Abstract
Background:
High-resolution esophageal manometry (HREM) is the gold standard test for esophageal motility disorders. Nasopharyngeal airway-assisted insertion of the HREM catheter is a suggested salvage technique for failure from the inability to pass the catheter through the upper esophageal sphincter (UES). It has not been demonstrated that the nasopharyngeal airway improves procedural success rate.
Methods:
Patients undergoing HREM between March 2019 and March 2023 were evaluated. Chart review was conducted for patient factors and procedural success rates before and after use of nasopharyngeal airway. Patients from March 2019 to May 2021 did not have nasopharyngeal airway available and were compared to patients from May 2021 to March 2023 who had the nasopharyngeal airway available.
Results:
523 HREM studies were conducted; 234 occurred prior to nasopharyngeal airway availability, and 289 occurred with nasopharyngeal airway availability.
There was no difference in HREM catheter UES intubation rates between periods when a nasopharyngeal airway attempt was considered procedural failure (85% vs 85%, p=0.9). Nasopharyngeal airway use after UES intubation failure lead to improved UES intubation rates (94% vs 85%), p<0.01). 36 patients that failed HREM catheter UES intubation had the procedure reattempted with a nasopharyngeal airway, 30 (83%) of which were successful. The nasopharyngeal airway assisted catheter UES intubation for failures attributed to nasal pain and hypersensitivity, gagging, coughing, and pharyngeal coiling.
Conclusion:
Utilization of the nasopharyngeal airway increased rates of UES intubation. When HREM catheter placement through the UES fails, placement of a nasopharyngeal airway can be trialed to overcome patient procedural intolerance.
Keywords: esophageal dysmotility, esophageal motility, high resolution esophageal manometry, achalasia, epiphrenic diverticulum, nasopharyngeal airway, nasal trumpet
Graphical Abstract
Two, sequential, 18-month periods of HREM studies were compared. Without usage of the nasopharyngeal airway, there was no change in procedural success, but after employment of the nasopharyngeal airway, technical success rates of HREM significantly improved between time periods.
Introduction
High resolution esophageal manometry (HREM) is the gold standard for esophageal motility disorder diagnosis.1,2 Prompted by the evaluation of symptoms of dysphagia, chest pain, and regurgitation, among others, HREM studies can confirm diagnosis of esophageal motility disorders, rumination syndrome, and supragastric belch.1,3 Complete HREM study acquisition can be crucial in making a definite diagnosis of esophageal dysmotility and guide therapy. HREM is also required for most 24-hour pH-impedance studies.
HREM is performed by passing a catheter intranasally through the pharynx, down the esophagus, and into the proximal stomach.1,4,5 Catheter placement can be difficult and uncomfortable for many patients.6 Causes of HREM catheter placement failure can be conceptualized through the location of the technical difficulty, as above the esophagus or within the esophagus. Prior studies have demonstrated that 17–29% of HREM studies are technically imperfect or failed.7–9 Causes of failure to complete HREM studies include patient intolerance through gagging or coughing, inability to traverse the nasopharynx, or inability to traverse the esophagogastric junction (EGJ).8,9
Failure to pass the lower esophageal sphincter (LES) and full EGJ with the HREM catheter has been associated with structural abnormalities of the esophagus causing obstruction, like large hiatal hernias, epiphrenic diverticula (ED), and achalasia in different studies.9,10 In these patients, esophageal motility evaluation must be made with different studies. Alternatives include HREM catheter placement with EGD assistance, endoscopic functional lumen imaging probe (FLIP), or barium esophagram.8,9,11
Difficulty with insertion of the HREM catheter into the esophagus can be caused by narrow or sensitive nares, or due to pharyngeal sensitivity from coughing or gagging. Strategies to help the HREM catheter pass the nares are focused on reducing sensitivity. Methods suggested to circumvent nasal issues include widening the nasal passage with decongestants or numbing the nostrils with topical lidocaine.12 Gagging and coughing are suggested to be overcome through relaxation techniques and patient distraction.12 When these strategies fail, the patient requires HREM catheter placement with EGD assistance, FLIP, or barium esophagram.8,9,11 This would delay diagnosis as a new appointment would need to be made to evaluate esophageal motility.8
We described another technique, i.e., the use of a nasopharyngeal airway to facilitate the passage of the HREM catheter through the nares.8,13 The nasopharyngeal airway is a soft, hollow, plastic tubing that runs externally through the nares, terminating in the pharynx. This technique has also been described to diminish coughing and gagging and allow for proper placement of the catheter. It has been suggested as a next step for HREM catheter placement that can be performed at the bedside during the same patient appointment to troubleshoot failures of HREM catheter upper esophageal sphincter (UES) intubation.13 However, while the nasopharyngeal airway has been used successfully to place HREM catheters, it has yet to be demonstrated if the placement the nasopharyngeal airway improves rates of procedure completion. This study aims to demonstrate all predictors of HREM catheter placement failure and determine if the nasopharyngeal airway improves technical rates of HREM catheter UES intubation.
Methods
Patient Cohort
This was a non-profit study of patients who had HREM studies at the Baltimore VA Medical Center and the University of Maryland Medical Center between March 2019 and March 2023 were evaluated. Starting from May 2021, the nasopharyngeal airway was available for daily use as a salvage technique for failed HREM catheter placement. Chart review was conducted for patient demographics and procedural success. Procedural success was determined prior to and after the use of nasopharyngeal airways and was defined as achieving a complete HREM study, as described below. All patients older than age 18 referred for HREM were included. Patients under the age of 18 were excluded. Any patient that had the study canceled without an attempt of placement of the HREM catheter were also excluded. Patients that were anxious about probe insertion, patients that could not follow commands, and a patient that was made uncomfortable by lidocaine application and did not want to proceed were excluded.
Patients undergoing HREM studies from March 2019 to May 2021 were compared to those who had HREM tests from May 2021 to March 2023. From March 2019 to May 2021, a nasopharyngeal airway was not used in any patients. Beginning May 2021, the nasopharyngeal airway was available for failed catheter placement.
Catheter placement failure definitions
An overall procedural failure is deemed if the HREM catheter is not positioned for acquisition of the study. This includes passage through the UES and LES into the proximal stomach. In this study, initial failure rate is defined by the inability to intubate the UES with the HREM catheter or the need to use the nasopharyngeal airway to intubate the UES with the HREM catheter. Final procedure failure rate compares the two time periods’ all cause ability to ascertain a complete HREM study, where usage of the nasopharyngeal airway is not considered a procedural failure. Failure to traverse the LES is defined by the presence of catheter curling patterns on HREM, or the inability to identify the LES. For this rate, patients that did not traverse the UES were not included. A large hiatal hernia is defined as greater than or equal to 3 cm.
HREM protocol
A standardized protocol was used for all HREM studies, as previously defined.13 All patients first gargled 10 mL of 2% lidocaine solution for 10 seconds. Then, 3–5 mL 4% lidocaine viscous solution is applied by syringe trans nasally. Patients are asked which nose they feel is more open prior to an attempt at insertion of the HREM catheter coated in surgical lubricant. If that nostril did not work, the other was attempted after a re-application of lidocaine viscous solution and re-lubrication of the catheter. For patients that failed HREM catheter placement due to tight nares, nasopharyngeal hypersensitivity indicated by patients expressing discomfort of the HREM catheter during insertion, gagging, or coughing, a nasopharyngeal airway was inserted. These patient responses are common when placing an HREM catheter, and not all instances of these symptoms require use of the nasopharyngeal airway. The nasopharyngeal airway was employed when a patient would verbally indicate that they thought the procedure was uncomfortable but were amenable to a reattempt through this method. Surgical lubricant is applied to the external surface of the nasopharyngeal airway prior to careful insertion into a patient’s nasopharynx. The HREM catheter was also coated in surgical lubricant. While keeping the patient’s neck in the flexed position, the HREM catheter was inserted through the lumen of the nasopharyngeal airway until the catheter is in the stomach. The nasopharyngeal airway was then withdrawn, and the catheter was taped in place before proceeding with testing. Manometry was performed by the same providers: two experienced medical assistants and a nurse practitioner in the presence of the same single gastroenterology physician motility specialist. Nasopharyngeal airways were disposed after use and were only used a single time.
The protocol for placement of the HREM catheter was standardized throughout both time periods. If initial HREM catheter placement failed from May 2021 to March 2023, a nasopharyngeal airway with adjustable flange [size 24 French, OD 8.0 mm (Teleflex Medical Inc.)] was placed (Figure 1A). Diversatek InSIGHT Ultima or InSIGHT G3 system and HREM catheters (Catalog # UNI-ESO-WG1A1) were used in all patients (Figure 1B).
Figure 1.
HREM catheter placement via a nasopharyngeal airway. A. A representative nasopharyngeal airway with adjustable flange used in the study. B. A representative Diversatek HREM catheter used in the study. C. A patient undergoing HREM using a nasal trumpet after successful insertion of a Diversatek HREM probe.
All HREM was re-interpreted to ensure the LES was identified and to identify catheter curling. Catheter looping or inability to identify the LES was considered both an overall procedural failure, and a failure to traverse the LES.
Statistical methods
Quantitative variables are displayed as means and standard deviations. Qualitative data is represented as percentages. Quantitative variables were analyzed using t-tests, and qualitative data was analyzed using chi-square tests and Fisher’s Exact tests when appropriate. A sensitivity analysis was used to select variables for the final model, using the Breslow-Day test to evaluate for effect modification. Multivariable analysis was conducted using binary logistic regression and a backwards elimination. For this model, the significant level for elimination was 0.10. This was used to determine variables that were significant for prediction of procedural failure between the two time periods. Data was analyzed using SAS (Cary, NC, USA).
Results
Cohort demographics
529 HREM studies were scheduled throughout the entirety of the period reviewed. 6 patients did not meet inclusion criteria due to inability to follow commands (2), anxiety about the procedure (2), gagging and discomfort after lidocaine application (1), and dyspnea with oxygen desaturation on presentation (1), resulting in in 523 patients having the procedure attempted. 234 occurred prior to nasopharyngeal airway availability. 289 occurred with a nasopharyngeal airway available for salvage (Figure 1C). There were no detectable differences between age, BMI, height, gender, distribution of studies between centers, or rates of nasal surgery when comparing those that successfully had the UES intubated with the HREM catheter without any nasopharyngeal airway assistance to those that did not have the UES successfully traversed with the catheter or required nasopharyngeal airway assistance (Table 1).
Table 1.
Summary of covariates for the prediction of initial UES intubation failure rate without incorporation of the nasopharyngeal airway, independent of sampling period. Initial procedural failure and success are determined prior to nasopharyngeal airway usage, such that employment of the nasopharyngeal airway use would count as a failure.
| Initial UES intubation failure | Initial UES intubation success | p-value | |
|---|---|---|---|
| N | 79 (15.1%) | 444 (84.9%) | - |
| Age (years) | 56.5±14.4 | 57.5±14.1 | 0.53 |
| BMI | 29.7±6.2 | 29.6±6.6 | 0.93 |
| Height (inches) | 66.6±4.1 | 67.0±4.0 | 0.39 |
| Gender (% female) | 41 (51.9%) | 223 (50.0%) | 0.76 |
| History of nasal surgery (%) | 6 (7.6%) | 31 (7.0%) | 0.84 |
| Location (% University) | 53 (67.1%) | 287 (64.6%) | 0.65 |
474 of the 523 patients had the UES traversed by the HREM catheter. Of these 474 patients, 25 had catheter curling patterns or did not reach the LES indicating a failure of traversal of the LES. When comparing those with complete HREM studies to those with LES traversal failure, there were no detected differences in BMI, height, gender, or study location. When compared to patients with complete HREM studies, patients that did not have the HREM catheter successfully traverse the LES were older (65.5±11.9 vs 57.0±14.2, p<0.01), more frequently had large hiatal hernias (60% vs 6.9%, p<0.01), more commonly were diagnosed with achalasia (36% vs 9.1%, p<0.01), and more frequently had ED (16% vs 0.9%, p<0.01). The presence of any hiatal hernia was also more likely in patients that failed to have the HREM catheters successfully placed (60% vs 39%, p=0.04), but notably, all of the failed LES traversals were in cases of large hiatal hernias, not small hiatal hernias (Table 2).
Table 2.
Summary of covariates for the prediction of the rate of failure to traverse the LES, independent of sampling period.
| Total that traversed the UES | LES failure | LES success | p-value | |
|---|---|---|---|---|
| N (%) | 475 | 25 (5.3%) | 450 (94.7%) | - |
| Age (years) | 57.4±14.1 | 65.5±11.9 | 57.0±14.2 | <0.01 |
| BMI | 29.7±6.6 | 28.4±6.5 | 29.7±6.6 | 0.37 |
| Height (inches) | 67.1±4.1 | 66.5±3.6 | 67.1±4.1 | 0.53 |
| Gender (% female) | 234 (49.4%) | 13 (52.0%) | 221 (49.2%) | 0.79 |
| Location (% University) | 302 (63.7%) | 17 (68.0%) | 285 (63.5%) | 0.83 |
| All hiatal hernias | 190 (40%) | 15 (60%) | 175 (39.15) | 0.04 |
| Large hiatal hernia | 31 (6.92%) | 15 (60%) | 31 (6.9%) | <0.01 |
| Achalasia | 50 (10.6%) | 9 (36%) | 41 (9.1%) | <0.01 |
| Epiphrenic diverticulum | 8 (1.7%) | 4 (16%) | 4 (0.9%) | <0.01 |
Effect modification of large hiatal hernia, ED, and achalasia was not detected by the Breslow-Day test, but notably, there was minimal overlap of these uncommon entities. Multivariable logistic regression was then performed to evaluate for prediction of failure to traverse the LES. The variables, age, height, BMI, gender, procedure location, presence of a large hiatal hernia, achalasia, and ED were included, and a backwards elimination method of variable selection was conducted. Gender, study location, BMI, height, and age were removed by the procedure. The odds of treatment failure were predicted by achalasia (odds ratio (OR)=21.2, 95% confidence interval (CI) =5.4–82.8, p<0.01), large hiatal hernias (OR=48.8, 95% CI=13.3–178.6, p<0.01), and ED (OR=81.7, 95% CI=11.3–591.3, p<0.01), with an overall significant model (p<0.01).
When evaluated by study time-period, initial all cause HREM catheter placement failure rate was 20.5% in the two initial years without nasopharyngeal airway availability, and 19.4% in the two years with nasopharyngeal availability prior to its use, with no difference in procedural success detected between these time periods (p=0.75). Initial UES intubation failure rate, defined as an inability to traverse the UES or requirement to use a nasopharyngeal airway, was similar between the two time periods (15.4% vs 14.9%, p=0.87). Impediments to procedural success included nasal hypersensitivity, nasal pain, and a narrow nasal passage. Rates of a nasal cause leading to placement failure were similar between groups (9.8 vs 11.8%, p=0.48). Rates of patient intolerance leading to initial HREM UES intubation failure included coughing and gagging, and trended toward a difference (5.6% vs 2.4%, p=0.06). Other causes for failure included coiling of the HREM catheter in the pharynx, inability to traverse the LES, and double swallows, all of which were similar between groups. Patients trended toward being more likely to undergo nasal surgery during the time-period prior to nasopharyngeal airway availability (9.4 vs 5.2 p=0.06) (Table 3).
Table 3.
Summary data for all patients in the study, and comparisons of patient characteristics, reason for failure, and final diagnosis stratified by time periods of the study.
| Overall | Prior to nasopharyngeal airway availability (March 2019-May 2021) |
Nasopharyngeal airway available (May 2021-March 2023) |
p-value | ||
|---|---|---|---|---|---|
| N | 523 | 234 | 289 | - | |
| Age (years) | 57.4±14.2 | 57.4±14.5 | 57.4±14.0 | 0.98 | |
| BMI | 29.6±6.5 | 29.4±6.4 | 29.8±6.7 | 0.51 | |
| Height (inches) | 67.0±4.0 | 67.1±4.0 | 66.9±4.1 | 0.61 | |
| Gender (% female) | 50.3 | 47% | 53% | 0.17 | |
| History of nasal surgery (%) | 37 (7.1%) | 22 (9.4%) | 15 (5.2%) | 0.06 | |
| Location (% University) | 339 (65%) | 157 (67%) | 182 (63%) | 0.33 | |
| Initial failure rate independent of nasopharyngeal airway placement | Total initial overall failure rate (%) | 104 (19.9%) | 48 (20.5%) | 56 (19.4%) | 0.75 |
| Initial failure rate to pass the UES | 79 (15.1%) | 36 (15.4%) | 43 (14.9%) | 0.87 | |
| Nasal hypersensitivity/ narrow nasal passage (%) | 57 (10.9%) | 23 (9.8%) | 34 (11.8%) | 0.48 | |
| Coughing/gagging (%) | 20 (3.8%) | 13 (5.6%) | 7 (2.4%) | 0.06 | |
| Pharyngeal coiling (%) | 2 (0.38%) | 0 (0%) | 2 (0.69%) | 0.20 | |
| Other (double swallows) | 1 (0.2%) | 0 (0%) | 1 (0.35%) | 0.37 | |
| Cannot traverse LES | 25 (4.8%) | 10 (4.3%) | 15 (5.2%) | 0.63 | |
| Nasopharyngeal airways attempted | 36 | - | 36 | - | |
| Successful catheter placement after nasopharyngeal airway (%) | 30 (83%) | - | 30 (83%) | - | |
| Final failure rate | Total final procedural failure rate (%) | 80 (15.3%) | 48 (20.5%) | 32 (11.1%) | <0.01 |
| Final failure rate to pass the UES | 53 (10.1%) | 36 (15.4%) | 17 (5.9%) | <0.01 | |
| Achalasia (%) | 50 (9.6%) | 24 (10.3%) | 26 (9.0%) | 0.63 | |
| Major Chicago Classification disorder (%) | 153 (32%) | 59 (25%) | 94 (32%) | 0.26 | |
The final UES intubation failure rate improved from 14.9% to 5.9% after the nasopharyngeal airway was available. The final procedural failure rate after employment of the nasopharyngeal airway subsequently was lower during the period where the nasopharyngeal airway was available. The period prior to nasopharyngeal airway availability yielded a final procedural failure rate of 20.5%, compared to a final procedural failure rate of 11.1% when the nasopharyngeal airway was available (p<0.01) (Table 3).
Multivariable logistic regression for final HREM UES intubation failure rate was conducted. The variables age, height, BMI, gender, history of nasal surgery, location of procedure, and availability of the nasopharyngeal airway were included, and a backwards elimination method for variable selection was conducted. Age, BMI, gender, history of nasal surgery, and procedure location were all removed by the procedure. The odds of catheter UES intubation failure was predicted by both lack of availability of a nasopharyngeal airway (OR=3.6, 95% CI of 1.9–6.9, p<0.01), and height (OR=0.91, 95% CI of 0.84–0.99, p=0.02) with an overall significant model (p<0.01).
36 of the 43 patients that failed HREM catheter placement during the period where the nasopharyngeal airway was available had the procedure attempted again during the same visit with the nasopharyngeal airway. 7 patients that failed HREM catheter placement during the time-period of nasopharyngeal airway availability did not have a nasopharyngeal airway placement. Of these 7 patients, 5 had nasopharyngeal pain, tightness, or hypersensitivity and 2 had coughing or gagging. These patients declined re-attempting the procedure with a nasopharyngeal airway. 2 of the patients that had a nasopharyngeal airway inserted to overcome nasal pain and gagging subsequently did not have a complete study due to an inability to traverse the LES despite the nasopharyngeal airway allowing successful placement of the catheter past the UES. Both patients were later diagnosed with achalasia through alternative means. Of the 36 patients that had a nasopharyngeal airway placed due to a failure to intubate the UES with the HREM catheter, 30 patients (83%) were able to have the catheter successfully placed in the esophagus. The nasopharyngeal airway was successful in achieving HREM catheter placement in 82.8% of failures from a nasal impediment, 80% of gagging and coughing, and 100% of oropharyngeal coiling (Table 4). There were no complications from placement of the nasopharyngeal airway.
Table 4.
Summary data for all patients that had a nasopharyngeal airway attempted. Those that subsequently achieved procedural success were compared to those that did not. Patient characteristics, reason for failure, and final diagnosis are included.
| Overall | Persistent HREM UES intubation failure after nasopharyngeal airway | UES intubation success after nasopharyngeal airway | ||
|---|---|---|---|---|
| N | 36 | 6 | 30 | |
| Age (years) | 53.4±15.9 | 46.8±24.2 | 54.7±14.0 | |
| BMI | 30.2±6.8 | 29.2±5.1 | 30.4±7.1 | |
| Height (inches) | 67.5±4.3 | 65.5±3.2 | 67.9±4.5 | |
| Gender (% female) | 16 (44.4%) | 4 (66.7%) | 12 (40%) | |
| History of nasal surgery (%) | 4 (11.1%) | 1 (16.7%) | 3 (10%) | |
| Location (% University) | 19 (52.8%) | 3 (50%) | 16 (53%) | |
| Cause of failure | Total | 36 | 6 (16.7%) | 30 (83.3%) |
| Nares (%) | 29 (80.6%) | 5 (17.2%) | 24 (82.8%) | |
| Coughing/gagging (%) | 5 (13.9%) | 1 (20%) | 4 (80%) | |
| Pharyngeal coiling (%) | 2 (5.6%) | 0 (%) | 2 (100%) | |
| Achalasia (%) | 2 (5.6%) | - | 2 (6.7%) | |
| Major Chicago Classification disorder (%) | 10 (27.8%) | - | 10 (33.3%) | |
Discussion
In this observational, cohort study, it was demonstrated that HREM catheter placement success improved in our motility labs after availability of a nasopharyngeal airway. Failure to traverse the nares due to pain, discomfort, or a narrow nasal passage were the most common causes for an inability to pass the nares and UES, followed by procedural intolerance due to gagging or coughing. Other reasons for inability to traverse the UES included coiling of the catheter in the pharynx. After introduction of the nasopharyngeal airway to our motility labs, total procedural success rate improved from 79.5% to 88.9% as UES intubation rates by the HREM catheter improved from 85.1% to 94.1%. The nasopharyngeal airway was successfully used to pass the UES in 83% of the studies.
Shorter stature also appeared to increase the likelihood of HREM catheter placement according to the multivariable logistic regression model. This is likely due to a correlation of patient size with the size of their nasal passage.14 Gender, age, and the location of the study between our two centers did not predict UES catheter traversal failure.
An inability to traverse the LES with the HREM catheter was predicted by the presence of ED, large hiatal hernias, and achalasia. This study newly identifies an association between catheter curling and large hiatal hernias, which was previously described as causing technically imperfect studies, not critically imperfect studies.9 In patients with known large hiatal hernias, catheter curling within the hernia appears possible. However, it is likely that withdrawing the catheter a few centimeters and reinserting it could allow for traversal of the LES. Careful attention should be given to patients with large hiatal hernias to ensure there is not a curling pattern, as it is possible that this can be circumvented. Future studies are warranted to explore this strategy. This study reinforces associations between achalasia and LES traversal failure, as similar rates are reported in this study to that performed by Hengehold et al.9 This study reinforces the association between ED and LES traversal failure described by Cohen et al, and this study does so with consecutive patients.10
Age and gender did not predict the failure of the HREM catheter to traverse the LES on multivariable analysis. This varies from what had been reported in literature, where age and gender have been reported to predict success of catheter placement. A prior study showing the significance of age in predicting failure of the catheter to traverse the LES was a three group comparison where the largest difference in age was between non-critically imperfect studies and technically perfect studies.9 In this study, we compare critically failed studies to acceptable studies, so this age and gender difference between groups is mitigated by inclusion of technically perfect and non-critically imperfect studies as a single group.
There are limitations to this study as a retrospective study performed under the same motility expert. Because the centers are affiliated and under the supervision of a single motility expert (GX), the generalizability of the study to other centers may be limited. The main criticism of this study is the potential for performance bias as a retrospective study. As a retrospective cohort study, the two groups, determined by nasopharyngeal airway availability occurred sequentially. This in theory could introduce a bias to the proceduralists, as they would have more experience by the time the nasopharyngeal airway was introduced to our motility labs. However, our pre-nasopharyngeal airway procedural success rate of passing the UES in this study was equivalent, at 85% in both 2019–2021 and 2021–2023. This appears to be consistent with our previously reported rate of 80% in 2017.8 After introduction of the nasopharyngeal airway, our ability to traverse the UES improved from 85% to 94%. Failure rate was reduced by 60% after adding the nasopharyngeal airway to our protocol for HREM catheter placement. We believe a change this large is still attributable to the employment of the nasopharyngeal airway.
The nasopharyngeal airway is smooth, hollow, flexible, and is easily compressible, making its placement easy. The HREM catheter is not smooth, as it has external bumps from the pressure sensors on the catheter, is not compressible like the nasopharyngeal airway, and is more rigid, especially at the tip (Figure 1B). The bumps from the pressure sensor create nonuniform contact with the nasal mucosa, creating intermittent pressure points on the mucosal surface, increasing hypersensitivity, and increasing the chance of the catheter to push deeply into the nasal mucosa. In addition, the less flexible tip may push into the nasal mucosa as the nasal passage makes its turn into the pharynx. We hypothesize that the naturally curved nasopharyngeal airway prevents the HREM catheter tip from pushing into the back walls of the nares, temporarily dilates a congested nasal passage, and assists in an even distribution of contact from the pressure sensors during the procedure. This diminishes hypersensitivity and prevents the catheter from getting stuck against the soft walls of the nares.
In six patients, the nasopharyngeal airway still did not allow for passage of the HREM catheter through the UES after initial failure. While a useful tool to surmount hypersensitivity and to prevent the HREM catheter from pushing against the walls of the nares and getting stuck, if the nasal passage is truly too narrow for the HREM catheter to pass, the nasopharyngeal airway would not be able to assist in its passage at it also reduces the circumferential area of the nasal passage.
Overall success in placing the HREM catheter in other labs, such as Washington University in St. Louis, has been reported to be as high as 97% using Medtronic’s ManoScan™ HREM catheters.9 This is higher than our motility labs success rate of 89% after employment of the nasopharyngeal airway. Reasons for procedural failure may be technician related, however the catheter used in these two studies are different. This study employs Diversatek catheters, which have pressure sensors external to the catheter (Figure 1B). This has the potential to cause friction to both cause patient sensitivity, as well as getting caught while traversing the nares. Another study that used the same catheters had an overall placement success rate of 92%.15 A multi-center cohort, reported HREM catheter placement success rate of 87%.16 No conclusions should be drawn regarding the success rates of different catheter placement from this study. The nasopharyngeal airway appears to hold value at improving HREM catheter placement rates, and the success rate in this study appears to be congruent with what has been described in literature.15,16 However, the utility of the nasopharyngeal airway in the most expert tertiary care centers has yet to be explored.
Our experience with the nasopharyngeal airway is that it is better tolerated than the previous HREM catheter placement attempts without the nasopharyngeal airway. Future studies could explore this with survey data exploring patient satisfaction with and without the nasopharyngeal airway.
When HREM catheter placement fails, there are alternative studies available for diagnosis.17 The advent of FLIP, and the utility of a timed barium esophagram should not be understated, especially in the cases of inability to traverse the LES with the HREM catheter.11,18 However, high-resolution esophageal manometry is still considered the gold standard for diagnosing esophageal motility disorders.1 Usage of a nasopharyngeal airway is technically easy. We demonstrate the improvement of our overall technical success from 80% to 89% by adding the nasopharyngeal airway to our protocol with no complications. When HREM catheter placement through the UES fails, placement of a nasopharyngeal airway can be trialed to overcome patient procedural intolerance.
Funding:
Andrew Leopold was supported by the US National institutes of Health, grant number T32 DK067872-19.
Abbreviations:
- HREM
high resolution manometry
- EGJ
esophagogastric junction
- UES
upper esophageal sphincter
- LES
lower esophageal sphincter
- FLIP
Functional lumen imaging probe
- ED
epiphrenic diverticulum
Footnotes
Conflict of Interest Statement: All authors have no conflicts of interest to disclose.
Data availability statement is as follows:
The data that support the findings of this study are available from the corresponding author upon reasonable request.
References
- 1.Yadlapati R, Kahrilas PJ, Fox MR, et al. Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0((c)). Neurogastroenterol Motil. 2021;33(1):e14058. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Kahrilas PJ, Clouse RE, Hogan WJ. American Gastroenterological Association technical review on the clinical use of esophageal manometry. Gastroenterology. 1994;107(6):1865–1884. [DOI] [PubMed] [Google Scholar]
- 3.Kessing BF, Bredenoord AJ, Smout AJ. Objective manometric criteria for the rumination syndrome. Am J Gastroenterol. 2014;109(1):52–59. [DOI] [PubMed] [Google Scholar]
- 4.Kahrilas PJ, Bredenoord AJ, Fox M, et al. The Chicago Classification of esophageal motility disorders, v3.0. Neurogastroenterol Motil. 2015;27(2):160–174. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Bredenoord AJ, Fox M, Kahrilas PJ, et al. Chicago classification criteria of esophageal motility disorders defined in high resolution esophageal pressure topography. Neurogastroenterol Motil. 2012;24 Suppl 1(Suppl 1):57–65. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Cohen DL, Shirin H. Technical success in performing esophageal high-resolution manometry: a review of competency recommendations, predictors of failure, and alternative techniques. Dis Esophagus. 2023;36(8). [DOI] [PubMed] [Google Scholar]
- 7.Roman S, Kahrilas PJ, Boris L, Bidari K, Luger D, Pandolfino JE. High-resolution manometry studies are frequently imperfect but usually still interpretable. Clin Gastroenterol Hepatol. 2011;9(12):1050–1055. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Christian KE, Morris JD, Xie G. Endoscopy- and Monitored Anesthesia Care-Assisted High-Resolution Impedance Manometry Improves Clinical Management. Case Rep Gastrointest Med. 2018;2018:9720243. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Hengehold T, Rogers B, Gyawali CP. Imperfect high-resolution manometry studies: Prevalence and predictive factors. Neurogastroenterol Motil. 2022;34(6):e14273. [DOI] [PubMed] [Google Scholar]
- 10.Cohen DL, Bermont A, Richter V, Avivi E, Mari A, Shirin H. Technical Success in Performing Esophageal High-Resolution Manometry in Patients with an Epiphrenic Diverticulum. Dysphagia. 2024;39(2):282–288. [DOI] [PubMed] [Google Scholar]
- 11.Carlson DA, Gyawali CP, Khan A, et al. Classifying Esophageal Motility by FLIP Panometry: A Study of 722 Subjects With Manometry. Am J Gastroenterol. 2021;116(12):2357–2366. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Gyawali CP. Making the most of imperfect high-resolution manometry studies. Clin Gastroenterol Hepatol. 2011;9(12):1015–1016. [DOI] [PubMed] [Google Scholar]
- 13.Leopold A, Wellington J, Jalalian A, Xie G. Nasal trumpet harmoniously improves tolerance to high-resolution impedance manometry catheter placement. Neurogastroenterol Motil. 2022;34(5):e14340. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Kim HJ, Roh Y, Yun SY, et al. Comparison of the selection of nasotracheal tube diameter based on the patient’s sex or size of the nasal airway: A prospective observational study. PLoS One. 2021;16(3):e0248296. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Tariq H, Makker J, Chime C, Kamal MU, Rafeeq A, Patel H. Revisiting the Reliability of the Endoscopy and Sedation-Assisted High-Resolution Esophageal Motility Assessment. Gastroenterology Res. 2019;12(3):157–165. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Sato C, Sato H, Kamei T, et al. Characteristics of patients with esophageal motility disorders on high-resolution manometry and esophagography-a large database analysis in Japan. Esophagus. 2022;19(1):182–188. [DOI] [PubMed] [Google Scholar]
- 17.Yadlapati R, Furuta GT, Menard-Katcher P. New Developments in Esophageal Motility Testing. Curr Treat Options Gastroenterol. 2019;17(1):76–88. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Blonski W, Kumar A, Feldman J, Richter JE. Timed Barium Swallow: Diagnostic Role and Predictive Value in Untreated Achalasia, Esophagogastric Junction Outflow Obstruction, and Non-Achalasia Dysphagia. Am J Gastroenterol. 2018;113(2):196–203. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.