This includes a set of examinations that enable us to study various aspects of swallowing physiology.
Videofluoroscopy (VFS) is currently considered to be the “gold standard” examination to assess oropharyngeal swallowing. It is a low-radiation radiological examination that enables real-time analysis of the transport of the food bolus from the mouth to the oesophagus, detects dysfunctions in the oral and pharyngeal phase of swallowing, guides the treatment of oropharyngeal dysphagia and assesses the efficacy of different therapeutic strategies.
Video 1 shows an example of normal swallowing.
The following contrast media are used: barium, iodine contrasts (used in our unit). Boluses of different volume (3, 5, 10 and 15 ml) and viscosity (liquid, nectar, pudding and solid) are examined in a lateral and anteroposterior projection, recording the images on a video camera.
In general, the examination starts with 3-ml boluses of a safe consistency (pudding). The boluses are gradually increased in volume (up to 15 ml), subsequently assessing the remaining viscosities (the examination is interrupted if aspiration occurs or if the patient does not collaborate with swallowing).
The most significant videofluorscopic parameters in the oral phase are: lingual propulsion, glossopalatal seal, delayed triggering of the swallowing reflex; and in the pharyngeal phase: pharyngeal residue (accumulated food debris in the pharynx) and tracheal aspiration (food contents entering the airway, with the risk of aspiration pneumonia) and dysfunction in the opening of the upper oesophageal sphincter.
Video 2 shows an example of tracheal aspiration.
Oesophageal manometry measures the motor activity of the oesophagus and its sphincters in baseline conditions and in response to swallowing. When studying oropharyngeal dysphagia this examination provides us with information about the strength of pharyngeal propulsion, pressure at rest and relaxation of upper oesophageal sphincter during swallowing.
The procedure uses a multichannel catheter connected to a manometric system. The patient must undergo the test after a few hours fasting to prevent the risk of vomiting. The manometric catheter is inserted through the nose and, once in place, pressures are measured at different point of the oesophagus. LES pressure is assessed at rest and after swallowing, the contractions of the oesophageal body, UES pressure at rest and pharyngoesophageal coordination after swallowing.
At our unit we use this examination to study UES function before indicating treatment with botulinum toxin.