The esophagus is the muscular tube that connects the pharynx to the stomach. As such, it’s buried a little more deeply in the digestive system than speech-language pathologists usually venture. SLPs have more commonly been the primary providers in treating oral and pharyngeal dysphagia, but physicians have traditionally been called in to diagnose and treat esophageal dysphagia.
But as with so much of the profession of speech-language pathology, technology is pushing some of the boundaries and giving SLPs greater agency to investigate dyshageas occurring more deeply in the swallowing tract.
One of these advances is the availability of transnasal esophagoscopy to perform manometry tests of the upper esophagus or lower pharyngeal tract.
Expanding the Diagnostic Range of Speech-Language Pathologists
Manometry is a measurement of pressure within the gastrointestinal (GI) tract. A thin, pressure-sensitive tube is passed through the nose and into the esophagus. Readings sent back through the tube can give an indication of the strength and coordination of the muscles used to perform the swallowing reflex.
Transnasal endoscopy uses the same basic technique, but rather than inserting a pressure sensing device, it makes use of a thin fiber-optic camera that allows for visual inspection of the esophagus.
In the past, most esophagoscope procedures were conducted transorally, a riskier procedure usually requiring a physician, and sometimes involving putting the patient under sedation.
The availability of transnasal insertion has lowered the risk factor and become a procedure that SLPs are increasingly being allowed to perform in their scope of practice.
How Transnasal Esophagoscopy Is Performed
A topical anesthetic is applied at the point of insertion and a water-based lubricant is used to help the tube pass through the nose more easily and comfortably. The insertion can be performed blindly, with physiognomic exercises used to ensure that it enters the esophagus, or it can be guided visually with an endoscope.
Once inserted, the patient is asked to swallow repeatedly so the sensors can measure the activity in the esophagus. A visual plot is displayed for the SLP to view and interpret. The most common of these is the Clouse Plot, a color-coded time/pressure plot that tracks the course of muscular activity through the swallowing movement.
Newer manometry sets incorporate more sensors along their length, which in turn presents a more detailed picture of muscle function in the esophagus. This high-resolution manometry is increasingly becoming incorporated into the SLP scope of practice both for diagnostic and post-therapeutic assessments.
Having gained an accurate picture of how the esophageal musculature functions, the SLP can diagnose the sources of the dysphagia. They may find:
- Weakened muscles in portions of the swallowing tract
- Spasms occurring in muscles
- Paralysis or hyper contractile dysfunction
Each of these will have a different treatment approach, which SLPs can assess later by performing another manometry scan.
Learning To Perform Transnasal Esophagoscopy as a Speech-Language Pathologist
Although transnasal esophagoscopy is a safer and simpler procedure than its predecessors, it still comes with risks and requires a high degree of technical competence to perform safely and accurately.
ASHA, the American Speech-Language-Hearing Association, has not developed a formal policy on training or service delivery for transnasal esophagoscopy, whether it is used for dysphagia patients or other purposes. However, part of ASHA’s code of ethics requires that all SLPs perform whatever services they are offering competently. It’s left to the SLP and medical professionals to determine what the exact standards are in this case.
Because esophagoscopy has traditionally been performed by physicians, training on the procedure is also most likely to be conducted by a doctor. Otolaryngologists and other specialists in the upper digestive tract will have been taught these subjects in medical school, and often pass their knowledge along to SLPs.
This is most common for SLPs who work in dedicated medical settings, such as hospitals. Transnasal esophagoscopy is an outpatient procedure that can be performed with the patient awake and back on the street in an hour, but it’s not something that is happening in the school nurse’s office just yet.
Some medical centers, such as at the University of Cincinnati, are establishing dedicated voice and swallowing clinics where SLPs and physicians work side by side to provide both treatment and follow-up therapy for speech and language issues that demand the services of both. These environments are ideal for learning transnasal esophagoscopy techniques under experienced and professional supervision.
As the technique expands, however, more and more SLPs are likely to begin learning and performing it. With a wider knowledge base and broader diagnostic tools in their kit, the profession will be even better equipped to handle swallowing disorders originating in any part of the swallowing tract.