John G. Carson
University of California, Davis
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Featured researches published by John G. Carson.
Journal of Vascular Surgery | 2013
Kevin C. Chun; Kai Y. Teng; Elyse N. Van Spyk; John G. Carson; Eugene S. Lee
OBJECTIVE In 2007, Medicare guidelines were established to identify persons at risk for the presence of an abdominal aortic aneurysm (AAA). The purpose of this study is to evaluate the 5-year outcomes of an AAA screening program in a regional Veterans Affairs (VA) health care system. METHODS Data were extracted from a regional VA health care network identifying all veteran males 65 to 75 years of age who smoked at least 100 cigarettes during their lifetime. In 2007, an AAA screening mandate was implemented allowing patients meeting screening criteria to be evaluated for AAA as part of the patients health maintenance. AAA is identified as an aortic diameter size of 3.0 cm or greater. Clinician adherence to screening protocols and referral to a vascular surgeon for aneurysms >5.5 cm were also evaluated. RESULTS A total of 9751 patients (71.5 ± 5.6 standard deviation years of age) were screened for an AAA over a 5-year period from January 1, 2007 to December 31, 2011. A total of 698 aneurysms (7.1%) were found. Referrals to a vascular surgeon were made on 45 patients with aneurysms >5.5 cm. Over a 5-year period, a total of 2754 patients (28.2%) were inappropriately screened: 416 patients were under 65 years old, 2243 patients were over 75 years old, 36 patients were women, and 123 patients without aneurysms had multiple screenings. In 2007, during the first year of implementation, 39.2% of patients were inappropriately screened. Over the next 4 years, inappropriate screenings decreased with 33.7% in 2008, 28.6% in 2009, 17.7% in 2010, and 14.3% in 2011. CONCLUSIONS A large AAA screening program at the VA detects more aneurysms, but at smaller diameters than that published in clinical trials. Over time, the number of inappropriate AAA screenings has continued to decrease, demonstrating greater awareness and application of the AAA screening guidelines by primary care providers. Developing surveillance guidelines for small and medium aneurysms is a potential area for future research.
Annals of Vascular Surgery | 2015
Melissa N. Loja; Ann Brunson; Chin Shang Li; John G. Carson; Richard H. White; Patrick S. Romano; Nasim Hedayati
BACKGROUND Racial/ethnic disparities in treatment outcomes of peripheral arterial disease (PAD) are well documented. Compared with non-Hispanic (NH) whites, blacks and Hispanics are more likely to undergo amputation and less likely to undergo bypass surgery for limb salvage. Endovascular procedures are being increasingly performed as first line of therapy for PAD. In this study, we examined the outcomes of endovascular PAD treatments based on race/ethnicity in a contemporary large population-based study. METHODS We used Patient Discharge Data from Californias Office of Statewide Health Planning and Development to identify all patients over the age of 35 who underwent a lower extremity arterial intervention from 2005 to 2009. A look-back period of 5 years was used to exclude all patients with prior lower extremity arterial revascularization procedures or major amputation. Cox proportional hazards regression was used to compare amputation-free survival and time to death within 365 days. Logistic regression was used for comparison of 1-month myocardial infarction, 1-month major amputation, 1-month all-cause mortality, 12-month major amputation, 12-month reintervention, and 12-month all-cause mortality rates among NH white, black, and Hispanic patients. These analyses were adjusted for age, gender, insurance status, severity of PAD, comorbidities, history of coronary artery angioplasty or bypass surgery, or history of carotid endarterectomy. RESULTS Between 2005 and 2009, a total of 41,507 individuals underwent PAD interventions, 25,635 (61.7%) of whom underwent endovascular procedures. There were 17,433 (68%) NH whites, 4,417 (17.2%) Hispanics, 1,979 (7.7%) blacks, 1,163 (4.5%) Asian/Native Hawaiians, and 643 (2.5%) others in this group. There was a statistically significant difference in the amputation-free survival within 365 days among the NH white, Hispanic, and black groups (P < 0.0001); the hazard ratio for amputation within 365 days was 1.69 in Hispanics (95% confidence interval [CI] 1.51-1.90, P < 0.0001) and 1.68 in blacks (95% CI 1.44-1.96, P < 0.001) compared with NH whites following endovascular procedures after adjusting for age, gender, insurance status, comorbidities, severity of PAD, history of coronary artery angioplasty or bypass surgery, or history of carotid endarterectomy. After adjusting for the aforementioned confounders, the first reintervention within 12 months was also significantly associated with race/ethnicity (P = 0.002). Odds ratio for reintervention was 1.17 in blacks (95% CI 1.06-1.30, P = 0.002) and 1.084 in Hispanics (95% CI 1.00-1.16, P = 0.04) compared with NH whites. CONCLUSIONS In this contemporary large population-based study, we demonstrated that even among matched cohorts Hispanics and blacks have worse amputation-free survival than NH whites following endovascular therapy. Our study also found that Hispanics and blacks are more likely to undergo lower extremity arterial reinterventions than NH whites. Further research is crucial in understanding if higher reintervention rates in Hispanics and blacks are because of more severe disease and/or poor access to proper follow-up care and optimal medical management.
Annals of Vascular Surgery | 2013
Darren S. Bryan; John G. Carson; Heather Hall; Qi He; Khalil Qato; Laurie Lozanski; Susan McCormick; Christopher L. Skelly
Carotid artery occlusion (CAO) is a risk factor for stroke ipsilateral to the occlusion and puts patients in a high-risk category when contralateral endarterectomy is performed. The purpose of this study was to evaluate the long-term outcomes of patients with internal CAO and to determine risk factors predictive of subsequent neurological event, contralateral carotid intervention, or death. Patients with internal CAO shown by duplex ultrasonography were retrospectively identified and followed between January 2002 and June 2010 (follow-up: 1-101 months, mean: 52 months) at a tertiary care hospital. All had multiple duplex examinations available for review. Chi-square analysis was used to determine risk factors for neurologic event, contralateral intervention, or all-cause morality. Multivariate Cox proportional hazard analysis was conducted using univariate risk factors with P values <0.1. Survival was estimated using the Kaplan-Meier method (P < 0.05 significant). Eighty patients with internal CAO were identified and available for analysis. On initial encounter, 30 (38%) were symptomatic, with 26 (87%) having symptoms referable to the side of the occluded internal carotid artery. During follow-up, seven (9%) had a neurologic event, of which six (86%) were referable to the occluded side; 14 (18%) patients underwent a contralateral operation. Nineteen (24%) patients died during the period of study. Although numerous variables of multivessel disease were significant with χ(2) analysis, there was no significant risk factor associated with neurologic event on multivariate analysis. However, the development of a hemodynamically significant stenosis (>50%) or occlusion of the external carotid artery (ECA) ipsilateral to the occlusion on follow-up (P < 0.027) was associated with increased risk of death. Kaplan-Meier analysis showed 7-year survival for patients with ECA disease at follow-up was significantly worse (16.2% ± 10.3% [n = 21] vs. 79% ± 8.7% [n = 59]; P < 0.00001). Frequently, patients present with neurological symptoms referable to the side of the internal CAO. Eighty-six percent of neurologic events that occur in follow-up are attributable to the side of the occluded carotid, indicating that the occluded side continues to contribute to neurologic morbidity over time. Multivariate analysis revealed no single factor to be predictive of subsequent neurologic events. With significant risk of death in patients found to have ipsilateral ECA stenosis during follow-up, it seems reasonable to continue surveillance of the occluded carotid.
Vascular Medicine | 2015
Nasim Hedayati; John G. Carson; Yung Wei Chi; Daniel P. Link
Mixed arterial venous disease is estimated to affect up to 26% of patients with lower extremity ulcerations. However, its clinical significance and pathophysiology are incompletely understood. Furthermore, there is no consensus on the optimal treatment modality, whether conservative or operative. In this review paper, we describe the current understanding of the pathophysiology of mixed arterial venous lower extremity ulcers. Guidelines for diagnostic tests for patients with mixed arterial venous diseases are discussed. We review some of the newer biological skin substitutes for conservative wound care. Finally, we propose a treatment algorithm based on current available data.
Journal of Vascular Surgery | 2017
Mimmie Kwong; John G. Carson; Julie A. Freischlag; Nasim Hedayati
Objective: In the last decade, there has been a dramatic increase in the number of women entering vascular surgery. Our goal was to evaluate the differences in career paths based on gender and to determine some of the factors that influence career decisions among young vascular surgeons. Methods: A 17‐item web‐based survey focusing on current employment status, reasons for choosing academic vs nonacademic positions, and career satisfaction was distributed to 900 members of the Society for Vascular Surgery who completed vascular surgery training in the past 10 years. Results: A total of 199 individuals responded to the survey (22.1%). The cohort included 49 (24.6%) women and 149 (74.9%) men. The majority of the respondents were non‐Hispanic white (66.3%). Sixty‐four percent of all respondents were younger than 40 years. Overall, 72.9% of women had applied to academic positions after their training compared with 58.8% of men. Women were more likely to apply for and to work in an academic setting (P = .0266 and P = .0198, respectively) and cited mentorship more frequently (P = .0474) as the reason for choosing an academic practice. Women respondents were less likely to have a spouse or children (P = .0269 and P < .001, respectively). More than 87.4% of all respondents were very satisfied or somewhat satisfied with their careers. However, men were more likely to be very satisfied compared with women (P = .0345). Conclusions: Career satisfaction remains high among young vascular surgeons. In this cohort of vascular surgery graduates, we found that women were more likely to pursue academic positions than men, with mentorship, ability to teach, and complexity of cases commonly cited as reasons for this career choice. However, whether young women stay in academia and what factors affect academic retention will need further evaluation.
Case reports in radiology | 2013
Daniel P. Link; Jennifer Feneis; John G. Carson
Objective. To report an incidence of reflux in the deep venous system reversed by ablation of a popliteal fossa vein (PFV). Method. A 40-year-old man with pain and swelling in the medial upper calf was found to have an incompetent PFV. Results. Reflux in the femoral and popliteal veins was reversed utilizing endovenous laser ablation and foam sclerotherapy, documented on Duplex studies before and after the intervention. There was also resolution of symptoms. Conclusion. A PFV can be associated with deep venous reflux. Correction of this reflux with ablation of the PFV suggests that his type of reflux is secondary to volume effects of the incompetent popliteal vein.
Annals of Vascular Surgery | 2009
John G. Carson; Gabriel Loor; Micheal J. Millis; Giuliano Testa; Giancarlo Piano
Superior mesenteric artery (SMA) aneurysms represent a minority of visceral aneurysms but may result in lethal complications if left untreated. Options for treatment include aneurysmorraphy, bypass, ligation, or embolization. Here we present a case of a man with a history of celiac graft thrombosis who presents with a recurrent symptomatic SMA aneurysm. Given his compromised celiac axis, ligation was not an option. His SMA aneurysm was repaired with a PTFE patch. However, to secure longstanding blood flow to the small bowel in the event of graft thrombosis, the distal SMA pedicle was dissected free of the ileocolic vessels and anastomosed to the aorta. Follow-up studies demonstrated an occluded PTFE patch with a patent SMA autotransplant. This case depicts a novel approach to the surgical management of complex recurrent SMA aneurysms.
Annals of Vascular Surgery | 2014
Kevin C. Chun; Kai Y. Teng; LeAnn A. Chavez; Elyse N. Van Spyk; Kiana M. Samadzadeh; John G. Carson; Eugene S. Lee
Annals of Vascular Surgery | 2010
Timothy Wu; John G. Carson; Christopher L. Skelly
Academic Psychiatry | 2016
Jessica Haskins; John G. Carson; Celia H. Chang; Carol Kirshnit; Daniel P. Link; Leslie Navarra; Lorin M. Scher; Andres F. Sciolla; Jeffrey Uppington; Peter Yellowlees