Safety and efficacy of argon plasma coagulation trimming of malpositioned and migrated biliary metal stents: a controlled study in the porcine model

Jailbreaking a metal biliary stent through a duodenal stent

Video 1.

An Update to Hepatobiliary Stents

Endoscopic stent placement is a common primary management therapy for benign and malignant biliary strictures. However, continuous use of stents is limited by occlusion and migration. Stent technology has evolved significantly over the past two decades to reduce these problems. The purpose of this article is to review current guidelines in managing malignant and benign biliary obstructions, current endoscopic techniques for stent placement, and emerging stent technology. What began as a simple plastic stent technology has evolved significantly to include uncovered, partially covered, and fully covered self-expanding metal stents (SEMS) as well as magnetic, bioabsorbable, drug-eluting, and antireflux stents.(1).

Endoscopic treatment of iatrogenic gastrointestinal perforations: an overview

In the past, the treatment of iatrogenic gastrointestinal perforations was limited to surgical management or to medical observation. Natural Orifice Transluminal Endoscopic Surgery (NOTES) has paved the way towards the development of reliable endoscopic closure techniques, which can be applicable in accidental perforations of the gastrointestinal tract. When endoscopic treatment is feasible, hemoclips are preferred in smaller perforations, while over-the-scope-clips or a combination of hemoclips, endoloops, and glue are used in larger ones. Endoscopic stitching is rarely utilized, and endoscopic stapling has been practically abandoned. The use of self-expandable covered stents can be considered in the esophagus and duodenum. Broad spectrum antibiotics are recommended in most cases. Clinical follow-up in a medico-surgical unit is mandatory and surgical intervention should not be delayed more than 24h if clinical or biological worsening occurs. Imaging with oral contrast medium is advisable before resumption of oral feeding in the case of large perforations.

Endoscopic Removal of a Proximally Migrated Metal Stent during Balloon Sweeping after Stent Trimming

Placement of a self-expanding metal stent (SEMS) is an effective method for palliation of a malignant biliary obstruction. However, metal stents can cause various complications, including stent migration. Distally migrated metal stents, particularly covered SEMS, can be removed successfully in most cases. Stent trimming using argon plasma coagulation may be helpful in difficult cases despite conventional methods. However, no serious complications related to the trimming or remnant stent removal method have been reported due to the limited number of cases. In particular, proximal migration of a remnant fragmented metal stent after stent trimming followed by balloon sweeping has not been reported. We report an unusual case of proximal migration of a remnant metal stent during balloon sweeping following stent trimming by argon plasma coagulation. The remnant metal stent was successfully removed with rotation technique using a basket and revised endoscopically.

Endoscopic management of malignant bile duct strictures

Malignant biliary obstruction can arise from intrahepatic, extrahepatic, and hilar locations from either primary or metastatic disease. Biliary-enteric surgical bypass has been surpassed in the last 20 years by endoscopic balloon dilation and stenting. The goal of stenting for biliary decompression is to palliate obstructive symptoms; it has not been shown that survival is affected by stenting alone. Novel endoscopic therapies, including photodynamic therapy and radiofrequency ablation, have been evaluated and show promise. Both therapies seem to be safe and effective in the treatment of malignant bile duct strictures but are in need of prospective studies of longer duration.

Recent advances of biliary stent management

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.

Endoscopic removal and trimming of distal self-expandable metallic biliary stents

AIM: To evaluate the efficacy and safety of endoscopic removal and trimming of self-expandable metallic stents (SEMS).

METHODS: All SEMS had been placed for distal biliary strictures. Twenty-seven endoscopic procedures were performed in 19 patients in whom SEMS (one uncovered and 18 covered) removal had been attempted, and 8 patients in whom stent trimming using argon plasma coagulation (APC) had been attempted at Tokyo Medical University Hospital. The APC settings were: voltage 60-80 W and gas flow at 1.5 L/min.

RESULTS: The mean stent indwelling period for all patients in whom stent removal had been attempted was 113.7 ± 77.6 d (range, 8-280 d). Of the 19 patients in whom removal of the SEMS had been attempted, the procedure was successful in 14 (73.7%) without procedure-related adverse events. The indwelling period in the stent removable group was shorter than that in the unremovable group (94.9 ± 71.5 d vs 166.2 ± 76.2 d, P = 0.08). Stent trimming was successful for all patients with one minor adverse event consisting of self-limited hemorrhage. Trimming time ranged from 11 to 16 min.

CONCLUSION: Although further investigations on larger numbers of cases are necessary to accumulate evidence, the present data suggested that stent removal and stent trimming is feasible and effective for stent-related complications.

Trimming of a migrated metal stent for malignant colonic stricture using argon plasma coagulation

We report the first case of trimming of a migrated metal colonic stent for stent induced severe anorectal pain. We present a case of a 54-year-old female with history of metastatic colorectal carcinoma who had stent placement secondary to obstruction. Subsequent distal migration of the stent caused ulcerations into the rectal mucosa and excruciating anorectal pain. We used argon plasma coagulation (APC) to successfully trim the exposed distal portion of the metal stent and rat tooth forceps to retrieve the stent fragments. The use of APC for trimming metallic stents is an effective procedure that can be used to trim migrated rectal stents that result in significant rectal pain. To date, few studies have been published that use APC to trim metallic stents placed in the gastrointestinal tract. To the best of our knowledge, ours is the only known case in which the indication for stent trimming was severe stent induced rectal pain. The procedure resulted in complete relief of patient symptoms. Therefore, APC is a safe and effective way to trim colo-rectal stents to definitively relieve the symptom of stent induced rectal pain in patients who have experienced distal stent migration and mucosal ulceration.

Gastrointestinal and biliary stents

Advances in stent design have led to a substantial increase in the use of stents for a variety of malignant and benign strictures in the gastrointestinal tract and biliary system. Whereas early stents were mostly composed of plastic, the majority of contemporary stents are self-expanding metal stents that are composed of either nitinol or stainless steel. These stents are able to exert an adequate expansile force and, at the same time, are highly flexible and biocompatible. Covered stents have been introduced to minimize tumor ingrowth through the metal mesh but are associated with higher rates for spontaneous migration. This has led to the development of covered stents with uncovered ends and stents with both covered and uncovered layers. Drug-eluting and biodegradable stents are also likely to become available in the near future. Although stents appear to be the preferred form of palliation for some patients with advanced cancer, many patients will benefit from a multidisciplinary approach that usually includes surgeons and oncologists.

Trimming of a Migrated Biliary Nitinol Stent Using Argon Plasma

Metallic stent migration is a well-known complication which cannot always be managed by removal or repositioning, especially in case of uncovered stent. We report a patient who developed obstructive jaundice due to migration of an expandable metallic stent (EMS) inserted in the lower bile duct. Trimming of the EMS using argon plasma was performed, with the power setting of 60 W and 2.0 l/min of argon flow. The distal part of the EMS was removed and mechanical cleaning using balloon catheter was performed for remnant EMS. Without additional stent insertion, jaundice was relieved in a few days. No complication was recognized during the procedure and no recurrence of jaundice in the rest of his life.

Endoscopic fenestration of duodenal stents using argon plasma to facilitate ERCP

BACKGROUND

The presence of a duodenal stent may hinder attempts at ERCP for treatment of malignant biliary obstruction.

OBJECTIVE

We describe 2 patients in whom endoscopic fenestration of indwelling duodenal stents with an argon plasma coagulator facilitated successful ERCP.

DESIGN

Single-center retrospective case series.

SETTING

Tertiary-referral center.

PATIENTS

Both patients had unresectable biliary malignancy with both duodenal and biliary obstruction.

INTERVENTION AND RESULTS

Windows were cut into indwelling duodenal stents with argon plasma, which exposed the underlying papilla and allowed successful ERCP and stent placement.

LIMITATIONS

Retrospective study and the small sample size.

CONCLUSIONS

Fenestration of duodenal stents using argon plasma is a simple technique that can facilitate ERCP.

Second-generation argon plasma coagulation: two-center experience with 600 patients

BACKGROUND AND AIM

Second-generation argon plasma coagulation (APC; APC 2/VIO APC) with its modes 'forced', 'pulsed', and 'precise' is a further development of the ICC/APC 300 system (first-generation APC). Until now, only limited data has existed on the use of APC 2.

METHODS

Fundamental data on the characteristics of the various APC 2 modes and clinical data from more than 600 patients treated in two high-volume endoscopy centers were analyzed. On the basis of these data, recommendations for the use of APC in daily gastroenterological practice were made.

RESULTS

In comparison to the ICC system, second-generation APC offers a broadened bandwidth of settings including different APC modes and a range of power settings from 1 to 120 W. Using the various modes of APC 2 in a variety of gastrointestinal diseases, minor complications were observed in 9-21% of patients. Major complications occurred in 1-7% of patients.

CONCLUSIONS

In a two-center experience treating a large group of patients with a wide variety of gastrointestinal conditions, the different APC 2 modes appeared to be safe and effective. Certain preventive measures before and during clinical application are recommended in order to avoid complications.

Endoscopic trimming of metallic stents with the use of argon plasma

BACKGROUND

The endoscopic placement of metallic stents for palliation of malignant obstruction of the GI or biliary tract is an established practice and as such is often applied. Use of these stents, however, has its problems. Stent migration may cause obstruction of the bowel lumen. Migration of a biliary stent into the contralateral duodenal wall may cause difficulty in gaining access to the biliary tract, as will the placement of a duodenal stent across the ampulla.

OBJECTIVE

We report on 6 patients in whom trimming of the metallic nitinol stent was performed.

DESIGN

Single-center, retrospective case series.

SETTING

Secondary referral center.

PATIENTS

Of 6 patients included, 2 patients each had an uncovered duodenal stent, 2 had an uncovered biliary stent each, 1 had an uncovered colorectal stent, and 1 had a covered gastroduodenal stent.

INTERVENTIONS

Under direct endoscopic vision, an argon plasma beam was used to cut self-expandable metallic stents, as appropriate.

MAIN OUTCOME MEASUREMENT

The main objective was relief of the obstruction to the bowel lumen or bile duct, facilitating successful passage of an endoscope or biliary canulation, respectively.

RESULTS

In all 5 patients with uncovered metallic stents, we were able to re-establish access to the obstructed bowel lumen or the biliary tree, as indicated. An attempt to tailor the length of a covered metallic gastroduodenal stent failed. No complications were observed and no hemorrhage or perforation occurred.

LIMITATIONS

The study was limited by retrospective design and small sample size.

CONCLUSIONS

The endoscopic cutting and tailoring of an uncovered metallic prosthesis, by means of an argon plasma beam, is feasible, effective, and safe. Trimming of covered stents is not advocated.