Title: Improving the Diagnostic Capability of the Modified Barium Swallow Study Through Standardization of an Esophageal Sweep Protocol
Authors: Watts, Gaziano, Jacobs, & Richter
Year of Publication: 2019
Design Type: two-phase retrospective review
Purpose: Aims of the current investigation were to (1) delineate the percentage of normal, oropharyngeal, esophageal, and mixed swallowing dysfunction, (2) develop operational definitions for rating our standardization cursory view of esophageal bolus flow, and (3) determine inter-rater reliability between speech pathology (SLP) and physician raters for categorizing esophageal abnormalities.
Population: outpatients referred to a university-based tertiary care center with an on-site dedicated swallowing staff
Inclusion criteria: patients referred for MBSS from variety of different provider specialties
Exclusion criteria: inability to complete the esophageal sweep protocol; this refers to patients with aspiration risk for large bolus swallows and positioning limitations who did not undergo the sweep protocol during evaluation and (2) previous enrollment in a research study that excluded esophageal observation from the protocol
At the end of a long VFSS, don’t you just wanna REST?! That is, a “Robust Esophageal Screening Tool!” This article is one that asks a question, uses that curiosity to find some possible solutions, and pushes our field forward in providing the best care for our patients and across disciplines.
- Only got a sec?
- Adding this screening to the MBS protocol for appropriately selected patients can facilitate improved accurate and timeliness of esophageal diagnoses, with more research needed for other populations
- Only got a minute?
- “we identified that one in four patients (26%) had an esophageal cause for their dysphagia, and this swallowing abnormality would have gone undetected in the standard MBS without esophageal observation“
- “Categorically, anatomic abnormality was the most common classified finding at 69% of the sample followed by dysmotility (such as retrograde bolus movement and obvious tertiary contractions) at 17% and a combined impairment at 14%“
- “When possible, additional esophageal testing confirmed the suspected etiology of esophageal dysphagia identified on MBS with appropriate standard esophageal testing…all 42 instances were found to have esophageal abnormality on gold standard testing“
- “This “modernized MBS” may reduce the risk that the etiology of a swallow complaint goes undetected and thus untreated. It is a simple, easily reproducible, efficient addition to the MBS study that has a high diagnostic yield“
- Got more time? Keep Reading!!
It’s the age-old, controversial question: “To sweep or not to sweep.” There’s much debate over this add-on to our radiographic swallow studies (although Dr. Martin-Harris is pioneering some more change!), but one thing is usually pretty certain: having some type of systematic way of identifying and describing physiology is much more helpful than going in blind, unaware, or avoiding.
If you’re wondering why we might even want to peek down the drain, besides pointing out the complex and dynamic multi-phase nature of swallowing, the authors also use the evidence to speak for itself:
“It has been shown that patients are more accurate in identifying the location of proximal dysphagia than distal problems. Therefore, up to one-third of patients who complain of lower throat symptoms may actually have an esophageal cause for dysphagia.” p.2
Add in the fact that there are multiple studies supporting this VFSS cursoryASHA but also The American College of Radiology (ARC). So while these 2 fields might be shutting the door on figuring this out, the authors decided to stick their foot in the door to hold it open and see what can be done.extra yet many vague recommendations for implementation from not only
At their “university-based tertiary care center with dedicated swallow staff” where unless it is deemed “unsafe for a patient” or “significant positioning limitations,” they are able to routinely implement a standardized esophageal sweep protocol for any patient referred for an MBS from any provider (including ENT, pulmonology, neurology, GI, internal medicine, allery, rheumatology).
From 2015 to 2016 the authors completed their 2 phases for the study:
- Phase 1:
- review of 205 MBS studies
- Phase 2:
- revision of operational scoring definitions
- after 4 months from initial review, 153 MBS studies were added to the originals which were also re-rated with new revised criteria (n=358 total randomized MBS studies reviewed)
Why were there 2 phases?
Along with getting more specific and descriptive in the terms and definition requirements they were going to use, the authors also incorporated the fact that “previous research has shown up to a 1 min transit time for normal bolus passage; (2–60 s for 20 mL of liquid, 1–60 s for a 13-mm tablet and, 4–60 s for barium paste),” and they decided to clarify the definitions and alter the protocol “by allowing for an upward limit of 60 s for bolus flow time for each bolus.”
The MBS Protocol:
What did their MBS studies look like??
- SLP who’s “jointly licensed to provide radiology technician services uner direct physician supervision“
- Lateral+AP viewing plane
- C-arm unit with recording at a rate of 29.98 fps
- Range of texures/volumes with compensatory strategies as needed
The R.E.S.T. protocol
And as for the rest of the R.E.S.T. protocol🥸:
“Judgements of bolus flow through the esophagus were made in AP view during 4 swallows:”
- ¼ graham cracker coated with 5 cc Varibar barium paste
- 13 mm barium tablet
- 1 large swallow of barium contrast through the length of the esophagus
- (uncontrolled volume) patient administered
- 1 large swallow of barium contrast at the lower esophagus through the LES
- (uncontrolled volume) patient administered
- 30 and 60 sec views taken if bolus passage was delayed
- sip of water provided if barium contrast did not clear at 60 sec with results recorded
And it keeps ketting better…
An SLP with “greater than 30 years of experience performing/interpreting MBS studies” and GI specialist who had “extensive swallowing specialization training” were blinded to patient demographics and diagnostic information when reviewing all MBS studies.
While I assume the SLP only rated the oropharyngeal as either “normal” or “abnormal” for study-purposes, both SLP+gastroenterologist used the operational definitions to have a final rating for the esophageal sweep as either:
- only if ALL 4 swallows were considered normal
- Anatomic Abnormality
- any deviation for solid, pill hang-up, liquid tapering, or deviation of straight esophageal contour
- Retention of bolus >1 min and following liquid wash, pill retrograde >1 min, non-peristaltic contractions with retention >1 min
- Combined abnormality
**(FYI the article also gives great images for examples of what these categories would look like on MBS🤩)
A quick look at who the MBSs looked at (and who they didn’t):
- Average age of sample: 60 y/o (range 15-95)
- 54% female
- Normal oropharyngeal swallow: 23% (n=71)
- Oropharyngeal dysphagia: 51% (n=156)
- Both oropharyngeal+esophageal deficit: 14% (n=43)
- Esophageal deficit only: 12% (n=37)
- “There was excellent agreement between the same raters [SLP and MD]“
Phase 1 looked pretty similarly in those results, the only difference?
The agreement between SLP and MD improved!! We also can’t overlook the fact that “14% in total from both groups one and two were excluded from the total sample analysis (n=51)” based off the exclusion criteria above. So with the majority of participants still able to complete the study and analysis, we’re looking at a pretty representative group (at least for outpatients😉)!
If you’re wondering which different diagnoses and specific populations they looked at, unfortunately we’ll have to wait for future studies to look deeper into this.
Please Keep In Mind:🤓
- We cannot 🤞yet🤞 directly generalize these findings to more inpatient or other practice settings other than outpatient
- We have to remember this was at only one specific (highly specialized) center, which could possibly inflate the likelihood of finding esophageal concerns (think about all those excluded😉)
- We don’t know for sure the sensitivity/specificity of the sweep protocol yet
- Most of us might not have the expertise of those involved, so we can’t be sure the results would have the same reliability across different experience levels or backgrounds
Luckily the authors are already “on it” and looking ahead at all these limitations:
“Typically these patients are more mobile, oriented, and able to follow multi-step commands needed to complete the sweep protocol than individuals in an inpatient setting. A prospective investigation on the feasibility of implementation of this sweep, percentage of esophageal findings in an inpatient setting, and the reliability of SLP ratings using our definitions is being implemented.”
“future studies should determine reliability of ratings between speech pathology raters with varying degree of swallowing expertise as well as speech pathologists and radiologists.”
“It would be beneficial to implement a prospective study and to confirm esophageal abnormalities detected on the sweep in all patients with standard esophageal testing to determine true indication of disease and calculate the presence of treatable disease.” p.8
But, we DO have lots of results as far as what the additional sweep found this time around!
**(The authors also share a very easy-to-read “contingency table” that is basically a 4-square for all the listed options above!)
“Using the revised operational definitions, esophageal dysfunction was identified in 80 (26%) patients. Categorically, anatomic abnormality was the most common classified finding at 69% of the sample followed by dysmotility (such as retrograde bolus movement and obvious tertiary contractions) at 17% and a combined impairment at 14%.”
“When possible, additional esophageal testing confirmed the suspected etiology of esophageal dysphagia identified on MBS with appropriate standard esophageal testing including: high-resolution esophageal manometry, endoscopy, or timed barium esophagram.” p.5
“From this additional testing, all 42 instances were found to have esophageal abnormality on gold standard testing. The following final diagnoses were made: achalasia/outflow obstruction (n=8), stricture (n= 5), combination of esophageal findings (n=12), and hiatal hernia (n=7).” p.5
Along with some more detailed diagnoses that physicians confirmed, the authors go on to share some treatment plans for those cases which included options such as dilation, botox, medication, surgery, behavioral strategies, or follow up when indicated (also the option of NO follow up).
So what have we learned?
Besides the fact that “a growing body of literature supports the inter-related swallowing systems and potential benefit of assessing swallow function more comprehensively; from mouth to esophagus into the stomach,” the use of the authors’ systematic approach and concise criteria resulted in:
“identified that one in four patients (26%) had an esophageal cause for their dysphagia, and this swallowing abnormality would have gone undetected in the standard MBS without esophageal observation.”
“Over half of patients identified had confirmed esophageal etiologies with standard esophageal
testing and underwent subsequent medical treatment such as upper endoscopy with dilation, pneumatic dilation, or were referred for a surgical consult.” p.5
The implications to that both clinically and in the research world are enlightening, a bit jaw-dropping, and inspiring. These are the kinds of facts and figures we as clinicians can push forth to admin, supervisors, and other medical professionals (whom we still need to be a part of a team) in order to provide the BEST care for all of our patients!👏👏
This initial evidence can be even more crucial especially when the authors make the case of the “dying art” that is barium studies due to a “sharp decline in barium imaging stuies performed” for the following reasons:
- increased use of endoscopy and advanced imaging techniques
- relatively low reimbursement rate
- perception of barium studies as “low tech” imaging
- labor-intensive workforce
- (in my opinion also the shortage in qualified radiologists/professionals as well!)
So, a lot more work still needs to be done not only to further confirm the results thus far, but also in gaining momentum and getting colleagues on board for change, advancements, and evidence. That being said, at least some of us can now feel better about getting a little more R.E.S.T.😉🥱😴
Watts, S., Gaziano, J., Jacobs, J., & Richter, J. (2019). Improving the Diagnostic Capability of the Modified Barium Swallow Study Through Standardization of an Esophageal Sweep Protocol. Dysphagia, 34(1), 34-42. doi: 10.1007/s00455-018-09966-5
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