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What neuro-motor diseases cause the lower esophageal sphincter (LES) to malfunction?

What neuro-motor diseases cause the lower esophageal sphincter (LES) to malfunction?


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Please note: This question is neither homework nor seeking medical advice. I'm simply asking for a factual, objective, biological explanation of the various neuro-motor diseases/illnesses that can act as the underlying cause to LES malfunction.


The primary function of the lower esophageal sphincter (LES) is to prevent stomach acid from backwashing into the esophagus. This sphincter is an involuntary muscle, and so, for it to malfunction (unable to fully or properly close), it must be the result of an underlying neuro-motor (autonomic) disease or condition.

What such condition attacks this sphincter/valve, thereby causing it to malfunction and not operate properly? How exactly does this condition effect the sphincter biologically/neurologically?


Update

Looks like the Vagus Nerve (10th Cranial) innervates this sphincter, so I guess the question is: What neuro-motor diseases attack the Vagus Nerve or cause it to malfunction?


This is called achalasia. According to UpToDate, the mechanism for this diseases are generally unknown. What is known, however, is that the esophagus has a neural system called the myenteric plexus and if these ganglion cells in the esophagus are damaged in any way (e.g. physically, followed by Wallerian degeneration, or the primary process of degeneration after physical damaging of neurons), it can lead to lower esophageal dysfunction as these neurons regulate the inhibition of the contraction of this sphincter muscle. Dysinhibition leads to a closed sphincter.

Yes, you are right in that the vagus nerve is the primary route of the myenteric plexus to the central nervous system, so damage here might result in dysfunction as well.

Histological studies have reported fewer myenteric neurons in people with achalasia, and inflammatory cells in the region, perhaps suggesting infection or autoimmune etiology 1.

Additionally, from the UpToDate article, Chagas Disease has been associated with this disease. Chagas disease is a parasitic disease caused by the species Tropanosoma Cruzi, and these parasites multiply within cells, causing them to burst.

Check out pathophysiology of achalasia on websites such as UpToDate.

1 "Histopathologic features in esophagomyotomy specimens from patients with achalasia." Goldblum JR, Rice TW, Richter JE. Gastroenterology. 1996;111(3):648.

EDIT:

I answered the opposite, but the principles still apply. Here is a wonderful resource on this topic ("Physiology of esophageal motility," http://www.nature.com/gimo/contents/pt1/full/gimo3.html. It includes a diagram showing the vagal neural pathway and the main neurotransmitters responsible for each action (relaxation and contraction).


The throat (pharynx) is lined with largely the same mucous membrane as the rest of the respiratory tract. It produces its own mucus in moderate quantities to both keep the throat moist and trap dust or other foreign particles, including microbes. However, mucus in the throat may also be due to other sources.

  • Nasal mucus since the throat (pharynx) and nasal cavity meet at the nasopharynx. Mucus from the paranasal sinuses may also empty into the nasal cavity and reach the throat.
  • Oral mucus since the throat and mouth cavity meet at the oropharynx.
  • Lower respiratory tract mucus from the larynx, trachea, bronchi and even lungs which may be coughed up into the throat.
  • Gastrointestinal mucus from the esophagus which continues from the throat and even stomach mucus can be carried up as high as the throat.

Read more on coughing up mucus.


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I have had cardiac sphincter spasms, periodically, for much of my life. It was originally caused by stress and/or aspirin and then later by too much Ibuprofen. It is very difficult to treat and comes and goes for days and most recently for weeks. Any ideas of what will help? anon349728 September 28, 2013

It is referred to as the cardiac sphincter and also the lower esophageal sphincter because it's position is anatomically near the cardia. seag47 September 20, 2012

@shell4life – My best friend had severe gastric reflux, and she opted to have this surgery. The surgeons created a new cardiac sphincter for her by moving some things around.

They wrapped the top part of her stomach around the bottom part of her esophagus. Somehow, this actually works.

She hasn't had that terrible heartburn and reflux that she suffered from for years anymore since the surgery. So, it is definitely worth it. shell4life September 19, 2012

I've been having a lot of issues with malfunction of my cardiac sphincter. I've heard that there is a kind of surgery that can help with this.

Has anyone here had this surgery? Can you tell me a little about it? kylee07drg September 19, 2012

I don't have gastric reflux disease, but I do experience occasional indigestion. It is so unpleasant when something vaguely resembling what I ate earlier suddenly comes back up my esophagus.

It tastes basically like vomit. I can tell there's a lot of acid in it.

Eating a saltine cracker gets rid of this acid taste. I wash it down with some water, and it's almost as if nothing happened. wavy58 September 18, 2012

You would think that the function of the cardiac sphincter would have something to do with the heart. I wonder why it's called this? I would have thought it would be called the “stomach sphincter” or the “esophagus sphincter” instead.


DIAGNOSIS

The diagnosis of GERD is typically made by a combination of clinical symptoms, response to acid suppression, as well as objective testing with upper endoscopy and esophageal pH monitoring. For example, the combination of moderate to severe typical symptoms and endoscopic changes (erosive esophagitis or Barrett’s esophagus) are highly specific (97%) for GERD (confirmed with pH testing)[10]. However, a well-taken history alone can prove very valuable in the diagnosis, especially in the setting of heartburn and acid regurgitation which have a very high specificity (89% and 95%, respectively), albeit low sensitivity (38% and 6%) for GERD[4]. This can allow one to make a presumptive diagnosis and begin empiric therapy, thereby avoiding a comprehensive and costly evaluation in every patient presenting with uncomplicated symptoms[11]. Additional testing may be necessary, however, for those who do not respond to acid suppression, those who have alarm symptoms (e.g., dysphagia, odynophagia, iron deficiency anemia, weight loss, etc.) and those who have suffered from the disease for an extended period of time due to concern for Barrett’s esophagus[1]. The rationale for pursuing additional testing includes confirmation of GERD as well as evaluation of GERD associated complications or alternate diagnoses (Table ​ (Table2 2 ).

Table 2

Diagnostic Testing for gastroesophageal reflux disease

Diagnostic testIndication
PPI trialClassic GERD symptoms with no alarm symptoms.
Esophageal pH monitoringRefractory symptoms where GERD diagnosis is in question, pre-operative evaluation for non-erosive disease
Upper endoscopyAlarm symptoms (e.g., dysphagia), PPI unresponsive patients, high risk for Barrett’s esophagus
Barium esophagramEvaluation of dysphagia, otherwise not recommended for GERD evaluation
Esophageal manometryPrior to anti-reflux surgery to rule out esophageal dysmotility (e.g., achalasia, scleroderma), otherwise not recommended for GERD evaluation

GERD: Gastroesophageal reflux disease PPI: Proton pump inhibitor.

Empirical therapy

As mentioned above, those with a history suggestive of uncomplicated GERD manifesting in typical symptoms of heartburn and/or regurgitation can be offered empiric treatment (see treatment section). Typical symptoms that are responsive to acid suppression offer additional evidence for pathologic esophageal acid exposure and it is reasonable to assume a diagnosis of GERD in patients who respond to appropriate therapy[1]. On the other hand, typical symptoms that do not improve warrant further evaluation to demonstrate the existence of GERD and evaluate for an alternate diagnosis. Likewise, patients with atypical symptoms or non-cardiac chest pain as their primary complaint should also be considered for further diagnostic evaluation prior to empiric therapy. It should be remembered that a minority of patients on even high dose proton pump inhibition will continue to have objective evidence of pathologic esophageal acid exposure on ambulatory pH monitoring[12], likely a result of medication non-compliance or PPI resistance.

Ambulatory pH monitoring

Ambulatory reflux monitoring is the only modality allowing direct measurement of esophageal acid exposure, reflux episode frequency and association between symptoms and reflux episodes. It is typically used to evaluate patients with persistent symptoms despite medical therapy, particularly those without endoscopic evidence of GERD, in order to confirm the diagnosis. It can also be employed to monitor the control of reflux in those on therapy with persistent symptoms[1] and is also recommended in endoscopy negative patients prior to undergoing anti-reflux surgery in order to confirm the diagnosis.

Reflux monitoring is typically performed using either a wireless capsule or a transnasal catheter (pH alone or combined pH-impedance) with the patient either on or off acid suppression. Though there is no uniform consensus regarding the most optimal method, each has its advantages and disadvantages. For either study, diet and activity should remain unchanged in order to capture an accurate depiction of day to day esophageal acid exposure.

Wireless capsule decreases patient discomfort, allows for longer recording time, and may improve accuracy by allowing the patient to resume normal activities without the presence of a transnasal catheter. The test involves endoscopic or transnasal placement of a radiotelemetry pH sensing capsule to the mucosa of the distal esophagus. The capsule (conventionally placed 6 cm above the squamocolumnar junction) measures pH and transmits the data via a radiofrequency signal to a small receiver clipped onto the patient’s belt[13]. Unlike with traditional catheter-based systems, this approach allows the patient to resume normal activity without the conspicuous presence of a transnasal catheter and also allows for additional recording time (typically 48 h compared to 24 h recording with catheter-based monitoring). Another advantage of wireless capsule is the fixed position of the capsule on the esophageal wall in comparison to catheter-based systems where migration due to swallowing or talking has been shown to occur[14,15]. Potential disadvantages include additional expense due to endoscopic placement (as nasal passage can be difficult due to size of capsule), early detachment in a minority of patients, patient discomfort which could require removal via repeat endoscopy, as well as overdiagnosis of GERD due to ingestion of acidic foods[16]. There is also some data suggesting an increased number of reflux episodes during the first 6 hour period following propofol administration[17].

Transnasal catheter pH testing is limited by patient tolerance and 24 h monitoring but has the unique advantage of adding impedance which allows distinguishing between acid and non-acid (weakly acidic or weakly alkaline) gastroesophageal reflux. Impedance monitoring detects changes in the resistance to electrical current across adjacent electrodes, allowing it to differentiate the antegrade and retrograde bolus transit of both liquids and gas. Due to the ability to detect both acid as well as nonacid reflux, impedance-pH monitoring has greater sensitivity than pH monitoring alone in the detection of gastroesophageal reflux[18]. It is the test of choice for on-PPI testing, as these patients have lower rates of acidic reflux with continued episodes of weakly acidic reflux which can then be detected with this modality. In contrast, both wireless capsule and catheter-based systems can be used for evaluation of GERD in patients off acid suppression[19].

Regardless of the pH monitoring system used, a symptom-reflux correlation is made using either the symptom index (SI) or symptom association probability (SAP), the latter being the preferred statistical calculation[20]. This allows for measurement of the strength of the association between reflux events and symptoms. A positive association combined with abnormal esophageal acid exposure provides evidence that symptoms are being caused by GERD.

Upper endoscopy

Upper endoscopy is the primary modality used in the evaluation of the esophageal mucosa in patients with GERD and also allows for biopsies of concerning lesions (e.g., Barrett’s metaplasia, strictures or masses). It is important though to understand that there are limitations with the use of upper endoscopy in the diagnosis of GERD. For instance, while an endoscopy showing esophagitis or Barrett’s esophagus essentially confirms the diagnosis of GERD (high specificity), a normal endoscopy does not refute the diagnosis. In fact, most patients with typical symptoms of GERD will have no endoscopic evidence of GERD on esophagogastroduodenoscopy. Therefore, an upper endoscopy is not required for the diagnosis and is mostly performed for evaluation of GERD associated complications and alternative diagnoses as well as for placement of wireless capsule pH probes. Patients with multiple risk factors for esophageal adenocarcinoma (age 50 years or older, male sex, white race, chronic GERD, hiatal hernia, elevated BMI, and intra-abdominal distribution of body fat) should receive screening endoscopy for Barrett’s esophagus[8].

Barium esophagram

Barium esophagram was once recommended as a screening test for GERD, but is no longer part of the diagnostic evaluation. A 1996 study of 125 patients compared barium esophagram to esophageal pH monitoring to assess the accuracy of barium screening as a predictor of abnormal esophageal acid exposure. A significantly greater degree of abnormal esophageal acid exposure occurred in patients who had a hiatal hernia or spontaneous reflux on barium radiography. However, the sensitivity and specificity of barium radiography for abnormal degrees of acid reflux were insufficient and therefore this test is no longer recommended in the diagnosis of GERD[21]. On the other hand, it is frequently used in the evaluation of complications related to GERD (e.g., peptic stricture) as well as in the evaluation of dysphagia in the post anti-reflux surgery patient, in conjunction with endoscopic evaluation.

Esophageal manometry

Esophageal manometry is most useful for the evaluation of dysmotility and has only limited utility in the evaluation of GERD. Although disruption of the anti-reflux barrier (gastroesophageal junction) and dysfunction of esophageal peristalsis are common in GERD patients, these findings are not diagnostic and therefore there is no manometric pattern which is pathognomonic for reflux[22]. The role of manometry in the evaluation of GERD remains limited to preoperative testing for exclusion of significant motility disorders such as achalasia or scleroderma (clear contraindications to anti-reflux surgery) as well as for assisting in proper positioning of transnasal pH probes. Otherwise, this test is not recommended for the diagnosis of GERD.


Ondine's curse

Ondine's curse, central alveolar hypoventilation syndrome, or primary alveolar hypoventilation, is a respiratory disorder that is fatal if untreated. Persons afflicted with Ondine's curse are unable to breathe without conscious intervention if they fall asleep, they will die. Its name is a reference to the myth of Ondine, who cursed her adulterous husband that he would stop breathing and die if he ever fell asleep. more.

This disorder is associated with a malfunction of the nerves that control involuntary body functions (autonomic nervous system) and abnormal development of early embryonic cells that form the spinal cord (neural crest). The abnormal neural crest development can lead to other abnormalities such as absent or impaired bowel function (Hirschsprung's disease). Most affected individuals have an abnormality in PHOX2B or other genes.

Most people with congenital Ondine's curse do not survive infancy, though they can be kept alive with a ventilator. It was first described in 1962 by Severinghaus and Mitchell in three patients following surgery to the upper cervical spinal cord and brainstem.

Congenital central hypoventilation syndrome (Ondine's curse) is a rare disorder with lack of automatic control of ventilation during sleep. We have reported a case of Ondine's curse in a patient who underwent Nissen's fundoplication for gastroesophageal reflux (GER) at age 5 months. Ventilatory challenge test during sleep was done to confirm central alveolar hypoventilation. This female patient, without cor pulmonale, was a good candidate for diaphragm pacing. Thus, the patient underwent implantation of a diaphragm pacer at age 3 years she had required mechanical ventilation since birth. Diagnosis, pathogenesis, and problems in the setting of diaphragm pacing for an infant are discussed. (CHEST 1996 110:850-52)

Key words: congenital central alveolar hypoventilation diaphragm pacing gastroesophageal reflux

Abbreviations: ET=endothelin GER=gastroesophageal reflux LES=lower esophageal sphincter NREM=nonrapid eye movement

Congenital central hypoventilation syndrome, so-called Ondine's curse, is an extremely rare disorder of ventilation control,[1-5] characterized by hypoventilation during sleep. To our knowledge, only 50 cases have been reported to date in the English-language literatures. This peculiar syndrome has been believed to be caused presumably by congenital failure of the central automatic system.[3-7] This report describes 1 case of a 3-year-old infant with Ondine's curse, who underwent Nissen's fundoplication for gastroesophageal reflux (GER), and finally underwent implantation of a diaphragm pacemaker:

A full-term female infant weighing 2,860 g was the product of a normal pregnancy and vaginal delivery. After delivery, the baby cried immediately and had an Apgar score of 9/10. During the first 8 h of her life, the infant experienced apneic episodes associated with cyanosis while sleeping. Results of laboratory examination were normal. Chest radiographs showed neither cardiomegaly nor pulmonary disease, and skull radiographs, cranial CT, and EEG were normal. Because cyanosis persisted without any improvement by medical treatment, the infant was intubated and placed on a regimen of mechanical ventilation on the first day of her life. The infant did well when awake however, mechanical ventilatory support was needed when she was sleeping. During the next 2 months, she received therapeutic trials with caffeine, progesterone, thyroxine, and oral doxapram for the sake of respiratory shmuli. None of these drugs were successful in improving sleep apnea. When she was 4 months of age, a tracheostomy was created, but ventilation was entirely normal while awake. Furthermore the parents gradually became aware of vomiting usually during sleep. Under a diagnosis of GER, Nissen's fundoplication was performed when she was 5 months old thereafter this symptom improved.

At 3 years of age, the patient was referred to our hospital for diaphragm pacer implantation. The patient was evaluated by measuring end-tidal [O.sub.2] and C[O.sub.2] (RM300 Minato Medical Science Ltd Osaka, Japan) and ventilatory movement by respiratory inductive plethysmograph (Respigraph NIMS Miami Beach, Fla). Soon after she fell sleep, electrodes for monitoring extraocular movements were attached and polygraphic recording was begun.[5,7] Long apnea persisted associated with oxygen desaturation with hypercapnea during quiet sleep (non[NREM]). During active sleep (REM), small irregular respiration was noted 10 to 15 s after interruption of the mechanical ventilation, followed by spontaneous arousal. Based on these findings, we have confirmed the diagnosis of congenital central hypoventilation syndrome. The patient was doing well when awake in room air, and an echocardiogram showed no evidence of pulmonary hypertension. Phrenic nerve stimulation test revealed normal conduction time and satisfactory diaphragm excursion. Implantation of diaphragm pacer was thus indicated and surgery was done at when the patient was 3 years, 1 month old.

When the patient was under general anesthesia, pacing electrodes were attached to the intrathoracic part of the bilateral phrenic nerves through third intercostal thoracotomy. Receivers were implanted in the subcutaneous pocket made on the wall of the abdomen. We applied four pole nerve electrodes with sequential stimulation system (Astrostim: Atrotech Co., Tampere, Finland) introduced by Talonen et al,[8] which have been widely used recently.[8-10] Bilateral diaphragm pacing was initiated on the 14th postoperative day without any problem while sleeping. In the postoperative periods, manometric study and upper GI series revealed slight residual GER as shown in Figure 1.

Trials for removal of the tracheostomy tube were unsuccessful due to upper airway obstruction during pacing. Except for a minor complication of wire breakage, the diaphragm pacing was uneventful, and the patient was discharged from the hospital and continued electrophrenic respiration at home.

Congenital central hypoventilation (Ondine's curse) is a rare and poorly understood condition this disorder is believed to be due to a lack of ventilatory response during sleep. No specific etiologic anatomic abnormalities have been identified thus far in these patients.[2-5,7] Usually ventilation is normal in these patients when they are awake, but it becomes markedly depressed or lost during sleep, particularly in REM periods.[5,7] According to the studies described by Paton et al,[6] hypoxic and hypercapnic ventilatory responses were also impaired even in the awake state, and actual normal ventilation can be maintained by behavioral control.

The most common associated anomaly is Hirshsprung's disease, which appeared in 17 cases,[9,11,12] and GER was also reported in 1 case.[12] In this patient, combination with GER was apparent during sleep and this combination seemed to be rare. In terms of motor control, lower esophageal sphincter (LES) muscle shares a similar neural pathway with the crural part of the diaphragm. Therefore, contraction of the diaphragm exerts an important sphincteric action at the LES, serving as an antireflux barrier.[13] One possible explanation for GER with Ondine's curse is that relaxation of the LES as well as the diaphragm might coexist during sleep whether apparent or subclinical.

A high incidence with an associated anomaly named as Ondine-Hirshsprung syndrome[12] has not been fully explained. Hirshsprung's disease is generally considered to be a result of impaired migration of neural crest cells during development. Recent dramatic progress in molecular biology has provided an insight for explanation of such congenital disorders. Endothelin-1 (ET-1), discovered as a vasoconstrictive peptide having various actions on circulation, has been found to play an important role in development.[14,15] ET-1 knockout mice showed craniofacial anomaly and died of respiratory failure due to the defect of central respiratory control.[14] However, all the mice that were ETB receptor (ETB) knockout exhibited a similar anatomic feature with Hirschsprung's disease[15] and this disorder has been explained as a defect of neural crest migration during development due to the genetic defect of ETB receptor. We speculate that Ondine-Hirshsprung syndrome maybe caused by the genetic disruption of an ET system, and further molecular biological studies are needed to elucidate the mechanism of Ondine's curse.

In patients with sleep apnea, prolonged mechanical ventilation is hazardous and difficult to accomplish at home. Diaphragm pacing during sleep is a more favorable treatment in terms of maintaining physiologic respiration.[1-3,7,9,10] In infants, unilateral pacing is not recommended because of inadequate ventilation.[1,2,9,10] To minimize phrenic nerve damage, four-pole sequential pacing[8] has been reported to be an improved pacing system, so we applied it for this patient. During diaphragm pacing, the tracheostomy had to be left because of upper airway obstruction, which was probably due to the absence of laryngeal muscle activation without central stimulus.[16,17]

One other case of Ondine's curse with GER is reported with discussion of possible pathogenesis and therapeutic yield.[12]

[1] Hunt CE, Matalon 8v, Thompson TR, et al. Central hypoventilation syndrome experience with bilateral phrenic nerve pacing in three neonates. Am Rev Respir Dis 1978 118:23-8

[2] Ruth v, Pesonen E, Raivio KO. Congenital central hypoventilation syndrome treated with diaphragm pacing. Acta Pediatr Scand 1983 72:295-97

[3] Wells HH, Kattwinkel J, Morrow JD. Control of ventilation in Ondine's curse. J Pediatr 1980 96:865-67

[4] Oren J, Kelly DD, Shannon DC. Long-term follow-up of children with congenital central hypoventilation syndrome. Pediatrics 1987 80:375-80

[5] Guilleminault C, McQuitty J, Ariagno RL, et al. Congenital central hypoventilation syndrome in six infants. Pediatrics 1982 70:684-94

[6] Paton JY, Swaminathan S, Sargent CW, et al. Hypoxic and hypercapnic ventilatory responses in awake children with congenital central hypoventilation syndrome. Am Rev Bespir Dis 1989 140:368-72

[7] Yasuma F, Nomura H, Sotobata I, et al. Congenital central hypoventilation (Ondine's curse): a case report and review of the literature. Eur J Pediatr 1987 146:81-3

[8] Talonen PP, Baer GA, Hakkinen V, et al. Neurophysiological and technical considerations for the design of an implantable phrenic nerve stimulator. Med Biol Eng Comput 1990 28:31-7

[9] Elageole H, Adorph VR, Davis GM, et al. Diaphragmatic pacing in children with congenital central hypoventilation syndrome. Surgery 1995 118:25-8

[10] Weese-Mayer DE, Morrow AS, Brouillette RT, et al. Diaphragm pacing in infants and children: a life-table analysis of implanted components. Am Bev Respir Dis 1989 139:974-79

[11] El-Halaby E, Coran AG. Hirchsprungs disease associated with Ondine's curse: report of three cases and review of the literature. J Pediatr Surg 1994 29:530-35

[12] Verloes A, Elmer C, Lacombe D, et al. Ondine-Hirshsprung syndrome (Haddad syndrome) further delineation m two cases amd review of the literature. Eur J Pediatr 1993 152:75-7

[13] Mittal RK, Rochester DF, McCallum BW. Electrical and mechanical activity in the human lower esophageal sphincter during diaphragmatic contraction. J Clin Invest 1988 81:1182-89

[14] Kurihara Y, Kurihara H, Suzaki H, et al. Elevated blood pressure and craniofacial abnormalities in mice deficient in endothelin-1. Nature 1994 368:703-10

[15] Hosoda K, Hammer RE, Richardson JA, et al. Targeted and neural (Piebald-Lethal) mutations of endothelin-B receptor gene produce megacolon associated with spotted coat color in mice. Cell 1994 79:1267-76

[16] Glenn WOOL, Gee JBL Cole DDR, et al. Combined central alveolar hypoventilation and upper airway obstruction: treatment by tracheostomy and diaphragm pacing. Am J Med 1978 64: 50-60

[17] Olson TS, Woodson GE, Heldt GP. Upper airway function in Ondine's curse. Arch Otolaryngol Head Neck Surg 1992 118:310-12

(*) From the First Department of Surgery, Osaka University Medical School (Drs. Takeda, Fujii, and Matsuda), Department of Pediatric Surgery, Kure National Hospital (Dr. Kawahara), and Department of Surgery, Ootemae Hospital (Dr. Nakahara), Osaka, Japan. Manuscript received January 23, 1996, revision accented March 13. Reprint requests: Dr. Takeda, First Department of Surgery, Osaka University Medical School, 2-2 Yamadaoka, Suita City, Osaka 565, Japan

COPYRIGHT 1996 American College of Chest Physicians
COPYRIGHT 2004 Gale Group


The Lowdown on GERD

As stomach acid comes up and goes back down, it can irritate the lining of your esophagus. This irritation can lead to what people commonly describe as heartburn because the pain occurs in the center of the chest behind the breastbone.

"Frequent irritation of the esophageal lining also can lead to scarring and narrowing of the esophagus, resulting in foods getting stuck, precancerous changes and even esophageal cancer," says Brooks Cash, MD, chief of gastroenterology, hepatology and nutrition at the University of Texas Health Science Center, in Houston. That's why it's important not to ignore GERD.

You can make lifestyle changes that can help protect your esophagus and prevent acid from refluxing upward, says the NIDDK. In addition, your doctor may prescribe medications that suppress stomach acid.

And if these remedies don't work, you may be a candidate for a surgical procedure that strengthens the muscular valve — the lower esophageal sphincter (LES) — which is the gatekeeper that prevents stomach contents from backing up, explains NIDDK.


Anti-Reflux barrier — How does your body prevent acid reflux?

In mid-nineteenth century and before the advent of modern endoscopes, Dr. Norman Barrett, a British thoracic surgeon, postulated the presence of a fold that functions as a flap valve between the esophagus and the stomach (gastroesophageal junction or GEJ) to prevent acid reflux. Eventually in 1996 Dr. Lucius Hill described and classified this gastroesophageal “flap valve.” Dr. Hill’s works resulted in inclusion of the flap valve in the Gray’s Anatomy reference book in 1999.

The flap valve is formed by the oblique angle at which the esophagus enters into and integrates with the stomach. GEJ is anchored under the diaphragm by phrenoesophageal ligaments. Lower esophageal sphincter is a muscle ring at the bottom of esophagus and is controlled by neural input. The sphincter and the valve work together and form a powerful anti-reflux barrier.

With each swallow, the esophageal body shortens and GEJ moves up. This dislocation results in opening of the flap valve and passage of the food into the stomach. After swallowing, stomach returns to its normal position under the diaphragm by the recoil of the phrenoesophageal ligaments.

In a normal individual, there is an acute angle between the esophagus and upper part of the stomach (fundus). This angle was described by Dr. Wilhem in the beginning of the 19th century and is named after him.

After the passage of food to the stomach, the GEJ closes to prevent the return of gastric fluid to the esophagus. This becomes possible by the contraction of the lower esophageal sphincter and closure of the flap valve. In the presence of an acute angle of His, the stomach fundus inflates by air and balloons up under the diaphragm dome after eating. The pressure from the inflated fundus transmits to the flap valve and seals the stomach.


The elasticity of the GEJ ligaments diminishes overtime due to ongoing wear-and-tear. As a result, the stomach loses its normal shape and becomes like a funnel. The Angle of His becomes obtuse and the flap valve fails. In the absence of an acute angle of His, the lower esophageal sphincter is the only anti-reflux mechanism and, usually, it fails too. This results in significant acid reflux and regurgitation.
Deterioration of the anti-reflux barrier is a gradual process: It starts by gradual loss of elasticity of the phrenoesophageal ligaments leading to gradual alteration of the stomach shape and progresses to continuous widening of the angle of His until the flap valve disappears and the lower esophageal sphincter eventually fails.

The next step in the natural progression of GERD is the formation of hiatal hernia. The upper part of the funnel-shaped stomach progressively displaces into the chest cavity after each swallow and does not completely return back to its original location under the diaphragm. The segment of the stomach that remains in the chest cavity is referred to as hiatal hernia.

Initially, this stomach segment can slide up and down freely (hence the term reducible or sliding hiatal hernia). Later, as the GERD progress, this portion of the stomach becomes fixed and stays permanently in the chest cavity. At this stage, the hiatal hernia is described as nonreducible hiatal hernia.
As the hiatal hernia increases in size, the esophagus continues to shrink and becomes more tortuous. This is believed to be caused by chronic inflammation, scar tissue formation or permanent spastic contraction of esophagus. Short esophagus syndrome and presbyesophagus (presby is Latin for old) are the terms used to describe the esophagus at this stage. Patients with these conditions commonly have difficulty swallowing and get the sensation of food stuck in their esophagus after eating.

Simply treating the GERD symptoms by medications for a long term without addressing the underlying anatomical problems, can lead to complete destruction of the flap valve, formation of a large nonreducible hiatal hernia and swallowing difficulties associated with short and tortuous esophagus.

When GERD progresses to such late stage, the medications do not subside the heartburn. There is significant regurgitation after eating and other organs such as throat, sinuses, and lungs gets affected by the acid reflux. Patients may also suffer significantly from swallowing disturbances.
The only viable option at this stage of the disease is major reconstructive surgery to create a new valve and rearrange the stomach under the diaphragm. The downside of this approach is that generally the affected individuals at this stage are elderly and affected with later-life comorbidities that significantly increase the risk of any surgical intervention.

Taking advantage of the available minimally invasive endoscopic interventions during earlier stages of the disease and before the complete failure of the valve could retard the natural progression of GERD and decrease the likelihood of need for open surgery later in life. In addition, such treatment strategy could save the patients from cost and long-term side effects of ongoing medication use.


Methods

Patients

This study was conducted with a retrospective manner in children with GERD at the Department of Pediatrics, National Taiwan University Hospital from January 1, 2010 through January 31, 2014. The patients were referred for evaluations due to either respiratory symptoms/signs (cough, asthma, hoarseness, stridor) or gastrointestinal diseases (nausea, vomiting, regurgitation, dysphagia, heartburn sensation). Children who underwent esophagogastroduodenoscopy (EGD) within 3 days before MII-pH monitoring examination, and never received any acid suppression therapy were eligible for inclusion in the study. GEFVs were graded from I to IV by retrograde endoscopic findings [6], [8]. Multiple impedance parameters were analyzed to define reflux episodes.

Ethics Statement

The written informed consents were obtained from the parents or guardians of the children. The study protocol was approved by the Ethics Committee of National Taiwan University Hospital’s Institutional Review Board.

Multichannel intraluminal impedance pH monitoring

Each MII-pH study was performed using an ambulatory polyurethane catheter incorporating six impedance amplifying electrodes 2.0 cm apart and a single pH sensor, positioned 5.0 cm above the tip (Medical Measurement Systems, Inc., Netherlands). The catheter was introduced transnasally and placed with the pH sensor 3–5 cm above the LES confirmed by chest radiography. The MII-pH electrodes were connected to an ambulatory recorder. All patients were allowed to maintain their usual activities, regular diet, and sleep routines. This study was carried out for at least 20 hours for each subject. During the study period, the patient or the caregiver was instructed to press event buttons and to keep a diary to record meal times, posture changes, and symptoms. At the end of the measurements, recordings within the device were uploaded to a computer and analyzed manually by the physician using a dedicated software program (Ohmega, Virtual Instructor Program, Medical Measurement Systems, Inc.).

While impedance can detect voltage and electrical current changes in consecutive sensors positioned along the catheter, the impedance wave was designed to change inversely to ionic concentration. Air with a relatively low ionic content results in a high impedance wave, and fluid with a higher ionic content results in a low wave. This principle provides an essential advantage in the assessment of the flow direction of bolus passage.

The impedance recording was analyzed according to the protocol recently proposed by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) [17]. A reflux episode was defined as sequential, progressive drops of impedance to at least 50% of the initial value in the most distal channels, and proceeding retrograde across two or more proximal channels. Reflux episodes were considered complete when the voltage value returned to baseline [18], [19].

With regards to pH recording data, catheter acidification by the surrounding contents causing the pH value to drop lower than 4 was classified as an acidic episode, and pH values remaining above 4 were classified as non-acidic episodes. A widely used pH reflux composite score was calculated based on the DeMeester criteria including both percent times in upright and supine acid reflux, total percent of time in acid reflux, duration of the longest acid reflux episode, the number of acid reflux episodes >5 minutes, and total number of reflux events. Pathological acid gastroesophageal reflux in our study population was defined based on the finding of total percent of time in acid reflux >4.2% or DeMeester score >14.7 [20], [21]. One of the authors (J-FW) interpreted all data of the MII-pH monitoring and reported the results.

Endoscopy

Flexible EGD was performed in each patient under general or local anesthesia, and the esophagus, stomach, and duodenum were examined with optimal visualization. The severity of erosive esophagitis was graded according to Los Angeles (LA) classification. In addition, we carefully examined the gastroesophageal junction to assess the geometry of the GEFV, using a retroflexed view during gastric inflation. The GEFV was graded from I to IV according to the Hill classification (Figure 1) [6], [8]. We defined GEFV grades I and II as the normal GEFV, and grades III and IV as the abnormal GEFV [22]–[24]. One author (K-CC) retrospectively reviewed all the EGD pictures of the enrolled subjects and re-graded the erosive esophagitis and GEFV, according to the LA and Hill classifications separately. The results of MII-pH monitoring and endoscopic findings were independently interpreted.

(a) Grade I. The prominent fold of tissue along the lesser curvature apposed closely to the endoscope. (b) Grade II. The fold was present but less well defined than in grade I, and some periods of opening and rapid closing around the endoscope were found. (c) Grade III. The fold was not prominent and often failed to close around the endoscope, gripping it tightly. (d) Grade IV. There was no fold and the lumen of the esophagus was open. The squamous epithelium of the esophagus could be seen below.

Statistical analysis

We used the X 2 test and Fisher’s exact test to examine differences in categorical variables between the two patient groups. The Mann-Whitney U test was applied to test the differences in median/25 th −75 th percentage values in the continuous variables. Linear regression analysis was performed to estimate the correlations between the variables of MII-pH monitoring and Hill classification. All p values were 2-sided, and a p value less than 0.05 were considered to be significant. Statistical calculations were performed with SPSS version 19.0 for Windows software (SPSS, Chicago, IL, USA).


Pyloric Sphincter Function

The muscular ring known as the Pyloric Sphincter has the ability to contract and relax. It thus allows food particles to pass to the duodenum from the stomach. The sympathetic nervous system manipulates the function of the pyloric sphincter. However, it is specially the Celiac Ganglion that monitors the motion of the pyloric sphincter muscles.

Apart from regulating digestion, the organ also helps prevent backflow of foods into the stomach from the intestines. Regurgitation is unhealthy as it can interrupt stomach activity and can also lead to sickness in someone. A healthy pyloric sphincter acts as a one-way channel that helps keep the digestive tract contents moving along in only a single direction.

When the Pyrolic valve opens, gastric secretions as well a thick mass of partly digested food (chyme) passed from the stomach enters the duodenum located in the small intestine.


The Integrity of Esophagogastric Junction Anatomy in Patients with Isolated Laryngopharyngeal Reflux Symptoms

Distortion of esophagogastric junction anatomy in patients with gastroesophageal reflux disease produces permanent dilation of the gastric cardia proportional to disease severity, but it remains unclear whether this mechanism underlies reflux in patients with isolated laryngopharyngeal reflux symptoms.

Method

In a prospective study, 113 patients were stratified into three populations based on symptom complex: laryngopharyngeal reflux symptoms, typical reflux symptoms, and both laryngopharyngeal and typical symptoms. Subjects underwent small-caliber upper endoscopy in the upright position. Outcome measures included gastric cardia circumference, presence and size of hiatal hernia, and prevalence of esophagitis and Barrett’s esophagus within each group.

Results

There were no differences in gastric cardia circumference between patient groups. The prevalence of Barrett’s esophagus was 20.4% overall and 15.6% in pure laryngopharyngeal reflux patients. Barrett’s esophagus patients had a greater cardia circumference compared to those without it. In the upright position, patients with isolated laryngopharyngeal reflux display the same degree of esophagogastric junction distortion as those with typical reflux symptoms, suggesting a similar pathophysiology.

Conclusion

This indicates that, although these patients may sense reflux differently, they have similar risks as patients with typical symptoms. Further, the identification of Barrett’s esophagus in the absence of typical reflux symptoms suggests the potential for occult disease progression and late discovery of cancer.


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Very helpful article towards coursework that I am completing in college to do with indigestion and treatment tablets for this. I very much appreciate the information provided. lluviaporos 23 hours ago

I had no idea that there were so many sphincters in the body. I always thought there was just one, or, at the most, two with one being at the top of the throat and one being at the other end.

I guess the body just works without you needing to be aware of all the little things that it's doing. I actually heard a scientist on a show the other day say that there were basically enough neurons in the human digestive system to make up an entire cat brain. And that's pretty impressive. indigomoth yesterday

@MrsPramm - There's another way to injure that sphincter which seems to be happening quite often these days. People who habitually overeat basically force it open, which lets the acid of the stomach injure the area and that's what causes heart burn. But if you overeat too often you can permanently injure the sphincter, and it will just stay open, which means you'll always have heartburn.

Because our meal portions have increased so much over the years we just don't think about the fact that the human stomach can only hold so much food. I don't really believe in telling people what to eat, but I do think that people should make sure they don't hurt themselves in the long run. MrsPramm yesterday

I never suffer from heartburn usually, but once when I was on a particular medication it gave me terrible heartburn. I always thought that it was just an uncomfortable feeling that went away fairly quickly. But it was horrible. I must have really injured my cardiac sphincter because it got to the point where I was in pain every time I swallowed anything, I'd never even been aware of that part of my insides before, but I could feel it every time something got to the bottom of my throat.

I was very grateful when it healed up again. Hopefully I'll never have to take that medication again either!