Estimation of Glomerular Filtration Rate in Obese Patients: Utility of a New Equation.

There is no consensus on the best equation to estimate glomerular filtration rate (eGFR) in obese patients (OP). Objective: to evaluate the performance of the current equations and the new Argentinian Equation ("AE") to estimate GFR in OP. Two validation samples were used: internal (IVS, using 10-fold cross-validation) and temporary (TVS). OP whose GFR was measured (mGFR) with clearance of iothalamate between 2007/2017 (IVS, n = 189) and 2018/2019 (TVS, n = 26) were included. To evaluate the performance of the equations we used: bias (difference between eGFR and mGFR), P30 (percentage of estimates within ±30% of mGFR), Pearson's correlation (r) and percentage of correct classification (%CC) according to the stages of CKD. The median age was 50 years. Sixty percent had grade I obesity (G1-Ob), 25.1% G2-Ob and 14.9% G3-Ob, with a wide range in mGFR (5.6-173.1 mL/min/1.73 m2). In the IVS, AE obtained a higher P30 (85.2%), r (0.86) and %CC (74.4%), with lower bias (-0.4 mL/min/1.73 m2). In the TVS, AE obtained a higher P30 (88.5%), r (0.89) and %CC (84.6%). The performance of all equations was reduced in G3-Ob, but AE was the only one that obtained a P30 > 80% in all degrees. AE obtained better overall performance to estimate GFR in OP and could be useful in this population. Conclusions from this study may not be generalizable to all populations of obese patients since they were derived from a study in a single center with a very specific ethnic mixed population.

Sleeve Gastrectomy after Renal Transplantation.

BACKGROUND: Obesity induces or accelerates diabetes (DBT), hypertension (HT), and dyslipidemia (DSL), which are the main causes of renal failure. Obesity exacerbates in patients after renal transplantation (RT), and it has been associated with increased mortality rate, postoperative complications, and graft loss. We hypothesize that bariatric surgery might have a positive effect on obese patients with history of previous RT. METHODS: This was a retrospective review from prospectively collected data. Patients with sleeve gastrectomy (SG) with history of RT were studied. Demographics, anthropometric data, effect on comorbidities, postoperative course, immunosuppressive treatment, reason for transplantation, kidney function, graft survival, and quality of life associated with SG in obese patients with previous RT were assessed using a survey. RESULTS: From January 1, 2012 to January 1, 2016, five kidney transplant patients were operated on; 80% were female, with an average preoperative BMI of 42.18 ± 8.5 kg/m2 (range 37-54). Related comorbidities: 100% of the patients had HT and DSL, whereas 40% had DBT and gout. The average time gap between RT and SG was 15 ± 8.4 years (range 3-22). Average operative time was 65 ± 12 min (range 60-85), and there were neither complications nor mortality. At 16.8 ± 14.5 months (range 5-46) of follow-up, BMI was 29.8 ± 7.3 kg/m2 (range 26-44). All patients with HT and DSL were able to decrease their medication, showing improvement in blood pressure levels and laboratory test values. Regarding DBT, insulin was discontinued in one case, limiting the treatment to the use of oral hypoglycemic agents only. In another case, insulin dosage was significantly reduced. Graft function and proteinuria level improved in 80% of patients. All patients experienced a significant improvement in their quality of life. CONCLUSION: In this specific group of high-risk patients, SG showed encouraging results in terms of weight loss and resolution/improvement of comorbidities, renal function, and quality of life.

Incidental Finding of Gastrointestinal Stromal Tumors during Laparoscopic Sleeve Gastrectomy in Obese Patients.

INTRODUCTION: The frequency of incidental pathology found during laparoscopic bariatric surgery has been estimated to be 2%. Gastrointestinal stromal tumors (GISTs) are infrequent lesions and account for less than 1% of all digestive tract tumors. The reported incidence of this type of tumors during bariatric surgery is around 0.8%. The objective of this study was to evaluate incidence, characteristics, and evolution of incidentally found GISTs in patients undergoing laparoscopic sleeve gastrectomy (LSG) for the treatment of obesity. MATERIAL AND METHODS: A retrospective analysis from a prospectively collected database was conducted. Demographic data, clinical data, laboratory tests, preoperative esophagogastroduodenoscopy (EGD), postoperative pathology report from surgical specimen with tumor markers, and patient's outcomes were evaluated. RESULTS: From June 2006 to January 2014, 915 patients underwent LSG at our institution. Five (0.5%) patients were found to have incidental GIST. There were four (80%) women; average age was 59.6 ± 6.3 years (range 46-63). None of them had symptoms that served as orientation for preoperative diagnosis. EGD findings were non-suggestive of this pathology in any of these cases. Superficial chronic gastritis was the most common finding in the endoscopic biopsy (60%). All the tumors found in the surgical specimen were of low or very low risk of malignancy, with less than 5 mitoses per 50 fields, less than 2 cm in diameter, and disease-free surgical margins. Cluster of differentiation (CD) 117 and CD 34 were positive in 100% of the cases. None of the patients required adjuvant therapy after the surgery. At 5-year follow-up, all patients were asymptomatic and disease free. CONCLUSION: The incidence of unsuspected GIST in LSG specimens in our series was low and similar to what has been reported. The lack of symptoms and the preoperative EGD findings were not suggestive of this diagnosis in any case. The degree of tumor malignancy was low in all patients and LSG was the definitive treatment, without recurrence at 5-year follow-up.