Desaturation and hypotension in a dog undergoing balloon valvuloplasty for pulmonic stenosis

A 4-year old male miniature schnauzer with severe pulmonic stenosis was presented for percutaneous balloon valvuloplasty. The dog had been managed medically with atenolol for a month prior to the procedure. Clinical examination was unremarkable except for auscultation of a grade V/VI left-sided systolic murmur. The dog was premedicated with pethidine. Anaesthesia was induced using diazepam and etomidate and maintained using sevoflurane in oxygen. Angiography was uneventful, but when the guidewire was threaded through the right side of the heart to allow insertion of the balloon catheter, marked desaturation with visible cyanosis developed. This resolved on withdrawal of the guidewire and catheter but recurred each time the guidewire and catheter were repositioned. Balloon valvuloplasty was eventually successful in reducing the pressure gradient across the stenotic valve from 102 to 52 mmHg. Hypoxaemia did not recur during recovery and the dog was discharged the following day.

Percutaneous balloon valvuloplasty of pulmonary valve stenosis: state of the art and future prospects

This study is aimed to delineate readers with an overview of percutaneous balloon pulmonary valvuloplasty (PBPV) of pulmonary valve stenosis (PVS) and highlighting outcome based on influential and recent studies. It has been four decades since Kan et al first introduce PBPV. Since then, PBPV has recognized as a gold standard therapy for PVS of all ages. Nowadays, PBPV is practiced for a broad range of indication such as PVS, PV dysplasia and pulmonary atresia. Typically, PBPV is recommended when gradient across the PV is >50 mmHg. The procedure involves the placement of one or more balloon catheters across the stenotic PV with the guidance of a guidewire; thereafter, inflation of the balloons is done by pressure, thus producing valvotomy. Nowadays, PBPV is done by echocardiographic guidance, but previously, it was done by fluoroscopic guidance. The main disadvantage of fluoroscopy was the radiation injury of patients. The recently recommended balloon/annulus ratio is 1.2 to 1.25. Following the procedure, the dramatic reduction of pressure gradient, free motion of the PV leaflets with less doming, the rise of cardiac output have been noted, whereas complications may occur but are unusual and minimal. Significant predictors of restenosis include balloon/annulus ratio <1.2 and immediate post-PBPV gradient ≥30 mmHg. Only a few percentages of patients needed repeat PBPV. Long-term follow-up results are surprisingly excellent. In conclusion, it is our opinion that PBPV is equally successful in patients of all ages, while worldwide recognized studies prove the safety, feasibility, and effectiveness. However, for early detection of any complication, life-long clinical follow-up is mandatory.

Long-term results of percutaneous balloon valvuloplasty in neonatal critical pulmonary valve stenosis: a 20-year, single-centre experience

IntroductionPercutaneous balloon valvuloplasty is the primary treatment for critical pulmonary valve stenosis in neonates. Thus far, a few studies have reported long-term results of this technique in neonatal critical pulmonary valve stenosis.MethodsWe carried out a retrospective study of all consecutive newborns with critical pulmonary valve stenosis subjected to percutaneous balloon valvuloplasty at a single centre, between 1994 and 2014, to assess its immediate and long-term safety and efficacy.ResultsA total of 24 neonates presented with critical pulmonary valve stenosis. The mean diameter of the pulmonary annulus was 7 mm (±1.19); 33.3% had a dysplastic pulmonary valve, and 92% were started on prostaglandin E1 treatment. Percutaneous balloon valvuloplasty was performed at a mean age of 4.0±4.3 days using, on average, a balloon-to-pulmonary annulus ratio of 1.18 mm (with a range from 0.9 to 1.43). Immediate success was achieved in 22/24 patients (92%) with a reduction in the pulmonary transvalvular peak gradient (p<0.05) and in the right ventricle/systemic pressure ratio (p<0.05). There was one death (4%) 6 days after the procedure, and 29.2% of them had transient rhythm complications. For a mean follow-up time of 8.4 years, the re-intervention rate was 42.9%. In total, 14 re-interventions were performed in nine neonates, including surgery in six. Freedom from re-intervention was 50% at 8 years and 43% at 10 and 15 years.ConclusionThis series, to the best of our knowledge, has had the longest follow-up of neonates with critical pulmonary valve stenosis. Percutaneous balloon valvuloplasty is a safe and effective treatment, and in our study 75% of the patients were exclusively treated using this technique.