Nationwide analysis of risk factors for in-hospital mortality in patients undergoing abdominal aortic aneurysm repair.

BACKGROUND: There is increasing awareness that women may have worse outcomes following repair of abdominal aortic aneurysm (AAA). The aim of this study was to analyse the association between sex, age and in-hospital mortality after AAA using hospital episode data collected routinely at the nationwide level. METHODS: Data were extracted from the nationwide statutory Diagnosis Related Group statistics provided by the German Federal Statistical Office. Patients with a diagnosis of intact (non-ruptured) AAA (ICD-10 GM I71.4) and procedure codes (OPS; 2005-2013) for endovascular aneurysm repair (EVAR) (5-38a.1*) or open aneurysm repair (5-384.5, 5-384.7), treated from 2005 to 2013, were included. A multilevel multivariable regression model was applied to adjust for medical risk (using the Elixhauser co-morbidity score), type of procedure, type of admission, and to account for clustering of patients within centres. The primary outcome was in-hospital mortality. RESULTS: Some 84 631 patients were identified, of whom 10 039 (11·9 per cent) were women. Women were significantly older than men at admission (median 74 (i.q.r. 69-80) versus 72 (66-77) years; P < 0·001). EVAR was used less frequently in women (48·1 versus 54·7 per cent; P < 0·001). The in-hospital mortality rate was higher in women, overall (5·0 versus 3·1 per cent; relative risk 1·60, 95 per cent c.i. 1·45 to 1·75), and for EVAR (2·8 versus 1·5 per cent; RR 1·90, 1·60 to 2·30) and open repair (6·8 versus 5·0 per cent; RR 1·36, 1·22 to 1·52). In-hospital mortality increased with age and was highest in patients aged over 80 years. In multivariable regression analysis, female sex (RR 1·20, 1·07 to 1·35) and age per 10-year increase (RR 1·83, 1·73 to 1·95) were independent risk factors for higher in-hospital mortality. CONCLUSION: In Germany, women were older when undergoing AAA repair and were less likely to receive EVAR. Mortality rates were higher in older patients and in women, irrespective of the surgical technique used.

Trends in Patient Safety of Intact Abdominal Aortic Aneurysm Repair: German Registry Data on 36,594 Procedures.

OBJECTIVE/BACKGROUND: The study aim was to determine whether patient safety for non-ruptured abdominal aortic aneurysm (nrAAA) repair has changed between 1999 and 2010 in a large German cohort. METHODS: The data source was the prospective quality assurance registry of the German Vascular Society from 1999 to 2010. Patient characteristics, surgical techniques (open aortic repair [OAR], endovascular aortic repair [EVAR]), procedural time and outcomes, including the length of hospital stay (LOS), were analysed using the Cochran-Armitage test for binary parameters and Spearman's correlation coefficient for quantitative parameters. RESULTS: A total of 36,594 operations (23,037 OAR, 13,557 EVAR) for infrarenal nrAAA in 201 hospitals in Germany were investigated. Patients' mean age increased from 69.6 to 72.0 years (p < .001). The rate of patients with American Society of Anesthesiologists scores of 3 or 4 increased (p < .001). Use of EVAR increased (1999: 16.7%; 2010: 62.7%; p < .001), and since 2009, EVAR has been more frequently used than OAR. The overall in hospital mortality decreased from 3.1% in 1999 to 2.3% in 2010 (p < .001). There were no temporal trends for mortality rates for EVAR (p = .233) or OAR (p = .281) when considered separately. Cardiac (1999: 8.1%; 2010: 5.1%; p < .001) and pulmonary (1999: 7.8%; 2010: 4.8%; p < .001) complications decreased. The rate of post-operative renal failure increased (1999: 3.6%; 2010 4.1%; p = .017), without increasing the rate of patients needing dialysis (1999: 1.7%; 2010: 1.7%; p = .171). The median LOS decreased from 17 days in 1999 to 10 days in 2010 (p < .001). CONCLUSION: This study shows significantly improved post-procedural in hospital outcomes and decreased use of resources for nrAAA repair. This trend can probably be attributed to the implementation of EVAR as a standard technique, but some trends could also possibly be explained by a change in the remuneration system. The main limitation of the registry is the lack of internal and external validation. However, in hospital patient safety for AAA repair seems to have improved significantly in the participating hospitals.

Measurements After Image Post-processing Are More Precise in the Morphometric Assessment of Thoracic Aortic Aneurysms: An Intermodal and Intra-observer Evaluation.

OBJECTIVES: Precise pre-procedural anatomical analysis of aneurysmal anatomy is essential for successful thoracic endovascular aortic repair (TEVAR). Since surgeons and radiologists have to perform multiple measurements in the same patient, high intra-observer reliability of any imaging method is mandatory. Commercially available three dimensional (3D) post-processing techniques are expected to be superior to conventional two dimensional multiplanar reconstructions (MPRs) derived from computed tomography angiograms (CTAs). However, few data exist to support this view. This study aims to evaluate the intermodal and intra-observer differences using 3D software (3surgery) in descending thoracic aortic aneurysms (dTAAs). METHODS: Pre-operative CTAs (performed between 2004 and 2010) of 30 dTAAs (mean maximum diameter 61.4 ± 13 mm) were assessed by three independent investigators with different experience in the measurement of aortic pathologies. Intra-observer reliability and intermodal differences (3D vs. 2D) were investigated using pre-specified measurement points (distances of total length, maximum diameter, proximal and distal landing zones). Statistical analyses were performed using the Bland-Altman method and a mixed regression model. RESULTS: Intermodal comparison showed that 2D measurements significantly underestimate the measured distances (maximum diameter 3.7 mm [95% CI -5.3 to -2.1] and landing zone maximum 1.4 mm [95% CI -2.0 to -0.2] shorter with 2D, p < .05). In almost all 3D measurements, all investigators showed lower variability comparing the intra-observer differences, most notably in the measuring point total length (reduction of the SD up to 7.9 mm). CONCLUSIONS: These data show that both techniques led to significant measurement disparity. This occurs especially at the point of indication (maximum diameter) and the total length of the aneurysm (important for correct stent graft selection). But overall the variability is reduced with the 3D technique, which also tends to measure greater distances. The use of post-processing software therefore leads to more precise device selection for TEVAR in TAA.

CXCR4: A Potential Marker for Inflammatory Activity in Abdominal Aortic Aneurysm Wall.

OBJECTIVES: The aim of the study was to evaluate the potential role of chemokine receptor CXCR4 and its ligand CXCL12 in the pathogenesis of abdominal aortic aneurysm (AAA). METHODS: AAA tissue specimens were obtained from the anterior or lateral aneurysm sac of patients (n = 32, 26 males, 6 females; 66.8 ± 11.2 years, diameter 64.4 ± 17.0 mm), who underwent elective open surgical repair. Twelve non-aneurysmal aortic specimens from transplant donors served as controls. Expression analysis of CXCR4 and CXCL12 at mRNA and protein level was determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Immunohistochemical staining of corresponding histological sections for CD3 (T-cells), CD20 (B-cells), and CD68 (macrophages) was performed to determine the cellular localization of CXCR4 and CXCL12. Data were analyzed with SPSS 20.0 using Mann-Whitney U test and Spearman's rank correlation coefficient. RESULTS: Gene expression of CXCR4 and CXCL12 was 9.6 and 4.6 fold higher in AAA than in non-aneurysmal aorta (p = .0004 and p < .0001, respectively). Likewise, the protein level of CXCR4 was increased 3.2 fold in AAA wall compared with non-aneurysmal aortic tissue (p < .0001), although CXCL12 could not be detected. Immunohistochemical analysis revealed that CXCR4 was expressed in B and T lymphocytes and macrophages, and CXCL12 was observed only in plasma cells. CONCLUSIONS: This study confirmed the over expression of CXCR4 in human AAA tissue. CXCR4 was detected both at the mRNA and the protein level and by immunohistochemistry, especially in inflammatory cells. In contrast, CXCL12 expression was observed only at the mRNA level, with the exception of plasma cells. The exact role of CXCR4/CXCL12 in AAA has to be further elucidated.