Keith S Gersin

Carolinas Medical Center University, Charlotte, North Carolina, United States

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Publications (62)221.89 Total impact

  • No preview · Article · Nov 2015 · Surgery for Obesity and Related Diseases
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    ABSTRACT: Obesity is an independent risk factor for the development of liver fibrosis/cirrhosis and hepatocellular carcinoma (HCC). Tenascin-C (TnC), an extracellular matrix protein, is transiently expressed during tissue injury and plays a role in fibrogenesis and tumorigenesis. However, the mechanistic role of TnC signaling in the development of HCC remains unknown. We developed a diet-induced obesity HCC mouse model and examined TnC expression and liver injury. To determine the cellular mechanism of TnC signaling in promoting inflammation and hepatocyte epithelial-mesenchymal transition and migration, we used primary hepatocytes and hepatoma and macrophage cell lines. Further, to determine whether elevated TnC expression correlated with obesity-associated HCC, we measured plasma TnC in obese patients with various levels of liver injury. Increased tissue inflammation accompanied with elevated hepatic stellate cell-derived TnC and Toll-like receptor 4 expression was observed in the diet-induced obesity HCC animal model. In vitro studies found enhanced Toll-like receptor 4 signaling activated by TnC, promoting an increased inflammatory response, hepatocyte transformation, and migration. Further, obese patients with cirrhosis alone and in combination with HCC showed significant increases in plasma TnC compared with healthy volunteers and patients with less severe liver injury. Overall, these studies suggest TnC/Toll-like receptor 4 signaling as an important regulator in HCC; inhibiting this signaling axis may be a viable therapeutic target for impeding HCC.
    No preview · Article · Nov 2015 · American Journal Of Pathology
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    ABSTRACT: Postoperative sepsis is a rare but serious complication following elective surgery. The purpose of this study was to identify the rate of postoperative sepsis following elective laparoscopic gastric bypass (LGBP) and to identify patients' modifiable, preoperative risk factors. The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2005 to 2013 for factors associated with the development of postoperative sepsis following elective LGBP. Patients who developed sepsis were compared to those who did not. Results were analyzed using the Chi-square test for categorical variables and Wilcoxon two-sample test for continuous variables. A multivariate logistic regression analysis was utilized to calculate adjusted odds ratios for factors contributing to sepsis. During the study period, 66,838 patients underwent LGBP. Of those, 546 patients developed postoperative sepsis (0.82 %). The development of sepsis was associated with increased operative time (161 ± 77.8 vs. 135.10 ± 56.5 min; p < 0.0001) and a greater number of preoperative comorbidities, including diabetes (39.6 vs. 30.6 %; p < 0.0001), hypertension requiring medication (65.2 vs. 54 %; p < 0.0001), current tobacco use (16.7 vs. 11.5 %; p = 0.0002), and increased pack-year history of smoking (8.6 ± 18.3 vs. 5.6 ± 14.2; p = 0.0006), and the Charlson Comorbidity Index (0.51 ± 0.74 vs. 0.35 ± 0.57, p < 0.0001). Sepsis resulted in an increased length of stay (10.1 ± 14.4 vs. 2.4 ± 4.8 days; p < 0.0001) and a 30 times greater chance of 30-day mortality (4.03 vs. 0.11 %, p < 0.0001). Multivariate logistic regression analysis showed that current smokers had a 63 % greater chance of developing sepsis compared to non-smokers, controlling for age, race, gender, BMI, and CCI score (OR 1.63, 95 % CI 1.23-2.14; p = 0.0006). Laparoscopic gastric bypass is uncommonly associated with postoperative sepsis. When it occurs, it portends a 30 times increased risk of death. A patient history of diabetes, hypertension, and increasing pack-years of smoking portend an increased risk of sepsis. Current smoking status, a preoperative modifiable risk factor, is independently associated with the chance of postoperative sepsis. Preoperative patient optimization and risk reduction should be a priority for elective surgery, and patients should be encouraged to stop smoking prior to gastric bypass.
    No preview · Article · Jul 2015 · Surgical Endoscopy
  • D Stefanidis · K Malireddy · T Kuwada · R Phillips · E Zoog · K S Gersin
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    ABSTRACT: Revisional bariatric procedures are on the rise. The higher complexity of these procedures has been reported to lead to increased risk of complications. The objective of our study was to compare the perioperative risk profile of revisional bariatric surgery with primary bariatric surgery in our experience. A prospectively maintained database of all patients undergoing bariatric surgery by three fellowship-trained bariatric surgeons from June 2005 to January 2013 at a center of excellence was reviewed. Patient demographics, type of initial and revisional operation, number of prior gastric surgeries, indications for revision, postoperative morbidity and mortality, length of stay, 30-day readmissions, and reoperations were recorded. These outcomes were compared between revisional and primary procedures by the Mann-Whitney or Chi square tests. Of 1,556 patients undergoing bariatric surgery, 102 patients (6.5 %) underwent revisional procedures during the study period. Indications for revisions included inadequate weight loss in 67, failed fundoplications with recurrent gastroesophageal reflux disease in 29, and other in 6 cases. Revisional bariatric procedures belonged into four categories: band to sleeve gastrectomy (n = 23), band to Roux-en-Y gastric bypass (n = 25), fundoplication to bypass (n = 29), and other (n = 25). Revisional procedures were associated with higher rates of readmissions and overall morbidity but no differences in leak rates and mortality compared with primary procedures. Band revisions had similar length of stay with primary procedures and had fewer complications compared with other revisions. Patients undergoing fundoplication to bypass revisions were older, had a higher number of prior gastric procedures, and the highest morbidity (40 %) and reoperation (20 %) rates. In experienced hands, many revisional bariatric procedures can be accomplished safely, with excellent perioperative outcomes that are similar to primary procedures. As the complexity of the revisional procedure and number of prior surgeries increases, however, so does the perioperative morbidity, with fundoplication revisions to gastric bypass representing the highest risk group.
    No preview · Article · Aug 2013 · Surgical Endoscopy
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    ABSTRACT: Nonalcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease in the USA. Biopsy has been the standard for determining fibrosis but is invasive, costly, and associated with risk. Previous studies report a calculated "NAFLD fibrosis scores" (cNFS) as a means to overcome the need for biopsy. We compared cNFS versus biopsy-pathological scoring for patients undergoing bariatric surgery. We retrospectively reviewed patients with available preoperative labs and patient information undergoing Roux-en-Y gastric bypass (RYGBP) surgery at a single institution over a 5.5-year period. Biopsy samples were blind scored by a single hepatopathologist and compared with scores calculated using a previously reported cNFS. Of the 225 patients that met the inclusion criteria, the mean body mass index was 44.6 ± 5.4 kg/m(2) and 85 % were female. Using the cNFS, 39.6 % of patients were categorized into low fibrosis, 52 % indeterminate, and 8.4 % high fibrosis groups. Analysis of fibrosis by pathology scoring demonstrated 2 of 89 (2.2 %) and 7 of 110 (3.4 %) had significant fibrosis in the low and intermediate groups, respectively. Conversely, in the high fibrosis group calculated by cNFS, only 6 of 19 (31.6 %) exhibited significant fibrosis by pathology scoring. No definitive model for accurately predicting presence of NAFLD and fibrosis currently exits. Furthermore, under no circumstances should a clinical "NAFLD fibrosis score" replace liver biopsy at this time for RYGBP patients.
    Full-text · Article · Aug 2013 · Obesity Surgery

  • No preview · Article · May 2013 · Gastroenterology
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    ABSTRACT: Background: In 2008, the Realize Band (RB) adopted a precurved design (RB-C). We present 2-year outcomes data from the first multiinstitutional study of RB-C. The objective of this study was to analyze weight loss and safety data from bariatric practices in the United States, including academic, nonacademic, public, and private. Methods: The study included adult RB-C patients with a preoperative body mass index (BMI)≥40 kg/m(2) or >35 kg/m(2) with co-morbidity. Exclusions included RB-C's label contraindications for use. Outcomes parameters were percent excess weight loss (%EWL), BMI change, number and volume of band adjustments, and adverse events. Results: A total of 231 patients met inclusion/exclusion criteria. Of these, 161 had 24-month data available. Mean %EWL was 44.4%±26.9% (P<.0001). BMI decreased from 44.1±5.7 kg/m(2) to 35.3±6.9 kg/m(2) (P<.0001). Percent EWL varied by preoperative BMI (P = .0002), bariatric practice (P<.0001), aftercare frequency (P = .0004), and band fill frequency (P = .0271), but %EWL was not influenced by gender, race, or age (P>.20 each). Adverse events were dysphagia (21.2%), gastroesophageal reflux (21.6%), and vomiting (30.7%). Incidence of pouch dilation, esophageal dilation, and slippage was ≤1%. Revisions (2.2%) were for unbuckled band, tube kinking, slippage, and suspected band leak (1 each). No erosions, explants, or mortality were reported. Conclusion: RB-C appears to be as well tolerated and effective as the first generation RB for weight loss. The near 45% EWL at 2 years is consistent with other high-quality publications on the RB. Preoperative BMI and frequency of postoperative care, including frequency of band fills, influence %EWL. Significant weight loss is achievable with RB-C despite variable postoperative management practices. The low morbidity and the absence of mortality at 24 months reflect positively on the RB-C characteristics.
    No preview · Article · Mar 2013 · Surgery for Obesity and Related Diseases

  • No preview · Article · Feb 2013 · Journal of Surgical Research
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    ABSTRACT: Rapid weight loss after bariatric surgery is associated with gallstone formation, and cholecystectomy is required in up to 15% of patients. Prophylactic cholecystectomy or prophylactic ursodiol administration in the postoperative period have been suggested to address this problem. The objectives of this study were to investigate the frequency and timing of cholecystectomies after bariatric surgery and to determine the associated risk factors in patients who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB), laparoscopic adjustable gastric band (LAGB), or laparoscopic sleeve gastrectomy (LSG).
    No preview · Article · Jan 2013 · Surgery for Obesity and Related Diseases
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    ABSTRACT: Background: Recent data suggest that reoperative fundoplication is associated with poor long-term control of reflux. For long-term reflux control, laparoscopic Roux-en-Y gastric bypass (LRYGB) may be a better option. This study assessed outcomes and quality-of-life data after fundoplication takedown and conversion to LRYGB for patients with failed fundoplications. Methods: After institutional review board approval, the medical records of 25 patients who underwent fundoplication takedown and LRYGB conversion between March 2007 and July 2011 were reviewed. The data recorded included patient demographics, body mass index (BMI), preoperative symptoms, operative duration and findings, hospital length of stay (LOS), estimated blood loss (EBL), length of the follow-up period, and postoperative outcomes. The gastrointestinal quality of life index (GIQLI) and the gastrointestinal symptoms rating scale (GSRS) were used at the most recent follow-up visit to assess symptom severity and quality of life. Results: The patients in this study had undergone 40 total prior antireflux surgeries. They had a median age of 55 years (range 36-72 years), a BMI of 34.4 kg/m(2) (range 22-50 kg/m(2)), an operative duration of 345 min (range 180-600 min), an EBL of 181 ml (range 50-500 ml), and an LOS of 7 days (range 2-30 days). Five patients had concomitant incisional hernia repair. There was no mortality. Of the 10 patients (40%) who had had complications, 5 required reoperation. During a 14-month follow-up period (range 1-48 months), 96% of the patients were reflux-free with a GIQLI score of 114 (range 80-135) and a GSRS score of 25 (range 17-45). Excess weight loss was 60%, and comorbidity resolution was 70%. Most of the patients (96%) were satisfied with their outcome and would undergo the surgery again, and 62% reported that their personal relationships and sexual life had improved. Conclusions: Patients who undergo LRYGB after failed fundoplications have excellent symptomatic control of reflux, excellent quality of life, and high rates of satisfaction with their outcome. Nevertheless, because the procedure is challenging and associated with considerable morbidity, it should be performed by surgeons experienced in antireflux and bariatric surgery.
    No preview · Article · Jun 2012 · Surgical Endoscopy
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    ABSTRACT: To evaluate safety, weight loss, and cardiometabolic changes in obese subjects implanted with the duodenal-jejunal bypass liner (DJBL) for 1 year. The DJBL is an endoscopic implant that mimics the duodenal-jejunal bypass component of the Roux-en-Y gastric bypass. Previous reports have shown significant weight loss and improvement in type 2 diabetes for up to 6 months. Morbidly obese subjects were enrolled in a single arm, open label, prospective trial and implanted with the DJBL. Primary endpoints included safety and weight change from baseline to week 52. Secondary endpoints included changes in waist circumference, blood pressure, lipids, glycemic control, and metabolic syndrome. The DJBL was implanted endoscopically in 39 of 42 subjects (age: 36 ± 10 years; 80% female; weight: 109 ± 18 kg; BMI: 43.7 ± 5.9 kg/m); 24 completed 52 weeks of follow-up. Three subjects could not be implanted due to short duodenal bulb. Implantation time was 24 ± 2 minutes. There were no procedure-related complications and there were 15 early endoscopic removals. In the 52-week completer population, total body weight change from baseline was -22.1 ± 2.1 kg (P < 0.0001) corresponding to 19.9 ± 1.8% of total body weight and 47.0 ± 4.4% excess of weight loss. There were also significant improvements in waist circumference, blood pressure, total and low-density lipoprotein cholesterol, triglycerides, and fasting glucose. The DJBL is safe when implanted for 1 year, and results in significant weight loss and improvements in cardiometabolic risk factors. These results suggest that this device may be suitable for the treatment of morbid obesity and its related comorbidities. This study was registered at (NCT00985491).
    No preview · Article · Apr 2012 · Annals of surgery
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    ABSTRACT: The percentage of excess weight loss (%EWL) is a common metric for reporting weight loss after bariatric surgery. The %EWL can vary depending on the definitions of ideal body weight (IBW) used and the preoperative weight. The present study examined the effect of variations in IBW and the preoperative weight on the %EWL at a tertiary care teaching hospital. After institutional review board approval, we reviewed the prospectively collected data from consecutive patients who had undergone laparoscopic adjustable gastric banding or laparoscopic Roux-en-Y gastric bypass (RYGB) at our center from 2005 to 2008 with a single surgeon (T.K.). All patients with ≥12 months of follow-up were included. The IBW was calculated using the mean weight of the "medium frame" and the maximum weight of the "large frame" for the corresponding height from the Metropolitan Life Insurance tables. The preoperative weight was defined as the weight on the day of surgery or the greatest recorded preoperative weight between the initial consult and the day of surgery. The postoperative weight was defined as the 12-month follow-up weight. Four methods were used to calculate the %EWL. Repeated measures analysis of variance was used to analyze the methods. A total of 173 patients met inclusion criteria. Of these 173 patients, 126 underwent RYGB and 47 underwent laparoscopic adjustable gastric banding. The calculated 12-month %EWL for these was 65-82% for RYGB and 31-46% for laparoscopic adjustable gastric banding using the calculation method. For a given postoperative weight loss, significant variance will be found in the %EWL (≤17%), depending on the definition of IBW used and the preoperative weight value used. This highlights the need for a standardized approach for reporting weight loss in bariatric studies. Investigators should define their methods clearly, and readers should keep this variability in mind when interpreting the %EWL.
    No preview · Article · Jul 2011 · Surgery for Obesity and Related Diseases
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    ABSTRACT: In 2008, the REALIZE Band (RB) adopted a precurved design (RB-C). The present study is the first multi-institutional report of RB-C outcomes. Our objective was to analyze the 1-year weight loss and safety data from adult RB-C patients treated at multiple U.S. centers (7 typical U.S. bariatric practices, including academic, nonacademic, public, and private practice). Patients implanted with the RB-C (preoperative body mass index ≥ 40 kg/m(2) or >35 kg/m(2) with co-morbidity) were recruited. The exclusion criteria included the RB-C label contraindications for use. The outcomes parameters were the percentage of excess weight loss (%EWL), change in body mass index, number and volume of band adjustments, and incidence of complications. Of the 239 patients enrolled in the 2-year study, 158 had 1-year data available for analysis in November 2010. The mean %EWL was 39.2% ± 20.5% (range -7.7 to -116.8, P < .0001). The body mass index decreased from 44.4 ± 5.5 kg/m(2) to 36.4 ± 5.8 kg/m(2) (P < .0001). The variability in the %EWL was significant among the study centers (P < .0001). The average band fill volume at 1 year was 8.0 ± 2.0 mL (range .0-11.1). The total fill volume was >11 mL in 1 patient. No band erosions/migrations, explants, or deaths occurred. RB-C appears to be as safe and effective as the first-generation RB. The near 40% EWL at 1 year was consistent with other high-quality publications of the RB. Good weight loss results are achievable, despite the varying postoperative management practices. The low morbidity and the absence of mortality at 12 months reflect positively on the RB-C characteristics. Our findings suggest that the learning curve, related to the postoperative management of the RB-C, might vary by practice and that a greater frequency and smaller band fills might result in better weight loss at 12 months.
    No preview · Article · May 2011 · Surgery for Obesity and Related Diseases

  • No preview · Article · May 2011 · Surgery for Obesity and Related Diseases
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    ABSTRACT: Student observation of surgical procedures is standard practice performed at the discretion of the attending surgeon and the participating medical facility. The goal of our study was to evaluate patient, physician, and operating room (OR) staff opinions concerning student observation of surgical procedures at different levels of academic training. Following Institutional Review Board approval, patients undergoing elective surgery were consented to participate in the survey. An anonymous online survey was sent to attending surgeons and OR staff. The majority of patients (97), physicians (91), and OR staff (71) believe that OR observational experience is important to medical student training. Patients (92%) and OR staff (97%) more so than physicians (72%) rated OR observational experience as important for nursing student education (P < 0.001). Comparatively, all groups believe this experience is less important for college and high school students (P < 0.01). When asked if patients should be informed preoperatively of student-observer presence during procedures, more patients and OR staff replied affirmatively compared with physicians (P < 0.001). Similarly, patients and OR staff more frequently believed that informed consent for OR student-observers was necessary (P < 0.0001). All groups acknowledged the educational value of student observational experience, although significant disparity was noted relative to academic level and the group responding. Additionally, opinions of the OR staff were more closely aligned with those of patients. Further assessment of the role of informed consent for student-observer OR presence and potential implications is needed.
    No preview · Article · Apr 2011 · Journal of Surgical Research
  • Article: Response.

    No preview · Article · Apr 2011 · Gastrointestinal endoscopy

  • No preview · Article · Feb 2011 · Journal of Surgical Research
  • Dimitrios Stefanidis · Timothy S Kuwada · Keith S Gersin
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    ABSTRACT: The ideal length of the gastric bypass limbs is debated. Recent evidence suggests that standard limb lengths used today have a limited impact on patient weight loss. Our objective was to appraise critically the available evidence on the influence of the length of gastric bypass limbs on weight loss outcomes. We systematically reviewed MEDLINE, the Cochrane database of evidence-based reviews, and the Database of Abstracts of Reviews of Effects for articles reporting the effect of gastric bypass length on outcomes published between 1987 and 2009. Four randomized controlled trials and several retrospective studies were identified and reviewed. Longer Roux limb lengths (at least 150 cm) were associated with a very modest weight loss advantage in the short term in superobese patients. No significant impact of alimentary limb length on weight loss for patients with body mass index (BMI) <50 was seen. When the length of the common channel approaches 100 cm, a significant impact on weight loss is observed. The currently available literature supports the notion that a longer Roux limb (at least 150 cm) may be associated with a very modest weight loss advantage in the short term in superobese patients but has no significant impact on patients with BMI ≤50. To achieve weight loss benefit due to malabsorption, bariatric surgeons should focus on the length of the common channel rather than the alimentary or biliopancreatic limbs when constructing a gastric bypass especially in the superobese population where failure rates after conventional gastric bypass are higher.
    No preview · Article · Jan 2011 · Obesity Surgery
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    ABSTRACT: The amount of excess weight loss (EWL) achieved after bariatric surgery has varied considerably. Reliable preoperative predictors of the postoperative %EWL do not exist. Patient compliance with the physician recommendations has generally been believed to be important for long-term success after bariatric surgery, especially after gastric banding. We hypothesized that poor preoperative patient compliance with office visits, a likely indicator of overall compliance, would be associated with lower %EWL after bariatric surgery at a teaching hospital in the United States. We performed an institutional review board-approved review of prospectively collected data from all patients undergoing bariatric surgery from 2007 to 2009. The patients were categorized into 2 groups: those who had missed <25% of all preoperative appointments at our bariatric center and those who had missed >25%. The average %EWL at 12 months between the 2 groups was compared using the unpaired t test separately for the gastric bypass and gastric banding patients. The gastric band patients with >25% missed appointments had lost 23% EWL at 12 months compared with 32% EWL for the gastric band patients who had missed <25% of their appointments (P = .01). No difference was found in the %EWL for the gastric bypass patients according to the missed preoperative appointments. The postoperative compliance was significantly poorer than preoperatively. The patients with a greater percentage of missed preoperative appointments had a lower postoperative %EWL at 1 year after gastric banding but not after gastric bypass. This information could prove useful during patient selection or when counseling patients about the type of bariatric surgery to pursue.
    No preview · Article · Dec 2010 · Surgery for Obesity and Related Diseases
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    Full-text · Article · Jun 2010 · Revista Chilena de Cirugia

Publication Stats

1k Citations
221.89 Total Impact Points


  • 2007-2015
    • Carolinas Medical Center University
      Charlotte, North Carolina, United States
  • 2009-2013
    • Carolinas HealthCare System
      Charlotte, North Carolina, United States
  • 2002-2008
    • University of Cincinnati
      • • Department of Surgery
      • • Division of Transplantation
      Cincinnati, Ohio, United States
  • 2002-2004
    • University of Cincinnati Medical Center
      Cincinnati, Ohio, United States
  • 2000-2001
    • University of Massachusetts Medical School
      • Department of Surgery
      Worcester, Massachusetts, United States
  • 1998
    • Royal Berkshire NHS Foundation Trust
      Reading, England, United Kingdom