Jennifer E. Keller

Duodenal- jejunal bypass sleeve: a totally endoscopic device for the treatment of morbid obesity.

Morbid obesity affects over 15 million people in the United States. Nonsurgical management produces sustained weight loss in less than 5% of patients. Despite associated comorbidities, less than 1% of obese patients seek surgical intervention. Less invasive procedures have been developed with varying success. The Endobarrier ™ (GI Dynamics™, Watertown, MA) duodenal—jejunal bypass sleeve is a totally endoscopically delivered device designed to produce weight loss in the morbidly obese. We describe the first placement of a duodenal—jejunal bypass sleeve in a patient in the United States. A blinded, randomized, prospective clinical trial was approved by the Food and Drug Administration to evaluate safety and efficacy of a novel device for weight loss in the obese. The first patient enrolled was a 36-year-old woman with body mass index of 45.2. After informed consent, endoscopic placement of the device under general anesthesia was performed using fluoroscopy to confirm positioning. The device was placed without complications. At conclusion of the 3-month study period, the device was removed endoscopically. Total weight lost by the patient was 9.09 kg. Described herein is the first deployment of the duodenal—jejunal bypass sleeve in North America. The device is delivered in a totally endoscopic manner in morbidly obese patients. In our patient, total weight loss at 3 months was 9.09 kg. Continued follow-up and enrollment is ongoing to demonstrate patient safety and efficacy. Additional studies are being performed to elucidate mechanism of weight loss and future clinical applications of this device.

Does liver appearance predict histopathologic findings: prospective analysis of routine liver biopsies during bariatric surgery

BACKGROUND Nonalcoholic fatty liver disease is associated with morbid obesity. Liver biopsy is the reference standard for the diagnosis of nonalcoholic fatty liver disease. It is unclear whether the macroscopic liver appearance correlates with the histopathologic findings. Our objective was to determine the relationship between the intraoperative liver appearance and the histopathologic findings during laparoscopic bariatric surgery at a tertiary medical center. METHODS Data were prospectively collected from 108 consecutive patients undergoing laparoscopic bariatric surgery with routine intraoperative liver biopsy. An intraoperative liver visual score was recorded according to the size, tan-speckling, and contour. The liver histologic findings were categorized into 3 groups: (1) normal; (2) bland steatosis; and (3) nonalcoholic steatohepatitis (NASH). The liver visual score was compared with the liver histologic findings. A recorded video of the liver was regraded at a later date to determine observer agreement. RESULTS The prevalence of NASH was 23% (n = 25). Of the 108 patients, 48% with NASH had normal-appearing livers and accounted for 24% (n = 12) of the 50 normal-appearing livers. A similar proportion of NASH cases was found in all 3 visual categories. Furthermore, no relationship was found between the number of abnormal visual cues and the liver histologic findings (P = .23). No complications were directly attributable to liver biopsy. The kappa values for intraobserver and interobserver agreement ranged from fair to almost perfect. CONCLUSION NASH is common in the morbidly obese population. There does not appear to be a relationship between liver appearance and the histopathologic findings. Intraoperative liver biopsy is a safe and accurate method of diagnosing liver disease and should be considered in all morbidly obese patients undergoing abdominal surgery.

Formula fortified with live probiotic culture reduces pulmonary and gastrointestinal bacterial colonization and translocation in a newborn animal model

BACKGROUND/PURPOSE Acidified diets are protective against intestinal bacterial colonization and translocation. Probiotic diets are designed to modulate the intestinal flora to enhance mucosal immunity. This study was designed to determine if formula acidified with live probiotic decreases bacterial gut colonization and translocation, and is equally tolerated as other acidified diets. METHODS One hundred twenty-eight rabbit pups delivered via cesarean section [cesarean delivery, cesarean birth, abdominal delivery] were randomly assigned to 4 feeding groups: NAN Nestle (control, pH 7.0), NAN acidified with citric acid (pH 4.55), biologically acidified Pelargon (pH 4.55), and NAN with live Lactococcus lactis culture (pH 4.2). Pups were gavage fed every 12 hours with Enterobacter cloacae challenges of 10 colony-forming units/mL per feed and killed on day of life 3. Lungs, liver, spleen, mesenteric lymph nodes (MLNs), stomach, and cecum were cultured and quantitatively analyzed for target organism growth. Results were analyzed using chi(2) tests. RESULTS NAN with live probiotic culture, when compared with Pelargon, acidified NAN, and NAN, significantly reduced the incidence of Enterobacter pulmonary colonization (P < .01), bacterial translocation (liver, P < .025; spleen and MLN, P < .05), and gastric and intestinal colonization (P < .001 for both). CONCLUSION Probiotic-fortified formula provides superior protection against pulmonary and gastrointestinal bacterial colonization and translocation compared with neutral and acidified formulas, and is equally tolerated.

Repair of esophageal atresia with tracheoesophageal fistula via thoracotomy: a contemporary series

BACKGROUND A recent series detailing thoracoscopic repair of esophageal atresia with tracheoesophageal fistula (EA/TEF) reported lower complication rates compared with historic controls. This study provides a contemporary cohort of patients repaired via thoracotomy for comparison with the recent large multi-institutional thoracoscopic series. METHODS Records of patients with EA/TEF between 1993 and 2008 were reviewed. Attention was focused on demographics and complications including anastomotic leak, recurrent fistulae, stricture formation, and need for fundoplication. RESULTS Seventy-two patients underwent repair of EA/TEF via thoracotomy. Complication rates in the current series compared with the thoracoscopic series were anastomotic leak, 2.7% versus 7.6%; recurrent fistulae, 2.7% versus 1.9%; stricture, 5.5% versus 3.8%; and need for fundoplication, 12% versus 24%. Differences in complication rates did not reach statistical significance. Two children in this cohort developed mild scoliosis attributed to congenital vertebral anomalies, neither of whom required intervention. CONCLUSIONS Thoracoscopic repair of EA/TEF yielded complication rates similar to this contemporary series; however, trends toward increased anastomotic leaks and greater need for fundoplication were noted. No musculoskeletal sequelae were directly attributable to thoracotomy.

Enoxaparin inhibits fibrin sheath formation and decreases central venous catheter colonization following bacteremic challenge

Objective:Inhibition of fibrin sheath formation by enoxaparin decreases catheter colonization. Fibrin-binding radioactive tracer and catheter weights quantify fibrin reduction. Design:Controlled experimental study of central venous line colonization. Setting:Animal laboratory. Subjects:Adult male Sprague-Dawley rats. Interventions:Central venous lines were introduced into right external jugular veins of 254 animals in three groups: enoxaparin, Fibrimage, and catheter weight. The enoxaparin group (n = 196) received daily enoxaparin injections (n = 97) or catheter implantation only (n = 99); 176 received tail vein injections of Staphylococcus epidermidis on postoperative day (POD) 10. Twenty rats received saline injections as a control. On POD 13, catheters were removed and incubated in broth at 37°C for 48 hrs. Turbid samples were plated. In the Fibrimage group (n = 39), 20 rats receiving enoxaparin were compared with 19 controls without enoxaparin; all received S. epidermidis injections on POD 10. Fibrimage, fibrin-binding radiolabeled tracer, was given 1 hr before catheter removal. In the weight group (n = 19), six rats received enoxaparin; 13 did not. All received injections of S. epidermidis on POD 10. Measurements and Main Results:Positive plates underwent analytic profile index testing, ensuring correlation with inoculum. Results were compared using Fisher’s exact or chi-square tests. Gamma counts were determined in the Fibrimage group. Catheter tip weights were recorded. Results from the Fibrimage and weight groups were compared using Student’s t-test. The enoxaparin group had fewer catheters colonized (17 of 77) vs. no enoxaparin (42 of 99; p < .01). Pericatheter sheaths contained less fibrin compared with controls. Fibrimage group gamma counts were significantly decreased for the enoxaparin subgroup (x = 2244 counts per minute) vs. controls (x = 3767 counts per minute; p < .0002). The weight of catheter tips treated with enoxaparin (x = 39 mg) vs. controls (x = 90 mg) was also significantly decreased (p < .0001). Conclusions:Enoxaparin decreases the amount of fibrin surrounding central venous catheters. The incidence of catheter colonization decreases when the amount of fibrin within the pericatheter sheath decreases.

Probiotic acidified formula in an animal model reduces pulmonary and gastric bacterial load

BACKGROUND/PURPOSE We previously reported that a diet acidified with citric acid effectively reinforces gastric acid protection against bacterial colonization and translocation. In this study, our objective was to examine a biologically acidified formula hypothesized to be more physiologic than formula acidified with free acid. This study was Institutional Animal Care and Use Committee (IACUC) approved and designed to determine whether this diet is better tolerated and equally effective to acidification with citric acid against gut colonization and subsequent bacterial translocation in a premature infant rabbit model. METHODS A total of 89 rabbit pups born via cesarean delivery 1 day preterm were randomly assigned to 3 feeding groups: Pelargon Nestle at pH 4.55; NAN Nestle, a control diet at pH 7.0 with similar composition; and NAN Nestle acidified in the laboratory with citric acid at pH 4.55. Pups were gavage fed every 12 hours with Enterobacter cloacae challenges of 10 colony-forming units per milliliter of diet per feed and killed on day 3 of life. Lungs, liver, spleen, mesenteric lymph nodes, stomach, and cecum were cultured and quantitatively analyzed for target organism growth and statistically analyzed using chi(2) and Kruskal-Wallis tests. RESULTS Pelargon, compared to acidified NAN and NAN, significantly reduced the incidence of gastric colonization (15/33 [45%], 21/27 [78%], and 25/29 [86%], respectively; P < .01) and pulmonary colonization (10/33 [30%], 19/27 [70%], 21/29 [72%]; P < .01). Comparing the bacterial logs of colonized groups, the same benefit is observed in the lungs (0.77 +/- 1.22, 1.89 +/- 1.41, 2.12 +/- 1.47; P < .01). Gut colonization and bacterial translocation were equivalent between treatment groups (mesenteric lymph nodes: 10/33 [30%], 11/27 [40%], 8/29 [27%]; spleen: 10/33 [30%], 7/27 [26%], 8/29 [27%]; liver: 10/33 [30%], 6/27 [22%], 9/29 [31%]; cecum: 33/33 [100%], 27/27 [100%], 29/29 [100%]). CONCLUSION Biologically acidified formula demonstrated superior protection against pulmonary and gastric colonization compared to normal pH and diets acidified with free acid. Its effects may potentially reduce clinical pulmonary infection.

Effect of Bacterial Exposure on Acellular Human Dermis in a Rat Ventral Hernia Model

BACKGROUND Effectiveness of acellular human dermis (AHD) as an alternative to synthetic mesh in contaminated fields has been described. Cellular migration after implantation and corresponding strength of attachment is not well documented. Our aim is to correlate AHD vascularization, fibroblast migration, and strength of attachment with presence of inflammatory cells in clean and contaminated fields. MATERIALS AND METHODS Lewis rats were randomized to a control and three experimental groups. AHD was placed as an onlay over the intact abdominal wall. Experimental groups (n=72) were exposed to Staphylococcus aureus at 1 x 10(4), 1 x 10(5), or 1 x 10(6) by direct application; controls (n=12) were not exposed. At 5 and 28 d, abdominal walls were explanted and tissue ingrowth assessed via tensiometry measuring energy (E) and max stress (MS) at the AHD-tissue interface. Vascularity, fibroblast migration, and inflammatory cell migration were compared using light microscopy. RESULTS Shear strength reported as energy and max stress were significantly greater at 28 versus 5 d in all experimental groups, remaining unchanged in controls. Plasma cells and histiocytes significantly increased in all groups; macrophages increased in experimental groups only. Vascular ingrowth increased significantly in all groups; fibroblast migration was greater in controls and 1 x 10(6) exposed group only. CONCLUSIONS Contamination of AHD results in inflammatory cell influx and a surprising increase in shear strength. Interestingly, shear strength does not increase without contamination. Inflammation stimulates vascular ingrowth, but not equally significant fibroblast migration. Longer survivals are required to determine if energy and max stress of controls increase, and fibroblast migration follows vascular ingrowth.

Evaluation of Soft Tissue Attachments to a Novel Intra-abdominal Prosthetic in a Rabbit Model

Background. Laparoscopic ventral hernia repair requires placement of an intraperitoneal prosthetic. Composite mesh types have been developed to address the shortcomings of standard meshes. The authors evaluated the host reaction to intraperitoneal placement of a novel composite material. Materials and Methods. A comparison of an innovative polypropylene/polylactide composite mesh was made to Parietex Composite (PCO), Proceed, and DualMesh. Eighteen meshes per group were implanted on intact peritoneum in New Zealand White rabbits. The main outcome measures included the formation of visceral adhesions, adhesion tenacity, tensiometric measurements, and histological analysis. Evaluations of adhesions were made at 1, 4, and 16 weeks using a 2-mm minilaparoscopy. Results. There were no significant differences in the mean adhesion scores between the composite mesh types at week 1 (P = .15) and week 16 (P = .06). At 4 weeks, PCO had significantly fewer adhesions when compared with the other 3 mesh types (P = .02). Adhesion tenacity was also equivalent within the group at 16 weeks (P = .06). Tensiometry and histological analysis revealed no statistically significant differences between the mesh types. Conclusions. Four different composite mesh types had equivalent intra-abdominal soft tissue attachments in a rabbit model after a 16-week implantation period. PCO demonstrated the lowest mean adhesion score of each mesh type. Each mesh exhibited equivalent stiffness and energy to failure after explantation. The 4 composite mesh types demonstrated the successful formation of a neoperitoneum and comparable host biocompatibility as evidenced by similar degrees of inflammation.