Minimally Invasive Surgical Approach for Odontoid Lesions: A Technical Description in a Case of High Cervical Osteomyelitis and Abscess.

Background: Cervical approaches to the dens are limited by the presence of several structures, including the spinal cord, vertebral arteries, C1 articular pillars, and C2 nerves. Surgical approaches to access the high anterior cervical spine classically encompass the extended anterior retropharyngeal route, transoral route, and extreme lateral route, each of which has its own pattern of morbidity or complications. Percutaneous procedures to drain infections in this area have a limited yield. Osteomyelitis of the dens is a rare but serious condition that is associated with significant mortality. Patients with cervical osteomyelitis and epidural abscess are likely to have significant coexistent medical comorbidities and are often poor candidates for extensive surgical procedures. A minimally invasive approach that gives access to the entire odontoid process would allow for more aggressive treatments and potentially even a complete odontoidectomy without resection of the C1 anterior arch.

Case Description: We describe a minimally invasive approach to drainage and debridement of an atlantoaxial epidural abscess and osteomyelitis. Using minimally invasive techniques from a posterolateral trajectory in a cadaveric specimen, we were able to safely access the anterior epidural space, odontoid, and retropharynx. We then performed this approach in our patient who was unable to tolerate a large surgical procedure.

Conclusions: We developed, tested, and then applied a minimally invasive approach that combined tubular retractors with positioning of the head and neck to optimize the exposure in a patient with a complex abscess that involved the ventral epidural space, odontoid process, and retropharyngeal space. The abscesses were successfully drained along with local tissue debridement without complication. A posterolateral minimally invasive approach is a safe alternative in patients with an atlantoaxial epidural abscess, odontoid osteomyelitis, or retropharyngeal abscess with significant medical comorbidities who are unlikely to tolerate a more extensive surgery. It can also be used for resections of lesions of an oncologic nature and could even be used to resect pannus or os odontoideum, without necessitating an anterior approach or resection even of the C1 arch.