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Dive into the research topics where William T. Bohannon is active.

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Featured researches published by William T. Bohannon.


Journal of Vascular Surgery | 2014

Outcome-based anatomic criteria for defining the hostile aortic neck

William D. Jordan; Kenneth Ouriel; Manish Mehta; David Varnagy; William M. Moore; Frank R. Arko; James Joye; Jean-Paul P.M. de Vries; Jean Paul de Vries; H.H. Eckstein; Joost A. van Herwaarden; Paul Bove; William T. Bohannon; Bram Fioole; Carlo Setacci; Timothy Resch; Vicente Riambau; Dierk Scheinert; Andrej Schmidt; Daniel G. Clair; Mohammed M. Moursi; Mark A. Farber; Joerg Tessarek; Giovanni Torsello; Mark F. Fillinger; Marc H. Glickman; John P. Henretta; Kim J. Hodgson; Jeffrey Jim; Barry T. Katzen

OBJECTIVE There is abundant evidence linking hostile proximal aortic neck anatomy to poor outcome after endovascular aortic aneurysm repair (EVAR), yet the definition of hostile anatomy varies from study to study. This current analysis was undertaken to identify anatomic criteria that are most predictive of success or failure at the aortic neck after EVAR. METHODS The study group comprised 221 patients in the Aneurysm Treatment using the Heli-FX Aortic Securement System Global Registry (ANCHOR) clinical trial, a population enriched with patients with challenging aortic neck anatomy and failure of sealing. Imaging protocols were not protocol specified but were performed according to the institutions standard of care. Core laboratory analysis assessed the three-dimensional centerline-reformatted computed tomography scans. Failure at the aortic neck was defined by type Ia endoleak occurring at the time of the initial endograft implantation or during follow-up. Receiver operating characteristic curve analysis was used to assess the value of each anatomic measure in the classification of aortic neck success and failure and to identify optimal thresholds of discrimination. Binary logistic regression was performed after excluding highly intercorrelated variables, creating a final model with significant predictors of outcome after EVAR. RESULTS Among the 221 patients, 121 (54.8%) remained free of type Ia endoleak and 100 (45.2%) did not. Type Ia endoleaks presented immediately after endograft deployment in 58 (58.0%) or during follow-up in 42 (42.0%). Receiver operating characteristic curve analysis identified 12 variables where the classification of patients with type Ia endoleak was significantly more accurate than chance alone. Increased aortic neck diameter at the lowest renal artery (P = .013) and at 5 mm (P = .008), 10 mm (P = .008), and 15 mm (P = .010) distally; aneurysm sac diameter (P = .001), common iliac artery diameters (right, P = .012; left, P = .032), and a conical (P = .049) neck configuration were predictive of endoleak. By contrast, increased aortic neck length (P = .050), a funnel-shaped aortic neck (P = .036), and neck mural thrombus content, as measured by average thickness (P = .044) or degrees of circumferential coverage (P = .029), were protective against endoleak. Binary logistic regression identified three variables independently predictive of type Ia endoleak. Neck diameter at the lowest renal artery (P = .002, cutpoint 26 mm) and neck length (P = .017, cutpoint 17 mm) were associated with endoleak, whereas some mural neck thrombus content was protective (P = .001, cutpoint 11° of circumferential coverage). CONCLUSIONS A limited number of independent anatomic variables are predictive of type Ia endoleak after EVAR, including aortic neck diameter and aortic neck length, whereas mural thrombus in the neck is protective. This study suggests that anatomic measures with identifiable threshold cutpoints should be considered when defining the hostile aortic neck and assessing the risk of complications after EVAR.


Journal of Vascular Surgery | 2014

Analysis of EndoAnchors for endovascular aneurysm repair by indications for use.

Jean-Paul P.M. de Vries; Kenneth Ouriel; Manish Mehta; David Varnagy; William M. Moore; Frank R. Arko; James Joye; William D. Jordan; Jean Paul de Vries; H.-H. Eckstein; Joost A. van Herwaarden; Paul Bove; William T. Bohannon; Bram Fioole; Carlo Setacci; Timothy Resch; Vicente Riambau; Dierk Scheinert; Daniel G. Clair; Mohammed M. Moursi; Mark A. Farber; Joerg Tessarek; Giovanni Torsello; Mark F. Fillinger; Marc H. Glickman; John P. Henretta; Kim J. Hodgson; Jeffrey Jim; Barry T. Katzen; Evan C. Lipsitz

OBJECTIVE The proximal aortic neck remains one of the challenges of endovascular aneurysm repair (EVAR), and the risk of type Ia endoleak and endograft migration is increased in patients with short, large-diameter, or highly angulated necks. EndoAnchors have been used as an adjunct to EVAR in such patients, and the aim of this study was to assess their benefit analyzed by indication for use. METHODS During a 2-year period, 319 patients were enrolled at 43 sites in the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) study. This prospective, multinational, real-world analysis of EndoAnchors comprised two groups of patients, those undergoing first-time EVAR (primary arm, 242) and those with proximal neck complications remote from the time of an initial endograft implantation (revision arm, 77). The primary arm was further subdivided into patients undergoing prophylactic EndoAnchor use for hostile proximal neck anatomy (178), with a type Ia endoleak evident during initial endograft deployment (60), and in conjunction with extender cuffs after unsatisfactory endograft deployment distally in the neck (four). The revision arm was subdivided into patients presenting with a type Ia endoleak alone (45), endograft migration alone (11), and migration with endoleak (21). Technical success was site reported as satisfactory deployment of the desired number of EndoAnchors without fracture or loss of integrity. Procedural success was defined as technical success without type Ia endoleak at completion arteriography. Core laboratory analysis was performed on 249 baseline and 192 follow-up computed tomographic studies, 66 of which were available within the 1-year window. RESULTS Technical and procedural success rates were highest in the prophylactically treated subset (172 of 178; 96.6%). Whereas the technical success of EndoAnchor deployment was also high in the other subsets, residual type Ia endoleaks were more frequent at completion angiography when the indication for EndoAnchor use was type Ia endoleak, both in the primary arm (17 of 60; 28%) and in the revision arm (9 of 45; 20%). During a median imaging follow-up of 7 months, 183 of 202 patients (90.1%) remained free of type Ia endoleaks. Primary prophylactic patients were free from type Ia endoleak in 110 of 114 cases (96.5%). The most challenging subset was revision patients treated for type Ia endoleak; type Ia endoleaks were evident during follow-up in 10 of 29 of the cases (34%). Sac regression >5 mm in patients with 1-year imaging was observed in 26 of 66 patients (39%) and was highest in the primary prophylaxis subset (20 of 43; 47%). CONCLUSIONS EndoAnchor implantation can be a useful adjunct to EVAR as prophylaxis against proximal attachment site complications in patients with hostile aortic neck anatomy, as treatment for early and late type Ia endoleaks, or, in conjunction with aortic extension cuffs, for endograft migration. Whereas the most challenging patients are those who present with type Ia endoleaks remote from initial EVAR, EndoAnchors are still effective in treating the majority of these cases.


Journal of Vascular Nursing | 2011

Portal vein aneurysm: a rare occurrence.

Kathy C. Turner; William T. Bohannon; Marvin D. Atkins

Portal vein aneurysms (PVA) are a rare vascular anomaly of the portal system, representing fewer than 3% of all venous aneurysms, with only 150 known cases since first reported in l956 by Barzilai and Kleckner. PVA can be divided into 2 categories: extrahepatic and intrahepatic with acquired and congenital etiologies. Bimodal treatment includes medical and surgical approaches. With increased use of noninvasive radiological imaging, PVA will be increasingly recognized in the practice of vascular surgery.


Journal of Endovascular Therapy | 2011

Endovascular Repair of a Pancreatic Allograft Mycotic Aneurysm: Two-year Follow-up

Gregory J. Jaffers; William T. Bohannon; Clifford J. Buckley

Purpose To describe midterm outcome of endovascular stent-graft repair of a mycotic aneurysm associated with a peripancreatic allograft abscess after transplantation. Case Report A 46-year-old woman underwent combined kidney and pancreas allograft transplantation under heavy immunosuppression. She developed a peripancreatic allograft abscess with associated mycotic aneurysm of the pancreatic allograft donor iliac artery 2 months after transplantation. Endovascular stent-grafts were used to exclude the aneurysm, retaining normal pancreatic allograft function over the next 2 years. Conclusion Allograft arterial mycotic aneurysm development after transplantation is a rare but potentially life-threatening problem. This case suggests that control of a mycotic aneurysm may be obtained with stent-grafting in the presence of active infection under intense immunosuppression, avoiding allograft pancreatectomy.


Proceedings (Baylor University. Medical Center) | 2016

Surgical management of carotid body tumors: a 15-year single institution experience employing an interdisciplinary approach.

Jennifer L. Dixon; Marvin D. Atkins; William T. Bohannon; Clifford J. Buckley; Terry C. Lairmore

Cervical paragangliomas are rare neoplasms that arise from extraadrenal paraganglia in close association with the cranial nerves and extracranial arterial system of the head and neck, and therefore surgical extirpation can be challenging. A retrospective study was conducted of all patients undergoing surgical excision of a cervical paraganglioma between 2000 and 2015. The demographic characteristics, clinical features, surgical approach, and outcomes were reviewed. A total of 20 cervical paragangliomas were excised in 17 patients. There were 14 female and 3 male patients with a mean age of 56.6 ± 17.0 at the time of operation. Twelve patients had unilateral tumors and 5 patients had bilateral tumors. Familial involvement was confirmed by history or direct genetic analysis in 8 (47%) of the 17 patients. There were no malignant paragangliomas, and only 3 patients had tumors that were determined to be functional. Tumor size ranged from 1.3 to 6.0 cm. Two patients required combined arterial resection as part of complete excision of the tumor. There were no permanent operative cranial nerve injuries, no recurrences, minimal morbidity, and no mortality. In conclusion, optimal management of cervical paragangliomas should include a thorough preoperative evaluation, accurate definition of the surgical anatomy, and exclusion of synchronous paragangliomas. A combined therapeutic approach by a multidisciplinary team including surgeons and interventional radiologists provides safe and effective management of cervical paragangliomas with very low morbidity and excellent outcomes.


Physiological Reports | 2018

Oxidative stress and antioxidant treatment in patients with peripheral artery disease

Panagiotis Koutakis; Ahmed Ismaeel; Patrick J. Farmer; Seth Purcell; Robert S. Smith; Jack L. Eidson; William T. Bohannon

Peripheral artery disease is an atherosclerotic disease of arterial vessels that mostly affects arteries of lower extremities. Effort induced cycles of ischemia and reperfusion lead to increased reactive oxygen species production by mitochondria. Therefore, the pathophysiology of peripheral artery disease is a consequence of metabolic myopathy, and oxidative stress is the putative major operating mechanism behind the structural and metabolic changes that occur in muscle. In this review, we discuss the evidence for oxidative damage in peripheral artery disease and discuss management strategies related to antioxidant supplementation. We also highlight the major pathways governing oxidative stress in the disease and discuss their implications in disease progression. Potential therapeutic targets and diagnostic methods related to these mechanisms are explored, with an emphasis on the Nrf2 pathway.


Journal of Surgical Research | 2018

Effects of Limb Revascularization Procedures on Oxidative Stress

Ahmed Ismaeel; Ramon Lavado; Robert S. Smith; Jack L. Eidson; Ian Sawicki; Jeffrey S. Kirk; William T. Bohannon; Panagiotis Koutakis

Revascularization procedures to treat patients with peripheral artery disease are among the most common operations performed by vascular surgeons. However, there are major limitations to revascularizations, readmission rates due to procedural complications are high, and greater risks of cardiovascular and limb adverse outcomes have been reported for patients with peripheral artery disease undergoing limb revascularization. Specifically, surgical revascularization may be associated with increased generation of reactive oxygen species based on the ischemia reperfusion injury theory, as restored blood flow and reoxygenation of ischemic areas may be accompanied by increased oxidative stress. In this review, we present the current evidence regarding the effects of revascularization procedures on oxidative stress. We also discuss potential therapeutic interventions to prevent ischemia reperfusion injury-mediated tissue damage.


Antioxidants | 2018

Oxidative Stress and Arterial Dysfunction in Peripheral Artery Disease

Ahmed Ismaeel; Robert Brumberg; Jeffrey S. Kirk; Evlampia Papoutsi; Patrick J. Farmer; William T. Bohannon; Robert S. Smith; Jack L. Eidson; Ian Sawicki; Panagiotis Koutakis

Peripheral artery disease (PAD) is an atherosclerotic disease characterized by a narrowing of the arteries in the lower extremities. Disease manifestations are the result of more than just reduced blood flow, and include endothelial dysfunction, arterial stiffness, and inflammation. Growing evidence suggests that these factors lead to functional impairment and decline in PAD patients. Oxidative stress also plays an important role in the disease, and a growing amount of data suggest a link between arterial dysfunction and oxidative stress. In this review, we present the current evidence for the involvement of endothelial dysfunction, arterial stiffness, and inflammation in the pathophysiology of PAD. We also discuss the links between these factors and oxidative stress, with a focus on nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2)-derived reactive oxygen species (ROS) and decreased nitric oxide (NO) bioavailability. Finally, the potential therapeutic role of NOX2 antioxidants for improving arterial function and functional status in PAD patients is explored.


Critical Care Medicine | 2012

267: INCREASING HEART RATE AND TIDAL VOLUME INCREASES PLETHYSMOGRAPHY VARIABILITY INDEX VALUES

Nathan Roeth; Timothy R. Ball; Marvin D. Atkins; William T. Bohannon; William C. Culp; William E. Johnston

Introduction Physiologic changes in heart rate and tidal volume alter preload responsiveness, but these changes have not been assessed by newer, non-invasive monitoring techniques. The non-invasive Masimo Rainbow pulse co-oximeter (Masimo Corporation; Irvine, CA) provides measurements that assess preload recruitable function. We propose that changes in heart rate (HR) and tidal volume (Vt) which alter stroke volume variability (SVV) with the Vigileo monitor (Edwards Lifesciences; Irvine, CA) will be similarly reflected in the plethysmography variability index (PVI). Hypothesis: Non-invasive PVI will change in a similar fashion with invasive SVV in differing physiologic states.


Journal of Vascular Surgery | 2014

Results of the ANCHOR prospective, multicenter registry of EndoAnchors for type Ia endoleaks and endograft migration in patients with challenging anatomy

William D. Jordan; Manish Mehta; David Varnagy; William M. Moore; Frank R. Arko; James Joye; Kenneth Ouriel; Jean-Paul P.M. de Vries; Jean Paul de Vries; H.H. Eckstein; Joost A. van Herwaarden; Paul Bove; William T. Bohannon; Bram Fioole; Carlo Setacci; Timothy Resch; Vicente Riambau; Dierk Scheinert; Andrej Schmidt; Daniel G. Clair; Mohammed M. Moursi; Mark A. Farber; Joerg Tessarek; Giovanni Torsello; Mark F. Fillinger; Marc H. Glickman; John P. Henretta; Kim J. Hodgson; Jeffrey Jim; Barry T. Katzen

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Michael B. Silva

Texas Tech University Health Sciences Center

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Kim J. Hodgson

Southern Illinois University Carbondale

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Barry T. Katzen

Baptist Hospital of Miami

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David Varnagy

Florida Hospital Orlando

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Frank R. Arko

Carolinas Medical Center

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Jeffrey Jim

Washington University in St. Louis

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