Angiographic embolization for the treatment of lower gastrointestinal bleeding

1. Angiographic embolization for the treatment of lower gastrointestinal bleeding Donald Baril Team IV Conference July 9, 2004

2. Case report - W.H. 76 yo M with past medical history of BPH and melanoma and known diverticulosis Transferred from an outside hospital with lower gastrointestinal bleeding Transfused 5U PRBC at outside hospital (Hct 26?35) Outside hospital colonoscopy - diverticulosis with no active bleeding; EGD - no pathology

3. Case report - W.H. Transferred to SICU Hemodynamically stable Continued to have hematochezia with dropping hematocrit (35 ? 22) and was transfused an additional 9U PRBC over the following 3 days Bleeding scan localized source to the cecum and ascending colon Proceeded to angiography and embolization

4. SMA angiogram

5. Selective SMA and ileocolic angiogram

6. Selective ileocolic angiogram with coil deployment

7. Post-embolization angiogram

8. Case report - W.H. Tolerated regular diet Hematocrit remained stable Discharged home on post-procedure day #3

9. Lower gastrointestinal bleeding Annual incidence of 25 per 100,000 patients Gastrointestinal bleeding accounts for 2% of all hospital admissions Lower gastrointestinal bleeds account for approximately ¼ of all patients admitted with gastrointestinal bleeding Incidence of bleeding increases with age Bleeding spontaneously ceases in 80% of cases Mortality rates of 10-15%

10. Etiology of lower gastrointestinal bleeding Adolescents and children Inflammatory bowel disease, polyps, Meckel’s diverticulum Adults < 60 Diverticular disease, neoplasms, inflammatory bowel disease Adults > 60 Diverticular disease, angiodysplasia, neoplasms

11. Etiology of lower gastrointestinal bleeding Diverticular disease - most likely cause of LGIH in adults 30 and 40 % Arteriovenous malformations 1 to 4 percent Diverticular disease - most likely cause of LGIH in adults 30 and 40 % Arteriovenous malformations 1 to 4 percent

12. Diverticular disease Present in 66% of patients older than 80 years Diverticuli form at the site where the vasa recta penetrate the muscular wall of the colon 10-20% of patients with diverticular disease will experience bleeding Right-sided diverticli have a higher incidence of bleeding

13. Diagnostic/Therapeutic options - Colonoscopy May be therapeutic (cauterization, injection of vasoconstricting agents, placement of hemostatic clips) Complete evaluation requires bowel preparation Often limited visualization in the presence of ongoing bleeding

14. Diagnostic options - Tagged red blood cell scanning Technetium-99 labeled red blood cell scanning detects 90% of active gastrointestinal bleeds May detect bleeding at a rate of 0.1ml/min Scanning is performed continuously over 2 hours Radiotracer remains active for 48 hours Should not be used alone to determine the location of a segmental resection If positive, patient should proceed to angiography

15. Tagged red blood cell scanning

16. Angiography and embolization Initially attempted in the mid-1970s During the 1980s, selective vasopressin infusion became the endovascular therapy of choice Re-emerged as a leading therapy in the early 1990s with the advent of microcatheters, torqueable guidewires and high-resolution angiographic equipment Currently, no prospective studies to evaluate the outcomes of angiographic embolization and no consensus on optimal post-embolization care Angiography remains the gold standard for the diagnosis of lower gastrointestinal bleeding (detects 0.5-1mL/min)

17. Mechanism of embolization Goal of embolization is to decrease perfusion pressure enough to stop hemorrhage but not to a level of complete devascularization Embolization materials decrease perfusion pressure and induce local vasospasm Allows for the patient to more effectively form clot Superselective placement less important in the upper gastrointestinal tract given the rich collateral supply

18. Typical arterial access via femoral or brachial artery 5 French catheter is used to select a first-order vessel (IMA or SMA) Microcatheter (2.5 to 3 French) may then be advanced to the marginal artery or vasa recta?“superselective catheterization” Angiographic embolization

19. Embolic agents Gelfoam Sterile gelatin sponge Insouble in water, pourous Temporary and allows for vessel recanalization in days to weeks Polyvinyl alcohol particles Incites intraluminal thrombosis with an associated inflammatory reaction Gross appearance similar to sand Microcoils Constructed from platinum Biocompatible but highly thrombogenic

20. Microcoils

21. Embolization outcomes Overall success rates of 70 to 100% Ischemic complications range from 0 to 20% Bowel necrosis requiring surgical intervention is less than 10%

22. Embolization outcomes - DeBarros et al. DCR 2002 27 patients: Diverticulosis - 22, AVM - 5 100% initial technical success with cessation of bleeding 22.2% rebleeding rate 5/6 patients who rebled underwent surgery 2 patients developed postembolization ischemia; 1 required operative intervention All patients had follow-up within one year and none demonstrated any evidence of ischemia (including stricture formation) on colonoscopy

23. Embolization outcomes - Kuo et al. JVIR 2003 22 patients: Diverticulosis - 7, Neoplasm - 5 100% initial technical success with cessation of bleeding 14% rebleeding rate All patients who rebled underwent colonoscopy with subsequent control of the bleeding 1 patient developed postembolization ischemia which was treated conservatively

24. Limitations of superselective embolization Unable to diagnose and treat patients who are not actively bleeding Target vessel may not be accessible due to atherosclerotic occlusive disease or vasospasm Bleeding from a surgical anastamosis should be a relative contraindication given the limited collateral blood supply

25. Vasopressin - Past its prime? Vasopressin Infusion leads to successful cessation of bleeding in 80% of cases Does not require superselective catheterization Bowel infarction is extremely rare Side effects reversible with cessation of infusion Infusion requires only a single 5 Fr catheter Requires ICU monitoring Infusion time may be greater than 24 hours Rebleeding rates of up to 50% Side effects include coronary vasoconstriction, arrhythmias, and bowel infarction

26. Control of LGIH with vasopressin

27. Conclusions Angiographic embolization is a relatively safe and effective procedure for patients with LGI bleeding Hemostasis achieved by angiographic embolization may be definitive therapy and, at least, allows for semi-elective operative resection Given superselective embolization, the risk of significant post-procedure ischemia is quite low Unknown if routine immediate post-procedure colonoscopy is of value Unknown long-term risks for rebleeding