Endoscopic cystostomy and biliary sphincterotomy for choledochoceles: A pediatric case series

Abstract

Management of choledochoceles (type III choledochal cysts) in children varies. We highlight the potential role of endoscopic management of choledochoceles with cystostomy and biliary sphincterotomy through a series of three successfully treated pediatric patients aged 12–13 at our tertiary center. Patients presented with symptoms including abdominal pain and pancreatitis. Choledochoceles were identified by preprocedure imaging on magnetic resonance imaging, with sizes ranging between 7 and 15 mm in maximal diameter. Histology revealed two choledochoceles lined by biliary epithelium and one by intestinal epithelium. Clinical improvement was sustained at a 2‐year follow‐up, with radiographic resolution on repeat imaging and normal tumor markers. We conclude that endoscopic management of choledochoceles with cystostomy and biliary sphincterotomy is a therapeutic option in children and can lead to sustained resolution of associated symptoms. While there is some lifetime risk of malignancy with choledochal cysts, malignancy in choledochoceles is rare.

1. INTRODUCTION

Choledochal cysts are rare biliary malformations, classified by Todani into five groups. Type III choledochal cysts, otherwise known as choledochoceles, are cystic dilations of the distal common bile duct (CBD) that project into the duodenum, further categorized into three subtypes. ¹ , ² These cysts are rare compared to other choledochal cysts, representing 1.4%–4.5% of all choledochal cysts. ³ In type A choledochoceles (67%), the CBD and pancreatic duct (PD) drain into the cyst that subsequently connects with the duodenum through a separate orifice. ² In type B choledochoceles (21%), a cystic diverticulum forms from the intraduodenal CBD or intra‐ampullary union of the pancreatic and biliary ducts. ⁴ Type C choledochoceles (12%) are classified by a cystic dilatation of the intramural bile duct that opens into the duodenum separately from the PD. Symptoms include abdominal pain, nausea and vomiting, pancreatitis, obstructive jaundice, and cholangitis. ⁵ A pediatric treatment algorithm for type III choledochal cysts was previously proposed and employs surgical intervention without leveraging the potential of therapeutic endoscopic retrograde cholangiopancreatography (ERCP). ⁶ Endoscopic therapy for choledochoceles has been proposed as the treatment of choice in adult patients, owing to a relatively low malignancy risk in these particular cysts. ⁷ , ⁸ The malignancy rate in choledochoceles is approximately 2.5%–5% overall and malignant transformation after endoscopic or surgical therapy is exceptionally rare with only one case of malignancy reported in the available literature. ² , ⁵ , ⁹ , ¹⁰ We report three pediatric patients with suspected choledochoceles who underwent ERCP with cystostomy and biliary sphincterotomy, avoiding surgical resection.

2. CASE REPORT

Following an informed discussion with families, three pediatric patients underwent ERCP with cystostomy (endoscopic incision and opening of the cyst using electrocautery device) and biliary sphincterotomy at our tertiary pediatric hospital. Treatment success was defined as improvement in clinical symptoms, laboratory markers, and/or imaging. A cystic structure was identified at the ampulla in each instance, via which an attempt was made to selectively cannulate the cyst and then the CBD. The cyst was entirely flayed open using electrocautery devices in each case.

2.1. Case 1

A 12‐year‐old boy with abdominal pain, frequent episodes of acute recurrent pancreatitis (ARP) every 1–2 months, and negative pancreatitis genetic risk factor testing underwent a magnetic resonance cholangiopancreatography (MRCP) to better delineate his pancreaticobiliary anatomy. It revealed pancreas divisum and a 6 mm saccular dilation of the distal CBD, suspicious for a choledochocele. Endoscopic ultrasound confirmed the cystic structure at the ampulla with the CBD inserting into the cyst. ERCP was performed with wire cannulation of the cyst and bile duct obtained. A cystostomy and biliary sphincterotomy were performed and the patient's anatomy was consistent with a type B choledochocele. Biopsies of the cyst lining revealed biliary epithelium (Figure 1). Carcinoembyonic antigen (CEA) and cancer antigen 19‐9 (CA‐19‐9) were unremarkable at diagnosis and remained normal at 2‐year follow‐up with normal MRCP, resolution of abdominal pain, and no further episodes of pancreatitis.

Figure 1.

Endoscopic, histologic, and imaging findings from patient 1. (A) Endoscopic view of the cyst (arrowhead); (B) endoscopic ultrasound view of the cyst and common bile duct (annotated); (C) endoscopic retrograde cholangiopancreatography cholangiogram showing a normal bile duct with choledochal cyst (arrowhead); (D) endoscopic view of postcystostomy and biliary sphincterotomy; (E) medium power image shows focal columnar epithelium (arrowhead), peribiliary glands (star), and smooth muscle (arrow) (hematoxylin and eosin).

2.2. Case 2

A 13‐year‐old girl with frequent episodes of ARP and no identified pancreatic genetic risk factors had an MRCP that suggested a 15 × 10 × 10 mm choledochocele. Preoperative tumor markers were not performed. ERCP confirmed a type A choledochocele, and a cystostomy and biliary sphincterotomy were performed. Biopsies of the cyst wall show denuded epithelial lining (Figure 2). At a 2‐year follow‐up, the patient did not have recurrent pancreatitis, there was resolution of the choledochocele on imaging and CEA and CA 19‐9 were normal.

Figure 2.

Endoscopic view and histology of the choledochal cyst identified in patient 2. (A) Endoscopic view of the cyst (arrowhead); (B) medium power histologic image shows inner cyst lining with denuded epithelium (arrow) and smooth muscle (arrowhead) (hematoxylin and eosin).

2.3. Case 3

A 13‐year‐old girl with a scalp melanoma undergoing staging workup was found to have an incidental 7 mm choledochocele on imaging, with elevated aspartate aminotransferase (40 U/L, normal range 5–26) and alanine aminotransferase (71 U/L, normal range ≤49) and normal bilirubin. Preoperative tumor markers were not done. ERCP confirmed the diagnosis of a type A choledochocele, and a cystostomy and biliary sphincterotomy were performed (Figure 3). Histology of the cyst lining showed intestinal‐type epithelium. Liver enzymes normalized and follow‐up at 2 years showed normal CEA and CA 19‐9.

Figure 3.

Endoscopic and imaging findings from patient 3. (A) Endoscopic view of the cyst with an abnormal cystic‐appearing ampulla (arrowhead); (B) cholangiogram image of the common bile duct and cystic lesion (arrowhead).

3. DISCUSSION

We highlight the role of ERCP as a less invasive diagnostic and therapeutic approach for choledochoceles in the pediatric population compared to open surgery. Patients had resolution of symptoms, normalization of laboratory markers, and sustained cyst resolution on imaging at 2 years follow‐up. Choledochoceles can be lined with intestinal or biliary epithelium, which has led to some speculation that cysts with intestinal lining could be periampullary duodenal duplication cysts involving the distal bile duct, which in contrast to choledochoceles contain a smooth muscle layer. ¹¹ , ¹² Choledochoceles do have potential for malignant transformation, which is suspected to be due to pancreaticobiliary reflux and stagnation of bile with chronic inflammation. While some small series have reported malignancy rates up to 14% at diagnosis, a literature review of reported cases has identified the overall rate as lower, between 2.5% and 5%. ² , ¹⁰ , ¹³ For context, the lifetime risk of colorectal cancer in an adult male is 4.4%. ¹⁴ Adenocarcinoma, anaplastic carcinoma, and squamous cell carcinoma can occur. Importantly, after endoscopic or surgical therapy, there has been only one case of malignant transformation reported. ² , ⁵ , ⁹ , ¹⁰

Transabdominal ultrasound or MRCP with contrast often constitute the first step in the diagnostic evaluation of patients with signs or symptoms of biliary abnormalities. Management of choledochoceles can be surgical, including cyst excision or transduodenal sphincteroplasty to allow outflow. ¹ , ⁴ , ⁵ Endoscopic sphincterotomy and/or cystostomy have been performed in adults with reported clinical improvement and have been suggested to be standard of care in adult patients. ² , ⁵ , ⁹ , ¹⁵ , ¹⁶ A recent systematic review identified 13 pediatric patients in the literature, five of whom were managed endoscopically with sphincterotomy or cyst unroofing. ⁶ , ¹⁷ , ¹⁸ , ¹⁹ Repeat imaging was not performed in any patients with a maximum of 2‐year follow‐up. This review promoted an algorithm emphasizing surgical management, particularly in patients with biliary cyst lining. ⁶

In this case series of three pediatric patients treated endoscopically through ERCP with cystostomy and biliary sphincterotomy, two had biliary epithelium histologically, and all had successful outcomes at 2 years with normal tumor markers and imaging. The risk of long‐term malignant transformation is uncertain, but a review of available literature suggests low risk of malignant transformation after endoscopy therapy. Endoscopic therapy allows symptomatic improvement with biliary decompression utilizing a less invasive approach compared to surgery. A multidisciplinary approach with at least involvement of gastroenterology and surgery is important. Risks and benefits should be discussed extensively with patients and families.

There is no current consensus regarding long‐term follow‐up and care in patients with choledochoceles following endoscopic therapy. Given the rarity of choledochoceles and the subsequent paucity of reported cases, the extremely low reported rates of malignant transformation after therapy is encouraging but should not obviate the need for follow‐up. An informal email survey of pediatric interventional endoscopists around the country revealed a wide variation in approaches, from no follow‐up to annual imaging and tumor markers, or annual endoscopy with biopsies of the remnant cyst lining. While tumor markers (particularly CEA and CA 19‐9) are potentially limited in application to pediatric patients they likely represent the least invasive way to continue to screen for malignant transformation. In the reported patients, follow‐up will consist of MRCP imaging and annual tumor markers. Further studies with long‐term follow‐up will be challenging given the paucity of cases but are necessary to determine the optimal therapy and monitoring strategies.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflicts of interest.

ETHICS STATEMENT

Informed consent for publication of case details was obtained from patients and their families verbally and documented in writing in the electronic medical records.

Saad M, Abu‐El‐Haija M, Lin TK, et al. Endoscopic cystostomy and biliary sphincterotomy for choledochoceles: a pediatric case series. JPGN Rep. 2024;5:475‐479. 10.1002/jpr3.12118