Smooth muscle cells and collagen fibres architecture in equivocal ureteropelvic junction obstruction: electron microscopy study with clinical correlation in adult egyptians

Adult patients with ureteropelvic junction obstruction (UPJO) would undergo operative pyeloplastyor considered an equivocal type, the decision for management of equivocal UPJOwhether pyeloplasty or watchful follow-up is debatable. Equivocal UPJO referred to findingsand patient’ symptoms suggested an obstruction, whereas the diuretic renogram is not conclusiveto 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 UPJOand normal UPJ segments using transmission electron microscopy (TEM) methods. The studydesign consisted of 30 adult Egyptian patients who underwent pyeloplasty for unilateral equivocalUPJO. Ten adult patients who had been operated on for oncological indications constitutedthe control group. Ten representative specimens of UPJO and 5 representative specimens of thecontrol group were examined by TEM. Clinical study comprised 30 patients having equivocalUPJO and operated upon with pyeloplasty were followed for 2 years. Retrospectively analysesof records of 42 adult patients who had unilateral equivocal UPJO and were on watchful followup for 2 years was done to compare results of Pyeloplasty to watchful follow-up. Electron microscopystudy of UPJ segment of equivocal UPJO and the normal control cases showed similarfindings with proper arrangement of smooth muscle fibers that were in close contact to eachother, 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 adultsshowed stable radiological findings, stable split renal function and diuretic renogram. In thewatchful follow-up group 12% of cases required pyeloplasty, indication for pyeloplasty wererepeated urinary tract infection, intolerable recurrent pain. The clinical series supported by ultrastructurefindings showed that watchful follow-up of equivocal UPJO was an accepted treatmentoption.