Reflux Disease [and other benign oesophageal disease]
(Gastro-oesophageal reflux disease, Hiatal Hernia, Achalasia)
What is Reflux Disease?
Reflux disease, correctly referred to as gastro-oesophageal reflux disease ( GORD for short, GERD in North America), is a condition where there is excessive backflow of gastric juices from the stomach into the oesophagus (gullet). This situation can manifest into a number of symptoms. The most common (typical symptoms) are:
- Heartburn : a feeling of severe discomfort and burning (usually felt in the lower middle chest, behind the sternum)
- Regurgitation : the backflow of stomach contents up the gullet and into the mouth
- Dysphagia : Difficulty in swallowing
In addition, there are the less common (atypical) symptoms), which can make the diagnosis of this condition difficult to make.
- Chest pain : may be mistaken as cardiac disease
- Cough or wheeze : Chronic cough without diagnosis, Can make asthma worse
- Sore throat, Hoarse voice : Recurrent laryngitis
Mild symptoms of reflux disease are quite common, affecting both women and men. These can usually be tolerated without medical intervention. However, a in a significant proportion of individuals, treatment for symptom relief may become necessary.
What Causes Reflux Disease?
The oesophagus is a long, hollow, muscular tube, running from the back of the mouth, into the neck (it lies behind the windpipe), through the entire length of the thorax (chest) and then joins into the stomach within the abdomen. It is responsible for propulsing swallowed food and liquid from the mouth safely into the stomach. This process of propulsion is know a peristalsis and is controlled by the layers of muscle within the wall of the oesophagus. The upper and lower parts of the oesophagus have a specialised area of circular muscle fibres, known respectively as the upper and lower oesophageal sphincters (UOS, LOS). These muscles are normally contracted and so close off the oesophagus. The LOS therefore prevent food or liquid from the stomach from escaping into the lower part of the oesophagus, and similarly, the UOS prevents any such material in the oesophagus from entering the back of the mouth (pharynx) where it could enter the airways and breathing apparatus. During normal swallowing, the UOS and LOS relax in synchrony with the oesophageal peristalsis to allow ingested material into the stomach, and the close immediately after its passage to keep it there. Occasionally, the LOS and UOS will relax to allow the escape of excess gas in the stomach (eructation, ie burping), and this is entirely normal.
The LOS, as mentioned above is a specialised muscle. It is usually about 2cm long, and has a resting pressure that keeps this valve between to oesophagus and stomach normally shut. In patients with reflux disease, this muscle is deficient, either in its length or resting pressure or both. Consequently, with little provocation, stomach contents enter the oesophagus, and this excessive phenomenon is known as gastro-oesophageal reflux, and when symptomatic becomes reflux disease or GORD.
What Causes all these Symptoms?
The stomach is a large muscular bag whose purpose is the initial storage and digestion of food and fluid. When ready, the stomach contents are released through an outlet valve, another sphincter called the pylorus. This then allows this material to enter the duodenum where further digestion takes place and then transfer on to the rest of the digestive tract. Specialised digestion with enzymes occurs in the stomach, which in order to function require a high level of acidity (pH 1-2) which is provided by the secretion of hydrochloric acid from the cells that form its inner lining (this may also kill of some bacteria). While the stomach lining is normally well adapted to this acid environment (although this can sometimes fail, causing a peptic ulcer), the lining of the oesophagus is made of a different kind of cell which is much more sensitive to noxious materials such as acid and digestive enzymes. In reflux disease, the lining of the lower oesophagus becomes inflamed and damaged (oesophagitis), and this causes the pain of heartburn. When large amounts of material enter the oesophagus in this way, it cannot cope, and this may then be reverse propulsed into rest of the gullet and eventually pharynx and mouth, causing a combination of the other symptoms described above.
In some patients, the pylorus may also be deficient. This allows digestive enzymes and juices, including bile from the duodenum (which has a normally alkaline pH 7-8) to enter the stomach (duodeno-gastric reflux, DGR), and then through a weak LOS, enter the oesophagus (duodeno-gastro-oesophageal reflux, DGER). While the symptoms of patients who have DGER may not be much different from those with straightforward reflux disease, it is thought that this may enhance the development of some of the long-term and potentially serious complications of reflux disease.
Complications and Long-term Problems of Reflux Disease
Reflux disease is a chronic disease. Even mild levels of disease can, over a number of years cause significant problems. Long standing inflammation of the oesophagus, chronic oesophagitis, may result in permanent scarring as the cells lining the lower portion of the oesophagus are replaced by fibrous tissue, causing a narrowing or stricture, which then may cause severe difficulty in swallowing. This is usually treated by endoscopy and dilatation (stretching) using a special balloon.
In some individuals, damaged cells in the lower oesophagus are replaced by new cells whose structure is more resistant to damage from refluxed material. This is referred to as columnar epithelium and they resemble the structure of cells lining the stomach. The columnar epithelium cells can then undergo further transformation ( specialisation), again providing better resistance to gastric juice attack, by displaying features (goblet cells), which make them appear similar to intestinal cells. When this tissue is seen in the lower oesophagus, it is referred to with a variety of terms, including Barrett’s oesophagus (named after Norman Barrett, the surgeon who first described it), Barrett’s metaplasia, and specialised intestinal metaplasia (SIM). This is a permanent change in the structure of the lower oesophagus, and is a response to the refluxed environment. While symptoms of reflux may be unchanged, or even improve after this transformation, this lesion is regarded as pre-malignant, in other words it has a risk of developing into cancer. Approximately 1 in 100 patients with Barrett’s metaplasia will develop cancer of the oesophagus every year. It is not possible yet to predict which individuals will go on the develop cancer but this is an area if much active research. There are no definite guidelines of what to do once Barrett’s metaplasia has developed. Most specialists would recommend some form of regular interval screening with endoscopy and biopsies to check for the development of cancer. The final stage before definite cancer has developed is known as high-grade dysplasia. If this is present, then it becomes a valid reason to have surgery to remove the oesophagus (oesophagectomy) to prevent the final step of cancer developing. In fact, in nearly 50% of patients who have had surgery for high-grade dysplasia, evidence of an undetected cancer (occult cancer) is found in the diseased oesophagus.
Minimally Invasive Oesophagectomy
How is Reflux Disease Diagnosed?
Since in most cases, reflux disease is a common and benign condition, many doctors are happy to treat this based on a history of symptoms alone. Objective evidence of reflux disease can however be demonstrated by endoscopy of the upper digestive tract (OGD). Presence of oesophagitis confirms the diagnosis if the symptoms are consistent. Endoscopy also has the benefit of visualising for the presence of the complications of reflux, namely Barrett’s metaplasia and early cancers. Because of the expense and invasive nature of endoscopy, the National Institute for Clinical Excellence (NICE) issued guidelines on who should or should not be investigated for reflux disease with this test. While these recommendations do apply to the majority of patients, there appears to be increasing evidence that some patients with early, and potentially curable oesophageal cancer will be missed. If this evidence becomes more convincing, then current guidelines may well have to be altered.
Definitive confirmation of reflux disease is performed by oesophageal manometry and pH recording. In this test, a sensor probe is placed into the oesophagus which measures the length and pressure of the oesophageal sphincters, and also assesses the oesophagus for normal peristalsis. Another probe is then placed into the lower oesophagus, and this then measures the pH at a specific location over 24-hours. This recording gives the duration and intensity of reflux over this period, and it can be compared to a control group of normal individuals. The level of acid reflux can be quantified in the percentage time the pH is below a certain level (normal pH 4) or quantified using a scoring system, the give a DeMeester score. Normal individuals have a DeMeester score of 14, and values above this are regarded as abnormal. Modified probes can be used to check for DGER.
How is Reflux Disease Treated?
There are three ways of treating reflux disease. Very mild symptoms can simply be treated with minor adjustments of lifestyle, such as sleeping with pillows at night (stops the stomach emptying into the oesophagus at night), avoiding large or liquid meals late at night, avoiding spices and alcohol (which may cause the LOS to relax spontaneously). However, this is highly unsatisfactory for the majority of patients with proven reflux disease, and they will require either medical or surgical treatment.
Medical therapy is widely offered for symptom control. Drugs classified as proton pump inhibitors ( PPI’s eg omeprazole, lansoprazole) are taken once or twice per day depending on disease severity. These tablets block the secretion of the cells that produce acid in the stomach. In this way, the acidity of the reflux, as well as its volume is greatly reduced. The disappearance of acid from the reflux reduces the pain of heartburn, and allows the oesophagitis to heal. Prescription of PPI’s is usually an excellent way of controlling symptoms of reflux disease. The drawbacks however are that if medication is stopped, the symptoms and oesophagitis return with vengeance, making patients dependant on this drug. Reflux disease has a tendency to deteriorate over time, and therefore the dose and frequency of the drug may have to be increased to keep symptoms under control. Some individuals may also suffer severe reactions or side-effects from these powerful drugs. PPI’s have been available for about a decade, and at present there are no proven long-term complications of this drug dependency. However, the profound nature by which the normal gastric physiology is altered has caused concern amongst some researchers. In particular, if DGER is present, the change from an acid to an alkaline gastric environment now activates duodenal enzymes and frees up bile, and these factors may accelerate the transformation to Barrett’s metaplasia and beyond.
Keyhole surgery is an alternative to medical therapy. The deficient LOS is surgically reconstructed to make it a competent valve. The aim is to restore normal oesophageal physiology, by having a sphincter that remains shut, keeping gastric juices in the stomach except during swallowing. Part of the stomach is used to make a wrap around the lower oesophagus. This is known as a fundoplication, There are a number of modifications to the exact type of surgery, but the most common and effective fundoplication is known as a Nissen fundoplication after the surgeon Rudolf Nissen who described it. This operation was originally designed for open surgery, but now is virtually always done using keyhole surgery. (Laparoscopic Anti-Reflux Surgery)
Hiatal (Hiatus) Hernia
The term hiatus hernia is often used synonymously with reflux disease. While it is true that the presence of a hiatal hernia can cause the symptoms of reflux disease, not everyone with reflux disease has a hiatal hernia. What is it?
The oesophagus enters the abdomen form the chest through a muscular sheet called the diaphragm, which is an essential part of our breathing apparatus. There is a small defect at the back of this muscular sheet that enables the oesophagus through; each wall of this oblique defect has a muscular pillar, which are called the right crus and left crus(pl. crura). These muscles add to the valve effect of the LOS. In some individuals, these muscles become weakened, and this defect (crural orifice) widens. This allows the stomach to start migrating upwards into the chest, and this is then known as a hiatal hernia.
Two types of hiatal hernia are described: A sliding hiatal hernia means that the stomach slips up and down from the stomach into the chest and back; a paraoesophageal hernia means that the upper part of the stomach, including the junction of the oesophagus and stomach (oesophago-gastric junction, OGJ) is all in the chest and stays there. In some cases, a hiatal hernia can get stuck in the chest (incarcerated) and this may then lead to a cut-off in its blood supply (strangulated), particularly if the stomach becomes twisted (gastric volvulus). This condition is seriously life threatening without emergency surgery.
The presence of a small hiatal hernia is very common, and because of the effect it has on the competency of the LOS, most individual complain of mild reflux symptoms, and the management of this is as described above. As hiatal hernia get larger, they can start to cause more serious problems. Reflux symptoms, particularly regurgitation and dysphagia become more intolerable, and this can lead to aspiration of gastric contents into the chest causing infection and pneumonia. Breathing itself can become compromised because of the space that the stomach now occupies within the chest. The part of the stomach trapped in the chest can get inflamed, causing bleeding and anaemia, and if the blood supply gets cut off, then the stomach itself is at risk.
The diagnosis of hiatal hernia is made in a similar fashion to reflux disease, usually with an endoscopy. A barium swallow test, where patients are asked to swallow a radio-opaque material followed by X-rays, or a CT scan of the chest and abdomen are also sometimes very useful in trying to establish the extent of the hiatal hernia, and planning surgical treatment.
How can it be treated?
Small hiatal hernias are treated in the same way as reflux disease. Medical therapy improves some of the symptoms (of reflux), but the hiatal hernia itself remains, and has the potential of getting worse exists. Larger hiatal hernia, which begin to produce the symptoms and problems of a hiatal hernia rather than just reflux require surgical intervention. This is done via keyhole surgery, and is known as a laparoscopic hiatal hernia repair. Achalasia
This is an uncommon but benign condition of the oesophagus, which can also benefit from keyhole surgery. For reasons that are yet to be fully understood, the muscular function of the oesophagus becomes disrupted. The resting pressure in the LOS becomes markedly increased (hypertensive) and furthermore fails to relax to enable food and liquid through during swallowing. The peristaltic function in the oesophagus itself becomes weak and loses co-ordination, failing to propel material downwards as normal. Consequently, patients with achalasia have severe dysphagia, which can then lead to weight loss and malnutrition.
Diagnosis is made on this kind of history, endoscopy, barium swallow and oesophageal manometry. Each of these investigations yields s results that are very characteristic if achalasia is present. Achalasia can effectively be treated by an operation known as a Heller’s procedure, and when performed using keyhole surgery, it is referred to as a Laparoscopic Cardiomyotomy.
There are numerous rare conditions of the oesophagus which are collectively referred to as non-specific oesophageal motility disorders (NSEMD). It is important that other diagnoses are excluded before this diagnosis is labelled.
Laparoscopic Anti-Reflux Surgery
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