Biomedical subjects

F Cornud

Publications and source records attributed to F Cornud.

At least 37 records · Page 2Linked to original sources

PubMed1995

[Zonal anatomy of the prostate using endorectal MRI].

The development of an endorectal surface coil now permits a partial study of the anatomical model developed by McNeal. Axial and coronal views, which were used to establish the model can be obtained in a short period of time with fast spin echo sequences. Axial views are performed along the proximal urethra and coronal views are performed along the axis of the distal urethra and the ejaculatory ducts. Anatomical boundaries of the transitional zone are well delineated on axial views, illustrating the concept of "inner gland". The prostatic capsule and the neuro-vascular bundles, pathways of extension of the cancer out of the prostate are also well delineated. Coronal sections allow a very good anatomical study of the caudal junction of the vas deferens and the seminal vesicles (the so called weak space), pathway of tumor extension to the seminal vesicles. Differences in signal of the prostatic zones make the outer gland cancers very conspicuous as well as some transitional cancers which can show, in some cases, an homogeneous hyposignal.

Humans↗

PubMed1994

[Color Doppler ultrasonography in urology].

Due to the development of the duplex mode, combining ultrasound images with Doppler recording, and especially the development of flow colour coding. Doppler is now increasingly used to investigate the kidney and male genital tract. It is now the technique of choice in the initial diagnosis of certain renal diseases: primary renal vein thrombosis, iatrogenic and malformative arteriovenous anomalies, vascular complications of renal transplantation, and for examination of the scrotal contents in a context of acute scrotum or investigation of the cavernosal arteries in the case of erection disorders. It allows a rapid diagnosis and guides the subsequent radiological assessment. Doppler can also provide useful or even essential additional information in the case of a known abnormality such as renal cancer, in which it defines the venous extension when CT scan is technically insufficient. In certain fields, such as diagnosis of renovascular hypertension or exploration of the prostate, the place of Doppler is still poorly defined and remains controversial, except in a few specialised centres equipped with sophisticated apparatuses used by experienced operators. After briefly reviewing Doppler techniques and the basic steps in interpretation, the authors define the contribution and limitations of colour Doppler in the investigation of the urinary tract and male genital tract. Normal appearances and the results of Doppler-ultrasound in nephrourological disease are illustrated.

Genital Diseases, Male↗

PubMed1994

[MRI in cancer of the prostate with T1-weighted sequences using fat suppression and injection of gadolinium].

The assessment of tumor extension in 20 patients with cancers of the prostate at a clinical stage A or B included MRI with a body coil before prostatectomy. Transverse and coronal T1-weighted sections with injections of gadopentate dimeglumine (gadolinium) and fat suppression were systematically taken to assess the vascularity of the various regions of the prostate and of the cancer, as well as the merits of such sequences for the assessment of extension. The normal, poorly vascularized peripheral area is only slightly enhanced by injection, while the transition area, which is most often hyperplastic in the age group studied, enhances heterogeneously with contrast. All cancers enhance after injection. In the assessment of extension, the major merit of gadolinium is that it allows exploration both of the vesiculodeferential junction on coronal sections and of the structure of the seminal vesicles. Thus a normal junction allows ruling out macroscopic invasion of the vesicles. In addition, gadolinium allows correcting false positive MRI findings when the areolar structure of the vesicles is preserved. Gadolinium does not provide additional evidence of extension through the capsule in comparison with T2-weighted sequences. On a whole, in our series, MRI with a body coil, associated T2-weighted sequences and T1-weighted sequences after gadolinium injection and fat suppression, has 58% sensitivity and 100% specificity for the diagnosis of stage C cancers.

Aged↗

PubMed1993

[Role of MRI in the diagnosis of kidney cancer].

The recent technical developments in magnetic resonance imaging (MRI) and the use of paramagnetic contrast media (gadolinium compounds) have considerably improved the performances of MRI for the detection and characterization of renal tumors. MRI does not have specific merits for the diagnosis of the typical form of cancer, nor for the detection of small kidney tumors, both being mainly based on computed tomography (CT). On the other hand, it can be used for the diagnosis of atypical forms of cancers (small, hypovascular, cystic or hemorrhagic cancers) which raise problems of differential diagnosis with some pseudotumoral lesions, complex cysts and benign tumors. Its complementarity to CT for the characterization of an atypical mass results from the signal information it provides, from a better contrast resolution, and from the possibility to make sections in all planes of space. Except for angiomyolipoma, which has a fatty content, there is no really specific MR criterion as present to evidence benign renal tumors. Concerning regional extension, CT remains the primary technique of choice, as it allows studying the limits of the tumor, the renal compartment ans its walls, the renal vein and the inferior vena cava, the neighboring organs and the contralateral kidney all together. Its findings allow defining the indications of MRI, which, as a complementary exploration, is often decisive to assess venous invasion.

Diagnosis, Differential↗

PubMed1992

[Imaging of renal cancer in adults].

In its typical form renal carcinoma shows at imaging as a solid, heterogeneous and vascularized mass deforming the kidney; its CT scan appearance is usually very suggestive. Atypical forms (small or cystic carcinomas, large carcinomas with exorenal extension, haemorrhagic carcinomas) mainly raise problems of characterization; the lesional image is always suspicious at CT or combined US, CT and MRI examinations. The detection of small tumours primarily rests on CT with contrast injection, a technique which is more sensitive (94%) than all other techniques. Among non-tumoral lesions which may look like renal carcinomas, some pseudotumoral inflammatory lesions and suspicious atypical cysts often require histological examination. With the exception of angiomyolipoma with its fat content detectable at CT or MRI, there is no truly specific criterion to differentiate benign tumour from cancer. The diagnosis of renal carcinoma extension primarily rests on MRI. In a number of cases the results are so inadequate for the study of renal veins and caval vein that a complementary exploration of these veins by Doppler ultrasonography or MRI must be requested.

Adult↗

PubMed1992

Fluoroscopically guided percutaneous transrenal electroincision of ureterointestinal anastomotic strictures.

A new technique for electroincision of a strictured ureterointestinal anastomosis is described that uses a sphincterotome and high frequency current. After placement of a percutaneous nephrostomy tube a 7F "wire guided" sphincterotome was placed into the stenosis. The cutting wire was then deflected while cutting current was applied intermittently. Injection of contrast medium through the papillotome probe assessed the depth of the incision. A 10 mm. angioplasty balloon was inflated at low pressure to verify that the anastomosis had been incised to a depth of 1 cm. The anastomosis was then stented for 8 weeks with an 18F stent. The operative time did not exceed 45 minutes. A total of 9 stenoses was treated in 7 patients: 4 were ileal conduit diversions and 5 were enterocystoplasties. No immediate complication was observed. In 1 case a small urinoma was surgically drained at removal of the stent. Six stenoses are patent with 2, 3, 4, 4, 10 and 13 months of followup after removal of the stent. One patient died of bladder tumor metastases during the stenting period and 1 with bilateral incision still has a stent. The technique can be performed without major complication (bleeding or digestive fistula). Long-term results remain to be assessed.

Constriction, Pathologic↗

PubMed1992

[What may be expected from endorectal echography and magnetic resonance imaging in the evaluation of local extension of cancer of the prostate?].

Thirty patients presenting with a clinical stage A or B cancer underwent TRUS and MRI with a body coil prior to radical prostatectomy. Imaging and pathology were correlated to assess the limits of TRUS and MRI in pre-operative staging of prostatic carcinoma. Results showed that TRUS and MRI had a sensitivity of 42 and 66% and a specificity of 89 and 94% respectively, for the diagnosis of macroscopic capsular effraction. Seminal vesicle invasion was diagnosed by TRUS with a sensitivity of 16% and a specificity of 81%. With MRI, the sensitivity and the specificity were 85 and 94% if only gross infiltration was considered. Sensitivity dropped to 45% if microscopic invasion was included. We conclude that: 1) postero-lateral venous plexus are more easily delineated by MRI, permitting a more accurate diagnosis of capsular penetration. 2) Seminal vesicle invasion cannot be diagnosed by TRUS as the echo-structure of the cancer and the caudal junction of the seminal vesicles and vas deferent are similar. 3) A normal caudal junction on TRUS or a normal bilateral hypersignal of the seminal vesicles on MRI are associated with seminal vesicle invasion in less than 5% of cases. 4) A normal caudal junction on TRUS eliminates false positive cases of MRI related to non tumoral hyposignals of the seminal vesicles.

Aged↗

PubMed1992

[Color doppler echography in the exploration of vasculogenic impotence].

102 patients with suspected vasculogenic impotence were evaluated with color doppler sonography. Measurement of normal systolic and diastolic velocities were obtained from the cavernosal arteries of patients responding by a full erection after intra-cavernosal injection of 20 mg of Papaverine. A correlation with cavernosometry was obtained in 61 patients and with selective internal pudendal arteriography in 11. The 10 patients with abnormal arteriograms had a systolic velocity < 25 cm/sec. 13 out of the 15 patients with an end diastolic velocity > 5 cm/sec had a venous leak defined by a maintenance flow rate of erection during cavernosometry > 25 ml/mn. End diastolic velocity is an excellent index of the function of the veno-occlusive system, provided the systolic velocity remains at a normal value. In case of arterial insufficiency, a diastolic flow < 5 cm/sec is of no value and cavernometry is mandatory to detect a mixed arterio-venous impotence. The addition of color doppler sonography permitted a more rapid detection of vessels and an easily reproducible measurement of velocities which makes color doppler sonography an excellent screening test for examining patients with potential vasculogenic impotence.

Adult↗

PubMed1992

[Role of MRI in the diagnosis of cancer of the kidney].

The recent technical developments in magnetic resonance imaging (MRI) and the use of paramagnetic contrast media (gadolinium compounds) have considerably improved the performances of MRI for the detection and characterization of renal tumors. MRI does not have specific merits for the diagnosis of the typical form of cancer, nor for the detection of small kidney tumors, both being mainly based on computed tomography (CT). On the other hand, it can be used for the diagnosis of atypical forms of cancers (small, hypovascular, cystic or hemorrhagic cancers) which raise problems of differential diagnosis with some pseudotumoral lesions, complex cysts and benign tumors. Its complementarity to CT for the characterization of an atypical mass results from the signal information it provides, from a better contrast resolution, and from the possibility to make sections in all planes of space. Except for angiomyolipoma, which has a fatty content, there is no really specific MR criterion as present to evidence benign renal tumors. Concerning regional extension, CT remains the primary technique of choice, as it allows studying the limits of the tumor, the renal compartment and its walls, the renal vein and the inferior vena cava, the neighboring organs and the contralateral kidney all together. Its findings allow defining the indications of MRI, which, as a complementary exploration, is often decisive to assess venous invasion.

Adenocarcinoma↗

PubMed1991

[What may be expected from endorectal ultrasonography and magnetic resonance imaging in the assessment of local extension of cancer of the prostate?].

30 patients presenting with a clinical stage A or B cancer underwent TRUS and MRI with a body coil prior to radical prostatectomy. Imaging and pathology were correlated to assess the limits of TRUS and MRI in pre-operative staging of prostatic carcinoma. Results showed that TRUS and MRI had a sensitivity of 42 and 66% and a specificity of 89 and 94% respectively, for the diagnosis of macroscopic capsular effraction. Seminal vesicle invasion was diagnosed by TRUS with a sensitivity of 16% and a specificity of 81%. With MRI, the sensitivity and the specificity were 85 and 94% if only gross infiltration was considered. Sensitivity dropped to 45% if microscopic invasion was included. We conclude that: (1) postero-lateral venous plexus are more easily delineated by MRI, permitting a more accurate diagnosis of capsular penetration. (2) Seminal vesicle invasion cannot be diagnosed by TRUS as the echostructure of the cancer and the caudal junction of the seminal vesicles and vas deferens are similar. (3) A normal caudal junction on TRUS or a normal bilateral hypersignal of the seminal vesicles on MRI are associated with seminal vesicle invasion in less than 5% of cases. (4) A normal caudal junction on TRUS eliminates false positive cases of MRI related to non tumoral hyposignals of the seminal vesicles.

Aged↗

PubMed1991

[Long-term results of angioplasty balloon dilatation of stenosed uretero-digestive anastomoses. Effect of prolonged pattern with large caliber prosthesis].

UNLABELLED: 16 strictured uretero enteric anastomoses were dilated and stented for 4 months with a large size stent (18F in fifteen cases and 14F in one case). All the patients had undergone a radical cystoprostactectomy, had received radiotherapy prior to surgery. The length of the stenosis did not exceed 3 cm in all cases. All the stenoses occurred within 2 years following the removal all of the stent. RESULTS: 6 cases (37%), have a patent anastomosis, 18 to 36 months following removal of the stent. Most of the recurrences occurred within six months following removal of the stent. We recommend a long term stenting with a large size stent to obtain long term patency of dilated anastomotic strictures.

Anastomosis, Surgical↗

PubMed1991

Endoscopic treatment of postoperative biliary fistulae.

Postoperative biliary fistulae are difficult to manage, particularly in the face of obstruction or malignancy. We used endoscopic sphincterotomy or endoprosthesis placement to aide fistula closure in 52 patients with postoperative biliary fistulae. Thirty-seven patients with a fistula were treated with endoscopic sphincterotomy alone. Twenty-four of these 37 patients had a history of lithiasis; 21 patients were treated successfully by endoscopic sphincterotomy alone. The fistula closed in 2.4 +/- 1.6 days. Among the other 13 patients without history of stone disease, the fistula closed in seven cases (54%), 8.4 +/- 2 days after endoscopic treatment. Three patients ultimately required surgical intervention. In 15 patients an attempt was made to pass a 10F endoprosthesis above the fistula. Among the eight patients with successful prosthesis insertion, the fistula healed in six patients (75%). In the seven patients in whom a prosthesis could not be passed endoscopically, the percutaneous transhepatic approach was used. Surgical treatment (hepaticojejunal anastomosis) was ultimately required in two of these seven patients. Sphincterotomy alone is the preferred treatment for biliary fistulae-complicating surgery for gallstone disease. Alternatively, when a fistula is large, endoscopic placement of a prosthesis can be proposed as the first treatment. In cases of endoscopic failure, placement of a prosthesis through the percutaneous transhepatic approach is a useful alternative, particularly when the fistula source is located in the intrahepatic biliary tract.

Biliary Fistula↗

PubMed1991

[Endoscopic and transhepatic intubation of malignant bile duct strictures for postoperative jaundice].

Out of 625 patients referred for stenting for a malignant stricture of the biliary tract, 97 (15.8%) had undergone previous surgery. Resection had been performed in 43 cases, by-pass in 15, surgical stenting in 11, laparotomy in 28. The stricture was located in the porta hepatis in 48 patients (49.5%) in the middle common bile duct (CBD) in 47 (48.5%) and juxtapapillary in 2 (2%). Endoscopic retrograde transhepatic stenting was successful in 51 patients (52.5%). Percutaneous transhepatic stenting was successful in 41 cases out of 46 (85%) and in 5 cases, only external drainage was possible. A 75% reduction in serum bilirubin was observed in 78 patients (81.5%) and normalization was observed in 66 (90%) who survived more than one month. The complication rate was 31.3% in the endoscopic group and 47.7% in the percutaneous transhepatic group, with a mortality related to early complications of 9.8% and 19.6% respectively. The higher complication rate of transhepatic stenting is at least partially related to an unfavourable selection of patients in this group: failures of endoscopic stenting, high frequency of hilar strictures. The mortality at D 30 was 24%, significantly higher in hilar strictures than in middle CBD strictures (p less than 0.02). A late obstruction of the stent occurred in 43 patients (58%) after an interval of 103 +/- 52 days, and endoscopic retreatment was possible in 65% of cases. The median survival was 153 days in subhilar strictures and 104 days in hilar strictures. These results justify considering the possibility of palliative stenting after failure of a surgical treatment especially in peri-ampullary and middle CBD strictures.

Aged↗

PubMed1991

[Magnetic resonance imaging and preoperative evaluation of cancer of the kidney. The results apropos of 60 cases].

Sixty renal carcinomas confirmed at surgery or autopsy were studied. Capsular effraction, present in 17 cases, was well assessed in 8 cases, under staged in 8 cases and over staged in 5 cases (sensitivity 47%, specificity 88%). Renal vein involvement was present in 11 cases. In 8 of these 11 cases, a thrombus was present in the inferior vena cava. MRI detected a thrombus in the renal veins in 10/11 cases and in 7/8 cases of caval invasion. The false negative case was due to a huge right upper pole tumor laminating the inferior vena cava. The false positive case was due to an enlarged lymph node compressing the inferior vena cava. Cranial extension of the thrombus was well assessed in 6 of the 7 cases. One thrombus in the right atrium was missed. Lymph node involvement was present in 10 cases and correctly diagnosed by MRI in 7 cases. Three false negative cases were noted, because of microscopic invasion in non enlarged lymph nodes. Adjacent organ invasion, present in 2 cases, was detected in 1 case of liver invasion. Initial results of MRI seem very promising and at present, the best indications of MRI in pre-operative evaluation of a renal carcinoma are assessment of caval extension and spread to adjacent organs in patients with large tumors.

Adult↗

PubMed1991

[Use of papillotome for antegrade treatment of ureteral stenoses and uretero-ileal anastomotic strictures under radioscopic control. Experimental study in dogs and clinical application].

A new technique of electro-incision of ureteral stenoses and strictured uretero-enteric anastomoses is presented. Incision is performed with a papillotome, routinely used to achieve endoscopic retrograde sphincterotomy of the duodenal papilla. Group I: 7 ureteral stenoses were performed, on a dog model after surgical ligation of the lumbar ureter. Ten days later, through a percutaneous approach, the papillotome was placed through the stenosis, deflected, and cutting current was applied to incise the stenosis. The IVP performed one month later showed disappearance of the stenosis in 4 cases, a residual stenosis without obstacle in 2 cases and a residual stenosis with obstacle in one case. Group II: 7 strictured uretero-enteric anastomoses on 6 patients. After placement of a percutaneous nephrostomy, a wire guided papillotome was placed into the stenosis. Cutting current was then applied to cut the stenosis. A 18 F ureteral stent was subsequently placed for 8 weeks. Two patients have a patent anastomosis, 7 and 10 months after removal of the stent. One patient died from metastases of bladder tumor. The three remaining patients are still stented. An urinoma occurred in one patient the day following removal of the stent, and was surgically drained. This new technique which combines electro-incision and stenting with a large caliber stent may be proposed as an alternative to surgery or balloon dilatation for the treatment of strictured uretero-digestive anastomoses.

Anastomosis, Surgical↗

PubMed1990

[Treatment using an endo-urologic approach of stenoses following uretero-intestinal anastomosis].

Twenty-one strictures following uretero-digestive anastomoses were treated by percutaneous transrenal dilatation. In 20 cases, an Olbert type angioplasty balloon on a guidewire was used. Rigid coaxial dilators were used in one patient after failure of the preceding technique and an electroincision was performed prior to dilatation in the remaining case. Overall, percutaneous transrenal dilatation was successful in nine patients, whereas ten dilatations failed and two patients are undergoing continued modeling with a mean follow-up of 16 months (range 1-42 months). Success rates by type of anastomosis were as follows: Bricker 5/12; Coffey 1/4; enterocystoplasty 2/4 and ureteroileovesical anastomosis 1/1. The date of development of the stricture, duration of modeling, and caliber of the indwelling catheter were apparently without influence on results. Because morbidity is low with percutaneous transrenal dilatation, this technique is advocated as first-line treatment, with surgery being reserved to failures.

Adult↗

PubMed1990

[Dissolution of gallbladder lithiasis with methyl tert-butyl ether (MTBE). Preliminary results in 9 cases].

Instillation of Methyl tert-butyl ether in the gallbladder permits the dissolution of cholesterol stones. Percutaneous transhepatic puncture of the gallbladder is the currently used approach; but shortcomings of this procedure could make the transpapillary cannulation of the cystic duct preferable. The reproducibility of this procedure, however, is not established. "In situ" dissolution is useful in cases of multiples stones which are not amenable to treatment with extra corporeal shock wave lithotripsy (ESWL). It can also be complementary to standard ESWL by promoting rapid disappearance of stones fragments. Preliminary results obtained in 9 patients suggest the necessity of rigorous selection criterias particularly regarding the chemical nature of the stones.

Adult↗

PubMed1990

[Cancer of the kidney: venous staging using magnetic resonance imaging].

Venous tumor invasion in 42 renal cell carcinomas was evaluated by MRI. A correct diagnosis of renal vein and inferior vena cava (IVC) involvement was made in 14 of 17 tumors: 1 false negative diagnosis of right renal vein invasion was due to a double renal vein in which the inferior vein (identified by MRI) was not involved; 2 cases of IVC involvement were understaged (1 case of suprahepatic extension) or not identified (the false negative of renal vein invasion previously described). One false positive (among 31 tumors without venous invasion) was reported in a case of a large tumor in which the compressed but free right renal vein was overevaluated by MRI.

Carcinoma, Renal Cell↗