What is the most common complication after parotid (parotid gland) surgery or parotidectomy (surgical removal of the parotid gland)?

Most Common Complication After Parotid Surgery

Frey's syndrome is the most common complication after parotid surgery or parotidectomy, occurring in up to 23.5% of patients following the procedure. 1

Understanding Frey's Syndrome

Frey's syndrome, also known as auriculotemporal syndrome or gustatory sweating, develops due to aberrant regeneration of damaged parasympathetic nerve fibers that inappropriately reinnervate sweat glands in the overlying skin. This causes gustatory sweating and flushing when stimulated by eating 2. The syndrome typically presents as:

• Sweating over the preauricular and temporal areas when eating
• Flushing and warming of the skin in the same region
• Symptoms that develop after an average of 12 months post-surgery 1

Incidence and Presentation

• Almost all patients who undergo parotidectomy will develop some degree of Frey syndrome, but only a minority become symptomatic 3
• Clinical studies show that approximately 23.5% of patients develop detectable Frey's syndrome after parotidectomy 1
• Of those who develop the syndrome, only about 44% are symptomatic enough to require treatment 1
• Recent data from 2023 shows varying incidence rates depending on surgical technique: 3.37% after extracapsular dissection versus 18.18% after superficial parotidectomy 4

Risk Factors for Frey's Syndrome

Several factors influence the development of Frey's syndrome:

• Tumor size: Larger tumors significantly increase risk (43.5 ± 38.4 mm in Frey group vs. 33.1 ± 27.5 mm in No Frey group) 5
• Extent of surgery: More extensive resections increase risk 2
  • Lumpectomy in pre-auricular area: 4.4× higher risk than tail lumpectomy
  • Superficial parotidectomy: 8× higher risk than tail lumpectomy
  • Total parotidectomy: 8.2× higher risk than tail lumpectomy 6
• Repeat parotidectomy: 3.2× increased risk 6
• Benign tumors: Higher risk compared to malignant tumors 6

Other Common Complications of Parotidectomy

While Frey's syndrome is the most common complication, other significant complications include:

1. Facial nerve palsy:

   • Temporary facial weakness: occurs in approximately 27% of cases
   • Permanent facial weakness: occurs in about 2.5% of patients with normal preoperative function 2
   • Rates vary by surgical technique: 4.49% temporary facial paralysis with extracapsular dissection vs. 17.67% with superficial parotidectomy 4

2. Skin flap anesthesia/sensory changes:

   • Often related to greater auricular nerve damage
   • Can cause numbness in the ear lobe and surrounding area

3. Other complications:

   • Salivary fistula: 6-8% of cases 4
   • Sialocele: 3-5% of cases 4
   • Wound dehiscence: 10-12% of cases 4
   • Pathological scarring: approximately 7-8% of cases 4

Prevention and Management

• Surgical techniques to minimize risk:

  • Maintaining thick skin flaps when oncologically appropriate 2
  • Partial superficial parotidectomy for appropriate cases 2

• Treatment options:

  • Intracutaneous injection of botulinum toxin A is the most effective treatment 2, 3
  • Treatment is long-lasting but may need to be repeated if symptoms recur 3

Key Considerations for Clinicians

• Inform patients about the high likelihood of developing Frey's syndrome
• Recognize that symptoms may develop late (average 12 months post-surgery)
• Consider preventive measures for high-risk patients (tumor size ≥4 cm doubles the risk) 5
• Reassure patients that while common, only a minority require treatment for symptoms

In conclusion, while facial nerve palsy and skin flap anesthesia are significant complications of parotid surgery, Frey's syndrome remains the most common complication following parotidectomy based on the available evidence.