After the kidney and ureteral lithotripsy with ureteral double J tube left for a period of time and pulled out, why did the hydronephrosis not disappear or the hydronephrosis was more serious after a period of review? It may be due to the long-term obstruction of ureter (such as stone), the ureteral muscle layer compensates for hyperplasia at the initial stage, if the obstruction is not released in time, at the later stage, the ureter gradually fibrosis, function dissipates, peristalsis weakens, and cannot eliminate urine. Even if the double J-tube is removed, the impairment of ureteral function may lead to hydronephrosis. Therefore, urinary obstruction needs to be removed in a timely manner. The obstruction of the urinary tract leads to dilatation of the renal pelvis and calyces in which urine is retained, collectively referred to as hydronephrosis. Because of the accumulation of urine in the kidney, the pressure rises, causing enlargement of the renal pelvis and calyces and atrophy of the renal parenchyma. If the trapped urine becomes infected, it is called infected hydronephrosis. When the kidney tissue loses function due to infection and the renal pelvis is filled with pus, it is called hydronephrosis or septic kidney. The most important cause of hydronephrosis is obstruction at the ureteropelvic junction.
Etiology
The causes of hydronephrosis are congenital and acquired, as well as hydronephrosis caused by extra-urinary and lower urinary tract etiologies.
1.Congenital causes of obstruction
(1) Segmental non-functionality Due to segmental muscle deficiency, underdevelopment or anatomical disorder at the ureteropelvic junction or upper ureter, which affects the normal peristaltic movement of this segment of ureter, resulting in dynamic obstruction. If such a lesion occurs at the entrance of the ureteral bladder, a congenital giant ureter is formed, with the consequence of dilated kidney and ureter with hydrocele.
(2) Intrinsic ureteral stenosis Mostly occurs at the ureteropelvic junction, where the stenotic segment is usually 1 to 2 mm, but can be as long as 1 to 75 px, producing incomplete obstruction and secondary distortion. Excessive collagen fibers are seen around and among the muscle cells in the obstructed segment under electron microscopy, and over time the muscle cells are damaged, forming an inelastic stenotic segment dominated by collagen fibers that impede urine transmission and form hydronephrosis.
(3) Ureteral distortion, adhesion, girdle or flap peg structure This can be congenital or acquired, and often occurs at the junction of pelvic ureter, ureteral lumbar segment, and almost 2/3 of children and infants.
(4) Ectopic vascular compression Located in front of the pelvic ureteric junction, others include hoof-shaped kidney and obstructed kidney rotation during embryonic development.
(5) High ureteral opening Can be congenital or can be caused by asymptomatic pelvic dilatation due to peripelvic fibrosis or vesicoureteral reflux, resulting in relative upward migration of the pelvic-ureteral junction and inability to detect stenosis intraoperatively.
(6) Congenital ureteral ectasia, cysts, double ureter, etc.
2.Acquired obstruction
(1) Post-inflammatory or ischemic scarring leading to local fixation.
(2) Distortion of the ureter caused by vesicoureteral reflux, coupled with periureteral fibrosis, eventually leads to obstruction of the pelvic-ureteral junction or ureter.
(3) Neoplasms, polyps, and other neoplastic organisms of the renal pelvis and ureter, which may be primary or metastatic.
(4) Ectopic kidney.
(5) Stones and scar stenosis after trauma and trauma.
3.Obstruction caused by foreign etiology
It mainly includes lesions of arteries and veins; lesions of female reproductive system; tumors and inflammation of pelvis; lesions of gastrointestinal tract; retroperitoneal lesions (including retroperitoneal fibrosis, abscess, hemorrhage, tumors, etc.).
4.Obstruction caused by various diseases of the lower urinary tract
Such as prostatic hyperplasia, bladder neck contracture, urethral stricture, tumor, stone or even encopresis, etc., can also cause difficulty in emptying the upper urinary tract and form hydronephrosis.
Clinical manifestations
Patients are often asymptomatic for a long period of time and are not noticed until they develop an abdominal mass and a feeling of swelling in the lower back. The masses are mostly found unintentionally and are usually cystic in nature. Pain is usually mild or even completely painless. However, in cases of intermittent hydronephrosis (caused by ectopic vascular compression or renal prolapse) renal colic may develop, with severe pain radiating along the rib cage and ureteral travel. It is mostly accompanied by nausea, vomiting, abdominal distension, and scanty urination. The pain is usually relieved within a short time or a few hours, followed by the discharge of a large amount of urine.
On examination, an enlarged kidney may be palpated. In the case of massive hydronephrosis, the tension may not be very high.
If the hydronephrosis is complicated by infection, there is purulent urine and systemic toxic symptoms, such as chills, fever, headache and gastrointestinal disorders. Some patients have urinary tract infection as the initial symptom. Any patient who has poor treatment effect on urinary tract infection must pay attention to the presence of obstructive factors. In severe obstruction, inflammatory exudate cannot be excreted through the urine, and there are no white blood cells in the urine, but local pain and pressure are more pronounced in such cases.
Distended hydronephrosis is more susceptible to trauma and may rupture and bleed with minor injury. The flow of urine into the retroperitoneal space or peritoneal cavity causes severe reactions, including pain, tenderness, and systemic symptoms.
Examination
1.B-type ultrasonic examination
Ultrasound examination is simple, non-invasive and helps to make a clear diagnosis. It can also show the morphology of the remaining kidney tissues of the hydronephrosis kidney, and is also helpful to understand the condition of the urinary tract (renal pelvis, renal calyces and proximal ureter of obstruction). It has diagnostic value for fetal urinary tract obstruction.
2.Diuretic nephrography
Diuretic nephrogram is one of the most important tests for the diagnosis of hydronephrosis in recent years. It is useful for clarifying early lesions (with or without hydronephrosis), determining whether hydronephrosis requires surgical treatment and the state of renal function damage. It is especially valuable in the case of a mild single hydronephrosis, or a severe bilateral hydronephrosis on one side and a milder hydronephrosis on the other, and in the case of a milder hydronephrosis, whether it requires surgical treatment. Diuretic nephrogram can also be used to monitor the recovery of function after surgery (pyeloplasty).
3.Pelvic flow pressure measurement
It is also one of the valuable clinical tests in recent years, and its significance is similar to that of diuretic nephrography.
4.Urography and other tests
It is extremely important to estimate the functional status of the hydronephrosis kidney. It is extremely important for whether surgery is needed, the way of surgery and the chance of recovery of kidney function after surgery.
5.Imaging
If the remaining parenchymal thickness of the hydronephrosis kidney exceeds 37,5px, the kidney has the value of preservation.
4.Diagnosis
The diagnosis can be made according to the clinical manifestations and the site of obstruction, time, rapidity of occurrence, the presence of secondary infection and the nature of the primary lesion and examination.