Biomedical subjects

Hiep T Nguyen

Publications and source records attributed to Hiep T Nguyen.

3 recordsLinked to original sources

PubMed2003

The outcome of bladder neck closure in children with severe urinary incontinence.

PURPOSE: We evaluated the outcome of children who underwent bladder neck closure for the management of severe urinary incontinence. MATERIALS AND METHODS: Bladder neck closure was performed in 12 patients with bladder exstrophy, 4 with myelomeningocele and 4 with urogenital sinus anomalies for severe urinary incontinence that persisted after multiple failed bladder outlet procedures. The effectiveness of bladder neck closure and the need for subsequent surgeries were ascertained. RESULTS: Mean followup was 5.4 years (range 1 to 12). At 3 months after surgery 40% of the patients were completely dry, 20% had leakage via the stoma and 40% had a urethral fistula. After additional surgeries 85% of the patients were completely continent 2 years following bladder neck closure (15% declined further surgeries or had an ileal conduit). Of the 15 patients with followup longer than 3 years only 40% remained completely dry, and leakage via the stoma developed in 47% after being dry for 1 year. Repeat urodynamic studies did not show any adverse changes in bladder dynamics in the incontinent patients. Stomal stenosis occurred in 30% of the patients and bladder stones developed in 40%. None of the patients had hydronephrosis or bladder perforation. The early complication of fistula formation and the late development of leakage via the stoma appear to be related in part to compliance with intermittent catheterization. CONCLUSIONS: Bladder neck closure is an effective method of achieving urinary continence in children in whom other bladder outlet surgery has failed. However, its success is dependent in part upon compliance with intermittent catheterization. Finally children who have undergone bladder neck closure are at an increased risk for stomal stenosis and bladder stones.

Adolescent↗

PubMed2002

Laparoscopic linear cutting stapler failure.

OBJECTIVES: To characterize the frequency and nature of problems with linear cutting staplers to help prevent complications in the future. These devices are often used during laparoscopic urologic procedures. METHODS: We retrospectively reviewed the experience with laparoscopic linear cutting staplers at two institutions routinely performing urologic laparoscopy and analyzed the difficulties with any staplers. Data from the Food and Drug Administration Center for Devices and Radiological Health were also examined to determine the prevalence and types of reported problems. RESULTS: In performing approximately 460 laparoscopic cases, we encountered 5 problems (1%) with endovascular gastrointestinal anastomosis staplers. Fifty-five additional cases in 50 patients were documented in the Food and Drug Administration database. Of the 55 patients, 15 (27%) required open conversion to manage the problem, 8 (15%) received blood transfusions, and 2 (4%) died postoperatively. Twenty-two events occurred during 19 laparoscopic donor nephrectomies (35%) without associated graft dysfunction, damage, or loss. All phases of instrument use were subject to problems; however, abnormal firing of the stapler and improper staple formation were the most common and morbid aspects of device malfunction. CONCLUSIONS: Despite the general reliability of linear cutting staplers, difficulties were encountered in every step of use. Most situations were successfully managed by prompt identification and appropriate intracorporeal maneuvers. Nevertheless, significant morbidity may occur, and conversion to an open operation should be considered. Many potential problems can be avoided by surgeon and staff education, and one should be aware of the alternative methods of tissue ligation currently available.

Equipment Failure↗

PubMed2002

Growth and metabolic consequences of bladder augmentation in children with myelomeningocele and bladder exstrophy.

OBJECTIVE: Bladder augmentation using intestinal segments is reported to cause decreased linear growth in bladder exstrophy and myelomeningocele patients. We studied changes in calcium metabolism, height, bone chemistry, and bone density in exstrophy and myelomeningocele patients after bladder augmentation. METHODS: Thirty-three patients were prospectively admitted to the Pediatric Clinical Research Center at the University of California San Francisco for 24 hours. Blood and urine were analyzed for electrolytes, and serum was obtained for markers of calcium metabolism. Dual radiograph bone densitometry of the forearm was performed. Myelomeningocele patients were compared with nonaugmented myelomeningocele patients matched by age, gender, level of defect, and ambulatory status. Exstrophy augmented patients were compared with nonaugmented exstrophy patients. The bone densities in both groups were compared with normal children. Laboratory values and percentile heights were statistically analyzed using the Student t test; bone densitometry was analyzed using the Tukey test. RESULTS: Twenty-two patients with myelomeningocele and 11 with bladder exstrophy were studied. Mean follow-up was 3.7 years postaugmentation (range: 1-13 years). The results indicate a significant difference in serum bicarbonate and chloride levels between myelomeningocele patients who underwent ileal augmentation and those who did not. Although this may be indicative of chronic metabolic acidosis, there was no affect on growth or bone density when compared with controls. There were no other significant differences in laboratory values, or percentile heights, nor were any differences noted in patients who underwent gastrocystoplasty. In the exstrophy group, there were no observable differences in percentile height or laboratory values between the augmented and nonaugmented group. There were no significant differences in bone density between these 2 groups when matched for age and gender. No significant difference was seen in bone density when these groups were compared with normal children. CONCLUSION: Bladder augmentation is safe and does not impact negatively on the linear growth or bone densities of patients with myelomeningocele or bladder exstrophy.

Adolescent↗