(Harntraktobstruktion)
Obstructive uropathy is an anatomically-organic or functional disability of the normal urine flow, which sometimes leads to renal dysfunction (obstructive uropathy). Symptoms may include – rare in chronic obstruction – include radiating from Th11- and T12 dermatome pain and abnormal micturition (eg difficulty in urination, anuria, nocturia and / or polyuria.). Depending on the amount of obstruction of the diagnosis is made based on the results of bladder catheterization, Zystourethroskopie and imaging techniques (for. Example, ultrasound, CT, pyelography). The treatment consists depending on the cause in immediate relief bladder, instrumentation, operation (z. B. endoscopy or lithotripsy), hormonal therapy (n. D. Ed .: in prostate cancer) or a combination of these.
The prevalence of obstructive uropathy, depending on the cause, is in the range from five to 10,000 to five to 1000. The age distribution is 2-gipflig. In childhood, it is mainly congenital anomalies of the urinary tract. The frequency then decreases until after age 60. After that, the incidence (BPH) and prostate cancer rises again, mainly in men due to the increase of benign prostatic hyperplasia. Overall, obstructive uropathy is responsible for about 4% of cases of chronic kidney failure. Hydronephrosis is found postmortem in 2-4% of patients.
Obstructive uropathy is an anatomically-organic or functional disability of the normal urine flow, which sometimes leads to renal dysfunction (obstructive uropathy). Symptoms may include – rare in chronic obstruction – include radiating from Th11- and T12 dermatome pain and abnormal micturition (eg difficulty in urination, anuria, nocturia and / or polyuria.). Depending on the amount of obstruction of the diagnosis is made based on the results of bladder catheterization, Zystourethroskopie and imaging techniques (for. Example, ultrasound, CT, pyelography). The treatment consists depending on the cause in immediate relief bladder, instrumentation, operation (z. B. endoscopy or lithotripsy), hormonal therapy (n. D. Ed .: in prostate cancer) or a combination of these. The prevalence of obstructive uropathy, depending on the cause, is in the range from five to 10,000 to five to 1000. The age distribution is 2-gipflig. In childhood, it is mainly congenital anomalies of the urinary tract. The frequency then decreases until after age 60. After that, the incidence (BPH) and prostate cancer rises again, mainly in men due to the increase of benign prostatic hyperplasia. Overall, obstructive uropathy is responsible for about 4% of cases of chronic kidney failure. Hydronephrosis is found postmortem in 2-4% of patients. Etiology Many changes can cause obstructive uropathy. It can be acute or chronic, partial or complete, one or both sides occur (see table: causes of obstructive uropathy). The most common causes are different, depending on age: Children: Anatomical abnormalities (including rear urethral valves or stricture and stenosis at the ureterovesical or uretropelvinen mouth) Young adults: stone formation Older Adults: BPH or prostate cancer, retroperitoneal or pelvic tumors (including metastatic cancer) and stone formation A obstruction may of the renal tubules (cylinders, crystals) to occur to the external meatus of the urethra at each site. Proximal to the obstruction can, to the effects of increased intraluminal pressure, urinary retention, UTI or stone formation (which can also worsen and may lead to an obstruction) count. The obstruction is more common in men (usually due to BPH), but acquired or congenital urethral strictures and Meatusstenosen come in both men and women. In women, a urethral obstruction can be caused by a primary or metastatic tumor or as a result of stricture formation following irradiation therapy, urological surgery or manipulation (repeated dilatations). Causes of obstructive uropathy place examples anatomical abnormalities bladder contracture of the bladder neck stricture, urethral polyp ureter Anomalous front or rear flap diverticulum injury (z. B. due to a pelvic fracture or straddle injury) meatal stenosis Paraphimosis phimosis stricture Compression by extrinsic masses or processes Female Reproductive abscess Gartner cyst pregnancy tubo-ovarian abscess tumor (cervical, ovarian) uterine prolapse gastrointestinal tract Appendixabszess Crohn’s disease (about inflammation or abscess) cyst diverticulitis tumor genitourinary tract Benign prostatic hyperplasia fibrotic chronic prostatitis Periurethralabszess prostate cancer blood vessels Aberrant blood vessels aneurysm Puerperal thrombophlebitis ovarian venous Retrokavaler ureter retroperitoneal fibrosis (idiopathic, surgical, drug-induced) hematoma lymphocele lymphoma Metastasis (eg. Example, breast, prostate, testicular) pelvic lipomatosis sarcoidosis TB Functional disorders bladder neck of the bladder dysfunction medication-induced bladder dysfunction (eg., By anticholinergics) dysfunction of the nervous system neurogenic bladder ureter caused dysfunction of reteropelvinen or ureterovesical mouth Mechanical obstruction of the lumen of the urinary tract renal pelvis or ureter clot Fungusbal l Repelled renal papillae urolithiasis Urotheliales carcinoma Renal tubule uric acid crystals Pathophysiology pathological findings consist of dilation of the collecting ducts and distal tubules and chronic tubular atrophy with little glomerular damage. Dilation lasts 3 days from the onset of obstructive uropathy to develop. Prior to the collection system reacts hardly and seems to extend only a low probability. Obstructive uropathy without dilation may be caused by fibrosis or retroperitoneal tumors, which include the collection system, when the obstructive uropathy only slightly and the kidney function is not damaged, and in the presence of an intra-renal pelvis. Obstructive nephropathy as obstructive nephropathy is referred to renal dysfunction (renal insufficiency, renal failure or tubulointerstitiale damage) caused by a urinary tract obstruction. Among many factors are part of the mechanism of increased intratubulärer pressure, local ischemia, and often HWI. If the obstruction is bilateral, nephropathy may lead to renal failure. Renal failure rarely occurs when the obstruction is unilateral. Sympathetic mediated vascular or ureteral spasm may affect the functioning kidneys. The time and the speed at which irreversible damage to the kidney (or renal) develops after an obstruction, depends on so many factors that a prediction is difficult. To prevent irreversible damage, obstruction of the urinary tract should be diagnosed and treated as soon as possible. Symptoms and signs The symptoms and signs of obstructive uropathy vary with the location, the extent and speed of their formation. Pain is often when the obstruction acute bladder, the collection system (i. E. Ureter, renal pelvis and renal calyces) or aufdehnt the kidney capsule. Congestion in the ureter or renal pelvis cause flank pain or flank pressure. An obstruction in the lower ureter, however, causes ipsilateral pain radiating to the ipsilateral testis or labium. The renal and Harnleiterschmerz normally runs along T11 to T12. In an acute complete Harnleiterverschluss (eg., By ureteral stones) can cause severe pain with nausea and vomiting. A strong urine (for. Example, by consumption of alcoholic or caffeinated beverages, or an osmotic diuresis by i.v. contrast media) causes a dilation and pain when the urine output is greater than the flow rate through the obstructed site in the urinary tract. Typically, the pain associated with only partially or slowly developing obstruction are slightly or completely missing (z. B. congenital renal outlet obstruction or renal pelvic tumor). Hydronephrosis can cause a palpable mass in the flank occasionally, especially with solid hydronephrosis in infancy and childhood. The urine output does not decrease in unilateral obstruction unless it occurs in a functional kidney (single kidney). An absolute anuria occurs at a complete obstruction at the level of the bladder or urethra. A partial obstruction at this level causes difficulty in urination or changes in urinary stream. In a partial obstruction of urinary excretion is often increased normal and rarely. Increased urine excretion in polyuria and nocturia occurs when the nephropathy draws a disorder of renal concentration and sodium reabsorption by itself. A long-standing nephropathy may also lead to high blood pressure. An additional infections, which exacerbates the obstruction, may dysuria, pyuria, urinary urgency and frequent urination and pain in the corresponding kidney or Harnleiterhöhe, pressure in costovertebral angle, fever and occasionally also lead to sepsis. Diagnostic urinalysis and serum electrolytes, urea nitrogen and creatinine urinary catheterization or by ultrasound at the bedside valued urine volume after emptying, sometimes followed by Zystourethroskopie and voiding cystourethrography on suspicion of urethral obstruction Imaging techniques for suspected ureteral or more proximal obstruction or hydronephrosis without apparent obstruction. Obstructive uropathy should be considered in patients with any of the following into consideration: reduced or lack of urination Unexplained renal pain suggestive of swelling in the urinary tract A pattern of oliguria or anuria alternating with polyuria The history may on symptoms of BPH, of past cancer indicate (z. B. prostate, kidney, ureter, bladder, gynecological, colorectal cancer), or urolithiasis. Because an early elimination of the obstruction usually achieved the best results, the diagnosis should be made as soon as possible. The investigations should urinalysis and blood chemistry (serum electrolytes, urea and creatinine). Further investigations arise depending on the symptoms and the suspected cause of obstruction. A Harninfekt in connection with a urinary obstruction requires immediate investigation and treatment. When asymptomatic patients with long-standing obstructive uropathy urine findings may be normal or may only a few cylinders, leukocytes or erythrocytes. In a patient with acute renal failure and normal urinalysis, should be considered a bilateral obstructive nephropathy. If the serum chemistry indicates a renal insufficiency, the obstruction is likely bilaterally and serious or completely. Other findings of a bilateral obstruction with nephropathy hyperkalemia can count. The Hyperkalemia may result from a type 1 tubular acidosis due to the decreased hydrogen ions and potassium secretion by distal segments of the nephron. The evaluation of suspected urethral obstruction When the urine is reduced or if an expanded bladder or suprapubic pain are present, a urinary catheterization should be performed. Posed by catheterisation a normal urine flow, or if the catheter is difficult to place, there is a near urethral obstruction (z. B. prostatic hyperplasia, urethral valves or Urethralstriktur). Can not be palpated a bubble expansion and is the inability to micturition before, an obstruction can be confirmed by ultrasonography at the bedside, which determines the bubble volume after micturition; Volume> 50 ml (slightly higher in older adults) indicates an obstruction. In patients with such findings, Zystourethroskopie and carried out a voiding cystourethrography in children generally should (Imaging techniques for the urogenital tract.). By a voiding cystourethrography (VCUG) almost all bladder neck – be detected and urethral obstruction and a vesicoureteral reflux by the corresponding representation of the anatomy and the volume of the residual urine after urination (residual urine volume). It is performed most often in children to diagnose anatomical or congenital anomalies. However, it can take place in adults when a urethral stricture is suspected. If no signs of urethral obstruction are present or if Zystourethroskopie and voiding cystourethrography show obstruction, this is probably in the ureters or the Nähe.Beurteilung the ureter or more proximal obstruction Imaging tests are performed in patients to determine the presence and location of the obstruction to recognize. The selection and sequence of the tests depend on the clinical scenario. In most patients without urethral changes the abdominal ultrasonography is the initial investigation of choice, as this potential allergic and toxic complications can be avoided by contrast, while an accompanying renal atrophy can be detected. An ultrasound is performed to detect hydronephrosis. In 25% of cases can be expected with a false-positive result if only minimum criteria (imaging of the pelvicalyceal system) will be considered in the diagnosis. The absence of hydronephrosis (and false negative results) can be determined if the obstruction still early (in the early days) or is weak, or when a retroperitoneal fibrosis or tumor enclose the collection system and prevent dilatation of the ureter. A CT is reliable to diagnose obstructive nephropathy and is used when the obstruction can not be shown by ultrasound or by intravenous urography. A helical CT without contrast is the procedure of choice for suspected kidney stones. A CT urography with and without contrast agent is especially useful in the evaluation of hematuria. A thinning of the renal parenchyma suggests a more chronic obstruction. The color duplex sonography kanne show a unilateral obstructive uropathy in the first days of acute obstruction before the pyelocaliceal system expands by an increased resistance index is detected as expression of an increased renal vascular resistance in the affected kidney. With obesity and bilateral obstruction that can not be distinguished from intrinsic renal diseases, this study promises less success. Excretory urography (Kontrasturographie, intravenous pyelogram [IVP], intravenous urography [IPPC]) has been largely replaced by CT or MRI scans (with or without contrast) (n. D. Talk .: only in the US). However, if the CT the extent of obstructive uropathy can not be determined or if the acute obstructive uropathy could be caused by stones, papillary necrosis or clots, which urography or retrograde pyelography is indicated (n. D. Talk .: only in the US) , Antegrade or retrograde pyelography is preferred in studies involving patients with a vascular Azotemie administration of contrast agents. The retrograde investigations are made through the cystoscope, while at the antegrade pyelography, a catheter must be percutaneously inserted into the renal pelvis. Patients with intermittent obstruction should be investigated if they have complaints because otherwise the obstruction could not be detected. Radionukliduntersuchungen put at least require some kidney function, but can reveal an obstruction without the use of contrast agents. In a non-functioning kidney scintigraphy can bring the blood circulation and the still functioning parenchyma for display. However, since no specific sites with obstruction can be detected by this test, it is used mainly for detecting an obstruction hydronephrosis without apparent in connection with the Belastungsisotopennephrographie. An MRI may be used if the avoidance of ionizing radiation is important (eg. As in young children or pregnant women). However, it is less accurate than ultrasound or CT, especially in the detection of Steinen.Beurteilung of hydronephrosis without apparent obstruction An investigation may be necessary to determine whether back or flank pain in patients suffering from hydronephrosis, due to an obstruction caused, even if no obvious obstruction was found by other imaging tests may also be performed to determine an otherwise unrecognized obstruction in patients with accidentally detected hydronephrosis. In a diuretic renography a loop diuretic (e.g., furosemide example, 0.5 mg / kg i.v.) is added prior to the radionuclide. The patient must have sufficient kidney function to respond to the diuretic. If an obstruction is present, is the elimination of the radionuclide (or contrast medium) from the time when the tracer in the renal pelvis appears to a half-life of> 20 min (normal is <15 min) reduced. In rare cases, when negative or inconclusive Urogram a symptomatic patients Pressure-flow (perfusion) is carried out study by a catheter percutaneously introduced into the dilated renal pelvis and renal pelvis at 10 ml / min is perfused. The patient is in a lateral position. In the presence of obstructive uropathy in spite of the increase in urine flow, the elimination of the radionuclide is delayed during scintigraphy, enhances the dilation of the renal pelvis system and the renal pelvis pressure increased to> 20 mmHg. The renogram or perfusion study are considered positive when the patient indicates the same pain as before. If the perfusion study is negative, the pain probably will not cause renal are. False-positive and false-negative results occur in both tests. Prognosis Most obstruction can be solved, but a delay of therapy leads to irreversible kidney damage. How long it takes to get a nephropathy developed and how reversible these is depends on the underlying pathological change, the presence or absence of UTI and the extent and duration of the obstruction from. In general, acute renal failure through a ureter (with regaining normal renal function) is reversible. In a chronic progressive obstructive uropathy may lead to a partial or total irreversible renal dysfunction. The prognosis is even worse when the UTI is left untreated. Therapy lifting of the obstruction The treatment consists in the elimination of the obstruction due to surgery, Instrumentation (endoscopy, lithotripsy) or drug therapy (eg. B. hormone therapy for prostate cancer). An immediate derivation of hydronephrosis is indicated if renal function is damaged, persists a urinary tract infection or be uncontrollable, persistent pain. Immediate dehydration is displayed when the obstruction is accompanied by an infection. In the lower urinary tract obstruction in a catheter treatment or proximal drainage is required. In special cases, the placement of a ureteral catheter for acute or long-term drainage is required. In severe obstructive uropathy, UTI or stone a temporary drainage via percutaneous nephrostomy may be necessary. An intensive treatment is mandatory at UTI and renal failure. In the case of hydronephrosis Proven without obstruction an operation (. D Red n.: Positive ING proves obstruction) should be considered, if the patient is in pain and a positive stress ING present. However, no therapy in asymptomatic patients with a negative or a positive Diureserenogramm Diureserenogramm but normal renal function indexes. Conclusion Common causes in children are congenital malformations, in young adults and stone formation in older men benign prostate enlargement. The consequences renal failure and infection may include. Pain is often when organs in the upper urogenital tract (often felt in the flank), or the bladder (often felt in the testes, the suprapubic area or the labia) be extended acute. Obstructive uropathy is suspected when patients have unexplained kidney failure, decreased urine output, pain which can indicate an obstruction, or oliguria or anuria alternating with polyuria. In a suspected obstruction in the lower GIT, then a catheterization of the bladder, then a Zystourethroskopie and in selected cases a voiding cystourethrography should be considered. Is an obstruction in the upper GIT suspected imaging studies are performed (z. B. abdominal ultrasonography, CT, duplex Doppler ultrasonography, intravenous pyelogram, MRI). The obstruction must be corrected immediately, especially when patients have a UTI.