Risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair

PURPOSE

We aimed to identify the risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

We retrospectively reviewed contrast-enhanced computed tomography (CT) images of 143 patients who were followed for ≥6 months after EVAR. Sac expansion was defined as an increase in sac diameter of 5 mm relative to the preoperative diameter. Univariate and multivariate analyses were performed to identify associated risk factors for late sac expansion after EVAR from the following variables: age, gender, device, endoleak, antiplatelet therapy, internal iliac artery embolization, and preprocedural variables (aneurysm diameter, proximal neck diameter, proximal neck length, suprarenal neck angulation, and infrarenal neck angulation).

RESULTS

Univariate analysis revealed female gender, endoleak, aneurysm diameter ≥60 mm, suprarenal neck angulation >45°, and infrarenal neck angulation >60° as factors associated with sac expansion. Multivariate analysis revealed endoleak, aneurysm diameter ≥60 mm, and infrarenal neck angulation >60° as independent predictors of sac expansion (P < 0.05, for all).

CONCLUSION

Our results suggest that patients with small abdominal aortic aneurysms (<60 mm) and infrarenal neck angulation ≤60° are more favorable candidates for EVAR. Intraprocedural treatments, such as prophylactic embolization of aortic branches or intrasac embolization, may reduce the risk of sac expansion in patients with larger abdominal aortic aneurysms or greater infrarenal neck angulation.The aim of endovascular abdominal aortic aneurysm repair (EVAR) is to prevent rupture of an abdominal aortic aneurysm (AAA) by depressurizing the aneurysm and excluding it from the systemic circulation using a stent-graft. Aneurysmal sac reduction is a reliable marker for the long-term prognosis after EVAR. Although most aneurysmal sacs shrink after EVAR, some sacs continue to expand. A relationship between aneurysm size and endoleaks was previously reported (1, 2). Most type II endoleaks spontaneously disappear over time, but 10%–25% persist for more than six months after EVAR (3–6). Persistent endoleaks with aneurysmal sac expansion are at high risk of rupture because of the continuously elevated intra-aneurysmal pressure and require a second intervention, such as embolization (7–11). However, it is difficult to predict sac expansion and persistent endoleak before performing EVAR. Although intraoperative intrasac thrombin injection and prophylactic embolization of aortic branches such as the inferior mesenteric artery and lumbar artery are reported to reduce the incidence of type II endoleak, the efficacy and clinical benefit of these procedures in terms of late postoperative aneurysm shrinkage have not been fully evaluated (12–15). Therefore, the purpose of this study was to identify the risk factors associated with late aneurysmal sac expansion after EVAR to determine possible indications for intrasac embolization and prophylactic embolization of aortic branches.     

Cancer-associated fibroblasts and CD163-positive macrophages in oral squamous cell carcinoma: their clinicopathological and prognostic significance

J Oral Pathol Med (2012) 41 : 444–451 Background: Stromal cells are believed to affect cancer invasion and metastasis. The purpose of this study was to evaluate the distribution of cancer‐associated fibroblasts (CAFs) and the incidence of tumor‐associated macrophages (TAMs) in oral squamous cell carcinoma (OSCC), focusing on clinicopathological factors and patient prognosis, as well as cancer invasion. Methods: The study included 108 patients with OSCC. Anti‐α‐smooth muscle actin, CD68, and CD163 antibodies were used to identify CAFs and TAMs. CAFs were divided into 4 grades on the basis of staining intensity: negative (0), scanty (1), focal (2), and abundant (3). The most intensive areas of macrophage concentration in each tumor invasive stroma were also evaluated. Results: The cancer specimens were divided into Grade 0/1, Grade 2, and Grade 3 on the basis of CAF grade. In addition, they were divided into low‐ and high‐grade groups on the basis of the number of CD68‐positive and CD163‐positive macrophages. The latter were significantly increased in the Grade 2 CAF group compared to the Grade 0/1 group (P = 0.009). Kaplan–Meier and multivariate survival analyses revealed that Grade 2 CAFs (P = 0.003) and high CD163‐positive macrophage levels (P = 0.007) significantly correlated with a poor outcome in patients with OSCC, and that a high CD163‐positive macrophage level was a significant and an independent prognostic factor (P = 0.045). Conclusions: Cancer‐associated fibroblasts and CD163‐positive macrophages may be potential prognostic predictors of OSCC.     

Silver oxide‐containing hydroxyapatite coating has in vivo antibacterial activity in the rat tibia

Bacterial infection is a serious postoperative complication of joint replacement. To prevent infections related to implantation, we have developed a novel antibacterial coating with Ag‐containing hydroxyapatite (Ag‐HA). In the present study, we examined the antibacterial activity of Ag‐HA implant coatings in the medullary cavity of rat tibiae. Forty 10‐week‐old rats received implantation of Ag‐HA‐ or HA‐coated titanium rods, then were inoculated with ～1.0 × 10² colony‐forming units of methicillin‐resistant Staphylococcus aureus. Bacterial counts were calculated for rats euthanized at 24, 48, and 72 h postoperatively. Serum levels of Ag (in the Ag‐HA group only) were calculated for rats euthanized at 24, 48, 72 h and 4 weeks. Radiographic evaluations of bone infection were also performed at 4 weeks. Tibiae from both groups showing infection were evaluated histologically. Significant differences in bacterial counts were seen at 24, 48, and 72 h. Mean concentrations of Ag in serum peaked about 48 h after implantation, then gradually decreased. Mean radiographic scores for infection were significantly lower with Ag‐HA implants than with HA implants. Histological examination showed better results for abscesses, bone resorption, and destruction of cortical bone around Ag‐HA‐coated implants. These results indicate that Ag‐HA coatings may help prevent surgical‐site infections associated with joint replacement. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1195–1200, 2013     

Insecticide resistance in potential vector mosquitoes for West Nile virus in Japan

Culex pipiens complex is the significant vector mosquito of West Nile virus. To take stock of the current situation of insecticide susceptibilities and design an ideal mosquito control strategy, we collected Culex pipiens pallens Coquillet, Culex pipiens form molestus Forskal, and Culex quinquefasciatus Say from fields in Japan and conducted bioassays for five larvicides (fenitrothion, temephos, etofenprox, diflubenzuron, and pyriproxyfen) by using a larval dipping method. Among five insecticides tested, obvious reduced susceptibilities were observed for etofenprox, which is the only pyrethroid compound registered as a larvicide in Japan. Twenty-two of 56 colonies exhibited a >10% survival rate at the etofenprox concentration of 5.7 microg/ml, which is a 10 times higher concentration of the working solution. The LC50 of a colony collected from Fukuoka prefecture for etofenprox exceeded 60 microg/ml (resistance ratio >2,307), and this colony also exhibited cross-resistance to other pyrethroids, permethrin (299-fold) and phenothrin (1,200-fold). The insect growth regulators diflubenzuron and pyriproxyfen were found to be sufficiently effective enough to control Culex larvae present, but decreased sensitivities to these insecticides were slightly detected in some colonies of Cx. p. form molestus collected from urban areas. Several etofenprox-resistant colonies of Cx. p. form molestus exhibited simultaneously decreased susceptibilities to other insecticides, including temephos, diflubenzuron, and pyriproxyfen.