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Achalasia is loss of the inhibitory neurons of the myenteric plexus, leaving a sphincter that won't relax and an esophageal body with no propagated wave. The episode follows a thirty-eight-year-old man from his history, which already points to achalasia, through endoscopy before manometry, then barium and high-resolution manometry that confirms the diagnosis and assigns a type that predicts response. It then turns to opioids and to pseudoachalasia, shown by a sixty-eight-year-old woman with the same tracing. Treatment choice by type follows: dilation, Heller with a partial wrap, POEM, and the limited roles of botulinum toxin and drugs. It closes with lifelong follow-up and the exam traps.
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Key decisions
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Welcome to Board Pearls. This is episode one of four of the Esophageal Motility chapter, in the Esophageal Disorders module. This episode is achalasia, through two patients. A thirty-eight-year-old man with two years of dysphagia to solids and liquids is followed from his first visit. His case teaches how his history already points to achalasia, what has gone wrong in his esophagus, why endoscopy comes before manometry, how manometry confirms the diagnosis and assigns a type that predicts response, what must be excluded before any treatment, how the treatment is chosen, and what follows in the long term. A sixty-eight-year-old woman with the same tracing, a short history, and heavy weight loss teaches pseudoachalasia, the cancer that imitates it.
Here's the first patient. A thirty-eight-year-old man has had two years of trouble swallowing. Solids and liquids both stick low in his chest, and they have from the start. He drinks a lot of water with every meal, stands up and stretches his neck to get food down, and has found that a carbonated drink helps push things through. Some mornings there's undigested food on his pillow. He has heartburn, but omeprazole hasn't helped. He's lost a few pounds, not many.
His story points to achalasia before any test. Achalasia is a failure of the lower esophageal sphincter to relax, with loss of peristalsis in the esophageal body. Solids and liquids sticking together from the start is the motility pattern: the propagated wave has failed, so it fails on every consistency, whatever is swallowed. The rest of his story is the classic picture, and its onset is insidious. He drinks water, stands, stretches, and uses carbonation because he's building a column of pressure above a sphincter that won't open on its own. Food on his pillow means a dilated, stagnant esophagus that holds food for hours and spills it when he lies down. His weight loss is minimal, which is typical of primary achalasia and is the feature that separates it from the cancer that imitates it. Achalasia is uncommon, with a prevalence of about one to three per ten thousand and an incidence of about one to three per hundred thousand a year.
His heartburn is a trap. More than forty percent of patients with achalasia report heartburn, but it isn't acid reflux. Acid can't get up through a sphincter that won't open. The burning comes from retained food fermenting in the esophagus and from the esophagus being stretched. That's why his proton pump inhibitor, PPI, failed, and it's why acid suppression isn't escalated in a patient whose dysphagia started with liquids too.
The mechanism explains every finding that follows, in the history and on the tests. In achalasia, the inhibitory neurons of the myenteric plexus degenerate. These are the nitric oxide-producing ganglion cells that tell the lower sphincter to relax when a swallow arrives and that coordinate the sequential wave down the body. The cholinergic excitatory neurons that keep the sphincter closed are relatively spared, which is why the resting sphincter pressure is often high and the sphincter can't let go. The body loses the gradient that generates a propagated contraction. In most patients the cause is unknown. The leading idea is autoimmune injury to those neurons, triggered by a viral infection such as measles, herpes simplex, or human papillomavirus in a genetically susceptible person, and a more recent idea links some cases to eosinophil and mast cell inflammation in the esophageal muscle. Secondary achalasia comes from Chagas disease, in which Trypanosoma cruzi destroys the same ganglion cells, from tumors infiltrating the junction, and from paraneoplastic injury, and that last group sets the order of testing.
Endoscopy comes before manometry, because primary achalasia is a diagnosis of exclusion and a cancer at the junction can imitate it. In achalasia, the endoscopist sees a dilated esophagus that often contains retained food and saliva, normal mucosa, and a tight junction that pops open with gentle pressure on the scope. A tumor feels firm and doesn't give. But endoscopy is normal in up to forty percent of patients with achalasia, so a normal scope doesn't rule it out; it rules out the things that look like it. His endoscopy shows a dilated esophagus with some retained liquid, normal mucosa, and a junction that opens with gentle pressure.
A barium esophagram then shows the shape: a dilated esophagus tapering smoothly to a narrow bird's beak at the junction, with barium held up above it and no peristaltic stripping. In advanced disease, a chest x-ray can show a widened mediastinum from the dilated esophagus, and no gastric air bubble, because air can't cross the closed sphincter into the stomach.
Manometry then makes the diagnosis and assigns the type. The high-resolution catheter carries thirty-six pressure sensors a centimeter apart from the upper sphincter to the stomach. The standard protocol under version four of the Chicago classification is ten five-milliliter water swallows lying down, then five sitting up, plus multiple rapid swallows and a rapid drink challenge; without the upright swallows, the classification can't be finished. The tracing is read for the two jobs of every swallow in a fixed order, relaxation first, because an outflow obstruction is the highest-stakes finding.
Relaxation is the integrated relaxation pressure, or IRP: how low the pressure across the junction falls during the swallow. On the most widely used system, a supine IRP under fifteen and an upright IRP under twelve millimeters of mercury are normal. Once relaxation is known, the body is read. The distal contractile integral measures how hard the smooth muscle squeezes: under one hundred is a failed swallow, one hundred to four hundred fifty is weak, four hundred fifty to eight thousand is normal, and over eight thousand is hypercontractile. Distal latency measures timing: under four and a half seconds means the contraction arrived too early, a premature, spastic contraction.
Achalasia is an elevated IRP with no normal peristalsis, and what the body does instead gives the type. Type one, classic achalasia, is an elevated IRP with every swallow failed and no pressurization. The body is silent; it has dilated, decompensated, and lost the tone to generate even passive pressure, which is why type one tends to be older, more advanced disease.
Type two is an elevated IRP with every swallow failed, but with panesophageal pressurization on at least twenty percent of swallows, a simultaneous rise of more than thirty millimeters of mercury along the whole length. The smooth muscle still has tone but can't generate a propagated wave, so the bolus is trapped between a closed sphincter and a tonically active body, and the whole column pressurizes at once.
Type three, spastic achalasia, is an elevated IRP with no normal peristalsis and premature, spastic contractions, a distal latency under four and a half seconds with a contractile integral over four hundred fifty, on at least twenty percent of swallows. The sphincter won't open, and the hyperexcitable distal body clamps down too early. These patients have more chest pain, from the spasm.
His IRP is elevated supine and upright, every swallow fails, and the whole esophagus pressurizes on most swallows. He has type two achalasia. The type matters, because it predicts how he'll respond to treatment. Type two responds best to every treatment, because the muscle that produces the pressurization is still alive and the esophagus hasn't decompensated. Type one is intermediate. Type three responds worst to pneumatic dilation and needs a tailored, longer myotomy that extends up over the spastic segment.
Before his tracing is trusted, he's asked about opioids. Chronic opioids distort every manometric measurement: they raise the IRP and the contractile vigor and shorten the latency, and they can produce a pattern that looks like achalasia, especially type three. In a patient on chronic opioids, stopping them comes before any procedure. He takes none.
With the diagnosis and type in hand, one thing must still be excluded before any treatment: pseudoachalasia. In up to five percent of patients who meet manometric criteria for achalasia, a cancer at the junction is producing the picture, by invading the myenteric plexus, by narrowing the junction mechanically, or through a paraneoplastic immune attack on the neurons, classically from small cell lung cancer with circulating anti-neuronal antibodies. The clues are age over sixty, symptoms for less than six to twelve months, and weight loss out of proportion to the dysphagia. Standard endoscopy often misses it, because the tumor infiltrates the muscularis propria and the plexus without producing a mucosal lesion.
The second patient shows those clues together. A sixty-eight-year-old woman with the same tracing, four months of dysphagia, and twenty pounds of weight loss doesn't go straight to a myotomy. Endoscopic ultrasound looks for a submucosal or extrinsic mass at the junction, and computed tomography, CT, of the chest and abdomen looks for thoracic, pulmonary, or upper abdominal cancer. The tumors implicated are adenocarcinoma of the gastric cardia, esophageal squamous cell carcinoma, lung cancer, lymphoma, and metastatic breast cancer. If one is found, treatment is directed at the cancer.
The first patient is thirty-eight, with two years of symptoms and little weight loss. He doesn't fit, and his endoscopy was clean, so he can be treated as primary achalasia.
Choosing his treatment starts with what treatment can and can't do. Nothing restores peristalsis. Every treatment works by lowering the sphincter pressure enough that gravity and the pressure in the esophagus can push the bolus through. And every treatment loses effect over time, so about one in three patients will need more treatment at some point. He's told that before he chooses, because achalasia is a chronic disease and he should expect follow-up for life.
For types one and two, the current consensus is that three definitive treatments are comparably effective, and each has its own trade-offs. Pneumatic dilation stretches the sphincter with progressively sized balloons, thirty to forty millimeters, tearing the muscle fibers. Sixty to eighty-five percent respond after one session in the short term, but about half of patients need more treatment within five years. Perforation happens in two to five percent, and about five percent develop reflux esophagitis.
Laparoscopic Heller myotomy cuts the sphincter muscle under direct surgical view and adds a partial fundoplication, a Dor, one hundred eighty degrees in front, or a Toupet, two hundred seventy degrees behind, to limit the reflux that follows. A full Nissen wrap is avoided, because an esophagus with no peristalsis can't push food past a full wrap. Heller gives good to excellent relief in seventy to ninety percent at one year, and about eighty-five percent remain in remission at ten years, with durability declining further by twenty. Reflux esophagitis develops in roughly ten percent. A randomized trial of about two hundred patients found pneumatic dilation and Heller essentially equivalent at one, two, and five years, with no difference in reflux.
Peroral endoscopic myotomy, POEM, creates a tunnel under the mucosa, cuts the inner circular muscle of the lower esophagus and sphincter through it with an electrosurgical knife, and closes the entry with clips. In randomized trials, POEM was as effective as Heller with a Dor through five years, and more durable than pneumatic dilation, still succeeding in about four in five at five years. Its drawback is reflux: POEM isn't routinely combined with an antireflux procedure, and close to half of patients have abnormal acid exposure afterward, far more than after Heller. Its advantage is that the operator can make the myotomy as long as needed.
For him, with type two, all three are reasonable, and the choice comes down to local expertise, his preference, and the trade-offs: dilation is slightly less durable, POEM brings the most reflux, and Heller is surgery. He chooses a Heller myotomy with a Dor fundoplication.
Type three would have changed the choice. The spastic segment extends well above the sphincter, and a balloon at the sphincter doesn't touch it, so pneumatic dilation is contraindicated. POEM, with the myotomy extended up over the spastic segment, is the treatment of choice, with clinical response over ninety percent in dedicated series.
The remaining options are for patients who can't have definitive treatment. Botulinum toxin, injected into the sphincter as eighty to one hundred units divided into four quadrants, poisons the cholinergic excitatory neurons and lowers sphincter pressure for a median of about six months, with less benefit each time it's repeated. It's kept for elderly or frail patients for whom dilation or myotomy is too risky. It isn't given to a young, fit patient like him, because it scars the submucosal plane and makes a later myotomy harder and riskier; intraoperative difficulty has been reported in about half of patients after prior injection, several times the rate without it. Calcium channel blockers and nitrates, taken under the tongue ten to thirty minutes before meals, give limited, short-lived relief, with headache, low blood pressure, and tachyphylaxis, and they're for patients who can't have procedures and have failed botulinum toxin.
His care doesn't end with the operation, because myotomy has its own long-term complication. A blown-out myotomy is a fifty percent increase in distal esophageal diameter at the myotomy site, and it causes treatment failure, more acid exposure, and recurrent regurgitation. It occurs in about thirty percent within five years of POEM and is most common after treatment of type three, where residual spastic contractions blow out the weakened site.
Achalasia also raises the risk of esophageal cancer. Older series reported relative risks anywhere from none to thirty-three-fold, and modern series suggest an absolute incidence of about seven tenths of a percent to just over three percent over ten years. The cancer is squamous cell carcinoma, and it arises mainly in long-standing disease with marked dilation. Even so, the American Society for Gastrointestinal Endoscopy found insufficient evidence to recommend routine endoscopic surveillance.
Here are the traps the boards set in these patients.
In diagnosis, treating the heartburn of achalasia as reflux misses that it's fermentation, not acid. Skipping endoscopy before manometry risks missing a tumor at the junction. And taking a normal endoscopy as proof there's no achalasia ignores that up to forty percent look normal.
Before treatment, forgetting to ask about opioids risks treating a drug effect. And missing pseudoachalasia in an older patient with a short history and weight loss sends a cancer to a myotomy.
In treatment, choosing pneumatic dilation for type three leaves the spastic segment untouched. Adding a Nissen wrap to a myotomy obstructs an esophagus with no peristalsis. Giving botulinum toxin to a young patient who will need a myotomy scars the plane the surgeon needs. And telling a patient that treatment is a cure sets up disappointment, because about a third need more treatment.
So, start to finish.
Achalasia is loss of the inhibitory neurons: a sphincter that won't relax and a body with no wave. It presents with dysphagia to solids and liquids from the start, regurgitation, little weight loss, and heartburn that isn't acid.
Endoscopy comes first to exclude a tumor, then barium and manometry. An elevated IRP with no normal peristalsis is achalasia: a silent body is type one, panesophageal pressurization is type two, and premature contractions are type three, and the type predicts the response. Ask about opioids, and before treating an older patient with a short history and weight loss, look for pseudoachalasia with endoscopic ultrasound and CT.
For types one and two, dilation, Heller with a partial wrap, and POEM are comparable, with POEM bringing the most reflux. For type three, POEM with a long myotomy. Botulinum toxin is only for those who can't have definitive treatment. Follow-up is lifelong, for recurrence and a blown-out myotomy.
Episode two is the patient whose sphincter doesn't relax fully but whose peristalsis is still there. Most of those patients don't have a primary motility disease at all, and the work is finding out which ones do.