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Dive into the research topics where Jason J. Rasmussen is active.

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Featured researches published by Jason J. Rasmussen.


Surgical Endoscopy and Other Interventional Techniques | 2007

The utility of routine postoperative upper GI series following laparoscopic gastric bypass

Asok Doraiswamy; Jason J. Rasmussen; Jonathan L. Pierce; William D. Fuller; Mohamed R. Ali

BackgroundRoutine upper gastrointestinal (UGI) studies following laparoscopic Roux-en-Y gastric bypass (LRYGBP) have the potential advantage of early identification of anastomotic complications. The aim of our study was to evaluate the efficacy of routine postoperative UGI and its relationship to clinical outcomes.MethodsOver a three-year period, 516 patients underwent LRYGBP followed by routine postoperative UGI studies. Data were collected on the results of the UGI, clinical parameters, and patient outcomes. Study groups were composed of patients with a normal UGI (Group I, n = 455), abnormal UGI not requiring further intervention (Group II, n = 36), and abnormal UGI requiring further intervention (Group III, n =25). Statistical significance was set at α= 0.05 level for all analyses.ResultsThe three study groups were not statistically different in mean age (42 years) or body mass index (BMI) (45) and were predominantly female (90%). Most patients had an uneventful postoperative course. Anastomotic complications (gastrojejunostomy and jejunojejunostomy) were uncommon (1.3%). The sensitivity of the UGI for anastomotic leak in this study was low (33%). However, all patients with alimentary limb obstruction (n = 3) had UGI evidence of this complication. Of the 516 UGI reports, there were only 25 (4.8%, Group III) that were abnormal and required some form of intervention ranging from serial imaging (84%) to reoperation (16%). Of the various clinical parameters examined, the patients in Group III demonstrated a significantly higher prevalence of fever (p < 0.001), tachycardia (p < 0.01), vomiting (p < 0.001), and postoperative day 1 leukocytosis (p < 0.005).ConclusionsOur data suggest that routine UGI after LRYGBP has limited utility as it may result in unnecessary intervention based on false-positive results or a delay in treatment based on false-negative results. We advocate selective UGI imaging following LRYGBP based on the patient’s clinical factors, particularly fever and tachycardia.


Surgical Endoscopy and Other Interventional Techniques | 2007

Teaching robotic surgery: a stepwise approach

Mohamed R. Ali; Jason J. Rasmussen; Bobby BhaskerRao

BackgroundAfter an initial institutional experience with 50 robot-assisted laparoscopic Roux-en-Y gastric bypass procedures, a curriculum was developed for fellowship training in robotic surgery.MethodsThirty consecutive robotic gastric bypasses were performed using the Zeus robotic surgical system to fashion a two-layer gastrojejunostomy. For teaching purposes, performance of the anastomosis was divided into three discrete tasks. Robotic suturing tasks were assigned to the trainee in cumulative order in ten-case increments. Our patient population averaged 44 years of age and 47 kg/m2 in BMI. Patients were predominantly female (87%).ResultsThe robotic training experience of the fellow defines the increases in surgical responsibility over the series of cases. Statistical analysis revealed no significant differences in task times or total robotic operative time as participation of the trainee in performing the gastrojejunostomy increased. No adverse robotic events or surgical complications occurred throughout this series. The learning curve of the fellow compared favorably with the initial experience of the institution.ConclusionRobotic surgery training may be safely implemented in a minimally invasive surgery training program. A gradual introduction of robotic technique appears to maximize the learning experience and minimize the potential for adverse outcomes.


Surgery for Obesity and Related Diseases | 2012

Sleep apnea syndrome is significantly underdiagnosed in bariatric surgical patients

Jason J. Rasmussen; William D. Fuller; Mohamed R. Ali

BACKGROUND Devastating morbidity and mortality can result when patients with undiagnosed sleep apnea syndrome (SAS) undergo bariatric surgery. We evaluated the prevalence of SAS and its rate of nondiagnosis in bariatric patients at a university hospital. METHODS The demographic, anthropomorphic, and co-morbidity data were collected from 1368 patients evaluated for bariatric surgery. All patients were screened for symptoms of SAS, and symptomatic patients were evaluated with polysomnography. RESULTS At the time of this report, 834 patients (61%) had completed the preoperative evaluation. Of these patients, 210 (25%) presented with previously diagnosed SAS. An additional 174 patients (21%) exhibited symptoms of SAS and underwent polysomnography. Most patients tested (127, 73%) had SAS that required treatment, 11 patients (6%) had mild SAS not requiring treatment, and 36 (21%) tested negative for SAS. Thus, symptom screening for SAS had a positive predictive value of 79% for predicting the presence of SAS and 73% for identifying patients who required SAS treatment. The patients with SAS tended to be older and male and have a greater body mass index (P < .05). CONCLUSION Overall, SAS that required treatment with an oral appliance was prevalent (40%) in patients who presented for bariatric surgery. However, many of these patients with significant SAS (38%) were previously undiagnosed, despite exhibiting clear symptoms of the disease. Symptom screening appears to be effective in identifying patients who should be evaluated by polysomnography. To avoid the potential perils of undiagnosed SAS during the perioperative period, patients who undergo bariatric surgery should be screened, tested, and treated for this co-morbidity.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2008

3-D Telestration: A Teaching Tool for Robotic Surgery

Mohamed R. Ali; Jamie P. Loggins; William D. Fuller; Brian E. Miller; Christopher J. Hasser; Peter Yellowlees; Tamas J. Vidovszky; Jason J. Rasmussen; Jonathan L. Pierce

BACKGROUND Telestration is an important teaching tool in minimally invasive surgery (MIS). While robotic surgery offers the added benefit of three-dimensional (3-D) visualization, telestration technology does not currently exist for this modality. This project aimed to develop a video algorithm to accurately translate a mentors two-dimensional (2-D) telestration into a 3-D telestration in the da Vinci visual field. MATERIALS AND METHODS A prototype 3-D telestration system was constructed to translate 2-D telestration from a mentor station into 3-D graphics for the trainee at the robotic console. This system uses fast image correlation algorithms to allow 2-D images to be placed over the same anatomic location in the two separate video channels of the stereoscopic robotic visualization system. Three subjects of varying surgical backgrounds, blinded to the mode of telestration (2-D vs. 3-D), were tested in the laboratory, using a simulated robotic task. RESULTS There were few technologic errors (2), only one of which resulted in a task error, in 99 total trials. Only the experienced MIS staff surgeon had a significantly faster task time in 2-D than in 3-D (P < 0.05). The MIS fellow recorded the fastest task times in 2-D and 3-D (P < 0.05). There were nine task errors, six of which were committed by the MIS fellow. The nonsurgeon trainee had the least number of errors but also had the slowest times. CONCLUSIONS Robotic telestration in 3-D is feasible and does not negatively impact performance in laboratory tasks. We plan to refine the prototype and investigate its use in vivo.


Surgery for Obesity and Related Diseases | 2009

Detailed description of early response of metabolic syndrome after laparoscopic Roux-en-Y gastric bypass

Mohamed R. Ali; William D. Fuller; Jason J. Rasmussen

BACKGROUND Previous outcome research in bariatric surgery has been unable to document quantitative changes in co-morbidities associated with obesity owing to a lack of a standardized instrument to grade the severity. We report a detailed description of the early resolution of the metabolic syndrome using our novel scheme for assessing co-morbidities. This study was performed at a tertiary care university hospital. METHODS Co-morbidity data were prospectively collected for 827 patients who underwent laparoscopic Roux-en-Y gastric bypass during a 4-year period using the Assessment of Obesity-Related Co-morbidities (AORC) scale. This scale assigns a score of 0-5 for the major medical conditions associated with obesity. The co-morbid conditions of obesity and biochemical markers of the metabolic syndrome were examined preoperatively and at the follow-up visits. RESULTS Of the 827 patients who underwent laparoscopic Roux-en-Y gastric bypass, 72 (8.7%) met the AORC criteria for the metabolic syndrome (AORC score >2 for diabetes mellitus [DM], hypertension [HTN], and dyslipidemia [DYS]). Overall, 75% of patients with DM, 69.4% of patients with HTN, and 76.4% of patients with DYS showed improvement in these co-morbidities (decrease from the preoperative AORC score) within 2 months after surgery. Within this period, DM, HTN, and DYS resolved in 65.3%, 51.4%, and 73.6% of patients, respectively. Concurrent decreases in hemoglobin A1c, serum lipids, and blood pressure were observed (P <.05). Patients exhibited a modest excess body weight loss of 27.7% during this period. However, the mean AORC score for the whole group decreased significantly for DM, DYS, and HTN (P <.001) before significant weight loss occurred. CONCLUSION We have demonstrated a new and novel approach to categorize and more accurately define the magnitude of improvement in co-morbidities after laparoscopic Roux-en-Y gastric bypass. This improvement preceded the weight loss effects on the metabolic syndrome.


Surgery for Obesity and Related Diseases | 2009

Depression is associated with increased severity of co-morbidities in bariatric surgical candidates

Mohamed R. Ali; Jason J. Rasmussen; Jeffrey B. Monash; William D. Fuller

BACKGROUND Depression is prevalent among bariatric surgical patients, and previous studies have suggested a link between depression and quality of life. Our objective was to examine the relationship between depression and other co-morbidities of obesity at a university hospital in the United States. METHODS Data were collected from 1368 consecutive patients evaluated for bariatric surgery. The demographic and co-morbidity profiles of these patients were compared between the depressed and nondepressed individuals. Depression was defined as an Assessment of Obesity-Related Co-morbidities score of > or = 3, signifying that the patient required medical treatment for (score of 3) or had complications of (score of 4-5) depression. RESULTS The prevalence of depression among these patients was 36%. The mean age of the patients with depression was older (44.3 + or - 9.4 versus 42.2 + or - 9.6, P <.05), but the mean body mass index was similar. Depression was more prevalent among the female patients (37.4% versus 29.6%, P <.05). Diabetes mellitus, hypertension, polycystic ovarian syndrome, idiopathic intracranial hypertension, and obesity hypoventilation syndrome occurred with similar frequency and severity in persons with and without depression. The analysis revealed a significantly greater prevalence and severity of dyslipidemia (P <.05), gastroesophageal reflux disease (P <.05), back pain (P <.0001), joint pain (P <.05), sleep apnea (P <.01), stress incontinence (P <.01), and hernia (P <.05) among patients with depression. Overall, patients with depression had more co-morbidities per patient (5.46 versus 4.55) and a greater likelihood of severe or complicated co-morbidities (2.67 versus 1.89 per patient). CONCLUSION This report has characterized a link between depression and other co-morbidities in bariatric surgical patients. This association was independent of the body mass index. Although a causal relationship could not yet be identified, our findings indicate that depression, in this patient population, is associated with a greater prevalence and increased severity of medical co-morbidities that express distinct physical symptoms.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2008

Switching Robotic Surgical Systems Does Not Impact Surgical Performance

Mohamed R. Ali; Jason J. Rasmussen

BACKGROUND Robotic surgery is heavily dependent on the availability of, and innovation in, technology. As new robotic systems become available, it will be important to identify the impact of emerging technology on clinical outcomes in robotic surgery. MATERIALS AND METHODS A total of 140 laparoscopic Roux-en-Y gastric bypass (LRYGB) procedures have been performed with robotic assistance (80 with Zeus and 60 with da Vinci). Data were collected regarding the robotic operative tasks performed, the robotic setup time, the robotic operative time, and the total operative time for all cases. RESULTS The 60 patients who had a da Vinci LRYGB had a statistically lower body mass index, when compared to patients who underwent Zeus LRYGB (n = 80; P < 0.05). The groups were otherwise statistically similar. The set-up time required for the Zeus cases decreased quickly but increased significantly once the switch was made to da Vinci. The da Vinci set-up time then decreased significantly after the first 10 cases (P < 0.05). There was no demonstrable regression in the robotic operative time when the robotic system was changed to da Vinci. Total operative time temporarily increased during the first 10 da Vinci cases but then decreased significantly (P < 0.05). There were two intraoperative gastrojejunostomy (GJ) leaks in this series (one with each system). There were no anastomotic strictures at the robotic GJ or mortalities throughout this series. CONCLUSIONS Our data suggest that the impact of robotic platform change should be minimal in an established program. Any regression in clinical efficacy should be short-lived and only minimally impact clinical performance and outcomes.


Surgery for Obesity and Related Diseases | 2007

Weight loss before gastric bypass: feasibility and effect on postoperative weight loss and weight loss maintenance

Mohamed R. Ali; Sky Baucom-Pro; Gregory A. Broderick-Villa; Jennifer Campbell; Jason J. Rasmussen; Abigail Weston; Judy Yamasaki; William D. Fuller; Jeffrey B. Monash; Robert A. Casillas


Obesity Surgery | 2007

Is Routine Cholecystectomy Indicated for Asymptomatic Cholelithiasis in Patients Undergoing Gastric Bypass

William D. Fuller; Jason J. Rasmussen; Jagannath Ghosh; Mohamed R. Ali


Surgery for Obesity and Related Diseases | 2010

P-135: Challenging the current paradigm in NASH: It takes more than obesity and metabolic syndrome to cause significant fibrosis

Jason J. Rasmussen; Jonathan L. Pierce; Mohamed R. Ali

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Mohamed R. Ali

University of California

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Abigail Weston

University of California

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Judy Yamasaki

University of California

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