Bridget Slusarek

Postgastric bypass hyperinsulinemic hypoglycemia syndrome: characterization and response to a modified diet

BACKGROUND Some alarming cases of hypoglycemic episodes in patients who have undergone Roux-en-Y gastric bypass have been reported. The syndrome of hyperinsulinemic hypoglycemia with nesidioblastosis after Roux-en-Y gastric bypass has been previously reported and is controversial. It has been suggested that subtotal or total pancreatectomy might be needed to control the symptoms in these patients. We have identified a similar cohort of patients with hyperinsulinemic hypoglycemia for whom we have reviewed patient characteristics and measured the glucose and insulin response to mixed meals. METHODS We reviewed the charts of 14 patients identified by clinic follow-up who reported episodes consistent with hyperinsulinemic hypoglycemia (lightheadedness or loss of consciousness after a high-carbohydrate meal). All patients were given a mixed meal consisting of high carbohydrates on day 1 and a low-carbohydrate meal on day 2. The plasma glucose and serum insulin levels were measured before (fasting) and 30, 60, 90, 120, 150, and 180 minutes after the meal. RESULTS After a high-carbohydrate meal, 12 of 14 patients demonstrated hyperglycemia associated with hyperinsulinemia at 30 minutes. These patients subsequently became hypoglycemic while the serum insulin was rapidly declining. After reaching a nadir at 120 minutes, the plasma glucose level corrected spontaneously. After a low-carbohydrate mixed meal, the patients demonstrated very little change in plasma glucose and only a modest increase in serum insulin. Of the 12 patients treated with a low-carbohydrate diet, 6 had substantive symptom improvement, and 10 exhibited at least some improvement. CONCLUSION The hyperinsulinemic hypoglycemia noted in some patients after Roux-en-Y gastric bypass has many similarities to the dumping syndrome. A low-carbohydrate diet successfully improved symptoms in most of our patients. Approaches to treatment should involve a low-carbohydrate diet and alpha-glucosidase inhibitors rather than pancreatectomy.

Risk for Hospital Readmission following Bariatric Surgery

Background and Objectives Complications resulting in hospital readmission are important concerns for those considering bariatric surgery, yet present understanding of the risk for these events is limited to a small number of patient factors. We sought to identify demographic characteristics, concomitant morbidities, and perioperative factors associated with hospital readmission following bariatric surgery. Methods We report on a prospective observational study of 24,662 patients undergoing primary RYGB and 26,002 patients undergoing primary AGB at 249 and 317 Bariatric Surgery Centers of Excellence (BSCOE), respectively, in the United States from January 2007 to August 2009. Data were collected using standardized assessments of demographic factors and comorbidities, as well as longitudinal records of hospital readmissions, complications, and mortality. Results The readmission rate was 5.8% for RYGB and 1.2% for AGB patients 30 days after discharge. The greatest predictors for readmission following RYGB were prolonged length of stay (adjusted odds ratio [OR], 2.3; 95% confidence interval [CI], 2.0–2.7), open surgery (OR, 1.8; CI, 1.4–2.2), and pseudotumor cerebri (OR, 1.6; CI, 1.1–2.4). Prolonged length of stay (OR, 2.3; CI, 1.6–3.3), history of deep venous thrombosis or pulmonary embolism (OR, 2.1; CI, 1.3–3.3), asthma (OR, 1.5; CI, 1.1–2.1), and obstructive sleep apnea (OR, 1.5; CI, 1.1–1.9) were associated with the greatest increases in readmission risk for AGB. The 30-day mortality rate was 0.14% for RYGB and 0.02% for AGB. Conclusion Readmission rates are low and mortality is very rare following bariatric surgery, but risk for both is significantly higher after RYGB. Predictors of readmission were disparate for the two procedures. Results do not support excluding patients with certain comorbidities since any reductions in overall readmission rates would be very small on the absolute risk scale. Future research should evaluate the efficacy of post-surgical managed care plans for patients at higher risk for readmission and adverse events.

Comparative effectiveness of bariatric surgery and nonsurgical therapy in adults with type 2 diabetes mellitus and body mass index <35 kg/m2

BACKGROUND Outcomes of bariatric surgery in patients with a body mass index (BMI) <35 kg/m(2) have been an active area of investigation. We examined the comparative effectiveness of Roux-en-Y gastric bypass (RYGB) to routine medical management (nonsurgical controls; NSCs) in achieving appropriate targets defined by the American Diabetes Association for type 2 diabetes mellitus (T2DM) in patients with class I obesity (BMI 30.0-34.9 kg/m(2)) T2DM at 1 year. METHODS We identified patients undergoing RYGB (N = 17) with both class I obesity and T2DM and compared them to similar NSC (N = 17) treated in the Primary Care Center. Data were collected at baseline and 1 year for systolic blood pressure (SBP), as well as blood levels for low-density lipoprotein (LDL) cholesterol and hemoglobin A1c (HbA1c). RESULTS After RYGB, BMI decreased from 34.6 ± 0.8 kg/m(2) to 25.8 ± 2.5 kg/m(2) (P < .001) and HbA1c decreased from 8.2 ± 2.0% to 6.1 ± 2.7% (P < .001). The NSC cohort had no significant change in either BMI or HbA1c. SBP and LDL did not significantly change in either group. The RYGB group had a decrease in medication use compared to the NSC group (P < .001). The RYGB group ceased the use of antihypertensive and antihyperlipidemia medications by 1 year despite abnormal values. CONCLUSION RYGB can be performed in patients with both a BMI <35 kg/m(2) and T2DM with better weight loss, glycemic control, and fewer antihyperglycemic medications than NSC. Inappropriate cessation of medications may partially explain the persistent increase in both SBP and LDL after RYGB.

Roux-en-Y Gastric Bypass is Associated with Early Increased Risk Factors for Development of Calcium Oxalate Nephrolithiasis

BACKGROUND Patients treated for obesity with jejunoileal bypass (JIB) experienced a marked increased risk of hyperoxaluria, nephrolithiasis, and oxalate nephropathy developing. Jejunoileal bypass has been abandoned and replaced with other options, including Roux-en-Y gastric bypass (RYGB). Changes in urinary lithogenic risk factors after RYGB are currently unknown. Our purpose was to determine whether RYGB is associated with elevated risk of developing calcium oxalate stone formation through increased urinary oxalate excretion and relative supersaturation of calcium oxalate. STUDY DESIGN A prospective longitudinal cohort study of 24 morbidly obese adults (9 men and 15 women) recruited from a university-based bariatric surgery clinic scheduled to undergo RYGB between December 2005 and April 2007. Patients provided 24-hour urine collections for analysis 7 days before and 90 days after operation. Primary outcomes were changes in 24-hour urinary oxalate excretion and relative supersaturation of calcium oxalate from baseline to 3 months post-RYGB. RESULTS Compared with their baseline, patients undergoing RYGB had increased urinary oxalate excretion (31 +/- 10 mg/d versus 41 +/- 18 mg/d; p = 0.026) and relative supersaturation of calcium oxalate (1.73 +/- 0.81 versus 3.47 +/- 2.59; p = 0.030) 3 months post-RYGB in six patients (25%). De novo hyperoxaluria developed. There were no preoperative patient characteristics predictive of development of de novo hyperoxaluria or the magnitude of change of daily oxalate excretion. CONCLUSIONS This prospective study indicates that RYGB is associated with an earlier increase in urinary oxalate excretion and relative supersaturation of calcium oxalate than previously reported. Additional studies are needed to determine longterm post-RYGB changes in urinary oxalate excretion and identify patients that might be at risk for hyperoxaluria developing.

Benefits and complications of the duodenal switch/biliopancreatic diversion compared to the Roux-en-Y gastric bypass

BACKGROUND Despite providing superb excess weight loss and increased resolution of comorbid diseases, such as type 2 diabetes mellitus, compared to other bariatric procedures, the duodenal switch/ biliopancreatic diversion (DS/BD) has not gained widespread acceptance among patients and physicians. In this study, we investigated outcomes, symptoms and complications among postsurgical DS patients compared to RYGB patients. METHODS We used propensity scores to retrospectively match patients who underwent DS/BD between 2005 and 2010 to comparable Roux-en-Y gastric bypass (RYGB) patients. We then reviewed patient charts, and surveyed patients using the University of Minnesota Bariatric Surgery Outcomes Survey tool to track outcomes, comorbid illnesses and complications. RESULTS One hundred ninety consecutive patients underwent primary DS/BD between 2005 and 2010 at the University of Minnesota Medical Center. There were 178 patients available for follow-up (93.7%) who were matched to 139 RYGB patients. Type 2 diabetes, hypertension, and hyperlipidemia all significantly improved in each group. Improvements were significantly higher in the DS/BD group. Percent total weight loss was not different between groups. Loose stools and bloating symptoms were more frequently reported among DS/BD patients. With the exception of increased emergency department visits among DS/BD patients (P < .01), overall complication rates were not significantly different between DS/BD and RYGB. There was no difference in mortality rates between the groups. CONCLUSION The DS/BD is a robust procedure that engenders both superior weight loss and improvement of major comorbidities. Complication and adverse event rates are similar to those of RYGB.

Gastric bypass after liver transplantation

Few data are available for assessing the outcomes of bariatric surgery for patients who have undergone orthotopic liver transplantation (OLT). The University of Minnesota bariatric surgery database and transplant registry were retrospectively reviewed to identify patients who had undergone OLT and then open Roux‐en‐Y gastric bypass (RYGB) surgery between 2001 and 2009. Comorbidity‐appropriate laboratory values, body mass indices (BMIs), histopathology reports, and immunosuppressive regimens were collected. Seven patients were identified with a mean age of 55.4 ± 8.64 years and a mean follow‐up of 59.14 ± 41.49 months from the time of RYGB. The mean time between OLT and RYGB was 26.57 ± 8.12 months. The liver disease etiologies were hepatitis C (n = 4), jejunoileal bypass surgery (n = 1), hemangioendothelioma (n = 1), and alcoholic cirrhosis (n = 1). There were 2 deaths for patients with hepatitis C 6 and 9 months after bariatric surgery due to multiple‐organ dysfunction syndrome and metastatic esophageal squamous carcinoma, respectively. One patient with hepatitis C required a reversal of the RYGB because of malnutrition and an inability to tolerate oral intake. Four of the 7 patients had type 2 diabetes mellitus (T2DM), 4 had hypertension, and 6 patients had dyslipidemia. All patients were on immunosuppressive medications, but only 4 were on corticosteroids. Glycemic control was improved in all surviving patients with T2DM. The mean BMI was 34.27 ± 5.51 kg/m2 before OLT and 44.34 ± 6.08 kg/m2 before RYGB; it declined to 26.47 ± 5.53 kg/m2 after RYGB. In conclusion, in this case series of patients undergoing RYGB after OLT, we observed therapeutic weight loss, improved glycemic control, and improved high‐density lipoprotein levels in the presence of continued dyslipidemia. RYGB may have contributed to the death of 1 patient due to multiple‐organ dysfunction syndrome. Liver Transpl 19:1324–1329, 2013.

Case-matched outcomes in bariatric surgery for treatment of type 2 diabetes in the morbidly obese patient.

Objective: To compare the relative efficacy of medical management, the duodenal switch (DS), and the laparoscopic adjustable gastric band (LAGB) to the Roux-en-Y gastric bypass (RYGB) for treatment of type 2 diabetes mellitus (T2DM). Background: The RYGB resolves T2DM in a high proportion of patients and is considered the standard operation for T2DM resolution in morbidly obese patients. However, no data exist comparing the efficacy of medical management and other bariatric operations to the RYGB for treatment of T2DM in comparable patient populations. Methods: We performed a retrospective case-matched study of morbidly obese patients with T2DM who had undergone medical management (nonsurgical controls [NSC]; N = 29), LAGB (N = 30), or DS (N = 27) and were compared with matched T2DM patients who had undergone RYGB. Matching was performed with respect to age, sex, body mass index, and hemoglobin A1C (HbA1C). Outcomes assessed were changes in body mass index, HbA1C, and diabetes medication scores at 1 year. Results: The Roux-en-Y gastric bypass produced greater weight loss, HbA1C normalization, and medication score reduction compared to both NSC and LAGB-matched cohorts. Duodenal switch produced greater reductions in HbA1C and medication score than RYGB, despite no greater weight loss at 1 year. Surgical complications were rarely life threatening. Conclusions: This study provides an important perspective about the comparative efficacy of LAGB, DS, and NSC to the RYGB for treatment of T2DM among obese patients. After 1 year of follow-up, RYGB is superior to NSC and LAGB with respect to weight loss and improvement in diabetes whereas DS is superior to RYGB in reducing HbA1C and medication score.

Small Bowel Obstruction and Internal Hernias during Pregnancy after Gastric Bypass Surgery

Small bowel obstruction (SBO) is a recognized complication of Roux-en-Y gastric bypass (RYGB) surgery. Internal hernia (IH) a potential problem associated with RYGB, can have severe consequences if not diagnosed. We present two cases of SBO due to IH during pregnancy after laparoscopic RYGB (LRYGB). Both patients underwent an antecolic, antegastric LRYGB. In both patients a Petersen’s type IH was found. We reviewed the cases reported in the literature of SBO during pregnancy after RYGB. IH should always be ruled out in pregnant patients with previous RYGB and abdominal pain. Prompt surgical intervention is mandatory for a good outcome.

Routine upper gastrointestinal imaging is superior to clinical signs for detecting gastrojejunal leak after laparoscopic roux-en-y gastric bypass

BACKGROUND There are myriad symptoms and signs of gastrojejunal leak; prompt recognition is essential. Many surgeons use clinical predictors to guide selective use of upper gastrointestinal imaging (UGI). The appropriate practice remains undefined. STUDY DESIGN A review of patients who underwent primary laparoscopic Roux-en-Y gastric bypass between January 2002 and December 2008 was conducted. All underwent routine UGI studies on postoperative day 1. Actual gastrojejunal leak within 7 days of surgery (actual leak [AL], radiologic leaks), operative reports, patient charts, and postoperative vital signs were retrospectively reviewed. RESULTS There were 2,099 operations. Eight ALs (0.43%) occurred without associated mortality. UGI was positive in 7 AL patients and falsely positive in 6 patients. The AL patients underwent laparoscopy on postoperative days 1 and 3 (n = 5 and n = 1, respectively), laparotomy on postoperative day 3 (n = 1), and peritoneal drainage (n = 1). False-positive UGIs prompted laparoscopy (n = 3) and close observation (n = 3). Pulse was 100 to 120 beats per minute in 2 patients and fever (>38.5°C) was present in 0 AL patients. AL patients had osteogenesis imperfecta (n = 1), macronodular cirrhosis (n = 1), positive bubble test (n = 3), and concomitant splenectomy (n = 1). No jejunojejunostomy leaks were identified. CONCLUSIONS Routine UGI after laparoscopic Roux-en-Y gastric bypass has greater sensitivity than clinical signs for detecting gastrojejunal leak. Delay in the diagnosis of leakage can impact mortality, and this suggests that indications for routine UGI might still exist. Tachycardia is not a reliable early marker of leak. There might be risk factors for leak in addition to vital signs, including patient medical history or intraoperative events, which should prompt routine UGI on postoperative day 1.

Distal Esophageal Erosion After Laparoscopic Adjustable Gastric Band Placement with Nissen Fundoplication Takedown

Although primary band placement is proven to be safe, gastric band placement after previous operations in the area of the gastroesophageal junction remains controversial. Erosion into the stomach has been described after failed vertical banded gastroplasty conversion to laparoscopic gastric banding (LAGB), but no reports in the English literature are available on erosion of an adjustable gastric band into the esophagus after conversion operations. To our knowledge, this is the first case report of distal esophageal erosion after LAGB placement with Nissen fundoplication takedown.