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Dive into the research topics where Jessica B. O'Connell is active.

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Featured researches published by Jessica B. O'Connell.


Annals of Surgery | 2004

Updated population-based review of carcinoid tumors.

Melinda A. Maggard; Jessica B. O'Connell; Clifford Y. Ko

Objective:To determine the population-based incidence, anatomic distribution, and survival rates of gastrointestinal carcinoid tumors. Background:Carcinoid tumors arise from neuroendocrine cells and may develop in almost any organ. Many textbooks and articles represent single institution studies and report varying incidence rates, anatomic distribution of tumors, and patient survival rates. Population-based statistics remain largely unknown. Methods:Data was obtained from the National Cancer Institute Surveillance, Epidemiology, and End Results program (1973 to 1997). Incidence rates, distribution, and 5-year survival rates were analyzed. Multivariate Cox regression was used to identify predictors of survival using age, race/ethnicity, gender, and tumor characteristics (size, lymph node status, and stage). Results:Of the 11,427 cases analyzed, the average age was 60.9 years, and 54.2% were female. The overall incidence rates for carcinoid tumors have increased significantly over the past 25 years, although rates for some sites have decreased (eg, appendix). The gastrointestinal tract accounted for 54.5% of the tumors. Within the gastrointestinal tract, the small intestine was the most common site (44.7%), followed by the rectum (19.6%), appendix (16.7%), colon (10.6%), and stomach (7.2%). The 5-year survival rates for the most common gastrointestinal sites were stomach (75.1%), small intestine (76.1%), appendix (76.3%), and rectum (87.5%). Conclusions:Using national, population-based cancer registry data, this study demonstrates that (1) incidence rates for carcinoid tumors have changed, (2) the most common gastrointestinal site is not the appendix (as is often quoted), but the small intestine, followed in frequency by the rectum, and (3) survival rates differ between individual anatomic sites.


Diseases of The Colon & Rectum | 2005

A 10-Year Outcomes Evaluation of Mucinous and Signet-Ring Cell Carcinoma of the Colon and Rectum

Hakjung Kang; Jessica B. O'Connell; Melinda A. Maggard; Jonathan Sack; Clifford Y. Ko

PURPOSEMost studies examining mucinous or signet-ring cell colorectal cancers are single institution reports. This study used a national cancer registry to analyze the epidemiology and survival outcomes of these two subtypes of colorectal cancer compared with adenocarcinoma tumors.METHODSAll patients diagnosed with mucinous (n = 16,991), signet-ring cell (n = 1,522), or adenocarcinoma (n = 146,115) colorectal cancer in the Surveillance, Epidemiology, and End Results database (1991–2000) were evaluated. Analyses were performed to obtain age-adjusted incidence rates, stage at presentation, tumor grade, and five-year relative survival for each subtype.RESULTSMucinous were slightly more common in females (53.4 percent). Incidence rates per 100,000 persons were: mucinous, 5.5; signet-ring cell, 0.6; and adenocarcinoma 46.6. The annual percent change during ten years was stable for mucinous, increased for signet-ring cell (4.8 percent; P < 0.05), and decreased for adenocarcinoma (−1.1 percent; P < 0.05). Fewer mucinous (18 percent) and signet-ring cell (21 percent) tumors were located in the rectum compared with adenocarcinoma (29 percent). Signet-ring cell presented at later stage (III/IV, 80.9 percent) more often than mucinous (52.8 percent) and adenocarcinoma (49.5 percent), and also had worse tumor grade (high grade: signet-ring cell, 73.5 percent; mucinous, 20.9 percent; adenocarcinoma, 17.5 percent). Relative five-year survival was worse for signet-ring cell than mucinous or adenocarcinoma.CONCLUSIONSWe present a large population-based review of colorectal cancer subtypes by analyzing national data from the past decade. Although the incidence of colorectal adenocarcinoma is decreasing in the United States, mucinous and signet-ring cell subtypes are stable and increasing, respectively. Importantly, it seems that the signet-ring cell subtype has worse outcomes, whereas survival rates for mucinous tumors are similar to adenocarcinomas.


Diseases of The Colon & Rectum | 2005

Malignancies of the Appendix: Beyond Case Series Reports

Marcia L. McGory; Melinda A. Maggard; Hakjung Kang; Jessica B. O'Connell; Clifford Y. Ko

PURPOSEA comprehensive analysis was performed for five histologic types of appendiceal tumors to compare incidence, clinicopathologic features, survival, and appropriateness of surgery.METHODSAll patients diagnosed with mucinous adenocarcinoma (n = 951), adenocarcinoma (n = 646), carcinoid (n = 435), goblet (n = 369), and signet-ring cell (n = 113) in the Surveillance, Epidemiology, and End Results database (1973–2001) were analyzed. Evaluation of incidence, stage, and five-year relative survival were determined for each histology. The appropriateness of the operative procedure (i.e. , appendectomy vs. colectomy) was examined by tumor type and size.RESULTSTumor incidence, patient demographics, survival outcomes, and appropriateness of surgery varied significantly among the different appendiceal tumor histologies. The most common appendiceal tumors were mucinous. With regard to patient demographics, carcinoids presented at an earlier mean age of 41 years and 71 percent were female (P < 0.001 for both). Overall five-year survival was highest for carcinoid (83 percent) and lowest for signet ring (18 percent). Although current guidelines specify that a right hemicolectomy (rather than an appendectomy) be performed for all noncarcinoid tumors and carcinoid tumors >2 cm, we found that 30 percent of noncarcinoids underwent appendectomy. Similarly, 28 percent of carcinoids >2 cm under-went appendectomy, which is a lesser resection than is indicated.CONCLUSIONSThis study provides a population-based analysis of epidemiology, tumor characteristics, survival, and quality of care for appendiceal carcinomas. This characterization provides a novel description of the presentation and outcomes for malignancies of the appendix and highlights that a substantial number of patients with appendiceal tumors may not be receiving appropriate surgical resection.


Diseases of The Colon & Rectum | 2004

Are Survival Rates Different for Young and Older Patients With Rectal Cancer

Jessica B. O'Connell; Melinda A. Maggard; Jerome H. Liu; David A. Etzioni; Clifford Y. Ko

PURPOSEAlthough it is generally believed that young patients with rectal cancer have worse survival rates, no comprehensive analysis has been reported. This study uses a national-level, population-based cancer registry to compare rectal cancer outcomes between young vs. older populations.METHODSAll patients with rectal carcinoma in the Surveillance, Epidemiology, and End Results cancer database from 1991 to 1999 were evaluated. Young (range, 20–40 years; n = 466) and older groups (range, 60–80 years; n = 11,312) were compared for patient and tumor characteristics, treatment patterns, and five-year overall and stage-specific survival. Cox multivariate regression analysis was performed to identify predictors of survival.RESULTSMean ages for the groups were 34.1 and 70 years. The young group was comprised of more black and Hispanic patients compared with the older group (P < 0.001). Young patients were more likely to present with late-stage disease (young vs. older: Stage III, 27 vs. 20 percent respectively, P < 0.001; Stage IV, 17.4 vs. 13.6 percent respectively, P < 0.02). The younger group also had worse grade tumors (poorly differentiated 24.3 vs. 14 percent respectively, P < 0.001). Although the majority of both groups received surgery (85 percent for each), significantly more young patients received radiation (P < 0.001). Importantly, overall and stage-specific, five-year survival rates were similar for both groups (P = not significant).CONCLUSIONSAlthough previous studies have found young rectal cancer patients to have poorer survival compared with older patients, this population-based study shows that young rectal cancer patients seem to have equivalent overall and stage-specific survival.


Seminars in Vascular Surgery | 2009

Proper Evaluation and Management of Acute Embolic versus Thrombotic Limb Ischemia

Jessica B. O'Connell; William J. Quinones-Baldrich

Acute limb ischemia is one of the most potentially devastating but treatable diseases faced by the vascular surgeon. It is crucial to identify the ischemic process early, as the outcomes of early intervention can lead to limb salvage, whereas late recognition places the patient at risk for limb loss and potential mortality. This article emphasizes the importance of properly evaluating the acutely ischemic extremity to ascertain whether the etiology is embolic or thrombotic. Appropriate treatment and management of the limb are determined by the underlying cause of the ischemia. The authors will review the clinical features, angiographic findings, and strategies for management for these similar but distinct etiologies: acute embolic versus thrombotic limb ischemia.


Journal of Vascular Surgery | 2011

Standardization is superior to traditional methods of teaching open vascular simulation

Jonathan Bath; Peter F. Lawrence; Ankur Chandra; Jessica B. O'Connell; Sebastian Uijtdehaage; Juan Carlos Jimenez; Gavin Davis; Jonathan Hiatt

OBJECTIVES Standardizing surgical skills teaching has been proposed as a method to rapidly attain technical competence. This study compared acquisition of vascular skills by standardized vs traditional teaching methods. METHODS The study randomized 18 first-year surgical residents to a standardized or traditional group. Participants were taught technical aspects of vascular anastomosis using femoral anastomosis simulation (Limbs & Things, Savannah, Ga), supplemented with factual information. One expert instructor taught a standardized anastomosis technique using the same method each time to one group over four sessions, while, similar to current vascular training, four different expert instructors each taught one session to the other (traditional) group. Knowledge and technical skill were assessed at study completion by an independent vascular expert using Objective Structured Assessment of Technical Skill (OSATS) performance metrics. Participants also provided a written evaluation of the study experience. RESULTS The standardized group had significantly higher mean overall technical (95.7% vs 75.8%; P = .038) and global skill scores (83.4% vs 67%; P = .006). Tissue handling, efficiency of motion, overall technical skill, and flow of operation were rated significantly higher in the standardized group (mean range, 88%-96% vs 67.6%-77.6%; P < .05). The standardized group trended to better cognitive knowledge (mean, 68.8% vs 60.7%; P = .182), creation of a secure knot at the toe of the anastomosis, fashioning an appropriate arteriotomy, better double-ended suture placement at the heel of the anastomosis (100% vs 62.7%; P = .07), and accurate suture placement (70% vs 25%; P = .153). Seventy-two percent of participant evaluations suggested a preference for a standardized approach. CONCLUSIONS This study demonstrates the feasibility of open vascular simulation to assess the effect of differing teaching methods on performance outcome. Findings from this report suggest that for simulation training, standardized may be more effective than traditional methods of teaching. Transferability of simulator-acquired skills to the clinical setting will be required before open simulation can be unequivocally recommended as a major component of resident technical skill training.


Journal of The American College of Surgeons | 2011

Coronary revascularization after myocardial infarction can reduce risks of noncardiac surgery.

Masha Livhits; Melinda Maggard Gibbons; Christian de Virgilio; Jessica B. O'Connell; Michael J. Leonardi; Clifford Y. Ko; David S. Zingmond

BACKGROUND Recent studies suggest that preoperative coronary revascularization overall does not improve outcomes after noncardiac surgery. It is not known whether this holds true for high-risk patients with a history of recent MI. Our objective was to determine whether preoperative revascularization improves outcomes after noncardiac surgery in patients with a recent MI. STUDY DESIGN Using the California Patient Discharge Database, we retrospectively analyzed patients with a recent MI who underwent hip surgery, cholecystectomy, bowel resection, elective abdominal aortic aneurysm repair, and lower extremity amputation from 1999 to 2004 (n = 16,478). Postoperative 30-day reinfarction and 30-day and 1-year mortality were compared for patients who underwent preoperative revascularization (percutaneous transluminal coronary angioplasty, coronary stenting, or coronary artery bypass graft) and those who were not revascularized using univariate analyses and multivariate logistic regression. Relative risks with 95% confidence intervals were estimated using bootstrapping with 1,000 repetitions. RESULTS Patients with a recent MI who were revascularized before surgery had an approximately 50% decreased rate of reinfarction (5.1% versus 10.0%; p < 0.001) and 30-day (5.2% versus 11.3%; p < 0.001) and 1-year mortality (18.3% versus 35.8%; p < 0.001) compared with those who were not. Stenting within 1 month of surgery was associated with a trend toward increased reinfarction (relative risk: 1.36; 95% CI, 0.96-1.97), and coronary artery bypass graft was associated with a decreased risk (relative risk: 0.70; 95% CI, 0.55-0.95). CONCLUSIONS This large sample representing real world practice suggests that patients with a recent MI can benefit from preoperative revascularization. Coronary artery bypass graft can improve outcomes more than stenting, especially when surgery is necessary within 1 month of revascularization, but additional prospective studies are indicated.


Archives of Surgery | 2003

Inpatient Surgery in California: 1990-2000

Jerome H. Liu; David A. Etzioni; Jessica B. O'Connell; Melinda A. Maggard; Darryl T. Hiyama; Clifford Y. Ko; Michael J. Stamos; Julie A. Freischlag; Clifford W. Deveney; Stanley R. Klein; Daniel R. Margulies; Thomas R. Russell

BACKGROUND The practice environment for surgery is changing. However, little is known regarding the trends or current status of inpatient surgery at a population level. HYPOTHESIS Inpatient surgical care has changed significantly over the last 10 years. DESIGN Longitudinal analysis of California inpatient discharge data (January 1, 1990, through December 31, 2000). SETTING All 503 nonfederal acute care hospitals in California. PATIENTS All inpatients undergoing general, vascular, and cardiothoracic surgery in California from January 1, 1990, through December 31, 2000, were obtained. MAIN OUTCOME MEASURES Volume, mean age, comorbidity profile, length of hospital stay, and in-hospital mortality were obtained for inpatient general, vascular, and cardiothoracic surgical procedures performed during the period 1990 to 2000. Rates of change and trends were evaluated for the 10-year period. RESULTS Between January 1, 1990, and December 31, 2000, 1.64 million surgical procedures were performed. The number of surgical procedures increased 20.4%, from 135,795 in 1990 to 163,468 in 2000. Overall, patients were older and had more comorbid disease in 2000 compared with 1990. Both crude and adjusted (by type of operation) in-hospital mortality decreased from 3.9% in 1990 to 2.75% (P<.001) and 2.58% (P<.001), respectively, in 2000. Length of hospital stay decreased over the period for all operations analyzed. CONCLUSIONS The total number of inpatient general, vascular, and cardiothoracic surgical procedures has increased over the past decade. Furthermore, our findings indicate that the outcomes of care (eg, in-hospital mortality and length of hospital stay) for patients who undergo general, vascular, and cardiothoracic surgical procedures have improved. However, continued evaluations at the population level are needed.


Journal of Vascular Surgery | 2012

Ethnic differences in arm vein diameter and arteriovenous fistula creation rates in men undergoing hemodialysis access

Brandon M. Ishaque; Mohamed A. Zayed; Jessica E. Miller; David Nguyen; Amy H. Kaji; Jason T. Lee; Jessica B. O'Connell; Christian de Virgilio

OBJECTIVE The National Kidney Foundation recommends that arteriovenous fistulas (AVFs) be placed in at least 65% of hemodialysis patients. Some studies suggest that African American patients are less likely to receive a first-time AVF than patients of other ethnicities, although the reason for this disparity is unclear. The purpose of our study is to determine (1) whether there are ethnic differences in AVF creation, (2) whether this may be related to differences in vein diameters, and (3) whether AVF patency rates are similar between African American and non-African American male patients. METHODS Consecutive male patients undergoing first-time hemodialysis access from 2006 to 2010 at two institutions were retrospectively reviewed. Data collected included age, ethnicity, weight, height, body mass index, diabetes, hypertension, congestive heart failure, smoking history, intravenous drug abuse, need for temporary access placement, and preoperative venous ultrasound measurements. Categoric variables were compared using χ(2) analysis, and the Wilcoxon rank-sum test was used to compare continuous variables. RESULTS Of 249 male patients identified, 95 were African American. Median age in African American and non-African American patients was 63 years. Hypertension and hyperlipidemia were statistically significantly greater in African American patients. The need for temporary access before hemoaccess was similar between the cohorts. African American patients demonstrated significantly smaller median basilic and cephalic vein diameters at most measured sites. Overall, 221 of 249 (88.8%) underwent AVF first. An AV graft was created in 17.9% of African American patients vs in only 7.1% of non-African Americans (odds ratio, 2.8; 95% confidence interval, 1.3-6.4; P = .009). The difference between median vein diameters used for autologous fistula creation in African American and non-African American patients was not significant. There was no significant difference in the primary patency (80.8% vs 76.2%; P = .4), primary functional patency (73.1% vs 69.2%; P = .5), or secondary functional patency rates (91.0% vs 96.5%; P = .1). Average primary fistula survival time was 257 days in African American and 256 in non-African American patients (P = .2). CONCLUSIONS African American patients are less likely than non-African American patients to undergo AVF during first-time hemodialysis access surgery. This ethnic discrepancy appears to be due to smaller arm vein diameters in African American patients. In African American patients with appropriate vein diameters who do undergo AVF, primary and functional patencies are equivalent to non-African American patients.


Journal of Surgical Research | 2003

Using Volume Criteria: Do California Hospitals Measure Up?

Jerome H. Liu; David A. Etzioni; Jessica B. O'Connell; Melinda A. Maggard; Clifford Y. Ko

BACKGROUND Many studies have demonstrated a significant relationship between high procedural volume and better outcomes. As the public becomes increasingly aware of this medical literature, consumer groups have collaborated with medical researchers to operationalize this body of evidence. One such organization, the Leapfrog Group, has proposed annual volume criteria for four operations: coronary bypass grafting (CABG), abdominal aortic aneurysm (AAA), carotid endarterectomy (CEA), and esophageal cancer resection (ECR). This study analyzes California hospitals within the context of these volume criteria. MATERIALS AND METHODS Using the California inpatient database from 2000, we identified all CABG, AAA, CEA, and ECR operations performed at metropolitan hospitals. The volume of each of the four operations was tabulated by hospital and evaluated. Comparisons were made between academic and nonacademic hospitals. RESULTS Most hospitals in California did not meet Leapfrogs volume criteria. Only 2 hospitals of 287 (0.7%) met the volume criteria for the operations that it performed. Of the 71 (25%) hospitals that performed all four procedures, none met the volume criteria of all four procedures. In fact, only 10% of California hospitals performing these operations were high-volume hospitals based on Leapfrogs volume criteria. When comparing academic to nonacademic hospitals, academic hospitals performed more AAA operations than nonacademic hospitals (36 vs 12, P = 0.02). Although academic hospitals tended to have higher caseloads for CABG, CEA, and ECR, these did not reach statistical significance. Also, academic hospitals were more likely to be high volume for AAA (43.8% vs 7.0%, P < 0.01) and for ECR (23.1% vs 4.0%, P < 0.01). CONCLUSIONS Californias hospital system is far from being regionalized. Although academic hospitals appear better positioned than nonacademic hospitals, the vast majority of all hospitals do not meet Leapfrogs volume criteria. As efforts to use volume as a proxy measure of quality gain momentum, hospitals and physicians will be forced to measure and report quality. As such, surgeons need to decide between accepting volume as an adequate measure of quality and developing other possibly more direct and reliable methods.

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Clifford Y. Ko

University of California

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Jerome H. Liu

University of California

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Sinan Jabori

University of California

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