From the Guidelines
Deep lobe parotidectomies and concurrent neck dissection are the primary risk factors that increase the likelihood of developing first bite syndrome after parotidectomy. The risk of first bite syndrome (FBS) after parotidectomy is primarily associated with damage to or resection of the sympathetic innervation to the parotid gland. Several specific risk factors increase the likelihood of developing this painful condition, including:
- Deep lobe parotidectomies, which carry a significantly higher risk compared to superficial procedures because they involve dissection closer to the sympathetic fibers that travel with the external carotid artery 1
- Concurrent neck dissection, particularly when it involves the area around the external carotid artery, substantially increases FBS risk by potentially damaging sympathetic nerves
- Resection of the external carotid artery itself is a major risk factor as it directly removes the pathway for sympathetic innervation
- Patients undergoing surgery for malignant tumors face higher risk due to more extensive dissection and greater likelihood of nerve sacrifice The underlying mechanism involves denervation of sympathetic fibers that normally inhibit myoepithelial cell contraction in the parotid gland, leading to an exaggerated parasympathetic response during the first bite of a meal, causing the characteristic acute pain. According to the management of salivary gland malignancy guideline, more aggressive surgery may result in higher risk to the facial nerve, and there are no data available that more aggressive surgery yields improved survival or locoregional control when adjuvant therapy is used 1.
From the Research
Risk Factors for First Bite Syndrome after Parotidectomy
The following factors increase the risk of first bite syndrome after parotidectomy:
- Sympathetic chain sacrifice [ 2 ]
- Parapharyngeal space (PPS) dissection [ 2 ]
- Resection of only the deep lobe of the parotid gland [ 2 ]
- Dissection into the parenchyma of the parotid gland during rhytidectomy [ 3 ]
- Injury or amputation of the cervical sympathetic trunk [ 4 ]
Surgical Procedures Associated with First Bite Syndrome
First bite syndrome has been reported after various surgical procedures, including:
- Parotidectomy [ 2, 5 ]
- Rhytidectomy (face-lift) [ 3 ]
- Carotid body tumor excision [ 4 ]
- Surgery involving the upper cervical region [ 5 ]
Incidence of First Bite Syndrome
The incidence of first bite syndrome after parotidectomy has been reported to be: