Ureteral stricture is an abnormal narrowing of the ureteral canal, completely or partially disrupting its patency. As a result of impaired urine outflow from the kidney, pathology causes the development of various diseases: pyelonephritis, stone formation, hydronephrosis, chronic renal failure, accompanied by characteristic symptoms. Ureteral stricture is diagnosed according to the results of urography, ultrasound, MRI and CT of the kidneys. The treatment is operative, consists in excision and plastic surgery of the pathological site, installation of a stent.
ICD 10
N13.5 Inflection and stricture of the ureter without hydronephrosis
Meaning
Ureteral stricture can occur in different parts of the organ and have different lengths. Strictures are most often observed in the juxtavesical (transition of the ureter to the bladder) and pyeloureteral (transition of the pelvis to the ureter) areas. Pathology can be congenital and acquired. Congenital narrowing is detected in 0.6% of children, usually of a unilateral nature. The most common specific cause of acquired structures is tuberculosis. Diagnosis and treatment of the disease is carried out by specialists in the field of practical urology.
Causes
Congenital strictures of the ureter include cicatricial changes in the duct wall due to existing hereditary abnormalities, as well as its compression at the intersection with blood vessels (for example, an additional renal vessel). The causes of acquired stricture are:
- damage to the ureter as a result of operations and various instrumental procedures (ureteral stenting, ureteroscopy, etc.), injuries, bedsores from stones
- urinary infections (tuberculosis, gonorrhea) and inflammation of surrounding tissues (periureteritis)
- radiation damage.
In tuberculosis, multiple cicatricial constrictions form in areas that have undergone infiltration and ulceration. Radiation strictures are observed, as a rule, in his pelvic region and may be associated with radiation therapy for prostate, rectal and female genital cancers. Narrowing of the ureter after urological surgical interventions (ureterolithotomy, reconstruction of the pelvic-ureteral segment) can be observed in any part of the organ.
Pathogenesis
The normal anatomical and physiological constrictions of the ureter, if necessary, are able to expand significantly due to its elastic wall. In contrast, with stricture of the ureter, fibrous-sclerotic changes occur, affecting the submucosal, muscular and outer layers of the ureter wall. In turn, this leads to atrophy of part of the muscle elements and their replacement by scar tissue, hypertrophy of transverse muscle fibers, as well as changes in the innervation of the wall.
As a result, there is a persistent decrease in the diameter of the excretory duct in the stricture area, leading to a violation of the normal function of the ureter. In the areas above the stricture, due to the stagnation of urine, pressure on the ureter increases, its stretching, elongation and tortuosity is observed, the pelvis may expand and the development of hydronephrosis (ureterohydronephrosis) is possible.
Classification
The true stricture of the ureter by origin can be congenital and acquired. Narrowing of the ureter can be unilateral and bilateral, single and multiple, true (due to changes affecting the wall) and false (due to its compression from the outside).
Ureteral stricture symptoms
The clinical picture is caused by a violation of the free outflow of urine from the kidney and the development of various pathological processes against this background: hydronephrosis, pyelonephritis, urolithiasis; with bilateral lesions – chronic renal failure. Patients complain of these diseases: dull or acute pain in the lower back, turbid urine, increased body temperature, decreased urine, general intoxication, hypertension, nausea, vomiting, muscle cramps, etc.
Diagnostics
The diagnosis of ureteral stricture is established by a urologist based on the results of kidney ultrasound, vascular ultrasound, radiopaque examination, kidney CT and MRI. Conducting three-dimensional ultrasound angiography with diuretic load allows you to simultaneously see the expanded ureter above the stricture and assess the renal vessels.
X-ray contrast urography (excretory, infusion, retrograde) makes it possible to visualize kidney tissue and urinary tract, to determine the narrowing of the ureters, the extent of strictures, to assess the decrease in the excretory ability of the kidneys. In difficult cases, CT or MRI is used, additionally detecting diseases of adjacent organs and tissues that affect the kidneys and ureters.
Ureteral stricture treatment
Pathology is an absolute indication for surgical treatment, the choice of which is determined by the structural and functional state of the ureters and kidneys, the extent and level of stenosis. With minimal damage to the renal tissue, various reconstructive operations of the corresponding part of the ureter are performed, the purpose of which is to eliminate the narrowing of the duct, to restore the free outflow of urine from the cup–pelvic apparatus of the kidneys.
With serious lesions of the upper urinary tract and the development of renal insufficiency, the first stage of surgical treatment is open or puncture nephrostomy. Sometimes endoureteral dissection of adhesions is performed with the installation of a stent, augmentation and balloon dilation of the narrowed ureter, but they do not give a lasting effect and can lead to even greater complications. Basic operations:
- Ureterolysis. It involves surgical removal of fibrous tissue, squeezing and deforming the ureters from the outside, for greater efficiency, combined with resection of the narrowed area and other reconstructive operations.
- Ureteroureteroanastamosis. An oblique resection of the ureteral stricture is performed and its ends are stitched on a specially inserted catheter; with pyeloureteroanastomosis – after a longitudinal dissection of the ureteral canal (including its healthy tissues, stricture and part of the pelvis), the walls are stitched in a transverse direction (side to side).
- Direct ureterocystoanastamosis. It is performed in the presence of a single stricture in the juxtaposed mouth, after cutting off which, the intact end of the ureter is sewn into the wall of the bladder.
- Indirect ureterocystoanastamosis. The modified Boari operation is used for strictures of the ureter of a large extent, allows the formation of a remote part of the ureter from the flap of the bladder. With stricture in the pelvic-ureteral segment, a flap is created from the lateral wall of the renal pelvis to replace part of the ureter at the site of narrowing (Foley operation).
- Intestinal ureteral plastic surgery. With extensive strictures, partial or complete intestinal plasty of the ureter is performed, in which its narrowed part is replaced with an autograft formed from the tissue of the intestinal wall. Intestinal plastic surgery is a rather large operation in terms of volume and duration, which is contraindicated in seriously ill and weakened patients in the acute post-traumatic period.
With ureteral strictures complicated by severe lesions of the renal tissue (polycavernous tuberculosis, hydronephrosis, pionephrosis, kidney wrinkling), nephroureterectomy (removal of the kidney and ureter) is performed.
Prognosis and prevention
To achieve a favorable result, reconstructive plastic surgery should be performed at an early stage before the development of chronic renal failure. Postoperative rehabilitation plays an important role after reconstructive plastic surgery. Possible complications of operations for ureteral strictures are the failure of anastomoses, leading to retroperitoneal urinary congestion, the development of urinary phlegmon, peritonitis. Prevention consists in the prevention and timely treatment of diseases that can cause this pathology.
