Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Guilherme M. Campos is active.

Publication


Featured researches published by Guilherme M. Campos.


Annals of Surgery | 2009

Endoscopic and surgical treatments for achalasia: a systematic review and meta-analysis.

Guilherme M. Campos; Eric Vittinghoff; Charlotte Rabl; Mark Takata; Michael Gadenstätter; Feng Lin; Ruxandra Ciovica

Background:Although rare, esophageal achalasia is the best described primary esophageal motility disorder. Commonly used treatments are endoscopic botulin toxin injection (EBTI), endoscopic balloon dilation (EBD), and surgical myotomy with or without a fundoplication; however, reported outcomes mostly come from cohort studies. Objective:To summarize and compare the safety and efficacy of endoscopic and surgical treatments for esophageal achalasia. Methods:A systematic electronic Medline literature search of articles on esophageal achalasia. Treatment options reviewed included EBTI, EBD, and surgical myotomy using open and minimally invasive techniques. Main outcome measures were frequency of symptom relief, prevalence of post-treatment gastroesophageal reflux (GER), and complications. Outcome probability was estimated using weighted averages of the sample prevalence in each study, with weights equal to the number of patients. Outcomes, within or across studies, were compared using meta-analysis and meta-regression, respectively. Results:A total of 105 articles reporting on 7855 patients were selected, tabulated and reviewed. Symptom relief after EBD was better than after EBTI (68.2% vs. 40.6%; OR 3.4; 95% CI, 1.2–9.8; P = 0.02), and the need for additional therapy was greater for patients receiving EBTI (46.6% vs. 25%; OR, 2.6; 95% CI, 1.05–6.5; P = 0.04). Laparoscopic myotomy, when combined with an antireflux procedure, provided better symptom relief (90%) than all endoscopic and other surgical approaches and a low complication rate (6.3%). The incidence of postoperative GER was lower when a fundoplication was added to a laparoscopic myotomy (31.5% without a fundoplication vs. 8.8% with; OR, 6.3; 95% CI, 2.0–19.4; P = 0.003). Conclusions:EBD is superior to EBTI. Laparoscopic myotomy with fundoplication was the most effective surgical technique and can be considered the operative procedure of choice.


Journal of Gastrointestinal Surgery | 1999

Multivariate analysis of factors predicting outcome after laparoscopic Nissen fundoplication.

Guilherme M. Campos; Jeffrey H. Peters; Tom R. DeMeester; Stefan Öberg; Peter F. Crookes; Silvia Tan; Steven R. DeMeester; Jeffrey A. Hagen; Cedric G. Bremner

Laparoscopic Nissen fundoplication has been applied with increasing frequency in the treatment of gastroesophageal reflux disease. The aim of this study was to determine the variahles that predict outcome of laparoscopic Nissen fundoplication. A multivariate analysis was performed on data from 199 consecutive patients undergoing laparoscopic Nissen fundoplication. Variables included age, sex, body mass index, primary symptoms, clinical response to acid suppression therapy, erosive esophagitis, 24-hour esophageal pH score, and the percentage of time the esophageal pH was less than 4 on 24-hour pH monitoring, lower esophageal sphincter competence, status of the esophageal body motility, hiatal hernia, carditis, intestinal metaplasia of cardiac epithelium limited to the gastroesophageal junction, and Barrett’s esophagus of any length. Clinical outcome was obtained from all patients at a median follow-up of 15 months (range 6 to 74 months) after surgery. One hundred seventy-three patients had an excellent or good outcome (87%) and 26 had a fair or poor outcome. Three factors were significantly predictive of a successful outcome: an abnormal 24-hour pH score (odds ratio = 5.4; 95% confidence interval [CI] = 1.9–15.3), a typical primary symptom (odds ratio = 5.1; 95% CI = 1.9–13.6), and a clinical response to acid suppression therapy (odds ratio = 3.3; 95% CI = 1.3 -8.7). We conclude that 24-hour pH monitoring provides the strongest outcome predictor of laparoscopic Nissen fundoplication and that outcome is based more on the correct identification of the disease than on its severity.


Annals of Surgery | 1999

Laparoscopic management of benign solid and cystic lesions of the liver.

Namir Katkhouda; Michael Hurwitz; Jean Gugenheim; Eli Mavor; Rodney J. Mason; Donald J. Waldrep; Raymond T. Rivera; Mudjianto Chandra; Guilherme M. Campos; Steven Offerman; Andrew Trussler; Pascal Fabiani; Jean Mouiel

OBJECTIVE The authors present their experience in the laparoscopic management of benign liver disease. The aim of the study is to analyze technical feasibility and evaluate immediate and long-term outcome. SUMMARY BACKGROUND DATA Indications for the laparoscopic management of varied abdominal conditions have evolved. Although the minimally invasive treatment of liver cysts has been reported, the laparoscopic approach to other liver lesions remains undefined. METHODS Between September 1990 and October 1997, 43 patients underwent laparoscopic liver surgery. There were two groups of benign lesions: cysts (n = 31) and solid tumors (n = 12). Indications were solitary giant liver cysts (n = 16), polycystic liver disease (n = 9), hydatid cyst (n = 6), focal nodular hyperplasia (n = 3), and adenoma (n = 9). Only solid tumors, hydatid cysts, and patients with polycystic disease and large dominant cysts located in anterior liver segments were included. All giant solitary liver cysts were considered for laparoscopy. Patients with cholangitis, cirrhosis, and significant cardiac disease were excluded. Data were collected prospectively. RESULTS The procedures were completed laparoscopically in 40 patients. Median size was 4 cm for solid nodules and 14 cm for solitary liver cysts. Conversion occurred in three patients (7%), for bleeding (n = 2) and impingement of a solid tumor on the inferior vena cava (n = 1). The median operative time was 179 minutes. All solitary liver cysts were fenestrated in less than 1 hour. There were no deaths. Complications occurred in 6 cases (14.1%). Two hemorrhagic and two infectious complications were noted after management of hydatid cysts. There were no complications after resection of solid tumors. Three patients received transfusions (7%). The median length of stay was 4.7 days. Median follow-up was 30 months. There was no recurrence of solitary liver or hydatid cysts. One patient with polycystic disease had symptomatic recurrent cysts at 6 months requiring laparotomy. CONCLUSION Laparoscopic liver surgery can be accomplished safely in selected patients with small benign solid tumors located in the anterior liver segments and giant solitary cysts. The laparoscopic management of polycystic liver disease should be reserved for patients with a limited number of large, anteriorly located cysts. Hydatid disease is best treated through an open approach.


The Journal of Thoracic and Cardiovascular Surgery | 1999

Node status in transmural esophageal adenocarcinoma and outcome after en bloc esophagectomy

John J. Nigro; Steven R. DeMeester; Jeffrey A. Hagen; Tom R. DeMeester; Jeffrey H. Peters; Milton Kiyabu; Guilherme M. Campos; Stefan Öberg; Otávio Leite Gastal; Peter F. Crookes; Cedric G. Bremner

OBJECTIVE Adenocarcinoma has replaced squamous cell as the most common esophageal cancer in the United States. The purpose of this study was to determine the prevalence and location of lymph node metastases, the feasibility of performing an R0 resection, and disease recurrence and survival in patients with transmural adenocarcinoma of the lower esophagus and gastroesophageal junction. METHODS Forty-four patients with transmural adenocarcinoma underwent en bloc esophagectomy with systematic thoracic and abdominal lymphadenectomy. They were followed up for a median of 23 months. RESULTS Actuarial survival for the entire group was 26% at 5 years. The most important predictors of the likelihood of recurrent disease and 5-year survival were the presence and number of lymph node metastases and the ratio of involved to total removed nodes. Seven patients (16%) were found to have no lymph node metastases and had an 85% 5-year survival. In contrast, patients with more than 4 involved nodes or a node ratio greater than 0.1 had a high likelihood of recurrence and death. Location of involved lymph nodes did not predict the likelihood of recurrence or death. Despite all patients having transmural tumors, recurrence within the field of the en bloc resection occurred in only 1 patient (2%). CONCLUSIONS En bloc esophagectomy in patients with transmural esophageal adenocarcinoma is required to obtain the survival benefit of an R0 resection, to adequately assess lymphatic tumor burden, and to be able to predict the likelihood of recurrence and death and thereby guide the use of postoperative adjuvant therapy.


The Journal of Thoracic and Cardiovascular Surgery | 1999

The extent of Barrett's esophagus depends on the status of the lower esophageal sphincter and the degree of esophageal acid exposure

Stefan Öberg; Tom R. DeMeester; Jeffrey H. Peters; Jeffrey A. Hagen; John J. Nigro; Steven R. DeMeester; Jörg Theisen; Guilherme M. Campos; Peter F. Crookes

OBJECTIVE The purpose of this study was to assess whether the extent of intestinal metaplasia is related to the severity of the gastroesophageal reflux disease. METHODS A total of 556 consecutive patients with symptoms suggestive of foregut disease had upper gastrointestinal endoscopy with extensive biopsies from the gastroesophageal junction and the esophagus. All patients had esophageal motility and 24-hour pH monitoring. In 411 patients, cardiac-type mucosa was identified; in 147 patients, the cardiac-type mucosa showed intestinal metaplasia. They were divided into 3 groups based on the extent of intestinal metaplasia commonly seen clinically: long segments (>3 cm), short segments (<3 cm), and limited to the gastroesophageal junction. The duration of symptoms, the status of the lower esophageal sphincter, the degree of esophageal acid exposure, and the time to clear a reflux episode were assessed in each group. RESULTS The presence of intestinal metaplasia in cardiac-type mucosa was associated with the hallmarks of gastroesophageal reflux disease. The extent of intestinal metaplasia correlated strongly with the degree of esophageal acid exposure (r = 0.711; P <.001) and inversely with the lower esophageal sphincter pressure (r = 0.351; P <.001) and length (r = 0. 259; P =.002). Patients with a long segment of intestinal metaplasia (>3 cm) had longer duration of symptoms (16 years) than those patients with a segment of intestinal metaplasia less than 3 cm (10 years; P =.048) or those patients with intestinal metaplasia limited to the gastroesophageal junction (10 years; P =.01). CONCLUSION The extent of intestinal metaplasia, that is, Barretts esophagus, is related to the status of the lower esophageal sphincter and the degree of esophageal acid exposure.


The American Journal of Medicine | 2010

Does Chronic Microaspiration Cause Idiopathic Pulmonary Fibrosis

Joyce S. Lee; Harold R. Collard; Ganesh Raghu; Matthew P. Sweet; Steven R. Hays; Guilherme M. Campos; Jeffrey A. Golden; Talmadge E. King

Idiopathic pulmonary fibrosis is a diffuse fibrotic lung disease of unknown etiology with no effective treatment. Emerging data support a role for chronic microaspiration (ie, subclinical aspiration of small droplets) in the pathogenesis and natural history of idiopathic pulmonary fibrosis. However, the precise relationship between chronic microaspiration and idiopathic pulmonary fibrosis remains unknown. Gastroesophageal reflux, a presumed risk factor for microaspiration, has been strongly associated with idiopathic pulmonary fibrosis with an estimated prevalence of up to 90%. This review aims to describe the relationship between chronic microaspiration and idiopathic pulmonary fibrosis by laying out the clinical and biologic rationale for this relationship and exploring the scientific evidence available. The gaps in our current understanding of the diagnosis of chronic microaspiration and idiopathic pulmonary fibrosis and the ongoing uncertainties in management and treatment will be highlighted. Defining the role of chronic microaspiration in idiopathic pulmonary fibrosis is essential as it has potential clinical, pathobiological, and treatment implications for this deadly disease.


Hepatology | 2008

A clinical scoring system for predicting nonalcoholic steatohepatitis in morbidly obese patients.

Guilherme M. Campos; Kiran Bambha; Eric Vittinghoff; Charlotte Rabl; Andrew M. Posselt; Ruxandra Ciovica; Umesh Tiwari; Linda Ferrel; Mark Pabst; Nathan M. Bass; Raphael B. Merriman

Nonalcoholic steatohepatitis (NASH) is common in morbidly obese persons. Liver biopsy is diagnostic but technically challenging in such individuals. This study was undertaken to develop a clinically useful scoring system to predict the probability of NASH in morbidly obese persons, thus assisting in the decision to perform liver biopsy. Consecutive subjects undergoing bariatric surgery without evidence of other liver disease underwent intraoperative liver biopsy. The outcome was pathologic diagnosis of NASH. Predictors evaluated were demographic, clinical, and laboratory variables. A clinical scoring system was constructed by rounding the estimated regression coefficients for the independent predictors in a multivariate logistic model for the diagnosis of NASH. Of 200 subjects studied, 64 (32%) had NASH. Median body mass index was 48 kg/m2 (interquartile range, 43‐55). Multivariate analysis identified six predictive factors for NASH: the diagnosis of hypertension (odds ratio [OR], 2.4; 95% confidence interval [CI], 1‐5.6), type 2 diabetes (OR, 2.6; 95% CI, 1.1‐6.3), sleep apnea (OR, 4.0; 95% CI, 1.3‐12.2), AST > 27 IU/L (OR, 2.9; 95% CI, 1.2‐7.0), alanine aminotransferase (ALT) > 27 IU/L (OR, 3.3; 95% CI, 1.4‐8.0), and non‐Black race (OR, 8.4; 95% CI, 1.9‐37.1). A NASH Clinical Scoring System for Morbid Obesity was derived to predict the probability of NASH in four categories (low, intermediate, high, and very high). Conclusion: The proposed clinical scoring can predict NASH in morbidly obese persons with sufficient accuracy to be considered for clinical use, identifying a very high‐risk group in whom liver biopsy would be very likely to detect NASH, as well as a low‐risk group in whom biopsy can be safely delayed or avoided. (HEPATOLOGY 2008.)


Surgery for Obesity and Related Diseases | 2008

Laparoscopic bariatric surgery improves candidacy in morbidly obese patients awaiting transplantation

Mark Takata; Guilherme M. Campos; Ruxandra Ciovica; Charlotte Rabl; Stanley J. Rogers; John P. Cello; Nancy L. Ascher; Andrew M. Posselt

BACKGROUND To evaluate, at a university tertiary referral center, the safety and efficacy of laparoscopic Roux-en-Y gastric bypass (LRYGB) in patients with end-stage renal disease (ESRD) and laparoscopic sleeve gastrectomy (LSG) in patients with cirrhosis or end-stage lung disease (ESLD); and to determine whether these procedures help patients become better candidates for transplantation. METHODS A retrospective review was performed of selected patients with end-stage organ failure who were not eligible for transplantation because of morbid obesity who underwent LRYGB or LSG. The prospectively collected data included demographics, operative details, complications, percentage of excess weight loss, postoperative laboratory data, and status of transplant candidacy. RESULTS Of the 15 patients, 7 with ESRD underwent LRYGB and 6 with cirrhosis and 2 with ESLD underwent LSG. Complications developed in 2 patients (both with cirrhosis); no patient died. The mean follow-up was 12.4 months, and the mean percentage of excess weight loss at > or =9 months was 61% (ESRD), 33% (cirrhosis), and 61.5% (ESLD). Obesity-associated co-morbidities improved or resolved in all patients. Serum albumin and other nutritional parameters at > or =9 months after surgery were similar to the preoperative levels in all 3 groups. At the most recent follow-up visit, 14 (93%) of 15 patients had reached our institutions body mass index limit for transplantation and were awaiting transplantation; 1 patient with ESLD underwent successful lung transplant. CONCLUSION The results of this pilot study have provided preliminary evidence that LRYGB in patients with ESRD and LSG in patients with cirrhosis or ESLD is safe, well-tolerated, and improves their candidacy for transplantation.


Archives of Surgery | 2008

Factors associated with weight loss after gastric bypass.

Guilherme M. Campos; Charlotte Rabl; Kathleen Mulligan; Andrew M. Posselt; Stanley J. Rogers; Antonio C. Westphalen; Feng Lin; Eric Vittinghoff

BACKGROUND Gastric bypass (GBP) is the most common operation performed in the United States for morbid obesity. However, weight loss is poor in 10% to 15% of patients. We sought to determine the independent factors associated with poor weight loss after GBP. DESIGN Prospective cohort study. We examined demographic, operative, and follow-up data by means of multivariate analysis. Variables investigated were age, sex, race, marital and insurance status, initial weight and body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared), comorbidities (diabetes mellitus, hypertension, joint disease, sleep apnea, hyperlipidemia, and psychiatric disease), laparoscopic vs open surgery, gastric pouch area, gastrojejunostomy technique, and alimentary limb length. SETTING University tertiary referral center. PATIENTS All patients at our institution who underwent GBP from January 1, 2003, through July 30, 2006. MAIN OUTCOME MEASURES Weight loss at 12 months defined as poor (< or =40% excess weight loss) or good (>40% excess weight loss). RESULTS Follow-up data at 12 months were available for 310 of the 361 patients (85.9%) undergoing GBP during the study period. Mean preoperative BMI was 52 (range, 36-108). Mean BMI and excess weight loss at follow-up were 34 (range, 17-74) and 60% (range, 8%-117%), respectively. Thirty-eight patients (12.3%) had poor weight loss. Of the 4 variables associated with poor weight loss in the univariate analysis (greater initial weight, diabetes, open approach, and larger pouch size), only diabetes (odds ratio, 3.09; 95% confidence interval, 1.35-7.09 [P = .007]) and larger pouch size (odds ratio, 2.77;95% confidence interval, 1.81-4.22 [P <.001]) remained after the multivariate analysis. CONCLUSIONS Gastric bypass results in substantial weight loss in most patients. Diabetes and larger pouch size are independently associated with poor weight loss after GBP.


Journal of The American College of Surgeons | 1999

A multivariate model to determine prognostic factors in gastrointestinal fistulas

Antonio Carlos Ligocki Campos; Dalton Francisco de Andrade; Guilherme M. Campos; Jorge Eduardo Fouto Matias; Júlio Cezar Uili Coelho

BACKGROUND Some studies have identified and selected factors that were associated with prognosis in patients with gastrointestinal fistulas, but a multivariate analysis to determine their relative importance and independent predictive value has not been done. The aim of this study was to determine independent prognostic factors for fistula closure and death in patients with gastrointestinal fistulas using a multivariate model. STUDY DESIGN Several variables were assessed related to spontaneous closure, surgical closure, and mortality in 188 patients with digestive fistulas (duodenal 22.3%, jejunoileal 28.7%, colonic 23.9%, biliopancreatic 25%). Selection of the variables was done through a forward stepwise logistic regression procedure; the final models were used to estimate the probability of closure, either spontaneous or surgical, and the probability of death. RESULTS Variables significant for spontaneous closure were: cause of the fistula (p = 0.027), fistula output (p = 0.037), institutional origin of the patient (p = 0.026), and occurrence of complications (p<0.001). Organ of origin of the fistula was only marginally significant (p = 0.068). Successful surgical closure was significantly associated with the presence of complications (p = 0.001) and was marginally associated with age (p = 0.069). Variables significant for death were fistula output (p = 0.009) and the presence of complications (p<0.001). CONCLUSIONS We conclude that the likelihood of spontaneous fistula closure is higher for fistulas with surgical causes, low output, and with no complications. Mortality is higher in patients with complications and with high-output fistulas.

Collaboration


Dive into the Guilherme M. Campos's collaboration.

Top Co-Authors

Avatar

Charlotte Rabl

University of California

View shared research outputs
Top Co-Authors

Avatar

Jad Khoraki

University of Wisconsin-Madison

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Cedric G. Bremner

University of Southern California

View shared research outputs
Top Co-Authors

Avatar

Jeffrey A. Hagen

University of Southern California

View shared research outputs
Top Co-Authors

Avatar

Jacob A. Greenberg

University of Wisconsin-Madison

View shared research outputs
Top Co-Authors

Avatar

Peter F. Crookes

University of Southern California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Tom R. DeMeester

University of Southern California

View shared research outputs
Researchain Logo
Decentralizing Knowledge