Diverse models for anti-HIV activity of purine nucleoside analogs

Background

Purine nucleoside analogs (PNAs) constitute an important group of cytotoxic drugs for the treatment of neoplastic and autoimmune diseases. In the present study, classification models have been developed for the prediction of the anti-HIV activity of purine nucleoside analogs.

Results

The topochemical version of superaugmented pendentic index-4 has been proposed and successfully utilized for the development of models. A total of 60 2D and 3D molecular descriptors (MDs) of diverse nature were selected for building the classification models using decision tree (DT), random forest (RF), support vector machine (SVM), and moving average analysis (MAA). The values of most of these descriptors for each of the analogs in the dataset were computed using the Dragon software (version 5.3). An in-house computer program was also employed to calculate additional MDs which were not included in the Dragon software. DT, RF, and SVM correctly classified the analogs into actives and inactives with an accuracy of 89 %, 83 %, and 78 %, respectively. MAA-based models predicted the anti-HIV activity of purine nucleoside analogs with a non-error rate up to 98 %. Therapeutic active spans of the suggested MAA-based models not only showed more potency but also exhibited enhanced safety as revealed by comparatively high values of selectivity index (SI). The statistical importance of the developed models was appraised via intercorrelation analysis, specificity, sensitivity, non-error rate, and Matthews correlation coefficient.

Conclusions

High predictability of the proposed models clearly indicates an immense potential for developing lead molecules for potent but safe anti-HIV purine nucleoside analogs.

Detour matrix-based adjacent path eccentric distance sum indices for (Q)SAR/QSPR. Part II: application in development of models for COX-2 inhibitory activity of indomethacin derivatives

In present study, adjacent path eccentric distance sum indices proposed in Part-I of the manuscript were successfully utilised for the development of models for cycloxygenase-2 (COX-2) inhibitory activity. Values of diverse molecular descriptors (MDs) for each of 38 indomethacin analogues involved in the dataset were computed. A total of 55 diverse MDs were ultimately shortlisted for further analysis. The suitable models were developed using decision tree (DT), random forest (RF) and moving average analysis (MAA). The DT identified the proposed topological index (TI)-(A)ξ(3)(PDS) as one of the important indices. The accuracy of prediction of DT, RF and MAA-based models varied from 81.58% to 97.37%. The statistical significance of proposed models was assessed through inter-correlation analysis, sensitivity, specificity, non-error rate and Mathews correlation coefficient. Proposed models offer vast potential for providing lead structures for the development of potent anti-inflammatory agents devoid of COX-1 side effects.

Detour matrix-based adjacent path eccentric distance sum indices for QSAR/QSPR. Part I: development and evaluation

In the present study, three detour matrix-based topological indices (TIs) termed as adjacent path eccentric distance sum indices 1-3 (denoted by (A)ξ(1)(PDS), (A)ξ(2)(PDS) and (A)ξ(3)(PDS)) as well as their topochemical versions (denoted by (A)ξ(1c)(PDS), (A)ξ(2c)(PDS) and (A)ξ(3c)(PDS)) have been conceptualised. Values of the proposed TIs were computed for all possible cyclic and acyclic structures containing three, four, five vertices using an in-house computer programme. Proposed TIs were evaluated for discriminating power, degeneracy, intercorrelation and sensitivity towards branching as well relative position of substituent(s) in cyclic structures. Mathematical properties of one of the proposed TIs were also studied. Exceptionally high discriminating power, high sensitivity towards branching as well as relative position(s) of substituent(s) in cyclic structures and negligible degeneracy offer proposed indices a vast potential for use in characterisation of structures, similarity/dissimilarity studies, lead identification and optimisation, combinatorial library design and quantitative structure-activity/property/toxicity/pharmacokinetic relationship studies so as to facilitate drug design.

Fourth generation detour matrix-based topological descriptors for QSAR/QSPR - Part-2: application in development of models for prediction of biological activity

Augmented path eccentric connectivity topochemical indices (reported in part-1 of the manuscript) along with 42 diverse non-correlating molecular descriptors (shortlisted from a large pool of 2D and 3D MDs) were successfully utilised for the development of models through decision tree, random forest and moving average analysis for the prediction of antitubercular activity of aza and diazabiphenyl analogues of active compound (6S)-2-Nitro-{[4-(trifluoromethoxy)benzyl]oxy}-6,7-dihydro-5H-imidazo[2,1-b][1,3] oxazine (PA-824). The statistical significance of the proposed models was assessed through overall accuracy of prediction, intercorrelation analysis, sensitivity, specificity and Matthew's correlation coefficient (MCC). The accuracy of prediction of the proposed models varied from a minimum of 81% to a maximum of ∼99%. High accuracy of prediction amalgamated with high MCC values clearly indicates robustness of the proposed models. The said models offer a vast potential for providing lead structures for the development of potent antitubercular drugs.

Models for H₃ receptor antagonist activity of sulfonylurea derivatives

The histamine H₃ receptor has been perceived as an auspicious target for the treatment of various central and peripheral nervous system diseases. In present study, a wide variety of 60 2D and 3D molecular descriptors (MDs) were successfully utilized for the development of models for the prediction of antagonist activity of sulfonylurea derivatives for histamine H₃ receptors. Models were developed through decision tree (DT), random forest (RF) and moving average analysis (MAA). Dragon software version 6.0.28 was employed for calculation of values of diverse MDs of each analogue involved in the data set. The DT classified and correctly predicted the input data with an impressive non-error rate of 94% in the training set and 82.5% during cross validation. RF correctly classified the analogues into active and inactive with a non-error rate of 79.3%. The MAA based models predicted the antagonist histamine H₃ receptor activity with non-error rate up to 90%. Active ranges of the proposed MAA based models not only exhibited high potency but also showed improved safety as indicated by relatively high values of selectivity index. The statistical significance of the models was assessed through sensitivity, specificity, non-error rate, Matthew's correlation coefficient and intercorrelation analysis. Proposed models offer vast potential for providing lead structures for development of potent but safe H₃ receptor antagonist sulfonylurea derivatives.

Models for the prediction of melanocortin-4 receptor agonist activity of 4-substituted piperidin-4-ol

In the present study both classification and correlation techniques have been successfully employed for the development of the models of diverse nature for the prediction of melanocortin 4-receptor (MC4 R) agonist activity using a dataset comprising of 56 analogues of 4-substituted piperidine-4-ol derivatives. Decision tree (DT), random forest (RF), moving average analysis (MAA) and multiple linear regression (MLR) were utilised for development of the said models. The statistical significance of models was assessed through specificity, sensitivity, overall accuracy, Mathew's correlation coefficient (MCC) and intercorrelation analysis. High accuracy of prediction up to 98% was observed using these models. Proposed models offer vast potential for providing lead structures for the development of potent therapeutic agents for the treatment of male sexual dysfunction.

Classification models for anticancer activity

Despite significant research in understanding of neoplastic diseases, the success rate for oncology drugs is relatively very low. A major challenge before the scientific community is to design new chemical entities that will be highly selective for cancer cells so as to minimize side effects. Classification models (CMs) models play a prominent role in prediction of the biological properties of newly designed compounds before their synthesis and prevent non-optimal use of resources. Though correlation models far outnumber classification models for development of various therapeutic agents but the significance of classification models for development of anti-cancer agents can not be underestimated. Various techniques employed for development of classification models for anti-cancer activity have been briefly reviewed. Moreover, successful use of some of these classification techniques for the development of models for anti-proliferative activity has been illustrated using a data set comprising of 53 analogues of N-Benzoylated phenoxazines and phenothiazines. Resulting classification models with high degree of accuracy can play a vital role in providing lead structures for the development of novel anti-proliferative agents for cancer chemotherapy.

Fourth generation detour matrix-based topological indices for QSAR/QSPR - part-1: development and evaluation

In the present study, four detour matrix-based Topological Indices (TIs) termed as augmented path eccentric connectivity indices 1-4 (denoted by (AP)ξ(1)(C), (AP)ξ(2)(C), (AP)ξ(3)(C) and (AP)ξ(4)(C)) as well as their topochemical versions (denoted by (AP)ξ(1c)(C), (AP)ξ(2c)(C), (AP)ξ(3c)(C) and (AP)ξ(4c)(C)) have been conceptualised. A modified detour matrix termed as chemical detour matrix (Δ(c)) has also been proposed so as to facilitate computation of index values of topochemical versions of the said TIs. Values of the proposed TIs were computed for all the possible structures containing three, four and five vertices using an in-house computer program. The said TIs exhibited exceptionally high discriminating power and high sensitivity towards branching/relative position of substituent(s) in cyclic structures amalgamated with negligible degeneracy. Due care was taken during the development of TIs so as to ensure that reduction in index values of complex chemical structures to be within reasonable limits without compromising discriminating power. The mathematical properties of one of the proposed TIs have also been studied. With exceptionally high discriminating power, high sensitivity towards branching as well as relative position(s) of substituents in cyclic structures and negligible degeneracy, the proposed indices offer a vast potential for use in characterisation of structures, similarity/dissimilarity studies, lead identification and optimisation, combinatorial library design and quantitative structure-activity/property/toxicity/pharmacokinetic relationship studies.

Predicting biological activity: computational approach using novel distance based molecular descriptors

Four novel distance based molecular descriptors termed as superpendentic eccentric distance sum indices 1-4 (denoted by:∫P-1EDS, ∫P-2EDS, ∫P-3EDS and ∫P-4EDS) as well as their topochemical counterparts (denoted by:∫cP-1EDS, ∫cP-2EDS, ∫cP-3EDS and ∫cP-4EDS) have been conceptualized and developed in the present study. The sensitivity towards branching, discriminating power, and degeneracy of the proposed novel descriptors were investigated. Utility of these indices was investigated for development of models through decision tree and moving average analysis for the prediction of human corticotropin releasing factor-1 receptor binding affinity of substituted pyrazines. A wide variety of 46 2D and 3D molecular descriptors including proposed indices was employed for development of models through decision tree and moving average analysis. The calculation of most of these descriptors for each compound of the dataset was performed using online E-Dragon software (version 1.0). An in-house computer programme was also employed to calculate additional topological descriptors which did not figure in E-Dragon software. The decision tree classified and correctly predicted the input data with an impressive accuracy of 92% in the training set and 71% during cross-validation. A total of three descriptors, identified by decision tree, were subsequently utilized for development of suitable models using moving average analysis. These models predicted human corticotropin releasing factor-1 receptor binding affinity with an accuracy of ≥85%. The statistical significance of models was assessed through sensitivity, specificity and Matthew's correlation coefficient. High discriminating power, high sensitivity towards branching amalgamated with negligible degeneracy offer proposed descriptors a vast potential for use in the quantitative structure-activity/property/toxicity relationships so as to facilitate drug design.

Consumer-based technology for distribution of surgical videos for objective evaluation

BACKGROUND

The Global Operative Assessment of Laparoscopic Skill (GOALS) is one validated metric utilized to grade laparoscopic skills and has been utilized to score recorded operative videos. To facilitate easier viewing of these recorded videos, we are developing novel techniques to enable surgeons to view these videos. The objective of this study is to determine the feasibility of utilizing widespread current consumer-based technology to assist in distributing appropriate videos for objective evaluation.

METHODS

Videos from residents were recorded via a direct connection from the camera processor via an S-video output via a cable into a hub to connect to a standard laptop computer via a universal serial bus (USB) port. A standard consumer-based video editing program was utilized to capture the video and record in appropriate format. We utilized mp4 format, and depending on the size of the file, the videos were scaled down (compressed), their format changed (using a standard video editing program), or sliced into multiple videos. Standard available consumer-based programs were utilized to convert the video into a more appropriate format for handheld personal digital assistants. In addition, the videos were uploaded to a social networking website and video sharing websites.

RESULTS

Recorded cases of laparoscopic cholecystectomy in a porcine model were utilized. Compression was required for all formats. All formats were accessed from home computers, work computers, and iPhones without difficulty. Qualitative analyses by four surgeons demonstrated appropriate quality to grade for these formats.

CONCLUSIONS

Our preliminary results show promise that, utilizing consumer-based technology, videos can be easily distributed to surgeons to grade via GOALS via various methods. Easy accessibility may help make evaluation of resident videos less complicated and cumbersome.

Prediction of pharmacokinetic parameters

In silico tools specifically developed for prediction of pharmacokinetic parameters are of particular interest to pharmaceutical industry because of the high potential of discarding inappropriate molecules during an early stage of drug development itself with consequent saving of vital resources and valuable time. The ultimate goal of the in silico models of absorption, distribution, metabolism, and excretion (ADME) properties is the accurate prediction of the in vivo pharmacokinetics of a potential drug molecule in man, whilst it exists only as a virtual structure. Various types of in silico models developed for successful prediction of the ADME parameters like oral absorption, bioavailability, plasma protein binding, tissue distribution, clearance, half-life, etc. have been briefly described in this chapter.

Models for prediction of (V)600(E)BRAF and melanoma cells growth inhibitory activities of pyridoimidazolones

Targeted inhibition of activated BRAF mutation has emerged as a most promising and putative therapeutic approach for the anticancer drug development. In the present study, an in-silico approach using decision tree and moving average analysis has been applied to a data set comprising of 43 analogues of pyridoimidazolones for development of models for prediction of both (V)600(E)BRAF and melanoma cells (BRAF WM266.4) growth inhibitory activities. A decision tree was mainly employed for determining the importance of molecular descriptors (n=46). The value of majority of these descriptors for each analogue in the dataset was computed using E-Dragon software (version 1.0). The decision tree learned the information from the input data with an accuracy of 98% and correctly predicted the cross-validated (10-fold) data with accuracy up to 79%. A total of three non-correlating descriptors, identified best by the decision tree analysis, were subsequently utilized for development of suitable models using moving average analysis. These proposed models resulted in the prediction of (V)600(E)BRAF inhibitory activity (IC50) and melanoma cells growth (SRB GI50) inhibitory activity with an overall accuracy of ≥90%. The statistical significance of models/descriptors was assessed through intercorrelation analysis, sensitivity, specificity and Matthew's correlation coefficient.

Decrease in sweet taste in rats after gastric bypass surgery

BACKGROUND

The literature contains evidence that Roux-en-Y gastric bypass (RYGB) surgery has an effect in humans on taste and preference for carbohydrate-rich foods. This study tested the hypothesis that RYGB affects sweet taste behavior using a rat model.

METHODS

Male Sprague-Dawley rats underwent either RYGB or sham surgery. Then 4 weeks after surgery, the rats were given taste-salient, brief-access lick tests with a series of sucrose concentrations.

RESULTS

The RYGB rats, but not the sham rats, lost weight over the 5-week postoperative period. The RYGB rats showed a significant decrease in mean licks for the highest concentration of sucrose (0.25-1.0 mol/l) but not for the low concentrations of sucrose or water.

CONCLUSIONS

The findings showed that RYGB surgery affected sweet taste behavior in rats, with postsurgical rats having lower sensitivity or avidity for sucrose than sham-treated control rats. This finding is similar to human reports that sweet taste and preferences for high-caloric foods are altered after bypass surgery.

Human epicardial adipokine messenger RNAs: comparisons of their expression in substernal, subcutaneous, and omental fat

We compared the gene expression of inflammatory and other proteins by real-time quantitative polymerase chain reaction in epicardial, substernal (mediastinal) and subcutaneous sternal, upper abdominal, and leg fat from coronary bypass patients and omental (visceral) fat from extremely obese women undergoing bariatric surgery. We hypothesized that (1) epicardial fat would exhibit higher expression of inflammatory messenger RNAs (mRNAs) than substernal and subcutaneous fat and (2) epicardial mRNAs would be similar to those in omental fat. Epicardial fat was clearly different from substernal fat because there was a far higher expression of haptoglobin, prostaglandin D(2) synthase, nerve growth factor beta, the soluble vascular endothelial growth factor receptor (FLT1), and alpha1 glycoprotein but not of inflammatory adipokines such as monocyte chemoattractant protein-1, interleukin (IL)-8, IL-1beta, tumor necrosis factor alpha, serum amyloid A, plasminogen activator inhibitor-1, or adiponectin despite underlying coronary atherosclerosis. However, the latter inflammatory adipokines as well as most other mRNAs were overexpressed in epicardial fat as compared with the subcutaneous depots except for IL-8, fatty acid binding protein 4, the angiotensin II receptor 1, IL-6, and superoxide dismutase-2. Relative to omental fat, about one third of the genes were expressed at the same levels, whereas monocyte chemoattractant protein-1, cyclooxygenase-2, plasminogen activator inhibitor-1, IL-1beta, and IL-6 were expressed at far lower levels in epicardial fat. In conclusion, epicardial fat does not appear to be a potentially more important source of inflammatory adipokines than substernal mediastinal fat. Furthermore, the expression of inflammatory cytokines such as IL-6 and IL-1beta is actually higher in omental fat from obese women without coronary atherosclerosis. The data do not support the hypothesis that most of the inflammatory adipokines are expressed at high levels in epicardial fat of humans.

Release of 12 adipokines by adipose tissue, nonfat cells, and fat cells from obese women

The relative release in vitro of endothelin-1, zinc-alpha2-glycoprotein (ZAG), lipocalin-2, CD14, RANTES (regulated on activation, normal T cell expressed and secreted protein), lipoprotein lipase (LPL), osteoprotegerin (OPG), fatty acid-binding protein 4 (FABP-4), visfatin/PBEF/Nampt, glutathione peroxidase-3 (GPX-3), intracellular cell adhesion molecule 1 (ICAM-1), and amyloid A was examined using explants of human adipose tissue as well as the nonfat cell fractions and adipocytes from obese women. Over a 48-h incubation the majority of the release of LPL was by fat cells whereas that of lipocalin-2, RANTES, and ICAM-1 was by the nonfat cells present in human adipose tissue. In contrast appreciable amounts of OPG, amyloid A, ZAG, FABP-4, GPX-3, CD14, and visfatin/PBEF/Nampt were released by both fat cells and nonfat cells. There was an excellent correlation (r = 0.75) between the ratios of adipokine release by fat cells to nonfat cells over 48 h and the ratio of their mRNAs in fat cells to nonfat cells at the start of the incubation. The total release of ZAG, OPG, RANTES, and amyloid A by incubated adipose tissue explants from women with a fat mass of 65 kg was not different from that by women with a fat mass of 29 kg. In contrast that of ICAM-1, FABP-4, GPX-3, visfatin/PBEF/Nampt, CD14, lipocalin-2, LP, and endothelin-1 was significantly greater in tissue from women with a total fat mass of 65 kg.

Urea inclusion compounds of enalapril maleate for the improvement of pharmaceutical characteristics

Urea is a well known adductor for linear organic compounds. In the present study, enalapril maleate, a substituted cyclic organic compound, was successfully included in urea together with a suitable rapidly adductible endocyte (RAE). Formation of the urea inclusion compound was confirmed by Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffraction. The modified Zimmerschied calorimetric method was used to estimate the minimum amount of RAE required for adduction of enalapril maleate in urea. Urea-enalapril maleate-RAE inclusion compounds containing varying proportions of guests were prepared and their thermal behaviour studied by differential scanning calorimetry. Regression analysis revealed an excellent r2 value with regard to the influence of the relative proportion of RAE on the heat of decomposition. The inclusion compounds were found to exhibit good content uniformity and improved dissolution profile as demonstrated by increased dissolution efficiency. Studies revealed that urea inclusion may be a promising alternative for the formulation of potent poorly soluble drugs into immediate release products.

Urea co-inclusion compounds of 13 cis-retinoic acid for simultaneous improvement of dissolution profile, photostability and safe handling characteristics

13-cis Retinoic acid (cis-RA), a synthetic retinoid used in the treatment of severe acne, is known to exhibit extremely low aqueous solubility and high photosensitivity. In this study, urea, a well-known adductor for linear compounds, was successfully employed for the adduction of cis-RA — a substituted cyclic organic compound. Formation of urea inclusion compounds was confirmed by FTIR, DSC and XRD. A modified Zimmerschied calorimetric method was employed for the estimation of the minimum amount of rapidly adductible endocyte (RAE) required for adduction of cis-RA in urea. Urea–cis-RA-RAE inclusion compounds containing varying proportions of guests were prepared and their thermal behaviour studied by DSC. The inclusion compounds were found to have an improved dissolution profile as demonstrated by an overall increase in the dissolution efficiency. An accelerated photostability study, conducted as per Q1B ICH guidelines, revealed that co-inclusion of cis-RA in urea delayed photo-degradation of the drug when compared with that of the pure drug. The results suggest the possibility of exploiting co-inclusion of the drug in a urea host lattice for improved solubility, stability and reduced handling problems for cis-RA.

Dexamethasone and the inflammatory response in explants of human omental adipose tissue

Dexamethasone is a synthetic glucocorticoid that is a potent anti-inflammatory agent. The present studies examined the changes in gene expression of 64 proteins in human omental adipose tissue explants incubated for 48h both in the absence and presence of dexamethasone as well as the release of 8 of these proteins that are putative adipokines. The proteins were chosen because they are inflammatory response proteins in other cells, are key regulatory proteins or are proteins with known functions. About 50% were significantly up-regulated while about 10% were unchanged and the remaining 40% were down-regulated. Dexamethasone significantly up-regulated the expression of about 33% of the proteins but down-regulated the expression of about 12% of the proteins. We conclude that dexamethasone is a selective anti-inflammatory agent since it inhibits only about one-fourth of the proteins up-regulated during in vitro incubation of human omental adipose tissue.

The inflammatory response seen when human omental adipose tissue explants are incubated in primary culture is not dependent upon albumin and is primarily in the nonfat cells

Background

The present studies were designed to investigate the changes in gene expression during in vitro incubation of human visceral omental adipose tissue explants as well as fat cells and nonfat cells derived from omental fat.

Methods

Adipose tissue was obtained from extremely obese women undergoing bariatric surgery. Explants of the tissue as well as fat cells and the nonfat cells derived by digestion with collagenase were incubated for 20 minutes to 48 h. The expression of interleukin 1β [IL-1β], tumor necrosis factor α [TNFα], interleukin 8 [IL-8], NFκB₁p50 subunit, hypoxia-inducible factor 1α [HIF1α], omentin/intelectin, and 11β-hydroxysteroid dehydrogenase 1 [11β-HSD1] mRNA were measured by qPCR as well as the release of IL-8 and TNFα.

Results

There was an inflammatory response at 2 h in explants of omental adipose tissue that was reduced but not abolished in the absence of albumin from the incubation buffer for IL-8, IL-1β and TNFα. There was also an inflammatory response with regard to upregulation of HIF1α and NFκB1 gene expression that was unaffected whether albumin was present or absent from the medium. In the nonfat cells derived by a 2 h collagenase digestion of omental fat there was an inflammatory response comparable but not greater than that seen in tissue. The exception was HIF1α where the marked increase in gene expression was primarily seen in intact tissue. The inflammatory response was not seen with respect to omentin/intelectin. Over a subsequent 48 h incubation there was a marked increase in IL-8 mRNA expression and IL-8 release in adipose tissue explants that was also seen to the same extent in the nonfat cells incubated in the absence of fat cells.

Conclusion

The marked inflammatory response seen when human omental adipose tissue is incubated in vitro is reduced but not abolished in the presence of albumin with respect to IL-1β, TNFα, IL-8, and is primarily in the nonfat cells of adipose tissue.

Models for cannabinoid-1 receptor antagonistic activity of substituted 2-(3-pyrazolyl)-1,3,4-oxadiazoles

Antagonism of cannabinoid receptor-1 has emerged as a most promising therapeutic target for the development of anti-obesity drugs. In the present study, an in silico approach using decision tree, random forest and moving average analysis has been applied to a data set comprising of 76 analogues of substituted 2-(3-pyrazolyl)-1,3,4-oxadiazoles for development of models for prediction of antagonistic activity of cannabinoid receptor-1. A total of 46 2D and 3D molecular descriptors of diverse nature were employed for decision tree and random forest analysis. The values of majority of these descriptors for each analogue involved in the dataset were computed using E-Dragon software (version 1.0). Random forest correctly classified the analogues into active and inactive with an accuracy of 95%. A decision tree was also utilized for determining the importance of molecular descriptors. The decision tree learned the information from the input data with an accuracy of 99% and correctly predicted the cross-validated (10 fold) data with an accuracy up to 90%. Finally, three molecular descriptors of diverse nature (including best descriptor identified by decision tree analysis) were subsequently used to build suitable models using moving average analysis. These models resulted in the prediction of cannabinoid receptor-1 antagonistic activity with an accuracy of 95-96%. High predictability of proposed models offer vast potential for providing lead structures for the development of potent cannabinoid receptor-1 antagonists for the treatment of obesity.

Omental reinforcement for intraoperative leak repairs during laparoscopic Roux-en-Y gastric bypass

Leaks from the gastrojejunostomy after laparoscopic Roux-en-Y gastric bypass (LRYGB) have the potential for significant morbidity and mortality. When intraoperative leaks are discovered, we choose to perform omental reinforcement around the gastrojejunostomy and pouch after suture repair of the leaks. This study examined the hypothesis that omental reinforcement would be useful after intraoperative leaks during LRYGB. Omental reinforcement was performed on gastrojejunostomies, in which leaks were seen, created using a circular stapler during LRYGB. Data were reviewed retrospectively on these patients. There were a total of 387 patients with 32 (8.26%) patients who had a staple line dehiscence or evidence of gastric pouch or gastrojejunostomy leak intraoperatively. Leaks/dehiscences were repaired with sutures and then reinforced with omentum. None of these patient developed anastomotic leak postoperatively. Of the other 365 patients, there were four (1.1%) leaks from the gastrojejunostomy and/or gastric pouch. Omental reinforcement may be useful in decreasing the incidence of postoperative leaks when an intraoperative leak is encountered during LRYGB. However, omental reinforcement does not completely prevent a postoperative leak. Consideration of reinforcement with omentum may be given for patients in whom an intraoperative leak is noted.

Omental Reinforcement for Intraoperative Leak Repairs during Laparoscopic Roux-en-Y Gastric Bypass

Leaks from the gastrojejunostomy after laparoscopic Roux-en-Y gastric bypass (LRYGB) have the potential for significant morbidity and mortality. When intraoperative leaks are discovered, we choose to perform omental reinforcement around the gastrojejunostomy and pouch after suture repair of the leaks. This study examined the hypothesis that omental reinforcement would be useful after intraoperative leaks during LRYGB. Omental reinforcement was performed on gastrojejunostomies, in which leaks were seen, created using a circular stapler during LRYGB. Data were reviewed retrospectively on these patients. There were a total of 387 patients with 32 (8.26%) patients who had a staple line dehiscence or evidence of gastric pouch or gastrojejunostomy leak intraoperatively Leaks/dehiscences were repaired with sutures and then reinforced with omentum. None of these patient developed anastomotic leak postoperatively. Of the other 365 patients, there were four (1.1%) leaks from the gastrojejunostomy and/or gastric pouch. Omental reinforcement may be useful in decreasing the incidence of postoperative leaks when an intraoperative leak is encountered during LRYGB. However, omental reinforcement does not completely prevent a postoperative leak. Consideration of reinforcement with omentum may be given for patients in whom an intraoperative leak is noted.

Laparoscopic revision of failed fundoplication and hiatal herniorraphy

OBJECTIVE

The aim of this study was to evaluate the mechanisms of failure after laparoscopic fundoplication and the results of revision laparoscopic fundoplication.

BACKGROUND

Laparoscopic Nissen fundoplication has become the most commonly performed antireflux procedure for the treatment of gastroesophageal reflux disease, with success rates from 90 to 95%. Persistent or new symptoms often warrant endoscopic and radiographic studies to find the cause of surgical failure. In experienced hands, reoperative antireflux surgery can be done laparoscopically. We performed a retrospective analysis of all laparoscopic revision of failed fundoplications done by the principle author and the respective fellow within the laparoscopic fellowship from 1992 to 2006.

METHODS

A review was performed on patients who underwent laparoscopic revision of a failed primary laparoscopic fundoplication.

RESULTS

Laparoscopic revision of failed fundoplication was performed on 68 patients between 1992 and 2006. The success rate of the laparoscopic redo Nissen fundoplication was 86%. Symptoms prior to the revision procedure included heartburn (69%), dysphagia (8.8%), or both (11.7%). Preoperative evaluation revealed esophagitis in 41%, hiatal hernia with esophagitis in 36%, hiatal hernia without esophagitis in 7.3%, stenosis in 11.74%, and dysmotility in 2.4%. The main laparoscopic revisions included fundoplication alone (41%) or fundoplication with hiatal hernia repair (50%). Four gastric perforations occurred; these were repaired primarily without further incident. An open conversion was performed in 1 patient. Length of stay was 2.5 +/- 1.0 days. Mean follow-up was 22 months (range, 6-42), during which failure of the redo procedure was noted in 9 patients (13.23%).

CONCLUSION

Laparoscopic redo antireflux surgery, performed in a laparoscopic fellowship program, produces excellent results that approach the success rates of primary operations.

Intraoperative endoscopy and leaks after laparoscopic Roux-en-Y gastric bypass

Postoperative leaks after laparoscopic Roux-en-Y gastric bypass (LRYGB) are a source of morbidity and mortality. Any intervention that would decrease leak rates after LRYGB would be useful. This investigation tested the hypothesis that postoperative leak rates are lower after LRYGB with the routine use of intraoperative endoscopy (EN). Consecutive patients who underwent LRYGB were included. Intraoperative leak testing with air and methylene blue through an orogastric tube (OG) was used in the first 200 patients. Intraoperative endoscopy was used after the first 200 patients. There were 400 patients in this study. Preoperative demographics did not differ between groups. The intraoperative leak rate of the EN group was double the OG group (8 vs 4%; P = not significant), although the difference was not statistically significant. The OG group had a postoperative leak rate of 4 per cent with a mortality rate of 1 per cent. The EN group had a postoperative leak rate of 0.5 per cent with a mortality rate of 0 per cent. The difference in leak rates was statistically significant (P < 0.04). Despite the issues of learning curve, EN demonstrates more intraoperative leaks than OG, indicating EN may be a more sensitive test than OG. Routine use of EN is associated with less postoperative leaks after LRYGB.

Intraoperative Endoscopy and Leaks after Laparoscopic Roux-en-Y Gastric Bypass

Postoperative leaks after laparoscopic Roux-en-Y gastric bypass (LRYGB) are a source of morbidity and mortality. Any intervention that would decrease leak rates after LRYGB would be useful. This investigation tested the hypothesis that postoperative leak rates are lower after LRYGB with the routine use of intraoperative endoscopy (EN). Consecutive patients who underwent LRYGB were included. Intraoperative leak testing with air and methylene blue through an orogastric tube (OG) was used in the first 200 patients. Intraoperative endoscopy was used after the first 200 patients. There were 400 patients in this study. Preoperative demographics did not differ between groups. The intraoperative leak rate of the EN group was double the OG group (8 vs 4%; P = not significant), although the difference was not statistically significant. The OG group had a postoperative leak rate of 4 per cent with a mortality rate of 1 per cent. The EN group had a postoperative leak rate of 0.5 per cent with a mortality rate of 0 per cent. The difference in leak rates was statistically significant ( P < 0.04). Despite the issues of learning curve, EN demonstrates more intraoperative leaks than OG, indicating EN may be a more sensitive test than OG. Routine use of EN is associated with less postoperative leaks after LRYGB.

Stimulation of human omental adipose tissue lipolysis by growth hormone plus dexamethasone

Growth hormone [GH] administration results in a reduction in adiposity of humans that is attributed to stimulation of lipolysis. We examined the effect of direct addition of human GH, in both the absence and presence of dexamethasone [Dex], as well as that of interferon beta on lipolysis by omental adipose tissue explants from obese women incubated for 48h in primary culture. There was a significant stimulation of lipolysis by GH in the presence of Dex but not by Dex or GH alone. There was also a significant further stimulation by GH in the presence of Dex of hormone-sensitive lipase, perilipin, lipoprotein lipase and beta1 adrenergic receptor mRNA. We conclude that the direct lipolytic effect of GH is accompanied by an increase in HSL mRNA in the presence of DEX, but GH also increased the mRNAs for other proteins that could explain all or part of its lipolytic action.

Patient perception of medicare fee schedule of laparoscopic procedures

INTRODUCTION

It seems that public perception is that physicians receive substantial payments for procedures. This investigation explores patient perception and opinion of Medicare reimbursements to surgeons related to laparoscopic surgery. Our hypothesis was that patients think the surgeon Medicare fee schedule is higher than actuality.

METHODS

Patients filled out an IRB exempted survey. The survey included a written description of laparoscopic gastric bypass, laparoscopic adjustable gastric band placement, laparoscopic cholecystectomy and an initial patient visit for 30 minutes. All participants were asked to give their thoughts of what Medicare currently reimburses for these procedures as well as what the payment should be. The survey also asked other questions about reimbursement related to Medicare.

RESULTS

There were 96 participants in the investigation with 43% of patients not filling in reimbursements for at least one procedure. Most patients (88%) looked at their bills from physicians and insurance companies carefully. For each procedure, the mean reimbursements were approximately 10 times higher than the patient perception of both the amount Medicare currently pays and the amount Medicare should pay compared to the actual fee. For the initial patient visit, the patients overestimated the payment by 158% and thought the Medicare should pay 199% of the actual fee. Most of the patients (98%) thought Medicare should pay more for more difficult cases and 85% thought Medicare should pay more if the patient visits the surgeon more times during the global period. While 32% of the patients feel Medicare pay physicians well, 91% thought that Medicare should increase fees.

CONCLUSION

Most of our patients overestimated what Medicare currently pays for some laparoscopic procedures. Surgeons need to do a better job in educating patients and the general public about the Medicare fee schedule.

Monitored anesthesia care with propofol versus surgeon-monitored sedation with benzodiazepines and narcotics for preoperative endoscopy in the morbidly obese

BACKGROUND

Although still controversial, upper endoscopy is frequently performed before bariatric surgery. This study investigated the hypothesis that morbidly obese patients would prefer anesthesiologist-monitored sedation (AMS) compared to surgeon-monitored sedation (SMS) during preoperative endoscopy.

METHODS

All patients who underwent endoscopy before their bariatric surgery were given a post-procedure survey regarding their experience with the preoperative endoscopy. The survey inquired about issues during and after the procedure. We compared patients who had AMS with IV propofol versus SMS IV narcotics and benzodiazepines.

RESULTS

There were 100 patients (SMS=49 and AMS=51). Few patients complained of pain in the abdomen or throat during the procedure (AMS vs. SMS=2 vs. 8% and 2 vs. 10%, respectively; p=NS). More patients complained about throat pain after the procedure (AMS vs. SMS=37 vs. 45%; p=NS). More patients in the SMS group remembered the scope being placed in the mouth versus AMS (33 vs. 10%; p<0.02). More patients remembered gagging during the procedure in the SMS group versus the AMS group, but this did not reach statistical significance (24 vs. 10%; p=0.06). There was a trend that more patients in the AMS group felt they recovered in less than 1 h (53%) compared to the SMS group (37%; p=0.1).

CONCLUSION

Patients who undergo upper endoscopy with either AMS or SMS seem to tolerate the procedure well. The preliminary benefits seen with AMS need to be further explored. AMS should be considered for patients undergoing preoperative upper endoscopy before bariatric surgery.

Comparison of two low-molecular-weight heparin dosing regimens for patients undergoing laparoscopic bariatric surgery

BACKGROUND

Venous thromboembolic events (VTE) are a morbidity and mortality concern for patients undergoing laparoscopic bariatric surgery. Although VTE prophylaxis is recommended in bariatric surgery, data with regard to monitoring and appropriate dosing of low-molecular-weight heparin are limited. Enoxaparin prophylactic doses ranging from 30 to 60 mg every 12 h have been used for this population. The authors hypothesized that higher prophylactic enoxaparin doses (60 mg) would yield more appropriate heparin antifactor Xa (anti-Xa) concentrations than the 40-mg dosage for bariatric surgery patients.

METHODS

Patients undergoing laparoscopic bariatric surgery by two surgeons during a 5-month period at one institution received enoxaprin 40 or 60 mg every 12 h. Anti-Xa levels were obtained 4 h after the first and third doses. Therapeutic levels were defined as 0.18 to 0.44 U/ml. Paired and unpaired t-tests and chi-square tests were used for statistical analysis as appropriate.

RESULTS

The first-dose mean anti-Xa concentration was 0.173 U/ml in the 40-mg group and 0.261 U/ml in the 60-mg group (p < 0.005), compared with the third-dose mean anti-Xa levels of 0.21 and 0.43 U/ml, respectively (p < 0.001). After the third dose of enoxaparin, the percentage of patients with anti-Xa concentrations who remained subtherapeutic showed a statistically significant difference: 44% in the 40-mg group versus 0% in the 60-mg group (p = 0.02). However, no supratherapeutic anti-Xa concentrations were observed in the 40-mg group, whereas 57% of the third-dose levels in the 60-mg group were supratheraputic. The highest anti-Xa level was 0.54 U/ml, but none of the patients with this level experienced bleeding events.

CONCLUSIONS

Enoxaparin 60-mg every 12 h was superior to a dosage of 40 mg every 12 h in achieving therapeutic anti-Xa concentrations and avoiding subtherapeutic anti-Xa levels. However, the 60-mg group had a number of supratherapeutic levels. Future studies evaluating the relationship of anti-Xa concentrations and outcomes with larger numbers of morbidly obese patients are needed.

Comparison of messenger RNA distribution for 60 proteins in fat cells vs the nonfat cells of human omental adipose tissue

The messenger RNA (mRNA) distribution of 60 proteins was examined in the 3 fractions obtained by collagenase digestion (fat cells and the nonfat cells comprising the tissue remaining after collagenase digestion [matrix] and the stromovascular cells) of omental adipose tissue obtained from morbidly obese women undergoing bariatric surgery. Fat cells were enriched by at least 3-fold as compared with nonfat cells in the mRNAs for retinol binding protein 4, angiotensinogen, adipsin, glutathione peroxidase 3, uncoupling protein 2, peroxisome proliferator-activated receptor gamma, cell death-inducing DFFA-like effector A, fat-specific protein 27, 11beta-hydroxysteroid dehydrogenase 1, glycerol channel aquaporin 7, NADPH:quinone oxidoreductase 1, cyclic adenosine monophosphate phosphodiesterase 3B, glyceraldehyde-3-phosphate dehydrogenase, insulin receptor, and amyloid A1. Fat cells were also enriched by at least 26-fold in the mRNAs for proteins involved in lipolysis such as hormone-sensitive lipase, lipoprotein lipase, adipose tissue triglyceride lipase, and FAT/CD36. The relative distribution of mRNAs in cultured preadipocytes was also compared with that of in vitro differentiated adipocytes derived from human omental adipose tissue. Cultured preadipocytes had far lower levels of the mRNAs for inflammatory proteins than the nonfat cells of omental adipose tissue. The nonfat cells were enriched by at least 5-fold in the mRNAs for proteins involved in the inflammatory response such as tumor necrosis factor alpha, interleukin lbeta, cyclooxygenase 2, interleukin 24, interleukin 6, and monocyte chemoattractant protein 1 plus the mRNAs for osteopontin, vaspin, endothelin, angiotensin II receptor 1, butyrylcholinesterase, lipocalin 2, and plasminogen activator inhibitor 1. The cells in the adipose tissue matrix were enriched at least 3-fold as compared with the isolated stromovascular cells in the mRNAs for proteins related to the inflammatory response, as well as osteopontin and endothelial nitric oxide synthase. We conclude that the mRNAs for inflammatory proteins are primarily present in the nonfat cells of human omental adipose tissue.

Gastric bypass surgery in rats produces weight loss modeling after human gastric bypass

BACKGROUND

The study of the mechanisms of weight loss after bariatric surgery requires an animal model that mimics the human procedure and subsequent weight loss. A rat model eliminates the cognitive efforts associated with human weight loss and gain.

METHODS

A technique for gastric bypass (Roux-en-Y gastric bypass [RYGB]) was developed in Sprague-Dawley rats. A 1- to 2-cc pouch is created from the uppermost stomach using a linear stapler. A 10-cm biliopancreatic limb and 15-cm Roux limb are anastomosed side to side with running nonabsorbable suture. The gastrojejunostomy is created with a single layer of running nonabsorbable suture. Four rats underwent RYGB. Weight loss was compared to four sham rats that had a midline incision and left 60 min with an open abdomen before closure.

RESULTS

RYGB rats lost an average of 16.5% body weight (BW) at 1 week, 22% BW at 2 weeks, 20% BW at 3 weeks, and 11% BW at 4 weeks. The RYGB rat's weight was basically level after 4 weeks. The shams lost an average of 4% BW at 1 week, 1% BW at 2 weeks, and 0% BW at 3 weeks and gained an average of 2% at weeks. Subjectively, the RYGB rats were less interested in chow and frequently had chow left in their cage.

CONCLUSION

A Sprague-Dawley rat model for gastric bypass has been developed and yields approximately 11% BW loss. This will allow investigators to objectively view factors associated with weight loss without the confounding cognitive factors in humans.

Effect of preoperative knowledge on weight loss after laparoscopic gastric bypass

INTRODUCTION

Gastric bypass surgery has been demonstrated to be an effective treatment for morbid obesity. Unfortunately, not all patients have the same weight loss after surgery. It may be that the more informed patients will have more weight loss than less informed patients. No study has investigated the relationship between initial preoperative knowledge and weight loss after laparoscopic gastric bypass surgery.

METHODS

All patients who underwent laparoscopic gastric bypass for a 6-month period were included in this study. Our preoperative education process includes a 21-question true/false test given at the appointment immediately before surgery. Patients repeat the test until all questions are answered correctly. We compared percentage of excess body weight loss (EBWL) between patients who correctly answered all the questions the first time (pass patients) and patients who did not correctly answer all the questions the first time (fail patients).

RESULTS

There were 104 patients involved in this study; although complete data were only available on 98 patients. The average preoperative body mass index was 48 kg/m(2). Forty-eight percent of patients answered all the questions correctly the first time. Follow-up ranged from 1 to 2 years on all 98 patients. Pass patients had an average of 73% EBWL, whereas fail patients had an average of 76% EBWL (p = NS).

CONCLUSIONS

Preoperative knowledge, assessed by a test, did not predict success after laparoscopic gastric bypass surgery. Patients who do not, at first, have full knowledge of bariatric surgery should not be discriminated against undergoing surgery if they are eventually properly educated.

Minimally invasive surgery fellows would perform a wider variety of cases in their "ideal" fellowship

BACKGROUND

With the increase in minimally invasive surgery (MIS) fellowships, the concept of the ideal and standardized training curriculum is emerging in importance. The authors hypothesize that the procedure mix in current MIS training is different from what current MIS fellows would expect for their "ideal" fellowship.

METHODS

An anonymous survey of current MIS fellows examined their perceptions of the case diversity and volume they expect to perform in their fellowships as compared with an ideal fellowship. Differences between expected and ideal case volume were analyzed using Wilcoxon tests.

RESULTS

A total of 32 questionnaires were returned. Current MIS fellows believe their expected training will exceed the ideal volume of laparoscopic cholecystectomies (p = 0.002). They believe their expected training is equivalent to ideal training in laparoscopic gastric bypass, ventral herniorraphy, inguinal herniorraphy, antireflux procedures, appendectomy, and diagnostic endoscopy (nonsignificant difference). However, current expected training falls short of their "ideal" case volume in laparoscopic gastric banding, colectomy, common bile duct exploration, gastrectomy, esophagectomy, splenectomy, adrenalectomy, hepatectomy, nephrectomy, and pancreatectomy (p < 0.05). The current MIS fellows also expect that their thoracoscopic, therapeutic endoscopy, and robotic procedure volume will be less than "ideal" (p < 0.05).

CONCLUSION

In 13 of 20 procedure types, current MIS fellows expect to perform a smaller case volume than in an "ideal" fellowship. The ideal case volume in the MIS fellowship curriculum needs to be defined better.

Body esteem improves after bariatric surgery

Body esteem is an issue for the morbidly obese. Although the primary goal of bariatric surgery is to improve, cure, and prevent medical comorbidities, the psychological aspect of bariatric surgery is just as important. Few studies have investigated the body esteem of patients after laparoscopic gastric bypass. This investigation tested the hypothesis that body esteem improves after bariatric surgery. Preoperative and postoperative patients were asked to fill out an institutional review board-exempted survey that included the Body-Esteem Scale for Adolescents and Adults (BESAA). The subscales include Appearance, Weight, and Attribution. Postoperative patients were told to fill the BESAA as they felt currently and as they felt before surgery. They felt that they had better scores currently than before surgery. Preoperative patients had worse scores than postoperative patients. As in many medical issues, body esteem improves after bariatric surgery. When discussing its benefits, psychological aspects of body esteem should be touted as well.

Cost analysis of laparoscopic gastric bypass practice using current Medicare reimbursement and practice costs

BACKGROUND

We performed a formal cost analysis of a hypothetical bariatric practice consisting of a surgeon, dietitian, clinical coordinator/office manager, receptionist, and certified medical assistant to determine whether a bariatric practice would have a difficult time surviving financially with the current Medicare reimbursement.

METHODS

The number of possible cases was calculated for the 2005 calendar year. Most of the costs and assumptions were taken from an actual bariatric practice. The malpractice insurance premium (but not physician salary and benefits) was calculated into the practice cost.

RESULTS

With a total of 231 days available for clinical work in 2005, 300 scheduled laparoscopic gastric bypasses could have been performed to allow for appropriate clinic time for new patient visits, postoperative visits, and annual visits. The total reimbursement from Medicare would have been $516,158, with most of the reimbursement coming from procedure fees ($407,063). The total practice cost would have been $444,592. Most of the costs were clinic staff salary and benefits ($207,065) and the malpractice premium ($55,150). The net difference of $71,566 was left to pay the salary and benefits of the bariatric surgeon.

CONCLUSION

The low reimbursement of Medicare for laparoscopic gastric bypass threatens the financial viability of a bariatric surgery practice. With the increasing cost of malpractice and the threatened decrease in Medicare physician reimbursement, Medicare recipients could see a decrease in the number of bariatric surgeons offering them service.

Anti-Xa levels in bariatric surgery patients receiving prophylactic enoxaparin

BACKGROUND

Limited data exist regarding efficacy and dosing of low-molecular-weight heparins, including enoxaparin, for morbidly obese patients. Prophylactic doses of 30 to 60 mg every 12 h have been described in bariatric surgery patients with appropriate anti-Xa levels reported between 0.18 and 0.6 units/mL.

METHODS

Fifty-two laparoscopic gastric bypass or banding patients were enrolled. Patients were divided into two groups by the dose of enoxaparin that was given: Group 1--enoxaparin 30 mg every 12 hours--and Group 2--enoxaparin 40 mg every 12 h. Anti-Xa levels were obtained 4 h after the first and third doses. Levels between 0.18-0.44 units/mL were considered appropriate.

RESULTS

There were 19 patients (74% female, mean body mass index [BMI] 48.4 kg/m2) in Group 1 and 33 patients (82% female, mean BMI 48.5 kg/m2) in Group 2. In Group 1, anti-Xa levels were 0.06 and 0.08 units/mL after the first and third doses, respectively. In Group 2, anti-Xa levels were 0.14 and 0.15 units/mL after first and third doses, respectively (p = NS). There was a statistically significant difference in anti-Xa levels between Group 1 first dose and Group 2 first dose (p < 0.05) and between Group 1 third dose and Group 2 third dose (p < 0.05). Percentage of appropriate anti-Xa levels at first dose differed 0% vs. 30.8% (Group 1 vs. Group 2; p = 0.01) and at third dose 9.1% vs. 41.7% (Group 1 vs. Group 2; p = 0.155).

CONCLUSION

When prophylactic dose enoxaparin of 30 mg every 12 h was changed to 40 mg every 12 h in bariatric surgery patients, anti-Xa levels significantly increased with prophylactic dose enoxaparin in bariatric surgery patients. The percentage of appropriate levels also increased; however, more than half of the patients receiving 40 mg every 12 hours failed to reach therapeutic levels. No levels were supratherapeutic. Dosage of 40 mg every 12 h may not be sufficient for bariatric surgery patients.

Techniques of laparoscopic gastric bypass: on-line survey of American Society for Bariatric Surgery practicing surgeons

BACKGROUND

Various techniques have been used for laparoscopic gastric bypass. This study was performed to survey American Society for Bariatric Surgery practicing surgeons on how they perform laparoscopic gastric bypass.

METHODS

An Internet-based survey was sent to all practicing surgeons in the American Society for Bariatric Surgery database by way of e-mail. The survey was divided into sections, including experience, pouch, limbs, gastrojejunostomy (GJ), jejunojejunostomy, and band. The survey results were collected from the Internet site after 4 months.

RESULTS

A total of 215 surgeons responded; 98% stated they performed laparoscopic gastric bypass. The surgeons had performed an average of 423 cases in their career and 95 cases during the past 12 months. The average pouch size was 25 cm(3) and approximately one half of the surgeons (49%) measured the pouch size by the distance for the gastroesophageal junction. Almost all surgeons (99.5%) performed Roux-en-Y and not loop GJ. The average biliopancreatic limb length was 48 cm, and the average Roux limb was 114 cm. About one half of the surgeons (46%) measured the limb length with an open grasper, and few (7%) used a suture or umbilical tape. The antecolic and antegastric approaches were the more common. The percentage of those using the circular stapler, linear stapler, and hand sewing was 43%, 41%, and 21% for the GJ technique. Most surgeons (93%) routinely tested the GJ intraoperatively. The percentage of those using staple anastomosis and hand-sewn common enterotomy, double stapling, triple stapling, and hand sewing was 53%, 36%, 13%, and 1% for the jejunojejunostomy technique. Most surgeons (94%) closed at least one mesenteric defect. Also, most surgeons (95%) did not place a band around the pouch.

CONCLUSION

Technical variations exist in how laparoscopic gastric bypass procedures are performed by American Society for Bariatric Surgery practicing surgeons. Additional research is needed to explore the links between the technical variations and outcomes.

Postoperative laparoscopic bariatric surgery patients do not remember potential complications

BACKGROUND

Despite comprehensive preoperative education, patients may forget important information such as potential complications.

METHODS

Patients who had undergone laparoscopic bariatric surgery were surveyed. All patients were asked to write down as many as possible of the potential complications. Preoperatively, patients had been given an educational book, two preoperative educational appointments, a test, and an informed consent discussion and form with clear presentation of complications which may occur.

RESULTS

There were 70 patients in this investigation (75% response rate), with 49 laparoscopic gastric bypass patients (bypass), 18 laparoscopic adjustable gastric banding patients (band), and 3 patients who did not indicate their procedure. Patients listed an average of 5.1 complications. Complications were grouped in 12 categories for each procedure. Percentages reported by patients (bypass vs band) were: Death 34 (69%) vs. 13 (72%), Injury to GI tract/leak 14 (29%) vs. 5 (28%), Conversion 1 (2%) vs 0 (0%), CV/pulmonary issues 11 (22%) vs. 4 (22%), Stenosis/ulcer 6 (12%) vs NA, Band erosion/migration NA vs 9 (50%), Malnutrition 24 (49%) vs, 4 (22%), GI symptoms 19 (39%) vs. 6 (33%), Infection 15 (31%) vs. 10 (56%), Weight regain/inadequate loss 5 (10%) vs. 3 (17%), Thromboembolic event 7 (14%) vs. 3 (17%), and Hemorrhage 8 (16%) vs. 0 (0%).

CONCLUSIONS

Many patients forget some of the serious complications after laparoscopic bariatric surgery. This may have important medicolegal consequences especially during malpractice lawsuits. These data underscore the need for continual follow-up and education in this patient population.