Massive Blood Transfusion in Patients with Ruptured Abdominal Aortic Aneurysm

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Time Distribution of Mortality After Ruptured Abdominal Aortic Aneurysm Repair

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) repair is still associated with high mortality. The aim of this population-based study was to analyze the time distribution of mortality and short-term mortality trends after rAAA repair.

METHODS

This was a nationwide retrospective registry study including all patients (n = 3,927) who underwent endovascular (EVAR) (n = 935) or open surgical repair (OSR) (n = 2,992) for rAAA between 2000 and 2018. The National Patient Register was used as a source to extract patient and medical data. The register was cross-linked with the national all-cause mortality registry. The postoperative time of death was divided into <48 hours, 2 to 5 days, 6 to 10 days, 11 to 20 days, 21 to 30 days, and 31 to 90 days during the year intervals 2000-2004, 2005-2009, 2010-2014, and 2015-2018, respectively. The proportion of patients who died within each postoperative time interval was calculated.

RESULTS

The overall median age was 75.0 years (interquartile range [IQR] 69.0-80.0) and females were 19.6% (n = 769). The EVAR cohort was older (77 vs. 65 years; P < 0.001) and had significantly more cardiovascular risk factors and a history of malignancy. The overall postoperative 90-day mortality was 33.2%, EVAR 25.7%, and OSR 35.5%. There was an overall improvement in 90-day mortality over time (odds ratio [OR] 0.70; 95% confidence interval [CI] 0.57-0.87; P = 0.001) but not separately for EVAR or OSR. Analyzing all postoperative mortalities within 90 days, 43.4% of deaths occurred within 48 hours followed by 16.3% in 2-5 days. The distribution of mortality proportions in each time interval after OSR was 15.4% in < 48 hours, 7.3% in 2-5 days, 4.4% in 6-10 days, 8.6% in 11-30 days, and 6.0% in 31-90 days and after EVAR 11.1% < 48 hours, 3.6% 2-5 days, 3.1% 6-10 days, 4.6% 11-30 days, and 6% 31-90 days. The overall mortality proportions for patients who died <48 hours after aortic repair had decreased over time (P = 0.024). A logistic regression analysis found the following risk factors associated with mortality <48 hours after rAAA, open repair (OR 1.48; 95% CI 1.17-1.89; P = 0.001), female gender (OR 1.41; 95% CI 1.14-1.75; P = 0.002), and history of heart failure (OR 1.63; 95% CI 1.19-2.22; P = 0.002) or angina pectoris (OR 1.37; 95% CI 1.03-1.81; P = 0.03). The recent operative year interval, 2015-2018, was associated with a lower risk for mortality <48 hours (OR 0.72; 95% 0.53-0.98; P = 0.04) and <90-days (OR 0.63; 95% CI 0.49-0.80; P < 0.001).

CONCLUSIONS

Overall mortality after rAAA repair had decreased but early deaths remained a significant challenge. The mortality was highest within two days of surgery but the proportion of patients who died <48 hours after aortic repair had decreased in recent years. Open repair, female gender, and cardiovascular comorbidities were associated with mortality within 48 hours after surgery. More focused research in the early postoperative phase after rAAA is warranted.

Platelet protects angiotensin II-driven abdominal aortic aneurysm formation through inhibition of inflammation

BACKGROUND

Inflammation is the primary cause of abdominal aortic aneurysm (AAA) formation and development. It has been reported that platelets protect against septic shock by inhibiting inflammation. However, it is unclear whether platelets protect AAA progress via suppressing inflammation.

METHODS

A mouse model of AAA was established by a daily administration of angiotensin II (Ang II, 1000 ng/kg/min) for 28-day. The AAA mice received 1 × 10⁹ platelets transfusion in normal saline every 3rd day for 1 month. Hematoxylin and eosin, Masson's trichrome, and elastic van Gieson staining techniques were used to analyze the morphology of the abdominal aorta. Immunohistochemistry was used to detect any infiltration of inflammatory cells, inflammatory factors, and matrix metalloproteins (MMPs) in the aortic tissue. Western blot and enzyme-linked immunosorbent assay (ELISA) were used to examine the inflammatory factor proteins levels in the aortic wall and peripheral blood, respectively.

RESULTS

Platelets infusion significantly suppressed the Ang II-driven elevation of aortic diameter, AAA formation (52.38% decrease, P < 0.05), aortic expansion, elastic lamina destruction, and inflammatory response. In addition, MMP-2 and MMP-9 production were also reduced by platelets transfusion.

CONCLUSIONS

For the first time, our study reported the beneficial effect of platelet transfusion in suppressing the Ang II-driven AAA progress in mice through the inhibition of inflammation.

Systematic review of plasma/packed red blood cell ratio on survival in ruptured abdominal aortic aneurysms

BACKGROUND

The ideal perioperative fluid resuscitation for patients with ruptured abdominal aortic aneurysms (rAAAs) is unknown. It has been shown in trauma studies that a higher ratio of plasma and platelets to packed red blood cells confers a mortality benefit. Controversy remains whether this is true also in the rAAA population. The objective of the present study was to investigate the benefit of a greater ratio of plasma/packed red blood cells in patients with rAAAs.

METHODS

A health sciences librarian searched four electronic databases, including PubMed, Embase, Cochrane, and ClinicalTrials.gov, using concepts for the terms "fluid resuscitation," "survival," and "ruptured abdominal aortic aneurysm." Two reviewers independently screened the studies that were identified through the search strategy and read in full any study that was potentially relevant. Studies were included if they had compared the mortality of patients with rAAAs who had received a greater ratio of plasma to other component therapy with that of patients who had received a lower ratio. The risk of bias was assessed using the ROBINS-I (risk of bias in nonrandomized studies of interventions) validated tool, and evidence quality was rated using the GRADE (grades of recommendation assessment, development, and evaluation) profile. No data synthesis or meta-analysis was planned or performed, given the anticipated paucity of research on this topic and the high degree of heterogeneity of available studies.

RESULTS

Our search identified seven observational studies for inclusion in the present review. Of these seven studies, three found an associated decrease in mortality with a greater ratio of plasma to packed red blood cells. The remaining four found no significant differences. The overall risk of bias was serious, and the evidence quality was very low.

CONCLUSIONS

Overall, the findings from the available studies would suggest that for patients who have undergone open surgery for a rAAA, mortality tends to be decreased when the amount of plasma transfused perioperatively is similar to the amount of packed red blood cells. However, the included studies reported very low-quality evidence based solely on highly heterogeneous observational studies, and further research is warranted.

Abdominal aortic aneurysms part one: Epidemiology, presentation and preoperative considerations

An abdominal aortic aneurysm is an irreversible dilatation of the abdominal aorta. The majority of abdominal aortic aneurysms are asymptomatic and identified incidentally while investigating a separate pathology. Others are detected by national screening programmes and some present due to a growth or rupture. Symptomatic or ruptured aneurysms require urgent or emergency repair in patients fit for surgery. Perioperative practitioners should therefore be aware of how patients with abdominal aortic aneurysms present and are investigated, so that they can implement timely management. Guidelines have been recently updated to reflect this. This literature review discusses these recommendations and explores the evidence upon which they are based. The aim of this article is to highlight the important preoperative principles that need to be considered in cases of abdominal aortic aneurysm.

Patterns of blood use in Sweden from 2008 to 2017: A nationwide cohort study

BACKGROUND

Transfusion patterns in Sweden have not been characterized on a nationwide level.

STUDY DESIGN AND METHODS

We conducted a nationwide descriptive cohort study in Sweden from 2008 to 2017. Data on blood donors, donations, component manufacture, transfusions, and transfused patients were extracted from Swedish portion of the Scandinavian Donations and Transfusions (SCANDAT3-S) database.

RESULTS

A total of 708 436 patients received 5 587 684 red cell, plasma, or platelet transfusions during the study period. The age-standardized transfusion rate decreased markedly during the study period for red cell units (from 53 to 39 units/1000 persons) and plasma units (from 11 to 4.9 units/1000 persons), but remained relatively constant for platelet concentrates. The transfusion rate was 30%-40% higher in males than in females in the first year of life, and higher in males over 45 years than in females. Between age 20 and 45, the majority of red cells were transfused to female patients with obstetric indications, whereas trauma was the predominant indication for male contemporaries. In females over 80 years, the largest proportion of red cells were administered due to trauma. Overall, hematological patients received 36% of all platelet units. There were large regional differences in transfusion rates for red cell units, ranging from less than 30 to greater than 60/1000 persons.

CONCLUSION

Transfusion rates in Sweden remain high but have decreased strikingly during the study period - with the exception of platelet transfusions. Based on the available data, it is difficult to draw firm conclusions about whether transfusion rates can be further reduced.

Inverse probability of treatment analysis of open vs endovascular repair in ruptured infrarenal aortic aneurysm - Cohort study

BACKGROUND

To compare open repair (OR) with EVAR for the management of ruptured infrarenal abdominal aortic aneurysms (RAAA) in a cohort study over a time period of 15 years with inverse probability of treatment weights.

MATERIAL AND METHODS

From 2000/01 through 2015/12 136 patients were treated for RAAA, 98 (72.1%) underwent OR, 38 (27.9%) were treated with EVAR. Thirty-day and long-term mortality (survival) were analyzed in this IRB-approved retrospective cohort study. Treatment modalities were compared using inverse probability of treatment weights to adjust for imbalances in demographic data and risk factors.

RESULTS

EVAR patients were older (75.11 ± 7.17 vs 69.79 ± 10.24; p=0.001). There was no statistical difference in gender, hypertension, COPD, CAD, or diabetes. GFR was significantly higher in OR patients (71.4 ± 31.09 vs. 53.68 ± 25.73). Postoperative dialysis was required more frequently in EVAR patients: 11% vs. 2% (p = 0.099). In the OR group, adjusted cumulative survival was 70.4% (61.1, 81.1) at 30 days, 47.0% (37.1, 59.6) at one year and 38.3% (28.6, 51.3) at 5 years. In the EVAR group the corresponding numbers were 77.0% (67.7, 87.5), 67.5% (57.0, 80.0) and 41.7% (30.4, 57.4), respectively.

CONCLUSION

There is evidence for EVAR patients exhibiting a benefit in one-year survival, while patients treated with OR may have more favorable long-term survival given they survive for at least one year. Herein we provide a statistically rigorous comparison of OR and EVAR in short and long-term outcomes with up to 15 years of follow-up.

A retrospective observational cohort study investigating the association between acute kidney injury and all-cause mortality among patients undergoing endovascular repair of abdominal aortic aneurysms

BACKGROUND

Acute kidney injury (AKI) has been found to be associated with short- and long-term mortality and morbidity in various clinical settings. However, it is unknown whether AKI after endovascular repair of abdominal aortic aneurysms (EVAR) is associated with postoperative mortality.

METHODS

This observational study analyzed patients who underwent EVAR. The primary outcome was all-cause mortality. The outcomes of patients with and without postoperative AKI were compared using the Kaplan-Meier method and log-rank test. Factors with P < 0.05 on the univariate analysis were entered into the multivariate Cox regression model. Predictors of AKI were also determined using Cox univariate and multivariate analysis. The identified predictors of AKI were excluded from multivariate analysis for all-cause mortality because these factors could intermediate outcome.

RESULTS

There were 490 eligible patients. After a follow-up of 28.3 (16.8) months [mean (standard deviation)], 62 patients (12.7%) died. AKI occurred in 59 patients (12.0%). AKI was found by the log-rank test to be associated with a significant increase of all-cause mortality (P < 0.001). Preoperative estimated glomerular filtration rate, preoperative peripheral vascular disease, and emergency surgery were found to be independent predictors of AKI and these variables were excluded from the main analysis. Multivariate analysis showed AKI [hazard ratio (HR) = 1.19, 95% confidence interval (CI) 1.01-3.60, P = 0.045] and transfusion (HR = 1.05, 95% CI 1.01-1.09, P = 0.011) were independent predictors of mortality.

CONCLUSIONS

In the present study, AKI and transfusion were associated with significant increases in all-cause mortality after EVAR.