What Is Renal Agenesis?

Renal hypoplasia means that the kidney volume is less than 50% of normal, but the nephron and differentiation are normal. Due to impaired blood supply during the embryonic period or other reasons, the raw kidney tissue has not fully developed, forming a small organ with a leaf-like surface, which maintains the original naive kidney state. The ureter is often stunted, the urinary function is abnormal, and the blood vessels, especially the arteries, are often small and hardened. Most patients are accompanied by hypertension. Such kidneys may be located in the normal position and are often associated with ectopic kidneys (there is a greater chance of ectopic kidney dysplasia). The position and function of the contralateral kidney are mostly normal, and there may be compensatory hypertrophy. The incidence of renal insufficiency is one in about 600 people.

Basic Information

English name

renal hypoplasia

Visiting department

Internal medicine

Common locations

kidney

Common causes

Embryo blood supply disorders or other causes

Common symptoms

Kidney dysplasia on both sides often dies soon after birth; unilateral dysplasia is often asymptomatic as without complications.

Clinical manifestations of renal hypoplasia

In the case of bilateral hypoplasia of the kidney, patients often die soon after birth. Unilateral hypoplasia is often undetected as it is without complications. Among the complications, hypertension is the most prominent. Clinically seen patients often develop hypertension in children or young people. In further examination, it was found that one side of the kidney was significantly reduced. This type of hypertension was often severe, the treatment effect was not good, and it developed rapidly. Visual impairment and even blindness occurred within 1 to 2 years.

Renal dysplasia

Imaging examination

(1) B-ultrasound can find that one or both kidneys are significantly smaller than normal ones.

(2) In the IVU, the affected kidney is reduced and the development is poor.

(3) Renal chart shows impaired renal function and delayed excretion.

(4) CT showed that the volume of the affected kidney was significantly reduced.

(5) Renal artery angiography The renal artery is small, and the renal vascular network is narrow and sparse.

2. Laboratory inspection

(1) Serum renin and angiotensin values may increase when renal hypoplasia is complicated by hypertension on one side.

(2) When bilateral renal insufficiency occurs, serum creatinine and urea nitrogen may increase.

Diagnosis of renal dysplasia

During pyelogram examination, the renal shadow was significantly reduced, the renal parenchyma was thin, and the renal pelvis was stunted, narrow, and absent, and rod-shaped. The kidney shape may be lobulated, or have other deformed changes and lose its normal contour. It can be combined with clinical manifestations and laboratory tests, such as hypertension, serum creatinine, and elevated urea nitrogen.

Renal hypoplasia treatment

Undeveloped kidneys are often complicated by ureteral bud branching. The kidneys are small but have histologically normal nephrons. Segmental renal dysplasia can lead to hypertension. In the case of contralateral renal function, the affected kidney is removed. Most of the blood pressure returns to normal after surgery, and vision also recovers shortly after surgery. The younger the age, the faster the postoperative recovery and the better the prognosis.