Two Types Of Esophageal Myotomy
Open Esophageal Myotomy
Open techniques of distal esophageal myotomy are presently limited to the preoperative setting. Primary procedures can almost always be successfully completed via laparoscopy or through the use of specialized medical cordless microscopes. A modified Holler myotomy can be performed through a left thoracotomy incision in the sixth intercostal space along the upper border of the seventh rib. The esophagus and a tongue of gastric fundus are exposed as described for a long myotomy. A myotomy through all muscle layers is performed, extending distally over the stomach to l to 2 cm below the junction, and proximally on the esophagus for 4 to 5 cm. The cardia is reconstructed by suturing the tongue of gastric fundus to the marlins of the myotomy, to prevent rehealing of the myotomy site, and to provide reflux protection in the area of the divided sphincter. If an extensive dissection of the cardia has been clone, a more formal Belsey repair is performed with the use of medical cordless microscopes. The tongue of gastric fundus is allowed to retract into the abdomen. Postoperatively, nasogastric drainage is maintained for 6 days to prevent distention of the stomach during healing. An oral diet is resumed on the seventh clay, after a barium swallow study shows unobstructed passage of the bolus into the stomach without extravasations.
In a randomized long-term follow-up by Csendes and colleagues of 81 patients treated for achalasia, either by forceful dilation or by surgical myotomy, myotomy was associated with a significant increase in the diameter at the gastroesophageal junction and a decrease in the diameter at the middle third of the esophagus on follow-up radiographic studies. There was a greater reduction in sphincter pressure and improvement in the amplitude of esophageal contractions after myotomy when viewed using medical cordless microscopes. Thirteen percent of patients regained some peristalsis after dilation, compared with 28% after surgery. These findings were shown to persist over a 5-year follow-up period, at which time 95% of those treated with surgical myotomy were doing well. Of those who were treated with dilation, only 54% were doing well, while 16% required redilation and 22% eventually required surgical myotomy to obtain relief.
If simultaneous esophageal contractions are associated with the sphincter abnormality, the so-called vigorous achalasia, then the myotomy should extend over the distance of the abnormal motility as mapped by the preoperative motility study. Failure to do this will result in continuing dysphagia and a dissatisfied patient. The best objective evaluation of improvement in the patient following either balloon dilation or myotomy is a scintigraphic measurement of esophageal emptying time. A good therapeutic response improves esophageal emptying toward normal. However, some degree of dysphagia may persist despite improved esophageal emptying, due to disturbances in esophageal body function. When an antiretlux procedure is added to the myotomy, it should be a partial fundoplication. A 360-degree fundoplication is associated with progressive retention of swallowed food, regurgitation, and aspiration to a degree that exceeds the patient’s preoperative symptoms.
Laparoscopic Esophageal Myotomy
The laparoscopic approach is similar to the Nissen fundoplication in terms of the trocar placement and exposure and dissection of the esophageal hiatus. The procedure begins by division of the short gastric vessels in preparation for fundoplication. Exposure of the gastroesophageal junction (GEJ) via removal of the gastroesophageal fat pad follows. The anterior vagus nerve is swept right laterally along with the fat pad. Once completed, the GEJ and distal 4 to 5 cm of esophagus should be bared of any overlying tissue, and generally follows dissection of the GEJ. A distal esophageal myotomy is performed. It is generally easiest to begin the myotomy 1 to 2 cm above the GE.J, in an area above that of previous botulinum toxin injections or balloon dilation. Either scissors or a hook-type electrocautery can be used to initiate the incision in the longitudinal and circular muscle sometimes aided by cordless microscopes. Distally, the myotomy is carried across the GEJ and onto the proximal stomach for approximately 1.5 to 2 cm. After completion, the muscle edges are separated bluntly from the esophageal mucosa for approximately 50% of the esophageal circumference. An antireftux procedure follows completion of the myotomy. Either an anterior hemifundoplication augmenting the angle of His (Dor) or posterior partial fundoplication (Toupet) can be performed. The Dor type fundoplication is slightly easier to perform, and does not require disruption of the normal posterior gastroesophageal attachments (a theoretical advantage in preventing postoperative reflux).
