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Objective: This study sought to identify risk factors associated with an unfavorable outcome after elective abdominal aortic aneurysm (AAA) repair in patients with chronic obstructive pulmonary disease (COPD). Methods: The clinical records of 158 patients who underwent elective open AAA repair with COPD determined from preadmission International Classification of Diseases-ninth revision codes during a 12-year period at the University of Michigan were reviewed. Patients with uncomplicated outcomes (group I) were compared with those with unfavorable postoperative outcomes (group II). The unfavorable outcomes were defined as myocardial infarction, acute renal failure, worsening respiratory insufficiency necessitating tracheostomy, or death within 30 days of surgery. Logistic regression analyses of variables that were identified as being statistically significant in the univariate analysis were used to develop a predictive model of these events. Results: Group I included 133 patients (77 men, 56 women) with a mean age of 70.1 years, and group II included 25 patients (13 men, 12 women) with a mean age of 71.4 years. Preoperative factors statistically related ( P =.002) to an unfavorable outcome in group II patients included: suboptimal COPD management (fewer prescribed inhalers), lower hematocrit, preoperative renal insufficiency, and coronary artery disease. Importantly, abnormal preoperative spirometry and arterial blood gases were not predictive of a poor outcome. Univariate analysis also revealed increased hospital (25 versus 13 days; P =.0001) and intensive care unit (14 versus 4 days; P =.001) length of stays and a greater need for prolonged ventilation (8 versus 1 day; P =.039) for group II patients compared with group I patients. The 30-day mortality rate in the entire experience was 3.2% (5/158). No specific variables associated with mortality were identified. Conclusion: Fewer prescribed inhalers, lower hematocrit, renal insufficiency, and coronary artery disease are preoperative factors associated with unfavorable outcomes after open elective surgical repair of AAA in patients with COPD. Intensive management of these factors may reduce the hazards of AAA operations in these patients. COPD alone should not be considered a deterrent to the surgical treatment of AAAs. (J Vasc Surg 2003;37:594-599.)

Objective: We tested the hypothesis that a venous thromboembolism to the pulmonary arterial system (pulmonary embolism [PE]) would cause an inflammatory response within the pulmonary arterial (PA) wall marked by elevated cytokines and chemokines and an influx of inflammatory cells. Methods: Experimental PE was induced in 70 rats and confirmed with angiography and O2 saturation depression, and an additional 70 rats underwent sham operations. PA and lung tissue were removed at 3 hours and at 1, 2, 4, 6, 8, and 14 days (n = 10 per time point), were analyzed for proinflammatory cytokines and chemokines, and underwent histologic analysis. Data were analyzed with analysis of variance and the unpaired Student t test. Results: Average gross PE resolution was 40% at 2 days, 90% at 4 days, and 100% at 6 days. Only monocyte chemoattractant protein-1 levels were greater in affected PAs compared with sham PAs at 3 hours, 1 day, and 2 days (137 ± 13 pg/mg protein, 285 ± 40 pg/mg protein, and 249 ± 36 pg/mg protein versus 101 ± 6 pg/mg protein, 150 ± 36 pg/mg protein, and 92 ± 3 pg/mg protein; P < .01 for all). Keratinocyte-derived chemokine, tissue necrosis factor, interleukin-10, nitric oxide, P-selectin, and E-selectin levels were not elevated. Neutrophils infiltrated the PA wall beginning at 3 hours, peaked at 2 days (69.4 ± 21.7 per five high-power fields; P < .01), and returned to baseline by 8 days after PE. Macrophages peaked at 1 day after PE (29.3 ± 6.9; P < .01) and returned to baseline by 4 days after PE. PE also was associated with a significantly increased intima to media ratio (P < .05), apparent at 4 days after PE and persisting through 14 days. Conclusion: PE is associated with an early influx of polymorphonuclears and macrophages and monocyte chemoattractant protein-1 elevation within the PA wall. These are temporally associated with thrombus resolution and intimal hyperplasia. These factors may mediate these two processes after PE. This offers targets for further study with the hopes of minimizing the pathophysiologic response to PE. (J Vasc Surg 2002;36:581-8.)

Objective. Nitric oxide (NO) may mediate vessel wall remodeling by regulating expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). This study tested the hypothesis that nitric oxide synthase (NOS) inhibition in whole aortic wall causes increases in cytokine-stimulated MMP and TIMP expression. Methods. Cultured infrarenal aortic segments from Sprague-Dawley rats were exposed to increasing concentrations (0, 0.1, 0.5, 1, and 5 mM; n = 6 per concentration) of NG-monomethyl-l-arginine (L-NMMA), a known inhibitor of NOS. This was in the presence of 2 ng/ml of interleukin-1β, a known inducer of NOS, MMP, and TIMP expression. Media nitrate and nitrite (NOx) were measured at 72 h using the Saville method. Media MMP activity was measured using gelatin zymography. MMP-2 and -9 protein and mRNA levels were determined by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). TIMP activity and mRNA levels were evaluated by reverse zymography and RT-PCR. Data were analyzed using ANOVA. Results. Increasing concentrations of L-NMMA produced a dose-dependent decrease in NOx (2214 ± 405 to 347 ± 37 ng/mg, P < 0.001). Zymography demonstrated a dose-dependent increase in 92-kDa MMP (pro-MMP-9) activity (P < 0.001) with corresponding increases in pro-MMP-9 protein (P = 0.03) and mRNA levels (P = 0.004). While there was a dose-dependent increase in 72-kDa MMP (pro-MMP-2) activity (P = 0.001), pro-MMP-2 protein and mRNA levels were unchanged. Reverse zymography demonstrated a dose-dependent increase in 29-kDa TIMP-1 activity (P = 0.01), but there was no change in TIMP-1 mRNA levels. Conclusions. NOS inhibition in ex vivo aortic tissue causes a dose-dependent increase in MMP-9 expression and activity. It is speculated that deficiencies of NO in vivo alter MMP and TIMP homeostasis, favoring matrix degradation.

Objective: Splanchnic arterial occlusive disease is rare in childhood. The purpose of this study was to review the clinical relevance and operative treatment of these lesions in a unique experience from a single institution. Methods: Seventeen children (11 boys and 6 girls) from 2 years to 17 years in age with critical narrowings of the celiac artery (CA) and superior mesenteric artery (SMA) underwent treatment at the University of Michigan from 1974 to 2000. Etiologic factors included embryologic fusion abnormalities of the fetal aortae during formation of the splanchnic arteries (n = 15), inflammatory aortoarteritis (n = 1), and radiation-induced arterial fibrosis (n = 1). Individual lesions included CA occlusions (n = 6) and stenoses (n = 7), SMA occlusions (n = 3) and stenoses (n = 11), and inferior mesenteric artery stenosis (n = 1). Fourteen children had abdominal aortic coarctations, and 15 had renal artery stenoses. Two patients had postprandial abdominal discomfort and food aversion, consistent with intestinal angina. Small stature affected five others, perhaps attributable to severe renovascular hypertension and failure to thrive. Ten children underwent intestinal revascularization, at the time of an aortoplasty or thoracoabdominal bypass for aortic coarctation (n = 7) or at the time of renal artery revascularization (n = 8). Primary splanchnic revascularization procedures included SMA-aortic implantation (n = 3), aorto-SMA and CA bypass with an internal iliac artery graft (n = 3) or a saphenous vein graft (n = 1), CA-aortic implantation at a stenotic SMA origin (n = 2), and CA and SMA intimectomy (n = 1). Secondary operations included SMA-aortic implantation (n = 2). Results: All 10 children who underwent splanchnic revascularization have thrived, gained weight, and are free of abdominal pain, with follow-up periods averaging 9 years. No intestinal ischemic manifestations occurred in the seven children who did not undergo operation. Conclusion: Pediatric splanchnic arterial occlusive disease is a rare illness appropriately treated with operation in properly selected children. (J Vasc Surg 2002;35:860-7.)

Objective This study evaluated and compared the long-term clinical outcomes of endovascular repair of infrarenal aortoiliac aneurysms (EVAR) vs EVAR with preservation of antegrade internal iliac artery (IIA) perfusion using iliac branched devices (EVAR-IBDs). Methods From October 1998 to August 2015, patients with infrarenal aortoiliac aneurysmal (AIA) disease at high risk for conventional open surgery were enrolled in a prospective physician-sponsored investigational device exemption trial. Clinical data of 75 patients treated with EVAR-IBD and 255 with standard EVAR were analyzed. Technical success, perioperative outcomes, mortality, device patency, endoleak rates, and reinterventions during a follow-up of 10 years were analyzed. Results There were 87 IBDs deployed in 75 patients. Technical success rate was 97%. Mortality at 30 days was 1.3%. Freedom from aneurysm-related mortality at 3, 5, and 10 years was 99%. Freedom from a type I or III endoleak at 3, 5, and 10 years was 99%. Freedom from secondary reinterventions at 3, 5, and 10 years was 86%, 81%, and 81%, respectively. Primary patency of the IBDs at 3, 5, and 10 years was 94%, 94%, and 77%, respectively. Twenty-four percent of patients underwent EVAR for concomitant AIA disease (EVAR-AIA), and 78% were managed by staged IIA embolization before EVAR. No statistically significant difference in freedom from aneurysm-related mortality, limb occlusions, or endoleak rates was identified in patients with EVAR-AIA vs EVAR-IBD ( P > .05). There were significantly more secondary reinterventions in the EVAR-AIA group compared with the EVAR-IBD group (hazard ratio, 0.476, 95% confidence interval, 0.226-1.001; P = .045). Conclusions EVAR of infrarenal AIAs with preservation of antegrade flow to the IIA using IBDs is feasible with long-term sustained durability. Serious considerations should be given to the use of IBDs in patients with infrarenal AIAs meeting appropriate anatomic criteria.

National guidelines by the American College of Cardiology, American Heart Association, and European Society of Cardiology have established benchmarks for patient transfer times (door-in-door-out time and door-to-balloon time) that serve as clinical performance measures for ST-segment–elevation myocardial infarction (STEMI) networks. Campaigns, such as D2B Alliance and Mission Lifeline, were also launched in an effort to reduce system delays in transfer and improve outcomes for subjects presenting with STEMI.1 This scrutiny on pre- and interhospital care has led to marked reductions in door-to-balloon times across the United States.2 Unlike STEMI, acute aortic syndrome (AAS) defined as acute aortic dissection, intramural hematoma, or penetrating aortic ulcer is a less frequent clinical event that lacks an effective diagnostic biomarker and requires definitive imaging for confirmation. The time-sensitive nature of AAS, complexity of surgery, and endovascular intervention and the relative paucity of institutions that deliver 24/7 state-of-the-art care strongly advocates for regional systems of care across the United States. Successful transfer of patients with AAS has previously been described through such efficient regional care models.3,4 Our aim was to evaluate safety and timeliness of transfer provided by our regional aortic network. The transfer metrics served by this analysis will help us improve as a network and more importantly serve as a benchmark to be replicated and improved on by others. Our AAS network shares a common hotline with our STEMI and stroke networks. On activation, a transfer team is dispatched immediately to the referring center. The transfer system is operated by critical care trained nurse practitioners and paramedics, who are equipped in handling all cardiovascular emergencies under direct consultation with cardiac intensive care unit (CCU) physicians. The transfer team’s goal is to expedite safe …

Background Branched endografts are a new option to treat arch aneurysm in high-risk patients. Methods and results We performed a retrospective multicenter analysis of all patients with arch aneurysms treated with a new branched endograft designed with 2 inner branches to perfuse the supra aortic trunks. Thirty-eight patients were included. The median age was 71 years (range, 64-74 years). An American Society of Anesthesiologists score of 3 or 4 was reported in 89.5% (95% confidence interval [CI], 79.7-99.3) of patients. The 30-day mortality rate was 13.2% (95% CI, 2.2-24.2). Technical success was obtained in 32 patients (84.2% [95% CI, 72.4-95.9]). Early secondary procedures were performed in 4 patients (10.5% [95% CI, 0.7-20.3]). Early cerebrovascular complications were diagnosed in 6 patients (15.8% [95% CI, 4.0-27.6]), including 4 transient ischemic attacks, 1 stroke, and 1 subarachnoid hemorrhage. The median follow-up was 12 months (range, 6-12 months). During follow-up, no aneurysm-related death was detected. Secondary procedures during follow-up were performed in 3 patients (9.1% [95% CI, 0.0-19.1]), including 1 conversion to open surgery. We compared the first 10 patients (early experience group) with the subsequent 28 patients. Intraoperative complications and secondary procedures were significantly higher in the early experience group. Although not statistically significant, the early mortality was higher in the early experience group (30% [95% CI, 0.0-60.0]) versus the remainder (7.1% [95% CI, 0.0-16.9]; P = .066). Being part of the early experience group and ascending aortic diameter ≥38 mm were found to be associated to higher rates of combined early mortality and neurologic complications. Conclusions Our preliminary study confirms the feasibility and safety of the endovascular repair of arch aneurysms in selected patients who may not have other conventional options. Clinical trial registration information: Thoracic IDE NCT00583817 , FDA IDE# 000101.

This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.

Background: Patients who require prosthetic infrapopliteal of the lower extremity have historically had dismal long-term results. This study examined the outcome of patients undergoing femoral-distal arterial bypass with expanded polytetrafluoroethylene (ePTFE) grafts. Methods: Femoral to infrapopliteal artery bypasses with ePTFE performed between 1990 and 1997 were reviewed. Graft patency, limb salvage, and survival rates were calculated by actuarial analysis. Different anastomotic adjuncts (direct end-to-side anastomosis, vein patch anastomosis, and arteriovenous fistula [AVF] anastomosis) were compared with the log-rank test. Results: Seventy-four femoral-infrapopliteal bypasses with ePTFE were performed in 67 patients for limb salvage. At 24 months the primary patency, assisted primary patency, and secondary patency rates were 40% ± 10% (SEM), 48% ± 11%, and 52% ± 11%, respectively. Limb salvage was successful in 62% ± 10% of the bypasses at 24 months. Forty-six percent of the bypasses were performed with an AVF; 35% were performed with direct end-to-side anastomosis, and 19% were performed with a vein patch anastomosis. Apparent trends in favor of the AVF group did not attain statistical significance with 24-month patency rates of 65% ± 19%, 44% ± 16%, and 35% ± 20%, respectively, in the 3 subgroups. Limb salvage rates were similar (64% ± 17%, 56% ± 15%, and 76% ± 22%, respectively) at 24 months. Conclusions: Patency and limb salvage rates are sufficient to justify the use of ePTFE grafts in infrapopliteal bypass when adequate autogenous material is unavailable. (Surgery 1999;126:759-65.)

Background. From the clinical oncologic experience, fractionation of the radiation dose offers a better therapeutic window, both with respect to effectiveness and unwanted side effects. Thus, we undertook a pilot study in a rodent model, using a single dose of 15 Gy compared with fractionation schedules of 5 or 10 daily applications of 3 Gy. Materials and Methods. Using a previously described rat angioplasty model, animals were randomly assigned to one of four groups: unilateral balloon injury, sham irradiation; unilateral balloon injury, bilateral 15 Gy single dose irradiation; unilateral balloon injury, bilateral 3 Gy × 5 daily fractions; or unilateral balloon injury, bilateral 3 Gy × 10 daily fractions. Results and Conclusions. All three radiation groups demonstrated a clear inhibition of neointimal hyperplasia. We therefore offer evidence for the effectiveness of fractionated radiation as a means to inhibit vascular restenosis in a rat carotid model. However, the 3 Gy × 5 schedule was less effective than either the 3 Gy × 10 schedule or the 15 Gy single dose. This study must be repeated using longer time points to provide proof of principle.

Popliteal artery aneurysms rarely rupture. We treated a 91-year-old man who presented with a deep venous thrombosis and anemia; rupture of a popliteal artery aneurysm was suspected only after compartment syndrome isolated to the thigh developed as the result of bleeding. Although fasciotomy was required on the basis of the clinical examination alone, the cause of the problem, operative strategy, and definitive treatment (i.e., resection and bypass) were clarified by the preoperative computed tomography scan. Ruptured popliteal aneurysm can manifest as a massively swollen leg with anemia and should be suspected if no other cause is evident. (J Vasc Surg 1998;27:783-7.)

Objective Endovascular aneurysm repair (EVAR) will fail over time in a percentage of patients. Mechanical failure of the device, progression of aortic disease, or interface complications between the device and the native vasculature may contribute. Our aim was to evaluate the role of fenestrated and branched endografts as treatment options for failed devices. Methods Between January 2001 and June 2013, 970 patients were enrolled into a physician-sponsored investigational device exemption (PSIDE) study and treated with a fenestrated/branched endograft. All patients treated for nonurgent proximal neck failure of an infrarenal endoprosthesis previously implanted during EVAR comprised the study group. Patients treated for a primary aneurysm within the PSIDE were evaluated as a comparison group to identify preoperative risk factors for failure. A retrospective review was undertaken to determine the details of the initial EVAR, whereas the prospective PSIDE database was used to assess outcomes of secondary treatment. Three-dimensional imaging techniques were used to define all morphologic measurements. Statistical analysis included comparisons between categoric variables with the χ 2 test and between continuous variables with the Wilcoxon rank sum test between patients with late failures and those with native aortic repair. Kaplan-Meier curves were used to analyze overall survival. Results Of 970 patients enrolled in the PSIDE, 54 (5.6%) had late failure of a prior endograft. Fenestrated/branched devices were used to address the failure in each patient. The etiology of failure was related to a proximal neck issue in all patients: type Ia endoleak in 38, stent migration in 18, neck degeneration in 28, or some combination of these factors. The endovascular rescue procedure took place a mean of 61 months after the primary procedure. The mean aneurysm diameter at reintervention was 67 mm. Patients requiring a secondary fenestrated procedure were younger at the time of their primary intervention ( P = .039) and were more likely to have a history of chronic renal insufficiency ( P = .05) compared with other patients in the PSIDE. Technical success rate in the study group was 85% (44 of 52). Successful stenting was achieved in 71 of 77 (92%) target vessels. Thirty-day mortality was 3.8% (two of 52). Fluoroscopy dose and operating time were longer in the rescue group ( P = .07) than in the control group ( P = .008). Secondary interventions were required in 36.5% (19 of 52) of patients. Conclusions Our series demonstrates the risk for late failure after EVAR is greater in patients who are younger and have chronic renal impairment at the time of implantation. Branched and fenestrated repair after failed EVAR is more complex than repair in the native aorta. More research is needed to identify patients at higher risk of failure after EVAR to prevent the need for rescue in the future.

ObjectiveSpinal cord ischemia (SCI) is a devastating complication associated with aortic aneurysm repair. The aim of the current study was to evaluate factors affecting outcomes from SCI associated with endovascular aortic aneurysm repair.MethodsA total of 1251 patients underwent endovascular repair of aortic aneurysm as part of a device trial between 1998 and 2010 utilizing endovascular abdominal aortic aneurysm repair (n = 351), thoracic endovascular aortic aneurysm repair (n = 201), fenestrated endovascular aortic aneurysm repair (n = 227), and visceral branched endografts (n = 472). Records and imaging studies were reviewed to supplement prospective outcome data. Demographics, type of repair, collateral bed (hypogastric/subclavian) patency, clinical presentation, and outcomes were evaluated on patients with SCI. Survival was calculated using life-table analysis.ResultsSCI occurred in 2.8% (n = 36) of patients: abdominal aortic aneurysm, 0.3%, juxtarenal, 0.4%, thoracic aortic aneurysm, 4.6%, and thoracoabdominal aortic aneurysm, 4.8%). Four (11%) required carotid-subclavian bypass prior to endografting, and two underwent coverage of the left subclavian artery. Unilateral hypogastric artery occlusion was present in 11 (31%) patients prior to endograft placement, and three had bilateral occlusions. An additional seven patients had occlusion of at least one hypogastric artery during surgery. SCI was apparent immediately in 15 (42%) patients. Immediate onset of symptoms was observed in 73% of patients with at least one occluded collateral bed but in only 24% of those with patent collateral beds (P = .021). Of those presenting in a delayed fashion, nine (43%) had a clear precipitating event prior to onset of SCI (hypotension, n = 6, and segmental artery drain removal, n = 3). Recovery occurred in 24 (67%) patients, most within 7 days. Immediate presentation was a negative predictor of recovery (P = .025), as was occlusion of at least one collateral bed (P = .035). Mean follow-up was 22 ± 4 months with 30-day and 1-year survival of 92 ± 4.6% and 56 ± 8.3%. Survival was only 36% at 3 months in those with permanent SCI compared with 92% (P

formed to evaluate rates and predictors of 30-day readmission from a multicenter trial data set. Methods: We analyzed the PREVENT III data set of 1404 CLI patients undergoing LEB at 83 North American centers. The primary end point was readmission 30 days of discharge. Secondary end points included graft patency and limb salvage evaluated in the context of readmission. Results: We analyzed 1356 patients, of these, 23 (1.7%) died inhospital and were excluded from re-admission analyses. Overall, 327 of 1333 patients (24.5%) were readmitted 30 days of discharge. Reasons for readmission included 127 (39%) wound infections in the index leg, 75 (23%) nonvascular reasons, 68 (20.9%) additional procedures in the index leg, and 19 graft failures (5.8%). Univariate predictors are shown in the Table. Adjusted independent predictors of 30-day readmission included wound infection (odds ratio [OR], 4.1; 95% confidence interval [CI], 3.0-5.4; P .0001), renal failure (OR, 4.1; 95% CI, 1.9-8.8; P .0004), early lost patency (OR, 1.9; 95% CI, 1.2-2.9; P .003), dialysis (OR, 1.8; 95% CI, 1.2-2.6; P .003), and female gender (OR, 1.3; 95% CI, 1.0-1.8; P .03). Patients readmitted 30 days had lower rates of limb salvage at 1 year (78% 2.4% vs 91% 0.9%, P .0001). Thirty-day readmission was predictive of limb loss (HR, 2.25; 95% CI, 1.6-3.1; P .0001) at 1 year, after adjustment for other factors. Conclusions: Readmission after LEB for CLI is common (24%) and associated with defined clinical predictors. Readmission is associated with long-term limb loss. These data provide benchmark values for this complex patient population and may prove useful as disease-specific bundling strategies are derived.

Abdominal aortic aneurysm (AAA) pathogenesis occurs as a result of the altered homeostasis of the aortic vessel wall structural proteins. This results in weakening, and subsequent expansion, of the aorta leading to aneurysm formation. Multiple mechanisms are involved in this process, including genetic abnormalities, biomechanical wall stress, apoptosis, and proteolytic degradation of the aortic wall. One key hallmark of this pathology, which orchestrates the interaction of the various pathologic processes, is inflammation. The inflammatory process is characterized by the infiltration of a variety of cells, which leads to the upregulation of multiple cytokines. The balance of the cellular type and resultant cytokine milieu determines the ultimate fate of the aortic wall – healing, atherosclerosis or aneurysm formation. This review highlights some of the known cellular and cytokine inflammatory events that are involved in aortic aneurysm formation.

Objective This article reports the early clinical outcomes and experiences of Zenith pivot branch device (p-branch) standard fenestrated endovascular graft (Cook, Bloomington, Ind) for treating juxtarenal abdominal aortic aneurysm (AAA) originating below the superior mesenteric artery (SMA). Methods A physician-sponsored investigational device exemption study was used to assess enrolled elective and emergency patients from August 2011 to September 2012 for treatment with an off-the-shelf Zenith p-branch device. Patients were included provided an anatomic seal could be established 4 mm below the SMA and the renal geometry fit the protocol based on reconstructed computed tomography data. The celiac artery was addressed with a scallop and the SMA with an 8-mm fenestration. The renal fenestrations were constructed as a modified design to allow a range of renal locations (7.5 mm radially from the center of the fenestration) to be acceptably treated with a single configuration. Two anatomic configurations were created for renal arteries (origins at the same level, or disparate renal arteries with left lower than right). Outcomes are reported in coherence with endovascular reporting standards documents. Results The study enrolled 16 patients (94% men; median age, 75 years [range, 59-87 years]) with a mean aneurysm size of 61 mm (range, 52-82 mm). Two were treated for aneurysm rupture. Technical success was achieved in all patients. The median fluoroscopy time was 62 minutes (range, 38-105 minutes), and the amount of contrast media was 69 mL (range, 31-121 mL). There were no aortic-related deaths, aneurysm ruptures, open surgical conversion, or type I/III endoleaks. One right renal artery occluded during follow-up in the setting of a conically shaped visceral aortic segment and was successfully treated with endovascular recanalization. Conclusions The use of the p-branch device for aneurysms originating infra-SMA is associated with a high rate of technical success and minimal problems during the short follow-up duration. The off-the-shelf design allows for the treatment of ruptures and other urgent situations. Additional patients and more follow-up will be required to further define the risks and benefits of such a treatment strategy.

ObjectiveTo characterize radiation exposure to patients and operating room personnel during fluoroscopic procedures.MethodsPatient dose information was collected from the imaging equipment. Real-time dosimetry was used to measure doses to the operators, scrub nurse, radiologic technologist (RT), and anesthesiologist in 39 cases of endovascular thoracoabdominal aortic aneurysm repair using fenestrated endografts. Overall equivalent doses and dose rates at time points of interest were noted and compared with the corresponding patient doses.ResultsThe dosimeter on the anesthesia equipment received 143 μSv (38-247) more radiation per case than the average operator, and the scrub nurse and RT received 106 μSv (66-146) and 100 μSv (55-145) less, respectively. Adjusting for protective lead aprons by the Webster methodology, the average operator received an effective dose of 38 μSv. Except for the RT, personnel doses were well correlated with patient dose as measured by kerma area product (KAP) (r = .82 for average operator, r = .85 for scrub nurse, and r = .86 for anesthesia; all P < .001) but less well correlated with fluoroscopy time or cumulative air kerma (CAK). When preoperative cone beam computed tomography was performed, the equivalent dose to the RT was 1.1 μSv (0.6-1.5) when using shielding and 37 μSv (22-53) when unshielded. Digital subtraction acquisitions accounted for a large fraction of all individuals' doses. Decreasing field size (and thus, increasing magnification) was associated with decreased KAP (r = .47; P < .001) and increased CAK (r = −.56; P < .001). The square of the field size correlated strongly with the KAP/CAK ratio (r = .99; P < .001). Increased lateral angulation of the C-arm increased both CAK and KAP (at field size, 22 cm; r = .54 and r = .44; both P < .001) and the average dose rate to an operator was 1.78 (1.37-2.31) times as high in a lateral projection as in a posterior-anterior projection.ConclusionsPersonnel doses were best correlated with KAP and less well correlated with fluoroscopy time or CAK. The dosimeter on the anesthesia equipment recorded the highest doses attributable to ineffective shielding. Operators can reduce the effective dose to themselves, the patient, and other personnel by minimizing the use of digital subtraction acquisitions, avoiding lateral angulation, using higher magnification levels when possible, and being diligent about the use of shielding during fluoroscopy cases.

Signal transducers and activators of transcription (STAT) proteins are transcription factors that, when activated by phosphorylation, regulate gene expression and cellular activity. The aim of this study was to evaluate the local and systemic expression and activation of STAT proteins associated with abdominal aortic aneurysms (AAA).Expression and activation of STAT proteins were assessed in aortic wall samples obtained from patients undergoing repair of AAA (n = 9) and from non-aneurysmal (NA) donors (n = 17). Aortic samples were evaluated for mRNA and protein expression for STAT1, 2, 3, 4, 5a, and 5b using RT-PCR and immunoblot (WB) assays and normalized to ß-actin (expressed as arbitrary units). STAT activation was assessed with WB assays using phosphorylated (p)-STAT-specific antibodies. Alterations in STAT activation were calculated by normalizing pSTAT proteins to corresponding total STAT levels. Immunohistochemistry was performed on AAA and NA samples using the total and pSTAT antibodies. Systemic alterations in STAT activation were assessed by evaluating circulating leukocytes for the presence of pSTAT from patients with AAA (AAA, n = 8), repaired aneurysm (RA, n = 8), or age/gender matched controls with no AAA (CT, n = 8). Flow cytometry was performed to assess for circulating levels of STAT1 (pY701), STAT3 (pY705), and STAT5a (pY694) in monocytes, granulocytes, and lymphocytes. Assessments were made at baseline and in response to in vitro stimulation with IFN-γ (50 ng/mL) or IL-6 (100 ng/mL). Results were analyzed using Student's t-test and are expressed as mean ± SEM.In AAA tissue compared with NA, STAT-1 (1.08 ± 0.09 versus 0.62 ± 0.07), -2 (0.98 ± 0.07 versus 0.55 ± 0.08), and -4 (0.89 ± 0.12 versus 0.35 ± 0.11) mRNA levels were elevated (P0.01, all). Corresponding increases in STAT protein were only observed for STAT1 (2.77 ± 0.93 versus 0.93 ± 0.08, P0.05). Increases in activation were observed in AAA compared with NA in pSTAT2 (0.77 ± 0.1 versus 0.1 ± 0.02, P0.01), pSTAT3 (1.6 ± 0.3 versus 0.2 ± 0.06, P0.02) and pSTAT5 (0.57 ± 0.03 versus 0.2 ± 0.03, P0.05) levels. Phosphorylated STAT1, 2, 3, and 5 were observed in inflammatory cells invading the AAA adventitia. In addition, STAT3 was observed in the media of AAA and NA, but pSTAT3 was only observed in the media of AAA. There were no differences in baseline levels of pSTAT-positive circulating leukocytes. IFN-γ stimulation decreased STAT-5a (pY694)-positive CT lymphocytes to 40% ± 13% of baseline, but had no effect on AAA or RA lymphocytes (116% ± 35%, 102% ± 19%, respectively; P = 0.01). STAT-5a (pY694)-positive CT granulocytes also decreased to 62% ± 18% of baseline compared with AAA or RA granulocytes (122% ± 25%, 126% ± 17%, respectively; P = 0.01). Alterations in STAT1 (pY701) and STAT3 (pY705) were not observed in leukocytes following cytokine stimulation.STAT proteins are important regulators of transcriptional activity and have been linked to cardiovascular disease. The present data suggest that altered levels of phosphorylated STATs are associated with AAA. Understanding their role may provide further insight into the mechanisms of AAA formation and allow for the development of medical treatment options.

Background The continued success of elective endovascular aneurysm repair (EVAR) has led to an extension of this technology to ruptured aortas. The purpose of this study was to evaluate our results of ruptured infrarenal aortic aneurysm (rAAA). Methods The treatment results of all patients who underwent repair of rAAAs between January 1990 and May 2008 were reviewed retrospectively. Comorbidities, intraoperative details, and postoperative complications were tabulated. EVAR and open repair were compared. Results Between January 1990 and May 2008, 160 patients underwent repair of rAAA. Of these, 32 (20%) underwent EVAR for rAAA; of 160 patients, 112 were considered to have free rupture (70%) and 48 had contained rupture (30%). The average Acute Physiology and Chronic Health Evaluation II score was 13.3 ± 6.7. The Kaplan–Meier survival rates at 30 days, 6 months, 1 year, and 5 years were 69% (62,77), 57% (50,65), 50% (43,59), and 25% (19,34), respectively, with no difference seen in EVAR group as compared with open surgery (p = 0.24). Intraoperative mortality was 5.6%, with no patient undergoing EVAR suffering an intraoperative death (p = 0.03). However, 30-day mortality was 31.9% with no difference between EVAR and open surgery (31.2% vs. 32%; p = 0.93) results. Multivariate analysis for 30-day mortality found renal insufficiency (RI) odds ratio (OR): 2.4 (1.1, 5.3), p = 0.04; hypotension OR: 2.4 (1.1, 5.3), p = 0.02; and cardiac arrest OR: 3.8 (1.1, 11.6, p = 0.03), were all associated with the greatest mortality. Of all predictors analyzed, multivariate analysis found preoperative RI OR: 2.32 (1.55, 3.47), p < 0.001, was the only independent predictor of decreased long-term survival. Conclusions Mortality rates for rAAA remain high. The use of EVAR for these procedures equals that for open repair with regard to 30-day and long-term mortality. Preoperative cardiac arrest and RI were associated with inferior results for both EVAR and open repair. Clinical judgment on when to use EVAR as a primary repair modality must be exercised.

ObjectivesFew centers have adopted endovascular therapy for the treatment of acute mesenteric ischemia (AMI). We sought to evaluate the effect of endovascular therapy on outcomes for the treatment of AMI.MethodsA single-center, retrospective cohort review was performed on all consecutive patients with thrombotic or embolic AMI presenting between 1999 and 2008. Patients with mesenteric venous thrombosis, nonocclusive mesenteric ischemia, and ischemia associated with aortic dissection were excluded. Demographic factors, preoperative metabolic status, and etiology were compared. Primary clinical outcomes included endovascular technical success, operative complications, and in-hospital mortality.ResultsSeventy consecutive patients were identified with AMI (mean age, 64 ± 13 years). Etiology of mesenteric ischemia was 65% thrombotic and 35% embolic occlusions. Endovascular revascularization was the preferred treatment (81%) vs operative therapy (19%). Successful endovascular treatment was achieved in 87%. Endovascular therapy required laparotomy in 69% vs traditional therapy in 100% (P < .05), with a median 52-cm necrotic bowel resected (interquartile range [IQR], 11-140 cm) vs 160 cm (IQR, 90-250 cm; P < .05), respectively. Acute renal failure and pulmonary failure occurred less frequently with endovascular therapy (27% vs 50%; P < .05 and 27% vs 64%; P < .05). Successful endovascular treatment resulted in a mortality rate of 36% compared with 50% (P < .05) with traditional therapy, whereas the mortality rate for endovascular failures was 50%. Endovascular therapy was associated with improved mortality in thrombotic AMI (odds ratio, 0.10; 95% confidence interval, 0.10-0.76; P < .05).ConclusionsEndovascular therapy has altered the management of AMI, and there are measurable advantages to this approach. Using endovascular therapy as the primary modality for AMI reduces complications and improves outcomes.

Perioperative proximal endoleaks during endovascular aneurysm repair potentiate graft migration, aneurysm sac expansion, and stent-graft failure. Adjunctive placement of a Palmaz stent at the proximal landing zone can improve proximal seal and eliminate perigraft flow; however, the long-term sequelae associated with this maneuver are unknown. We sought to evaluate the effect of Palmaz stent placement for type Ia endoleaks on delayed endoleak formation, graft migration, and aneurysm expansion.A retrospective cohort review of a prospectively maintained database was performed. Between 2000 and 2005, all consecutive patients who had undergone infrarenal endovascular aneurysm repair were evaluated for a type I endoleak that was treated with Palmaz stent placement. Fenestrated, juxtarenal, and investigational devices were excluded from the analysis. Postoperative and follow-up axial imaging were analyzed for the following three primary endpoints: type I endoleak formation, stent-graft migration, and aneurysm sac expansion. In addition, a paired analysis was performed comparing suprarenal aortic diameters, infrarenal aortic neck diameters, aortic neck lengths, and proximal seal zones.In all, 36 consecutive patients were identified with intraoperative type I endoleaks that were treated with Palmaz stenting. Five patients with ruptured abdominal aortic aneurysms died before discharge; the remaining 31 patients comprised the cohort for analysis. During a median follow-up period of 53 months (interquartile range: 14-91 months), no type I endoleak developed after Palmaz stent placement. Despite patients experiencing shortening of aortic neck length (26%) and loss of the proximal seal zone (35%), no stent-graft migration was seen in this population. Continued aortic degeneration accounted for proximal seal zone loss. At a distance 15 mm below the lowest renal artery, the mean aortic diameter increased by 3.2 mm (95% confidence interval: 0.4-6, p0.5), and 63% of patients demonstrated an increase of10%. Mean aortic sac regression was 5.8 mm (95% confidence interval: 0.5-11.0, p0.05). Overall, at the final follow-up evaluation, aortic sac regression was found to have occurred in 55% of patients, aortic sac increased up to 10% in 20% of the patients, and by more than 10% in 25% of the patients.Proximal neck reinforcement with a Palmaz stent serves as an effective endovascular adjunct to treat intraoperative type I endoleaks, and has a very high technical success rate. Most importantly, it has a clinical effect on delayed type I endoleak formation and stent-graft migration.

IntroductionPatients with chronic distal aortic dissection (CDAD) remain at high risk for late aorta-related events and reinterventions, and the ideal management strategy remains undefined. Open surgical procedures carry morbidity, but scant data for thoracic endovascular aortic repair (TEVAR) of CDAD exist. This study reports our intermediate-term results with TEVAR for complicated CDAD.MethodsAll cases of TEVAR for complicated (aortic growth, malperfusion, intractable pain) CDAD at our institution between 2000 and 2007 were retrospectively reviewed. Demographic information, indications for repair, complications, and aortic morphologic changes were collected from medical records and imaging studies. Aortic morphology (aneurysm size, false lumen thrombosis) was assessed at multiple levels with 3-dimensional image analysis techniques. Kaplan-Meier analysis was used to estimate survival, freedom from reintervention, and likelihood of false lumen thrombosis, with log-rank tests used to discriminate between Kaplan-Meier curves.ResultsIn total, 144 stent–grafts were implanted in 76 consecutive patients (49 male) with complicated CDAD. Early (

The National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF-DOQI) recommends the use of a permanent vascular access for pediatric hemodialysis (HD) patients; however, central venous catheters are the most common vascular access used among children. In children receiving HD, central venous catheters, while suboptimal, are the most common vascular access used. As such, it is imperative that pediatric HD providers optimize vascular access techniques. We report outcomes of arteriovenous fistula (AVF) creation by a single surgeon in pediatric HD patients dialyzed at a single center. We further describe our experience and outcomes with the use of the operating microscope in the United States in children receiving HD under 15 kg in weight and as young as 4 years of age. AVF usage rates as well as short- and long-term patency rates can be quite high with proper management. We further illustrate that the Fistula First principles can be applied to the pediatric population in the setting of a single surgeon with single center experience. As such, we have surpassed the current NKF-DOQI recommendation of 50% fistula use in prevalent HD patients.

PURPOSE To review our experience with the endovascular treatment of chronic infrarenal aortic occlusion with regard to technical success and midterm patency, as well as perioperative mortality and morbidity. METHODS A retrospective review was performed of patients who presented from January 1, 2000, to December 31, 2005, with a diagnosis of chronic infrarenal aortic occlusion (TASC D) treated with endovascular techniques. In this time period, 31 patients (22 women; mean age 63 years) underwent attempted recanalization of the occluded aorta and iliac arteries. Claudication was the most common presenting symptom (14, 45%). Patients were treated solely with angioplasty and stenting or thrombolysis followed by angioplasty/stenting based on surgeon preference. RESULTS Technical success was 93%. The 2 failures were individual cases of wire-induced iliac artery perforation and failed access; both patients were treated with bypass grafting. Nine (29%) patients had thrombolysis prior to angioplasty. There were no perioperative deaths. Postoperative ankle-brachial indexes increased significantly from preoperative values (p

The effect of cellular differentiation on the response of cells to hypoxic stress has been evaluated using the myogenic cell line BC3H1. Aerobic myocytes were predominantly in G0/G1 of the cell cycle and could be induced into S and G2/M of the cell cycle only by replating in high serum-containing medium at subconfluent cell density. In contrast, hypoxic myocytes demonstrated marked progression into S and G2/M upon reoxygenation without replating in the presence of serum. This modulation of myocytes by hypoxia was suggested further by the induction of 100-kDa and 9-kDa proteins (PSP 100 and PSP 9) which were otherwise only detectable in myoblasts. Two-dimensional gel analysis of newly synthesized proteins demonstrated that the five major glucose/oxygen-regulated proteins (GRP/ORP 260, 150, 100, 80, and 33) were induced in hypoxic myogenic cells independent of their state of differentiation. In addition to the GRP/ORPs, synthesis of 20 and 23 other major proteins was influenced in myocytes and myoblasts, respectively. The bulk of these alterations in myoblasts (70%) were inhibitions. In contrast, 75% of the alterations in myocyte protein synthesis were either enhancements or inductions. The data show that hypoxia can modulate the myocyte phenotype and invoke proliferative characteristics. Moreover, the data suggest that ischemia will have a different effect on and prognosis for tissues with a high mitotic index compared with differentiated tissues.

Purpose: To compare angiograms, considered the gold standard for diagnostic imaging of peripheral arterial disease (PAD), to the corresponding histological sections of popliteal and tibial vessels obtained after amputation to determine if angiography fails to define atheroma burden in “normal appearing” arteries in patients with PAD. Methods: Between 2004 and 2006, 69 patients underwent amputation of a lower extremity for severe tissue loss, gangrene, or pedal sepsis precluding limb salvage. Popliteal and tibial vessels were harvested, perfusion-fixed, and analyzed histologically. Thirty-four of these patients had pre-amputation angiography during attempted salvage procedures. Angiograms with patent or minimally diseased vessel segments (n = 19) were assessed for stenoses, diameter, and calcification by 3 vascular surgeons (n = 72 evaluations). These results were compared to corresponding cross-sectional histological slides (n = 66) in a blinded manner. Results: Angiograms performed prior to above-knee (n = 9) or below-knee (n = 10) amputation revealed 24 stenoses with a mean (±SD) diameter-reducing stenosis of 19.5%±15.2%. Corresponding histological cross sections revealed greater linear stenoses measured via boundaries of the internal elastic lamina (IEL stenosis, 28.9%±20.2%, p = 0.003 versus angiography) or via boundaries of the external elastic membrane (vessel stenosis, 43.1%±15.2%, p

PurposePercutaneous angioplasty and stenting (PTAS) is emerging as a therapeutic option for patients with chronic mesenteric ischemia. This study evaluated patency and mortality, and their relationship between degree of vessel occlusion (stenotic or totally occluded), stent characteristics, and comorbidities in patients who were treated with PTAS of the visceral vessels for chronic mesenteric ischemia.MethodsA retrospective review was performed of the records of all patients who underwent PTAS of the celiac, superior mesenteric, or inferior mesenteric arteries, or both, for symptomatic chronic mesenteric ischemia between January 2001 and December 2005. Patient demographics, lesion characteristics (stenosis or occlusion), interventional details, and early and late mortality rates were recorded. Cumulative mortality and patency rates and factors associated with outcomes were determined using Kaplan-Meier method and Cox proportional hazards modeling.ResultsEighty-seven mesenteric vessels (57 superior mesenteric, 23 celiac, and 7 inferior mesenteric arteries) were treated in 65 patients (29 men and 36 women). Completely occluded vessels were treated in 18 patients (28%), and >60% stenosis was treated in 47 patients (72%). Mesenteric angina was the most common symptom (97%). For the entire series, the cumulative 1-year results were primary patency, 65% (95% confidence interval [CI], 50%-80%); primary assisted patency, 97% (95% CI, 92%-100%); secondary patency, 99% (95% CI, 96%-100%); and survival, 89% (95% CI, 80%-98%). All deaths occurred ≤60 days after treatment. The endovascular treatment of visceral artery occlusion was not associated with diminished patency or survival, irrespective of stent size or number. Patients requiring bowel resection were less likely to survive than those who did not (odds ratio [OR], 26; 95% CI, 3.5-192; P < .001). One-year primary patency was worse among patients with chronic obstructive pulmonary disease (OR, 3.2; 95% CI, 1.4-7.7; P = .009) or who had femoral access (OR, 3.0; 95% CI, 1.1-7.9; P = .015).ConclusionsFor patients with chronic mesenteric ischemia, the results of endovascular treatment of occluded mesenteric arteries are indistinguishable from those treated for stenotic vessels. Patients requiring bowel resection are less likely to survive, and those with chronic obstructive pulmonary disease or who had femoral access have higher reintervention rates.

Objectives: Open aortoiliac grafts have been constructed with a short aortic bifurcation sewn near or to the visceral vessels to avoid limb kinking. Similarly, the majority of endovascular bifurcated stent grafts have short aortic main body ranging from 4 to 5 cm. In these patients and in those with short infrarenal aortic lengths, endovascular salvage with fenestrated-branched stent grafts is technically challenging because of the short distance between the renal arteries and the flow divider of the graft. Custom-manufactured fenestrated-branched stent grafts can be extended into the prior open surgical graft or stent graft using a short distal bifurcated stent graft with inverted iliac limb (Fig) for the contralateral gate. The aim of this study was to evaluate outcomes of patients treated with fenestrated-branched stent grafts coupled with inverted iliac limbs for salvage of failed open surgical and endovascular stent grafts. Methods: The clinical data of three high-volume, complex aortic referral centers using fenestrated-branched stent grafts were entered into prospectively maintained databases from January 2011 to June 2014. All patients had investigational manufactured devices under physician-sponsored investigational device exemption protocols. In addition to the proximal fenestrated-branched component, all patients received custom-manufactured distal bifurcated devices constructed with a main body

Male gender 270 (76.3%) 82 (64.1%) 188 (83.2%)

Our objective was to examine the role of an exogenous nitric oxide (NO) donor, DETA-NONOate (DETA), on matrix metalloproteinase (MMP)-9, MMP-2, and tissue inhibitor of matrix metalloproteinases (TIMP)-1 expression and activity in interleukin (IL)-1beta-induced rat aortic smooth muscle cells (RA-SMCs) and rat aortic explants (RAEs). RA-SMCs were incubated with IL-1beta (2 ng/ml), an inflammatory cytokine known to induce MMP-9 expression, and increasing concentrations of DETA (0, 1.0, 10, 100 microM; n = 3/group) for 48 hr. RAEs were incubated with IL-1beta (2 ng/mL) and increasing concentrations of DETA (0, 5.0, 50, 100, and 500 microM; n = 3/group) for 48 hr. Media were collected and assayed for NO(x) by the Griess reaction and MMP-9 activity by zymography. Messenger RNA (mRNA) was extracted from cells and analyzed for MMP-9, MMP-2, and TIMP-1 expression levels by quantitative real-time reverse-transcriptase polymerase chain reaction. All statistical analyses were performed by analysis of variance. In RA-SMCs and RAEs, DETA administration resulted in a dose-dependent increase in media NOx concentration (RA-SCM p0.01, RAE p0.01) and a concurrent decrease in both MMP-9 expression (RASMC p = 0.01, RAE p = 0.01) and activity (RASMC p = 0.04, RAE p = 0.006). There were no significant differences seen in MMP-2 and TIMP-1 expression or activity in response to DETA exposure. DETA decreased IL-1beta-induced MMP-9 expression and activity in both RA-SMCs and RAEs in a dose-dependent fashion. In addition, DETA administration had no effect on MMP-2 or TIMP-1 expression or activity in vitro. These data suggest that NO donors may be beneficial in decreasing MMP-9 levels and might serve to inhibit MMP-9-dependent vessel wall remodeling seen during abdominal aortic aneurysm formation.

ObjectiveThis study was undertaken to define matrix metalloproteinase (MMP) expression in the anterior and posterior wall of descending thoracic aortic aneurysms (TAAs) and correlate it with specific computed tomography (CT) image sites within the descending thoracic aorta.MethodsSerial CT images of patients with TAAs were compared with age- and gender-matched normal descending thoracic aortas at levels T4-T12. The mean circumference of the TAAs was 153 mm (n = 12) and 148 mm (n = 11) at T8 and T10, respectively, compared with 75 mm (n = 12) and 75 mm (n = 10) in controls (P < .001). Aortic tissue was collected from a separate set of eight patients undergoing descending TAA resection (processed ≤12 hours of excision) and six cadavers (processed ≤24 hours of death). Tissue collected between the intercostals arteries was defined as posterior wall, and directly opposite was the anterior wall. MMP-9 and MMP-2 messenger RNA (mRNA) extracted from aortic tissue was analyzed by quantitative real time polymerase chain reaction (PCR) and normalized to β-actin. Immunohistochemistry was performed for MMP-9 and MMP-2. CT aortic measurements and MMP expression were compared by t tests and analysis of variance, respectively.ResultsThe ratio of arc distance between the intercostals on the posterior wall to total aortic circumference was 0.14 in healthy controls compared with 0.08 in TAAs at vertebral level T8 (P = .001). At T10, the ratio was 0.15 in healthy controls compared with 0.11 in TAAs (P = .001). MMP-9 expression in TAAs was 4.3-fold higher in the anterior wall compared with the posterior wall (P = .03). Conversely, MMP-2 expression in TAAs was 3.2-fold higher in the posterior wall compared with the anterior wall (P = .008). MMP expression was not detected in control cadaver aortas.ConclusionAnterior walls of expanding TAAs grow at a greater rate than the posterior wall, as determined from the lower ratio of intercostal arc distance to total circumference in TAAs. Differential MMP expression appears to be a biologic marker for asymmetric growth in the TAA wall.Clinical RelevanceThe pathogenesis of thoracic aortic aneurysms (TAAs) is poorly understood. Multiple lines of evidence suggest that matrix metalloproteinases (MMPs), a family of enzymes, are important in aneurysm development. Earlier experiments documented a regional variation of MMP-9 in stimulated rodent aortas, with production greater in the abdominal aorta compared with the thoracic aorta. The present study extends that observation and documents asymmetric aneurysm development in the TAA wall, with increased anterior wall growth in correlation to increased MMP-9 production. An improved understanding of the mechanisms by which MMP production is regulated is critical.

Objectives. While extrinsic mechanisms of apoptosis in abdominal aortic aneurysms (AAAs) are recognized, this project hypothesizes that an intrinsic, mitochondrial-dependent, mechanism of apoptosis also contributes to experimental AAA formation. Methods. Rat aortas were perfused with either saline or elastase (N = 5 per group) and harvested 7 days postperfusion. The aortas were placed in gluteraldehyde for subsequent transmission electron microscopy, Bouin's solution for TUNEL, or paraformaldehyde for immunohistochemical staining for caspase-9, caspase-3, and Bid. Results. Abdominal aortic diameters increased 168 ± 25 % (mean ± SEM) after elastase perfusion. compared with 30 ± 5% after saline perfusion (P

The objective of the current study was to characterize temporal trends in the treatment of aorto-iliac occlusive disease (AIOD) and the impact of the introduction of less invasive therapy on overall intervention rates.Patients with diagnostic codes for AIOD, and procedure codes for aortofemoral bypass (AFB) or iliac artery angioplasty and stenting were selected from the Nationwide Inpatient Sample for 1996 to 2000. Utilization rates of both intervention types were determined. Outcome variables including in-hospital mortality and duration of stay were assessed.The rate of iliac artery angioplasty and stenting increased 850%, from 0.4 to 3.4 cases per 100,000 adults (P.001). The rate of AFB declined 15.5%, from 5.8 to 4.9 cases per 100,000 adults (P.005). Older age, white race, and higher-income patients were more likely to undergo angioplasty and stenting. AFB had a higher mortality rate, longer duration of stay, and higher hospital charges compared to angioplasty and stenting.Iliac artery angioplasty and stenting has rapidly gained a large market share in the treatment of AIOD. Acceptable clinical outcomes have likely lowered the threshold for treatment and contributed to the rapid diffusion of this technology for the treatment of AIOD.

Pulmonary embolism (PE) is a major health concern that affects approximately 600,000 new patients annually. The diagnosis of PE can be difficult to make, and several imaging studies have been developed to aid in this process. Initial evaluation involves the acquisition of a chest radiograph. Findings on radiography, however, are often non-specific. The gold-standard study historically has been pulmonary angiography, with increasing diagnostic yield since the implementation of digital subtraction technology. This is an invasive procedure, however, but the incidence of major complications is low. Less invasive modalities have been developed and include ventilation-perfusion lung scans. These are used as one of the initial screening tests in evaluation of patients with suspected PE. The presence of a high-probability scan usually indicates the presence of a PE, although few patients have high probability scans. The test is significantly affected by underlying pulmonary disease or previous PE. Given this, ventilation-perfusion lung scans are limited as a primary diagnostic tool in the evaluation of suspected PE. Helical computed tomography (CT) is currently under much scrutiny as a diagnostic tool for PE. Currently a prospective, multicenter trial evaluating its efficacy (PIOPED II) has been initiated, but the results are pending. Preliminary reports suggest the helical CT and venous phase CT may become a first line study in patient evaluation. The diagnosis of PE is challenging and several imaging modalities are currently used to assist the clinician. Currently, multiple modalities are often required to make the diagnosis. With the advent of new technology and improved imaging techniques, the diagnosis of PE will become easier.

Objective To determine the mechanism underlying increased expression and activity of matrix metalloproteinase 9 (MMP-9) by rat aortic smooth muscle cells (RA-SMC) after inhibition of inducible nitric oxide synthase (iNOS). Methods and results Treatment of interleukin-1β-stimulated RA-SMC with aminoguanidine led to an increase of 96% in MMP-9 activity ( P = 0.003) by gelatin zymography, a 40% increase in pro-MMP-9 protein ( P = 0.018) by Western blot, and a 155% increase in MMP-9 mRNA ( P = 0.06) by reverse transcription polymerase chain reaction. Aminoguanidine also caused a 26% decrease in cytosolic IκB levels ( P = 0.014) by Western blot, as well as a 97% increase in nuclear factor-κB binding and a 216% increase in activator protein-1 binding as measured by electrophoretic mobility shift assay. No significant changes were noted in MMP-2 or TIMP-1 expression, protein levels, or activity after aminoguanidine administration. Conclusion MMP-9 expression and activity is increased in cytokine stimulated RA-SMCs after iNOS inhibition, coincident with activation of the nuclear factor-κB and activator protein-1 pathways. We speculate that local derangements in iNOS may favor MMP-9-dependent vessel wall damage in vivo via an inflammatory cascade mechanism.