Aims
Lumen-apposing metal stents (LAMS) have transformed endoscopic management of walled-off necrosis (WON) and large pseudocysts by permitting wide, stable cyst-gastrostomy and direct necrosectomy. Current societies advise retrieval at 3–5 weeks, yet these statements are based on limited data and conflicting single-center series.
Methods
All adults who underwent trans-gastric Hot AXIOS™ placement for WON or symptomatic pseudocyst between January 2017 and March 2025 were retrospectively reviewed. The composite 30-day adverse-event (AE) endpoint captured any post-removal bleeding, migration/burial, new or recurrent fluid collection >4 cm, unplanned readmission or death. Clinical success required radiographic resolution without further intervention. Categorical outcomes were compared with Fisher’s exact test; absolute risk differences (RD) carry 95% CIs.
Results
Forty-nine patients met inclusion (median age 57 yr, IQR 48–66; 65% male). Twenty-seven had WON and 22 pseudocysts. Twelve stents were removed early, 17 in the standard window and 20 after >28 d, yielding median dwell times of 11, 21 and 47 d, respectively. Composite 30-day AEs occurred in 2/12 (16.7%) early, 9/17 (52.9%) standard and 4/20 (20%) delayed removals; RD standard–early = +36.3% (95% 4.5–68.0) and RD standard–delayed = +32.9% (3.4–62.4), whereas early and delayed differed less (–3.3%, –30.8–24.1). Bleeding was uncommon (8%) and evenly distributed, but unplanned readmissions were highest with standard timing (35.3% vs 8.3% early, 15.0% delayed). Clinical success was achieved in 10/11 early (90.9%), 12/15 standard (80.0%) and 17/17 delayed cases (100%). Multivariable analysis in 44 patients retained a non-significant but directionally consistent effect for standard removal (adjusted OR 4.95 vs early, 95% 0.67–36.3); no demographic or procedural covariate independently predicted AE. Subgroup analysis reinforced the pattern: in WON, AEs were 14.3% early, 54.5% standard and 33.3% delayed, while pseudocyst rates remained ≤25% irrespective of timing.
Table 1. Baseline Characteristics by Indwell-Time Group
|
Characteristic |
Early(n = 12) |
Standard(n = 17) |
Delayed(n = 20) |
p-value† |
|
Age, yr (mean ± SD) |
56.0 ± 13.1 |
59.0 ± 12.6 |
53.5 ± 12.8 |
0.44 |
|
Male sex, % |
83.3 % |
64.7 % |
55.0 % |
0.26 |
|
Charlson index (mean ± SD) |
2.50 ± 1.62 |
2.71 ± 1.45 |
2.45 ± 1.67 |
0.88 |
|
Stent diameter, mm (mean ± SD) |
18.2 ± 2.5 |
17.7 ± 2.6 |
15.8 ± 1.9 |
0.02 |
|
Plastic pigtail stent, % |
83.3 % |
88.2 % |
90.0 % |
0.85 |
|
Balloon dilation used, % |
91.7 % |
100 % |
100 % |
0.15 |
|
Necrosectomy sessions, median (IQR) |
2 (1-3) |
2 (1-3) |
1.5 (1-3) |
0.30‡ |
|
Collection size, cm (mean ± SD) |
13.2 ± 5.6 |
12.6 ± 5.8 |
11.5 ± 5.4 |
0.71 |
|
Pseudocyst pathology, % |
41.7 % |
23.5 % |
65.0 % |
0.17 |
†χ²/ANOVA where appropriate; ‡Kruskal–Wallis for counts.
Conclusions
In patients with large pseudocysts and WONs, removal of LAMS early (<14 days) in showed lowest AE rates when compared to “standard” (14-28 days) and delayed (>28 days) without compromising clinical success. Additionally, delayed removals also had lower AE rates when compared to standard window of removal. These findings question current LAMS removal timing and indicate that earlier removal may be safe in selected patients, warranting prospective validation.