The Effect of STW5 (Iberogast) on Reflux Symptoms in Patients With Concurrent Dyspeptic Symptoms: A Double-blind Randomized Placebo-controlled Crossover Trial.

Background/Aims: It has been suggested that STW5 (Iberogast) reduces heartburn symptoms in patients with functional dyspepsia, but underlying mechanisms of action are unclear. The aim of this study is to investigate whether STW5 affects esophageal sensitivity or esophageal motility, thereby reducing occurrence and perception of reflux events. Methods: We performed a double-blind, randomized, placebo-controlled, crossover trial in patients with functional dyspepsia (Rome IV) and reflux symptoms. After 4 weeks of treatment with either placebo or STW5, patients were studied with an esophageal acid perfusion test and ambulatory 24-hour pH-impedance monitoring. Results: A total of 18 patients (7 men, median age 54, range [19-76]), were included in the study. Although we found no statistical difference in our primary outcome the total Reflux Disease Questionnaire score 2.33 (0.25-4.33) vs 2.67 (1.17-4.00), P = 0.347, "gastroesophageal reflux disease" and "regurgitation" subscale scores were lower after STW5 treatment compared to placebo (P = 0.049 and P = 0.007). There was no statistical difference in number of reflux events, acid exposure time and acid sensitivity scores between STW5 and placebo. In a subgroup analysis of patients with pH-metry confirmed gastroesophageal reflux disease, treatment with STW5 significantly reduced the total number of acidic reflux events (P = 0.028). Moreover, in patients with reflux esophagitis, the median lag time to acid perception increased after STW5 treatment (P = 0.042). Conclusions: We found some indications pointing towards a beneficial effect of STW5 on reflux symptoms in dyspeptic patients, with reduction of esophageal hypersensitivity as a potential underlying mechanism. Our findings will have to be confirmed in larger studies.

The inability to belch syndrome: A study using concurrent high-resolution manometry and impedance monitoring.

INTRODUCTION: Although inability to belch has previously been linked to dysfunction of the upper esophageal sphincter (UES), its underlying pathogenesis remains unclear. Our aim was to study mechanisms underlying inability to belch and the effect of UES botulinum toxin (botox) injections in these patients. METHODS: We prospectively enrolled consecutive patients with symptoms of inability to belch. Patients underwent stationary high-resolution impedance manometry (HRIM) with belch provocation and ambulatory 24-h pH-impedance monitoring before and 3 months after UES botox injection. RESULTS: Eight patients (four males, age 18-37 years) were included. Complete and normal UES relaxation occurred in response to deglutition in all patients. A median number of 33(15-64) gastroesophageal gas reflux episodes were observed. Despite the subsequent increase in esophageal pressure (from -4.0 [-7.7-4.2] to 8 [3.3-16.1] mmHg; p < 0.012), none of the gastroesophageal gas reflux events resulted in UES relaxation. Periods of continuous high impedance levels, indicating air entrapment (median air presence time 10.5% [0-43]), were observed during 24-h impedance monitoring. UES botox reduced UES basal pressure (from 95.7[41.2-154.0] to 29.2 [16.7-45.6] mmHg; p < 0.02) and restored belching capacity in all patients. As a result, esophageal air presence time decreased from 10.5% (0-43.4) to 0.7% (0.1-18.6; p < 0.02) and esophageal symptoms improved in all patients (VAS 6.0 [1.0-7.9] to 1.0 [0.0-2.5]; p < 0.012). CONCLUSION: The results of this study underpin the existence of a syndrome characterized by an inability to belch and support the hypothesis that ineffective UES relaxation, with subsequent esophageal air entrapment, may lead to esophageal symptoms.

Long-term effects of anti-reflux surgery on the physiology of the esophagogastric junction.

BACKGROUND: Studies performed shortly after anti-reflux surgery have demonstrated that the reduction of reflux episodes is caused by a decrease in the rate of transient lower esophageal sphincter relaxations (TLESRs) and a decrease in the distensibility of the esophagogastric junction (EGJ). We aimed to assess the long-term effects of surgical fundoplication on the physiology of the EGJ. METHODS: We included 18 patients who underwent surgical fundoplication >5 years before and 10 GERD patients who did not have surgery. Patients underwent 90-min combined high-resolution manometry and pH-impedance monitoring, and EGJ distensibility was assessed. RESULTS: Post-fundoplication patients exhibited a lower frequency of reflux events than GERD patients (2.0 ± 0.5 vs 15.1 ± 4.3, p < 0.05). The rate of TLESRs (6.1 ± 0.9 vs 12.6 ± 1.0, p < 0.05) and their association with reflux (28.3 ± 9.0 vs 74.9 ± 6.9 %, p < 0.05) was lower in post-fundoplication patients than in GERD patients. EGJ distensibility was significantly lower in post-fundoplication patients than in GERD patients. Recurrence of GERD symptoms after fundoplication was not associated with an increased number of reflux episodes, nor was it associated with an increased distensibility of the EGJ or an increase in the number of TLESRs. CONCLUSION: More than 5 years after anti-reflux surgery, patients still exhibit a lower rate of TLESRs and a reduced distensibility of the EGJ compared with medically treated GERD patients. These data suggest that the effects of surgical fundoplication on EGJ physiology persist at the long term and underlie the persistent reduction of reflux events.

Effects of anxiety and depression in patients with gastroesophageal reflux disease.

BACKGROUND & AIMS: Increased levels of anxiety and depression have been associated with esophageal hyperalgesia and an increased risk of gastroesophageal reflux disease (GERD). We investigated the effects of anxiety and depression on GERD symptoms and the perception of reflux episodes in a well-characterized group of patients. METHODS: We performed a prospective study of 225 consecutive patients who had symptoms of GERD evaluated. Patients underwent ambulatory 24-hour pH impedance monitoring, and levels of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. RESULTS: GERD was diagnosed in 147 patients (78 patients had functional heartburn); 36 patients were hypersensitive to gastroesophageal reflux. Among patients with GERD, increased levels of anxiety were associated with more severe retrosternal pain and retrosternal burning. Furthermore, increased levels of anxiety and depression each were associated with lower scores of the mental component of quality of life questionnaire. Levels of anxiety or depression were not associated with the number of reflux symptoms reported during 24-hour pH impedance monitoring or with the number of symptoms associated with a reflux event. Among GERD patients with hypersensitivity to reflux, levels of anxiety and depression and decreases in quality of life were similar to those of other patients with GERD. Patients with functional heartburn had higher levels of anxiety than patients with GERD. CONCLUSIONS: In patients with GERD, increased levels of anxiety are associated with increased severity of retrosternal pain and heartburn and reduced quality of life. Patients with GERD with hypersensitivity to gastroesophageal reflux have similar levels of anxiety and similar quality-of-life scores as other patients with GERD.

The pathophysiology, diagnosis and treatment of excessive belching symptoms.

Excessive belching is a commonly observed complaint in clinical practice that can occur not only as an isolated symptom but also as a concomitant symptom in patients with gastroesophageal reflux disease (GERD) or functional dyspepsia. Impedance monitoring has revealed that there are two mechanisms through which belching can occur: the gastric belch and the supragastric belch. The gastric belch is the result of a vagally mediated reflex leading to relaxation of the lower esophageal sphincter and venting of gastric air. The supragastric belch is a behavioral peculiarity. During this type of belch, pharyngeal air is sucked or injected into the esophagus, after which it is immediately expulsed before it has reached the stomach. Patients who belch excessively invariably exhibit an increased incidence of supragastric, not of gastric belches. Moreover, supragastric belches can elicit regurgitation episodes in patients with the rumination syndrome and sometimes appear to induce reflux episodes as well. Behavioral therapy has been proven to decrease belching complaints in patients with isolated excessive belching, but its effect is unknown in frequently belching patients with GERD, functional dyspepsia or rumination.

Current diagnosis and management of the rumination syndrome.

The rumination syndrome is a behavioral condition characterized by postprandial regurgitation. In contrast to what many think, the disorder does not exclusively occur in mentally disabled patients or children but also in otherwise healthy adults. As symptoms of postprandial regurgitation are often mistaken for gastroesophageal reflux disease or vomiting, the rumination syndrome is an underappreciated condition. Rumination episodes are caused by an intragastric pressure increases which forces the gastric content into the esophagus and mouth and occurs during 3 distinct mechanisms: primary rumination, secondary rumination, and supragastric belch-associated rumination. Combined manometry-impedance can distinguish rumination from gastroesophageal reflux disease. Treatment of the rumination syndrome consists of a thorough explanation of the mechanisms underlying the rumination episodes and behavioral therapy. As behavioral therapy is a time-consuming and often expensive treatment, we propose that a clinical suspicion of the disorder is always confirmed by a manometry-impedance measurement.

Water-perfused esophageal high-resolution manometry: normal values and validation.

Water-perfused high-resolution manometry (HRM) catheters with 36 unidirectional pressure channels have recently been developed, but normal values are not yet available. Furthermore, the technique has not been validated and compared with solid-state HRM. We therefore aimed to develop normal values for water-perfused HRM and to assess the level of agreement between water-perfused HRM and solid-state HRM. We included 50 healthy volunteers (mean age 35 yr, range 21-64 yr; 15 women, 35 men). Water-perfused HRM and solid-state HRM were performed in a randomized order. Normal values were calculated as 5th and 95th percentile ranges, and agreement between the two systems was assessed with intraclass correlation coefficient (ICC) statistics. The 5th-95th percentile range was 3.0-6.6 cm/s for contractile front velocity (CFV), 141.6-3,674 mmHg·s·cm for distal contractile integral (DCI), 6.2-8.7 s for distal contraction latency (DL), and 1.0-18.8 mmHg for integrated relaxation pressure (IRP 4s). Mean (SD) and ICC for water-perfused HRM and solid-state HRM were 4.4 (1.1) vs. 3.9 (0.9) cm/s, ICC: 0.49 for CFV; 1,189 (1,023) vs. 1,092 (1,019) mmHg·s·cm, ICC: 0.90 for DCI; 7.4 (0.8) vs. 6.9 (0.9) s, ICC: 0.50 for DL; and 8.1 (4.8) vs. 7.9 (5.1), ICC: 0.39 for IRP 4s. The normal values for this water-perfused HRM system are only slightly different from previously published values with solid-state HRM, and moderate to good agreement was observed between the two systems, with only small differences in outcome measures.

Objective manometric criteria for the rumination syndrome.

OBJECTIVES: The rumination syndrome is a behavioral disorder resulting in recurrent regurgitation of undigested food. The diagnosis of this syndrome is currently based on clinical features. We aimed to determine criteria for the rumination syndrome based on physiological measurements. METHODS: We studied patients with clinically confirmed rumination syndrome and gastroesophageal reflux disease (GERD) patients with predominant symptoms of regurgitation. All patients underwent combined high-resolution manometry and pH-impedance measurement after a standardized meal. All reflux events extending to the proximal esophagus were analyzed. Furthermore, ambulatory measurements were performed in the majority of patients. RESULTS: In the rumination group, the amplitude of the abdominal pressure increase during proximal reflux events and the esophageal pressure peaks were significantly higher compared with GERD patients. None of the GERD patients exhibited abdominal pressure peaks >30 mm Hg, whereas in the rumination patients 70% of the pressure peaks had an amplitude >30 mm Hg. Abdominal pressure patterns were also observed during ambulatory pH impedance-pressure monitoring in the rumination patients. pH-impedance monitoring alone could not differentiate between GERD and rumination, however, a higher percentage of reflux events reached the proximal esophagus in the rumination patients. Notably, three different mechanisms of rumination were observed: (i) primary rumination, in which the abdominal pressure increase preceded the retrograde flow, (ii) secondary rumination, consisting of an increase in abdominal pressure following the onset of a reflux event and (iii) supragastric belch-associated rumination, consisting of a supragastric belch immediately followed by a rumination event. CONCLUSIONS: The diagnosis of the rumination syndrome can be made when reflux events extending to the proximal esophagus that are closely associated with an abdominal pressure increase >30 mm Hg and an esophageal pressure increase are observed during combined pressure-impedance monitoring.

Effect of transoral incisionless fundoplication on reflux mechanisms.

OBJECTIVES: Transoral incisionless fundoplication (TIF) is a new endoscopic treatment option for gastroesophageal reflux disease (GERD). The mechanisms underlying the anti-reflux effect of this new procedure have not been studied. We therefore conducted this explorative study to evaluate the effect of TIF on reflux mechanisms, focusing on transient lower esophageal sphincter relaxations (TLESRs) and esophagogastric junction (EGJ) distensibility. METHODS: GERD patients (N = 15; 11 males, mean age 41 years, range 23-66), dissatisfied with medical treatment were studied before and 6 months after TIF. We performed 90-min postprandial combined high-resolution manometry and impedance-pH monitoring and an ambulatory 24-h pH-impedance monitoring. EGJ distensibility was evaluated using an endoscopic functional luminal imaging probe before and directly after the procedure. RESULTS: TIF reduced the number of postprandial TLESRs (16.8 ± 1.5 vs. 9.2 ± 1.3; p < 0.01) and the number of postprandial TLESRs associated with reflux (11.1 ± 1.6 vs. 5.6 ± 0.6; p < 0.01), but the proportion of TLESRs associated with reflux was unaltered (67.6 ± 6.9 vs. 69.9 ± 6.3 %). TIF also led to a decrease in the number and proximal extent of reflux episodes and an improvement of acid exposure in the upright position; conversely, TIF had no effect on the number of gas reflux episodes. EGJ distensibility was reduced after the procedure (2.4 ± 0.3 vs. 1.6 ± 0.2 mm(2)/mmHg; p < 0.05). CONCLUSIONS: TIF reduced the number of postprandial TLESRs, the number of TLESRs associated with reflux and EGJ distensibility. This resulted in a reduction of the number and proximal extent of reflux episodes and improvement of acid exposure in the upright position. The anti-reflux effect of TIF showed to be selective for liquid-containing reflux only, thereby preserving the ability of venting gastric air.

Gas-related symptoms after antireflux surgery.

BACKGROUND: Gas-related symptoms such as bloating, flatulence, and impaired ability to belch are frequent after antireflux surgery, but it is not known how these symptoms affect patient satisfaction with the procedure or what determines the severity of these complaints. We aimed to assess the impact of gas-related symptoms on patient-perceived success of surgery and to determine whether the severity of gas-related complaints after antireflux surgery is associated with objectively measured abnormalities. METHODS: Fifty-two patients were studied at a median of 27 months after antireflux surgery. The influence of gas-related symptoms on their quality of life and satisfaction with surgical outcome was assessed. The rates of air swallows and gastric and supragastric belches before and after surgery were assessed using impedance measurements. RESULTS: Bloating and flatulence were associated with a decreased quality of life and less satisfaction with surgical outcome. Notably, 9 % of the patients would not opt for surgery again due to gas-related symptoms. Antireflux surgery decreased the total number of gastric belches but did not affect the number of air swallows. The severity of gas-related symptoms was not associated with an increased number of preoperative air swallows and/or belches or a larger postoperative decrease in the number of gastric belches. CONCLUSION: Gas-related symptoms are associated with less satisfaction with surgical outcome. The severity of gas-related symptoms is not determined by the number of preoperative air swallows or a more severe impairment of the ability to belch after surgery. Preoperative predictors of postoperative gas-related symptoms therefore could not be identified.

Revisional laparoscopic antireflux surgery after unsuccessful endoscopic fundoplication.

BACKGROUND: Transoral incisionless fundoplication (TIF), a novel endoscopic procedure for treating gastroesophageal reflux disease (GERD), currently is under evaluation. In case of treatment failure, subsequent revisional laparoscopic antireflux surgery (rLARS) may be required. This study aimed to evaluate the feasibility, safety, and outcomes of revisional antireflux surgery after previous endoscopic fundoplication. METHODS: Chronic GERD patients who underwent rLARS after a previous TIF procedure were included in the study. Pre- and postoperative assessment included GERD-related quality-of-life scores, proton pump inhibitor (PPI) usage, 24-h pH-metry, upper gastrointestinal endoscopy, and registration of adverse events. RESULTS: Revisional laparoscopic Nissen fundoplication was feasible for all 15 patients included in the study without conversions to open surgery. Acid exposure of the distal esophagus improved significantly after rLARS, and esophagitis, PPI usage, and hiatal hernia decreased. Quality of life did not improve significantly after rLARS, and 33 % of the patients experienced dysphagia. CONCLUSION: Revisional laparoscopic Nissen fundoplication was feasible and safe after unsuccessful endoscopic fundoplication, resulting in objective reflux control at the cost of a relatively high rate of dysphagia.

Oesophageal baseline impedance values are decreased in patients with eosinophilic oesophagitis.

BACKGROUND: Gastro-oesophageal reflux has been suggested to play a role in eosinophilic oesophagitis (EoO). Oesophageal acid exposure decreases baseline intraluminal impedance, a marker of mucosal integrity, in patients with gastro-oesophageal reflux disease (GORD). OBJECTIVES: The aim of this study was to assess oesophageal baseline impedance levels in EoO patients and to investigate their relationship with oesophageal acid exposure. METHODS: Ambulatory 24-h pH-impedance monitoring was performed in 11 EoO patients and in 11 healthy controls with matched oesophageal acid exposure. We assessed baseline impedance levels in the distal, mid-, and proximal oesophageal impedance channels. RESULTS: BASELINE IMPEDANCE LEVELS IN EOO PATIENTS WERE MARKEDLY LOWER COMPARED TO CONTROLS IN THE DISTAL OESOPHAGUS (MEDIAN (INTERQUARTILE RANGE): 988 (757-1978) vs. 2259 (1767-2896) Ω, p = 0.015), mid-oesophagus (1420 (836-2164) vs. 2614 (2374-3879) Ω, p = 0.003), and proximal oesophagus (1856 (1006-2625) vs. 2868 (2397-3439) Ω, p = 0.005). Whereas baseline impedance decreased from proximal to distal in healthy subjects (p = 0.037), no such gradient was seen in EoO patients (p = 0.123). CONCLUSIONS: Throughout the oesophagus, baseline impedance values are decreased in EoO patients, indicating impaired mucosal integrity. Our findings suggest that factors other than acid reflux are the cause of low baseline impedance in EoO.

Efficacy of treatment for patients with achalasia depends on the distensibility of the esophagogastric junction.

BACKGROUND & AIMS: Many patients with persistent dysphagia and regurgitation after therapy have low or no lower esophageal sphincter (LES) pressure. Distensibility of the esophagogastric junction (EGJ) largely determines esophageal emptying. We investigated whether assessment of the distensibility of the EGJ is a better and more integrated parameter than LES pressure for determining efficacy of treatment for patients with achalasia. METHODS: We measured distensibility of the EGJ using an endoscopic functional luminal imaging probe (EndoFLIP) in 15 healthy volunteers (controls; 8 male; age, 40 ± 4.1 years) and 30 patients with achalasia (16 male; age, 51 ± 3.1 years). Patients were also assessed by esophageal manometry and a timed barium esophagogram. Symptom scores were assessed using the Eckardt score, with a score <4 indicating treatment success. The effect of initial and additional treatment on distensibility and symptoms was evaluated in 7 and 5 patients, respectively. RESULTS: EGJ distensibility was significantly reduced in untreated patients with achalasia compared with controls (0.7 ± 0.9 vs 6.3 ± 0.7 mm(2)/mm Hg; P < .001). In patients with achalasia, EGJ distensibility correlated with esophageal emptying (r = -0.72; P < .01) and symptoms (r = 0.61; P < .01) and was significantly increased with treatment. EGJ distensibility was significantly higher in patients successfully treated (Eckardt score <3) compared with those with an Eckardt score >3 (1.6 ± 0.3 vs 4.4 ± 0.5 mm(2)/mm Hg; P = .001). Even when LES pressure was low, EGJ distensibility could be reduced, which was associated with impaired emptying and recurrent symptoms. CONCLUSIONS: EGJ distensibility is impaired in patients with achalasia and, in contrast to LES pressure, is associated with esophageal emptying and clinical response. Assessment of EGJ distensibility by EndoFLIP is a better parameter than LES pressure for evaluating efficacy of treatment for achalasia.

Clinical applications of esophageal impedance monitoring and high-resolution manometry.

Esophageal impedance monitoring and high-resolution manometry (HRM) are useful tools in the diagnostic work-up of patients with upper gastrointestinal complaints. Impedance monitoring increases the diagnostic yield for gastroesophageal reflux disease in adults and children and has become the gold standard in the diagnostic work-up of reflux symptoms. Its role in the work-up for belching disorders and rumination seems promising. HRM is superior to other diagnostic tools for the evaluation of achalasia and contributes to a more specific classification of esophageal disorders in patients with non-obstructive dysphagia. The role of HRM in patients with dysphagia after laparoscopic placement of an adjustable gastric band seems promising. Future studies will further determine the clinical implications of the new insights which have been acquired with these techniques. This review aims to describe the clinical applications of impedance monitoring and HRM.

Impedance measurements and high-resolution manometry help to better define rumination episodes.

BACKGROUND: Rumination syndrome is a disorder of unknown etiology characterized by regurgitation of recently ingested food. We aimed to improve the diagnosis of rumination syndrome by classification of separate rumination symptoms using (1) an ambulatory manometry/impedance (AMIM) measurement and (2) a single-catheter high-resolution manometry/impedance (HRIM) measurement. METHODS: A total of 96 symptoms during AMIM and 37 symptoms during HRIM were analyzed in five patients with clinically diagnosed rumination syndrome. KEY RESULTS: AMIM identified rumination events in 85 out of 96 reported symptoms (symptom index (SI): 89%). Of these events, 63% were non-acidic and would have been missed by pH-metry. HRIM identified 32 out of 37 reported symptoms (SI: 86%). Upper esophageal sphincter (UES) relaxation was observed during all rumination events identified by HRIM and could be an additional criterion in the definition of rumination events. CONCLUSIONS: Impedance measurement and high-resolution manometry contribute to a more detailed description of rumination events. Rumination events defined as gastric strain, common cavity phenomenon, retrograde esophageal fluid flow, and UES relaxation show a high SI when measured with AMIM or single-catheter HRIM.

Esophageal acid exposure decreases intraluminal baseline impedance levels.

OBJECTIVES: Intraluminal baseline impedance levels are determined by the conductivity of the esophageal wall and can be decreased in gastroesophageal reflux disease (GERD) patients. The aim of this study was to investigate the baseline impedance in GERD patients, on and off proton pump inhibitor (PPI), and in healthy controls. METHODS: Ambulatory 24-h pH-impedance monitoring was performed in (i) 24 GERD patients with and 24 without pathological esophageal acid exposure as well as in 10 healthy controls and in (ii) 20 patients with refractory GERD symptoms despite PPI, once on PPI and once off PPI. Baseline impedance levels in the most distal and the most proximal impedance channels were assessed. RESULTS: Median (interquartile range) distal baseline impedance in patients with physiological (2,090 (1,537-2,547) Ω) and pathological (781 (612-1,137) Ω) acid exposure was lower than in controls (2,827 (2,127-3,270) Ω, P<0.05 and P<0.001). A negative correlation between 24-h acid exposure time and baseline impedance was observed (r=-0.7, P<0.001). In patients measured off and on PPI, median distal baseline impedance off PPI was significantly lower than on PPI (886 (716-1,354) vs. 1,372 (961-1,955) Ω, P<0.05) and distal baseline impedance in these groups was significantly lower than in healthy controls (P<0.05 and P<0.001). Proximal baseline impedance did not differ significantly between the patients off PPI and on PPI (1,793 (1,384-2,489) vs. 1,893 (1,610-2,561) Ω); however, baseline impedance values in both measurements were significantly lower than in healthy controls (3,648 (2,815-3,932) Ω, both P<0.001). CONCLUSIONS: These findings suggest that baseline impedance is related to esophageal acid exposure and could be a marker of reflux-induced changes to the esophageal mucosa.

Erroneous diagnosis of gastroesophageal reflux disease in achalasia.

BACKGROUND & AIMS: Most experienced gastroenterologists have seen one or several cases of achalasia patients who have been erroneously diagnosed with gastroesophageal reflux disease (GERD) or even underwent antireflux surgery. We aim to describe the current knowledge about the diagnostic features of achalasia and their overlap with GERD. Furthermore, we present 3 cases in which achalasia was mistaken for GERD. METHODS: Search of the literature published in English using the PubMed database and relevant abstracts presented at international conventions. RESULTS: Typical features of GERD such as heartburn, retrosternal pain, esophagitis, and pathologic acid exposure can be observed in achalasia patients. Diagnostic tests such as endoscopy and radiography lack sensitivity and specificity for achalasia. Current diagnostic guidelines for antireflux surgery do not stipulate that achalasia should be ruled out preoperatively. CONCLUSIONS: Clinical presentation as well as the diagnostic work-up of achalasia patients can show overlap with GERD. Mistaking achalasia for GERD can be avoided by esophageal manometry and this should therefore be performed in all patients undergoing surgical fundoplication.