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A Gelet

Publications and source records attributed to A Gelet.

At least 37 records · Page 2Linked to original sources
PubMed1998

Differential attenuation imaging for the characterization of high intensity focused ultrasound lesions.

High intensity focused ultrasound (HIFU) is an effective technique for creating coagulative necrotic lesions in biological tissue, with a view to treating localized tumors. Although good results have already been obtained, notably in urology, current systems lack a real time monitoring system to check the efficacy of the treatment procedures. This study describes the development and assessment of a noninvasive system for making local measurements of attentuation variations during HIFU treatment procedures. An apparatus (Ablatherm, Edap-Technomed, France), combining a 2.5 MHz therapeutic transducer and a 5.5 MHz twin plane imaging probe (connected to an ultrasound scanner), was used to produce lesions. The rf signals needed to calculate the attenuation were recorded as outputs from the ultrasound scanner, before and after the high intensity firing sequences, which were performed on ten pieces of porcine liver. Each firing sequence involved producing a lesion volume comprising 42 individual lesions. A number of recordings were also made without producing lesions, in order to test the reproducibility of the measurements. The attenuation function was evaluated locally using the centroid and the multinarrowband methods. Initially, changes in the integrated attenuation alpha (mean attenuation in the 4-7 MHz range) and the attenuation slope beta were examined for the lesion volume. beta values did not vary significantly within this range, whereas alpha values varied significantly (in the region of 86% of the initial level) in comparison to measurements performed without forming lesions. The differential attenuation delta alpha (representing local variations in alpha) was subsequently used to generate images revealing the lesion areas. There was a strong similarity between these 'delta alpha images' and the lesion volumes defined by the operator. 'delta alpha images' offer several advantages over existing attenuation imaging techniques. Any problems related to the heterogeneity of the medium are eliminated, since only the change in attenuation is taken into account. Furthermore, there is no need to compensate for diffraction when estimating delta alpha, as the rf signals are captured in exactly the same positions before and after treatment. This technique can be used during in vivo treatment procedures. It can be implemented in real time, since the computational algorithms (based primarily on FFT calculations) are very fast. The technique should provide clinical practitioners with valuable qualitative and quantitative information for use in HIFU ultrasound surgery.

Algorithms↗
PubMed1998

[Preliminary results of the treatment of 44 patients with localized cancer of the prostate using transrectal focused ultrasound].

OBJECTIVE: To evaluate the efficacy and morbidity of treatment of localized prostatic cancer using transrectal high-intensity focused ultrasound. MATERIAL AND METHODS: 44 patients (mean age: 72 years) with clinical stage T1 (20) or T2 (24) prostatic cancer, not eligible for radical prostatectomy, were treated by two different prototypes of the Ablatherm (Technomed Medical System). The second prototype includes several safety devices designed to reduce morbidity. 99 sessions were performed, i.e. an average of 2.25 sessions per patient: the prostate was treated in one session (5 patients), 2 sessions (26 patients), 3 sessions (10 patients), or 4 sessions (3 patients), usually under spinal anaesthesia. The mean PSA was 9.92 ng/ml and the mean prostatic weight was 37 g. RESULTS: Complications occurred in 10 (50%) of the first 20 patients treated (1993-1995): 2 recto-urethral fistulas, 2 asymptomatic rectal burns, 2 cases of stable urinary retention, 1 case of severe incontinence, 3 cases of bladder neck sclerosis, and 1 febrile urinary tract infection. In the 24 patients treated subsequently (1995-1997), complications occurred in only 4 patients (16%): 1 case of stable urinary retention, 1 febrile urinary tract infection, 1 case of bladder neck sclerosis, 1 case of stress incontinence. A complete response (repeated negative follow-up biopsies) was obtained in 27 patients (61%). The mean post-treatment PSA level in patients of this group was 1.09 +/- 1.06 and remained stable (mean follow-up: 346 days; range: 60-1250). A residual cancer was detected in 17 patients (39%). 8 patients were considered to be failures (mean post-treatment PSA: 4.8 ng/ml) and received adjuvant treatment (hormonal: 3; external radiotherapy: 5). Complementary treatment by focused ultrasound will be performed in another 9 patients, if their PSA rises above 3 ng/ml (patients of this group are symptomatic with a mean post-treatment PSA of 1.6 ng/ml). CONCLUSION: The morbidity of treatment by transrectal focused ultrasound has now been reduced. These results suggest that this new treatment can constitute a useful option for certain patients with localized cancer, not suitable for radical prostatectomy.

Adenocarcinoma↗
PubMed1998

[Laparoscopic surgical treatment of simple cysts of the kidney].

OBJECTIVE: To demonstrate the efficacy of laparoscopic treatment of symptomatic renal cysts or cysts suspicious of malignancy. MATERIAL AND METHODS: 10 patients (mean age: 58 years) were operated by laparoscopy either for compressive or symptomatic cysts (7 cases), or for cysts suspicious of malignancy (3 cases). The mean cyst diameter was 7.8 cm. All patients were evaluated by preoperative CT scan. There were 8 Bosniak type I and 3 Bosniak type II cysts. RESULTS: The procedure was performed via an intraperitoneal approach (8 cases) or via a retroperitoneal approach (2 cases). The mean operating time was 92 min and the mean hospital stay was 5.4 days. One patient was operated (conversion to lumbotomy) for uncontrolled haemorrhage of the base of the cyst. The 10 cysts were found to be benign histologically. All 10 patients are asymptomatic (mean follow-up: 8.3 months) with disappearance of the cyst on the follow-up CT scan. CONCLUSION: Laparoscopic treatment of renal cysts is feasible and effective. However, this treatment must be reserved for Bosniak type I and II cysts, associated with a low risk of malignancy.

Adult↗
PubMed1998

[Hazards of lumbar ureteroscopy: apropos of 4 cases of avulsion of the ureter].

Ureteroscopy is frequently indicated in the treatment of stones of the pelvic ureter. Access to the lumbar ureter is associated with a higher complication rate: wounds, ureteric rupture, haemorrhage, or more serious lesions such as avulsions of the ureter. We present 4 cases of avulsion of the ureter seen in our department, corresponding to 4 men with stones of the lumbar ureter treated by ureteroscopy, 2 of them after failure of in situ extracorporeal lithotripsy (ESWL) and an attempt to "flush" the stone and the other two because ESWL was not available. The ureteric lesion was related to a Dormia catheter in 2 cases and the ureteroscope in 2 cases. The lesion was diagnosed and treated immediately in 2 patients and after a delay in the other 2 cases. Repair consisted of ureteric reimplantation on a Boari flap (1 case), implantation onto a psoas bladder (1 case), ureteroileoplasty (1 case) and autologous transplantation (1 case). Ureteric lesions prevented uretero-ureterostomy. Ureteric reimplantation on psoas bladder and/or Boari flap appears to be the simplest method, but it cannot always be performed. In the case of avulsion of the ureteropelvic junction with a large defect, autologous transplantation is a method of choice in young subjects. Ureteroileoplasty appears to be reserved for elderly patients.

Adult↗
PubMed1997

Treatment of dual urinary and fecal incontinence by implantation of two AMS 800 artificial sphincters. Case report.

We report the case of a 61-year-old woman with urinary and anal incontinence due to neurologic disease. An AMS 800 artificial sphincter was implanted first round the bladder neck with recovery of satisfactory urinary continence. Four months later, another AMS 800 artificial sphincter was implanted round the anal sphincter. Two revisional procedures had to be performed: replacement of the pump for mechanical failure, and replacement of the low-pressure balloon by a high-pressure one. Finally the patient has been almost completely continent with only occasional leakage of feces or liquid stools (follow-up 24 months after activation). Defecography shows total rectal evacuation and anorectal manometry records an anal closing pressure of 70 cm H2O. Dual implantation of artificial sphincters is possible for incontinence of neurological origin, provided bladder and rectal compliance are normal.

Anal Canal↗
PubMed1997

Endopyelotomy with the Acucise cutting balloon device. Early clinical experience.

OBJECTIVES: To evaluate the efficacy of the Acucise balloon cutting device in the treatment of ureteropelvic junction (UPJ) stenosis. METHODS: Forty-four patients with primary (21) or secondary (23) UPJ stenosis underwent Acucise endopyelotomy between July 1992 and February 1995. RESULTS: The average operating time was 53 min and the average hospital stay was 6 +/- 4 days. The follow-up schedule included a symptom questionnaire, intravenous urography and diuretic renal scan. Of the 44 patients, 38 have been followed for a minimum of 3 months postoperatively (mean: 12 months, range: 3-39 months). Overall success was achieved in 29 (76%). The procedure was successful in 16 out of 19 cases (84%) with secondary strictures. When the technique was used for the treatment of primary UPJ strictures, the success rate was only 68% (13 out 19). The presence of a large periureteric urinoma was identified as the cause of failure in 2 cases of primary strictures. CONCLUSION: We recommend the use of the Acucise device as the first-line therapy for treatment of secondary UPJ stenosis (except in the presence of large enclosed stones). We do not approve the use of the Acucise device for treatment of primary UPJ strictures. In primary hydronephrosis, the negative role of periureteric extravasation probably explains the low success rate of 68% (as opposed to 85% for a large series of percutaneous endopyelotomies.

Adolescent↗
PubMed1997

[Contribution of computed tomography in the staging of upper urinary tract urothelial tumors. Importance of the tumor diameter measurement].

OBJECTIVES: To demonstrate a correlation between abdominal computed tomography (CT) data and the histological stage of upper urinary tract tumour (UUTT) in order to more accurately define therapeutic indications. MATERIALS AND METHODS: From 1984 to 1995, 51 patients were treated for UUTT and were assessed by preoperative abdominal CT. 41 of the 51 CT scans were considered to be interpretable and were reviewed retrospectively by a single radiologist. The CT stage and tumour diameter were compared to the pathological stage. RESULTS: CT staging had a reliability of 76%, by combining stages Ta-T2, which could not be distinguished. The sensitivity of CT to assess invasion of the renal parenchyma and ureteric or perirenal fat was 100% and 70%, respectively, with a specificity of 82% and 97%. The accuracy can be improved by decreasing the thickness of sections of the tumour. Tumour diameters (d) of pyelocaliceal tumours, measured by CT and pathology, were closely correlated (r2 = 0.83). All UUTTs less than 3 cm in diameter were found to be superficial on histology. CT correctly estimated the size of these small tumours in 14/15 cases. Overall, by setting the limit at 3 cm, CT was able to detect a superficial pyelocaliceal tumour with a specificity of 92% and a PPV of 93%; however, a CT size > or = 3 cm is not predictive of the histological stage of the lesion. CONCLUSIONS: CT is still imprecise for the staging of UUTT, as it cannot distinguish between Ta, T1 and T2 lesions, and is still not sufficiently reliable in the assessment of invasion of the periurothelial fat or of the renal parenchyma. CT measurement of the diameter of pyelocaliceal tumours can provide an argument in favour of the superficial nature of the lesion and therefore guide the therapeutic decision towards a conservative approach.

Adult↗
PubMed1996

Ureteropelvic invagination procedure for endopyelotomy (Gelet technique): review of 51 consecutive cases.

Between 1990 and 1995, we performed 51 endopyelotomies on 38 cases of primary and 13 of secondary obstruction of the ureteropelvic junction (UPJ) using the ureteropelvic invagination technique. Of the 51 patients in the series, 49 have been followed for a minimum of 3 months postoperatively (mean follow-up 16 months). Overall, success was achieved in 38 (77.5%). Endoscopic endopyelotomy was successful in 11 of 13 cases (84.5%) with secondary strictures. When the technique was used for the treatment of primary UPJ stricture, the success rate was only 75% (27 of 36). The presence of a crossing vessel was identified as the cause of failure in five cases of primary strictures; hence, we advocate the use of angiography to identify crossing vessels preoperatively. We recommend the use of the ureteropelvic invagination technique as the first-line therapy for primary hydronephrosis in adults in the absence of a crossing vessel.

Adolescent↗
PubMed1996

Treatment of prostate cancer with transrectal focused ultrasound: early clinical experience.

OBJECTIVES: To evaluate the efficacy of transrectal focused ultrasound on localized prostatic cancer. METHODS: Fourteen patients (mean age 72.5 years) with clinical stage T1 (3) and T2 (11) prostatic cancers, who were not suitable candidates for surgery were treated. The mean PSA pretreatment level was 12 +/- 10 ng/ml (Hybritech). The device used (Ablatherm, Technomed M.S.) combines a 2.25-MHz therapy transducer and a 7.5-MHz transrectal biplane ultrasound scanner probe (linked to a software enabling the operator to determine precisely the zone of the prostate to be treated. The prostate was treated in one (3 patients), two (7 patients) or three sessions (4 patients) under spinal (25 sessions) or general anesthesia (4 sessions). RESULTS: Complications occurred in 9 of the 14 patients (64%): early complications occurred in 6 (rectal burns 3, urinary retention 2, transient incontinence 1) and late complications in 5 (incontinence 2, bladder neck stenosis 3). The median PSA NADIR value (1.79 +/- 2.35 ng/ml) was achieved at 6 months and the final PSA value was 2.94 +/- 3.27 ng/ml (mean follow-up 380 days). Control biopsies demonstrated coagulative necrotic lesions of the treated prostate zones with secondary development into fibrosis. No residual cancer was observed in 7 patients after several random sextant biopsies. Residual cancer was found in 7 patients: 4 required complementary treatment (orchidectomy 2, external beam radiation therapy 2). Adjuvant therapy was deferred in 3 patients with stable PSA values under 2 ng/ml. CONCLUSIONS: A satisfactory local control with negative control biopsies was achieved in 50% of the cases in this pilot study. However, this therapy is an investigational procedure: long-term follow-up will be necessary to confirm these early results.

Aged↗
PubMed1996

[Treatment of lymphocele after kidney transplantation].

Lymphocele is a possible postoperative complication of renal transplantation and its treatment is still controversial. Over a 3-year period (January 1992 to December 1993), 7 patients with a complicated lymphocele were treated by various modalities. Puncture-drainage was used in 7 cases, Povidone sclerotherapy was performed in 4 cases and internal drainage was performed by surgical marsupialization in one case and by laparoscopy in 4 cases. The results of external drainage and sclerotherapy were disappointing, with 1 good result out of 7 and 1 moderate result out of 4, respectively. On the other hand, internal drainage was effective in every case, whether it was performed by surgical or laparoscopic marsupialization. The latter technique avoids the disadvantages of open surgery in high-risk patients. Laparoscopy appears to be the treatment of choice for post-renal transplantation lymphoceles, as it is simple, rapid and effective.

Adult↗
PubMed1995

[Lymphoma with bladder involvement and renal transplantation].

Based on the case of a renal transplant recipient who developed a monoclonal B cell lymphoma with plasma cell differentiation, arising in the bladder, the authors discuss the responsibility of intensive immunosuppressant protocols in the development of post-transplantation lymphoproliferative syndromes. The Epstein-Barr virus favours the development of these lymphomas. The bladder is a rare site. Diagnosis was based on endoscopic resection with immunohistochemical analysis. The prognosis depends on the stage at the time of diagnosis. At an early stage, resection of the tumour combined with reduction of immunosuppressant therapy may be sufficient, but more aggressive treatment is required for more advanced stages. Anti-B lymphocyte monoclonal antibodies (CD21, CD24) give good results, especially in polyclonal forms and Epstein-Barr virus primo-infections. Anti-CD38 monoclonal antibodies are currently being investigated and appear to be very promising. Conventional radiotherapy and chemotherapy are disappointing.

Herpesviridae Infections↗
PubMed1995

[First clinical trials of a new endoscopic lithotriptor with ballistic energy (Waltz EL 25 Combilith)].

The Waltz Combilith EL 25 is an endoscopic lithotriptor equipped with an electrohydraulic and ballistic function. The device which generates the ballistic energy is a hand-piece in which a projectile, driven by an electromagnet, strikes a metal rod which transmits the energy to the stone. The diameter and length of the rod are adapted to the site of the stone (bladder + kidney: 1.7 mm rod; ureter: 0.8 mm rod). 29 stones in 25 patients with a mean age of 43 years (range: 25-72) were treated using ballistic energy: 22 ureteric stones (mean dimensions: 9 x 6 mm), 2 renal stones (mean dimensions: 20 x 30 mm) and 5 bladder stones (mean dimensions: 15 mm). Satisfactory stone fragmentation was obtained for 26 of the 29 stones (89.6%) with a mean fragmentation time of 142 seconds. One minimal ureteric perforation was observed (cure without sequelae after drainage by a double J stent). The Combilith EL 25 presents an excellent efficacy/safety ratio and can be used throughout the urinary tract.

Adult↗
PubMed1995

[Endoscopic treatment of intermittent vesico-ureteral reflux in women. Apropos of 40 cases].

UNLABELLED: To evaluate the clinical efficacy of endoscopic treatment of intermittent vesicoureteric reflux in adult females. METHODS: Forty women presenting with recurrent urinary tract infection related to intermittent vesicoureteric reflux, underwent subureteric Teflon injection according to the O'Donnell procedure (mean volume of Teflon 1 cc). Thirty patients required one injection, while nine patients needed two injections. Meatostomy or urethral dilatation were associated in 29 cases (72.5%). RESULTS: No complication occurred. Clinical results were evaluated using a questionnaire. The mean follow-up was 33.5 months (range 12-72), complete disappearance of infection was obtained in 31 out of 40 cases (77.5%). Recurrent urinary infection occurred in 9 cases. After complementary Teflon injection, urinary infection disappeared in 5 patients and finally a complete cure was obtained in 36 out of 40 cases (90%). CONCLUSION: Intermittent vesicoureteric reflux could be easily cured by an endoscopic procedure. This minimally invasive technique is simple and well adapted to this relatively benign disease.

Adolescent↗
PubMed1994

[Endoscopic treatment of vesico-ureteral reflux using teflon injections].

We have reviewed 124 patients with vesicoureteral reflux who were treated by endoscopic injection of polytetrafluoroethylene (Teflon) in four institutions. Of these patients 71 had bilateral reflux and 53 had unilateral reflux. In all, 195 ureters were treated. Reflux was primary in 94 cases (143 ureters) and secondary in 30 cases (52 ureters). Only 118 ureters (60.5%) showed no more reflux after a single injection. Seventy-seven ureters needed a second or third Teflon injection to control their reflux. In this group, reflux was cured in 46 ureters (23.6%) for a total cure rate by Teflon injection of 84.1%. Thirty-one ureters (15.9%) needed reimplantation (follow-up ranged from 1-4 years). In this study we assessed results in relation to the grade and type of reflux, the injected dose of Teflon and the technique used. The possible causes of failure and the reported complications are discussed.

Adolescent↗
PubMed1994

[The contribution of endoscopy in the diagnosis of unilateral hematuria of renal origin and pseudotumors of the upper urinary tract].

From 1985 to 1992, 9 patients (6 males, 3 females) with a mean age of 47 years, presenting with a clinical picture suggestive of a tumour of the upper urinary tract (haematuria and/or pelvic or caliceal radiolucent filling defect), underwent retrograde (6 cases) and/or percutaneous (9 cases) endoscopic exploration of the upper urinary tract. The percutaneous examination allowed a precise diagnosis and appropriate treatment adapted to the lesion detected (papillary necrosis: 2 cases; ectopic papilla: 2 cases; hypertrophy of Brunn's nests: 1 case; papillary angioma: 1 case; haemorrhagic papillitis: 3 cases) in every case. Endoscopic exploration of radiolucent lesions of the upper tract and unexplained renal haematuria is therefore justified whenever the diagnosis of upper tract tumour is uncertain on the basis of the radiological and cytological assessment.

Adult↗
PubMed1993

Prostatic tissue destruction by high-intensity focused ultrasound: experimentation on canine prostate.

High-intensity focused ultrasound (HIFU) has been used transrectally to induce intraprostatic coagulation necrosis lesion in the canine prostate. The device combines a firing system (power amplifier and therapy transducer) and a localization system (ultrasound scanner). Thirty-seven dogs have been treated with ultrasound intensity ranging from 720 W/cm2 to 2300 W/cm2 and shot durations ranging from 1 to 4 seconds. The threshold for focal ultrasonic lesions was determined to be 1000 W/cm2 with a 1-second shot duration. Intraprostatic lesions were obtained without any damage to the rectal wall. These lesions were homogeneous coagulation necroses and progressed first to an inflammatory fibrosis and then to sclerosis with cavity formation. Intraprostatic lesions also occurred with a combination of moderate acoustic intensity (720 W/cm2) and longer shot duration (4 seconds). The temperature reached at the focal point of the transducer was 85 degrees C. The study confirms the possibility of creating irreversible lesions in the prostatic tissue through the rectal wall. The destruction of localized prostatic cancer seems to be possible in the near future using HIFU delivered by the transrectal route.

Animals↗
PubMed1993

Endoscopic treatment of vesicoureteric reflux in transplanted kidneys.

Twenty-one patients underwent endoscopic subureteric injection of Polytef paste for the correction of secondary vesicoureteric reflux (VUR) in transplanted kidneys. Ureteroneocystotomy was performed in renal transplants using an extravesical technique in 19 patients and the Leadbetter-Politano technique in 2 cases. Success was achieved in only 6 patients, including the 2 ureters reimplanted according to the Leadbetter-Politano technique. No significant complication relating to the technique was observed. Despite the low success rate (30%), endoscopic treatment of VUR in transplanted kidneys is justified as a first attempt in view of the morbidity of VUR and the difficulties of repeated surgical reimplantation in this population.

Adolescent↗