Patient: right pelvic ureteral junction stenosis and severe hydronephrosis in the right kidney; left pelvic ureteral junction stenosis and hydronephrosis Laboratory tests and right nephrostomy on October 29, 2005 showed: right pelvic ureteral junction stenosis; intravenous pyelogram on May 8, 2006 showed: mild hydronephrosis in the bilateral pelvis. The left pelvic ureteral junction was obstructed. On October 29, 2005, a percutaneous right nephrostomy was performed; on November 3, a right pelvic ureteroplasty was performed. On July 17, 2007, ultrasound showed a small amount of fluid in the left kidney and a limited amount of fluid in the right kidney. Why is there still fluid in the kidney after surgery? Does the fluid accumulation have any effect on the growth and development of the child and the future kidney function? What are the precautions? Is the surgery considered successful? The ultrasound is still suggestive of hydronephrosis after surgery. Here I would like to explain to you and some parents of children with hydronephrosis after pyeloplasty about the misunderstanding of this aspect: hydronephrosis caused by stenosis (or obstruction) of the ureteropelvic junction is the most common type of congenital hydronephrosis in pediatric patients. It is the most common type of congenital hydronephrosis in children. It is often caused by a progressive increase in hydronephrosis due to stenosis of the pelvic-ureteral junction, which is manifested by an ultrasound indicating an increase in the separation of the pelvis of the affected kidney, a diuretic (isotope) nephrogram showing mechanical obstruction of the affected kidney, a non-decreasing excretion curve after diuresis, and a decrease in the function of the affected kidney. Surgery mainly addresses the lesioned part, i.e., the narrowed part, with the aim of resolving the urinary drainage, stabilizing the degree of hydronephrosis, stabilizing the function of the affected kidney, and preventing further aggravation of hydronephrosis and progressive decline of kidney function. Of course, there may be some improvement of hydronephrosis after surgery, but it varies from person to person and depending on the degree of hydronephrosis before surgery, for example, if the hydronephrosis is severe before surgery, it may return to mild or moderate hydronephrosis after surgery. Of course, some children with mild hydronephrosis, but with abdominal pain and hematuria, also need surgery. These children will recover better after surgery, and may have mild hydronephrosis or even no hydronephrosis as indicated by postoperative ultrasound. If the ultrasound indicates that the degree of hydronephrosis is stable or improving after surgery, and the diuretic (isotope) nephrogram indicates that the kidney function has improved, the surgery should be considered a success. Of course, before puberty, children still have a growth and development process, therefore, after the postoperative review (ultrasound, isotope) indicates a good recovery, it is recommended to review the ultrasound at least once a year, especially for children with more serious hydronephrosis before surgery. Patient: Doctor: Hello! Thank you very much for taking time out of your busy schedule to give me a reply. I also want to ask, is my child’s ultrasound showing a small amount of fluid in the left kidney and a limited fluid in the right kidney mild or severe? Is this surgery a success? Will my child’s kidneys be stable in the future? I am always worried if he will have any sequelae when he becomes an adult, so I am going to take him for another ultrasound review this week. Thank you again for your trouble. Thank you! I don’t understand the meaning of “small amount of fluid in the left kidney and limited fluid in the right kidney”, but in general, if the fluid in the renal pelvis (dilated) has Generally speaking, if the hydronephrosis (dilatation) is reduced and the child has no abdominal pain, hematuria and other symptoms, it can be said that the operation is successful and the degree of hydronephrosis in both kidneys can be stabilized in the future, and there are usually no sequelae in adulthood. Patient: Doctor: Hello! Thank you for your reply. My child will have an ultrasound next week and then I will give you a look for me. Thank you very much! I wish you a happy Mid-Autumn Festival in advance! Happy family! Children’s Hospital Pediatric Urology: Thank you! Happy Mid-Autumn Festival to you and your family!