Renal and ureteral duplication anomalies

　　At the sixth week of human embryo development, the distal end of the mesonephric duct (Wolffian duct) extends into the cloaca and forms a small blind duct called the ureteric bud. The ureteric bud grows rapidly, with its apex surrounded by primitive renal tissue, resembling a broad bean. The ureteric bud develops into the renal pelvis, branching into calyces, further branching into minor calyces, and ultimately into collecting tubules. If branching occurs too early, it can lead to duplicated ureteral anomalies. The height and number of branches can determine whether the anomaly is complete or incomplete, single or multiple. Duplicated ureters often accompany duplicated kidneys. Most duplicated kidneys are fused into one, with a common capsule, a shallow groove on the surface, but the renal pelvis, ureters, and blood vessels are all separate. It is very rare for duplicated kidneys to be completely separate.

　　1. Pyelonephritis:Pyelonephritis is an infectious inflammatory disease of the renal pelvis and calyces, renal tubules, and interstitium caused by direct invasion of various pathogenic microorganisms. Pyelonephritis can be divided into acute and chronic stages, and chronic pyelonephritis is an important cause of chronic renal insufficiency. The most common pathogenic bacteria causing pyelonephritis are Escherichia coli, followed by Klebsiella pneumoniae, Proteus, Streptococcus faecalis, and others.

　　2. Kidney stones:Refers to the formation of kidney stones in the renal pelvis, calyces, and the junction between the renal pelvis and ureter. Most are located in the renal pelvis and calyces, while renal parenchymal stones are rare. X-ray films show single or multiple round, oval, or obtuse triangular dense shadows in the renal area, with high and even density, and smooth edges, but some may be uneven and look like mulberries.

　　3. Renal tumors:Renal tumors are mostly malignant. It was previously commonly believed that 'any renal tumor should be considered malignant before histological examination.' With the widespread application of imaging diagnoses such as ultrasound, CT, and MRI, the detection rate of benign tumors has increased, and this concept has changed. Among the 770 renal parenchymal tumors at the Cancer Hospital of the Chinese Academy of Medical Sciences, 48 were benign tumors, accounting for 6.29%. In addition to primary malignant renal tumors, there are secondary renal tumors from metastases of malignant tumors in other parts of the body, with lung cancer renal metastasis being the most common, followed by malignant lymphoma, testis, ovary. Malignant tumors of the large and small intestines can also have renal metastases. Such patients may not have been treated due to widespread metastasis before death, and most are only found during post-mortem examination.

　　4. Hydronephrosis:Due to the obstruction of urine excretion from the kidneys, accumulation leads to urine retention and increased intrarenal pressure, resulting in the gradual expansion of the renal pelvis and calyces, atrophy and destruction of renal parenchyma, collectively known as hydronephrosis.

　　Ureteropelvic imaging is particularly important. When retrograde ureteropelvic imaging can be performed, it is recommended to use it due to its clear imaging. If the catheter is restricted and the examination is not satisfactory, switch to intravenous ureteropelvic imaging. If the upper kidney cannot be visualized due to renal function issues and there is a high suspicion, then double contrast imaging and delayed film-taking methods can be used to ensure clear imaging for accurate diagnosis.

　　1. The preventive method of drinking plenty of water is to increase the intake of water, which can dilute urine and prevent the accumulation of high concentrations of salts and minerals into kidney stones. The appropriate amount of water to drink is to produce 2 liters of urine per day, which is sufficient. However, if you work all day under the scorching sun, you need to drink 2 gallons of water.

　　2. Supplement fiber and eat bran.

　　3. Timely check-ups of the kidneys, regular lifestyle, and avoid strenuous activities.

　　Urological examination and intravenous pyelography:

　　1. Laboratory Tests

　　Urine routine examination can show red blood cells, white blood cells, or crystals, and the urine pH is often acidic in patients with oxalate and uric acid stones; phosphorus stones are often alkaline. When there is infection, there are more pus cells in the urine, and when the infection is severe, the total white blood cell count and neutrophils can be elevated in blood routine examination.

　　2. Radiographic Examination

　　X-ray examination is an important method for diagnosing renal and ureteral stones, with more than 95% of urinary tract stones visible on X-ray films. Assisted by excretory or retrograde pyeloureterography, it can determine the location of the stones, whether there is obstruction and the degree of obstruction, whether the contralateral renal function is good, distinguish calcium shadows from outside the urinary tract, exclude other lesions in the upper urinary tract, determine the treatment plan, and compare the location, size, and number of stones after treatment, which is of great value.

　　3. Other Examinations

　　Ultrasound can detect dense light spots or light clusters at the stone location, and a liquid level segment can be detected when there is hydronephrosis. Isotope renal imaging can show an obstructive pattern on the affected side of the urinary tract.

　　In addition to conventional treatment, attention should also be paid to related matters in diet for renal and ureteral duplication anomalies. Patients with renal and ureteral duplication anomalies should pay attention to a light diet, drink more water appropriately, and exercise.

　　1. In the case of the first condition mentioned above, no special treatment is required.

　　2. In the case of the second condition, due to obvious complications, an upper renal segment (renal segment with complications) resection is performed. This type of surgery is much easier to handle than general partial nephrectomy due to its own blood supply.

　　3. In the case of the third condition, if there are complications, a nephrectomy of the renal segment at the waist is performed as described above; if there are no complications, and it is only a urinary incontinence issue, then surgery is performed in the lower abdomen, and the abnormal ureter can also be relocated to the bladder.