Tracheobronchial Foreign Body Retrieval: Large airway foreign bodies are rare and dogs and cats. When present, however, they most often cause manifestations of fixed airway obstruction. If the foreign object is mobile, dynamic airway obstruction may also result. Non-cardiogenic pulmonary edema may be a sequelae. With the aid of general anesthesia, an endotracheal tube can be positioned just beyond the larynx. Using a bronchoscope adapter to maintain insufflations of inhaled anesthetic in oxygen, a stone basket commonly utilized for endoscopic retrieval of uroliths may be passed down the endotracheal tube to "capture" the foreign body. Alternatively, various grabbing instruments or a foley catheter passed beyond the foreign object and inflated and withdrawn slowly may help facilitate mobilizing the object proximally. The author has had the most success with the stone basket. Careful manipulation of instruments and the foreign object must be performed to minimize the chance of tracheal trauma.

Retrograde Bladder Access / Antegrade Urethral Access / Percutaneous Cystostomy: Numerous clinical conditions necessitate placement of a urinary catheter in the critical care setting. However, on rare occasion, retrograde access using a urinary catheter is not possible due to urethral damage/disruption, very small patient size, complex anatomy, or the presence of a diverticulum(s) associated with prostatic neoplasia or infection. In this patient population, using fluoroscopic guidance, retrograde guide wire (0.035in standard stiffness, angled tip, hydrophilic guide wire)a access to the bladder can be accomplished in some cases and a urinary catheter placed over the guide wire. The angled tip of the guide wire allows it to be directed across areas of complex anatomy and regions of partial urethral disruption or stenosis.

In some instances, however, retrograde access with a urinary catheter or a guide wire is unsuccessful. In this patient population, antegrade urethral access is very often possible. The patient is sedated in lateral recumbency and the abdomen is clipped and prepared as if for surgery. The entire procedure is performed with the aid of fluoroscopic guidance. Cystocentesis is performed using an 18g catheter near the apex of the bladder. A small amount of urine is withdrawn and replaced with 5-10mL of sterile iodinated contrast agent (200-300mgI/mL) to help illustrate the bladder. Through this catheter, a 0.035in standard stiffness, angled tip, hydrophilic guide wirea is passed. The slight angle at the tip of the guide wire allows it to be directed. The guide wire is directed down the urethra. Most times, with the exception of complete urethral transection, the guide wire will traverse areas of the urethra that are damaged or disrupted, obstructed, and those that display complex anatomy and will be exteriorized at the level of the penis or vulva. A urinary catheter can then be placed retrograde over the guide wire and the guide wire removed. This technique is not expected to be useful in cats with urethral obstruction due to urethral plug or stones. Standard techniques for dislodging the plug/stone should be undertaken.

Malignant Urethral Obstruction: Transitional cell carcinoma, prostatic carcinoma, and other intrapelvic neoplasia may result in urethral obstruction. Traditional therapy has been centered on diverting urine via surgical placement of a cystostomy tube while pursuing traditional tumor-directed therapies. Cystostomy tube placement requires surgery and requires significant owner maintenance for the duration of the pet's life. In addition, complications including tube dislodgement and recurrent urinary tract infection are not uncommon. Using IR techniques, an intraluminal self-expanding metallic urethral stent can be placed (non-surgically) via the vulva or penis to open the urethral lumen. Note that stents for this purpose are very different than those used for tracheal applications. Using fluoroscopy, the length and width of the obstruction can be very precisely measured and a stent of an appropriate length and width to span the obstruction chosen. The stent is deployed from a delivery system introduced via the urethral orifice. The entire procedure takes approximately 1hour and is associated with little to no patient discomfort. Patients are able to urinate immediately after stent placement. The greatest complication of the procedure is incontinence. Incontinence results from the stent spanning the urethral sphincter and at times, a significant portion of the urethra. The overall incidence of incontinence after stent placement is <20%. Females logically may have greater problems with this than males. In a case series by Weisse et al. and based on the MSU experience, no patients died in the short or long term due to recurrent urethral obstruction.3 With the symptom of the neoplastic condition palliated, chemotherapy, radiation therapy or other adjunctive treatments may be utilized to address the tumor directly.