Open Abdominal Aortic Aneurysm Research Articles

Predictors of Mortality in Ruptured Abdominal Aortic Aneurysms.

Introduction The outcome of a ruptured abdominal aortic aneurysm (AAA) without any interventions is close to uniformly fatal. The Society for Vascular Surgery suggests a door-to-intervention time of less than 90 minutes in a patient with a ruptured AAA. Admission factorsassociated with poor outcomes in ruptured AAAs include hypotension, renal insufficiency, severe anemia, advanced age, and cardiac arrest. Patients who are particularly at high risk for open AAA repair may be candidates for endovascular repair, which may decrease mortality. This study aimed to assess the relationship between systolic blood pressure (SBP) and serum bicarbonate levels in predicting mortality in patients with ruptured AAAs. Methods This retrospective study was performed using the United States Collaborative Network of 57 academic medical centers/healthcare organizations in the TriNetX database. A total of 4,226 patients with ruptured AAAs were identified. Patients were categorized based on SBP of ≤90 mmHg, any SBP, or >90 mmHgand further stratified by bicarbonate levels. Rounded cutoffs of the bicarbonate ranges (<10, 10.01-15; 15.01-20, >20.01) were chosen for interpretative purposes. Mortality outcome was assessed within 90 days after presentation for the ruptured AAA. Results After exclusions, 4,174 patients presented with ruptured AAA between September 30, 2003, and September 30, 2023, in the database. Overall, 90-day mortality in any SPB cohort was 28%. Patients who presented with a ruptured AAA with an SBP ≤ 90 had a 46.3% mortality. Those who presented with a SBP > 90 had a 20.1% mortality. Additionally, as bicarbonate levels decreased, mortality increased within each SBP group. Conclusions Early recognition and intervention are critical for survival in patients with ruptured AAAs. Metabolic acidosis is an important marker of the severity of hemorrhage in these patients. In this large cohort study of ruptured AAAs, mortality increases significantly with hypotension and metabolic acidosis, represented by lower bicarbonate levels. Abnormalities in the serum bicarbonate may be seen before severe changes invital signs in hemorrhaging patients. Early recognition of metabolic acidosis may lead to earlier life-saving interventions in patients with ruptured AAAs.

Comparison of Hospital Stay After Open Abdominal Aortic Aneurysm Repair With or Without Enhanced Recovery Protocol

ObjectiveEnhanced recovery after surgery (ERAS) is a protocol of evidence based practices applied in major surgery. Open aortic aneurysm repair is major surgery in terms of complications and mortality. This study aimed to compare early outcomes of ERAS with a traditional post-operative protocol in patients undergoing elective open aortic surgery. MethodsThis retrospective cohort study was conducted between 2018 – 2022 in two tertiary vascular surgery centres. The ERAS program was routinely implemented in one centre, while the other one used a standard peri-operative protocol. The primary outcome was post-operative length of stay (pLOS). Secondary outcomes were 30 day mortality, complications, re-interventions, and rehospitalisations. Propensity score weighting was used to balance the two groups by comorbidities. Inverse probability of treatment weight (IPTW) was used to estimate the average treatment effect on the treated patients. ResultsA total of 198 patients were enrolled: 128 in the ERAS group (EG) and 70 in the standard group (SG). Mean age was 70.8 ± 6.7 years in EG and 71.1 ± 6.7 in SG (p = .34). No significant differences were observed in pre-operative cardiovascular risk factors. Median pLOS was 5 days (IQR 3, 6) in the EG group and 8 days (IQR 6, 11) in the SG group (p < .001). No differences in terms of mortality, re-operations, and rehospitalisations were observed. The IPTW analyses showed a 40% reduction in pLOS and a significant reduction in major complications in EG (OR 0.41, 95% CI 0.26 – 0.66; p < .001). A 45% increase in pLOS in patients with chronic obstructive pulmonary disease was found in both groups. ConclusionEnhanced recovery after surgery is safe and feasible for elective open aortic surgery, and associated with earlier hospital discharge without differences in terms of mortality and lower complication rates compared with a standard protocol. Chronic obstructive pulmonary disease is a major risk factor for an increase in pLOS. The ERAS protocol is promising in terms of resource utilisation.

Risk factors for incisional hernia after open abdominal aortic aneurysm repair: a systematic review and meta-analysis.

The incidence of incisional hernia (IH) after an open abdominal aortic aneurysm (AAA) repair can reach up to 35%, contributing to long-term morbidity. Individual studies have been limited in identifying modifiable risk factors for IH after an open AAA repair. This meta-analysis aims to review all the risk factors for IH after an open AAA repair. We searched Cochrane Central, Embase, PubMed, MEDLINE, and Web of Science databases for original studies. Risk factors assessed were age, sex, comorbidities, surgical incision, blood loss, and surgical site infection (SSI). Data analysis was done using RStudio 4.1.2. We computed Relative Risk (RR) for dichotomous outcomes and Mean differences (MD) with 95% Confidence Interval (CI) for continuous outcomes. P-values less than 0.05 were considered statistically significant. Ten studies met the inclusion criteria among 1,795 screened articles. Among those ten studies, there were a total of 1,806 patients of which 341 patients developed IH. Older age (Mean 69.6-70.7 years, MD 1.39 years, CI [1.12-1.66], P < 0.01), midline vertical incision (RR 1.55, CI [1.06-2.25], P = 0.02) and increased intraoperative blood loss (MD 429.8ml, CI [234.8- 624.8], P < 0.01) were associated with an increased incidence of IH. Surgical site infection (SSI) was noted as a risk factor for IH after open AAA repair (RR 2.36, CI [1.31-4.24], P = 0.004). No statistically significant association was found between the incidence of IH and sex (RR 1.0, CI [0.8-1.14], P = 0.98), smoking (RR 1.01, CI [0.93-1.09], P = 0.88), diabetes (RR 1.38, CI [0.85-2.25], P = 0.19), and chronic kidney disease (RR 1.55, CI [0.47-5.09], P = 0.46). This meta-analysis shows that age, midline vertical incision, intraoperative blood loss, and SSI are risk factors for IH after open AAA repair.

Ultrasound-guided transversus abdominis plane block is an effective opioid-sparing alternative to epidural anesthesia in open abdominal aortic aneurysm repair

ObjectiveThis study evaluated the effectiveness of ultrasound-guided transversus abdominis plane (TAP) blocks compared with epidural (EPI) and general anesthesia (GA) in managing postoperative pain following open abdominal aortic aneurysm (AAA) repair. MethodsA retrospective review was conducted on 61 elective open AAA repairs performed between January 2016 and December 2021. Patients were categorized into three groups: GA, GA plus EPI, and GA plus TAP block. The primary outcome measured was opioid requirements, reported as morphine milligram equivalents (MME) at 48, 72, and 120 hours postoperatively. The additional opioid requirements between 48 and 72 hours (ΔMME₁) and between 72 and 120 hours (ΔMME₂) were also evaluated. Secondary outcomes included vasopressor requirements, extubation in the operating room, and length of stay in the intensive care unit and hospital. ResultsThe mean MMEs at 48, 72, and 120 hours were statistically significant across all groups. The mean MME at 48 hours was 51.1 ± 71.9 in the TAP group compared with 140.5 ± 121.7 in the GA group. Pairwise comparisons showed a significant difference between the GA and TAP groups at 48 hours (P = .002), whereas the difference between EPI and TAP at 48 hours was not significant (P = .098). Additional opioid requirements between 48 and 72 hours after surgery (ΔMME₁) showed a significant difference between EPI and TAP (P = .045). All groups had significantly different MMEs at 72 hours, with no significant differences observed at 120 hours. Secondary outcomes were not significantly different across the groups. ConclusionsTAP blocks provide effective postoperative pain control with decreased opioid requirements similar to EPI anesthesia during the first 48 hours postoperatively. This factor makes TAP blocks a viable alternative to EPI anesthesia in open AAA repairs. Further multicenter studies are recommended to validate these findings.

Anaesthetic concerns in a patient with aortic aneurysm for non-cardiac surgery: A case report.

Abdominal aortic aneurysm poses a significant risk of rupture, with mortality rates of 80% to 90% if untreated. Management focuses on identifying and repairing the aneurysm before rupture, considering factors like size, type and symptoms. We report successful anaesthetic management in a case of intertrochanteric fracture of femur of an elderly patient who was to undergo elective surgery for abdominal aortic aneurysm. Few cases detail abdominal aortic aneurysm management during non-cardiac surgery, emphasising careful anaesthesia titration. This case report underscores the importance of precise intraoperative anaesthesia management in emergency non-cardiac surgery for abdominal aortic aneurysm patients.

High proportion of undiagnosed diabetes in patients surgically treated for infrarenal abdominal aortic aneurysm: findings from the multicentre Norwegian Aortic Aneurysm and Diabetes (ABANDIA) Study

BackgroundThe aim was to investigate the total prevalence of known and undiagnosed diabetes mellitus (DM), and the association of DM with perioperative complications following elective, infrarenal, open surgical (OSR) or endovascular (EVAR), Abdominal Aortic Aneurysm (AAA) repair.MethodsIn this Norwegian prospective multicentre study, 877 patients underwent preoperative screening for DM by HbA1c measurements from November 2017 to December 2020. Diabetes was defined as screening detected HbA1c ≥ 48 mmol/mol (6.5%) or previously diagnosed diabetes. The association of DM with in-hospital complications, length of stay, and 30-day mortality rate were evaluated using adjusted and unadjusted logistic regression models.ResultsThe total prevalence of DM was 15% (95% CI 13%,17%), of which 25% of the DM cases (95% CI 18%,33%) were undiagnosed upon admission for AAA surgery. The OSR to EVAR ratio was 52% versus 48%, with similar distribution among DM patients, and no differences in the prevalence of known and undiagnosed DM in the EVAR versus the OSR group. Total 30-day mortality rate was 0.6% (5/877). Sixty-six organ-related complications occurred in 58 (7%) of the patients. DM was not statistically significantly associated with a higher risk of in-hospital organ-related complications (OR 1.23, 95% CI 0.57,2.39, p = 0.57), procedure-related complications (OR 1.48, 95% CI 0.79,2.63, p = 0.20), 30-day mortality (p = 0.09) or length of stay (HR 1.06, 95% CI 0.88,1.28, p = 0.54). According to post-hoc-analyses, organ-related complications were more frequent in patients with newly diagnosed DM (n = 32) than in non-DM patients (OR 4.92; 95% CI 1.53,14.3, p = 0.005).ConclusionTwenty-five percent of all DM cases were undiagnosed at the time of AAA surgery. Based on post-hoc analyses, undiagnosed DM seems to be associated with an increased risk of organ related complications following AAA surgery. This study suggests universal DM screening in AAA patients to reduce the number of DM patients being undiagnosed and to improve proactive diabetes care in this population. The results from post-hoc analyses should be confirmed in future studies.

Heart rate variability as a dynamic marker of surgeons' stress during vascular surgery.

A surgeon experiences elevated stress levels when operating. Acute stress is linked to cognitive overload, worsening surgical performance. Chronic stress poses a significant risk to a surgeon's health. Identifying intraoperative stress may allow for preventative strategies that reduce surgeons' stress and subsequently improve patient outcomes. The aim of this study was to assess the feasibility of using heart rate variability as a marker of stress during vascular surgery. A total of 11 senior surgeons were evaluated performing three different vascular surgery procedures. Heart rate variability metrics (low-frequency to high-frequency ratio and standard deviation of the normal-normal interval) were determined from single-lead ECG traces at predetermined procedural performance points. State-Trait Anxiety Inventory-6, a validated stress tool, was used to assess surgeon-reported stress. Subjective reports of procedural difficulty were also collected. One-way ANOVA compared heart rate variability at key performance points with baseline. Pearson's coefficient assessed correlation between heart rate variability and subjective stress. Data were collected for six carotid endarterectomies, six open abdominal aortic aneurysm repairs, and five lower limb bypasses. Heart rate variability metrics indicating markedly greater stress were observed at key performance points across all procedures. Peaks in stress were consistent across different surgeons performing the same procedure. A significant correlation was observed between heart rate variability metrics and subjective State-Trait Anxiety Inventory-6 stress reports (r = 0.768, P =<0.001). The most difficult procedural steps reported corresponded with heart rate variability metrics displaying the greatest stress. Heart rate variability may be a viable approach to assess intraoperative stress and cognitive load during vascular surgery and could be used to evaluate whether a theatre intervention (for example timeout) could reduce stress in areas of surgical difficulty.

A Novel Preoperative Risk Score to Identify Patients at High Risk for Nonhome Discharge after Elective Open Abdominal Aortic Aneurysm Repair

Non-home discharge (NHD) to a rehabilitation or skilled nursing facility after vascular surgery is poorly described despite its impact on patients. For home-dwelling patients undergoing elective surgery, the need for postoperative NHD can have meaningful implications on quality of life, long-term outcomes, and healthcare spending. Understanding post-surgical NHD risk is essential to preoperative counseling and shared decision making. This is particularly true for the treatment of abdominal aortic aneurysms as the postoperative course can vary between open and endovascular surgery. We aimed to identify independent predictors of NHD following elective open abdominal aortic aneurysm repair (OAR), and to create a clinically useful preoperative risk score. Elective OAR cases were queried from the SVS Vascular Quality Initiative from years 2013-2022. A risk score was created by splitting the data set into two-thirds for development and one-third for validation. A parsimonious stepwise hierarchical multivariable logistic regression controlling for hospital level variation was performed in the development dataset, and the beta-coefficients were used to assign points for a risk score. The score was then validated, and model performance assessed. Overall, 8,274 patients were included and 1,502 (18.2%) required NHD. At baseline, patients who required NHD were more likely to be ≥ 80 years old (23.6% vs. 6.5%), female (35.9% vs. 23.1%), not independently ambulatory (14.6% vs. 4.3%), anemic (24.4% vs. 13.9%), have COPD (41.6% vs. 30.7%), ASA class ≥ 4 (41.0% vs. 32.5%), and a supraceliac proximal clamp (9.8% vs. 5.7%; all P<0.05). Multivariable analysis in the development group identified the following independent predictors of NHD: age ≥ 80 years, not independently ambulatory, proximal clamp location, hypogastric artery occlusion, anemia (Hb <12 g/dL), chronic obstructive pulmonary disease, female sex, hypertension, and American Society of Anesthesiologists class ≥ 4. These were then used to create a 14-point risk score. Patients were stratified into three groups based upon their risk score: low risk (0-4 points; n=4,966) with an NHD rate of 9.9%, moderate risk (5-6 points; n=2,442) with an NHD rate of 25.5%, and high risk (≥ 7 points; n=886) with an NHD rate of 44.6%. The risk score had good predictive ability with c-statistic=0.73 for model development and c-statistic=0.72 in the validation dataset. This novel risk score can predict NHD following elective OAR using characteristics that can be identified preoperatively. Utilization of this score may allow for improved risk assessment, preoperative counseling, and shared decision making.

Gender-Specific Long-Term Results After Elective Open Abdominal Aortic Aneurysm Repair Depending on the Site of Distal Anastomosis.

Analysis of gender-specific differences in short- and long-term outcome after elective open abdominal aortic aneurysm repair (OAR) regarding the distal anastomosis. In this retrospective cohort study, data from 4853 patients of a German health insurance company undergoing OAR for infrarenal abdominal aortic aneurysms (AAAs) between 2010 and 2016 were analysed. The patients were followed through 2018. A total of 4050 (83.5%) men and 803 (16.6%) women underwent OAR. Women were older than men (72.9 ± 8.7 vs 69.8 ± 8.5years; P < .001). A tube graft was used in 2644 (54.5%) patients, an aorto-biiliac bifurcated graft in 1657 (34.1%) and an aorto-bifemoral bifurcated graft in 552 (11.4%). Perioperative mortality was not significantly different between men (5.7%) and women (6.5%) in the total patient population (P = .411). This was true for aorto-aortic tube grafting (P = .361), aorto-biiliac reconstructions (P = 1.000) and aorto-bifemoral reconstructions (P = .345). Kaplan-Meier estimated long-term survival of men after 9years was better than that of women (55.0% vs 43.8%; P = .006). However, separated by the site of the distal anastomosis, this was only true for aorto-aortic reconstructions (survival men vs women 56.0% vs 42.1%; P = .005), not for aorto-biiliac and aorto-bifemoral reconstructions. In the multivariate Cox regression analysis, age over 80years, heart failure, aorto-bifemoral reconstruction, chronic kidney disease stage 3-5, chronic obstructive pulmonary disease, peripheral artery disease, arterial hypertension, but not gender (P = .531), had a negative impact on long-term survival. If possible, an aorto-aortic tube graft should be preferred to aorto-biiliac and aorto-bifemoral reconstructions in OAR. Patients selected for aorto-bifemoral artery reconstruction exhibit higher perioperative morbidity and mortality as well as worse long-term survival compared to patients selected for an intra-abdominal reconstruction. In the multivariate regression analysis, gender was not an independent risk factor for either short- or long-term outcomes.

Outcome analysis of the surgical team in open surgical repair of intact abdominal aortic aneurysm surgery.

To analyze how the experience of the surgical team went to impact the outcomes after open surgical repair (OSR) of intact abdominal aortic aneurysms (AAAs). This is a single-center, observational cohort study with retrospective analysis of all OR for intact AAA performed between 1 January 2010 and 31 December 2022. The primary outcome was survival at 30 days and in follow-up, and a composite outcome of mortality and major complication. The secondary outcome was freedom from aorta-related reintervention. All outcomes were stratified according to the experience of the operating team (surgeons and anesthesiology). We analyzed 103 (7.2%) patients: 97 (94.2%) males and 6 (5.8%) females. The mean age was 76 ± 8 years (range, 55-93). The best possible team composition was present in 52 (50.5%) interventions. The follow-up index was 0.82 ± 0.18 (range, 0.6-1.0). Mean follow-up duration was 59 ± 43 months (range, 0-158). We observed no differences between teams in major complications (best, 17.3% vs mixed, 21.6%; OR: 0.4, P = 0.622), 30 days mortality (best, 0% vs mixed, 5.9%; OR: 7.6, P = 0.118) and composite outcome (best, 11.5% vs mixed, 17.6%; OR: 0.8, P = 0.416). Cox regression analysis identified the best possible team as a protective factor against the need for reintervention (hazard ratio: 0.2; 95% confidence interval: 0.06-0.88, P = 0.032). In our experience, OR of AAA yielded satisfactory results in terms of safety and efficacy independently of the team's experience. A more experienced team may protect against aorta-related reintervention.

Identifying risk factors for postoperative ileus following open abdominal aortic aneurysm repair

BackgroundPostoperative ileus (POI) is a common complication following major abdominal surgery. The majority of the data available regarding POI after abdominal surgery is from the gastrointestinal and urological literature. These data have been extrapolated to vascular surgery, especially with regard to enhanced recovery programs for open abdominal aortic aneurysm (AAA) surgery. However, vascular patients are a unique patient population and extrapolation of gastrointestinal and urological data may not necessarily be appropriate. Therefore, the purpose of this study was to delineate the prevalence and risk factors of POI in patients undergoing open AAA surgery. MethodsThis was a retrospective, single-institution study of patients who underwent open AAA surgery from January 2016 to July 2023. Patients were excluded if they had undergone nonelective repairs or had expired within 72 hours of their index operation. The primary outcome was rates of POI, which was defined as the presence of two or more of the following after the third postoperative day: nausea and/or vomiting, inability to tolerate oral food intake, absence of flatus, abdominal distension, or radiological evidence of ileus. ResultsA total of 123 patients met study criteria with an overall POI rate of 8.9% (n = 11). Patients who developed a POI had a significantly lower body mass index (24.3 kg/m2 vs 27.1 kg/m2; P = .003), were more likely to undergo a transperitoneal approach (81.8% vs 42.0%; P = .022), midline laparotomy (81.8% vs 37.5%; P = .008), longer total clamp times (151.6 minutes vs 97.7 minutes; P = .018), greater amounts of intraoperative crystalloid infusion (3495 mL vs 2628 mL; P = .029), and were more likely to return to the operating room (27.3% vs 3.6%; P = .016). Proximal clamp site was not associated with POI (P=.463). Patients with POI also had higher rates of postoperative vasopressor use (100% vs 61.1%; P = .014) and greater amounts of oral morphine equivalents in the first 3 postoperative days (488.0 ± 216.0 mg vs 203.8 ± 29.6 mg; P = .016). Patients who developed POI had longer lengths of stay (12.5 days vs 7.6 days; P < .001), a longer duration of nasogastric tube decompression (5.9 days vs 2.2 days; P < .001), and a longer period of time before diet tolerance (9.1 days vs 3.7 days; P < .001). Of those who developed a POI (n = 11), four (36.4%) required total parental nutrition during the admission. ConclusionsPOI is a morbid complication among patients undergoing elective open AAA surgery that prolongs hospital stay. Patients at risk for developing a POI are those with a lower body mass index, as well as those who had an operative repair via a transperitoneal approach, midline laparotomy, longer clamp times, larger amounts of intraoperative crystalloid infusion, a return to the operating room, postoperative vasopressor use, and higher amounts of oral morphine equivalents. These data highlight important perioperative opportunities to decrease the prevalence of POI.

Association between diabetes status and long-term outcomes following open and endovascular repair of infrarenal abdominal aortic aneurysms

ObjectiveCurrent literature reports conflicting findings regarding the effect of diabetes mellitus (DM) on outcomes of abdominal aortic aneurysm (AAA) repair. In this study we examined the effect of DM and its management on outcomes after open AAA repair (OAR) and endovascular AAA repair (EVAR). MethodsWe identified all patients undergoing OAR or EVAR for infrarenal AAA between 2003 and 2018 in the Vascular Quality Initiative registry data linked with Medicare claims. We excluded patients with missing DM status. Patients were stratified by their preoperative DM status, and then further stratified by DM management: dietary, noninsulin antidiabetic medications (NIMs), or insulin. Outcomes of interest included 1-year aneurysm sac dynamics, 8-year aneurysm rupture, reintervention, and all-cause mortality. These outcomes were analyzed with the χ2 test, Kaplan-Meier methods, and multivariable Cox regression analyses. ResultsWe identified 34,021 EVAR patients and 4127 OAR patients, of whom 20% and 16% had DM, respectively. Of all DM patients, 22% were managed by dietary management, 59% by NIM, and 19% by insulin. After EVAR, DM patients were more likely to have stable sacs, whereas non-DM patients were more likely to have sac regression at 1 year. Compared with non-DM, DM was associated with a significantly lower risk for 8-year rupture in EVAR (EVAR hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.51-0.92). Compared with non-DM, NIM was associated with lower risk of rupture within 8-years for both EVAR and OAR (EVAR HR, 0.64; 95% CI, 0.44-0.94; OAR HR, 0.29; 95% CI, 0.41-0.80), whereas dietary control and insulin had a similar rupture risk compared with non-DM. However, compared with non-DM, DM was associated with a higher risk of 8-year all-cause mortality after EVAR and OAR (DM vs non-DM: EVAR HR, 1.17; 95% CI, 1.11-1.23; OAR HR, 1.16; 95% CI, 1.00-1.36). After further DM management substratification, compared with non-DM, management with NIM and insulin were associated with a higher 8-year mortality in EVAR and OAR (EVAR: NIM HR, 1.12; 95% CI, 1.05-1.20; insulin: HR, 1.40; 95% CI, 1.26-1.55; OAR: NIM HR, 1.27; 95% CI, 1.06-1.54; and insulin: HR, 1.57; 95% CI, 1.15-2.13). Finally, there was a similar risk of reintervention across the DM and non-DM populations for EVAR and OAR. ConclusionsDM was associated with a lower adjusted risk of rupture after EVAR as well as OAR in patients managed with NIM. Nevertheless, just as in patients without AAA, preoperative DM was associated with a higher adjusted risk of all-cause mortality. Further study is needed to evaluate for differences in aneurysm-related mortality between DM and non-DM patients, and studies are planned to evaluate the independent effect of NIM on aneurysm-related outcomes.

Acute Intraoperative Conversion from Endovascular to Open vs Planned Open Operation for Abdominal Aortic Aneurysm: A Propensity-Score Matched Study from the American College of Surgeons NSQIP-Targeted Database.

Evaluating outcomes for acute intraoperative conversion to open surgery during endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) was difficult due to low incidence. This study aimed to compare 30-day outcomes between patients with acute intraoperative conversion during EVAR and planned open surgery, and to identify risk factors associated with acute conversion. Patients who underwent EVAR or planned open AAA repair were identified in American College of Surgeons NSQIP-targeted databases from 2012 to 2021. Patients with acute intraoperative conversion during EVAR were selected. A 1:3 propensity-score matching was used to match demographics, baseline characteristics, surgical indications, aneurysm size and extent, and emergency cases between the conversion open and planned open groups. Thirty-day postoperative outcomes were assessed. Of 20,566 EVAR cases, 177 (0.86%) had acute intraoperative conversion to open surgery. The conversion open group was matched to 504 of 5,249 planned open patients. Conversion open and planned open groups had comparable 30-day mortality (23.43% vs 17.46%, p = 0.09) and organ system complications, including major adverse cardiovascular event (14.86% vs 10.71%, p = 0.17), pulmonary complications (17.71% vs 24.01%, p = 0.09), and renal complications (8.57% vs 11.11%, p = 0.39). The conversion open group had lower bleeding requiring transfusion (48.57% vs 75.60%, p < 0.01), shorter operation time (p < 0.01), and shorter length of stay (p < 0.01). Other postoperative outcomes did not differ. Risk factors associated with acute intraoperative conversion included ruptured aneurysm with or without hypotension. Protective factors included hypertension and aortic distal aneurysm extent. Although this study does not endorse a universal "EVAR first" strategy for all patients with AAA, EVAR can be attempted first in eligible patients with AAA. Even when EVAR is unsuccessful, intraoperative conversion to open surgery still appears to be safe compared with planned open repair.

Lessons Learned with Enhanced Recovery for Open Abdominal Aortic Aneurysm Surgery: A Long Term Regional Network Experience

This enhanced recovery programme (ERP) aimed to achieve early recovery for patients undergoing major surgery. Results of a standardised ERP protocol for open infrarenal abdominal aortic aneurysm (AAA) repair within a hub and spoke regional network are presented. In this monocentric prospective study (January 2004 - December 2021), consecutive AAAs (≥ 55 mm) were included in the ERP (patient discharge on post-operative day [POD] 4). The four phases of the ERP were pre-admission, pre-operative, intra-operative, and post-operative. Exclusion criteria were BMI > 35 kg/m2, functional capacity < 4 MET, previous aortic or abdominal surgery, and life expectancy < 5 years. Transperitoneal surgery was undertaken with routine AAA resection, graft interposition, and closure. Consecutive patients (n = 778) were enrolled into the study (mean age 72.3 ± 3.2 years; n = 712 men); 160 (20.5%) were treated in spoke hospitals. Median follow up was 78 (IQR 28, 128) months; median length of stay, procedure time, and blood loss were 4 days (IQR 3, 5), 190 min (IQR 170, 225), and 564 mL (IQR 300, 600). Infrarenal clamping and tube graft configuration were used in 96.5% (n = 751) and 72.5% (n = 564) of patients; 30 day mortality and complication rates were 0.4% (n = 3) and 9.2% (n = 72). Discharge after POD 4 occurred in 15.0%, and most significant predictors for discharge after POD 4 were haemotransfusion, re-intervention, and ileus over 3 days. Overall survival was: 98.2% at 1 year, 85.0% at 5 years, and 59.9% at 10 years. Freedom from re-intervention was 97.9% at 1 year, 94.1% at 5 years, and 86.8% at 10 years. Short and long term outcomes were comparable between hub and spoke hospitals. The ERP protocol was associated with low short and long term mortality and complication rates. Future studies should apply the ERP protocol to other vascular centres.

Early Opioid Use and Postoperative Delirium Following Open Abdominal Aortic Aneurysm Repair

Postoperative delirium is a common complication following open abdominal aortic aneurysm repair (OAR). Opioids have been found to contribute to delirium, especially at higher doses. This study assessed the impact of early postoperative opioid analgesia on postoperative delirium incidence and time to onset. We hypothesized that higher early postoperative opioid utilization would be associated with increased postoperative delirium incidence. This was a retrospective analysis of OAR cases at a single quaternary care center from years 2012-2020. The primary exposure was oral morphine equivalents use (OME), calculated for postoperative days 1-7. A cut point analysis using a receiver operator curve for postoperative delirium determined the threshold for high OME (OME>37mg). The primary outcome was postoperative delirium incidence identified via chart review. Multivariable logistic regression was performed for postoperative delirium and adjusted for covariates meeting P<0.1 on bivariate analysis. Among 194 OAR cases, 67 (35%) developed postoperative delirium with median time to onset of 3days (IQR=2-6). Patients with postoperative delirium were older (74years vs. 69years), more frequently presented with symptomatic AAA (47% vs. 27%) and had a higher proportion of comorbidities (all P<0.05). Cases with high OME utilization on postoperative day 1 (55%) were younger (69 vs. 73years), less frequently had an epidural (46% vs. 77%), and more frequently developed delirium (42% vs. 25%, all P<0.05). Epidural use was associated with a significant decrease in OME utilization on postoperative day 1 (33 vs. 83, P<0.01). Postoperative delirium onset was later in those with high OME use (4 vs. 2days, P=0.04). On multivariable analysis, high OME remained associated with postoperative delirium (Table II). High opioid utilization on postoperative day 1 is associated with increased postoperative delirium and epidural along with acetaminophen use reduced opioid utilization. Future study should examine the impact of opioid reduction strategies on outcomes after major vascular surgery.

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

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. 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. 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. 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.

Geographical disparities in access to surgical treatment and mortality rates from abdominal aortic aneurysms in Brazil: A retrospective longitudinal study.

Abdominal aortic aneurysm (AAA) is a growing public health problem, and not all patients have access to surgery when needed. This study aimed to analyze spatiotemporal variations in AAA mortality and surgical procedures in Brazilian intermediate geographic regions and explore the impact of different surgical techniques on operative mortality. A retrospective longitudinal study was conducted to evaluate AAA mortality from 2008 to 2020 using space-time cube (STC) analysis and the emerging hot spot analysis tool through the Getis-Ord Gi* method. There were 34,255 deaths due to AAA, 13,075 surgeries to repair AAA, and a surgical mortality of 14.92%. STC analysis revealed an increase in AAA mortality rates (trend statistic = +1.7693, p = 0.0769) and a significant reduction in AAA surgery rates (trend statistic = -3.8436, p = 0.0001). Analysis of emerging hotspots revealed high AAA mortality rates in the South, Southeast, and Central-West, with a reduction in procedures in São Paulo and Minas Gerais States (Southeast). In the Northeast, there were extensive areas of increasing mortality rates and decreasing procedure rates (cold spots). AAA mortality increased in several regions of the country while surgery rates decreased, demonstrating the need for implementing public health policies to increase the availability of surgical procedures, particularly in less developed regions with limited access to services.

A patient-centered textbook outcome measure effectively discriminates contemporary elective open abdominal aortic aneurysm repair quality

BackgroundThere is persistent controversy surrounding the merit of surgical volume benchmarks being used solely as a sufficient proxy for assessing the quality of open abdominal aortic aneurysm (AAA) repair. Importantly, operative volume quotas may fail to reflect a more nuanced and comprehensive depiction of surgical outcomes most relevant to patients. Accordingly, we herein propose a patient-centered textbook outcome (TO) for AAA repair that is analogous to other large magnitude extirpative operations performed in other surgical specialties, and test its feasibility to discriminate hospital performance using Society for Vascular Surgery (SVS) volume guidelines. MethodsAll elective open infrarenal AAA repairs (OAR) in the SVS-Vascular Quality Initiative were examined (2009-2022). The primary end point was a TO, defined as a composite of no in-hospital complication or reintervention/reoperation, length of stay of ≤10 days, home discharge, and 1-year survival rates. The discriminatory ability of the TO measure was assessed by comparing centers that did or did not meet the SVS annual OAR volume threshold recommendation (high volume ≥10 OARs/year; low volume <10 OARs/year). Logistic regression and multivariable models adjusted for patient and procedure-related differences. ResultsA total of 9657 OARs across 198 centers were analyzed (mean age, 69.5 ± 8.4 years; female, 26%; non-White, 12%). A TO was identified in 44% (n = 4293) of the overall cohort. The incidence of individual TO components included no in-hospital complication (61%), no in-hospital reintervention or reoperation (92%), length of stay of ≤10 days (78%), home discharge (76%), and 1-year survival (91%). Median annual center volume was 6 (interquartile range, 3-10) and a majority of centers did not meet the SVS volume suggested threshold (<10 OARs/year, n = 148 [74%]). However, most patients (6265 of 9657 [65%]) underwent OAR in high-volume hospitals. When comparing high- and low-volume centers, a TO was more likely to occur in high-volume institutions: ≥10 OARs/year (46%) vs <10 OARs/year (42%; P = .0006). The association of a protective effect for higher center volume remained after risk adjustment (odds ratio, 1.1; 95% confidence interval, 1.05-1.26; P = .003). ConclusionsTOs for elective OAR reflect a more nuanced and comprehensive patient centered proxy to measure care delivery, consistent with other surgical specialties. Surprisingly, a TO was achieved in <50% of elective AAA cases nationally. Although the likelihood of a TO seems to correlate with SVS center volume recommendations, it more importantly reflects elements which may be prioritized by patients and thus offers insights into further improving real-world AAA care.

Temporal Trends and Outcomes of Abdominal Aortic Aneurysm Care in the United States.

Endovascular aortic aneurysm repair (EVAR) has had a dynamic impact on abdominal aortic aneurysm (AAA) care, often supplanting open AAA repair (OAR). Accordingly, US AAA management is often highlighted by disparities in patient selection and guideline compliance. The purpose of this analysis was to define secular trends in AAA care. The Society for Vascular Surgery Vascular Quality Initiative was queried for all EVARs and OARs (2011-2021). End points included procedure utilization, change in mortality, patient risk profile, Society for Vascular Surgery-endorsed diameter compliance, off-label EVAR use, cross-clamp location, blood loss, in-hospital complications, and post-EVAR surveillance missingness. Linear regression was used without risk adjustment for all end points except for mortality and complications, for which logistic regression with risk adjustment was used. In all, 66 609 EVARs (elective, 85% [n=55 805] and nonelective, 15% [n=9976]) and 13 818 OARs (elective, 70% [n=9706] and nonelective, 30% [n=4081]) were analyzed. Elective EVAR:OAR ratios were increased (0.2 per year [95% CI, 0.01-0.32]), while nonelective ratios were unchanged. Elective diameter threshold noncompliance decreased for OAR (24%→17%; P=0.01) but not EVAR (mean, 37%). Low-risk patients increasingly underwent elective repairs (EVAR, +0.4%per year [95% CI, 0.2-0.6]; OAR, +0.6 points per year [95% CI, 0.2-1.0]). Off-label EVAR frequency was unchanged (mean, 39%) but intraoperative complications decreased (0.5% per year [95% CI, 0.2-0.9]). OAR complexity increased reflecting greater suprarenal cross-clamp rates (0.4% per year [95% CI, 0.1-0.8]) and blood loss (33 mL/y [95% CI, 19-47]). In-hospital complications decreased for elective (0.7% per year [95% CI, 0.4-0.9]) and nonelective EVAR (1.7% per year [95% CI, 1.1-2.3]) but not OAR (mean, 42%). A 30-day mortality was unchanged for both elective OAR (mean, 4%) and EVAR (mean, 1%). Among nonelective OARs, an increase in both 30-day (0.8% per year [95% CI, 0.1-1.5]) and 1-year mortality (0.8% per year [95% CI, 0.3-1.6]) was observed. Postoperative EVAR surveillance acquisition decreased (67%→49%), while 1-year mortality among patients without imaging was 4-fold greater (9.2% versus imaging, 2.0%; odds ratio, 4.1 [95% CI, 3.8-4.3]; P<0.0001). There has been an increase in EVAR and a corresponding reduction in OAR across the United States, despite established concerns surrounding guideline adherence, reintervention, follow-up, and cost. Although EVAR morbidity has declined, OAR complication rates remain unchanged and unexpectedly high. Opportunities remain for improving AAA care delivery, patient and procedure selection, guideline compliance, and surveillance.

Changes in the Remaining Iliac Artery According to Retrograde Flow after Aorto-Femoral Bypass in Abdominal Aortic Aneurysms

Considering a patient's anatomy and vascular conditions, aorto-femoral bypass is a treatment approach for the open repair of abdominal aortic aneurysms. This study aimed at evaluating changes in the remnant iliac artery and their correlation with the preservation state of retrograde flow from femoral anastomosis. Of 221 patients who underwent abdominal aortic aneurysm surgery between 2007 and 2022 in Pusan National University Hospital, 29 patients who underwent aorto-femoral bypass were included in this retrospective cohort study. Of these patients, 21 underwent aortobifemoral bypass and 8 underwent aortoiliac-and-femoral bypass. The change in size of the iliac artery from preoperative to postoperative and whether this difference in size depended on the status of postoperative retrograde flow were investigated. Additionally, factors affecting overall mortality and ischemic complications were identified. The median duration from operation to the last follow-up was 2069.5days (about 5.7years). The average age of the patients was 78.1years, and the proportion of males was 75.9%. In cases of disappearance of postoperative retrograde flow from the femoral anastomosis, the postoperative iliac artery size was significantly reduced compared to its preoperative size (18.4±18.9mm vs. 13.2±7.9mm, respectively; P=0.04). The group with maintained retrograde flow had significantly larger residual common iliac artery size than the group with disappearance of flow. (20.0±28.0mm vs. 14.6±8.5mm, respectively; P=0.02). Disappearance of retrograde flow was a significant factor in the iliac artery size reduction after surgery (odds ratio, 2.5; 95% confidence interval, 1.9-5.3; P=0.02). Three patients with maintained retrograde flow (18.8%) required intervention owing to an increase in the size of the iliac artery. The factors that significantly influenced overall death as analyzed by Cox proportional hazard regression were chronic obstructive pulmonary disease (hazard ratio, 36.8; 95% confidence interval, 1.6-870.0; P=0.03), peripheral arterial occlusive disease (hazard ratio, 12.7; 95% confidence interval, 1.4-115.8; P=0.02), and disappearance of retrograde flow (hazard ratio, 8.7; 95% confidence interval, 1.2-63.9; P=0.03). Among the open repair methods for abdominal aortic aneurysms, if retrograde flow was not maintained through femoral anastomosis when aorto-femoral bypass was performed, the size of the remaining iliac artery decreased. However, loss of retrograde flow increased long-term mortality. When aorto-femoral bypass is performed, regular imaging follow-up is necessary at appropriate intervals to check the remnant iliac artery and retrograde flow.