SMOOTH MUSCLE CELLS AND COLLAGEN FIBRES ARCHITECTURE IN EQUIVOCAL URETEROPELVIC JUNCTION OBSTRUCTION: ELECTRON MICROSCOPY STUDY WITH CLINICAL CORRELATION IN ADULT EGYPTIANS

Document Type : Original Article

Authors

1 Department of Urology

2 Department of Pathology and Electron Microscopy

Abstract

Adult patients with ureteropelvic junction obstruction (UPJO) would undergo operative pyeloplasty
or considered an equivocal type, the decision for management of equivocal UPJO
whether pyeloplasty or watchful follow-up is debatable. Equivocal UPJO referred to findings
and patient’ symptoms suggested an obstruction, whereas the diuretic renogram is not conclusive
to have a decision of pyeloplasty. This study evaluated the smooth muscle arrangement,
distribution of collagen fibers, and presence of fibrosis in the UPJ segment in equivocal UPJO
and normal UPJ segments using transmission electron microscopy (TEM) methods. The study
design consisted of 30 adult Egyptian patients who underwent pyeloplasty for unilateral equivocal
UPJO. Ten adult patients who had been operated on for oncological indications constituted
the control group. Ten representative specimens of UPJO and 5 representative specimens of the
control group were examined by TEM. Clinical study comprised 30 patients having equivocal
UPJO and operated upon with pyeloplasty were followed for 2 years. Retrospectively analyses
of records of 42 adult patients who had unilateral equivocal UPJO and were on watchful followup < br />for 2 years was done to compare results of Pyeloplasty to watchful follow-up. Electron microscopy
study of UPJ segment of equivocal UPJO and the normal control cases showed similar
findings with proper arrangement of smooth muscle fibers that were in close contact to each
other, without fibroblast imposed between muscle bundles, and few collagen fibers were found.
Clinical evaluation of results of pyeloplasty or watchful follow-up in equivocal UOJO in adults
showed stable radiological findings, stable split renal function and diuretic renogram. In the
watchful follow-up group 12% of cases required pyeloplasty, indication for pyeloplasty were
repeated urinary tract infection, intolerable recurrent pain. The clinical series supported by ultrastructure
findings showed that watchful follow-up of equivocal UPJO was an accepted treatment
option.

Keywords