Pneumatic balloon dilation in pediatric achalasia: efficacy and factors predicting outcome at a...

ORIGINAL ARTICLE: Clinical Endoscopy

Pneumatic balloon dilation in pediatric achalasia: efficacy and factorspredicting outcome at a single tertiary pediatricgastroenterology center

Giovanni Di Nardo, MD,1 Paolo Rossi, MD,1 Salvatore Oliva, MD,1 Marina Aloi, MD,1 Denis A. Cozzi, MD,2

Simone Frediani, MD,2 Adriano Redler, MD,3 Saverio Mallardo, MD,1 Federica Ferrari, MD,1

Salvatore Cucchiara, MD, PhD1

Rome, Italy

Background: The use of pneumatic dilation (PD) is well established in adults with achalasia; however, it is lesscommonly used in children.

Objective: To evaluate the efficacy of PD in pediatric achalasia and to define predictive factors for its treatmentfailure.

Design: Single-center, prospective cohort study.

Setting: Academic tertiary referral center.

Patients: Twenty-four patients with achalasia were enrolled from January 2004 to November 2009 and werefollowed for a median of 6 years.

Intervention: PD was performed with the patients under general anesthesia.

Main Outcome Measurements: Efficacy and safety of PD. Follow-up was performed by using the Eckardt score,barium swallow contrast studies, and esophageal manometry at baseline; 1, 3, and 6 months after dilation; and everyyear thereafter. A Cox regression model was used to identify independent predictors of failure after the first PD.

Results: The PD success rate was 67%. In 8 patients, the first PD failed, but the parents of one patient refuseda second PD and requested surgery. Of the 7 patients who underwent repeated treatment, the second PD failedin 3 (43%). Overall, only 3 of the 24 patients underwent surgery (overall success rate after a maximum of 3 PDswas 87%). Multivariate analysis showed that only older age was independently associated with a higherprobability of the procedure success (hazard ratio [HR] 0.66; 95% CI, 0.45-0.97).

Limitations: Small sample size, single-center study.

Conclusions: PD is a safe and effective technique in the management of pediatric achalasia. Young age is anindependent negative predictive factor for successful clinical outcome. (Gastrointest Endosc 2012;76:927-32.)

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Achalasia is a rare primary esophageal dysmotility dis-order, with an estimated annual incidence in children of0.11 cases per 100,000 pediatric patients. It is characterizedby functional obstruction of the esophagus because offailed relaxation of the lower esophageal sphincter (LES)

Abbreviations: HR, hazard ratio; LES, lower esophageal sphincter; PD,pneumatic dilation.

DISCLOSURE: The authors disclosed no financial relationships relevantto this publication.

See CME section; p. 1020.

Copyright © 2012 by the American Society for Gastrointestinal Endoscopy0016-5107/$36.00
http://dx.doi.org/10.1016/j.gie.2012.06.035
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n combination with absent peristalsis of the distalsophagus.1-3 The imbalance between defective inhibitorynnervation and apparently spared excitatory (cholinergic/achykinergic) neuronal components is thought to play aajor role in the pathogenesis of esophageal motor ab-

eceived May 20, 2012. Accepted June 23, 2012.

urrent affiliations: Department of Pediatrics, Pediatric Gastroenterologynd Liver Unit (1), Pediatric Surgical Unit (2), Department of Surgical Science3), “Sapienza” University of Rome, Rome, Italy.

eprint requests: Salvatore Cucchiara, MD, PhD, Department of Pediatrics,ediatric Gastroenterology and Liver Unit, Sapienza University of Rome,iale Regina Elena 324, 00161 Rome, Italy.

olume 76, No. 5 : 2012 GASTROINTESTINAL ENDOSCOPY 927

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Pneumatic balloon dilation in pediatric achalasia Di Nardo et al

normalities and LES dysfunction.4 Although the exact eti-logy of neuronal alterations in primary achalasia remainsnknown, several lines of evidence indicate that infec-ious, immune, and genetic factors may play importantoles in the mechanisms of this neuropathy.5 The distinc-

tive symptoms of achalasia are dysphagia for solids andliquids, regurgitation of undigested food, respiratorysymptoms (nocturnal cough, aspiration), retrosternal pain,and weight loss.3

All therapeutic options focus on reducing the pressuregradient across the LES because no treatment can restoremuscular activity.6 This can be achieved by pharmacologicalagents, injected endoscopically (botulinum toxin) or takenorally (Ca2� channel blockers and nitrates), but the clinicalffects of these agents are short-lived.7 Alternatively, LES

pressure can be reduced by pneumatic dilation (PD) or bysurgical myotomy, which are considered the main proce-dures for treating achalasia.8-10 Many authors consider PD therst choice in adults because of its high degree of effective-ess and low degree of morbidity and mortality, with thedditional advantage of a short hospital stay and lower in-trumental cost. Surgery is usually reserved for patients whoo not respond to PD.7,8

Knowing the possible predictive response factors for PD isvery useful in selecting patients who could benefit fromsurgery early on. Several adult studies found that older age,female sex, a long history of symptoms before diagnosis,high pretherapeutic LES pressure, a postdilation LES pressureof less than 10 mm Hg, limited contrast retention on postdi-lation barium esophagram, and a higher number of repeatedbaseline PD dilations were associated with a favorable out-come for PD.11-22 All of these studies were performed inadults, and often retrospectively. Experience with pediatricpatients is limited to small retrospective series,23-30 and pos-sible predictive response factors have never been studied inthe pediatric age group.

This study, performed in pediatric patients with acha-lasia, aimed to assess the efficacy and safety of PD and todefine predictive factors for symptom recurrence requiringrepeated PD and surgery.

PATIENTS AND METHODS

Twenty-four patients (11 female patients; mean age 10years; range 5-17 years) with a diagnosis of achalasia whowere treated in our unit from January 2004 to November 2009were prospectively included in this study. The diagnosis ofachalasia was made based on clinical symptoms, a bariumesophagogram, and the absence of peristalsis and impairedrelaxation of the LES (lowest pressure of �10 mm Hg duringwallow-induced relaxation) at esophageal manometry.

Exclusion criteria were (1) short duration of follow-up�12 months), (2) parents of patients who refused PD andequested surgery, (3) patients who did not attend theontrol sessions, and (4) patients receiving an initial diag-
osis and/or balloon dilation in another center. The pa- A
928 GASTROINTESTINAL ENDOSCOPY Volume 76, No. 5 : 2012

ients were not treated with drugs that could alter theilation results.

ndoscopic training before enrollmentThe first author (G.D.N.) completed 2 years of training

t an adult GI endoscopy center. During the second year,e began to perform endoscopy in pediatric patients. Dur-ng this period, he routinely performed balloon dilation forifferent conditions; in particular, he acquired experiencen the use of the Rigiflex dilator (Rigiflex; Microvasive,oston Scientific, Natick Mass) in both adult and pediatricchalasia patients (22 PDs in 16 patients, 3 pediatric and 13dult; these pediatric patients were not enrolled in thetudy). Dr Oliva completed 2 years of training at an adultI endoscopy center. During the second year, he began toerform endoscopy in pediatric patients. During this pe-iod, he performed 18 PDs in 12 adults with achalasia. Heas actively involved in the study under the supervision ofr. Di Nardo, who acquired additional experience in pe-iatric therapeutic endoscopy. In addition, Drs Di Nardond Oliva were supervised by Dr Cucchiara, who is theead of the Pediatric Gastroenterology and Liver Unit of

he University of Rome and has 30 years of experience inotility GI disorders and pediatric diagnostic and opera-

ive endoscopy.The study was approved by our Ethics Committee.

valuation of symptomsClinical manifestations evaluated by history (dysphagia,

egurgitation, chest pain, and weight loss) were recordedy using a scoring system of 0 to 3 for each of them. Theollowing clinical stages were established in accordanceith Eckardt scoring system: 0 (scores of 0-1), I (scores of-3), II (scores of 4-6), and III (scores �6).13 The clinicaltage of all patients was monitored at baseline; 1, 3, and 6onths after dilation; and every year thereafter. Patients in

linical stages 0/I were considered to be in clinical remis-ion and those in stages II/III in treatment failure.

adiological evaluationThe maximum caliber of the esophageal body was

easured before dilation, 6 months after dilation, andvery year thereafter by using barium esophagraphy.

Take-home Message

● Pneumatic dilation (PD) can be used as first-line therapyin pediatric achalasia because of its safety and efficacy.

● The study results show that most children can be eligiblefor repeat PD; however, some patients, such as thosepatients younger than 6 years of age, may be referred forsurgery earlier if they experience a recurrence.

chalasia was classified into 3 groups based on the maxi-

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Di Nardo et al Pneumatic balloon dilation in pediatric achalasia

mum diameter of the esophageal body (�35 mm, 35-59 mm,�60 mm).

Esophageal manometryEsophageal manometry was performed after an 8-hour

overnight fast and a semiliquid diet the day before using adent-sleeve catheter perfused with distilled water at a rate of0.5 mL/min by using a low-compliance pump connectedthrough a separate pressure transducer (Medtronic AB, Kista,Sweden) to an 8-channel polygraph (Medtronic). The mano-metric endoscope was passed through the nose to thegastric cavity, and, with the patient in the dorsal decubitusposition, the LES was located by manually drawing theendoscope back at 1-cm intervals. During this procedure,the LES resting pressure and relaxation as well as esoph-ageal body motility occurring in response to 10 wet swal-lows were recorded. The basal LES pressure, reported inmillimeters of mercury (mm Hg), was determined by thedifference between the maximum value of end-expiratorypressure and expiratory fundic pressure. Relaxation of theLES after swallowing a 5-mL bolus of water was consid-ered normal if it reached 80% of the basal pressure.

Endoscopic dilation: technique and evaluationof efficacy

Pneumatic dilations were performed with the patientsunder general anesthesia by using a polyethylene balloonsystem (Rigiflex; Microvasive, Boston Scientific).

We generally perform the procedure in the morning,after the patient has fasted overnight. The patient is placedin the left lateral position. The endoscope is advanced intothe stomach, the guidewire is placed in the stomach, andthe endoscope is then removed. The balloon dilator isadvanced over the guidewire and positioned across thegastroesophageal junction under fluoroscopic control. Theballoon is inflated to 5 psi for 1 minute and subsequentlyto 10 to 12 psi, and the pressure is maintained until oblit-eration of the waist occurred. All patients were observedfor 8 hours after the procedure. If no symptoms developedduring the control period, patients were allowed to eat. Ifsymptoms (fever, chest pain, or cough) or abnormality onchest auscultation occurred, a gastrografin swallow wasperformed. The first pneumatic dilation was performedwith the use of a 30-mm balloon; if, 4 weeks later, theEckardt score was greater than 3, a second dilation wasperformed by using a 35-mm balloon. If the Eckardt scoreremained greater than 3 (stages II/III), the treatment wasconsidered to have failed. Patients with a recurrence ofsymptoms during the follow-up period underwent dilationagain, this time by using a 35-mm balloon and, if necessary(ie, if the Eckardt score remained �3), with the use of a40-mm balloon. A third and final series of dilations wasallowed only if symptoms recurred more than 1 year after
the second series. o

tatistical analysisWe estimated the overall rate of success of the first

ilation as the percentage of patients who did not expe-ience a relapse during follow-up. Univariate survival anal-sis was performed to test whether sociodemographicage, sex) or clinical (baseline clinical score, baseline max-mum caliber of the esophageal body, basal LES pressure,nd the percentage of decrease in caliber of the esopha-eal body and LES pressure after PD) characteristics weressociated with a higher risk of treatment failure. Becausef the small sample size, we limited this analysis at the firstilation. Kaplan-Meier curves were estimated, and theog-rank test was performed.

Finally, we performed a multivariate analysis to evalu-te the independent effect of factors that resulted in sig-ificance on univariate analysis by using a Cox survivalnalysis.

ESULTS

Twenty-four patients were enrolled in the study andnderwent a first PD (34 sessions of PD). Table 1 showshe demographic and clinical characteristics of the studiedopulation. All patients were observed for at least 2 yearsith a median follow-up of 6 years (range 2-7 years). Therst PD failed in 8 patients, corresponding to a success ratef 67% (95% CI, 0.45-0.84); parents of one patient refusedsecond PD and requested surgery for personal choice,hereas the treatment was repeated in the remaining 7atients. Of the latter, PD failed in 3 patients (43%) and ahird PD was needed. Of these 3 patients, PD failed againn 2 patients who then underwent surgery, whereas 1atient had a good response (Fig. 1). Overall, only 3 of the4 patients enrolled in the study underwent surgery (over-ll success rate after a maximum of 3 PDs was 87%).

The first recurrences occurred at a mean interval of 12.2onths (range 2.8-17.6 months), whereas the second re-

urrences occurred at 10, 12, and 14 months in each of thepatients, respectively.Of a total of 34 PDs performed in 24 patients, no serious

omplications occurred. Postprocedural pain occurred af-er 4 of 34 procedures (11%). In all 4 of these patients, painersisted for less than 24 hours and did not require the usef narcotics. The median age of children in whom the firstD failed was 6 years (SD), whereas for those who did notndergo a second PD, the median age was 12 years. Webserved a significantly higher probability of first PD suc-ess among older children (log-rank test, P � .0048) (Fig.), those with a higher LES pressure at baseline (log-rankest, P � .0134), and those with a higher percentage ofecrease in LES pressure after the first PD (log-rank test, P

.003) (Fig. 3). No differences were observed for thether evaluated parameters (sex, baseline esophageal di-meter, pre-/post-PD variation in esophageal diameters).

However, the multivariate analysis showed that only
lder age was independently associated with a higher

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probability of procedure success (hazard ratio 0.66; 95%CI, 0.45-0.97) (Table 2). Of 3 patients in whom a secondPD failed, 2 were boys 5 and 6 years of age, respectively,and 1 was a 5-year-old girl. They had baseline clinicalscores of 10 and 12 (in 2 of them), which is higher than themedian value of the whole sample, and esophagealsphincter pressure of 70, 42, and 30 mm Hg, respectively.

DISCUSSION

Achalasia is a rare disorder with an annual incidence of1 case per 100,000, of which childhood achalasia accountsfor less than 5%.2,3 In adults, PD is recommended as the

TABLE 1. Demographic and clinical characteristics of the enroll

Characteristic

Total, no. (%)

Sex

Male

Female

Mea

Age at diagnosis, y 11.8

Clinical score at baseline 9.9

LES pressure at baseline 67.9

Esophageal diameter at baseline 6.15

Pre-/postdilation variation in LES pressure, % 48.0

Pre-/postdilation variation in esophageal diameter, % 37.0

PD, Pneumatic dilation; SD, standard deviation; LES, lower esophageal sphinct

Figure 1. Study flow

initial treatment because of its low morbidity, low cost, o


nd short postprocedural hospital stay. In contrast, expe-ience in the pediatric population is limited because ofhe rarity of the disease in children. A review of theiterature shows that PD is successful in the majority ofeported pediatric series, with success rates of 45% to0%; this method has not gained universal acceptance inhildren.23-30 Azizkhan et al25 and Nakayama et al26

eported that PD was unsuccessful in children youngerhan 9 years of age and technically difficult to perform inhildren younger than 5 years of age.

This is the largest prospective study in pediatric acha-asia aimed at evaluating the efficacy and safety of PD asell as factors predicting outcome. In our study, 1 session

tients

1 PD >1 PD Total

6.7) 8 (33.3) 24 (100)

0.0) 5 (62.5) 13 (54.2)

0.0) 3 (37.5) 11 (45.8)

SD Mean SD Mean SD

2.5 6.4 2.2 10.0 3.5

1.4 10.8 1.5 10.2 1.4

13.2 57.7 21.0 64.5 16.5

1.4 6.9 0.3 6.4 1.2

11.0 19.0 25.0 38.o 22.0

14.0 23.0 14.0 32.0 16.0

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described in the majority of adult studies reporting analmost 80% success rate, with therapeutic effectivenesssimilar to that in patients undergoing surgery.9,31-34

Although there are reported perforation rates of 4% to

Figure 2. Kaplan-Meier curve of time free of repeat pneumatic dilationPD) after the first PD, by age.

Figure 3. Kaplan-Meier curve of time free of repeat pneumatic dilationPD) after the first PD, by before and after percentage of decrease inower esophageal sphincter pressure.

TABLE 2. Cox model analysis of time free of repeat PDafter first PD

Covariates HR SE 95% CI

Pre-/postdilation variationin LES pressure, %

�55 1.0 — —

30-54 2.1 3.39 0.089-49.814

�30 11.64 14.66 0.986-137.435

Age at diagnosis, y 0.66 0.13 0.452-0.73

HR, Hazard ratio; SE, standard error, CI, confidence; LES, loweresophageal sphincter.

12% in adult patients,10-22 no perforations have been doc-


mented in pediatric patients.23-30 In our series, we did notbserve serious complications, only self-limited postpro-edural pain in 11% of patients.

Recurrence of symptoms usually occurs early, mainlyuring the first year post-PD11 with the need for repeatilation and/or surgery. The median time between the firstnd the second dilations was 12.2 months (range 2.8-17.6onths) in our patients, whereas the second recurrencesccurred at 10, 12, and 14 months in 3 patients. Conse-uently, it is of value to know the predictive response vari-bles to PD that affect long-lasting clinical improvement.

A first statistical analysis showed that predictive factorsf failure after the first PD were young age, low basal LESressure, and a small decrease in the LES pressure. How-ver, we observed that the last 2 factors were highlyorrelated, ie, patients with a low baseline LES pressureere those exhibiting a small decrease in the LES pressurefter PD. Therefore, it was not advisable to analyze the 2ariables in a multivariate model, and we performed aultivariate Cox regression analysis including only age

nd the percentage of decrease in the LES pressure afterD. This model shows that when controlling for age, theercentage of decrease in the LES pressure after PD waso longer significant.Our observations suggest that the only independent

redictor of PD failure is young age. A larger sample sizeould probably confirm these results. This is in accor-ance with other published adult studies in which aounger age (between 20 and 40 years) was a predictiveactor for a worse response.11,20,35,36

In conclusion, PD is a safe and effective procedure forhe treatment of pediatric achalasia, with an 87% overall-year success rate. Young age at presentation seems to behe only independent negative predictive factor for theeed for a repeat PD and surgery. This factor should beaken into account in the follow-up strategy of the pedi-tric patients with achalasia, leading to a stricter follow-uprotocol in patient younger than 6 years of age.Our results show that most patients can be eligible for

epeat PD; however, some patients, such as those youngerhan 6 years of age, may be referred for surgery earlier ifhey experience a recurrence.

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