Parapharangeal edema: an uncommon complication of TMJ arthroscopy

Case Presentation

We report a 42-year-old woman of Pakistani origin initially presenting with limited mouth opening and TMJ crepitus worse on the left side. She had failed to respond to conservative measures to treat pain, clicking, and locking of the TMJ. She had no other significant past medical history.

Investigations

An MRI scan confirmed that there was evidence of internal derangement of the left TMJ (Wilke stage II). The scan indicated that there was bone marrow edema at the left mandibular condyle and the articular disk is dislocated anterolaterally with its posterior edge contacting the mandibular condyle at 9 o clock position.

Treatment

The patient was scheduled to have left TMJ arthroscopy and arthrocentesis. The procedure was performed under nasoendotracheal general anesthesia. A careful joint puncture was made with an 18-g needle in the posterior recess of the superior compartment from an inferolateral approach, and then a trocar followed by insertion of the scope into the superior compartment. Backflow of the irrigation fluid was confirmed along with intra-articular visualization. The joint compartment was continually lavaged with approximately 200 ml of saline. The OnPoint-TM 1.2 mm Scope System was used. (Biomet).

Outcome and Follow-up

Patent backflow of the irrigation fluid was obtained. However, immediately postoperatively we noticed swelling and edema of the left lateral face and neck that would not settle. Inspection by the anesthetist with a laryngoscope confirmed the presence of floor of the mouth swelling and left parapharangeal swelling following extravasation of fluid (Fig. 1). Fifteen minutes postoperatively the swelling and edema worsened (Fig. 2).

The decision was made to delay extubation by one hour because the patient was at risk of airway obstruction. One hour later the swelling had begun to resolve sufficiently for extubation. Six hours postextubation, the swelling and edema had completely resolved (Fig. 3). The patient was kept under observation overnight on the ward.

Discussion

As the number of performed TMJ arthroscopy increases, the case reports of related complications have also increased 3. Reported cases of complications include vascular injury 4, otologic injury 5, neurologic injury 5, instrument failure 6, and perforation of the middle cranial fossa 7 and extradural hematoma 8. There have only been a few published cases of the complication of parapharangeal edema resulting in a prolonged intubation period. Carls et al. in 1996 9 reported one case out of a study of 451 TMJ arthroscopies to have the complication of ipsilateral parapharyngeal swelling noticed at the end of the arthroscopic procedure and extubation was postponed for one hour. Ahmed et al. in 2012 10 reported another case out of a study of 244 patients that were kept in overnight for observation after prolonged intubation of 4 h because of involvement of the vocal folds in tissue edema. In both cases, extravasation of fluid through the medial joint capsule was attributed as the cause of the complication. Figure 4 illustrates the fascial spaces in the head and neck. Note the fluid leakage into the lateral pharyngeal space deep to the medial pterygoid muscle.

Learning Points

Conflict of Interest

None declared.