Long-term outcome of permanent tracheostomy management in two brachycephalic dogs using a commercial and a three-dimensional-printed silicone stent.

OBJECTIVE: To report the long-term outcome of utilization of a silicone stent to support the management of a permanent tracheostomy. STUDY DESIGN: Short case series. ANIMALS: Two client-owned brachycephalic dogs. METHODS: Two brachycephalic dogs with stage III laryngeal collapse underwent permanent tracheostomy. After the tracheostomy had healed, a silicone stent was inserted to support the stoma and facilitate home care. One dog wore a commercially available silicone stent for the follow-up period of 2 years. For the dog in Case 2, a 3D-printed, medical-grade silicone stent with an increased length was designed, as the dog had developed skin sores from the commercial device. RESULTS: Both dogs tolerated the silicone stent well. Stent care was managed by the owners without need for assistance. They reported that the silicone stent facilitated cleaning of the stoma surroundings and that they felt an increased confidence in airway patency, as the device prevented the tracheal stoma from collapsing. In Case 1, tracheoscopy 1 year after first stent insertion revealed minimal visible changes to the tracheal stoma. In Case 2, the 3D printed silicone stent led to a remission of skin sores and the dog wore the device comfortably until succumbing to an unrelated disease 13 months later. CONCLUSION: The insertion of a silicone stent is a simple and cost-effective method to improve home care of dogs with permanent tracheostomy. Larger dogs, as in Case 2, may benefit from custom-designed 3D-printed stents.

Clinical use of uncovered balloon-expandable metallic biliary stents for treatment of extrahepatic biliary tract obstructions in cats and dogs: 11 cases (2012-2022).

OBJECTIVE: To describe the application of uncovered balloon-expandable metallic biliary stents for treatment of extrahepatic biliary obstructions (EHBOs) and the outcomes for dogs and cats treated for EHBO with this technique. STUDY DESIGN: Retrospective single institutional study. ANIMALS: Eight dogs and three cats treated at the Veterinary Specialty Hospital of San Diego for EHBO between January 2012 and February 2022. METHODS: Data collected from the medical records included signalment, presenting complaint, laboratory and imaging findings, surgical findings, hospitalization time, complications, and follow-up information. RESULTS: Median duration of short-term follow up was 16 days (6-45 days). Improved biochemical abnormalities and resolution of clinical signs were recorded in 10/11 cases. Two dogs died within 2 weeks of surgery. One dog developed systemic inflammatory response syndrome 5 days postoperatively and was euthanized; the cause of death in the second case was unknown. Long-term follow up was available in seven cases, with a median duration of 307.5 days (62-2268 days). Bile-duct patency was maintained for at least 356-622 days (median: 446 days) in three cats and 62-2268 days (median: 650.5 days) in four dogs with long-term follow up available. One cat had recurrent obstruction with choledocholiths 446 days postoperatively. One stent was removed 614 days postoperatively due to recurrent cholangiohepatitis. CONCLUSION: Uncovered balloon-expandable metallic biliary stents were placed successfully and relieved EHBO in all cases that survived to discharge. CLINICAL SIGNIFICANCE: Use of uncovered balloon-expandable metallic biliary stents should be considered as an alternative to temporary choledochal luminal stenting or cholecystoenterostomy to manage EHBO.

Combined cholecystotomy, retrograde hydropulsion, and choledochal stenting to treat extrahepatic biliary tract obstruction in 3 cats.

Extrahepatic biliary tract obstruction (EHBO) is uncommonly encountered in cats. Surgical treatment aims to decompress the biliary tract and insure bile duct patency. In veterinary medicine, cholecystotomy is not widely used in practice. The objective was to describe the use of cholecystotomy, retrograde hydropulsion of choleliths, and choledochal stenting to remove choleliths from the extrahepatic biliary tract back in the gallbladder. Three adult domestic shorthair cats were presented with anorexia, lethargy, and vomiting. Serum biochemistry revealed hyperbilirubinemia and increased hepatic enzymes. Abdominal ultrasonography showed evidence of EHBO requiring surgical intervention. Choleliths were localized in the proximal and middle portions of the common bile duct (CBD) in the first case, in the distal portion of the CBD and within the major duodenal papilla in the second case, and in the middle and distal portions of the CBD in the third case. Cholecystotomy was followed by retrograde hydropulsion of the choleliths into the gallbladder, after which choledochal stenting was performed. Complications were defined as major when requiring additional medical or surgical treatment, or minor when not. Three major complications were reported. In 2 cases, severe anemia requiring blood transfusion occurred 24 h postoperatively; in 1 case, EHBO recurrence was encountered 41 d postoperatively. All cats were discharged within 4 d following surgery. Two cats were still alive at 12 and 14 mo after surgery, respectively. In the last case, owners refused revision surgery and the cat was euthanized. Key clinical message: Cholecystotomy combined with retrograde hydropulsion of choleliths permitted removal of choleliths and decompression of the biliary tract in 3 cats. Major complications included severe anemia and EHBO recurrence.

Cholécystotomie combinée, hydropulsion rétrograde et pose de stent cholédocien pour traiter l'obstruction des voies biliaires extra-hépatiques chez 3 chats. Les obstructions biliaires extra-hépatiques (OBEH) sont peu fréquentes chez le chat. Le traitement chirurgical vise à lever l'obstruction et s'assurer de la perméabilité des voies biliaires. En médecine vétérinaire, la cholécystotomie est une technique peu pratiquée. L'objectif de ce rapport de cas était de décrire l'utilisation de la cholécystotomie, de l'hydropulsion rétrograde des cholélithes et d'une prothèse endoluminale cholédoquale (PEC) pour repousser les cholélithes présents dans les voies biliaires extrahépatiques dans la vésicule biliaire (VB).Trois chats européens adultes ont été présentés pour anorexie, léthargie et vomissements. La biochimie sérique a révélé une hyperbilirubinémie et une augmentation des enzymes hépatiques. L'échographie abdominale a mis en évidence une OBEH nécessitant une intervention chirurgicale. Les cholélithes étaient situés dans la portion proximale et moyenne du canal cholédoque pour le premier cas; dans la portion distale et la papille duodénale majeure dans le second cas; dans la portion moyenne et distale pour le troisième cas. Une cholécystotomie a été suivie d'une rétro-hydropulsion des cholélithes dans la VB, puis une PEC a été placée. Les complications ont été définies comme majeures lorsqu'elles nécessitaient un traitement médical ou chirurgical supplémentaire, ou mineures lorsqu'elles n'en nécessitaient pas.Trois complications majeures ont été rapportées : chez 2 cas, une anémie sévère a été observée 24 h après l'intervention, nécessitant une transfusion sanguine; chez un cas, une récidive d'obstruction biliaire a eu lieu à 41 jours postopératoire. Tous les patients sont sortis de l'hôpital dans les 4 jours suivant l'opération. Deux cas étaient encore en vie 12 et 14 mois après l'intervention. Pour le dernier cas, la seconde chirurgie a été refusée par les propriétaires et le chat a été euthanasié.Message clinique clé :La cholécystotomie combinée à l'hydropulsion rétrograde des cholélithes a permis le retrait de cholélithes obstructives (dont certaines distales) et la décompression du tractus biliaire chez 3 chats. Les complications majeures incluaient une anémie sévère et une récidive d'obstruction biliaire.(Traduit par les auteurs).

Bilateral neoureterocystostomy with distal ureteral tapering in a dog with severe bilateral hydroureteronephrosis.

A 3.5-year-old intact male Labrador retriever was seen for hematuria. The results of clinical pathology tests were unremarkable. However, urinalysis revealed dark, cloudy, alkalotic, and isosthenuric urine containing red and white blood cells, epithelial cells, and struvite crystals. Severe bilateral enlargement of ureters and markedly enlarged kidneys were identified on abdominal radiographs. Computerized tomography revealed extensive bilateral hydroureteronephrosis with no definitive cause of obstruction. The dog underwent bilateral ureteral tapering with bilateral neoureterocystostomy and placement of temporary bilateral ureteral stents and a cystostomy tube. The dog was monitored in the intensive care unit for 7 d after surgery and was discharged 9 d after surgery and after the stent and cystostomy tube were removed. The dog remained clinically normal and was reported to have been euthanized at 11 y of age (2021) due to unspecified causes. Key clinical message: There are several potential causes of severe bilateral hydroureteronephrosis in animals. Based on this case report, dogs with severe bilateral hydroureteronephrosis that are clinically asymptomatic may have favorable outcomes following bilateral ureteral reconstruction and neoureterocystostomy, even if a definitive cause is not identified.

Néourétérocystostomie bilatérale avec effilement urétéral chez un chien avec hydrourétéronéphrose bilatérale sévère. Un labrador mâle non-castré âgé de 3,5 ans a été vu pour hématurie. Les résultats des tests de pathologie clinique ne présentaient pas d'anomalie. Toutefois, l'analyse d'urine a mis en évidence une urine foncée, trouble, alcaline et isosthénurique, contenant des globules rouges et blancs, des cellules épithéliales et des cristaux de struvite. Une augmentation bilatérale sévère de la taille des urètres ainsi qu'une augmentation de la taille des reins ont été notées lors des radiographies abdominales. Un examen par tomodensitométrie a révélé une hydrourétéronéphrose bilatérale marquée sans cause identifiable d'obstruction. On procéda à un effilement urétéral bilatéral avec néourétérocystostomie bilatérale et mise en place de stents urétéraux bilatéraux temporaires et un tube à cystotomie. Le chien a été sous surveillance à l'unité des soins intensifs pendant 7 j après la chirurgie et a obtenu son congé 9 j après la chirurgie, après que les stents et le tube à cystotomie aient été retirés. Le chien est demeuré cliniquement normal jusqu'à son euthanasie à l'âge de 11 ans (2021) pour des raisons non-spécifiées.Message clinique clé :Il y a plusieurs causes potentielles d'hydrourétéronéphrose bilatérale chez les animaux. Sur la base de ce rapport de cas, les chiens avec hydrourétéronéphrose bilatérale sévère qui sont cliniquement asymptomatique un résultat favorable peut être obtenu à la suite d'une reconstruction urétérale bilatérale et une néourétérocystostomie même si une cause définitive n'est pas identifiée.(Traduit par Dr Serge Messier).

Stenting of a partially obstructed nasolacrimal duct using a steerable angle-tipped hydrophilic guidewire in a cat.

OBJECTIVE: This case report describes the successful correction of partial obstruction of the NL duct in a cat by means of a modified retrograde NL duct cannulation using a steerable angle-tipped hydrophilic guidewire (AH guidewire) following a paranasal incision. ANIMAL STUDIED: A 2-year-old neutered male American domestic shorthair cat was referred to the Purdue University Veterinary Hospital (PUVH) for chronic epiphora suspected secondary to nasolacrimal (NL) system obstruction. PROCEDURES: At the first visit, the cat had epiphora OD and facial dermatitis but no other abnormalities on physical and ophthalmic examinations. Computed tomography (CT)-dacryocystorhinography revealed partial obstruction of the NL duct secondary to stenosis near the distal root of the right maxillary third premolar (107). A digital three-dimensional (3D) model of the right maxilla and NL duct was created for inspection and virtual cannulation of the NL. The model was 3D printed and cannulation of the NL duct was rehearsed with various stent materials. Retrograde NL stenting with the guidance of a steerable angle-tipped hydrophilic guidewire was conducted following a paranasal incision. A urethral catheter was cannulated over the guidewire and maintained for 44 days. RESULTS: The epiphora resolved immediately after stenting. At 21 days post-stenting, the cat developed acute bullous keratopathy secondary to self-trauma which was treated with a third eyelid flap. On the final follow-up communication with the owner at 210 days post-stenting, no epiphora or any other concerns were reported. CONCLUSION: To the authors' knowledge, this is the first report of successful NL stenting and resolution of epiphora in a cat with a partial NL system obstruction.

Endoscopic-guided diagnosis of and interventional stent placement for nasolacrimal duct obstruction in a horse.

OBJECTIVE: To describe the successful use of endoscopy to visualize and place a soft canine ureteral stent to relieve a chronic nasolacrimal duct (NLD) obstruction in a horse. ANIMAL STUDIED: A 7-year-old, Quarter horse gelding. PROCEDURE: Under general anesthesia, retrograde nasolacrimal endoscopy was performed using an 8.5 Fr Storz Flex XC ureteroscope through the nasal punctum (NP). An obstructive web of fibrous tissue was visualized approximately 20 cm proximal to the NP. A 0.035″/150 cm hydrophilic guidewire was passed normograde from the ventral lacrimal punctum and used to puncture the stenotic tissue. Then, a 5.0Fr/70 cm open-end ureteral catheter was threaded normograde over the guidewire and NLD patency was re-established. The catheter confirmed a NLD length of 30 cm and was then removed. A 5.0Fr/22-32 cm Universa© Soft Ureteral Stent was threaded normograde over the guidewire until the loops of the stent were exposed at each end. The guidewire was removed and the stent loops were sutured in place. RESULTS: The stent was withdrawn 1 month after the procedure. Telephone follow-up with the client reported significant improvement in the amount of ocular discharge and decreased sensitivity around the face and ears. CONCLUSION: Endoscopy is a safe and effective procedure allowing for definitive diagnosis of NLD obstruction and to assist in interventional procedures. Placement of a canine indwelling ureteral stent seems to be an effective alternative treatment option for equine NLD obstruction compared to conventional invasive surgical procedures.

Bronchial Stent Placement for Palliative Treatment of Pulmonary Carcinoma with Bronchial Obstruction in a Cat.

A feral, domestic shorthair was evaluated for palliative treatment of a pulmonary mass with secondary pneumonia. Because of the patient's temperament and extent of the mass, tracheobronchoscopy, bronchial stenting, and biopsy were elected, followed by adjuvant radiation therapy. Stent placement across the malignantly obstructed bronchus permitted drainage and recruitment of the infected lung lobe. Uncomplicated radiation therapy, stent extension, and debulking due to tissue ingrowth were subsequently performed. Successful palliation was achieved for 323 days with subsequent progressive pulmonary and liver metastases.

NEOURETEROCYSTOSTOMY AND URETHRAL STENT PLACEMENT IN A BLACK-HANDED SPIDER MONKEY (ATELES GEOFFROYI).

A 27-y-old female black-handed spider monkey (Ateles geoffroyi) was evaluated 13 d after an ovariohysterectomy because of abdominal distension, anorexia, and absent urination. The animal was diagnosed with a uroabdomen and urethral obstruction from computed tomographic findings and fluid creatinine levels. During exploratory laparotomy, a defect in the right ureter was confirmed as the source of the uroabdomen. Utilizing intraoperative fluoroscopy, a urethral obstruction with an irregular luminal filling defect was evident. A self-expanding nitinol urethral stent was placed, and a ureteral transposition was performed. Two months after the procedure, the animal developed dysuria, a urinary tract infection, recurrent bladder distension and a partial urethral obstruction. Treatment with prazosin 1 mg/kg PO q12h improved urination. Reobstruction of the urethra occurred 17 mo postsurgery, and the animal was euthanatized. On postmortem examination, the animal had ingrowth into the stent with proliferative granulation tissue, detrusor muscle degeneration, pelvic adhesions, cystitis, pyelonephritis, and hydronephrosis.

In vitro evaluation and in vivo use of a novel surgical stent to minimize suture pressure necrosis.

OBJECTIVE: To evaluate the efficacy of stents to distribute pressure when incorporated into tension-relieving sutures. STUDY DESIGN: An in vitro study and case report. ANIMAL: One common bottlenose dolphin (Tursiops truncates). METHODS: Three novel silicone stents, a traditional stent, and a control were tested in vitro by using a suture simulator. Stent surface area was measured by using a pressure mapping sensor. Pressure was derived from the measured surface area and the downward force of the suture simulator. Novel silicone stents were also used in the closure of an incision in a bottlenose dolphin. RESULTS: No difference was found in surface area or pressure among the three silicone stents (adjusted P > .05). Silicone stents yielded an average, 2.69 cm2 more surface area and 842.37 kPa less pressure compared with the control as well as 1.67 cm2 more surface area and 110.67 kPa less pressure compared with the traditional stent. The traditional stent yielded 1.02 cm2 more surface area and 731.7 kPa less pressure compared with the control. Incision site and silicone stent assessment performed postoperatively revealed no obvious pressure necrosis. CONCLUSION: Stents improved distribution of suture pressure, and novel silicone stents were more effective compared with traditional stents. Novel silicone stents appear to have preliminary clinical success in vivo. CLINICAL SIGNIFICANCE: Our study provides evidence that stents effectively help distribute suture pressure, and their incorporation might minimize the risk of suture pressure necrosis. Novel silicone stents should be integrated into tension-relieving suture patterns when closing wounds and incisions, particularly in aquatic animals.

Intrasinus bolstering of traumatic maxillary sinus fractures by using Foley catheter balloons in two foals.

OBJECTIVE: To describe the repair of unstable facial fractures by using Foley catheter balloons as intrasinus bolsters. STUDY DESIGN: Case report ANIMALS: Two weanling foals with unilateral fractures of the sinus and orbit secondary to kick injuries. Preoperative imaging that included positive contrast dacrocystorhinography and computed tomography confirmed severe comminution of facial fractures and nasolacrimal duct disruption in both foals. METHODS: Small bone fragments were surgically removed, and large fragments were retained even when denuded of periosteum. Repair procedures included nasolacrimal canaliculosinusotomy and suturing fracture fragments together with polydioxanone sutures. After fixation, the fracture fragments could be depressed into the sinus with manual pressure, so two intrasinus Foley catheters were placed to bolster the sinus wall, with the tubing exiting through a frontal sinus trephine. The skin was completely closed over the fractures. Catheters and nasolacrimal stenting were maintained in place during fracture healing. RESULTS: One foal prematurely dislodged catheters and nasolacrimal stent 11 days after fixation. The catheters and stenting were removed as planned 4 weeks after surgery in the second foal. Wound, fracture healing, and overall cosmesis was good in both foals, and epiphora resolved. Surgical site infection, sinusitis, and sequestration did not occur. Both foals became high-level performance horses with acceptable cosmetic outcome and good bilateral nasal airflow. CONCLUSION: Foley catheter balloons supported sinus fracture repair and maintained stability of the surgical reconstruction during convalescence. CLINICAL SIGNIFICANCE: Suture repair of comminuted sinus fractures can be supported by using Foley catheters, which are readily available.

Uretero-Cutaneous Fistula and Renal Abscessation as a Complication of Ureteral Stenting in a Dog.

An 11 yr old female spayed shih tzu was referred for treatment of left ureterolithiasis with complete obstruction of the left ureter and pyonephrosis. A ureteral stent was placed surgically to relieve the obstruction and pyonephrosis was treated with antibiotics. Three and a half years following stent placement, the patient developed an abscess on the left flank with chronic purulent discharge. Diagnostic imaging confirmed the presence of a left uretero-cutaneous fistula and renal abscess. A left ureteronephrectomy was performed. The dog was euthanatized 4 mo later for cardiac insufficiency unresponsive to medical treatment. This is the first report of a uretero-cutaneous fistula and renal abscessation as a complication of ureteral stenting in a dog.

Use of a cervical stent for long-term treatment of pyometra in the mare: A report of three cases.

An effective long-term treatment is necessary for mares with pyometra, because the condition tends to recur. In many affected animals, several conformational or anatomical anomalies contribute to impaired uterine clearance. Ovariohysterectomy is the surgical procedure of choice. Conservative therapy consists of draining and flushing the uterus, and systemic anti-inflammatory and antimicrobial treatment. Uterine secretions tend to accumulate again after local treatment, especially in mares with poor vaginal conformation or cervical adhesions. Herein, we describe three cases in which a cervical stent was used in mares after mechanical or manual dilation of the cervix to achieve permanent draining of the uterus. The mares remained symptom-free for up to 6 years and exhibited good clinical progress and good performance in competitions. Potential complications of the procedure include loss of the stent and obstruction caused by viscous secretion. A cervical stent is a relatively easy and low-cost option for the long-term treatment of pyometra in mares, particularly in cases where excessive costs of surgery and risks of a general anaesthesia are to be avoided.

Fluoroscopically guided neocanalization for treatment of nasolacrimal atresia in two horses.

CASE DESCRIPTION: A yearling Thoroughbred stallion and an 8-year-old Saddlebred mare were evaluated for persistent mucoid ocular discharge. CLINICAL FINDINGS: Examination of both horses revealed copious yellow-tan mucoid ocular discharge with a negative Jones I test, absent nasal punctum, and unsuccessful anterograde nasolacrimal duct (NLD) irrigation. Clinical abnormalities were present on the right side only in one horse and bilaterally in the other. Computed tomography (CT) with contrast confirmed nasolacrimal duct atresia in both horses. TREATMENT AND OUTCOME: Under general anesthesia, the affected NLD was catheterized anterograde and contrast injected. Using fluoroscopic guidance, retrograde access to the distal NLD was obtained for through-and-through wire access. Over the wire, the stoma was dilated and a temporary stent placed for 4-8 weeks. After the procedure, both horses were comfortable and free of ocular discharge at the minimum time of last follow-up, 9 months postoperatively. CLINICAL RELEVANCE: Fluoroscopically guided neocanalization is a viable alternative to traditional surgical approaches for NLD atresia, especially when access to the site of obstruction is limited.

Congenital lacrimal fistula in two prim'Holstein calves.

Two 4- and 8-month-old prim'Holstein calves were presented for chronic epiphora. Examination of the affected eyes revealed an abnormal duct opening inferonasal to the medial canthus. A diagnosis of congenital lacrimal fistula was made based on conventional and computed tomographic-dacryocystography findings. These revealed an ectopic channel connecting the nasolacrimal duct to the skin opening near the medial canthus. Both of the calves were surgically treated with resection and closure of the ectopic duct and placement of a nasolacrimal stent.

Long-term outcomes of 54 dogs with tracheal collapse treated with a continuous extraluminal tracheal prosthesis.

OBJECTIVE: To describe the surgical placement of a continuous extraluminal tracheal prosthesis (CETP) and report the subsequent postoperative clinical outcomes in dogs with tracheal collapse. STUDY DESIGN: Retrospective case series. ANIMALS: Fifty-four dogs. METHODS: Medical records of dogs in which cervical and/or thoracic inlet tracheal collapse was diagnosed and treated by placement of a CETP between 2010 and 2017 were reviewed to evaluate postoperative complications, changes in respiratory function, and survival. Histological examinations of tracheal tissues performed in 2 dogs at 51 and 57 months after surgery were also reviewed. RESULTS: Fifty-three (98%) dogs survived to discharge. Postoperative complications included laryngeal paralysis (1 dog), disseminated intravascular coagulation (1 dog), and recurrent tracheal collapse (2 dogs). None of the dogs exhibited clinical evidence of tracheal necrosis. Preoperative dry, harsh cough resolved in 87% of the dogs after surgery. Goose honking cough was resolved in 25 of 26 (96%) dogs. Median follow-up time was 30 months (range, 16 days to 76 months). The survival rate at 36 months was 86% (CI: 75%-96%). On histological examination in 2 dogs, the tracheal tissue surrounding the prosthesis was well preserved and without evidence of chronic inflammation. CONCLUSION: Continuous extraluminal tracheal prosthesis placement in dogs with tracheal collapse resulted in low postoperative complication rates and good long-term outcomes. CLINICAL SIGNIFICANCE: Continuous extraluminal tracheal prosthesis placement provides a viable alternative surgical option for managing dogs with tracheal collapse.

Use of a modified Boari flap for the treatment of a proximal ureteral obstruction in a cat.

OBJECTIVE: To describe the use and long term outcome of a novel surgical technique developed to treat a proximal ureteral obstruction in a cat. STUDY DESIGN: Case report. ANIMALS: A 3-year-old female spayed Russian blue cat. METHODS: A 3-year-old female spayed Russian blue cat presented with a fever, decreased appetite, vomiting, and abdominal discomfort. A proximal left ureteral obstruction was noted on ultrasonographic examination. No filling defect was noted on antegrade pyelography. Due to the proximal location of the obstruction, a modification of a Boari flap was performed. In the current technique, the ureter was cut proximal to the level of obstruction, and the distal ureter was resected. A flap was created on the ventral surface of the bladder, the cut end of the ureter was pulled through the flap, and a ureteroneocystostomy was performed. The bladder was closed in a simple interrupted pattern. RESULTS: At re-evaluation 2 and 4 weeks after surgery, azotemia had resolved. According to ultrasonography, the ureteroneocystostomy site appeared to be healing, and pelvic dilation had resolved. One year later, the cat continued to do well, with no lower urinary tract signs and no abnormality noted on blood tests or ultrasonography. CONCLUSION: The tubularized bladder flap originally described by Boari was modified to create a tension-free ureteroneocystostomy, without complication. This technique relied on surrounding native tissues and resulted in long-term resolution of the ureteral obstruction. CLINICAL SIGNIFICANCE: A modified Boari flap can lead to long-term resolution of proximal ureteral obstruction in cats, without requiring stents or permanent implants.

Use of an Absorbable Urethral Stent for the Management of a Urethral Stricture in a Stallion.

OBJECTIVE: To describe the successful management of a urethral stricture with an absorbable stent in a stallion. STUDY DESIGN: Clinical report. ANIMALS: Stallion with a urethral stricture. RESULTS: A 12-year-old Thoroughbred breeding stallion was evaluated for acute onset of colic. Uroperitoneum because of presumptive urinary bladder rupture, with urethral obstruction by a urethrolith, was diagnosed. The uroperitoneum was treated conservatively. The urethrolith was removed through a perineal urethrotomy. Approximately 15 weeks after urethrolith removal, the stallion presented with a urethral stricture. The stricture was unsuccessfully treated with an indwelling urinary catheter and 4 attempts at balloon dilation. Eight weeks after diagnosis of stricture, an absorbable polydioxanone (20 mm × 80 mm) urethral stent was implanted under percutaneous, ultrasound guidance. Urethroscopy was performed at 70, 155, and 230 days after stent placement and the endoscope passed through the affected site without complication. Urethroscopy at 155 days showed the stent had been reabsorbed. Follow-up 20 months after stent placement reports the stallion was able to void a normal urine stream. CONCLUSIONS: Absorbable urethral stent placement was a feasible treatment for urethral stricture in this stallion.

COMPARISON OF FLUOROSCOPY AND COMPUTED TOMOGRAPHY FOR TRACHEAL LUMEN DIAMETER MEASUREMENT AND DETERMINATION OF INTRALUMINAL STENT SIZE IN HEALTHY DOGS.

Tracheal collapse is a progressive airway disease that can ultimately result in complete airway obstruction. Intraluminal tracheal stents are a minimally invasive and viable treatment for tracheal collapse once the disease becomes refractory to medical management. Intraluminal stent size is chosen based on the maximum measured tracheal diameter during maximum inflation. The purpose of this prospective, cross-sectional study was to compare tracheal lumen diameter measurements and subsequent selected stent size using both fluoroscopy and CT and to evaluate inter- and intraobserver variability of the measurements. Seventeen healthy Beagles were anesthetized and imaged with fluoroscopy and CT with positive pressure ventilation to 20 cm H2 O. Fluoroscopic and CT maximum tracheal diameters were measured by three readers. Three individual measurements were made at eight predetermined tracheal sites for dorsoventral (height) and laterolateral (width) dimensions. Tracheal diameters and stent sizes (based on the maximum tracheal diameter + 10%) were analyzed using a linear mixed model. CT tracheal lumen diameters were larger compared to fluoroscopy at all locations (P-value < 0.0001). When comparing modalities, fluoroscopic and CT stent sizes were statistically different. Greater overall variation in tracheal diameter measurement (height or width) existed for fluoroscopy compared to CT, both within and among observers. The greater tracheal diameter measured with CT and lower measurement variability has clinical significance, as this may be the imaging modality of choice for appropriate stent selection to minimize complications in veterinary patients.

Comparison of Outcome After Use of Extra-Luminal Rings and Intra-Luminal Stents for Treatment of Tracheal Collapse in Dogs.

OBJECTIVE: To report short- and long-term complications and outcomes of dogs treated for tracheal collapse secondary to chondromalacia with extra-luminal rings (ELR) or intra-luminal stents (ILS). STUDY DESIGN: Retrospective cohort. SAMPLE POPULATION: Dogs with naturally occurring tracheal collapse (n = 103). METHODS: Medical records (2002-2012) of dogs diagnosed with tracheal collapse that had treatment with ELR (n = 73) or ILS (30) were reviewed. Demographic information, procedural information, complications, survival time, and subjective outcomes were recorded. Follow-up periods were defined as <730 days (short-term) and >730 days (long-term). RESULTS: Ninety-two percent of dogs undergoing ELR and 100% of dogs undergoing ILS survived to hospital discharge. ELR dogs were significantly younger (P = .009) and significantly fewer had main-stem bronchial collapse (P < .001). After accounting for effects of age and presence of main-stem bronchial collapse, there was no significant difference in median survival time between groups. Dogs with main-stem bronchial collapse (regardless of treatment type) had a shorter survival time than dogs without main-stem bronchial collapse. Major complications occurred in ELR (42%) and ILS dogs (43%). CONCLUSIONS: Both ELR and ILS are associated with high complication rates. Younger dogs and dogs without main-stem bronchial collapse had a longer survival time, regardless of treatment.

Comparison of radiography and computed tomography for determining tracheal diameter and length in dogs.

OBJECTIVE: To compare radiographic and computed tomography (CT) measurements of tracheal size as would be made for the purpose of tracheal stent size selection. STUDY DESIGN: Cross-over. ANIMALS: Dogs (n = 15). METHODS: Canine cadavers without evidence of tracheal or respiratory disease were used for CT and digital radiography of the neck and thorax. Three observers each made 3 independent measurements at each of 5 tracheal locations, and also measured tracheal length, on each radiograph and for each CT scan on each cadaver. RESULTS: CT tracheal measurements were on average 1.03 mm larger (P < .01) compared with radiographic measurements for all 3 observers. CONCLUSIONS: Radiographic measurements of the canine trachea consistently underestimate tracheal size, and CT measurements are preferable for selecting tracheal stent size.