Minimally Invasive Esophageal Procedures

Left Thoracoscopic Myotomy

Preoperative evaluation is essentially the same as that for laparoscopic Heller myotomy.

The patient is placed under general anesthesia and intubated with a double-lumen endotracheal tube so that the left lung can be deflated during the procedure. As for a left thoracotomy, the patient is placed in the right lateral decubitus position over an inflated bean bag. The instrumentation is similar to that for a laparoscopic Nissen or Guarner fundoplication. Instead of conventional trocars, four or five thoracoports with blunt obturators are employed, because insufflation of the thoracic cavity is not required. The myotomy can be performed with a monopolar hook cautery, bipolar scissors, or an ultrasonic scalpel. A 30º scope and a 45º scope are essential for thoracoscopic procedures. In addition, an endoscope is used for intraoperative endoscopy.

Step 1: Placement of Thoracoports

Five ports are usually placed (see Figure 11). Port A, used for the 30º scope, is inserted in the sixth intercostal space about 3.5 to 5 cm behind the posterior axillary line. Port B, used for the lung retractor, is placed in the third intercostal space about 1.25 to 2.5 cm anterior to the posterior axillary line. Port C, used for insertion of a grasper, is placed in the sixth intercostal space in the anterior axillary line. Port D, used for insertion of the instrument employed for the myotomy, is placed in the seventh intercostal space in the midaxillary line. Port E is placed in the eighth intercostal space between the anterior axillary line and the midaxillary line. This port is optional: it is needed in about 30% of cases to allow the surgeon to obtain further exposure of the esophagogastric junction through retraction of the diaphragm.

Troubleshooting. A common mistake is to insert port A too anteriorly. This port must be placed well beyond the posterior axillary line to provide the best angle for the 30º scope. Often, the other ports are placed one or two intercostal spaces too high. This mistake hampers the performance of the most delicate portion of the operation, the myotomy of the distal portion of the esophagus and the stomach.

Sometimes, chest wall bleeding occurs as a consequence of port insertion. This bleeding will obscure the operating field and therefore must be stopped before the intrathoracic portion of the procedure is begun. This is accomplished either by using the cautery from the inside or by applying a stitch from the outside if an intercostal vessel has been damaged.

Step 2: Retraction of Left Lung and Division of Inferior Pulmonary Ligament

Once the ports are in place, the deflated left lung is retracted cephalad with a fan retractor introduced through port B. This maneuver places tension on the inferior pulmonary ligament, which is then divided. After the ligament is divided, the fan retractor can be held in place by a self-retaining system fixed to the operating table.

Troubleshooting. Before the inferior pulmonary ligament is divided, the inferior pulmonary vein must be identified to prevent a life-threatening injury to this vessel. If oxygen saturation decreases, particularly in patients with lung disease, the retractor should be removed and the lung inflated intermittently.

Step 3: Division of Mediastinal Pleura and Dissection of Periesophageal Tissues

The mediastinal pleura is divided, and the tissues overlying the esophageal wall are dissected until the wall of the esophagus is visible. This maneuver varies in difficulty depending on the width of the space between the aorta and the pericardium (which sometimes is very small) and on the size and shape of the esophagus. Large (sigmoid) esophagi tend to curve to the right, which makes identification of the wall difficult. If the esophagus is not immediately apparent, it can be easily identified in the groove between the heart and the aorta by means of transillumination provided by an endoscope (see Figure 12).

Troubleshooting. The endoscope placed inside the esophagus at the beginning of the procedure plays an important role. In the early stages of the procedure, it allows identification of the esophagus via transillumination. When the light intensity of the 30º scope is turned down, the esophagus appears as a bright structure. In addition, tilting the tip of the endoscope brings the esophagus into view as it is lifted from the groove between the aorta and the heart.

Step 4: Initiation of Myotomy and Entry into Submucosal Plane at Single Point

As in a laparoscopic Heller myotomy, it is helpful to mark the surface of the esophagus along the line through which the myotomy will be carried out. The myotomy is started halfway between the diaphragm and the inferior pulmonary vein. Again, the proper submucosal plane should be reached at a single point before the myotomy is extended upward and downward.

Troubleshooting. Troubleshooting for this step is essentially the same as that for step 8 of a laparoscopic Heller myotomy, with the exception that here the myotomy is started 4 to 5 cm (rather than 3 cm) above the esophagogastric junction.

Step 5: Proximal and Distal Extension of Myotomy

Once the mucosa has been exposed, the myotomy can safely be extended proximally and distally (see Figure 13). I usually extend the myotomy for about 5 mm onto the gastric wall, without adding an antireflux procedure.^[3,4] Typically, the total length of the myotomy is about 6 cm for patients with achalasia.

Troubleshooting. Proximally, the myotomy is extended all the way to the inferior pulmonary vein only in cases of vigorous achalasia (high-amplitude simultaneous contractions associated with chest pain in addition to dysphagia) or diffuse esophageal spasm; otherwise, it is limited to the distal 5 to 6 cm of the esophagus. If a longer myotomy is needed, the lung is displaced anteriorly and the myotomy extended to the aortic arch.

Distally, the myotomy is continued for 5 mm past the esophagogastric junction. The endoluminal view provided by the endoscope is useful for assessing the location of the esophagogastric junction. Often, the stomach is distended by the air insufflated by the endoscope and pushes the diaphragm upward, thereby limiting the view of the esophagogastric junction. If sucking air out of the stomach does not resolve this problem, an additional port (i.e., port E) may be placed in the eighth intercostal space, and a fan retractor may be introduced through this port to push the diaphragm down.

Because the myotomy of the gastric wall is the most challenging part of the operation, good exposure is essential. It is at this level that an esophageal perforation is most likely to occur. The risk is particularly high in patients who have undergone pneumatic dilatation or injection of botulinum toxin, both of which may lead to the replacement of muscle layers by scar tissue and the consequent loss of the regular planes. Perforations recognized in the OR can be repaired by thoracoscopic intracorporeal suturing or, if this fails, by thoracotomy and open repair. The gastric fundus can be used to buttress the repair. If it is unclear whether a perforation has occurred, the esophagus should be covered with water and air insufflated through the endoscope as described earlier (see "Laparoscopic Heller Myotomy with Partial Fundoplication, Operative Technique, Step 7").

Step 6: Insertion of Chest Tube and Removal of Thoracoports

A 24 French angled chest tube is inserted under direct vision through port D or port E. The ports are removed under direct vision, and the thoracic wall is inspected for bleeding.

As with laparoscopic Heller myotomy, delayed esophageal leakage is a common postoperative complication, and treatment options are similar.

If the myotomy is not extended far enough onto the gastric wall, residual dysphagia occurs. To prevent this problem, the distal extent of the myotomy should be assessed by means of endoscopy with the goal of including 5 mm of the gastric wall. Patients with residual dysphagia must be evaluated by means of esophageal manometry, which will document the extent of the residual high-pressure zone and the pressure within it. The myotomy can be easily extended by a laparoscopic approach, and a Dor fundoplication can be added.

If, on the other hand, the myotomy is extended too far onto the gastric wall, abnormal gastroesophageal reflux occurs. Some patients present with heartburn; others are asymptomatic. It is essential to evaluate patients postoperatively with manometry and prolonged pH monitoring. Mild reflux can be treated with acid-reducing medications, particularly in elderly patients. In younger patients, abnormal reflux should be corrected with a laparoscopic partial fundoplication (e.g., Dor fundoplication).

Patients are started on a liquid diet the morning of postoperative day 1; on postoperative day 2, they are started on a soft mechanical diet, which is continued for the rest of the first week. I do not routinely obtain an esophagogram before starting feedings. The chest tube is removed after 24 hours if the lung is fully expanded and there is no air leak. Patients are discharged after 48 to 72 hours and are able to resume regular activities in 7 to 10 days.

The results obtained with thoracoscopic myotomy are generally comparable to those obtained with open surgical procedures. In a 1999 study from UCSF,^[4] 26 (87%) of the first 30 patients with achalasia who were treated in this fashion experienced good or excellent results (see Table 2 ). Currently, however, this procedure is rarely used to treat esophageal achalasia: laparoscopic Heller myotomy and Dor fundoplication is now the treatment of choice.^[32]

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Cite this: Minimally Invasive Esophageal Procedures - Medscape - Mar 01, 2005.