Khashayar Vaziri

Preoperative Liver Reduction Utilizing a Novel Nutritional Supplement

BACKGROUND One of the most common reasons for conversion in bariatric surgery is hepatomegaly caused by inadequate exposure of the proximal stomach. This study utilizes a novel nutritional supplement with a calorie-restricted diet to reduce liver volume preoperatively. METHODS A consecutive series of morbidly obese patients consumed a nutritional supplement called Nuvista(®) for 4 weeks preoperatively. Preoperatively, each patient completed baseline demographics, blood work, urine ketone analysis, ultrasonography of the left lateral segment, and multiple questionnaires. At the time of surgery, these studies were repeated. Data were analyzed using a paired t-test and bivariate analysis where appropriate. A P<.05 was considered significant. RESULTS Four men and 17 women were recruited with a mean preoperative weight and body mass index of 122.7±15.9  kg and 44.5±3.9, respectively. Mean preoperative liver volume of the left lateral segment was 562.5±291.3  cm(3). After 4 weeks of Nuvista, the mean weight and body mass index decreased significantly to 118.9±15.5  kg and 43.1±3.4, respectively (P<.001). The mean liver volume of the left lateral segment was significantly reduced to 299.9±162.1  cm(3) (P<.001). Mean liver reduction was 43.4%±17.2% (13.6%-81.9%, P<.05). Urinary ketone scores did not show any evidence of starvation. No preoperative factors correlated with liver volume reduction. CONCLUSION Utilizing Nuvista, as part of a preoperative 4-week calorie-restricted regimen, significantly reduced lateral segment liver volume by 43.4%. This preoperative regimen incorporates healthy behavioral changes that are necessary to sustain long-term weight loss.

A Calculator for Mortality Following Emergency General Surgery Based on the American College of Surgeons National Surgical Quality Improvement Program Database.

BACKGROUND The complex nature of current morbidity and mortality predictor models do not lend themselves to clinical application at the bedside of patients undergoing emergency general surgery (EGS). Our aim was to develop a simplified risk calculator for prediction of early postoperative mortality after EGS. METHODS EGS cases other than appendectomy and cholecystectomy were identified within the American College of Surgeons National Surgery Quality Improvement Program database from 2005 to 2014. Seventy-five percent of the cases were selected at random for model development, whereas 25% of the cases were used for model testing. Stepwise logistic regression was performed for creation of a 30-day mortality risk calculator. Model accuracy and reproducibility was investigated using the concordance index (c statistic) and Pearson correlations. RESULTS A total of 79,835 patients met inclusion criteria. Overall, 30-day mortality was 12.6%. A simplified risk model formula was derived from five readily available preoperative variables as follows: 0.034*age + 0.8*nonindependent status + 0.88*sepsis + 1.1 (if bun ≥ 29) or 0.57 (if bun ≥18 and < 29) + 1.16 (if albumin < 2.7), or 0.61 (if albumin ≥ 2.7 and < 3.4). The risk of 30-day mortality was stratified into deciles. The risk of 30-day mortality ranged from 2% for patients in the lowest risk level to 31% for patients in the highest risk level. The c statistic was 0.83 in both the derivation and testing samples. CONCLUSION Five readily available preoperative variables can be used to predict the 30-day mortality risk for patients undergoing EGS. Further studies are needed to validate this risk calculator and to determine its bedside applicability. LEVEL OF EVIDENCE Prognostic/epidemiological study, level III.

A novel single agent for nutritional supplementation following roux-en-Y gastric bypass

BACKGROUND Duodenal bypass and intestinal malabsorption from Roux-en-Y gastric bypass (RYGB) can exacerbate known nutritional deficiencies of morbidly obese patients and worsen symptoms. Preventatively, most bariatric patients use postoperative nutritional supplementation. This study evaluated Nuvista(®) (Nutricia North America, Rockville, MD) and its potential as an adequate single nutritional supplement. SUBJECTS AND METHODS From October 2009 to June 2010, 25 patients enrolled in a prospective, consecutive pilot study. Each underwent laparoscopic RYGB. The study group consumed two packs of Nuvista daily. The control group received standard nutritional supplements. Both groups had the same postoperative diet. Laboratory and demographics were compared at baseline and 12 months. Statistical analysis included paired t test, and a value of P<.05 was significant. RESULTS The study and control groups (16 and 9 patients, respectively) had statistically similar demographic profiles. Both groups had preoperative elevations of hemoglobin A1c (HbA1c) (6.2% and 6.2%, respectively), low-density lipoprotein (LDL) (108.2 mg/dL and 199.2 mg/dL, respectively), and high-density lipoprotein (HDL) (55.1 mg/dL and 48.0 mg/dL, respectively) and deficiencies in vitamin D with respective mean values of 20.6 ng/mL and 22.7 ng/mL (normal range, 30-100 ng/mL). Postoperatively, the study group had significant increases in phosphorus (P=.02), iron (P=.03), vitamin D (P=.05), zinc (P=.01), and HDL (P≤.01) and significant decreases in body mass index (BMI) (P≤.01), creatinine (P=.02), HbA1c (P=.01), triglycerides (P≤.01), and LDL (P≤.01). The control group had a significant increase in HDL (P=.01) and significant decreases in BMI (P≤.01), hemoglobin (P=.01), creatinine (P≤.01), albumin (P=.05), HbA1c (P=.05), zinc (P≤.01), triglycerides (P=.03), and LDL (P=.01). No change in mean parathyroid hormone value was seen. CONCLUSIONS Nuvista can provide adequate supplementation to bariatric patients 12 months after RYGB. Lifelong biochemical follow-up is necessary to personalize the diet and nutritional supplementation to compensate for the pathophysiologic changes of the gastric bypass.

Neoadjuvant Radiation Is Associated with Fistula Formation Following Pancreaticoduodenectomy

BackgroundPost-operative pancreatic fistulas remain a significant source of morbidity following pancreatic surgery. Few studies have evaluated the effect of neoadjuvant chemotherapy and radiation on this adverse outcome. This study aims to evaluate the effects of neoadjuvant therapy on 30-day morbidity and mortality following pancreaticoduodenectomy.Study DesignA retrospective analysis was performed utilizing the targeted pancreas module of the National Surgical Quality Improvement Project (NSQIP) from 2014 to 2015 for patients undergoing pancreaticoduodenectomy with pancreaticojejunal reconstruction. A fistula was defined according to the NSQIP definition. Patient demographics, operative variables, and 30-day outcomes were compared between those who received no neoadjuvant therapy, chemoradiation, chemotherapy alone, and radiation alone. Univariate analysis was completed using chi-square, Fisher exact test, Student’s t test, and Mann-Whitney U test where appropriate. Independent predictors of fistula formation were established using multivariable regression. A P value < 0.05 was considered significant.ResultsThree thousand one hundred fourteen patients were included of which 559 patients (18%) developed a pancreatic fistula. Two thousand six hundred thirty-five (85%) patients did not undergo neoadjuvant therapy, 207 (6.6%) had chemoradiation, 256 (8.2%) had chemotherapy alone, and 16 (0.5%) had radiation alone. Patients who developed a fistula had increased 30-day mortality (4.9 vs. 1.7%, P < .001) and major morbidities. Following multivariable analysis, neoadjuvant radiation (OR 2.1, 95% CI 1.0–4.5) was associated with increased fistula formation while neoadjuvant chemotherapy (OR 0.5, 95% CI 0.3–0.9) was protective.ConclusionNeoadjuvant chemotherapy provides protection against the development of pancreatic fistulas while neoadjuvant radiation potentiates formation likely due to their effects on the texture of the pancreatic gland. Given the morbidity of pancreatic fistula formation, these factors should be considered in neoadjuvant regimens.