Pouch Size Research Articles

Gastric bypass: increased restriction for poor weight loss

Gastric bypass, the most common bariatric procedure performed in the United States, is becoming increasingly popular worldwide. Currently, gastric bypass is most often performed laparoscopically, and anecdotal experience has helped to evolve this operation, minimizing complications and optimizing long-term weight management. With better visualization and video documentation, we can compare outcomes based on anatomic differences between centers. As we debate the nuances concerning the optimal size and configuration of the gastric pouch and the amount of intestine that can or should be bypassed, it is clear that we are only on the verge of understanding the mechanism by which this procedure produces weight loss. Anatomic manipulation is important only if it produces a physiologic response. Whether one subscribes to the theory of a mediated incretin or a purely mechanical mechanism for sustained weight loss, it is agreed that there almost certainly is a metabolic effect associated with the gastric bypass as opposed to the adjustable gastric band or the vertical-banded gastroplasty. Creation of a standard ‘‘gastric reservoir’’ and ‘‘stoma’’ independent of the initial size, energy requirements, gender, or age of the patient is standard for most surgeons. Yet, patients respond with a predictable percentage of excess weight loss. This should be sufficient evidence to refute a purely mechanical mechanism of action for the gastric bypass. In addition, MacLean [3] has shown stoma dilation after gastric bypass to be a consistent finding not necessarily corresponding to inadequate weight loss or weight recidivism. In separate studies, Fobi et al. [2] and Capella and Capella [1] have achieved greater weight loss and maintenance with the banded approach, stabilizing at least one aspect of the anatomy: pouch diameter. Despite long-term data, few surgeons have adopted the banded gastric bypass as a primary operation compared with the majority who have embraced the laparoscopic approach. Debate continues as to the risks and benefits of a reinforced stoma, or more correctly, a stabilized gastric pouch, but most agree that initial, if not, permanent restriction is at least one important aspect of the gastric bypass. More controversial is whether increased restriction is appropriate for patients with inadequate initial weight loss or weight recidivism. Evaluation of patients with inadequate weight loss or recidivism after gastric bypass begins with defining the current anatomy in the context of the potential for optimization. Horizontal pouches will dilate along with the stoma due to the inclusion of the gastric fundus. Surgeons differ concerning the actual size and consistency of the anatomy. Therefore, both upper gastrointestinal and flexible endoscopies are useful and complementary studies. If the current anatomy appears optimal, then other options such as conversion to a duodenal switch or alteration of the intestinal limb lengths should be considered. However, increasing malabsorption with maintenance of restriction may impart a higher risk of protein–calorie malnutrition [4]. Presented at the annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) in Las Vegas, NV, 20 April 2007

Comparison of size of proximal gastric pouch and short-term weight loss following routine upper gastrointestinal contrast study after laparoscopic Roux-en-Y gastric bypass

The authors investigated whether there is any correlation between gastric pouch size measured by routine upper gastrointestinal contrast study (UGI) after laparoscopic Roux-en-Y gastric bypass (LRYGBP) and short-term weight loss. The study group consisted of 82 patients (66F, 16M) who underwent LRYGBP. Body mass index before surgery ranged from 35.4 to 71.7 kg/m2, with a mean of 47.4 kg/m2. UGI was performed 1 day after LRYGBP in all patients. Proximal gastric pouch size was estimated by multiplying maximal transverse and longitudinal diameters on AP spot image or film. Percent excess weight loss (%EWL) obtained at 3, 6, 12 and 24 months after surgery was used as an indicator of short-term results. According to the presence of contrast passage through the gastrojejunostomy, each patient was classified into 2 groups: Group A, negative; Group B, positive. There was no correlation between proximal gastric pouch size and %EWL at any point of time (P>0.05). The correlation coefficients calculated for 3, 6, 12 and 24 months after surgery were 0.038, 0.110, 0.015 and 0.042, respectively (Pearson correlation test). The gastric pouch size of Group A was larger than that of Group B (Student t-test, P<0.001). There was no difference in %EWL between Groups A and B at 3 and 6 months after surgery (P>0.05). Pouch size area, measured by routine UGI study on the first postoperative day, does not influence short-term postoperative weight loss.

Comparison of size of proximal gastric pouch and short-term weight loss following routine upper gastrointestinal contrast study after laparoscopic Roux-en-Y gastric bypass

Comparison of size of proximal gastric pouch and short-term weight loss following routine upper gastrointestinal contrast study after laparoscopic Roux-en-Y gastric bypass

P29: Size doesn’t matter: Lack of correlation between gastric pouch size and weight loss after laparoscopic gastric bypass

strictive part of biliopancreatic diversion duodenal switch (BPD) that has recently been used as an isolated operation in a staged therapy concept. We investigated early results of LSG in a prospective pilot study. Methods: Between 6/04 and 10/06 LSG was performed on 52 pts, 23 times after failed gastric banding, 71% were female, mean age was 43 (24-64) years, mean initial BMI 49 (38-58) kg/m. Mean follow-up time was 9 (1-25) months, the rate was 100%. Results: Mean operative time was 101 (70-200) minutes for primary LSG. No intraoperative complications were observed. There was one conversion to an open procedure. Early morbidity was 8% (dysphagia: 1, portal vein thrombosis: 1, non-surgical: 2). Mean BMI loss 12 months postop. was 12 kg/m following LSG, corresponding to an excessive weight loss of 54% respectively. Up to date laparoscopic BPD had to be performed twice after insufficient weight loss following LSG. Conclusion: LSG is a safe initial bariatric procedure in a staged concept and has the potential to be sufficient as definitive operation in some patients. PII: S1550-7289(07)00268-7

Improved Colostomy Technique and Excrement (Urine) Collection Device for Broilers and Broiler Breeder Hens

In conducting nutritional experiments using chickens, scientists are limited in determining the urinary excretion of nutrients because of the difficulty of separating urine from feces. Our main objective was to improve the colostomy procedure for urine collection in broilers and both urine and egg collection for broiler breeder hens. Ketamine HCl (10 to 30 mg/kg i.m.) in combination with Xylazine (2 to 6 mg/kg i.m.) was used to anesthetize broilers (4 wk old) and broiler breeder hens (25 wk old). The colostomy technique involved: 1) transecting the distal colon at approximately 1.5 to 2 cm from the proximal cloaca and ligating the distal colonic segment with 3-0 absorbable surgical suture, 2) ligating the seromuscular coat of the colon to the peritoneal tissue at 3 points in a triangular shape using 4-0 silk suture, 3) ligating the mesentery at the skin level to prevent continued bleeding of the colostomy stoma, and 4) placing 3 sutures using a triangulation technique that consisted of the seromuscular aspect of the transected proximal colonic segment and the skin, and finally, 5) suturing all exteriorized edges of the transected proximal colonic segment after mucosal eversion to the skin with simple interrupted sutures using absorbable suture. For the purpose of urine or egg collection or both, the appropriate size of drainable pouch with a curved tail closure was used. Feces were collected on a tray. The colostomized broilers could be kept for several days and the colostomized broiler breeder hens for several months to collect urine, eggs (for breeder hens), and feces separately without the problem of cross-contamination.

Size matters: gastric pouch size correlates with weight loss after laparoscopic Roux-en-Y gastric bypass

Over the past 20 years, there has been an ongoing discussion about the importance of gastric pouch size as a key factor influencing weight loss after bariatric surgery. This analysis aimed to determine the relationship between initial gastric pouch size and excess weight loss (EWL) after laparoscopic Roux-en-Y gastric bypass (LRYGB). Between August 2002 and March 2005, 320 LRYGB were performed at Yale New Haven Hospital. The patients' demographics were entered into a longitudinal, prospective database. Upper gastrointestinal series were routinely performed on postoperative day 1. Pouch size was measured as area (cm2) on an anteroposterior radiograph at maximum pouch distention. Linear regression analysis was performed to determine the association between pouch size and weight loss at 6 and 12 months postoperatively. Adjustments were made for age, gender, and preoperative body mass index (BMI). The mean age of the patients was 41.2 years. Of the 320 study patients, 261 were women (81.6%) and 59 were men (18.4%). The mean preoperative BMI was 51.1 kg/m2; the mean 6-month EWL was 50.5%; the mean 12-month EWL was 62.5%; and the mean pouch size was 63.9 cm2. A statistically significant, negative correlation between pouch size and EWL was found at 6 months (beta = -0.241; p < 0.01) and at 12 months (beta = -0.302; p < 0.02). The findings show that male gender (beta = 0.147; p < 0.04) and preoperative BMI (beta = 0.190; p < 0.01) are positively correlated with pouch size. The analysis demonstrates that initial gastric pouch size is not the only significant component for successful weight loss after LRYGB. Male gender and increased preoperative BMI were identified as factors predicting pouch size. Efforts to standardize small pouch size for all patients seems important to the success of surgical therapy for morbid obesity.

Does Pouch Size Matter?

Mechanical restriction, malabsorption, and hormonal changes appear to play a role in weight loss after Roux-en-Y gastric bypass (RYGBP). This investigation chose to investigate one aspect of the restrictive role of gastric bypass: the pouch size. Our hypothesis was that a small pouch size with no fundus after laparoscopic RYGBP (LRYGBP) would lead to greater loss of excess weight and weight loss success. Upper gastrointestinal radiological (UGI) studies were retrospectively reviewed by three blinded experts (2 bariatric surgeons and 1 expert radiologist), to determine pouch size and fundus size. The following grading system was utilized: Size I - smaller than average pouch, Size II - average pouch, Size III larger than average pouch, and Size IV - over 3 times the size of an average pouch. Fundus 0 - no fundus appreciated, Fundus I - slight amount of fundus barely noted, Fundus II - fundus noted, Fundus III - large amount of fundus noted, and Fundus IV - majority of the pouch was fundus. Percentage of excess weight loss (%EWL) and successful weight loss (A. >50% EWL, B. within 50% of ideal body weight, C. loss of >25% of preoperative weight) were calculated. There were 59 patients in this study with 97% follow-up of >1 year. No Size IV or Fundus IV were noted. There were no statistically significant differences between in %EWL or success for either pouch size or fundus size. While there may be a trend for the mean %EWL to be lower with larger pouches and larger amounts of fundus, no significant differences were found. Larger pouches and the presence of fundus (within reason) still result in a high rate of success after LRYGBP.

Morphology and Ornamentation in Male Magnificent Frigatebirds: Variation with Age Class and Mating Status

Male magnificent frigatebird (Fregata magnificens) ornamentation includes bright iridescent plumage and a red inflatable gular pouch. These signals are displayed during courtship, along with a drumming sound produced through specialized beak clackings resonating in the gular pouch. The extent of white in the plumage identifies three age classes of nonjuvenile male. Here we investigate how morphological and secondary sexual traits correlate with age class and mating status. Even though several age class-related differences in morphology and visual appearance can be identified, the only features that significantly predict mating success are acoustic components of courtship display. Specifically, males that mate drum at lower fundamental frequencies--that is, they have larger gular pouches--and have a quicker and more constant drumming cadence than unsuccessful males. The fundamental frequency decreases with age class, reflecting an increase in gular pouch size. This implies that females prefer older or possibly more experienced or viable males. Drumming cadence speed and stability might reflect male stamina. Apart from the acoustic differences with mating status, there is a nonsignificant tendency for back-feather iridescence to be of shorter reflectance wavelength spectra in mated than in unmated males, which, when combined with acoustic variables, improves prediction of age class and mating status.

New applications for endoscopy: the emerging field of endoluminal and transgastric bariatric surgery

Endoluminal and transgastric procedures are evolving concepts that combine the skills and techniques of flexible endoscopy with minimally invasive surgery. Precisely how this technology and skill set will be applied in the field of general surgery is not yet known, but the treatment of obesity with an endoluminal or transgastric procedure holds great promise. As the demand for bariatric surgery increases, efforts will be directed toward developing less morbid and less costly treatment options that can provide substantial weight loss and resolution of comorbid conditions. Natural orifice bariatric procedures may include short-term weight loss in preparation for a definitive laparoscopic procedure, revisional procedures to reduce stoma or pouch size or repair fistulas, or primary therapy that provides durable weight loss. The latter application will undoubtedly appeal to patients and referring physicians if it can be performed as an outpatient procedure with significantly less morbidity than a laparoscopic procedure. Early preclinical and clinical work has been published in this area, but many technical obstacles must be overcome before a primary endoluminal or transgastric bariatric procedure can be offered. This article reviews the endoluminal and transgastric technology currently available, the endoluminal procedures currently performed, and the future of these technologies with respect to bariatric surgery.

Effect of parental age and associated size on fecundity, growth and survival in the yellow seahorseHippocampus kuda

Seahorses, together with the pipefishes (Family Syngnathidae), are the only vertebrates in which embryonic development takes place within a specialised body compartment, the brood pouch, of the male instead of the female. Embryos develop in close association with the brood pouch epithelium in a manner that bears some resemblance to embryo-placental relationships in mammals. We have explored the hypothesis that parental body size and age should affect offspring postnatal growth and survival if brood pouch quality impacts upon prenatal embryonic nutrition or respiration. Using an aquarium population of the yellow seahorse, Hippocampus kuda, we show here that large parents produce offspring whose initial postnatal growth rates (weeks one to three) were significantly higher than those of the offspring of younger and smaller parents. Whereas 90% of offspring from the larger parents survived for the duration of the study (7 weeks), less that 50% of offspring from smaller parents survived for the same period. For the offspring of large parents, growth rates from individual males were negatively correlated with the number of offspring in the cohort (r=-0.82; P<0.05); this was not the case for offspring from small parents (r=0.048; P>0.9). Observations of embryos within the pouch suggested that when relatively few embryos are present they may attach to functionally advantageous sites and thus gain physiological support during gestation. These results suggest that male body size, and pouch size and function, may influence the future fitness and survival of their offspring.

62: Does (pouch) size really matter?

62: Does (pouch) size really matter?

Pouch Design and Size Paradox (aka) the Potty Paradox—A Topic for an “Incontinent” Ostomy Consensus Panel

Pouch Design and Size Paradox (aka) the Potty Paradox—A Topic for an “Incontinent” Ostomy Consensus Panel

Endoscopic Stapling Diverticulotomy: An Audit of Difficulties, Outcome, and Patient Satisfaction

To evaluate the procedure in terms of technical difficulties, patient satisfaction, symptom relief, recurrence, and further management. Retrospective study including 41 patients who underwent endoscopic stapling diverticulotomy. Clinical notes were reviewed, and patients were sent a patient satisfaction questionnaire. Statistical analysis was done using the chi(2) square test. Teaching hospital. Larger pouches had the best results; 81.578% were satisfied with the surgery, and 86.84% had improved swallowing. Complications presented in 6 patients (15%), including a perforated pouch and an esophageal perforation. Complications were more frequent in small pouches. Endoscopic stapling diverticulotomy offers rapid recovery in most patients, with early oral intake and short hospital stay. There is a high degree of symptoms relief, and the patient's satisfaction rate is high. The assessment of the pharyngeal pouch size is an important factor when deciding the best management for a patient with a pharyngeal pouch.

Pouch size: The important functional determinant after restorative proctocolectomy

Sixty-seven patients with a J-shaped ileonanal pouch were studied over a 2-year period with regular recording of sphincter and pouch characteristics and analysis of their role in functional outcome. Although there was a 27 per cent permanent reduction in resting anal pressure (RAP) (P less than 0.001), two-thirds of the patients still had a RAP within the normal range. The mean(s.d.) pouch volume increased during the first year from 132(46) ml to 282(85) ml. RAP was not related to functional outcome and preoperative RAP was not predictive of subsequent function. Large pouch volume and compliance correlated with low defaecation frequency (range of r = 0.27-0.36; P less than 0.05) and good overall function (r = 0.37-0.56; P less than 0.01). The initial pouch volume was predictive of subsequent overall function. The ileal length used for pouch construction predicted subsequent pouch volume (r = 0.48; P less than 0.001) and to some extent functional outcome (r = 0.28-0.37; P less than 0.05). However, the studied variables accounted for only 21 per cent of the total variance of functional outcome.

Measurement of gastric emptying after gastric bypass surgery using radionuclides.

The pattern of gastric emptying has been assessed after gastric bypass surgery using a double isotope technique for measuring solid and liquid emptying with a scintillation camera. Eleven control subjects and 12 patients, 12 months post-gastric bypass, were studied. Stomal and gastric pouch size were assessed at endoscopy. Solid emptying was slower and liquid emptying was more rapid after gastric bypass surgery. Initial rapid emptying of solid occurred in the 4 patients with the smallest pouch diameters. There was no correlation between stomal size and rates of solid or liquid emptying nor between the weight loss produced by the operation and the rates of solid or liquid emptying, stoma or pouch size.

Gastroplasty for morbid obesity: Technique, complications and results in 60 cases

A series of 60 gastroplasty operations based on Mason's vertical banded procedure are described. Details of technique, modifications, complications and results are discussed. Operative treatment results in a reduction to within 40 per cent of ideal weight in 80 per cent of patients between 12 and 18 months after surgery. The constricting band should not be greater than 5 cm; if it is most procedures will fail after 18 months. Pouch size should be measured and made no greater than 20 ml. The importance of nutritional counselling is emphasized. The surgical treatment should form part of a multidisciplinary approach with careful selection and long-term follow-up.

Adjustable Gastric Banding as a Revisional Bariatric Procedure after Failed Gastric Bypass

Inadequate weight loss after proximal gastric bypass presents a clinical challenge to bariatric surgeons. Pouch size, stoma size and limb length are the variables that can be surgically altered. Aside from conversion to distal bypass, which may have significant negative nutritional sequelae, revisional surgery for this group of patients has not often been reported. The addition of adjustable silicone gastric banding (ASGB) to Roux-en-Y gastric bypass (RYGBP) may be a useful revision strategy because it has potential safety benefits over other revisional approaches. We report on 8 patients who presented with inadequate weight loss or significant weight regain after proximal gastric bypass. All patients underwent revision with the placement of an ASGB around the proximal gastric pouch. Bands were adjusted at 6 weeks postoperatively and beyond as needed. Complications and weight loss at the most recent follow-up visit were evaluated. Mean age and body mass index (BMI) at the time of revision were 39 +/- 9.9 years and 44.0 +/- 4.5 kg/m2 respectively. No patients were lost to follow-up, and they lost an average of 38.1 +/- 10.4% and 44.0 +/- 36.3% of excess weight and 49.1 +/- 20.9% and 52.0 +/- 46.0% of excess BMI in 12 and 24 months respectively. Patients lost an average of 62.0 +/- 20.5% of excess weight from the combined surgeries in 67 (48-84) months. The only complication was the development of a seroma overlying the area of the port adjustment in one patient. There have been no erosions or band slippages to date. These results indicate that the addition of an ASGB causes significant weight loss in patients with poor weight loss outcome after RYGBP. The fact that no anastomosis or change in absorption is required may make this an attractive revisional strategy. Long- term evaluation in a larger population is warranted.

The Proximal Gastric Pouch Invariably Contains Acid-Producing Parietal Cells in Roux-en-Y Gastric Bypass

Roux-en-Y gastric bypass (RYGBP) is well tolerated and effective in ameliorating diseases common to morbidly obese patients. A potential drawback, however, is the risk for stomal ulcers, probably due to acid and peptic digestion of the mucosa in the proximal Roux limb. In 23 RYGBP patients (mean BMI 45 kg/m(2), age 39 years), the gastro-jejunostomy was performed by circular stapler and the gastric suture ring retrieved for histological examination. 13 consecutive patients received our standard totally transected 4 x 3 cm proximal gastric pouch. The anvil was passed transgastricly and reference biopsies were taken from the gastrotomy in the corpus of the stomach. In the last 10 patients, the pouch size was reduced to 2 x 3 cm by a modified surgical technique. All suture rings from the standard pouches consisted of corpus-fundus mucosa with a large amount of parietal cells, histologically identical to the reference biopsies from the gastrotomy. Also, the 10 suture rings from the modified small pouches contained corpus-fundus mucosa. In 5 of these samples, cardiac mucosa was found, but only in a small segment (6 mm). In addition, 3 patients had esophageal epithelium in the suture ring. The proximal pouch invariably contains acid-producing parietal cells. In order to reduce acid production and, hence, the risk of stomal ulcers, the pouch has to be made as small as possible.

Transverse Coloplasty Pouch After Total Mesorectal Excision: Functional Assessment of Evacuation

Colon pouch reconstruction after total mesorectal excision is functionally superior to straight colorectal/ anal anastomosis. In the long-term, stool evacuation difficulties could jeopardize the functional benefit. The transverse coloplasty pouch presents an alternative to the standard J-pouch. This study was designed to analyze functional outcome and defecography findings after total mesorectal excision and transverse coloplasty pouch reconstruction. Thirty consecutive patients with cancer of the middle and lower third of the rectum underwent a total mesorectal excision and were examined in a prospective study. In all patients, reconstruction was performed with a transverse coloplasty pouch. Pouch and anastomosis were checked by Gastrografin enema postoperatively. Patients were examined within eight months by means of defecography, manometry, pouch volumetry, and a standardized continence questionnaire. Total mesorectal excision with transverse coloplasty pouch anastomosis was performed successfully in all patients. Symptomatic anastomotic leakage was observed in 2 of 30 patients and the radiologic leak rate was 4 of 30. All patients evacuated the pouch completely; none needed enemas or suppositories to facilitate defecation. Twenty-five of 27 patients had a maximum of three bowel movements per day, and all patients were continent for solid stools. Patients with abnormal findings on defecography proved more likely to have anal dysfunction. Transverse coloplasty pouch reconstruction after total mesorectal excision leads to good functional results and is not associated with stool evacuation problems. Urgency and incontinence correlate rather with impaired pelvic floor movement than with pouch size or anal sphincter tonus.

Design of the Driving System of an Automatic Vacuum Packer using Functional Virtual Prototyping

The main objective of this study was to model and simulate a reduced three-dimensional (3D) model for designing the driving system of an automatic vacuum packer. The 3D reduced model consisted of a pressing board sub-model, a taping sub-model, and a vibrating board sub-model. The reduced 3D model was parameterised using the variable of pouch thickness. The sub-models were driven by three virtual motors. To fulfil the required processing capacity of 6 pouches min −1 (pouch size of 45 cm by 35 cm; 5 kg −1 pouch) of the vacuum packer, three rotational motions for the motors were properly designed. When sub-models were driven according to the developed motions, the rated powers of the motors were estimated to be 100, 25, and 90 W, respectively. A real prototype of the vacuum packer was manufactured and controlled according to the developed motions to validate the simulation results. The motors determined by simulating the reduced 3D model drove the three units of the real prototype successfully. The developed motions of the motors satisfied the required operating sequences of the vacuum packer with a processing capacity of 6·7 pouches min −1. Vacuum-packaging tests showed that the success rate of the vacuum packer was 92·6%.