Valerio Balassone, Mike Thomson, and George Gershman Achalasia is a life‐long debilitating condition characterized by incomplete lower esophageal sphincter (LES) relaxation, increased LES tone and aperistalsis of the esophagus, which leads to slow or absent bolus transit into the stomach. Diagnosis of achalasia in children is generally made between 7 and 15 years of age. The incidence ranges between 0.1 and 0.18/100 000 children per year [1].The etiology of achalasia is unknown. It is thought to be an autoimmune‐mediated disease with a presumed correlation with viral infection and genetical susceptibility [2]. Achalasia may be part of the triple A syndrome (achalasia, alacrimia, and ACTH insensitivity) and an association with Down’s syndrome is possible [3]. Main reported symptoms are vomiting/regurgitation (80%), dysphagia (75%) and weight loss or growth retardation (64%). Chest pain is also frequent. Severity of symptoms may be evaluated according to Eckardt’s score. Unlike adults, children tend to experience more respiratory symptoms like chronic or night cough as well as extraesophageal complications (recurrent aspiration, tracheal compression by megaesophagus). Refusal of food and failure to thrive have been reported in infants with early achalasia [4]. Once the diagnosis has been established, therapeutic options are represented by medications, endoscopy, and surgery. Clinical history, upper endoscopy, and esophagram are useful in suspected achalasia and to exclude an outlet obstruction, eosinophilic esophagitis or benign esophageal stricture. The gold standard for diagnosis is high‐resolution manometry (HRM) which allows classification of the disorder according to the Chicago Classification (CC) into three subtypes of achalasia plus another separate group of esophageal spastic disorders [5]. A few CC parameters are necessary to classify achalasia subtypes: integrated relaxation pressure (IRP) is the most important. It is a complex metric depending on the adequacy of LES relaxation, crural contraction, and pattern and timing of distal esophageal contraction. An IRP >15 mmHg is present in each subtype of achalasia. In type I achalasia (Figure 27.1a), there is negligible pressurization in the esophageal body, evidentced by the absence of any area circumscribed by the 30 mmHg isobaric contour (black line). In type II (Figure 27.1b), panesophageal pressurization occurs, evident by the banding pattern of the 30 mmHg isobaric contour spanning from the upper esophageal sphincter (UES) to the esophagogastric junction (EGJ). Type III achalasia (Figure 27.1c) is characterized by spastic contractions with or without periods of compartmentalized pressurization. Spastic esophageal disorders (SEDs) include spastic achalasia (type III), diffuse esophageal spasm (DES), and nutcracker/jackhammer esophagus (JH). Although treatment of type I and II achalasia is mainly focused on LES obliteration, management of SEDs may require adjunct treatments on esophageal body spasm. Van Lennep et al. have recently proposed an updated management algorithm of achalasia in children (Figure 27.2) [6]. After diagnosis is made, a number of therapeutic options are available. The aim is to decrease LES pressure, improve bolus clearance and, if present, reduce symptoms related to spasms (i.e., chest pain). Pharmacological treatments such as calcium channel blocker or botulin toxin injection are rarely used in the pediatric population because of the short‐term effectiveness and the risk of side effects [7,8]. Pneumatic dilation (PD) and surgical myotomy, namely laparoscopic Heller myotomy (LHM), are frequently employed. Peroral endoscopic myotomy (POEM) is a recently established procedure in the adult population but experience with children is limited. Because of LES disruption, GERD may occur after any achalasia intervention. Figure 27.1 Subtypes of achalasia on high‐resolution manometry: (a) I, (b) II, (c) III. Figure 27.2 Diagnosis and treatment algorithm based on expert opinion and current knowledge from the literature. EGD, sophagogastroduodenoscopy; HRIM, high‐resolution impedance manometry; HRM, high‐resolution manometry; LHM, laparoscopic Heller myotomy; PD, pneumatic dilation; POEM, peroral endoscopic myotomy; PPI, proton pump inhibitors. Source: Van Lennep et al. [6]. Use of PD in children is relatively uncommon. A practicing pediatric gastroenterologist usually lacks experience in PD in achalasia. Therefore, children with achalasia should be referred to high‐volume centers of excellence. Pneumatic dilation works by stretching and rupturing fibers of the circular muscle of the LES. The degree of muscle rupture is related to pressure, diameter of the dilator and time of dilation. In general, high pressure associated with use of large balloons and prolonged duration of dilation increases the risk of perforation. Progressive ischemic necrosis of the esophageal mucosa could explain so‐called delayed perforation and false‐negative results of immediate postprocedure chest and abdominal films and an esophagogram with water‐soluble contrast. Two techniques of PD have been described: traditional, or so‐called fluoroscopic‐guided technique, and endoscope‐guided PD without fluoroscopy, which is not validated in children. The child should be well prepared before dilation to decrease the risk of aspiration with residual food in the dilated and poorly emptying esophagus. Liquid diet for 24 hours and overnight fasting are recommended. Pneumatic dilation is quite painful so PD requires deep sedation or general anesthesia without muscle relaxant. The initial steps are similar for fluoroscopic‐ and endoscope‐guided PD. A few additional steps are involved in the fluoroscopic‐guided technique. The Rigiflex® 30 mm diameter dilator (Boston Scientific, Boston, MA) (Figure 27.3) is primed by injecting a small amount of diluted water‐soluble contrast into the balloon, dispersing it manually and aspirating completely. Then the well‐lubricated dilator is inserted into the mouth and slowly advanced into the esophagus over the guidewire under fluoroscopic guidance until two radiopaque markers in the middle of the balloon traverse the diaphragm. Then, the dilator is pulled back slowly until the markers appear 1 cm above the diaphragm. The position of the balloon is secured by holding the dilator firmly up against the bite block, preventing displacement of the balloon into the stomach. During inflation, a high‐pressure zone in the LES creates an hourglass‐shaped fluoroscopic image of the balloon dilator. This so‐called “waist” disappears once the pressure within the balloon reaches 7–12 psi. Current data support the graded dilator approach. Initial dilation using a 30 mm balloon is recommended for most patients followed by symptomatic and objective assessment in 4–6 weeks. If patients continue to be symptomatic, the next size dilator may be employed. The safety and efficacy of the 35 mm dilator in children 8 years and older have been proved [9]. There is no consensus on the duration of inflation. However, longer sessions increase the risk of mucosal ischemia and subsequent perforation. The endoscope‐guided technique eliminates exposure to radiation. The technique requires a few additional steps. Figure 27.3 Rigiflex dilator. Please note that this technique is not validated in children. Careful observation for at least six hours and postprocedure chest X‐ray and esophagogram with water‐soluble contrast are mandatory to exclude esophageal perforation. Persistent chest pain for more than one hour and fever should be considered as red flags of complications and indication for treatment even without a proven pneumomediastinum or radiographic signs of perforation. Immediate symptomatic improvement after the first dilation occurs in the majority of adults and children. Multiple dilations are often required to achieve sustained relief of symptoms. Reported efficacy of multiple PDs ranges between 60% and 90% in the pediatric population. Type 2 achalasia (Chicago 3.0 Classification) is associated with better results of PD [10]. According to some adult studies, young age at presentation, classic achalasia, high LES pressure three months after PD, and incomplete obliteration of the balloon’s waist during PD are the most important predicting factors of the need for repeated treatment during follow‐up. However different outcome measures have been employed to assess effectiveness, including Eckardt’s score <3, need for repeat dilation or response evaluated by clinicians in various studies [11–13]. According to some studies, pneumatic dilation is an effective and safe initial treatment for achalasia and may spare children with achalasia an operation [14]. On the other hand, severe fibrosis generated by repeated PDs is associated with failure of surgical and endoscopic myotomy and increased morbidity [15]. Balloon dilation requires short length of stay and is generally cost‐effective. The major complication of PD is esophageal perforation. Over the last 15 years, the reported rate of this complication in children and adults has been under 2%. Conservative management of perforation with broad‐spectrum antibiotics, proton pump inhibitors, withholding of oral feeds, and parenteral nutrition is very effective and carries less risk of morbidity associated with surgery [16]. Laparoscopic Heller myotomy should be considered after three failed PD attempts. Peroral endoscopic myotomy (POEM) was introduced in Japan by Inoue in 2008 for nonsigmoid achalasia. Subsequently, the indication was extended to spastic esophageal disorders and sigmoid esophagus [17]. After a mucosal incision, a submucosal tunnel is created to reach the GEJ and to protect the mucosal flap from thermal damage (Figure 27.4–Figure 27.8 ). A myotomy is performed for the total length of the submucosal tunnel. The mucosal incision is closed using standards clips. The tunnel can be created in the anterior (2 o’ clock) or posterior (5 o’ clock) wall of the esophagus according to the operator’s preference. This possibility to choose between two alternative tunnel orientations is particularly useful in the management of recurrent symptoms after POEM or LHM as it avoids the fibrosis caused by previous myotomy [18]. Because no antireflux flap valve is created, GERD after POEM and PD is reported to be higher than LHM. Therefore, diligent follow‐up with pH impedance monitoring and surveillance endoscopy of patients undergoing POEM or PD is required. On the other hand, management of recurrent symptoms is generally easier after POEM comparing to LHM because no flap valve can impair clearance of the esophagus with ineffective peristalsis. For this reason, many pediatric surgeons perform a Heller procedure without flap valve as first choice in children with achalasia and a second antireflux procedure only in selected patients with GERD unresponsive to proton pump inhibitor. Figure 27.4 Submucosal injection of methylene blue prior to mucosotomy. Figure 27.5 Lineal mucosal incision. Figure 27.6 Initial stage of tunnel development. Figure 27.7 Creation of a tunnel using an electrical knife and pressure from the cup on the endoscope. Figure 27.8 Completion of the tunnel with exposed circular muscle. Midterm effectiveness results in adult are extremely satisfactory; Eckardt’s score is less than 3 points in 98% of patients and postoperative stay is generally around 3–4 days. However, data in pediatric population are limited and less than 100 children have undergone POEM worldwide [19–22]. The safety profile in expert hands is extremely satisfactory; the most common complication is mucosal perforation that is reported in up to 3% of POEMs and is generally evident by the day after endoscopy or esophagram. Management of mucosal perforation after POEM is generally conservative (prolonged fasting, antibiotics, endoscopic treatment). Capnoperitoneum/capnomediastinum requiring decompression, pleural effusion, and submucosal bleeding have also been reported as major adverse events. No mortality or emergency surgery after POEM has been reported [14].
27
Pneumatic balloon dilation and peroral endoscopic myotomy for achalasia
Introduction
Diagnosis and management of achalasia
Therapeutic options
Pneumatic balloon dilation
Peroral endoscopic myotomy
Related posts:
Pediatric endoscopy training and ongoing assessment
Pediatric procedural sedation and general anesthesia for gastrointestinal endoscopy
Celiac disease
Transnasal gastrointestinal endoscopy
Endoscopic management of esophageal strictures
Endoscopic approaches to the treatment of gastroesophageal reflux disease
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
