Predictors of response to intra-arterial vasodilatory therapy of non-occlusive mesenteric ischemia in patients with severe shock: results from a prospective observational study

Background: Non-occlusive mesenteric ischemia (NOMI) is a life-threatening condition occurring in patients with shock and is characterized by vasoconstriction of the mesenteric arteries leading to intestinal ischemia and multi-organ failure. Although minimal invasive local intra-arterial infusion of vasodilators into the mesenteric circulation has been suggested as a therapeutic option in NOMI, current knowledge is based on retrospective case series and it remains unclear which patients might benefit. Here, we prospectively analyzed predictors of response to intra-arterial therapy in patients with NOMI. Methods: This is a prospective single-center observational study to analyze improvement of ischemia (indicated by reduction of blood lactate > 2 mmol/l from baseline after 24 h, primary endpoint) and 28-day mortality (key secondary endpoint) in patients with NOMI undergoing intra-arterial vasodilatory therapy. Predictors of response to therapy concerning primary and key secondary endpoint were identified using a) clinical parameters as well as b) data from 2D-perfusion angiography and c) experimental biomarkers of intestinal injury. Results: A total of 42 patients were included into this study. At inclusion patients had severe shock, indicated by high doses of norepinephrine (NE) (median (interquartile range (IQR)) 0.37 (0.21-0.60) μg/kg/min), elevated lactate concentrations (9.2 (5.2-13) mmol/l) and multi-organ failure. Patients showed a continuous reduction of lactate following intra-arterial prostaglandin infusion (baseline: (9.2 (5.2-13) mmol/l vs. 24 h: 4.4 (2.5-9.1) mmol/l, p 2 mmol/l at 24 h following intervention. Initial higher lactate concentrations and lower NE doses at baseline were independent predictors of an improvement of ischemia. 28-day mortality was 59% in patients with a reduction of lactate > 2 mmol/l 24 h after inclusion, while it was 85% in all other patients (hazard ratio 0.409; 95% CI, 0.14-0.631, p = 0.005). Conclusions: A reduction of lactate concentrations was observed following implementation of intra-arterial therapy, and lactate reduction was associated with better survival. Our findings concerning outcome predictors in NOMI patients undergoing intra-arterial prostaglandin therapy might help designing a randomized controlled trial to further investigate this therapeutic approach. Trial registration Retrospectively registered on January 22, 2020, at clinicaltrials.gov (REPERFUSE, NCT04235634), https://clinicaltrials.gov/ct2/show/NCT04235634?cond=NOMI&draw=2&rank=1 . Keywords: Intestinal failure; Non-occlusive mesenteric ischemia; Sepsis; Shoc

Out of sight for the endoscopist? Gastrointestinal bleeding after aortic repair

Background and study aim: Secondary Aortoenteric Fistulas (sAEF) are difficult to diagnose and usually result in fatal gastrointestinal (GI) bleeding following aortic repair. Outcomes are largely dependent on a timely diagnosis, but AEFs remain challenging to identify endoscopically and are usually diagnosed on computed tomography (CT) scans. The aim of our study was optimize diagnosis of AEF by identifying patients developing GI bleeding after aortic repair, investigate their clinical course and identify factors specific to different bleeding sources. Methods: A retrospective, single-center study capturing all patients developing upper or lower GI bleeding after aortic surgery between January 2009 and March 2020 was performed. Electronic health records were screened for diagnostic codes of the relevant procedures. Bleeding was classified into three groups: AEF with demonstrable fistula, ischemic - macroscopic ulceration plus histological confirmation or imaging and "other" due to other recognized conventional cause, such as peptic ulcer disease. Results: 47 GI bleeding episodes in 39 patients were identified. Of these, 10 episodes (21%) were caused by AEF, 16 (34%) by ischemic ulceration and 21 (45%) due to other causes. Patients with AEF exhibited more frequent hemodynamic instability requiring vasopressors and had higher mortality, while ischemic ulcerations were associated with more recent operation or hypotensive episode. Conclusions: GI bleeding complications are uncommon following aortic surgery. AEF and ischemic ulceration are however frequent bleeding causes in this cohort. In patients presenting with fulminant bleeding, primary CT-scanning should be considered. Keywords: Aortoenteric Fistula (AEF); gastrointestinal bleeding; ischemic ulceration; aortic repair; endoscopy

Non-occlusive mesenteric ischemia (NOMI): evaluation of 2D-perfusion angiography (2D-PA) for early treatment response assessment

Purpose!#!To evaluate the feasibility of 2D-perfusion angiography (2D-PA) for the analysis of intra-procedural treatment response after intra-arterial prostaglandin E1 therapy in patients with non-occlusive mesenteric ischemia (NOMI).!##!Methods!#!Overall, 20 procedures in 18 NOMI patients were included in this retrospective case-control study. To evaluate intra-procedural splanchnic circulation changes, post-processing of digital subtraction angiography (DSA) series was performed. Regions of interest (ROIs) were placed in the superior mesenteric artery (SMA; reference), the portal vein (PV; ROI!##!Results!#!Vasodilator therapy leads to a significant decrease of the 2D-PA-derived values PD!##!Conclusion!#!2D-PA offers an objective approach to analyze immediate flow and perfusion changes following vasodilatory therapies of NOMI patients and may be a valuable tool for assessing treatment response