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The use of a retrievable self-expanding stent in treatingchildhood benign esophageal strictures

Chi Zhanga,*, Ju-Ming Yub, Guo-Ping Fanb, Cheng-Ren Shia, Shi-Yao Yua,Han-Ping Wanga, Li Gea, Wei-Xing Zhongb

aDepartment of Pediatric Surgery, Shanghai Children Medical Center, Xinhua Hospital,

Shanghai Second Medical University, Shanghai 200092, P.R. ChinabDepartment of Radiology, Shanghai Children Medical Center, Xinhua Hospital,

Shanghai Second Medical University, Shanghai 200092, P.R. China

0022-3468/05/4003-0008$30.00/0 D 20

doi:10.1016/j.jpedsurg.2004.11.041

* Corresponding author. Tel.: +86 2

E-mail address: zhangchi31@sina.co

Index words:Esophageal stenosis;

Stent;

Child

AbstractBackground/Purpose: Esophageal stenting is a popular form of treatment of esophageal strictures in

adults but is not widely used in children. The aim of the current study was to investigate whether

esophageal stents could be used safely and effectively in the treatment of esophageal stenosis in children.

Methods: Covered retrievable expandable nitinol stents were placed in 8 children with corrosive

esophageal stenosis. The stents were removed 1 to 4 weeks after insertion.

Results: The stents were placed in all patients without complications and were later removed

successfully. After stent placement, all patients could take solid food without dysphagia. Stent migration

occurred in one patient and so the insertion procedure was repeated to reposition the stent. During the

3-month follow-up period after stent removal, all children could eat satisfactorily. After 6 months,

2 children required balloon dilation (3 times in one and 5 times in the other). The dysphagia score

improved in all patients.

Conclusions: The use of the covered retrievable expandable stent is an effective and safe method in

treating childhood corrosive esophageal stenosis.

D 2005 Elsevier Inc. All rights reserved.

Esophageal stenting is a popular form of treatment of

esophageal strictures in adults but is not widely used in

children [1,2]. Childhood caustic esophageal strictures are

refractory to medical treatment and balloon dilation.

Esophageal replacement is a popular procedure, but it

carries risks of morbidity and mortality [3-5].

We have been using a retrievable expandable stent in

treating childhood intractable benign esophageal strictures

05 Elsevier Inc. All rights reserved.

1 65790000 7125.

m.cn (C. Zhang).

since 2002. The aim of the present study was to evaluate the

effectiveness and safety of the use of this type of stent

in children.

1. Materials and methods

Eight children aged between 2 and 12 years (mean age,

8 years) were admitted to our hospital between April and

August 2002 after ingesting the following corrosive agents:

sodium hydroxide (n = 4), oil of vitriol (n = 2), hydrochloric

acid (n = 1), and concentrated hydrogen peroxide (n = 1).

Journal of Pediatric Surgery (2005) 40, 501–504

ig. 2 A nitinol-alloy self-expanding esophageal stent with a

tring loop at the proximal end (length, 70 mm; diameter, 18 mm).

C. Zhang et al.502

Each patient had a nasogastric tube insertion and was initially

given broad-spectrum antibiotics and steroids. Balloon

dilation treatment was given under fluoroscopy after 1month,

to 12 mm for 6 months or to 16 mm for 1 year. The balloon

dilation was not effective. The 8 patients still displayed

dysphagia to liquids, with a dysphagia score of 3 [6].

All patients were given a contrast swallow to locate the

site, severity, and length of the strictures (Fig. 1). All the stric-

tures were located in the middle of the thoracic esophagus,

and their positions were confirmed by barium swallow.

Retrievable expandable stents were then placed at the

middle of the strictures. The stents (Nanjin Microinvasive

Co. Ltd. Nanjin, P.R. China), made of nitinol alloy and

coated with silicon, ranged from 14 to 20 mm in diameter

and from 5 to 10 cm in length. The stents responded to

changes in temperature. They were very pliable at low

temperatures but firm at body temperature (378C). Theirlength and diameter were also smaller at low temperatures

than at high temperatures (Fig. 2). They were compressed

into a small-caliber introducer system until used.

Intravenous sedation (ketamine, 2 mg/kg) was routinely

administered to the patients before the stent placement

procedure. A 3-F catheter was inserted through each

patient’s mouth to the upper end of the stricture. A small

amount of water-soluble contrast was injected to locate the

stricture, and each patient’s skin was marked under

fluoroscopy. An exchange guide wire was inserted through

the catheter across the stricture into the stomach. A 12-mm

Fig. 1 Barium swallow was performed before stent insertion to

identify the site, severity, and length of the stricture.

Fs

balloon was passed over the guide wire for dilation. The

stent was then introduced over the guide wire and de-

ployed under fluoroscopic guidance at the middle of the

stricture (Fig. 3).

The stents were removed within 1 to 4 weeks (mean,

13.3 days) after placement, depending on the degree of

stricture. Ice water was used under endoscopic guidance to

soften the stent for 1 minute. The stent was then pulled out

with the help of a string that passed via the string loop at the

proximal end of the stent (Fig. 2).

All patients were asked to attend the outpatient clinic

once a month for 18 months after the removal of the stent

for follow-up tests (routine clinical examinations and

esophagography). They were also advised to visit the clinic

if dysphagia symptoms recurred.

Fig. 3 The stent was inserted at the middle of the stricture.

The use of a retrievable self-expanding stent 503

2. Results

All patients experienced chest pains and vomiting in the

days immediately following the insertion of the stent.

The chest pains were mild and did not need treatment.

The vomiting subsided after drug treatment [domperidone,

0.3 mg/kg; cimetidine, 5 mg/kg (orally)]. Distal stent

migration for 3 cm occurred in one patient.

On the day after the insertion of the stent, patients were

allowed a liquid diet. On the third day, they could ingest soft

food. While the stent remained in place, it was important

that food taken was warm and that very hot and very cold

food were avoided.

In all patients, a plain chest x-ray was taken the day

after the stent was placed to verify its position and degree

of expansion. The stents were removed on the appointed

days successfully. All patients were thereafter able to take

solids without any dysphagia. The dysphagia scores were

0. Between 1 and 3 months after the removal of the stent,

all patients were able to ingest solid food without

dysphagia. No obvious strictures showed up in the barium

swallow. The dysphagia scores were 0. After 6 months of

follow-up, the patient with stent migration was only able

to swallow semisolid and liquid food. The patient’s

barium esophagography showed restricture and she had

a second procedure. Two patients showed mild strictures

in the barium swallow. One required 3 and the other

required 5 dilations for treatment of stenosis. The other

patients on follow-up had no dysphagia and no strictures

showed up in the barium swallow. The dysphagia scores

were 0 to 1. No serious complications occurred in any of

these patients.

3. Discussion

Ingestion of corrosive agents remains a major problem in

children [6]. In developed countries, most corrosive agents

ingested are cleansing substances and bleaches [8,9]. Most

of our patients came from the countryside, and the corrosive

agents were oil of vitriol, hydrochloric acid, sodium

hydroxide, and other industrial corrosive agents. All these

agents can cause deep corrosive burns after ingestion. These

patients do not respond to neither medical treatment nor

repeated dilation.

The retrievable expandable esophageal stents used in

this study were made of nitinol alloy, coated with silicon to

avoid mucosal ingrowth, and were easy to remove. The

nitinol alloy is responsive to temperature change, enabling

the material to exist in 2 predetermined physical forms

depending on the temperature. At low temperatures (08C-48C), as in ice water, the material quickly becomes very

pliable. At body temperature (378C), the stent gradually

transforms into a firm but flexible tube shape. The stent

expands as the temperature rises and reaches its preset

diameter 24 hours after placement. The tensile force to the

wall of the esophagus is uniform. Tearing in the

esophageal tissue is slow and lighter than with balloon

dilation, and the restricture rate is lower than with balloon

dilation [10].

The stent can prevent cross-fusion of the adjacent

damaged areas, contraction of the fibrous scar formed, and

adhesion of the esophageal lumen. According to Cardona

and Daly [11], various factors are responsible for stricture

development: (1) obliteration of the esophageal lumen by

edema and excessive granulation tissue; (2) adhesions

between adjacent ulcerated areas; (3) contraction of the

fibrous scar formed in the esophageal wall; and (4) des-

truction of the myenteric plexus. Based on these possible

causes, the use of this type of stent to treat corrosive

esophageal stenosis is better.

Some reports have suggested that a longer period of

stenting might be able to prevent the development of

strictures. In animal studies, stents maintained for 2 weeks

caused less stenosis in recipients than in controls without

stents. After 3 weeks, strictures were virtually eliminated

[7,12]. In our group, one patient had a stent in place for 4

weeks, and it was difficult to remove. Upon removal, it was

found that epithelium tissue had grown onto the stent. We

therefore recommend that the stent be kept in place for no

longer than 4 weeks.

None of the complications of stenting were serious.

Chest pain and vomiting occurred in all patients. These may

be caused by visceral tension or gastroesophageal reflux

[13]. These symptoms were relieved with medical therapy.

They disappeared after the removal of the stent. Only one

patient had stent migration. In our experience, migration

can be prevented if the stent is of the appropriate diameter

and length.

Some reports have suggested that the best form of

treatment for corrosive stricture of the esophagus is

surgical [3-5]. In recent years, progress in endoscopic

techniques has enabled a conservative treatment of

esophageal stenosis to be developed. In our opinion,

treatment of benign esophageal stenosis in children should

initially rely on conservative medical treatment and

stenting. Surgical treatment would only be indicated in

the case of tracheoesophageal fistula or failure of

conservative treatment for 2 years. The presentation of

gastroesophageal reflux after stenting and the development

of squamous cell carcinoma have been reported [14,15].

Because of these possibilities, long-term follow-up of such

patients is required.

Acknowledgment

The authors thank Dr KL Chan, Department of Surgery,

University of Hong Kong Medical Center, Queen Mary

Hospital, Hong Kong, and Dr David Wilmshurst, the

University’s technical writer, for their editorial assistance

during the preparation of this manuscript.

C. Zhang et al.504

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