Hemolysis associated with patent ductus arteriosus coil embolization in a dog

Red blood cell abnormalities occur in dogs with congenital ventricular outflow tract obstruction

OBJECTIVE

To document RBC abnormalities in dogs with congenital ventricular outflow tract obstruction.

ANIMALS

62 dogs with pulmonic stenosis (PS) or aortic stenosis (AS) and 20 control dogs were recruited.

PROCEDURES

The proportions of RBCs that were schistocytes, acanthocytes, and keratocytes were assessed. Complete blood cell counts were performed. Tested variables included hemoglobin concentration, hematocrit, and erythrocyte count.

RESULTS

Median (interquartile range [IQR]) peak systolic Doppler-derived trans-stenotic pressure gradient (∆P) values were 161 mm Hg (108 to 215 mm Hg) and 134 mm Hg (125 to 165 mm Hg) for dogs with PS and AS, respectively. Hematologic abnormalities were detected in most dogs with AS or PS (54/62 [87%]) versus 8/20 [40%] in control dogs, with schistocytes found in 40 of 62 (65%; median, 0.1% RBCs; IQR, 0% to 0.3%), acanthocytes in 29 of 62 (47%; median, 0.3% RBCs; IQR, 0% to 0.9%), keratocytes in 39 of 62 (63%; median, 0% RBCs; IQR, 0% to 0.2%), and hemolytic anemia in 4 dogs with PS. No significant association was identified between these abnormalities and ∆P. However, 3 of 4 dogs with anemia had a ∆P > 200 mm Hg (range, 242 to 340 mm Hg). The dog with the highest ∆P value also had the most severe anemia and schistocytosis, and both resolved after balloon valvuloplasty.

CLINICAL RELEVANCE

Poikilocytosis is common in dogs with congenital ventricular outflow tract obstruction, with anemia only observed in few dogs with high ∆P values.

Transatrial stenting for long-term management of cardiac tumor obstruction of the right atrium in 3 dogs

Background

Venous obstruction in dogs caused by large intracardiac masses can result in severe morbidity with few safe treatments.

Hypothesis/Objectives

Retrospective study to report results after transatrial stent placement in dogs with naturally occurring cardiac masses causing venous obstruction.

Animals

Three client‐owned dogs diagnosed with large cardiac masses.

Methods

Retrospective study of patients that received transatrial stents extending from the caudal vena cava, across the right atrium, and into the cranial vena cava (CrVC). Procedures, complications, and outcomes were recorded based upon medical records, referring veterinarians, and client communications.

Results

Two dogs had similar clinical signs suggestive of congestive hepatopathy including marked ascites and lethargy. One dog had clinical signs of CrVC syndrome including head and neck swelling with pitting edema and pleural effusion. After stent placement, venous pressure gradients were decreased and repeat angiography confirmed that vascular patency was reestablished. Resolution of clinical signs was marked in all 3 dogs with only mild complications including tachyarrhythmias and hypertension in 1 dog during the perioperative period. Two dogs that required additional transatrial stent placement for reobstruction 6 and 14 months later improved after the second stent implantation. Survival times poststenting for the dogs were 3, 21, and 37 months, with cause of death related to the cardiac tumor in all dogs.

Conclusions and Clinical Importance

Endovascular transatrial stenting may provide a long‐term palliative treatment option for dogs with clinical signs attributable to tumor‐induced venous obstruction when more traditional treatments are declined or not indicated.

Transcatheter embolisation of patent ductus arteriosus using an Amplatzer vascular plug in six dogs

OBJECTIVES

The objective of this study was to assess the feasibility of transcatheter embolisation of a patent ductus arteriosus using an Amplatzer vascular plug (Amplatzer Medical UK) in six dogs.

METHODS

The Amplatzer vascular plug is a self-expandable, cylindrical device attached to a delivery cable. In all the dogs, the device was delivered transvenously. Successful device implantation was defined as firm anchorage of the device squarely within the distal part of the ductus arteriosus with no intra- or postoperative dislodgement. Successful occlusion of the ductus arteriosus occurred if a disappearance of the continuous murmur was achieved 24 hours after placement of the Amplatzer vascular plug.

RESULTS

The age of the dogs ranged from 16 weeks to 7.5 years. Their weights ranged from 2.9 to 27.6 kg (median 6 kg). Two dogs had congestive heart failure before embolisation. Successful device implantation was achieved in all dogs. Successful occlusion of the ductus arteriosus was achieved in four of the six dogs. Complications included mild lameness, residual shunting, and bruising and pruritus around the surgical wound site. At follow-up, two dogs had a continuous murmur and one required treatment for congestive heart failure.

CLINICAL SIGNIFICANCE

This technique may represent a clinically effective and less expensive alternative to the use of an Amplatzer duct occluder (Amplatzer Medical UK) in dogs with medium-sized patent ductus arteriosus. Further investigations are required to fully evaluate its efficacy and safety in various sizes and types of patent ductus arteriosus, and to determine the optimal device size in relation to the size of the ductus.

Retrospective Comparison of Surgical Ligation and Transarterial Catheter Occlusion for Treatment of Patent Ductus Arteriosus in Two Hundred and Four Dogs (1993?2003)

OBJECTIVE

To compare procedure time, complications, mortality, and short-term outcome in dogs with patent ductus arteriosus (PDA) treated by surgical ligation (SL) or transarterial coil occlusion (TCO).

STUDY DESIGN

Retrospective study.

ANIMALS

Dogs with PDA (n=204).

METHODS

Medical records of dogs treated for PDA were reviewed. Dogs treated by SL when it was the primary method used for PDA treatment (1993-1998) were compared with dogs treated by TCO when it was the primary method used for PDA treatment (1999-2003). Dogs treated during the transition between techniques, dogs treated with SL (1999-2003) and dogs treated with TCO before 1999, as well as dogs with pulmonary hypertension, or bidirectional or reversed (right-to-left) flow through the PDA were excluded from analysis.

RESULTS

Age, weight, gender distribution, and procedure times (P=.43) were similar for both groups. Major complications were more common with SL (12% versus 4.3%; P=.035) whereas minor complications were more common with TCO (12% versus 26%; P=.015). Initial success rate was higher for SL (94%) compared with TCO (84%; P=.027). There was no significant difference in mortality between SL (5.6%) and TCO (2.6%; P=.27).

CONCLUSIONS

Both SL and TCO are acceptable PDA treatments with comparable mortality; however, SL was associated with a higher risk of major complications and TCO was associated with a lower initial success rate.

Coil embolization of a congenital orbital varix in a dog

A 10-week-old Labrador Retriever was examined because of a swelling above the left eye. Ophthalmic examination revealed a tubular, light-pink, slightly raised lesion of the left conjunctiva that extended from the limbus to the fornix and into the dorsal eyelid. The lesion affected the entire margin of the dorsal eyelid and extended 2 cm dorsal to the eyelid margin. With compression of the left jugular vein, the exophthalmos worsened immediately and the subconjunctival and eyelid lesion enlarged. Results of ultrasonography, computed tomography, and contrast venography were consistent with a diagnosis of an orbital varix. Coil embolization was elected for treatment of the varix to prevent the pain and morbidity associated with an orbitotomy. Coils were introduced through a 22-gauge IV catheter inserted through the upper eyelid into the varix. The only complication was moderately severe orbital swelling. The owners reported that the lesion had resolved by 2 weeks after coil embolization.

Transvenous coil embolization of portosystemic shunt in dogs

This paper describes transvenous coil embolization of portosystemic shunt in 10 dogs. Clinical signs resolved in 4 dogs with extrahepatic shunt, and in 3 dogs with intrahepatic shunt. Two dogs of less than 3 kg died because of migration of coils to the level of the main pulmonary artery. One dog was euthanized when acute portal hypertension developed following transvenous coil embolization. Transvenous coil embolization seems to be a less invasive alternative to surgical ligation in dogs with a single intrahepatic portosystemic shunt.

Retrieval of a patent ductus arteriosus coil following embolisation to the right subclavian artery

A two-month-old female Tibetan terrier was re-presented with an incomplete closure of the patent ductus arteriosus. Following a second attempt to close the shunt by coil embolisation, arterial embolisation occurred. The successful removal of the embolised coil is described.