The prognostic value of histopathological pattern of the pelviureteric junction in the outcome of pyeloplasty in children

Abstract
Background
The cause of pyeloplasty failure remains unclear; therefore, increasing interest has been directed to identify the reason for dissatisfactory surgical results. Some studies attempted to investigate the role of the histopathological pattern. The aim of the work is to study the correlation between the histopathological pattern of obstructed pelviureteric junction (PUJ) segment and the outcome of pyeloplasty in children with the PUJ.

Methods
Fifty-four patients with pelviureteric junction obstruction (PUJO) were included in the study; patients were evaluated preoperative. All patients were operated by the same surgeon using Anderson–Hynes pyeloplasty; the resected obstructed PUJ segment examined histopathological using light microscope and image analyzer system to identify mean renal pelvis smooth muscle thickness (mRPSMT), collagen-to-smooth muscle ratio and elastin content.

Results
The study includes 50 patients with mean age Mean 24.48 ± 15.3 months. Two patients show no improvement, while 24 improved at 3 months, 16 improved at 6 months, and 8 improved at 12 months. mRPSMT showed significant difference between improvement groups (136.02 ± 44.4, 173.47 ± 49.69 and 258.56 ± 96.82 μm), while elastin content or collagen-to-smooth muscle ratio showed no significant difference.

Conclusions
Our data showed a clear relationship between mRPSMT and the time over which radiological improvement occurs; increase in mRPSMT is associated with a delay in postoperative radiological improvement time. We found no relation between elastin content nor collagen-to-smooth muscle thickness and postoperative improvement course.