br mention of rupture br Bronchopneumonia unspecified br
mention of rupture
Bronchopneumonia, unspecified 2.4
AAA, Abdominal aortic aneurysm; EVAR, endovascular aneurysm repair.
Table III. Summary of the modeling using G-computation formula and inverse probability weights (IPW)
CI, Confidence interval; HR, hazard ratio.
proportion of deaths caused by ruptured aneurysm for elective operations was 3.8% for open surgery and 2.3% for EVAR (Table II). Follow-up was up to 7 years after
1782 Markar et al Journal of Vascular Surgery
Fig 3. Comparison of endovascular aneurysm repair (EVAR) patients receiving computed tomography (CT) sur-veillance or non-CT surveillance, showing no difference between the groups in the incidence of abdominal cancer or abdominal cancer as cause of death. Univariate Cox model: hazard ratio (HR), 0.87; 95% confidence interval (CI), 0.67-1.13; P ¼ .308.
The results of this study suggest that an increased risk of abdominal cancer was associated with EVAR rather than with open repair, whereas no such association was found for lung cancer and nonabdominal obesity-related cancers. Furthermore, there was no consistent significant difference in the incidence of abdominal can-cer within the EVAR group in comparing patients followed up by CT surveillance or not.
Radiation exposure during fluoroscopy may be associ-ated with an increased long-term incidence of abdominal cancers arising within the Herboxidiene field. Previous investi-gations have demonstrated short-term effects in DNA damage observed with radiation exposure, which might be an explanatory factor for the greater long-term associ-ation with cancer risk after EVAR observed in this study.30
Large variations in fluoroscopy times have been demonstrated during EVAR, which may in turn lead to variation in radiation exposure.31,32 Fluoroscopy time and radiation exposure should be reduced to an abso-lute minimum to minimize DNA damage to patients during surgery and long-term cancer risk. Other intrao-perative factors, such as the angulation of the C-arm, frame rate, table position, and protective materials, may also modify effective dose yet are poorly recorded at patient level in representative national data sets or
quality registers, and therefore they are difficult to analyze at scale or in populations representative of national practice.33 However, in the recently published 15-year results from the EVAR trial 1 of 1252 patients, there was an increase in cancer-related deaths beyond 8 years within the EVAR group (28% vs 20%), paralleling the results observed from this population-based cohort study.6
The widespread use of CT for abdominal investigation
was previously suggested to be associated with an increased lifetime risk of cancer.34,35 Since these early publications, radiation protocols have changed with the introduction of low-radiation dose CT, ensuring that the long-term risks of cancer are now negligible.36 However, low-dose CT is not routinely recommended for endograft surveillance. Despite evidence that duplex ultrasound appears equivalent to CT for safe first-line endograft imaging, not all centers or practitioners have moved away from CT protocols for surveillance.37 Further work is required to ascertain whether there is a link of the radiation exposure of patients during EVAR and endog-raft surveillance with differential late cancer risk.
This study represents the largest contribution to the pub-lished literature regarding cancer risk after EVAR, with previous results being conflicting in their outcome.8-13 An important limitation of all observational studies is
Journal of Vascular Surgery Markar et al 1783
Fig 4. Comparison of endovascular aneurysm repair (EVAR) patients receiving computed tomography (CT) sur-veillance or non-CT surveillance, showing no difference between the groups in the incidence of all cancers or all cancers as cause of death. Univariate Cox model: hazard ratio (HR), 0.92; 95% confidence interval (CI), 0.77-1.10; P ¼