The urinary tract including the ureters allows urine flow from the kidneys to the bladder. Ureters are active members. Their wall contains muscle fibers which contract. A wave of contraction is triggered in the kidney calyx and spreads like a wave throughout the pelvis and all of the ureter.

The ureter is very thin. If there is a severe suffering on a portion of the ureter, it shrinks circumferentially and obstructs its own light. This wall destroyed will never heal. It must be removed (cut and paste) or occupied for life with a "plastic" tube.
 

Diseases of the ureter

The pathology of the ureter is large and complicated. Diseases of the ureter are very interesting. I suggest you to explain by the following short video "Autopsy of a obstructive double-pigtail tumorstent" and by the page below, why it's a challenge.
 
 

When the ureter is obstructive and it is not a stone or a ureteropelvic junction, it is essential to discover the mechanism of the obstruction.
The mechanism is sometimes suspected by the history of the patient (malignant diseases, surgical treatment for a tumor, radiotherapy). But sometimes it origin is only discovered during the drainage of the kidney.
 

The origin of the obstruction

  • The ureter may be the cause of his own obstruction. If a tumor growth in the wall, it clogs progressively its light. The tumor of the ureter may be malignant or not. A dilation of the kidney appears often without any pain. The tumor can bleed and thus be discovered by red urine (hematuria). The tumor can suddenly be obstructive by abundant bleeding and causes severe pain with renal colic.

  • The ureter may be crashed by a foreign process. Processes can be of different origins:

- They can be benign (not malignant). This is the case of endometriosis, or retroperitoneal fibrosis, or traumatic by difficult surgery around the ureter.

- They can be malignant. This is the case of cancers that directly reach the ureter (colon, uterus), or via a node cancer (metastasis prostate, bladder, ureter, colon, uterus), or malignant retroperitoneal fibrosis of the breast. In fact, breast cancer metastasis can reach this region and can realize an extremely rigid matrix crushing the ureters.

Obstruction of the right ureter by prostate cancer nodes.

Side effects of the obstruction

If the ureter is gradually dilated, no pain is observed. But a suddenly edema of the tumor may obstruct the kidney and causes severe pain with renal colic.

The silent obstructions may have important functional side effect: complete destruction of one or both kidneys.

The suddenly obstruction of one or both ureters can have serious or critical side effect: pain, fever, sepsis, renal failure, death.
 

Treatments

The treatment is to restore urinary flow and prevent renal destruction.

  • In case of ureteral tumor, tumor must be removed with all ureter below the tumor. There are often tumor grafts on the entire length of the ureter. Thus, kidney is loss because no ureter exists to connect to the bladder.

  • In case of ureteral tumor compression or ureteral stricture after radiotherapy, a double-pigtail stent is currently inserted to bypassed the obstacle.
 

Drainage of the right ureter by a strong (reinforced) double-pigtail stent.

But insertion of double-pigtail stent in a compressed ureter is not equivalent to success.

The stent will be obstructive quickly ...

The tumor is sometimes very compressive and breast tumors are the hardest tumors. Then, reinforced double-pigtail stent are marketed with reinforcing tube, or metal coils.

With the tumor, the stent must be very strong against compressive and kinking forces. It needs allowing patency. There may be deposits by stagnation and particle-forming by infection. These particles are embedded in the wall and decrease the light of the stent. The compression of the stent reduces the obstructive light of the stent and, full obstruction of the stent may occur.

The suddendly obstruction of the stent may have serious or critical consequences: pain, fever, sepsis, renal failure, death. The silent obstructions of the stent may have functional consequences by destroying the kidneys. This obstruction occurs in a tired patient and may kill this patient. This death is not directly induced by chemotherapy or cancer but just by the effects of the stent's obstruction. 
Finally, repeated stent's exchange and poor tolerance of the stent affect patients' quality of life.

For this reason, it seems to me essential to place the most "efficient" stent and detect any incompetence of the stent. This strategy require that the urologist frequently exchanges the stent, even if it is designed for one year. 
These tumorstents "special for tumor" whatever their composition are not be efficient more than 6 months. 40% are obstructive within 3 months and sometimes in less than a week. In the latter case, it is crushed. Everyone agrees that we must find an optimal type of stent with adequate permeability and resistance [références 1-3]

In case of emergency or impossibility to insert a double-pigtail stent, a nephrostomy (through the back) is possible. But this drainage is uncomfortable and unstable. The probe may move out of the kidney.
 

Right nephrostomy tube draining urine by the back.

Personally, I struggle to find an original solution. I have to understand why the stent does not work (twisted ? ), or be obstructed too quickly (crashed ?). Then, I have to adjust the drainage means.

  • For example, I can use 2 large stents of 9 French side by side to stiffen and verticalize ureter.
 

Insertion of large stents to drain a tortuous left ureter.

  • For example, I can use 1 large stent 8 French with a reinforced double-pigtail stent.
 

Insertion of large stents for draining heavily crushed ureters.

The patient must return to the operating room but finally urine patency is effective and patient's life is better.

Of course, the amount of material in the bladder may induce bladder irritation. In some cases, these stents can be cut and become reinforced JFil® stent and improve the patient's life comfort [références 4-7].
 

Reinforced JFil® stent using the stent into the tumor and a single thread in the rest of the ureter and the bladder.	Reinforced JFil® stent using the stent in the tumor. The thread in the bladder is not visible on the X-Ray.

In other cases, the lower part of the ureter is obstructive and the use of a stent with a thread is not possible. Then, I cut the stent to eliminate purely bladder part and thus reduce bladder irritation. An end piece is put at the bottom of the stent. These procedures have been made more than 40 times and the results are very encouraging [référence 8]. This new stent improves patient comfort of life and I am looking for industrial partner. A clinical trial is now readfy to start by Dr. B. Vogt.
 
 

Reinforced JClip stent using the stent into the tumor and an end piece in the bladder.	Reinforced JClip stent using the stent in the tumor. The end piece in the bladder is not visible on the X-Ray.

Surveillance of patient

In case of kidney pain, unexplained fever or renale failure, we must realize sonography of the kidneys and compare pelvic dilation.
My advice is to check sonography each 2-3 months.

1. Yossepowitch O et al. Predicting the success of retrograde stenting for managing ureteral obstruction. J Urol 2001, 166: 1746-9. 

2. Chung SY et al. 15-year experience with the management of extrinsic ureteral obstruction with indwelling ureteral stents. J Urol 2004, 172: 592-5.

3. Hendlin K. In vitro evaluation of ureteral stent compression. Urology 2006, 67: 679-82.

4. Vogt B et al. Sondes JFil et MiniJFil : progrès décisifs dans la tolérance des sondes urétérales et propriétés inattendues du fil urétéral. Prog Urol 2014, 24: 441-50. doi: 10.1016/j.purol.2013.12.007. http://www.sciencedirect.com/science/article/pii/S1166708714000189

5. Vogt B et al. Changing the double pigtail stent by a new suture stent to improve patient quality of life. A prospective study. World J of Urology 2015, 33: 1061-8. doi: 10.1007/s00345-014-1394-2. (Open Access) 
link.springer.com/article/10.1007%2Fs00345-014-1394-2

6. Vogt B et al. Improving the quality of life of patients with ureteral malignant obstruction. J Palliat Care Med 2014, 4: 196. doi: 10.4172/2165-7386.1000196. (Open Access) 
omicsgroup.org/journals/ArchiveJPCM/articleinpress-palliative-care-medicine-open-access.php

7. Vogt B et al. Changing the shape of the double-pigtail stent to attenuate urinary stent's symptoms. J Palliat Care Med 2014, 4: I101. doi: 10.4172/2165-7386.1000I101. (Open Access) 
omicsgroup.org/journals/ArchiveJPCM/articleinpress-palliative-care-medicine-open-access.php 

8. B. Vogt et al. Improving Comfort of Patients with Ureteral Obstruction and Malignant Disease Should Be of Concern. J Palliat Med. 2016 Nov;19(11):1132-1133. OpenAccess. DOI: 10.1089/jpm.2016.0276