If you are like most people, you take your body for granted. As long as all is working well, you seldom think of it. One thing we all take for granted is the simple act of swallowing. You swallow your saliva. You swallow your food. You swallow fluids. Down they all go - while you pay attention to your busy day. You may swallow several times per minute - thousands of times a day, without ever thinking about it. What if every time you swallowed, it was an ordeal? You never knew if your food would go down - or come back up. Every time you ate, you were afraid. Eventually, you might quit eating out in public for fear of an attack. This is what happens to patients with achalasia, an uncommon motility disorder which affects swallowing.
How we Swallow
To better understand achalasia, you need to learn how we normally swallow. The trick is to get the food to go down into the stomach and not regurgitate. Your esophagus, or foodpipe, is not just a hollow lifeless tube. Rather, it is a made of several layers of muscle tissue that contract in a rhythmic fashion, like waves on a beach. These so-called peristaltic waves carry the food down to your stomach like a conveyor belt. That is why you can hang upside down and still eat a sandwich.
At the lower end of the esophagus, is a one-way valve - named the lower esophageal sphincter, or LES. This valve is the guardian of the gate. It is normally tightly closed to prevent the backsplash of acidic stomach contents upward into your esophagus. When you swallow, the valve should relax and open briefly, allowing food to enter your stomach. It then snaps shut. When this valve is too weak, acid and food can reflux up into your esophagus causing heartburn. This is a common problem, termed GERD, or gastroesophageal reflux disease.
What, if instead, the lower esophageal valve was too tight? When you try to swallow, it would not open completely and the food would not enter your stomach right away like it was supposed to do. The food would begin to accumulate in your lower esophagus. It may cause you to stop eating and even regurgitate undigested food. Not a pretty sight. Over time, the esophagus muscle would become stretched out and the esophagus may weaken. This is called aperistalsis. The walls of the esophagus no longer contract and push the food down into the stomach. The food would have to be propelled by gravity. When the esophageal wall muscles become weak and the valve below becomes too tight, this is called achalasia - a bad combination if swallowing is what you are trying to do. Doctors have known of this condition for over 300 years, but it was first termed achalasia in 1927.
What causes achalasia?
Unfortunately, the cause of achalasia is not known. Biopsies have shown some damage to the nerves that control the esophagus and the LES. Why this happens to an individual is not known and cannot be predicted. It is not due to something one did or did not do. It is just a case of bad luck.
Who gets it?
Achalasia is more common in adults, but affects both sexes equally. Fortunately, it is quite uncommon, affecting only about 1 in 10,000 Americans. It is not inherited.
What are the symptoms?
Of course, the most frequent symptom is trouble with swallowing. The medical term for this symptom is dysphagia. This does not happen overnight, but gradually over a period of many months or years. In fact, the average patient has symptoms for over 2 years before seeking medical attention. They complain about being slow eaters - always the last one to finish a meal, often consuming large amounts of fluid while eating. They may become full before the meal is over. Regurgitation of undigested food is quite common and it may even be found on the pillowcase in the morning. If food enters the lungs, it can cause severe coughing and even pneumonia. Repeated lung infections may lead to permanent lung injury. With such difficulty eating it is not unusual for these patients to lose considerable weight and become malnourished. Achalasia is not cancer, but untreated achalasia does increase the risk of squamous cell cancer of the esophagus about ten times above normal. It is important to treat this disease as early as possible, and aggressively.
How does the doctor know?
If you have trouble swallowing, your doctor may order several special tests to assess your swallowing function. These may include:
Esophageal manometry - this important test is done by placing a thin catheter down the nose and into the esophagus. On the tip of the catheter is a pressure sensor that is connected to a computer. This allows measurement of strength and rhythm of esophageal contractions. Manometry also allows measurement of the pressure of the lower esophageal sphincter, both at rest and when you swallow. In patients with achalasia, manometry typically shows a weakened esophageal muscle and an overly tight LES with a high resting pressure that fails to relax with swallowing. There is also a spastic variant of this disease called vigorous achalasia, which can cause symptoms of chest pain and difficulty with swallowing.
Gastroscopy - Many other conditions can cause difficulty with swallowing. Gastroscopy is a special "scope test" that is performed to rule out more common problems such as a ring of scar tissue, benign strictures, or cancer. This test is painlessly done under "twilight sleep" anesthesia and allows the doctor to directly examine the inside of the esophagus. A dilated esophagus with a tight LES is characteristic of achalasia.
Since there currently is no treatment to strengthen the dilated esophagus, treatment focuses on correcting the tight LES. Once the diagnosis has been confirmed, the patient has several options. The best treatment depends on the details of each individual case. These may include:
First, a trial of oral medications may be prescribed. These drugs are marketed to treat heart disease and high blood pressure, but seem to also temporarily relax the LES. Nitroglycerine, Isordil, Verapamil, and Nifedipine are a few of the drugs that have been successful in relaxing the LES, but have short-lived effectiveness. They may help in mild cases and are most helpful treating the chest pain seen in vigorous achalasia.
Botox is often tried, especially in patients who cannot tolerate surgery. Botox is a toxin produced by the bacterium Clostridium botulinum. It causes muscle paralysis and prevents spasm. Botox was originally introduced for the safe and effective treatment of muscle spasms. It was discovered that it is also useful in preventing spasm of the LES. It is injected directly into the LES muscle with a small needle during a gastroscopy examination, a painless outpatient procedure. This procedure is very safe. Botox does not paralyze the body as in food poisoning, or botulism. In the concentrations used, it only weakens the spot where it is injected - in this case the valve. Botox has not only been helpful, but has also been disappointing. The effect only lasts a few months and may become less effective with each additional treatment. It is also very expensive and you have to add the cost of the gastroscopy with each retreatment.
Forceful balloon dilation was the mainstay of treatment for achalasia for many years. In this procedure, a pneumatic balloon is passed down the esophagus, half above and half below the LES. The balloon is then rapidly inflated for about a minute. As the balloon expands, it forcefully stretches and weakens the LES. Forceful pneumatic dilatation can be very successful and may last for a decade or longer. The downside is that this balloon is much larger than the balloon dilators normally used to dilate an esophageal stricture or tight hiatal hernia. It has to be big enough to actually rip the tight LES valve and weaken it. As a consequence, this procedure is often quite painful and can even rupture the esophagus in about 5% of cases. This is a very serious complication that requires an emergency chest operation for repair.
The best way to permanently weaken a overly tight LES valve is to cut it . The procedure is called a surgical myotomy and has over a 90% success rate in alleviating the symptoms of achalasia. Surgery is not as successful in cases of vigorous achalasia. For many years, this has been performed through an open chest incision (Heller Myotomy). In the past few years, there has been much interest in a laparoscopic technique which uses smaller incisions, allowing for a faster recovery and an earlier return to work. Most patients leave the hospital in just a few days and are able to return to work within two weeks.