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F Joffre

Publications and source records attributed to F Joffre.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Risk of embolism in diagnostic and therapeutic intravascular procedures--in vitro model].

The purpose of the study was to evaluate the risk of distal embolisation in a silicon model during different endovascular diagnostic and therapeutic procedures. Endovascular technics, such as guidewire and catheter advancement, metal stent placement, balloon angioplasty and thrombectomy device were compared. Clots were produced from human blood sample. The transparent silicon model was filled with saline, flow was generated by an hydraulic pump. Stenosis was created by mechanical compression. The size of the circulating particles were measured with a mesh of nylon filters. No loose particles were detected using guidewire, pigtail and straight catheters. Balloon inflation induced embolisation of particles ranging from 100 microns-12 mm in length. Deployment of self expandable metallic stents did not result in particle migration but secondary angioplasty inside the stent detached particles (ranging from 400 microns to 12 mm in length). Use of thrombectomy device resulted in significant particle migration (ranging from 400 microns to 1500 microns in length).

Angioplasty, Balloon↗
PubMed2001

Imaging of retroperitoneal ganglioneuroma.

The aim of this study was to describe the radiological appearance of retroperitoneal ganglioneuroma. We retrospectively reviewed seven cases of histologically proven retroperitoneal ganglioneuroma. Ultrasound and enhanced CT were obtained in all cases, and MRI in three cases. The masses were well-circumscribed, ranged in size from 5 x 3 x 3 to 10 x 6 x 4 cm. In three cases close relationships between the tumor mass and major blood vessels were noted, resulting in vessel displacement or surrounding, but without compression or occlusion. On ultrasound examination the tumor showed a heterogeneous solid echostructure. Non-enhanced CT showed homogeneous or mildly heterogeneous low attenuation, and a punctate calcification was seen in one case. Contrast uptake was absent (n = 1) or delayed (n = 6). Progressive but incomplete enhancement was observed in three cases. On MRI, T2-weighted images showed a high signal intensity. Dynamic studies depicted the same enhancement pattern as described on CT. Ganglioneuroma is a rare tumor which should nevertheless be included in differential diagnosis of retroperitoneal masses when presenting as a well-delimited tumor with possible tendency to surround or displace major blood vessels, low density on non-enhanced CT, and delayed progressive enhancement on CT and MRI.

Adult↗
PubMed2001

Assessment of the risk of positive surgical margins with pelvic phased-array magnetic resonance imaging in patients with clinically localized prostate cancer: a prospective study.

OBJECTIVES: We assessed magnetic resonance imaging (MRI) performance in the prediction of positive surgical margins (PSMs) before radical prostatectomy in a prospective study correlating the MRI results and pathologic findings. METHODS: Between January 1995 and December 1999, 176 patients (mean age 64.2 years, range 49 to 75), with localized prostate cancer (49 with Stage T1 and 127 with Stage T2) underwent preoperative MRI with a pelvic phased-array coil (Tesla-1, Siemens) at a mean interval of 35 days after randomized transrectal biopsies. The mean preoperative prostate-specific antigen level was 10.9 ng/mL (range 1.2 to 39). The MRI studies and specimen analysis were performed by one radiologist unaware of the clinical and biopsy findings and by one pathologist, respectively. Multivariate analysis was performed to compare the predictive value of MRI staging, prostate-specific antigen value, and preoperative Gleason score to identify the PSM rate. RESULTS: Of the 176 patients, 131 (74%) had Stage T2 disease by MRI and 45 (26%) Stage T3 disease by MRI. Pathologic staging showed 103 with pT2 and 73 with pT3. Overall, the PSM rate of the series was 18%. The PSM rate was 13.7% and 31% for patients with T2 and T3 disease by MRI, respectively. For the T3 MRI cases, the PSM rate was 2.32-fold higher. MRI staging, like the prostate-specific antigen value, was a predictive factor of PSMs (P = 0.05). CONCLUSIONS: The results of this study show that preoperative MRI staging with the phased-array coil may be helpful in predicting the PSM risk in radical prostatectomy candidates with clinically localized prostate cancer.

Aged↗
PubMed2001

Kinetic parameters of hepatic oxidation of cyclic fatty acid monomers formed from linoleic and linolenic acids.

Cyclic fatty acid monomers (CFAM) occur from linoleic (CFAM-18:2) or linolenic (CFAM-18:3) acids present in some edible oils as a result of domestic frying or industrial refining. They present adverse effects in pups and weaning rats. In the present work, we studied the importance of hepatic oxidation in the metabolism of CFAM. For this purpose, kinetic parameters of Carnitine Palmitoyl Transferase I (key enzyme of the channeling of the fatty acids into the mitochondrial beta-oxidation pathway) and Acyl CoA Oxidase (key enzyme of the peroxisomal oxidation pathway) towards CFAM-18:2 and CFAM-18:3 were calculated on hepatic sub-cellular fractions of rats. For mitochondrial oxidation of CFAM, we observed a lower oxygen consumption and a lower activity of Carnitine Palmitoyl Transferase compared to 18:2w6 and 16:0. For peroxisomal oxidation, CFAM-18:2 showed the same kinetic parameters (Vm and K(0.5)) as 18:2w6 and 16:0, used for oxidative controls, whereas CFAM-18:3 presented a lower Vm (-50%). This difference should induce a lower catabolism of CFAM-18:3 in liver. This could contribute to their accumulation and probably to their toxic effect.

Journal Article↗
PubMed2001

Macroporous polyester-covered stent in an experimental abdominal aortic aneurysm model.

PURPOSE: To validate a recently described animal model of abdominal aortic aneurysm (AAA) and to assess a new macroporous polyester-covered stent for endovascular AAA exclusion. METHODS: Twenty adult sheep had AAAs surgically created by replacing a segment of the infrarenal aorta with an autologous jugular venous graft. Three months later, surviving animals underwent percutaneous implantation of macroporous polyester-covered nitinol stents; 3 animals with untreated AAAs served as controls. Follow-up surveillance included spiral computed tomography at 1 month and digital subtraction angiography at 3 and 6 months. Endografted animals were sacrificed at 1, 3, and 6 months after implantation; specimens from all animals were examined grossly and microscopically. RESULTS: Seven (35%) animals died within 24 hours of causes related to the technique; 1 animal developed paraplegia and was sacrificed on day 1. Three (25%) animals died of spontaneous aneurysm rupture at <10 days, and 6 received the stent-graft at 3 months. The macroporous cover did not prevent continued perfusion of the sac early after stent-graft deployment, but all aneurysms were excluded on the 1-month CT. CONCLUSIONS: Spontaneous AAA rupture occurred earlier and was not as frequent as previously described for this model. Implantation of the covered stent was feasible, but aneurysm exclusion was not immediate.

Animals↗
PubMed2001

Pseudoaneurysm and aortobronchial fistula after surgical bypass for aortic coarctation: management with endovascular stent-graft.

PURPOSE: To report the endovascular repair of an aortobronchial fistula at the distal anastomosis of a complex thoracic graft. CASE REPORT: A 61-year-old man operated 18 years prior for aortic coarctation presented with hemoptysis. An aortobronchial fistula was suspected, but spiral computed tomography and angiography showed only a small pseudoaneurysm at the distal anastomosis without revealing the fistulous tract. A Talent stent-graft was successfully deployed through a femoral access, but the large delivery system injured the external iliac artery, producing a retroperitoneal hemorrhage. Prompt balloon occlusion of the aorta and subsequent bypass graft repair of the arterial injury prevented serious sequelae. The patient recovered without further complications. Follow-up imaging to 2 years has documented exclusion of the pseudoaneurysm with no hemoptysis or signs of new false aneurysm formation. CONCLUSIONS: Endovascular exclusion of anastomotic pseudoaneurysms even in complicated cases can be an efficient treatment option, but the procedure must be carefully planned and executed in order to achieve good results.

Anastomosis, Surgical↗
PubMed2001

[Radiologic study of renal colic].

Ureterolithiasis is a common disease responsible for a large number of admissions in emergency departments and a wide utilization of imaging studies. The purpose of this review was to analyze the respective role of the different available imaging techniques. Intravenous urography is the gold-standard for diagnosis of acute obstruction, but positive detection of a stone may prove difficult at times. US is less accurate than urography for both diagnoses of obstruction and lithiasis, but it represents a non invasive alternative to IVU (no ionizing radiation and no IV contrast). The information obtained from measurements of intra-renal resistive index is poorly contributive. Non contrast helical CT has become the gold-standard for the diagnosis of ureterolithiasis, the two main factors limiting its widespread use are its accessibility and the radiation exposure. Nevertheless, its excellent diagnostic performance tends to dramatically reduce the need for IVU.

Colic↗
PubMed2001

[Endoluminal treatment of peripheral aneurysm with covered endoprosthesis].

PURPOSE: To evaluate the feasibility and middle term patency results, for endovascular treatment of peripheral aneurysms, using covered stents. MATERIALS AND METHODS: Between December 1993 and may 2000 25 peripheral aneurysms on 24 patients, mean age 67.8 years (42-81), were treated with covered stents (Cragg EndoPro system or passenger, hemobahn, Word Medical). Aneurysm locations were: 17 iliac, 4 popliteal, 1 femoral, 1 subclavian, 1 carotid. The follow-up range from 1 to 75 months (mean 30.1 months). RESULTS: Successful aneurysm exclusion was achieved in all patients, while maintaining good lower extremity perfusion. All but one stent remained patent during the early follow-up period. At one year 94.4% stents were patent, at two years 90.2. CONCLUSION: Treatment of peripheral aneurysms with covered stents has a high rate of immediate procedural and clinical success. At middle term follow-up patency is encouraging except with popliteal procedure, however long term follow-up and larger series is warranted to assess the place of this procedure as an alternative to the surgery.

Adult↗
PubMed2000

Rapid relaxation times measurements by MRI: an in vivo application to contrast agent modeling for muscle fiber types characterization.

This paper is a description of a simulation method to evaluate the contrast in NMR imaging and its aim is to help to optimize the use of contrast media in clinical imaging. Indeed, there is a need to define objective criteria in order to choose among several contrast media the ones that are the most effective and to define their optimal conditions of use, such as: the dose to be injected, the required time after injection to obtain the best enhancement and the optimal imaging sequence parameter values. The method is based on NMR signal simulation in the presence of contrast media and requires the fast measurement of the T1 and T2 relaxation times to obtain the dynamic relaxometry variation of tissues after contrast injection. In this work the fast imaging techniques that are to be described enable the measurement of T1 and T2 with a 30sec temporal resolution on 128*256 matrix images. The accuracy of the method was assessed in rabbit muscles after the injection of two gadolinium chelates (Gd-DTPA and Gd-DOTA) with the aim of improving the in vivo characterization of fast-twitch and slow-twitch muscle fiber types. The simulation results were in close agreement with contrast image analysis and showed, for relevant clinical doses, a small efficacy for both chelates. The interest of the proposed simulation method lies in the fact that it enables to objectively compare the efficacy of different contrast agents, to forecast the efficacy of a given contrast reagent and to define the optimal dose and the optimal imaging sequence parameters that give the best contrast. This simulation method obviates numerous prior experiments to evaluate the benefit expected from different contrast media. The method, which has been evaluated here for muscle investigations is applicable to any tissue analysis and can help to guide the best condition of use of contrast agents in MR imaging.

Animals↗
PubMed2000

Aortoduodenal fistula after endovascular stent-graft of an abdominal aortic aneurysm.

Despite satisfying short- and middle-term effectiveness and feasibility, endovascular stent-grafting for abdominal aortic aneurysm is still under evaluation. We report a case of an aortoduodenal fistula after the use of this technique. Enlargement of the upper aneurysmal neck was followed by caudal migration of the major portion of the stent-graft, which resulted in kinking of the device in the aneurysmal sac. Ulcerations were found on adjacent portions of both the aneurysmal sac and the adjacent duodenum. Only the textile portion of the prosthetic contralateral limb separated the aortic lumen from the corresponding duodenal lumen. Early detection of complications after stent-grafting is essential to allow successful treatment, either surgical or endoluminal.

Angioplasty↗
PubMed2000

Transjugular intrahepatic portosystemic shunts in the treatment of refractory ascites: results in 48 consecutive patients.

PURPOSE: To assess the efficacy, morbidity, and mortality involved in the creation of transjugular intrahepatic portosystemic shunts (TIPS) in the treatment of patients with refractory ascites in Child-Pugh classes B and C. MATERIALS AND METHODS: Forty-eight consecutive patients with refractory ascites were treated with TIPS creation in a tertiary care institution. They were followed for a median of 337 days (range, 3-1376 d). RESULTS: TIPS significantly decreased the portohepatic pressure gradient (20.7 +/- 5.9 mm Hg vs. 6.8 +/- 4.1 mm Hg; P < .0001). Seventy-three percent of patients had complete or partial response. One year after TIPS creation, survival was 73% in Child class B patients and 56% in Child class C patients. Thirteen patients experienced procedural complications (portal vein thrombosis, peritoneal bleeding, acute renal failure, pneumothorax, hemoptysis, spontaneous bacterial peritonitis, and heart failure) and TIPS creation was considered the cause of death in five patients (10.4%). Primary patency was 65% at 3 months and 23% at 1 year, but shunt obstruction was accessible for a second intervention. Ten patients (21%) had de novo encephalopathy after TIPS creation. CONCLUSIONS: This series suggests that TIPS is an effective treatment for refractory ascites; however, it is a challenging procedure and serious complications--usually renal and heart failure--can be seen. A careful selection of patients is mandatory.

Ascites↗
PubMed2000

Cyclic fatty acid monomers from heated oil modify the activities of lipid synthesizing and oxidizing enzymes in rat liver.

Cyclic fatty acid monomers purified from a heated linseed oil were given for 2 wk to adult rats as triacylglycerol at two dose levels, i.e., 0.1 and 1 g/100 g diet, to determine their effect on some aspects of lipid metabolism. Indirect evidence of a peroxisome proliferator-like effect was observed, as determined by an elevation of some characteristic enzyme activities, such as peroxisomal acyl-CoA oxidase, and the microsomal omega- but also (omega-1)-laurate hydroxylase (CYP4A1 and CYP2E1, respectively). The dietary cyclic fatty acids induced a coordinated regulation between the activities of the lipogenic enzymes studied (Delta9-desaturase, phosphatidate phosphohydrolase) and peroxisomal oxidation, but not with mitochondrial beta-oxidation. The dose-dependent decrease of Delta9-desaturase activity (P < 0.05) with cyclic fatty acid monomer intake was accompanied by a similar decrease of the monounsaturated fatty acid level in liver. The increase in the gamma-linolenic acid level also suggested an increase in Delta6-desaturase activity with cyclic fatty acid intake (P < 0.05). In addition, our results strongly suggested that the altered liver levels of eicosapentaenoic and arachidonic acids were due to the peroxisomal retroconversion process in rats fed cyclic acids. Finally, an effect of these cyclic compounds on the carbohydrate metabolism cannot be disregarded because they decreased liver glycogen concentration. We conclude that cyclic fatty acid monomers affect different aspects of lipid metabolism, including a phenotypic peroxisome proliferator response. This provides the ground for further studies investigating the biochemical pathways that underlie the nutritional effect of such molecules.

Acyl-CoA Oxidase↗
PubMed2000

Imaging and endovascular treatment of renal artery stenosis in the diabetic patient.

Although diabetes is a classical risk factor for macroangiopathy, the prevalence of renal artery stenosis (RAS) in this type of pathology has not been clearly determined. More than 50% of RAS occur in diabetic patients (almost exclusively Type 2), whereas autopsy findings and the few clinical surveys reported indicate that the percentage of RAS within the diabetic population is close to 30%. RAS occur especially in elderly subjects with Type 2 diabetes and multiple vascular involvement, and bilateral stenoses are frequent. Diagnostic imaging of RAS can cause adverse effects in the diabetic patient if iodinated contrast media are used, especially in cases of renal insufficiency. The presence of this risk factor requires that iodinated radiological explorations be performed with due caution, or that another product be substituted as a contrast agent (CO(2) or gadolinium), or that an imaging technique without iodine be used (colour Doppler ultrasound, magnetic resonance angiography). The therapeutic management of RAS in the diabetic patient differs little from that employed for other atheromatous stenoses of the renal artery. Endovascular treatment of RAS is the technique of choice for most patients, whether diabetic or not. The existence of diabetes has little effect on therapeutic strategy, except in cases of renal insufficiency when the risk of iodine overload should limit the doses of contrast medium or require the partial or even total substitution of another agent (CO(2), gadolinium). As in the case of other RAS, the indications depend on the lesion and the clinical presentation. Similarly, the results are both clinical and anatomical, and the existence of diabetes has a limited impact on these different parameters.

Angioplasty, Balloon↗
PubMed1999

Delayed treatment of traumatic rupture of the thoracic aorta with endoluminal covered stent.

BACKGROUND: Stent grafting is emerging as a new treatment for several pathological conditions involving the thoracic aorta. We studied the feasibility and safety of this technique for delayed treatment of ruptures of the aortic isthmus. METHODS AND RESULTS: Nine patients (14 to 76 years old; mean, 37 years; male/female ratio, 8/1) underwent stent grafting of the aortic isthmus in subacute (n=5) or chronic (n=4) aortic traumatic rupture after a motor accident. In subacute ruptures, this treatment was delayed (1 to 8 months; mean, 5.4 months) because of the severity of other associated injuries. Stent grafting was technically successful (defined as complete exclusion of the pseudoaneurysmal sac) in all patients. Short-term fever and biological inflammatory syndrome occurred in 3 patients. Two major complications occurred: in 1 patient, an early occlusion of the left subclavian artery was treated by placement of 2 Palmaz stents. In another patient, an atelectasis related to an increase of preexisting compression of the left main bronchus by the pseudoaneurysmal sac was successfully treated by temporary placement of an endobronchial silicone stent. Mean follow-up was 11.6 months (range, 3 to 21 months). Thrombosis of the pseudoaneurysmal sac was found in all patients. CONCLUSIONS: In the absence of available extended follow-up about the safety and effectiveness of endovascular grafting, this approach seems to be a viable therapeutic option for traumatic rupture of the aortic isthmus, but appropriately controlled prospective studies are needed before we can recommend its widespread use.

Accidents, Traffic↗
PubMed1999

Transjugular intrahepatic portosystemic shunt in the treatment of refractory bleeding from ruptured gastric varices.

The optimal management of ruptured gastric varices in patients with cirrhosis has not been codified yet. The present study reports the use of transjugular intrahepatic portosystemic shunt (TIPS) in patients with refractory gastric variceal bleeding. Thirty-two consecutive patients were included. All had been unresponsive to vasoactive agents infusion, sclerotherapy, and/or tamponade and were considered poor surgical candidates. They were followed-up until death, transplantation, or at least 1 year (median: 509 days; range 4 to 2,230). Hemostasis was achieved in 18 out of 20 patients actively bleeding at the time of the procedure. In the whole sample of 32 patients, rebleeding rates were 14%, 26%, and 31%, respectively at 1 month, 6 months, and 1 year. De novo encephalopathy was observed in 5 (16%) patients. Seven patients experienced complications and consequently 4 of these patients died. TIPS primary patency rates were 84%, 74%, and 51%, respectively, at 1 month, 6 months, and 1 year. For the same periods of time, survival rates were 75%, 62%, and 59%. These results suggest that TIPS can be used in cirrhotic patients with refractory gastric variceal bleeding and are effective in achieving hemostasis as well as in preventing rebleeding.

Actuarial Analysis↗
PubMed1999

Aortic stent grafting and side-branch embolization in an expanding chronic type B dissection.

OBJECTIVE: This is a report of endovascular treatment of a case of type B thoracoabdominal aortic dissection in a patient with progressive dyspnea, dorsolumbar pain, and expanding aortic diameter over a 1-year period. METHODS: Pretreatment imaging evaluation showed that the false lumen supplied only the celiac trunk. Endovascular treatment combined (1) embolization of the first segment of the celiac trunk to avoid distal back-flow into the false lumen and (2) stent grafting to occlude the initial entry tear. RESULTS: The treatment resulted in technical and clinical success. The patient remains asymptomatic 12 months after treatment. CONCLUSION: Stent grafting offers an interesting therapeutic alternative to exclude the initial entry tear in aortic dissection and may be combined with other endovascular procedures.

Aortic Dissection↗
PubMed1999

High occlusion rate in experimental transjugular intrahepatic portosystemic shunt created with a Dacron-covered nitinol stent.

PURPOSE: To assess whether the use of a prosthesis covered by a Dacron sheath might prevent pseudointimal hyperplasia in a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: A TIPS procedure was performed in nine pigs, after creation of a portal vein microembolization model of portal hypertension, by using a Dacron-covered nitinol stent. The first centimeter on the lower extremity of this specially made prototype was uncovered, to avoid portal vein thrombosis. Three weeks later, the seven surviving animals underwent transjugular hemodynamic and angiographic follow-up and were then killed for gross and histologic evaluation. RESULTS: Shunt insertion was possible in all pigs; two died of complications of the procedure. After 3 weeks only two shunts were patent, although a 50%-60% narrowing of the initial portion of the shunt was present; the remaining shunts were occluded. Histologic examination showed pseudointimal hyperplasia associated, in the cases of occlusion, with a luminal thrombosis. CONCLUSION: This Dacron-covered stent did not prevent pseudointima formation over the stent and resulted in a high early occlusion rate, probably related to a pronounced tissue fibrotic response likely due to Dacron-induced inflammation.

Alloys↗