Red blood cell transfusion associated with increased morbidity and mortality in patients undergoing elective open abdominal aortic aneurysm repair

The effect of incremental increases in the number of packed red blood cell units transfused on perioperative outcomes in open abdominal aortic aneurysm repair

INTRODUCTION

Despite abundant evidence in the surgical and critical care literature demonstrating inferior outcomes in transfused patients, liberal use of blood transfusion, particularly after the initial unit, remains common in vascular surgery. We therefore sought to investigate the incremental risk of each additional unit of blood transfused intraoperatively for patients undergoing elective open repair of abdominal aortic aneurysm (AAA) with regards to postoperative mortality and complications.

METHODS

Patients in the Vascular Quality Initiative registry undergoing elective open infrarenal AAA repair from 2003 to 2020 were included. Exclusion criteria were age greater than 90, prior aortic surgery, concomitant iliac aneurysm, and concomitant additional major procedure. Multivariable logistic regression was used to calculate adjusted odds ratios for in-hospital mortality with incremental increases in packed red blood cells (pRBCs) given intraoperatively. Univariate analysis was performed for secondary outcomes including postoperative cardiac, respiratory, renal, and wound complications.

RESULTS

Of 4608 patients who underwent elective open AAA repair, 796 patients (16.9%) underwent perioperative transfusion. The overall in-hospital mortality rate was 2.5%. Adjusting for relevant factors, there was an increase in the odds of in-hospital mortality of 24% for each additional unit transfused. Incremental increases in the number of units transfused were associated with significantly higher risk of postoperative myocardial infarction, congestive heart failure, pulmonary complications, renal failure, and wound complications.

DISCUSSION

There appears to be an important increase in the odds of mortality for each additional unit transfused during infrarenal open AAA repair even when controlling for confounders.

Prognostic value of extended cardiac risk assessment before elective open abdominal aortic surgery

BACKGROUND

Major vascular surgery is associated with a high perioperative risk and significant mortality. Despite advances in risk stratification, monitoring, and management of perioperative complications, cardiac complications are still common. Stress echocardiography is well established in coronary artery disease diagnostics; however, its prognostic value before high-risk aortic surgery is unknown. This prospective, single-center study compared the outcome of patients undergoing extended cardiac risk assessment before open abdominal aortic surgery with the outcome of patients who had received standard preoperative assessment.

METHODS

The study included patients undergoing elective open abdominal aortic surgery. Patients who underwent standard preoperative assessment before the start of a dedicated protocol were compared with patients who had extended cardiac risk assessment, including dobutamine stress echocardiography, as part of a stepwise interdisciplinary cardiovascular team approach. The combined primary endpoint was cardiovascular death, myocardial infarction, emergency coronary revascularization, and life-threatening arrhythmia within 30 days. The secondary endpoint was acute renal failure and severe bleeding.

RESULTS

In total, 77 patients (mean age 68.1 ± 8.1 years, 70% male) were included: 39 underwent standard and 38 underwent cardiac risk assessment. The combined primary endpoint was reached significantly more often in patients before than after implementation of the extended cardiac stratification procedure (15% vs. 0%, p = 0.025). The combined secondary endpoint did not differ between the groups.

CONCLUSIONS

Patients with extended cardiac risk assessment undergoing elective open abdominal aortic surgery had better 30-day outcomes than did those who had standard preoperative assessment.

Risk factors of 30-day and long-term mortality and outcomes in open repair of thoracoabdominal aortic aneurysm

BACKGROUND

Open repair of thoracoabdominal aortic aneurysm (TAAA) was characterized by significant risk of postoperative mortality and morbidity. The aim of this study was to determine the perioperative predictors of early and long-term mortality in patients undergoing open repair of TAAA. Besides, the postoperative outcomes in patients with open repair of TAAA were described.

METHODS

This is a single-center retrospective study, and 146 patients with open repair of TAAA from January 4, 2011, to November 22, 2018 was involved. Categorical variables were analyzed by the Chi-square test or Fisher's exact test, and continuous variables were analyzed by the independent sample t-test and the WilCoxon rank-sum test. Multivariate Logistic regression and Cox regression were applied to identify the predictors of 30-day and long-term mortality, respectively. The Kaplan Meier curves were used to illustrate survival with the Log-rank test.

RESULTS

The 30-day mortality was 9.59% (n = 14). Older than 50 years, the intraoperative volume of red blood cell (RBC) and epinephrine use were independently associated with postoperative 30-day mortality in open repair of TAAA. Long-term mortality was 17.12% (n = 25) (median of 3.5 years (IQR = 2-5 years) of follow-up). Prior open thoracoabdominal aortic aneurysm (TAAA) repair, aortic cross-clamping (ACC) time, intraoperative volume of RBC and use of epinephrine were independently correlated with long-term mortality.

CONCLUSIONS

Identifying perioperative risk factors of early and long-term mortaliy is crucial for surgeons. Intraoperative volume of RBC and use of epinephrine were predictors of both early and long-term mortality. In addition, patients of advanced age, prior open repair of TAAA and prolonged ACC time should be paid more attention.

Perioperative Blood Transfusion Is Associated with Worse 30-Day Mortality and Complications After Thoracic Endovascular Aortic Repair

BACKGROUND

It is not uncommon for patients requiring vascular surgery, and in particular aortic surgery, to have increased requirements for blood transfusion. However, studies examining the effects of perioperative transfusion for thoracic endovascular aortic repair (TEVAR) are limited. Using large multicenter data, we aimed to study the impact of perioperative blood transfusion on 30-day mortality and complications after TEVAR.

METHODS

A total of 9,263 patients who underwent TEVAR were included in this retrospective study from the multicenter Vascular Quality Initiative cohort spanning 2010-2022. We excluded patients who were post-traumatic, anemic (World Health Organization criteria: hemoglobin < 12 g/dl and < 13 g/dl for females and males respectively), who underwent open conversions or presented with ruptured aneurysms. Primary outcomes were 30-day mortality and stroke. Secondary outcomes were postop congestive heart failure (CHF), respiratory complications, spinal cord ischemia (SCI), myocardial infarction (MI) and any postop complications (composite variable). Poisson regression with robust variance was performed to determine the risk of post op outcomes comparing patients who received red blood cells (RBCs) to those who did not.

RESULTS

Comparing patients without any transfusion (n = 8,223), perioperative transfusion of 1-3 units (n = 735) was associated with 3-fold increased risk of 30-day mortality (adjusted relative risk [aRR] 3.30, 95% confidence interval [CI] 2.39,4.57, P < 0.001), almost 2-fold increased risk of stroke (aRR 1.98, 95% CI 1.24,3.15, P = 0.004), 2.7-fold increased risk of SCI (aRR 2.66, 95% CI 1.87-3.77, P < 0.001), 3-fold increased risk of MI (aRR 3.40, 95% CI 2.30, 5.03, P < 0.001), 2-fold increased risk of CHF (aRR 2.04, 95% CI 1.09, 3.83, P = 0.03), 3.5-fold increased risk of respiratory complications (aRR 3.49, 95% CI 2.67, 4.56, P < 0.001), and 2-fold increased risk of any postop complication (aRR 2.36, 95% CI 2.04, 2.73, P < 0.001). These effects were even higher in patients transfused 4 or more units (n = 305) than seen in the effects seen in those transfused 1-3 units; comparing each group to patients who received none.

CONCLUSIONS

In hemodynamically stable patients undergoing TEVAR for nonemergent/emergent and nontraumatic indications, transfusion of any amount perioperatively is associated with worse 30-day mortality, stroke, SCI, MI, CHF, and respiratory complications. A conservative transfusion approach and multidisciplinary care to identify complications and rescue TEVAR patients who receive any amount of RBCs perioperatively might help improve outcomes. Future studies to understand the mechanisms of outcomes for transfused patients are needed.

Analysis of Early Death after Elective Open Abdominal Aortic Aneurysm Repair

BACKGROUND

Mortality after open abdominal aortic aneurysm repair is a quality measure and early death may represent a technical complication or poor patient selection. Our objective was to analyze patients who died in the hospital within postoperative day (POD) 0-2 after elective abdominal aortic aneurysm repair.

METHODS

The Vascular Quality Initiative was queried from 2003-2019 for elective open abdominal aortic aneurysm repairs. Operations were categorized as in-hospital death on POD 0-2 (POD 0-2 Death), in-hospital death beyond POD 2 (POD ≥3 Death), and those alive at discharge. Univariable and multivariable analyses were performed.

RESULTS

There were 7,592 elective open abdominal aortic aneurysm repairs with 61 (0.8%) POD 0-2 Death, 156 (2.1%) POD ≥3 Death, and 7,375 (97.1%) alive at discharge. Overall, median age was 70 years and 73.6% were male. Iliac aneurysm repair and surgical approach (anterior/retroperitoneal) were similar among groups. POD 0-2 Death, compared to POD ≥3 Death and those alive at discharge, had the longest renal/visceral ischemia time, more commonly had proximal clamp placement above both renal arteries, an aortic distal anastomosis, longest operative time, and largest estimated blood loss (all P < 0.05). Postoperative vasopressor usage, myocardial infarction, stroke, and return to the operating room were most frequent in POD 0-2 Death and extubation in the operating room was least frequent (all P < 0.001). Postoperative bowel ischemia and renal failure occurred most commonly among POD ≥3 Death (all P < 0.001).On multivariable analysis, POD 0-2 Death was associated with congestive heart failure, prior peripheral vascular intervention, female sex, preoperative aspirin use, lower center volume quartile, renal/visceral ischemia time, estimated blood loss, and older age (all P < 0.05).

CONCLUSIONS

POD 0-2 Death was associated with comorbidities, center volume, renal/visceral ischemia time, and estimated blood loss. Referral to high-volume aortic centers could improve outcomes.

Tourniquet use for people with peripheral arterial disease undergoing major lower limb amputations

BACKGROUND

At least 7000 major lower limb amputations (MLLAs) are performed in the UK each year, 80% of which are due to peripheral arterial disease (PAD). Intraoperative blood loss can have a deleterious effect on patient outcomes, and its replacement with transfused blood is not without risk. Tourniquets can be used in lower limb surgical procedures to provide a bloodless surgical field, minimise intraoperative blood loss, and reduce perioperative blood transfusion requirements. Although their safety has been demonstrated in certain orthopaedic operations, their use among people with PAD undergoing MLLA remains controversial. Many clinicians are concerned about tourniquets potentially compromising perfusion of the stump and thereby impacting wound healing through direct tissue injury, damage to the arterial supply of the wound, or both.

OBJECTIVES

To assess the safety and effectiveness of tourniquet use in people undergoing MLLA for complications of PAD, specifically with regard to intraoperative blood loss, change in haemoglobin levels, transfusion rates, wound healing, need for revision surgery, and postoperative complications including mortality.

SEARCH METHODS

We searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers from inception to 17 May 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing tourniquet use to no tourniquet use among people with PAD undergoing MLLA.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Primary outcomes were intraoperative blood loss, fall in haemoglobin levels, and perioperative blood transfusion requirement. Secondary outcomes were primary wound-healing rates, stump revision rates, other postoperative complications defined as per Clavien-Dindo classification, and postoperative mortality at 30 days and at maximal follow-up. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

One RCT met our inclusion criteria, which was a prospective randomised blinded controlled trial conducted in Sheffield, UK in 2006. In total 64 participants undergoing transtibial amputation for non-reconstructable PAD were randomised to either tourniquet or no tourniquet to assess for intraoperative blood loss, fall in haemoglobin, transfusion requirement, wound healing, stump breakdown and revision. Ten participants were excluded postrandomisation (five from the tourniquet group and five from the no tourniquet group). The reported median volume of intraoperative blood loss was significantly less in the tourniquet group (255 mL (interquartile range (IQR) 150 to 572.5 mL))) compared to the control group (550 mL (IQR 255 to 1050 mL)) (P = 0.014). There was a significantly lower median drop in haemoglobin concentration in the tourniquet group (1.0 g/dL (IQR 0.6 to 2.4 g/dL)) compared to the control group (1.8 g/dL (IRQ 0 to 1.2 g/dL)) (P = 0.035). There was a significantly lower perioperative blood transfusion requirement in the tourniquet group (8 participants, 32%) compared to the control group (14 participants, 48%) (P = 0.047). There were no clear differences in wound breakdown, stump revision, primary wound healing at six weeks, postoperative complications (myocardial infarction, cardiac arrhythmias, pulmonary oedema), and death between groups. We assessed the one included study as at low risk of bias for sequence generation and blinding of outcome assessors; high risk of bias for incomplete outcome data and selective outcome reporting; and unclear risk of bias for allocation concealment, blinding of participants and personnel, and other sources of bias. We assessed the certainty of the evidence as low or very low due to risk of bias, small sample size, and the study being insufficiently powered for most outcomes.

AUTHORS' CONCLUSIONS

This review identified only one small historical RCT evaluating tourniquet use in MLLA. Tourniquets appeared to reduce intraoperative blood loss, drop in haemoglobin, and blood transfusion requirements following transtibial amputations for people with PAD. However, it is unclear whether tourniquets affect wound healing, stump revision rates, postoperative complications, or mortality. High-certainty evidence is required to inform clinical decision-making for the use of tourniquets in these patients.

Intraoperative cell salvage using swab wash and serial thromboelastography in elective abdominal aortic aneurysm surgery involving massive blood loss

The loss of 50% blood volume is one accepted definition of massive haemorrhage, which ordinarily would trigger the massive transfusion protocol, involving the administration of high ratios of fresh frozen plasma and platelets to allogeneic red cells. We investigated 53 patients who experienced >50% blood loss during open elective abdominal aortic aneurysm surgery to assess allogeneic blood component usage and coagulopathy. Specialist patient blood management practitioners used a tailored cell salvage technique including swab wash to maximise blood return. We assessed the proportion of patients who did not require allogeneic blood components and develop evidence of coagulopathy by thromboelastography (TEG) parameters. Blood loss was 50%-174% (mean [SD] 68% [27%]) of blood volume. The mean (SD) intraoperative decrease in haemoglobin concentration, assessed by arterial blood gas analysis, was 5 (13) g/l. No patient received allogeneic red cells intraoperatively. Four of the 53 (8%) patients received blood components in the first 24 h postoperatively at the anaesthetists' discretion. No patient had intraoperative TEG changes indicative of fibrinolysis or coagulopathy. The 30-day mortality was 2% (one of 53). Reduction of allogeneic transfusion is one aim of patient blood management techniques. We have demonstrated virtual avoidance of allogeneic blood product transfusion despite massive blood loss. These data show possible alternatives to the current massive transfusion protocols to the management of elective vascular surgical patients.

Comparison of contemporary and historical outcomes of elective and ruptured open abdominal aortic aneurysm repair

BACKGROUND

Recently, open abdominal aortic aneurysm (AAA) repair (OSR) has become less common and will often be reserved for patients with more complex aortic anatomy. Despite improvements in patient management, the reduced surgical volume has raised concerns for potentially worsened outcomes in the contemporary era (2014-2019) compared with an earlier era in which OSR was more widely practiced (2005-2010). In the present study, we compared the 30-day outcomes of open AAA repair between these two eras.

METHODS

The American College of Surgeons National Quality Improvement Program general database was queried for open AAA repair using the Current Procedural Terminology and International Classification of Diseases, 9th and 10th, codes. The cases were stratified into two groups by operation year: 2005 to 2010 (early) and 2014 to 2019 (contemporary). In each era, the cases were further divided into elective and ruptured groups. The 30-day outcomes, including mortality, major morbidity, postoperative sepsis, and unplanned reoperation, were compared between the contemporary and early eras in the elective and ruptured groups. Preoperative variables with a P value <.25 were adjusted for in the multivariate analysis.

RESULTS

In the contemporary and early eras, 3749 and 3798 patients had undergone elective OSR and 1148 and 907 had undergone ruptured OSR, respectively. These samples were of similar sizes owing to the National Quality Improvement Program sampling process and our relatively strict inclusion criteria. In the contemporary era, fewer patients were elderly and fewer were smokers or had hypertension or dyspnea in the elective and rupture cohorts. More patients had had American Society of Anesthesiologists class >3 in the elective contemporary era (39% vs 24%; P < .0001). The contemporary elective repair group demonstrated increased 30-day mortality (3.7% vs 3.2%; adjusted odds ratio [aOR], 1.36; P = .006), major adverse cardiac events (5.7% vs 3.4%; aOR, 1.87; P < .0001), and bleeding requiring transfusion (58.5% vs 13.7%; aOR, 8.96; P < .0001). The incidence of pulmonary complications (12.1% vs 15.2%; aOR, 0.80; P = .02) and sepsis (3.7% vs 8.4%; aOR, 0.47; P < .0001) had decreased in the contemporary era, with a similar rate of unplanned reoperations (8.4% vs 7.7%; aOR, 1.16; P = .09). The incidence of renal complications in the contemporary era had increased, with a statistically significant difference. However, the absolute increase of <0.5% was likely not clinically relevant (5.5% vs 5.1%; aOR, 1.23; P = .049). In the ruptured cohort, contemporary repair was associated with increased 30-day mortality (41.4% vs 40%; aOR, 1.53; P < .0001), major adverse cardiac events (25.8% vs 12.8%; aOR, 2.49; P < .0001), and bleeding requiring transfusion (88.2% vs 27%; aOR, 23.03; P < .0001). The incidence of pulmonary complications (36.9% vs 48.1%; aOR, 0.67; P < .0001), sepsis (14.6% vs 23%; aOR, 0.75; P = .03), and unplanned reoperations (18.1% vs 22.7%; aOR, 0.74; P = .008) had decreased in the contemporary OSR group. No differences were detected in the incidence of renal complications.

CONCLUSIONS

The 30-day mortality has worsened after open AAA repair in the elective and rupture settings despite the improvements in perioperative management over the years. These complications likely stem from increased bleeding events and major cardiac events, which were increased in the contemporary era.

Early-to-midterm outcomes of aortic balloon occlusion technique versus hybrid procedure for aortic arch diseases

OBJECTIVES

The goal of this study was to compare the early-to-midterm outcomes of patients treated with the frozen elephant trunk procedure with aortic balloon occlusion (FET-ABO) versus hybrid repair for aortic arch diseases.

METHODS

Patients who underwent the FET-ABO (n = 134) and the hybrid procedure (n = 220) from 2017 to 2020 at our institution were analysed retrospectively. Early-to-midterm outcomes were compared using inverse probability weighting. Low-risk and high-risk subgroup analyses were performed according to the cut-off of the additive European System for Cardiac Operative Evaluation value of 6.

RESULTS

The present study demonstrated similar 30-day mortality (3.7% vs 8.6%; P = 0.118) and adverse events between the FET-ABO and the hybrid groups. Fewer intraoperative red blood cell transfusions (0.54 ± 1.45 vs 1.26 ± 2.47 U; P = 0.001), decreased total hospital costs (P < 0.001) and considerable early-to-midterm survival [crude: hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.17-0.91; P = 0.030; adjusted: HR 0.35, 95% CI 0.13-0.91; P = 0.032) were obtained with the FET-ABO compared to the hybrid procedure. The inverse probability weighting method substantiated the foregoing results. Adjusted subgroup analyses suggested that the FET-ABO procedure had a trend towards improved survival in low-risk patients (HR 0.17, 95% CI 0.03-0.93; P = 0.041) and achieved outcomes comparable to those of the hybrid procedure in high-risk patients (HR 0.46, 95% CI 0.15-1.42; P = 0.176).

CONCLUSIONS

The FET-ABO technique could be better promoted in hospitals lacking experience and equipment and could be more viable and cost-effective for selected patients compared with the hybrid procedure.

Predictors of Operative Mortality of 928 Intact Aortoiliac Aneurysms

BACKGROUND

The aim of this study is to identify preoperative and intraoperative factors associated with in-hospital mortality of intact abdominal aortoiliac aneurysm repair.

METHODS

In this observational study, prospectively collected information included demographics, risk factors, comorbidities, aneurysm characteristics (including special aneurysm presentation, i.e., inflammatory, mycotic/infected, aortocaval fistula), investigations, and operative variables. Receiver operating characteristic) curve analysis of the Glasgow aneurysm score (GAS) and the Vascular Study Group of New England (VSGNE) score was performed in the subgroup of bland aneurysms undergoing isolated elective repair.

RESULTS

A total of 928 cases with intact aortoiliac aneurysms had an elective (n = 882) or urgent (n = 46) repair, associated with an in-hospital mortality of 1.7% and 8.7%, respectively (P = 0.01). Open repair (n = 514) was a predictor of higher mortality (3.3% vs. 0.5% for endovascular aneurysm repair [EVAR], n = 414, odds ratio [OR] 7.1, P = 0.003), and so was the pre-EVAR era (4.8% vs. 1.3% in the EVAR era, OR 4.0, P = 0.004). Other significant predictors included the presence of abdominal/back pain (7.5% vs. 1.3%, OR = 6.0, P = 0.001), preoperative angiography (7% vs. 1.6%, OR = 4.5, P = 0.01), special aneurysm presentation (10.9% vs. 1.5%, OR = 8.1, P < 0.001), concomitant major procedures (19% vs. 1.7%, OR = 14.0, P < 0.001), serious intraoperative complications (9.1% vs. 1.5%, OR = 6.6, P = 0.001), median number of transfused units of blood intraoperatively (2 and 0 for cases with and without mortality, respectively, P < 0.001), and procedure duration (270 and 150 min for cases with and without mortality, respectively, P < 0.001). Open repair (OR = 4.5, P = 0.05), special aneurysm presentation (OR = 6.58, P = 0.001), and concomitant major procedures (OR = 14.3, P < 0.001) were independent predictors of higher mortality. ROC curve analysis for the GAS (P = 0.87) and VSGNE score (P = 0.10) failed to demonstrate statistical significance in the subgroup of bland aneurysms undergoing isolated elective repair.

CONCLUSIONS

Our study has demonstrated independent risk factors for mortality, which should be considered when contemplating aortoiliac aneurysm repair. We failed to externally validate the GAS and VSGNE score.

The Need for Red Cell Support During Non-Cardiac Surgery Is Associated to Pre-Transfusion Levels of FXIII and the Platelet Count

Unexpected intraoperative bleeding is associated with a reduced availability of crosslinking capacity (provided through factor XIII (FXIII)) per unit of generated thrombin. Furthermore, FXIII deficiency and thrombocytopenia (but not fibrinogen deficiency) are the most prevalent modulators of clot firmness in the immediate postoperative setting. In this study, we therefore evaluated whether levels of FXIII, fibrinogen, or the platelet count influenced the probability of intraoperative red cell transfusions in patients in the operating theatre. This retrospective study was comprised of 1023 patients, which were in need of blood product support in the operating theatre and of which 443 received red cell transfusions. Due to standard operating procedures, FXIII activity, fibrinogen concentration, and platelet count were measured before transfusion took place, but without influencing the decision to transfuse. FXIII deficiency was frequent (50%), as was thrombocytopenia (49%), but not fibrinogen deficiency (9%). FXIII deficiency was associated with a significantly increased probability to receive red cell transfusions (OR 4.58, 95% CI 3.46–6.05) as was thrombocytopenia (OR 1.94, 95% CI 1.47–2.56), but not fibrinogen deficiency (OR 1.09, 95% CI 0.67–1.76). Similar results were seen for cut-off independent evaluations (receiver operating characteristics (ROC) curves, using continuously distributed variables), where the areas under the curves (AUC) of red cell transfusion for FXIII activity was 0.744 (95% CI 0.716–0.770)/0.632 (95% CI 0.601–0.661) for the platelet count, and 0.578 (95% CI 0.547–0.609) for fibrinogen concentration. All AUCs were significantly different from each other (p < 0.0001 and p = 0.0106, respectively), indicating that FXIII activity was a significantly better predictor of red blood cell (RBC) transfusion than platelet count and fibrinogen concentration. These results suggest that pre-transfusion FXIII activity and to a lesser extent the platelet count influence the probability of intraoperative red cell transfusions. Modifying FXIII activity and/or the platelet count might influence the need for downstream red cell transfusion, thus potentially reducing transfusion associated morbidity. This, however, needs confirmation in future studies.