Introduction

Gastric mucosal visibility is essential for high-quality upper gastrointestinal (GI) endoscopy. While simethicone and N-acetylcysteine (NAC) have been shown to improve mucosal visibility, the optimal time interval between preparation and endoscopy remains undefined.

Aims & Methods

This randomized controlled trial evaluated the effect of timing on mucosal visibility and explored the upper limit beyond which visibility begins to decline.
In this single-center, randomized controlled trial, adult patients undergoing elective upper GI endoscopy were randomized into four groups: placebo, simethicone + NAC with endoscopy performed after 10–20 minutes, 20–30 minutes, and >30 minutes. The primary outcome was the proportion of patients achieving adequate gastric mucosal visibility (GMV), defined as a score of <7 on a validated visibility scale. A pre-specified subgroup analysis of the >30 minute group was performed by stratifying patients into 20-minute intervals (31–50, 51–70, and 71–90 minutes) to assess the durability of mucosal clarity over time.

Results

Comparison	Adequate gastric mucosal visibility (%)	P
10–20 min vs 20–30 min	27% vs 62%	0.001
10–20 min vs >30 min	27% vs 67%	0.001
10–20 min vs Placebo	27% vs 2.6%	0.001
20–30 min vs >30 min	62% vs 67%	0.174
20–30 min vs Placebo	62% vs 2.6%	0.001

1,140 patients (median age 42years, 63.2% males) were included in the study. Adequate GMV was significantly higher in all preparation groups compared to placebo (p < 0.001). The 20–30 minute and >30 minute groups demonstrated the highest rates of adequate visibility (61.5% and 73.5%, respectively), both significantly superior to the 10–20 minute group (26.9%) and placebo (2.6%). In the >30 minute subgroup analysis, the 31–50 minute interval demonstrated the highest adequacy (73.5%). The 51–70 minute group showed moderate adequacy (52.1%), which was not significantly different from the 20–30 minute group (p = 0.207). However, the 71–90 minute group had reduced adequacy (43.8%) and did not differ significantly from the 10–20 minute group (p = 0.145). No adverse events were reported across study arms.

Conclusion

Endoscopy performed between 20 and 50 minutes after mucosal preparation yields optimal gastric mucosal visibility. A decline in visibility beyond 50 minutes suggests a practical upper limit for endoscopy timing following preparation. These findings support structured, time-sensitive scheduling following mucosal cleansing to enhance procedural quality.

Disclosure

None

Introduction

Radiation proctopathy (RP) is a common late complication of pelvic radiotherapy, affecting up to 20% of patients treated for pelvic malignancies. It manifests as rectal bleeding, anaemia, urgency, and diarrhoea, significantly reducing quality of life. Argon Plasma Coagulation (APC) remains the standard endoscopic therapy but has notable limitations, including high recurrence rates, the need for multiple sessions, and risks such as ulceration and perforation.
PuraStat, a synthetic self-assembling peptide hydrogel, offers an innovative alternative by creating a transparent matrix that promotes haemostasis and mucosal healing without thermal injury. While small series have shown benefit, robust real-world evidence is lacking.

Aims & Methods

We assessed real-world outcomes of PuraStat in RP at a UK tertiary centre (2023–2024). Consecutive patients with chronic radiation-induced rectal bleeding were included and treated by a single endoscopist. Patients were stratified into two cohorts:
1. De novo PuraStat – no prior APC (n=50)
2. APC→PuraStat – persistent or recurrent symptoms despite APC (n=50)
PuraStat was applied during flexible sigmoidoscopy, either as monotherapy or following APC. The primary outcome was resolution or improvement of rectal bleeding. Secondary outcomes included the number of repeat endoscopic interventions within 6 months and treatment-related adverse events.

Results

A total of 100 patients were included (median age: 74 years, range 64–85; 52% male). Most had prostate or gynaecological cancer treated with pelvic radiotherapy.
- De novo PuraStat (n=50): All achieved symptomatic relief, with marked bleeding reduction and endoscopic improvement. Follow-up sigmoidoscopy showed mucosal healing or mild residual proctitis in 92%. Mean repeat sessions: 1.3 (range 0–3) over 6 months.
- APC→PuraStat (n=50): These patients had undergone a median of 3 APC sessions with limited success. PuraStat led to complete symptom control in all cases, reducing the need for frequent interventions (mean: 1.5 sessions over 6 months).
No adverse events (e.g., perforation, infection, severe pain) were reported in either group. Patients with severe radiation-associated vascular ectasia (RAVE) and refractory bleeding demonstrated excellent response to PuraStat.

Conclusion

This large real-world series demonstrates that PuraStat is a safe, effective, and well-tolerated therapy for radiation proctopathy, whether used as first-line treatment or following APC failure. It provided rapid and sustained bleeding control, significantly reduced the need for repeat endoscopic interventions, and promoted mucosal healing without the risks associated with thermal therapies. Importantly, PuraStat showed consistent efficacy even in patients with severe radiation-associated vascular ectasia (RAVE) and those refractory to conventional modalities, highlighting its role as both a frontline and salvage option. These findings position PuraStat as a valuable addition to the therapeutic armamentarium for radiation-induced rectal bleeding. Larger prospective, multicentre studies and cost-effectiveness analyses are warranted to validate these results and define its optimal place in treatment algorithms.

Table 1: Treatment Outcomes by Group

Group	n	Symptom Relief	Mean Repeat Sessions
De novo PuraStat	50	100%	1.3
APC→PuraStat	50	100%	1.5

References

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