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Biomedical subjects

Sergio Huerta

Publications and source records attributed to Sergio Huerta.

At least 19 recordsLinked to original sources
PubMed2006

Surgical bypass versus endoscopic stenting for malignant gastroduodenal obstruction: a decision analysis.

The treatment options for palliating malignant gastroduodenal obstruction include open gastrojejunostomy (OGJ), laparoscopic gastrojejunostomy (LGJ), and endoscopic stenting (ES). The aim of this study was to compare the clinical outcomes and costs among ES, OGJ, and LGJ in patients who present with gastroduodenal obstruction from advanced upper gastrointestinal tract cancer. We designed a model for patients with malignant gastroduodenal obstruction. We analyzed success rates, complication rates and costs of the three treatment modalities: ES, OGJ, and LGJ. Baseline outcomes and costs were based on published reports. Success was defined as no major procedure-related and long-term complications over a 1-month period. Failure of therapy was defined as recurrent symptoms or death due to a procedural complication. Sensitivity analyses and cost-effectiveness analyses for the various strategies were performed. ES resulted in the lowest mortality rate and the lowest cost of the three treatment options analyzed. Mortality in the OGJ group was 2.1 times that in the ES cohort and 1.8 times that in the LGJ cohort. Sensitivity analyses confirmed ES as the dominant strategy. In conclusion, ES is the preferred treatment for palliation of duodenal obstruction due to advanced upper gastrointestinal tract cancer.

Decision Support Techniques↗
PubMed2006

The role of endoscopic ultrasound in the evaluation of rectal cancer.

Accurate staging of rectal cancer is essential for selecting patients who can undergo sphincter-preserving surgery. It may also identify patients who could benefit from neoadjuvant therapy. Clinical staging is usually accomplished using a combination of physical examination, CT scanning, MRI and endoscopic ultrasound (EUS). Transrectal EUS is increasingly being used for locoregional staging of rectal cancer. The accuracy of EUS for the T staging of rectal carcinoma ranges from 80-95% compared with CT (65-75%) and MR imaging (75-85%). In comparison to CT, EUS can potentially upstage patients, making them eligible for neoadjuvant treatment. The accuracy to determine metastatic nodal involvement by EUS is approximately 70-75% compared with CT (55-65%) and MR imaging (60-70%). EUS guided FNA may be beneficial in patients who appear to have early T stage disease and suspicious peri-iliac lymphadenopathy to exclude metastatic disease.

Journal Article↗
PubMed2006

Colon cancer and apoptosis.

BACKGROUND: The implementation of new therapeutic options for the management of metastatic colon cancer mandates a revisit to apoptosis and its role in colon cancer tumorigenesis with an emphasis on the mechanisms leading to chemotherapeutic resistance and immune system evasion of colon cancer cells. DATA SOURCES: Literature regarding molecular apoptosis mechanisms and the role of apoptosis in colon cancer progression are reviewed by this article. CONCLUSION: Programmed cell death has rapidly emerged as a potential target for cancer treatment at various stages of tumor progression. Chemoprevention, immuno-regulation, and metastasis are prospective targets by which apoptotic mechanisms could be utilized in the prevention and management of tumorigenesis. Understanding how defects in the death receptor pathway of apoptosis permit colon cancer cells to escape the immune system would allow for treatment options whereby the body's immune system could again recognize and eliminate unwanted cells.

Antineoplastic Agents↗
PubMed2006

Negative pressure wound therapy with off-the-shelf components.

BACKGROUND: The KCI Wound VAC system (Kinetic Concepts, Inc, San Antonio, TX) for providing negative-pressure therapy for wounds is expensive and may not be available for patients without insurance. We have examined the feasibility of using off-the-shelf components to provide comparable negative pressure therapy at less cost. METHODS: Adhesive iodine-impregnated drape, a flat Jackson-Pratt drain (Cardinal Health, McGaw Park, IL), and foam prep sponges stapled together are used to assemble a dressing connected to wall suction (negative 75-100 mm Hg) to create negative pressure wound therapy that is relatively inexpensive (<60 US dollars component cost). RESULTS: We have used this system in more than 40 cases with results that seem comparable to the commercial system and have not seen bleeding or other complications. CONCLUSION: Off-the-shelf components can be safely employed to provide effective negative pressure therapy for wounds and skin grafts.

Equipment Design↗
PubMed2006

Transmetatarsal amputation: assessment of current selection criteria.

BACKGROUND: Transmetatarsal amputation (TMA) is an operation designed to remove a limited area of irremediable tissue ischemia and/or infection and preserve limb function. Patients are selected for TMA based on degree of tissue loss/infection, adequacy of tissue perfusion at the transmetatarsal level, current ambulatory status, and estimation of the likelihood of postprocedure ambulation. The purpose of this study was to assess the validity of these selection criteria. METHODS: An institutional review board-approved retrospective review was conducted of all patients undergoing TMA from January 1, 1997, until January 1, 2006. Information was collected on patient demographics, medical comorbidity, and clinical and surgical variables. Outcome measures included the proportion of patients requiring amputation revision to a more proximal level and ambulatory status at last follow-up. RESULTS: Fifty-two TMAs were performed. In 35 procedures, the skin was left open, and in 17 TMA was closed primarily. Primary indications for the procedure were vascular insufficiency or infection in 50 of 52 patients, whereas 2 patients required amputation for malignancy. The majority (46/52, 89%) of patients were diabetic. After the index TMA, 85 additional operations were required. Only 9 patients (18%) underwent a single operation. Revision of the TMA to a more proximal level was required in 29 of 52 (56%) patients, resulting in 4 Syme, 20 transtibial, and 5 transfemoral amputations. Non-insulin-dependent diabetes was associated with an increased likelihood of revision to a more proximal amputation (odds ratio [OR] = 5.4; 95% confidence interval [CI], 1.2-24). At the time of last follow-up (median 18 months), 37 of 50 (74%) patients were ambulatory (83% for TMAs and 67% for more proximal amputations, P = 0.18). Prior vascular procedures were associated with a significantly decreased likelihood of ambulation (OR = 14; 95% CI, 1.9-103). CONCLUSIONS: Although most patients retain the ability to ambulate after TMA, multiple operations should be anticipated in the majority of patients and revision of a TMA to a more proximal level may be required. These data suggest that current selection criteria for TMA may be inadequate.

Amputation, Surgical↗
PubMed2006

Predictors of recurrence in veteran patients with umbilical hernia: single center experience.

BACKGROUND: Different medical and social conditions have been associated with primary and recurrent hernias. Possible predictors of recurrence after elective umbilical hernia repair have not been defined clearly. The aim of this study was to determine factors that predict recurrence in patients after elective repair of umbilical hernias. METHODS: A 6-year retrospective review of patients with elective umbilical hernia repair at the Dallas VA Medical Center was performed. Clinical and pathologic data were evaluated by univariate analysis to identify predictive factors for recurrence. RESULTS: A total of 244 patients underwent elective hernia repair within the study period (male, 96%; mean age, 56 y; Caucasian, 74%; African American, 14%; Hispanic, 8%). Because 15 patients were not compliant with follow-up requirements, 229 were eligible for the study. Ninety-seven underwent suture repair (42.4%) and 132 underwent mesh repair (57.3%). Eleven recurrences were identified (4.8%): 7 in the suture repair group (7.7%) and 4 in the mesh repair group (3%). Univariate analysis showed that patients likely to develop recurrences were as follows: African American (15.6% vs. 3.5%; P = .017), type II diabetics (14.2% vs. 2.6%; P = .002), patients with hyperlipidemia (9.2% vs. 2.6%; P = .028), and human immunodeficiency virus-positive patients (66.6% vs. 3.9%; P = .000). CONCLUSIONS: Smoking, obesity, size of hernia, type of repair, or chronic obstructive pulmonary disease do not seem to predict recurrence of hernias in our VA population. African Americans, patients with type II diabetes, hyperlipidemia, and positive for human immunodeficiency virus, may have a higher risk for recurrence after elective umbilical hernia repair.

Adult↗
PubMed2006

A comparison of open and laparoscopic Roux-en-Y gastric bypass surgery for morbid and super obesity: a decision-analysis model.

BACKGROUND: The aim of this study was to compare laparoscopic Roux-en-Y gastric bypass (LGBP) with open Roux-en-Y gastric bypass (OGBP) to determine which approach resulted in better clinical outcomes and cost effectiveness in patients with morbid obesity. METHODS: A decision-analysis model was constructed to evaluate outcomes of LGBP versus OGBP in patients with body mass index (BMI) ranges of 35 to 49, 50 to 60, and greater than 60. Baseline assumptions for the model were derived from published reports. Sensitivity and cost-effectiveness analyses were performed to determine the optimal strategy. Success was defined as no major procedure-related complications and no long-term complications over a 1-year period after surgery. Failure of therapy was defined as either recurrent symptoms or death attributed to a surgical complication. RESULTS: In patients with a BMI of 35 to 49, LGBP failed in 14% and OGBP failed in 18% of patients, favoring LGBP alone as the dominant strategy. Mortality in the OGBP group was 1.3 times that of the LGBP group. For a BMI of 50 to 60, LGBP was dominant with an overall success rate of 82% as compared with OGBP (77%). Mortality in the OGBP group was 1.3 times that of the LGBP group. For a BMI of greater than 60, LGBP was the dominant strategy with an overall success rate of 67% compared with OGBP (63%). Sensitivity and cost-effective analysis showed that LGBP was the dominant strategy in terms of greater success and less overall morbidity and mortality for all 3 groups. CONCLUSIONS: This analysis suggests that for all BMI ranges evaluated, LGBP is preferable to OGBP. These conclusions are limited by potential selection and publication bias in the trials assessed for this analysis. These limitations can be resolved only by randomized control trials.

Body Mass Index↗
PubMed2006

Outcome of portal injuries following bariatric operations.

BACKGROUND: Portal vein thrombosis is rare following Roux-en-Y gastric bypass (RYGBP). Its natural history is dependent on the etiology of the thrombosis. Iatrogenic injuries at bariatric operations resulting in portal vein thrombosis are lethal complications typically necessitating a liver transplant, whereas postoperative portal vein thrombosis without an injury to the portal vein has a benign course. There are currently no data on management or prognostic factors of portal vein thrombosis after bariatric operations. METHODS: 3 patients referred for liver transplantation secondary to portal vein injury following bariatric surgery between 2000 and 2003 are presented. RESULTS: 2 super-obese (BMI>or=50 kg/m2) and 1 morbidly obese (BMI 44 kg/m2) patients sustained portal vein injuries during bariatric surgery (RYGBP 2, VBG 1) by experienced bariatric surgeons. In each case, the portal injury was identified and repaired. Thrombosis followed reconstruction in all 3 patients. All 3 underwent emergency liver transplantation, but died of sepsis and multi-organ failure following transplantation. Review of the literature found no cases of traumatic portal vein injuries following bariatric operations and 2 cases of postoperative portal vein thrombosis: 1 following LRYGBP (BMI 46) and one after a Lap-Band (BMI 41). CONCLUSION: Injury to the portal vein resulting from difficulty in discerning the anatomy of the intra-abdominal structures in the morbidly obese, is a lethal complication of bariatric surgery. Super-obese patients submitting to bariatric surgery should lose weight, undergo a two-stage bariatric procedure, or undergo laparoscopic RYGBP to minimize the risk of portal injury. Postoperative portal vein thrombosis has a benign course and can be managed conservatively.

Adult↗
PubMed2006

Predictors of mortality and management of patients with traumatic inferior vena cava injuries.

The aim of this study was to determine factors that predict mortality in patients with traumatic inferior vena cava (IVC) injuries and to review the current management of this lethal injury. A 7-year retrospective review of all trauma patients with IVC injuries was performed. Factors associated with mortality were assessed by univariate analysis. Significant variables were included in a multivariate regression analysis model to determine independent predictors of mortality. Statistical significance was determined at P < or = 0.05. A literature review of traumatic IVC injuries was performed and compared with our institutional experience. Thirty-six IVC injuries were identified (mortality, 56%; mechanisms of injury, 28% blunt and 72% penetrating). There was no difference in mortality based on mechanism of injury. Injuries with closer proximity to the heart were associated with increased mortality (P < 0.001). Univariate analysis demonstrated that nonsurvivors had a higher injury severity scale, a lower systolic blood pressure in the emergency department, a lower Glasgow coma score (GCS), and were more likely to have thoracotomies performed in the emergency department or operating room. Multivariate analysis revealed that only GCS (P = 0.03) was an independent predictor of mortality. Typical factors predicting mortality were identified in our cohort of patients, including GCS. The mechanism of injury is not associated with survival outcome, although mortality is higher with injuries more proximal to the heart. The form of management by IVC level is reviewed in our patient population and compared with the literature.

Adult↗
PubMed2005

Inhibition of prostate cancer cell growth by an avocado extract: role of lipid-soluble bioactive substances.

Although the avocado is known as a rich source of monounsaturated fatty acids, there has been far less attention given to its content of other bioactive substances including carotenoids, which might contribute to cancer preventive properties similar to those attributed to other fruits and vegetables. The yellow-green color of the avocado prompted us to study the carotenoid content of this fruit using established methods in our laboratory. The California Hass avocado (Persea americana Mill.) was selected for study, because it is the most commonly consumed variety in the southwest United States. These avocados were found to contain the highest content of lutein among commonly eaten fruits as well as measurable amounts of related carotenoids (zeaxanthin, alpha-carotene, and beta-carotene). Lutein accounted for 70% of the measured carotenoids, and the avocado also contained significant quantities of vitamin E. An acetone extract of avocado containing these carotenoids and tocopherols was shown to inhibit the growth of both androgen-dependent (LNCaP) and androgen-independent (PC-3) prostate cancer cell lines in vitro. Incubation of PC-3 cells with the avocado extract led to G(2)/M cell cycle arrest accompanied by an increase in p27 protein expression. Lutein alone did not reproduce the effects of the avocado extract on cancer cell proliferation. In common with other colorful fruits and vegetables, the avocado contains numerous bioactive carotenoids. Because the avocado also contains a significant amount of monounsaturated fat, these bioactive carotenoids are likely to be absorbed into the bloodstream, where in combination with other diet-derived phytochemicals they may contribute to the significant cancer risk reduction associated with a diet of fruits and vegetables.

Blotting, Western↗
PubMed2005

Mesenteric fibromatosis in a young girl without familial adenomatous polyposis.

Mesenteric fibromatosis (MF) is a rare, benign tumor commonly associated with Gardner's syndrome. The signs and symptoms in patients with MF are insidious. Patients may present with abdominal pain or discomfort when the tumors reach large sizes, which is typical at the time of diagnosis. Differentiating MF from other neoplasms such as gastrointestinal stromal tumors may present a diagnostic dilemma, especially in patients without any history of familial adenomatous polyposis. In the present report, we discuss a young girl who presented with MF. A pertinent review of the literature is also presented. This case is peculiar in that MF presented at a young age in a patient without history of familial adenomatous polyposis and occurred in the omentum with local invasion to the stomach.

Adenomatous Polyposis Coli↗
PubMed2005

Predictors of morbidity and mortality in patients with traumatic duodenal injuries.

The aim of our study is to determine factors that predict morbidity and mortality in patients with traumatic duodenal injury (DI). A retrospective review from July 1996 to March 2003 identified 52 patients admitted to our trauma center (age 24.4 +/- 2.1 years, ISS = 18.8 +/- 1.76). The mortality rate for patients with duodenal injury was 15.4 per cent (n = 8). The mechanisms of injury were blunt (62%), gun shot wound (GSW) (27%), and stab wound (SW) (11%). There was no difference in mortality based on mechanism of injury. Management was primarily nonoperative [n = 30 (57%)]. Of those with perforation (n = 22), 64 per cent underwent primary repair (n = 14), 23 per cent duodenal resection (n = 5), 9 per cent duodenal exclusion (n = 2), and one patient pancreaticoduodenectomy. The method of initial surgical management was not related to patient outcome. Univariate analysis demonstrated that nonsurvivors were older, more, hypotensive in the emergency department, had a more negative initial base deficit, had a lower initial arterial pH, and had a higher Injury Severity Score. Nonsurvivors were also more likely to have an associated inferior vena cava (IVC) injury. Multivariate regression analysis revealed age, initial lowest pH, and Glasgow Coma Score to be independent predictors of mortality, suggesting that the physiologic presentation of the patient is the most important factor in predicting mortality in patients with traumatic DIs.

Abdominal Injuries↗
PubMed2004

Pancreatic schwannoma. A case report and review of the literature.

CONTEXT: Pancreatic schwannomas are rare neoplasms. These tumors vary in size and two thirds are partially cystic which grossly mimic pancreatic cystic lesions. Computed tomography and magnetic resonance imaging are the primary initial imaging modalities. Definitive diagnosis is typically made at the time of laparotomy following biopsy. Surgical resection is the mainstay of treatment. CASE REPORT: A 69-year-old woman presented with abdominal pain in the epigastric and left upper quadrant. The patient had no systemic symptom and laboratory results including tumor markers were negative. A CT scan of the abdomen showed a 5 cm mass arising from the head of the pancreas. Needle biopsy revealed a mass consistent with schwannoma. At laparotomy, a large pancreatic head mass was found to encase the superior mesenteric artery, and portal vein confluence. Frozen biopsy showed schwannoma. Curative resection was deferred due to extensive vascular involvement and favorable tumor biology. A gastrojejunostomy was performed and radiation therapy was instituted post-operatively. CONCLUSIONS: Only 24 cases of pancreatic schwannoma had been previously reported. Definitive diagnosis is obtained with routine histology. Most tumors are benign and surgical resection is curative. The role of radiation therapy in the management of unresectable tumors is still unclear.

Abdominal Pain↗
PubMed2004

Bowel obstruction after laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Bowel obstruction has been frequently reported after laparoscopic Roux-en-Y gastric bypass (LRYGBP). The aim of this study was to review our experience with bowel obstruction following LRYGBP, specifically examining its etiology and management and to strategize maneuvers to minimize this complication. METHODS: We retrospectively reviewed the charts of 9 patients who developed postoperative bowel obstruction after LRYGBP. Each chart was reviewed for demographics, timing of bowel obstruction from the primary operation, etiology of obstruction, and management. RESULTS: 9 of our initial 225 patients (4%) who underwent LRYGBP developed postoperative bowel obstruction. The mean age was 46 +/- 12 years, with mean BMI 47 +/- 9 kg/m(2). 6 patients developed early bowel obstruction, and 3 patients developed late bowel obstruction. The mean time interval for development of early bowel obstruction was 16 +/-16 days. The causes for early bowel obstruction included narrowing of the jejunojenunostomy anastomosis (n=3), angulation of the Roux limb (n=2), and obstruction of the Roux limb at the level of the transverse mesocolon (n=1). The mean time interval for development of late bowel obstruction was 7.4 +/- 0.5 months. The causes for late bowel obstruction included internal herniation (n=2) and adhesions (n=1). 6 of 9 bowel obstructions (66%) were considered technically related to the learning curve of the laparoscopic approach. Eight of the 9 patients required operative intervention, and 6 of the 8 reoperations were managed laparoscopically. Management included laparoscopic bypass of the jejunojejunostomy obstruction site (n=5), open reduction of internal hernia (n=2), and laparoscopic lysis of adhesion (n=1). CONCLUSIONS: Bowel obstruction is a frequent complication after LRYGBP, particularly during the learn ing curve of the laparoscopic approach. Specific measures should be instituted to minimize bowel obstruction after LRYGBP as most of these complications are considered technically preventable.

Adult↗
PubMed2003

Intestinal polyp formation in the Apcmin mouse: effects of levels of dietary calcium and altered vitamin D homeostasis.

This study evaluated the effects of various levels of dietary calcium on polyp formation, vitamin D homeostasis, and fecal bile acids in the Apcmin mouse. Female Apcmin mice were randomized to three groups and fed a purified diet with either half or double the level of calcium in control AIN-93G. Serum 25-OH-D and fecal bile acids were measured at weeks 0 and 12 of treatment. Mice were killed for polyp scoring by two observers blinded to treatment after 12 weeks. Results show there was no difference in polyp number or tumor load with dietary calcium in any treatment group. Serum 25-OH-D was reduced and total fecal bile acids were increased in animals that received the high calcium diet. We have previously shown that vitamin D supplementation diminishes polyp load; the lack of effect of an altered calcium diet seen here may be due to a disturbance in vitamin D homeostasis.

Animals↗