The endoscopic gluing technique using the Cyanoacrylate Super Glue. In the following teaching video, we will describe the endoscopic gluing technique using the cyanoacrylate superglue. We will focus on the most common indication of its use, the treatment of bleeding gastric varices. The endoscopic treatment of gastric varices is an example in the history of modern medicine that is riddled with discovery, skepticism, rejection. The first paper describing the use of cyanoacrylate to treat gastric varices was described by Sahendra in 1986. 25 years later, it is accepted and routinely practiced globally with the exception of in the United States. Bleeding from gastric varices has a mortality of 30%. Indeed, endoscopy can be diagnostic and life-saving. The Practice Guidelines Committee of the American Association for the Study of Liver Diseases and the Practice Parameters Committee of the American College of Gastroenterology state that cyanoacrylate injection, if available, is the preferred treatment of bleeding gastric fundal varices and that transjugular intrahepatic portosystemic shunts is for bleeding fundal varices that cannot be controlled or for bleeding fundal varices that recur despite combined pharmacologic and endoscopic therapy. Both of these recommendations are made with a Class I grade, meaning that there is evidence and general agreement that a given diagnostic evaluation, procedure, or treatment is beneficial, useful, and effective. And it is assigned a Level B grade, meaning that the data is derived from a single randomized trial or non-randomized studies. Glue injection has also been studied for the purpose of prophylaxis of gastric variceal bleeding. The most recent randomized controlled trial showed that patients with gastric varices who were treated with cyanoacrylate had significantly lower bleeding incidence as well as bleeding-associated mortality compared to those treated with a non-selective beta blocker or with nothing. Prevention of gastric variceal bleeding can be accomplished, reducing the complications and the mortality from bleeding. In comparison, banding gastric varices has been shown to be ineffective and has a high bleeding rate. An essential difference between esophageal varices and gastric varices is their position in the gastrointestinal wall. Esophageal varices form in the lamina propria mucosa and submucosa, whereas gastric varices lie deep in the submucosa under the gastric mucosa, which is relatively thick compared with that of the esophagus. Looping gastric varices is equally difficult and ineffective. Cyanoacrylate is a plastic polymer that immediately hardens with blood or salt, including the varix. In the following teaching video, we will focus on the readily available cyanoacrylate glue, the preparation of the glue for the injection of gastric varices, the injection technique of the glue into the gastric varices, the injection technique of the glue into complex esophageal varices, the complications of cyanoacrylate glue injection, and other endoscopic uses of cyanoacrylate glue, such as to seal fistulas. A variety of cyanoacrylate glues are available. It is important to note the specific type, as they are not the same and exhibit different properties, particularly in the speed of polymerization. For example, N-butyl-2 cyanoacrylate, with trade names of histoacryl, indermyl, etc., has a fast rate of polymerization, whereas 2-octyl cyanoacrylate, with trade names of dermabond or surgiceal, has a slower rate of polymerization. The type of glue is thus important to ensure proper technique. We use straight indermyl glue injection, meaning without oil. It rapidly polymerizes, thus potentially reducing the most dreaded complication of glue injection, that of massive embolism. The recent randomized controlled trials have also used straight glue injection. In the United States, cyanoacrylate is FDA approved for the treatment of cerebral aneurysm, but in Europe it is approved to treat gastric varices. Knowing the risk of bleeding when evaluating gastric varices is important. This involves understanding the varic's location, shape, and stigmata. As such, SARIN has proposed a classification that categorizes gastric varices based on their location. Isolated gastric varices, IgV1, located in the fundus, have the highest incidence of bleeding, and gastroesophageal varices, GoV2, are the most common, with the second highest bleeding incidence. The shape of the varic is also related to the risk of bleeding. The nodular shape has the highest risk. A red spot on the surface confers almost a two-fold risk of bleeding, and a fibrin clot is an ominous sign of recent bleeding. Gastric varices have high flow bleeding. As such, endoscope selection is of utmost importance in order to optimize the visualization and subsequent treatment. For example, a mega-channel gastroscope can dramatically increase suction ability. As shown here, the maximum fluid suction when using a six-millimeter channel therapeutic gastroscope is over six-fold higher when compared to a double-channel or single-channel therapeutic scope. The six-millimeter channel can suction over one liter a minute compared to the 200 milliliters a minute for the other gastroscopes. We have cyanoacrylate readily available in our endoscopy unit. It is distributed by central supply, not by pharmacy, and we store it in our unit refrigerator at 4 degrees Celsius. At the time of a bleeding case, we immediately prepare the glue at the bedside. For gastric varices, we prepare 1 cc in a 3 cc syringe, and for esophageal varices, we prepare 0.5 cc aliquots in a 3 cc syringe. We also prepare two 3 cc syringes of sterile water for each syringe of glue. The preparation of the glue and the endoscope are shown in the following videos. Here we have estimated that the patient will need perhaps about two injections, so I will prepare three syringes of Indermil and about four syringes of water. So we draw it, each one of them is 0.5 cc. So we will draw three syringes full, and we will draw the water. Because the needle may get clogged with its injection, we will have on the bedside three needles ready. We will just put some inside the accessory channel, and then we will use a Q-tip to go around and into the channel. Gastric varices causes massive bleeding, leading to significant morbidity and mortality. Thus, endoscopy should be performed in a controlled setting, with adequate patient resuscitation with blood and fluids, as well as intubation of the patient. The don'ts of the technique of cyanoacrylate glue injection of gastric varices must be underscored. An endoscopic ultrasound is rarely needed. Focus treatment on the visible varix and its associated stigmata. Fibrin clot is stigmata of bleeding. Don't wash the clot. Dislodgement can precipitate recurrent bleeding and obscure visualization for treatment. Choose your point of injection and stay there. Always be prepared and make sure the needle is stable. It is important to maintain a stable needle, and avoid creation of a defect due to withdrawal of the needle prior to glue injection, or a lacervation of the varix due to unnecessary movement. Glue injection at or too close to the fibrin clot may dislodge it and precipitate active bleeding. Similarly, direct puncture of the varix with the needle catheter through the fibrin clot or mucosal defect is not advised. One-hand retroflexion is critical for safe and effective glue injection of fundal varices. As you can see, use of a two-handed retroflexion technique creates an unstable scope position for therapy, and you would not have a free hand to control the needle catheter. We will now outline an illustration of the use of one-hand retroflexion. We will now outline and illustrate the proper technique of cyanoacrylate glue injection of gastric varices. Again, the one-hand retroflexion technique is critical for safe and effective glue injection of fundal varices. For optimal retroflexion, the small dial is maximally turned right, and the large dial is maximally turned up. With antiflex injection of glue, the use of a cap, a distal translucent attachment device, can facilitate the stability of injection by keeping the targeted cardiac varix in view. Direct the injection intra-variceal, a few millimeters away from the bleeding stigmata. Stable scope handling is critical. One-hand retroflexion technique is also critical. Using straight glue, you can see that it rapidly polymerizes when mixed with blood. Thus, the speed of injection is vital to the success of the technique. If you inject too quickly, the glue will embolize. And if you inject too slowly, the glue will harden within the needle. It requires the team to understand where the glue is at all times. We have prepared a trajectory that we are going to send our needle to. So needle out. Needle is out. And we are going to inject. So I'm injecting glue into the needle. Needle is out. And now I'm going to flush the glue with water, slowly. I'm injecting. I've injected a half of the needle. I'm injecting. I've injected a half a CC of water. I'm injecting slowly. I've injected 1.2 CC of water. The glue should be into the varic. Okay, so keep flushing. Keep flushing. Okay. Keep flushing hard. Needle back. Needle back. Here is the technique of glue injection and animation. Use a sclerotherapy needle 25 gauge with a 5 millimeter tip. Use water in a small syringe. Measure the dead space of the needle, usually 1 to 1.5 CC. Flush the needle with water. Then switch the syringe to a 3 CC syringe of glue. Always put only 1 CC of glue per syringe. Puncture the varic. The first injection is actually to place the glue into the sclerotherapy needle. So 1 CC of glue will be pushed into the sclerotherapy needle. Then switch to the water syringe. And then inject steadily the water using approximately the same amount of water as the dead space of the needle. Don't inject excessively as it may push the glue and embolize it. Once the glue is injected, pull the needle out of the varic. Pull the needle out of the varic. Repeated injections of 1 CC of glue may be necessary in cases where there is active bleeding or hemostasis that has not been achieved. Always repeat the injection until hemostasis is achieved. The key is to use only 1 CC of glue per injection at a time. The injection technique is again demonstrated in this case. Okay. Pull back now, Tanya. Pull back. Pull back now. Pull back. Okay. Good. Needle down. Needle down. Okay. One injection is done. We are now going to check. Glue is being infused. Slowly. Being infused. Being infused. Pull needle back. Needle is going to come out. Needle is out. Glue it in the... Glue it in the needle. We are injecting. Injecting. Push the pin into the needle. Okay. Injecting. Injecting. Needle back. Pull back. When active bleeding is encountered, mechanical hemostasis using endoscopic clips can serve as a temporary measure while preparing for the glue injection. Ten minutes following the clip placement, glue injection is performed to treat the bleeding varices. We'll target the injection a few millimeters away from the mucosal defect. The needle is deeply punctured into the varix. And the standardized glue injection technique is then followed. We standardly reassess the varix for repeat injection within the first week of treatment. Minor bleeding can occur after glue injection. Bleeding typically ceases as the glue solidified and forms a thrombus. There are times when the needle appears slightly stuck in the varix. As in this case, this technique to withdraw the needle when stuck in the varix is illustrated in the following schematic. First, if this occurs, do not panic. Simply bring the endoscope closer to the varix. Pull the needle catheter against the endoscope. Continue to pull the needle catheter against the endoscope. And ultimately, free the needle from the varix. It is critical to assure that the entire varix has been glued, otherwise recurrent bleeding may occur as the glue is being extruded. During the first session, glue is injected as much as possible to obturate the gastric varix. Because re-bleeding typically occurs early, we perform that second session within a week of the initial session. Patients are then followed at 2, 6, and 12 months. Patients are given clear liquids for 1 or 2 days post-glue injection. Glue is not water-soluble and does not get degraded by the body. This is important to remember. With time, the glue is completely extruded out of the varix as it's obturated. Not all gastric varices are amenable to glue injection. Diffuse, not isolated gastric varices, as shown here, are not candidates for glue therapy. Cyanoacrylate glue injection can also treat esophageal varices. In this case, the patient was life-flighted from an area hospital due to massive esophageal variceal bleeding that was refractory to band ligation due to scarring, as well as to sclerotherapy. On our endoscopy, we immediately clip the bleeding site to temporize the bleeding while preparing for glue injection. Into the varix, we injected 0.5 cc's of glue. We injected a second site. was seen, and the patient had no recurrent bleeding. Glue to treat esophageal varices should be considered in cases of complex varices, massive bleeding, failed band ligation, or in patients with contraindication to tips. In this case, the varices in the distal esophagus appeared to form from a network rather than from a single column. Glue was injected at 0.5 cc aliquots in the treatment of the esophageal varices. A second site is punctured, and the glue is again injected into the varix. 0.5 cc aliquots are repeated until the varix is obturated. The complications of glue injection have been well studied. The less than 1% risk of embolization of cyanoacrylate glue for gastric varices is the complication most feared by U.S. endoscopists. Notably, the risk of death alone during admission for gastric variceal bleeding is up to 30%. Embolization can be associated with several factors. When the glue volume is too large, when the glue injection is too fast, when the glue polymerization is too slow, all of these factors can lead to systemic migration of the glue. Cyanoacrylate glue has been used to close fistulas, just like in this case of a patient who developed an esophageal pleural fistula after an esophagectomy and gastric pull-up. The glue is seen being injected into the opening and hardening. In this case, however, the fistula reopened after the glue is extruded. By being plastic, the glue did not allow tissue to develop a permanent seal at the fistula's opening. Endoscopic gluing technique using the cyanoacrylate superglue has been well described to treat gastric variceal bleeding. We hope that this self-educational program has been useful in providing illustrations of the standardized injection technique of cyanoacrylate superglue.

endoscopic gluing technique

Cyanoacrylate Super Glue

bleeding gastric varices

injection techniques

embolization prevention

esophageal varices