Question Title: What is a primary mega ureter?

My son was born with grade 2 hydronephrosis of the left kidney. He has had several ultrasounds which show that the hydronephrosis is worsening. He also had a VCUG which showed he had a rear disorder, and that his ureter is enlarged. The urologist decided they would have to do surgery and move his ureter. At the last test he had, a laso something, it showed that his kidney is functioning normally and that he now has a primamry mega ureter. Now they canceled the surgery..What is a primary mega ureter and will this go away on its own?

Dear Melissa,
Several schemes for classifying the megaureter have been proposed. The definition of a megaureter is a ureter greater than 7mm in diameter although the radiographic appearance is usually striking. Ureteral tortuosity also may be present. Renal damage or parenchymal scarring or loss is variable depending on the back pressure atrophy or secondary infection. The easiest scheme to understand is to identify an obstructed megaureter from a non-obstructed megaureter, and a refluxing megaureter from a non-refluxing megaureter. The trouble for urologists is to consider the non-obstructed, non-refluxing megaureter. And lastly, there is the primary megaureter vs. the secondary megaureter. This terminology describes the difference between a lesion an individual was born with vs. a lesion that developed secondary to a bladder problem. In all cases, the ureter is significantly dilated.
The basic investigative procedures include an IVP and a VCUG. This usually defines, reflux vs. non-reflux, obstructive vs. non-obstructive and gives clue to whether the process is primary or secondary.
The theories to what is a megaureter or why they form consist of an adynamic segment of ureter with proximal dilation, to an obstructive process, usually ureteral valves, congenital ureteral stricture, ectopic ureter or a ureterocele. Secondary causes include urethral valves, neurogenic bladder, vascular compression, and fibrosis. What ever the cause, the important aspect of care consists of maintaining good kidney function. This may require surgery to reimplant and tailor the ureter if a significant obstruction is found, or reflux is not improving over time. A diuretic renogram and ultrasound are tests that can also help diagnose and monitor the kidneys growth and function over time. This may have been the test you are referring to when you said his kidney was functioning fine.
I would discuss your options with your doctor and if possible see a pediatric urologist. Surgery is a good option and is quite successful particularly if the ureter is tailored by a number of approaches. Although if the ureter is unobstructed and not refluxing, interval evaluation of the kidneys may also be appropriate.
This information is provided for general medical educational purposes only. Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition. More individualized care is available at the Henry Ford Hospital and its satellites (1 800 653-6568).

Sincerely,
HFHS M.D.-AK
*keyword:Megaureter