Abdominal Aortic Aneurysm Procedures Research Articles

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.

Adoption and clinical outcomes of fenestrated endovascular aneurysm repair in a regional, multistate community hospital system

ObjectiveComplex endovascular abdominal aortic aneurysm (AAA) repair techniques have evolved over the last decade, yet patterns of physician and hospital system adoption of fenestrated endovascular aneurysm repair (FEVAR) remain poorly defined. We investigated clinical outcomes, use trends, and surgeon and hospital experience for FEVAR in a large community hospital system. MethodsWe conducted a retrospective cohort study of all FEVAR procedures within our 5-state hospital system between April 2012 and June 2021. AAA repair volumes (open, EVAR, and FEVAR) were captured at the hospital and surgeon levels using Current Procedural Terminology and International Classification of Diseases codes. Clinical and outcomes data were collected for FEVAR patients. To consider if surgeon or hospital experience influenced outcomes, sequential case number was used to divide patients into surgeon experience and hospital experience groups. Inverse probability weighted and generalized linear mixed models, adjusted for demographics and comorbidities, were built to examine risk-adjusted outcomes for surgeon and hospital experience groups. ResultsOf 3850 patients treated with AAA procedures of any kind between 2012 and 2021, 160 (4.2%) underwent FEVAR. FEVAR procedures were performed by 34 different surgeons at 12 hospitals, with intraoperative complications and unplanned adjunctive procedures occurring in 18.8% (n = 30) and 19.4% (n = 31) of patients, respectively. Among FEVAR patients, in-hospital mortality was 1.3% (n = 2) and postoperative morbidity was 16.9% (n = 27). Renal function decline occurred postoperatively in 5.1% of patients. Early (<30 day) postoperative endoleaks occurred in 15.3% of patients (n = 21). Target vessel patency was 95.6% on initial postoperative imaging. Surgeon and hospital experience had a small positive impact on outcomes after the first one to three cases. Significant decreases in operative time, fluoroscopy time, and estimated blood loss were observed with increased surgeon experience, relative to a surgeon's first case (P < .05). There were lower odds of intraoperative complications after a surgeon's first case (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.03-0.77, for cases 2-3) or after a hospital's first one to three cases (OR, 0.19; 95% CI, 0.04-0.89, for cases 4-8; OR, 0.12; 95% CI, 0.03-0.55 for cases 9-49). ConclusionsClinical outcomes of FEVAR across our hospital system compare favorably with previously published reports. Although system-wide FEVAR adoption increased 3-fold over the last decade, FEVAR continued to be performed by a minority of hospitals in our system. The results from this cohort demonstrate low rates of adverse events, high rates of technical efficiency, and a small impact of surgeon and hospital experience, thereby supporting this advanced endovascular technology as a safe, efficacious, and generalizable treatment alternative to open repair for patients with complex aortic anatomy.

Editor's Choice – Comparison of Open Surgery and Endovascular Techniques for Juxtarenal and Complex Neck Aortic Aneurysms: The UK COMPlex AneurySm Study (UK-COMPASS) – Peri-operative and Midterm Outcomes

Treatment of juxtarenal and complex neck abdominal aortic aneurysms (AAAs) is now commonly by endovascular rather than open surgical repair (OSR). Published comparisons show poor validity and scientific precision. UK-COMPASS is a comparative cohort study of endovascular treatments vs. OSR for patients with an AAA unsuitable for standard on label endovascular aneurysm repair (EVAR). All procedures for AAA in England (November 2017 to October 2019) were identified, AAA anatomy assessed in a Corelab, peri-operative risk scores determined, and propensity scoring used to identify patients suitable for either endovascular treatment or OSR. Patients were stratified by aneurysm neck length (0 - 4 mm, 5 - 9 mm, or ≥ 10 mm) and operative risk; the highest quartile was considered high risk and the remainder standard risk. Death was the primary outcome measure. Endovascular treatments included fenestrated EVAR (FEVAR) and off label standard EVAR (± adjuncts). Among 8 994 patients, 2 757 had AAAs that were juxtarenal, short neck, or complex neck in morphology. Propensity score stratification and adjustment method comparisons included 1 916 patients. Widespread off label use of standard EVAR devices was noted (35.6% of patients). The adjusted peri-operative mortality rate was 2.9%, lower for EVAR (1.2%; p= .001) and FEVAR (2.2%; p= .001) than OSR (4.5%). In standard risk patients with a 0 - 4 mm neck, the mortality rate was 7.4% following OSR and 2.3% following FEVAR. Differences were smaller for patients with a neck length ≥ 5 mm: 2.1% OSR vs. 1.0% FEVAR. At 3.5 years of follow up, the overall mortality rate was 20.7% in the whole study population, higher following FEVAR (27.6%) and EVAR (25.2%) than after OSR (14.2%). However, in the 0 - 4 mm neck subgroup, overall survival remained equivalent. The aneurysm related mortality rate was equivalent between treatments, but re-intervention was more common after EVAR and FEVAR than OSR. FEVAR proves notably safer than OSR in the peri-operative period for juxtarenal aneurysms (0 - 4 mm neck length), with comparable midterm survival. For patients with short neck (5 - 9 mm) and complex neck (≥10mm) AAAs, overall survival was worse in endovascularly treated patients compared with OSR despite relative peri-operative safety. This warrants further research and a re-appraisal of the current clinical application of endovascular strategies, particularly in patients with poor general survival outlook owing to comorbidity and age.

The Treatment of Patients With an Unruptured Abdominal Aortic Aneurysm and a Concomitant Malignancy—Short- and Long-Term Results.

Having cancer adversely effects the outcome of treatment for an unruptured abdominal aortic aneurysm (AAA). A retrospective secondary analysis was performed on the basis of anonymized data from AOK, a German nationwide statutory health-insurance carrier. Data were evaluated from all of the 20 683 patients who underwent either endovascular (EVAR, 15 792) or open surgical (OAR, 4891) treatment for an unruptured AAA in the years 2010-2016. It was determined in each case whether the patient had a known cancer at the time of the procedure to treat AAA. The analysis concerned patient characteristics, periprocedural complications, and survival after the procedure up to 31 December 2018. 18 222 patients were free of cancer. In accordance with the known 6:1 sex ratio of AAA, 85.3% of the cancer-free patients and 92.8% of those with cancer were men. At the time of their AAA procedure, 1398 had cancer of the intestine (n = 318), lung (n = 301), prostate (n = 380), or bladder or ureter (n = 399). One-year survival after the AAA procedure was 91.5% in cancer-free patients and 84%, 74.4%, 85.8%, and 85.5% in the patients with the respective types of cancer just mentioned. Having cancer was a significant risk factor for periprocedural mortality (OR 1.326, p = 0.041) and for long-term survival (HR 1.515; p < 0.001). Having cancer is a risk factor for periprocedural mortality and long-term survival in patients undergoing treatment for an unruptured AAA. This implies that the indications for surgery should be considered with care, particularly in patients with lung cancer, whose 5-year survival rate is only 37.2%.

Anaesthetic management of an abdominal aortic aneurysmorrhaphy in Klippel-Trenaunay-Weber syndrome: a case report

BackgroundKlippel-Trenaunay-Weber syndrome (KTWS) is a rare congenital malformation. Although there have been few reports on anaesthetic management of patients with KTWS, there is a lack of data on anaesthetic management for abdominal aortic aneurysm (AAA) surgeries in these patients.Case presentationA 74-year-old man (height, 160 cm and body weight, 51.5 kg) with KTWS was scheduled for AAA replacement. Abdominal computed tomography (CT) showed prominent tortuosity below the abdominal aorta with an infrarenal abdominal aortic aneurysm, right common iliac artery aneurysm, and right external iliac artery aneurysm. Moreover, a remarkably noted arteriovenous fistula had developed between the aneurysm and peripheral artery. General anaesthesia was induced. Furthermore, a central venous catheter and an 8.5 French sheath in the left internal jugular vein were inserted. During the operation, bleeding from a collateral vessel in the cross-clamped aorta led the surgeon to decide to perform aneurysmorrhaphy. Intraoperatively, blood loss was 1500 ml, and 20 units of red blood cell concentrate were used.ConclusionsRegarding AAA procedures in patients with KTWS, aortic cross-clamping may not sufficiently intercept blood flow due to collateral vessels. In these patients, the anaesthesiologist must be prepared to transfuse blood more rapidly and frequently than during normal AAA procedures.

Trends in annual open abdominal aortic surgical volumes for vascular trainees compared with annual national volumes in the endovascular era

ObjectiveA prior analysis predicted a shortfall in open abdominal aortic repair (OAR) experience for vascular trainees resulting from the rapid adoption, and increased anatomic suitability, of endovascular aortic aneurysm repair (EVAR) technology. We explored how EVAR has transformed contemporary open aortic surgical education for vascular trainees. MethodsWe examined the Accreditation Council for Graduate Medical Education case volumes of open abdominal aortic aneurysm (AAA) repair and reconstruction for aortoiliac occlusive disease via aortoiliac or femoral bypass (AFB) from integrated vascular surgery residents (VSRs) and fellows (VSFs) graduating from 2006 to 2017 and compared them to the national estimates of total OAR (open AAA repair plus AFB) in the Agency for Healthcare Research and Quality National Inpatient Sample using the International Classification of Diseases, 9th and 10th revision, procedural codes. Changes over time were assessed using the χ2 test, Student’s t test, and linear regression. ResultsDuring the 12-year study period, the national annual total OAR and open AAA repair estimates had decreased: total OAR by 72.5% (estimate ± standard error: 2006, 24,255 ± 1185; vs 2017, 6690 ± 274; P < .001) and open AAA repair by 84.7% (estimate ± standard error: 2006, 18,619 ± 924; vs 2017, 2850 ± 168; P < .001). The AFB estimates had decreased by 33.0% (P < .001). The percentage of total OAR, open AAA repair, and AFB performed at teaching hospitals had significantly increased, from ∼55% to 80% (P < .001 for all). A 40.9% decrease was found for open AAA repairs performed by graduating VSFs (mean, 18.6 vs 11) but only a 6.9% decrease in total OAR cases (mean, 27.6 vs 25.7) owing to increasing AFB volumes (mean, 9.0 vs 14.7). The VSR graduates had consistently logged an average of ∼10 open AAA repairs, with a 31.0% increase in total OARs (mean, 23.2 vs 30.4), again secondary to increasing AFB volumes (mean, 11.4 vs 17.5). Although an absolute decrease was found in open aortic experience for VSFs, the rate of decline for the total OAR case volumes was not significantly different after VSR programs had been established (P = .40). ConclusionsAs the incidence has decreased nationally, the use of OAR has been shifting toward teaching hospitals. Although open AAA procedures for trainees have been declining with the increased use of EVAR, open aortic reconstruction for aortoiliac occlusive disease has been increasing, playing an important role in ensuring that vascular trainees continue to have satisfactory OAR experience sufficient for meeting minimum graduation requirements. Strategies to maintain and maximize the education and experience from these cases should be the top priority for vascular surgery program directors.

Non-guideline-compliant endovascular abdominal aortic aneurysm repair in women is associated with increased mortality and reintervention compared with men.

Sex-based disparities in surgical outcomes have emerged as an important focus in contemporary healthcare delivery. Likewise, the appropriate usage of endovascular abdominal aortic aneurysm repair (EVAR) in the United States remains a subject of ongoing controversy, with a significant number of U.S. EVARs failing to adhere to the Society for Vascular Surgery (SVS) clinical practice guideline (CPG) diameter thresholds. The purpose of the present study was to determine the effect of sex among patients undergoing EVAR that was not compliant with the SVS CPGs. All elective EVAR procedures for abdominal aortic aneurysms without a concomitant iliac aneurysm (≥3.0cm) in the SVS Vascular Quality Initiative were analyzed (2015-2019; n= 25,112). SVS CPG noncompliant repairs were defined as a size of<5.5cm for men and<5.0cm for women. The primary endpoint was 30-day mortality. The secondary endpoints were all-cause mortality, complications, and reintervention. Logistic regression was performed to control for surgeon- and patient-level factors. Freedom from the endpoints was determined using the Kaplan-Meier method. Noncompliant EVAR was performed in 9675 patients (38.5%). Although men were significantly more likely to undergo such procedures (90% vs 10%; odds ratio [OR], 3.1; 95% confidence interval [CI], 2.9-3.4; P< .0001), the 30-day mortality was greater for the women than the men (1.8% vs 0.5%; P= .0003). Women also experienced significantly higher rates of multiple complications, including postoperative myocardial infarction (1% vs 0.3%; P= .006), respiratory failure (1.4% vs 0.6%; P= .01), intestinal ischemia (0.7% vs 0.2%; P= .003), access vessel hematoma (3% vs 1.2%; P= .0006), and iliac access vessel injury (2.4% vs 0.8%; P< .0001). Additionally, women experienced increased overall 1-year reintervention rates (11.5% vs 5.8%; P< .0001). In the adjusted analysis, 30-day mortality and any in-hospital complication risk remained significantly greater for the women (30-day death: OR, 3.1; 95% CI, 1.6-5.8; P= .0005; in-hospital complication: OR, 1.9; 95% CI, 1.4-2.6; P< .0001). Women also experienced increased reintervention rates over time compared with men (OR, 1.5; 95% CI, 1.1-2.2; P= .02). Although men were more likely to undergo non-CPG compliant EVAR, women experienced increased short-term morbidity and 30-day mortality and higher rates of reintervention when undergoing non-CPG compliant EVAR. These unanticipated findings necessitate increased scrutiny of current U.S. sex-based EVAR practice and should caution against the use of non-CPG compliant EVAR for women.

Intensive versus standard blood pressure control and vascular procedures: insights from the Systolic Blood Pressure Intervention Trial

Abstract Background The Systolic Blood Pressure Intervention Trial (SPRINT) found that intensive versus standard blood pressure control reduced cardiovascular (CV) morbidity and mortality. Previous studies have shown that control of blood pressure reduces the risk of stroke and is one of the most modifiable risk factors for carotid artery disease. On the other hand, data on effect of blood pressure control on peripheral artery disease are more diverse. In addition, it is unknown whether intensive blood pressure control affects the risk of vascular procedures. Purpose To assess the relationship between intensive blood pressure control and incident vascular procedures. Methods SPRINT was a randomized, controlled trial comprising 9,361 individuals ≥50 years of age at high CV risk but without diabetes who had a systolic BP (SBP) 130–180 mmHg. Patients were randomized to intensive (target SBP &amp;lt;120mmHg) or standard antihypertensive treatment (target SBP &amp;lt;140mmHg). The primary efficacy endpoint was the composite of acute coronary syndromes, stroke, heart failure, or death from CV causes. The primary safety endpoint was the composite of serious adverse events. We examined the risk of composite and individual vascular procedures with intensive versus standard blood pressure control. We further examined subgroup heterogeneity using interaction analyses. Results During a median follow-up time of 3.3 years (range 0–5.5 years), a total of 174 (1.9%) composite vascular procedures were recorded. Intensive blood pressure control did not significantly reduce the risk of composite vascular procedures (intensive blood pressure control, 76 (1.6%) versus standard blood pressure control, 98 (2.1%), hazard ratio 0.76, 95% confidence interval, 0.57 to 1.03; P=0.08) (Figure 1). Similarly, the risks of the individual endpoints of carotid angioplasty, carotid endarterectomy, peripheral angioplasty or thrombolysis, lower extremity amputation for ischemia and gangrene, surgical or vascular procedure for abdominal aortic aneurysm, surgical or vascular procedure for thoracic aortic aneurysm, and surgical or vascular procedure for other problems were not significantly affected (P≥0.05 for all). Intensive blood pressure control reduced the risk of peripheral vascular surgery (intensive blood pressure control, 7 (0.2%) versus standard blood pressure control, 21 (0.5%), hazard ratio 0.33, 95% confidence interval, 0.14 to 0.77; P=0.01), though this was based on a small number of events. The safety and efficacy of intensive BP lowering was not modified by chronic kidney disease, age, sex, race, previous cardiovascular disease, or baseline systolic blood pressure tertile (P≥0.05 for all). Conclusions In SPRINT, intensive versus standard blood pressure control did not reduce the risk of composite incident vascular procedures. Figure 1. Vascular procedures Funding Acknowledgement Type of funding source: None

Open Abdominal Aortic Aneurysm Repair Is Associated with Higher Mortality Among Nonobese Patients and Higher Risk of Deep Wound Infections Among Obese Patients

Prevalence of obesity in the United States is increasing. The impact of obesity on outcomes after endovascular and open abdominal aortic aneurysm (AAA) repair is largely unknown. The purpose of this analysis was to compare the postoperative outcomes between obese and nonobese patients after these operations. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from years 2013-2015 was analyzed. Preoperative, intraoperative, and postoperative variables were compared between obese and nonobese patient groups. Then obese and nonobese patients were divided into 2 groups each, based on the type of surgery (endovascular repair of abdominal aortic aneurysms (EVAR) versus. open AAA repair), and the outcomes were compared. Then multivariant analysis was used to compare impact of operative modality on outcomes for obese and nonobese patients. A total of 6,859 patients (men 80%, women 20%) underwent surgical procedures for AAA during this time period. Among these patients, 2,218 (32.3%) had body mass index (BMI) ≥30, and 4,641 (67.7%) had BMI <30. Obese patients were less likely to be>80years old, women, nonwhites, and smokers. Obese patients had lower mortality and higher risk of deep wound infections after surgery (P<0.05). Among the obese patients, 83.1% underwent EVAR and 16.9% underwent open AAA repair; patients undergoing EVAR had shorter operative times, shorter length of hospital stays, and mortality (P<0.05). Among nonobese patients, 81% underwent EVAR and 19% underwent open AAA repair. Patients undergoing EVAR had shorter duration of operation, length of hospital stay, and mortality (P<0.05). Overall, mortality was the highest among nonobese patients undergoing open AAA repair (odds ratio (OR) 0.66, confidence interval (CI) 0.44-0.99, P<0.05). Incidence of deep wound infections was the highest among obese patients undergoing open AAA repair (OR 4.3, CI: 1.2-14.6, P<0.05). Nonobese patients have high mortality after open AAA repair, and obese patients have higher incidence of deep wound infections after open AAA repair. For patients deemed appropriate anatomic candidates, EVAR should be preferred for nonobese patients to improve mortality and for obese patients to reduce the incidence of deep wound infections.

National Numbers of Secondary Aortic Reinterventions after Primary Abdominal Aortic Aneurysm Surgery from the Dutch Surgical Aneurysm Audit

Long-term secondary aortic reinterventions (SARs) can be a sign of (lack of) effectiveness of abdominal aortic aneurysm (AAA) surgery. This study provides insight into the national number of SARs after primary AAA repair by endovascular aneurysm repair (EVAR) or by open surgical repair in the Netherlands. Observational study included all patients undergoing SAR between 2016 and 2017, registered in the compulsory Dutch Surgical Aneurysm Audit (DSAA). The DSAA started in 2013, SARs are registered from 2016. Characteristics of SAR and postoperative outcomes (mortality/complications) were analyzed, stratified by urgency of SAR. Data of SARs were merged with data of their preceded primary AAA repair, registered in the DSAA after January 2013. In these patients undergoing SAR, treatment characteristics of the preceded primary AAA repair were additionally described, with focus on differences between stent grafts. Between 2016 and 2017, 691 patients underwent SAR, this concerned 9.3% of all AAA procedures (infrarenal/juxtarenal/suprarenal) in the Netherlands (77% elective/11% acute symptomatic/12% ruptured). Endoleak (60%) was the most frequent indication for SAR. SARs were performed with EVAR in 66%. Postoperative mortalities after SAR were 3.4%, 11%, and 29% in elective, acute symptomatic, and ruptured patients, respectively. In 26% (n=181) of the patients undergoing SAR their primary AAA repair was performed after January 2013 and data of primary and SAR procedures could be merged. In 93% (n=136), primary AAA repair was EVAR. Endografts primarily used were nitinol/polyester (62%), nitinol/polytetrafluoroethylene (8%), endovascular sealing (21%), and others (9%), compared with their national market share of 76% (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.38-0.71), 15% (OR, 0.50; CI, 0.29-0.89), 4.9% (OR, 5.04; CI, 3.44-7.38), and 4.1% (OR, 2.81; CI, 1.66-4.74), respectively. In the Netherlands, about one-tenth of the annual AAA procedures concerns an SAR. A quarter of this cohort had an SAR within 1-5years after their primary AAA repair. Most SARs followed after primary EVAR procedures, in which an overrepresentation of endovascular sealing grafts was seen. Postoperative mortality after SAR is comparable with primary AAA repair.

Retrospective review of abdominal aortic aneurysm deaths in New Zealand: what proportion of deaths is potentially preventable by a screening programme in the contemporary setting?

ObjectivesTo describe the proportions of people dying from abdominal aortic aneurysm (AAA) who might have benefited from a formal screening programme for AAA.DesignRetrospective cross-sectional review of deaths.Setting and study populationsAll...

Epidural Analgesia in Open Thoraco-Abdominal Aortic Aneurysm Repair

Epidural analgesia improves pain control and outcomes of abdominal aortic aneurysm procedures, while the effect of thoracic epidural analgesia on thoraco-abdominal aortic aneurysm (TAAA) repair is unknown. The aim of the study was to evaluate thoracic epidural analgesia effects in patients undergoing open TAAA repair in terms of pain control and clinically relevant outcomes. This was a retrospective study of a prospectively collected database. Patients undergoing open TAAA repair between January 2009 and December 2016. Four hundred and fifty-nine consecutive patients were included. Thoracic epidural analgesia was used in 409 (89%) of cases. On multivariable analysis, patients who received thoracic epidural analgesia experienced reduced post-operative pain (odds ratio [OR] 0.003, 95% confidence interval [CI] 0.0007–0.009; p < .001), a lower rate of acute kidney injury (AKI; OR 0.39, 95% CI 0.21–0.71 [p = .002]), atrial fibrillation (OR 0.47, 95% CI 0.23–0.95; p = .04), acute myocardial infarction (AMI; OR 0.189, 95% CI 0.05–0.64; p = .008), and paraplegia (OR 0.31, 95% CI 0.157–0.615; p = .001) compared with the conventional analgesia (CA) group. After propensity score matching, 43 patients in the CA group were compared with 43 in thoracic epidural analgesia group. On case match analysis thoracic epidural analgesia showed a significant reduction in post-operative pain (p < .001) and no differences in the incidence of AKI, atrial fibrillation, AMI, and paraplegia. In the thoracic epidural analgesia group there were no epidural haematomas. Thoracic epidural analgesia was effective in reducing post-operative pain with no effect on major post-operative complications. The use of thoracic epidural analgesia, if not contraindicated, might be considered in clinical practice, even in patients undergoing Open TAAA repair. Whether a better post-operative management enhances patient's recovery in this setting remains to be tested.

Synchronous Gastrointestinal Tumor and Abdominal Aortic Aneurysm or Dissection Treated with Endovascular Aneurysm Repair Followed by Tumor Resection.

Objective To evaluate the strategy in the management of patients with synchronous gastrointestinal tumor and abdominal aortic aneurysm (AAA) or abdominal aortic dissection (AAD) undergoing endovascular repair followed by tumor resection. Materials and Methods Five patients with synchronous gastrointestinal tumor and AAA or AAD were treated by endovascular repair followed by tumor resection. Clinical data were retrospectively analyzed with respect to the management strategy, safety, and outcome. Results Endovascular repair was technically successful in all patients. All the stents were well positioned and well patent, and the AAA (n = 3) or AAD (n = 2) were correctly excluded without endoleaks. After endovascular repair, all patients underwent resection of gastrointestinal tumor. No late mortality or major complications related to the two procedures were observed in the subsequent follow-up. Conclusion Our results demonstrate that EVAR could significantly shorten the delay between AAA and gastrointestinal procedure with an excellent postoperative outcome. If the anatomical criteria are satisfied, EVAR followed by tumor resection might be an effective treatment for concomitant AAA and gastrointestinal tumor.

Five-year results of endovascular aortic repair used according to instructions for use give a good general outcome for abdominal aortic aneurysm.

Objectives:The primary aim of this study was to investigate the rate of sac enlargement and secondary procedures after 5 years when instructions for use are strictly applied with endovascular aortic repair. The secondary aim was to investigate if strict indications with endovascular aortic repair, rendering more open operations, would change the general outcome of patients with abdominal aortic aneurysm.Materials and methods:Patients having their abdominal aortic aneurysm procedure in a single institution between 01 January 2002 and 31 December 2006 were included. Indications for endovascular aortic repair were as follows: aortic neck: length 15 mm or more, diameter 32 mm or less and straight configuration; iliac arteries: length > 10 mm, 7.5–20 mm in diameter. Sac enlargement was defined as an increase in diameter of 5 mm or more.Results:A total of 123 patients were intended to be treated electively with endovascular aortic repair from 2002 to 2007 using Cook Zenith stent grafts. In the same period, 147 patients were treated with elective open repair. At 5 years, 7.3% (N = 9) of the elective intended-to-treat patients with endovascular aortic repair had a sac enlargement. Thirty-five percent of the patients were registered with endoleaks, 13% of the patients had secondary procedures, 12.2% of the patients had early and 6.5% late complications during the follow-up period. Aneurysm rupture was seen in 1.6% of the patients. During the 5-year follow-up period, 34 (27.6%) of the endovascular aortic repair patients died. Five-year mortality for open repair was 23.8%, and 12.2% of the open repair patients had secondary procedures.Conclusion:Endovascular aortic repair for abdominal aortic aneurysm in accordance with instructions for use gives a low long-term risk for increased diameter and low rate of secondary procedures. There was similar mortality after elective endovascular aortic repair and open repair for abdominal aortic aneurysm. Applying endovascular aortic repair according to instructions for use does not seem to change the general outcome of patients with abdominal aortic aneurysm but improves the outcome with the method.

Frequency of 30-Day Readmission and Its Causes After Endovascular Aneurysm Intervention of Abdominal Aortic Aneurysm (from the Nationwide Readmission Database)

Endovascular aneurysm intervention (EVAI) is one of the most commonly performed vascular interventions for abdominal aortic aneurysm (AAA). Data regarding 30-day readmission rates after EVAI are poorly reported in the literature. We used the United States Nationwide Readmission Database from 2010 to 2014 to identify all patients ≥18 years who were readmitted within 30 days after a hospital discharge for EVAI of the AAA. Incidence, etiologies, predictors of 30-day readmission, and trends of readmission rates were analyzed. In 138,014 patients who survived to discharge after an EVAI procedure for AAA, 14,146 (10.24%) were readmitted within 30 days. Median time to readmission was 11 days. Cardiac causes (16.34%) followed by infections (15.40%) and vascular complications (12.86%) were common etiologies of readmission. Greater patient age, female sex, coexisting co-morbidities such as heart failure, atrial fibrillation, peripheral vascular disease, lung disease, and chronic kidney disease were independent predictors of 30-day readmission. In-hospital complications during an index admission such as major bleeding or vascular complications were also predictive of 30-day readmission. Trend analysis showed a progressive decline in readmission rates from 11.3% in 2010 to 9.6% in 2014 (ptrend <0.0001), 20% lower odds in 2014 compared with 2010 (odds ratio 0.80, 95% confidence interval 0.72 to 0.87, p <0.0001). In this contemporary study of EVAI for AAA, nearly 1 in 10 patients was readmitted within 30 days of discharge after an index admission. Cardiac complications and infections were common causes of readmission within 30 days.

Epidural Analgesia in Open Thoraco-abdominal Aortic Aneurysm Repair

Epidural analgesia improves pain control and outcomes of abdominal aortic aneurysm procedures, while the effect of thoracic epidural analgesia on thoraco-abdominal aortic aneurysm (TAAA) repair is unknown. The aim of the study was to evaluate thoracic epidural analgesia effects in patients undergoing open TAAA repair in terms of pain control and clinically relevant outcomes. This was a retrospective study of a prospectively collected database. Patients undergoing open TAAA repair between January 2009 and December 2016. Four hundred and fifty-nine consecutive patients were included. Thoracic epidural analgesia was used in 409 (89%) of cases. On multivariable analysis, patients who received thoracic epidural analgesia experienced reduced post-operative pain (odds ratio [OR] 0.003, 95% confidence interval [CI] 0.0007-0.009; p<.001), a lower rate of acute kidney injury (AKI; OR 0.39, 95% CI 0.21-0.71 [p=.002]), atrial fibrillation (OR 0.47, 95% CI 0.23-0.95; p=.04), acute myocardial infarction (AMI; OR 0.189, 95% CI 0.05-0.64; p=.008), and paraplegia (OR 0.31, 95% CI 0.157-0.615; p=.001) compared with the conventional analgesia (CA) group. After propensity score matching, 43 patients in the CA group were compared with 43 in thoracic epidural analgesia group. On case match analysis thoracic epidural analgesia showed a significant reduction in post-operative pain (p<.001) and no differences in the incidence of AKI, atrial fibrillation, AMI, and paraplegia. In the thoracic epidural analgesia group there were no epidural haematomas. Thoracic epidural analgesia was effective in reducing post-operative pain with no effect on major post-operative complications. The use of thoracic epidural analgesia, if not contraindicated, might be considered in clinical practice, even in patients undergoing open TAAA repair. Whether a better post-operative management enhances patient's recovery in this setting remains to be tested.

Instrumental variable based estimation under the semiparametric accelerated failure time model.

Randomized controlled trials are the gold standard for estimating causal effects of treatments or interventions, but in many cases are too costly, too difficult, or even unethical to conduct. Hence, many pressing medical questions can only be investigated using observational studies. However, direct statistical modeling of observational data can result in biased estimates of treatment effects due to unmeasured confounding. In certain cases, instrumental variable based techniques can be used to remove such biases. These techniques are indeed widely studied and used in econometrics under parametric outcome models, however limited works have focused on the utilization of instrumental variables in survival analysis, where semiparametric models are often necessary. The additional challenge in analyzing survival data is the presence of censoring. In this paper, we introduce an instrumental variable method that relaxes the strong assumptions of previous works and provides consistent estimation of the causal effect of a treatment on a survival outcome. We demonstrate the efficacy of our method in various simulated settings and an analysis of Medicare enrollment data comparing two prevalent surgical procedures for abdominal aortic aneurysm from an observational study.

Early results with the custom-made Fenestrated Anaconda aortic cuff in the treatment of complex abdominal aortic aneurysm

ObjectiveThe objective of this study was to investigate the feasibility of a specific custom-made fenestrated aortic cuff in the treatment of complex abdominal aortic aneurysms (AAAs). MethodsBetween 2013 and 2016, a total of 57 custom-made Fenestrated Anaconda (Vascutek, Inchinnan, Scotland, UK) aortic cuffs were placed in 38 centers worldwide. All centers were invited to participate in this retrospective analysis. Postoperative and follow-up data included the presence of adverse events, necessity for reintervention, and renal function. ResultsFifteen clinics participated, leading to 29 cases. Median age at operation was 74 years (interquartile range [IQR], 71-78 years); five patients were female. Two patients were treated for a para-anastomotic AAA after open AAA repair, 19 patients were treated because of a complicated course after primary endovascular AAA repair, and 8 cases were primary procedures for AAA. A total of 76 fenestrations (mean, 2.6 per case) were used. Four patients needed seven adjunctive procedures. Two patients underwent conversion, one because of a dissection of the superior mesenteric artery and one because of perforation of a renal artery. Median operation time was 225 minutes (IQR, 150-260 minutes); median blood loss, 200 mL (IQR, 100-500 mL); and median contrast volume, 150 mL (IQR, 92-260 mL). Primary technical success was achieved in 86% and secondary technical success in 93%. The 30-day morbidity was 7 of 29 with a mortality rate of 4 of 29. Estimated glomerular filtration rate remained unchanged before and after surgery (76 to 77 mL/min/m2). Between preoperative and median follow-up of 11 months, estimated glomerular filtration rate was reduced statistically significantly (76 to 63 mL/min/m2). During follow-up, 9 cases had an increase in aneurysm sac diameter (5 cases >5 mm); 14 cases had a stable or decreased aneurysm sac diameter; and in 2 cases, no aneurysm size was reported. No type I endoleak was reported, and two cases with a type III endoleak were treated by endovascular means during follow-up. Survival, reintervention-free survival, and target vessel patency at 1 year were 81% ± 8%, 75% ± 9%, and 99% ± 1%, respectively. After 2 years, these numbers were 81% ± 8%, 67% ± 11%, and 88% ± 6%, respectively. During follow-up, the two patients with a type III endoleak needed endograft-related reinterventions. ConclusionsTreatment with this specific custom-made fenestrated aortic cuff is feasible after complicated previous (endovascular) aortic repair or in complex AAAs. The complexity of certain AAA cases is underlined in this study, and the Fenestrated Anaconda aortic cuff is a valid option in selected cases in which few treatment options are left.

Thirty-day readmission and mortality among Medicare beneficiaries discharged to skilled nursing facilities after vascular surgery

BackgroundReadmission within 30 d of an acute hospital stay is frequent, costly, and increasingly subject to penalties. Early readmission is most common after vascular surgery; these patients are often discharged to skilled nursing facilities (SNFs), making postacute care an essential partner in reducing readmissions. We characterize 30-day readmissions among vascular surgery patients discharged to SNF to provide evidence for this understudied segment of readmission after specialty surgery. MethodsWe utilize the Centers for Medicare & Medicaid Services Chronic Conditions Warehouse, a longitudinal 5% national random sample of Medicare beneficiaries to study 30-day readmission or death after discharge to SNF following abdominal aortic aneurysm repair or lower extremity revascularization from 2005-2009. Descriptive statistics and logistic regression with Least Adaptive Shrinkage and Selection Operator were used for analysis. ResultsTwo thousand one hundred ninety-seven patients underwent an abdominal aortic aneurysm procedure or lower extremity revascularization at 686 hospitals and discharged to 1714 SNFs. Eight hundred (36%) were readmitted or had died at 30 d. In adjusted analysis, predictors of readmission or death at 30 d included SNF for-profit status (OR [odds ratio] = 1.2; P = 0.032), number of hospitalizations in the previous year (OR = 1.06; P = 0.011), number of comorbidities (OR = 1.06; P = 0.004), emergent procedure (OR = 1.69; P < 0.001), renal complication (OR = 1.38; P = 0.003), respiratory complication (OR = 1.45; P < 0.001), thromboembolic complication (OR = 1.57; P = 0.019), and wound complication (OR = 0.70; P = 0.017). ConclusionsPatients discharged to SNF following vascular surgery have exceptionally high rates of readmission or death at 30 d. Many factors predicting readmission or death potentially modify decision-making around discharge, making early detection, discharge planning, and matching patient needs to SNF capabilities essential to improving outcomes.

Trends in open abdominal exposure among vascular surgery trainees

BackgroundThis retrospective study evaluates the trends in open abdominal surgery cases among integrated vascular surgery residents compared with their 5 + 2 counterparts. MethodsThe Accreditation Council for Graduate Medical Education (ACGME) case logs between 2007 and 2016 were collected from a pool of 9861 residents and fellows from 371 institutions. Trainees were grouped into three categories: general surgery residency (GSR), integrated vascular surgery residency (IVSR), and vascular surgery fellowship in the United States. Inclusion criteria were specific to open abdominal cases of or including the anatomy adjacent to the aorta performed by the surgeon chief. ResultsThe 5 + 2 graduates have obtained significantly more open vascular surgery training experience than their IVSR graduate counterparts (P < .01). GSR chief residents performed significantly more open abdomen cases than IVSR chief residents (P < .01). IVSR chiefs performed significantly more open vascular procedures than GSR chiefs (P < .01). On the completion of vascular surgery fellowship, 5 + 2 graduates had significantly more open abdominal aortic aneurysm (AAA) exposure during training than IVSR graduates did (P < .01); however, IVSR trainees had performed significantly more open AAA procedures than their GSR counterparts (P < .01). ConclusionsUp to 2016, graduates of the 5 + 2 vascular training pathway had significantly higher open abdominal exposure than those of the IVSR track. However, graduates of the IVSR track had significantly higher open AAA exposure than GSR graduates.