A Perspective on Cold Snaring

Gastroenterology / Cold Snaring Perspectives

Video

Watch Dr. Rex’s complete presentation and learn about his cold snaring technique.

Watch the video

The movement towards cold snaring is what Dr. Rex refers to as the “cold revolution” in polypectomy. Here, he discusses the benefits of cold snaring, and the size and types of polyps that can be resected using the cold snaring technique.

Terms: Diminutive polyps are 1 to 5 millimeters in size. Small polyps are 6 to 9 millimeters in size. Most, but not all the evidence there is about cold snaring applies to polyps that are under 1 centimeter.

Managing Complications of Hot Polypectomy

The complications of hot polypectomy are related primarily to thermal injury. When electrocautery is applied, it generally prevents immediate bleeding. However, the thermal injury may spread down into the submucosa and sometimes it injures the blood vessels in the deep submucosa, including arteries. Later as the ulceration from the cautery is healing, the eschar comes off the top of the artery and the result can be a delayed hemorrhage in some instances. A delayed hemorrhage is a much bigger problem than an immediate hemorrhage because it’s going to cause the patient in many cases to come back to the hospital where they may require admission, repeat colonoscopy, even a blood transfusion. Immediate bleeding on the other hand is something that can be dealt with during the procedure. Fortunately, with small polyps the blood vessels are very small. In my experience, it is unlikely that cold snaring would result in anything more than a trickle of blood. Getting an arterial hemorrhage from resection of a polyp under one centimeter in size is very rare.

Cold Forceps or Snares

Cold forceps and cold snares are both options when using cold techniques. Several randomized controlled trials have compared cold forceps to cold snares for diminutive polyps. These studies have shown that when polyp size reaches 4 millimeters, it is more effective to use a snare.^1,2 For polyps that are above 3 millimeters in size, using forceps means probably having to remove the tissue in a piecemeal fashion. Any time that piecemealing is done, there may be a greater chance of leaving residual polyp. In many cases, a small snare is just as easy to use as forceps even for polyps that are 3 millimeters and under in size. I almost never use cold forceps for polypectomy. Cold snares are emerging as the dominant strategy for diminutive polyps. An exception is a lesion located in the upper left endoscopic field when the lesion is difficult to reach because it’s not feasible to rotate the scope. This is often because of a loop in the scope. Under those circumstances, especially if the lesion is very flat it might be appropriate to remove it with cold forceps.

Uses for Cold and Hot Snaring

For polyps that are 6 to 9 millimeters there are a few randomized controlled trials, the largest one from Japan. In it they have shown that the rate of complete resection with cold snaring is very close to or equal to hot snaring. Therefore, based upon the results of this study, cold snaring can be seen as an effective method for small polyps and the advantage is that cold snaring reduces the risk of delayed complications in most cases.²

There could be some exceptions. In my experience, hot snaring may be suitable for the occasional 6-9 mm polyp that’s pedunculated with a thicker stalk or one that has a very prominent sessile component to it. When dealing with a large number of polyps cold snaring can be very effective and safe.³