Preoperative physiological esophageal assessment for anti-reflux surgery: A guide for surgeons on high-resolution manometry and pH testing

Table 1 Esophageal disorders with gastroesophageal reflux disease-like symptoms

Diagnosis	Definition	Clinical symptoms	Pathophysiology	Diagnostic evaluation
Structural disorders
GERD	Symptoms and complications secondary to the reflux of gastic contents above the lower esophageal sphincter[5]	Regurgitation, reflux, dysphagia, retrosternal non-cardiac chest pain, globus sensation, extra esophageal symptoms	Abnormal transient LES relaxation, LES dysfunction secondary to anatomic abnormality such as hiatal hernia	Upper endoscopy, high resolution manometry, ambulatory pH testing, ambulatory impedance testing
Weak acid reflux	Symptoms secondary to reflux of gastric contents above the LES with pH ranging from 4-7[32]	Reflux, regurgitation, non-cardiac chest pain	Persistent reflux with pH from 4-7 due to transient LES relaxation	pH studies - on maximum PPI therapy
Eosinophilic esophagitis	Presence of symptoms of esophageal dysfunction such as reflux or dysphagia, eosinophilic inflammation on esophageal biopsy with ≥ 15 eosinophils per high power field, and exclusion of other disorders with similar presentations[81]	Dysphagia, reflux, non-cardiac chest pain	Eosinophil mediated inflammatory response in the esophagus secondary to allergenic antigens	Upper endoscopy with biopsy
Motility disorders
Achalasia	Elevated IRP > 15 mmHg and absence of normal peristalsis[44]	Dysphagia, regurgitation, non-cardiac chest pain	Failure of LES relaxation and absence of normal peristalsis	High resolution manometry, upper endoscopy, barium studies
Absent peristalsis	Systemic symptoms with aperistalsis with failed peristalsis on 100% of swallows[49]	Reflux, dysphagia, non-cardiac chest pain	Lower esophageal collagen deposition leading to LES dysfunction	High resolution manometry, autoimmune antibody workup
Distal esophageal spasm	Normal IRP and ≥ 20% premature contractions with DCI > 450 mmHg[44]	Dysphagia, regurgitation, reflux, non-cardiac chest pain	Impaired inhibition and coordination of esophageal muscle contraction	High resolution manometry, Barium swallow “corkscrew esophagus”
Hypercontractile esophagus	Minimum of 2 swallows with DCI > 8000 mmHg[44]	Retrosternal non-cardiac chest pain, dysphagia, regurgitation	Increased contraction of esophageal smooth muscle	Upper endoscopy, barium studies, high resolution manometry
Esophagogastric junction outflow obstruction	Elevated median IRP > 15 mmHg with evidence of peristalsis on swallows[44]	Dysphagia, reflux, regurgitation	Impairment of esophagogastric junction relaxation with normal or weakened esophageal peristalsis	High resolution manometry, needs to be confirmed with further studies such as barium swallow or endoflip, must rule out artifact that can be seen with a hiatal hernia
Opioid induced esophageal dysfunction	Presence of symptoms of esophageal dysfunction with manometric evidence of esophageal dysmotility in the presence of chronic opioid use[55]	Regurgitation, dysphagia, reflux	Opioid induced blocking of esophageal inhibitory signals leading to increased spastic contraction and decreased LES relaxation	Clinical history, high resolution manometry
Gastroparesis	Presence of symptoms such as nausea, vomiting, and early satiety with mechanical obstruction ruled out and evidence of delayed gastric emptying on testing[82]	Nausea, reflux, regurgitation, early satiety, abdominal pain and bloating	Multiple etiologies caused slowed peristalsis and delayed gastric emptying	Gastric emptying study
Functional disorders
Functional heartburn	Presence of burning retrosternal discomfort, no symptoms relief on optimal therapy, absence of GERD or EOE as cause of symptoms, and absence of major motility disorder[83]	Reflux, regurgitation, globus sensation	Potentially secondary to increased esophageal sensitivity	Upper endoscopy, high resolution manometry, pH-impedance studies
Reflux hypersensitivity	Presence of retrosternal chest pain, normal endoscopy and absence of EOE, absence of major motility disorder, and symptom association with reflux events with normal acid exposure on pH-impedance tests[83]	Reflux	Hypersensitization of esophageal nerve endings leading to pain secondary to physiologic esophageal stimuli	Upper endoscopy, high resolution manometry, pH-impedance studies
Rumination	Must include both persistent regurgitation of recently ingested food with subsequent spitting or re-mastication, and regurgitation that is not preceded by retching[83]	Regurgitation (frequently after meals), reflux	Behavioral contraction of abdominal muscles leading to increased intragastric pressure and reflux	Clinical history, high resolution manometry, pH-impedance studies
Supragastric belching	Presence of frequent repetitive belching, no established clinical correlate for gastric belching, and evidence of supragastric origin on impedance testing[83]	Frequent belching, reflux, regurgitation, globus sensation	Behavioral swallowing of air without LES relaxation	Clinical history, high resolution manometry, pH-impedance studies

LES: Lower esophageal sphincter; GERD: Gastroesophageal reflux disease; IRP: Integrated relaxation pressure; DCI: Distal contractile integral; EOE: Eosinophilic esophagitis.

Table 2 Esophageal pH measurement options

	Overview	Benefits	Limitations
Twenty-four hours ambulatory catheter	Trans-nasal catheter placed 5 cm above the LES. Measures time of pH < 4	Can be placed in office	Catheter may cause discomfort; Patients may deviate from daily routine; Patients should refrain from taking PPI therapy during testing; False positives secondary eating/drinking acidic food
Wireless capsule	Small probe that is placed endoscopically in esophagus 5-6 cm above LES. Measures time of pH < 4	Little patient discomfort; Battery life of 48-96 h allows for better measurement of physiologic acid exposure	Must be placed endoscopically; Patients should refrain from taking PPI therapy during testing; False positives secondary eating/drinking acidic food
MII-pH catheter	Trans-nasal catheter placed 5 cm above LES. Contains pH probe along with electrodes to measure reflux episodes	Can be done on or off PPI; Measures pH and reflux independently; Patients can continue taking PPIs; Can identify patients with weak acid reflux	Catheter may cause discomfort; Patients must have prior manometry testing; False positive possible in patients with rumination, achalasia, and scleroderma

LES: Lower esophageal sphincter; PPI: Proton pump inhibitor.

Table 3 Key measurements on high resolution manometry

Measurement	Utility
Integrated relaxation pressure	Measures esophageal pressures during transit and passage through esophagogastric junction. Can be used to diagnose achalasia and other hypomotility disorders
Distal contractile integral	Measures strength of esophageal contractions. Can diagnose hypercontractile disorders such as jackhammer esophagus
Distal latency	Measurement of esophageal transit and contraction time. Can indicate impaired or spastic peristalsis
DCI ratio	Ratio of DCI on normal swallows and MRS testing. Used to assess peristaltic reserve. This can be used to predict risk of post-operative dysphagia

DCI: Distal contractile integral; MRS: Multiple rapid swallow.