Disseminated intravascular coagulopathy in aortic aneurysms

Disseminated Intravascular Coagulation Post Endovascular Aortic Repair

BACKGROUND

Disseminated Intravascular Coagulation (DIC) after Endo-Vascular Aneurysm Repair (EVAR) is a highly uncommon clinical entity. With only a few case-reports available, its management strategy still remains enigmatic.

OBJECTIVES

The purpose of this study was to retrieve, synthesize, and appraise all existing data for DIC after EVAR.

MATERIALS AND METHODS

All published articles regarding DIC post-EVAR were identified from 3 major databases and analyzed. Clinical parameters, predisposing factors, along with mortality and morbidly were assessed.

RESULTS

The total number of publications included in the review was 15 describing 17 cases. DIC presented with a broad spectrum of clinical manifestations, while the time of diagnosis varied significantly. Endoleak was the main causative factor, with an incidence reaching 71%. The mortality of DIC after EVAR reached 29%, regardless of the therapeutic approach chosen. DIC was treated effectively in 47% of the patients (8/17), with better outcomes among patients who received conservative therapy or among those who were submitted to endovascular interventions.

CONCLUSIONS

DIC after EVAR, although rare, is a potentially lethal clinical condition which requires prompt diagnosis and urgent medical consideration. Treatment of endoleak may help in quick restoration of normal parameters.

Thrombosis in the pathogenesis of abdominal aortic aneurysm

Background

Abdominal aortic aneurysms (AAAs) are a relatively common vascular pathology of the elderly with high morbidity potential. Irreversible degeneration of the aortic wall leads to lethal rupture if left untreated. Nearly all AAAs contain intraluminal thrombus (ILT) to a varying degree, yet the mechanisms explaining how thrombosis is disturbed in AAA are relatively unknown. This review examined the thrombotic complications associated with AAA, the impact of thrombosis on AAA surgical outcomes and AAA pathogenesis, and the use of antithrombotic therapy in the management of this disease.

Methods

A literature search of the PubMed database was conducted using relevant keywords related to thrombosis and AAAs.

Results

Thrombotic complications are relatively infrequent in AAA yet carry significant morbidity risks. The ILT can impact endovascular aneurysm repair by limiting anatomic suitability and influence the risk of endoleaks. Many of the pathologic mechanisms involved in AAA development, including hemodynamics, inflammation, oxidative stress, and aortic wall remodeling, contain pathways that interact with thrombosis. Conversely, the ILT can also be a source of biochemical stress and exacerbate these aneurysmal processes. In animal AAA models, antithrombotic therapies have shown favorable results in preventing and stabilizing AAA. Antiplatelet agents may be beneficial for reducing risks of major adverse cardiovascular events in AAA patients; however, neither antiplatelet nor anticoagulation is currently used solely for the management of AAA.

Conclusions

Thrombosis and ILT may have detrimental effects on AAA growth, rupture risk, and patient outcomes, yet there is limited understanding of the pathologic thrombotic mechanisms in aneurysmal disease at the molecular level. Preventing ILT using platelet and coagulation inhibitors may be a reasonable theoretical target for aneurysm progression and stability; however, the practical benefits of current antithrombotic therapies in AAA are unclear. Further research is needed to demonstrate the extent to which thrombosis impacts AAA pathogenesis and to develop novel pharmacologic strategies for the medical management of this disease.

Platelet Count Recovery after Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

Objective: To find a new predictor of endoleak (EL) and aneurysm sac expansion after endovascular aneurysm repair (EVAR), we evaluated the platelet count recovery (PCR) process after EVAR.

Materials and Methods: Two hundred five patients treated with elective EVAR from 2007 to 2015 were retrospectively analyzed. We compared the platelet count ratio until postoperative day (POD) 7 to the presurgical baseline between patients with and without persistent EL (≥ 6 months). Subsequently, we calculated the optimal platelet count ratio for distinguishing persistent EL using receiver-operating characteristics analysis. A platelet count ratio on POD7 ≥118% was defined as the PCR. We evaluated the PCR’s influence on the cumulative aneurysm sac expansion rate.

Results: The average platelet count ratio on POD7 rose above baseline (112%), and the ratio was attenuated by persistent EL (103%). Of 205 patients, 126 (61%) were assigned to the disturbed PCR group (PCR(−) group). Cumulative aneurysm sac expansion rate was higher in the PCR(−) group than the PCR(+) group (34.4% vs. 12.8% in 5 years, p=0.01).

Conclusion: Disturbed PCR after EVAR may be associated with ELs and eventual aneurysm sac expansion.

Delayed disseminated intravascular coagulopathy post thoracic endovascular aortic repair (TEVAR)

Disseminated intravascular coagulopathy (DIC) is a very rare outcome post endovascular repair of aortic aneurysm dissections. We present a case of a 70-year-old male who presented with DIC post a thoracic endovascular aortic repair (TEVAR) procedure due to a type 1A endoleak. Initially, the patient was treated with red blood cells and blood products; however, when failing to improve, he underwent a hybrid arch replacement. In this study, we will analyze the management of DIC post TEVAR and look at its presentation more extensively, as it is currently a topic that is poorly studied.

Phospholipid membranes drive abdominal aortic aneurysm development through stimulating coagulation factor activity

Abdominal aortic aneurysm (AAA) is a disease of the abdominal aorta where inflammation causes damage and can ultimately lead to rupture. When this happens, uncontrolled internal bleeding can lead to death within minutes. Many aneurysms are not detected until they rupture, and for those that are, treatments to stop them progressing are limited. Here we used biophysics and genetically modified mice to show that a new family of lipids (fats) made by circulating blood cells promote AAA formation in the vessel wall because they directly regulate blood clotting. An approach that prevents AAA development was identified, based on intravenous administration of lipids. The studies provide insights into how AAA develops and may lead to novel therapies for this disease.

Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease with high mortality and limited treatment options. How blood lipids regulate AAA development is unknown. Here lipidomics and genetic models demonstrate a central role for procoagulant enzymatically oxidized phospholipids (eoxPL) in regulating AAA. Specifically, through activating coagulation, eoxPL either promoted or inhibited AAA depending on tissue localization. Ang II administration to ApoE^−/− mice increased intravascular coagulation during AAA development. Lipidomics revealed large numbers of eoxPL formed within mouse and human AAA lesions. Deletion of eoxPL-generating enzymes (Alox12 or Alox15) or administration of the factor Xa inhibitor rivaroxaban significantly reduced AAA. Alox-deficient mice displayed constitutively dysregulated hemostasis, including a consumptive coagulopathy, characterized by compensatory increase in prothrombotic aminophospholipids (aPL) in circulating cell membranes. Intravenously administered procoagulant PL caused clotting factor activation and depletion, induced a bleeding defect, and significantly reduced AAA development. These data suggest that Alox deletion reduces AAA through diverting coagulation away from the vessel wall due to eoxPL deficiency, instead activating clotting factor consumption and depletion in the circulation. In mouse whole blood, ∼44 eoxPL molecular species formed within minutes of clot initiation. These were significantly elevated with ApoE^−/− deletion, and many were absent in Alox^−/− mice, identifying specific eoxPL that modulate AAA. Correlation networks demonstrated eoxPL belonged to subfamilies defined by oxylipin composition. Thus, procoagulant PL regulate AAA development through complex interactions with clotting factors. Modulation of the delicate balance between bleeding and thrombosis within either the vessel wall or circulation was revealed that can either drive or prevent disease development.

Disseminated intravascular coagulopathy caused by type II endoleak after endovascular aneurysm repair in severe aortic stenosis

A 72-year-old man with severe aortic stenosis (AS) presented with a type II endoleak after endovascular aneurysm repair (EVAR). Laboratory findings were consistent with disseminated intravascular coagulopathy (DIC) with thrombocytopenia. The platelet count increased slightly after aortic valve replacement but fully recovered with the reversal of DIC after surgical repair of the type II endoleak.

Effective treatment with para-aminomethylbenzoic acid for chronic disseminated intravascular coagulation associated with aortic dissection

Chronic disseminated intravascular coagulation is a rare complication of aortic dissection. Surgical correction or low molecular weight heparin is treatment of choice, but for a severe bleeding problem due to excessive fibrinolysis, para-aminomethylbenzoic acid would be a simple and effective therapeutic approach.

In-hospital efficacy of endovascular aortic repair in patients with impending rupture versus contained rupture of abdominal aortic aneurysms

BACKGROUND

The purpose of our study was to compare the efficacy of endovascular aortic repair (EVAR) in patients with impending rupture of abdominal aortic aneurysm (IRAAA) versus contained rupture of abdominal aortic aneurysm (CRAAA).

METHODS

Of the 21 patients who underwent EVAR for infrarenal AAA from January 2009 to May 2011, 11 did so for IRAAA and 10 for CRAAA. We compared their demographic and aneurysmal characteristics, comorbidities, complications, and clinical outcomes during hospitalization.

RESULTS

The CRAAA group was younger than the IRAAA group. There were no group differences in AAA size, operation time, volume of contrast agent, length of hospital stay (LOHS), or preoperative LOHS. A small difference in mean intraoperative blood loss of ∼4 mL was noted, but was recognized as clinically insignificant. ICU stay and postoperative LOHS were greater in the CRAAA than in the IRAAA. One patient in the IRAAA group had a mild headache after EVAR. Four patients in the CRAAA group had postoperative complications: 1 had acute renal dysfunction; 1 had retroperitoneal infection; 1 had respiratory failure and myocardial infarction; and 1 died of respiratory tract infection and respiratory and cardiac failure.

CONCLUSIONS

Patients undergoing EVAR for CRAAA have a higher incidence of postprocedural severe complications and death than patients undergoing EVAR for IRAAA.

Lessons learned from a case of abdominal aortic aneurysm accompanied by unstable coagulopathy

Preoperative examination for abdominal aortic aneurysms (AAAs) occasionally reveals an abnormal decrease in coagulation factors and thrombocytopenia, fulfilling the criteria for disseminated intravascular coagulation (DIC). Treatment of the underlying disorder is indispensable for alleviating DIC. We report an uncommon case of a patient with AAA and DIC who showed prolonged thrombocytopenia despite successful treatment of AAA and temporary recovery of coagulation factors. A 70-year-old man presented with AAA and shaggy aorta accompanied by DIC and underwent aneurysmectomy. Combined preoperative use of nafamostat mesilate and recombinant human soluble thrombomodulin was effective in controlling DIC. Although recovery of coagulation factors was observed after surgery, the thrombocytopenia continued throughout the postoperative course and was refractory to platelet transfusion. Because HPA antibody and PA-IgG were present, a trial administration of γ-globulin was performed; this resulted in rapid improvement of thrombocytopenia. Although DIC recurred again 2 weeks thereafter, coagulation factors subsequently recovered without any medication.

Aortic Aneurysm–Induced Disseminated Intravascular Coagulopathy: Successful Surgical Repair

Aortic aneurysm is a rare cause of disseminated intravascular coagulopathy (DIC). We present the developmental course of DIC in a 70-year-old male patient who had a thoracoabdominal aortic aneurysm characterized by a progressive descending aortic aneurysm presenting as subcutaneous hemorrhage of acute onset. He was diagnosed as having aortic aneurysm–induced DIC. After adequate infusion of blood components, surgical repair of the descending aortic aneurysm was carried out successfully. The patient's bleeding tendency stopped dramatically in the early postoperative period as identified by clinical and laboratory findings. We concluded that the occurrence of DIC was due mainly to the progressive descending aortic aneurysm in the present patient and that surgical repair could be the definitive treatment of DIC in this setting.