Biomedical subjects

Andrew H Hwang

Publications and source records attributed to Andrew H Hwang.

6 recordsLinked to original sources

PubMed2006

Penile torsion repair by suturing tunica albuginea to the pubic periosteum.

PURPOSE: The aim of the study was to evaluate the effectiveness of a new technique to repair penile torsion in children. METHODS: Eighteen boys with penile torsion were evaluated in our department from 1989 to 2003. Eleven had associated hypospadias, 4 had chordee without hypospadias, and 3 had torsion only. The direction of rotation was counterclockwise in 16 cases and clockwise in 2 cases. Torsion was repaired in 6 patients by degloving the penis and reattaching the dartos and the skin (comparative group). In 11 patients (1 with prior repair), the torsion was corrected by suturing the lateral edge of the corpus cavernosum to the pubic periosteum (study group). Two patients were not treated. RESULT: Follow-up ranges from 6 months to 7 years. All of the 11 cases in the study group had satisfactory correction of the penile torsion. All of the urethroplasties for hypospadias were successful. In the comparative group, none of 6 patients had satisfactory correction of the rotation. CONCLUSION: The technique of degloving the penis and reattaching the skin cannot reliably correct penile torsion in our experience. Lateral suturing of tunica albuginea to the pubic periosteum to repair penile torsion appears to be a better technique.

Child↗

PubMed2005

Risk factors for short- and long-term survival of primary cadaveric renal allografts in pediatric recipients: a UNOS analysis.

BACKGROUND: Pediatric kidney graft survival rates have improved in the United States. This study evaluates early and late risk factors for cadaveric graft loss in pediatric recipients. METHODS: From January 1994 to December 2002, 2,597 primary cadaveric kidney-alone transplants (donor age 5-45 years, recipient age 2-20 years) were reported to the United Network for Organ Sharing (UNOS). The analysis includes follow-up information based on OPTN data as of October 14, 2003. Odds ratio of early graft loss and relative risk of late graft loss are estimated using logistic regression and Cox proportional hazards model, respectively. RESULTS: Graft survival rates significantly improved during 1999-2002 (95% and 79% at 1-year and 3-years, respectively) compared with those of 1994-1998 (88% and 76% at 1-year and 3-years, respectively) (log rank P=0.02). After adjusting for other variables, the factors that significantly affected early transplant outcome adversely within 3 months posttransplant were prolonged cold ischemia time (>36 hours, odds ratio [OR]=3.38 vs. 0-36 hours) and young recipient age (2-5 years old, OR=2.02 vs. 6-12 years). Beyond 3 months, significant risk factors were African-American recipients (relative risk [RR]=1.93 vs. others), teenage recipients (13-20 yrs, RR=1.50 vs. 6-12 yrs), and patients with focal glomerulosclerosis (FGS) (RR=1.27 vs. others). CONCLUSIONS: The short-term graft survival rate of pediatric cadaveric kidney transplants has significantly improved, yet the long-term outcome has changed little. The long-term outcomes for teenagers (13-20 yrs), patients with FGS, and African-Americans lag significantly behind other groups. In order to improve long-term graft survival in these high-risk patients, newer preventive or treatment strategies must be developed.

Acute Disease↗

PubMed2005

Access to urologic care for children in California: Medicaid versus private insurance.

OBJECTIVES: To compare the access to urologic care for a child with cryptorchidism insured by Medi-Cal versus one insured by private insurance. Medi-Cal (California State Medicaid) is a joint state and federal health insurance program that plays a significant role in providing healthcare coverage to low-income children. METHODS: A total of 54 randomly chosen urology offices throughout California were surveyed by telephone to determine whether the office accepted pediatric patients, accepted Medi-Cal, and when the earliest appointment date would be for a patient with Medi-Cal versus one with private insurance. RESULTS: Of the 46 practices that accepted pediatric patients, 96% offered a new patient appointment to a child with private insurance, but only 41% were willing to offer an appointment to a child with Medi-Cal (P < 0.0001). Of the offices that would not see a child with Medi-Cal, 75% were unable to recommend a urology office that might accept Medi-Cal. CONCLUSIONS: Children insured by Medi-Cal have significantly less access to necessary urologic care compared with children with private insurance.

California↗

PubMed2005

Congenital mid ureteral strictures.

PURPOSE: Congenital mid ureteral stricture is rare. We report 7 cases, and discuss the differences in preoperative evaluation and surgical management compared to other obstructive entities. MATERIALS AND METHODS: Medical records and imaging studies of 7 children identified with mid ureteral strictures between 1998 and 2002 were reviewed retrospectively. Five newborns presented with prenatal hydronephrosis, and 2 children presented at age 15 years, one in the course of evaluation of blunt trauma, and one due to pain and abdominal mass. Imaging studies included renal ultrasound, voiding cystourethrography, radionuclide renography and computerized tomography. All patients underwent retrograde pyelography. Pathological examination of each specimen was undertaken at the respective institutions. RESULTS: Prenatal hydronephrosis was the most common presentation. There were no urinary tract infections. All patients had significant obstruction on the affected side. No patient had vesicoureteral reflux. After imaging but before surgery the urinary obstruction was believed to be at the ureteropelvic junction in 4 patients and the ureterovesical junction in 2, and secondary to posterior urethral valves in 1. At cystoscopy all of the affected ureters had a normally located and normally configured orifice. Retrograde pyelography led to an accurate diagnosis of mid ureteral narrowing in all patients. Six patients underwent ureteroureterostomy, all of whom had satisfactory outcomes. In 1 of these patients contralateral nephrectomy was performed due to nonfunction of the multicystic dysplastic kidney. The remaining patient underwent nephrectomy for ipsilateral end stage kidney disease and hydronephrosis. In this patient the ureters were stenotic and suggested asymmetry in the thickness of the muscular coat, perhaps secondary to extrinsic compression. CONCLUSIONS: Congenital mid ureteral stricture is rare. Renal ultrasound and radionuclide renography alone do not reliably demonstrate the site of obstruction. Retrograde pyelography at the time of surgical correction of presumed ureteral obstruction is an important adjunct for correctly identifying the site of narrowing in the affected ureteral segment, unless the ureter has been imaged with another modality.

Adolescent↗

PubMed2003

The management of old urethral injury in young girls: analysis of 44 cases.

BACKGROUND/PURPOSE: Traumatic urethral injury in girls is rare, and there is no consensus on its management. The authors report their 22-year experience. METHODS: Forty girls presented with urethrovaginal fistula. Twenty-six girls presented with cystostomy tube in place, whereas 17 girls presented with complete urinary incontinence. Incision and dilatation of the obliterated urethra was carried out in 7 patients. Vaginal repair of urethrovaginal fistula was performed in 4 patients. Transpubic reconstruction of the urethra using a modified Young-Dees-Leadbetter procedure with simultaneous repair of the urethrovaginal fistula was performed in 35 patients (once in 27, twice in 5, and 3 times in 3 patients). RESULTS: Follow-up in 40 girls averaged 3.5 years. Twenty-nine patients have regained normal urinary control, and 11 patients have mild stress urinary incontinence. Four patients were lost to follow-up. CONCLUSIONS: Simple dilation of the obliterated urethra can reestablish satisfactory urethral patency if the obliterated segment is short. The vaginal approach to urethrovaginal fistula may be successful in patients without concomitant urethral stricture or in those with stricture amenable to simple dilation. The transpubic approach remains the method of choice for repairing complete urethral disruption and severe urethral stricture, especially when associated with urethrovaginal fistula.

Adolescent↗

PubMed2002

Dual-modality imaging of function and physiology.

Dual-modality imaging is a technique in which computed tomography (CT) or magnetic resonance imaging is combined with positron emission tomography or single-photon emission CT to acquire structural and functional images with an integated system. The data are acquired in a single procedure; the patient remains on the scanner table while undergoing both x-ray and radionuclide studies to facilitate correlation between the structural and functional images. The resulting data can aid in localization, enabling more specific diagnosis than can be obtained with a conventional imaging study. In addition, the anatomic information can be used to compensate the correlated radionuclide data for physical perturbations such as photon attenuation, scatter radiation, and partial volume errors. Thus, dual-modality imaging provides a priori information that can improve both the visual quality and the quantitative accuracy of the radionuclide images. Dual-modality imaging systems are also being developed for biologic research involving small animals. Small-animal dual-modality systems offer advantages for measurements that currently are performed invasively with autoradiography and tissue sampling. By acquiring data noninvasively, dual-modality imaging permits serial studies in a single animal, enables measurements to be performed with fewer animals, and improves the statistical quality of the data.

Animals↗