Diffuse esophageal spasm (DES) is one of several nonspecific smooth muscle esophageal motility disorders associated with intermittent debilitating dysphagia and chest pain. The efficacy of long esophageal myotomy for the surgical treatment of DES has not been as favorable as myotomy has been for achalasia (see Chap. 26). Surgical treatment in this patient group therefore remains controversial. Long esophageal myotomy was first described for the treatment of DES in 1950 by Professor Lortat-Jacob of Paris, France.¹ Although the surgical principles remain the same, a few modifications have been made in the approach to diagnosis and treatment.

GENERAL PRINCIPLES AND PATIENT SELECTION

The pathophysiology of DES is still poorly understood. It is thought to be a neuropathy involving the smooth muscle layer of the esophageal wall that causes an inhibitory effect in the distal esophagus and hypotension of the lower esophageal sphincter (LES), giving rise to incomplete LES relaxation after a wet swallow. Gastroesophageal reflux disease (GERD) also has been implicated in the etiology of DES.² Dysphagia to solids and liquids, sometimes exacerbated by very cold or very hot foods, and intermittent chest pain are the predominant symptoms. The dysmotility, which is characterized by the presence of incoordinated nonperistaltic esophageal contractions of high, medium, or low amplitude, may progress or, in rare cases, has been observed to normalize. Progression of DES to achalasia is uncommon but has been reported in a prospective cohort study. No manometric or demographic predictors of progression have been identified.³

The condition continues to represent a therapeutic challenge. For some patients, medical therapy with smooth muscle relaxants (e.g., long-acting nitrates), calcium channel antagonists, and/or psychotropic drugs has proved beneficial.^4,5 Anticholinergics, pneumatic dilation, and botulinum toxin (Botox) injections produce brief and partial symptomatic relief.

Surgery is offered when symptoms are refractory to medical treatment or when complications arise. In general, surgical therapy can control symptoms in approximately 80% of patients. Patients with spastic disorder in addition to a pulsion diverticulum will benefit more from surgery than patients with spastic disorder only.⁶ Long myotomy is often combined with an antireflux operation.

A successful outcome for surgical treatment of DES requires the elimination or reduction of episodes of dysphagia and/or chest pain and prevention of postoperative GERD. Some consider long esophageal myotomy for DES to be a palliative procedure because swallowing is never perfectly restored.

PREOPERATIVE ASSESSMENT

Since esophageal motility dysfunction is thought to represent a continuum of disease, establishing the correct diagnosis is important to selecting the most appropriate treatment, reducing the incidence of postoperative complications, and achieving the best therapeutic outcome. The standard diagnostic workup for DES includes barium swallow, esophageal manometry, esophagogastroduodenoscopy (EGD), and endoscopic ultrasound (EUS). pH studies can confirm the presence or absence of gastroesophageal reflux and may guide therapeutic maneuvers.

Radiologic examination with barium swallow reveals the characteristic corkscrew appearance of the esophagus first described by Moersch and Camp⁷ (Fig. 27-1). The contractions are relatively constant in their location and usually confined to the lower half of the intrathoracic esophagus. On esophageal manometry, DES is characterized by the presence of intermittent simultaneous contractions (range 30–100 mm Hg) intermixed with normal peristalsis (Fig. 27-2). The disorder is variously defined by the presence of simultaneous contractions after 10–30% or more of wet swallows.^8,9 The greater the percentage, the more certain is the diagnosis. The mean simultaneous contraction amplitude in DES should exceed 30 mm Hg. Other manometric findings may include spontaneous contractions and repetitive contractions (multiple-peaked contractions).^8,10

EGD is indicated to exclude organic pathology such as an obstructing lesion, benign stricture, or cancer. Endoscopic observation of DES also has revealed that the tighter muscular rings tend to be fixed in location and that the less constricting spastic muscle causes the mucosa to have a corrugated appearance^11,12 (Fig. 27-3).

EUS can be quite useful for assessing the extent of the spastic segment when used in combination with barium esophagram and manometric analysis. The spastic segment is revealed by a thickened muscle layer in the esophageal wall¹³ (Fig. 27-4). The esophageal wall muscle is thicker at rest (baseline) in patients with DES than in normal subjects, and there is a significant correlation between baseline muscle thickening and peak pressure.^11,14

SURGICAL TECHNIQUE

Anesthesia and Positioning

Long esophageal myotomy can be performed via thoracotomy or minimally invasive thoracoscopy. Whenever a thoracotomy is planned, an epidural catheter should be placed. With the minimally invasive approach, depending on the surgeon's experience and confidence that the procedure can be completed without conversion to an open technique, the epidural may not be necessary.¹⁵ A double-lumen endotracheal tube permitting lung isolation is necessary, regardless of approach. A nasogastric tube is inserted, and the patient is placed in right lateral decubitus position. The position of the endotracheal tube is reconfirmed before draping.

Open Thoracotomy Approach

A left posterolateral thoracotomy is preferred because it is easier to perform an antireflux procedure, if needed, through the left chest. The left lung is isolated. The sixth or preferably seventh intercostal space is entered (Fig. 27-5). The inferior pulmonary ligament is mobilized up to the inferior pulmonary vein. The lung is retracted medially and cephalad, and the mediastinal pleura is incised over the esophagus. A Penrose drain is placed around the esophagus to assist with mobilization. Care should be taken to identify and preserve both vagal nerve trunks. A complete longitudinal extramucosal myotomy in the spastic segment of the esophagus is made using scissors, knife, diathermy, LigaSure (Valleylab, Boulder, CO), or Harmonic Scalpel (Ethicon Endosurgery, Inc.). The segment of spastic smooth muscle usually is located in the middle and lower esophageal wall in patients with DES. The myotomy thus is usually performed inferior to the level of the aortic arch.

The surgical technique described by Henderson and colleagues involved a total thoracic myotomy that extended to the thoracic inlet.¹⁶ Ellis and others²² found later that a total intrathoracic myotomy was rarely indicated. In most patients with DES, the LES is normal, and therefore, a myotomy extending superiorly to the aortic arch level is sufficient (Fig. 27-6). If the preoperative workup reveals an abnormal LES, the myotomy should be extended inferiorly onto the gastric cardia. This, however, increases the risk of postoperative gastroesophageal reflux, and a fundoplication or fundic patch procedure ranging from 2 to 3 cm in length may be required.¹⁷

The reasons for performing a fundic patch procedure are to preserve the separation of each myotomized edge, to reinforce the wall of the surface of the myotomized mucosa, and to avoid postoperative leak complications. Some surgeons claim that the patch procedure also prevents adhesion and contraction of the myotomy wound and the possible development of postoperative segmental diverticulous dilatation at the myotomy site. The number of patients who have been reported to undergo this technique, however, is limited, and there is no long-term follow-up.¹³

Thoracoscopic Approach

Thoracoscopic esophageal myotomy has been performed in several centers with early satisfactory results.^18–20 Although in the open approach the esophagus is exposed through the left chest, in a minimally invasive approach, a right-sided approach is sometimes easier because it avoids the aorta. The patient is placed in the left lateral decubitus position. A double-lumen endotracheal tube is required for the thoracoscopic approach. A 10-mm port is placed in the anterior axillary line at approximately the sixth or seventh intercostal space. Additional 5-mm ports are placed in the posterior axillary space at the eighth intercostal space and posterior and inferior to the scapular tip. An additional 10-mm port may be placed in the fourth intercostal space anteriorly near the axilla. The ports for trocar placement are placed as illustrated in Fig. 27-7.

A stitch is often placed on the dome of the diaphragm and pulled inferiorly to expose the hiatus and lower esophagus. The inferior pulmonary ligament is mobilized first, followed by mobilization of the distal esophagus. The pleura is divided to the level of the azygos vein, but this can be extended to the thoracic inlet if needed. The vagus nerves should be identified and preserved. The circumferential esophagus is mobilized by 90–120 degrees. The myotomy is begun 6–7 cm superior to the gastroesophageal junction (GEJ) (Fig. 27-8). The plane between the muscularis mucosa and the circular muscle layer is entered using hook electrocautery, LigaSure, or Harmonic Scalpel. The extent of the extramucosal esophageal myotomy is guided by the manometric tracing acquired during the preoperative workup because it precisely defines the anatomic and functional boundaries of the spastic portion. Reliance on the manometric data is often more important when performing redo surgery after an incomplete myotomy has failed.

The mucosa should be inspected closely to identify mucosal perforations irrespective of the approach to surgery. Filling the pleural space with saline and gently insufflating air into the esophagus is a useful technique in this regard, but it is far from 100% accurate. Before closure, the pleural space is drained with a single 28F chest tube.

POSTOPERATIVE CARE

Postoperative care after long myotomy for DES follows the same principles of care for any noncardiac surgery of the chest. Unique to surgery of the esophagus, however, is a high index of suspicion for unidentified esophageal leak, for this can be a catastrophic complication. Patients are extubated preferably in the OR or postanesthesia recovery room. At our institution, patients are admitted to a step-down thoracic ICU. Attention to pulmonary toilet is essential, and chest physiotherapy, performed at our institution by a thoracic intensive care nurse, is instituted to avoid the complication of atelectasis or sputum retention. The nasogastric tube is placed on low intermittent suction, and the chest tube is set at –20 cm H₂O of water-seal suction until the next morning. A barium swallow study is performed on the first postoperative day, and if there is no evidence of leak, the nasogastric tube is removed, and the patient is started on sips of clear liquids. If liquids are well-tolerated, the patient is advanced to a clear liquid diet. There should be no expectation of air leak unless there is a known surgical complication. If the fluid output from the chest tube is low and there is no air leak, the chest tube can be removed on the first postoperative day after the barium swallow. The patient is encouraged to ambulate aggressively on the first postoperative day. Once oral intake is tolerated, oral analgesics are introduced. The epidural is later removed after a small period of overlap with oral analgesics. The length of stay for a thoracoscopic procedure is 3–5 days. Longer stays are required after thoracotomy. The patient is seen again in follow-up 2–3 months after surgery (Fig. 27-9).

PROCEDURE-SPECIFIC COMPLICATIONS

Perforation and Leak

An unidentified mucosal injury will give rise to an esophageal leak in the postoperative interval. Management depends on the extent of the injury and whether or not it is drained completely.

Reflux

Gastroesophageal reflux is reported to occur in up to 50% of patients when an antireflux procedure is not performed concomitant with myotomy,²¹ especially if the myotomy extends onto the cardia.

Dysphagia and Failure

Surgical failures generally are attributed to either incomplete myotomy or incomplete or erroneous diagnosis.¹⁶ Fibrous adhesions or contraction at the site of the myotomy also may result in failure.

SUMMARY

Whether a long esophageal myotomy is performed via posterolateral thoracotomy or minimally invasive thoracoscopy, one should ensure that the correct diagnosis has been made and that all the preoperative investigations are reviewed thoroughly. Extending the myotomy superiorly to the level of the aortic arch will ensure that the spastic segment is completely excluded. The vagus trunks should be identified and preserved, and all the extramucosal layers should be divided. A debate still exists as to whether an antireflux procedure should be included in the operative plan. In our practice, we base this decision on the following factors: Whenever the spastic segment extends onto the gastric cardia or if the patient has preexisting symptoms of reflux that have been confirmed with pH studies, we always include an antireflux operation. In this case, we generally perform a Dor or Belsey wrap. The procedure can be performed through the left chest or abdomen. If there is minimal or limited distal involvement of the cardia with no reflux symptoms, we opt for a sphincter-sparing myotomy with good long-term outcome.

EDITOR'S COMMENT

It may be technically advantageous to place a gastroscope into the stomach instead of a nasogastric tube. The gastroscope distends the esophagus, but not too much, and facilitates the performance of the myotomy. It also allows the surgeon to immediately verify, endoscopically, the sufficient extent of the myotomy and absence of leak.

–RB

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