Laparoscopic approach is feasible in Crohn's complex enterovisceral fistulas: a case-match review.

BACKGROUND: Complex enterovisceral fistulas are internal fistulas joining a "diseased" organ to any intra-abdominal "victim" organ, with the exception of ileoileal fistulas. Few publications have addressed laparoscopic surgery for complex fistulas in Crohn's disease. OBJECTIVE: The aim of this study was to evaluate the feasibility of such an approach. DESIGN: This study is a retrospective, case-match review. SETTINGS: This study was conducted at a tertiary academic hospital. PATIENTS: : All patients who underwent a laparoscopic ileocecal resection for complex enterovisceral fistulas between January 2004 and August 2011 were included. They were matched to a control group undergoing operation for nonfistulizing Crohn's disease according to age, sex, nutritional state, preoperative use of steroids, and type of resection performed. Matching was performed blind to the peri- and postoperative results of each patient. MAIN OUTCOME MEASURES: The 2 groups were compared in terms of operative time, conversion to open surgery, morbidity and mortality rates, and length of stay. RESULTS: Eleven patients presenting with 13 complex fistulas were included and matched with 22 controls. Group 1 contained 5 ileosigmoid fistulas (38%), 3 ileotransverse fistulas (23%), 3 ileovesical fistulas (23%), 1 colocolic fistula (8%), and 1 ileosalpingeal fistula (8%). There were no significant differences between the groups in terms of operative time (120 (range, 75-270) vs 120 (range, 50-160) minutes, p = 0.65), conversion to open surgery (9% vs 0%, p = 0.33), stoma creation (9% vs 14%, p = 1), global postoperative morbidity (18% vs 32%, p = 0.68), and major complications (Dindo III: 0% vs 9%, p = 0.54; Dindo IV: 0% vs 0%, p = 1), as well as in terms of length of stay (8 (range, 7-32) vs 9 (range, 5-17) days, p = 0.72). No patients died. LIMITATIONS: This is a retrospective review with a small sample size. CONCLUSION: A laparoscopic approach for complex fistulas is feasible in Crohn's disease, with outcomes similar to those reported for nonfistulizing forms.

Effect of natural iron fertilization on carbon sequestration in the Southern Ocean.

The availability of iron limits primary productivity and the associated uptake of carbon over large areas of the ocean. Iron thus plays an important role in the carbon cycle, and changes in its supply to the surface ocean may have had a significant effect on atmospheric carbon dioxide concentrations over glacial-interglacial cycles. To date, the role of iron in carbon cycling has largely been assessed using short-term iron-addition experiments. It is difficult, however, to reliably assess the magnitude of carbon export to the ocean interior using such methods, and the short observational periods preclude extrapolation of the results to longer timescales. Here we report observations of a phytoplankton bloom induced by natural iron fertilization--an approach that offers the opportunity to overcome some of the limitations of short-term experiments. We found that a large phytoplankton bloom over the Kerguelen plateau in the Southern Ocean was sustained by the supply of iron and major nutrients to surface waters from iron-rich deep water below. The efficiency of fertilization, defined as the ratio of the carbon export to the amount of iron supplied, was at least ten times higher than previous estimates from short-term blooms induced by iron-addition experiments. This result sheds new light on the effect of long-term fertilization by iron and macronutrients on carbon sequestration, suggesting that changes in iron supply from below--as invoked in some palaeoclimatic and future climate change scenarios--may have a more significant effect on atmospheric carbon dioxide concentrations than previously thought.

Three-dimensional determination of variability in colon anatomy: applications for numerical modeling of the intestine.

BACKGROUND: Precise knowledge of variability in colonic anatomy is of great importance for numerical modeling studies of the abdomen. This knowledge would allow the creation of personalized models for the gastrointestinal tract used for surgical simulations or in studies of virtual trauma. MATERIALS AND METHODS: To determine the colonic configuration in the general population and define its variability by gender, age, and corpulence, the layout of the colon was determined via the following reference points: ileocecal junction, left and right colonic flexures, and colosigmoid junction (CSJ). Three-dimensional coordinates for each point were recorded on scanned sections of 100 healthy adults to examine the colonic layout under physiological conditions. Coordinates were repositioned in a new anatomical reference for comparison. The average points' coordinates, standard deviations, and distances between them were compared for each group. RESULTS: The right colonic flexure was the most variable point. The CSJ was the least variable. Gender affected mainly the height of the colonic flexures and the length of its segments. Age affected the length of the transverse mesocolon root. Corpulence affected both the position of the ileocecal and CSJs and the length of the right colon. Differences in size and perivisceral fat distribution between groups explained these differences. Three-dimensional anatomical models of the colon were defined for each group by statistical equations. CONCLUSION: These equations, combined with data concerning the actual lengths of the colonic segments, enable reconstruction of different anatomical models of the colon that are representative according to gender, age, and corpulence.

An endoscopic strategy for management of anastomotic complications from bariatric surgery: a prospective study.

BACKGROUND: Treatment of anastomotic fistulas after bariatric surgery is difficult, and they are often associated with additional surgery, sepsis, and prolonged non-oral feeding. OBJECTIVE: To assess a new, totally endoscopic strategy to manage anastomotic fistulas. DESIGN: Prospective study. SETTING: Tertiary-care university hospital. PATIENTS: This study involved 27 consecutive patients from July 2007 to December 2009. INTERVENTION: This strategy involved successive procedures for endoscopic drainage of the residual cavity, diversion of the fistula with a stent, and then closure of the residual orifice with surgical clips or sealant. MAIN OUTCOME MEASUREMENTS: Technical success, mortality and morbidity, migration of the stent. RESULTS: Multiple or complex fistulas were present in 16 cases (59%). Endoscopic drainage (nasal-fistula drain or necrosectomy) was used in 19 cases (70%). Diversion by a covered colorectal stent was used in 22 patients (81%). To close the residual or initial opening, wound clips and glue (cyanoacrylate) were used in 15 cases (55%). Neither mortality nor severe morbidity occurred. Migration of the stent occurred in 13 cases (59%) and was treated by replacement with either a longer stent or with 2 nested stents. The mean time until resolution of fistula was 86 days from the start of endoscopic management, with a mean of 4.4 endoscopies per patient. LIMITATIONS: Moderate sample size, nonrandomized study. CONCLUSION: An entirely endoscopic approach to the management of anastomosing fistulas that develop after bariatric surgery--using sequential drainage, sutures, and diversion by stents--achieved resolution of the fistulas with minimal morbidity.

Very low stapling of the anal canal in laparoscopic ileal pouch-anal anastomosis.

Performing a double-stapled ileal pouch-anal anastomosis requires very low stapling of the anal canal. However, this laparoscopic procedure is often difficult to perform. We describe here a transanal method of everting the rectum, which allows easier transection under visual control and a sufficiently low anastomosis. Once the entire colon and rectum have been dissected out at laparoscopy, a plastic tube is introduced per anum and advanced into the mid sigmoid. The rectum is then divided at the level of the rectosigmoid junction by an endostapler, which also attaches the plastic tube to the rectum. The colon specimen is removed by a small incision at the chosen stoma site. Gentle traction on the plastic tube at the perineum everts the rectal tube. The anal canal is then transected at the desired level relative to the dentate line.

Preoperative infliximab treatment and postoperative complications after laparoscopic restorative proctocolectomy with ileal pouch-anal anastomosis: a case-matched study.

BACKGROUND: Infliximab offers promising new therapeutic options for treatment of moderate to severe ulcerative colitis. However, several studies suggest that it increases postoperative complication rates for patients who later require a restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). This study aimed to assess the postoperative course of patients after laparoscopic IPAA, comparing those who had and those who had not received infliximab before surgery. METHODS: The authors identified patients from their institution's IPAA database, finding 13 patients who had received preoperative infliximab treatment. Using age, gender, and type of procedure (2 or 3 stages) as criteria, they matched these cases with infliximab-naive patients drawn from the same database. The differences in perioperative data between the two groups were analyzed. Complications and their severity were assessed using the Strasberg classification. RESULTS: No significant difference was found between patients treated with and those treated without infliximab for each variable studied, namely, mean operative time (353 vs. 355 min), complication rate (23 vs. 38%), and mean hospital stay (22 vs. 25 days). CONCLUSION: The study findings showed no adverse impact from previous infliximab therapy on the laparoscopic IPAA postoperative course.

A three-dimensional human trunk model for the analysis of respiratory mechanics.

Over the past decade, road safety research and impact biomechanics have strongly stimulated the development of anatomical human numerical models using the finite element (FE) approach. The good accuracy of these models, in terms of geometric definition and mechanical response, should now find new areas of application. We focus here on the use of such a model to investigate its potential when studying respiratory mechanics. The human body FE model used in this study was derived from the RADIOSS HUMOS model. Modifications first concerned the integration and interfacing of a user-controlled respiratory muscular system including intercostal muscles, scalene muscles, the sternocleidomastoid muscle, and the diaphragm and abdominal wall muscles. Volumetric and pressure measurement procedures for the lungs and both the thoracic and abdominal chambers were also implemented. Validation of the respiratory module was assessed by comparing a simulated maximum inspiration maneuver to volunteer studies in the literature. Validation parameters included lung volume changes, rib rotations, diaphragm shape and vertical deflexion, and intra-abdominal pressure variation. The HUMOS model, initially dedicated to road safety research, could be turned into a promising, realistic 3D model of respiration with only minor modifications.

Anthropometric characterization of the child liver.

PURPOSE: The major purpose of this retrospective study on 25 CT scans of child liver aged from 2 to 13 years was to investigate the growth, morphologic variations and modifications of the liver position as a function of the children age. The objective was to characterize the 3D geometry of the child liver, which is still unknown. METHODS: 3D reconstruction of child liver was performed using the Mimics(®) software. Measurements of volumes (total liver and right lobe), distances between anatomic reference points and angles were performed. The liver position was calculated with respect to the 11th thoracic vertebra. RESULTS: The liver shows a harmonious volume growth between the right and the left lobes, but a disharmonious one for the measurements in relation to the falciform ligament. The liver position, with respect to the vertebral column, in the peritoneal cavity was unchanged during the liver growth. CONCLUSION: The obtained results from this preliminary work give a description of the child liver during the growth and are of interest for the numerical modeling.

Anthropometric characterization of spleen in children.

PURPOSE: This paper aims to characterize the 3D geometry of the child spleen which is still unknown. METHODS: An anthropological measurement protocol, based upon 3D modeling using spleen-computed tomography data, was set up. Characteristic measurements were defined to allow dimensions and spatial localization description from classical anatomical landmarks (11th dorsal vertebra and 10th left rib). RESULTS: Growth patterns showed a global enlargement without significant changes in distance to anatomical bone points. CONCLUSIONS: This preliminary study describes a validated measurement protocol based on 3D reconstructions and gives description of the child spleen during growth.

From iatrogenic digestive perforation to complete anastomotic disunion: endoscopic stenting as a new concept of "stent-guided regeneration and re-epithelialization".

BACKGROUND: Iatrogenic intestinal tract perforation and anastomotic disunion traditionally required surgical treatment. Complete anastomotic break was considered until now as an absolute contraindication for endoscopic management. OBJECTIVE: The aim of this series was to show that endoscopic management is able to treat a spectrum of bowel wall breaks, from focal perforation to complete anastomotic disunion. SETTING: A single-center prospective cohort study. PATIENTS: Nine consecutive patients with nonmalignant gastrointestinal perforations were treated with endoscopic stenting between 2005 and 2008. Perforations were related to endoscopic perforations (4 cases: 2 esophageal and 2 colorectal), postoperative fistula or leakage (2 cases: 1 colorectal anastomosis and 1 esophageal), and complete anastomotic disunion (3 cases: 2 ileoanal anastomosis and 1 esophagogastric anastomosis). INTERVENTIONS: All 9 patients underwent endoscopic installation of fully covered stents under endoscopic and radiologic guidance, sometimes associated with simultaneous endoscopic collection drainage. Oral feeding was resumed when radiologic contrast studies showed no residual leak. RESULTS: The outcome in all 9 patients was favorable. Two migrated stents were replaced, and 2 stents were spontaneously expelled without consequence. All stents were withdrawn within an average of 5 weeks. LIMITATIONS: Uncontrolled pilot study, small sample size. CONCLUSION: The successful endoscopic management of bowel wall breaks ranging from perforation to complete postoperative disunion with fully covered stent could support a new concept of "stent-guided regeneration and re-epithelialization." Controlled trials are needed before this new endoscopic treatment can be proposed as a substitute for traditional treatments.

Comparison of the biomechanical behavior of the liver during frontal and lateral deceleration.

BACKGROUND: The trunk of a car occupant can be injured by a frontal or lateral impact. Lesions can be either intrusion injuries or due to the effects of deceleration alone. The aim of this study conducted with human cadavers was to explore the effects of deceleration on the liver during frontal or lateral deceleration. METHODS: Trunks previously instrumented with accelerometers in three sites, the left and right lobes of the liver and the retrohepatic inferior vena cava, were subjected to substantial deceleration in three orientations: frontal, left, and right lateral. The anatomic consequences and deceleration data were measured. A deceleration ratio was defined as a peak deceleration measured in the liver divided by peak deceleration imposed on the trunk. RESULTS: Peak deceleration imposed on the trunks was up to 60 g, which caused peak deceleration up to 26 g in the liver. No anatomic injury was observed. For each orientation, deceleration ratios were not significantly different among the three sites (p = 0.64) or between left and right lateral decelerations (p = 0.12). Deceleration ratios were significantly different (p = 0.001) between frontal (3 sites combined) and lateral (3 sites of left and right lateral orientations combined) decelerations: 39.4% (+/-6) versus 48.4% (+/-11). CONCLUSIONS: In conclusion, at tested decelerations, under the hepatic injury threshold, cadaveric liver seemed to be subjected to higher deceleration when the trunk was decelerated in lateral than in frontal direction, without terminal impact.

Mid-term functional outcome of laparoscopic restorative proctocolectomy: a prospective study of 40 consecutive cases.

INTRODUCTION: This prospective study aimed to analyze the functional outcome after a two-stage laparoscopic total proctocolectomy with ileal pouch-anal anastomosis. MATERIALS AND METHODS: From May 1999 to May 2008, 68 consecutive two-stage laparoscopic total proctocolectomies with ileal pouch-anal anastomosis were performed (ulcerative colitis: n = 61; familial adenomatous polyposis: n = 7). A covering ileostomy was used in all patients. Forty patients whose covering ileostomy had been closed for a minimum of 2 years were included in this series. RESULTS: Conversion to laparotomy was necessary in 4 of 40 patients (10%). Thirteen postoperative complications occurred in 13 of 40 patients (30%). At a median follow-up of 38 months (range, 26-90), the median number of bowel movements was 4 per 24 hours (range, 2-10); 15 patients (38%) had no nighttime bowel movements. None of the patients had fecal incontinence or urgency. Thirty-four of the 40 patients (85%) experienced no soiling. Seven patients (18%) took regular antidiarrheal medication. All patients were able to resume all activities practiced prior to illness onset, and 36 of 40 (90%) were satisfied with their overall quality of life (very good or good). CONCLUSION: Laparoscopic total proctocolectomy with ileal pouch-anal anastomosis provides satisfying mid-term functional outcome.

Does faecal diversion prevent morbidity after ileocecal resection for Crohn's disease? Retrospective series of 80 cases.

BACKGROUND: After ileocecal resection for Crohn's disease, a temporary faecal diversion is indicated in high-risk patients. The impact of a temporary stoma on post-operative morbidity has been poorly assessed so far. The aim was to analyse post-operative morbidity of temporary faecal diversion after ileocecal resection for Crohn's disease. METHODS: Patients undergoing temporary faecal diversion combined with ileocecal resection were retrospectively included. Patients presenting with complications were compared with patients with an uneventful post-operative course, to identify any predictive factor for morbidity. RESULTS: Eighty faecal diversions were performed (43 males, 33.5 (18-75) years), including 63 split stoma (79%) and 17 covering loop ileostomies (21%). Fifty-two patients (65%) presented with a perforating disease. Post-operative complications occurred in 15 patients (19%), 15 days after surgery (1-30). The main complications were intra-abdominal abscess (n = 6), functional renal failure (n = 6), fistula (n = 2) and stomal prolapse (n = 2). Two patients required surgery. Previous bowel resections (60% versus 28%, P = 0.01) were significantly associated with post-operative morbidity. CONCLUSIONS: Temporary faecal diversion is useful in high-risk patients after ileocecal resection for Crohn's disease. Patients' information about post-operative risks remains an important issue. Risk factors for post-operative morbidity despite faecal diversion are previous bowel resections.

Material properties of the placenta under dynamic loading conditions.

Trauma during pregnancy especially occurring during car crashes leads to many foetal losses. Numerical modelling is widely used in car occupant safety issue and injury mechanisms analysis and is particularly adapted to the pregnant woman. Material modelling of the gravid uterus tissues is crucial for injury risk evaluation especially for the abruption placentae which is widely assumed as the leading cause of foetal loss. Experimental studies on placenta behaviour in tension are reported in the literature, but none in compression to the authors' knowledge. This lack of data is addressed in this study. To complement the already available experimental literature data on the placenta mechanical behaviour and characterise it in a compression loading condition, 80 indentation tests on fresh placentae are presented. Hyperelastic like mean experimental stress versus strain and corridors are exposed. The results of the experimental placenta indentations compared with the tensile literature results tend to show a quasi-symmetrical behaviour of the tissue. An inverse analysis using simple finite element models has permitted to propose parameters for an Ogden material model for the placenta which exhibits a realistic behaviour in both tension and compression.

Petrous bone fracture: a virtual trauma analysis.

OBJECTIVE: The temporal bone shields sensorineural, nervous, and vascular structures explaining the potential severity and complications of trauma related to road and sport accidents. So far, no clear data are available on the exact mechanisms involved for fracture processes. Modelization of structures helps to answer these concerns. Our objective was to design a finite element model of the petrous bone structure to modelize temporal bone fracture propagation in a scenario of lateral impact. MATERIALS AND METHODS: A finite element model of the petrous bone structure was designed based on computed tomography data. A 7-m/s lateral impact was simulated to reproduce a typical lateral trauma. Results of model analysis was based on force recorded, stress level on bone structure up to induce a solution of continuity of the bony structure. RESULTS: Model simulation showed that bone fractures follow the main axes of the petrous bone and occurred in a 2-step process: first, a crush, and second, a massive fissuration of the petrous bone. The lines of fracture obtained by simulation of a lateral impact converge toward the middle ear region. This longitudinal fracture is located at the mastoid-petrous pyramid junction. DISCUSSION: Using this model, it was possible to map petrous bone fractures including fracture chronology and areas of fusion of the middle ear region. This technique may represent a first step to investigate the pathophysiology of the petrous bone fractures, aiming to define prognostic criteria for patients' care.

Biomechanical characterisation of fresh and cadaverous human small intestine: applications for abdominal trauma.

Intestinal injuries are responsible for significant morbidity and mortality arising from trauma to the abdomen. The biomechanical characterisation of the small intestine allows for the understanding of the pathophysiological mechanisms responsible for these injuries. Studies reported in the literature focus principally on quasi-static tests, which do not take into account the stresses experienced during high kinetic trauma. In addition, the use of embalmed human tissue can alter the recorded response. The stress-strain curves from 43 tensile tests performed at 1 m/s were analysed. Samples were prepared from four fresh human intestines and from four embalmed cadaveric intestines. The data indicated a two-phase response, with each response consisting of a quasi-linear increase in the stress followed by an inflection in the curve before a peak preceding the loss of stress. The fresh tissue was more deformable than the embalmed tissue, and its first peak stress was lower (P = 0.034). A complementary histological analysis was performed. The results of the analysis enable an investigation of the response of the intestinal wall layers to stress as a two-layer structure and highlight the high sensitivity of the structure's mechanical behaviour to the speed of loading and the method of preservation.

The Rapunzel syndrome: a hard-to-swallow tale.

INTRODUCTION: Rapunzel syndrome is a rare entity comprising of a large gastroduodenal trichobezoar due to trichotillomania. Its treatment is often surgical. CASE REPORT: A 27-year-old patient was investigated after an upper gastro-intestinal tract obstruction. Computed tomography and endoscopy showed a large gastric trichobezoar with a duodenojejunal tail. Conservative treatments failed to remove the bezoar. We performed a short laparotomy which allowed the removal of the bezoar through a longitudinal gastrotomy. Postoperative course was uneventful.

Biomechanical response of impacted bony pelvis: influence of the morphometry and bone density.

Mechanical properties of human pelvic bone tissue according morphological parameters were few studied in anterior-posterior compression tests and few data are available to correctly validate finite element pelvis models. In order to reduce this gap, 12 pelvic bones were removed from male and female embalmed cadavers and compressed. Anatomic angles were measured and bone's density was calculated after each test. Fractures observed during those tests were coherent with those observed in real life. Bone's density and percentage of mineralisation were not significantly different between the male and female groups. The retropubic angle was significantly larger in the female group (p < 0.05). Mean load necessary to obtain the collapse was significantly higher in the male group (p < 0.05).

Child pedestrian anthropometry: evaluation of potential impact points during a crash.

This paper highlights the potential impact points of a child pedestrian during a crash with the front end of a vehicle. Child anthropometry was defined for ages between 3 and 15 years. It was based on the measurement of seven different segment body heights (knee, femur, pelvis, shoulder, neck, chin, vertex) performed on about 2,000 French children. For each dimension, the 5(th), 50(th) and 95(th) percentile values were reported, and the corresponding linear regression lines were given. Then these heights were confronted with three different vehicle shapes, corresponding to a passenger car, a sport utility vehicle and a light truck, to identify impact points. In particular, we show that the thigh is directly hit by the bumper for children above 12 years of age, whereas the head principally impacts the hood. The influence of child anthropometry on the pedestrian trajectory and the comparison with test procedures in regulation are discussed.

Posture and muscular behaviour in emergency braking: an experimental approach.

In the field of numerical crash simulations in road safety research, there is a need to accurately define the initial conditions of a frontal impact for the car occupant. In particular, human models used to simulate such impacts barely take into account muscular contracting effects. This study aims to quantify drivers' behaviour in terms of posture and muscular activity just before a frontal impact. Experiments on volunteers were performed in order to define these conditions, both on a driving simulator and on a real moving car. Brake pedal loads, lower limbs kinematics and muscle activation were recorded. Coupling instantaneous data from both experimental protocols (simulator versus Real car), a standard emergency braking configuration could be defined as (1) joint flexion angles of 96 degrees, 56 degrees and 13 degrees for the right hip, knee and ankle respectively; (2) a maximum brake pedal load of 780N; (3) a muscular activation of 55% for the anterior thigh, 26% for the posterior thigh, 18% for the anterior leg and 43% for the posterior leg. The first application of this research is the implementation of muscle tone in human models designed to evaluate new safety systems.