Variational convergences of dual energy functionals for elastic materials with a ε thin strong inclusion

International audienceWe give a new derivation, based on the complementary energy formulation, of a simplified model for a multi-structure made up of two anisotropic hyper-elastic bodies connected by a thin strong material layer. The model is obtained by identifying the Mosco limit of the stored complementary energy functional when the thickness is of order ε and the stiffness of order 1/ε where ε is a positive real adimensional parameter. In order to prove the existence of the displacement associated with the stress we use a suitable weak version of the Saint-Venant compatibility condition also known as Donati's theorem

Preoperative portal vein embolization with a combination of trisacryl microspheres, gelfoam and coils

AbstractPurposeTo evaluate the safety and efficiency of preoperative portal vein embolization (PVE) with a combination of trisacryl microspheres, gelfoam and coils for inducing lobar hypertrophy in hepatobiliary malignancy patients.Materials and methodsPVE was performed by a percutaneous left approach in 63 patients with hepatic malignancy (hepatocarcinoma=38, colorectal metastasis=14, cholangiocarcinoma=11). The indication of PVE and surgery was evaluated by hepatic tumor board take into consideration to the tumor extension and the hepatic volume on initial and post-embolization CT-scans. The total functional liver volume (TELV) and future liver remnant (FLR) volume were measured before and 24±5days after PVE to assess FLR, TELV and FLR/TELV ratios. Efficiency evaluation was based on FLR increase, the ability to perform the hepatectomy and the hepatic function after surgery. Safety evaluation was determined by clinical and biological follow-up after embolization and surgery.ResultsPVE was successful in all the patients. The mean FLR volume increases by 57±56% after embolization (449±180cm3 to 663±254cm3) (P<0.0001). The FLR/TELV ratio increases by 11% after PVE (25±8% to 36±12%). Three minors’ complications were registered without impact on surgery, and four patients developed portal hypertension. Forty-nine patients underwent hepatectomy; none of them developed liver failure. Surgery was not performed in 14 patients due to tumor progression (n=9), inadequate hypertrophy of FLR (n=1) and portal hypertension (n=4).ConclusionPreoperative PVE with a combination of trisacryl microspheres, gelfoam and coils is a safe and effective method for inducing contralateral hypertrophy before right hepatectomy in patients with advanced hepatobiliary malignancy

Interventional management of gastroduodenal lesions complicating intra-arterial hepatic chemotherapy

Herein we report the efficacy of embolization of small patent gastric or duodenal vessels for treating gastroduodenal complications after hepatic arterial infusion therapy (HAIC). Catheter ports were implanted percutaneously from a femoral approach in three cases or surgically in the gastroduodenal artery in two cases. Acute abdominal pain developed on average after four HAIC courses of 5FU-oxaliplatin, mytomycin, oxaliplatin or fotemustine. Esophagogastroduodenoscopy showed gastroduodenal lesions (gastroduodenitis with or without ulcerations) in all cases. Despite the interruption of the HAIC, symptoms persisted and led to selective hepatic arteriography showing a patent right gastric artery (n = 4) or a recanalized gastroduodenal artery (n = 1) responsible for gastroduodenal misperfusion. Successful embolizations of the arteries responsible for gastroduodenal misperfusion (right gastric artery in four cases and gastroduodenal artery in one case) using 0.018 platinium coils relieved the patients' symptoms and allowed the HAIC to continue. In gastroduodenal complications of HAIC, a selective hepatic arteriography should be performed to search any artery responsible for the misperfusion of the toxic agent in the gastroduodenal area. Embolization of these arteries allowed the HAIC to be restore

Interventional radiology in the management of complications after liver transplantation

The arrival of new surgical transplantation techniques, such as split living donor or auxiliary liver transplantation, have increased the incidence of vascular and biliary complications. The causes, symptoms, and diagnostic modalities of arterial, portal caval, and biliary complications are detailed. Interventional techniques, such as balloon angioplasty and stent placement in the arterial and portal tree, as well as biliary interventional techniques, are discusse

Diagnostic performance of MRI for detection of intestinal fistulas in patients with complicated inflammatory bowel conditions

The diagnostic performance of magnetic resonance imaging (MRI) for detection of intestinal fistulas, other than perianal, in patients with known complicated inflammatory bowel conditions (CIBC) was investigated. Our study group consisted of 20 patients (12 women, mean age 43years) with CIBC, including Crohn's disease (n=13), colonic diverticulitis (n=3), colitis after radiotherapy (n=3) and of postoperative origin (n=1). Eleven surgically proven enteral fistulas were known in ten (50%) of these patients, being of enterovesical (n=3), enterocolic (n=2), enteroenteral (n=2), rectovaginal (n=2), rectovaginovesical (n=1) and of entercutaneous (n=1) localisation. The other ten patients (50%), used as the control group, showed MR features of CIBC, although without any fistulous tract. Multiplanar T1- and T2-weighted sequences had been performed, including gadolinium-enhanced acquisition with fat saturation (1.5T). MR findings were independently blindly and retrospectively reviewed by three radiologists for the presence and etiology of any fistula, as well as visualization and characterization of the fistulous tract. Results were compared with surgical findings (n=16) and clinical evolution (n=4). Interobserver agreement was calculated. Interobserver agreement kappa for fistula detection was 0.71. Overall sensitivity, specificity and accuracy for fistula detection were 78.6%, 75% and 77.2%, respectively. Sensitivity for fistula characterization was 80.6%, with visualization of the fistulous tract in all cases, whereby T1-weighted gadolinium-enhanced fat-saturated images were considered the most useful sequences. Gadolinium-enhanced MRI is a reliable and reproducible tool for detection of enteral fistulas secondary to inflammatory condition

Multidetector CT enteroclysis: comparison of the reading performance for axial and coronal views

The purpose of this study was to compare the diagnostic performance of axial and coronal views in multidetector CT enteroclysis (MDCTE). We retrospectively evaluated 48 patients with pathological correlation investigated by MDCTE for small bowel disorders. After nasojejunal administration of 2l of 5% methylcellulose axial arterial and venous acquisition of MDCTE was followed by coronal reconstructions using equal slice thicknesses of 2.5mm with 2mm increments. Spatial resolution of both planes was evaluated by phantom. Three radiologists independently read axial and coronal images concerning 12 pathological features. The interobserver agreement and time of reading was calculated. Sensitivity and specificity resulted from comparison with histopathology (n=39) or follow-up (n=9). Phantom study revealed higher spatial resolution for axial than coronal views, whatever reconstruction interval was used. However, spatial frequency always remained high. Most pathological signs, such as bowel wall thickening (BWT), bowel wall enhancement (BWE) and intraperitoneal fluid (IPF), showed better interobserver agreement on axial than coronal views (BWT: 0.61 vs. 0.44; BWE: 0.56 vs. 0.5; IPF:0.53 vs. 0.43). The Wilcoxon signed-rank test revealed significantly higher sensitivity for axial than coronal views (P=0.0453); the time of reading was significantly shorter for the latter (P=0.0146). The diagnostic value of axial slices is superior to coronal reconstructions despite the reduced data volume and display of the physiological course of bowel loops on the coronal plan