Related Experiment Video
Updated: Jun 17, 2025
Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection
Published on: October 12, 2017
Pathological characteristics analysis of children with intermittent and persistent hydronephrosis due to
Ma Yan1, Zou Jizhen2, Xiao Ping2
1Department of Urology, Children's Hospital, Capital Institute of Pediatrics, Beijing, China.
Objective:
To analyze from a pathological perspective the differences between intermittent and persistent hydronephrosis in children with uretero-pelvic junction obstruction.
Methods:
23 children who underwent unilateral dismembered pyeloplasty (Anderson-Hynes operation) for intermittent hydronephrosis from September 2017 to March 2024 were included in the observation group. They were compared with a control group consisting of 23 children with persistent hydronephrosis matched for age, gender, and affected side. All children had the narrowed segment surgically excised during the operation, while other obstructive causes (such as polyps, crossing vessels, or tumor compression) were excluded. The specimens were analyzed for muscle and collagen content using Masson's trichrome staining, and the collagen-to-muscle ratio (CMR) was calculated. The number of Cajal-like cells was quantified with c-kit immunohistochemical staining. For all slides, 10 random fields of view were selected under a 400× optical microscope to record pathological data and calculate mean values. Pathological indicators between the two groups were compared using the T-test and the Chi-square test, with P < 0.05 considered statistically significant.
Results:
The observation group showed a significant difference in the number of fields with low, medium, and high densities of Cajal-like cells compared to the control group [132 (57.4%) vs. 173 (75.2%); 70 (30.4%) vs. 38 (16.5%); 28(12.2%) vs. 19 (8.3%), P < 0.001]. The uretero-pelvic junction in children with intermittent hydronephrosis had lower collagen content, higher muscle content, and a more regular arrangement. The collagen-muscle ratio was significantly lower than that in children with persistent hydronephrosis [(1.59 ± 0.65) vs. (3.98 ± 1.19), P < 0.001].
Conclusion:
Compared with persistent hydronephrosis, the narrowed segment at the uretero-pelvic junction in children with intermittent hydronephrosis has a higher density of Cajal-like cells; lower collagen content, and higher muscle content (lower collagen-muscle ratio).
Related Concept Videos
01:20Disorders of the Urinary System
Urinary tract infections (UTIs) are one of the most common urinary system disorders. They are caused by bacteria that enter the urethra and can spread to the bladder resulting in cystitis. Pyelonephritis is the result of a UTI that has ascended to the level of the...
01:22Ureters
01:24Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
01:10Nephrons
01:23Urinary Bladder
In males, the bladder is situated in front of the rectum, while in females, it is positioned anterior to the vagina and uterus. The bladder floor contains an inverted triangular area called the trigone, defined by the two ureteric...
01:20Formation of Dilute Urine
Filtrate Osmolarity in the PCT
Initially, as the filtrate passes through the proximal convoluted tubule (PCT), its...