Background
Delayed bleeding can occur after endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) in up to 15.6% of cases. Current hemostatic methods to minimize delayed bleeding risk have limitations. Epinephrine injection effect is transient. Excessive electrocoagulation may cause thermal damage or perforation. The location and the size of lesions may not permit use of endoclips or endoscopic suturing after endoscopic resection. A self-assembling peptide (SAP; PuraStat ®; 3D Matrix Ltd, France) gel can be used as a hemostatic agent, which is applied as transparent, viscous gel via an endoscopic catheter (Figure 1). This study aims to evaluate the efficacy and safety of the peptide gel for prevention of delayed bleeding after large endoscopic resections.
Methods
A retrospective observational study was conducted at 8 institutions. It included large endoscopic resections for which SAP gel was applied. Clinical and technical data were collected. Primary outcomes were technical success (successful application of SAP gel), clinical success (no bleeding post procedure at 30 days), and adverse events.
Results
210 patients were included with median follow up of 3 months. Descriptive data are in Tables 1 and 2. Mean age was 64+12 years. 111 patients were male (53%) and 99 patients were female (47%). 92 patients were ASA III and 3 patients were ASA IV. 32 patients (15%) were on anticoagulation. Mean size of the lesion was 4.09+2.53 cm, mean defect size was 16.3+27.8 cm2, and mean volume of SAP gel used was 3.54+1.24 ml, and mean volume of SAP per cm2 was 1.03+4.56. There were 6 ampullectomies, 67 ESD, 124 EMR, and 13 Hybrid ESD/EMR. The largest resected lesion was ESD of a 15 cm rectal adenocarcinoma, which did not bleed post-procedure. Technical success rate was 100% (210/210). Clinical success was 92.38% (194/210). 16 patients (7.62%) had bleeding after mean of 4.6+5.2 days after procedure requiring endoscopy to achieve hemostasis and 5 patients required blood transfusions (2%). The mean age of those who bled was 69+8 years. 9 patients (56%) were ASA III and 4 patients (25%) were on anticoagulation. The mean size of resected lesion was 4.26+1.48 cm with defect size of 19.6+11.9cm2, mean volume SAP gel use of 3.9+1.4 ml, with mean amount of SAP gel per cm2 of 1.09+4.75. There were no treatment related adverse events or deaths.
Conclusion
Delayed bleeding can occur in up to 15.6% of all EMR or ESD cases with proportionally higher risk for larger resections. This study demonstrates safety and efficacy of using SAP gel to reduce delayed bleeding risk after large endoscopic resections. This is the largest North American study on the use of SAP gel for prevention of delayed bleeding after large endoscopic resections and we eagerly await accruing more data from other participating centers to further validate these findings in future studies.

Figure 1. Demonstration of the application of the self-assembling peptide gel. Left photo shows application to gastric ESD defect along the incisura. Right photo shows application to a 10 cm circumferential esophageal ESD defect site. The transparent gel is easy to apply with a supplied catheter and does not obscure the view.
Table 1. Patient Characteristics
Table 2. Procedure Details, Technical and Clinical Success, and Adverse Events