Surgical treatment of pulmonic stenosis in dogs under cardiopulmonary bypass: outcome in nine dogs

Type B valvular and supravalvular pulmonic stenosis with aberrant pre-pulmonic right coronary artery diagnosed by non-electrocardiography-gated, multislice computed tomography in a Boston terrier

Pulmonic stenosis (PS) is a common congenital heart disease in dogs. It may be associated with an aberrant coronary artery (CA) in brachycephalic breeds. If present, a CA anomaly must be identified before pulmonic valvuloplasty. A 1.7-year-old Boston terrier was referred for a grade V/VI systolic heart murmur and exercise intolerance. Echocardiography revealed combined type B valvular and supravalvular PS; an aberrant CA was also suspected. Non-electrocardiography (ECG)-gated, 160-multislice computed tomographic angiography (CTA) confirmed severe right ventricular wall hypertrophy, a hypoplastic pulmonic valve annulus, and severe supravalvular PS with a marked main pulmonary artery bulge; a single left coronary ostium with an anomalous pre-pulmonic right CA was also identified. Surgical correction with pulmonic valvuloplasty and pulmonary artery patch angioplasty under cardiopulmonary bypass was planned. The patient died intraoperatively due to profound hypotension after weaning from extracorporeal circulation. However, this is the first case report in which type B valvular and supravalvular PS with an aberrant pre-pulmonic right CA was diagnosed by non-ECG-gated, 160-multislice CTA in a Boston terrier, showing a similar level of image quality to ECG-gated CTA. Thus, in PS cases, high-slice CTA may be helpful to determine if CA anomalies are present and to establish a therapeutic plan.

Transvalvular pulmonic stent angioplasty: procedural outcomes and complications in 15 dogs with pulmonic stenosis

INTRODUCTION

Balloon valvuloplasty is the treatment of choice for dogs with severe type A pulmonic stenosis (PS), but less successful for dogs with annular hypoplasia and unsuitable for supravalvular stenosis or cases with a circumpulmonary coronary malformation. We report outcomes and complications of the first 15 consecutive transvalvular pulmonic stent angioplasty procedures performed by a single center in dogs with PS.

ANIMALS

Fifteen dogs with naturally occurring PS were included in the study.

MATERIALS AND METHODS

Dogs underwent echocardiography before and four weeks after the procedure. Transvenous approaches were used to deploy a pre-mounted, balloon-expandable metallic stent in all cases.

RESULTS

Of 15 dogs, all had annular hypoplasia, and in addition, supravalvular stenosis was diagnosed in 11 of 15 dogs, and three had R2A coronary malformation. All dogs survived to discharge. One dog died less than four weeks postoperatively (non-cardiac), but 14 of 15 dogs were re-examined at four weeks. Severity reduced in all cases; median pressure gradient reduced from 137 mmHg (range 81-202 mmHg) to 83 mmHg (range 31-155 mmHg). Clinical signs improved in all cases, and hematocrit reduced in all dogs with erythrocytosis. The median follow-up time was 280 days (range 95-896 days). Over one-year follow-up was available in six of fifteen dogs. Two dogs died because of refractory right-sided congestive heart failure signs: one at 10 months and one at 22 months postoperatively.

CONCLUSIONS

Transvalvular pulmonic stent angioplasty technique was associated with an improvement in clinical signs and reduction in stenosis severity for all dogs in this population, including cases with supravalvular PS or circumpulmonary coronary malformation.

Key considerations in the approach to congenital heart disease in dogs and cats

Congenital heart disease is an important subset of all cardiovascular disease in dogs and cats that is present at birth and most often detected in young animals but can be diagnosed in adulthood. The range of abnormalities that can occur during development of the heart is vast incorporating simple and complex defects, varying degrees of severity and clinical presentations that include heart failure and cyanosis. While some defects do not result in morbidity in an individual animal, others cause severe clinical signs and death at a young age. Advances in imaging and expanding treatment options offer increasingly more possibilities in the diagnosis and management of congenital heart disease which is the focus of this review. The objective is to provide a broad overview of current practice and highlight key aspects to guide practitioners in their approach to congenital heart disease diagnosis and knowledge of available treatment options.

Immediate outcomes of low-pressure balloon valvuloplasty for severe pulmonary valve stenosis in 20 dogs: a retrospective, single-center case series

INTRODUCTION

The primary objective of this study was to describe the immediate post-procedural outcomes in dogs with severe pulmonary stenosis that were treated with low-pressure balloon valvuloplasty (BV) at a single institution.

ANIMALS, MATERIALS AND METHODS

Retrospective case series; medical records of dogs that underwent BV performed with a balloon dilation catheter >20 mm in diameter and a burst pressure of less than 4 atm (atm) were retrospectively reviewed. Twenty animals were identified fitting the criteria. Pre-procedural and post-procedural echocardiograms and peri-procedural angiograms were reviewed. Procedural success was defined as greater than 50% reduction in echocardiographically derived transpulmonary systolic pressure gradient (TPPG) or post-procedural TPPG of less than 50 mmHg.

RESULTS

The median percent reduction from initial TPPG was 53% (range = 15-90%). Sixty percent of the dogs met the pre-specified criteria for a successful outcome. Post-procedural TPPG was not different based on valve types A or B (p=0.67), presence or absence of additional supravalvular (p=0.23) or subvalvular (p=0.83) obstructive components.

DISCUSSION

The proportion of dogs that reach the successful outcome were not different based on valve type A or B. No relationship was noted between immediate outcomes and bodyweight or pulmonary annulus diameter.

CONCLUSION

Dogs with severe pulmonic stenosis that underwent low-pressure BV had good immediate outcomes with no difference in outcome based on valve morphology. Further randomized controlled studies are needed to compare the outcomes of different strategies for BV in dogs with large-diameter pulmonary annulus.

Clinical features and outcome of dogs and cats with bidirectional and continuous right-to-left shunting patent ductus arteriosus

Background

Studies describing the clinical progression of animals with reverse patent ductus arteriosus (PDA) are lacking.

Objectives

To describe the signalment, presenting signs, echocardiographic features, and survival in a group of dogs and cats with bidirectional and continuous right‐to‐left PDA.

Animals

Forty‐six client‐owned animals included, comprising 43 dogs and 3 cats with bidirectional or continuous right‐to‐left PDA.

Methods

Retrospective multicenter study. Medical records and echocardiographic findings reviewed from animals diagnosed with bidirectional or continuous right‐to‐left PDA. Impact of ductal morphology, spectral Doppler flow profile, PCV, sildenafil treatment at presentation, sildenafil dose, severity of pulmonary hypertension, general anesthesia with or without surgery and the presence of right‐sided congestive heart failure (R‐CHF) on crude mortality rate were evaluated via Mantel‐Cox log rank comparison of Kaplan‐Meier survival curves. Univariable and multivariable Cox proportional hazards analysis was performed, and hazard ratio (HR) (95% confidence intervals [CI]) was presented.

Results

Hindlimb collapse was the most common presenting sign in dogs (n = 16). Clinical signs in cats were variable. Median survival time was 626 days in dogs (range 1‐3628 days). Dogs with R‐CHF had a shorter median survival time (58 days vs 1839 days, P = .03). Dogs treated with sildenafil at initial presentation survived longer (1839 days vs 302 days, P = .03), which was the only independent predictor of survival (HR 0.35, CI 0.15‐0.86, P = 0.021).

Conclusions and Clinical Importance

Dogs and cats with reverse PDA have a variable clinical presentation and prognosis. Survival time was longer in animals prescribed sildenafil at diagnosis. Dogs with R‐CHF at presentation have a worse overall outcome.

Combined interventional procedure and cardiopulmonary bypass surgery in a dog with cor triatriatum dexter, patent foramen ovale, and pulmonary stenosis

A 2‐year‐old American Pit Bull dog was presented for surgical evaluation of imperforate cor triatriatum dexter (CTD) and patent foramen ovale (PFO). Echocardiography identified an imperforate CTD associated with a right‐to‐left shunting PFO and valvular pulmonary stenosis. A 2‐step interventional and surgical approach was used. Initially, a pulmonary balloon valvuloplasty was performed, and subsequently the dog underwent a surgical correction of the atrial anomaly under cardiopulmonary bypass.