Selective deep lobe parotidectomy for pleomorphic adenomas

Abstract

The authors’ experience of the selective deep lobe parotidectomy for the treatment of pleomorphic adenomas of the deep parotid lobe is presented. A retrospective analysis of 11 patients treated between 1997 and 2010 was performed; seven were males and four were females, ranging in age from 35 to 51 years. Parameters evaluated included facial nerve weakness, the occurrence of Frey’s syndrome, cosmetic outcome, and recurrence. Follow-up ranged from 18 months to 11 years. No major complications, permanent facial nerve weakness, or Frey’s syndrome occurred. Four patients developed temporary facial nerve impairments that lasted between 2 and 6 weeks, and two developed a sialocele that healed in 9 days in one case and 12 days in the other. The overall cosmetic assessment was excellent in eight patients, good in two, and satisfactory in the remaining one. No recurrences occurred. The selective deep lobe parotidectomy can be considered an effective technique for the management of deep parotid lobe pleomorphic adenomas. The major advantages of this procedure include a reduction in complications such as facial nerve impairments and Frey’s syndrome, and an improved cosmetic outcome.

Over the past three decades, the approach to parotid gland benign tumors has changed from superficial or total parotidectomies to partial/selective parotidectomies or extracapsular dissection. Despite the controversies in the international literature, a general agreement on the effectiveness of the partial parotidectomy approach is presently well established. Partial/selective parotidectomies allow complete and safe tumor removal, better functional outcomes, and a reduction in complications such as facial nerve impairment and Frey’s syndrome. Furthermore, the preservation of healthy parotid tissue allows reconstruction of the parotid bed and a reduction in facial contour deficiency, thus improving the cosmetic outcome.

The principles of partial/selective parotidectomies have recently been extended by some authors to the management of deep parotid lobe benign tumors, shifting surgical treatment of these neoplasms from total or near total parotidectomies to selective deep lobe resections. This procedure preserves the superficial parotid lobe, ensuring better function and cosmesis, and reduces the complications associated with more extensive procedures. Despite the effectiveness of this technique, a complete literature review revealed only four papers on this topic. Authors present herein the authors’ experience of the selective deep lobe parotidectomy, discussing the surgical technique, indications, and results of this approach.

Methods

Surgical technique

Usually a standard face-lift incision is performed and a comprehensive flap of skin, subcutaneous tissue, and superficial musculo-aponeurotic system (SMAS) tissue is elevated. The flap is dissected less far forward than a standard superficial parotidectomy to preserve some vascularization to the superficial parotid lobe that will later be dissected. The great auricular nerve and its posterior branch are identified on the surface of the sternocleidomastoid muscle, dissected and preserved. The main trunk of the facial nerve is identified using classical landmarks and by electrostimulation, if needed, and is carefully dissected. The facial nerve division is identified and the superficial lobe of the parotid is elevated from behind, with dissection of the facial nerve branches. In seven cases, the superficial lobe was also split into two halves (superior and inferior) to achieve an easier and quicker approach to the deep lobe. The superficial lobe (in one or two pieces) is left pedicled anteriorly. Once the tumor is identified it is preferable to free completely (also in the deep surface) only those nerve branches that it is essential to dissect in order to achieve a complete and safe dissection of the tumor. In this way the tumor is dissected below the plane of the facial nerve and removed, if possible, with a cuff of healthy deep lobe glandular tissue. Then the superficial parotid lobe is repositioned and sutured to the pre-tragal tissues and to the sternocleidomastoid muscle with resorbable sutures, achieving a complete reconstruction of the parotid fascia. A suction drain is placed and the skin flap is repositioned and sutured by planes.

Patients

From 1 January 1997 to 31 December 2010, 368 patients were treated for benign tumors affecting the parotid gland. A retrospective evaluation of the clinical data revealed 11 cases of deep parotid lobe pleomorphic adenoma treated with a selective deep lobe parotidectomy; these cases were included in the study. Patient data are summarized in Table 1 . The study was granted exemption from institutional review board approval due its retrospective nature and was performed in compliance with the World Medical Association Declaration of Helsinki on medical research protocols and ethics. Seven patients were female and four male, ranging in age from 35 to 51 years (mean 42.8 years). The right parotid was involved in eight cases and the left in the remaining three. Preoperative assessment included ultrasound (US) and fine-needle aspiration biopsy (FNAB), followed by magnetic resonance imaging (MRI) or contrast enhanced computed tomography (CT) in all cases (eight MRI and three CT). FNAB was diagnostic for pleomorphic adenoma in nine patients, but was non-diagnostic in the remaining two. Histological examination of frozen specimens confirmed the diagnosis of pleomorphic adenoma in all cases.

Table 1
Patients with deep parotid lobe pleomorphic adenomas treated with selective deep lobe parotidectomy.
Patient, sex and age Side FNAB result Imaging
Male, 49 years Right Pleomorphic adenoma CT
Female, 39 years Left Pleomorphic adenoma MRI
Female, 48 years Right Non-diagnostic MRI
Male, 42 years Left Pleomorphic adenoma CT
Female, 41 years Right Pleomorphic adenoma MRI
Female, 51 years Right Pleomorphic adenoma MRI
Female, 40 years Right Pleomorphic adenoma MRI
Male, 45 years Left Non-diagnostic MRI
Female, 44 years Right Pleomorphic adenoma CT
Male, 37 years Right Pleomorphic adenoma MRI
Female, 35 years Right Pleomorphic adenoma MRI

FNAB, fine-needle aspiration biopsy; CT, computed tomography; MRI, magnetic resonance imaging.

All patients were treated according to the surgical technique described above, selecting a face-lift incision approach in all but one case, and preserving the posterior branch of the great auricular nerve. The duration of hospitalization ranged from 2 to 5 days (mean 3.4 days).

Results

Follow-up ranged from 18 months to 11 years (mean 67.8 months) and the results of the surgery are summarized in Table 2 . No major complications occurred. Minor complications included temporary facial nerve weakness in four patients that lasted for 2–6 weeks, and sialocele in another two patients, which was treated with drainage and daily dressing and resolved in 9 and 12 days, respectively. No gustatory sweating (Frey’s syndrome) occurred and no cases of permanent facial nerve palsy or weakness were encountered. Despite the short follow-up period of some of the patients, which limited the oncologic evaluation, no recurrences were seen.

Table 2
Results of the surgery.
Patient, sex and age Complication Hospitalization Follow-up (months) Cosmesis: scar Cosmesis: contour Cosmesis: overall
Male, 49 years Temporary facial nerve weakness (3 weeks) 5 days 131 Good Excellent Good
Female, 39 years None 2 days 118 Excellent Excellent Excellent
Female, 48 years None 2 days 105 Excellent Excellent Excellent
Male, 42 years Sialocele (12 days) 4 days 96 Excellent Excellent Excellent
Female, 41 years None 2 days 82 Good Good Good
Female, 51 years Temporary facial nerve weakness (2 weeks) 4 days 68 Excellent Excellent Excellent
Female, 40 years Sialocele (9 days) 5 days 53 Excellent Excellent Excellent
Male, 45 years None 3 days 39 Good Excellent Good
Female, 44 years Temporary facial nerve weakness (6 weeks) 5 days 27 Satisfactory Satisfactory Satisfactory
Male, 37 years None 2 days 19 Excellent Excellent Excellent
Female, 35 years Temporary facial nerve weakness (2 weeks) 3 days 8 Excellent Excellent Excellent
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Jan 24, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Selective deep lobe parotidectomy for pleomorphic adenomas
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