高リスク患者における内視鏡的スクラルファート噴霧によるポリペクトミー後遅発性出血の予防：無作為化比較試験

Colonoscopic polypectomy is a key procedure for prevention of colorectal cancer and reduction of associated mortality risk. However, this procedure carries a risk of postpolypectomy bleeding. Postoperative bleeding can occur immediately (intraoperatively, manageable during colonoscopy) or after a while (for example, a month after colonoscopy). The causes of delayed postpolypectomy bleeding include detachment of eschar due to stool passage and extension of submucosal necrosis due to hot snare polypectomy. The incidence rate of delayed postpolypectomy bleeding ranges from 1% to 2%; this rate increases to 6% in patients with large (> 2 cm) colon polyps. Risk factors for this complication include hot snare polypectomy, chronic kidney disease, liver cirrhosis, antiplatelet agent or anticoagulant use, and pedunculated colon polyps. Delayed postpolypectomy bleeding is a major complication that requires prompt management. Patients with delayed bleeding usually present with hematochezia, anemia, hemodynamic instability, or end-organ damage. Hemostasis often requires repeated colonoscopic procedures and hospitalization, which increases patient discomfort and treatment costs. In complex cases, emergent surgical intervention or transarterial embolization may become necessary. Therefore, the prevention of delayed postpolypectomy bleeding is crucial for both patients and clinicians.

Sucralfate, a basic aluminum salt of sucrose octa sulfate, has been used in the treatment of gastrointestinal ulcers; this powder accelerates healing and prevents bleeding. The mechanisms underlying its effects involve binding to exposed proteins on damaged cells and creating a protective layer that shields the mucosa from further injury. Sucralfate can also bind to growth factors and thus promote angiogenesis and mucosal healing. Pharmacodynamic insights have suggested that local application of sucralfate is more effective in promoting wound healing than systemic administration, likely because of its ability to locally adhere to damaged mucosa, forming a sticky coating that accelerates healing.

Liquid sucralfate has demonstrated healing efficacy in endoscopic mucosal resection-induced gastric ulcers. Rectosigmoid ulcer lesions can also be treated with topical sucralfate by enema. In radiation proctitis and idiopathic ulcerative proctitis, sucralfate enemas produced clinical and endoscopic improvement. Compared to the drug powder, we think the liquid formulation would soon drain away from the wound. Therefore, we assume that the local application of sucralfate powder to polypectomy wounds would effectively prevent delayed postpolypectomy bleeding.

In our preliminary data of a pilot study (IRB: A-BR-111-085, ClinicalTrials.gov ID: NCT05817656), a total of 160 patients with polyps (size≥0.5cm) who had undergone colonoscopic polypectomy were enrolled. divided into the sucralfate and control groups (80 per group). After polypectomy, the patients received standard treatment for immediate bleeding. Then, they were randomly allocated to either a sucralfate group (prophylactic spraying of 3g sucralfate powder on polypectomy wounds) or a control group. As a result, the rate of delayed postpolypectomy bleeding (0% vs 6.3%, respectively; P=0.029) and postpolypectomy overt bloody stool (2.4% vs 18.8%, respectively; P=0.001) were lower in the sucralfate group than in the control group. The duration of freedom from delayed bleeding was longer in the sucralfate group than in the control group (P=0.024). Colonoscopic spraying of sucralfate powder is a safe approach with potential to reduce the risk of delayed postpolypectomy bleeding among the general population.

However, whether this method can be applied to high-risk polyps were indetermined, such as large polyps > 1cm under hot snare polypectomy, especially in those who take antiplatelets or anticoagulants. Moreover, the prophylactic potency comparison between sucralfate spray and prophylactic clips was also unknown. Therefore, a head-to-head comparison between sucralfate powder and clipping is needed to identify the preventative potency.