Videofluoroscopic Swallow Study: Techniques, Signs and Reports Margareta Bülow
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Detection Cichero J, Clavé P (eds): Stepping Stones to Living Well with Dysphagia. Nestlé Nutr Inst Workshop Ser, vol 72, pp 43–52, Nestec Ltd., Vevey/S. Karger AG., Basel, © 2012 Videofluoroscopic Swallow Study: Techniques, Signs and Reports Margareta Bülow Diagnostic Centre of Imaging and Functional Medicine, Skåne University Hospital Malmö, Malmö, Sweden Abstract Management of oropharyngeal swallowing dysfunction often requires both a clinical and an instrumental examination. A videofluoroscopic swallowing study is an instrumental examination that often could be a good option and a very useful tool for the swallowing clinician. At Skåne University Hospital, Malmö, Sweden, the name of such examination is therapeutic videoradiographic swallowing study (TVSS). A TVSS examination should always be performed in collaboration between a speech language pathologist and a radi- ologist. During the examination, the patient is seated in an upright position, but the examination can also be performed with the patient lying down. The TVSS examination can be performed both in frontal and lateral projection. Test material with varied consis- tencies as well as different therapeutic strategies can be tested during the examination. Any oral and/or pharyngeal dysfunction can be defined, for example a delay in the initia- tion of the pharyngeal swallow or an absent pharyngeal swallow, pharyngeal retention, penetration, and silent aspiration. After the examination, an analysis is performed, and it is studied how different textures affect the physiology of swallowing. A report is then written in which the actual dysfunction is described in detail, and recommendations regarding modified textures and swallowing techniques are given. Copyright © 2012 Nestec Ltd., Vevey/S. Karger AG, Basel Introduction In the management of oropharyngeal swallowing dysfunction, both clinical and instrumental swallowing examinations may be necessary. Clinical experience and research findings provide evidence that aspiration, and more importantly the cause of aspiration, can be missed during observations made from test swal- lows included in a clinical or bedside examination [1]. The instrumental technique has to be chosen based on what the clinician wants to know to be able to take decisions regarding appropriate therapeutic management. At the Diagnostic Centre of Imaging and Functional Medicine, Skåne University Hospital, Malmö, Sweden, radiology has for many years been the first- choice instrumental technique to examine oropharyngeal swallowing problems. We differentiate between two radiological swallowing examinations. One is the more traditional hypopharynx- esophagus examination with focus on morphologic aspects. The other one is the videofluoroscopic swallowing exami- nation with focus on swallowing function, and at our hospital it is named thera- peutic videoradiographic swallowing study (TVSS). The therapeutic swallowing study is a dynamic procedure, and the mechanical passage of food and liquid with varied textures and viscosity can be followed from the mouth to the stomach. For a comprehensive examination, observation of oral bolus manipulation, lingual motility efficiency of mastication, timing of pharyngeal swallow initiation, soft palate elevation and retraction, tongue base retraction, pharyngeal contraction, superior and anterior hyolaryngeal movement, epiglottic inversion and extent and duration of pharyngoesophageal segment opening have to be observed. Also therapeutic strategies can be tested during such swallowing examinations, and their effect on the swallowing physiology analyzed [2– 11]. The TVSS examina- tion should always be performed in collaboration between a speech language pathologist (SLP) and a radiologist. The combination of the expertise of the two professionals makes the examination an excellent diagnostic tool (fig. 1). Equipment To perform a TVSS examination, a laboratory with radiologic fluoroscopic equipment is required. Recording and storage of the examination require a com- puter disc or videotape that makes it possible to analyze structural movements in relation to contrast flow in slow motion and frame by frame after the exami- nation. However, in most radiological settings, digital radiography is nowadays used, and for storage different high- resolution videofluoroscopic digital record- ing devices are used. Afterwards, the examination can be transmitted digitally to an electronic picture archiving and communication system. Such techniques are easy to handle, provide rapid retrieval, and the availability is excellent. Any pathophysiology can be analyzed in detail related to the flow of the given tex- tures. Disordered timing and coordination of structural movement as well as the presence, degree, timing and cause of aspiration can be documented. The examination can be performed using minimal radiation doses. In a study from the UK, the authors found that the radiation doses were 0.2 mSv dose area for the average videofluoroscopic examination [12]. From our clinical experi- ence, we have found that the radiation exposure time in the average case is 2– 3 min (fig. 2). 44 Bülow Fig. 1. The fluoroscopy suite with the SLP, the radiologist, and the patient prepared for a swallowing examination in lateral projection. The Procedure To be able to perform a TVSS examination, and for an accurate and reliable implementation and interpretation of test results, specialized training for both the SLP and the radiologist is required [13]. At our hospital, the SLP has her own schedule at the laboratory and has the opportunity to schedule 8 patients every week. This makes the availability to the radiology suite easier, and the patient can often be scheduled for the examina- tion within short time, and sometimes if necessary the same day the clinical examination has been performed. During the examination, the radiologist operates the fluoroscopic equipment and observes anatomic abnormalities. The SLP takes decides how to perform the exam- ination often based on observations of the patient during a bedside examination. The assistant nurse feeds the patient. If possible, the patients feed themselves, which gives important information about their habitual eating and drinking behaviors. Videofluoroscopy 45 Fig. 2. Patient positioned in lateral view during a videofluoroscopic swallowing examina- tion. A severe dysfunction can be seen with both aspiration to the trachea, and pharyn- geal residue. Focus during the TVSS examination is on the oral and the pharyngeal phases of swallowing. Most often, the study begins with the subject positioned in lat- eral view, the optimal position for visualizing penetration or aspiration of mate- rial into the laryngeal vestibule before, during, and after swallowing. The profile contours of the soft palate, base of the tongue, posterior pharyngeal wall, epi- glottis, aryepiglottic folds, anterior hypo- pharyngeal wall and the region of the cricopharyngeal muscle or pharyngoesophageal segment can be observed in the lateral view. If necessary, the patient is then positioned in a frontal view permit- ting observation regarding asymmetric contours, the surface of the base of the tongue, median and lateral glossoepiglottic folds, tonsillar fossa, valleculae and hypopharynx. In most cases, the patient is seated in an upright position, but if necessary it is also possible to perform the examination with the patient lying down. Fixed routines are used, but it is also possible, if necessary, with an individually adapted examination (table 1). Different textures are given to the patient to identify optimal food and liquid that facilitates a safe and efficient oral intake. Every patient has to be given his or her individual combination of test material depending on the nature of the swallowing problem. 46 Bülow Table 1. Routines during the examination Radiologist Operates the fluoroscopic equipment Observes anatomic abnormalities Analyzes the exam together with the SLP SLP Makes decisions about how to perform the procedure, often based on a clinical examination Completes the swallowing protocol Analyzes the exam together with the radiologist Writes the report Assistant nurse Prepares the fluoroscopy suite for examination Assists the patient before and after the procedure Prepares the test material Feeds the patient In our research, we have found that carbonated liquids can be a good option to improve swallowing for many of our patients, and such liquids are therefore included in our routine protocol. It is, however, of importance that the liquid has been individually tested before being prescribed [14]. Also, cold sour tex- ture may be a good option for several dysphagic patients [15]. Sometimes, it could be observed that oral nutrition is not possible due to a severe swallowing dysfunction. In such cases, tube feeding may be regarded as the only safe and efficient option for feeding. However, sometimes the patient could have tube feedings as the primary source of nutrition and hydration, com- bined with safe supplementation of small amounts of modified food and liquid textures for pleasure and optimization of quality of life. The test material is prepared according to our recipe, composed after many years of clinical experience and collaboration with a dietician. The test material is mixed with barium contrast in the hospital kitchen, with assis- tance from a nurse from the radiological department. Our test materials are prepared from ordinary food that makes it easy to recognize and is thereby familiar to our patients.