The act of swallowing involves a sequence of carefully timed events which proceed normally without any conscious effort or thought. As food or liquid is pushed into the back of the throat by the tongue, a wave of contraction begins in the throat which pushes it smoothly down the esophagus and into the stomach.
As the food passes through the upper throat, the vocal cords close to prevent foreign matter from entering the windpipe. A sphincter or valve in the upper throat normally stays closed to prevent esophageal contents from returning back into the mouth. A similar valve is present in the lower end of the esophagus to prevent stomach contents from passing back into the esophagus. Swallowing difficulties may occur with malfunctions of any of these mechanisms.
Upper Esophageal Disorders
Disorders of the upper esophageal sphincter in the neck often results in choking due to food or liquid entering the windpipe or air passages. This may be due to a stroke or other damage to the nervous system or may be a consequence of surgery or damage from a tumor involving these areas. These problems are very difficult to treat and may necessitate an alternate route for feeding the patient. Commonly we use a gastrostomy, a tube directly into the stomach, to alleviate this situation.
Hiatal hernia is an anatomic variation which occurs in about 20% of the population. Normally, the junction of the esophagus and stomach is at the level of the diaphragm. The pressure of the diaphragm around the lower end of the esophagus augments the function of the lower esophageal sphincter (LES) or valve which prevents reflux of stomach acid into the esophagus. If a hiatal hernia is present, the LES is above the level of the diaphragm and is less effective. The patient is thus more prone to having reflux. Prolonged reflux leads to inflammation (esophagitis) and ultimately may cause scarring and narrowing of the lower esophagus (esophageal stricture. Reflux esophagitis and stricture formation may occur even in the absence of a hiatal hernia. The significance of the hiatal hernia is that reflux and its complications occur much more frequently. Hiatal hernia does not cause abdominal pain.
The most common swallowing disorder involves a narrowing of the lower esophagus. In this situation, the initial portion of the swallowing mechanism is normal, but the passage of food or liquid is blocked by a narrowed segment of the esophagus. When this type of swallowing problem occurs, many people assume that they have a hiatal hernia and that major surgery will be required. In the past, hiatal hernia operations were performed quite frequently. Modern medical therapy and endoscopy have largely eliminated the need for surgery to treat these disorders.
Esophageal stricture and the associated difficulty swallowing is easily and effectively treated by esophageal dilation which is done at the same time as gastroscopy. While the patient is still sedated, a series of tapered rubber tubes are passed down the throat and through the narrowed area to enlarge it. This allows food to pass normally and usually gives excellent relief of the swallowing difficulty in most patients.
Recurrent Esophageal Stricture
Unfortunately strictures may recur and may require repeated dilatation. If this occurs frequently, or only a short time after dilation, then additional treatment may be necessary to try and prevent or delay recurrence. Control of reflux by the use of a proton pump inhibitor (Prilosec, Prevacid, Aciphex, Protonix) has been shown to decrease the number of dilations required to keep strictures open. Even though these are expensive drugs, treatment actually reduces the overall costs of treating patients with esophageal strictures. Other drugs such as Zantac, were not found to be effective in this situation, even though they may be effective for treating reflux symptoms. Depo-Medrol (a type of cortisone) can be injected directly into the stricture at the time of endoscopy and dilation. We have used this technique in many patients with strictures which were difficult to dilate and keep open. It seems to be effective.
Esophageal cancer is fortunately an uncommon cause of swallowing difficulty. This is a very serious and potentially lethal problem. The possibility of this disease makes it imperative that patients with swallowing disorders be evaluated very carefully to make sure that cancer is not the underlying cause. Smoking and heavy alcohol consumption are important risk factors for the development of esophageal cancer. Chronic reflux and Barrett's esophagus is the other major risk factor.
Esophageal spasm is another relatively infrequent cause of swallowing difficulty. This is often associated with chest pain and may result in difficulty swallowing both liquids and solids. In this condition, there is no mechanical blockage in the esophagus. Instead of a normally moving contraction wave going down the esophagus, there are irregular contractions in the esophagus which may actually block the passage of food or liquid. These contractions or spasms may also cause severe chest pain. This condition can sometimes be difficult to diagnose. It may be treated by esophageal dilation or medications.