Percutaneous balloon valvuloplasty in four dogs with pulmonic stenosis

Congenital Pulmonic Stenosis a Retrospective study of 24 cases seen between 1990-1999

BACKGROUND

PBV is the treatment of choice for humans with pulmonic stenosis and whilst this procedure has been used in dogs the longer term benefits remain to be evaluated.

OBJECTIVES

The purpose of this study was to evaluate the long term effects of pulmonary balloon valvuloplasty (PBV) in dogs with congenital pulmonic stenosis, with respect to clinical signs, echocardiographic parameters and survival time. Methods - Pulmonic stenosis was diagnosed in 24 dogs between 1990-1999. Eighteen cases were treated with PBV, six were not treated.

RESULTS

Twelve of the treated cases were alive and asymptomatic at the time of writing. Follow up periods ranged from six months to nine years post PBV. Prior to treatment the mean Doppler pressure gradient across the pulmonic valve was 98mmHg, 24 hours post treatment the mean was 65mmHg and in the long term this was maintained at 64mmHg. Three of the dogs (17 per cent) treated with PBV restenosed during the follow up period. Four of the six untreated dogs were alive at the time of writing, two to four and a half years after presentation. The mean Doppler gradient for this group was 89 mm Hg on presentation.

CONCLUSION

At this stage in the follow up period there is no significant difference in survival times between the treated and untreated groups. However, symptomatic dogs with pulmonic stenosis treated with PBV have experienced a reduction in clinical signs and therefore an improved quality of life.

Results of balloon valvuloplasty in 40 dogs with pulmonic stenosis

The records of 43 dogs presenting with severe pulmonic stenosis in which balloon valvuloplasty was attempted were reviewed. Thirty-four dogs (79 per cent) were symptomatic at initial presentation. All patients were selected for balloon valvuloplasty on the basis of a Doppler-derived trans-stenotic pressure gradient of over 80 mmHg and concurrent evidence of mild to severe right ventricular hypertrophy. Forty dogs underwent balloon valvuloplasty; the procedure was not performed in three dogs because of an aberrant coronary artery in two cases and because catheterisation of the pulmonary artery was not possible in the third. Overall, 37 out of the 40 dogs (93 per cent) were successfully ballooned, resulting in a mean reduction in the pressure gradient of 46 per cent, with a mean pressure gradient of 124 mmHg on presentation and 67 mmHg six months after the procedure. Three dogs died during balloon valvuloplasty (all of which had a concurrent defect) and three dogs showed a poor clinical response to the procedure. Thus balloon valvuloplasty was successful and resulted in a sustained clinical improvement in 80 per cent of previously symptomatic cases. This study was undertaken to document the results of balloon valvuloplasty in a larger population of dogs than has previously been published.

Pulmonic stenosis in two cats

The clinical, radiographic and echocardiographic features of two cases of pulmonic stenosis in cats are presented. A rarely reported combination of pulmonic stenosis and tricuspid valve dysplasia is described.

Use of a modified open patch-graft technique and valvulectomy for correction of severe pulmonic stenosis in dogs: eight consecutive cases

A modified open patch-graft technique was used to correct congenital pulmonic stenosis in 8 dogs. Pulmonary valve dysplasia was moderate to severe in all cases, based upon clinical and echocardiographic criteria, and 3 dogs were in right-sided congestive heart failure at the time of surgery. Seven of the 8 dogs survived the surgery. One surviving dog displayed cerebral cortical dysfunction, the remaining 6 had no detectable neurological sequelae. Right ventricular failure was alleviated in all 7 surviving dogs, but right ventricular dilatation persisted post-operatively. Pulmonary valvulectomy and open patch-grafting provides an effective means of alleviating signs of congestive heart failure caused by pulmonary valve dysplasia, even in the presence of severe infundibular hypertrophy and dynamic outflow obstruction.