Supplemental embolization coil implantation for closure of patent ductus arteriosus in a beagle dog

Minimally invasive per-catheter occlusion and dilation procedures for congenital cardiovascular abnormalities in dogs

With ever-increasing sophistication of veterinary cardiology, minimally invasive per-catheter occlusion and dilation procedures for the treatment of various congenital cardiovascular abnormalities in dogs have become not only available, but mainstream. Much new information about minimally invasive per-catheter patent ductus arteriosus occlusion has been published and presented during the past few years. Consequently, patent ductus arteriosus occlusion is the primary focus of this article. Occlusion of other less common congenital cardiac defects is also briefly reviewed. Balloon dilation of pulmonic stenosis, as well as other congenital obstructive cardiovascular abnormalities is discussed in the latter part of the article.

Evaluation of the efficacy and safety of coil occlusion for patent ductus arteriosus in dogs

We performed a retrospective study of 56 dogs with Patent Ductus Arteriosus (PDA) to evaluate the indications for and efficacy of transarterial PDA coil embolization. Transarterial PDA coil embolization was conducted in 37 cases (66.1%) and surgical ligation was conducted in 16 cases (28.6%). Three cases (5.4%) were diagnosed as pulmonary hypertension and were excluded from surgical intervention. Although coil dislodgement was observed in the pulmonary artery in one case, no death occurred during coil embolization or surgical ligation. Echocardiography showed that fractional shortening decreased from 35.4 +/- 6.8% to 30.2 +/- 5.9% (P<0.05) after transarterial PDA coil embolization. Although slight residual shunts were observed in 18 cases, transarterial PDA coil embolization was effective treatment of PDA.

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.

Percutaneous transcatheter coil embolization of a ventricular septal defect in a dog

A 4-month-old male French Bulldog weighing 5.0 kg (11 lb) was referred for a heart murmur. A grade 3/6 systolic murmur was detected at the left heart base and a grade 4/6 systolic murmur was detected at the right heart base. By use of color-flow Doppler ultrasonography and cardiac catheterization, a diagnosis of supracristal ventricular septal defect (VSD) with accompanying aortic regurgitation was made. Percutaneous transcatheter coil embolization was used to close the VSD. Because residual shunt was detected via echocardiography after coil implantation, the residual shunt was followed periodically via echocardiography to detect spontaneous closure of the VSD. Volume overload in the left ventricle was detected in the dog 131 days after admission. Additional coils were placed 137 days after admission. Hemolysis resulting in hemoglobinuria was detected, but this complication was mild. In the dog of this report, results of coil occlusion for correction of VSD were promising. Thus, coil occlusion should be considered as an alternative treatment for VSD in dogs.