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Biomedical subjects

M Cendron

Publications and source records attributed to M Cendron.

At least 19 recordsLinked to original sources
PubMed2001

Cystoscopy at the time of ureteral reimplantation for primary vesicoureteral reflux: is it necessary? Incidence of undetected anomalies and cost.

OBJECTIVES: To evaluate the impact on the planned procedure and associated cost of cystoscopy performed immediately before the surgical repair of vesicoureteral reflux. Cystoscopy is commonly performed at the time of ureteroneocystostomy to rule out a previously unsuspected anomaly such as ureterocele or ureteral duplication. METHODS: We retrospectively reviewed the results of preoperative voiding cystourethrograms and ultrasound studies performed on 128 patients who underwent ureteral reimplantation for primary vesicoureteral reflux between 1994 and 2000. Radiographic findings were compared with observations made at cystoscopy and reimplantation to determine the rate of unsuspected ureterocele or duplication in the presence of a radiologic evaluation considered adequate by the operating surgeon and/or radiologist. We then performed an itemized analysis to determine the cost cystoscopy contributed to the procedure. RESULTS: Of the 128 patients, 1 (0.7%) was found to have a small, undiagnosed ureterocele at cystoscopy. A review of this patient's preoperative evaluation revealed that her ultrasound examination was incomplete, lacking views of the bladder. At our institution, cystoscopy increased the total direct and indirect operating room costs of this procedure by 16.2%, adding $123.77 to the original cost of $762.97. CONCLUSIONS: Routine cystoscopic examination before ureteral reimplantation in the setting of an adequate preoperative radiologic evaluation yields little diagnostic information. In this series, it did not have an impact on the surgical procedure to be performed but did add significantly to the cost. Cystoscopy before ureteral reimplantation for primary reflux should only be considered in those children with suspicious or inadequate radiologic studies.

Cystoscopy↗
PubMed2001

Histological analysis of urethral healing after tubularized incised plate urethroplasty.

PURPOSE: Tubularized incised plate urethroplasty has rapidly gained popularity for treating hypospadias. It is presumed that healing occurs with the postoperative migration of epithelial cells into the incised urethral plate. We describe the time course and histology of the healing urethral wound in an animal model after dorsal incision and stenting. MATERIALS AND METHODS: A procedure was developed for use in an immature porcine model. The ventral aspect of the urethra was opened and a dorsal incision was made in the urethra to the level of the corpus spongiosum. The urethra was then catheterized and closed ventrally. Animals were sacrificed at intervals of 1, 2, 3, 5, 7, 14 and 21 days. Slides were made from multiple cross sections taken from each penis, and stained with hematoxylin and eosin, and Masson trichrome before analysis. RESULTS: Migration of epithelial cells into the dorsal epithelial defect was evident on postoperative day 2 with apparent complete re-epithelialization by postoperative day 5. Regions of increased fibroblastic activity were observed in the subepithelial stroma below the incised area on postoperative day 3 and early collagen deposition was noted in these areas when stained with Masson trichrome. These areas appeared to organize and by postoperative day 21 there was little evidence of increased fibroblastic activity or excess collagen deposition. CONCLUSIONS: Urethral healing after incision and tubularization over a catheter in our model occurred through normal re-epithelialization without excess collagen deposition or scarring.

Animals↗
PubMed2000

Surgical management of vesicoureteral reflux.

Vesicoureteral reflux (VUR) is a urologic condition in which there is a retrograde flow of urine from the bladder through the ureter back up to the upper urinary tract. The condition may be classified as primary or secondary and is more often identified in Caucasian females. The primary goal in the management of VUR is the prevention of pyelonephritis and subsequent renal scarring.

Aftercare↗
PubMed2000

Early diagnosis of fetal bladder outlet obstruction.

Prenatal ultrasonography has facilitated early diagnosis of in utero bladder outlet obstruction. This represents one of the earliest diagnoses of prune-belly syndrome and sheds light on the natural history of the bladder outlet obstruction in the fetus.

Adult↗
PubMed1999

Primary nocturnal enuresis: current.

Primary nocturnal enuresis sometimes presents significant psychosocial problems for children and their parents. Causative factors may include maturational delay, genetic influence, difficulties in waking and decreased nighttime secretion of antidiuretic hormone. Anatomic abnormalities are usually not found, and psychologic causes are unlikely. Evaluation of enuresis usually requires no more than a complete history, a focused physical examination, and urine specific gravity and dipstick tests. Nonpharmacologic treatments include motivational therapy, behavioral conditioning and bladder-training exercises. Pharmacologic therapy includes imipramine, anticholinergic medication and desmopressin. These drugs have been used with varying degrees of success.

Enuresis↗
PubMed1999

The biological behavior of autologous collagen-based extracellular matrix injected into the rabbit bladder wall.

Endoscopic techniques are providing a minimally invasive approach to the treatment of vesicoureteral reflux and urinary incontinence. Bovine collagen has been used, but potential degradation over time and sensitivity reactions have limited its usefulness. We evaluate the use of an autologous collagen-based extracellular matrix preparation injected within the rabbit bladder submucosa and compare it to the stability of bovine collagen-injected similarly. Of 28 New Zealand white rabbits, 12 underwent injection of autologous collagen-based extracellular matrix, 12 bovine collagen, and four normal saline sham injections into the anterior bladder submucosa. Twelve collagen specimens were iodinated with iodine 125 ((125)I) paraaminobenzoate reagent. The (125)I-labeled rabbits were monitored with a gamma camera to assess the level of decay of radioactivity over 12 weeks. All animals were killed 12 weeks post-injection. Assessment of radioactivity showed minimal difference in radioisotope labeling between the autologous and bovine collagen (total counts and decay kinetics). Compared to bovine collagen, the autologous collagen- based extracellular matrix implants histologically showed increased fibroblastic and vascular infiltration focally. The most significant histologic difference was the marked inflammatory response associated with the bovine collagen implants. These data suggest that in the short term, autologous and bovine collagen appear to have similar stability. The response to autologous collagen-based extracellular matrix may increase longevity of the implant, primarily by reducing immunologic rejection and improving biocompatibility within the host tissue. Further long-term studies are necessary to assess the long-term stability of autologous collagen-based extracellular matrix. Neurourol. Urodynam. 18:487-495, 1999.

Animals↗
PubMed1999

Hypospadias repair in the 1990s.

Hypospadias is a congenital anomaly in which the urethral meatus is abnormally located anywhere from the glans to the perineum. Refinements in pediatric anesthesia, surgical technique and instrumentation, and a greater understanding of the psychologic and emotional issues related to hypospadias repair have led to this procedure being performed at an earlier age. The goal of reconstruction is to bring the urethral meatus to the tip of the penis, to correct associated penile curvature if present, to create a conical-shaped glans, and to achieve cosmetically acceptable penile shaft skin coverage. The surgical technique employed varies with the penile anatomy and surgeon's preference. Complications may occur both immediately and long after the surgical procedure, and thus follow-up is necessary.

Child Development↗
PubMed1999

[Treatment of complex hypospadias by the Snodgrass technique].

PURPOSE: Successful use of the Snodgrass modification of Tiersch-Duplay urethroplasty for repair of distal hypospadias has been reported. Given the features of the repair: technical simplicity, preservation of the urethral plate, single suture line in the urethroplasty and no need for vascularized pedicle graft, we felt that the technique could be applied to the treatment of proximal hypospadias. METHODS: A retrospective review of the records of 35 patients with either midshaft or penoscrotal hypospadias who underwent a Snodgrass type of hypospadias repair was carried out. Age at surgery was 3 to 54 months (mean age: 8.4 months). No patients with significant chordee were included. All patients had indwelling urethral stents for 5 to 7 days postoperatively. Follow-up ranged from 6 months to 3 years. RESULTS: There were no immediate postoperative complications. Four patients experienced a urethrocutaneous fistula in association with meatal stenosis. After meatal dilatation, 2 of these fistulae closed spontaneously for an overall fistula rate of 5.7%. The overall cosmetic result of the glans and urethral meatus was noted to be excellent. Urinary stream was normal in all cases. CONCLUSION: Our results indicate that the Snodgrass modification of Tiersch-Duplay hypospadias repair provides satisfactory cosmetic and functional results in the treatment of proximal hypospadias with a low surgical complication rate. In young patients, it is our procedure of choice for penile and penoscrotal hypospadias without major degrees of chordee.

Child, Preschool↗
PubMed1998

Cognitive and Metacognitive Abilities Involved in the Solution of Mathematical Word Problems: Validation of a Comprehensive Model.

With this investigation we tried to validate an economic model of the cognitive and metacognitive abilities involved in Mathematical Word Problems. From the literature we chose seven abilities: text comprehension, problem representation, problem categorization, solution estimate, planning the solution, procedure self-evaluation, calculus self-evaluation. In order to measure these abilities, we devised a series of mathematical word problems (partitioned problem) where, for each ability, subjects have to answer a multiple choice question. A hierarchical regression model with only five variables (excluding solution estimate and calculus self-evaluation) explained more than 50% of the variance of the solution scores of the Partitioned Problems, and 40% of the variance of the solution of a series of problems presented with only the text. The model was validated with five different samples of subjects of different school grade and with a bootstrap procedure. Furthermore the relationship of the variables was tested using a path analysis. The discrimination validity of three different levels of problem solving efficiency give further support to the validity of the model. The model obtained may be utilized in order to devise practical instruments for the analysis of mathematical word problem difficulties. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

99mTechnetium-dimercapto-succinic acid renal scan in the evaluation of potential long-term renal parenchymal damage associated with extracorporeal shock wave lithotripsy in children.

PURPOSE: Extracorporeal shock wave lithotripsy (ESWL) has been reported as efficient and safe in children. Because of reports of renal parenchymal damage in adults, this study was designed to assess the effects of ESWL in pediatric kidneys evaluated before and after treatment with (99m)technetium dimercapto-succinic acid (DMSA) renal scan. MATERIALS AND METHODS: A total of 15 children, 9 months to 15 years old (mean age 6.5 years), underwent ESWL treatment for urolithiasis. Evaluation imaging included plain abdominal radiography, excretory urogram and/or renal sonography. DMSA renal scan was performed 24 hours before ESWL and at least 6 months after treatment. RESULTS: ESWL was performed in 1 session for 8 patients, 2 sessions for 6 and 3 sessions for 1, delivering a range of 600 to 3,000 shock waves per session. Treatment was successful in achieving stone-free status in 87% of the cases. Long-term followup (1 to 5 years) showed no blood pressure changes. On DMSA renal scan no acquired parenchymal scar was identified at least 6 months after ESWL treatment. CONCLUSIONS: The efficacy of ESWL in treating pediatric urolithiasis is confirmed. Renal parenchymal trauma associated with ESWL does not appear to cause long-term lesions identifiable by DMSA renal scan.

Adolescent↗
PubMed1998

Laparoscopy for the evaluation and management of the nonpalpable testicle.

OBJECTIVE: To assess the usefulness of laparoscopy for the diagnosis and treatment of the nonpalpable testicle and to evaluate the results of laparoscopic orchidopexy. METHODS: We retrospectively reviewed the charts of 91 laparoscopies performed over a period of 4 years. We reviewed the following parameters: findings, complications, patency of the processus vaginalis, appearance of the cord structures, and the success of the different procedures performed for the intra-abdominal testicle. RESULTS: Fourteen patients had bilateral and 77 unilateral nonpalpable testicles. The mean age of the patients was 39.5 +/- 50.8 months. There were three laparoscopic complications (3.2%) one of which was a major bowel laceration. Laparoscopy defined the intra-abdominal anatomy accurately in 90 of the 91 cases Of the 26 intra-abdominal testicles above the ring, a one-stage laparoscopic orchidopexy was performed in five and a single-stage standard orchidopexy in seven. All of these testicles remain viable and are in good position. Eight patients underwent a staged Fowler-Stephens orchidopexy with laparoscopic clipping of the spermatic vessels as the first stage. Of these, a second-stage open orchidopexy was performed in five and a laparoscopic orchidopexy in three. Testicular atrophy occurred in two of the patients who underwent the second-stage open orchidopexy. Three one-stage Fowler-Stephens orchidopexies were performed with testicular atrophy occurring in two of these testicles. Laparoscopic orchiectomy was performed on two patients. CONCLUSIONS: Laparoscopy is a valuable tool in the diagnosis and treatment of the nonpalpable testicle. Laparoscopic orchidopexy may decrease the rate of testicular atrophy since most of these can be performed laparoscopically in one stage, thus preserving the vascular supply.

Adolescent↗
PubMed1998

Prenatal failure to visualize kidneys: a spectrum of disease.

OBJECTIVES: To better understand the outcomes and management of patients when there is a failure to visualize kidneys on prenatal ultrasound. METHODS: Nine thousand five hundred twelve prenatal ultrasound studies performed on 4900 patients were reviewed retrospectively for the findings of a failure to visualize kidneys. The prenatal ultrasounds, pregnancy outcomes, and postmortem studies were reviewed for each of the 10 patients identified. RESULTS: Nine of 10 patients experienced fetal death in the index pregnancy: 7 had therapeutic abortions, 1 had an intrauterine fetal demise, and 1 gave birth to a stillborn infant. One patient gave birth to a live infant with Bartter's syndrome and grossly normal kidneys, as diagnosed by ultrasound. Developmental renal anomalies were identified in only 4 of 10 cases, and only 2 patients had true bilateral renal agenesis. There was 1 case each of bilateral renal medullary cystic dysplasia and bilateral renal hypoplasia. Three cases had no renal anomalies and included 1 case each of Turner's syndrome, chronic abruption, and a cord accident. In 2 cases, postmortem examinations were not performed because of family wishes. CONCLUSIONS: Prenatal failure to visualize kidneys represents a spectrum of clinical problems not all of which are fatal. Close consultation with an experienced ultrasonographer is essential to provide informed counseling to expectant parents. Pathologic examination should be recommended when there is fetal demise and a suspicion of genitourinary anomalies. Screening of family members of the index patient and genetic counseling may be indicated.

Female↗
PubMed1998

Combination therapy in the treatment of persistent nocturnal enuresis.

OBJECTIVE: To evaluate, in a retrospective study, the response rate of older children to combination therapy using a sustained-release anticholinergic agent, hyoscyamine, and a synthetic analogue of antidiuretic hormone, desmopressin acetate. PATIENTS AND METHOD: Twenty-eight patients (20 males and eight females, aged 9-18 years) diagnosed with nocturnal enuresis were evaluated using a questionnaire, history and physical examination. None had success with single-agent pharmacological therapy. All were begun on 0.375 mg of hyoscyamine and 20 microg of desmopressin intranasally at bedtime. The response rate was monitored at 2 and 4 weeks, and then every 3 months by recording dry nights on a calendar. To improve efficacy, the dosage of medication was adjusted up to 0.750 mg of hyoscyamine and 60 microg of desmopressin. Upon achieving dryness and spontaneous awakening to void, medication doses were tapered. RESULTS: Within 6 months 16 (57%) patients were completely dry and six (21%) were dry at least 80% of nights. Nine patients relapsed during dose tapering and therapy was reinstituted. Presently, 17 (60%) patients are off medication (after a mean of 8 months of medication). Eight patients are still on medication and are dry at least 80% of nights. Combination therapy failed in three patients and they have transferred to a different regimen. None experienced untoward side-effects from the medications. CONCLUSION: Most older children with nocturnal enuresis responded to combination therapy. These children require long-term follow-up and may need medication for up to 6 months because the relapse rate is fairly high. Combination therapy appears safe and reliable in treating nocturnal enuresis in older children who have had no success with other treatment modalities.

Adolescent↗
PubMed1998

Histological evaluation of the testicular nubbin in the vanishing testis syndrome.

PURPOSE: We reviewed histopathological studies of the testicular nubbins associated with the vanishing testis syndrome, and determined whether surgical removal is indicated based on the histological findings. MATERIALS AND METHODS: Between 1983 and 1997 a unilateral testicular nubbin consistent with a vanishing testis was excised in 29 patients an average of 28.6 months old. We retrospectively reviewed the gross pathology reports and microscopic slides, and prospectively performed histochemical stain analysis. RESULTS: Gross evaluation of the specimens revealed an identifiable cord structure in the majority of cases with the vas deferens most commonly identified in 72.4%. No recognizable testicular elements were present in any nubbin. In 3 cases the original pathology report identified cells with features consistent with Leydig cells, which immunohistochemical staining revealed to be atrophied cremasteric muscle fibers. CONCLUSIONS: In this series testicular nubbins in vanishing testes contained no viable testicular tissue. Since the risk of testicular cancer in an undescended testis is 8 to 10% and the incidence of viable testicular tissue in these nubbins ranges from 0% in our series to 11% in others, there is only a 0 to 1.1% risk of testicular cancer in the nubbin. Thus, surgical removal may not be warranted.

Abnormalities, Multiple↗