Percutaneous shunt vessel embolisation with Amplatzer vascular plugs II and IV in the treatment of dogs with splenophrenic shunts: four cases (2019-2022).

OBJECTIVES: To describe the treatment of four dogs with splenophrenic shunts using percutaneous shunting vessel embolisation with Amplatzer vascular plugs II and IV and provide information on their clinical outcomes. MATERIALS AND METHODS: Dogs with splenophrenic shunts treated at a veterinary hospital from January 2019 to December 2022 were identified through a medical record search. RESULTS: Six dogs with splenophrenic shunts were identified. Two dogs were excluded because they were treated with laparoscopic surgery. Four underwent percutaneous shunting vessel embolization with Amplatzer vascular plugs and were included in the case series. A sheath was placed in the left external jugular vein and a balloon catheter was advanced to the shunting vessel under fluoroscopy. Portal vein pressure was confirmed to be within an acceptable range during temporary balloon occlusion. Based on preoperative CT angiography and intraoperative contrast examination, Amplatzer vascular plugs II were selected for two dogs and IV were selected for two dogs. Under fluoroscopy, the plug was deployed into the shunting vessel, and angiography confirmed occlusion. In all cases, the increase in portal pressure after temporary occlusion was within the acceptable range, and complete occlusion of blood flow was possible with a single plug. There were no major procedure-related complications. No dogs developed post-ligation seizures or signs of portal hypertension. In addition, improvements in ammonia values were observed in all cases. CLINICAL SIGNIFICANCE: Percutaneous splenophrenic shunt embolisation using Amplatzer vascular plugs II and IV is technically feasible in dogs, and assessed by intra-procedure angiography, a single plug completely obstructed blood flow in all dogs. Based on the literature search, this is the first report describing Amplatzer vascular plugs for the treatment of splenophrenic shunts.

Therapeutic response and prognostic factors of 14 dogs undergoing transcatheter arterial embolization for hepatocellular masses: A retrospective study.

BACKGROUND: Information regarding the therapeutic effect and outcome of transcatheter arterial embolization (TAE) for hepatic masses is limited in veterinary medicine. HYPOTHESIS/OBJECTIVES: To analyze the therapeutic response, outcome (overall survival), and their predictors in dogs that underwent TAE for primary hepatocellular masses. We hypothesized that larger pre-TAE tumors would be associated with worse outcomes. ANIMALS: Fourteen client-owned dogs. METHODS: Retrospective study. Medical records between 1 September 2016 and 30 April 2022 were reviewed to identify dogs treated with TAE for hepatic masses diagnosed as hepatocellular origin by cytological or histopathological examination. Computed tomography images were compared before and after TAE. The univariate Cox proportional hazards test was performed to assess the associations between variables and survival. Univariate linear regression analysis was performed to assess the associations between variables and the tumor reduction percentage: ([post-TAE volume - pre-TAE volume]/pre-TAE volume) × 100. RESULTS: The median survival time was 419 days (95% confidence interval, 82-474). History of intra-abdominal hemorrhage (P = .03) and pre-TAE tumor volume/body weight (P = .009) were significantly associated with overall survival. The mean reduction percentage was -51% ± 40%. Pre-TAE tumor volume/body weight ratio (cm3 /kg; P = .02, correlation coefficient = 0.704) was significantly correlated with the volume reduction percentage. CONCLUSIONS: History of intra-abdominal hemorrhage and large pre-TAE tumor volume/body weight ratio could be predictive factors for adverse outcomes after TAE. Pre-TAE tumor volume/body weight ratio could be a predictive factor for therapeutic effect.

Transvenous correction of patent ductus arteriosus in two toy-breed dogs with the Amplatzer™ Vascular Plug 4.

Two Pomeranian dogs referred for interventional correction of a left-to-right shunting patent ductus arteriosus (PDA) had inadequate femoral arterial access for any occlusion device other than micro coils. The decision was made to attempt correction of the PDA using the Amplatzer™ Vascular Plug 4 (AVP4) from a femoral venous approach. An AVP4 was successfully deployed in each dog with complete occlusion noted within 5 min. Complete occlusion was persistent at 24 h after the procedure, while both dogs were subclinical, had no residual ductal flow, and complete or near complete reverse cardiac remodeling at subsequent visits. This report demonstrates the feasibility of PDA occlusion with the AVP4 from the femoral venous approach in small dogs where femoral arterial access is inadequate for other occlusion devices.

Percutaneous transvenous coil embolization of congenital intrahepatic portosystemic shunts in small- and toy-breed dogs: 20 cases (2015-2021).

OBJECTIVE: To describe outcomes of small- and toy-breed dogs with a congenital intrahepatic portosystemic shunt (IHPSS) treated with percutaneous transvenous coil embolization (PTCE). ANIMALS: 20 small- and toy-breed dogs with an IHPSS. PROCEDURES: All dogs underwent CT angiography for shunt evaluation as well as PTCE. Medical records were reviewed for pertinent data, and owners and primary veterinarians were contacted for long-term follow-up information. RESULTS: Dogs ranged from 1.5 to 10.0 kg (mean ± SD, 6.32 ± 2.57 kg) in weight. The equipment used to perform PTCE tended to be smaller than that previously described for larger breed dogs. Intra- and postoperative complication rates were 20% (4/20) and 5% (1/20), respectively, and included hypotension, bradycardia, hypercapnia, ventricular premature contractions, hypothermia, and regurgitation. Dogs were discharged a median of 3 days (range, 1 to 3 days) after surgery, and all dogs survived to discharge. Clinical signs resolved in 95% (19/20) of the dogs a median of 21 days after the procedure. One- and 2-year survival rates were 92%. Three dogs had died by the time of data collection; 2 of these dogs died of causes related to the IHPSS 267 and 1,178 days, respectively, after the procedure. CLINICAL RELEVANCE: Percutaneous transvenous coil embolization was a safe and effective option for treatment of IHPSS in small- and toy-breed dogs and offered a minimally invasive alternative to open surgical techniques. Complication and survival rates in this cohort were similar to or better than those reported in previous studies evaluating PTCE and open surgical techniques for treatment of IHPSS in dogs.

Transvenous detachable coiling of patent ductus arteriosus in small dogs.

OBJECTIVE: To report on transvenous detachable coiling in small dogs deemed ineligible for traditional transarterial patent ductus arteriosus occlusion and compare transthoracic echocardiographic and angiographic measurements to determine their equivalence. MATERIALS AND METHODS: A retrospective study of 35 dogs that underwent transvenous coiling of a patent ductus arteriosus. Demographic information, echocardiographic and angiographic studies, surgery reports, and follow-up evaluation of residual flow were obtained. A Bland-Altman analysis was used to compare echocardiographic and angiographic measurements of the minimal ductal diameter (Echo-MDD, Ang-MDD) and ampulla diameter (Echo-A, Ang-A). RESULTS: Thirty-four of 35 dogs had successful deployment of a coil, with one dog undergoing occlusion with a different device after the exteriorized coil pulled through the ductus. Complete occlusion was achieved in 18 dogs within 24 h; four dogs were lost to follow-up, and the remaining 12 dogs had no residual flow or a significant reduction in shunting with normalization in cardiac chamber dimensions by a median of 99 days. Thirty percent of dogs (11/35) experienced perioperative complications of which 10 were minor complications. The analysis of 26 dogs with both echocardiographic and angiographic ductal measurements showed a -0.14 mm mean difference (95% limits of agreement -1.08 to 0.8 mm) in minimal ductal diameter and -0.68 mm mean difference (95% limits of agreement -2.73 to 1.37 mm) in ampulla diameter. CONCLUSIONS: Dogs less than 3 kg deemed too small for transarterial occlusion can successfully undergo transvenous coil embolization of patent ductus arteriosus.

Transvenous embolization of moderate to large patent ductus arteriosus in dogs using the Amplatzer vascular plug II.

BACKGROUND: Catheter-based occlusion of patent ductus arteriosus (PDA) can be performed using different devices. Transvenous embolization using the Amplatzer vascular plug II (AVP-II) has been studied in humans, but it has not been described in dogs. OBJECTIVE: Evaluate the feasibility and success of transvenous embolization of PDA using the AVP-II in dogs. ANIMALS: Nineteen client-owned dogs with left-to-right shunting PDA, with minimal ductal diameter >2.5 mm. METHODS: Prospective observational study using AVP-II with transvenous access for PDA closure in dogs. RESULTS: Angiography showed a conical ductus with a long (n = 17) or short (n = 2) ampulla. The minimal diameter of the duct was 4.34 ± 1.11 mm, and the maximal diameter of the ampulla was 13.18 ± 3.47 mm. Technical success was achieved in 18 of the 19 (94.7%) patients after the first intervention and in all 19 (100%) patients after the second intervention. Postrelease angiography documented complete occlusion of the PDA in 10 of 19 (52.6%) dogs. Mild flow acceleration or stenosis of the left pulmonary artery was found in 6 and 1 of the 17 analyzed cases, respectively, by Doppler examination. The closure rate 24 hours after intervention was 94.7% (18/19). The remaining dog had a moderate residual shunt, and delayed complete closure after 3 months led to a 100% closure rate. CONCLUSION AND CLINICAL IMPORTANCE: The AVP-II is a safe and effective device for transvenous embolization in dogs with moderate to large PDA.

Procedural description and prospective evaluation of short-term outcome for the use of prostatic artery embolization in dogs with carcinoma of the prostate.

OBJECTIVE: To describe the procedure of prostatic artery embolization (PAE) in dogs with prostatic carcinoma and to evaluate the short-term outcome for treated dogs. ANIMALS: 20 client-owned dogs with prostatic carcinomas between May 2014 and July 2017. PROCEDURES: In this prospective cohort study, dogs with carcinoma of the prostate underwent PAE with fluoroscopic guidance. Before and after PAE, dogs underwent CT and ultrasonographic examinations of the prostate, and each owner completed a questionnaire about the dog's clinical signs. Results for before versus after PAE were compared. RESULTS: Prostatic artery embolization was successfully performed in all 20 dogs. Tenesmus, stranguria, and lethargy were significantly less common 30 days after PAE (n = 2, 1, and 0 dogs, respectively), compared with before PAE (9, 10, and 6 dogs, respectively). Median prostatic volume was significantly less 30 days after PAE (14.8 cm3; range, 0.4 to 48.1 cm3; interquartile [25th to 75th percentile] range, 6.7 to 19.5 cm3), compared with before PAE (21.7 cm3; range, 2.9 to 77.7 cm3; interquartile range, 11.0 to 35.1 cm3). All dogs had a reduction in prostatic volume after PAE, with a median prostatic volume loss of 39.4% (95% CI, 20.3% to 59.3%). CONCLUSIONS AND CLINICAL RELEVANCE: Prostatic artery embolization was associated with decreased prostate volume and improved clinical signs in this cohort. The short-term response to PAE appears promising, and evaluation of the long-term impact on survival time is needed.

Transjugular patent ductus arteriosus occlusion in a cat with a peripheral vascular occlusion device.

A five-month-old, intact female domestic shorthair cat was presented to a specialty referral hospital for evaluation of a patent ductus arteriosus. Transvenous embolization of the defect was achieved with a commercially available peripheral vascular plug. The use of vascular plugs for the closure of patent ductus arteriosus has been validated in dogs, yet literature for its use in cats is lacking. The product and procedural details of the device are described.

Dominant outflow vein occlusion in the management of naturally occurring peripheral arteriovenous anomalies in cats and dogs.

Two dogs and 1 cat were referred to a tertiary veterinary center for the consultation and treatment of limb edema, variable dermal sanguineous crusting lesions, and intermittent lameness. A peripheral arteriovenous anomaly (PAA) was diagnosed via computed tomographic angiography (CTA) in each case. Arteriography enabled further evaluation of the PAA with confirmation of a dominant outflow vein. Dominant outflow vein occlusion was achieved by direct ligation in 1 dog and retrograde transvenous glue embolization in the cat and other dog. Repeat arteriography demonstrated resolution of arteriovenous shunting. Presenting clinical signs resolved in all animals. The previously identified aberrant vessels in 1 dog were not identified after CTA 40 days postoperatively. No postoperative complications or recurrence was identified in any case during the 6- to 55-month follow-up period.

Ethylene vinyl alcohol copolymer to treat an intracranial arteriovenous malformation in a dog.

A 6-year-old neutered male German shepherd dog was evaluated for obtundation, blindness, and bilateral exophthalmos. A magnetic resonance imaging scan of the brain was performed and identified an arteriovenous malformation (AVM) with several feeding arterial branches, and venous drainage through the cavernous sinus. Venous vessels rostral to the AVM were severely distended and extended into the retrobulbar spaces. Liquid embolization by injection of ethylene vinyl alcohol copolymer was performed from access points in the maxillary arteries and internal carotid arteries. No intraprocedural complications were encountered, and the dog was discharged the next day. Bilateral enucleation eventually was performed because of exposure keratopathy. At 31 months post-embolization, owners reported that the dog was doing very well clinically with high activity level and normal appetite, and the dog also appeared to be pain free. Although intracranial AVMs are very rare in companion animals, successful treatment using liquid embolization is possible and should be considered.

Use of percutaneous transvenous coil embolization in the treatment of intrahepatic portosystemic shunts in four cats.

CASE DESCRIPTION: 4 cats (6 to 9 months old) were evaluated because of clinical signs consistent with a portosystemic shunt (PSS). CLINICAL FINDINGS: Among the 4 cats, 3 had neurologic abnormalities including ataxia, head pressing, disorientation, and obtundation. One cat was evaluated because of urethral obstruction; a retrieved urethral stone was determined to have urate composition. Clinicopathologic findings (hypoproteinemia, low BUN concentration, and high serum bile acids concentration) were consistent with a PSS in all cats. A diagnosis of intrahepatic PSS (IHPSS) was made for all cats on the basis of ultrasonographic and CT findings. TREATMENT AND OUTCOME: All cats underwent percutaneous transvenous coil embolization (PTCE). No major intraprocedural complications were encountered, and all cats were discharged from the hospital. For the 3 cats that were presented with neurologic signs, an evaluation performed at 12, 14, or 48 months after the procedure revealed resolution of the neurologic signs, and owners reported that the behavior of each cat appeared normal. One cat that initially had neurologic and gastrointestinal signs had lower urinary tract signs after PTCE and developed an acquired extrahepatic PSS. CLINICAL RELEVANCE: Although IHPSSs in cats are uncommon, the outcomes of PTCE for the 4 cats of the present report suggested that this treatment may benefit cats with an IHPSS. No short-term complications were encountered, and all cats had improvement in clinical signs following PTCE, although an acquired extrahepatic PSS was later identified in 1 cat. Further investigation of the use of endovascular techniques for the treatment of IHPSSs in cats and other species is warranted.

Effect of transcatheter arterial embolisation in normal canine liver using trisacryl gelatine microspheres (Embosphere).

The effect of selective transcatheter arterial embolisation (TAE) using trisacryl gelatine microspheres (TGMs) in the normal canine liver was investigated. Selective embolisation was achieved by injecting TGMs into the left hepatic artery through a microcatheter in four healthy dogs. After embolisation, computed tomography (CT), biochemical analysis and histological examination were performed during a 12-week observation period. Embolisation was successful in all four dogs. Postoperative CT revealed consistent embolisation of the artery within the experimental period in three dogs. Hepatic enzyme levels slightly increased after embolisation but tapered to normal ranges. Histological examinations revealed no abnormal changes. Thus, selective TAE with TGMs was well tolerated in normal dogs and may be applicable to canine hepatocellular carcinoma.

Transcatheter embolization of systemic-to-pulmonary artery fistulas in a dog using embolization coils and silk suture.

A 4-month-old intact female Cavalier King Charles spaniel presented for evaluation of a left, basilar continuous murmur. Transthoracic echocardiography suggested anomalous vessels around the main pulmonary artery, and computed tomography angiography revealed two systemic-to-pulmonary artery fistulas. Transcatheter embolization of these fistulas was achieved with a combination of embolization coils and silk suture threads delivered through a microcatheter.

Transcatheter arterial embolisation in four dogs with hepatocellular carcinoma.

Four dogs with hepatocellular carcinoma were treated by transcatheter arterial embolisation. In all dogs, the tumour-supplying arteries were selectively embolised with gelatine sponge particles. Post-embolisation tumour volumes decreased relative to pre-embolisation volumes in all dogs. No adverse reactions were observed in three dogs after treatment but one dog showed pancreatitis. These results suggest that transcatheter arterial embolisation is a feasible treatment for dogs with hepatocellular carcinoma.

Successful transcatheter retrieval of embolized Amplatz Canine Duct Occluders in two dogs.

Transcatheter occlusion of patent ductus arteriosus (PDA) using an Amplatz® Canine Duct Occluder (ACDO) is routinely performed in dogs. Pulmonary embolization of the device is a rarely reported complication of this procedure. We report here the first two cases of successful transcatheter retrieval of an embolized ACDO. An 8-month-old, 21-kg, German shepherd (case 1) was referred for pulmonary edema secondary to a large PDA with left-to-right shunting. After medical stabilization, an emergency procedure for PDA closure was recommended. An 8-mm ACDO was deployed under general anesthesia. The device was released after confirming its stability with a gentle tug test but migrated into the pulmonary trunk. A 10-mm ACDO was subsequently successfully deployed and released. Vascular access was then obtained from the right jugular vein so that a vascular snare could be used to capture the ACDO waist and pull it back toward the right ventricle and then the right atrium. It was then removed through the jugular vein. The dog recovered uneventfully and was discharged after confirmation of complete ductal occlusion. The same complication occurred in a second case (case 2, asymptomatic 6-month-old, 7.9-kg, cocker spaniel), and a similar procedure was used to successfully retrieve the embolized device. Both dogs are still doing well 9 and 21 months, respectively, after the procedure. These cases illustrate that transcatheter retrieval of ACDO devices embolized in the pulmonary artery using vascular snares is technically feasible in the dog.

Hybrid surgical treatment for 2 feline cases of intrahepatic shunt.

Intrahepatic portosystemic shunt was encountered in 2 cats (10 and 5 months old) exhibiting neurological symptoms and general deterioration. Both cats were treated with coil embolization using a hybrid surgical technique combining conventional open surgery and interventional radiology techniques, achieving good postoperative outcomes (follow-up: 22 and 10 months, respectively).

Traitement chirurgical hybride pour deux cas félins de shunt intrahépatique. Un shunt portosystémique intrahépatique a été observé chez deux chats (âgés de 10 et de 5 mois) manifestant des symptômes neurologiques et une détérioration générale. Les deux chats ont été traités par une embolisation utilisant des spires à l'aide d'une technique chirurgicale hybride combinant une chirurgie ouverte conventionnelle et des techniques de radiologie d'intervention afin d'obtenir de bons résultats postopératoires (suivi : 22 et 10 mois, respectivement).(Traduit par Isabelle Vallières).

Outcomes of cellophane banding or percutaneous transvenous coil embolization of canine intrahepatic portosystemic shunts.

OBJECTIVE: To compare clinical outcomes of dogs with congenital intrahepatic portosystemic shunts (CIHPSS) treated with cellophane banding (CB) or percutaneous transvenous coil embolization (PTCE). STUDY DESIGN: Dual-institutional retrospective study. ANIMALS: Fifty-eight dogs with CIHPSS (2001-2016). METHODS: Medical records of dogs undergoing CB or PTCE for CIHPSS were reviewed for signalment, body weight, hematologic values, shunt location, attenuation technique, procedure time, duration of hospitalization, complications, date of follow-up, and cause of death if applicable. RESULTS: Thirty-one dogs underwent CB, and 27 dogs underwent PTCE. No differences were detected between groups for gender, preoperative packed cell volume, albumin, cholesterol, or bile acids. Body weight was greater in dogs treated via PTCE. Shunts differed in location because dogs undergoing CB were diagnosed with more left divisional shunts compared with PTCE dogs. Procedural duration of CB and PTCE did not differ. Dogs treated with CB sustained more minor postoperative complications and were hospitalized longer than dogs treated with PTCE. The 1-year and 2-year survival rates were 89% for the CB group and 87% and 80% for the PTCE group, respectively. The proportion surviving at 5 years was 75% and 80% for CB dogs and PTCE dogs, respectively. CONCLUSION: CB and PTCE are associated with similar short-term and intermediate-term survival. PTCE is a minimally invasive alternative to CB via celiotomy. However, CB allows concurrent abdominal procedures requiring the same approach.

Prospective evaluation of outcome of dogs with intrahepatic portosystemic shunts treated via percutaneous transvenous coil embolization.

OBJECTIVE: To report outcome and complications after percutaneous transvenous coil embolization (PTCE) and evaluate the clinical, laboratory, and imaging changes in dogs with intrahepatic portosystemic shunts (IHPSS) pre-PTCE and post-PTCE. STUDY DESIGN: Prospective clinical trial. ANIMALS: Twenty-five dogs (15 dogs in imaging subgroup) with IHPSS. METHODS: Clinical signs, hematologic, and biochemical parameters were recorded before and 3 months after PTCE. All dogs received the same medical treatment and underwent PTCE. In the imaging subgroup, ultrasonography, hepatic portal scintigraphy, and computed tomography-angiography were performed pre-PTCE and post-PTCE. RESULTS: All evaluated bloodwork values improved by at least 50% of their initial value, by 3 months post-PTCE. Liver volume increased after PTCE (P = .001), but remained lower than normal in 11/15 dogs. Hepatic arterial fraction decreased after PTCE (P = .029), consistent with increased portal blood flow to the liver. Twenty-four of 25 dogs were available for reevaluation at 3 months, and all abnormal clinical signs had resolved in 22/24 dogs. CONCLUSION: PTCE appears promising as a treatment for IHPSS, as clinical signs resolved in most cases, bloodwork abnormalities often normalized, and the procedure was performed safely with minimal complications. PTCE increased hepatic portal perfusion and liver volume in most dogs. These promising results justify a future randomized clinical trial comparing PTCE, other attenuation options, and medical management alone.

Minimally invasive treatment of mesenteric arterioportal fistulas in two dogs.

CASE DESCRIPTION Two Pembroke Welsh Corgis with gastrointestinal signs including inappetence, diarrhea, lethargy, and hypersalivation were referred for evaluation. CLINICAL FINDINGS Diagnostic testing included abdominal ultrasonography and CT angiography. One patient had a cranial mesenteric artery-to-mesenteric vein fistula with multiple acquired extrahepatic portosystemic shunts. The second patient had both cranial and caudal mesenteric artery-to-mesenteric vein fistulas and multiple acquired extrahepatic portosystemic shunts. TREATMENT AND OUTCOME Both patients underwent minimally invasive coil embolization of the mesenteric arterioportal fistulas, with complete occlusion confirmed by means of angiography at procedure completion. Clinical outcome approximately 1 year after treatment was assessed as fair to good because of recurrence of clinical signs that required medical management in 1 dog and some persistent serum biochemical abnormalities. CLINICAL RELEVANCE Outcome for the 2 patients described suggested that coil embolization may be a feasible and effective minimally invasive technique for the treatment of mesenteric arterioportal fistulas in dogs. However, further investigation of the potential for chronic hepatic disease in patients with a history of acquired portosystemic shunts is warranted.

Incidence of postoperative implant-related bacterial endocarditis in dogs that underwent trans-catheter embolization of a patent ductus arteriosus without intra- and post-procedural prophylactic antibiotics.

Intra- and post-procedural prophylactic antibiotics are routinely administered by veterinary cardiologists to dogs that undergo trans-catheter embolization of a patent ductus arteriosus for prevention of implant-related infective endocarditis. The hypothesis of our study was that primary antibiotic prophylaxis is not necessary to prevent bacterial endocarditis. In this retrospective case series 54 client-owned dogs that underwent trans-catheter occlusion of a patent ductus arteriosus in a single tertiary veterinary referral center between 2004 and 2016 were evaluated. Follow-up information was gained by telephone interviews with the owners or the referring veterinarians, or from the digital archives of the authors' clinic. Inclusion criteria were that at least one metal implant (a coil or an Amplatz duct occluder) had to be delivered in the ductal ampulla, no local or systemic antibiotics were given on the day of the intervention or the week thereafter, at least 3 months of postoperative follow-up information was available, and the author was performing the procedure either as the primary or as the supervising cardiology specialist. None of the 54 dogs developed infective endocarditis in the postoperative 3 months. A study describing a similar population reports 2 of the included 47 dogs having developed infective endocarditis in the postoperative period despite the administration of intra- and post-procedural prophylactic antibiotics. We conclude that intra- and post-procedural antibiotic prophylaxis is not justified in dogs that undergo trans-catheter closure of a patent ductus arteriosus. Proper surgical technique and the use of new sterile catheters and implants are sufficient to prevent infective endocarditis in these dogs.