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

A Case of Non-occlusive Mesenteric Ischemia with Massive Hepatic Portal Venous Gas Treated Conservatively

Non-occlusive mesenteric ischemia (NOMI) is caused by ischemia and necrosis of the intestinal tract without organic obstruction of the main mesenteric artery. Accordingly, in many cases, resection of the ischemic intestinal tract is performed to save the life of the patient. However, conservative treatment has also been reported in some cases. Arterial vasodilator therapy using angiography is considered the gold standard for NOMI treatment. However, for facilities without capacity for angiography, conservative management is needed. Herein, we report a case of NOMI in an 85-year-old woman hospitalized for an odontoid process fracture. On post-admission day 14, the patient developed acute onset of epigastric pain, with evidence of hepatic portal venous gas (HPVG) on computed tomography (CT) abdominal imaging. In the absence of peritoneal irritation and findings suggestive of intestinal necrosis on blood tests, combined with the risk of cervical cord injury with intubation for surgery, we initiated continuous intravenous administration of prostaglandin E1 (PGE1, 0.01 μg/kg/min) on the same day of symptom onset, achieving resolution of epigastric pain on the next day. PGE1 administration was continued to day 5 after symptom onset, with no worsening of symptoms after PGE1 discontinuation. Blood tests showed no deterioration (Fig. 1). The patient was discharged on day 63. Continuous intravenous infusion of PGE1 for NOMI may be an option for the conservative treatment of early onset or no intestinal necrosis-associated NOMI.信州医学雑誌 72(5) : 271-276, (2024)journal articl

Influencing the macro- and microcirculatory complications of nonocclusive mesenteric ischemia by complement C5a inhibitor treatments

Nonocclusive mesenteric ischemia (NOMI) can develop in the absence of apparent anatomical obstruction of the mesenteric circulation in a variety of low flow states. The pathophysiology of NOMI is unexplored, the early diagnosis is challenging and the available treatments are of questionable effectiveness. In this respect, new experimental models are sought to clarify the exact pathomechanisms and new, effective therapeutic ways are needed to reduce the increasingly high mortality. Our first aim was to develop clinically relevant in vivo models to investigate the macro- and microcirculatory effects of NOMI. Also, we hypothesized the role of complement activation in the acute and subacute consequences of NOMI and our objectives were to characterize the effects of the inhibition of complement protein known as C5a during this condition. Acetyl-peptide-A (AcPepA) is an antisense-homology box-derived peptide, which is capable to inhibit the C5a effects by binding directly to the anaphylatoxin. We hypothesized that the inhibition of C5a can decrease the intensity of inflammatory reactions and in parallel, to normalize the impaired mesenteric circulation. Acute experimental pericardial tamponade (PT) was established in anesthetized minipigs, while partial aorta occlusion (PAO) was induced in rats to investigate the circulatory and inflammatory changes of NOMI in clinically relevant time frames. After the relief of PT, elevated levels of oxidative stress markers and inflammatory mediators were detected in association with the signs of diminished splanchnic microcirculation. 24 hours after PAO the macrocirculatory parameters improved significantly, while the intramural microcirculation was significantly impaired and accompanied by increased leukocyte infiltration. The in vivo histology confirmed the structural and microvascular damage of the mucosa. In both animal models of NOMI, the administration of AcPepA moderated the hemodynamic changes, improved the intramural microcirculation, reduced the inflammatory activations and the histological signs of mucosal damage. In conclusion we can say that our newly developed animal models provide a cross section for events in the short and long time frames and proved to be suitable for the investigations of the pathophysiology of NOMI. The hemodynamic changes in the acute PT together with those observed after PAO suggest that complement activation plays central role in the early and late macro- and microcirculatory disturbances during NOMI. The results suggest that C5a inhibitor treatment influences favourably the hemodynamic effects and reduces the potentially harmful inflammatory activation after experimental NOMI as well

Acute mesenteric ischemia : updated guidelines of the World Society of Emergency Surgery

Acute mesenteric ischemia (AMI) is a group of diseases characterized by an interruption of the blood supply to varying portions of the intestine, leading to ischemia and secondary inflammatory changes. If untreated, this process may progress to life-threatening intestinal necrosis. The incidence is low, estimated at 0.09-0.2% of all acute surgical admissions, but increases with age. Although the entity is an uncommon cause of abdominal pain, diligence is required because if untreated, mortality remains in the range of 50%. Early diagnosis and timely surgical intervention are the cornerstones of modern treatment to reduce the high mortality associated with this entity. The advent of endovascular approaches in parallel with modern imaging techniques is evolving and provides new treatment options. Lastly, a focused multidisciplinary approach based on early diagnosis and individualized treatment is essential. Thus, we believe that updated guidelines from World Society of Emergency Surgery are warranted, in order to provide the most recent and practical recommendations for diagnosis and treatment of AMI.Peer reviewe