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Biomedical subjects

H G Rushton

Publications and source records attributed to H G Rushton.

At least 19 recordsLinked to original sources

Early diuresis renogram findings predict success following pyeloplasty.

PURPOSE: We sought to determine whether drainage across the ureteropelvic junction, as indicated by diuretic renography 3 months after pyeloplasty, is an adequate predictor of surgical success. MATERIALS AND METHODS: The medical records of 150 children who underwent pyeloplasty from 1986 to 1995 were reviewed. After excluding nonevaluable cases a total of 127 renal units remained for investigation. Preoperatively each renal unit was examined with a standardized (well-tempered) furosemide stimulated renal scan. Postoperatively 60 renal units were evaluated with standardized diuretic renal scans at 3 and 12 months, 33 renal units at 3 months only and 34 renal units at 12 months only. Surgical success was defined by half-time less than 20 minutes on a standardized diuretic renogram. RESULTS: Of the 33 renal units with a single postoperative study at 3 months 32 (97%) had halftime less than 20 minutes on diuretic renography. The remaining patient in this group with half-time greater than 20 minutes showed 60% improvement in half-time and did not require reoperation. Excluding those without delayed followup, surgical success was obtained in 93 of the 94 (99%) renal units. Among the 60 renal units evaluated with 2 postoperative renal scans success was noted in 48 (80%) and 59 (98%) at 3 and 12 months, respectively. Stenosis did not recur in 48 renal units with half-time less than 20 minutes 3 months after repair. In 1 case that had been treated for postoperative urinoma half-time was greater than 40 minutes at 3 months and repeat pyeloplasty was required. CONCLUSIONS: Half-time less than 20 minutes 3 months after pyeloplasty predicts surgical success. Most renal units that improve but still have half-times greater than 20 minutes on an early diuretic renogram will demonstrate continued improvement in drainage patterns at 12 months. Those renal units that show no improvement at 3 months may require reoperation and those with half-time less than 20 minutes at 3 months do not require further evaluation.

Child↗

Is the vanished testis always a scrotal event?

OBJECTIVE: To determine if perinatal testicular torsion resulting in a vanished testis is an event that primarily occurs in the scrotum. PATIENTS AND METHODS: The records of 54 boys identified as having a solitary testis were reviewed. The side of absence, size of the solitary testis, method of surgical evaluation (scrotal, inguinal or abdominal), surgical findings and histology of the tissue removed were noted. RESULTS: The testis was absent twice as often on the left side, the solitary testis was hypertrophic in 25 of 42 boys in whom it was evaluated, and tissue grossly or histologically consistent with a testicular 'nubbin' was removed in 52 boys. Scrotal (47) or inguinal (seven) exploration was carried out in all. Laparoscopy (28) or abdominal exploration (two) was undertaken to confirm that no testicular tissue was present in the abdomen in 30 boys, including the two in whom no tissue was found on scrotal or inguinal exploration. CONCLUSIONS: Perinatal testicular torsion occurs after descent but before fixation of the tunica vaginalis to the scrotal wall. These testes atrophy, leaving a remnant of tissue in the scrotum that can be identified on scrotal exploration in almost all cases. Therefore, it is recommended that the evaluation of the child with a solitary palpable testis start with scrotal exploration. Laparoscopy should be reserved for those in whom no tissue consistent with a testicular nubbin is found in the scrotum.

Atrophy↗

Acute pyelonephritis: comparison of diagnosis with 99mTc-DMSA, SPECT, spiral CT, MR imaging, and power Doppler US in an experimental pig model.

PURPOSE: To compare the sensitivity and specificity of technetium-99m dimercaptosuccinic acid (DMSA) single photon emission computed tomography (SPECT), spiral computed tomography (CT), magnetic resonance (MR) imaging, and power Doppler ultrasonography (US) for the detection and localization of acute pyelonephritis by using histopathologic findings as the standard of reference. MATERIALS AND METHODS: Bilateral vesicoureteric reflux was surgically created in 35 piglets (70 kidneys). One week later, a liquid bacterial culture of Escherichia coli was injected into the bladder. Three days after induction of urinary infection, imaging studies were performed, and the kidneys were removed for histopathologic examination. SPECT images were obtained 2-3 hours after injection of 99mTc-DMSA. Transverse and coronal MR images were obtained with gadolinium-enhanced fast inversion recovery. Transverse CT images were obtained before and after injection of contrast agent. Power Doppler US was performed in longitudinal, transverse, and coronal planes. Each kidney was divided into three zones for correlation of findings. RESULTS: Histopathologic examination revealed pyelonephritis in 102 zones in 38 kidneys. Sensitivity and specificity for detecting pyelonephritis in the kidneys were 92.1% and 93.8% for SPECT, 89.5% and 87.5% for MR imaging, 86.8% and 87.5% for CT, and 74.3% and 56.7% for US. Sensitivity and specificity for detecting pyelonephritis in the zones were 94.1% and 95.4% for SPECT, 91.2% and 92.6% for MR imaging, 88.2% and 93.5% for CT, and 56.6% and 81.4% for US. The pairwise comparison of these modalities showed no statistically significant difference among them except for US. CONCLUSION: 99mTc-DMSA SPECT, spiral CT, and MR imaging appear to be equally sensitive and reliable for the detection of acute pyelonephritis; power Doppler US is significantly less accurate.

Acute Disease↗

Parental preferences in the management of vesicoureteral reflux.

PURPOSE: We determined parental preferences for the treatment of vesicoureteral reflux in their child. MATERIALS AND METHODS: Parents of children with vesicoureteral reflux were prospectively recruited to evaluate choices in reflux management. In each case a standard questionnaire that described the treatment options for reflux was administered. Parents were asked to choose between long-term antibacterial prophylaxis with annual radiography studies and open or endoscopic treatment at each of 1 to 5 years of followup. They were also given the choice between open or endoscopic treatment. Annual resolution and/or correction rates provided for medical, surgical and endoscopic management were 20%, 95% to 100% and 80% after 1 or 2 injections, respectively. RESULTS: We queried 91 families of female (81%) and male (19%) patients. Average duration of reflux followup was 2 years and mean patient age was 49.8 months. At diagnosis reflux was grades I to II in 65% of cases, grade III in 26% and grades IV to V in 9%. The majority of parents chose daily antibiotics over surgery if the child was predicted to have vesicoureteral reflux for 1 to 4 years. However, the majority chose ureteral reimplantation over daily antibiotics and yearly x-ray if a 5-year course was predicted. In contrast, parents chose daily antibiotics rather than endoscopic treatment if the anticipated interval was 1 to 3 years. After 3 years the majority preferred the endoscopic approach. Also, 60% of parents stated that they would choose endoscopic treatment over reimplantation, although the child may require repeat endoscopic treatment and there was a 20% chance of persistent vesicoureteral reflux. CONCLUSIONS: Parents of children with vesicoureteral reflux prefer antibiotic prophylaxis as initial treatment. However, when daily antibiotics and yearly cystography may be required beyond 3 to 4 years, most parents would choose definitive correction. While endoscopic treatment is less effective than surgery, parents prefer endoscopic treatment, most likely because it is less invasive. Also, when compared directly against each other, the majority of parents stated that they would choose endoscopic treatment over surgery, although it has a lower success rate.

Antibiotic Prophylaxis↗

Diagnosis and management of teratomas and epidermoid cysts.

One can strongly suspect a benign lesion in a prepubertal child on the basis of preoperative sonographic, biochemical, and clinical evaluation; however, when considering a testis-sparing enucleation, the definitive diagnosis must be established by pathologic frozen section of the tumor. The high incidence of benign testicular lesions in the prepubertal patient, the absence of associated carcinoma in situ in prepubertal germ cell tumors, and the universally benign behavior of the specific tumors described in this article are supportive evidence for testis-sparing surgery versus orchiectomy, for these benign lesions.

Epidermal Cyst↗

Adjunctive oral corticosteroids reduce renal scarring: the piglet model of reflux and acute experimental pyelonephritis.

PURPOSE: We investigate the efficacy of antibiotics combined with corticosteroid in diminishing post-pyelonephritic renal scarring compared to standard antibiotic therapy. MATERIALS AND METHODS: Bilateral vesicoureteral reflux was surgically created in 36 piglets (72 kidneys). A week later each bladder was inoculated by percutaneous injection with a standardized broth culture of Escherichia coli and molten paraffin. 99mTechnetium dimercapto-succinic acid (DMSA) scintigraphy was performed 3 days after introduction of urinary infection to detect the presence of acute pyelonephritis. Acute pyelonephritic lesions seen on DMSA scans were graded according to the percentage of renal zone involvement as grade 1--less than 33%, grade 2--33 to 66% and grade 3--greater than 66% involved. When pyelonephritis was present, piglets were randomized to receive either standard antibiotics or antibiotics and 2 mg./kg. prednisolone daily. 99mTechnetium-DMSA scintigraphy was repeated 2 months after completion of therapy, and the kidneys were harvested for gross and histopathological examination. Each kidney was divided into upper, middle and lower zones for correlation of pathological and imaging findings. Severity of renal scarring was then assessed using histopathological confirmation of gross anatomical findings as grade 1--less than 1, grade 2-1 to 2 and grade 3-greater than 2 cm. RESULTS: Acute pyelonephritis was induced in 136 of 216 renal zones. The sites of renal scarring corresponded anatomically to sites of acute pyelonephritis in all but 5 cases. Overall, the prevalence of post-pyelonephritic scarring was 56.6% (77 of 136) of renal zones. The severity of scarring in both groups correlated with the severity of the initial pyelonephritic lesion. Of the 31 zones that formed grade 3 renal scars the distribution of grades 1, 2 and 3 acute pyelonephritis on the initial DMSA scan was 3, 26 and 71%, respectively. Grade 3 acute pyelonephritis was more likely to result in severe (grade 3) renal scars in the control compared to the steroid treated group (59 versus 31%). Overall, acute pyelonephritis completely resolved in 40% of controls and 51% of steroid treated animals. However, only 9% of control animals with grade 3 acute pyelonephritis demonstrated complete resolution, as opposed to 28% of those receiving steroids. CONCLUSIONS: The risk of renal scarring is greatest after severe acute pyelonephritis involving greater than 66% of a renal zone. Adjunctive oral prednisolone appears to be effective in diminishing renal scarring in severely affected kidneys. In kidneys with mild and moderate acute pyelonephritis antibiotics alone appear to be equally effective in preventing scarring.

Acute Disease↗

The role of 99mtechnetium dimercapto-succinic acid renal scans in the evaluation of occult ectopic ureters in girls with paradoxical incontinence.

PURPOSE: We describe the use of 99mtechnetium (Tc) dimercapto-succinic acid (DMSA) renal scintigraphy to document poorly functioning and/or ectopic renal units associated with occult ectopic ureters. MATERIALS AND METHODS: During the last 8 years 6 toilet-trained girls were referred for lifelong continuous urinary dribbling. Initial radiological evaluation included renal and bladder sonography in 6, excretory urography in 4, a mercaptoacetyltriglycine-3 renal scan in 1 and cystovaginoscopy in 2. Ultimately a 99mTc-DMSA renal scan was performed in all 6 girls before surgical intervention. RESULTS: Sonography failed to establish the diagnosis of ureteral ectopia in all cases, and revealed a normal solitary kidney in 3, normal kidneys in 1, an apparently uncomplicated unilateral duplication without hydroureteronephrosis in 1 and a contralateral uncomplicated duplication in 1. Excretory urography in 4 cases was inconclusive and showed a solitary kidney in 1, ipsilateral duplication without a normal appearing upper pole collecting system in 1, contralateral uncomplicated duplication in 1 and normal kidneys in 1. A mercaptoacetyltriglycine-3 renal scan in another girl with a solitary kidney on sonography failed to demonstrate a contralateral small ectopic kidney. Cystovaginoscopy performed in 2 patients by other pediatric urologists was nondiagnostic. 99mTc-DMSA renal scintigraphy was diagnostic in all 6 cases, and revealed a small poorly functioning ectopic kidney in 3 and a poorly functioning dysplastic upper pole moiety in 3, which were consistent with a diagnosis of ureteral ectopia. An ectopic ureter was confirmed by cystoscopic and surgical findings in all girls. CONCLUSIONS: 99mTc-DMSA renal scintigraphy reliably detects and localizes hypoplastic ectopic kidneys and poorly functioning upper pole moieties associated with occult ectopic ureters in girls with continuous urinary leakage.

Child↗

Bladder distention and pyelectasis in the male fetus: causes, comparisons, and contrasts.

The objective of this paper was to determine if prenatal sonographic findings can accurately differentiate between the causes of bladder distention and pyelectasis in the male fetus. Twenty-one cases were evaluated for the presence of oligohydramnios, posterior urethral dilation, bladder wall thickening, urachal patency, cortical thinning, cortical cysts, and increased renal echogenicity. Postnatal diagnosis included posterior urethral valves (10 cases), prune belly syndrome (four cases), vesicoureteral reflux (four cases), left ureterovesical junction obstruction (one case), and nonrefluxing, nonobstructive megacystis-megaureter (two cases). Oligohydramnios was present in eight of 10 cases of posterior urethral valves and in one of four cases of prune belly syndrome. A dilated posterior urethra was noted in seven of 10 cases of posterior urethral valves and transiently in two of four cases of prune belly syndrome. Bladder wall thickening developed in all cases of posterior urethral valves and was noted in two of four patients with prune belly syndrome. A patent urachus likewise was identified in two of four cases of prune belly syndrome. The presence of oligohydramnios, progressive bladder wall thickening, and dilated posterior urethra was most suggestive of posterior urethral valves, whereas the presence of a patent urachus was most suggestive of prune belly syndrome. The presence of pyelectasis and megacystis without additional amniotic fluid, bladder, urethral, or renal abnormalities was most suggestive of vesicoureteral reflux, ureterovesical junction obstruction, or nonrefluxing, nonobstructive megacystis-megaureter. Owing to the overlap and evolution of these findings, close follow-up evaluation is recommended.

Dilatation, Pathologic↗

The split prepuce in situ onlay hypospadias repair.

PURPOSE: We describe the surgical technique and report the results of the first 100 patients who underwent a modification of the onlay hypospadias repair, which we refer to as split prepuce in situ onlay repair. MATERIALS AND METHODS: We treated 100 boys with a mean age of 11 months at surgery who had coronal to mid shaft hypospadias with split prepuce in situ onlay hypospadias repair. The operative technique varies from that of the standard onlay procedure by preserving the whole blood supply of the half of the prepuce used for the island onlay flap, and using its abundant subcutaneous tissue to cover completely the suture lines used to create the neourethra. RESULTS: Only 5 complications required reoperation, including 1 hematoma evacuation and 4 urethrocutaneous fistulas. No patient had meatal stenosis, urethral stricture, meatal retraction or acquired urethral diverticulum necessitating reoperation. A good cosmetic result was obtained in all cases. CONCLUSIONS: Split prepuce in situ onlay hypospadias repair is applicable in virtually all cases of coronal to mid shaft hypospadias. It optimizes the blood supply to the island flap and provides well vascularized coverage of the neourethra, resulting in a decreased complication rate.

Humans↗

The evaluation of acute pyelonephritis and renal scarring with technetium 99m-dimercaptosuccinic acid renal scintigraphy: evolving concepts and future directions.

Technetium 99m-dimercaptosuccinic acid (DMSA) scintigraphy has emerged as the imaging agent of choice for the detection and evaluation of acute pyelonephritis and renal cortical scarring in children. Consequently, DMSA scintigraphy provides a unique opportunity to study the progression of renal damage and functional loss from the initial insult of acute pyelonephritis to the subsequent development of irreversible renal scarring. Over the last few years, clinical and experimental investigations using DMSA renal scintigraphy have provided new insights into the etiology, pathophysiology, and clinical outcome of acute pyelonephritis in children. These studies have confirmed the primary role of the acute inflammatory response, associated with both reflux and nonreflux pyelonephritis, in the etiology of irreversible renal scarring. Furthermore, several studies have shown that renal scarring can be prevented or diminished by the early diagnosis and treatment of pyelonephritis. This review highlights these recent observations and makes recommendations regarding current clinical and future research applications.

Humans↗

Urinary tract infections in children. Epidemiology, evaluation, and management.

Accurate documentation of UTIs in children is essential for proper evaluation and management. Urine cultures with multiple organisms or colony counts less than 50,000 to 100,000 CFU/ml should be considered suspect and require confirmation, particularly with clean-catch specimens. Children with well-documented UTIs should be evaluated based on their age and presenting symptoms. Infants and young children require imaging, usually with a cystogram and sonogram of the kidneys and bladder. Older girls with febrile UTIs and boys at any age should also be considered for urinary tract imaging. Renal cortical scintigraphy with 99mTc-DMSA has emerged as the imaging study of choice for acute pyelonephritis and renal scarring in children with UTIs. Treatment of UTIs in children ideally commences with culture-specific antimicrobial therapy, although treatment may be started in sick children before culture results are available. Short-course treatment (3-5 days) is sufficient for children with acute uncomplicated lower UTIs. Children with acute pyelonephritis require 10 to 14 days of antibiotics, which can be administered on an outpatient basis in older infants and children who are not toxic, as long as good compliance is expected. Patients with first-time UTIs who require imaging should be maintained on low-dose antibiotic prophylaxis until their workup is completed. Treatment of ABU does not seem necessary if the urinary tract is otherwise normal. Long-term antibiotic prophylaxis is indicated for children with frequent symptomatic recurrences of UTI and for those with known VUR. Diagnosis and treatment of underlying voiding dysfunction and constipation is an essential component of the successful management of UTIs in children.

Acute Disease↗

The influence of small functional bladder capacity and other predictors on the response to desmopressin in the management of monosymptomatic nocturnal enuresis.

PURPOSE: The relationship of functional bladder capacity as well as other variables to the responsiveness to desmopressin in children with monosymptomatic nocturnal enuresis was investigated. MATERIALS AND METHODS: A total of 95 children 8 to 14 years old with monosymptomatic nocturnal enuresis (6 or more of 14 nights wet) were evaluated in a double-blind study followed by open label crossover extension using 20 to 40 mcg. desmopressin. Evaluated predictors of response included patient age, gender, race, family history, number of baseline wet nights, urine osmolality parameters and maximum functional bladder capacity (as a percent of predicted bladder capacity based on the formula, patient age + 2 x 30 = cc). Responders to desmopressin were classified as excellent (2 or less of 14 nights wet) or good (50% or greater decrease but more than 2 of 14 nights wet) and nonresponders were defined by a less than 50% decrease in wet nights. RESULTS: Of the 95 patients 25 (29.5%) achieved an excellent response to desmopressin and 18 (18.9%) had a good response for a cumulative response rate of 45.3%. The remaining 52 patients (54.7%) were nonresponders. There were no significant differences between responders and nonresponders in regard to gender, race, positive family history or baseline urine osmolality parameters. Response to desmopressin was associated with older age, fewer baseline wet nights and larger bladder capacity. Patients with a functional bladder capacity greater than 70% predicted bladder capacity were 2 times more likely to respond to desmopressin. CONCLUSIONS: The responsiveness of children with nocturnal enuresis to desmopressin is adversely affected by reduced functional bladder capacity. The results of this study have implications regarding the potential use of combination pharmacotherapy with desmopressin and an anticholinergic for enuretic patients who are nonresponsive to single drug therapy.

Adolescent↗

Technetium-99m-DMSA renal cortical scintigraphy to detect experimental acute pyelonephritis in piglets: comparison of planar (pinhole) and SPECT imaging.

UNLABELLED: The purpose of this study was to directly compare the sensitivity and specificity of SPECT and pinhole imaging for the detection of acute pyelonephritis using histology as the standard of reference. METHODS: Bilateral vesicoureteral reflux of infected urine was induced in 16 piglets (32 kidneys) by unroofing the intravesical ureter and subsequently instilling a broth culture of E. coli into the bladder. DMSA scans were obtained by both pinhole and SPECT techniques at 24 hr (4 piglets), 48 hr (5 piglets), 72 hr (4 piglets) and 10 days (3 piglets) after instillation of bacteria into the bladder. Kidneys were harvested immediately after scintigraphy for histopathologic examination. Results of the SPECT images, pinhole images and histologic findings were interpreted independently in a blinded fashion. The images of each kidney were classified as positive or negative for pyelonephritis regardless of the severity and number of lesions. To evaluate accuracy of SPECT and pinhole imaging for the detection of individual lesions, each kidney was arbitrarily divided into three zones (upper, middle and lower). Image findings were then compared with the pathology results for the presence or absence of pyelonephritis in each zone. RESULTS: Histopathology revealed pyelonephritis in 24 of 32 kidneys (58 of 96 zones). The sensitivity of the DMSA scan for detection of affected kidneys was 92% for SPECT and 83% for pinhole; overall accuracy was 88% for both. The sensitivity of SPECT for the detection of affected renal zones was slightly better than pinhole imaging (91% compared with 86%), but its specificity was lower (82% compared with 95%) resulting in a similar accuracy. Excluding four piglets where scans were obtained within 24 hr after instillation of bacteria into the bladder, the sensitivity of SPECT and pinhole for the detection of affected kidneys were 95% and 90%, respectively. Their overall accuracy were 96% and 92%. In this subgroup, the sensitivity, specificity and accuracy of SPECT for the detection of involved zones were 96%, 95% and 96%, respectively. The corresponding values for pinhole imaging were 90%, 95% and 92%, respectively. CONCLUSION: Although the sensitivity of SPECT for the detection of acute pyelonephritis is slightly better than pinhole DMSA scan, the overall accuracy of these two imaging techniques is essentially the same.

Acute Disease↗