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Dive into the research topics where Mauricio Sierra is active.

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Featured researches published by Mauricio Sierra.


World Journal of Surgery | 2002

Videolaparoscopic Resection of Insulinomas: Experience in Two Institutions

L. Gramatica; Miguel F. Herrera; Andrés Mercado-Luna; Mauricio Sierra; Guillermo Verasay

Abstract Laparoscopic resection of islet cell tumors has been performed in some selected cases. The aim of the study was to analyze the experience of two institutions in the laparoscopic management of insulinomas. In a 4-year period, videolaparoscopic resection of sporadic insulinomas was performed in 9 patients. All patients had hypoglycemia/hyperinsulinism and a solitary tumor demonstrated by image studies. Demographics, surgical findings, results, and complications were analyzed. Mean age of the patients was 43 years. One patient was male and eight were females. One tumor was located in the head of the pancreas, 4 in the body, and 4 in the tail. Laparoscopic resection was completed in all patients. Procedures included 4 enucleations and 5 distal pancreatectomies. Pancreatic resection with splenic preservation was achieved in 4 cases. Intraoperative ultrasound was used in 7 patients. Mean size of the tumors was 1.6 cm. All patients became normoglycemic after surgery. Complications included one pancreatic fistula, one pleural effusion, and one peripancreatic fluid collection. All resolved spontaneously. In a follow-up period between 3 and 48 months no evidence of recurrence has been observed. This series supports laparoscopic resection of preoperatively localized benign solitary insulinomas. The operation provides the advantages of minimally invasive surgery and can be safely performed in most cases.


Langenbeck's Archives of Surgery | 2006

Thyroid surgery: postoperative hematoma—prevention and treatment

Jane Harding; Frederic Sebag; Mauricio Sierra; Fausto Palazzo; Jean-François Henry

Background and aimsPostoperative haematoma formation is a fortunately rare but potentially life-threatening complication of thyroid surgery. This paper aims to identify potential aetiological factors, describe surgical techniques and newer haemostatic agents that may be used to minimise the risk of haematoma formation and propose surgical strategies to deal with haematoma formation.Materials and methodsAn extensive literature search as well as own considerable experience in a tertiary referral centre endocrine surgical unit was drawn upon to review this topic.ConclusionsPostoperative haematoma may have a multifactorial aetiology. Numerous manoeuvres and surgical haemostatic agents may be employed to minimise the risk of haematoma formation but are no substitute for meticulous haemostasis. In the event of haematoma formation, early surgical re-intervention is strongly advocated with due care given to at risk structures.


Obesity Surgery | 2002

Quality of Life in Bariatric Surgery

Denise Arcila; David Velázquez; Rosa Gamino; Mauricio Sierra; Rafael Salin-Pascual; Jorge González-Barranco; Miguel F. Herrera

Background: Bariatric surgery is the treatment of choice for morbid obesity.Since bariatric operations alter gastrointestinal anatomy, they may induce symptoms that have a negative impact on quality of life (QOL).The aim of this study was to prospectively analyze QOL after bariatric surgery. Methods: The QOL index questionnaire (GIQLI) was applied to 45 surgically treated morbidly obese patients (15 vertical banded gastroplasty, 15 Roux-en-Y gastric bypass (RYGBP), and 15 distal RYGBP) and to 15 non-operated morbidly obese controls. Follow-up was of 1-year minimum. The GIQLI evaluates physical and mental well-being, digestion and bowel habits. Results: Physical and mental well-being as well as the overall QOL were significantly higher in the operated patients. There were no significant differences in digestion and bowel habits between the groups. Differences in QOL were not related to the type of surgical procedure. Conclusion. Overall QOL was significantly better in operated than in non-operated patients. There is no negative impact of bariatric surgery on QOL related to GI symptoms.


World Journal of Surgery | 2006

Long-term Outcome following Laparoscopic Adrenalectomy for Large Solid Adrenal Cortex Tumors

Fausto Palazzo; Frederic Sebag; Mauricio Sierra; Giuseppe Ippolito; Philippe Souteyrand; Jean-François Henry

IntroductionLaparoscopic adrenalectomy (LA) is the procedure of choice for small benign adrenal tumors. In the absence of local invasion or metastases, the preoperative diagnosis of an adrenocortical carcinoma (ACC) is difficult, often leaving size as the principal predictor of malignancy. Large tumors are resectable laparoscopically, but the long-term outcome and therefore appropriateness of LA for cortical tumors > 6 cm is not known.MethodsWe reviewed the LA experience in our institution since its introduction in June 1994. Patients who underwent LA for solid cortical tumors ≥ 60 mm in diameter without preoperative or intraoperative evidence of malignancy were reviewed. Follow-up data, including clinical examination, biochemical analysis, and repeat scans, were reviewed for evidence of local or systemic recurrent disease.ResultsBetween 1994 and 2004 a total of 462 adrenalectomies were performed, 391 of which were done laparoscopically. Among them, 19 were solid cortical tumors ≥ 60 mm in diameter with no overt malignant preoperative or intraoperative characteristics: 9 nonsecreting tumors, 8 Cushing’s syndrome tumors (including 2 virilizing variants), 1 virilizing tumor, and 1 aldosteronoma. The mean age of the patients was 49.9 years (range 22–77 years), and the mean tumor size was 69.0 mm (range 60–80 mm). Histology confirmed a cortical adenoma in eight patients, malignant tumors in three, and indeterminate tumors in eight. The mean follow-up was 34 months (range 4–108 months). Two patients died of systemic recurrent disease (liver metastases) at 10 and 19 months, respectively, following surgery; two other patients died 12 and 21 months, respectively following surgery owing to unrelated cardiovascular and cerebrovascular pathology. One patient underwent surgery for local recurrence 54 months after primary surgery; the remaining 14 patients are well with no clinical or radiologic evidence of recurrent disease.ConclusionsLaparoscopic adrenalectomy for large solid cortical tumors without pre- or intraoperative evidence of malignancy is not contraindicated, and it is unlikely to have a deleterious effect on long-term outcome. Each case should be considered individually. We provide an algorithm for the approach to adrenocortical tumors ≥ 6 cm.


Langenbeck's Archives of Surgery | 2006

A single-institution 25-year review of true parathyroid cysts

Giuseppe Ippolito; Fausto Palazzo; Frederic Sebag; Mauricio Sierra; Catherine De Micco; Jean-François Henry

BackgroundParathyroid cysts (PCs) are rare, and their origin is a subject of debate. They have been described as either functional, causing hyperparathyroidism, or non-functional in eucalcaemic patients.Patients and methodsWe have performed a 25-year departmental review of PCs. Features studied included the clinical presentation and intra-operative findings, and a histological review was performed. Cases of cystic degeneration of parathyroid adenomas and pseudocystic change were excluded.ResultsOver 25 years, 22,009 thyroidectomies and 2,505 parathyroidectomies were performed in our department. Amongst these, 38 non-functional PCs were documented in 37 patients. The mode of presentation included incidental findings on routine chest x-ray, compressive symptoms or an asymptomatic palpable neck mass. Aspiration was the initial treatment in 14 patients and was curative in 10 of these. Four out of 14 patients underwent surgical procedures for recurrence of the cyst that occurred 6 to 48 months after aspiration. In 27 patients, surgery was performed and all identified PCs were localized in the inferior parathyroid glands. Histologically, the cyst wall consisted in associations of lymphoid, muscular, thymic, salivary, adipose and mesenchymal tissues.ConclusionsPCs are rare but should be included within the differential diagnosis of a neck lump. True PCs are non-functional. Pathological and immunohistochemical findings are suggestive of a branchial origin. Fine-needle aspiration may be curative and is diagnostic due to the characteristic appearance of the fluid and high PTH levels on assay.


World Journal of Surgery | 2004

Risk Factors for Recurrent Nodular Goiter after Thyroidectomy for Benign Disease: Case-control Study of 244 Patients

Hélène Gibelin; Mauricio Sierra; Denis Mothes; Pierre Ingrand; Pierre Levillain; Corinne Jones; Sammy Hadjadj; Florence Torremocha; Richard Marechaud; J. Barbier; Jean-Louis Kraimps

Surgery for recurrent nodular goiter is associated with a significant risk of parathyroid and recurrent laryngeal nerve (RLN) morbidity. Total thyroidectomy for benign disease is assessed. The aim of this study was to evaluate the risk factors for recurrence and the morbidity associated with reoperation. From 1969 to 1996 a total of 4334 thyroidectomies were performed, of which 122 were for recurrent nodular goiter (group I: 116 women, 6 men). A matched case-control study of 122 patients operated on for nonrecurrent multinodular goiter was performed (group II: 112 women, 10 men). Age, family history, initial surgery, pathology, and morbidity were compared in the two groups by ċ2 test, Fisher’s exact test, and the Mantel-Haenszel test. The mean age was 39.88 years in group I and 47.89 years in group II. There was no statistical difference in relation to the extent of thyroidectomy or morbidity after initial surgery. Statistical differences were identified regarding age (p = 0.000002) and the multinodular nature of the initial goiter (p = 0.005). Bilaterality and family history were less significant (p = 0.09 and p = 0.08, respectively). Temporary RLN palsy and temporary hypoparathyroidism were higher in group I (12.3% vs. 5.7%, p = 0.0737; 10.6% vs. 1.7%, p = 0.00337). Permanent RLN palsy was found in 0.8% in group I and in none in group II (p = 0.5, NS). Young age and multiple nodules at initial surgery are risk factors for recurrence. A higher rate of temporary morbidity was demonstrated after surgery for recurrent goiter. Total thyroidectomy for multinodular goiter is advisable.


World Journal of Surgery | 2006

Endoscopic Lateral Approach Thyroid Lobectomy: Safe Evolution from Endoscopic Parathyroidectomy

F. Sebag; Fausto Palazzo; J. Harding; Mauricio Sierra; Giuseppe Ippolito; J.F. Henry

IntroductionEndoscopic thyroid surgery has been shown to be feasible. Most minimal access procedures have been performed via a midline approach. Based on our experience of more than 500 endoscopic parathyroidectomies via a lateral approach we have used the same method for thyroid lobectomy.MethodsWe present our experience of endoscopic thyroid lobectomy via a lateral approach (ETLA) and review of the results over a 1-year period (2004). Inclusion criteria for ETLA were (1) solitary nodule with atypical/suspicious fine–needle biopsy (FNB) or solitary toxic nodule; (2) lesions with a diameter of <3 cm. Patients with a history of previous neck surgery or radiation exposure were excluded. All patients underwent postoperative vocal cord checks and plasma calcium evaluation.ResultsA total of 742 thyroid procedures were performed during 2004. Among them, 38 patients (5.1%) underwent ETLA. Indications for surgery were suspicious FNB results (36 patients) and a toxic nodule (2 patients). Mean nodule size was 19.2 mm. Mean ± SD operating time was 102 ± 27 minutes. All recurrent laryngeal nerves were identified (including one that was nonrecurrent). Of the 38 patients, the superior parathyroid gland was identified in 36 and the inferior parathyroid gland in 33. There were two conversions due to difficulty with the dissection. Two operations were converted because malignancy was diagnosed on frozen section examination. Two patients underwent a delayed completion thyroidectomy when definitive histology necessitated it. There were no permanent operative complications, and all patients were discharged on the first postoperative day.ConclusionsETLA offers excellent intraoperative visualization of the vital structures and is a safe alternative to conventional thyroid lobectomy in selected cases.


Diabetes & Metabolism | 2008

Aggressive multimodal therapy of sporadic malignant insulinoma can improve survival: a retrospective 35-year study of 12 patients.

René Valéro; V. Moutardier; J. F. Henry; Y.P. Le Treut; M. Gueydan; C. De Micco; Mauricio Sierra; Bernard Conte-Devolx; C. Oliver; D. Raccah; R. Favre; L. Digue; M Heim; Jean Francois Seitz; J.-R. Delpero; Bernard Vialettes

AIM Sporadic malignant insulinoma (SMI) is a rare disease, and the consequent paucity of data in the literature and the development of aggressive treatments for liver metastases have led us to retrospectively analyze a series of 12 cases of SMI. METHODS Every patient presenting with SMI, according to the WHO 2004 histopathology criteria, between 1970 and June 2005 in Marseille was included in the study. Patients with multiple endocrine neoplasia type 1 (MEN-1) and tumours of uncertain malignant potential were excluded. RESULTS The ratio of male/female was 4/8, and mean age at diagnosis was 52.5 years. A 48-h fasting test in 10 patients was conclusive in nine, after a mean duration of 12 h 45 min. SMI size ranged from 7-120 mm (mean 30.3mm). Six patients had liver metastases and one had isolated lymph-node invasion. Surgery was performed in 12 patients. Five persisting diseases (mean follow-up of 1.8 years) required other treatments (chemoembolization, radiofrequency thermoablation [RFTA], liver transplantation); one patient relapsed 8.5 years after surgery; six were still in complete remission (mean follow-up of 5.8 years), and one patient had died by the time of the 24-month follow-up. CONCLUSION Aggressive sequential multimodal therapy can prolong the survival of patients with SMI even in the presence of liver metastases.


Surgery | 2017

Comparative analysis between a bipolar vessel sealing and cutting device and the tie and suture technique in thyroidectomy: A randomized clinical trial

K. Verónica Chavez; E. Manuel Barajas; Jaqueline Ramírez; Juan Pablo Pantoja; Mauricio Sierra; David Velázquez-Fernández; Miguel F. Herrera

BACKGROUND Advanced bipolar and ultrasonic devices have shown significant reduction in the surgical time of thyroid operations. This randomized, controlled trial assessed if operative time and other relevant outcomes are different for thyroidectomies performed either with a second‐generation advanced bipolar device or traditional tie and suture technique. METHODS Forty‐one patients were randomized into 2 groups (advanced bipolar device and traditional tie and suture). Secondary end points included estimated blood loss, postoperative hemorrhage or hematoma requiring operative reintervention, recurrent laryngeal nerve injury, hypoparathyroidism, pain intensity, number of ligatures, analgesia usage, and loss of signal during recurrent laryngeal nerve monitoring. RESULTS Preoperative characteristics were similar between both groups. Mean operative time in the advanced bipolar device group was reduced by 32.5 minutes compared with the traditional tie and suture group (P = .006). Intraoperative blood loss was similar in both groups. Four patients presented postoperative vocal cord dysmotility, 3 in the traditional tie and suture group and 1 in the advanced bipolar device group (P = ns). Two of these 4 patients also had a >50% amplitude decrease during continuous intraoperative neuromonitoring, 1 in each group. Pain intensity, 12 hours after operation, was significantly greater in the traditional tie and suture group (P = .015), even though pain medication requirements during the initial 24 hours after operation were similar between groups (P = .97). There were no cases of postoperative hemorrhage or hematoma requiring reintervention. Postoperative, symptomatic hypocalcemia occurred in 6 patients, 4 in the traditional tie and suture, and 2 in the advanced bipolar device group. One of them developed permanent hypocalcemia. CONCLUSION The use of an advanced bipolar device in thyroid operation reduces operative time by >30 minutes, with a similar postoperative outcome profile when compared with the traditional tie and suture technique.


Annals of Plastic Surgery | 2017

Absence of an Additional Metabolic Effect of Body Contour Surgery in Patients With Massive Weight Loss After Laparoscopic Roux-En-Y Gastric Bypass

Luis A. Martin-del-Campo; Miguel F. Herrera; Juan Pablo Pantoja; Mauricio Sierra; Martin Iglesias; Patricia Butrón; Julio Herrera-Zamora; Gonzalo Torres-Villalobos

Introduction Body contour surgery (BCS) is a combination of soft tissue resections that have proven to be an effective treatment for the aesthetic and functional problems related to massive weight loss (MWL). There are no studies analyzing the metabolic effect of large volume adipose tissue flap resection in patients with MWL after bariatric surgery. Methods This study was a retrospective review of adults who underwent BCS after gastric bypass. Preoperative clinical and laboratory data were compared with 1- and 2-year postoperative follow-up. Results A total of 62 patients with a mean age of 41 years were analyzed. Seventy-nine percent of them were women. Most procedures included abdominal flap resection alone or in combination with other areas. Mean resected tissue weight was 6.2 kg. We found that weight and body mass index (BMI) were lower 1 year after BCS (P < 0.05), but this was not maintained after 2 years. There were no differences for systolic or diastolic blood pressure, total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, or fasting glucose after 1 and 2 years of the BCS. A subgroup analysis showed that the transient weight and BMI improvement was only apparent 1 year after BCS in those patients with flap resections more than 8 kg. Conclusions There are no differences in blood pressure, total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, or fasting glucose 1 and 2 years after BCS in patients who experienced MWL after gastric bypass. Although weight and BMI were transiently lower in those patients with tissue flap resections more than 8 kg, this effect disappeared after 2 years.

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Frederic Sebag

University of California

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F. Sebag

Aix-Marseille University

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J. F. Henry

Mediterranean University

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Arturo Olvera Rodríguez

Mexican Social Security Institute

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Francisco J. Gómez-Pérez

National Autonomous University of Mexico

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Alvaro Aguayo

University of Texas MD Anderson Cancer Center

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