Thorascopic Myotomy Technique

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

Approach Considerations

Ernst Heller first described the 2-cardiomyotomy technique (one anterior and one posterior) along the gastroesophageal junction (GEJ) for achalasia in 1914. [10] It is currently modified such that only an anterior myotomy is performed. Heller myotomy provides excellent results and relief of dysphagia in 90-95% of patients. [4, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 1, 9, 21, 22, 23] Traditionally, surgery was accomplished via a transthoracic or transabdominal approach. Each was associated with the morbidity of a major open procedure, often with expected hospital stays of 7-10 days.

For this reason, 10-15 years ago most patients were treated by less-invasive therapies such as pneumatic dilatation despite superior long-term results from surgical myotomy. In the early 1990s, as minimally invasive techniques developed, surgery became more acceptable. The thoracoscopic approach was first described in 1991. This minimally invasive approach decreased postoperative pain and shortened hospital stays without compromising the relief of dysphagia. [24, 25]

In the mid 1990s, multiple factors led to a change from the thoracoscopic to the laparoscopic approach. First, with the increase in the number of laparoscopic fundoplications being performed, surgeons became more adept at laparoscopically operating on and around the esophageal hiatus. Second, many recognize that extending the myotomy well onto the stomach was critical for consistent and durable relief of dysphagia. [9]

Third, the incidence of postoperative reflux was high with the thoracoscopic approach even with limited gastric myotomy; thus, the need for a fundoplication became apparent. This is much easier to perform laparoscopically rather than from the chest. Additionally, laparoscopy avoids the need for single-lung ventilation with a double-lumen endotracheal tube and tube thoracostomy. The laparoscopic approach has since been proven superior to both open and thoracoscopic procedures with respect to complications, morbidity, mortality, length of hospital stay, relief of dysphagia, prevention of postoperative reflux, and operative times. [19, 9, 8, 26, 27]

University of Washington Experience

At the University of Washington, surgeons converted from a thoracoscopic to a laparoscopic Heller myotomy in 1994 for two distinct reasons. First, the surgeons recognized that a limited gastric myotomy (0.5–1.0 cm) failed to protect the patient from gastroesophageal reflux (GER). In fact, when pH monitoring was performed, 80% of patients had pathologic reflux. [9] Second, 17% of patients in their series returned with recurrent dysphagia, and half of them responded to extension of the gastric myotomy between 1.5 and 2.0 cm via the laparoscopic approach.

Between 1994 and 1998, 52 patients underwent laparoscopic myotomy with this longer gastric myotomy, yielding excellent improvement in dysphagia in over 90% of the patients. Still, occasional patients had inadequate relief or recurrence of dysphagia, some of whom improved with further extension of the gastric myotomy. Therefore, they began extending the gastric myotomy a full 3 cm in 1998. They also began performing a Toupet, rather than a Dor fundoplication. They felt an anterior fundoplication was more difficult with a 3-cm cardiomyotomy and suspected the 270° posterior Toupet would provide better control of reflux.

A comparison of the 2 approaches confirmed that an extended myotomy with Toupet fundoplication (EM/Toupet) more effectively obliterated the LES than the shorter myotomy with Dor fundoplication (SM/Dor). The evidence for this was a greater reduction in the residual LES pressure (9.5 vs. 15.8 mmHg respectively), as well as better, more durable relief of dysphagia. Dysphagia was both less frequent (once a month vs once a week on average) and less severe (3.2 vs 5.3 on a 10-point visual analog scale) in the EM/Toupet group. Most importantly, in the subsequent 7 years, no patient has required surgical intervention for recurrent dysphagia. Furthermore, this complete obliteration of the LES did not result in more reflux, as the mean distal esophageal acid exposure was equivalent in the 2 groups (EM/Toupet6.0% vs SM/Dor 5.9%).

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Port Placement

Pneumoperitoneum is usually established with a Veress needle and the use of an optical trocar. For a myotomy, 4 working ports are inserted under direct vision. The port for the camera is placed about 10-12 cm inferior to the left upper quadrant port and about 4-6 cm left of the midline. The remaining ports include a 5-mm trocar inserted in the right upper quadrant, a 100-mm trocar in the left lower quadrant and a 100-mm trocar in the right lateral quadrant to retract the liver. After the ports have been inserted, the patient is usually placed in a steep reverse Trendelenburg position. A 100-mm 30° angled camera is used.

Operative Steps

Our initial approach involves dividing the left phrenoesophageal and phrenogastric ligaments, allowing exposure of the left crus. Next, we mobilize the gastric fundus to create a tension-free fundoplication. An ultrasound dissector (Autosonix, United States Surgical Corp, Norwalk, CT) is used to divide the short gastric vessels beginning at the inferior pole of the spleen and continuing superiorly to the previously exposed left crus.

After the left phrenoesophageal ligament is divided, the gastrohepatic ligament is incised. The right and anterior phrenoesophageal ligament and peritoneum overlying the anterior abdominal esophagus are divided, being cognizant of the underlying anterior vagus nerve. When a posterior Toupet fundoplication is planned, a posterior esophageal window is created. During this step, the posterior vagus nerve should be visualized and protected. If an anterior fundoplication is performed, only the anterior esophagus requires full exposure.

Adequate mediastinal esophageal mobilization is crucial for a long esophageal myotomy and tension-free fundoplication. A Penrose drain may be placed around the GEJ and used to retract the esophagus caudally and laterally during hiatal and mediastinal mobilization. To clear a path for the myotomy across the GEJ, the authors resect the cardioesophageal fat pad to the left of the anterior vagus nerve while simultaneously mobilizing the vagus from the esophagus. This allows a straight plane to perform the myotomy.

Excellent visualization and exposure is essential to performing a safe and adequate myotomy. A lighted 52-F bougie is placed into the body of the stomach, serving both to illuminate the esophagus and muscle layers as well as to provide a stable platform to perform the myotomy. The myotomy is begun approximately 3 cm below the GEJ, and an L-shaped hook electrocautery device is used to divide the muscle fibers.

During the myotomy, electrocautery should be avoided unless absolutely necessary. Individual muscle fibers are divided by hooking them and applying gentle upward traction. Bleeding from the muscle or submucosa is controlled with pressure and time. These steps are important to avoid delayed perforation from unrecognized thermal mucosal injury.

Progressive division of the longitudinal and then circular muscle layer is performed as the myotomy is carried superiorly, 6-8 cm above the GEJ. Once the circular muscles are divided, a mucosal plane is reached with smooth, white, bulging mucosa. Thus, the entire myotomy spans approximately 9-11 cm (3 cm below to 6-8 cm above the GEJ). The most difficult dissection involves the 3-cm myotomy on the stomach where the plane of dissection becomes blurred with intervening sling muscular fibers and the underlying gastric mucosa is thinner, increasing the risk of perforation.

Mucosal perforations are repaired with a fine (4-0 or 5-0) absorbable monofilament suture and rarely require further intervention. In cases with a perforation, performing an anterior (Dor) fundoplication is prudent to buttress mucosal repairs and prevent leakage or fistula formation. Endoscopy can be used to evaluate the completeness of the myotomy and check for a missed perforation.

After satisfactory cardioesophageal myotomy, we perform a Toupet fundoplication. The posterior fundus of the stomach is brought around the esophagus and secured to the right crus and the right cut edge of the myotomy. In a similar (in fact, mirror image) fashion the anterior fundus is sutured to the left crus and left edge of the myotomy. Rarely, patients with large hiatal hernias require crurapexy closure of the hiatus.

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Surgery for Symptom Recurrence

For patients who have recurrence of symptoms or if the myotomy was not adequate or for patients who underwent a prior thoracoscopic myotomy, laparoscopic surgery is the procedure of choice. The procedure allows for extension of the myotomy and an additional reflux procedure if required.

To ensure that the dysphagia caused by achalasia is effectively relieved, complete division of the LES muscles is necessary.

In the last few years, thoracoscopic long myotomy has been performed with moderate success in patients with diffuse esophageal spasm. [28]

Beware: A thoracic approach for myotomy does not allow one to completely extend the myotomy to the cardia, which is a common reason for recurrence of dysphagia. Redo surgeries are generally more difficult and do require advanced laparoscopic skill and a good understanding of the abdominal and thoracic anatomy

If the patient has had a myotomy and has recurrence but is not a candidate for surgery, another noninvasive option is pneumatic dilatation. Recently, Botox has been used to treat achalasia and is an option in poor surgery candidates. Botox should not be used in surgical candidates because it induces severe fibrosis and makes surgery difficult. The intense fibrosis often lasts 6-12 months.

With the advent of minimally invasive surgery, laparoscopic Heller myotomy now is the first procedure of choice for most patients. [29, 30, 31]

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Robot-Assisted Surgery

Today, robot-assisted surgery is also used to treat achalasia. Robotic surgery can perform both an anterior reflux procedure and a myotomy without the aid of an assistance. The chief advantages of robotic surgery include greater flexibility, better visualization, increased range of motion of instruments, and ease of fine manipulations in tiny spaces.

The anatomy of the esophagus lends itself well to robotic surgery because the approach is direct and allows the robotic arms a full range of mobility and flexibility. Once the instruments are inserted, not much maneuvering is required except fine dissection.

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