Search

Objective: The goal of this project is to examine the role of an exogenous NO donor, DETA-NONOate (DETA), on MMP-9, MMP-2, and TIMP-1 expression and activity in interleukin-1β (IL-1β) induced rat aortic explants (RAE). Methods: RAEs were incubated with IL-1β (2 ng/ml) and increasing concentrations of DETA (0, 5.0, 50, 100, and 500 μM) (n = 3 per group). Messenger RNA (mRNA) was extracted from cells after 24 hours and analyzed for MMP-9, MMP-2, and TIMP-1 expression levels by real time RT-PCR. Media at 48 hours was collected and assayed for NO2 and NO3 (NOx) by the Saville Assay, MMP-9 and MMP-2 activity by gelatin zymography, and TIMP-1 activity by reverse zymography. All statistical analyses were performed by ANOVA and Pearson correlation. Results: DETA administration resulted in a dose-dependent increase in media NOx concentration (0.001 +/- 0.0003 ng NOx / mg protein to 0.062 +/- 0.004 ng NOx / mg protein, p < 0.01). In RAE, MMP-9 expression and activity decreased significantly in a dose dependent fashion with increasing DETA concentrations (p < 0.01). At the maximal dose of 500 μM DETA, a 78% decrease in MMP-9 expression (p < 0.05) and a 72% decrease in pro-MMP-9 activity (p < 0.05) was demonstrated compared to RAE treated with IL-1β alone (0 μM DETA). There were no significant differences seen in MMP-2 and TIMP-1 expression or activity in response to DETA exposure. Conclusion: The NO donor DETA-NONOate decreased IL-1β induced MMP-9 expression and activity in RAE in a dose dependent fashion. These data suggest that NO donors may be beneficial in decreasing MMP-9 levels, an enzyme believed to be critical in vessel wall remodeling, and therefore may serve to inhibit MMP-9 dependent vessel wall degradation seen during AAA formation.

BackgroundRisk factors and outcomes after iliofemoral complications after thoracic aortic endovascular repair remain poorly characterized. This study was performed to characterize factors influencing perioperative iliofemoral complications during thoracic aortic endovascular repair.MethodsAll patients undergoing transfemoral thoracic aortic endovascular repair since 2005 with adequate preoperative aortoiliac 3-dimensional imaging (n = 126) were identified. Assessment of imaging was blinded with regard to occurrence of iliofemoral complications, defined as anything other than successful transfemoral device delivery and primary closure of an arteriotomy.ResultsThe complication rate was 12% (n = 15). Univariate analysis identified that female gender, preoperative ankle-brachial index, average and minimal iliac diameters, diameter difference between iliac artery and sheath size, and iliac morphology score (calculated by combining iliac tortuosity, calcification, and vessel diameter) were associated with iliofemoral complications (all P

Background Iliac artery endoconduits (ECs) have emerged as important alternatives to retroperitoneal open iliac conduits (ROICs) to aid in transfemoral delivery for thoracic endovascular aortic repair (TEVAR). We present, to our knowledge, the first comparative analysis between these alternative approaches. Methods All patients undergoing TEVAR with either ROIC (n = 23) or internal EC (n = 16) were identified. The mean age of the cohort was 72.4 ± 11.5 years (82.1% female). Device delivery was accomplished in 100% of cases. The primary outcome was the presence of iliofemoral complications, which was defined as: (1) the inability to successfully deliver the device into the aorta via the ROIC or EC approach; (2) rupture, dissection, or thrombosis of the ipsilateral iliac or femoral artery; and/or (3) retroperitoneal hematoma requiring exploration and evacuation. Secondary outcomes were 30-day mortality and rates of limb loss, claudication, or revascularization. Results At a median follow-up of 10.1 months, the incidence of iliofemoral complications was less for the EC approach compared with the ROIC technique (12.5% vs 26.1%; P = .301). No patients sustained limb loss. Revascularization was performed in two patients after ROIC. Lower extremity claudication occurred in one patient after EC. Early mortality was seen in one patient who underwent EC. Two-year Kaplan-Meier survival for the entire cohort was 74.4%, and did not differ between groups (ROIC, 78.3% vs EC, 68.8%; P = .350). Two-year Kaplan-Meier freedom from limb loss, claudication, or revascularization did not differ between the two approaches (ROIC, 91.3% vs EC, 93.8%; P = .961). Conclusions Results of this early comparative evaluation of alternative access routes for TEVAR suggest that an EC approach is safe, effective, and associated with low rates of early mortality and late iliofemoral complications. In selected patients, the EC may be considered an appropriate delivery route for transfemoral TEVAR.

Eighteen patients (14 men, 4 women), ages 24 to 77 years, with a common celiacomesenteric trunk (CMT) were treated between 1965 and 2004 at the University of Michigan. Four patients had CMT aneurysmal or occlusive disease that led to operative treatment. Pertinent arteriographic findings in these 4 patients included a CMT aneurysm (n = 2), an occluded proximal CMT (n = 1), and a type III aortic dissection that was compressing the CMT (n = 1). Therapy in these 4 patients included placement of a polytetrafluoroethylene bypass graft from the supraceliac aorta to the CMT (n = 2) or a Dacron bypass graft from a thoracoabdominal bypass to the CMT (n = 1), and endovascular fenestration of the septum between the true and false lumens of an aortic dissection at the level of the CMT (n = 1).

Background Although the management of vascular injury in coalition forces during Operation Iraqi Freedom has been described, there are no reports on the in-theater treatment of wartime vascular injury in the local population. This study reports the complete management of extremity vascular injury in a local wartime population and illustrates the unique aspects of this cohort and management strategy. Methods From September 1, 2004, to August 31, 2006, all vascular injuries treated at the Air Force Theater Hospital (AFTH) in Balad, Iraq, were registered. Those in noncoalition troops were identified and retrospectively reviewed. Results During the study period, 192 major vascular injuries were treated in the local population in the following distribution: extremity 70% (n = 134), neck and great vessel 17% (n = 33), and thoracoabdominal 13% (n = 25). For the extremity cohort, the age range was 4 to 68 years and included 12 pediatric injuries. Autologous vein was the conduit of choice for these vascular reconstructions. A strict wound management strategy providing repeat operative washout and application of the closed negative pressure adjunct was used. Delayed primary closure or secondary coverage with a split-thickness skin graft was required in 57% of extremity wounds. All patients in this cohort remained at the theater hospital through definitive wound healing, with an average length of stay of 15 days (median 11 days). Patients required an average of 3.3 operations (median 3) from the initial injury to definitive wound closure. Major complications in extremity vascular patients, including mortality, were present in 15.7% (n = 21). Surgical wound infection occurred in 3.7% (n = 5), and acute anastomotic disruption in 3% (n = 4). Graft thrombosis occurred in 4.5% (n = 6), and early amputation and mortality rates during the study period were 3.0% (n = 4) and 1.5% (n = 2), respectively. Conclusions To our knowledge, this study represents the first large report of wartime extremity vascular injury management in a local population. These injuries present unique challenges related to complex wounds that require their complete management to occur in-theater. Vascular reconstruction using vein, combined with a strict wound management strategy, results in successful limb salvage with remarkably low infection, amputation and mortality rates.

Objective Hybrid thoracic endovascular aneurysm repair (H-TEVAR) to include visceral and renal debranching has emerged as a potential therapeutic option for thoracoabdominal aneurysms (TAAA). This study was performed to characterize the frequently noted development of postoperative fluid collections surrounding the bypass grafts. Methods All patients undergoing H-TEVAR from 2000-2010 (n = 39, 43.6% male) were identified. One hundred thirty-two bypasses were constructed (median 4 per patient) using either polyester (30), thin-walled polytetrafluoroethylene (ePTFE, 100) or saphenous vein (2). Follow-up computed tomography (CT) imaging was routinely performed at 1 and 6 months, and annually thereafter. Results Of the 37 patients with one follow-up CT, 20 (54.1%) were found to have fluid collections. The natural history of the 17 patients with collections and further follow-up imaging was variable, with 2 resolving, 6 stable, and 9 enlarging. Two patients with collections developed evidence of graft infection requiring reoperation. Two patients with enlarging sterile collections required evacuation for symptoms. By multivariate analysis, both preoperative creatinine (P = .005) and number of bypasses constructed (P = .04) independently correlated with the development of a fluid collection. Conclusions Postoperative fluid collections following hybrid debranching procedures identified in this series represent a unique complication not previously described. The subsequent clinical course of these fluid collections is variable and ranges from benign to frank graft infection and relate both to patient factors, as well as specific operative strategies. Longer-term studies with more robust numbers of patient numbers are warranted to determine whether this complication may limit the long-term durability of this procedure.

Endovascular Interventions With Carbon Dioxide (CO2) in Renal Transplant Patients With Peripheral Arterial Disease (PAD) Is Safer and Offers Equivalent Patency Over Interventions With Standard Contrast Agents and Traditional Open Surgery Shipra Arya, Stephanie Kingman, Danielle N. Campbell, Dawn M. Coleman, Peter K. Henke, Narasimhan Dasika, Jonathan L. Eliason, John E. Rectenwald, Katherine A. Gallagher. University of Michigan, Ann Arbor, Mich

Background. Optimal treatment of chronic type B aortic dissection (CBAD), whether open (open descending aortic repair, OAR) or endovascular (thoracic endovascular aortic repair, TEVAR), is controversial, suggesting a comparative analysis is warranted. Methods. One hundred twenty-two of 1,049 patients (1993 to 2013) undergoing descending aortic repair required intervention for CBAD 29.2 ± 34.9 months after the initial acute event and formed the study cohort (mean age 59.7 years). Those with degenerated residual type A dissection were excluded (n[ 65). Eighty-eight had extent IIIB CBAD; 11 had intramural hematoma. Indications for surgery included aneurysmal degeneration (n [ 105), rupture (n [ 8), acute or chronic dissection (n [ 8), and extension of dissection (n [ 1). Open strategy included descending (n [ 71) and thoracoabdominal repair (n [ 19), with hypothermic circulatory arrest used in 70 patients. The TEVAR was performed with (n [ 2) or without (n [ 30) visceral debranching. A treatment strategy propensity score incorporating time since initial acute event, CBAD extent, year of intervention, age, and selected comorbidities was constructed for multivariable analysis. Results. Early outcome included the following: 30-day mortality 4% (n [ 5); stroke 2% (n [ 2); permanent

ObjectiveRecently, failure to rescue (FTR; death following major complication) has been shown to be a primary driver of mortality in highly morbid operations. Establishing this relationship for open and endovascular repair of abdominal aortic aneurysms may be a critical first step in improving mortality following these procedures. We sought to examine the relative contribution of severe complications and FTR to variations in mortality rate.MethodsWe examined endovascular aortic repair (EVAR) and open aortic repair (OAR; n = 3215) performed in 40 hospitals participating in the Michigan Surgical Quality Collaborative from 2007 to 2012. Hospitals were first divided into risk-adjusted mortality tertiles. We then determined rates of severe complications and FTR within each tertile.ResultsFor EVAR, risk-adjusted hospital mortality rates varied significantly between the lowest and highest tertiles (0.07% vs 6.14%; P < .01). However, while major complication rates were almost identical (9.0 vs 9.8; P = NS), FTR rates were about 35 times greater in high-mortality hospitals (4.0% vs 33.3%). Similar associations with mortality, severe complications, and FTR were seen for OAR as well. The most common complications that led to FTR events were postoperative transfusion (OAR 29.8% vs EVAR 5.8%) and prolonged ventilation (OAR 18.2% vs EVAR 1.0%). The average number of severe complications per FTR event was 2.85 and 2.66 for OAR and EVAR, respectively.ConclusionsFTR appears to drive a large proportion of the variation in mortality associated with abdominal aortic aneurysm repair. The exact mechanisms underlying this variation remain unknown. Nonetheless, FTR is influenced by the structural characteristics and safety culture related to the timely recognition and management of severe complications. Hospitals that are unable to effectively handle severe complications following EVAR or OAR require close scrutiny.