BPH is a common problem experienced by aging men that can lead to serious outcomes, including acute urinary retention and bladder stone formation. Its prevalence is directly proportional to increase in age. At 80 years of age, its prevalence is 95% [
3]. These prostatic changes begin at 40 years of age, and prostate volume increases by around 0.6ml/yr and is associated with a reduction of mean urinary flow at the rate of 0.2ml/s [
6]. This is not necessarily definitive, because prostate growth and the severity of its symptoms are erratic in the patient population. Known as prostatism, this constellation of clinical symptoms is characterized by the presence of irritable and obstructive lower urinary tract symptoms, which are evaluated in a general manner on the basis of the International Prostate Symptom Score. Chronic or acute obstructive renal failure is a serious condition associated with premature mortality, decreased quality of life and increased health-care expenditures. Both diseases are extremely common among aging men, leading some to suggest that it is a natural concomitant of aging. Nonetheless, quite recently, evidence of an association between BPH and chronic kidney disease (CKD) has arisen in two different studies. In a study by Yamasaki
et al. [
7], the PVR of patients with CKD was significantly greater than that of patients without CKD, and the presence of PVR urine was independently associated with CKD, indicating a close association between CKD and residual urine. In that study, PVR was used as a surrogate measure of bladder outlet obstruction and thus of urodynamically relevant BPH [
7]. Yamasaki
et al. reported a higher prevalence (31.8%) of CKD among BPH patients than those without BPH. Although the prevalence of CKD can be considered relatively low among men with BPH, the possibility of CKD should be considered in those who have a low maximum flow rate and obstructive urinary symptoms. Chronic urinary retention is thought to be the dominant mechanism by which BPH can cause chronic renal failure, Rule
et al. defined chronic urinary retention (CUR) as PVR urine levels higher than 100ml and reported that CUR was significantly associated in CKD in community-dwelling men [
8‐
10].
For years, it has been well-described that large urinary volume (greater than 300ml) affects renal function in patients with advanced BPH. To the best of our knowledge, the case of our patient involved the largest urinary volume reported in the literature. In our patient, the ureterovesical junction obstruction caused by detrusor hypertrophy seems to have been the principal contributing factor to renal failure in BPH. Upper tract dilation occurs as a consequence of a continuum of bladder outlet obstruction and remodeling (detrusor hypertrophy and scarring), leading to anatomical ureterovesical junction obstruction. Upper urinary tract dilation or hydronephrosis is consistent with chronic renal failure due to obstructive uropathy. In men with BPH and increased serum creatinine levels, hydronephrosis is common (occurring in one-third of patients), with a prevalence of 90% in men with BPH who are hospitalized for uremic symptoms. In ultrasound evaluation of patients with bilateral hydroureteronephrosis, it is common to observe compressing and thinning of the renal cortex with obvious impact on renal function. Imaging studies are an excellent diagnostic tool. These tools include ultrasonography and excretory urography. Because IVU has not routinely been conducted in patients with creatinine levels (180mmol/L), patients without impaired renal function still represent the best examples for showing this relationship by revealing bilateral upper urinary tract dilation with regular ureterovesical junction obstruction. Transurethral resection of the prostate is still the gold standard treatment of benign prostatic hypertrophy, even in cases with associated hydronephrosis and ureterovesical junction obstruction caused by detrusor hypertrophy [
11]. The surgical treatment options for BPH have dramatically changed with the development of minimally invasive therapies over the past two decades. They include holmium laser enucleation of the prostate, transurethral electrovaporization of the prostate, transurethral microwave thermotherapy and other modalities [
11]. However, these techniques are also performed in patients with slightly to moderately enlarged prostates. Rocco
et al. stated that 100ml is regarded as the prostate weight limit for those minimally invasive procedures [
12]. European Association of Urology guidelines state that open prostatectomy is the treatment of choice for large prostate glands more than 80ml to 100ml in size [
13]. If ureterohydronephrosis and azotemia persist despite bladder unblocking, ureterovesical junction obstruction should be considered, and bilateral percutaneous nephrostomy or bilateral ureteric stents are advisable for temporary drainage, as we have reported in our present case. We think that our case is interesting and rare, particularly with regard to the patient’s lumbar pain due to bilateral ureterohydronephrosis as the first and principal symptom of benign prostatic hypertrophy.