Novel insight into the pathobiology of abdominal aortic aneurysm and potential future treatment concepts

The patient with abdominal aortic aneurysm (AAA) commonly is a nondiabetic, white man with a history of smoking. Moreover, AAA represents a leading cause of death in elderly men in Western countries. The purpose of this manuscript is to review current evidence as to the pathobiology of AAA as well as potential future drug targets to prevent progression of AAA.

Port-a-Cath perforation of the right atrium closed with an amplatzer ASD occluder

Right atrial perforation can lead to tamponade and death. Closure devices are used for sealing of shunts in the heart. We describe an indwelling catheter that caused perforation of the right atrium and was treated with a percutaneous closure device.

Small is beautiful: why profundaplasty should not be forgotten

BACKGROUND: Surgical profundaplasty (SP)is used mainly as an adjunct to endovascular management of peripheral vascular disease (PAD) today. Results from earlier series of profundaplasty alone have been controversial, especially regarding its hemodynamic effect. The question is: Can profundaplasty alone still be useful? Our aim was to evaluate its role in the modern management of vascular patients. METHODS: This was a retrospective outcome study. A consecutive series of 97 patients (106 legs) from January 2000 through December 2003 were included. In 55 (52%) legs, the superficial femoral artery was occluded. These patients were included in the current analysis. Of these patients 14 (25%) were female. Mean age was 71 ((11) years. Nineteen (35%) were diabetic. The indication for operation was claudication in 29 (53%), critical leg ischemia (CLI) in 26 (47%), either with rest pain in 17 (31%), or ulcer/gangrene in 9 (16%). Endarterectomy with patch angioplasty with bovine pericardium was performed in all cases. Mean follow-up was 33 ( 14 months. Mean preoperative ankle brachial index (ABI) was 0.6. Sustained clinical efficacy was defined as upward shift of 1 or greater on the Rutherford scale without repeat target limb revascularization (TLR) or amputation. Mortality, morbidity, need for TLR, or amputation were separate endpoints. RESULTS: Postoperatively, ABI was significantly improved (mean = 0.7), in 24 (44%) by more than 0.15. At three years, cumulative clinical success rate was 80%. Overall, patients with claudication had a better outcome than those with CLI (p = 0.04). Two (4%) major amputations and 2 (4%) minor ones were performed, all in patients with CLI. None of the 9 (16%) ulcers healed. CONCLUSION: Profundaplasty is still a valuable option for patients with femoral PAD and claudication without tissue loss. It is a straightforward procedure that combines good efficacy with low complication rates. Further endovascular treatment may be facilitated. It is not useful for patients with the combination of critical ischemia and tissue loss.

Influence of pulmonary status and diabetes mellitus on aortic neck dilatation following endovascular repair of abdominal aortic aneurysms: a EUROSTAR report

PURPOSE: To elucidate the association of impaired pulmonary status (IPS) and diabetes mellitus (DM) with clinical outcome and the incidences of aortic neck dilatation and type I endoleak after elective endovascular infrarenal aortic aneurysm repair (EVAR). METHODS: In 164 European institutions participating in the EUROSTAR registry, 6383 patients (5985 men; mean age 72.4+/-7.6 years) underwent EVAR. Patients were divided into patients without versus with IPS or with/without DM. Clinical assessment and contrast-enhanced computed tomography (CT) were performed at 1, 3, 6, 12, 18, and 24 months and annually thereafter. Cumulative endpoint analysis comprised death, aortic rupture, type I endoleak, endovascular reintervention, and surgical conversion. RESULTS: Prevalence of IPS was 2733/6383 (43%) and prevalence of DM was 810/6383 (13%). Mean follow-up was 21.1+/-18.4 months. Thirty-day mortality, AAA rupture, and conversion rates did not differ between patients with versus without IPS and between patients with versus without DM. All-cause and AAA-related mortality, respectively, were significantly higher in patients with IPS compared to patients with normal pulmonary status (31.0% versus 19.0%, p<0.0001 and 6.8% versus 3.3%, p = 0.0057) throughout follow-up. In multivariate analysis adjusted for smoking, age, gender, comorbidities, fitness for open repair, co-existing common iliac aneurysm, neck and aneurysm size, arterial angulations, aneurysm classification, endograft oversizing >or=15%, and type of stent-graft, the presence of IPS was not associated with significantly higher rates of aortic neck dilatation (30.6% versus 38.0%, p>0.05) and did not influence cumulative rates of type I endoleak, endovascular reintervention, or conversion to open surgery (p>0.05). Similarly, the presence of DM did not influence the above-mentioned study endpoints. CONCLUSION: In contrast to observations regarding the natural course of AAAs, impaired pulmonary status does not negatively influence aortic neck dilatation, while the presence of diabetes does not protect from these dismal events after EVAR.

Effect of chest compressions only during experimental basic life support on alveolar collapse and recruitment

AIM: The importance of ventilatory support during cardiac arrest and basic life support is controversial. This experimental study used dynamic computed tomography (CT) to assess the effects of chest compressions only during cardiopulmonary resuscitation (CCO-CPR) on alveolar recruitment and haemodynamic parameters in porcine model of ventricular fibrillation. MATERIALS AND METHODS: Twelve anaesthetized pigs (26+/-1kg) were randomly assigned to one of the following groups: (1) intermittent positive pressure ventilation (IPPV) both during basic life support and advanced cardiac life support, or (2) CCO during basic life support and IPPV during advanced cardiac life support. Measurements were acquired at baseline prior to cardiac arrest, during basic life support, during advanced life support, and after return of spontaneous circulation (ROSC), as follows: dynamic CT series, arterial and central venous pressures, blood gases, and regional organ blood flow. The ventilated and atelectatic lung area was quantified from dynamic CT images. Differences between groups were analyzed using the Kruskal-Wallis test, and a p<0.05 was considered statistically significant. RESULTS: IPPV was associated with cyclic alveolar recruitment and de-recruitment. Compared with controls, the CCO-CPR group had a significantly larger mean fractional area of atelectasis (p=0.009), and significantly lower PaO(2) (p=0.002) and mean arterial pressure (p=0.023). The increase in mean atelectatic lung area observed during basic life support in the CCO-CPR group remained clinically relevant throughout the subsequent advanced cardiac life support period and following ROSC, and was associated with prolonged impaired haemodynamics. No inter-group differences in myocardial and cerebral blood flow were observed. CONCLUSION: A lack of ventilation during basic life support is associated with excessive atelectasis, arterial hypoxaemia and compromised CPR haemodynamics. Moreover, these detrimental effects remain evident even after restoration of IPPV.

Statins are associated with decreased mortality in abdominal, but not in thoracic aortic aneurysm patients undergoing endovascular repair: propensity score-adjusted analysis

BACKGROUND: Purpose of this study was to compare the correlation of statin use with long-term mortality in patients with abdominal (AAA) and thoracic aortic aneurysm (TAA). PATIENTS AND METHODS: We compared long-term survival of 731 AAA and 59 TAA patients undergoing elective endovascular repair (EVAR). Kaplan-Meier survival curves were compared by the log-rank method. Propensity score-adjusted multivariable logistic regression models were used to determine independent associations of statin use on vital status after EVAR. RESULTS: Statin use was associated with decreased long-term mortality in AAA patients in bivariate and multivariable regression analysis, in which the effect of propensity to receive a statin was considered (adjusted HR: .613, 95%-CI: .379- .993, p = .047) whereas mortality of TAA patients was not associated with use of statins (adjusted HR: 1.795, 95%-CI: .147 -21.942, p = .647). CONCLUSIONS: Use of statins is an independent predictor of decreased mortality after elective EVAR in AAA, but not in TAA patients. These findings indirectly support the concept of a distinct pathogenesis of AAA and TAA.

Aortic neck dilatation after endovascular abdominal aortic aneurysm repair: a word of caution

Continuing aortic neck dilatation, most probably an expression of ongoing aneurysmal wall degeneration of the infrarenal aortic segment, has been shown to seriously impair clinical results after endovascular abdominal aortic aneurysm repair. However, conflicting data on the extent and clinical relevance on this observation have recently been published. This article reviews the recent literature, summarizing our current understanding of the role of aortic neck dilatation after open surgical and endovascular abdominal aortic aneurysm repair. In addition, differences in methodology of studies on aortic neck dilatation are highlighted.

Peripheral endovascular revascularization trials: high noon for uniform reporting standards

In the era of evidence based medicine, proof of clinical benefits and cost-effectiveness need to be firmly based on transparent comparisons between various therapeutic alternatives. Standards for reports are a prerequisite for comparisons across reports and should reflect the patient's perspective. According standards have been successfully introduced in many fields of modern medicine, but not yet for peripheral endovascular interventions. Given the overwhelmingly increasing importance of endovascular revascularization in patients with chronic lower limb ischemia, this report provides an updated outline of the heterogeneity of current reporting practice and highlights the need for uniform reporting standards.

Influence of stent type on hemodynamic depression after carotid artery stent placement

PURPOSE: To assess the effect of stent type on hypotension and bradycardia after carotid artery stent placement. MATERIALS AND METHODS: A retrospective analysis on a prospectively maintained database was conducted in 256 patients (126 men; mean age, 71.8 years +/- 8.6; 194 de novo lesions) undergoing carotid artery stent placement between January 1996 and January 2007 by using self-expanding stents. Braided Elgiloy stents (Wallstents) were used in 44 of the 256 patients (17.2%) and slotted-tube nitinol stents were deployed in 212 (82.8%). Bivariate and multivariable logistic regression models were used to determine the influence of stent design on procedural and 24-hour hypotension and bradycardia. RESULTS: Procedural hemodynamic depression (HD) was encountered in 73 of the 256 patients (28.5%) due to hypotension in 24 (9.4%), bradycardia in 12 (4.7%), or both in 37 (14.5%) patients. Rates of procedural hypotension were 11.3% with nitinol stents and 0% with braided Elgiloy stents (P = .0188). Persistent postprocedural HD occurred in 91 of the 256 patients (35.5%) due to hypotension in 40 patients (15.6%), bradycardia in 23 (9.0%), or both in 28 (10.9%). Within a multivariable analysis adjusted for clinically relevant factors affecting rates of HD, the use of braided Elgiloy stents was associated with a decreased rate of procedural hypotension (odds ratio: 0.165; 95% confidence interval: 0.038, 0.721; P = .017). Procedural hypotension and bradycardia were not correlated to incidence of major adverse events but were associated with an increased duration of hospital stay (P = .0059 and P = .0335, respectively). CONCLUSIONS: Nitinol stents are associated with a higher risk of hypotension as compared to braided Elgiloy stents during carotid artery stent placement.

Sixty-four-detector CT angiography of infrarenal aortic neck length and angulation: prospective analysis of interobserver variability

PURPOSE: To quantify the interobserver variability of abdominal aortic aneurysm (AAA) neck length and angulation measurements. MATERIALS AND METHODS: A total of 25 consecutive patients scheduled for endovascular AAA repair underwent follow-up 64-row computed tomographic (CT) angiography in 0.625-mm collimation. AAA neck length and angulation were determined by four blinded, independent readers. AAA neck length was defined as the longitudinal distance between the first transverse CT slice directly distal to the lowermost renal artery and the first transverse CT slice that showed at least a 15% larger outer aortic wall diameter versus the diameter measured directly below the lowermost renal artery. Infrarenal AAA neck angulation was defined as the true angle between the longitudinal axis of the proximal AAA neck and the longitudinal axis of the AAA lumen as analyzed on three-dimensional CT reconstructions. RESULTS: Mean deviation in aortic neck length determination was 32.3% and that in aortic neck angulation was 32.1%. Interobserver variability of aortic neck length and angulation measurements was considerable: in any reader combination, at least one measurement difference was outside the predefined limits of agreement. CONCLUSIONS: Assessment of the longitudinal extension and angulation of the infrarenal aortic neck is associated with substantial observer variability, even if measurement is carried out according to a standardized protocol. Further studies are mandatory to assess dedicated technical approaches to minimize variance in the determination of the longitudinal extension and angulation of the infrarenal aortic neck.

Matched-pair analysis of endovascular versus open surgical repair of abdominal aortic aneurysms in young patients at low risk

PURPOSE: To compare clinical outcomes of endovascular and open aortic repair of abdominal aortic aneurysms (AAAs) in young patients at low risk. It was hypothesized that endovascular aneurysm repair (EVAR) compares favorably with open aneurysm repair (OAR) in these patients. MATERIALS AND METHODS: Twenty-five patients aged 65 years or younger with a low perioperative surgical risk profile underwent EVAR at a single institution between April 1994 and May 2007 (23 men; mean age, 62 years+/-2.8). A sex- and risk-matched control group of 25 consecutive patients aged 65 years or younger who underwent OAR was used as a control group (23 men; mean age, 59 years+/-3.9). Patient outcomes and complications were classified according to Society of Vascular Surgery/International Society for Cardiovascular Surgery reporting standards. RESULTS: Mean follow-up times were 7.1 years+/-3.2 after EVAR and 5.9 years+/-1.8 after OAR (P=.1020). Total complication rates were 20% after EVAR and 52% after OAR (P=.0378), and all complications were mild or moderate. Mean intensive care unit times were 0.2 days+/-0.4 after EVAR and 1.1 days+/-0.4 after OAR (P<.0001) and mean lengths of hospital stay were 2.3 days+/-1.0 after EVAR and 5.0 days+/-2.1 after OAR (P<.0001). Cumulative rates of long-term patient survival did not differ between EVAR and OAR (P=.144). No AAA-related deaths or aortoiliac ruptures occurred during follow-up for EVAR and OAR. In addition, no surgical conversions were necessary in EVAR recipients. Cumulative rates of freedom from secondary procedures were not significantly different between the EVAR and OAR groups (P=.418). Within a multivariable Cox proportional-hazards analysis adjusted for patient age, maximum AAA diameter, and cardiac risk score, all-cause mortality rates (odds ratio [OR], 0.125; 95% CI, 0.010-1.493; P=.100) and need for secondary procedures (OR, 5.014; 95% CI, 0.325-77.410; P=.537) were not different between EVAR and OAR. CONCLUSIONS: Results from this observational study indicate that EVAR offers a favorable alternative to OAR in young patients at low risk.

Age-dependent decrease in 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) activity in hypertensive patients

BACKGROUND: The prevalence of arterial hypertension lacking a defined underlying cause increases with age. Age-related arterial hypertension is insufficiently understood, yet known characteristics suggest an aldosterone-independent activation of the mineralocorticoid receptor. Therefore, we hypothesized that 11beta-HSD2 activity is age-dependently impaired, resulting in a compromised intracellular inactivation of cortisol (F) with F-mediated mineralocorticoid hypertension. METHODS: Steroid hormone metabolites in 24-h urine samples of 165 consecutive hypertensive patients were analyzed for F and cortisone (E), and their TH-metabolites tetrahydro-F (THF), 5alphaTHF, TH-deoxycortisol (THS), and THE by gas chromatography-mass spectroscopy. Apparent 11beta-HSD2 and 11beta-hydroxylase activity and excretion of F metabolites were assessed. RESULTS: In 72 female and 93 male patients aged 18-84 years, age correlated positively with the ratios of (THF + 5alphaTHF)/THE (P = 0.065) and F/E (P < 0.002) suggesting an age-dependent reduction in the apparent 11beta-HSD2 activity, which persisted (F/E; P = 0.020) after excluding impaired renal function. Excretion of F metabolites remained age-independent most likely as a consequence of an age-dependent diminished apparent 11beta-hydroxylase activity (P = 0.038). CONCLUSION: Reduced 11beta-HSD2 activity emerges as a previously unrecognized risk factor contributing to the rising prevalence of arterial hypertension in elderly. This opens new perspectives for targeted treatment of age-related hypertension.

Basic control of reperfusion effectively protects against reperfusion injury in a realistic rodent model of acute limb ischemia

BACKGROUND: Reperfusion injury is insufficiently addressed in current clinical management of acute limb ischemia. Controlled reperfusion carries an enormous clinical potential and was tested in a new reality-driven rodent model. METHODS AND RESULTS: Acute hind-limb ischemia was induced in Wistar rats and maintained for 4 hours. Unlike previous tourniquets models, femoral vessels were surgically prepared to facilitate controlled reperfusion and to prevent venous stasis. Rats were randomized into an experimental group (n=7), in which limbs were selectively perfused with a cooled isotone heparin solution at a limited flow rate before blood flow was restored, and a conventional group (n=7; uncontrolled blood reperfusion). Rats were killed 4 hours after blood reperfusion. Nonischemic limbs served as controls. Ischemia/reperfusion injury was significant in both groups; total wet-to-dry ratio was 159+/-44% of normal (P=0.016), whereas muscle viability and contraction force were reduced to 65+/-13% (P=0.016) and 45+/-34% (P=0.045), respectively. Controlled reperfusion, however, attenuated reperfusion injury significantly. Tissue edema was less pronounced (132+/-16% versus 185+/-42%; P=0.011) and muscle viability (74+/-11% versus 57+/-9%; P=0.004) and contraction force (68+/-40% versus 26+/-7%; P=0.045) were better preserved than after uncontrolled reperfusion. Moreover, subsequent blood circulation as assessed by laser Doppler recovered completely after controlled reperfusion but stayed durably impaired after uncontrolled reperfusion (P=0.027). CONCLUSIONS: Reperfusion injury was significantly alleviated by basic modifications of the initial reperfusion period in a new in vivo model of acute limb ischemia. With this model, systematic optimizations of according protocols may eventually translate into improved clinical management of acute limb ischemia.