Chronic mesenteric ischemia: Clinical practice guidelines from the Society for Vascular Surgery.

BACKGROUND: Chronic mesenteric ischemia (CMI) results from the inability to achieve adequate postprandial intestinal blood flow, usually from atherosclerotic occlusive disease at the origins of the mesenteric vessels. Patients typically present with postprandial pain, food fear, and weight loss, although they can present with acute mesenteric ischemia and bowel infarction. The diagnosis requires a combination of the appropriate clinical symptoms and significant mesenteric artery occlusive disease, although it is often delayed given the spectrum of gastrointestinal disorders associated with abdominal pain and weight loss. The treatment goals include relieving the presenting symptoms, preventing progression to acute mesenteric ischemia, and improving overall quality of life. These practice guidelines were developed to provide the best possible evidence for the diagnosis and treatment of patients with CMI from atherosclerosis. METHODS: The Society for Vascular Surgery established a committee composed of vascular surgeons and individuals experienced with evidence-based reviews. The committee focused on six specific areas, including the diagnostic evaluation, indications for treatment, choice of treatment, perioperative evaluation, endovascular/open revascularization, and surveillance/remediation. A formal systematic review was performed by the evidence team to identify the optimal technique for revascularization. Specific practice recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation system based on review of literature, the strength of the data, and consensus. RESULTS: Patients with symptoms consistent with CMI should undergo an expedited workup, including a computed tomography arteriogram, to exclude other potential causes. The diagnosis is supported by significant arterial occlusive disease in the mesenteric vessels, particularly the superior mesenteric artery. Treatment requires revascularization with the primary target being the superior mesenteric artery. Endovascular revascularization with a balloon-expandable covered intraluminal stent is the recommended initial treatment with open repair reserved for select younger patients and those who are not endovascular candidates. Long-term follow-up and surveillance are recommended after revascularization and for asymptomatic patients with severe mesenteric occlusive disease. Patient with recurrent symptoms after revascularization owing to recurrent stenoses should be treated with an endovascular-first approach, similar to the de novo lesion. CONCLUSIONS: These practice guidelines were developed based on the best available evidence. They should help to optimize the care of patients with CMI. Multiple areas for future research were identified.

Long-term outcomes after pediatric peripheral revascularization secondary to trauma at an urban level I center.

OBJECTIVE: The purpose of this investigation was to determine our limb-related contemporary pediatric revascularization perioperative and follow-up outcomes after major blunt and penetrating trauma. METHODS: A retrospective review was performed of a prospectively maintained pediatric trauma database spanning January 2010 to December 2017 to capture all level I trauma activations that resulted in a peripheral arterial revascularization procedure. All preoperative, intraoperative, and postoperative continuous variables are reported as a mean ± standard deviation; categorical variables are reported as a percentage of the population of interest. RESULTS: During the study period, 1399 level I trauma activations occurred at a large-volume, urban children's hospital. The vascular surgery service was consulted in 2.6% (n = 36) of these cases for suspected vascular injury based on imaging or physical examination. Our study population included only patients who received an arterial revascularization, which was performed in 23 of the 36 consultations (1.6% of total traumas; median age, 11 years). These injuries were localized to the upper extremity in 60.9% (n = 14), lower extremity in 30.4% (n = 7), and neck in 8.7% (n = 2). The mean Injury Severity Score in the revascularized cohort was 14.0 (±7.6). Bone fractures were associated with 39.1% of the vascular injuries (90% of blunt injuries). Restoration of in-line flow was achieved by an endovascular solution in one patient and open surgery in the remainder, consisting of arterial bypass in 59.1% and direct repair in 40.9%. Within 30 days of the operation, we observed no deaths, no infections of the arterial reconstruction, and no major amputations. One patient required perioperative reintervention by the vascular team secondary to the development of a superficial seroma without evidence of graft involvement. Mean follow-up in our cohort was 43.3 (±35.4) months. During this phase, no additional deaths, amputations, chronic wounds, or limb length discrepancies were observed. All vascular repairs were patent, and all but one patient reported normal function of the affected limb at the latest clinic visit. CONCLUSIONS: Traumatic peripheral vascular injury is rare in the pediatric population but is often observed secondary to a penetrating force or after long bone fracture. However, contemporary perioperative and long-term outcomes after surgical revascularization are excellent as demonstrated in this institutional case series.

Outcomes associated with a transcarotid artery revascularization-centered protocol in high-risk carotid revascularizations using the ENROUTE neuroprotection system.

OBJECTIVE: This investigation describes the perioperative and early follow-up results associated with transcarotid artery revascularization (TCAR) in patients not participating in the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure II (ROADSTER-2) registry using the ENROUTE neuroprotection system (ENPS; Silk Road Medical, Sunnyvale, Calif). METHODS: A retrospective review was performed capturing all TCAR/ENPS procedures in patients deemed to be at high risk for complications after traditional carotid endarterectomy. All patients enrolled in the ROADSTER-2 registry were excluded, leaving only those treated outside trial regulations for analysis. Preoperative demographics, intraoperative variables, and perioperative and follow-up outcomes were abstracted and reported herein. RESULTS: From December 2015 to January 2018, there were 75 carotid arteries treated at our institution. All interventions were performed on carotid arteries that were symptomatic with ≥50% stenosis (46.7%) or asymptomatic with ≥80% stenosis (53.3%) by duplex ultrasound and computed tomography angiography. Technical success in our series was 97.3% (73/75), with treatment failures attributed to one case of common carotid artery dissection and another secondary to stent maldeployment in the external carotid artery. Perioperative (30-day) ipsilateral stroke rate was 2.7% (n = 2), myocardial infarction incidence was 0%, and mortality rate was 2.7% (n = 2). We did not observe any cranial nerve injuries. After a mean follow-up of 8.0 ± 6.7 months, no carotid stents required reintervention. However, we noted one instance of minor (<50%) in-stent stenosis and one asymptomatic stent thrombosis. One additional ipsilateral stroke was observed on follow-up, probably from a cardiac source. CONCLUSIONS: We report that dynamic reverse-flow TCAR using the ENPS continues to be safe, feasible, and efficacious with minimal risks of postoperative stroke, myocardial infarction, and mortality outside of ROADSTER-2 regulations.

Fenestrated endovascular aneurysm repair-induced acute kidney injury does not result in chronic renal dysfunction.

OBJECTIVE: Acute kidney injury (AKI) is a common physiologic complication after fenestrated endovascular aneurysm repair (FEVAR). This investigation was initiated to determine the unknown impact of post-FEVAR AKI on long-term renal function after index hospital discharge. METHODS: A retrospective review was performed of an institutional FEVAR database capturing preoperative, intraoperative, and postoperative variables related to the implantation of consecutive Zenith Fenestrated endografts (ZFEN; Cook Medical, Bloomington, Ind) between October 2012 and April 2018. AKI in this study was bimodally defined as qualification by either Risk, Injury, Failure, Loss of kidney function, and End-stage (RIFLE) criteria or a postoperative serum creatinine (sCr) concentration increase of 0.5 mg/dL from baseline. Glomerular filtration rate (GFR) was calculated using the validated Modification of Diet in Renal Disease (MDRD) study equation. RESULTS: During the study period, 120 FEVARs were performed at our institution. Twenty-four (20%) patients exhibited postoperative AKI by our established definitions. Two in-hospital deaths occurred in the AKI cohort compared with none in the remaining FEVARs (P = .04). Four (16.7%) AKI patients required perioperative (<30-day) renal replacement therapy, three of whom were successfully weaned before discharge. FEVARs uncomplicated by AKI exhibited no differences in sCr concentration from baseline to 1-month, 6-month, 1-year, and 2-year follow-up (mean, 1.8 ± 1.4 years). In contrast, patients exhibiting AKI experienced an sCr concentration increase of 57.1% (P = .01) at 1 month after the procedure. This elevation decreased to 14.3% (P = .35) at 6 months after the procedure and was maintained at baseline values at 1- and 2-year office visits (follow-up, 1.3 ± 1.5 years). A similar pattern of gradual recovery during follow-up was also observed with respect to calculated GFR. CONCLUSIONS: AKI is common after FEVAR but rarely results in permanent renal dysfunction as both sCr concentration and GFR return to baseline by 6 months after the procedure.

Procedural Complexity of TransCarotid Artery Revascularization Is Not Increased in Irradiated and Reoperative Necks.

BACKGROUND: TransCarotid Revascularization (TCAR) with dynamic flow reversal using the ENROUTE Neuroprotection System (ENPS) is a Food and Drug Administration-approved alternative carotid revascularization modality. The purpose of this investigation was to determine whether TCAR in a hostile (fibrotic) surgical field increases procedural complexity and postoperative complications. METHODS: Perioperative variables for all institutional TCARs performed between December 2015 and April 2019 were prospectively captured. Procedures performed as part of the ongoing ROADSTER-2 registry were excluded. Univariate analysis, consisting of Student's T and Fisher's exact testing, comparing virgin and hostile neck TCAR, was performed at an alpha of 0.05. RESULTS: During the study period, 149 total procedures (n = 30, hostile ipsilateral necks) qualified for inclusion. Both hostile and virgin neck groups were comparable with respect to preoperative comorbidities and medication profiles. The ipsilateral hostile neck cohort consisted of ten patients who underwent previous ipsilateral neck radiation and 23 who were status after neck dissection (3 had both). Intraoperatively, there were no differences with respect to estimated blood loss (47.2 vs. 44.8 mL, P = 0.81), operative time (69.5 vs. 74.5 min, P = 0.38), reverse flow time (12.4 vs. 10.4 min, P = 0.34), radiation exposure (217.7 vs. 226.2 mGy, P = 0.88), fluoroscopy time (5.4 vs. 5.0 min, P = 0.65), contrast usage (23.5 vs. 25.0 mL, P = 0.55), and ability to achieve technical success (96.7% vs. 100%, P = 0.58) between virgin and hostile necks, respectively. Perioperative (30-day) ipsilateral stroke and death rate was 2.5% vs. 0% (P = 1.0) and 2.5% vs. 0% (P = 1.0), respectively, between virgin and hostile necks. We observed one postoperative cranial nerve injury in any of our TCAR patients (hostile neck, P = 0.20). Finally, a total of 3 hematomas (requiring washout) occurred in our (2 in virgin necks and one in a hostile neck) surgical cohort (P = 0.49). CONCLUSIONS: Based on this limited, small series, TCAR in hostile surgical fields is not associated with an increase in case complexity and maintains a similar perioperative risk to virgin field procedures.

Aggressive Surveillance Is Needed to Detect Endoleaks and Junctional Separation between Device Components after Zenith Fenestrated Aortic Reconstruction.

BACKGROUND: Junctional separation and resulting type IIIa endoleak is a well-known problem after EVAR (endovascular aneurysm repair). This complication results in sac pressurization, enlargement, and eventual rupture. In this manuscript, we review the incidence of this late finding in our experience with the Cook Zenith fenestrated endoprosthesis (ZFEN, Bloomington, IN). METHODS: A retrospective review was performed of a prospectively maintained institutional ZFEN fenestrated EVAR database capturing all ZFENs implanted at a large-volume, academic hospital system. Patients who experienced junctional separation between the fenestrated main body and distal bifurcated graft (with or without type IIIa endoleak) at any time after initial endoprosthesis implantation were subject to further evaluation of imaging and medical records to abstract clinical courses. RESULTS: In 110 ZFENs implanted from October 2012 to December 2017 followed for a mean of 1.5 years, we observed a 4.5% and 2.7% incidence of clinically significant junctional separation and type IIIa endoleak, respectively. Junctional separation was directly related to concurrent type Ib endoleak in all 5 patients. Three patients presented with sac enlargement. One patient did not demonstrate any evidence of clinically significant endoleak and had a decreasing sac size during follow-up imaging. The mean time to diagnosis of modular separation in these patients was 40 months. Junctional separation was captured in surveillance in 2 patients and reintervened upon before manifestation of endoleak. However, the remaining 3 patients completed modular separation resulting in rupture and emergent intervention in 2 and an aortic-related mortality in the other. CONCLUSIONS: Junctional separation between the fenestrated main and distal bifurcated body with the potential for type IIIa endoleak is an established complication associated with the ZFEN platform. Therefore, we advocate for maximizing aortic overlap during the index procedure followed by aggressive surveillance and treatment of stent overlap loss captured on imaging.

The five things we all need to know about MACRA and alternative payment systems to compete and flourish.

Changes in how patient care will be reimbursed in the future are being determined right now. The law has changed to eliminate the past method of fee for service funded by the sustainable growth rate formula to payment based on quality. You need to know how the system functions to prevent a 4% reduction in Medicare reimbursement in 2019. You need to know this now because data collected today in 2017 will determine your rate for 2019. This review provides you knowledge of how the system has changed, what is required of you right now to be successful, and how you can succeed in the future. Pertinent references are provided to allow you to query the Centers for Medicare and Medicaid Services for the most up-to-date information.

Results of nonoperative management of acute limb ischemia in infants.

OBJECTIVE: Acute limb ischemia (ALI) in infants poses a challenge to the clinician secondary to poor operative outcomes, limb loss risk, and lifelong morbidity. This retrospective study reviewed a 10-year institutional experience with the nonoperative management of ALI in infants. METHODS: Infants (aged ≤12 months) diagnosed with ALI by duplex ultrasound and treated with initial nonoperative management at a tertiary care children's hospital were identified through vascular laboratory arterial duplex ultrasound records and International Classification of Diseases and Current Procedural Terminology codes associated with ALI. Demographics of the patients, injury characteristics, treatment administered, and outcomes were abstracted by chart review and presented using descriptive statistics. RESULTS: During the study period, a total of 25 (28% female) infant patients were diagnosed with ALI. The average age for this cohort was 3.5 ± 3.2 months (standard deviation). Most cases were secondary to iatrogenic injury (88%) from arterial cannulation. Injury sites were more concentrated to the lower extremities (84%) compared with the upper. Absence of Doppler signals was noted in 64% of infants, whereas limb cyanosis was observed in 60% at the time of presentation. Infants were initially treated with anticoagulation (80%) when possible. Two patients failed to respond to nonoperative management and required thrombolysis secondary to progression of thrombus burden while anticoagulated. There were no major (above-ankle) amputations at 30 days. Three deaths occurred within 30 days; all were unrelated to limb ischemia. In the 30-day survivors, overall duration of follow-up was 53.5 ± 38.5 months. One infant required above-knee amputation 6 weeks after diagnosis, resulting in an overall limb salvage rate of 96% on follow-up. Long-term morbidity included two patients with a chronic wound of the affected limb and one patient with limb length discrepancy. No subjects reported claudication at the latest follow-up appointment. In addition, all patients were independently ambulatory except for one adolescent girl who was using a walker with leg braces. CONCLUSIONS: In contrast to the adult population, ALI in infants can be managed with anticoagulation alone with good results. Long-term follow-up continues to demonstrate excellent functional results and minimal disability.

Adjunctive visceral artery chimney in patients undergoing Zenith Fenestrated aortic repair.

OBJECTIVE: Visceral artery chimneys have been employed as an adjunct to endovascular aneurysm repair (EVAR) to treat short-neck infrarenal and juxtarenal aortic aneurysms for more than two decades. With the widespread introduction of fenestrated endovascular aneurysm repair by the Food and Drug Administration-approved Zenith Fenestrated endograft (ZFEN; Cook Medical, Bloomington, Ind) to the United States in 2012, clinicians gained the ability to apply the chimney technique to these custom devices for difficult anatomy. The purpose of this report was to demonstrate feasibility and to provide evidence on the performance of chimneys for the treatment of complex juxtarenal aneurysms that could not be adequately treated with ZFEN alone. METHODS: A retrospective analysis was performed of a prospectively maintained institutional ZFEN database capturing 110 fenestrated endovascular aneurysm repairs from October 2012 to January 2018 to identify patients undergoing a concomitant visceral artery chimney. All patients with <12 months of follow-up were excluded from further analysis. Demographic, anatomic, intraoperative, perioperative, and follow-up characteristics were tabulated and analyzed. RESULTS: Six patients met criteria and were included in this investigation. They were universally male with a mean age of 76.2 years at the time of ZFEN/chimney. Chimneys were placed in a total of six visceral arteries (n = 1 per patient) consisting of three renal arteries, two celiac arteries, and one accessory renal artery. Mean estimated blood loss and operative time were 283 mL and 298 minutes, respectively. Technical success was achieved in all cases. Two small type IA "gutter" endoleaks were detected early; both spontaneously resolved on follow-up. We observed no instances of chimney migration, stenosis, or thrombosis perioperatively or on follow-up. Two reinterventions were performed in these six patients; these consisted of a repeated renal stent for ostial stenosis at a main body fenestration and a common femoral artery endarterectomy and patch angioplasty for an access-related common femoral artery occlusion. CONCLUSIONS: Use of ZFEN in conjunction with a singular chimney is safe, feasible, and durable in patients with difficult anatomy who do not meet instructions for use as demonstrated in this limited series.

Use of the Zenith Fenestrated platform to rescue failing endovascular and open aortic reconstructions is safe and technically feasible.

OBJECTIVE: Proximal neck dilation is a serious long-term complication directly causing the failure of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) of abdominal aortic aneurysms. However, the implantation of a fenestrated device presents the opportunity for proximal extension of the aortic reconstruction into a healthy segment while maintaining patency of the visceral vessels. The objective of this investigation was to report perioperative and follow-up outcomes using the Zenith Fenestrated (ZFEN; Cook Medical, Bloomington, Ind) aortic stent system in salvaging previous aortic repairs undergoing type IA endoleak or aneurysmal degeneration of the proximal neck. METHODS: We performed a retrospective review of a prospectively maintained institutional database capturing all fenestrated EVAR (FEVAR) cases with the ZFEN platform. Fenestrated cases were classified as primary FEVAR or reoperative FEVAR (rFEVAR) after previous EVAR or OSR. Cohort comparisons were performed using Fisher exact tests and Student t-tests for categorical and continuous variables, respectively. RESULTS: Between October 2012 and March 2017, a total of 103 patients diagnosed with abdominal aortic aneurysm with an inadequate proximal seal zone for traditional EVAR were treated with ZFEN. In 12 patients, FEVAR was performed as a reoperation after previous EVAR (n = 6) or OSR (n = 6). The indications for rFEVAR were proximal neck dilation (>55 mm) after OSR (n = 6), type IA endoleak after EVAR (n = 5), and proximal neck dilation after EVAR without endoleak (n = 1). No difference in ability to achieve technical success was observed between primary FEVAR and rFEVAR (97.8% vs 100%; P = 1.00). In addition, there were no differences in estimated blood loss (363 vs 500 mL; P = .25) and intraoperative use of contrast material (97.3 vs 104.0 mL; P = .55). However, a significant increase in fluoroscopy time (61.1 vs 79.8 minutes; P = .04), radiation exposure (415.9 vs 606.3 rad; P = .02), and operative time (228.4 vs 287.6 minutes; P = .03) in the rFEVAR cohort was observed. In the 30-day perioperative period, there were no significant differences with regard to mortality (2.2% vs 0%; P = 1.0), major adverse cardiovascular events (5.5% vs 0%, P = 1.0), and stent-related adverse events (2.2% vs 0%; P = 1.0). There were no differences in rates of perioperative (5.5% vs 0%; P = 1.0) or follow-up reintervention after a mean follow-up duration of 20.8 months (18.6% vs 25.0%; P = .70). CONCLUSIONS: FEVAR with the ZFEN platform of failed and failing aortic reconstructions due to disease progression is safe and feasible without increased morbidity and mortality in select patients. These preliminary results support the inclusion of ZFEN as a treatment option for aortic reintervention.

Perioperative Outcomes are Adversely Affected by Poor Pretransfer Adherence to Acute Limb Ischemia Practice Guidelines.

BACKGROUND: The accepted treatment for acute limb ischemia (ALI) is immediate systemic anticoagulation and timely reperfusion to restore blood flow. In this study, we describe the retrospective assessment of pretransfer management decisions by referring hospitals to an academic tertiary care facility and its impact on perioperative adverse events. METHODS: A retrospective analysis of ALI patients transferred to us via our Level I Vascular Emergency Program from 2010 to 2013 was performed. Patient demographics, comorbidities, Rutherford ischemia classification, time to anticoagulation, and time to reperfusion were tabulated and analyzed for correlation to incidence of major adverse limb events (MALEs), mortality, and bypass patency in the perioperative period (30-day postoperative). All intervals were calculated from the onset of symptoms and categorized into 3 subcohorts (<6 hr, 6-48 hr, and >48 hr). RESULTS: Eighty-seven patients with an average age of 64.0 (±16.2) years presented to outlying hospitals and were transferred to us with lower extremity ALI. The mean delay from symptom onset to initial referring physician evaluation was 18.3 hr. At that time of evaluation, 53.8% had Rutherford class IIA ischemia and 36.3% had class IIB ischemia. Seventy-six patients (87.4%) were started on heparin previous to transfer. However, only 44 patients (57.9%) reached therapeutic levels as measured by activated partial thromboplastin time before definitive revascularization. A delay of anticoagulation initiation >48 hr from symptom onset was associated with increased 30-day reintervention rates compared with the <6 hr group (66.7% vs. 23.5%; P < 0.05). However, time to reperfusion had no statistically significant impact on MALE, 30-day mortality, or 30-day interventional patency in our small cohorts. Additionally, patients with a previous revascularization had a higher 30-day reintervention rate (46.5%; P < 0.05). CONCLUSIONS: The practice of timely therapeutic anticoagulation of patients referred for ALI from community facilities occurs less frequently than expected and is associated with an increased perioperative reintervention rate.

Cryopreserved Homografts in Infected Infrainguinal Fields Are Associated with Frequent Reinterventions and Poor Amputation-Free Survival.

BACKGROUND: Single-length saphenous vein continues to be the conduit of choice in infected-field critical limb ischemia. However, half of these individuals have inadequate vein secondary to previous use or chronic venous disease. We reviewed our outcomes of infected-field infrainguinal bypasses performed with cryopreserved homografts (CHs), a widely accepted alternative to autogenous vein in this setting. METHODS: This is a retrospective, institutional descriptive analysis of infected-field infrainguinal revascularizations between 2012 and 2015. RESULTS: Twenty-four operations were performed in the same number of patients for limb ischemia with signs of active infection. The mean age of the cohort examined was 62.5 ± 14.4 (standard deviation) years. Mean Society of Vascular Surgery risk score was 3.9 with a baseline Rutherford's chronic ischemia score of 4.3 at presentation. Emergent procedures constituted 29% of cases, and the remainder cases were urgent procedures. The CH bypass captured was a reoperative procedure in all but one of the patients. Culture positivity was present in 75% of cases with Staphylococcus aureus (29%), the most commonly isolated organism. Thirty-day mortality and major adverse cardiovascular events were both 4%. Amputation-free survival (AFS) was 75% at 30 days. Similarly, 30-day reintervention was 38% with debridement (43%) and bleeding (29%), the most common indications. Average duration of follow-up was 27.9 ± 20.4 months (range: 0.5-60.4). Mean length of stay was 14.8 days. Reinfection requiring an additional procedure or antibiotic regimen separate from the index antibiotic course was 13%. Primary patency and AFS at 1 year was 50% and 58%, respectively. Primary patency and AFS at 2 years was 38% and 52%, respectively. Limb salvage at 1 and 2 years was 70% and 65%, respectively. Fifteen patients (63%) required reintervention during the follow-up period with 40% of those subjects undergoing multiple procedures. CONCLUSIONS: CHs remain a marginal salvage conduit in the setting of infection and no autogenous choices. Therefore, clinicians should individualize usage of this high-cost product in highly selected patients only.

Adult venous endothelium is a niche for highly proliferative and vasculogenic endothelial colony-forming cells.

OBJECTIVE: Postnatal resident endothelium of blood vessels has been proposed to represent terminally differentiated tissue that does not replicate. We previously isolated endothelial colony-forming cells (ECFCs) from human umbilical cord blood (CB) and term placenta by using colony-forming assays and immunocytochemistry. We showed that ECFCs are highly proliferative and form functioning vessels in vivo, the defining characteristics of a true endothelial progenitor cell. This exploratory investigation was conducted to determine whether the endothelium of healthy adult blood vessels contained resident ECFCs. METHODS: The endothelium of great saphenous vein (GSV) obtained from vein stripping procedures was collected with mechanical scraping, and ECFCs were isolated according to established protocols. RESULTS: GSV ECFCs incorporated acetylated low-density lipoprotein, formed tubules in Matrigel (BD Biosciences, San Jose, Calif) at 24 hours, and expressed endothelial antigens cluster of differentiation (CD) 144, CD31, CD105, and kinase insert domain receptor but not hematopoietic antigen CD45. Using cumulative population doublings and single-cell assays, we demonstrated that GSV ECFCs exhibited comparable proliferative capacities compared with CB ECFCs, including similar numbers of highly proliferative cells. When injected in collagen/fibronectin gels implanted in nonobese diabetic/severe combined immune deficiency mice, GSV ECFCs formed blood vessels with circulating murine red blood cells, demonstrating their vasculogenic potential. CONCLUSIONS: The ECFCs of the GSV contain a hierarchy of progenitor cells with a comparable number of highly proliferative clones as ECFCs of CB. The results of this investigation demonstrate that the adult endothelium contains resident progenitor cells that may have a critical role in vascular homeostasis and repair and could potentially be used as a source of autologous cells for cell therapies focusing on vasculogenesis.

Failure mode analysis of the Endologix endograft.

OBJECTIVE: Type III (T-III) endoleaks following endovascular aneurysm repair (EVAR) remain a major concern. Our center experienced a recent concentration of T-III endoleaks requiring elective and emergency treatment and prompted our review of all EVAR implants over a 40-month period from April 2011 until August 2014. This report represents a single center experience with T-III endoleak management with analysis of factors leading to the T-III-related failure of EVAR. METHODS: A retrospective review of all the operative reports, medical records, and computed tomography scans were reviewed from practice surveillance. Using Society for Vascular Surgery aneurysm reporting standards, we analyzed the morphology of the aneurysms before and after EVAR implant using computed tomography. Index procedure and frequency of reinterventions required to maintain aneurysm freedom from rupture were compared across all devices using SAS v 9.4 (SAS Institute, Inc, Cary, NC). Major adverse events (MAEs) requiring secondary interventions for aneurysm treatment beyond primary implant were analyzed for methods of failure. Aneurysm morphology of patients requiring EVAR was compared across all endograft devices used for repair. For purposes of MAE analysis, patients receiving Endologix (ELX) endograft were combined into group 1; Gore, Cook, and Medtronic endograft patients were placed into group 2. RESULTS: Overall, technical success and discharge survival were achieved in 97.3% and 98% of patients regardless of device usage. There was no significant device related difference identified between patient survival or freedom from intervention. MAEs involving aneurysm treatment were over seven-fold more frequent with ELX (group 1) vs non-ELX (group 2) endografts (P < .01). Group 1 patients with aneurysm diameters larger than 65 mm were associated with a highly significant value for development of a T-III endoleak (odds ratio, 11.16; 95% confidence interval, 2.17, 57.27; P = .0038). CONCLUSIONS: While EVAR technical success and survival were similar across all devices, ELX devices exhibited an unusually high incidence of T-III endoleaks when implanted in abdominal aortic aneurysms with a diameter of more than 65 mm. Frequent reinterventions were required for Endologix devices for prevention of aneurysm rupture due to T-III endoleaks.

Novel method to assess arterial insufficiency in rodent hind limb.

BACKGROUND: Lack of techniques to assess maximal blood flow capacity thwarts the use of rodent models of arterial insufficiency to evaluate therapies for intermittent claudication. We evaluated femoral vein outflow (VO) in combination with stimulated muscle contraction as a potential method to assess functional hind limb arterial reserve and therapeutic efficacy in a rodent model of subcritical limb ischemia. MATERIALS AND METHODS: VO was measured with perivascular flow probes at rest and during stimulated calf muscle contraction in young, healthy rats (Wistar Kyoto, WKY; lean Zucker rats, LZR) and rats with cardiovascular risk factors (spontaneously hypertensive [SHR]; obese Zucker rats [OZR]) with acute and/or chronic femoral arterial occlusion. Therapeutic efficacy was assessed by administration of Ramipril or Losartan to SHR after femoral artery excision. RESULTS: VO measurement in WKY demonstrated the utility of this method to assess hind limb perfusion at rest and during calf muscle contraction. Although application to diseased models (OZR and SHR) demonstrated normal resting perfusion compared with contralateral limbs, a significant reduction in reserve capacity was uncovered with muscle stimulation. Administration of Ramipril and Losartan demonstrated significant improvement in functional arterial reserve. CONCLUSIONS: The results demonstrate that this novel method to assess distal limb perfusion in small rodents with subcritical limb ischemia is sufficient to unmask perfusion deficits not apparent at rest, detect impaired compensation in diseased animal models with risk factors, and assess therapeutic efficacy. The approach provides a significant advance in methods to investigate potential mechanisms and novel therapies for subcritical limb ischemia in preclinical rodent models.

Impaired compensation to femoral artery ligation in diet-induced obese mice is primarily mediated via suppression of collateral growth by Nox2 and p47phox.

The present study was undertaken to establish the role of NADPH oxidase (Nox) in impaired vascular compensation to arterial occlusion that occurs in the presence of risk factors associated with oxidative stress. Diet-induced obese (DIO) mice characterized by multiple comorbidities including diabetes and hyperlipidemia were used as a preclinical model. Arterial occlusion was induced by distal femoral artery ligation in lean and DIO mice. Proximal collateral arteries were identified as the site of major (∼70%) vascular resistance to calf perfusion by distal arterial pressures, which decreased from ∼80 to ∼30 mmHg with ligation in both lean and DIO mice. Two weeks after ligation, significant vascular compensation occurred in lean but not DIO mice as evidenced by increased perfusion (147 ± 48% vs. 49 ± 29%) and collateral diameter (151 ± 30% vs. 44 ± 17%). Vascular mRNA expression of p22(phox), Nox2, Nox4, and p47(phox) were all increased in DIO mice. Treatment of DIO mice with either apocynin or Nox2ds-tat or with whole body ablation of either Nox2 or p47(phox) ameliorated the impairment in both collateral growth and hindlimb perfusion. Multiparametric flow cytometry analysis demonstrated elevated levels of circulating monocytes in DIO mice without impaired mobilization and demargination after femoral artery ligation. These results establish collateral resistance as the major limitation to calf perfusion in this preclinical model, demonstrate than monocyte mobilization and demarginatin is not suppressed, implicate Nox2-p47(phox) interactions in the impairment of vascular compensation to arterial occlusion in DIO mice, and suggest that selective Nox component suppression/inhibition may be effective as either primary or adjuvant therapy for claudicants.