Penn Veterinary Medicine | University of Pennsylvania

Palliative Stenting for Benign Stenoses

In contrast to the dynamic obstruction often identified with tracheal collapse, animals can develop fixed obstructions from congenital (e.g. nasopharyngeal stenosis) or acquired (e.g. nasopharyngeal stenosis, esophageal strictures, urethral strictures, etc.) causes. Historically, stenting has been avoided in benign human diseases because of the risk of potential long-term complications such as stricture and granulation tissue formation or stent fracture. The introduction of removable (and more recently bio-absorbable) stents helps to avoid these potential long-term complications. These technological advancements have led to re-evaluation of these devices for use in benign disease. Initial balloon dilation under endoscopic or fluoroscopic guidance remains the standard of care for veterinary patients with benign strictures in most locations, particularly those not amenable to easy surgical excision or repair. However, certain cases either fail repeated balloon dilation therapy or the repeated procedures may be declined by pet owners. IR techniques have been used to perform palliative stenting for benign strictures in the airway18, esophagus (Figure 4A), nasopharynx (Figure 4B), colon, and urethra when conventional therapies have failed or were declined.

	Figure 4A. Esophageal stenting for benign stricture in a ferret. (A) Double contrast esophagram through marker catheter in esophagus in order to determine esophageal diameter and stricture (white arrow) length. (B) Partial deployment of mesh nitinol stent (black arrows) beyond stricture. (C) Radiograph following complete deployment of stent across esophageal stricture. Notice incomplete stent expansion across stricture (black arrow). (D) Radiograph one day post-stent placement demonstrating complete expansion of stent across stricture (white arrows).
	Figure 4B. Nasopharyngeal stenosis (NPS) in a cat. (A) Retroflexed endoscopic image of stenotic nasopharynx. (B) Fluoroscopic-guided placement of hydrophilic guidewire through nares and across NPS lesion with balloon-expandable stent (BEMS) mounted on angioplasty balloon passed over guidewire. (C) Fluoroscopic image of BEMS partially inflated demonstrating stenotic lesion identified as balloon waist. (D) Fluoroscopic image following complete balloon inflation demonstrating effacement of stenotic area. (E) Fluoroscopic image following balloon deflation and removal, leaving BEMS expanded and in place across previously narrowed NPS.