Biomedical subjects

O Traxer

Publications and source records attributed to O Traxer.

At least 19 recordsLinked to original sources

PubMed2003

Emergency extracorporeal shock wave lithotripsy (ESWL) for obstructing ureteral stones.

OBJECTIVE: To evaluate emergency treatment of obstructing ureteral stones by in situ extracorporeal shock wave lithotripsy (ESWL) during acute renal colic. PATIENTS AND METHODS: From January 1994 to February 2000, 200 patients (mean age: 42 years) were treated by ESWL (EDAP LT-02) for obstructing ureteral stones causing acute renal colic refractory to medical treatment or recurring within 24hours of such treatment. Stones were visualised by fluoroscopic imaging and/or ultrasound. Follow-up included radiological and/or ultrasound examinations and lasted three months. RESULTS: Mean stone size was 7mm (3-20mm). At three months, 164/200 (82%) patients were stone-free. This rate ranged from 79% to 83% according to the location of the stone, and from 75% to 86% according to the size of the stone. These differences in rate were not significant. Two or three ESWL sessions were required in 79 patients. ESWL was well tolerated in 90% of patients. The only complication was a case of pyelonephritis requiring the placement of a JJ stent, administration of antibiotics, and distant ureteroscopy. The 36 patients, in whom ESWL failed, underwent ureteroscopy (n=23) or lithotripsy with a Dornier machine (n=13). CONCLUSION: Non-deferred ESWL for acute renal colic secondary to obstructing ureteral stones has a satisfactory success rate and very low morbidity.

Acute Disease↗

PubMed2001

Monotherapy extracorporeal shock wave lithotripsy for the treatment of staghorn calculi in children.

PURPOSE: We evaluate the efficacy and parenchymal consequences of extracorporeal shock wave lithotripsy (ESWL) for staghorn calculi in children. MATERIALS AND METHODS: From 1991 to 1999, 16 young patients 5.5 months to 2 years old and 7 older children 6 to 11 years old were treated for complete (6) or partial (17) staghorn calculi. Infection was the main factor of lithogenesis, particularly in younger children. In 21 patients the stone burden was more than 20 mm. All patients were treated under general anesthesia using a 14 kV. Sonolith 3000 (14) or a 12 to 20 kV. Nova (9) lithotriptor. In 5 of the 7 older children a Double J section sign stent was inserted before treatment. In the younger children group calculi were fragmented after 1 (11) or 2 (5) sessions. Of the 7 older children 3 required 3 (1) and 4 (2) treatment sessions. To assess the long-term effect of ESWL on the parenchyma, dimercapto-succinic acid renal scan was performed the day before and 6 months after therapy in 20 patients. RESULTS: Of the 16 younger children 14 became stone-free (87.5%) and 2 had small asymptomatic residual fragments. Of the 7 older children 5 were stone-free (71.4%) and 2 required additional surgery. No steinstrasse or pyelonephritis occurred after ESWL and no parenchymal or ureteral lesion related to ESWL was identified on conventional dimercapto-succinic acid scintigraphy. At a followup of 9 months to 9 years all patients have normal blood pressure. CONCLUSIONS: ESWL as a first option is safe and appropriate for the treatment of staghorn calculi in children particularly in younger children with infected calculi.

Adolescent↗

PubMed2001

Subtotal cystectomy with ileocystoplasty for severe hemorrhagic cystitis after bone marrow transplantation.

In a retrospective analysis of hemorrhagic cystitis subsequent to allogeneic bone marrow transplantation, we focused on patients who underwent subtotal cystectomy with ileocystoplasty because stepwise use of conservative treatments had failed. Severe lasting hemorrhagic cystitis (more than 40 days) led to urinary tract obstruction and sepsis that required subtotal cystectomy in 3 of 1300 bone graft patients. Hematuria did not recur after surgery with a satisfactory functional result (follow-up 10 months to 17 years). Subtotal cystectomy with detubularized ileocystoplasty can be used to control life-threatening hemorrhagic cystitis.

Bone Marrow Transplantation↗

PubMed2001

Hemostatic laparoscopic partial nephrectomy: cable-tie compression.

OBJECTIVES: Laparoscopic partial nephrectomy (LPN) has generally been reserved for small exophytic lesions because of the limited hemostatic capabilities when excising large segments of renal parenchyma. To overcome this problem, we investigated a technique of laparoscopic reversible, regional hypoperfusion using a cable-tie to minimize blood loss and optimize exposure. METHODS: Ten domestic pigs underwent LPN after securing a cable-tie around one pole of the kidney and tightening it until the distal parenchymal surface blanched completely. Eight large amputations involving the collecting system and eight smaller amputations excluding the collecting system were performed using laparoscopic scissors. Fibrin glue was applied to seal the cut surface prior to cable-tie removal. Four pigs (4 large and 4 small amputations) were killed immediately and methylene blue was injected retrograde into the ureter to identify collecting system leaks. The remaining 6 pigs (4 large and 4 small amputations) were killed 4 weeks later and retrograde urograms were performed to assess collecting system integrity. RESULTS: Median cable-tie ischemia time was 15 minutes (range 7 to 48) and median blood loss was 30 mL (range 10 to 300). In each case, hemostasis was attained with fibrin glue. In the survival group, all 4 small amputations healed with a fibrotic scar. In the large amputation group, 1 animal died from urinary extravasation on postoperative day 4. The collecting systems of the remaining 3 pigs sealed completely. CONCLUSIONS: In the porcine model, cable-tie-assisted LPN provides an almost bloodless surgical field that facilitates rapid resection of large renal segments and hemostasis during a short ischemic period. We anticipate that this technique will broaden the clinical application of LPN.

Animals↗

PubMed2001

Tension-free vaginal tape: why an unusual concept is so successful.

The surgical treatment of female stress urinary incontinence has been dramatically changed during the last 5 years, after Ulmsten introduced the tension-free vaginal tape procedure. This technique is based on a series of experimental investigations of the urethral closure mechanisms in women. The procedure is easy to learn, could be performed on an outpatient basis, and is recognized as a minimally invasive surgery. Despite these arguments, the most probable reason for its present success is the reproducibility of the results in the various published series. The success rate is estimated at between 85 and 95% for correction of genuine stress urinary incontinence. However, longer follow-up will be necessary to confirm these preliminary results, and probably to determine what are the most valuable prognostic factors.

Female↗

PubMed2001

Renal parenchymal injury after standard and mini percutaneous nephrostolithotomy.

PURPOSE: Mini percutaneous nephrostolithotomy was developed for use in children and in adults with a reduced renal reserve to minimize the morbidity and renal parenchymal damage presumed to occur with traditional percutaneous nephrostolithotomy. We compared the extent of renal injury incurred by different sized nephrostomy tracts in female farm pigs undergoing 11 or 30Fr percutaneous nephrostomy. MATERIALS AND METHODS: Bilateral percutaneous nephrostomy was attempted via a mid or lower pole calix under fluoroscopic guidance in 6 pigs. In 2 pigs the procedure was unsuccessful on 1 side, leaving 5 successfully established nephrostomy tracts on each side. In each pig the right percutaneous tract was dilated with a 28Fr dilating balloon and a 30Fr Amplatz working sheath (Cook Urological, Spencer, Indiana) was positioned in the collecting system. On the left side an 11Fr sheath (Cook Urological) was placed. The sheaths were removed after 1 hour and nephrostomy tubes (22Fr on the right and 8Fr on the left side) were left in place overnight and then removed. Six weeks later the pigs were sacrificed and the kidneys were harvested. The nephrostomy tracts were identified grossly and examined microscopically, and the fibrotic scar was measured using digital analysis. The volume of scar was estimated using the calculated volume of a cylinder. RESULTS: At kidney harvest all 10 kidneys appeared grossly normal. No intra-abdominal urine collection or perirenal hematoma was noted. Mean estimated scar volume of the 30 and 11Fr tracts was 0.29 and 0.40 cc, which translates into a mean fractional loss of parenchyma of 0.63% and 0.91%, respectively (p not significant). CONCLUSIONS: Renal parenchymal damage resulting from the creation of a nephrostomy tract is small compared to overall renal volume regardless of the size of the nephrostomy tract. Consequently there is no advantage to the use of a small access sheath based on renal scarring alone.

Animals↗

PubMed2001

Laparoscopic radiofrequency thermal ablation of renal tissue with and without hilar occlusion.

PURPOSE: Few studies have evaluated the effect of radiofrequency thermal ablation on renal tissue, although it has been used clinically to treat small renal masses. We studied the size and histology of lesions created with radiofrequency thermal ablation administered via the laparoscopic approach with and without hilar occlusion in a porcine model. MATERIALS AND METHODS: The lower pole of each kidney was exposed laparoscopically in 11 farm pigs. In each kidney a 7-electrode dry radiofrequency thermal ablation probe was inserted at an identical location and deployed to a diameter of 2 cm. Energy was applied for 8 minutes at an average temperature of 100C. The left renal hilum of each pig was clamped during radiofrequency thermal ablation. Two pigs were sacrificed immediately, and 3 each were sacrificed at 24 hours, 2 and 4 weeks. The size and shape of the lesions created were measured and examined histologically. RESULTS: There were no intraoperative or postoperative complications. Laparoscopic ultrasound confirmed probe placement but did not monitor lesion progression. Acutely lesions were firm and white with a small adjacent hemorrhagic zone. Histological evaluation revealed preserved renal architecture but the loss of distinct cytoplasmic features. Nicotinamide adenine dinucleotide staining demonstrated no viable cells within the lesions. In surviving animals pelvicaliceal integrity was preserved. In the 2 and 4-week survival groups kidneys treated with hilar occlusion had larger lesions than nonoccluded kidneys but the differences were not significant at 4 weeks (3.2 x 2.7 x 2.5 cm. and 3.5 x 1.7 x 2.0, respectively, p >0.05). Histologically untreated parenchyma of hilar occluded kidneys demonstrated changes consistent with chronic pyelonephritis. In 1 kidney radiofrequency thermal ablation with hilar occlusion resulted in complete lower pole loss at 4 weeks. CONCLUSIONS: In the porcine model renal radiofrequency thermal ablation creates rapid and completely devitalized lesions of consistent size and shape. Hilar occlusion may result in slightly larger lesions but risks damage to the whole renal unit.

Animals↗

PubMed2001

The impact of intense laparoscopic skills training on the operative performance of urology residents.

PURPOSE: As laparoscopy has become more commonplace in urology, increased emphasis has been placed on laparoscopic education. We assessed the impact of laparoscopic skills training on the operative performance of urological surgeons inexperienced with laparoscopy. MATERIALS AND METHODS: Urology residents were prospectively randomized to undergo laparoscopic skills training (6) or no training (6). Baseline assessment of operative performance (scale 0 to 35) during porcine laparoscopic nephrectomy was completed by all subjects. Cumulative time to complete laparoscopic tasks using an inanimate trainer was also recorded. The skills training group then practiced inanimate trainer tasks for 30 minutes daily for 10 days. The 2 groups then repeated the timed inanimate trainer tasks and underwent repeat assessment of the ability to perform porcine laparoscopic nephrectomy. RESULTS: At baseline no statistical difference was noted in laparoscopic experience, inanimate trainer time or overall operative assessment in the 2 groups. In the skills training group mean cumulative time to complete inanimate trainer tasks decreased from 341 to 176 seconds (p = 0.003), while in the control group it decreased from 365 to 301 (p = 0.15). Operative assessment improved from initial to repeat porcine laparoscopic nephrectomy regardless of the trained versus control randomization grouping (22.0 to 27.8, p = 0.0008 and 20.8 to 26.5, p = 0.00007, respectively). CONCLUSIONS: In vivo experience enables urological surgeons inexperienced with laparoscopy to improve significantly in all aspects of complex laparoscopic procedures. In this pilot study the magnitude of improvement was independent of additional training in laparoscopic skills. Educational curriculum should include in vivo practice in addition to skills training.

Animals↗

PubMed2001

[Hemorrhagic cystitis: etiology and treatment].

Haemorrhagic cystitis consists of acute or insidious diffuse bleeding from the bladder mucosa. Although the aetiology of haemorrhagic cystitis is varied, the two predominant causes are chemical and irradiation. The chemical compounds most frequently responsible for haemorrhagic cystitis are oxaphosphorines (cyclophosphamide, ifosfamide). Haemorrhagic cystitis may also be due to toxic or infectious causes (bacterial, fungal, parasitic or viral). Finally, haemorrhagic cystitis can occur in the context of a systemic disease or may be isolated and idiopathic. Prevention of haemorrhagic cystitis, based on general measures and specific measures, is essential, but is not always effective. In the case of proven haemorrhagic cystitis, various treatment options are available, including and can associate clot extraction, continuous bladder irrigation, bladder instillations of haemostatic factors, formalin, hyperbaric oxygen therapy, arterial embolization or salvage surgery. Although therapeutic management is usually effective, it can sometimes be difficult due to the severity of the bleeding and its repercussions on the patient's general state. Deaths are not exceptional, emphasizing the seriousness of haemorrhagic cystitis. Based on a review of the literature, the authors review the aetiology and treatment of haemorrhagic cystitis.

Cystitis↗

PubMed2000

Renal cystic disease. Laparoscopic management.

Laparoscopy offers a safe and efficacious means of ablating symptomatic simple renal cysts while conferring the usual benefits of shorter hospital stay, quicker convalescence, and reduced postoperative pain, although no direct comparison with open surgery has been performed. For indeterminate, complex renal cysts, laparoscopic exploration may spare the patient a morbid open operation to assess a cystic lesion of indeterminant risk. Although laparoscopic removal of kidneys with ADPKD remains a technically challenging exercise, centers of laparoscopic expertise have demonstrated the safety and feasibility of the procedure, thereby expanding the benefits of laparoscopic surgery to patients traditionally relegated to open surgical management.

Humans↗

PubMed2000

The efficacy and parenchymal consequences of extracorporeal shock wave lithotripsy in infants.

OBJECTIVES: To determine the efficacy of extracorporeal shock-wave lithotripsy (ESWL) in young children and to evaluate, using renal scintigraphy, any possible adverse effects on renal parenchyma. PATIENTS AND METHODS: From January 1991 to October 1998, 19 infants (aged 5-24 months) underwent ESWL for kidney urolithiasis using a Sonolith 3000 (14 kV, Technomed Corp, Lyon, France) or a Nova (14-20 kV, Direx Medical Systems, Paris, France) lithotripter. The treatment and its effects were evaluated using a physical examination, conventional imaging (plain abdominal X-ray and ultrasonography) and renal scintigraphy 24 h before ESWL and again at least 6 months after the last session of treatment. RESULTS: Ten children were rendered stone-free by ESWL after one session and 18 after two sessions. At the follow-up (8 months to 8 years, mean 36 months) no hypertension was recorded and no acquired parenchymal damage was detected with conventional imaging. No scars or significant variation of differential function attributable to ESWL were identified on renal scintigraphy. CONCLUSION: ESWL is clearly effective for treating infant urolithiasis. There were no renal parenchymal lesions associated with ESWL, even in previously damaged kidneys or after the treatment of staghorn calculi. A long-term follow-up (assessing blood pressure) is mandatory and renal scintigraphy before and 6 months after ESWL in infants is recommended to confirm these results in a larger series.

Child, Preschool↗

PubMed2000

A new prostatic stent for the treatment of benign prostatic hyperplasia in high-risk patients.

OBJECTIVES: The objective of this study was to evaluate the efficacy and safety of a new prostatic stent (Trestle((R)), Boston Scientific Microvasive) for the treatment of BPH in patients with complete urinary retention and considered to be inoperable. METHODS: The efficacy of the stent was evaluated in terms of return of micturition, level of patient satisfaction, uroflowmetry and residual urine. Any stents removed were examined by infrared spectrophotometry for the presence of crystalline encrustations. RESULTS: From December 1997 to April 1999, 20 stents were inserted under local anaesthesia in 17 patients aged 54-90 years. Stents remained in place for an average of 3.5 months. Two migrations were reported. The mean maximum flow rate was 13.7 ml/s and the mean residual urine was 110 ml. The infrared spectrophotometry study revealed a glycoprotein film on stents in place for 1-6 months, accompanied by uric acid crystals on stents in place for 9 months. CONCLUSION: The Trestle prostatic stent is effective and constitutes a good alternative to surgical treatment in patients with a high operative risk.

Aged↗

PubMed2000

[Balloon catheter parieto-renal dilatation in percutaneous kidney surgery].

OBJECTIVE: To compare two techniques of parieto-renal dilatation for percutaneous surgery: Alken dilators and balloon catheter. MATERIAL AND METHODS: This prospective, non-randomized study was conducted between July 1999 and April 2000 in 20 patients undergoing percutaneous renal surgery. 10 patients were dilated with a balloon catheter (NephroMax, Boston Scientific) and the other 10 patients were dilated with Alken metal dilators. Statistical analysis was performed with the Mann-Whitney test. RESULT: The dilatation time and x-ray exposure time were shorter during balloon catheter dilatation (statistically significant difference) and the two techniques were associated with a comparable morbidity. CONCLUSION: Balloon catheter parieto-renal dilatation significantly decrease dilatation and x-ray exposure times and very considerably simplifies this operative step, essential to the success of percutaneous surgery.

Adult↗

PubMed2000

[Extra-corporeal lithotripsy in children].

Extracorporeal shock-wave lithotripsy (ESWL) constitutes the reference treatment for renal and ureteric stones in adults, but its use and development in children have been accompanied by a certain degree of caution and reticence. A large number of paediatric series have been published since 1986, confirming the efficacy and minimally invasive nature of this technique. Modification of the nature of the shock waves and release onto the market of second and third generation apparatuses have simplified the management of urinary stones in children. However, several questions persist concerning the maximum number of impacts, the recommended interval between two sessions and the long-term effects of shock waves on the growing renal parenchyma. The objective of this study was to review the current state of ESWL in children based on a review of the literature, the GEUP report and our own experience.

Adolescent↗

PubMed2000

Laparoscopic nephrectomy for benign disease.

Nearly 10 years of experience with laparoscopic nephrectomy for benign renal disease has shown that the procedure can be performed safely with a complication rate comparable with open surgery. Improvements in the skill, instrumentation, and technique of the laparoscopist have expanded the indications for the procedure to include larger (polycystic kidneys) and in some cases more complex (xanthogranulomotous pyelonephritis) specimens. Continued demonstration of reduced postoperative pain, shorter hospital stay, and more rapid recovery along with decreasing operative times have made laparoscopy the preferred approach for the surgical removal of benign kidneys.

Humans↗

PubMed1999

[Extracorporeal lithotripsy in children. Study of its efficacy and evaluation of renal parenchymal damage by DMSA-Tc 99m scintigraphy: a series of 39 children].

AIM: The objectives of the study were to confirm the efficacy of extracorporeal shock wave lithotripsy (ESWL) in infants and children and to evaluate potential long-term renal parenchymal damage by 99m Tc DMSA renal scan. MATERIALS AND METHODS: Between November 1989 and November 1997, 39 children between 10 months and 17-1/2 years of age (average: 7 years) were treated by extracorporeal shock wave lithotripsy for kidney or ureteral stones with a Sonolith 3000 lithotriptor (Technomed Corp). Forty-six stones were treated. Eight metabolic and 11 urological abnormalities were identified. The evaluation of the treatment and its consequences were based on a clinical examination, conventional imaging and a DMSA renal scan performed 24 h before extracorporeal shock wave lithotripsy and at least 6 months after treatment. RESULTS: Treatment was successful (stone fragmented and eliminated) in 84.6% at 3 months after one to four sessions. Sixty-one sessions were necessary and two patients underwent open surgery for failed extracorporeal shock wave lithotripsy. Three recurrences were also retreated. At long term follow-up (6 months to 8 years) no incidents of high blood pressure were observed, nor parenchymal lesions imputable to extracorporeal shock wave lithotripsy. CONCLUSIONS: The efficacy of the extracorporeal shock wave lithotripsy for children is proven. This study also confirms the innocuousness of extracorporeal shock wave lithotripsy for renal parenchyma even in infants. However, long term follow-up and further evaluation with the other categories of lithotriptors are necessary to make definitive conclusions.

Adolescent↗

PubMed1999

[Posterior approach to the bladder for implantation of the 800 AMS artificial sphincter in children and adolescents: techniques and results in eight patients].

Blind dissection of the bladder neck during implantation of an artificial urinary sphincter (AMS 800) may lead to injury of either the bladder, genital tract or even the rectum. Significant bleeding may occur. A posterior approach to the bladder neck allowing visual control of the anatomical structures is described. From November 1995 to February 1998, 8 adolescents (12-19 years old) underwent AMS 800 artificial urinary sphincter implantation for the treatment of severe incontinence associated with neurogen bladder; one patient had had a previous augmentation. Three had a simultaneous ileocystoplasty and another patient had a simultaneous bilateral extravesical ureteric reimplant. The procedure consisted of separation of the bladder from the peritoneum, allowing the development of a dissection plane between the rectum and genital tracts posteriorly and the ureters and bladder neck anteriorly; the dissection is extended to the base of the prostate. The endopelvic fascia is then incised laterally and on both sides the neurovascular bundles are perforated under visual control and the cuff is positioned safely around the bladder neck, above the prostate and in front of the genital tract. The bladder was opened only in the case of associated ileocystoplasty, thus avoiding prolonged bladder drainage. The mean operating time was 2.5 hours and the blood loss never exceeded 300 cc. This route was not found to be convenient in the case of the patient with a previous augmentation; 7 sphincters function normally with a follow-up of 18 to 44 months; one was never activated and the patient is dry under CIC. This route for exposure of the bladder neck allows visual control of the anatomical structures, accurate positioning of the cuff, avoids bladder opening and reduces bleeding. It can be used for other procedures such as bladder neck suspension or Müllerian cavity removal.

Adolescent↗

PubMed1999

[Comparison of biomechanical properties of the vaginal fixation in bladder neck suspensions according to the Burch technique and a percutaneous technique].

UNLABELLED: Bladder neck suspension or colpo-suspension can be performed via retropubic or percutaneous transvaginal approaches. A higher success rate is observed for retropubic procedures. One of the hypotheses proposed, but not yet verified, is that the retropubic approach allows better quality vaginal fixation than the percutaneous approach. OBJECTIVE: The objective of this study was to compare the biomechanical properties of vaginal fixation according to the Burch procedure and according to a percutaneous technique (Vesica; Boston Scientific). MATERIAL AND METHODS: We performed bladder neck suspension according to the Burch technique (2 points) on the left and according to the Vesica percutaneous technique on the right, on 6 fresh cadavers (mean age 8-5 years), using the same suture material. Vaginal fixations were subsequently excised. The depth of penetration into the vagina was measured and a computerized traction test (Lloyd Instruments, France) was performed on these fixations. The maximum force of traction before rupture was measured. RESULTS: No significant difference was demonstrated for any of the measurements. CONCLUSION: Vaginal fixation of bladder neck suspension performed according to the Burch technique or via a percutaneous technique (Vesica) present equivalent biomechanical properties.

Aged↗