Urinary tract obstruction explained

Urinary tract obstruction is a urologic disease consisting of a decrease in the free passage of urine through one or both ureters and/or the urethra. It is a cause of urinary retention. Complete obstruction of the urinary tract requires prompt treatment for renal preservation.^[1] Any sign of infection, such as fever and chills, in the context of obstruction to urine flow constitutes a urologic emergency.^[1]

Causes

Causes of urinary tract obstruction include:

Bladder stone and renal stone
Benign prostatic hyperplasia
Obstruction as a congenital disorder.
Foreign object such as a bullet or pellet.^[2]

Congenital urinary tract obstruction

Urinary tract obstruction as a congenital disorder results in oligohydramnios which in turn can lead to the Potter sequence of atypical physical appearance. Pulmonary hypoplasia is by far the main cause of death in the early neonatal period for children with congenital lower urinary tract obstruction.

Fetal surgery of congenital lower urinary tract obstruction seems to improve survival, according to a randomized yet small study.^[3]

Urinary tract obstruction due to foreign object

While uncommon, there are case reports in the human and veterinary literature of a bullet or other ballistic projectile migrating to the urethra and causing a urinary tract obstruction. This has been reported in people, small animals, and a goat.^[4]

Sitting voiding position

A meta-analysis on the influence of voiding position on urodynamics in healthy males and males with LUTS showed that in the sitting position, the residual urine in the bladder was significantly reduced. The other parameters, namely the maximum urinary flow and the voiding time were increased and decreased respectively. For healthy males, no influence was found on these parameters, meaning that they can urinate in either position.^[5]

Treatment

Treatment depends on the underlying cause of the obstruction and the severity of the symptoms.

Notes and References

Chowdhury SH, Cozma AI, Chowdhury JH. Urinary Tract Obstruction. Essentials for the Canadian Medical Licensing Exam: Review and Prep for MCCQE Part I. 2nd edition. Wolters Kluwer. Hong Kong. 2017.
Smith . Joe S. . Hespel . Adrien-Maxence . Garcia . Jessica D. . Lipe . Krista L. . Kleine . Stephanie A. . Mulon . Pierre-Yves . 2023-07-17 . Delayed Urethral Obstruction after Migration of a Ballistic Pellet in an Alpine Wether . Case Reports in Veterinary Medicine . en . 2023 . e3531856 . 10.1155/2023/3531856 . 2090-7001. free . 10365913 .
Morris . R. K. . Malin . G. L. . Quinlan-Jones . E. . Middleton . L. J. . Hemming . K. . Burke . D. . Daniels . J. P. . Khan . K. S. . Deeks . J. . Kilby . M. D. . 10.1016/S0140-6736(13)60992-7 . Percutaneous vesicoamniotic shunting versus conservative management for fetal lower urinary tract obstruction (PLUTO): A randomised trial . The Lancet . 382 . 9903 . 1496–506 . 2013 . 23953766. 3898962.
Smith . Joe S. . Hespel . Adrien-Maxence . Garcia . Jessica D. . Lipe . Krista L. . Kleine . Stephanie A. . Mulon . Pierre-Yves . 2023-07-17 . Delayed Urethral Obstruction after Migration of a Ballistic Pellet in an Alpine Wether . Case Reports in Veterinary Medicine . en . 2023 . e3531856 . 10.1155/2023/3531856 . 2090-7001. free . 10365913 .
de Jong. Y. Pinckaers. JH. Ten Brinck. RM. Lycklama À Nijeholt. AA. Dekkers. OM. Urinating Standing versus Sitting: Position Is of Influence in Men with Prostate Enlargement. A Systematic Review and Meta-Analysis.. PLOS ONE. 2014. 9. 7. e101320. 10.1371/journal.pone.0101320. 25051345. 4106761. 2014PLoSO...9j1320D. free.