Nephroscopy

What is Nephroscopy?

Nephroscopy is an endoscopic diagnostic and therapeutic procedure to check the interior of the kidney -renal calyces and pelvis in particular. Renal calyces are the exit point of the urine that has been produced in the renal parenchyma. Renal pelvis is the spot of the kidney where the urine accumulates before transferring to the bladder through the ureter.  There are two different nephroscopic techniques, which differ a lot one from the other: Flexible Nephroscopy (with the use of flexible ureteroscope) and Percutaneous Nephroscopy (approaching the pyelocalyceal system percutaneously).

When is Nephroscopy performed?

Nephroscopy is performed mainly in renal lithiasis that does not respond to extracorporeal lithotripsy. Thus, when extracorporeal lithotripsy has failed or the size of the stone is such that extracorporeal lithotripsy is bound to fail, Nephroscopy can provide the solution for the stone fragmentation and removal. Nephroscopy is also used to diagnose and probably treat renal pyelocalyceal tumors and ureteropelvic junction (UPJ) obstructions.

What preparation is needed for Nephroscopy?

Nephroscopy is an invasive medical procedure, which is performed under anaesthesia in an organized operation theater. In every case, it is necessary to carry out full preoperative screening, detailed history-taking and anaesthesiology evaluation.  The Urologist and Anaesthesiologist must be well informed about the pharmacotherapy that the patient may potentially be taking, the history of previous severe diseases or chronic disorders and surgical procedures the patient has undergone in the past. The patient should always report any potentially occurring allergies, and /or pregnancy  if the woman is at reproductive age, for Nephroscopy is conducted with the use of X-rays.

Flexible Nephroscopy is easier and more convenient for the patient; it can be performed with either general or dorsal anaesthesia in a One-Day Clinic. In this case, the patient should be NPO (nothing to eat or drink) 8 hours prior Nephroscopy, remains at the clinic for a few hours and then goes back home but should not resume the usual everyday activities on the very same day of the procedure.

Percutaneous Nephroscopy combined with Nephrolithotripsy is not a minimal diagnostic test but a full surgical procedure of high severity.  Besides the preparation mentioned above, the patient should also give 2-3 blood units before the procedure, in case there is need for blood transfusion. The Anaesthesiologist may also order a cardiological or pulmonary preoperative evaluation.  Following Percutaneous Nephroscopy, the patient remains in hospital for a few days.

How is Nephroscopy performed?

Flexible Nephroscopy does not differ significantly from Ureteroscopy; the main difference is that the Urologist advances further down into the body reaching the renal pelvis and calyces. The patient is put under anaesthesia. The Urologist lubricates the patient’s urethra, inserts the ureteroscope into the bladder, passes through the ureteral orifices into the ureter advancing the nephroscope up to the kidney. According to the disease and type of ureteroscope used, the Urologist may use other instruments as well, such as biopsy forceps, stone removal forceps, laser fibers etc. At the end of the procedure, a self-retaining ureteral double-J catheter (DJ) is placed, which remains for a few days.

Percutaneous Nephroscopy is a different procedure. Following anaesthesia, a ureteral catheter is placed to the kidney that is to be examined. The patient lies prone (on stomach) and a specific contrast medium is infused through the ureteral catheter, so that the kidney shape appears with the use of X-rays. The Urologist places a needle to the patient’s lumbar region to advance further into the kidney. Various guide-wires are advanced through this needle creating a working channel 10ml in diameter starting from the skin surface advancing deep to the interior of the kidney –hence the technique called ‘percutaneous’. Then, the Urologist uses the nephroscope to examine thoroughly the interior of the kidney by passing through other instruments, such as biopsy forceps, stone removal forceps, lithotripsy probes or laser fibers, according to every therapeutic step conducted. Once the procedure completed, the nephroscope is removed and then a self-retaining ureteral catheter or nephrostomy tube or both are placed. These catheters remain for a few days, until the nephroscopy trauma is totally healed.

How are the results of Nephroscopy interpreted?

Nephroscopy is used for the fragmentation and removal of renal stones which cannot be achieved with other less invasive methods. It can also be applied for the therapeutic treatment of ureteropelvic junction (UPJ) obstructions and some tumors of the pyelocalyceal system. However, as Nephroscopy is an invasive procedure, there is the risk for minor to major complications.  In every case, there may be anaesthetic adverse events, always depending on the patient’s general health condition. There may occur postoperative fever, urinary tract infection (of low or high severity), trauma or penetration of the ureter or renal pelvis, hemorrhage from the kidney. Should hemorrhage from the kidney be highly severe, the Urologist is forced to interrupt the nephroscopic procedure before its completion.