Browsing by Author "Wang, S. Keisin"
Now showing 1 - 10 of 15
Results Per Page
Sort Options
Item Aggressive Surveillance Is Needed to Detect Endoleaks and Junctional Separation between Device Components after Zenith Fenestrated Aortic Reconstruction(Elsevier, 2019) Wang, S. Keisin; Lemmon, Gary W.; Gupta, Alok K.; Dalsing, Michael C.; Sawchuk, Alan P.; Motaganahalli, Raghu L.; Murphy, Michael P.; Fajardo, Andres; Surgery, School of MedicineBackground 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.Item Combined transbrachial and transfemoral strategy to deploy an iliac branch endoprosthesis in the setting of a pre-existing endovascular aortic aneurysm repair(Elsevier, 2019-06-29) Wang, S. Keisin; Miladore, Julia N.; Yee, Elliott J.; Liao, Jane L.; Donde, Nikunj N.; Motaganahalli, Raghu L.; Surgery, School of MedicineThis article describes brachial access to position a long sheath in the abdominal aorta in conjunction with a large caliber sheath via the femoral artery ipsilateral to the target site to deliver a 0.018 bodyfloss wire. This bodyfloss wire is inserted into the precannulation port of the iliac branch endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz), which is then advanced from the groin. Once the bifurcated device is deployed, hypogastric access and stenting is achieved from the upper extremity. This technique is an alternative to safely extend the distal seal while preserving the hypogastric artery and has the advantage of limited iliac bifurcation manipulation.Item Cryopreserved Homografts in Infected Infrainguinal Fields Are Associated with Frequent Reinterventions and Poor Amputation-Free Survival(Elsevier, 2018) Wang, S. Keisin; Gutwein, Ashley R.; Drucker, Natalie A.; Murphy, Michael P.; Fajardo, Andres; Dalsing, Michael C.; Motaganahalli, Raghu L.; Lemmon, Gary W.; Surgery, School of MedicineBackground 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.Item Description of human AAA by cytokine and immune cell aberrations compared to risk-factor matched controls(Elsevier, 2018-08) Wang, S. Keisin; Green, Linden A.; Gutwein, Ashley R.; Drucker, Natalie A.; Motaganahalli, Raghu L.; Gupta, Alok K.; Fajardo, Andres; Murphy, Michael P.; Surgery, School of MedicineBACKGROUND: The pathogenesis driving the formation of abdominal aortic aneurysms continues to be poorly understood. Therefore, we systemically define the cytokine and circulating immune cell environment observed in human abdominal aortic aneurysm compared with risk-factor matched controls. METHODS: From 2015 to 2017, a total of 274 patients donated blood to the Indiana University Center for Aortic Disease. Absolute concentrations of circulating cytokines were determined, using enzyme-linked immunosorbent assays while the expression of circulating immune cell phenotypes were assayed via flow cytometric analysis. RESULTS: Human abdominal aortic aneurysm is characterized by a significant depletion of the antigen-specific, CD4+ Tr1 regulatory lymphocyte that corresponds to an upregulation of the antigen-specific, inflammatory Th17 cell. We found no differences in the incidence of Treg, B10, and myeloid-derived suppressor regulatory cells. Similarly, no disparities were noted in the following inflammatory cytokines: IL-1β, C-reactive protein, tumor necrosis factor α, interferon γ, and IL-23. However, significant upregulation of the inflammatory cytokines osteopontin, IL-6, and IL-17 were noted. Additionally, no changes were observed in the regulatory cytokines IL-2, IL-4, IL-13, TNF-stimulated gene 6 protein, and prostaglandin E2, but we did observe a significant decrease in the essential regulatory cytokine IL-10. CONCLUSION: In this investigation, we systematically characterize the abdominal aortic aneurysm-immune environment and present preliminary evidence that faulty immune regulation may also contribute to aneurysm formation and growth.Item Diagnosis and management of the venous malformations of Klippel-Trénaunay syndrome(Elsevier, 2017-07) Wang, S. Keisin; Drucker, Natalie A.; Gupta, Alok K.; Marshalleck, Francis E.; Dalsing, Michael C.; Surgery, School of MedicineObjective A dearth of information exists in the literature regarding current practice in the management of Klippel-Trénaunay syndrome (KTS), a rare condition. We review and describe the etiology, diagnosis, and treatment of KTS. Methods Relevant data were synthesized from a Medline review using a combination of the keyterms “Klippel” and “Trénaunay.” The majority of hits described singular case reports and were subsequently excluded. The remaining papers were then reviewed and included on the basis of the quality of evidence and the authors' discretion. Conclusions KTS is characterized by a clinical triad of extremity varicosities, cutaneous vascular malformations, and hypertrophy of soft tissues and long bones. The diagnosis is clinically supplemented with magnetic resonance imaging and computed tomography. Although this syndrome is associated with significant comorbidities, such as pain, edema, ulcerations, and pruritus, it is rarely the cause of death. The backbone of treatment is nonoperative in nature but should be supplemented with minimally invasive, endovascular, and rarely open surgical procedures for refractory cases.Item Getting A Leg Up on Cell Therapy for Critical Limb Ischemia(American Heart Association, 2017-04-14) Wang, S. Keisin; Murphy, Michael P.; Surgery, School of MedicineItem Immune Modulation as a Treatment for Abdominal Aortic Aneurysms(American Heart Association, 2018-03-30) Wang, S. Keisin; Murphy, Michael P.; Surgery, School of MedicineIn the United States, over 200,000 new patients are diagnosed with abdominal aortic aneurysm (AAA) each year. Consequently, over 40,000 highly morbid aortic reconstructions are performed each year to prevent aneurysm rupture, a catastrophic event associated with near-certain mortality. No pharmaceutical currently exists to slow aneurysm growth, but a 50% reduction in diameter growth per annum could halve the number of aortic reconstructions required. Therefore, successful use of cell therapy to modulate chronic inflammation hallmark to AAA to slow diameter expansion represents a potentially paradigm-altering treatment.Item Metformin does not reduce inflammation in diabetics with abdominal aortic aneurysm or at high risk of abdominal aortic aneurysm formation(Sage, 2018-12) Wang, S. Keisin; Green, Linden A.; Gutwein, Ashley R.; Kenyon, Bianca; Motaganahalli, Raghu L.; Fajardo, Andres; Gupta, Alok K.; Murphy, Michael P.; Surgery, School of MedicineIntroduction The protective effect of diabetes mellitus on abdominal aortic aneurysm formation and growth has been repeatedly observed in population studies but continues to be poorly understood. However, recent investigations have suggested that metformin, a staple antihyperglycemic medication, may be independently protective against abdominal aortic aneurysm formation and growth. Therefore, we describe the effect of metformin in abdominal aortic aneurysm and at-risk patients on markers of inflammation, the driver of early abdominal aortic aneurysm formation and growth. Methods Peripheral blood was collected from patients previously diagnosed with abdominal aortic aneurysm or presenting for their U.S. Preventive Task Force-recommended abdominal aortic aneurysm screening. Plasma and circulating peripheral blood mononuclear cells were isolated using Ficoll density centrifugation. Circulating plasma inflammatory and regulatory cytokines were assessed with enzyme-linked immunosorbent assays. CD4+ cell phenotyping was performed using flow cytometric analysis and expressed as a proportion of total CD4+ cells. To determine the circulating antibody to self-antigen response, a modified enzyme-linked immunosorbent assay was performed against antibodies to collagen type V and elastin fragments. Results Peripheral blood was isolated from 266 patients without diabetes mellitus (n=182), with diabetes mellitus not treated with metformin (n=34), and with diabetes mellitus actively taking metformin (n=50) from 2015 to 2017. We found no differences in the expression of Tr1, Th17, and Treg CD4+ fractions within diabetics ± metformin. When comparing inflammatory cytokines, we detected no differences in IL-1β, IL-6, IL-17, IL-23, IFN-γ, and TNF-α. Conversely, no differences were observed pertaining to the expression to regulatory cytokines IL-4, IL-10, IL-13, TSG-6, or TGF-β. Lastly, no differences in expression of collagen type V and elastin fragment antigen and/or antibodies were detected with metformin use in diabetics. Conclusion Metformin in diabetics at-risk for abdominal aortic aneurysm or diagnosed with abdominal aortic aneurysm does not seem to alter the peripheral inflammatory environment.Item Perioperative Outcomes are Adversely Affected by Poor Pretransfer Adherence to Acute Limb Ischemia Practice Guidelines(Elsevier, 2018) Wang, S. Keisin; Murphy, Michael P.; Gutwein, Ashley R.; Drucker, Natalie A.; Dalsing, Michael C.; Motaganahalli, Raghu L.; Lemmon, Gary W.; Akingba, A. George; Surgery, School of MedicineObjectives 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 (MALE), mortality, and bypass patency in the perioperative period (30-day postoperative). All time intervals were calculated from the onset of symptoms and categorized into three subcohorts (<6 hrs, 6-48 hrs, and >48 hrs). Results Eighty-seven patients with an average age of 64.0 (± 16.2) years presented to outlying hospitals and was transferred to us with lower extremity ALI. The mean delay from symptom onset to initial referring physician evaluation was 18.3 hrs. At that time of evaluation, 53.8% had Rutherford class IIA ischemia and 36.3% had class IIB ischemia. Seventy-six (87.4%) patients were started on heparin previous to transfer. However, only 44 (57.9%) patients reached therapeutic levels as measured by activated partial thromboplastin time (aPTT) prior to definitive revascularization. A delay of anticoagulation initiation >48 hrs from symptom onset was associated with increased 30-day reintervention rates compared with the <6 hrs 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.Item Rationale and Design of the ARREST Trial Investigating Mesenchymal Stem Cells in the Treatment of Small Abdominal Aortic Aneurysm(Elsevier, 2017) Wang, S. Keisin; Green, Linden A.; Gutwein, Ashley R.; Drucker, Natalie A.; Motaganahalli, Raghu L.; Fajardo, Andres; Babbey, Clifford C.; Murphy, Michael P.; Surgery, School of MedicineBackground Abdominal aortic aneurysms (AAAs) are a major source of morbidity and mortality despite continuing advances in surgical technique and care. Although the inciting factors for AAA development continue to be elusive, accumulating evidence suggests a significant periaortic inflammatory response leading to degradation and dilation of the aortic wall. Previous human trials have demonstrated safety and efficacy of mesenchymal stem cells (MSCs) in the treatment of inflammation-related pathologies such as rheumatoid arthritis, graft versus host disease, and transplant rejection. Therefore, herein, we describe the Aortic Aneurysm Repression with Mesenchymal Stem Cells (ARREST) trial, a phase I investigation into the safety of MSC infusion for patients with small AAA and the cells' effects on modulation of AAA-related inflammation. Methods ARREST is a phase I, single-center, double-blind, randomized controlled trial (RCT) investigating infusion both dilute and concentrated MSCs compared to placebo in 36 small AAA (35–45 mm) patients. Subjects will be followed by study personnel for 12 months to ascertain incidence of adverse events, immune cell phenotype expression, peripheral cytokine profile, and periaortic inflammation. Maximum transverse aortic diameter will be assessed regularly for 5 years by a combination of computed tomography and duplex sonography. Results Four patients have thus far been enrolled, randomized, and treated per protocol. We anticipate the conclusion of the treatment phase within the next 24 months with ongoing long-term follow-up. Conclusions ARREST will be pivotal in assessing the safety of MSC infusion and provide preliminary data on the ability of MSCs to favorably modulate the pathogenic AAA host immune response. The data gleaned from this phase I trial will provide the groundwork for a larger, phase III RCT which may provide the first pharmaceutical intervention for AAA.