Enlarged ureter

What is a megaureter?

Urine drains from the kidneys into the renal pelvis. From there it is transported to the bladder via the ureter. If the ureter’s diameter is ≥ 6 mm it is termed a megaureter. Causes include 1) a narrowing of the ureter where it enters the bladder; 2) a backflow of urine from the bladder into the ureter (vesicouretereal reflux); or, 3) a weakness in the tissue that keeps the ureter from contracting, causing it to fill with urine and stretch. That can lead to urine backing up into the renal pelvis (= hydronephrosis). An enlarged ureter with or without widening of the renal pelvis can in some cases be diagnosed by ultrasound before birth, but often it is discovered by accident in symptom-free children.


How do you diagnose a megaureter?

An enlarged ureter with or without widening of the renal pelvis can be seen with ultrasound. This examination can be made on an outpatient basis, for example, during a specialist consultation with the pediatric urologist. If warranted by the findings, a renal scintigraphy is also done. This test allows drawing conclusions about the functioning and urine flow conditions of each kidney separately. In order to exclude backflow of urine from the bladder into the ureter (vesicoureteral reflux), which can also accompany an enlarged ureter, a micturating cysto-urethrogram  may be required under certain circumstances. Both this procedure and renal scintigraphy can be performed on an outpatient basis.


How do you treat a megaureter?

If kidney functions are not impaired by the urine backing up, conservative treatment can ensue. It includes a antibiotic prophylaxis, that is, taking a low-dose antibiotic to prevent kidney infections. This is accompanied by regular ultrasound checkups and keeping an accurate record of the course taken by the disease.

An impairment of kidney functions caused by the accumulation of urine calls for an operation. First the ureter is disconnected from the bladder and routed outside the abdominal wall. The urine can then simply drain out, and ureter and kidney can recover. Once the incision heals, the patient is allowed to return home. This is followed by continual ultrasound checkups. Additionally, the pressure in the rerouted ureter is measured with a catheter. Should the pressure in the ureter reach normal values again, the ureter is repositioned, that is, reconnected to the bladder. This operation takes place about 12 months after the first intervention. Reconnecting the ureter to the bladder (uretrocystoneotomy) is done under loupe glasses using the finest,  absorbable suturing material. During the operation, a ureteral stent, a so- called double-J catheter, is inserted into the ureter to ensure problem-free urination. This is needed because post-operative tissue swelling can impede the flow of urine from renal pelvis to the bladder.

The double-J catheter is removed by means of cystoscopy under sedation. With a  90% success rate, the uretrocystoneotomy is an excellent, safe operation for restoring continuity in the upper urinary tract region.


Frequently asked questions:

Does a megaureter require an emergency operation? - Usually this is not an emergency. It is important to know if kidney function impairment is total, if the findings apply only to one side and if the ureter is infected. In the presence of these factors,  going into action quickly may be indicated.

Is antibiotic prophylaxis really necessary and, if so, how long does it last and is it harmful? - A low-dosage antibiotic prophylaxis may be necessary in connection with a widening of the efferent ureters, depending on the findings. Thanks to the low dosage, the children do not normally experience serious side effects or increased susceptibility to infections.

How do the operation and hospital stay typically proceed? - Hospital check in is on the day before the operation, if desired accompanied by a parent. of course. The operation will be preceded by an ultrasound examination, a thorough-going exploratory conversation with the chief physician and a discussion about the anesthesia. The operation is done under general anesthesia and takes about 2 hours. There will be regularly scheduled check- ups using ultrasound after the operation. Release from the hospital occurs between 5 – 7 days later. The double-J catheter that was emplaced during the operation will be removed after 6 weeks with a cystoscopy under sedation. An antibiotic prophylaxis continues up to that point.

What sort of complications arise and how do you follow up? - Complications are rare in general. Infections and problems with healing of the incision ought to be mentioned, but also special complications such as seepage of urine in the sutured area and a renewed narrowing of the ureter because of scar tissue build up. Continuous monitoring takes place in the course of our specialist’s consultation for evaluating how the kidney is developing and detecting possible sequelae.



Clinic and Polyclinic for Pediatric Surgery
Phone: 03834 - 86 7037
Fax: 03834 - 86 7038
Email: kinderchirurgie@uni-greifswald.de


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