The duplex renal system involves the presence of two ureters in a single kidney. The renal duplex system may be complete or incomplete. Many patients do not have symptoms. Most of these cases are diagnosed on antenatal scan or when they present with urinary tract infections. It is a congenital condition and may require various procedures to salvage the renal functions.
Duplex Renal System
The duplex renal system is also known as a duplicated collecting system or renal duplex. Urine formation takes place in the kidney. From kidneys, the urine flows to the urinary bladder through small tube-like structures. These tube-like structures are known as ureters. In normal case, one ureter from each kidney drains the urine to the bladder. However, in duplex system kidney gets duplicated forming two system with two ureters each. One ureter drains the urine from the upper part of the kidney while another drains urine from the lower part.
Types Of Duplex Renal System
The duplex renal system may be of the following two types:
Incomplete duplex renal system: In the incomplete duplex renal system, two ureters drain the urine from a kidney. However, the ureters join somewhere between the kidney and the bladder and enter the bladder as a single ureter.
Complete duplex renal system: In the complete duplex urinary system, two ureters drain urine from a kidney and enters the bladder at two different points.
Prevalence Of Duplex Renal System
Approximately 0.7% of healthy people may have a duplex renal system. The incidence of this condition increases to 2-4% in patients who already have urinary tract issues. The prevalence of incomplete duplex system is three times more in comparison to the complete duplex system. The condition is more common in females.
Symptoms Of Duplex Renal System
Till the urine from the duplex ureters drains normally into the bladder and is not refluxing, the person may not experience any symptoms. Sometimes the ectopic uretermay open outside the bladder like urethta or vaginal in fenmales causing urinary incontinent. Some of the common presentation and symptoms are :
- Recurrent urinary tract infection
- Urinary incontinence
- Vesicoureteral reflux
Causes Of Duplex Renal System
The condition of the renal duplex system is congenital i.e., it is present by birth. It may be due to abnormal development of the urinary tract system. What causes this in the womb remains unknown.
Diagnosis Of Duplex Renal System
Your doctor may diagnose the condition through the following methods:
- Physical examination: The doctor may perform the physical examination and ask you various questions about your symptoms. The doctor may ask you about an alteration in urination, medical history of urinary tract infection, and if you have a family history of a renal duplex system.
- Ultrasound: Ultrasound may help in determining the presence of the duplex urinary system and associated hydronephrosis.
- MRI Urogram or CT Urogram: The doctor recommends scanning to determine the presence of duplex ureters through 3-D imaging.
- VCUG (voiding cysto-urethrogram) : To know the presence of vesico-ureteric reflux which is commonly associated with duplex system.
Treatment Of Duplex Renal System
Most people do not require treatment for the duplex renal system.
Surgery is recommended in a symptomatic child or in case of deteriorating renal function.
In case the patients require treatment, the doctor may recommend the following procedures:
Ureteral reimplantation: In this procedure, obstructed or refluxing ureter is disconnected and again reimplanted in bladder.
Ureteroureterostomy: The obstructed or refluxing ureter is joined to normal ureter.
Hemi-Nephrectomy: The doctor does not commonly use this procedure. The doctor removes the part of kidney, which is not working properly. This helps in avoiding symptoms such as urinary tract infection and urinary incontinence.