Changes in renal blood flow after surgically induced weight loss: can bariatric surgery halt the progression of chronic kidney disease?

BACKGROUND: We previously demonstrated how kidney injury in patients with morbid obesity can be reversed by bariatric surgery (BaS). OBJECTIVE(S): Based on previous experience, we hypothesize patients' potentially reversible kidney injury might be secondary to reduction in renal blood flow (RBF), which improves following BaS. SETTING: Academic Hospital. METHODS: We conducted a retrospective analysis of patients who underwent BaS at our institution from 2002 to 2019. We identified patients with chronic kidney disease (CKD) using the estimated glomerular filtration rate (eGFR) from the CKD Epidemiology Collaboration Study (CKD-EPI) classification system. We used the BUN/Creatinine (Cr) ratio pre- and postoperatively to determine a prerenal (decreased RBF) versus intrinsic component as the responsible cause of CKD in this patient population. Decreased RBF was defined as BUN/Cr > 20 preoperatively. RESULTS: Our analysis included n = 2924 patients, of which 11% (n = 325) presented decreased RBF. From our original sample, only n = 228 patients had the complete data necessary to assess both eGFR and RBF (BUN/Cr). Patients with baseline CKD stage 2 demonstrated preoperative BUN/Cr 20.85 ± 10.23 decreasing to 14.99 ± 9.10 at 12-month follow-up (P < .01). Patients with baseline CKD stage 3 presented with preoperative BUN/Cr 23.88 ± 8.75; after 12-month follow-up, BUN/Cr ratio decreased to 16.38 ± 9.27 (P < .01). Patients with CKD stage 4 and ESRD (eGFR < 30) did not demonstrate a difference for pre- and postoperative BUN/Cr 21.71 ± 9.28 and 19.21 ± 14.58, respectively. CONCLUSION(S): According to our findings, patients with CKD stages 1-3 present improvement of their kidney function after BaS. This amelioration could be secondary to improvement of the RBF, an unstudied reversible mechanism of kidney injury in the bariatric population.

Sleeve gastrectomy in patients with severe obesity and baseline chronic kidney disease improves kidney function independently of weight loss: a propensity score matched analysis.

BACKGROUND: In the last 10 years, severe obesity and the associated metabolic syndrome have reached pandemic proportions and consequently have significantly increased the prevalence of related co-morbidities such as chronic kidney disease (CKD). One in 7 people in the United States have CKD, and 90% of those are not aware of it. OBJECTIVES: Following sleeve gastrectomy (SG) in patients with severe obesity and baseline CKD stage ≥2, to determine improvement of glomerular function and analyze the relationship between kidney function and weight loss. SETTING: US Hospital, Academic Institution. METHODS: We retrospectively reviewed the charts of all patients who underwent SG at our institution from 2010 to 2019. Kidney function assessment using the Chronic Kidney Disease Epidemiology Collaboration Study (CKD-EPI) equation and classification was carried out preoperatively and postoperatively at 12-months follow-up. Propensity score matching (1:1 ratio) was used to balance the distribution of covariates between patients with a baseline estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m2 and patients with normal kidney function. RESULTS: We calculated the eGFR of 1330 bariatric patients who underwent SG. Of these patients, 18.79% (n = 250) met the criteria for CKD-EPI eGFR calculation preoperatively and at 12-months follow-up after SG. From the 250 patients included in the analysis, 42% (n = 105) were classified as CKD stage ≥2. When comparing the baseline preoperative eGFR at 12-months follow-up after SG, we observed an improvement of 8.26 ± 11.89 mL/min/1.73 m2 in CKD stage ≥2 (eGFR <90 mL/min/1.73 m2) as compared with 1.98 ± 10.25 mL/min/1.73 m2 in patients with eGFR >90 mL/min/1.73 m2 (P < .001). CONCLUSION: There is short-term improvement of the eGFR in patients with severe obesity following SG. This improvement is significant in CKD stages ≥2 and seems unrelated to weight loss.

Prevalence of chronic kidney disease and end-stage renal disease in a bariatric versus nonbariatric population: a retrospective analysis of the U.S. National Inpatient Sample database.

BACKGROUND: In the past five 5 years our team has studied the effects of bariatric surgery on chronic kidney disease (CKD) at our institution. OBJECTIVES: The objective of this study was to assess the impact of bariatric surgery (BaS) on the prevalence and likelihood of CKD and end-stage renal disease (ESRD) nationwide. SETTING: Academic hospital, United States. METHODS: We conducted a retrospective analysis of the U.S. National Inpatient Sample (NIS) database for the years 2010-2015 and compared. Univariate and multivariable analysis were performed to assess the impact of BaS on the point prevalence and the probability of CKD and ESRD. Similarly, a multivariable logistic regression was conducted to measure the impact of the most important risk factors for CKD exclusively in a severely obese population. RESULTS: Data on 296,041 BaS cases and 2,004,804 severely obese controls was extracted from the NIS database and relative to controls, all baseline CKD risk factors were less common among bariatric surgery cases. Nonetheless, even after adjusting for all CKD risk factors, controls exhibited marked increases in the odds of CKD-stage III (odds ratio [OR] 3.10 [3.05-3.14], P < .0001) and modes increase for ESRD (OR 1.13 [1.09-1.18], P < .0001). Overall, even after adjusting for risk factors we observed that the rate of CKD is significantly higher in the control group, 12% when compared with 5.3% in the bariatric surgery group (P < .0001). CONCLUSION: In this retrospective, case control study of a large, representative national sample of patients with severe obesity, BaS was found to be associated with significantly reduced point-prevalence and likelihood for CKD when adjusted for baseline CKD risk factors as compared with patients with obesity who did not undergo BaS. Overall, BaS resulted in a reduced rate and a moderate decrease in the likelihood of ESRD.

Does Transverse Abdominis Plane Block Increase the Risk of Postoperative Urinary Retention after Inguinal Hernia Repair?

BACKGROUND AND OBJECTIVE: Postoperative urinary retention (POUR) is a common adverse event after inguinal hernia repair (IHR), with an incidence of up to 22.2%. The aim of this study is to determine if pre-operative transverse abdominis plane (TAP) block increases the incidence of POUR. METHODS: A retrospective review was performed for all patients who underwent IHR (open or laparoscopic) at this institution, from January 1, 2016 to December 31, 2017. Patients were divided into two groups: Patients that had a TAP block before surgery (group 1) and patients with no TAP block (group 2). Common demographics and comorbidities were collected along with postoperative outcomes and POUR incidence rates for every group to determine procedural influence. RESULTS: From 276 patients reviewed, 28.2% (N = 78) underwent TAP block before surgery. The patient cohort mean age was 61.1 ± 14.4 years. Most the interventions were laparoscopic (81.2%) and an overall POUR incidence rate of 7.6% (N = 21) was observed. Comparatively, common demographics and comorbidities were statistically similar for both groups, with the exception of type 2 diabetes mellitus (p = 0.049). Individually, group 1 and 2 presented POUR incidence rates of 14.1% and 5.05%, respectively. While intraoperative fluid administration, early readmission rate, and length were similar in both groups, there was a significant difference in POUR incidence rates (p = 0.01). CONCLUSION: Patients undergoing TAP block during IHR might have an increased risk of developing POUR. Further larger, prospective, and randomized controlled studies are necessary to better assess these findings.

Short-term multiorgan metabolic benefits of rapid weight loss after sleeve gastrectomy in severely obese patients.

BACKGROUND: Sleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective. OBJECTIVE: Comprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG. SETTING: Academic hospital, United States. METHODS: We retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up. RESULTS: A total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein. CONCLUSION: There are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy.

Google Trends as a resource for bariatric education: what do patients want to know?

BACKGROUND: Bariatric surgery (BaS) is the safest, most effective, and most durable therapy for obesity but is performed in less than 1% of the affected United States (US) population. It is challenging to determine from traditional surveys if this phenomenon is the result of poor access to care or lack of interest among Internet users. OBJECTIVES: The aim of this study was to use Google Trends (GT) as a tool to analyze the US general population interest in BaS. SETTING: Academic Hospital, United States. METHODS: GT was used to access data searched for the term bariatric surgery. The gathered information included data from 2008 through 2018 in English within the US. Search frequency, time intervals, locations, frequent topics of interest, and related searches were analyzed. GT reports search frequency on means, and a value of 100 represented peak popularity. RESULTS: The number of Google searches related to the term bariatric surgery has gradually increased over time, from a mean of 67% in 2008 to a 94% interest in 2017. Regarding interest by subregion in 2017, the state of Michigan lead the frequency of searches, followed by Indiana, Delaware, West Virginia, and Tennessee. Top searched terms by frequency were the following: patient eligibility for BaS, what is BaS, what are the complications of BaS, financial costs of BaS, and what insurance companies cover BaS. It appears that traditional Web sites only address a few. CONCLUSIONS: GT complements the understanding of interest in BaS. Using these trends can improve an Internet user's education, and tailor specific official Web sites for the public's general interest.

Metabolic Surgery Reduces the Risk of Progression From Chronic Kidney Disease to Kidney Failure.

INTRODUCTION: According to the Chronic Kidney Disease Prognosis Consortium (CKD-PC), 1 in 4 patients age ≥ 65 in North America has some form of chronic kidney disease (CKD), while 3 in 100 will progress to kidney failure. The aim of this study was to evaluate whether bariatric surgery alters the progression of CKD to kidney failure in patients who are severely obese. METHODS: We conducted a retrospective review of all patients who underwent bariatric surgery at our institution over the last 16 years. Kidney function and injury were assessed using the average estimated glomerular filtration rate and urinary albumin-to-creatinine ratio (uACR) over 3 months preoperatively and postoperative at 12-month follow-up. The risk of progression from CKD to kidney failure was assessed using the Chronic Kidney Disease Prognosis Consortium (CKD-PC) equation. RESULTS: Out of 2924 patients reviewed over this period of time, 69 (2.4%) had the recorded data necessary to assess kidney injury and the risk of disease progression to kidney failure. Patients within moderate and severe stages of CKD-related albuminuria improved the most at 12-month follow-up (by 48% and 79%; P = 0.0001 and P = 0.025, respectively). This translated to a relative risk reduction for progression to kidney failure in CKD ≥ stage 3 patients of 70% at 2 years and 60% at 5 years (both P = 0.001). CONCLUSIONS: Bariatric surgery seems to improve kidney injury, especially among patients with the most severe stages of CKD. Marked 2- and 5-year risk reduction in the progression from CKD to kidney failure was observed.

Laparoscopic sleeve gastrectomy versus Roux-en-Y gastric bypass in cardiovascular risk reduction: A match control study.

BACKGROUND: There is a paucity of studies comparing risk reduction of the atherosclerotic cardiovascular disease (ASCVD) and Framingham-body mass index (BMI) Coronary Heart risk score after a laparoscopic Roux-en-Y gastric bypass (RYGB), and few studies have assessed the efficacy of laparoscopic sleeve gastrectomy (SG) in reducing cardiovascular risk. OBJECTIVE: Our goal in this study was to compare the impact of SG and RYGB on cardiovascular risk reduction. SETTING: U.S. university hospital. METHODS: We retrospectively reviewed the records of all SG or RYGB cases at our institution between 2010 and 2015. Patients who met the criteria for calculating the ASCVD 10-year and Framingham-BMI score were included in the study. Propensity score matching was used to match SG and RYGB on demographic characteristics and co-morbidities. RESULTS: Of the 1330 bariatric patients reviewed in the study period, 219 (19.3%) patients met the criteria for risk score calculation. SG was the most prevalent surgery in 72.6% (N = 159) of cases compared with RYGB in 27.4% (N = 60) of cases. At 12-month follow-up, ASCVD 10-year score had an absolute risk reduction of 3.9 ± 6.5% in SG patients and 2.9 ± 5.8% in RYGB patients (P = .3). Framingham-BMI score absolute risk reduction was 11.0 ± 12.0% in SG and 9.0 ± 11.0% in RYGB patients (P = .4), and the decrease in estimated heart age was 12.1 ± 15.6 years in SG versus 9.2 ± 9.6 years in RYGB (P = .1). The percentage of estimated BMI loss at 1 year was 68.1 ± 23.3% in SG versus 74.2 ± 24.8% in RYGB (P = .1). CONCLUSION: Our results suggest that SG and RYGB are equally effective in improving cardiovascular risk and decreasing the estimated vascular/heart age at 12-month follow-up.

High cardiovascular risk patients benefit more from bariatric surgery than low cardiovascular risk patients.

INTRODUCTION: Atherosclerotic cardiovascular disease (ASCVD) and Framingham risk scores (FRS) are used to calculate 10-year risk of coronary death, nonfatal myocardial infarction, or fatal/nonfatal stroke. Our goal is to evaluate the association between preoperative cardiovascular risk and weight loss. METHODS: We retrospectively reviewed bariatric surgeries from 2010 to 2016. Patients who met criteria for calculating 10-year ASCVD score and FRS were included. Data collected included baseline demographics, perioperative parameters, and postoperative outcomes at 12 months. Simple linear regression and multiple linear regression models were applied to test influence of individual or multiple factors of interest on 12-month weight loss outcomes. RESULTS: Of 1330 bariatric patients studied, 360 patients met criteria for ASCVD and FRS calculation. Sleeve gastrectomy (LSG) was the most prevalent surgery 63.05%, followed by Roux-en-Y gastric bypass (LRYGB) 20.55%, revision procedures 11.9%, and adjustable gastric banding (LAGB) 4.4%. Initial BMI was 42.71 ± 7.85 kg/m2 for females and 42.72k ± 7.42 kg/m2 for males, with a 12-month percentage of estimated BMI loss (%EBMIL) of 66.51% in females and 60.29% in males. Preoperative 10-year ASCVD score was higher in males than females with a 34.73% relative risk reduction (RRR) in males and 35.3% RRR in females at 12-month follow-up. Regarding FRS, preoperative risk was 33.13 ± 21.1% in males and 15.71 ± 14.52% in females, with an RRR of 25.8% in males and 32.2% in females. Univariate analysis of preoperative FRS and %EBMIL showed that for every percentage unit increase in the patient's preoperative FRS, %EBMIL decreases 0.31 percentile unit (P < 0.001). Furthermore, preoperative ASCVD score is also significantly associated with %EMBIL-for every percentage unit increase in preoperative ASCVD score, %EBMIL decreases 0.42 percentile credits. CONCLUSION: Study results suggest ASCVD and FRS are equally reduced after bariatric surgery, especially after LSG and LRYGB. Moreover, preoperative FRS and ASCVD risk score showed an inversely proportional relationship with %EBMIL loss at 12 months.

Assessing risk factors, presentation, and management of portomesenteric vein thrombosis after sleeve gastrectomy: a multicenter case-control study.

BACKGROUND: Portomesenteric vein thrombosis (PMVT) is a rare complication of laparoscopic sleeve gastrectomy. OBJECTIVES: To identify incidence, patient factors, diagnosis, and treatment of PMVT after laparoscopic sleeve gastrectomy in a large administrative data registry. SETTING: Academic Hospitals and Private Practices, United States. METHODS: A retrospective chart review of 5538 sleeve gastrectomy patients between January 1, 2008 and September 30, 2016 was performed at 5 bariatric centers in the United States. A total of 11 patients were identified as developing PMVT, and 3 controls for each patient were selected by matching age, sex, preoperative body mass index, and center. RESULTS: After adjusting for confounding variables, 2 patient factors significantly impacted the risk of PMVT after sleeve gastrectomy including personal history of malignancy (odds ratio 62, 95% confidence interval (CI) 1.4-99.9), and type 2 diabetes (odds ratio 12.7, 95% CI 1.2-137.3) compared with controls. Mean period from laparoscopic sleeve gastrectomy to presentation of PMVT was 19.3 ± 15.11 days (range, 8-62). All patients except 1 complained of abdominal pain as the main presenting symptom. Other complaints included nausea and vomiting, no bowel movement, decreased appetite, diarrhea, and dehydration, and leukocytosis was present in 45.5% of the patients. All diagnoses were made by using computed tomography. All initial treatments were anticoagulation, heparin drip being the most common method (90.9%). Of patients, 9 (81.8%) required a secondary anticoagulation therapy, and 1 (9.1%) patient required a reoperation. CONCLUSION: Incidence of PMVT is low after sleeve gastrectomy. A personal history of malignancy and type 2 diabetes increase the risk of PMVT. Increasing abdominal pain in a context of dehydration is common presenting symptoms with diagnosis confirmed by computed tomography. Anticoagulation is the standard treatment. There was no mortality associated with the occurrence of PMVT in this cohort.