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Dive into the research topics where Michael J. Stamos is active.

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Featured researches published by Michael J. Stamos.


Diseases of The Colon & Rectum | 2006

Reduction in adhesive small-bowel obstruction by Seprafilm adhesion barrier after intestinal resection.

Victor W. Fazio; Zane Cohen; James W. Fleshman; Harry van Goor; Joel J. Bauer; Bruce G. Wolff; Marvin L. Corman; Robert W. Beart; Steven D. Wexner; James M. Becker; John R. T. Monson; Howard S. Kaufman; David E. Beck; H. Randolph Bailey; Kirk A. Ludwig; Michael J. Stamos; Ara Darzi; Ronald Bleday; Richard Dorazio; Robert D. Madoff; Lee E. Smith; Susan L. Gearhart; Keith D. Lillemoe; J. Göhl

IntroductionAlthough Seprafilm® has been demonstrated to reduce adhesion formation, it is not known whether its usage would translate into a reduction in adhesive small-bowel obstruction.MethodsThis was a prospective, randomized, multicenter, multinational, single-blind, controlled study. This report focuses on those patients who underwent intestinal resection (n = 1,701). Before closure of the abdomen, patients were randomized to receive Seprafilm® or no treatment. Seprafilm® was applied to adhesiogenic tissues throughout the abdomen. The incidence and type of bowel obstruction was compared between the two groups. Time to first adhesive small-bowel obstruction was compared during the course of the study by using survival analysis methods. The mean follow-up time for the occurrence of adhesive small-bowel obstruction was 3.5 years.ResultsThere was no difference between the treatment and control group in overall rate of bowel obstruction. The incidence of adhesive small-bowel obstruction requiring reoperation was significantly lower for Seprafilm® patients compared with no-treatment patients: 1.8 vs. 3.4 percent (P < 0.05). This finding represents an absolute reduction in adhesive small-bowel obstruction requiring reoperation of 1.6 percent and a relative reduction of 47 percent. In addition, a stepwise multivariate analysis indicated that the use of Seprafilm® was the only predictive factor for reducing adhesive small-bowel obstruction requiring reoperation. In both groups, 50 percent of first adhesive small-bowel obstruction episodes occurred within 6 months after the initial surgery with nearly 30 percent occurring within the first 30 days. Additionally no first adhesive small-bowel obstruction events were reported in Years 4 and 5 of follow-up.ConclusionsThe overall bowel obstruction rate was unchanged; however, adhesive small-bowel obstruction requiring reoperation was significantly reduced by the use of Seprafilm®, which was the only factor that predicted this outcome.


JAMA Surgery | 2013

Risk Factors for Anastomotic Leakage After Anterior Resection for Rectal Cancer

Celeste Y. Kang; Wissam J. Halabi; Obaid O. Chaudhry; Vinh Q. Nguyen; Alessio Pigazzi; Joseph C. Carmichael; Steven Mills; Michael J. Stamos

BACKGROUND The risk factors for anastomotic leak (AL) after anterior resection have been evaluated in several studies and remain controversial as the findings are often inconsistent or inconclusive. OBJECTIVE To analyze the risk factors for AL after anterior resection in patients with rectal cancer. DESIGN Retrospective analysis. SETTING The Nationwide Inpatient Sample 2006 to 2009. PATIENTS A total of 72 055 patients with rectal cancer who underwent elective anterior resection. MAIN OUTCOME MEASURES To build a predictive model for AL using demographic characteristics and preadmission comorbidities, the lasso algorithm for logistic regression was used to select variables most predictive of AL. RESULTS The AL rate was 13.68%. The AL group had higher mortality vs the non-AL group (1.78% vs 0.74%). Hospital length of stay and cost were significantly higher in the AL group. Laparoscopic and open resections with a diverting stoma had a higher incidence of AL than those without a stoma (15.97% vs 13.25%). Multivariate analysis revealed that weight loss and malnutrition, fluid and electrolyte disorders, male sex, and stoma placement were associated with a higher risk of AL. The use of laparoscopy was associated with a lower risk of AL. Postoperative ileus, wound infection, respiratory/renal failure, urinary tract infection, pneumonia, deep vein thrombosis, and myocardial infarction were independently associated with AL. CONCLUSIONS Anastomotic leak after anterior resection increased mortality rates and health care costs. Weight loss and malnutrition, fluid and electrolyte disorders, male sex, and stoma placement independently increased the risk of leak. Laparoscopy independently decreased the risk of leak. Further studies are needed to delineate the significance of these findings.


Archives of Surgery | 2011

Trends in Diverticulitis Management in the United States From 2002 to 2007

Hossein Masoomi; Brian Buchberg; Cheryl P. Magno; Steven Mills; Michael J. Stamos

OBJECTIVE To demonstrate the recent trends of admission and surgical management for diverticulitis in the United States. DESIGN Retrospective database analysis. SETTING The National Inpatient Sample database. PATIENTS Patients admitted to the hospital for diverticulitis from 2002 to 2007. MAIN OUTCOME MEASURES Patient characteristics, surgical approach, and mortality were evaluated for elective or emergent admission. RESULTS A total of 1,073,397 patients were admitted with diverticulitis (emergent: 78.3%, elective: 21.7%). The emergent admission rate increased by 9.5% over the study period. For emergent patients, 12.2% underwent urgent surgical resection and 87.8% were treated with nonoperative methods (percutaneous abscess drainage: 1.88% and medical treatment: 85.92%). There was only a 4.3% increase in urgent surgical resections, while elective surgical resections increased by 38.7.%. The overall rate of elective laparoscopic colon resection was 10.5%. Elective laparoscopic surgery nearly doubled from 6.9% in 2002 to 13.5% in 2007 (P < .001). Primary anastomosis rates increased for elective resections over time (92.1% in 2002 to 94.5% in 2007; P < .001). For urgent open operation, use of colostomy decreased significantly from 61.2% in 2002 to 54.0% in 2007 (P < .001). In-hospital mortality significantly decreased in both elective and urgent surgery (elective: 0.53% in 2002 to 0.44% in 2007; P = .001; urgent: 4.5% in 2002 to 2.5% in 2007; P < .001). CONCLUSION Diverticulitis continues to be a source of significant morbidity in the United States. However, our data show a trend toward increased use of laparoscopic techniques for elective operations and primary anastomosis for urgent operations.


American Journal of Surgery | 2000

Nonoperative management of perforated appendicitis without periappendiceal mass

David Oliak; Dan Yamini; Vikram M. Udani; Roger J. Lewis; Hernan I. Vargas; Tracey D. Arnell; Michael J. Stamos

BACKGROUND Initial nonoperative treatment for patients with periappendiceal mass has been shown to be safe and effective. Our goal was to evaluate the safety and efficacy of initial nonoperative management for perforated appendicitis not accompanied by a palpable mass. METHODS The study population consisted of 77 patients with appendicitis treated initially nonoperatively between 1992 and 1998. All had localized abdominal tenderness and computed tomography findings of abscess or phlegmon. None had a palpable abdominal mass. Outcome parameters evaluated were rate of failure, complication, and recurrence. RESULTS There were 49 males and 28 females with a mean age of 35 years (range 16 to 75). Initial nonoperative management was successful in 95% of patients. Complications occurred in 12% of patients. Recurrent appendicitis developed in 6.5% of patients after an average follow-up of 30 weeks. CONCLUSIONS Perforated appendicitis patients with localized abdominal tenderness and abscess or phlegmon can safely and effectively be treated in an initial nonoperative fashion.


Clinical Cancer Research | 2007

Discussion: Diagnostic issues in early-stage disease

Carolyn C. Compton; Kenneth J. Chang; Al B. Benson; Daniel G. Haller; Patrick M. Lynch; Heidi Nelson; Michael J. Stamos; Lee S. Rosen; Robert W. Beart; Axel Grothey; Anton J. Bilchik

At present, several modalities exist for the preoperative staging of rectal lesions, including computed tomography (CT), body coil or endorectal coil magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) done by rigid or flexible probes, and positron emission tomography (PET). Staging accuracy for CT ranges from 53% to 94% for T-stage accuracy and from 54% to 70% for N-stage accuracy. Improved CT accuracy is observed at higher disease stages. Body coil MRI has shown T- and N-stage accuracy ranging from 59% to 95% and 39% to 95%, respectively. Endorectal coil MRI has shown improved T- and N-stage accuracy, with rates of 66% to 91% and 72% to 79%, respectively. The development of phased-array MRI, combining high spatial resolution with a larger field of view, offers promise to improve on these rates. EUS, considered the current gold standard, has shown T-stage accuracy ranging from 75% to 95%, with N-stage accuracy ranging from 65% to 80%. Flexible EUS probes have the advantage of being able to access and sample iliac nodes. Recent studies also suggest that three-dimensional EUS may provide greater accuracy than conventional two-dimensional EUS. Limited studies exist on the use of PET in primary tumor staging. PET may upstage disease in 8% to 24% of patients and has also been used in posttreatment restaging and surveillance. Postradiation edema, necrosis, and fibrosis seem to decrease restaging accuracy in all modalities. This article reviews the current literature about the staging accuracy of the various modalities and suggests a staging algorithm for rectal cancer.At present, several modalities exist for the preoperative staging of rectal lesions, including computed tomography (CT), body coil or endorectal coil magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) done by rigid or flexible probes, and positron emission tomography (PET). Staging accuracy for CT ranges from 53% to 94% for T-stage accuracy and from 54% to 70% for N-stage accuracy. Improved CT accuracy is observed at higher disease stages. Body coil MRI has shown T- and N-stage accuracy ranging from 59% to 95% and 39% to 95%, respectively. Endorectal coil MRI has shown improved T- and N-stage accuracy, with rates of 66% to 91% and 72% to 79%, respectively. The development of phased-array MRI, combining high spatial resolution with a larger field of view, offers promise to improve on these rates. EUS, considered the current gold standard, has shown T-stage accuracy ranging from 75% to 95%, with N-stage accuracy ranging from 65% to 80%. Flexible EUS probes have the advantage of being able to access and sample iliac nodes. Recent studies also suggest that three-dimensional EUS may provide greater accuracy than conventional two-dimensional EUS. Limited studies exist on the use of PET in primary tumor staging. PET may upstage disease in 8% to 24% of patients and has also been used in posttreatment restaging and surveillance. Postradiation edema, necrosis, and fibrosis seem to decrease restaging accuracy in all modalities. This article reviews the current literature about the staging accuracy of the various modalities and suggests a staging algorithm for rectal cancer.


Annals of Surgery | 2007

Laparoscopic surgery is associated with a lower incidence of venous thromboembolism compared with open surgery.

Ninh T. Nguyen; Marcelo W. Hinojosa; Christine Fayad; Esteban Varela; Viken R. Konyalian; Michael J. Stamos; Samuel E. Wilson

Background:Although laparoscopy now plays a major role in most general surgical procedures, little is known about the relative risk of venous thromboembolism (VTE) after laparoscopic compared with open procedures. Objective:To compare the incidence of VTE after laparoscopic and open surgery over a 5-year period. Patients and Interventions:Clinical data of patients who underwent open or laparoscopic appendectomy, cholecystectomy, antireflux surgery, and gastric bypass between 2002 and 2006 were obtained from the University HealthSystem Consortium Clinical Database. The principal outcome measure was the incidence of venous thrombosis or pulmonary embolism occurring during the initial hospitalization after laparoscopic and open surgery. Results:During the 60-month period, a total of 138,595 patients underwent 1 of the 4 selected procedures. Overall, the incidence of VTE was significantly higher in open cases (271 of 46,105, 0.59%) compared with laparoscopic cases (259 of 92,490, 0.28%, P < 0.01). Our finding persists even when the groups were stratified according to level of severity of illness. The odds ratio (OR) for VTE in open procedures compared with laparoscopic procedures was 1.8 [95% confidence interval (CI) 1.3–2.5]. On subset analysis of individual procedures, patients with minor/moderate severity of illness level who underwent open cholecystectomy, antireflux surgery, and gastric bypass had a greater risk for developing perioperative VTE than patients who underwent laparoscopic cholecystectomy (OR: 2.0; 95% CI: 1.2–3.3; P < 0.01), antireflux surgery (OR: 24.7; 95% CI: 2.6–580.9; P < 0.01), and gastric bypass (OR: 3.4; 95% CI: 1.8–6.5; P < 0.01). Conclusions:Within the context of this large administrative clinical data set, the frequency of perioperative VTE is lower after laparoscopic compared with open surgery. The findings of this study can provide a basis to help surgeons estimate the risk of VTE and implement appropriate prophylaxis for patients undergoing laparoscopic surgical procedures.


Diseases of The Colon & Rectum | 2009

Tumor subsite location within the colon is prognostic for survival after colon cancer diagnosis.

Charlie M. Wray; Argyrios Ziogas; Marcelo W. Hinojosa; Hoa Le; Michael J. Stamos; Jason A. Zell

PURPOSE: Proximal colon cancers are more likely to present with advanced stage than distal cancers; however, previous reports conflict regarding the independent prognostic significance of tumor location on survival. We examined survival by colon cancer subsite location by use of data from the California Cancer Registry. METHODS: An analysis of colon cancer cases from 1994 to 2004 was conducted, with follow-up through 2006. Colon subsite location was defined as proximal colon (cecum, ascending colon, hepatic flexure), transverse colon, descending colon (splenic flexure, descending colon), and sigmoid colon. Subsite-specific survival analyses were conducted with use of the Kaplan-Meier method and Cox proportional hazards ratios. RESULTS: A total of 82,926 colon cancer cases were identified, including 40,078 proximal (48%), 8,023 transverse (10%), 8,657 descending (10%), and 26,168 sigmoid cancers (32%). A larger proportion of sigmoid cancers (30.5%) presented as Stage I compared with proximal (18.5%), transverse (16.8%), or descending colon cancers (20.1%). Proximal cancers had the greater proportion with high tumor grade (27%), and had a greater mean number of lymph nodes examined. There were no differences in treatment rendered when each colon subsite was stratified by stage. After adjustment for stage, grade, treatment, lymph node examination, and other relevant clinical variables, sigmoid cancers had decreased colorectal cancer-specific mortality compared with proximal tumors (hazards ratio = 0.88; 95% confidence interval, 0.85–0.92). CONCLUSIONS: In this analysis, sigmoid colon cancers were observed to have earlier stage, lower tumor grade, and independently decreased colorectal cancer-specific mortality compared with proximal tumors.


Diseases of The Colon & Rectum | 2002

A study to determine the nitroglycerin ointment dose and dosing interval that best promote the healing of chronic anal fissures

H. Randolph Bailey; David E. Beck; Richard P. Billingham; Sander R. Binderow; Lester Gottesman; Tracy L. Hull; Sergio W. Larach; David A. Margolin; Jeffrey W. Milsom; Fabio M. Potenti; Janice F. Rafferty; Dennis S. Riff; Lawrence R. Sands; Anthony J. Senagore; Michael J. Stamos; Laurence F. Yee; Tonia M. Young-Fadok; Robert D. Gibbons

AbstractPURPOSE: The aim of this study was to determine the optimal dose and dosing interval of nitroglycerin ointment to heal chronic anal fissures. METHOD: A randomized, double-blind study of intra-anally applied nitroglycerin ointment (Anogesic™) was conducted in 17 centers in 304 patients with chronic anal fissures. The patients were randomly assigned to one of eight treatment regimens (0.0, 0.1, 0.2, 0.4 percent nitroglycerin ointment applied twice or three times per day), for up to eight weeks. A dose-measuring device standardized the delivery of 374 mg ointment. Healing of fissures (complete reepithelialization) was assessed by physical examination using an observer unaware of treatment allocation. The subjects assessed pain intensity daily by completing a diary containing a visual analog scale for average pain intensity for the day, the worst pain intensity for the day, and pain intensity at the last defecation. RESULTS: There were no significant differences in fissure healing among any of the treatment groups; all groups, including placebo had a healing rate of approximately 50 percent. This rate of placebo response was inexplicably higher than previously reported in the literature. Treatment with 0.4 percent (1.5 mg) nitroglycerin ointment was associated with a significant (P < 0.0002) decrease in average pain intensity compared with vehicle as assessed by patients with a visual analog scale. The decreases were observed by Day 4 of treatment. At 8 weeks the magnitude of the difference between 0.4 percent nitroglycerin and control was a 21 percent reduction in average pain. Treatment was well tolerated, with only 3.29 percent of patients discontinuing treatment because of headache. Headaches were the primary adverse event and were dose related. CONCLUSION: Nitroglycerin ointment did not alter healing but significantly and rapidly reduced the pain associated with chronic anal fissures.


American Journal of Surgery | 2012

Outcomes of laparoscopic colorectal surgery: data from the Nationwide Inpatient Sample 2009.

Celeste Y. Kang; Obaid O. Chaudhry; Wissam J. Halabi; Vinh Q. Nguyen; Joseph C. Carmichael; Michael J. Stamos; Steven Mills

BACKGROUND Specific International Classification of Diseases, Ninth Revision, codes for laparoscopic procedures introduced in 2008 allow a more accurate evaluation of laparoscopic colorectal surgery. METHODS Using the Nationwide Inpatient Sample 2009, a retrospective analysis of surgical colorectal cancer and diverticulitis patients was conducted. Logistic regression was used to estimate odds ratios comparing the outcomes of laparoscopic, open, and converted surgery. RESULTS A total of 121,910 patients underwent resection for cancer and diverticulitis, 35.41% of whom underwent laparoscopic surgery. Compared with open surgery, laparoscopic surgery had lower postoperative complication rates, lower mortality, shorter hospital stays, and lower costs. Compared to open surgery, laparoscopic surgery independently decreased mortality, postoperative anastomotic leak, urinary tract infection, ileus or obstruction, pneumonia, respiratory failure, and wound infection. Converted surgery was independently associated with anastomotic leak, wound infection, ileus or obstruction, and urinary tract infection. CONCLUSIONS Laparoscopic colorectal surgery has lower postoperative complications, lower mortality, lower costs, and shorter hospital stays. Conversion had higher complications compared with laparoscopy. The use of laparoscopy should increase with efforts to minimize conversion.


Diseases of The Colon & Rectum | 2001

Initial nonoperative management for periappendiceal abscess.

David Oliak; Dan Yamini; Vikram M. Udani; Roger J. Lewis; Tracey D. Arnell; Hernan I. Vargas; Michael J. Stamos

PURPOSE: Our goal was to compare initial operative and nonoperative management for periappendiceal abscess complicating appendicitis. METHODS: This study is a retrospective review of 155 consecutive patients with appendicitis complicated by periappendiceal abscess treated between 1992 and 1998. Eighty-eight patients were treated initially nonoperatively, and 67 patients were treated operatively. All patients had localized abdominal tenderness and either computed tomography or intraoperative documentation of an abscess. RESULTS: Our patient population consisted of 107 males and 48 females, with an average age of 33 (range, 16–75) years. Age, gender, comorbidity, white blood cell count, temperature, and heart rate did not differ significantly between groups. For the initial nonoperative management group, the failure rate was 5.8 percent and the appendicitis recurrence rate was 8 percent after a mean follow-up of 36 weeks. The response to treatment of the initial nonoperative group and the initial operative group was compared by length of stay (9±5 daysvs. 9±3 days;P=not significant), days until white blood cell count normalized (3.8±4 daysvs. 3.1±3 days;P=not significant), days until temperature normalized (3.2±3 daysvs. 3.1±2 days;P=not significant), and days until a regular diet was tolerated (4.7±4 daysvs. 4.6±3 days;P=not significant). Complication rate was significantly lower in the nonoperative group (17vs. 36 percent;P=0.008). CONCLUSIONS: Initial nonoperative management of appendicitis complicated by periappendiceal abscess is safe and effective. Patients undergoing initial nonoperative management have a lower rate of complications, but they are at risk for recurrent appendicitis.

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Steven Mills

University of California

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Ninh T. Nguyen

University of California

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David E. Beck

University of Queensland

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Mark H. Hanna

University of California

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