An Analysis of Cost-Effectiveness and Clinical Outcomes of a Comprehensive Aortic Service in a Tertiary Center over One Year.

BACKGROUND: Endovascular aortic repair (EVAR) is an established and attractive alternative to open surgical repair (OSR) of abdominal aortic aneurysms (AAA) due to its superior short-term safety profile. However, opinions are divided regarding its long-term cost-effectiveness. We compared the total yearly cost of running endovascular and OSR services in a single tertiary center to determine whether fenestrated EVAR (FEVAR) represents a clinically efficacious, affordable treatment option. METHODS: A single-center retrospective review was performed on 109 patients undergoing a procedure related to index or previous abdominal aortic repair, with 1 year follow-up. Data was collected from the National Vascular Registry and hospital records. The primary outcome was cost per quality-adjusted life year. Secondary outcomes included 30-day mortality and morbidity, reintervention rates, length of hospital stay, aneurysm, and all-cause mortality at 1 year for elective index procedures. RESULTS: The average cost per patient of all FEVAR was £16,041.53 (±8,857.54), £13,893.51 (±£21,425.25) for standard EVAR, and £15,357.22 (±£15,904.49) for OSR (FEVAR versus EVAR P = 0.55, FEVAR versus OSR P = 0.83, OSR versus EVAR P = 0.76). Of the secondary outcomes, significant findings included increased length of stay and respiratory morbidity for patients undergoing open versus endovascular repair. There was no significant difference in 30-day or 1-year mortality between groups. CONCLUSIONS: FEVAR, EVAR, and OSR all represent cost-effective options for aortic repair with similar outcomes. Our data highlights the potential for FEVAR to present a viable alternative to open repair, particularly in higher-risk groups, when performed in specialist centers.

An in vitro Assessment of the Haemodynamic Features Occurring Within the True and False Lumens Separated by a Dissection Flap for a Patient-Specific Type B Aortic Dissection.

One of the highest mortality rates of cardiovascular diseases is aortic dissections with challenging treatment options. Currently, less study has been conducted in developing in vitro patient-specific Type B aortic dissection models, which mimic physiological flow conditions along the true and false lumens separated by a dissection flap with multiple entry and exit tears. A patient-specific Stanford Type B aortic dissection scan was replicated by an in-house manufactured automatic injection moulding system and a novel modelling technique for creating the ascending aorta, aortic arch, and descending aorta incorporating arterial branching, the true/false lumens, and dissection flap with entry and exit intimal tears. The physiological flowrates and pressure values were monitored, which identified jet stream fluid flows entering and exiting the dissection tears. Pressure in the aorta's true lumen region was controlled at 125/85 mmHg for systolic and diastolic values. Pressure values were obtained in eight sections along the false lumen using a pressure transducer. The true lumen systolic pressure varied from 122 to 128 mmHg along the length. Flow patterns were monitored by ultrasound along 12 sections. Detailed images obtained from the ultrasound transducer probe showed varied flow patterns with one or multiple jet steam vortices along the aorta model. The dissection flap movement was assessed at four sections of the patient-specific aorta model. The displacement values of the flap varied from 0.5 to 3 mm along the model. This model provides a unique insight into aortic dissection flow patterns and pressure distributions. This dissection phantom model can be used to assess various treatment options based on the surgical, endovascular, or hybrid techniques.

Cost-effectiveness analysis of endovascular versus open repair of abdominal aortic aneurysm in a high-volume center.

OBJECTIVE: Endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) is the standard treatment for anatomically suitable patients. EVAR has been associated with a lower perioperative morbidity and mortality compared with open surgical repair (OSR) at the expense of increased reinterventions and costs. We aimed to compare the outcomes of EVAR and OSR for elective AAA repair. The primary end point was cost per QALY at 3 years. Secondary end points were perioperative morbidity and mortality; freedom from reintervention; length of hospital, high-dependency unit, and intensive care unit stay; and freedom from all-cause mortality. METHODS: The project was approved by the Galway Clinical Research Ethics Committee. This project followed the Declaration of Helsinki. This was an audit of interventions that had already taken place. No active clinical intervention was undertaken, and patients' anonymity was preserved; thus, individual patient consent was not obtained. Data on all elective AAA repairs at a tertiary referral vascular center were collected from 2002 to 2015. Demographics and outcomes were reported according to the Society for Vascular Surgery guidelines. QALY was measured on the basis of a quality-adjusted time without symptoms or toxicity assessment. Data were analyzed using parametric and nonparametric tests. RESULTS: Between 2002 and 2015, a total of 494 patients required elective AAA surgery; 401 underwent EVAR and 93 underwent OSR. Demographics and vascular-related risk factors were similar in both groups. Median (interquartile range) cost per QALY at 3 years was €5776 (€5541-€6481) for EVAR vs €7101 (€5812-€8952) for OSR (P < .001). EVAR was associated with reduced perioperative morbidity (12.2% vs 50%; P < .001). There was no significant association between procedure and perioperative mortality (EVAR, 1.7%; OSR, 4.3%; P = .130). There was no significant association found between the procedure and reintervention (P = .502). Our subgroup analysis found no association between procedure and improvement in all-cause mortality, QALYs, costs, or cost per QALY. CONCLUSIONS: EVAR is cost-effective with improved cost per QALY compared with OSR.

Q-TWiST and Cost-Effectiveness Analysis of Endovascular versus Open Repair for Ruptured Abdominal Aortic Aneurysms in a High Deliberate Practice Volume Center.

BACKGROUND: The objective of the study was to compare the cost-effectiveness of endovascular aortic repair (rEVAR) versus open surgical repair (rOSR) for ruptured abdominal aortic aneurysm (rAAA), where rEVAR is regularly performed outside of instructions for use (IFUs) (shorter and more angulated necks). Primary end point is incremental cost-effectiveness ratio (ICER) of rEVAR versus rOSR and aneurysm-related mortality. Secondary end points are cost per quality-adjusted life years (QALYs), perioperative morbidity and mortality, reintervention, and all-cause mortality. METHODS: All rAAA repairs performed between 2002 and 2016 in a single center were scrutinized. Between 2002 and 2007, most rAAAs were repaired using rOSR. From 2007 to 2016, we implemented a rEVAR with an anatomically possible protocol. During this time, severe angulation was rarely seen as a contraindication to rEVAR, and rEVAR was performed on aneurysms with an infrarenal aortic neck cranial to the aneurysm with a diameter of 20-33 mm and a length of at least 5 mm. Demographics and outcomes were reported according to the Society for Vascular Surgery guidelines. QALY was measured based on quality of time spent without symptoms of disease or toxicity of treatment (Q-TWiST) assessment. RESULTS: Eight hundred aneurysm surgeries were performed; of these, 135 were emergency surgeries of which 88 were for rAAA; (42 rEVARs and 46 rOSRs). Primary technical success (rEVAR 89.1% vs. rOSR 87.8%; P = 0.1), perioperative morbidity (rEVAR 56.5% vs. rOSR 64.3%; P = 0.457), and mortality (rEVAR 26.1% vs. rOSR 28.6%; P = 0.794) were nonsignificantly favorable in rEVAR patients. Freedom from reintervention was significantly lower in rEVAR patients at 3 years (rEVAR 74% vs. rOSR 90%; P = 0.038). Three-year aneurysm-related survival (rEVAR 65% vs. rOSR 62%; P = 0.848) and all-cause survival (rEVAR 56% vs. rOSR 51%; P = 0.577) were higher in rEVAR patients. At 3 years, rEVAR patients had a higher QALY of 1.671 versus OSR of 1.549 (P = 0.502). Operating room (P = 0.001) and total accommodation costs (P = 0.139) were lower in rEVAR patients, while equipment (P < 0.001), surveillance, and reintervention (P < 0.001) costs were higher. Median cost of rEVAR at 3 years was €23,352 vs. €20,494 for OSR (P < 0.084) (power>80%). Median cost per QALY of rEVAR at 3 years was €13,974 vs. €13,230 for rOSR (P = 0.296). ICER for rEVAR versus rOSR was €23,426 (95% confidence interval [CI] < €0 to > €30,000). At 3 years, the area under the curve and 95% CI for Q-TWiST was higher in rEVAR compared with OSR (rEVAR 500.819 vs. rOSR 437.838). CONCLUSIONS: There is no significant difference in cost or QALYs between rEVAR and rOSR even when rEVAR is performed on complex cases outside of IFU (shorter and more angulated necks). There is a significantly higher freedom from secondary intervention in rOSR patients compared with rEVAR patients at 3 years.

An in vitro assessment of the cerebral hemodynamics through three patient specific circle of Willis geometries.

The Circle of Willis (CoW) is a complex pentagonal network comprised of fourteen cerebral vessels located at the base of the brain. The collateral flow feature within the circle of Willis allows the ability to maintain cerebral perfusion of the brain. Unfortunately, this collateral flow feature can create undesirable flow impact locations due to anatomical variations within the CoW. The interaction between hemodynamic forces and the arterial wall are believed to be involved in the formation of cerebral aneurysms, especially at irregular geometries such as tortuous segments, bends, and bifurcations. The highest propensity of aneurysm formation is known to form at the anterior communicating artery (AcoA) and at the junctions of the internal carotid and posterior communicating arteries (PcoAs). Controversy still remains as to the existence of blood flow paths through the communicating arteries for a normal CoW. This paper experimentally describes the hemodynamic conditions through three thin walled patient specific models of a complete CoW based on medical images. These models were manufactured by a horizontal dip spin coating method and positioned within a custom made cerebral testing system that simulated symmetrical physiological afferent flow conditions through the internal carotid and vertebral arteries. The dip spin coating procedure produced excellent dimensional accuracy. There was an average of less than 4% variation in diameters and wall thicknesses throughout all manufactured CoW models. Our cerebral test facility demonstrated excellent cycle to cycle repeatability, with variations of less than 2% and 1% for the time and cycle averaged flow rates, respectively. The peak systolic flow rates had less than a 4% variation. Our flow visualizations showed four independent flow sources originating from all four inlet arteries impacting at and crossing the AcoA with bidirectional cross flows. The flow paths entering the left and right vertebral arteries dissipated throughout the CoW vasculature from the posterior to anterior sides, exiting through all efferent vessels. Two of the models had five flow impact locations, while the third model had an additional two impact locations within the posterior circulation caused by an additional bidirectional cross flows along the PcoAs during the accelerating and part of the decelerating phases. For a complete CoW, bidirectional cross flows exist within the AcoA and geometrical variations within the CoW geometry can either promote uni- or bidirectional cross flows along the PcoAs.

Cardiac risk assessment, morbidity prediction, and outcome in the vascular intensive care unit.

OBJECTIVES: The aim of this study is to examine the predictive value of the Lee revised cardiac risk index (RCRI) for a standard vascular intensive care unit (ICU) population as well as assessing the utility of transthoracic echocardiography and the impact of prior coronary artery disease (CAD) and coronary revascularization on patient outcome. DESIGN: This is a retrospective review of prospectively maintained Vascubase and prospectively collected ICU data. MATERIALS AND METHODS: Data from 363 consecutive vascular ICU admissions were collected. Findings were used to calculate the RCRI, which was then correlated with patient outcomes. All patients were on optimal medical therapy (OMT) in the form of cardioselective ß-blocker, aspirin, statin, and folic acid. RESULTS: There was no relationship found between a reduced ejection fraction and patient outcome. Mortality was significantly increased for patients with left ventricular hypertrophy (LVH) as identified on echo (14.9% vs 6.5%, P = .028). The overall complication rates were significantly elevated for patients with valvular dysfunction. Discrimination for the RCRI on receiver-operating characteristic analysis was poor, with an area under the receiver-operating characteristic curve of .621. Model calibration was reasonable with an Hosmer-Lemeshow C statistic of 2.726 (P = .256). Of those with known CAD, 41.22% of the patients receiving best medical treatment developed acute myocardial infarction (AMI) compared to 35.3% of those who previously underwent percutaneous cardiac intervention and 23.5% of those who had undergone coronary artery bypass grafting. There was 3-fold increase in major adverse clinical events in patients with troponin rise and LVH. CONCLUSIONS: The RCRI's discriminatory capacity is low, and this raises difficulties in assessing cardiac risk in patients undergoing vascular intervention. The AMI is highest in the OMT group without prior cardiac intervention, which mandates protocols to identify patients requiring cardiac intervention prior to vascular procedures.

Sequential compression biomechanical device versus primary amputation in patients with critical limb ischemia.

INTRODUCTION: Patients with critical limb ischemia (CLI), who are unsuitable for intervention, face the consequence of primary amputation. Sequential compression biomechanical device (SCBD) therapy provides a limb salvage option for these patients. OBJECTIVES: To assess the outcome of SCBD in patients with severe CLI who are unsuitable for revascularization. Primary end points were limb salvage and 30-day mortality. METHODS: From 2005 to 2012, 189 patients with severe CLI were not suitable for revascularization. In all, 171 joined the SCBD program. We match controlled 75 primary amputations. RESULTS: All patients were Rutherford category 4 or higher. Sustained clinical improvement was 68% at 1 year. Mean toe pressure increased from 19.9 to 35.42 mm Hg, P < .0001. Mean popliteal flow increased from 35.44 to 55.91 cm/sec, P < .0001. The 30-day mortality was 0.6%. Limb salvage was 94% at 5 years. Freedom from major adverse clinical events was 62.5%. All-cause survival was 69%. Median cost of managing a primary amputation patient is €29,815 compared to €3,985 for SCBD. We treated 171 patients with artassist at a cost of €681,965. However, primary amputation for 75 patients cost €2,236,125. CONCLUSION: The SCBD therapy is a cost-effective and clinically effective solution in patients with CLI having no option of revascularization. It provides adequate limb salvage while providing relief of rest pain without any intervention.

Cool excimer laser-assisted angioplasty (CELA) and tibial balloon angioplasty (TBA) in management of infragenicular arterial occlusion in critical lower limb ischemia (CLI).

We aim to compare cool excimer laser-assisted angioplasty (CELA) versus tibial balloon angioplasty (TBA) in patients with critical limb ischemia (CLI) with tibial artery occlusive disease. The primary end point is sustained clinical improvement (SCI) and amputation-free survival (AFS). The secondary end points are binary restenosis, target extremity revascularization (TER), and cost-effectiveness. From June 2005 to October 2010, 1506 patients were referred with peripheral vascular disease and 572 with CLI. A total of 80 patients underwent 89 endovascular revascularizations (EVRs) for tibial occlusions, 47 using TBA and 42 using CELA. All patients were Rutherford category 4 to 6. Three-year SCI was enhanced with CELA (81%) compared to TBA (63.8%; P = .013). Three-year AFS significantly improved with CELA (95.2%) versus TBA (89.4%; P = .0165). Three-year freedom from TER was significantly improved with CELA (92.9%) versus 78.7% TBA (P = .026). Three-year freedom from MACE was comparable in both the groups (P = .455). Patients with CELA had significantly improved quality time without symptoms of disease or toxicity of treatment (Q-TWiST) at 3 years (10.5 months; P = .048) with incremental cost of €2073.19 per quality-adjusted life year gained. Tibial EVR provides exceptional outcome in CLI. The CELA has superior SCI, AFS, and freedom from TER, with improved Q-TWiST and cost-effectiveness.

Sequential compression biomechanical device in patients with critical limb ischemia and nonreconstructible peripheral vascular disease.

OBJECTIVES: Critical limb ischemia (CLI) patients who are unsuitable for intervention face the dire prospect of primary amputation. Sequential compression biomechanical device (SCBD) therapy provides a limb salvage option for these patients. This study assessed the outcome of SCBD in severe CLI patients who otherwise would face an amputation. Primary end points were limb salvage and 30-day mortality. Secondary end points were hemodynamic outcomes (increase in popliteal artery flow and toe pressure), ulcer healing, quality-adjusted time without symptoms of disease or toxicity of treatment (Q-TwiST), and cost-effectiveness. METHODS: From 2004 to 2009, we assessed 4538 patients with peripheral vascular disease (PVD). Of these, 707 had CLI, 518 underwent intervention, and 189 were not suitable for any intervention. A total of 171 patients joined the SCBD program for 3 months. RESULTS: All patients were Rutherford category ≥4. Median follow-up was 13 months. Mean toe pressure increased from 39.9 to 55.42 mm Hg, with a mean difference in toe pressure of 15.49 mm Hg (P = .0001). Mean popliteal flow increased from 35.44 to 55.91 cm/s, with mean difference in popliteal flow of 20.47 cm/s (P < .0001). Mortality at 30 days was 0.6%. Median amputation-free survival was 18 months. Limb salvage at 3.5 years was 94%. Freedom from major adverse clinical events (MACE) at 4.5 years was 62.5%. We treated 171 patients with SCBD at a cost of €681,948, with an estimated median per-patient cost of treatment with SCBD of €3988. CONCLUSION: SCBD therapy is a cost-effective and clinically efficacious solution in CLI patients with no option of revascularization. It provides adequate limb salvage and ameliorated amputation-free survival while providing relief of rest pain without any intervention.

Clinical efficacy and cost per quality-adjusted life years of pararenal endovascular aortic aneurysm repair compared with open surgical repair.

PURPOSE: To gauge the efficacy of applying commercially-available endografts to pararenal endovascular abdominal aortic aneurysm (AAA) repair compared with open surgical repair (OSR). METHODS: From 2001 to 2009, 1868 AAA patients were referred to our service for evaluation; of these, 118 patients had pararenal AAAs. Sixty-six patients (51 men; mean age 70.8±7.6 years) had OSR and 52 (44 men; mean age 74.3±7.2 years) underwent pararenal endovascular aneurysm repair (EVAR). The pararenal EVAR patients were older (74.3 versus 70.8 years, p = 0.014), with higher mean comorbidity severity scores (p = 0.0001). Mean aneurysm diameter was larger in the OSR patients (6.6 versus 5.9 cm, p = 0.01). Primary endpoints were aneurysm-related survival and cost per quality-adjusted life years (QALY). Secondary endpoints included 3-year freedom from major adverse clinical events, all-cause mortality, and secondary intervention. RESULTS: There was no perioperative mortality in the pararenal EVAR group versus 3 (4.5%) deaths among the OSR patients (p = 0.122). The 15% 30-day morbidity with pararenal EVAR was half that of OSR (p = 0.059). Mean follow-up was 28.8 ±21.6 months for pararenal EVAR and 35.7±23.2 months for OSR. There were no aneurysm ruptures in either group and no conversions to open repair in the pararenal EVAR group. Three-year aneurysm-related survival was significantly higher with pararenal EVAR (100%) versus OSR (92.4%, p = 0.045), but the freedom from any-cause death was lower with pararenal EVAR (57.1%) than OSR (84.8%, p = 0.195). Three-year freedom from secondary intervention (pararenal EVAR 83.4% versus OSR 95.5%, p = 0.301) and all-cause survival (pararenal EVAR 57.1% versus OSR 84.8%, p = 0.195) were similar. Over a 3-year period, pararenal EVAR costs (including follow-up and reintervention) averaged €20,375 per patient to give a QALY value of 0.90, while mean costs for OSR were €23,928 per patient (0.86 QALY). The incremental cost-effectiveness ratio for pararenal EVAR was €129,586 saved per QALY gained. CONCLUSION: Pararenal EVAR afforded patients longer quality-adjusted time without symptoms or toxicity and superior freedom from major adverse events up to 3 years. Although the relatively low 3-year survival rate reflected the greater comorbidity of the EVAR patients, pararenal EVAR was cost-effective.

Implementation of the Continuous AutoTransfusion System (C.A.T.S) in open abdominal aortic aneurysm repair: an observational comparative cohort study.

The use of the Continuous AutoTransfusion System (C.A.T.S; Fresenius Hemotechnology, Bad Homburg v.d.H., Germany), which conserves allogenic blood, is reported in 187 patients having abdominal aortic aneurysm repair during a 9-year period. Patients were allocated to C.A.T.S if a Haemovigilance technician was available. A mean of 685 mL of retrieved blood was reinfused in 101 patients receiving C.A.T.S; 61% required 2 U or less. All control patients required 3 U or more of allogenic blood. Allogenic transfusion in C.A.T.S patients decreased significantly (P < .0001). Mean intensive care unit stay was significantly reduced in C.A.T.S patients (P = .042). Mean postoperative hospital stay was 18 days for C.A.T.S group and 25 days in control patients (P = .014). The respective 30-day mortality was 12% versus 19% (P = .199). The C.A.T.S markedly reduced the amount of blood transfused, was associated with reduced intensive care unit and postoperative hospital stay, and was cost-effective.

A prospective clinical, economic, and quality-of-life analysis comparing endovascular aneurysm repair (EVAR), open repair, and best medical treatment in high-risk patients with abdominal aortic aneurysms suitable for EVAR: the Irish patient trial.

PURPOSE: To report the results of a trial comparing endovascular aneurysm repair (EVAR) to open repair (OR) and best medical therapy (BMT) involving high-risk patients with abdominal aortic aneurysms (AAA) suitable for EVAR. METHODS: From 2002 to 2007, 1083 patients with aortic aneurysm disease were referred to a tertiary care university hospital. Of these, 162 (119 men; mean age 76 years) were high-risk patients with AAAs anatomically suitable for EVAR. Following comprehensive consultation with the patient, the family, and the primary physician, elective treatment was selected: OR (n=52), EVAR (n=66), or BMT (n=44). Outcomes were compared using Kaplan-Meier survival analyses and a parameter that measured the quality time spent without symptoms of disease or toxicity of treatment (Q-TWIST). RESULTS: Four-year freedom from aneurysm-related death following EVAR (96.7%) was markedly better compared to BMT (66.8%; p=0.002) and was similar to OR (93.9%, p=0.483). Four-year freedom from major adverse clinical events was significantly better with EVAR (78%) compared with BMT (28%; p=0.001) and was equivalent to OR (75%; p=0.519). The 4-year intervention-free survival rate for EVAR (95%) almost matched OR (98%; p=0.410). At 4 years, Q-TWIST was 3.64 years for EVAR patients, 3.60 years for OR, and 2.22 years for BMT. Q-TWIST significantly improved with EVAR compared to OR (p<0.003). In the cost analysis, 52 high-risk patients were treated with OR over the 5-year period (2002-2007) at a total inpatient cost of 1,257,457 euro. The 66 patients treated with EVAR (14 patients more than OR) incurred a lower cost of 1,129,138 euro. Including the cost of follow-up over 4 years, the mean cost per patient was 18,476 euro for EVAR and 24,252 euro for OR, a savings of 5,776 euro per patient treated with EVAR. CONCLUSION: In high-risk patients, EVAR reduces aneurysm-related death compared to BMT. Equated to the gold standard of open repair, EVAR, as a "one-time procedure," substantially reduces operative morbidity, hospital stay, costs, and utilization of intensive care facilities if performed in a high-volume center.