What is Endo Spray and How Does It Stop GI Bleeding?

October 7, 2025 •

4 min read

Acute upper gastrointestinal bleeding (UGIB) has an incidence of approximately 67 per 100,000 people and accounts for about 300,000 hospitalizations annually in the U.S. [1.8.2, 1.8.3]. So, what is Endo Spray? It is a type of hemostatic powder used to control this bleeding.

Quick Summary

Endo Spray refers to a class of medical devices that deliver a proprietary mineral powder to control gastrointestinal bleeding. The most studied brand, Hemospray, stops bleeding by forming a mechanical barrier over the bleed site.

Key Points

What it is: Endo Spray is a hemostatic powder, like Hemospray, delivered via an endoscope to control GI bleeding [1.2.3].
Mechanism: The powder absorbs water from blood to form a mechanical barrier over the bleeding site, stopping blood flow [1.6.5].
High Success Rate: It achieves initial hemostasis in over 95% of cases, often within minutes [1.2.1].
Key Advantage: Its main benefits are ease of use, ability to cover large bleeding areas, and a non-traumatic application [1.6.1, 1.7.4].
Primary Limitation: A significant rate of re-bleeding (around 20-27%) is a major concern, often requiring follow-up treatment [1.2.1, 1.9.3].
Regulatory Status: Hemospray was granted marketing permission by the FDA in 2018 for non-variceal GI bleeding [1.5.5].
Best Use Cases: It is especially useful for diffuse bleeding, bleeding from tumors, and as a stabilizing 'bridge' to more definitive therapy [1.7.2, 1.7.4].

The Challenge of Gastrointestinal Bleeding

Gastrointestinal (GI) bleeding is a common and serious medical emergency, leading to significant morbidity and mortality [1.2.3, 1.5.1]. Upper GI bleeding (UGIB), occurring from the mouth to the ligament of Treitz, is more common than lower GI bleeding (LGIB) [1.8.3]. The causes are varied, including peptic ulcers, esophagitis, tumors, and complications from endoscopic procedures [1.2.3, 1.8.1]. Standard treatment involves endoscopic hemostasis, where a gastroenterologist uses tools like clips, thermal probes, or injections to stop the bleeding [1.2.3]. However, these methods can be challenging in certain situations, such as with diffuse bleeding, bleeding from tumors, or in anatomically difficult locations [1.4.2, 1.7.4]. These challenges have driven the development of novel technologies like endoscopic hemostatic powders.

What is Endo Spray? A Closer Look at Hemospray

"Endo Spray" is a broad term for hemostatic powders applied during an endoscopy. The most prominent and widely studied product in this category is Hemospray (TC-325), manufactured by Cook Medical [1.2.3, 1.3.3]. It is a single-use device that consists of a delivery catheter and a canister containing a proprietary, inert, inorganic mineral powder propelled by compressed carbon dioxide [1.3.2, 1.6.5].

Hemospray received FDA marketing permission in the United States in May 2018 for treating non-variceal GI bleeding in both the upper and lower GI tract [1.2.1, 1.5.5]. This made a new, non-thermal, non-traumatic, and non-contact treatment option available to clinicians in the U.S., where it was already in use in Europe and Canada since 2011 [1.2.5, 1.5.3].

How Does It Work?

The mechanism of action for Hemospray is primarily mechanical [1.6.1].

Application: The powder is delivered in short bursts through a catheter passed through the working channel of an endoscope [1.3.2, 1.6.5]. It is applied from a distance of 1-2 cm from the bleeding source [1.6.2].
Absorption and Adhesion: When the powder contacts blood or fluid, it rapidly absorbs water [1.3.2].
Barrier Formation: This absorption process causes the powder to swell, forming a cohesive and adhesive gel-like layer that covers the bleeding site [1.3.2, 1.5.1].
Hemostasis: This layer acts as a mechanical barrier, staunching the blood flow [1.6.5]. It also appears to concentrate platelets and clotting factors at the site, which may help activate the natural coagulation cascade [1.3.2, 1.3.3].

The resulting coagulum remains in place for approximately one to three days before it naturally sloughs off and is eliminated from the GI tract [1.2.2, 1.3.1]. The powder itself is not metabolized or absorbed by the body [1.3.2].

Clinical Applications and Efficacy

Hemospray is indicated for a variety of non-variceal GI bleeding sources, including peptic ulcers, malignancies, and post-procedural bleeding (e.g., after a polypectomy) [1.3.3]. Its ability to cover a large, diffuse area makes it particularly useful for bleeding from tumors or large ulcers where precise targeting with a clip or probe is difficult [1.2.4, 1.7.4].

Clinical studies have shown high rates of success in achieving initial hemostasis. The FDA review noted that Hemospray stopped bleeding within five minutes in 95% of patients [1.2.1]. A meta-analysis involving 1280 patients found a technical success rate of 97% and a clinical success rate of 91% [1.4.4, 1.9.2].

Comparison of Hemostatic Techniques

Hemospray offers a different approach compared to traditional endoscopic methods.


Feature	Endo Spray (Hemospray)	Traditional Therapy (Clips, Cautery)
Mechanism	Mechanical barrier, absorbs water, concentrates clotting factors [1.3.2, 1.6.5].	Mechanical ligation (clips) or thermal coagulation to seal vessels [1.2.3].
Application	Non-contact, aerosol spray covers large areas [1.6.1].	Requires precise, direct contact and targeting of the bleeding vessel [1.4.2].
Ease of Use	Considered easier to apply, especially for non-experts and in difficult locations [1.4.2, 1.7.1].	Requires a higher level of endoscopic skill and precision [1.4.2].
Tissue Trauma	Non-traumatic, as no direct force is applied [1.6.1].	Risk of thermal injury (cautery) or mechanical trauma [1.6.1].
Initial Success	Very high rates of achieving initial hemostasis (95-97%) [1.2.1, 1.9.2].	High, but can be difficult for diffuse or inaccessible bleeds [1.4.2].
Re-bleeding Rate	A notable concern, with rates around 20-27% reported in various studies [1.2.1, 1.4.5, 1.9.3].	Varies by lesion, generally around 12-20% [1.4.1].

Benefits and Limitations

Advantages:

Ease of Use: Can be deployed quickly by endoscopists with basic skills, making it valuable in emergency situations or facilities with less expertise [1.2.5, 1.7.3].
Broad Coverage: Effective for large, diffuse bleeding surfaces like tumors where other methods fail [1.7.4].
Non-Traumatic: Being a non-contact, non-thermal method, it avoids further tissue injury [1.6.1].
Bridge to Definitive Therapy: It can be used to stabilize a patient, allowing for a subsequent, planned endoscopy to apply more durable treatment [1.7.2, 1.7.3].

Limitations and Risks:

Re-bleeding: The primary concern is the rate of re-bleeding, which can be high as the powder sloughs off after a few days [1.7.3, 1.9.3]. This may necessitate a "second-look" endoscopy for definitive treatment [1.7.3].
Obscured Visualization: The applied powder coats the mucosa, which can obscure the view for any immediate follow-up therapy during the same procedure [1.2.5, 1.7.3].
Adverse Events: Though rare, serious side effects have been reported, including bowel perforation (approx. 1% of patients) and a risk of gas embolism [1.2.1, 1.7.1]. It is contraindicated in patients with known gastrointestinal fistulas [1.2.1].

Conclusion

Endo Spray, exemplified by Hemospray, represents a significant advance in the management of gastrointestinal bleeding. It provides a rapid, easy-to-use, and effective method for achieving initial hemostasis, particularly in challenging bleeding scenarios. While a meta-analysis showed it has a higher likelihood of achieving primary hemostasis compared to standard care, clinicians must remain vigilant about the risk of re-bleeding and consider its role often as a bridge to more definitive, durable therapies [1.4.2, 1.7.3]. Its availability provides a crucial tool in the gastroenterologist's armamentarium for managing this life-threatening condition.

For more information from a regulatory perspective, you may visit the FDA's announcement on Hemospray. [1.2.1]

Frequently Asked Questions

Hemospray is the brand name for the most widely studied type of endoscopic hemostatic powder, often referred to generically as 'Endo Spray' [1.2.3, 1.3.3]. Other hemostatic powders exist, but Hemospray (TC-325) is the most prominent.

It is applied through a catheter passed through an endoscope during a procedure. A CO2 canister propels the powder in short bursts onto the bleeding site without direct contact [1.6.1, 1.6.5].

The procedure is performed during an endoscopy, for which patients are typically sedated. The application of the powder itself is non-traumatic and does not cause pain or thermal injury to the tissue [1.6.1, 1.6.2].

The mechanical barrier formed by the powder and clotted blood typically sloughs off and is passed from the body within 1 to 3 days [1.2.2, 1.3.1]. This is why there is a risk of re-bleeding once the barrier is gone.

The most common concern is re-bleeding after the initial hemostasis [1.7.3]. Rare but serious side effects can include bowel perforation (about 1% risk) and potential for gas embolism [1.2.1, 1.7.1].

The FDA approved it for non-variceal upper and lower gastrointestinal bleeding [1.5.2]. While some studies have explored its use in variceal bleeding, this is often considered a contraindication by the manufacturer due to safety concerns [1.2.2].

Frequently, yes. Because of the risk of re-bleeding once the powder matrix dissolves, many clinicians use Hemospray as a temporary measure to stabilize a patient and will perform a 'second-look' endoscopy to apply a more durable treatment like clips [1.7.3].