorded.
| Results|| |
A detailed study of 17 patients showed that 12 (70.5%) patients were male and 5 (29.5%) female, with ages ranging from 21 to 65. The mean age was 38.2. All patients had undergone superficial parotidectomy, and all were new patients, and no patients were operated on after a recurrence. There were 16 pleomorphic adenomas 94.1% and 1 adenolymphoma. Of 17 patients, 10 (58.9%), complained of numbness of the ear lobule which gradually improved with time. None of our patients had an infection, permanent facial weakness, or tumor recurrence.
As seen in [Table 1], partial or temporary facial nerve damage was seen in 6 patients 35.3%. At 6 months follow-up, however, recovery was complete, and we had no permanent nerve damage.
|Table 1: Outcomes of major complications following superficial parotidectomy in various series|
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Freys syndrome occurred in four patients (11.7%) and gradually improved with time. None required any form of surgical treatment.
[Table 2] shows no recurrence in our study as well as negligible recurrent rates in other series.
|Table 2: Outcomes of tumor control/recurrence after superficial parotidectomy|
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| Discussion|| |
Pleomorphic adenomas are the most common benign salivary gland neoplasm and, although usually found in the parotid, may also arise in the submandibular, sublingual, and minor salivary glands. It occurs most often between the ages of 30 and 60 years and is found more commonly in females than in males.
Patients usually present with a painless, slow-growing mass. The duration of symptoms is variable. Although progression is slow, left untreated, the tumor can cause significant morbidity and rarely, death. Involvement of the facial nerve at initial presentation almost always indicates malignancy.
The etiology of pleomorphic adenoma is unknown. The likelihood of malignant transformation increases with the duration of the lesion. Very rarely these tumors can metastasize.
The optimal treatment for benign parotid tumors, of which pleomorphic adenomas is the most common is superficial parotidectomy with dissection and preservation of the facial nerve. Local control rates are approach 95% or higher after optimal surgery alone.
The risk of major complications is relatively low after surgery for previously untreated pleomorphic adenomas. However, the risk of complications, particularly 7th nerve injury, is increased after salvage surgery for locally recurrent tumors.
Postoperative radiotherapy (RT) is advised for the small subset of patients with positive margins and/or multifocal recurrences.
The important complications of parotid gland surgery are hematoma formation, flap necrosis, infection, temporary facial nerve weakness, transaction of the nerve with permanent damage, sialocele, permanent numbness of the ear lobe due to transaction of the greater auricular nerve, Freys syndrome, facial asymmetry and tumor recurrence.
Hematoma formation, infection, and flap necrosis can be taken care of by maintaining careful hemostasis. To prevent flap necrosis, the anterior skin flap which tends to get thin and devoid of its blood supply, especially in large tumors can be trimmed to ensure that the edge bleeds well. We follow this procedure routinely and have had no flap necrosis.
Unintentional injury to the facial nerve is the most devastating complication of parotid surgery. In a study of surgery for benign disease, temporary postoperative weakness was reported in 18–65% and permanent weakness in 0–19%.
This risk must be explicitly discussed with every patient undergoing parotid surgery. Even with ostensibly perfect technique, facial nerve injury can occur for unknown reasons. If an injury occurs, timely diagnosis and a sensitive bedside manner are essential to prevent further complications and minimize potential litigation.
If the motor supply to the orbicularis oculi is weak or absent, aggressive eye care must be instituted to prevent corneal drying and injury. Such care includes the use of lubricants, taping the eye shut at night, and moisture chambers during the day. Consultation with an ophthalmologist may be warranted.
If long-term paralysis occurs, static facial rehabilitation techniques may be used, including brow lift, gold weight insertion and canthoplasty, and facial slings. Dynamic techniques or nerve repair may also be appropriate.
Raw gland surface can result in a collection of saliva below the skin resulting in a sialocele or leakage of saliva from the wound giving rise to a salivary fistula in 1–14% of patients. Conservative measures include drainage of sialoceles with pressure dressings. Salivary fistula can be treated with local wound revision if low-flow leakage is present.
Numbness of the ear lobule can be minimized by avoiding damage to the greater auricular nerve. The branch that supplies the ear lobule should be protected. If the nerve gets damaged an attempt should be made to repair it. Numbness tends to improve with passage of time.
Frey syndrome also called as gustatory sweating occurs as a result of aberrant innervation of cutaneous sweat glands overlying the parotid by postganglionic parasympathetic salivary nerves resulting in localized sweating during eating or salivation. Keeping the platysma on the anterior skin flap tends to decrease the incidence of this complication. The surgical interposition of tissue like temporoparietal fascia or sternomastoid muscle flap, or implantable material (e.g., acellular dermis) between the skin and parotid fascia also helps. If Frey syndrome develops, various interventions may be employed, including topical application of antiperspirant, injection of botulinum toxin, and denervation by tympanic neurectomy.
Superficial parotidectomy, especially in a large tumor and thin patient can result in facial asymmetry. The significance of the defect and the resulting facial asymmetry after parotidectomy is related to the amount of gland removed and the thinness of the patient. Patients with more subcutaneous fat may be better able to hide small defects than thin patients can, and therefore may not require reconstruction. We routinely divide the posterior belly of the digastrics muscle at the central tendon and reflect it back on itself, and suture it in place. This helps to bring about facial symmetry.
Tumor recurrence - Parotid tumors can recur as a result of positive margins, microsatellite disease, or unrecognized nerve invasion. Adjuvant RT should be considered in such cases. Adjuvant RT improves the likelihood of local control in the subset of patients with inadequate margins and/or multinodular recurrence. Optimal dose-fractionation schedules are similar to those employed for salivary gland carcinomas.
Due to the short follow-up of 1 year; however, the relapse rates in our study, although comparable with other studies as shown in [Table 2], could represent a limitation to the study.
Recent studies have suggested that ECD is an option for the resection of certain benign parotid tumors. Approximately, 90% of the parotid gland neoplasms are located within the superficial lobe, lateral to the facial nerve. The majority of parotid tumors present as discrete lumps arising within the superficial portion of the gland.. The two main aspects of parotid surgery for benign tumors are the removal of the lesion with adequate margins of healthy parotid tissue surrounding it and preservation of the facial nerve. Conventional teaching prescribes removal of these tumors by superficial parotidectomy, which encompasses facial nerve identification and en bloc removal of the superficial portion of the gland.
ECD is an alternative approach to the removal of such lumps, involving meticulous dissection immediately outside the tumor capsule while still preserving the facial nerve, and is distinct from enucleation which should be condemned.. A margin of 3–4 mm is kept around the capsule of the tumor, and the tumor removed intact with this margin.
Cristofaro et al. carried out a retrospective cohort study of 198 patients with pleomorphic adenomas of the parotid gland. ECD or superficial parotidectomy was performed. They found that transient facial nerve injury and facial paralysis were significantly more frequent after superficial parotidectomy than after ECD. No significant differences in capsular rupture, recurrence, and salivary fistula were observed after both the procedures.
| Conclusions|| |
They concluded that ECD may be considered the treatment of choice for pleomorphic adenomas located in the superficial portion of the parotid gland because this technique showed the similar effectiveness and fewer side effects than superficial parotidectomy. However, they recommend superficial parotidectomy for tumors larger than 3.5cm in diameter when the lesion is located in a deeper portion of the parotid gland or in cases of tumor recurrence. A prolonged follow-up is necessary as capsular invasion is more frequent and severe in pleomorphic adenomas larger than 40mm as they generally contain more myxoid stroma which promotes vascular invasion.,
A systematic review with meta-analysis conducted by Albergotti et al. suggests that ECD has a similar recurrence rate as superficial parotidectomy with fewer postoperative complications. ECD may be considered an alternative surgical modality for select benign parotid neoplasms. Its main criticism is that its use is confined to smaller less challenging tumors.
Superficial parotidectomy is a safe operation if performed with attention to detail, meticulous gentle dissection and avoidance of direct trauma or stretches to the nerve to prevent facial weakness. It is the procedure against which all other procedures should be compared, and certainly the procedure of choice in large and challenging tumors.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]