PDA closure
PDA closure: The PDA is a persistent connection between Aorta and Pulmonary artery which has not closed after birth. Untreated it will result in left sided heart failure in many patients. The heart failure signs are usually difficult to control. Further, it can trigger changes in the pulmonary vessels resulting in severe pulmonary hypertension. Both scenarios have a huge impact on the quality of life and will lead to premature death. Treated early in life will however give many patients a completely normal life expectancy. Early diagnosis and treatment is therefore very important. Continuous heart murmurs which are typical for patients with a PDA should therefore always prompt cardiac workup.
The team at SCVS has pioniered a novel keyhole method for PDA closure in the UK, which allows us to close PDAs in patients as small and smaller than 1kg and preserve the femoral artery, which is not possible with the more routinely used ACDO technique. At SCVS, the PDA closed by with a special vascular plug. It is positioned in the ductus following percutaneous punction of the femoral vein and retrograde catherisation of the heart. The recovery time is very short and patients usually can be discharged the following day.
Balloon valvulplasty
Balloon Valvuloplasty is a technique used to improve the function of stenotic valves. The most common stenosis we see is pulmonic stenosis. Patients with marked pulmonic stenosis usually present with a systolic heart murmur. Untreated, the pressure in the right ventricle can be very high, which results in myocardial damange and subsequently arrhythmias and / or heart failure. Patients will develop syncope, exercise intolerance and / or ascites over time or they can suffer from sudden cardiac death. Performing a balloon valvulplasty will dramatically improve the function of the abnormal valve, improving life expectancy and alleviating clinical signs.
The earlier in life the intervention is performed the better the chances for a good outcome. In addition, use of high pressure balloons has an impact on the outcome. At SCVS we are using exclusively high quality high pressure balloons for these procedures to achieve the best possible outcome.
Our percutaneous technique allows rapid recovery and patients are usually discharged the following day.
Besides the Pulmonic valve, also other heart valves like Aortic valve or Tricuspid valve and other obstructions like a Cor Triatriatum Dexter can be approached by balloon valvuloplasty if indicated.
Pulmonic Valve Stenting
While balloon valvuloplasty is usually the method of choice in patients with pulmonic stenosis, there are indications for placing a stent accross the valve such as
- Re-stenosis following balloon valvulplasty
- Some morphologies such as hypoplastic pulmonic annulus
- Aberant coronary arteries
In such scenarios, very careful patient assessment is key before making a decision towards stenting as stent placement carries higher risks than balloon dilation. For good outcomes, precise stent positioning is key. This requires advanced interventional skills which the cardiology team at SCVS provides.
Pacemaker Implantation
Bradyarrhythmias as AV-block or Sinusarrest often require implantation of a pacemaker to restore a normal heart rate. Untreated these conditions lead to exercise intolerance, syncope, heart failure or even sudden cardiac death. More commonly these problems are found in older patients, but are sometimes also seen in younger animals.
Implantation of a pacemaker gives patients usually a normal quality of life. Clinical signs like exercise intolerance and syncope will disappear.
Many different pacemaker systems exist. Most commonly single chamber pacemaker systems with only one pacemaker lead in the right ventricle are fitted in dogs. This is probably sufficient for many patients and takes care of the risk of sudden cardiac death. Nevertheless, implantation of the more complex dual chamber pacemaker units which we also offer at SCVS units can be beneficial in certain patients and could result in superior outcome.
Implantation of pacemakers is performed via cutdown to the jugular vein. The vein is used to feed the electrode(s) into the heart. The pacemaker itself is then positioned subcutaneously in the neck area. Implantation is therefore very minimal invasive and patients can usually be discharged 1-2 days following surgery.
Optimal programming of the pacemaker is essential for best results. We are running pacemaker clinics a cooperation with human electrophysiologists to ensure the pacemakers of all our patients are set in the best possible way.
Other interventions
Besides the interventions explained above, there are various other vascular abnormalities which can be addressed via keyhole procedures. Arterio venous fistulas, aorto pulmonary fistulas as in the picture below, compressed vessels due the neoplastic mass lesions are some examples of complex interventions performed at SCVS.
