J Vet Sci.  2008 Jun;9(2):197-202. 10.4142/jvs.2008.9.2.197.

Percutaneous heartworm removal from dogs with severe heart worm (Dirofilaria immitis) infestation

• Lee SG
• Moon HS
• Hyun C

• KMID: 1106236
• DOI: http://doi.org/10.4142/jvs.2008.9.2.197

Abstract

Canine heart worm disease is often life-threatening due to its various complications, including right side heart failure, caval syndrome and pulmonary eosinophilic granulomatosis. Several preventive medications and melarsomine have been developed and they are very effective to control heartworm infestation. However, in a case of severe infestation, melarsomine therapy often results in an unfavorable outcome because of the severe immune reaction caused by rapid killing of the adult worm. Surgical removal and an interventional method using flexible alligator forceps have been well described in the literature. Despite the usefulness of mechanical removal using flexible alligator forceps, the methodology still needs to be upgraded for increasing the applicability for treating dogs with severe infestation. We describe herein a newly developed percutaneous removal method for heartworms and this was successfully applied to 4 dogs with severe heartworm infestation. The follow-up studies also showed favorable outcomes with no complications.

Keyword

caval syndrome; dirofilariasis; dogs; heartworm; percutaneous removal

MeSH Terms

Animals
Catheterization/veterinary
*Dirofilaria immitis
Dirofilariasis/*surgery
Dog Diseases/*surgery
Dogs
Echocardiography
Electrocardiography
Fluoroscopy/methods/veterinary
Surgical Instruments/veterinary
Thoracic Surgical Procedures/methods/*veterinary

Figure

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  Fig. 1 The heartworm removal devices used in this study. (A) Endoscopic grasping forceps. (B) Flexible three wires nail-tipped forceps.

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  Fig. 2 The procedure for mechanical heartworm removal. (A) After achieving surgical anesthesia, venipuncture was performed at the right jugular vein with an 18G needle. Then a guidewire was inserted into the needle and this was located at the pulmonary artery. (B) An introducer sheath was inserted to the right external jugular vein with guidance of a pre-placed guidewire, and the sheath was located at the pulmonary artery. (C) The guide catheter was then removed from the sheath. (D) The sheath was temporarily tied with simple interrupted suture.

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  Fig. 3 The procedure for mechanical heartworm removal (continued). (A) After the sheath was inserted into the right cardiac chamber or pulmonary artery, the removal device was inserted into the sheath. (B) Heartworm removal was performed at the pulmonary artery with fluoroscopic guidance. (C) The heartworms were removed from the sheath. (D) The mechanically removed heartworms. E: An introducer sheath used in this study.

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  Fig. 4 Images from Case No. 2. (A) The heartworms (8 females, 7 males) removed from the right atrium with a single retrieval. (B) The urine before and after (inset) the heartworm removal. The dog's hemoglobinuria disappeared after the heartworm removal.

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  Fig. 5 Electrocardiograms (ECG) from Case No. 2. (A) The ECG recorded before the heartworm removal revealed normal sinus rhythm with occasional ventricular premature complexes (the 4th, 5th, 7th 8th and 10th QRS complexes). (B) The heart rhythm returned to sinus rhythm. No ventricular premature complexes were recorded on the 1 h ECG recordings.

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  Fig. 6 Echocardiographic evaluation of Case 2 before and after the heartworm removal (right parasternal short axis view, right outflow tract level) Left: before the procedure, many heartworms (arrowheads) are visible in the right ventricular outflow tract and pulmonary arteries. Right: after the procedure, no heartworms are visible in the right ventricular outflow tract and pulmonary arteries.

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