The Management of Achalasia of the Esophagus
BACKGROUND Esophageal achalasia is a rare motility disorder that affects 1 person per 100,000 and is characterized by the failure of the lower esophageal sphincter (LES) to relax appropriately in response to swallowing and the decrease or absence of peristalsis. Findings that have been associated with the diagnosis include myenteric inflammation with associated injury and loss of ganglion cells, along with fibrosis of myenteric nerves, reduced synthesis of nitric oxide, and vasoactive intestinal polypeptide. The exact etiology of achalasia remains unknown; however, autoimmune-mediated destruction of inhibitory neurons is a possible explanation. Common symptoms associated with achalasia include progressive chest pain, odynophagia, dysphagia, regurgitation, and weight loss. DIAGNOSIS The diagnostic workup typically includes esophagogastroduodenoscopy (EGD), contrast esophagram, and esophageal manometry. Esophagogastroduodenoscopy: EGD may show a dilated esophagus with retained saliva, fluid, and food and increased resistance to passage of the scope through the esophagogastric junction. EGD may also be used to assess for the presence of other diagnoses, including pseudoachalasia, esophageal tumors, reflux induced strictures, and eosinophilic esophagitis. Pseudoachalasia is defined as a spectrum of diseases that secondarily impair distal esophageal motility and imperfectly mimic achalasia. Originally described by Oglive in 1947, it is the result of a primary or metastatic submucosal cancer that involves the distal esophagus or esophagogastric junction. If pseudoachalasia is suggested on EGD, further investigations should include computed tomographic (CT) scan or endoscopic ultrasound scan. EGD is often suggestive but is not typically diagnostic of achalasia. Contrast esophagram: The classic appearance seen with a contrast esophagram is tapering of the lower esophagus, described as a bird’s beak (Figure 1). Other features may include a dilated esophageal body with an air-fluid level, the absence of a gastric air bubble, and absent or asynchronous esophageal contractions. Contrast studies have historically been considered diagnostic in approximately two thirds of patients. Esophageal manometry: This test shows incomplete or absent LES relaxation and the absence of esophageal peristalsis during swallowing and sometimes elevated resting LES pressure. Manometry is considered the gold standard preoperative assessment and is diagnostic of achalasia in 90% of cases. Occasionally, manometric catheters do not pass into the stomach without fluoroscopic or endoscopic guidance. Treatment for achalasia is not curative; it is primarily aimed at improving esophageal emptying by decreasing the functional obstruction at the level of the gastroesophageal junction, providing symptomatic relief and preventing the long-term development of megaesophagus. MEDICAL THERAPY Pharmacologic Calcium channel blockers and long-acting nitrates that act as smooth muscle relaxants have been shown to be effective in reducing LES pressure and providing temporary relief of dysphagia in a small proportion of patients. However, their use is limited because they do not improve LES relaxation or peristalsis and they have a short duration of action and typically provide incomplete symptom relief. Their role is limited to symptom relief in patients with very early achalasia or those who are at high risk or refuse more aggressive treatments; in patients with severe achalasia, pharmacologic treatments have not been shown to be beneficial. Botulinum Toxin Injection Botulinum toxin is a neurotoxin that inhibits acetylcholine release at motor neuron presynaptic terminals and thereby promotes LES relaxation. Botulinum toxin is injected endoscopically with a sclerotherapy needle in four aliquots into each quadrant of the LES, with a total of 100 units. The complication rate associated with botulinum toxin injection is very low, and this method has been shown to provide a good short-term response, with symptomatic reduction in up to 75% of cases. However, beneficial effects decrease over time, with symptoms typically recurring in 1 to 4 months. A recent Cochrane review of four randomized controlled trials suggested that when compared with pneumatic dilation, botulinum toxin injection was less effective in the long-term control of symptoms arising from achalasia, with only 25.6% having symptomatic remission at 1 year compared with 70.2% in the pneumatic dilation group (Table 1). Furthermore, botulinum toxin injections can hypothetically produce submucosal scarring that impacts the dissection of the mucosal plane at myotomy, which some surgeons believe can increase the risk of intraoperative esophageal mucosal injury. Thus, currently botulinum toxin injection should be reserved for patients who do not wish to have other treatments or those who are at too high a risk for more invasive procedures, including pneumatic dilation and surgical myotomy. Esophageal Pneumatic Dilation Endoscopic pneumatic dilation is considered the most effective nonsurgical treatment for the palliation of dysphagia associated with achalasia. Pneumatic dilation is preferred over standard balloon or bougie dilation because it not only stretches but also produces localized rupture of the LES muscle fibers. Most endoscopists advocate a sequential graded approach to pneumatic dilation, with noncompliant polyethylene balloon diameters currently used being 30, 35, and 40â•¯mm. The most commonly used system is the Microinvasive Rigiflex balloon system (Boston Scientific Corporation, Natick, Mass). The balloon is placed across the LES, and position is confirmed with fluoroscopy with radiopaque markers on the catheter and within the balloon (Figure 2). The pressure necessary is usually 7 to 15 psi, with balloon inflation maintained for 15 to 60 seconds with confirmation of LES waist obliteration with fluoroscopy. Commonly, a multiple treatment regimen is used, based on active surveillance for symptomatic recurrence; this has been shown to be effective in the palliation of dysphagia associated with achalasia. The most severe complication associated with pneumatic dilation is esophageal perforation, which is quoted to occur in 4% to 7% of dilations and which occurred in 4% of patients in a recent randomized controlled trial. Esophageal perforation in this context is a serious complication, requiring urgent surgery, combining primary repair with surgical myotomy. Longterm functional results of perforation when managed by an experienced surgical team can be comparable with primary surgical treatment. Many gastroenterologists perform a postprocedure esophageal contrast swallow to rule out perforation before discharge from
TABLE 1:â•‡ Endoscopic pneumatic dilation versus botulinum toxin injection in the management of primary achalasia Follow-up period Pneumatic dilation: symptom remission (N = 158) Botulinum toxin: symptom remission (N = 121) 6 months 76% 26% 12 months 70% 25% Data from Leyden JE, Moss AC, MacMathuna P: Endoscopic pneumatic dilation versus botulinum toxin injection in the management of primary achalasia. Cochrane Database Sys Rev (4):CD005046, 2006.
hospital. Furthermore, the long-term effectiveness of pneumatic dilation regimens is questionable, with treatment success rates of 50% at 5 years. A major advantage of pneumatic dilation is that it can be performed in an outpatient setting, enhancing its cost effectiveness in the treatment of esophageal achalasia. Per-Oral Endoscopic Myotomy Per-oral endoscopic myotomy (POEM) has been recently introduced as a potential new endoscopic approach to myotomy. Significant variability has been found in the technical approach used in POEM surgery. The most commonly described technique involves submucosal injection of saline solution at the midesophageal level approximately 13â•¯cm from the gastroesophageal junction. A standard endoscope with a cap is introduced into the submucosal layer through a 2-cm longitudinal incision on the mucosal surface. A submucosal tunnel is then created and extended to 3â•¯cm onto the stomach with a triangular tip knife and spray coagulation with direct endoscopic vision, or blunt dissection with the flexible endoscope or standard balloon dilation. Dissection of the circular muscle begins approximately 7â•¯cm from the gastroesophageal junction with spray coagulation and a triangular tip knife. Division of the muscle continues for approximately 2â•¯cm distal to the gastroesophageal junction; narrowing is typically seen endoscopically during passage through the LES. The outer longitudinal muscles are identified at the limit of the dissected area, and after myotomy, smooth passage of the endoscope through the gastroesophageal junction should be seen. The site of entry in the mucosa is then closed with hemostatic clips or fibrin glue. Table 2 discusses the results from clinical POEM studies to date. The attraction of this technique is the minimally invasive nature of the procedure, with no external scarring and less surgical stress, but the creation of a myotomy that replicates what is done surgically. This is an innovative and potentially important addition to the treatment approaches for achalasia. However, currently, insufficient follow-up assessment exists on the long-term success rate or consequences of POEM.
TABLE 2:â•… Results from clinical trials of per-oral endoscopic myotomy Author No. of patients Myotomy length (cm) Follow-up period Dysphagia score improvement LES pressure change Inoue (2010) 17 8.1 (6.1 in esophagus + 2 in stomach) 5â•¯mo (1-16â•¯mo) 10 to 1.3 (0-4) 52.4 to 19.8 (9.3-42.7) Von Renteln (2011) 16 12 (8-17) 3â•¯mo 94% patients with Eckhard score of ≤3 27.2 to 11.8 Swanstrom (2011) 5 7 (6-12) 2â•¯wk All patients reported immediate dysphagia relief No postoperative study Costamagna (2012) 11 10.2 ± 2.8 1â•¯mo 7.1 to 1.1 (Eckardt score) 45.1 to 16.9 LES, Lower esophageal sphincter.
SURGICAL TREATMENT Myotomy Technique and Outcomes Surgical myotomy with division of the muscle fibers of the cardia for the treatment of achalasia was first described by Ernst Heller in 1913. Over the years, several technical issues have undergone clinical assessment; transthoracic versus transabdominal, open versus laparoscopic, and extended versus limited myotomy and whether a concomitant antireflux procedure including Nissen, Toupet, or Dor fundoplication should be done in conjunction with the myotomy. The authors describe the method of esophageal myotomy that is used routinely at their institution and discuss some of the issues regarding modifications of this technique. Most commonly, the authors use a laparoscopic transabdominal approach to esophageal myotomy. The patient is positioned in a modified lithotomy position in reverse Trendenlenburg’s position. A five-port technique is used: one camera port, two ports for retraction, and two working ports. The first incision is made typically one third to one half the distance from the umbilicus to the xiphisternum, to allow placement of a 12-mm Hassan or Optiview port (Johnson & Johnson, Calif). A 12-mm working port is placed in the left upper quadrant adjacent to the costal margin as high as possible but also maximizing triangulation of the right and left working ports. A 5-mm port is placed in the groove between the xiphisternum and the right costal margin to allow insertion of the liver retractor (Nathanson liver retractor, Cook Medical Bloomington, Ind), which is used to retract the liver anteriorly and to the right. Two further 5-mm ports are placed to the left and right of the camera port, the one on the right used for retraction and taking down the short gastric vessels and one on the left to be the other dissection or working port. The left 5-mm port is typically placed through or beneath the falciform ligament. The assistant stands on the left side of the patient, the camera operator to the right, and the operating surgeon between the legs. Dissection begins with division of the phrenoesophageal membrane and gastrophrenic ligaments, with dissection extending posteriorly to the decussation of the crura. This dissection is continued circumferentially, the right and left crura are freed, and the dissection is carried into the mediastinum to allow adequate circumferential mobilization of the esophagus, which is encircled by a Penrose drain. Esophageal mobilization is continued until there are 4 to 5â•¯cm below the hiatus without tension. This mobilization is done to a greater degree when the distal esophagus is tortuous. The authors divide the short gastric vessels and omental attachments over a distance of 15â•¯cm until the fundus is completely free. The anterior esophageal fat pad is removed down to the gastric serosa to expose the gastroesophageal junction and increase the ease of doing the myotomy. This dissection is typically started to the left of the anterior vagus nerve and can facilitate the mobilization of the anterior vagus nerve to the right to take it well away from the site of the proposed myotomy. The myotomy is initiated 1 to 2â•¯cm above the esophagogastric junction, typically with hook cautery initially but then with blunt tearing of the last circular muscle fibers. The authors commonly extend the myotomy a minimum of 5â•¯cm in a cephalad direction along the anterior esophagus then across the esophagogastric junction, continuing for a minimum of 2â•¯cm caudally onto the stomach (Figure 3). The change from esophageal to gastric muscle fibers can be seen as they change from a horizontal circular orientation to an oblique direction and are more adherent to mucosa in the region of the LES. Once the myotomy is completed, a 48F to 52F bougie is passed with laparoscopic guidance, which stretches the mucosa and helps to ensure that all muscle fibers are divided. At the end of the myotomy, intraoperative endoscopy is selectively undertaken to confirm an adequate myotomy has been performed, with the easy passage of the endoscope into the stomach, and to transilluminate the mucosa, checking for defects with air insufflations. The crura are loosely opposed posterior to the esophagus with permanent sutures. After myotomy, the authors typically perform an antireflux procedure, most commonly a Toupet but selectively a Dor fundoplication. For a Toupet fundoplication, the fundus is brought posterior to the esophagus where it should sit in place without any tendency to retract. The right limb of the fundus is then sutured to the right edge of the esophageal myotomy with three interrupted 2-0 Ethibond sutures (Ethicon, Johnson & Johnson, Calif) placed 1â•¯cm apart and careful avoidance of the anterior vagus nerve. The most superior suture includes a bite of the edge of the hiatus and the fundus and esophageal muscular wall. The left limb of the fundus is then sutured in a similar manner to the left side of the esophageal myotomy with interrupted Ethibond sutures placed 1â•¯cm apart to create a 2-cm fundoplication over 270 degrees. The fundus lateral to the fundoplication is tacked to the undersurface of the diaphragm with an additional 2-0 Ethibond suture to accentuate the antireflux valve and remove any residual drag on the repair sutures. For a Dor fundoplication, the authors use interrupted sutures to fix the posterior wall of the left anterior fundus to the esophagus to the left of the myotomy and to the left crus of the diaphragm. The leading edge of the fundus is then positioned anteriorly to the esophagus overlying the myotomy and is sutured to the right side of the esophagus to the right of the myotomy, with separate sutures placed into the right crus of the diaphragm. FURTHER DISCUSSION Transthoracic Versus Transabdominal Open transthoracic and transabdominal myotomy have similar outcomes in terms of postoperative complications, palliation of dysphagia, and symptom control for the treatment of achalasia. However, transabdominal esophageal myotomy is associated with less physio- logic impact than a thoracotomy and, when combined with an antireflux procedure, produces less postoperative reflux. Open Versus Laparoscopic Versus Thoracoscopic In comparison of laparoscopic and thoracoscopic approaches with myotomy, the outcomes of the laparoscopic approach are superior, particularly with respect to symptomatic improvement. Laparoscopic myotomy has several advantages over an open approach, including reduced postoperative pain, length of hospital stay, and pulmonary dysfunction and shorter return to normal activities. The authors advocate the preferential use of laparoscopic esophageal myotomy with partial fundoplication for the treatment of achalasia, where a contraindication to laparoscopic surgery does not exist. Length of Myotomy Palliation of dysphagia remains the most important treatment outcome after surgical myotomy for achalasia; for this reason, a longer myotomy is considered the most appropriate approach in all cases. The acceptable length for myotomy ranges from 4 to 8â•¯cm on the esophageal aspect and from 2 to 3â•¯cm on the stomach. Within this range, symptomatic improvement and lower esophageal resting pressure reduction are equivalent. Concomitant Antireflux Procedure: Nissen/Toupet/Dor The authors advocate the use of a partial fundoplication procedure (Toupet or Dor) as a routine addition to the surgical esophageal myotomy for the treatment of achalasia. The rate of dysphagia improvement is not affected; however, the incidence rate of gastroesophageal reflux symptoms is greater when an antireflux procedure is not combined with myotomy. Furthermore, poor long-term outcomes associated with surgical myotomy are commonly the result of severe uncontrolled reflux. The authors preferentially use a Toupet or Dor fundoplication over a 360-degree Nissen fundoplication. Controversy exists as to whether a full 360-degree Nissen fundoplication increases the rate of dysphagia compared with an incomplete fundoplication. Currently, no significant difference in short-term clinical outcomes, including dysphagia control and reflux symptoms, has been shown in comparison of Toupet and Dor fundoplications after esophageal myotomy. Potential benefits of Toupet fundoplication include improved long-term reflux control; however, the benefits of Dor fundoplication include less disruption of hiatal anatomy and fundal coverage of the esophageal mucosa after myotomy. The authors use a Toupet reconstruction in most cases for better visualization during the myotomy and the production of a more robust antireflux gastroesophageal valve. There is a hypothetical advantage of using the two limbs of the fundoplication to hold the edges of the myotomy apart. In cases with concern regarding the integrity of the mucosa after myotomy, the authors use a Dor repair to allow fundal coverage of the esophageal mucosa. Sigmoid Esophagus or Megaesophagus Sigmoid esophagus is characterized by a widened (>6-cm diameter) and tortuous esophageal body that results in a sigmoid-shaped appearance and a more advanced stage of achalasia. Surgical treatment for sigmoid achalasia has traditionally been esophagectomy because the suggestion was that the dilated tortuous and aperistaltic esophagus would not empty sufficiently to improve dysphagia after myotomy of the LES. More recently, many surgeons have shown successful outcomes with myotomy and Dor fundoplication as the treatment of choice, with 92% of patients reporting improvement in dysphagia. The benefits of myotomy in this situation are clear with the avoidance of the morbidity and mortality associated with esophagectomy. However, in certain cases of megaesophagus (Figure 4), myotomy is unlikely to provide adequate relief from dysphagia, and primary esophageal resection is indicated. Surgical Myotomy Versus Endoscopic Treatment The debate regarding what is the “best” treatment for achalasia remains unresolved in the current literature. The advantages of endoscopic treatment with pneumatic dilation include a less invasive approach and good short-term relief of dysphagia. Many gastroenterologists find a 5% risk of perforation associated with this procedure unacceptable. There is also the well-documented issue of the need for sequential treatments in many patients. Surgical myotomy when performed laparoscopically has the benefits of good long-term relief of dysphagia and symptom control. The disadvantages are related to the risks of surgery and include bleeding, infection, reflux symptoms, and esophageal perforation (although in the context of surgery, this is typically recognized and addressed at the time of the myotomy). The most recent multicenter randomized control trial comparing surgical myotomy with pneumatic dilation showed equivalent rates of success at 2 years. In spite of this trial showing a total perforation rate of 4%, the authors believe that in experienced hands pneumatic dilation should still remain a treatment option for patients. However, at their center, they are currently offering laparoscopic myotomy and antireflux reconstruction as primary treatment for all appropriate patients. SUMMARY Esophageal achalasia is a rare disorder, and treatment approach is dependent on several factors, including patient’s severity of symptoms, patient’s medical comorbidities and physiologic fitness, and the level of experience of the managing gastroenterologist or surgeon. Centers of excellence that are experienced in managing esophageal motility disorders including achalasia allow specialized gastroenterologists and surgeons to work together to provide the best outcomes for patients with esophageal achalasia. ACKNOWLEDGMENT This work was supported in part by the Ryan Hill Research Foundation. S u g g e s t e d R e a d i n g s Boeckxstaens GE, Annese V, Bruley des Varammes S, et al: Pneumatic dilation versus laparoscopic Heller myotomy for idiopathic achalasia, N Engl J Med 364:1807–1816, 2011. Campos GM, Vittinghoff E, Rabl C, et al: Endoscopic and surgical treatments for achalasia: a systematic review and meta-analysis, Ann Surg 249:45–57, 2009. Ferguson MK, Reeder LB, Olak J: Results of myotomy and partial fundoplication after pneumatic dilation for achalasia, Ann Thorac Surg 62:327–330, 1996. Inoue H, Tianle KM, Ikeda H, et al: Peroral endoscopic myotomy for esophageal achalasia: technique, indication and outcomes, Thorac Surg Clin 21:519–525, 2011. Leyden JE, Moss AC, MacMathuna P: Endoscopic pneumatic dilation versus botulinum toxin injection in the management of primary achalasia, Cochrane Database Sys Rev (4):CD005046, 2006. Patti MG, Fisichella PM, Perretta S, et al: Impact of minimally invasive surgery on the treatment of achalasia: a decade of change, J Am Coll Surg 196:698– 703, 2003. Rawlings A, Soper N, Oelschlager B, et al: Laparoscopic Dor versus Toupet fundoplication following Heller myotomy for achalasia: results of a multicenter, prospective randomized-controlled trial, Surg Endosc 26:18–26, 2012. Richter JE, Boeckxstaens GE: Management of achalasia: surgery or pneumatic dilation, Gut 60:869–876, 2011. Stefanidis D, Richardson W, Farrell TM, et al: SAGES guidelines for the surgical treatment of esophageal achalasia, Surg Endosc 26:296–311, 2012. West RL, Hirsch DP, Bartelsman JF, et al: Long term results of pneumatic dilation in achalasia followed for more than 5 years, Am J Gastroenterol 97:1346–1351, 2002.
direction along the anterior esophagus and a minimum of 2â•¯cmcaudally onto the stomach.