Computational Tools for the Reliability Assessment and the Engineering Design of Procedures and Devices in Bariatric Surgery.

Obesity is one of the main health concerns worldwide. Bariatric Surgery (BS) is the gold standard treatment for severe obesity. Nevertheless, unsatisfactory weight loss and complications can occur. The efficacy of BS is mainly defined on experiential bases; therefore, a more rational approach is required. The here reported activities aim to show the strength of experimental and computational biomechanics in evaluating stomach functionality depending on bariatric procedure. The experimental activities consisted in insufflation tests on samples of swine stomach to assess the pressure-volume behaviour both in pre- and post-surgical configurations. The investigation pertained to two main bariatric procedures: adjustable gastric banding (AGB) and laparoscopic sleeve gastrectomy (LSG). Subsequently, a computational model of the stomach was exploited to validate and to integrate results from experimental activities, as well as to broad the investigation to a wider scenario of surgical procedures and techniques. Furthermore, the computational approach allowed analysing stress and strain fields within stomach tissues because of food ingestion. Such fields elicit mechanical stimulation of gastric receptors, contributing to release satiety signals. Pressure-volume curves assessed stomach capacity and stiffness according to the surgical procedure. Both AGB and LSG proved to reduce stomach capacity and to increase stiffness, with markedly greater effect for LSG. At an internal pressure of 5 kPa, outcomes showed that in pre-surgical configuration the inflated volume was about 1000 mL, after AGB the inflated volume was slightly lower, while after LSG it fell significantly, reaching 100 mL. Computational modelling techniques showed the influence of bariatric intervention on mechanical stimulation of gastric receptors due to food ingestion. AGB markedly enhanced the mechanical stimulation within the fundus region, while LSG significantly reduced stress and strain intensities. Further computational investigations revealed the potentialities of hybrid endoscopic procedures to induce both reduction of stomach capacity and enhancement of gastric receptors mechanical stimulation. In conclusion, biomechanics proved to be useful for the investigation of BS effects. Future exploitations of the biomechanical methods may largely improve BS reliability, efficacy and penetration rate.

Risk factors including the presence of inflammation at the resection margins for colorectal anastomotic stenosis following surgery for diverticular disease.

AIM: The aim of this study was to investigate risk factors for anastomotic stenosis in patients operated on for diverticular disease. Histological inflammation and diverticula at the resection margins were also considered. METHOD: Patients' characteristics, the surgical technique and postoperative complications were collected from the medical records. Anastomotic stenoses were evaluated prospectively by rigid sigmoidoscopy during follow-up examination. Histological specimens were examined by a single pathologist who investigated inflammation and diverticula at the resection margins. Twenty patients with anastomotic colorectal stenosis from a single tertiary centre were compared with 24 consecutive patients without stenosis. They were all operated on for diverticular disease over a specified time period. RESULTS: Histological inflammation and diverticula were found in 25% and 30% of the resection margins respectively. Univariate analysis showed that age > 71 years (P = 0.0002), female gender (P = 0.0069) and anastomoses located below 12 cm from the anal verge (P = 0.020) were risk factors for stenosis. No correlation was found between anastomotic stenosis and the presence of histological inflammation or diverticula at the resection margins. By multivariate analysis, only age > 71 years was found to be a statistically significant risk factor for stenosis (P = 0.0003, OR = 60.8, 95% CI: 6.4-575.5). CONCLUSION: Anastomotic stenosis is a frequent, long-term complication following surgery for diverticular disease. An analysis demonstrated that age is a risk factor for colorectal stenosis and that histological inflammation and the presence of diverticula near/at the resection margins have no effect on the incidence of stenosis.

Transanal ileoproctostomy is feasible in human cadavers.

AIM: An ileorectal bypass performed entirely through a transanal route has recently been described in an animal model. The present study aimed to demonstrate its technical feasibility in four human cadavers. METHOD: A transanal endoscopic microsurgery (TEM) device and endoscopic instruments were used. The principal steps of the procedure included insertion of the TEM device, rectostomy above the peritoneal reflection, peritoneoscopy using a standard gastroscope and delivery of the small bowel through the proctostomy to perform an anastomosis. RESULTS: The procedure was successfully completed using transanal access in all cases. The mean procedure time was 90 min. The bypass was patent, and the anastomosis between the intraperitoneal rectum and the terminal ileum was leakproof. CONCLUSION: Transanal ileoproctostomy is technically feasible in human cadavers. The procedure may become an alternative to stoma formation in selected patients with colonic obstruction.

Risk factors for colorectal anastomotic stenoses and their impact on quality of life: what are the lessons to learn?

AIM: The aim of the study was to analyse the incidence of benign colorectal anastomotic stenoses in consecutive patients operated on in a single institution and to assess risk factors for their development. Their impact on quality of life was also evaluated. METHOD: Patient characteristics, indications for surgery, surgical technique and postoperative complications were prospectively recorded. Stenosis was evaluated by rectoscopy at regular intervals, and patients were treated only if symptomatic. After at least 6 months following surgery, patients were asked to respond to the Short Form 36-item quality-of-life questionnaire during a telephone interview. RESULTS: Of the original 211 patients considered, 195 underwent a follow-up rectoscopy and were included in the study. Benign stenosis were found in 26 (13%), and 19 (73%) symptomatic patients were treated successfully (15 with endoscopic dilatation and four with radial diathermic surgical incisions). Risk factors for anastomotic stenosis according to univariate analysis were female sex, diverticulitis, mechanical anastomosis, and anastomosis located between 8 and 12 cm from the anal verge. The significant risk factors identified by multivariate analysis were diverticulitis (OR 5, P=0.002) and mechanical anastomosis (OR 9, P=0.04). The self-perceived quality of life of patients with stenosis was significantly worse compared with controls. CONCLUSION: Since diverticulitis and mechanical anastomosis are risk factors for anastomotic stenosis, surgeons should take this into account when they are considering what type of anastomotic technique to utilize.

Report on a case of Rothmund-Thomson syndrome associated with esophageal stenosis.

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis. While its incidence is unknown, approximately 300 cases have been reported in the literature. The syndrome typically presents with a characteristic facial rash (poikiloderma), its diagnostic hallmark, and heterogeneous clinical features including congenital skeletal abnormalities, sparse hair distribution, juvenile cataracts, and a predisposition to osteosarcoma. Gastrointestinal symptoms, such as pyloric stenosis, anal atresia, annular pancreas, and rectovaginal fistula, have also been reported sporadically. This is a report describing a patient diagnosed with RTS referred to us because of dysphagia caused by esophageal stenosis. Long-term results of endoscopic dilation are also presented.

Endoscopic ultrasound-guided drainage of abdominal abscesses and infected necrosis.

Traditionally abdominal abscesses have been treated with either surgical or radiologically guided percutaneous drainage. Surgical drainage procedures may be associated with considerable morbidity and mortality, and serious complications may also arise from percutaneous drainage. Endoscopic ultrasound (EUS)-guided drainage of well-demarcated abdominal abscesses, with adjunctive endoscopic debridement in the presence of solid necrotic debris, has been shown to be feasible and safe. This multicenter review summarizes the current status of the EUS-guided approach, describes the available and emerging techniques, and highlights the indications, limitations, and safety issues.

Caffeine consumption among eating disorder patients: epidemiology, motivations, and potential of abuse.

OBJECTIVE: Aim of the study was to investigate caffeine use in different types of eating disorders (ED) patients either using a categorical approach [Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition - Text Revision (DSM-IV-TR) diagnostic criteria] or a dimensional perspective. METHOD: Fifty-eight ED female patients [anorexia nervosa (AN), restricting and binge-eating/purging type, N=15; bulimia nervosa (BN) purging type/nonpurging type, N=26; binge eating disorder (BED), N=17] referred to an Eating Disorder Unit and 15 non-clinical controls were administered the Eating Disorder Inventory-2 (EDI-2), the Clinical Global Impression (CGI) and the Caffeine Use Test, an interview specifically developed to investigate caffeine intake. Statistical analyses were then repeated clustering patients according to the presence/absence of purging behaviors (purgers, N=22; non-purgers, N=19; BED, N=17). RESULTS: Current and lifetime caffeine use, measured as mg/day, were similar comparing controls and ED patients as a whole. BN patients showed a significantly higher maximum lifetime caffeine intake (817.4+/-528,9 vs 325.0+/-294.6 mg/die, F=3.246, p<0.05); the same for purgers vs controls (p<0.05). Caffeine abuse was significantly more represented among patients vs controls (p<0.01), but similar among different patients' groups. As for diagnoses according to DSM-IV-TR Substance Use modified for caffeine, no significant difference was found among the different groups, for either Dependence, Intoxication or Withdrawal. Most of patients and controls reported pleasure as the main motivation for caffeine use, followed by increased vigilance and attention and appetite suppression in AN and BN patients. Note that a shift in diagnosis in the course of the ED from non-purging to purging type was associated with an increase in caffeine current, lifetime and maximum lifetime intake (F=1.667 p<0.05), except for BED patients. Severity of the ED measured as CGI score or comorbidity did not affect caffeine intake in patients as a whole, but in the purging subgroup current caffeine use was increased in presence of an anxiety disorder (p<0.05), and decreased in presence of a mood disorder (p<0.01). CONCLUSIONS: Data from the present study are in agreement with previous evidence in literature that a high percentage of ED patients ordinarily use caffeine with an average intake similar to that of the general population, however with a kind of binge attitude. Among heavy drinkers, daily caffeine intake and alcohol/cigarettes use are associated supporting the link with the dimension of impulse disregulation. The substantial number of subjects from our sample satisfying research criteria for Dependence, together with increasing reports of caffeine intoxication, suggests the growing relevance of these issues that deserve further investigation.

Gastrointestinal telangiectasia: a study by EGD, colonoscopy, and capsule endoscopy in 75 patients.

BACKGROUND: The distribution of lesions in the gastrointestinal tract in patients with sporadic telangiectasia is at present unknown. PATIENTS AND METHODS: 75 patients with sporadic telangiectasia underwent esophagogastroduodenoscopy (EGD), capsule endoscopy, and colonoscopy. Endoscopic diagnosis of telangiectasia and gastrointestinal bleeding were required for enrollment in the study. Hemorrhagic diathesis, co-morbidity, number of blood transfusions, and subsequent management were also noted. RESULTS: 35 of the patients presented with gastroduodenal vascular lesions, 51 with small-bowel lesions, and 28 with colonic lesions. 67 % of patients in whom EGD found telangiectasia also presented small-bowel vascular lesions at capsule endoscopy and 43 % colonic lesions at colonoscopy. 54 % percent of patients with positive colonoscopy also presented gastroduodenal lesions and 48 % small-bowel lesions. Patients with known duodenal lesions were more likely to have small-bowel lesions at capsule endoscopy (odds ratio [OR] 10.19, 95 % CI 2.1 - 49.33, P = 0.003). Patients with associated diseases, such as liver cirrhosis, chronic renal failure, or heart valvulopathy, presented more severe disease requiring blood transfusions (OR 6.37, 95 % CI 1.39 - 29.2, P = 0.015). The number of blood transfusions correlated with the number of sites affected ( R = 0.35, P = 0.002). The detection of new lesions at capsule endoscopy allowed new treatment in 46 % of patients. Mean follow-up was 18 months. CONCLUSIONS: Sporadic telangiectasia is a multifocal disease potentially involving the whole digestive tract. Patients with duodenal telangiectasia show a higher risk of jejunal or ileal lesions. Capsule endoscopy is a useful diagnostic tool for the detection of such small-bowel vascular lesions, indicating a more specific prognosis and treatment strategy.

Endoscopic treatment of bile duct complications after orthotopic liver transplantation.

AIM: To assess the indications and results of endoscopic retrograde cholangio-pancreatography (ERCP) in patients who have undergone ortotopic liver transplantation (OLT). METHODS: We reviewed data from 42 consecutive patients who underwent ERCP for biliary complications after OLT over an 8-year period, in particular recording indications and success of the treatment after a mean of 17 months follow-up. RESULTS: Cholangiograms performed in 33/42 patients (79%) displayed anastomotic strictures in 17 patients (52%), bile duct stones in 8 (24%), both bile duct stones and an anastomotic stricture in 2 (6%), papillary stenosis in 1 (3%), and anastomotic biliary leakage in 1 (3%). In contrast, the contrastogram was normal in four patients (12%). Stone extraction was completed in 9/10 patients (90%) with a mean of 1.2 sessions, while stricture dilation was achieved in 12/19 patients (63%) after a mean of 1.7 sessions, by stent positioning (n = 7), balloon dilation (n = 4), or Soehendra dilator (n = 1). Both biliary leakage and papillary stenosis were cured by ERCP. Only one procedure-related complication -- severe pancreatitis (2.4%) -- was observed and no mortality. CONCLUSION: ERCP is a safe and effective mode of management of bile duct complications after OLT. It should be attempted before a surgical approach. Better results are obtained for treatment of biliary stones than of anastomotic strictures.

Laser photoablation of colorectal adenomas: a 12-year experience.

BACKGROUND: We analyze laser photoablation as an alternative treatment of large sessile polyps in inoperable patients. METHODS: Ninety-four colorectal polyps (mean diameter 3.09 +/- 2.7 cm, range 1-15 cm) were treated using high-energy lasers (Nd:YAG and diode). Grade of dysplasia was low in 51, high in 35, with focally invasive cancer in eight. RESULTS: After 405 laser sessions (4.3 per polyp) five procedure-related complications were observed: two strictures, two bleedings, and one perforation. The last needed a surgical resection; the others were successfully treated by endoscopic therapy. Fifty-seven polyps (61%) were completely eradicated and the growth was controlled in all but two (98%). No degeneration was found after 28-month follow-up of treated adenomas with low- or high-grade dysplasia. Outcome of treatment was dependent on the dimension and grade of the dysplasia (p < 0.05), but not on the polyps' position (rectum or colon). Relief of rectal bleeding was obtained in 90%, of mucus discharge in 77%, and of tenesmus in 100% of cases. CONCLUSIONS: Laser photoablation of colonic adenomas can be considered a valid procedure not only to relieve symptoms, but also to control the risk of degeneration in patients unfit for surgery or when surgical treatment is considered excessively invalidating.

Quality of life in patients with an ileostomy.

AIM: Temporary or permanent ileostomy is a common procedure in colorectal surgery. Our aim was to assess the impact of ileostomy on quality of life and the relevant risk factors. METHODS: A 33-question questionnaire was sent, by mail, to 74 patients (over 70, between 70 and 50 and under 50 y old). The questionnaire explored 5 parameters of function: systemic symptoms, bowel symptoms, functional impairment, social impairment and emotional impairment. Further questions investigated the need for a nurse or relative to assist with management of the stoma, the frequency of changing the bag and the appliance, diet and the ability of patients to attend their normal daily activity. RESULTS: Thirty-four patients completed the questionnaire. The final quality of life score was similar for all the 3 age groups but elderly patients needed more assistance in the stoma management. The quality of life scores in males patients were significantly better than in females. No statistically significant difference was observed comparing loop ileostomy versus end ileostomy and Crohn's disease versus ulcerative colitis. CONCLUSIONS: Quality of life is not influenced by age, underlying inflammatory disease or type of ileostomy. Males report less impact on quality of life than women.

Determination of pesticide residues in coconut water by liquid-liquid extraction and gas chromatography with electron-capture plus thermionic specific detection and solid-phase extraction and high-performance liquid chromatography with ultraviolet detection.

Two simple methods were developed to determine 11 pesticides in coconut water, a natural isotonic drink rich in salts, sugars and vitamins consumed by the people and athletes. The first procedure involves solid-phase extraction using Sep-Pak Vac C18 disposable cartridges with methanol for elution. Isocratic analysis was carried out by means of high-performance liquid chromatography with ultraviolet detection at 254 nm to analyse captan, chlorothalonil, carbendazim, lufenuron and diafenthiuron. The other procedure is based on liquid-liquid extraction with hexane-dichloromethane (1:1, v/v), followed by gas chromatographic analysis with effluent splitting to electron-capture detection for determination of endosulfan, captan, tetradifon and trichlorfon and thermionic specific detection for determination of malathion, parathion-methyl and monocrotophos. The methods were validated with fortified samples at different concentration levels (0.01-12.0 mg/kg). Average recoveries ranged from 75 to 104% with relative standard deviations between 1.4 and 11.5%. Each recovery analysis was repeated at least five times. Limits of detection ranged from 0.002 to 2.0 mg/kg. The analytical procedures were applied to 15 samples and no detectable amounts of the pesticides were found in any samples under the conditions described.

Effect of a pilot washing system on dicofol levels in orange matrix.

An efficient analytical method is described for the analysis of dicofol residues in pulp and orange peel. Samples are mixed with Celite and transferred to chromatographic columns prepacked with silica gel. Dicofol is eluted with ethyl acetate, and the extracts are analyzed by gas chromatography with electron capture detection. Mean recoveries for dicofol at levels of 0.5, 2.0, 5.0, and 10 mg/kg ranged from 87 to 95% with relative standard deviation values between 2.6 and 9.0%. To investigate the effect of a pilot washing system on dicofol residues in oranges, the analytical procedure was applied to samples submitted to different treatments with commercial formulations under field and laboratory conditions. The orange samples with and without washing were analyzed in duplicate, and the results indicated that washing under the described conditions did not allow a complete removal of dicofol residues from orange peel.

Extraction and clean-up procedure for analysis of organochlorine pesticide residues in ethoxylated lanolin.

In the present study an evaluation was made of a method for the determination of organochlorine pesticide residues in ethoxylated lanolin. Samples were homogenized with Celite, transferred to chromatographic columns, prepacked with silica gel deactivated to 10%. The pesticide elution was processed with n-hexane-dichloromethane and the concentrated eluate was analyzed using gas-liquid chromatography (GC) with electron capture detection (ECD). The composition of the elution solvent was a significant factor for the recovery of the pesticides. Mean recoveries obtained for fortified samples ranged from 87 to 94% for p,p'-DDE, dieldrin, endrin, p,p'-DDD and p,p'-DDT. Optimization of the experimental conditions resulted in a small-scale method that combines extraction and cleanup in a single step.

Methods for determination of hexachlorobenzene and pentachlorophenol in soil samples.

The efficiency of methods for the determination of hexachlorobenzene (HCB) and pentachlorophenol (PCP) in soil samples was evaluated. An on-line method was applied for HCB determination. Soil samples were transferred to chromatographic columns prepacked with alumina. The HCB elution was processed with n-hexane. The PCP was extracted from soil samples with n-hexane-acetone in an ultrasonic bath. After re-extraction with K(2)CO(3) solution PCP was acetylated with acetic anhydride. The pentachlorophenyl acetate derivative was then extracted with n-hexane. The HCB and PCP derivative were analyzed by gas chromatography with electron capture detection (GC-ECD). Mean recoveries obtained from soil samples fortified at levels of 0.5; 4 and 20 ng g(-1), ranged from 91 to 100% for HCB, and for PCP, at levels of 10; 40 and 200 ng g(-1), ranged from 88 to 101%. These results demonstrated the efficiency of the proposed methods.

Small-scale method for the determination of selected organochlorine pesticides in soil.

A small-scale method was developed for the simultaneous determination of gamma-HCH, heptachlor, aldrin, dicofol, mirex, endosulfan I, endosulfan II and endosulfan sulphate in soil. The extraction and clean-up steps were combined into one step by transferring soil samples to chromatographic columns prepacked with neutral alumina. The pesticides elution was processed with n-hexane : dichloromethane (7 : 3) and the concentrated eluate was analysed using gas-liquid chromatography with electron capture detection. Analyses of the "in vitro" fortified samples with the selected pesticides were performed at three different levels. Mean recoveries for aldrin, gamma-HCH and heptachlor, at levels of 2, 10 and 20 ng/g, ranged from 71 to 87%; for dicofol, at levels of 8, 40 and 80 ng/g, ranged from 97 to 103%; for endosulfan I and II, at levels of 5, 25 and 50 ng/g, ranged from 88 to 96%; for mirex, at levels of 6, 30 and 60 ng/g, ranged from 86 to 110%; and for endosulfan sulphate, at levels of 15, 75 and 150 ng/g, ranged from 93 to 104%. The method can be used for rapid determination of these pesticides in soil.