S. Berdah

Hollow viscus injury due to blunt trauma: A review.

Blunt abdominal trauma results in injury to the bowel and mesenteries in 3-5% of cases. The injuries are polymorphic including hematoma, seromuscular tear, perforation, and ischemia. They preferentially involve the small bowel and may result in bleeding and/or peritonitis. An urgent laparotomy is necessary if there is evidence of active bleeding or peritonitis at the initial examination, but these situations are uncommon. The main diagnostic challenge is to promptly and correctly identify lesions that require surgical repair. Diagnostic delay exceeding eight hours before surgical repair is associated with increased morbidity and probably with mortality. Because of this risk, the traditional therapeutic approach has been to operate on all patients with suspected bowel or mesenteric injury. However, this approach leads to a high rate of non-therapeutic laparotomy. A new approach of non-operative management (NOM) may be applicable to hemodynamically stable patients with no signs of perforation or peritonitis, and is being increasingly employed. This attitude has been described in several recent studies, and can be applied to nearly 40% of patients. However, there is no consensual agreement on which criteria or combination of clinical and radiological signs can insure the safety of NOM. When NOM is decided upon at the outset, very close monitoring is mandatory with repeated clinical examinations and interval computerized tomography (CT). Larger multicenter studies are needed to better define the selection criteria and modalities for NOM.

Dynamic biomechanical characterization of colon tissue according to anatomical factors.

INTRODUCTION The aim of this study was to determine the mechanical response of colonic specimens retrieved from the entire human colon and placed under dynamic solicitation until the tissue ruptured. MATERIAL AND METHODS Specimens were taken from 20 refrigerated cadavers from different locations of the colonic frame (ascending, transverse, descending and sigmoid colon) in two different directions (longitudinal and circumferential), with or without muscle strips (taenia coli). A total of 120 specimens were subjected to tensile tests, after preconditioning, at the speed of 1m/s. RESULTS High-speed video analysis showed a bilayer injury process with an initial rupture of the serosa / external muscular layer followed by a second rupture of the inner layer consisting of the internal muscle / submucosa / mucosa. The mechanical response was biphasic, with a first point of initial damage followed by a complete rupture. The levels of stress and strain at the failure site were statistically greater in terms of circumferential stress (respectively 69±22% and 1.02±0.50MPa) than for longitudinal stress (respectively 55±32% and 0.70±0.34MPa). The difference between longitudinal and circumferential stress was not statistically significant (3.17±2.05MPa for longitudinal stress and 3.15±1.73MPa for circumferential stress). The location on colic frame significantly modified the mechanical response both longitudinally and circumferentially, whereas longitudinal taenia coli showed no mechanical influence. CONCLUSION The mechanical response of the colon specimen under dynamic uniaxial solicitation showed a bilayer and biphasic injury process depending on the direction of solicitation and colic localization. Furthermore these results could be integrated into a numeric model reproducing abdominal trauma to better understand and prevent intestinal injuries.

An anatomic and morphometric analysis of splenic variability using 3D reconstruction and spatial orientation from computed tomography

INTRODUCTION In terms of frequency, the spleen is the first organ affected in abdominal trauma, resulting even today in a high rate of mortality (10%). Nevertheless, very few studies have investigated splenic quantitative morphometry as to shape and spatial orientation. Therefore, we analysed healthy spleen variability in order to integrate it in its environment and to correlate its morphometric parameters to anthropometric characteristics. METHODS Ninety abdominopelvic CT-scans performed on patients over 16 years with no splenic pathology were retrospectively selected among a Mediterranean population. Three age groups ([16-30], [30-60] and [over 60 years]), equally distributed among genders, were created. Parameters, such as volume, characteristic checkpoints, orientation, and morphology, were measured on the spleen, the 11th thoracic vertebra and the 10th ribs in three-dimensional reconstructions. Anthropometric parameters were characterised by waist circumference, costo-xiphoid angle, abdominal height and chest depth. RESULTS Observed variations in splenic morphology were divided into three groups: cupped (66.7%), coiled (17.8%), and flat (15.5%). Splenic morphometry tends to be abdominal-shaped (54.5%) or dorsal-shaped (45.5%). The mean of the angle between the main axis of the spleen and the CT-scan horizontal axis was 40±14°. Correlations were highlighted between volume and gender (p<0.05), splenic morphology and liver morphometry (p<0.05) as well as between orientation of hilar surface and splenic morphometry (p<0.01). Moreover, the spleen is more horizontal in women (p<0.05), in the elderly (p<0.05) and in the obese (p<0.01). CONCLUSION This study defines three groups based on shape and highlights correlations between parameters describing healthy splenic variability and its anthropometric characteristics, which are of great importance for numerical modelling in splenic studies.