Hepatic arterio-venous fistulae in dogs : diagnosis, treatment, prognosis

There are two types of congenital vascular disorders affecting the liver in small animals: portosystemic shunts, object of extensive studies and publications, and arteriovenous fistulae (HAVF), which on the contrary are poorly documented in veterinary medicine. In hepatic arteriovenous fistulae (HAVF), part of the hepatic arterial circulation communicates directly with the portal system within the hepatic parenchyma. This disorder affects young animals. Symptoms include ascites, delayed growth and occasionally neurological signs due to multiple portocaval shunts resulting from the portal hypertension. Surgical treatment includes 1) resection of the affected lobe(s), 2) ligation of the hepatic artery branch feeding the fistula, or 3) endovascular embolization of the artery. The prognosis of this condition is fair and though the success rate of surgical treatments is non-negligible. In most cases, post-surgical treatment includes medication and a special diet (low in proteins). The overall survival rate is comparable to that seen in intrahepatic portosystemic shunts.La pathologie vasculaire congénitale du foie chez les carnivores domestiques est divisée en 2 entités : les shunts porto-systémiques, qui ont fait l'objet de nombreuses études et publications et les fistules artério-veineuses (FAVH), à l'inverse peu documentées en médecine vétérinaire. Lors de FAVH, une partie de la vascularisation artérielle hépatique communique avec le système porte au sein du parenchyme hépatique. Cette affection touche les animaux jeunes. Les symptômes rencontrés sont : ascite, retard de croissance et parfois, signes neurologiques, dus aux shunts porto-caves multiples résultant de l'hypertension portale. Il existe 3 modalités de traitement chirurgical : 1) résection du ou des lobe(s) hépatique(s) concerné(s), 2) ligature de la branche de l'artère hépatique desservant la fistule ou 3) embolisation par voie endovasculaire de l'artère au niveau de la communication artério-veineuse. Le pronostic de cette affection est variable, bien que le taux de succès thérapeutique soit non négligeable. Dans la plupart des cas, les animaux traités chirurgicalement doivent recevoir des médicaments après l'opération et suivre un régime alimentaire particulier (pauvre en protéines). Le taux de survie est globalement comparable à celui observé lors de shunts porto-systémiques intrahépatiques

Evaluation of Adeno-Associated Viral Vectors for Liver-Directed Gene Transfer in Dogs

This study evaluated six adeno-associated viral (AAV) vectors expressing green fluorescent protein (GFP) from the liver-specific thyroid hormone–binding globulin (TBG) promoter made with novel capsids in canine liver-directed gene transfer. Studies in 1.5-month-old dogs, which were administered vector through a peripheral vein, showed that AAV8 capsid vectors had the most favorable performance profiles. Interestingly, the absolute levels of hepatocyte transduction achieved with AAV8 were lower in dogs compared with what had been achieved in mice and nonhuman primates. Additional studies were performed with AAV8 delivered into the hepatic artery in adult dogs, with higher doses of vector used to assess potential dose-limiting toxicities. These studies showed good transduction on day 7 in one dog that apparently was lost by day 28 in another dog through the generation of GFP-specific T cells. Each adult dog was carefully monitored for any hemodynamic changes associated with vector infusion. Both animals demonstrated mild to moderate hypotension and bradycardia, which appeared to be anesthesia-related, making it difficult to evaluate contributions of the vector

Treatment of congenital distal ureteral orifice stenosis by endoscopic laser ablation in dogs: 16 cases (2010-2014)

OBJECTIVE: To determine characteristics of and outcomes for dogs with congenital distal ureteral orifice stenosis (CDUOS) treated by cystoscopic-guided laser ablation (CLA).DESIGNRetrospective case series. ANIMALS: 16 client-owned dogs with CDUOS treated by CLA at 2 veterinary hospitals between 2010 and 2014. PROCEDURES: Medical records were reviewed and data collected regarding clinical findings, imaging results, surgery characteristics, treatment, and outcome. Follow-up information was collected from dog owners and referring veterinarians via standardized interview.RESULTSDogs included 10 males and 6 females; median age was 11.5 months (range, 4 to 112 months). Labrador Retriever (n = 6; 3 males) was the most common breed. Intramural ectopic ureteral openings were identified at the site of stenosis in 15 dogs (18/20 stenotic ureteral openings). Treatment with CLA to enlarge and relocate the stenotic opening was successful in all dogs. Median duration of anesthesia and hospitalization was 105 minutes and 24 hours, respectively. No complications were noted. Fourteen dogs remained alive (2 lost to follow-up) during a median follow-up period of 14.5 months. Owners of 11 of 13 dogs reported improvement in their dog's quality of life after CLA. The treated ureteral orifice remained patent in the 2 dogs that were reimaged. CONCLUSIONS AND CLINICAL RELEVANCE: CDUOS should be considered as a differential diagnosis for dogs with idiopathic distal ureteral obstruction, particularly young male Labrador Retrievers, and was most often associated with an intramural ectopic ureter in this study. Treatment with CLA was safe and effective for opening the ureteral orifice

Intra‐arterial renal infusion of autologous mesenchymal stem cells for treatment of chronic kidney disease in cats: Phase I clinical trial

Abstract Background There are no known treatments that halt or reverse chronic kidney disease (CKD) in cats. In rodent models, stem cell treatment has been associated with improvement in renal function parameters, especially when stem cells were delivered intra‐arterially to the kidney. To date, only IV and intrarenal stem cell infusions have been studied in cats with CKD with no clinically relevant improvement noted. Objective To assess the safety and feasibility of intra‐arterial delivery of autologous mesenchymal stem cells (MSC) in stromal vascular fraction (SVF) to the kidney in cats with CKD. Animals Five client‐owned domestic cats with International Renal Interest Society stage III CKD. Methods Prospective cohort study (phase I clinical trial). Adipose tissue was harvested from study animals on day 0. On days 2 and 14, an infusion of MSC in SVF was administered into the renal artery via the femoral or carotid artery using fluoroscopic guidance. Serum creatinine and blood urea nitrogen concentration, plasma iohexol clearance, and quality of life assessments were monitored between days 0 and 90. Results The procedure was performed successfully in all cats. No severe adverse events were observed in any cat during the study period. Conclusions and Clinical Importance Intra‐arterial infusion of MSC into the renal artery in CKD cats was feasible and safe within a 3‐month postoperative period. Efficacy and long‐term safety have yet to be established. This procedure requires careful technique and training