Deep neck infection (DNI) is a serious and potentially life-threatening condition that involves the deep fascial spaces of the neck and sometimes the mediastinum [2]. DNI, especially in the anterior cervical spaces, causes substantial scarring due to inflammation and abscesses. This scarring can impair cervical muscle function, which may lead to persistent dysphagia, even after the resolution of infection. Severe scarring may also restrict neck movements. Even with effective acute-phase treatment for DNI, scarring of the pharynx may cause complications, such as pharyngeal stenosis, laryngeal elevation impairment, and reduced pharyngeal contraction, ultimately resulting in dysphagia in approximately 20% of cases [2, 3]. Swallowing rehabilitation and other conservative treatments typically lead to improvement in swallowing in most cases; however, severe cases may require surgical intervention [4].

Osteophytes are bony outgrowths that form on vertebrae, often as a result of chronic inflammation or injury [5, 6]. The formation of anterior cervical osteophytes is a potential long-term complication, especially in severe or recurrent DNIs involving the retropharyngeal and prevertebral spaces [7]. Early and aggressive management of DNIs, including surgical drainage, antibiotic therapy, and prompt initiation of swallowing rehabilitation, is crucial for minimizing the risk of severe scarring and osteophyte formation. Regular follow-up and monitoring of these complications are recommended for patients with a history of deep neck abscesses.

When considering surgical treatment for dysphagia, an important aspect is the accurate evaluation of swallowing function using various imaging tests to identify the underlying cause and location of the impairment. Therefore, it is necessary to select an appropriate surgical procedure to address these issues. In other words, comprehensive and precise imaging examinations are pivotal for understanding the pathology of dysphagia. In the present case, VR rendering of the swallowing CT data allowed near-life-size, three-dimensional visualization, which was useful for easily understanding the movements of bony structures during swallowing, as well as identifying anatomical abnormalities and spatial changes in the pharyngeal cavity. The static imaging evaluation revealed the proximity of the abnormally proliferated cervical vertebrae and the thyroid cartilage; however, it did not allow us to observe how their positional relationship changed during swallowing movements, nor could it visualize pharyngeal contraction three-dimensionally. Moreover, as the abnormal outgrowth of the cervical vertebra was not clearly shown in VFSS, without a CT scan, we might have missed part of the pathological cause of the swallowing disorder in this patient. When a VR system is not available, swallowing dynamics can be simulated by reconstructing the swallowing CT images on a two-dimensional display. However, this image reconstruction typically requires considerable time and does not provide the same flexibility as a VR system for observing swallowing dynamics from different angles.

Swallowing VR has high usability, as it enables the visualization of swallowing dynamic images in a virtual space in approximately 3–5 min by incorporating large amounts of swallowing CT data into the system developed by the corresponding author [1].

This report presents a case of severe dysphagia resulting from extensive neck scarring and adhesion between an abnormal bony outgrowth of the cervical vertebra and thyroid cartilage following deep neck and mediastinal abscesses. To address this, we accurately assessed the condition using HRM and swallowing VR and then conducted the necessary surgical interventions, resulting in an improvement in swallowing function. In conclusion, given the complex pathophysiology of dysphagia after DNI, comprehensive evaluation using HRM and swallowing VR is useful for evaluating these patients and is anticipated to be integrated into clinical practice in the future.