Incidence of marginal mandibular nerve palsy in neck

Incidence of marginal mandibular nerve palsy in neck dissection N Amin, H Dixon, N Gibbins, S Lew-Gor Brighton and Sussex University Hospitals United Kingdom

Marginal Mandibular Nerve

Our Project • Limited data • Informed consent important part of preassessment • Communication errors heart of many complaints

Our Project • Rate of MMN palsy (temporary/permanent) vs. Type of ND

Method • • Retrospective 2 year review 88 neck dissections (ND) reviewed 4 excluded 84 total – Pre- and post-operative MMN function including whether the MMN was sacrificed intra-operatively. – Time until palsy resolution – Type of neck dissection – The grade of the operating surgeon • Statistical analysis

AAO-HNS classification of neck dissections • Radical neck dissection (RND) – removal of ipsilateral cervical lymph nodes in levels 1 -5 as well as the sternocleidomastoid muscle (SCM), internal jugular vein (IJV) and the spinal accessory nerve (SAN). • Modified radical neck dissection (MRND) – removal of ipsilateral cervical lymph nodes in levels 1 -5 with preservation of one or more of the SCM, IJV and SAN. • Selective neck dissection (SND) – there is preservation of one or more groups of lymph nodes as well as the SCM, IJV and SAN. • Extended neck dissection (END) – involves a RND with removal of another group of lymph nodes or another non-lymphatic structure.

Results • 75 patients • 84 neck dissections • Mean age 66. 1 (32 – 89 years) • M 4. 55: 1 F

Results • • 20 RND 20 MRND 28 SND 16 END; 16% SND; 28% • 8 patients had preoperative radiotherapy RND; 20% MRND; 20%

Results • 10/84 (11. 9%) – MMN palsy No MMN Palsy Permanent MMN Palsy Temporary MMN Palsy • 8/84 (9. 5%) – permanent • 2/84 (2. 4%) – temporary

Results • 57 neck dissections involved level I • Total palsy rate was 10/57 (18. 5%) 60 50 40 Temporary MMN palsy 30 • 14. 0% (8/57) – permanent • 3. 5% (2/57) – temporary • p-value = 0. 046 Permanent MMN palsy 20 No MMN palsy 10 0 Level II - VI

Results • In RND there was a higher risk of a permanent MMN palsy (20%) compared to MRND (10%), SND (3. 6%) or END (6. 2%) 25 20 • 10% risk of a temporary MMN palsy in patients undergoing MRND 3. 6% 30 20% 10% 6. 2% Temporary MMN palsy 15 Permanent MMN palsy No MMN palsy 10 5 • Statistically insignificant 0 RND MRND SND END

Results • Parotid gland – 2 • Oral cavity – 5 • Larynx – 1 Parotid Oral cavity Larynx

Discussion • Informed consent is a vital part of preoperative assessment. • Incidence of MMN palsy post level I ND is not widely quoted. • Important patients are aware of potential morbidity and potential treatment options.

Conclusion • If level I dissection is performed, a permanent MMN palsy rate of 14% or 1 in 7 may be quoted to the patient. • Adequate resection of disease in level I and the parotid region may require sacrifice of the MMN.

References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Robbins KT, Clayman G, Levine PA, Medina J, Sessions R, Shaha A, et al. Neck dissection classification update: revisions proposed by the American Head and Neck Society and the American Academy of Otolaryngology-Head and Neck Surgery. Arch Otolaryngol Head Neck Surg 2002; 128: 751 -8. Hazani R, Chowdhry S, Mowlavi A, Wilhelmi BJ. Bony anatomic landmarks to avoid injury to the marginal mandibular nerve. Aesthet Surg J. 2011 Mar; 31(3): 286 -9. Batra AP, Mahajan A, Gupta K. Marginal mandibular branch of the facial nerve: An anatomical study. Indian J Plast Surg. 2010 Jan; 43(1): 60 -4. Dingman RO, Grabb WC. Surgical anatomy of the mandibular ramus of the facial nerve based on the dissection of 100 facial halves. Plast Reconstr Surg 1962; 29: 266– 272 House JW, Brackman DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985; 93: 146– 147 Bron LP, O'Brien CJ. Facial nerve function after parotidectomy. Arch Otolaryngol Head Neck Surg. 1997 Oct; 123(10): 1091 -6. Møller MN, Sørensen CH. Risk of marginal mandibular nerve injury in neck dissection. Eur Arch Otorhinolaryngol. 2012 Feb; 269(2): 601 -5. Batstone MD, Scott B, Lowe D, Rogers SN. Marginal mandibular nerve injury during neck dissection and its impact on patient perception of appearance. Head Neck. 2009 May; 31(5): 673 -8 Gosain AK. Surgical anatomy of the facial nerve. Clin Plast Surg. 1995 Apr; 22(2): 241 -51. Baker BC, Conley J. Avoiding facial nerve injuries in rhytidectomy. Anatomical variations and pitfalls. Plast Reconstr Surg 1979; 64: 781– 795 Ducic Y, Young L, Mc. Intyre J. Neck dissection: past and present. Minerva Chir. 2010 Feb; 65(1): 45 -58. Seddon HJ. Three types of nerve injury. Brain 1943; 66(4): 237 -288 Meier JD, Wenig BL, Manders EC, Nenonene Continuous intraoperative facial nerve monitoring in predicting postoperative injury during parotidectomy, Laryngoscope. 2006 Sep; 116(9): 1569 -72

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