par Ibrahim, Mostafa 
Président du jury McEntee, Kathleen
Promoteur Devière, Jacques
Co-Promoteur Arvanitakis, Marianna
Publication Non publié, 2020-02-26
Président du jury McEntee, Kathleen
Promoteur Devière, Jacques
Co-Promoteur Arvanitakis, Marianna
Publication Non publié, 2020-02-26
Thèse de doctorat
| Résumé : | Acute variceal bleeding (AVB) is the most dramatic complication of portalhypertension. It occurs in one-third of cirrhotic patients with varices and causes70% of all upper gastrointestinal (GI) bleeding episodes in cirrhotic patientsresulting in major morbidity and mortality despite improvements in primaryprophylaxis and management of acute bleeding episodes over the past threedecades. The best strategies for management of AVB have been investigated innumerous clinical trials and this has led to multiple guidelines. Endoscopicmanagement combined with pharmacotherapy is the ideal strategy to controlvariceal bleeding, but this can be challenging. Bleeding may be difficult to identifyor may occur from sites that are difficult to approach. A trained multidisciplinaryteam consisting of endoscopists, hepatologists, and specialized nurses as well asinterventional radiologists is required to administer the ideal treatment for AVB.However, this setup is not available everywhere. Early management of AVB ismandatory within 24 hours of admission and better outcomes are reported in thosepatients who receive endoscopic therapy within 12 hours. Although this is stillcontroversial, it seems to be increasingly obvious that earlier hemostasis leads tobetter outcomes.In practice, treatment for AVB is often delayed by a lack of expert endoscopists.Therefore, having a simple endoscopic hemostatic technique that does not requirean experienced team could have a major impact on AVB management.Hemospray powder (Hemospray, TC-325; Cook Medical Inc., Winston-Salem, NC,USA) is an FDA-approved organic powder made from a proprietary mineral blend.The material works in two different ways: as a mechanical barrier and byabsorption. When in contact with the bleeding site, the powder forms a barrier over6the vessel wall, quickly stopping the bleeding. In addition, the absorbent powderincreases the local concentration of clotting factors and enhances clot formation.Previous studies described Hemospray as a simple and feasible new modality forobtaining rapid hemostasis of peptic ulcer bleeding during gastrointestinalendoscopy, either as primary treatment or as a salvage indication.The work presented here evaluated the safety, feasibility, clinical efficacy, andpotential outcome benefits of applying this hemostatic powder early in themanagement of AVB, as a potential new clinical indication. We have performedour research in three phases, starting with a safety study on AVB that originatedfrom esophageal varices and two case reports on portal hypertension-relatedbleeding. This was followed by an efficacy study and then we confirmed our datain a randomized controlled study where we observed a potential impact on survival,opening the door to additional clinical investigations.The aim of the research was to investigate the concept of treating portalhypertension-related AVB with early endoscopic hemostasis using a novelhemostatic powder which can be applied without the need for a skilled team.We showed that this easy-to-perform technique, in a novel indication, is indeed safeand effective when added to the gold standard of care for AVB and can improveendoscopic and clinical hemostasis, providing easier elective treatment with lessneed for experienced teams. An effect on mortality was also observed in therandomized controlled study as a secondary outcome measure.The next step is to design a study focused on survival, perhaps with a simplifieddesign in which the spraying catheter can be used without the need for endoscopyor sedation. Another interesting future investigation will be to design a study thatcompares two groups with early powder application that are randomized within 247to 48 hours either to elective endoscopic treatment or a transjugular intrahepaticportosystemic shunt (TIPS) procedure. This would allow us to learn whether thisnew therapeutic approach impacts the need for early TIPS placement in severe casesof AVB. |
