10% of bladder tumors end up progressing to tumors of the ureter and renal pelvis
Approximately 10% of patients with bladder cancer develop cancer of the ureter and renal pelvis over time. Dr. Carlos Nuñez, head of the Department of Urology at MD Anderson Cancer Center Madrid, explains that “the kidney has two parts: the cortex and the renal medulla, the so-called renal parenchyma, whose function is the production of urine, and the ureter and the renal pelvis, whose function is excretory”. Of all kidney tumors, 7% occur in the renal pelvis and ureter. In addition, explains the specialist, “between 75% and 80% of patients with an infiltrating or high-grade tumor will develop new tumors in the same ureter or contralateral ureter”.
Given this situation, the usual surgical technique in this type of patient is nephroureteroctomy, that is, the removal or complete extirpation of the kidney and ureter to the bladder, with the problem involved in the removal of the kidney in a patient due to subsequent complications: dialysis or transplant. "To live, a person must have at least 60% of a kidney," emphasizes Dr. Carlos Nuñez. Therefore, conservative surgery is an option with many advantages for patients with non-infiltrating or low-grade tumors, that is, those patients with more superficial tumors that do not affect the wall of the ureter or the renal pelvis.
In these cases, a technique called a ureteroscopy may be performed, which involves the use of a very fine tube that is inserted through the urethra (the penis in men and the urinary meatus in women) to reach the bladder and subsequently, the ureter and the renal pelvis through the mouth of the ureter. "It is an endourological technique, we use the normal conduit to ascend and treat the tumor growing inside," explains Dr. Nuñez. Once the tumor is located, Holmio laser is used to proceed with the photovaporization, so called because, as Dr. Nuñez points out, "it vaporizes the tissue, it fulminates it, turning it into vapor and thus makes it disappear".
In fact, due to this characteristic of photovaporization, in many cases the diagnosis and surgical treatment of the tumor are done in the same session. "When we suspect a cancer of the ureter or renal pelvis, we perform a first ureteroscopy to take a sample of the tumor, perform a biopsy and assess the type of tumor," explains Dr. Nuñez, who goes on to explain that "if the patient is a candidate, that is, he/she has a non-infiltrating or low-grade tumor, we try not to remove the kidney and the ureter and treat the tumor with this photovaporization laser ". Regarding the results of tumor monitoring, Dr. Nuñez explains that they are similar to those obtained with nephroureteroctomy if candidate patients are well selected.
In fact, the specialist emphasizes, "laser photovaporization is effective in 75% of cases, that is to say, it is possible to eliminate by means of an endourological approach 75% of these tumors of the upper urinary tract, some of them of substantial size". In the remaining 25%, a second ureteroscopy is used or, in some cases, laparoscopic surgery.
Another advantage of this technique is time. While a patient undergoing an extirpation of the kidney is subjected to an intervention that can last about two hours and requires a subsequent hospitalization of several days, a patient undergoing a ureteroscopy takes between thirty minutes and an hour to be diagnosed and treated and can go home in the next 24 hours.
Flexible vs. rigid ureteroscope
Previously, a ureteroscopy was performed with a rigid ureteroscope, with the access limitations that entailed. The current use of flexible ureteroscopes, which are also somewhat finer, has allowed doctors to reach much higher and more complicated areas of the kidney, which has increased the percentage of patients who can benefit from this option. In addition, the flexible ureteroscope has a mobile end, which makes the intervention even easier.
The ureter and pelvis, at the level of the kidney, open in different calyces, called the upper, middle and lower calyceal group, and it is in the treatment of the tumors that are just here where more possibilities have been opened with the arrival of the flexible ureteroscope. As Dr. Nuñez points out, "with the rigid ureteroscope, we could only access what we had in a straight line, so it was almost impossible to access an inferior or middle calyce if the circumstances were not very favorable; instead, with a flexible ureteroscope, we can enter each of the calyces and even angle the ureteroscope to better access these tumors."
In the last two years, more than 20 patients with suspected ureter and / or renal pelvis tumors have been treated at MD Anderson Madrid by Dr. Nuñez’s team, who also highlights the collaboration of the Radiology Service in the intervention. This technique, which is used very frequently in the treatment of kidney stones, requires the participation of expert personnel with extensive experience in the treatment of tumors of the ureter and / or renal pelvis.