Dr. Koneti Nageswara Rao. 

Hyderabad: Pediatric cardiologist from Hyderabad, Dr. Koneti Nageswara Rao, has recently received patent rights for his cardiac device `KONAR-MF’.

Since 2013, Dr. Rao, who is also the director of Rainbow Children’s Heart Institute, and his team have been working on developing the technique and the appropriate multi-functional occluder for the transcatheter device closure of Ventricular Septal Defect (VSD).

The team first developed a retrograde technique of VSD closure using a device ADO2 meant for a congenital heart defect called Patent Ductus Arteriosus (PDA). The early results were presented at the American College of Cardiology meeting in Chicago in 2012.

This paper was awarded as the best innovation paper from India. They started developing an occluder useful for closing defects even in small-size babies. The occluder could be delivered through small catheters and would not produce heart block and be useful in closing other defects such as fistulas, paravalvular leaks, etc.

“The new occluder design was developed using a medium profile NITINOL (nickel and titanium alloy) wire braid. The device has a narrow connector to elongate and reduce the stress on the electrical system of the heart so that a heart block will not be produced. Other advantages included hemodynamic advantage, delivery screws on either side making the operator deploy easily from both venous and arterial sides. This device will go through smaller catheters so that it can be used even for smaller babies (weighing 1.5 kg).

The KONAR-MF (Koneti Nageswara Rao-Multi Functional) occluder is unique in its design of incremental diameter and stretchability to prevent clamping force and shear stress. It got European EC approval in 2019. Euro-African and Korean patents were granted in 2021 and 2022. Finally, the Indian patent was granted after several critical examinations in 2023,” said Dr. Rao.

“Globally, around 10 out of 1,000 babies are born with congenital (by birth) heart defects every day. Ventricular septal defect (VSD) - a hole between two lower chambers (ventricles) of the heart is the commonest and constitutes 25% to 30% of all congenital heart defects. Children born with VSDs present with heart failure symptoms like feeding difficulties, breathing problems, and poor weight gain.

Untreated children may develop complications like frequent pneumonia, pulmonary hypertension (high lung blood pressure), and infection of the heart (endocarditis). These serious complications may cause significant morbidity and mortality and need to be closed." he said.

Complications caused by early devices

Nearly 60% of VSDs are closed spontaneously over three to five years of age. Patients with early diagnosis and severe heart failure may be benefitted from surgery between three to six months of age. However, the complications of open-heart surgery are always an issue and necessitated the invention of a less invasive procedure called transcatheter device closure. This procedure became popular for closing VSDs in early 2000 but caused serious complications like the development of heart block leading to the withdrawal of its usage.

The early devices called Amplatzer occluder caused clamping force and shear stress on the electrical conduction system of the heart and therefore FDA recommended its withdrawal from the market. So, patients with VSDs had only one option of treatment, namely open heart surgery (even for the moderately suitable holes for device closure in children).

The device is an alternative to open-heart surgery

Now the KONAR-MF device is available commercially through Lifetech Scientific Co, Schengen. More than 10,000 patients got benefited in the last three years using the device in more than 80 countries including Germany, Italy, UK, USA, and Japan. The cost of the device in India is around Rs 50,000, which is around 75%-50 % less than in other European and Asian countries.