Acute limb ischemia in elderly patients: can iloprost be useful as an adjuvant to surgery? Results from the ILAILL study

Acute aortic occlusion: A narrative review for emergency clinicians

INTRODUCTION

Acute aortic occlusion (AAO) is a rare but serious condition associated with significant morbidity and mortality.

OBJECTIVE

This review provides an emergency medicine focused evaluation of AAO, including presentation, assessment, and emergency department (ED) management based on current evidence.

DISCUSSION

AAO refers to obstruction of blood flow through the aorta due to either thrombosis or embolism. This condition primarily affects older adults ages 60-70 with cardiovascular comorbidities and most commonly presents with signs and symptoms of acute limb ischemia, though the gastrointestinal tract, kidneys, and spinal cord may be affected. The first line imaging modality includes computed tomography angiography of the chest, abdomen, and pelvis. ED resuscitative management consists of avoiding extremes of blood pressure or heart rate, maintaining normal oxygen saturation and euvolemic status, anticoagulation with heparin, and pain control. Emergent consultation with the vascular surgery specialist is recommended to establish a plan for restoration of perfusion to ischemic tissues via endovascular or open techniques. High rates of baseline comorbidities present in the affected population as well as ischemic and reperfusion injuries place AAO patients at high risk for complications in an immediate and delayed fashion after surgical management.

CONCLUSIONS

An understanding of AAO can assist emergency clinicians in diagnosing and managing this rare but devastating disease.

The relation between neutrophil/lymphocyte and platelet/lymphocyte ratios with mortality and limb amputation after acute limb ischaemia

OBJECTIVE

Acute limb ischaemia is still considered a significant event, with considerable early- and long-term amputation and mortality risk. Our study aims to investigate the predictive role of pre-operative neutrophil/lymphocyte and platelet/lymphocyte ratios in terms of mortality and amputation risk in patients with acute limb ischaemia.

METHODS

Pre-operative blood samples of all patients admitted with acute limb ischaemia were used to calculate neutrophil/lymphocyte and platelet/lymphocyte ratios. Population was subdivided into quartiles by platelet/lymphocyte ratio and neutrophil/lymphocyte ratio values, and Kaplan-Meier life tables were obtained for overall survival and limb salvage. The optimal neutrophil/lymphocyte ratio and platelet/lymphocyte ratio cut-offs were obtained from receiver operating characteristic curves with all-cause mortality and all kinds of amputation. Stepwise multivariate analysis was performed in order to identify independent risk and protective factors for mortality and amputations.

RESULTS

A total of 168 patients were included in the analysis. Receiver operating characteristic curves identified cut-off values for neutrophil/lymphocyte ratio and platelet/lymphocyte ratio: neutrophil/lymphocyte ratio ≥5.57 for mortality; neutrophil/lymphocyte ratio ≥6.66 and platelet/lymphocyte ratio ≥269.9 for all amputations. Kaplan-Meier analysis revealed that survival rate in group neutrophil/lymphocyte ratio <5.57 was 83.4%, 78.9%, 73.7%, and 59.8%, respectively, at 12, 24, 36, and 48 months; in neutrophil/lymphocyte ratio ≥5.57 group was 62.4%, 51.3%, 47.8, and 43.7%, respectively (p < 0.0001). Freedom from all amputations was significantly higher in case of neutrophil/lymphocyte ratio and platelet/lymphocyte ratio below the identified cut-off values (p < 0.0001). Neutrophil/lymphocyte ratio and platelet/lymphocyte ratio were found as independent risk factors.

CONCLUSION

Neutrophil/lymphocyte ratio and platelet/lymphocyte ratio are reliable markers for stratification of mortality and limb amputations in patients with acute limb ischaemia. The inexpensive nature and ready availability of these biomarkers' values reinforced their usefulness in everyday clinical practice.

Severe mesenteric traction syndrome is associated with increased systemic inflammatory response, endothelial dysfunction, and major postoperative morbidity

This study aimed to determine if mesenteric traction syndrome (MTS) triggers increased systemic inflammation and endothelial cell dysfunction. Patients developing severe MTS had pronounced early IL6 elevations followed by endothelial cell damage. Furthermore, these processes were associated with increased postoperative morbidity.

OBJECTIVE

To determine whether mesenteric traction syndrome (MTS) leads to increased systemic inflammation and dysfunction of the glycocalyx and endothelial cell and whether this correlates with the degree of postoperative morbidity.

INTRODUCTION

Severe MTS is associated with increased postoperative morbidity following major gastrointestinal surgery, but the pathophysiological mechanism has not been previously explored. Systemic inflammatory response and impaired glycocalyx and endothelial cells may be responsible for the development of symptoms.

METHODS

The study analyzed prospectively collected data from two cohorts (n = 67). The severity of the MTS response was graded intraoperatively and blood samples for PGI₂, catecholamines, IL6, and endothelial biomarkers obtained at predefined time points.

RESULTS

Patients undergoing either esophagectomy (n = 45) or gastrectomy (n = 22) were included. Surgery led to significantly increased plasma concentrations of all biomarkers. Yet, patients who developed severe MTS had higher baseline epinephrine levels (p < 0.05) and higher levels of PGI₂ (p < 0.05), Syndecan-1 (p < 0.001), and sVEGFR1 (p < 0.001). Peak values of IL6, Syndecan-1, sVEGFR1, and sTM all correlated to peak PGI₂. Lastly, patients with high postoperative morbidity had higher baseline epinephrine (p = 0.009) and developed higher plasma IL6 (p = 0.007) and sTM (p = 0.022).

CONCLUSION

The development of severe MTS during upper gastrointestinal surgery is associated with preoperative elevated plasma epinephrine and further a more pronounced proinflammatory response and damage to the vascular endothelium. The increased postoperative morbidity seen in patients with severe MTS may thus, in part, be explained by an inherent susceptibility towards an inappropriate secretion of PGI₂, which leads to an increased surgical stress response and endothelial damage. These findings must be confirmed in a new prospective cohort.

Evaluation of Clinical Outcomes After Revascularization in Patients With Chronic Limb-Threatening Ischemia: Results From a Prospective National Cohort Study (RIVALUTANDO)

We evaluated the outcomes of revascularization in patients with chronic limb-threatening ischemia (CLTI) treated in real-world settings. This is a prospective multicenter cohort study with 12-month follow-up enrolling patients (n = 287) with CLTI undergoing open, endovascular, or hybrid lower extremity revascularization. The primary end point was amputation-free survival (AFS) at 12 months. Cox proportional analysis was used to determine independent predictors of amputation and restenosis. At 30 days, major adverse cardiovascular and major adverse limb events (MALE) rates were 3.1% and 2.1%, respectively. At 1 year, the overall survival rate was 88.8%, the AFS was 86.6%, and the primary patency was 70.5%. Freedom from MALE was 62.5%. After multivariate analysis, smoking (hazard ratio [HR] = 2.2, P = 0.04), renal failure (HR = 2.3, P = 0.03), Rutherford class (≥5) (HR = 3.2, P = 0.01), and below-the-knee disease (HR = 2.0, P = 0.05) were significant predictors of amputation; iloprost infusion (>10 vials) (HR = 0.64, P = 0.05) was a significant protective factor. Cilostazol administration (HR = 0.77, P = 0.05) was a significant protective factor for restenosis. Results from this prospective multicenter registry offer a consistent overview of clinical outcomes of CLTI patients at 1 year when adequately revascularized. Medical treatment, including statins, cilostazol and iloprost, were associated with improved 1-year freedom from restenosis and amputation.

Prostanoids for Critical Limb Ischemia: A Clinical Review and Consideration of Current Guideline Recommendations

For many years, the only pharmacological option for patients with critical limb ischemia (CLI) unsuitable for revascularization has been prostanoids; however, some recent guidelines have become very restrictive regarding their use. We review the available evidence on the use of prostanoids and analyze the guideline positions as well as the possible reasons for changes over time. In most placebo-controlled trials and meta-analyses, prostanoids showed a significant effect in improving rest pain, promoting ulcer healing and reducing major amputations. Results for iloprost were especially consistent. Different prostanoid drugs have different evidence of efficacy, thus using a generic term "prostanoids" is misleading. Unfortunately, the available evidence is often of low quality and probably not sufficient to support an extensive use of prostanoids in all patients, and further high-quality randomized trials are needed. Consequently, some recent guidelines do not recommend treatment with prostanoids in this setting. However, in our opinion, pending definitive evidence, patients with CLI who have a viable limb in whom revascularization is unfeasible or has a poor chance of success, without alternative to amputation, may benefit from treatment with iloprost, balancing harms and benefits in each case.

The effect of intraoperative and 6-h postoperative intravenous administration of low-dose prostacyclin on the endothelium, hemostasis, and hemodynamics in patients undergoing a pancreaticoduodenoctemy: a randomized-controlled pilot study

BACKGROUND

Capillary leakage, secondary to endothelial breakdown, is common in patients undergoing major surgical procedures with extensive tissue injury and this is associated with increased morbidity and mortality. Prostacyclin has been ascribed cytoprotective properties together with its vasodilatory and antiplatelet effects. The present pilot study investigated the safety and endothelial protective effects of low-dose prostacyclin infusion.

PATIENTS AND METHODS

A randomized placebo-controlled pilot study evaluating the effect of prostacyclin (iloprost) infusion (1.0 ng/kg/min) versus placebo (saline infusion) intraoperatively and 6 h postoperatively in patients undergoing a pancreaticoduodenoctemy was carried out. Hemodynamics were evaluated by Nexfin, hemostasis was evaluated by thrombelastography, and transfusion requirements were registered. Endothelial damage was evaluated by circulating sE-selectin, soluble thrombomodulin, and nucleosomes.

RESULTS

Comparable baseline demography and surgical time were found. Hemodynamics were comparable between groups. The placebo group received more red blood cells, median 115 ml [interquartile range (IQR): 0-296 ml] versus 0 ml (IQR: 0-0 ml), P=0.027, at the postoperative ward and after 6 h. Thrombelastography maximum clot firmness decreased intraoperatively only in the placebo group (P=0.034)). Soluble thrombomodulin increased more in the placebo group postoperatively [1.63 ng/ml (IQR: 0.65-2.55 ng/ml) versus 0.40 ng/ml (IQR: 0.21-0.63 ng/ml), P=0.027] and 6 h postoperatively [1.83 (1.1-2.36) versus 0.67 (0.42-0.91), P=0.027]. Nucleosomes increased intraoperatively and postoperatively only in the placebo group; thus, the overall level of nucleosomes was higher in the placebo group (P=0.019).

CONCLUSION

Intraoperative and postoperative low-dose prostacyclin infusion is safe and associated with reduced endothelial cell damage in patients undergoing a pancreaticoduodenoctemy compared with those receiving placebo.

Comparison of hyperbaric oxygen versus iloprost treatment in an experimental rat central retinal artery occlusion model

PURPOSE

Central retinal artery occlusion (CRAO) is one of the serious ophthalmological emergencies with poor visual prognosis. Iloprost is a stable prostacyclin analogue and has prominent anti-edema, anti-inflammatory, vasodilatory, and antiagregant effects. The main objective of this work was to investigate iloprost as an alternative agent versus hyperbaric oxygen (HBO) in the treatment of CRAO.

METHODS

Twenty-eight healthy Wistar albino male rats were randomly assigned into control (n = 7, sham operation), HBO (n = 7), iloprost (n = 7), and sham groups (n = 7). CRAO model was created through optic nerve exploration and ligation. Full-thickness retina (FTR), outer nuclear layer (ONL), inner nuclear layer (INL) and ganglion cell layer (GCL) thickness were measured on Hematoxylin/Eosin (H&E) stained retinal sections and immunohistochemical analysis including terminal deoxynucleotidyl transferase-mediated biotindeoxyuridine triphosphate nick-end labeling (TUNEL) assay was performed to determine the apoptotic index (AI).

RESULTS

AI values of HBO (0.204 ± 0.067) and iloprost (0.197 ± 0.052) groups were significantly lower than sham (0.487 ± 0.046) group (p < 0.001). Any significant difference was found between the HBO and iloprost groups in terms of AI (p = 0.514). A statistically significant increase in thickness of FTR, ONL, INL and GCL was detected in HBO, iloprost and sham groups compared to the control group (p = 0.002). FTR, ONL, INL and GCL thickness were significantly thinner in HBO and iloprost groups than in the sham group (p = 0.002). A significant lesser increase was observed in all the retinal layers thickness in iloprost group versus HBO group (p = 0.002) except for INL (p = 0.665).

CONCLUSIONS

The study results demonstrated anti-edema, neuroprotective, and anti-apoptotic effects of iloprost quantitatively; thus, iloprost may be a beneficial alternative agent in the treatment of CRAO.

Successful treatment of jellyfish sting-induced severe digital ischemia with intravenous iloprost infusion

Jellyfish sting-induced vasospasm and vasculitis is a rare complication that could lead to severe digital ischemia and gangrene. We report a 39-year-old woman with severe pain in her right middle, ring, and little fingers after being stung by a jellyfish. Therapy was initiated with a course of intravenous iloprost infusion and subcutaneous low-molecular-weight heparin, with successful revascularization. Our case illustrates that although emergency transfer to a vascular center is ideal, even in a delayed setting, patients can still benefit from specialist vascular care with a combination of medication and iloprost treatment, with acceptable functional outcome.

Endothelial progenitor cells (EPCs) in ageing and age-related diseases: How currently available treatment modalities affect EPC biology, atherosclerosis, and cardiovascular outcomes

Endothelial progenitor cells (EPCs) are mononuclear cells that circulate in the blood and are derived from different tissues, expressing cell surface markers that are similar to mature endothelial cells. The discovery of EPCs has lead to new insights in vascular repair and atherosclerosis and also a new theory for ageing. EPCs from the bone marrow and some other organs aid in vascular repair by migrating to distant vessels where they differentiate into mature endothelial cells and replace old and injured endothelial cells. The ability of EPCs to repair vascular damage depends on their number and functionality. Currently marketed drugs used in a variety of diseases can modulate these characteristics. In this review, the effect of currently available treatment options for cardiovascular and metabolic disorders on EPC biology will be discussed. The various EPC-based therapies that will be discussed include lipid-lowering agents, antihypertensive agents, antidiabetic drugs, phosphodiesteraze inhibitors, hormones, as well as EPC capturing stents.

Iloprost reduces myocardial edema in a rat model of myocardial ischemia reperfusion

OBJECTIVE

Myocardial ischemia severely reduces myocyte longevity and function. Extensive interstitial edema and cell damage occur as a result of myocardial reperfusion injury. Current therapies are directed at prevention of ischemia-induced damage to cardiac tissue. Iloprost is a novel pharmaceutical agent for the treatment of ischemia.

METHODS

Twenty rats were segregated into four experimental groups. The procedure control group consisted of four rats undergoing a sham operation. The remaining 16 rats were divided into two equal groups. The first group (control group) received a continuous intravenous infusion of physiological serum immediately prior to the procedure. Iloprost was administered by a continuous intravenous infusion into the right jugular vein at an infusion rate of 100 ng/kg/min for 30 minutes prior to reperfusion in the experimental group (study group). Following the infusion treatments, ligation of the left coronary artery was conducted for 30 minutes to induce myocardial ischemia. The rats were euthanized 24 hours after reperfusion and cardiac tissue was harvested from all specimens for analysis.

RESULTS

Histological examination revealed three myocardial tissue specimens with grade II damage and five myocardial tissue specimens with grade III reperfusion injury in the control group. However, the study group consisted of two grade III myocardial tissue specimens, five grade II myocardial tissue specimens and one grade I myocardial tissue specimen. Moreover, a statistically significant reduction in myocardial edema was observed in the study group (p=0.022).

CONCLUSION

Our results support the hypothesis that iloprost enhances protection against cardiac ischemia reperfusion injury. This protective effect may be associated with vasodilation, antioxidant or anti-edema mechanisms.

Therapeutic effect of liposomal prostaglandin E1 in acute lower limb ischemia as an adjuvant to hybrid procedures

Prostaglandin E₁ (PGE₁) is widely used in the treatment of limb ischemia for its potent vasodilatory and antiplatelet effects. In order to assess the curative effect of liposomal PGE₁ (lipo-PGE₁) as an adjuvant to surgery in patients with acute lower limb ischemia (ALLI), 204 patients who underwent hybrid procedures (operative thromboembolectomy or bypass and necessary endovascular interventions) for ALLI were randomly divided into a blank control group and a lipo-PGE₁ group (intravenous infusion of 20 μg/day for 12–14 consecutive days following surgery). Patients were followed-up for 6 months after surgical revascularization for clinical events. The primary study endpoint, which was the combined incidence of perioperative (30 days) mortality (POM) and major adverse limb events (MALE; amputation or major intervention), was significantly reduced in patients treated with lipo-PGE₁ (5.1% compared with 13.2% in the control group). The overall incidence of clinical events, including POM, MALE and major adverse cardiovascular events, was significantly reduced in patients receiving lipo-PGE₁ (8.2%) compared with the controls (20.8%). Hybrid procedures are an improved method for treating ALLI and may remedy underlying lesions of vessels following thromboembolectomy.

Femorofemoral bypass as an alternative to a direct aortic approach in daily practice: appraisal of its current indications and midterm results

BACKGROUND

To assess our current practice concerning the indications and the immediate and midterm results of femorofemoral bypass.

METHODS

We retrospectively included all patients, from 1997 to 2008, operated on for aortoiliac occlusive disease using an extra-anatomical bypass from a donor iliac artery or a femoral artery to the contralateral femoral artery (common or profunda artery). Demographic data, initial clinical status, characteristics of the interventions, and short- and midterm results were collected. Elective surgery was distinguished from urgent surgery (critical limb ischemia, acute ischemia, vascular infection).

RESULTS

One hundred twenty-four femorofemoral bypasses were performed (103 male), mean age 68 (±12) years. Indications were critical limb ischemia (47.1%), intermittent claudication (38.8%), acute ischemia (12.1%), and vascular infections (1.7%). Perioperative outcomes were 5.6% mortality (elective surgery 0.0%, urgent surgery 9.7%, P = 0.02) and 27.4% morbidity without any secondary graft infections (elective surgery 22.5%, urgent surgery 31.9%, P = 0.17). Mean follow-up period was 3 years, and overall survival was 69.4% (elective surgery 88.7%, urgent surgery 56.7%, P = 0.08). At 3 years, primary patency was 81.8% and secondary patency was 89.3% (elective surgery 96.4%, urgent surgery 84.2%, P = 0.68). No significant risk factors for immediate and secondary thromboses were found.

CONCLUSION

In our current practice, femorofemoral bypasses are applied mainly for urgent procedures when avoiding a direct aortic approach is mandatory, with good midterm results. Although indications are limited for good-fit patients, femorofemoral bypass has confirmed safety (no perioperative deaths, no infections) and high durability (good secondary patency).

Evaluation of iloprost to prevent vasospasm in coronary artery bypass grafts

This study assessed the efficacy of iloprost in relieving vasospasm in coronary artery bypass grafts. Radial artery (RA), left internal thoracic artery (LITA) and saphenous vein (SV) grafts were taken from 20 patients (13 men and seven women, mean age 63.8 years [range 48-74 years]) scheduled to undergo coronary artery bypass grafting. Ten 3 mm vascular rings were cut from each graft and kept under tension for at least 60 min. They were kept alive with 37 degrees C oxygenated Krebs solution. Smooth muscle contraction was achieved with phenylephrine before iloprost was administered every 2 min, starting at a concentration of 10(-9) mol/l and increasing in logarithmic increments to a concentration of 10(-5) mol/l. The vasodilation response to iloprost started in all samples at a concentration of 10(-9) mol/l and increased with each incremental increase in iloprost concentration up to 10(-5) mol/l. These data suggest that local administration of iloprost has a role in relieving graft vasospasm during harvesting and preparation for coronary artery bypass grafting.