Clinical Tolerance of an Intraparotid Injection of Bupivacaine, Combined With Dexamethasone, After Parotidectomy for Benign Tumor

There has been a paradigm shift toward less invasive surgical techniques for parotidectomies, primarily to mitigate post-surgical complications. However, preserving more parotid tissue than with traditional methods can lead to an increased incidence of salivary fistulas and sialoceles after parotidectomy. The incidence of sialoceles varies considerably from 4.9% to 39%, while salivary fistula rates after parotidectomy range from 1% to 21%. Other wound complications, such as wound dehiscence, inflammation, and infection, can also occur, typically within the first month following surgery. No preventive technique has yet demonstrated clear efficacy or superiority in clinical practice.

Bupivacaine is an amino-amide commonly used for local anesthesia. With its long-acting anesthetic effects, bupivacaine blocks the autonomic pathways (parasympathetic and sympathetic), then the sensory pathways, and finally the motor pathways. By providing prolonged blockade of the parasympathetic nerve pathways that induce salivary secretion, bupivacaine injected into the parotid tissue during surgery could be a potentially effective prophylactic agent for preventing salivary fistulas after parotidectomy. Certain adjuvants can be used locally in combination with bupivacaine to prolong the duration of nerve blocks and improve postoperative pain management. Dexamethasone is the most effective adjuvant to long-acting local anesthetics. This combination is widely used in routine practice.

Due to its sustained blockade of parasympathetic nerve fibers, intraparotid bupivacaine, combined with local dexamethasone, could be an effective tool for reducing various postoperative complications, including sialoceles and salivary fistulas, after partial parotidectomy. It could also play a major role in postoperative analgesia. Although bupivacaine is commonly used in surgical practice, there are no data regarding the injection of bupivacaine combined with dexamethasone into the parotid tissue to prevent salivary complications after partial parotidectomy. Therefore, the safety of its use when injected specifically into the parotid tissue has never been evaluated.

The aim of this pilot study is to assess the tolerability of intraparotid injection of bupivacaine combined with a local injection of dexamethasone after partial parotidectomy for a benign tumor.