Stenting of Malignant Urinary Tract Obstructions in Humans and Companion Animals

Abstract

Urine retention secondary to neoplastic obstructions of the upper and lower urinary tracts is a life-threatening condition in both humans and companion animals. Stents can be placed to temporarily or permanently open obstructed urinary tract lumens and are often able to be placed using minimally invasive techniques with guidance via ultrasonography or fluoroscopy. The literature for these techniques is vast for humans and growing for companion animals. The below review provides a discussion of the principles of stenting and types of ureteral and urethral stents, as well as the techniques for placing these stents in humans and companion animals.

Canine Prostate Cancer: Current Treatments and the Role of Interventional Oncology

“…Additionally, while no data exist comparing embolization to radiotherapy or surgery, the less invasive nature and high tolerability makes embolization an exciting treatment option for the local prostatic disease. Urethral and ureteral stenting can be used in the treatment of progressive obstructive disease within the lower urinary tract which may mitigate life-limiting complications that are frequent to prostate carcinoma locoregional progression [48][49][50][51]58]. Lower urinary tract stenting appears to be well tolerated and is considered a good option in the palliation of this disease.…”

“…Temporary stents are placed less frequently and typically as a bridging therapy until permanent stents can be placed. These are often rubber or polyurethane and can be temporarily managed by an owner at home [50]. In one study, temporary urethral stents placed for benign or malignant etiologies were successfully placed and well tolerated but led to urinary incontinence in all dogs they were placed in, if they spanned from bladder to urethral orifice, and were associated with complications such as bacteriuria and stent migration [51].…”

“…Additionally, the long-term outcome in dogs following stent placement for malignant obstruction is often poor; therefore, prolonged patency may be less important. In dogs, percutaneous antegrade ureteral stent placement is advocated for relief of malignant ureteral obstruction [50]. Due to the decreased visibility or access to the ureterovesicular junctions, these are most often placed percutaneously and antegrade (Figure 2), which is technically challenging and requires substantial experience with ultrasound-guided and fluoroscopic-guided procedures.…”