Does wire-guided cystotome dilation for difficult benign bilio-pancreatic strictures guarantee long-term patency? A narrative mini-review of the literature

Abstract

BACKGROUND

Difficult benign biliary and pancreatic strictures are generally managed by using a Soehendra screw or cystotome. Many previous studies described the techniques without information even of mid-term follow-up.

AIM

To confirm the long-term patency of dilated strictures following the application of a cystotome.

METHODS

Data were collected from analysis of the literature using appropriate key words. Technical success was defined as the ability to traverse the stricture. Clinical success was defined as drainage of biliary or pancreatic strictures and symptoms’ resolution. PRISMA criteria were followed to write the present review.

RESULTS

Three papers were selected following the inclusion criteria. Our case series was added to the review of the literature. Reported technical and clinical success rates were 100% in all the studies and the rate of adverse events was reported from 9.1% to 60%. However, data on follow-up and long-term patency are scant.

CONCLUSION

The use of a cystotome can be considered an alternative method for dilation of difficult pancreatic and biliary strictures, after the failure of conventional modalities. According to available literature, long-term results are rarely described, and this is still a crucial issue to evaluate the effectiveness of the technique.

Key Words: Biliary stricture; Pancreatic stricture; Difficult stricture; Cystotome; Endoscopic retrograde cholangiopancreatography

Core Tip: Cystotome use for the dilation of difficult strictures has been reported as both technically feasible and clinically effective. Nonetheless, the literature remains limited, likely due to the technical complexity of the procedure and the specialized expertise that it requires. The present mini-review underlines the need of long-term outcomes after cystotomy dilation of difficult biblio-pancreatic strictures. Technical feasibility was determined but recurrence rate and long-term latency are still almost not reported.

INTRODUCTION

Endoscopic treatment of benign biliary and pancreatic strictures using conventional devices is generally effective[1-4]. The standard approach typically involves dilation with a biliary balloon or mechanical dilator, followed by the placement of a plastic or metal stent. When these techniques fail, the stricture is classified as difficult[3]. In such cases, a cystotome may be employed to achieve stricture dilation, as described in a limited number of published studies[1,3-5]. The aim of this study was to evaluate the technical and clinical success, as well as the adverse events (AEs), associated with cystotome dilation in difficult benign biliary and pancreatic strictures, with a particular focus on long-term patency. While the technical feasibility of this approach has been demonstrated, data on long-term outcomes remain scarce.

MATERIALS AND METHODS

A literature search was conducted in the PubMed-MEDLINE database using the following keywords: “Cystotome difficult stricture”, “stricture diathermy dilator”, and “recalcitrant strictures cystotome”. The search focused on studies published within the past 10 years. Studies reporting long-term patency outcomes following cystotome dilation were prioritized. The inclusion criteria were: Full-text availability and primary focus on technical and clinical outcomes of cystotome use in difficult biliary or pancreatic strictures. The exclusion criteria included commentaries, editorials, case reports, non-English language publications, and studies examining cystotome use in non-biliopancreatic settings.

The dilation procedure was described as follows: A 6-Fr or 8.5-Fr cystotome was advanced over a guidewire under fluoroscopic guidance to the site of the stricture. Diathermy current was applied to facilitate the passage of the cystotome through the stricture. Technical success was defined as successful passage of the cystotome through the stricture and, when applicable, successful stent placement. Clinical success was defined as effective drainage of the biliary or pancreatic duct, resulting in the resolution of related symptoms, such as abdominal pain or jaundice. AEs were classified according to the Cotton classification[6]. Stricture recurrence was defined as the return of symptoms accompanied by radiologic evidence of stricture on cholangiography or pancreatography. Stricture resolution was defined by the normalization of laboratory parameters and the absence of related clinical symptoms. This review was conducted in accordance with PRISMA guidelines. Extracted data were compared with outcomes from a case series at our tertiary referral center.

RESULTS

The literature search yielded 29 results. Of these, 22 were excluded as unrelated to cystotome use in the bilio-pancreatic context. One additional study was excluded as it was a commentary rather than a full research article.

Only four studies investigating the use of diathermy catheters (cystotomes) for dilation of biliary or pancreatic strictures were included (Table 1).

Table 1 Results of included studies, n (%).

Ref.	Number of patients	Technical success	Procedure-related AEs	Severe AEs1	Type of AEs	Follow-up data on long-term patency
Kawakami et al[2], 2014	22	22 (100)	2 (9.1)	0	Mild hemobilia, mild post-ERCP pancreatitis	No
Puri et al[3], 2018	25	25 (100)	15 (60)	0	Mild upper abdominal discomfort	No
Sundaram et al[4], 2021	10	10 (100)	2 (20)	0	Mild post-ERCP pancreatitis, self-limiting bleeding	No
Kato et al[5], 2019	13	13 (100)	2 (15.4)	0	Mild hemobilia, cholangitis	1115 days, 61.5%

¹Death, major bleeding, perforation.

AEs: Adverse events; ERCP: Endoscopic retrograde cholangiopancreatography.

Kawakami et al[2] reported on 22 patients—16 with difficult biliary strictures and 6 with severe pancreatic strictures refractory to conventional dilation using Hurricane balloons and Soehendra bougies. All underwent dilation with a 6-Fr diathermy catheter. Technical and clinical success was achieved in 100% of cases. Mild AEs occurred in 2 patients (9.1%): One case of mild hemobilia following biliary dilation and one case of mild post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis in a patient with a pancreatic stricture.

Puri et al[3] evaluated 25 patients (19 with severe biliary strictures and 6 with severe pancreatic strictures). Dilation with a 6-Fr cystotome was technically and clinically successful in all cases (100%). Mild AEs were reported in 15 patients (60%), consisting mainly of upper abdominal discomfort.

Sundaram et al[4] assessed 10 patients with benign, difficult pancreatic strictures due to chronic pancreatitis. Dilation was performed using a wire-guided cystotome. Strictures were located in the pancreatic head (6 patients), isthmus (2), and body (2). Technical and clinical success was achieved in all cases (100%). AEs occurred in 2 patients (20%): One case of mild post-ERCP pancreatitis and one case of self-limited bleeding.

Kato et al[5] was the only study to report long-term outcomes. Diathermic dilation was technically successful in all 13 cases (100%), with successful stent placement in 12 (92.3%). AEs occurred in 2 patients (15.4%): Mild hemobilia and cholangitis. During a median follow-up of 1115 days, biliary stricture recurrence occurred in 5 of 12 patients (41.7%). A stent-free state was achieved in 8 patients (61.5%) who remained asymptomatic, with no evidence of cholangitis or abnormal liver function tests. Notably, among the included studies, only one provided follow-up data. Consequently, evidence regarding long-term patency after cystotome dilation remains limited.

DISCUSSION

ERCP-guided dilation using standard techniques—such as balloon or mechanical dilators—is widely accepted as a safe and effective treatment for benign biliary and pancreatic strictures. However, in difficult cases, these conventional methods may fail, requiring alternative endoscopic approaches. Such techniques often demand significant operator expertise and are typically confined to high-volume centers specializing in biliopancreatic endoscopy.

Among these alternatives, cystotome use has been reported as both technically feasible and clinically effective for the dilation of difficult strictures. Nonetheless, the literature remains limited, likely due to the technical complexity of the procedure and the specialized expertise that it requires.

In the reviewed studies, both technical and clinical success rates reached 100%, underscoring cystotome dilation as a promising salvage technique when conventional methods fail. Reported AE rates ranged from 9.1% to 60%, though most events were mild. It should be noted that abdominal discomfort—commonly experienced after ERCP for various reasons—was included in AE reporting, potentially inflating the overall incidence.

A significant limitation across studies is the lack of long-term follow-up data. This restricts the evaluation of the procedure’s true effectiveness. The need for a non-standard device such as a cystotome may itself indicate a higher baseline risk of recurrence. Moreover, the thermal mechanism of cystotome dilation could potentially induce fibrosis, thereby contributing to stricture recurrence.

Experimental evidence supports this concern, suggesting that thermal coagulation may compromise ductal integrity and promote fibrotic scarring[7]. In the only study with a follow-up period of approximately 3 years, around 60% of patients remained free of recurrence. Similarly, in our own retrospective observational study (approval No. 2021/07) conducted at a tertiary referral center and currently unpublished, 54% of 13 patients showed sustained stricture resolution after a median follow-up of 28 months. Recurrence occurred in 31%, necessitating further endoscopic intervention. Two patients did not achieve clinical improvement, likely due to significant tissue loss at the stricture site. This study has several limitations, including a small sample size, heterogeneity of cases (biliary vs pancreatic strictures), and a retrospective design, limiting statistical power and generalizability.

CONCLUSION

Despite these limitations, our review highlights the potential role of cystotome dilation as a rescue technique for managing difficult biliary and pancreatic strictures. However, to define its optimal use in clinical practice and evaluate long-term outcomes, further research is warranted. Future directions should include multicenter prospective studies and randomized controlled trials comparing cystotome-assisted dilation with conventional methods and emerging techniques such as magnet-assisted intraluminal anastomosis.