Thorascopic Myotomy

Updated: Feb 06, 2014
  • Author: Shabir Bhimji, MD, PhD; Chief Editor: Dale K Mueller, MD  more...
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Overview

Background

Achalasia is an uncommon disorder of the esophagus. The disorder is characterized by inadequate relaxation of the lower esophageal sphincter and concomitant loss of peristalsis in the body of the esophagus. Patients are usually young and often present with dysphagia to both solids and liquids at the same time. Other symptoms may include regurgitation, chest pain, aspiration, and weight loss. The disorder is often misdiagnosed for gastroesophageal reflux disease (GERD) and is a common reason for a delay in diagnosis.

Achalasia is most common between the second and fifth decade of life but has been reported in people of all ages. In the United States, the incidence is about 1 per 200,000 population.

With achalasia, the essential problem is lack of normal esophageal motility and a hypertonic lower esophageal sphincter (LE)S which fails to relax. The aim of surgery is to disrupt the muscle fibers of the LES to relax the esophagus and allow for passage of food.

Today, many surgeons offer a laparoscopic procedure for the treatment of achalasia. Current result indicate that this surgery offers durable results with good short-term benefits. More than 90% of patients have relief of their symptoms immediately after surgery. In addition, the use of minimally invasive surgery has also reduced the morbidity associated with open esophageal surgery.

There are many treatments for achalasia. However, over the years, the role of surgery has become better defined. For mild cases of achalasia, medical therapies still play a role. Botox and pneumatic dilatation are good choices in patients who want to wait or would like a nonsurgical alternative. However, the results of these treatments are not sustained, and the relief from symptoms is variable. Minimally invasive surgery has now supplanted most medical therapies for achalasia. The minimally invasive approaches have a far much lower morbidity and mortality compared to the open technique. More than 90% of patients find effective relief from dysphagia. For those who have associated GERD, an antireflux procedure can be combined without any added morbidity.

Etiology

Achalasia has been known to occur for more than 200 years, but its cause still remains unknown. Biopsy of the mucosa in the affected part of the esophagus often reveals loss of ganglion cells and fibrosis of myenteric plexus.

This process is likely autoimmune regulated because T-cell lymphocytes predominate in the inflammatory infiltrate. [1] Additional research has shown that achalasia patients have decreased nitric oxide synthase in the myenteric plexus, resulting in reduced nitric oxide production. [2] Because nitric oxide is a key factor in gastrointestinal smooth muscle relaxation, it at least partly explains the dysfunction of the LES.

Symptoms

The hallmark symptom of achalasia is progressive dysphagia, often first to solids and then to liquids. Because the dysphagia usually worsens very gradually, it is often quite severe upon presentation. Most patients adapt their eating behavior long before the diagnosis is made. Because stress and cold liquids may exacerbate the dysphagia, both liquids and solids may be poorly tolerated simultaneously at presentation.

Chest pain is also a common symptom, and patients often undergo extensive cardiac evaluation prior to diagnosis. Previously, 10-39% of patients suffered bronchopulmonary complications from repeated regurgitation and aspiration. [3] Now many of these complications are avoided by earlier diagnosis and treatment. Dyspepsia occurs in about one fourth of cases, although it is usually caused by fermentation of unevacuated food in the esophagus rather than gastroesophageal reflux. [4, 5]

Patients often have a long history of symptoms, some greater than 30 years. Weight loss is common, although usually patients alter their diets enough to maintain body mass until the disease becomes intolerable and they seek therapy. Acute onset of symptoms or rapid weight loss should be a red flag for clinicians to rule out malignancy. Ruling out pseudoachalasia (presence of a distal esophageal tumor causing dysphagia) in older patients (>55 years) is crucial, as is ruling it out in those with a shorter duration of symptoms (< 6 months), or more profound, rapid weight loss (>15 lb). Any patient with a questionable diagnosis should be carefully evaluated, including the use of endoscopic ultrasound and computed tomography (CT) scan to rule out pseudoachalasia. [4, 6, 7]

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Indications

Sigmoid-Shaped or Megaesophagus

Some patients with achalasia develop a megaesophagus, which is usually the end stage of achalasia. This disorder is characterized by an aperistaltic esophagus and failure of the LES to relax. Over time, progressive dilatation and lengthening of the esophagus occurs. In the past, the only surgical option these patients had was total esophagectomy because no matter what type of surgery was performed, the dilated and tortuous esophagus had no motility and dysphagia persisted.

In the last decade, some surgeons have been offering laparoscopic myotomy to these patients. The myotomy significantly lowers the morbidity and mortality that is associated with a total esophagectomy. The few studies done so far reveal that laparoscopic myotomy is beneficial in these patients and provide moderate to excellent relief of symptoms. Short-term evaluation of these patients has revealed no reflux and improvement of dysphagia. However, long-term results are not available.

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Contraindications

To be able to undergo a laparoscopic myotomy under general anesthesia, the patient must be surgically fit. A relative contraindication may be prior esophageal or hiatal hernia surgery. Some surgeons feel that a megaesophagus or grade 1V dilatation (>8 cm) is a contraindication to a myotomy because poor relief from dysphagia occurs. Instead, these patients may be better served with an esophagectomy.

In any case, other surgeons feel that a minimally invasive procedure may be attempted and an esophagectomy can be performed if it fails.

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Technical Considerations

Length of the Myotomy

No absolute rule exists regarding the extent of the myotomy. In the past, most surgeons have elected to perform a myotomy of 3-5 cm. However, numerous studies have shown a direct correlation between length of myotomy and relief from dysphagia . Ample evidence shows that a myotomy that is less than 1 cm on the gastric wall is associated with persistent dysphagia. Most experts recommend making a myotomy of about 1.5 cm over the gastric wall to ensure that no residual dysphagia exists. Some surgeons also recommend that extending a myotomy to about 3 cm has better outcomes, but no long-term results with this approach are available.

A controversial aspect of laparoscopic myotomy is whether to perform an antireflux procedure at the same time. Some surgeons recommend this procedure each and every time, but others say that it depends on the patient and status of the esophagus.

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Outcomes

Long-term outcomes data from the open surgical era suggests successful relief of dysphagia in 65-70% of patients. However, most of these patients underwent open thoracotomy with minimal extension of the myotomy onto the stomach. This lack of sufficient myotomy onto the cardia has been proven to be the cause of most recurrent dysphagia after thoracoscopic or open myotomy via the chest.

Additionally, many of these late failures are the result of severe, intractable reflux affecting quality of life and requiring surgical intervention. Since the advent of the abdominal approach, and because laparoscopic techniques greatly improve visualization and allow longer transabdominal myotomies, success rates have improved dramatically. Several authors now support performing the myotomy with intraoperative endoscopic or manometric guidance to ensure complete obliteration of the LES. Specifically the sling fibers of Willis (the oblique component of the LES) must be surgically divided to provide adequate passage of food.

Transthoracic approaches also make performing an antireflux procedure more difficult. These problems have been substantially corrected with laparoscopic techniques. [8] Long-term outcomes for dysphagia in patients undergoing a laparoscopic Heller myotomy and antireflux procedure range from 80-95% in large studies. [9] Results for control of reflux may be inferior to results for dysphagia.

Early Complications

Perforation of the esophagus is known to occur in 1-5% of cases. The vast majority of perforations are identified in the operating room and easily repaired with minimal morbidity and no affect on the relief of dysphagia. This is vastly different from the morbidity associated with esophageal rupture that occurs following balloon dilatation for achalasia

Other complications of surgery seen in 3% of patients include bleeding, pneumothorax, wound infection, and ileus. The pneumothorax rarely requires treatment except for observation with serial chest radiographs. Other rare complications include splenic injury and injury to the vagus nerve.

Late Complications

Late complications from the surgery include recurrent dysphagia. Other common complications include incomplete myotomy, scarring in the hiatal region, or stricture formation.

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