Endoscopic ultrasound-guided pancreatic pseudocyst drainage in pediatric patients

Abstract

BACKGROUND

Pancreatic pseudocyst (PPC) is a well-encapsulated peri-pancreatic fluid collection that occurs at least 4 weeks after acute pancreatitis. The prevalence of PPC is 8%-41% among patients with a history of pancreatitis. Management includes conventional surgery and percutaneous radiological or endoscopic approaches. Endoscopic ultrasound (EUS)-guided drainage of PPC appears to be a safe and less invasive treatment option. Its efficacy is well established in the adult population. However, data regarding its usage in the pediatric population are limited.

AIM

To determine the safety and efficacy of EUS-guided PPC drainage in children over 10 years.

METHODS

A retrospective review was conducted of pediatric patients (aged < 18 years) who were referred for EUS-guided PPC drainage between 2015 and 2024. Twenty-eight patients were identified who had been referred to our department for EUS-guided PPC drainage, including 21 patients with symptoms who underwent the procedure. Effectiveness was assessed based on technical success and clinical resolution of symptoms.

RESULTS

The mean age was 13.81 ± 3.25 years (range: 6-18 years) with 52.4% males. The locations of the PPCs were distributed along the pancreatic body (38.1%) and head/neck regions (38.1%). EUS-guided drainage was performed under general anesthesia. Complete aspiration without stent placement was performed in 11 patients (52.4%) with an average PPC size of 4.3 cm × 3.9 cm. Two double-pigtail plastic stents were required in 9 patients (47.6%) with a mean size of 8.4 cm × 8.0 cm. Lumen-apposing metal stents were required in 1 patient. Technical and clinical successes were achieved in all cases. One patient (4.8%) experienced recurrence that required repeat drainage. No major complications were observed.

CONCLUSION

EUS-guided PPC drainage was a safe and effective procedure for our pediatric population and should be preferred over conventional techniques, performed by experienced endoscopists under general anesthesia by pediatric anesthetists.

Key Words: Pancreatic pseudocyst; Endoscopic ultrasound; Endoscopic ultrasound-guided drainage; Pediatric endoscopy; Drainage techniques; Double pigtail plastic stent; Lumen-apposing metal stents

Core Tip: Pancreatic pseudocysts are uncommon in children. However, they are clinically significant complications of pancreatitis. This 10-year retrospective review evaluated the safety and efficacy of endoscopic ultrasound-guided drainage of pancreatic pseudocysts in a pediatric population. The study demonstrated 100% technical and clinical success with minimal complications. Endoscopic ultrasound-guided drainage is a safe and effective first-line approach in children, particularly when performed under general anesthesia by an experienced endoscopist.

INTRODUCTION

Acute pancreatitis has an incidence of 3.6 cases to 13.2 cases per 100000 in the pediatric population[1,2], and 20% of these cases develop complications[3]. The incidence of acute pancreatitis is increasing over time due to advancements in diagnostic modalities[4,5]. Pancreatic pseudocyst (PPC) is a complication of acute pancreatitis and occurs in 8%-41% of children with a history of pancreatitis[6-8]. The Revised Atlanta Classification from 2012 defines PPC as a localized collection of homogenous fluid surrounded by a well-defined inflammatory wall in the peri-pancreatic region that develops at least 4 weeks after acute pancreatitis[8,9]. Abdominal trauma has been documented in several studies as the most common risk factor for the development of PPC in the pediatric population[10,11]. PPCs are often managed conservatively because they tend to resolve spontaneously. However, some patients require intervention due to persistent symptoms. There are several methods to drain the PPC, including transmural conventional endoscopy-guided cystogastrostomy, endoscopic ultrasound (EUS)-guided cystogastrostomy, radiology-guided percutaneous drainage, and surgical drainage or excision[3]. Historically, laparotomy was the preferred approach for PPC drainage. However, with advancements in endoscopic techniques, EUS-guided drainage is now preferred[12].

EUS-guided PPC drainage has been widely used in adult patients. However, limited data exist on its utility in the pediatric population. This is attributed to the complex structure of the echo-endoscope, including its rigidity and traumatic distal end, and the requirement for monitored anesthesia care or general anesthesia, making EUS procedures more challenging in children[13]. The first pediatric case of EUS-guided percutaneous drainage was reported in 1996[14]. Although a few studies have demonstrated the safety of EUS-guided PPC drainage, they included small sample sizes[12,15]. Herein, we discuss our experience with EUS-guided PPC drainage at our center, a tertiary referral endoscopy facility with a comparatively substantial volume of pediatric patients undergoing this procedure, over a 10-year period. Our study evaluated the safety and effectiveness of EUS-guided PPC drainage in the pediatric population (up to 18 years of age) by assessing technical success, clinical success, complications, and the need for additional interventions.

MATERIALS AND METHODS

Study design

A retrospective chart review of pediatric patients (≤ 18 years) who underwent EUS-guided PPC drainage from 2015 to 2024 at the Sindh Institute of Advanced Endoscopy and Gastroenterology was conducted.

Study setting

At the beginning of the study, our department was the Endoscopy Suite of the Surgical IV Unit at the Civil Hospital, Karachi. It was a tertiary referral center for endoscopy. Since May 2023, it has been functioning as a separate, independent endoscopy unit. Our institute serves as a tertiary referral center for endoscopy located in Karachi, the largest city in Pakistan.

Inclusion and exclusion criteria

All patients aged 18 years and younger who were referred for EUS-guided PPC drainage between 2015 and 2024 were included in the study. Patients with incomplete records were excluded from the final analysis.

Procedural protocol

All EUS-guided PPC drainage procedures were performed by experienced endoscopists formally trained in EUS. All procedures were performed under general anesthesia administered by an anesthetist. Airway protection was achieved through endotracheal intubation to minimize the risk of airway compromise, aspiration, and hemodynamic instability. Intravenous antibiotics were administered 30-60 minutes prior to the procedure. Post-procedure oral antibiotics were advised for 5 days to all patients.

Data collection

Data for the study were extracted from patient records maintained in the hospital’s health information system from 2015 to 2024. The collected data included patient demographics (age, sex), clinical history, PPC characteristics (site, size), anesthesia-related details, procedural information (stent type, number, and size of stents used), and post-procedure outcomes (success, complications).

Study outcomes

The primary outcome of this study was to evaluate the effectiveness and safety of EUS-guided PPC transmural drainage in a pediatric population. Secondary outcomes included assessment of technical success and clinical outcomes, such as resolution of PPC, recurrence, and procedure-related complications.

Definitions

Effectiveness was defined as a measure of the degree of beneficial impact of an intervention under real-world clinical conditions[16]. In our study, the effectiveness of EUS-guided PPC drainage was assessed based on technical success[17]. Technical success of PPC drainage was defined as the successful placement of a stent, including either a double-pigtail plastic stent (DPPS) or a lumen-apposing metal stent (LAMS), across the cystogastrostomy tract created under EUS guidance, enabling adequate drainage of the PPC.

Statistical analysis

Statistical analysis was conducted using IBM^® SPSS Statistics Software, version 25 (IBM Corp., Armonk, NY, United States). Categorical variables were reported as frequencies and percentages. Quantitative variables were presented as mean ± SD for normally distributed data, while median values with interquartile ranges were reported for data that did not follow a normal distribution. The Shapiro-Kolmogorov test was used to assess the normality of numerical variables. A P-value < 0.05 was considered statistically significant.

RESULTS

Patient cohort

Twenty-eight patients were referred to our institute for EUS-guided PPC drainage from 2015 to 2024. A total of 21 patients were symptomatic at presentation and underwent EUS-guided PPC drainage. The age of patients ranged from 6 years to 18 years, with a mean age of 13.81 ± 3.37 years. Of the 21 patients who received treatment, 11 (52.40%) were male, and 10 (47.60%) were female.

PPC location

The locations of the PPCs are shown in Table 1.

Table 1 Location of the pseudocysts, n (%).

Location of pseudocyst	Frequency
Pancreatic body	8 (38.10)
Head and neck of the pancreas	8 (38.10)
Pancreatic tail region	5 (23.80)

Etiology

A total of 16 patients had chronic pancreatitis, and 3 patients had a history of blunt trauma to the abdomen. Two patients had neither chronic pancreatitis nor abdominal trauma.

Drainage type and PPC characteristics

Among the patients, 11 (52.4%) required EUS-guided complete aspiration of the PPC due to the size of the cyst. The average size of the PPC in this group was 4.5 cm × 3.4 cm and ranged from 2.0 cm × 1.2 cm to 6.7 cm × 5.6 cm. The remaining 10 patients (47.6%) underwent EUS-guided PPC drainage via stent placement with an average pseudocyst size of 8.5 cm × 8.2 cm and ranged from 5.0 cm × 6.0 cm to 14.0 cm × 10.0 cm.

Stent selection

In 9 patients, two DPPS (7 Fr × 4 cm) were placed transmurally into the cystogastrostomy tract. A LAMS Hot Axios (10 mm × 20 mm) was placed in 1 patient (Supplementary Table 1).

Clinical outcomes

Only 1 patient experienced a recurrence of symptomatic PPC after 3 months and required repeat drainage. No major complications were observed in any of the patients.

DISCUSSION

Surgical and percutaneous drainage approaches were the preferred treatment options for symptomatic PPC[18]. However, as surgical methods such as open laparotomy evolved into laparoscopic approaches, they were eventually replaced by endoscopic cystogastrostomy over the decades. Percutaneous drainage is associated with a high risk of recurrence and pancreatic fistula formation and was the less preferred technique[12]. Recent advancements in endoscopic techniques, particularly the development of EUS, have led to the frequent use of EUS-guided PPC drainage because it is safe, has a low complication rate, and is cost-effective compared with other interventions[19-21]. Although multiple studies have reported that EUS-guided PPC drainage in adult populations is safe and effective, the data on the pediatric population are limited[22-25]. A meta-analysis by Nabi et al[15] included 14 studies on PPC and walled-off necrosis drainage via endoscopy with or without EUS. They found that the largest number of PPC cases drained under EUS guidance in a single study was 13[15,26]. Our study included 21 patients who underwent EUS-guided PPC drainage, contributing one of the largest datasets reported.

We found that 75% of the patients with PPC referred to our center underwent EUS-guided drainage. The remaining patients did not require intervention as their symptoms subsided upon presentation to our institute. Similarly, in a previous study, drainage was only performed in 50% of patients with symptomatic PPC[27]. In the adult population, drainage is typically indicated for persistent PPCs larger than 6 cm[28]. However, there are no data available to indicate the cutoff size for drainage of PPC in the pediatric population. Rupture and other major complications, such as abscess formation, hemorrhage, and fistulae, are rare in pediatric patients with PPC[22]. Therefore, asymptomatic patients can be safely monitored regardless of the size or duration of the PPC. Drainage should only be considered when symptoms are present[27-29].

The average age of our patients was 13.81 years, with the youngest being 6-years-old. Our data were similar to those in a previous study, from which a mean age of 13 years was reported[30]. A slightly higher incidence of PPC has been reported in male children, which was also observed in our study[26,28,31]. However, a small retrospective study on EUS-guided PPC drainage reported a higher proportion of female patients with a mean age of 11.8 years[22]. In our cohort, the location of the PPC was most commonly positioned along the body and the head/neck regions of the pancreas, constituting 76.1% of cases. Similarly, a previous study of EUS-guided PPC drainage with stent placement in an adult population found that most PPCs occurred along the body of the pancreas, followed by the head region, with both regions accounting for 73% of total cases[17].

Anesthesia is a critical factor in ensuring the safety of EUS procedures in children. According to the guidelines and most studies, general anesthesia with endotracheal intubation is preferred over moderate sedation[30]. Likewise, all patients included in our study underwent EUS-guided PPC drainage under general anesthesia and endotracheal intubation. We noted that 3 (14.29%) patients who underwent EUS-guided PPC drainage had a history of trauma to the abdomen. In contrast, abdominal trauma was the most common cause of PPC in children in several other studies[32,33]. Interestingly, 2 (9.52%) of our patients had neither a history of pancreatitis nor EUS findings suggestive of pancreatitis. The remaining patients (n = 16, 76.19%) who underwent EUS-guided PPC drainage had idiopathic chronic pancreatitis.

EUS-guided drainage provides real-time imaging, making the procedure safer by allowing the operator to avoid intervening in blood vessels[12]. EUS-guided approaches in adult patients have been successfully used to drain pancreatic fluid collections that were otherwise inaccessible and have achieved high technical success with a low complication rate[34]. Stent placement during EUS-guided PPC drainage is often indicated in cases with infected cysts or less solid debris components[12,22]. Smaller caliber stents and the presence of debris increase the risk of stent clogging and lead to complications such as infection or incomplete resolution[34].

A previous study reported successful EUS-guided aspiration without stent placement in small symptomatic PPCs following failed conservative therapy[22]. Similarly, in our study, 52.4% of patients underwent complete aspiration without the need for stent placement. These patients had an average PPC size of 4.5 cm × 3.4 cm, aligning with previous findings that showed that EUS-guided drainage without stent placement was an effective approach for PPCs smaller than 5 cm[22]. Notably, the largest PPC drained without a stent measured 6.7 cm × 5.6 cm in our cohort. None of these patients experienced complications or recurrence, confirming results from prior studies that showed long-term clinical and radiological resolution.

A systematic review comparing stent types for PPC drainage found a higher clinical success rate for metallic stents compared with plastic stents (98.3% vs 89.4%)[35]. LAMS were associated with a lower risk of migration, dislocation, and occlusion[17]. Another study demonstrated the safety and effectiveness of EUS-guided LAMS placement for PPC drainage[36]. In our study, LAMS was successfully used in 1 case without any complications. Of note, LAMS is not readily available at our center due to its high cost. Moreover, a systematic review showed no significant difference in treatment success between DPPS and LAMS (85% vs 83%)[37]. Another study demonstrated higher technical and clinical success rates with DPPS than with LAMS (100% vs 80%)[38]. Therefore, recent studies support DPPS as a suitable first-line option for EUS-guided PPC drainage due to its safety and efficacy[17]. However, the optimal number or size of plastic stents in pediatric PPC drainage has not been established[12]. A previous study involving 7 Fr and 10 Fr stents with single, double, or triple deployment found no significant difference in clinical outcomes[22]. Similarly, another study in adult patients reported equal success with a single 7 Fr DPPS compared with larger or multiple stents[39].

In our study, 42.9% of patients underwent EUS-guided PPC drainage using two 7 Fr DPPS with no technical failures. This contrasts with a previous study in an adult population in which placement of a second DPPS failed in 3 cases due to technical difficulties[17]. The average PPC size was 9.4 cm (range: 5.3-13.5 cm) in their study. In our patients with two DPPS placed, the mean size was 8.5 cm × 8.2 cm (range: 5.0 cm × 6.0 cm to 14.0 cm × 10.0 cm), which was slightly smaller than the adult study and another pediatric study[40]. In the pediatric study, the mean age of the patients was 8.4 years, and the average PPC size was 12 cm (range: 8-17 cm).

Our PPC patients who underwent EUS-guided drainage with two DPPS showed 100% clinical success without major complications, confirming results from other retrospective studies[17,34]. However, 1 patient experienced recurrence of symptomatic PPC after 3 months and required repeat drainage. However, no recurrence was reported in a previous study with a 2-6 months follow-up[17]. Additionally, no stent displacement within the cyst was reported in any of our patients. Similarly, another study reported a 100% technical success rate[34]. The patient who underwent LAMS placement did not have any complications or recurrence. Few studies have shown that LAMS placement is safe in pediatric populations, and additional data are needed to determine its long-term outcomes[41-43]. While our study provided valuable insights, it is important to acknowledge certain limitations. As a single-center retrospective study with a limited sample size, the findings may have limited generalizability to the larger population. Future studies with larger, prospective cohorts, longitudinal follow-up, and comprehensive statistical analysis would further strengthen and expand upon these findings.

CONCLUSION

Our study demonstrated that EUS-guided PPC drainage in a pediatric population was a safe and effective intervention and achieved a high technical success and favorable clinical outcomes with a low rate of complications. Complete aspiration without stent placement was effective for smaller pseudocysts, while stent placement (primarily DPPS) was successful for larger collections. Although rare recurrence and stent displacement can occur, highlighting the importance of trained, experienced endoscopists performing the procedure under general anesthesia with a pediatric anesthetist and careful follow-up. These findings support EUS-guided drainage as a preferred first-line option for symptomatic PPC in children.