A risk-adjusted and anatomically stratified cohort comparison study of open surgery, endovascular techniques and medical management for juxtarenal aortic aneurysms-the UK COMPlex AneurySm Study (UK-COMPASS): a study protocol.

INTRODUCTION: In one-third of all abdominal aortic aneurysms (AAAs), the aneurysm neck is short (juxtarenal) or shows other adverse anatomical features rendering operations more complex, hazardous and expensive. Surgical options include open surgical repair and endovascular aneurysm repair (EVAR) techniques including fenestrated EVAR, EVAR with adjuncts (chimneys/endoanchors) and off-label standard EVAR. The aim of the UK COMPlex AneurySm Study (UK-COMPASS) is to answer the research question identified by the National Institute for Health Research Health Technology Assessment (NIHR HTA) Programme: 'What is the clinical and cost-effectiveness of strategies for the management of juxtarenal AAA, including fenestrated endovascular repair?' METHODS AND ANALYSIS: UK-COMPASS is a cohort study comparing clinical and cost-effectiveness of different strategies used to manage complex AAAs with stratification of physiological fitness and anatomical complexity, with statistical correction for baseline risk and indication biases. There are two data streams. First, a stream of routinely collected data from Hospital Episode Statistics and National Vascular Registry (NVR). Preoperative CT scans of all patients who underwent elective AAA repair in England between 1 November 2017 and 31 October 2019 are subjected to Corelab analysis to accurately identify and include every complex aneurysm treated. Second, a site-reported data stream regarding quality of life and treatment costs from prospectively recruited patients across England. Site recruitment also includes patients with complex aneurysms larger than 55 mm diameter in whom an operation is deferred (medical management). The primary outcome measure is perioperative all-cause mortality. Follow-up will be to a median of 5 years. ETHICS AND DISSEMINATION: The study has received full regulatory approvals from a Research Ethics Committee, the Confidentiality Advisory Group and the Health Research Authority. Data sharing agreements are in place with National Health Service Digital and the NVR. Dissemination will be via NIHR HTA reporting, peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: ISRCTN85731188.

Outcomes of persistent intraoperative type Ia endoleak after standard endovascular aneurysm repair.

OBJECTIVE: This study analyzed outcomes for patients with persistent intraoperative type Ia endoleaks after standard endovascular aneurysm repair (EVAR). METHODS: The study group was identified from a consecutive cohort of 209 patients undergoing EVAR in a tertiary center in the United Kingdom during a 2-year period. Data prospectively collected on departmental computerized databases were retrospectively analyzed. Primary outcome parameters were defined as freedom from type Ia endoleak, EVAR-related reintervention, aneurysm rupture, and aneurysm-related mortality. RESULTS: A completion angiogram identified 44 patients (21%) as having a type Ia endoleak, and 33 (75%) had a persistent endoleak after intraoperative adjunctive procedures, including repeated balloon moulding, aortic cuff extension, and Palmaz stent (Cordis, Miami Lakes, Fla) deployment. In the 11 patients (25%) whose endoleak was successfully abolished intraoperatively, there was no recurrence of type Ia endoleak or secondary intervention to treat type 1a endoleak during a median follow-up period of 27 months. Of the 33 patients with persistent endoleak, 31 (94%) demonstrated resolution of the endoleak on first surveillance computed tomography angiography. One patient was lost to follow-up. Embolization of the endoleak in another patient was successful using Onyx (Micro Therapeutics, Inc, Irvine, Calif) 8 days after the initial procedure. No type Ia endoleak was identified after this on any surveillance imaging, and the patient was alive 28 months later with a stable aneurysm size. In the rest of the patients, no recurrence of the endoleak in any subsequent imaging was noticed, and no secondary intervention was required during follow-up. No aneurysm-related deaths occurred, and 91% of the patients had a stable or shrinking aneurysm. CONCLUSIONS: Despite adjunctive intraoperative maneuvers, persistent type Ia endoleaks can be relatively common. Our study indicates that they may be observed in selected patients. Further research is required to investigate the natural course and management of type Ia endoleaks identified intraoperatively.

Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery.

BACKGROUND: Compelling evidence from large randomized trials demonstrates the salutary effects of statins on primary and secondary protection from adverse cardiovascular events in high-risk populations. Our objective was to investigate the role of perioperative statin therapy in noncardiac vascular and endovascular surgery. METHODS: Electronic information sources were systematically searched to identify studies comparing outcomes after noncardiac surgical or endovascular arterial reconstruction in patients who were and were not taking statin in the perioperative or peri-interventional period. The Cochrane Collaboration's tool and the Newcastle-Ottawa scale were used to assess the methodologic quality and risk of bias of the selected studies. Random-effects models were applied to calculate pooled outcome data. RESULTS: Four randomized controlled trials and 20 observational cohort or case-control studies were selected for analysis. The randomized studies enrolled 675 patients, and the observational studies enrolled 22,861 patients. Statin therapy was associated with a significantly lower risk of all-cause mortality (odds ratio [OR], 0.54; 95% CI, [CI], 0.38-0.78), myocardial infarction (OR, 0.62; 95% CI, 0.45-0.87), stroke (OR, 0.51; 95% CI, 0.39-0.67), and the composite of myocardial infarction, stroke, and death (OR, 0.45; 95% CI, 0.29-0.70). No significant differences in cardiovascular mortality (OR, 0.82; 95% CI, 0.41-1.63) and the incidence of kidney injury (OR, 0.90; 95% CI, 0.58-1.39) between the groups were identified. CONCLUSIONS: Our analysis demonstrated that statin therapy is beneficial in improving operative and interventional outcomes and should be considered as part of the optimization strategy for prevention of adverse cardiovascular and cerebrovascular events and death.

Computational fluid dynamic analysis of the effect of morphologic features on distraction forces in fenestrated stent grafts.

OBJECTIVE: Secure fixation of endovascular stent grafts is essential for successful endovascular aneurysm repair. Hemodynamic distraction forces are generated by blood pressure and blood flow and act against fixation force to encourage migration that may eventually lead to late stent graft failure. The aim of this in silico study was to determine which morphologic features were associated with greater distraction force. METHODS: Computer models of 54 in situ fenestrated stent grafts were constructed from postoperative computed tomography scans by use of image processing software. Computational fluid dynamic analysis was then performed by use of a commercial finite volume solver with boundary conditions representative of peak systole. Distraction force results were obtained for each component of the stent graft. Distraction force was correlated with lumen cross-sectional area (XSA) at the inlet and outlet of components and was compared between groups of components, depending on the magnitude of four predefined angles within the aortoiliac territory that we describe in detail. RESULTS: Median total resultant distraction force (RDF) acting on the fenestrated proximal bodies was 4.8 N (1.3-15.7 N); bifurcated distal bodies, 5.6N (1.0-8.0 N); and limb extensions, 1.7 N (0.6-8.4N). Inlet XSA exhibited strong, positive correlation with total RDF in proximal body and distal body components (Spearman correlation coefficient ρ, 0.883 and 0.802, respectively). Outlet XSA exhibited a similarly strong, positive correlation with total RDF in limb extension components (ρ, 0.822). Outlet angulation ≥ 45 degrees was associated with greater total RDF in the limb extension components only (P = .004). CONCLUSIONS: For a given blood pressure, XSA was the most important morphologic determinant of total RDF. Angulation within the aorta was not large enough to influence this, whereas iliac angulation affecting outlet angulation of limb extension components was associated with significantly greater total RDF.

Closure technique after carotid endarterectomy influences local hemodynamics.

BACKGROUND: Meta-analysis supports patch angioplasty after carotid endarterectomy (CEA); however, studies indicate considerable variation in practice. The hemodynamic effect of a patch is unclear and this study attempted to elucidate this and guide patch width selection. METHODS: Four groups were selected: healthy volunteers and patients undergoing CEA with primary closure, trimmed patch (5 mm), or 8-mm patch angioplasty. Computer-generated three-dimensional models of carotid bifurcations were produced from transverse ultrasound images recorded at 1-mm intervals. Rapid prototyping generated models for flow visualization studies. Computational fluid dynamic studies were performed for each model and validated by flow visualization. Mean wall shear stress (WSS) and oscillatory shear index (OSI) maps were created for each model using pulsatile inflow at 300 mL/min. WSS of <0.4 Pa and OSI >0.3 were considered pathological, predisposing to accretion of intimal hyperplasia. The resultant WSS and OSI maps were compared. RESULTS: The four groups comprised 8 normal carotid arteries, 6 primary closures, 6 trimmed patches, and seven 8-mm patches. Flow visualization identified flow separation and recirculation at the bifurcation increased with a patch and was related to the patch width. Computational fluid dynamic identified that primary closure had the fewest areas of low WSS or elevated OSI but did have mild common carotid artery stenoses at the proximal arteriotomy that caused turbulence. Trimmed patches had more regions of abnormal WSS and OSI at the bifurcation, but 8-mm patches had the largest areas of deleteriously low WSS and high OSI. Qualitative comparison among the four groups confirmed that incorporation of a patch increased areas of low WSS and high OSI at the bifurcation and that this was related to patch width. CONCLUSIONS: Closure technique after CEA influences the hemodynamic profile. Patching does not appear to generate favorable flow dynamics. However, a trimmed 5-mm patch may offer hemodynamic benefits over an 8-mm patch and may be the preferred option.

Combined cardiac surgery and endovascular repair of abdominal aortic aneurysms.

PURPOSE: To report an initial experience of concomitant endovascular repair of abdominal aortic aneurysms (AAA) and cardiac surgery. METHODS: Records for 10 consecutive patients (all men; median age 68 years, range 60-79) with AAA treated by a multidisciplinary team at a tertiary specialist center were retrospectively reviewed. Each patient had independent indications for surgical correction of their cardiac disease and AAAs. The patients underwent endovascular aneurysm repair (EVAR) followed by cardiac surgery under the same anesthesia. Eight patients had concomitant coronary artery bypass grafting (CABG; 4 off-pump), 1 patient had CABG and left ventricular aneurysmectomy, and 1 patient required aortic root replacement. RESULTS: All combined procedures were performed successfully under a single general anesthesia and took a median of 508 minutes (range 425-625). Median intensive care stay was 3 days (range 2-4), while hospital stay was 8 days (range 7-21) days. There were no deaths in-hospital or within 30 days. Complications were minor and self-limiting; there were no instances of renal failure. At a median follow-up of 29 months (range 14-38), no EVAR-related secondary interventions were required. CONCLUSION: Concomitant EVAR and cardiac surgery delivered by a multidisciplinary team is feasible, appears safe, and eliminates the risk associated with staged operations. Improved patient satisfaction and efficient use of resources are potential advantages.

Migration of fenestrated aortic stent grafts.

OBJECTIVE: This article reports the incidence, timing, and related sequelae for proximal and distal migration of the Zenith Fenestrated AAA Endovascular Graft (Cook Medical, Bloomington, Ind) used to treat abdominal aortic aneurysms. METHOD: A prospectively maintained database at a tertiary referral hospital was used to identify 83 patients who underwent endovascular repair using the Zenith fenestrated stent graft. Inclusion criteria included a postoperative computed tomography (CT) scan within 6 weeks of implantation and at least one additional follow-up CT scan (>5 months) available electronically at our institution. Eligible patients underwent assessment of stent graft migration using a CT-based central luminal line (CLL) technique. The proximal and distal margins of the stent graft were measured using CLLs relative to vascular landmarks on all available follow-up CT scans. Migration was defined as stent graft movement ≥4 mm. RESULTS: Fifty-five patients were included in this study, mean age was 74 ± 7 years, and 89% were men. Mean preoperative aneurysm diameter was 67 ± 9 mm. In these 55 patients, fenestrations were applied to 162 target vessels with the commonest design accommodating two renal arteries (RAs) and the superior mesenteric artery (SMA). Median follow-up was 24 (range, 5-97) months; 80% of patients (n = 44) had both the proximal and two distal attachment sites assessed for evidence of migration. Twelve iliac limbs in 11 patients were excluded from analysis due to occlusion of one internal iliac artery precluding CLL assessment (n = 7), or image quality issues (n = 5). Using CLLs and based on those patients who exhibited migration, the median proximal and distal migration distances were +5.0 (range, +4.0 to +8.1) mm and -5.0 (range, -4.3 to -21.3) mm, respectively. Kaplan-Meier analysis for proximal migration revealed migration rates of 14% and 22% at 12 and 36 months, respectively. Distal migration rates were lower at 3% and 8%, respectively. There have been no incidences of late rupture or open conversion. Of the patients with proximal migration, two patients lost a single target vessel (two RAs) and three patients were reported to have target vessel stenosis (two SMAs, one RA). These cases did not require reintervention. CONCLUSIONS: Both suprarenal fabric extension and visceral artery stenting are known to provide additional fixation for fenestrated aortic stent grafts. Despite this, minor proximal migration still occurs in up to one quarter of fenestrated endovascular repair patients by 4 years. We believe this is mainly due to the engagement of the barbs of the anchoring stent. Distal migrations occur with lower frequency.

Fractured superior mesenteric artery stents after fenestrated endovascular aneurysm repair.

Stent fracture after fenestrated endovascular aneurysm repair is a recognized complication. In this report, we record the occurrence of superior mesenteric artery stent fractures in our series and describe the management of embolized stent fragments during secondary intervention.

Intra- and interobserver variability of target vessel measurement for fenestrated endovascular aneurysm repair.

PURPOSE: To evaluate intra- and interobserver agreement of target vessel measured from computed tomography (CT) scans with 2 measuring techniques used in planning fenestrated endovascular aneurysm repairs (FEVAR): multiplanar reconstruction (MPR) and semi-automated central lumen line (CLL). METHODS: CT datasets from 25 FEVAR patients were independently analyzed by 2 experienced observers according to a standardized protocol using the MPR (Leonardo workstation) and CLL (Aquarius workstation) techniques for each patient. Longitudinal vessel separation and clock-face position of the visceral aortic branches were measured twice. The repeatability coefficient (RC) was calculated using the Bland and Altman method to measure intra- and interobserver variability. Differences between groups were examined by paired t test (continuous data) or chi-squared analysis (categorical). Clock-face discrepancy >30 minutes was considered significant. RESULTS: Intraobserver mean difference was insignificant regardless of the measurement technique: the observer and workstation-specific RCs varied between 3.9 and 4.9 mm. Paired measurements differed by >3 mm in 8%. Interobserver variability was greater: observer and workstation-specific RC varied between 5.6 and 7.4 mm, with a tendency toward consistency using MPR, although the mean difference was insignificant. Paired measurements differed by >3 mm in 18%. There was no significant intraobserver variation in clock-face measurement, while interobserver variation was significant in 12% of measurements using the Aquarius workstation and 6% using the Leonardo workstation (p = 0.19). CONCLUSION: Subjective interpretation of anatomical landmarks is more important than measurement techniques or workstations used in the generation of measurement inconsistencies. Introduction of consensus regarding interpretation of anatomical detail and development of fenestrated stent-grafts tolerant of measurement errors might ameliorate some of the problems encountered in FEVAR.

The role of the emergency physician in emergency medical services for children.

Emergency physicians have a duty to advance the care of pediatric patients in the emergency medical services (EMS) system. This policy resource and education paper, designed to support the American College of Emergency Physicians policy paper "The Role of the Emergency Physician in Emergency Medical Services for Children," describes the development of the federal EMS for Children Program, the importance of the integration of EMS for children into EMS systems, and the role of the emergency physician in EMS for children.

Ulcerative ileitis encountered at ileo-colonoscopy: likely role of nonsteroidal agents.

BACKGROUND & AIMS: Ileoscopy is increasingly practiced, but it is unclear what diagnostic and management decisions should ensue if ulcerations are encountered. METHODS: The lead author identified 40 patients with ulcerative ileitis during 1900 consecutive ileoscopies in a community practice. We analyzed the clinical, endoscopic, and histopathologic findings in these patients and related them to drug usage. RESULTS: Although most patients were asymptomatic, ileitis likely contributed to blood loss in 14 and to right lower quadrant pain in one. Endoscopy revealed multiple, discrete, fibrin-covered ulcerations in the prevalvular segment with patches of erythematous stippling, normal intervening mucosa, and occasional mucosal scars or webs. Histologic findings included focal superficial neutrophilic infiltrates, edema, mucosal hemorrhage, lymphatic dilatation, fibromuscular hyperplasia, prominence of the muscularis mucosae, and antral and Paneth cell metaplasia. Granulomas, fissure ulcers, and apoptosis were notably absent. No specific disease process developed in a median follow-up of 3.2 years. Thirty-three patients admitted recently taking nonsteroidal anti-inflammatory drugs (NSAIDs), notably: enteric-coated aspirin at 325 mg/day or less (19), selective cyclooxygenase-2 inhibitors (5), and nonacetylated salicylates (3). Three fourths of nonsteroidal users were taking agents with low or intermediate gastroduodenal toxicity. Lesions disappeared after drug withdrawal, and reappeared on resumption. CONCLUSIONS: Ileoscopy during colonoscopy may identify an ulcerative ileitis. This lesion likely contributes to gastrointestinal blood loss and other clinical manifestations, and likely is caused by NSAID use, including those usually associated with low toxicity or at low doses. Features of NSAID-ileitis overlap with Crohn's ileitis, but differentiation of the 2 entities is critical for appropriate management.