Parotidectomy - Superficial

Considerations

• • Parotid FNA

  • 2011: A systematic review and meta-analysis of the diagnostic accuracy of fine-needle aspiration cytology for parotid gland lesions

  • 2016: 2016: Sensitivity, Specificity, and Posttest Probability of Parotid Fine-Needle Aspiration: A Systematic Review and Meta-analysis

  • The Facial Nerve in parotidectomy 

    • Superficial: resects majority of gland lateral to facial nerve (CN-7); typically preserves CN-7

    • Total: resects entire gland; may sacrifice CN-7

    • Radical: resects gland with possible sacrifice of CN-7, mandibulectomy, petrosectomy, periglandular skin

  • Common surgical landmarks for locating the main trunk of the facial nerve

    • • 5 landmarks are typically described

      • Tragal pointer

      • Tympanomastoid suture

      • Posterior belly of digastric

      • Peripheral branches of the facial nerve

      • Mastoid / styloid process and the stylomastoid foramen

      • Additional key landmarks 

      • Stylomastoid artery

        • 2009: The stylomastoid artery as an anatomical landmark to the facial nerve during parotid surgery: a clinico-anatomic study

        • Parotid-mastoid fascia (aka "Rasgon's fascia")

          • The last barrier between you and the facial nerve 

        • https://www.ncbi.nlm.nih.gov/pubmed/31581824

    • Anatomic studies provide some norms for distance and relative positioning of CN-7 and these landmarks 

      • 78 patients underwent parotidectomy (2004: Facial nerve in parotidectomy: a topographical analysis)

        • Tip of the tragal cartilage: 6.37 mm (95% CI 5.84-6.89 mm)

          • significantly less (t-test, p < .000) than the previously accepted 1 cm 

      • 26 embalmed cadavers via anterograde dissection (2009: The precision of four commonly used surgical landmarks for locating the facial nerve in anterograde parotidectomy)

        • Tragal pointer: 6.9+/-1.8 mm

        • Posterior belly of digastric muscle: 5.5+/-2.1mm 

        • Tympanomastoid suture: 2.5+/-0.4 mm

        • External auditory meatus: 10.9+/-1.7 mm

    • 2008: Practical Tips to Identify the Main Trunk of the Facial Nerve

      • • Pearls

          • The tragal pointer indicates the position of CN VII trunk

          • In re-operations or when the identification is obscured (by the tumor), try the retrograde approach

        • Pitfalls

          • Avoid going directly to the CN VII trunk area before identifying the anatomic landmarks

          • The styloid process is not a good landmark to retrieve the CN VII

  • Extratemporal seventh cranial nerve, components

    • Motor: all the muscles of facial expression, posterior belly of digastric m., stylohyoid m., stapedius m., auricularis posterior m., and occipitalis m.

      • 5 facial branches within parotid: temporal, zygomatic, buccal, marginal mandibular, cervical

    • Sensory: the nervus intermedius of Wrisberg; taste to anterior 2/3 of tongue (via chorda tympani), variably cutaneous sensation from the anterior wall of the EAC

    • Parasympathetic: lacrimal and nasal glands (via greater superficial petrosal nerve), sublingual and submaxillary glands (via chorda tympani)

  • Electrophysiologic facial nerve monitoring during parotidectomy (2010: Electrophysiologic facial nerve monitoring during parotidectomy)

    • 2 case–control studies demonstrated a statistically significant reduction in temporary facial paralysis

    • 1 study demonstrated lower House–Brackmann grade of facial paresis and a shorter duration of paresis

    • 1 study showed a statistically significant reduction in permanent facial paralysis

    • 2 studies demonstrated reduced operative time

  • Incision types 

    • Modified Blair 

    • 2010: Cervicomastoidfacial versus modified facelift incision for parotid surgery: a patient feedback comparison

    • 2015: Modified Blair Incision versus Modified Facelift Incision Combined with Sternocleidomastoid Muscular Flap in Parotidectomy

    • Facelift

    • 2009: Superficial parotidectomy via facelift incision

    • 2011: The extended indication of parotidectomy using the modified facelift incision in benign lesions: retrospective analysis of a single institution

    • 2011: Improving esthetic results in benign parotid surgery: statistical evaluation of facelift approach, sternocleidomastoid flap, and superficial musculoaponeurotic system flap application

      • 2013: Facelift approach for parotidectomy: an evolving aesthetic technique [Review]

    • 2015: Facelift incision and superficial musculoaponeurotic system advancement in parotidectomy: case reports

    • Post-aural hairline

    • 2014: Partial Superficial Parotidectomy via Retroauricular Hairline Incision

    • 2016: Small access postaural parotidectomy: an analysis of techniques, feasibility and safety

  • Neck dissection 

    • General indications for neck dissection related to parotid pathology: 

      • Clinically apparent cervical adenopathy 

      • Parotid tumor > 4 cm 

      • High-grade histology (>40% risk of occult nodal metastasis) - high-grade mucoepidermoid, SCC, adenocarcinoma, undifferentiated carcinoma 

Preparation

• • Ultrasound

  • Facial nerve monitor

    • Tegaderm to secure leads on face 

  • Avoid long-term paralytic agents 

  • Local anesthesia

    • Some (Dr. Rasgon, Dr. Lando, Dr. Fong) prefer to avoid Lidocaine (use pure 1:100,000 Epinephrine) in order to prevent the chance of confounding temporary FN paresis

    • Others permit the use of Lidocaine but infiltrate "superficially"

  • Plan the incision

    • Always anticipate possible future neck dissection 

    • Dr. Rasgon pearl: Post-tragal modified Blair for the cosmetically sensitive patient

Procedure

• Tape ETT to opposite site 

• Tuck ipsilateral arm 

• FN monitor 

  • Mark incision 

• Local injection 

• Broad prep over face, ear and neck

  • Dry prep with sterile towel 

• Drape with 4 towels with exposure of ipsilateral face, ear, and neck

  • 1000 drape for face to keep corner of eye and mouth visible 

• Hash mark at lobule and apex of neck incision

• Incision with 15 blade

• Identify parotid fascia superiorly, may see platsyma inferiorly 

  • Avoid the branches of the greater auricular nerve

• Raise sub-SMAS flap over parotid and sub-platysmal flap in neck anteriorly

  • Avoid penetrating the parotid fascia and the tumor   

• Dissect anterior border of SCM as the posterior limit of dissection

• Identify posterior belly of digastric (most reliable for FN depth) 

• Identify FN landmarks (TM suture line, tragal pointer, parotid-mastoid fascia)

• Dissect the Facial Nerve

  • • Critical portion of the case - meticulously and systematically dissect the FN as needed to gain the ability to excise the tumor and surrounding parotid parenchyma 

  • Divide parotid parenchyma using bipolar or Ligature or Harmonic shears or Shaw knife with 12 blade 

• Irrigate and obtain hemostasis  

• Closure

  • Dr. Wang

    • • Round drain (smallest one) to bulb suction using the "spear"

    • Deep dermis and muscle with buried interrupted 3-0 and 4-0 Polysorb, outer skin with running 5-0 Fast Gut 

    • Bacitracin

  • Dr. Jiang closure

    • • JP drain

      • 3-0 Chromic (parotid fascia to SCM fascia) and buried interrupted 4-0 Chromic (deep dermis)

      • Dermabond, Steri-strips

  • Dr. Rasgon closure

    • Blake #19 (round) drain, exiting 1-2 cm posterior to the inferior aspect of the incision

      • 3-0 Polysorb (parotid fascia to SCM fascia) and 4-0 Polysorb buried (deep dermis), 5-0 Fast Gut running (epidermis)

      • Mastisol, Steri-strips

    • Dr. Iaquinta closure 

      • JP #7 drain

      • 4-0 Chromic (dermis), 5-0 Fast Gut running

      • Bacitracin

    • Dr. Fong / G

      • TLS vs Blake #15 (round) drain, exiting 1-2 cm posterior to the inferior aspect of the incision

      • 4-0 Polysorb buried (deep dermis and platysma), 5-0 Biosyn running subcuticular (epidermis)

      • Mastisol, Steri-strips, Telfa, Tegaderm

Post-op

• • Medications 

    • Analgesic

    • Bacitracin, if suture line is exposed

    • No antibiotics 

  • RTC: Drain removal in ~ POD 3

  • RTC: Remove steri-strips ~ POD 7

  • Complications

  • Sialocele / salivary duct fistula (2005: Treatment of complications of parotid gland surgery, eMedicine: Parotid Duct Injuries)

    • Overall rate ~ 14%, persistent rate ~ 4%

    • Management

      • Reduce oral intake (NGT)

      • Antibiotic (Augmentin), Anticholinergic (glycopyrolate, propantheline)

      • Serial aspiration and pressure dressing +/- Botox injection

      • Non-responsive: Completion parotidectomy, tympanic neurectomy

    • Frey's syndrome 

    • Facial nerve injury

    • Facial Nerve injury s/p parotidectomy (Bailey, Byron J. Head and neck surgery–otolaryngology – 4th ed. Lippincott Williams & Wilkins, Philadelphia, 2006)

      • Temporary facial nerve paralysis involving all or just one of the branches: 10% to 30%

      • Permanent facial nerve paralysis: fewer than 3%

      • Marginal mandibular branch is most at risk for injury

    • Factors associated with facial nerve injury (2005: Facial nerve dysfunction after parotidectomy: the role of local factors)

      • Total parotidectomy (vs. superficial): may be related to stretch injury or interference of vasa nervorum

      • Reoperation, radiation, malignancy, inflammation, extent of nerve dissection, greater size of lesion(s)

      • Overstimulation of the nerve with a nerve stimulator also may be responsible for a temporary paresis

      • Types of nerve injury

      • Seddon's and Sunderland's classification systems

    • Post-operative care and prognosis of FN paresis

      • Describe according to the House-Brackmann Facial Nerve Grading System

      • Provide ophthalmologic care: moisturizing eye drop and ointment, tape eye shut while sleeping

      • Corticosteroids may be used in hopes of avoiding post-op paresis by reducing edema and inflammation; However, studies have failed to demonstrate a benefit in using peri-operative corticosteroids (2008: A prospective, randomized trial for use of prednisolone in patients with facial nerve paralysis after parotidectomy)

      • Temporary paresis usually resolves from weeks to months post-op (2005: Facial nerve dysfunction after parotidectomy: the role of local factors)

        • CN-7 paresis in 131 consecutive parotidectomies: 42.7% POD #1, 30.5% 1 month, 0% at 6 months 

      • Facial nerve reconstruction after injury during parotidectomy

Pearls & Pitfalls

• • Pearls 

    • The anterior limb of the incision extends just anterior to the palpable mass

    • After identifying the FN, retract the parotid toward the surgeon, not away, so that the tissue is lifted up away from the nerve rather than pulling the nerve up

    • Preserve the GAN, if possible - serve as a good warm up nerve dissection before working on the FN

    • Remember to palpate when dissecting down to the FN trunk - feel the tragal pointer and styloid process and TM suture line to know the location of the trunk within ~ 5 mm

    • Keep you exposure during FN dissection as wide as possible 

    • When dissecting the FN, remember "in, up, open" - never open and close, never twist the tips under the FN

    • Dermal-fat graft from the abdomen serves as an excellent source of bulk soft tissue recon over the residual parotid bed 

      • Digastric and SCM are also options

High-Yield

• • What causes Frey's syndrome? 

    • Injury to PARA post from CN 9 via the auriculotemporal nerve (CN 5) = gustatory sweating

Links

• YouTube (7:25) - Superficial Parotidectomy by Dr. Chaplin, New Zealand

• YouTube (8:08) - How to Save to the FN during Parotidectomy by Dr. Soh, Singapore

• Iowa Protocols: Parotidectomy with Facial Nerve Dissection

• eMedicine article: Parotidectomy