Laparoscopic mesh hiatoplasty for paraesophageal hernias and fundoplications: a critical analysis of the available literature.

BACKGROUND: Little grade A medical evidence exists to support the use of prosthetic material for hiatal closure. Therefore, the authors compiled and analyzed all the available literature to determine whether the use of prosthetic mesh in hiatoplasty for routine laparoscopic fundoplications (LF) or for the repair of large (>5 cm) paraesophageal hernias (PEH) would decrease recurrence. METHODS: A literature search was performed using an inclusive list of relevant search terms via Medline/PubMed to identify papers (n = 19) describing the use of prosthetic material to repair the crura of patients undergoing laparoscopic PEH reduction, LF, or both. RESULTS: Case series (n = 5), retrospective reviews (n = 6), and prospective randomized (n = 4) and nonrandomized (n = 4) trials were identified. Laparoscopic procedures (n = 1,368) were performed for PEH, gastroesophageal reflux disease (GERD), hiatal hernia, or a combination of the three. Group A (n = 729) had primary suture repair of the crura, and group B (n = 639) had repair with either interposition of mesh to close the hiatus or onlay of prosthetic material after hiatal or crural closure. The use of mesh was associated with fewer recurrences than primary suture repair in both the LF and PEH groups. The mean follow-up period did not differ between the groups (20.7 months for group A vs. 19.2 months for group B). None of the papers cited any instance of prosthetic erosion into the gastrointestinal tract. CONCLUSIONS: The current data tend to support the use of prosthetic materials for hiatal repair in both routine LF and the repair of large PEHs. Longer and more stringent follow-up evaluation is necessary to delineate better the safety profile of mesh hiatoplasty. Future randomized trials are needed to confirm that mesh repair is superior to simple crural closure.

Postoperative complications are not increased in super-super obese patients who undergo laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: It has been suggested that super-super obesity (body mass index [BMI] > or =60 kg/m2) increases the risk of complications after laparoscopic Roux-en-Y gastric bypass (LapRYGB). We hypothesized that a higher BMI does not increase risk the morbidity or mortality rate. METHODS: Complication rates for patients with a BMI > or =60 kg/m2 were compared to those for patients with a BMI <60 kg/m2 who underwent LapRYGB during the same time period. Differences between the groups were analyzed by Fisher's exact test, t-tests, and analysis of variance. RESULTS: Forty-five patients with a BMI > or =60 kg/m2 and 640 patients with a BMI <60 kg/m2 underwent LapRYGB. There were no statistically significant differences between the two groups in the complication or mortality rates. Excess weight loss was less, but actual weight lost was greater in the BMI > or =60 kg/m2 group. CONCLUSIONS: The complication and mortality rates are not increased in super-super obese patients who undergo LapRYGB. Acceptable weight loss can be achieved safely in these patients.

Experience with over 3,000 open and laparoscopic bariatric procedures: multivariate analysis of factors related to leak and resultant mortality.

BACKGROUND: Intestinal leak is a potentially lethal complication of Roux en-Y gastric bypass (GBP). Identification of patients at high risk for leak may reduce complication rates of surgeons early in the procedure learning curve. METHODS: A total of 3073 patients who underwent GBP were analyzed using univariate and multivariate logistic regression analyses of the following preoperative factors: hypertension (HTN), diabetes mellitus (DM), sleep apnea (SA), age, gender, weight, body mass index (BMI), and surgery type. Multivariate logistic regression analysis was performed for each procedure type. RESULTS: There were 48 (1.5%) deaths. Independent risk factors for death included leak, weight, procedure type, and HTN. A total of 102 (3.2%) leaks were found. Independent factors for leak included age, male gender, SA, and procedure type. CONCLUSION: The data suggests that older, heavier male patients with multiple comorbid conditions are at increased risk for leak and mortality. Surgeons early in their learning curve should avoid these high-risk patients to reduce complications.

Hand-assisted laparoscopic gastric bypass does not improve outcome and increases costs when compared to open gastric bypass for the surgical treatment of obesity.

BACKGROUND: Hand-assisted laparoscopic Roux-en-Y gastric bypass (Hand-Lap GB) has been adopted by some surgeons to treat morbid obesity because it is easier to perform than the total laparoscopic procedure, but to date no study has compared the outcomes of patients undergoing the Hand-Lap GB to those obtained with the open procedure (Open GB). We hypothesized that patients undergoing Hand-Lap GB would lose a similar amount of weight when compared to Open GB patients, while experiencing no increase in complications, a shorter hospital stay, and lower overall costs of care, in part as a result of fewer incisional hernias requiring subsequent surgery. METHODS: Nonrandomized, prospective data were collected on all patients undergoing proximal GB via Hand-Lap or open approaches between May 1998 and July 1999. Our first 25 Hand-Lap GB procedures, performed in selected patients (with no extensive previous abdominal surgery) referred to two of us (E.J.D, M.A.S), were compared to all other (n = 62) concurrent open proximal GB performed by the group during this period of time in patients with body mass index (BMI) <50 kg/m2. RESULTS: Preoperatively, Hand-Lap GB patients did not differ from Open GB patients in age (40 +/- 11 vs 43 +/- 11 years), gender (92% female vs 81% female), incidence or type of preoperative comorbid conditions, preoperative weight (282 +/- 33 vs 280 +/- 37 lb), or BMI (45.5 +/- 5.4 vs 44.1 +/- 3.3 kg/m2). (Data given as mean +/- standard deviation). Although length of hospital stay did not differ between groups (3.6 +/- 1.3 vs 4.2 +/- 4.6 days), total hospital costs were significantly higher for Hand-Lap GB ($14,725 +/- 3089 vs. $10,281 +/- 3687, p <0.01 ANOVA). One patient in the Open GB group developed an anastomotic leak from the gastrojejunostomy. Follow-up revealed that Hand-Lap GB patients had a similar risk of postoperative complications as the Open GB group, including marginal ulcer (16% vs 14.5%), stomal stenosis (24% vs 23%), and, most notably, incisional hernia (20% vs 27%). There were no major wound infections or deaths in either group. One patient in each group developed a postoperative small bowel obstruction. Loss of excess weight in Hand-Lap GB patients at 12 months postoperatively was 66 +/- 14% vs 77 +/- 14% in the Open GB group. CONCLUSIONS: The Hand-Lap GB yielded good weight reduction in a population of morbidly obese patients, but at a higher cost for hospital care than Open GB. There was no decrease in the incidence of incisional hernias with the Hand-Lap GB procedure. Although Hand-Lap GB appears to be safe and effective, its failure to provide a decrease in hospital stay or risk of incisional hernia requiring subsequent surgical repair is significant. The primary role for the Hand-Lap GB procedure should therefore be to aid surgeons in developing skills to climb the steep learning curve for total laparoscopic gastric bypass, since Hand-Lap GB does not improve patient outcome and increases cost in comparison to the open GB procedure.

Both serotonin and a nitric-oxide donor cause chloride secretion in rat colonocytes by stimulating cGMP.

BACKGROUND: Previous studies have demonstrated that an antagonist of nitric oxide synthase inhibits neurally mediated chloride secretion in response to serotonin (5-HT). The purpose of this study was to demonstrate that chloride secretion in rat colonocytes that were caused by stimulation of neural 5-HT receptors is mediated by way of a nitrergic pathway that involves the activation of guanylate cyclase. METHODS: The nitric oxide (NO) donor, diethylenetriamine/NO (DNO), was added to an enriched suspension of rat colonocytes that were preloaded with (36)Cl(-). In parallel experiments, DNO (1 micromol/L) was added to cells that were pretreated with the specific inhibitor of soluble guanylate cyclase, NS2028 (2 micromol/L). In additional studies, the neural 5-HT(3) receptor agonist, 2-methyl-5-HT (10 micromol/L), was added to the serosal surface of muscle-stripped sheets of rat colonic mucosa that were mounted in Ussing chambers under voltage clamp conditions, both in the absence and presence of NS2028 (20 mircro). RESULTS: DNO induced 18.0% +/- 8.0% greater (36)Cl(-) efflux than controls (P <.05; n = 14 animals). This efflux was abolished by previous treatment with NS2028. In the chamber experiments, 2-methyl-5-HT induced electrogenic chloride secretion that was significantly inhibited by previous treatment with NS2028 (2.2 +/- 0.5 microA/cm(2) vs 13.1 +/- 2.1 microA/cm(2); P <.001; n = 9 animals). CONCLUSIONS: The predominant secretomotor neurotransmitter that mediates the chloride secretory effects of 5-HT in vitro is nitric oxide. Both the secretory effect initiated at the 5-HT(3) receptor on enteric neurons and at the NO(-) receptor on the rat colonocytes are mediated through the activation of intracellular guanylate cyclase and the production of cyclic guanosine monophosphate.

Risks and benefits of gastric bypass in morbidly obese patients with severe venous stasis disease.

OBJECTIVE: To determine the risks and benefits of gastric bypass-induced weight loss on severe venous stasis disease in morbid obesity. SUMMARY BACKGROUND DATA: Severe obesity is associated with a risk of lower extremity venous stasis disease, pretibial ulceration, cellulitis, and bronze edema. METHODS: The GBP database was queried for venous stasis disease including pretibial venous stasis ulcers, bronze edema, and cellulitis. RESULTS: Of 1,976 patients undergoing GBP, 64 (45% female) met the criteria. Mean age was 44 +/- 10 years. Thirty-seven patients had pretibial venous stasis ulcers, 4 had bronze edema, 23 had both, and 17 had recurrent cellulitis. All had 2 to 4+ pitting pretibial edema. Mean preoperative body mass index (BMI) was 61 +/- 12 kg/m(2) and weight was 179 +/- 39 kg (270 +/- 51% ideal body weight), significantly greater than in patients who underwent GBP without venous stasis disease. Two patients had a pulmonary embolus and four had Greenfield filters in the remote past. Additional comorbidities included obesity hypoventilation syndrome, sleep apnea syndrome, hypertension, gastroesophageal reflux, degenerative joint disease symptoms, type 2 diabetes mellitus, pseudotumor cerebri, and urinary incontinence. Comorbidities were significantly more frequent in the patients with venous stasis disease than for those without. At 3.9 +/- 4 years after surgery, patients lost 55 +/- 21 % of excess weight, 62 +/- 33 kg, reaching 40 +/- 9 kg/m(2) BMI or 176 +/- 41% ideal body weight. Venous stasis ulcers resolved in all but three patients. Complications included anastomotic leaks with peritonitis and death, fatal pulmonary embolism, fatal respiratory arrest, wound infections or seromas, staple line disruptions, marginal ulcerations treated with acid suppression, stomal stenoses treated with endoscopic dilatation, late small bowel obstructions, and incisional hernias. There were six other late deaths. CONCLUSIONS: Severe venous stasis disease was associated with a significantly greater weight, BMI, male sex, age, comorbidity, and surgical risk (pulmonary embolus, leak, death, incisional hernia) than in other patients who underwent GBP. Surgically induced weight loss corrected the venous stasis disease in almost all patients as well as their other obesity-related problems.

High failure rate after laparoscopic adjustable silicone gastric banding for treatment of morbid obesity.

OBJECTIVE: To report the results from one of the eight original U.S. centers performing laparoscopic adjustable silicone gastric banding (LASGB), a new minimally invasive surgical technique for treatment of morbid obesity. SUMMARY BACKGROUND DATA: Laparoscopic adjustable silicone gastric banding is under evaluation by the Food & Drug Administration in the United States in an initial cohort of 300 patients. METHODS: Of 37 patients undergoing laparoscopic placement of the LASGB device, successful placement occurred in 36 from March 1996 to May 1998. Patients have been followed up for up to 4 years. RESULTS: Five patients (14%) have been lost to follow-up for more than 2 years but at last available follow-up (3-18 months after surgery) had achieved only 18% (range 5-38%) excess weight loss. African American patients had poor weight loss after LASGB compared with whites. The LASGB devices were removed in 15 (41%) patients 10 days to 42 months after surgery. Four patients underwent simple removal; 11 were converted to gastric bypass. The most common reason for removal was inadequate weight loss in the presence of a functioning band. The primary reasons for removal in others were infection, leakage from the inflatable silicone ring causing inadequate weight loss, or band slippage. The patients with band slippage had concomitant poor weight loss. Bands were removed in two others as a result of symptoms related to esophageal dilatation. In 18 of 25 patients (71%) who underwent preoperative and long-term postoperative contrast evaluation, a significantly increased esophageal diameter developed; of these, 13 (72%) had prominent dysphagia, vomiting, or reflux symptoms. Of the remaining 21 patients with bands, 8 currently desire removal and conversion to gastric bypass for inadequate weight loss. Six of the remaining patients have persistent morbid obesity at least 2 years after surgery but refuse to undergo further surgery or claim to be satisfied with the results. Overall, only four patients achieved a body-mass index of less than 35 and/or at least a 50% reduction in excess weight. Thus, the overall need for band removal and conversion to GBP in this series will ultimately exceed 50%. CONCLUSIONS: The authors did not find LASGB to be an effective procedure for the surgical treatment of morbid obesity. Complications after LASGB include esophageal dilatation, band leakage, infection, erosion, and slippage. Inadequate weight loss is common, particularly in African American patients. More study is required to determine the long-term efficacy of the LASGB

Ileal pouch anal anastomosis without ileal diversion.

OBJECTIVE: To evaluate continued experience with a one-stage stapled ileoanal pouch procedure without temporary ileostomy diversion. SUMMARY BACKGROUND DATA: Most centers perform colectomy, proctectomy, and ileal pouch anal anastomoses (IPAA) with a protective ileostomy. Following a previous report, the authors performed 126 additional stapled IPAA procedures for ulcerative colitis and familial adenomatous polyposis, of which all but 2 were without an ileostomy. Outcomes in these patients question the need for temporary ileal diversion, with its complications and need for subsequent surgical closure. METHODS: Two hundred one patients underwent a stapled IPAA since May 1989, 192 as a one-stage procedure without ileostomy, and 1 with a concurrent Whipple procedure for duodenal adenocarcinoma. Patient charts were reviewed or patients were contacted by phone to evaluate their clinical status at least 1 year after their surgery. RESULTS: Among the patients who underwent the one-stage procedure, 178 had ulcerative colitis (38 fulminant), 5 had Crohn's disease (diagnosed after IPAA), 1 had indeterminate colitis, and 8 had familial adenomatous polyposis. The mean age was 38 +/- 7 (range 7--70) years; there were 98 male patients and 94 female patients. The average amount of diseased tissue between the dentate line and the anastomosis was 0.9 +/- 0.1 cm, with 35% of the anastomoses at the dentate line. With 89% follow-up at 1 year or more (mean 5.1 +/- 2.4 years) after surgery, the average 24-hour stool frequency was 7.1 +/- 3.3, of which 0.9 +/- 1.4 were at night. Daytime stool control was 95% and night-time control was 90%. Only 2.3% needed to wear a perineal pad. Average length of hospital stay was 10 +/- 0.3 days, with 1.5 +/- 0.5 days readmission for complications. Abscesses or enteric leaks occurred in 23 patients; IPAA function was excellent in 19 of these patients (2 have permanent ileostomies). In patients taking steroids, there was no significant difference in leak rate with duration of use (29 +/- 8 with vs. 22 +/- 2 months without leak) or dose (32 +/- 13 mg with vs. 35 +/- 3 mg without leak). Two (1%) patients died (myocardial infarction, mesenteric infarction). CONCLUSIONS: The triple-stapled IPAA without temporary ileal diversion has a relatively low complication rate and a low rate of small bowel obstruction, provides excellent fecal control, permits an early return to a functional life, and can be performed in morbidly obese and older patients.

Nitric oxide is a neurotransmitter in the chloride secretory response to serotonin in rat colon.

BACKGROUND: Serotonin (5-hydroxytryptamine [5-HT]) has been shown to induce chloride secretion through a nonadrenergic/noncholinergic neural pathway, mediated by a 5-HT(3) receptor. We hypothesized that 5-HT(3)-induced Cl(-) secretion is ultimately mediated by nitric oxide (NO). METHODS: Unstripped sheets of rat distal colon were mounted in Ussing chambers and short-circuited. The 5-HT(3) receptor agonist, 2-methyl-5-HT, was added in the absence and presence of the NO synthase inhibitor, L-NAME. Companion studies involved the addition of sodium nitroprusside to tissue that was incubated with or without tetrodotoxin. RESULTS: L-NAME caused a significant reduction in the 2-methyl-5-HT-induced change in circuit current, in a concentration-dependent manner. Sodium nitroprusside caused a change in circuit current over baseline in 5 minutes. The addition of tetrodotoxin did not significantly alter the change in circuit current; however, the apical Cl(-) channel blocker, anthracene-9-carboxylic acid, abolished this response. CONCLUSIONS: Neurally mediated Cl(-) secretion in response to 2-methyl-5-HT is inhibited by an NO synthase inhibitor. Exogenous NO mimics this response, which is unaffected by tetrodotoxin. These data suggest that neurally mediated serotoninergic Cl(-) secretion is, in part, mediated by NO. The ability of exogenous NO to induce a change in circuit current in the presence of tetrodotoxin suggests that NO is a final neurotransmitter in this neural-mucosal reflex and therefore acts directly on the enterocyte to induce secretion.

Complementary roles of laparoscopic abdominal exploration and diagnostic peritoneal lavage for evaluating abdominal stab wounds: a prospective study.

PURPOSE: To determine the roles of laparoscopic abdominal exploration (LE) and diagnostic peritoneal lavage (DPL) in the evaluation of abdominal stab wounds, we prospectively compared LE with mandatory celiotomy (MC) in 76 patients having anterior abdominal stab wounds penetrating the fascia over a 22-month period. PATIENTS AND METHODS: Twenty-two patients underwent emergency celiotomy. The remaining patients were subjected to DPL and assigned to treatment by either celiotomy or initial LE with subsequent conversion to open exploration at the discretion of the attending surgeon. RESULTS: Laparotomy was avoided in 55% of the 31 patients undergoing initial laparoscopy, and this group demonstrated a significant decrease in the incidence of nontherapeutic celiotomy, from 19% to 57% (P < 0.05), as well as decreased length of hospital stay (4 +/- 0.6 v 5.9 +/- 0.4 days; P < 0.05), and total hospital cost ($6119 +/- 756 v $8312 +/- 627; P < 0.05). There were no missed intraabdominal injuries or morbidity from laparoscopy identified in follow-up. The DPL (N = 36) was positive in 11 of the 12 patients with injury requiring surgical repair and was negative in 16 of the 25 patients not requiring repair. The sensitivity and specificity of DPL were 0.91 and 0.64 compared with 1.0 and 0.74 for laparoscopy. CONCLUSIONS: An algorithm to evaluate stable patients with anterior abdominal stab wounds and minimize overall costs of care, incidence of nontherapeutic celiotomy, and rate of missed injuries is suggested consisting of DPL followed by observation in patients with negative DPL and by laparoscopy in patients with positive DPL. Wounds to the thoracoabdominal region may be best evaluated by initial LE, as diaphragmatic wounds may result in a false-negative DPL.

Vasoactive intestinal peptide is a neuropeptide mediator of the secretory response to serotonin in rat.

BACKGROUND: The chloride secretory response to serotonin (5-HT) has nonneural and neural mechanisms, the latter mediated through a 5-HT(3) receptor. We hypothesized that 5-HT(3)-induced C1(-) secretion is partially mediated by VIP as a neurosecretory transmitter. Therefore it should be inhibited by a VIP receptor antagonist, VIP 6-28. Furthermore, exogenous VIP should induce secretion in the presence of tetrodotoxin (TTX). METHODS: Unstripped sheets of rat colon (n = 6) were mounted in Ussing chambers. The 5-HT(3) receptor agonist 2-Me-5-HT (10 microM) was added in the absence and presence of VIP 6-28 (30 microM). In companion studies VIP (1 microM) was added to tissue with or without TTX. Changes in short-circuit current (DeltaI(SC)) were recorded and repeat-measure ANOVA was used to analyze data. RESULTS: Addition of 2-Me-5-HT induced a rise in DeltaI(SC) seen in controls at 1 to 5 min (3.2 +/- 1.5 to 12.3 +/- 3.7 microA/cm(2), P < 0.02). VIP 6-28 blunted DeltaI(SC) (1.2 +/- 0.4 to 3.7 +/- 1.3 microA/cm(2), P < 0.01). VIP caused DeltaI(SC) to increase above baseline in 15 min (4.7 +/- 2.6 to 10.4 +/- 3.0 microA/cm(2), P < 0.01). The addition of TTX prior to VIP did not alter DeltaI(SC). CONCLUSION: Activation of the neural 5-HT(3) receptor by 2-Me-5-HT induces a secretory response in rat colon that is inhibited by a VIP receptor antagonist. Exogenous VIP mimics this response and is unaffected by TTX. VIP is a likely nonadrenergic, noncholinergic neurotransmitter in this pathway.

Stroking human jejunal mucosa induces 5-HT release and Cl- secretion via afferent neurons and 5-HT4 receptors.

5-Hydroxytryptamine (5-HT) release and neural reflex pathways activated in response to mucosal stroking were investigated in muscle-stripped human jejunum mounted in modified Ussing chambers. The mucosa was stroked with a brush at 1/s for 1-10 s. Mucosal stroking resulted in a significant increase in the concentration of 5-HT in the mucosal bath within 5 min. It also was associated with a reproducible positive change (Delta) in short-circuit current (Isc), which was abolished by inhibitors of chloride secretion. Capsaicin and hexamethonium significantly inhibited the DeltaIsc but not the release of 5-HT. The DeltaIsc was inhibited by TTX but not by atropine. It was also inhibited by the 5-HT(3,4) receptor antagonist tropisetron (10 microM) and the 5-HT(4,3) receptor antagonist SDZ-205-557 (10 microM) but not by preferential antagonists of 5-HT(1P), 5-HT(2A), or 5-HT3 receptors. These results suggest that mucosal stroking induces release of mucosal 5-HT, which activates a 5-HT4 receptor on enteric sensory neurons, evoking a neuronal reflex that stimulates chloride secretion.

Gastric surgery for pseudotumor cerebri associated with severe obesity.

OBJECTIVE: To study the efficacy of gastric surgery-induced weight loss for the treatment of pseudotumor cerebri (PTC). SUMMARY BACKGROUND DATA: Pseudotumor cerebri (also called idiopathic intracranial hypertension), a known complication of severe obesity, is associated with severe headaches, pulsatile tinnitus, elevated cerebrospinal fluid (CSF) pressures, and normal brain imaging. The authors have found in previous clinical and animal studies that PTC in obese persons is probably secondary to a chronic increase in intraabdominal pressure leading to increased intrathoracic pressure. CSF-peritoneal shunts have a high failure rate, probably because they involve shunting from a high-pressure system to another high-pressure zone. In an earlier study of gastric bypass surgery in eight patients, CSF pressure decreased from 353+/-35 to 168+/-12 mm H2O at 34+/-8 months after surgery, with resolution of headaches in all. METHODS: Twenty-four severely obese women underwent bariatric surgery--23 gastric bypasses and one laparoscopic adjustable gastric banding--62+/-52 months ago for the control of severe obesity associated with PTC. CSF pressures were 324+/-83 mm H2O. Additional PTC central nervous system and cranial nerve problems included peripheral visual field loss, trigeminal neuralgia, recurrent Bell's palsy, and pulsatile tinnitus. Spontaneous CSF rhinorrhea occurred in one patient, and hemiplegia with homonymous hemianopsia developed as a complication of ventriculoperitoneal shunt placement in another. There were two occluded lumboperitoneal shunts and another functional but ineffective lumboperitoneal shunt. Additional obesity comorbidity in these patients included degenerative joint disease, gastroesophageal reflux disease, hypertension, urinary stress incontinence, sleep apnea, obesity hypoventilation, and type II diabetes mellitus. RESULTS: At 1 year after bariatric surgery, 19 patients lost an average of 45+/-12 kg, which was 71+/-18% of their excess weight. Their body mass index and percentage of ideal body weight had fallen to 30+/-5 kg/m2 and 133+/-22%, respectively. In four patients, less than 1 year had elapsed since surgery. Five patients were lost to follow-up. Surgically induced weight loss was associated with resolution of headache and pulsatile tinnitus in all but one patient within 4 months of the procedure. The cranial nerve dysfunctions resolved in all patients. The patient with CSF rhinorrhea had resolution within 4 weeks of gastric bypass. Of the 19 patients not lost to follow-up, 2 regained weight, with recurrence of headache and pulsatile tinnitus. Additional resolved associated comorbidities were 6/14 degenerative joint disease, 9/10 gastroesophageal reflux disorder, 2/6 hypertension, and all with sleep apnea, hypoventilation, type II diabetes mellitus, and urinary incontinence. CONCLUSIONS: Bariatric surgery is the long-term procedure of choice for severely obese patients with PTC and is shown to have a much higher rate of success than CSF-peritoneal shunting reported in the literature, as well as providing resolution of additional obesity comorbidity. Increased intraabdominal pressure associated with central obesity is the probable etiology of PTC, a condition that should no longer be considered idiopathic.

5-HT induces cAMP production in crypt colonocytes at a 5-HT4 receptor.

Previous studies demonstrate that both 5-hydroxytryptamine (5-HT) and cyclic AMP (cAMP) induce chloride efflux from crypt colonocytes in the rat distal colon; antagonist studies suggest that the 5-HT response is mediated primarily by the 5-HT4 receptor. Since this receptor is known to be positively coupled to adenylate cyclase, we postulated that 5-HT should induce generation of cAMP, which should be inhibited by 5-HT4 antagonists. Method. Mucosal cells from rat distal colon were taken by a sequential calcium chelation technique for enrichment of crypt cells. Cytokeratin stains demonstrated that >99% of cells were colonocytes. [3H]Thymidine uptake studies demonstrate a fivefold increased incorporation in this cell preparation compared to earlier fractions. 3-Isobutyl-l-methylxanthine (IBMX, 100 microM) was added to all cell suspensions in order to prevent cAMP metabolism. Cell suspensions were incubated for 2 min at 37 degreesC with different concentrations of 5-HT (n = 7). cAMP was measured by enzyme immunoassay. In another series of experiments, 5-HT (0.3 microM) stimulation of cAMP was similarly measured in the presence and absence of 5-HT receptor antagonists: 10 microM 5-HTP-DP (5-HT1P; n = 4), 0.1 microM ketanserin (5-HT2A; n = 4), 0.3 microM ondansetron (5-HT3; n = 4), 3 microM tropisetron (5-HT3 and 5-HT4; n = 4), and 10 nM GR-113808 (5-HT4; n = 5). Results. 5-HT produced a dose-dependent increase in cAMP. The increase was significant at concentrations >/=0.3 microM when compared to cells incubated with IBMX alone. In the second series of experiment, 5-HT-induced generation of cAMP at a dose of 0.3 microM was significantly inhibited in the presence of GR-113808 and tropisetron. Conclusion. 5-HT acts at a 5-HT4 receptor to induce production of cAMP in rat distal crypt colonocytes.

Adjustable laparoscopic gastric band for the treatment of morbid obesity: radiologic evaluation.

OBJECTIVE: This article describes the radiographic appearance of a recently developed laparoscopically placed adjustable gastric band for the treatment of morbid obesity. The optimal technique for contrast evaluation of the device, complications associated with its use, and the technique for stoma adjustments are also discussed. SUBJECTS AND METHODS: Between May and December 1996, 23 patients at our institution underwent laparoscopic placement of adjustable silicone gastric bands for treatment of morbid obesity. All patients underwent a barium upper gastrointestinal series before surgery, 1 day after band placement, at variable intervals when each patient returned for band adjustment, and at 1 year. RESULTS: Unlike the case in other gastric weight loss procedures, the optimal patient position for contrast evaluation of gastric bands was anteroposterior or slightly right posterior oblique. Twenty-one of 23 patients had no complications shown on the postoperative upper gastrointestinal series. Stoma size was approximately 3-8 mm, and most patients showed delayed esophageal emptying without obstruction. Two patients had herniation of the stomach through the gastric band with pouch enlargement, resulting in obstruction and the need for additional surgery. We saw no leaks or band erosions. Nineteen stoma adjustments were performed in 13 patients. One patient had an inverted port that could not be accessed for adjustment. CONCLUSION: As adjustable gastric bands become more widely used, radiologists need to be familiar with the radiographic appearance of the devices, the complications associated with their use, and the optimal patient positioning for contrast evaluation. Radiologists may also be involved with band adjustment to decrease or increase the stoma size and therefore need to understand the technique and potential difficulties of adjusting the stoma.

Conversion of proximal to distal gastric bypass for failed gastric bypass for superobesity.

The purpose of this study was to analyze outcome following malabsorptive distal gastric bypass (D-GBP) in superobese patients who were reoperated for recurrent obesity comorbidity after a failed standard gastric bypass (S-GBP). Twenty-seven formerly superobese patients with a failed S-GBP converted to a D-GBP were studied. The small bowel was anastomosed 250 cm from the ileocecal valve to the disconnected Roux limb; the bypassed small intestine was connected to the ileum 50 cm from the ileocecal valve in five patients between 1985 and 1986 and 150 cm from the ileocecal valve in 22 patients thereafter. Comorbidity was reassessed yearly following conversion to D-GBP. Malnutrition occurred in all five patients with a 50 cm "common tract"; all required further revision and two died of hepatic failure. Three of 22 patients with a 150 cm common tract were reoperated with bowel lengthening because of malnutrition. Initial body mass index was 57+/-2 kg/m2 and fell from 46+/-2 kg/m2 before revision to 37+/-2 kg/m2 at 1 year and 32+/-2 kg/m2 at 5 years after revision; the percentage of excess weight lost went from 30+/-4% to 61+/-4% at 1 year and 69+/-5% at 5 years after revision. Preoperative comorbidity in patients undergoing revision included 14 with insulin-dependent type II diabetes mellitus, 11 with sleep apnea, 14 with hypoventilation, 13 with hypertension, and two with venous stasis ulcers. Obesity comorbidity was corrected within 1 year in all but two patients with hypertension and remained stable in all patients followed for 5 years. Revision of a failed S-GBP to a 150 cm common tract D-GBP corrects failed weight loss and severe obesity comorbidity but requires nutritional support to prevent protein-calorie malnutrition, iron and fat-soluble vitamin deficiencies, and further revision in some patients to correct malnutrition. A 50 cm common tract has an unacceptable morbidity and mortality.

The role of the 5-HT4 receptor in Cl- secretion in human jejunal mucosa.

5-Hydroxytryptamine (5-HT) is a mediator of chloride ion (Cl-) secretion in the intestine which can be seen as a rise in short circuit current (Isc) in the Ussing chamber model. We investigated the 5-HT receptor mediating 5-HT-induced Cl- secretion in the human jejunum in vitro. Jejunal segments obtained from patients having gastric bypass surgery for obesity, were stripped of muscularis and mounted in Ussing chambers and short-circuited. The 5-HT receptor agonist-induced change (delta) in Isc was recorded in the presence and and absence of 5-HT receptor antagonists. The rank order of agonist potency was: 5-HT > 5-methoxytryptamine > renzapride (BRL 24924 > alpha-methyl-5-HT >> 2-methyl-5-HT. In the presence of Cl(-)-free media or 100 microM furosemide, 5-HT-induced delta Isc was significantly reduced. It was also antagonized by > or = 1 microM tropisetron (a 5-HT 3/5-HT4 receptor antagonist) and > or = 10 nM GR 113808 (a selective 5-HT4 receptor antagonist) with pA2 values of 6.5 and 7.9, respectively. Another 5-HT4 receptor antagonist, SC 53606 (0.1 microM), antagonized the 5-HT-induced response with a pA2 of 7.3 5-HT1-like/5-HT2 (methysergide), 5-HT1P [N-acetyl-5-hydroxytryptophyl 5-hydroxytryptophan amide (5-HT-DP], 5-HT2A (ketanserin) and 5-HT3 (ondansetron) receptor antagonists and tetrodotoxin, had no significant effect on the EC50 for 5-HT. In conclusion, this study demonstrates that in the human muscle-stripped jejunum in vitro, 5-HT induced change in short circuit current is mediated by a 5-HT4 receptor via a non-neural pathway.

5-Hydroxytryptamine-induced Cl- transport is mediated by 5-HT3 and 5-HT4 receptors in the rat distal colon.

In the rat distal colon, 5-hydroxytryptamine (5-HT)-induced Cl- secretion is seen as a rise in short circuit current (Isc). We investigated the 5-HT receptor mediating 5-HT-induced Cl- secretion in the rat distal colon. Rat distal colon was prepared either by stripping away the muscularis propria with the neural ganglia, or by leaving it intact. The tissue was mounted in Ussing chambers and short circuited. 5-HT receptor agonist-induced changes (delta) in Isc were recorded in the presence and absence of 5-HT receptor antagonists. In stripped preparations, the rank order of potency of agonists was: 5-HT > 5-methoxytryptamine > alpha-methyl-5-HT >> 2-methyl-5-HT. 5-HT and 5-methoxytryptamine-induced changes in Isc were antagonized by > or = 0.3 microM tropisetron with pA2 values 6.5 and 6.4, respectively. The 5-HT4 antagonist, SC 53606, antagonized the 5-HT-induced response with a pA2 of 7.2. 5-HT1-like (methysergide), 5-HT1P (N-acetyl-5-hydroxytryptophyl 5-hydroxytryptophan amide (5-HTP-DP)), 5-HT2A (ketanserin) and 5-HT3 (ondansetron) receptor antagonists had no significant effect on the 5-HT response in stripped tissue. 3 microM forskolin, or 10 microM 3-isobutyl-1-methyl-xanthine (IBMX), decreased the EC50 and increased the maximum 5-HT response. The 2-methyl-5-HT and 5-HT-induced delta Isc in the unstripped colon preparation were antagonized by the 5-HT3 antagonist, ondansetron (0.3 nM), and 2-methyl-5-HT activity was abolished by pretreatment with tetrodotoxin. In conclusion, 5-HT-induced delta Isc is neurally mediated via a 5-HT3 receptor, and non-neurally mediated via a 5-HT4 receptor in the rat distal colon.