In practice, bleeding from the upper GIT accounts for 70% of GIT bleeding  and ulcer disease being the most common cause . In hemodynamically unstable patients with upper gastrointestinal bleeding, intensive care is needed for patient stabilization, followed by subsequent endoscopic examination, which is a remarkably successful treatment option. In direct contrast, hemodynamically significant bleeding into the lower GIT is less common. Hemodynamic instability and insufficient bowel cleansing are relative complications of colonoscopy. Despite stabilization, colonoscopy can, in the acute phase for insufficient patient preparation, prove the possible source of bleeding in only 42% of cases . CT examination aimed at detecting GIT bleeding performed with the correct protocol can accurately detect an extravasation with a higher sensitivity compared to that in conventional angiography (0.3 ml/min vs. 0.5 ml/min) . CT examination is therefore recommended before digital subtraction angiography (DSA) in case of bleeding from the lower GIT and endoscopically non-localized bleeding from the upper GIT. Its practical implementation remains questionable in the case of localized, endoscopically untreatable bleeding from the upper GIT, when endoscopy should provide sufficient necessary information before DSA . Indications for endovascular treatment traditionally include technical failure of endoscopic treatment, recurrent bleeding despite a second endoscopic treatment and an endoscopically non-localizable source of bleeding . Contraindications to standard angiographic examination are only relative in life-threatening bleeding. The modern development of embolic material has provided various practical possibilities of proper use, according to the required properties and nature of embolization. The procedures were performed by using coils at our institution in most cases. Coils as the only embolic agent have been successfully used in several studies [7, 9 and 10]. Their advantage is precise placement, saving of the distal vasculature and the minimal risk of ischemia. Coil embolization is permanent, therefore blocking re-access to the target vessel or to its more distal branches in the future. The potential disadvantage in common is their effectiveness depends on the patient’s own blood clotting. The exclusive use of coils as the sole embolic material is naturally associated with an increased risk of recurrent bleeding in critical patients with coagulation disorders .
In our group of patients, coil embolization was performed in 12 cases and four of these patients suffered repeated bleeding. An example is the recanalization of a pseudoaneurysm of the hepatic artery in a patient with consumption coagulopathy. The pseudoaneurysm was occluded with liquid embolic material in the second treatment session. This is a certain advantage of LEAs, providing immediate hemostasis that is especially needed in hemodynamically unstable patients and vulnerable patients with coagulopathy. Several agents are available, such as n-butyl cyanoacrylate, ethylene vinyl alcohol copolymer (Onyx, Medtronic or Squid, Balt), and biocompatible polymer agents (PHIL, MicroVention). Their use has also recently proved successful in the effective treatment of GIT bleeding [11–16].
The LEA (Onyx or PHIL) was utilized solo five times and twice in the proper combination. Its local application has been technically and clinically successful without ischemic complications. Other embolic agent, e.g. a Spongostan, was carefully applied for treatment of GIT lesions exclusively. It is a temporary occlusion material, and its usage as a stand-alone embolic agent is naturally associated with increased re-bleeding rate . The Spongostan was optionally used in our cohort only once in a selected patient with a rectal tumor due to the probable risk of post-ischemic neuropathy. This patient developed re-bleeding, which was carefully managed by Onyx application, after a negative Mesocaine test, with technical and clinical success. Microparticles are considered frequent use in the embolization of bleeding tumors. In case of intestinal embolization, the use of particles with diameter larger than 500 µm is recommended because of the risk of ischemia. Ischemic complications are uncommon in the upper GIT area thanks to the extensive collateral network. To prevent the so-called backdoor bleeding in the specific case of dual arterial supply, embolization of both dominant sources is necessary. A typical example of such embolization is the so-called sandwich technique of embolization of the GDA. In our documented case of a bleeding duodenal ulcer, the right gastroepiploic artery and pancreatic arcade were embolized primary, promptly followed the proximal GDA occlusion. This is efficient technique to prevent continued bleeding through the collateral branches from the splenic artery and SMA .
The embolization is associated with a higher risk of ischemic complications in the lower GIT. Due to superselective embolization and occlusion of less than three rectal artery branches, this terrible risk is minimal .
Empirical or blind embolization refers to embolization based on endoscopic findings without confirmed extravasation during angiographic examination. This valuable method is traditionally accepted in the upper GIT bleeding, and do not differ in published results of its use compared to targeted embolization with proven hemorrhage . The empirical embolization was performed by us in two cases of refractory bleeding ulcer with technical and clinical success. The procedure can be facilitated by an endoscopically placed clip on the edge of a suspicious lesion. This helps the radiologist target the local treatment of the bleeding area (Fig. 2). Recent findings powerfully suggest the potential benefits of the preventive embolization in bleeding duodenal ulcers in patients at significant risk of recurrent blood loose .
In a published analysis that included 15 studies (a total of 829 patients) focusing on the TAE in the upper GIT bleeding, the technical success rate was 93% (62-100%), the clinical success rate was 67% (52-94%), the risk of re-bleeding was 33% (9-66%) and the 30-day mortality was 28% (4-46%) . The results of embolization from the lower GIT range with a technical success rate above 90%, a clinical favorable outcome rate of 86% and an occurrence of ischemic complications of 4-6% [22, 23].
In our study, all pathological lesions detected by angiography were treated. Notable clinical success with an acceptable re-bleeding rate of 29.6% was confirmed by our analysis, which depended significantly on the occurrence of comorbidities. In addition to the number of comorbidities, other studies have identified next risk factors for early recurrent hemorrhage, like coagulopathy, prolonged time from bleeding to angiography and a higher number of transfusions . The total 30-day mortality was 22%, and it was significantly higher in the group of patients with recurrent bleeding.