Etiological Spectrum and Anatomical Locations of Hydronephrosis in Western Region of Yemen

Abstract

Background & Objective: Hydronephrosis is the dilatation of renal pelvis and calices with urine as due to obstruction of urine flow along the urinary tract. This study aimed to report the causes of hydronephrosis in the western region of Yemen.

Methodology: This retrospective study reviewed the electronic medical records of 418 patients diagnosed with hydronephrosis between June 2024 to December 2024 at Advanced AlRazi Diagnostic Center, Al-Hodeidah, Republic of Yemen.

Results: A total of 418 patients with 476 kidneys affected by hydronephrosis were included in this study. There were 265 (63.4%) male and 153 (36.6%) females, aged 1 to 80 years (mean age: 31.11±11.14). Hydronephrosis was most commonly among young adults (n=316, 66.4%). It was predominantly unilateral 361 (86.4), with right side more frequently affected than the left. The most common grade observed was Grade-II (69.7%), followed by Grade-III (17.9%). The leading cause of hydronephrosis was stones (74.4%), followed by reflux (9.5%) and pregnancy (8.8%). The stones causing hydronephrosis were most often located in the distal ureter (DU) (43.7%), followed by the middle ureter (MU) (18.5%), upper ureter (UU) (17%), vesicoureteral junction (10.5%), renal pelvis (2.3%) and urethra (0.8%). The non-parametric Kruskal-Wallis test revealed that the mean stone size increased with the grade of hydronephrosis from Grade-I to Grade-IV (p <0.001).

Conclusion: This study concluded that ureteric or renal stones (nephrolithiasis) were the predominant cause of hydronephrosis, followed by reflux, pregnancy and underactive bladder. Ureteric strictures and infections were rare causes. Nephrolithiasis were commonly found in the DU, MU and UU. Grade-II hydronephrosis was the most frequently reported, with strong correlation between stone size and hydronephrosis grade, as the mean stone size increased from Grade-I to Grade-IV.