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Case Reports Indian Pediatrics 2001; 38: 783-788 |
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Congenital Cricopharyngeal Achalasia |
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From
the Referral Neonatal Unit, Department of Pediatrics, Maulana Azad Medical
College and Associated Lok Nayak Hospital, New Delhi 110 002, India
and *The Department of Pediatric Surgery, All India Institute of Medical
Sciences, New Delhi 110 029, India. Manuscript
received: August 11, 2000; Initial
review completed: September 20, 2000; Cricopharynageal achalasia is failure of the cricopharyngeus muscle to relax completely enough, during deglutition, to enable free passage of the bolus from the hypopharynx into the esophagus(1). Most cases of crico-pharyngeal achalasia are seen in adults. A medline search revealed that since the first pediatric case reported in 1969(2) only thirty six such cases have been reported worldwide, so far. To our knowledge this is the first case of it’s kind to have been reported from India. Case Report A male neonate, born at term to a third gravida, presented at 16 hours of age to the Referral Neonatal Unit of Lok Nayak Hospital with noisy breathing, respiratory distress, excessive oral secretions and refusal to feed. The baby was a product of a non-consan-guineous marriage. The mother gave a history suggestive of polyhydramnios in the third trimester. The baby had cried immediately at birth. Attempts had been made to feed the baby which was followed immediately by episodes of choking, bluish discoloration and expulsion of the feed. On examination the baby was term and appropriate for gestational age. There were dysmorphic features in the form of microg-nathia, a right cleft lip, an incomplete cleft confined to the posterior one-third of the palate, bilateral lobed ears and a left pre-auricular sinus. He had copious oral secretions, an audible stridor and marked respiratory distress. Peripheral cyanosis was present. Crepitations and conducted sounds could be auscultated bilaterally. Neurlogical examina-tion revealed spontaneous cry and activity. The Moro’s reflex was present. There was an immediate spasm of the masseters on introduction of a finger in the mouth which relaxed spon-taneously. Suck was slow. The gag reflex was normal. The rest of the systmic examination was normal. The respiratory distress gradually resolved, although the copious oral secretions persisted, associated with episodes of choking and intermittent episodes of increased tone, neck retraction and fisting. Investigations revealed no evidence of sepsis. There were patchy opacities in both lung fields on the X-ray of the chest which substantiated the diagnosis of an aspiration pneumonia. A direct laryngoscopic examina-tion revealed normal movements of the vocal cords. Ultrasound examination of the cranium and abdomen as well as an echocardiography were normal. A contrast swallow was conducted which led to the detection of a shelf like projection arising from the cricopharyn-geal posterior wall. There was no evidence of any outpoching or leak and the rest of the esophagus was normal. An upper gastro-intestinal endoscopy was then performed which revealed a spasm at the cricopharyngeal level. The pylorus was normal. A confirmatory contrast cine-fluoroscopy revealed a shelf like filling defect from the posterior wall of the esophagus at the level of the sixth cervical vertebra leadig to indentation and narrowing of the column of contrast at that point, which was suggestive of over activity of the cricopharyngeus muscles. Obstruction to the flow at that level led to tracheo-esophageal reflux (Fig. 1). The final diagnosis was con-genital cricopharyngeal achalasia. Additional studies, a MRI of the brain and a 24 hour pH monitoring were conducted in order to rule out known associations - posterior fossa structural anomalies and gastro-esophageal reflux, respectively. Both investigations were normal. Once the baby’s respiratory distress had settled down, Ryle’s tube feedings were started. Frequent oral suctioning of the oropharynx was required. Supervised trial feeds were attempted at the age of two weeks and four weeks but were unsuccessful. Cricopharyngeal dilatation using bougies were performed thrice at five, seven and nine weeks, respectively but brought no relief sympto-matically. The baby had three episodes of aspiration pneumonia during his hospital stay of twelve weeks which were treated sympto-matically. The baby’s weight, length and head circumference increased appropriately. His milestones were also attained normally. At the age of twelve weeks, a cricopharyngeal myo-tomy was performed by a cervical approach under endotracheal tube general anesthesisa. The procedure was performed under magni-fication. The myotomy was extended for 1.5 cm onto the esophagus. All the muscle fibers were divided until the mucosa was seen bulging out. During the entire procedure the lung compliance was poor and high pressures were required for proper ventilation. This continued in the post operative period and ventilatory support with very high pressure and FiO2 was required. It became progressively difficult to maintain oxygen saturation. On the fourth post operative day the child suffered a cardiac arrest from which he could not be revived. Consent to perform autopsy was not given.
Discussion The cricopharyngeus muscle consists of two parts; oblique fibers, which arise from the posterior portion of the lateral surface of the cricoid cartilage and sweep upwards to be inserted into the median raphe and transverse fibers which arise from the lateral margins of the cricoid cartilage, pass horizontally backwards and form a sphincter(3). The former fuse with the fibers of the inferior constrictor muscles and have an identical function, whereas the latter act along with the uppermost fibers of the esophageal circular muscle for the closure of the mouth of the esophagus. Physiologically it is a striated muscle. However, since it lies distal to the area of voluntary control, it can be made to function indirectly by simply initiating a swallow. In the resting state, the upper end of the esophagus is closed by the tonic contraction of the crico-pharyngeus muscle(4). This tonic contraction relaxes momentarily during swallowing, belching or vomiting. During swallowing, the sphincter opens immediately upon the entry of a bolus into the pharynx before maximal contraction of the pharyngeal constrictors but after the larynx has started moving upwards. This state of active inhibi-tion of the tonic contraction of the cricopharynageus lasts for 0.5-1.2 seconds. Hence, complete or incomplete failure of relaxation of this muscle disturbs the split-second timing required for proper co-ordination during swallowing and leads to dysphagia. The onset of presenting symptoms begins at birth or shortly afterwards and have a wide range of severity. These consist of regurgita-tion of feeds, choking, gagging and coughing on attempted swallowing. Misdirection of the bolus into the nasopharynx leads to nasal reflux and into the trachea leads to recurrent aspiration pneumonias. Inadequate nutrition leads to failure to thrive. During examination it is important to look for repeated swallowing attemps, an intact gag reflex and rule out other causes which could lead to difficulty in swallowing (Table I). Associations with masseter spasms, micrognathia, myelo-meningocele, Arnold-Chiari malformation, other Central Nervous System anomalies and mental retardation have been documented(6). Hence, detailed developmental assessment is also very important. Table I - Differential Diagnosis of Dysphagia in Neonates (5)
The definitive investigations for this entity are endoscopic evaluation of the esophagus and fluoroscopic contrast studies. Esophago-scopy is important to exclude other endo-luminal lesions at the cricopharyngeal junction and to examine the rest of the distal esophagus and pylorus. In cricopharyngeal achalasia, a transverse submucosal bar may be visualized at the level of the cricopharyngeal muscle. Contrast fluoroscopic studies can be performed as either spot imaging or by cinefluoroscopy. Normally the posterior wall of the fully distended pharynx has a smooth contour. In cricopharyngeal achalasia, the appearance is variable, ranging from a minimal protrusion into the tail of passing contrast bolus to a horizontal, hemispheric or trangular shelf that completely occludes the lumen at the level of the fifth or sixth vertebral body. However, it has also been seen that a prominent cricopharyngeal bar can be visualized in about 5% of contrast studies of the pharyngo-esophaeal area of normal asymptomatic individuals(4). Whether this is an anatomical variant or of any clinical significance in asymptomatic individuals is still a point of debate. The disadvantage of a spot image is that it may be difficult to observe since the duration for which the achalasia may be apparent is only about a tenth of second. This may be overcome by using video or cinefluoroscopy(7,8) in which the speed of the imaging ranges from 30-100 frames per second. Another advantage of this modality is that it permits a frame by frame analysis of individual swallows which are necessary to completely understand the complex and rapid sequence of events which occur during deglutition. Swallowing disorders can be divided into motility disturbances, retention in the pharyngeal recesses, pharyn-geal stasis and misdirected swallowing based on cinefluorosocopy. This investigation can thus determine which one of the phases of swallowing is abnormal. Normal propulsion of the contrast bolus from the mouth into the pharynx can be seen to be followed by weak or incoordinated pharyngeal contraction with multiple attempts to force the meal distally by to-and-fro movements. A dilated hypopharynx and delayed emptying can also be visualized. Aspiration of the contrast into the trachea and nasopharyngeal reflux can also be seen. The drawback of this study is that being a quali-tative study it cannot quantify the extent of upper esophageal sphincter (UES) relaxation or the degree of UES inco-ordination with pharyngeal contraction. Esophageal
manometry or motility stu Supportive management consists of semi-recumbent positioning, elevation of the head end of the bed and frequent suctioning for the prevention of aspiration pneumonias. Main-tenance of nutritional status should be achieved by either nasogastric feeding or gastrostomy if prolonged nasogastric feeding is required(9). The definitive treatment options include either dilatation of the cricopharyngeus muscle or myotomy(10). The former is performed with bougies or balloon catheters. Myotomy can be performed either extramucosally by conven-tional surgery(11) or transmucosally by using electocautery or laser techniques(12,13). Although no absolute guidelines have been established, the general consensus is that patients with mild to moderate symptoms usually warrant a trial of dilatation whereas myotomy should be reserved for those patients with severe symptoms and a compromised respiratory status, failure of dilatation or early diverticular formation(1). The success of myotomy depends on the absence of gastro-esophageal reflux and the other aforementioned associated conditions as well as the pre-existing state of the lungs. Contributors: NBM, SB and AM reviewed the literature. VB contributed to the surgical aspect of the case. NBM, SB and VB participated in drafting the report. NBM will act as the guarantor for the manuscript. Funding:
None
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