Ureteral bulge is a cyst that forms when the ureter is covered by mucous membrane at the point where it enters the bladder. Usually there is a very small hole at the tip of this cyst, and although urine can slowly leak out, the obstruction is severe enough to cause ipsilateral urinary dilatation (ureteral effusion, giant ureter, or even hydronephrosis). This malformation is more common in girls (male:female = 1:4), more common on the left side, and also affects both sides (10%). The majority of ureteral bulges (80%) originate in the upper half of the duplicated kidney. The discovery of symptoms without a heavy kidney (single system) may be delayed in the adult age group. 1. Symptoms Today many of them are detected by prenatal ultrasound (about 30% or more). Ureteral dilatation can lead to ipsilateral urinary obstruction, resulting in hydronephrosis and giant ureter. Some prolapsed ureters can lead to urinary tamponade. Once the urinary system is not normal, urinary tract infections, even stones, and sepsis can occur. The child may present with urinary urgency, incontinence, high fever, vomiting, or difficulty urinating. Physical examination can sometimes reveal a bulging prolapsed ureter in girls. The bladder may be palpated for urine flow, or even pressure from hydronephrosis or a renal abscess. In some cases, this can lead to urinary incontinence or urgency. The purpose of these tests is to establish whether there are duplicated kidneys, whether the urinary system is obstructed, and how much kidney function there is on each side. Only when these facts are clear, together with the clinical symptoms (frequency of infection), can we balance the pros and cons of various factors and make the right treatment plan. (1) Renal ultrasound can require a trained and experienced physician to show many malformations, ureteral bulges, duplicated kidneys, duplicated ureters, etc. …… without any radiation. (2) Magnetic Resonance Unit (MRU) is becoming more common and can show very clear anatomy with 3D imaging. With the addition of a control agent (Gadolinium), it is also possible to calculate the renal excretory function. The advantage of this test is that there is no radiation. The disadvantage is that it requires the child to lie still for 20 minutes. In many cases, sedation or light general anesthesia is required. (3) Nuclear scan (MAG3) Not only does it allow further identification of duplicate kidneys, but it also allows detailed determination of the function of each kidney. This is important when deciding whether the upper half of the kidney that is functioning poorly should be removed. The radiation is actually lower than an X-ray. (4) CT scan + control agent. The procedure is quick, but there is greater radiation. Both intravenous pyelogram (intravenous pyelogram) and voiding cystouretherogram (voiding cystouretherogram) can show a filling defect. In addition to ultrasound, at least one of MRI or nuclear scan should be added to determine renal function. 3, treatment methods prenatal detection of ureteral dilatation of the baby after birth, should immediately start taking prophylactic antibiotics to reduce urinary tract infections. Difficulty in urination should be followed by immediate catheterization. Among pediatric urologists, there is still a debate between superior and inferior access methods of treatment (J Pediatr Urol. 2015 Feb;11(1):29.e1-6.). Because of this relatively rare malformation, it is more difficult to do prospective double-blind comparative studies of treatment outcomes. The superior approach advocates a one-time resection of the upper half of the kidney as well as its ureter, or an end-to-end uretero-ureteral anastomosis, which is a larger procedure. The inferior approach advocates incision of the ureteral bulge followed by management of possible vesicoureteral reflux. The most serious problem of ureteral dilatation is urinary obstruction. The ureteral bulge can be incised through a non-invasive cystoscope with a cold knife, laser, or electrodesiccation, which immediately allows urinary drainage and greatly reduces the chance of infection (this ureteral bulge is traditionally an open bladder procedure). The child can be discharged immediately after surgery. This cystoscopic procedure is sometimes not easy to do, and the removal of the ureteral bulge with a minimally invasive method using the air bladder is clear and very safe (unpublished). About half of the children will have some postoperative vesicoureteral reflux. Much of this reflux will heal spontaneously. This practice is more popular in Australia and Hong Kong. Those children who still have an infection can be treated further on an individual basis, possibly when the child is older, on an elective basis. If the upper half of the kidney in question still has some function, then ureteral reimplantation may be considered. If there is little or no function left, then a hemianephrectomy may be considered.