To keep or not to keep the lumen-apposing metal stent during endoscopic necrosectomy?

Binmoeller et al. reported the first use of a lumen-apposing metal stent (LAMS) for transluminal drainage of a fluid collection in a porcine model in 2011 [1]. One year later, Itoi et al. reported the first clinical use of LAMS [2]. In their study, endoscopic ultrasound (EUS)-guided drainage with LAMS was performed in 15 patients with symptomatic pseudocysts and 5 patients with acute cholecystitis. Since then, numerous studies have reported on the topic of EUS-guided drainage of pancreatic fluid collections with LAMS. The technique seems to have gained popularity especially for walled-off pancreatic necrosis (WOPN), as the LAMS can serve as a gateway to the cavity to facilitate repetitive endoscope insertions, withdrawals, and removal of necrotic debris.

“I know that I will now be considering redeployment of the same LAMS if the transluminal tract needs to be maintained for a subsequent necrosectomy session.”

In this issue of Endoscopy, Gulati and Rustagi describe a series of patients with WOPN in whom purposeful removal and replacement of the same LAMS was performed to theoretically facilitate endoscopic necrosectomy [3]. The authors posited that removal of the LAMS would allow: 1) greater endoscope maneuverability and access inside the cavity, and (2) easier removal of larger solid debris without the impediment of the fixed diameter and potentially restrictive intracavity flange of the LAMS. They initially placed larger-diameter LAMS (mainly 15 mm) using a freehand technique with the cautery-enhanced LAMS model (Hot Axios; Boston Scientific, Marlborough, Massachusetts, USA). Endoscopic necrosectomy was not performed at the time of initial LAMS drainage. During subsequent sessions for endoscopic necrosectomy, LAMS were removed, necrosectomy was performed using standard devices, and the same LAMS was replaced across the transmural tract (unless necrosectomy was complete). This technique was used in 40 patients who required more than one session of endoscopic necrosectomy. In this group, the technique was successfully applied in 81 necrosectomy sessions, and included removal and replacement of LAMS at least three times in 25 % of patients. The study cohort required a mean 2.4 necrosectomy sessions to achieve clearance.

The technique of redeploying an accidentally, and even intentionally, dislodged LAMS during endoscopic necrosectomy has been previously described in case reports [4] [5]; however, the current study appears to be the first large series of purposeful removal and replacement. The main clinical question at hand is: Does removal of an in situ LAMS truly facilitate endoscopic necrosectomy? The authors suggest this to be the case, and support the notion by mentioning that large necrotic pieces measuring up to 12 × 2 cm could be removed during a single withdrawal. However, there is no control group to properly compare. The authors also mention that the mean number of necrosectomy sessions needed in their cohort (2.4) was significantly less compared with the weighted mean number (4.1) from a recent meta-analysis [6]. I am not certain of the validity of this type of comparison from a statistical standpoint. Regardless, comparing these results would not be on equal ground given that the referenced meta-analysis mainly included studies pre-dating the availability of LAMS. A more appropriate comparison would be of endoscopic necrosectomy with removal/redeployment versus in situ LAMS. One large multicenter study from the USA in which in situ LAMS was used for endoscopic necrosectomy revealed high technical and clinical success rates with a median 2 endoscopy sessions [7]. These results are seemingly on par with results from the current study.

Nonetheless, the authors are to be congratulated in helping disseminate this potentially valuable technique. From personal experience with accidental LAMS dislodgment during endoscopic necrosectomy, I know that I will now be considering redeployment of the same LAMS if the transluminal tract needs to be maintained for a subsequent necrosectomy session. In theory, the purposeful removal of LAMS during endoscopic necrosectomy may facilitate more efficient removal of larger necrotic tissue and easier access into intracavitary recesses. However, direct comparative studies would be needed to make any firm conclusions. As I write this commentary, I do recall a handful of cases in which the intentional removal of the LAMS may have facilitated endoscopic necrosectomy. While we await results from comparative studies, I do plan to consider utilizing this technique on a case-by-case basis.

Publication History

Article published online:
17 December 2020

• References

• 1 Binmoeller KF, Shah JN. A novel lumen-apposing metal stent for transluminal drainage of nonadherent extraintestinal fluid collections. Endoscopy 2011; 43: 337-342
• 2 Itoi T, Binmoeller KF, Shah JN. et al. Clinical evaluation of a novel lumen-apposing metal stent for endosonography-guided pancreatic pseudocyst and gallbladder drainage (with videos). Gastrointest Endosc 2012; 75: 870-876
• 3 Gulati R, Rustagi T. Endoscopic removal and replacement of the same lumen-apposing metal stent for multiple endoscopic necrosectomy sessions. Endoscopy 2021; 53: 71-74
• 4 Chandrasekhara V, Topazian M, Abu Dayyeh BK. et al. Re-deployment of a dislodged lumen-apposing metal stent (LAMS): avoiding the sacrificial LAMS. Endoscopy 2018; 50: E233-E234
• 5 Guarner-Argente C, Colan-Hernandez J, Concepcion-Martin M. et al. Replacement of the same lumen-apposing metallic stent for multiple necrosectomy sessions. Endoscopy 2015; 47: E447-E448
• 6 Puli SR, Graumlich JF, Pamulaparthy SR. et al. Endoscopic transmural necrosectomy for walled-off pancreatic necrosis: a systematic review and meta-analysis. Can J Gastroenterol Hepatol 2014; 28: 50-53
• 7 Sharaiha R, Tyberg A, Khashab MA. et al. Endoscopic therapy with lumen-apposing metal stents is safe and effective for patients with pancreatic walled-off necrosis. Clin Gastroenterol Hepatol 2016; 14: 1797-1803