Nephroscopy is a method of endoscopic examination that allows to obtain complete visual information about the state of the calyx-pelvic system. With the help of nephroscopy, it is possible to diagnose inflammation, volumetric processes, developmental anomalies, the formation of adhesions, strictures and X-ray negative stones. Nephroscopy allows you to take a biopsy, perform medical procedures. There are retrograde nephroscopy, in which a nephroscope is inserted through the urethra, and antegrade or percutaneous nephroscopy, which is performed with ultrasound or X-ray control under local or general anesthesia using puncture, nephrostomy or through a small incision. Antegrade nephroscopy is more informative, therefore it is used more often retrograde.
Nephroscopy as a part of endoscopy has gone a long way. The first rigid endoscope was tested at the end of the XVIII century when examining the rectum, laparoscopy with a cystoscope with a light bulb was first used at the beginning of the twentieth century by a domestic surgeon D.Ott. Flexible nephroscope, which opened the era of nephroscopy, began to be used in practical urology and nephrology only after the development of fiber optics, at the end of the last century. The modern nephroscope is electronic, invented in the USA in 1984 by Boyle and Smith. The principle of its operation is based on the conversion of optical signals into electrical impulses. As a result of the use of high-precision lenses, digital video signal processing systems with megapixel CCD arrays, a high-precision, tenfold magnified high-quality image is obtained during nephroscopy.
Modern models of nephroscopes – LED or halogen – give the clearest picture of the studied area. The nephroscope itself is a channel through which medical instruments and fiber optics are delivered to the examined area, transmitting the image to the eyepiece lenses. The device can be used not only for diagnostic, but also for therapeutic purposes. Prices for nephroscopy vary depending on the specific clinic, the type of procedure and some other factors.
Nephroscopy is prescribed by a nephrologist or urologist, performed in three main directions: to assess the condition of the kidneys, to conduct differential diagnosis, for therapeutic and diagnostic purposes. Nephroscopy is used to differentiate nephrological, urological and gynecological pathology. Nephroscopy is used to assess the condition of the kidneys with confirmed inflammatory processes (pyelonephritis, hydronephrosis, diphtheria, tuberculosis), to diagnose the expansion of the renal pelvis – a symptom of impaired urine outflow in bacterial infections (the cause may be kidney stones, strictures and kidney tumors). In the process of nephroscopy, a visual assessment of the urinary tract mucosa is carried out, the number, localization, size, shape of pathological foci are determined. If necessary, an additional biopsy is performed.
Nephroscopy confirms the suspicion of the presence of congenital anomalies of the development of the urinary system, in the event of macrohematuria, it helps to exclude a tumor. In addition, nephroscopy is performed to diagnose calculus formation in the kidneys and urinary tract, to detect X-ray negative stones (urates, cystine and xanthine stones), as well as to simultaneously remove small-sized concretions using endoscopic instruments. Nephroscopy allows a biopsy to be performed if a tumor is suspected in the cup-pelvic system. Nephroscopy is used to diagnose and remove polyps, papillomas, benign neoplasms (electrocoagulation).
Contraindications to nephroscopy are inflammatory processes of the urinary tract in the acute stage (pyelonephritis, cystitis, urethritis). Antegrade nephroscopy is not performed with the “miniaturization” of the cup-pelvic system and ureter, established according to other studies. Retrograde nephroscopy is sometimes impossible due to the anatomical features of the ureteral anastomosis, narrowing of the ureter or urethra, “fixed” ureter after surgery and radiation therapy. With caution (for vital indications), nephroscopy is performed for coagulopathy (pathology caused by blood clotting disorders), obesity, and recently undergone abdominal surgery.
Methodology of conducting
Manipulation does not require special training. The area of the skin through which surgical intervention is planned is treated with antiseptics. The procedure is performed under local anesthesia or general anesthesia is used, suggesting abstinence in food 8 hours before the start of the study. Nephroscopy is performed in two ways: retrograde and antegrade.
Retrograde method of diagnostic is not usually used for therapeutic purposes, as an independent method is rarely used. This type of nephroscopy is performed using a flexible nephroscope through natural anatomical pathways. The patient is lying down during retrograde nephroscopy. A flexible tube of the device is inserted through the external opening of the urethra. Sometimes, before nephroscopy, dilators dilate the ureter. The nephroscope sequentially passes through the urethra, bladder, ureters and enters the pelvis of the kidney – the ultimate goal of the study. When conducting a flexible probe from the urethra to the pelvis, all anatomical features of the structure of the patient’s urinary system are taken into account.
If the patient suffers from chronic inflammatory processes of the urinary system, they may worsen due to mechanical irritation of the urinary tract during nephroscopy. If the patient has strictures of the urinary tract, then the lumen of the urethra, ureters may be sharply narrowed, which will exclude the possibility of the procedure, or require balloon dilation (expansion) of the affected area, dissection of the stricture. When passing bottlenecks, care should be taken to avoid damage to the urinary tract. In addition, the patient, even if the procedure is completely atraumatic and delicate, will experience a feeling of discomfort after nephroscopy due to the long path to the study area.
Antegrade method of diagnostic is performed with a rigid or flexible nephroscope (depending on the purpose of the manipulation) by creating a trans-lumbar access using a puncture with an endoscopic needle. A nephroscope can also be inserted through a nephrostomy after an earlier operation or directly at the time of performing a planned surgical intervention. Percutaneous puncture (puncture) during nephroscopy is performed using a needle 12 cm long and 1.2 mm in diameter with a special cannula. The correct position and fixation of the needle is controlled by ultrasound of the kidneys or X-ray. The choice of the dotted area depends on the scale of the nephroscopic examination, the volume of the enlarged pelvis, the localization of the pathological process. After X-ray confirmation of the correctness of the puncture, a special string and a connector tube are inserted into the cannula, together with which the puncture needle is removed.
At the next stage of nephroscopy, bougie tubes of various diameters are alternately placed in the cannula, gradually increasing the lumen of the channel to No. 26-30 according to the French catheter diameter scale (Charriere scale) or telescopic metal dilators are used. Extremely rarely, nephroscopy causes bleeding or perforation of the pelvis, cups. In the absence of complications during nephroscopy, a nephroscope is inserted through the tube, with the help of which a visual revision of the examined organ is carried out. Antegrade nephroscopy is especially effective for X-ray negative concretions and papillomatosis.
Antegrade nephroscopy can be a component of a complex examination (pyeloureteroscopy), the purpose of which is to examine the upper third of the ureter with therapeutic manipulations. In this case, there is a risk of loss of the fistula entrance due to insufficient length of the nephroscope. This happens when the patient is obese or because of the small size of the tub. This diagnostic can also be complicated by a tangent wound of the colon or pleura. In addition, during nephroscopy, you may encounter filled pelvises. In this case, the outflow of the contents of the pelvis through the working channel becomes the main indicator of the accuracy of nephroscopy.
This method of diagnostic is performed in a hospital setting. The course of the study is recorded in detail in the patient’s medical history. The conclusion on visual revision, therapeutic procedures, complications is given to the patient at discharge. Patients receive the results of the biopsy as soon as the histological conclusion is ready within 7 days after nephroscopy.