Gregorio A. Sicard

Washington University in St. Louis, San Luis, Missouri, United States

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Publications (241)

  • Jeffrey Jim · Luis A. Sanchez · Gregorio A. Sicard
    Article · Sep 2015 · Journal of Vascular Surgery
  • Francis J. Caputo · Gregorio A. Sicard
    [Show abstract] [Hide abstract] ABSTRACT: Popliteal artery aneurysms carry a significant risk of thromboembolic events. While traditional open surgery (bypass and exclusion) has been shown to have excellent outcomes, endovascular alternatives may prove useful in those patients not suitable for open repair as well as those with straightforward anatomy.
    Chapter · Jan 2014
  • Abdulhameed Aziz · Gregorio A Sicard
    [Show abstract] [Hide abstract] ABSTRACT: Endovascular repair of abdominal aneurysms has become the dominant treatment modality for infrarenal aneurysms. Initial reports showed a constant number of open repairs although there was a shift toward complicated juxtra-renal aneurysms. In the past several years, more aggressive endoluminal approaches and the introduction of fenestrated grafts have appeared to dilute the open aneurysm operating experience. Coupled with work hours restrictions and shorter training paradigms, opportunities for training residents in open repair of abdominal aneurysms are decreasing. We envision that future treatment of complicated aortic aneurysms will likely entail advanced fellowship training in open repair and referral of complicated abdominal aneurysms to tertiary care centers.
    Article · Jul 2013
  • Source
    Jeffrey Jim · Brian G Rubin · Joseph J Ricotta · [...] · Gregorio A Sicard
    [Show abstract] [Hide abstract] ABSTRACT: Recent randomized controlled trials have shown that age significantly affects the outcome of carotid revascularization procedures. This study used data from the Society for Vascular Surgery Vascular Registry (VR) to report the influence of age on the comparative effectiveness of carotid endarterectomy (CEA) and carotid artery stenting (CAS). VR collects provider-reported data on patients using a Web-based database. Patients were stratified by age and symptoms. The primary end point was the composite outcome of death, stroke, or myocardial infarction (MI) at 30 days. As of December 7, 2010, there were 1347 CEA and 861 CAS patients aged < 65 years and 4169 CEA and 2536 CAS patients aged ≥ 65 years. CAS patients in both age groups were more likely to have a disease etiology of radiation or restenosis, be symptomatic, and have more cardiac comorbidities. In patients aged <65 years, the primary end point (5.23% CAS vs 3.56% CEA; P = .065) did not reach statistical significance. Subgroup analyses showed that CAS had a higher combined death/stroke/MI rate (4.44% vs 2.10%; P < .031) in asymptomatic patients but there was no difference in the symptomatic (6.00% vs 5.47%; P = .79) group. In patients aged ≥ 65 years, CEA had lower rates of death (0.91% vs 1.97%; P < .01), stroke (2.52% vs 4.89%; P < .01), and composite death/stroke/MI (4.27% vs 7.14%; P < .01). CEA in patients aged ≥ 65 years was associated with lower rates of the primary end point in symptomatic (5.27% vs 9.52%; P < .01) and asymptomatic (3.31% vs 5.27%; P < .01) subgroups. After risk adjustment, CAS patients aged ≥ 65 years were more likely to reach the primary end point. Compared with CEA, CAS resulted in inferior 30-day outcomes in symptomatic and asymptomatic patients aged ≥ 65 years. These findings do not support the widespread use of CAS in patients aged ≥ 65 years.
    Full-text Article · Mar 2012 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
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    Full-text Article · Nov 2011 · Journal of Vascular Surgery
  • [Show abstract] [Hide abstract] ABSTRACT: The goal of rehabilitation following lower extremity amputation is to restore the highest level of independent function. As much as possible, this includes the functional use of a prosthetic device fitted to the residual limb. Early prosthetic fit depends, in turn, on rapid healing of the amputation site. We hypothesized that compliance with a novel custom-designed amputation protection and compression system (CAPCS) to the residual limb can accelerate and improve the likelihood of successful prosthesis use. We conducted a retrospective study of all patients who were offered CAPCS by certified prosthetists (Hanger Prosthetics and Orthotics, Bethesda, MD) during the period between April 2004 and November 2009. Variables included age, sex, indication for amputation, and compliance with CAPCS. Compliance was defined as consistent observed wearing of the CAPCS as directed. The primary end point was the fitting of a prosthetic device to the amputated limb, with time to prosthetic fit being the secondary outcome. Out of 100 patients who were offered CAPCS (n = 100) during the study period, 76% were considered compliant (n = 76). Sixty five patients (65%) were ultimately fitted with prosthetic limbs. In multivariate analysis, we found that patients who had compliant use of CAPCS were significantly more likely to be successfully fit with prosthesis (72 vs. 42%, p = 0.005). At 100 days post amputation, the cumulative incidence of prosthesis fitting was significantly higher in CAPCS compliant patients (69.7 vs. 22.2%, p = 0.012). Compliant use of a CAPCS following amputation is associated with earlier and more frequent use of a prosthetic. Based on this limited data set, a conclusion can be drawn that the potential exists to significantly improve functional outcomes after amputation, but well-designed prospective studies are needed to confirm this association.
    Article · Nov 2011 · Annals of Vascular Surgery
  • Dataset: Table S1
    [Show abstract] [Hide abstract] ABSTRACT: Experimental Subjects. (PDF)
    Dataset · Oct 2011
  • Dataset: Figure S3
    [Show abstract] [Hide abstract] ABSTRACT: Light microscopy for histological staining of aortic sections. A: H&E staining of 12 month cholesterol diet rabbit aorta showing morphology of plaque intima. B: Ram11 staining of plaque macrophages and foam cells (brown). C: Oil red O stain of lipids (red). D: Van Kossa staining for calcification (black). E: Alpha-smooth muscle actin staining of smooth muscle cells (and myofibroblasts) (purple). F: Alcian blue staining for glycosaminoglycans (blue). G: Tunel staining manifesting endothelial cell apoptosis at plaque surface and intima (arrow). H: Pecam-1 staining with angiogenesis expressed on adventitia of 12 month cholesterol diet rabbit aorta (arrow). Lu: lumen; I: intima; M: media; A: adventitia. (PDF)
    Dataset · Oct 2011
  • Dataset: Figure S5
    [Show abstract] [Hide abstract] ABSTRACT: Fluorescent microscopy for a range of particle sizes penetrating plaque after 6 hour ex vivo incubation. A: 53 nm diameter fluorescent polymer beads. B: 250 nm diameter CE nanoparticles labeled with Alexa Fluor 488. C: 2 um diameter fluorescent polymer beads. (scale bar = 100 um). (PDF)
    Dataset · Oct 2011
  • Dataset: Figure S4
    [Show abstract] [Hide abstract] ABSTRACT: Control tests for NP penetration. A: Ex vivo CE NP 6 hour incubation without fluorescent label in 12 month cholesterol diet rabbit aorta showing no intimal fluorescence signal, or autofluorescence (yellow), confirming that fluorescent signals originate from Alexa Fluor 488 labeled NP. B: Ex vivo 6 hour incubation with Alexa Fluor 488 labeled NP in 11month cholesterol diet rabbit aorta plaque stripped of adventitia, demonstrating equivalent NP penetration through the endothelium. C: Ex vivo 6 hour incubation with Alexa Fluor 488 labeled NP after 1 hour azide pre-treatment in 12 month cholesterol diet rabbit aorta does not affect the passive NP penetration and trapping. (scale bar = 100 um) Lu: Lumen. (PDF)
    Dataset · Oct 2011
  • Dataset: Figure S1
    [Show abstract] [Hide abstract] ABSTRACT: Fluorescence microscopy and 19F MRI. A: Intimal penetration of NP into aortic segment after 6 hours circulation in vivo (Alexa Fluor 488-labeled) in 9 month cholesterol diet rabbit aorta (green signal). Blue: DAPI nuclear stain, (scale bar = 100 um) B: Control study of nonfluorescent NP circulated for 6 hours in vivo in 9 month cholesterol diet rabbit aorta. Note lack of intimal fluorescent signal. Blue: DAPI nuclear stain. (scale bar = 100 um) C & D: Overlay of 19F (color) and 1H (gray) MR image (“en face” view) of the aorta tissues (same as A&B, respectively) confirmed strong heterogeneously distributed signals from trapped CE NP (color) in both samples. (scale bar = 3 mm). (PDF)
    Dataset · Oct 2011
  • Dataset: Figure S2
    [Show abstract] [Hide abstract] ABSTRACT: NP signals quantified by MRI/MRS. A: Whole-mount surface fluorescence image over a grayscale coregistered photo of thoracoabdominal aorta from 10 month cholesterol fed rabbit after NP circulation in vivo for 1 hour (en face view). (scale bar = 10 mm) B: Local 19F (CE) MR spectroscopy of selected segment of aorta in C. An internal PFOB standard was used to enable quantification of CE NP shown in the chart. (scale bar = 2 mm) C: En face projection 19F MR image (color) overlaid onto 1H MR image (gray) of opened aortic segment (same as A) illustrates the heterogeneity of plaque and NP distribution. Various color bars in the right illustrate different possible metrics for NP quantification. (PDF)
    Dataset · Oct 2011
  • Source
    [Show abstract] [Hide abstract] ABSTRACT: Acute atherothrombotic occlusion in heart attack and stroke implies disruption of the vascular endothelial barrier that exposes a highly procoagulant intimal milieu. However, the evolution, severity, and pathophysiological consequences of vascular barrier damage in atherosclerotic plaque remain unknown, in part because quantifiable methods and experimental models are lacking for its in vivo assessment. To develop quantitative nondestructive methodologies and models for detecting vascular barrier disruption in advanced plaques. Sustained hypercholesterolemia in New Zealand White (NZW) rabbits for >7-14 months engendered endothelial barrier disruption that was evident from massive and rapid passive penetration and intimal trapping of perfluorocarbon-core nanoparticles (PFC-NP: ∼250 nm diameter) after in vivo circulation for as little as 1 hour. Only older plaques (>7 mo), but not younger plaques (<3 mo) demonstrated the marked enhancement of endothelial permeability to these particles. Electron microscopy revealed a complex of subintimal spongiform channels associated with endothelial apoptosis, superficial erosions, and surface-penetrating cholesterol crystals. Fluorine ((19)F) magnetic resonance imaging and spectroscopy (MRI/MRS) enabled absolute quantification (in nanoMolar) of the passive permeation of PFC-NP into the disrupted vascular lesions by sensing the unique spectral signatures from the fluorine core of plaque-bound PFC-NP. The application of semipermeant nanoparticles reveals the presence of profound barrier disruption in later stage plaques and focuses attention on the disrupted endothelium as a potential contributor to plaque vulnerability. The response to sustained high cholesterol levels yields a progressive deterioration of the vascular barrier that can be quantified with fluorine MRI/MRS of passively permeable nanostructures. The possibility of plaque classification based on the metric of endothelial permeability to nanoparticles is suggested.
    Full-text Article · Oct 2011 · PLoS ONE
  • [Show abstract] [Hide abstract] ABSTRACT: Fond Le traitement ouvert traditionnel des anévrysmes aortiques de l'arche distal exige une procédure en deux temps associée à une morbidité et à une mortalité significative. L'introduction du traitement endovasculaire des anévrysmes thoraciques représente une option moins invasive pour accomplir le second temps du traitement après création proximale de la trompe d'éléphant. Cette étude présente une série de patients traités par technique hybride proximale ouverte et distale endovasculaire des anévrysmes aortiques de l'arche distal. Méthodes Une revue rétrospective a été réalisée dans un centre médical universitaire. Tous les patients traités par technique hybride étaient identifiés. Les patients étaient évalués selon leurs données démographiques, l'imagerie préopératoire, le succès technique, les complications postopératoires, la longueur du séjour hospitalier, le recours à une intervention secondaire, et la survie globale. Résultats Un total de 10 patients (3 hommes, âge moyen : 67,5 ans) a été identifié au cours d'une période de quatre ans entre août 2005 et juillet 2009. Tous les patients étaient traités de façon élective et le diamètre maximum moyen de l'anévrysme était de 70,8 mm. Sur les 10 patients, quatre avaient subi une thoracotomie précédente (trois traitements aortiques, une résection pulmonaire pour lésion maligne) et tous étaient considérés à risque élevé pour la chirurgie ouverte du deuxième temps. Les trois premiers patients ont été traités avec une intervention endovasculaire secondaire par accès artériel rétrograde. Les sept patients plus récents ont subi un traitement en un seul temps avec pose de l'endoprothèse par un accès aortique ascendant antérograde. Le succès technique a été obtenu dans tous les cas. Aucune paraplégie ou accident vasculaire cérébral periopératoire n'a été rapporté. Un patient a été traité avec succès de façon endovasculaire d'une endofuite de type IB à 38 mois. Un autre a présenté un élargissement de son anévrysme thoraco-abdominal entrainant une endofuite de type IB qui a été détecté à 43 mois. Il y avait un décès dans les 30 jours postopératoires. Les neuf autres patients sont tous vivants, avec une survie moyenne de 35,1 mois (extrêmes: 8-53) après la chirurgie. Conclusions L'approche hybride du traitement des anévrysmes aortiques de l'arche distal est sûre et représente une d'alternative à la chirurgie ouverte conventionnelle. Son caractère moins invasif techniquement, le fait d'éviter un deuxième temps chirurgical et d'éliminer le risque de perte de suivi, ou de mortalité dans l'intervalle, nous ont menés à préférer le traitement en une seule étape en utilisant un abord antérograde.
    Article · Jul 2011 · Annales de Chirurgie Vasculaire
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    Jeffrey Jim · Brian G. Rubin · Joseph J. Ricotta · [...] · Gregorio A. Sicard
    Full-text Article · Jun 2011 · Journal of Vascular Surgery
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    Full-text Article · Jun 2011 · Journal of Vascular Surgery
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    Full-text Article · Jun 2011 · Journal of Vascular Surgery
  • Jeffrey Jim · Brian G Rubin · Gregg S Landis · [...] · Gregorio A Sicard
    [Show abstract] [Hide abstract] ABSTRACT: The Society for Vascular Surgery (SVS) Vascular Registry (VR) collects data on outcomes of carotid endarterectomy and carotid artery stenting (CAS). The purpose of this study was to evaluate the impact of open vs closed cell stent design on the in-hospital and 30-day outcome of CAS. The VR collects provider-reported data on patients using a Web-based database. Data were analyzed both in-hospital and at 30 days postprocedure. The primary outcome is combined death/stroke/myocardial infarction (MI). As of October 14, 2009, there were 4337 CAS with discharge data and 2397 with 30-day data. Open cell stents (OPEN) were used in 3451 patients (79.6%), and closed cell stents (CLOSED) were used in 866 patients (20.4%). Baseline demographics showed no differences in age, gender, race, and ethnicity. However, the OPEN group had more patients with atherosclerosis (74.5% vs 67.4%; P = .0003) as the etiology of carotid artery disease. The OPEN group also had a higher prevalence of preprocedural stroke (25.8% vs 21.4%; P = .0079), chronic obstructive pulmonary disease (COPD; 21.0% vs 17.6%; P = .0277), cardiac arrhythmia (14.7% vs 11.4%; P = .0108), valvular heart disease (7.4% vs 3.7%; P < .0001), peripheral vascular disease (PVD; 40.0% vs 35.3%; P = .0109), and smoking history (59.0% vs 54.1%; P = .0085). There are no statistically significant differences in the in-hospital or 30-day outcomes between the OPEN and CLOSED patients. Further subgroup analyses demonstrated symptomatic patients had a higher event rate than the asymptomatic cohort in both the OPEN and CLOSED groups. Among symptomatic patients, the OPEN patients had a lower (0.43% vs 1.41%; P = .0349) rate of in-hospital mortality with no difference in stroke or transient ischemic attack (TIA). There were no differences in 30-day event rates. In asymptomatic patients, there were also no statistically significant differences between the OPEN and CLOSED groups. After risk adjustment, there remained no statistically significant differences between groups of the primary endpoint (death/stroke/MI) during in-hospital or 30 days. In-hospital and 30-day outcomes after CAS were not significantly influenced by stent cell design. Symptomatic patients had higher adverse event rates compared to the asymptomatic cohort. As there is no current evidence of differential outcome between the use of open and closed cell stents, physicians should continue to use approved stent platforms based on criteria other than stent cell design.
    Article · Mar 2011 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
  • [Show abstract] [Hide abstract] ABSTRACT: Traditional open repair of distal arch aortic aneurysms requires a two-stage procedure associated with significant morbidity and mortality. The introduction of thoracic endovascular aneurysm repair has created a less invasive option to complete the second stage of the repair after proximal elephant trunk creation. The present study reports a series of patients treated with a combined open proximal and endovascular distal repair of distal arch aortic aneurysms. A retrospective review was undertaken at a university medical center. All patients treated with the hybrid approach were identified. The patients were evaluated for demographics, preoperative imaging, technical success, postoperative complications, length of hospital stay, need for secondary intervention, and overall survival. A total of 10 patients (3 men, mean age: 67.5 years) were identified during a 4-year period between August 2005 and July 2009. All patients were treated electively and the mean maximum aneurysm diameter was 70.8 mm. Of the 10 patients, four had undergone previous thoracotomy (three aortic repair, one pulmonary resection for malignancy) and all were deemed at prohibitive risk for open second-stage surgery. The first three patients had staged reconstruction with delayed endovascular intervention through retrograde arterial access. The more recent seven patients underwent single-stage repair with endograft delivery through an antegrade ascending aortic access. Technical success was achieved in all cases. No perioperative paraplegias or strokes were reported. One patient had successful endovascular treatment of a type IB endoleak at 38 months. Another had an enlarging thoracoabdominal aneurysm resulting in a type IB endoleak which was detected at 43 months. There was one death within 30 days after the procedure. The remaining nine patients are all alive, with a mean survival of 35.1 months (range: 8-53) after surgery. The hybrid approach to treatment of distal arch aortic aneurysms is safe and serves as a viable alternative to conventional open repair. Less technically challenging, avoidance of a second surgery as well as elimination of the possibility of becoming lost to follow-up, or interval mortality have led us to consider a single-stage repair using an antegrade approach as the preferred option.
    Article · Dec 2010 · Annals of Vascular Surgery
  • [Show abstract] [Hide abstract] ABSTRACT: Objectifs Les anévrysmes de l’artère poplitée ont traditionnellement été réparés par voie chirurgicale ouverte. Cependant, la réparation endovasculaire de l’artère poplitée (REVAP) a été employée chez des malades choisis en raison de sa nature moins invasive. Dans ce travail, nous présentons nos résultats à long terme pour REVAP. Méthodes Une revue rétrospective de tous les malades qui ont eu une REVAP dans une seule institution académique de septembre 2002 à mars 2006. Ces malades ont été évalués pour la perméabilité, le besoin d’une intervention secondaire, la survie sans amputation, et la survie globale. Résultats Un total de 15 membres chez 13 malades ont été traités par REVAP au cours de la période d’étude. Toutes les REVAP ont été faites avec des endoprothèses Viabahn®, avec une moyenne de 1,67 stents par membre. L’âge moyen des patients était de 74,6 ans (extrêmes, 66-84). Le succès technique a été obtenu dans 100% des cas et tous les membres avaient des index cheville-bras postopératoires initiaux ≥1,0. La durée moyenne du suivi était de 54 mois (extrêmes, 42-70). Deux malades sont morts de causes indépendantes à 3 et 38 mois avec des membres intacts, et un malade a été perdu de vue. Deux membres ont présenté des endofuites de types I ou III, et ont été traités avec succès par la mise en place endovasculaire d’un stent additionnel, ayant pour résultat un taux de perméabilité primaire de 84,6% et un taux de perméabilité secondaire de 100%. Il n’y avait aucune perte de membre au cours de la période de suivi, avec des taux de survie sans amputation et de survie globale de 85,7%. Conclusions Le suivi à long terme de cette cohorte de malades REVAP suggère que chez des malades choisis, il s’agit d’une technique durable, capable d’obtenir d’excellents taux de perméabilité et de sauvetage de membre. D’autres études cliniques à plus grande échelle sont justifiées pour aider à définir les candidats optimaux pour cette technique.
    Article · Oct 2010 · Annales de Chirurgie Vasculaire

Publication Stats

8k Citations


  • 1978-2015
    • Washington University in St. Louis
      • Department of Surgery
      San Luis, Missouri, United States
  • 2006
    • Worcester Polytechnic Institute
      • Department of Mathematical Sciences
      Worcester, MA, United States
  • 2005
    • Barnes Jewish Hospital
      San Luis, Missouri, United States
  • 2003
    • University of South Florida
      • Division of Vascular and Endovascular Surgery
      Tampa, FL, United States
  • 1998
    • Washington & Lee University
      Лексингтон, Virginia, United States
  • 1987
    • Tulane University
      • Department of Surgery
      New Orleans, LA, United States