The dynamic speciality of Cardiac surgery is relatively new in the field of Medicine. The first open heart surgery was done just 65 years back after the invention of heart lung machine in 1953 by Dr John Gibbon. Rapid advancement in the field is happening with gain in knowledge, introduction of technology and procurement of skills. Dramatic advances is expected in the near future which will make the cardiologist and cardiac surgeon work as a team developing patient friendly, less risky and less morbid procedures focusing on early recovery with good cosmetic appeal.
Ischemic Heart Disease
Primary culprit vessel angioplasty is the treatment for acute heart attack. Only very rarely is cardiac surgery indicated in the acute scenario, for example, when complications of heart attack occur like sudden severe valve leak or severe muscle damage causing holes between the chambers of the heart or when the heart muscle ruptures externally into the pericardial cavity. In the future, effective use of devices may help to tackle these complications without resorting to cardiac surgery.
In nonacute cases, there are circumstances where the interventional cardiologist and cardiac surgeon have difference of opinion regarding best line of management. Evolution of more scientific evidence will help to focus on best practices, reducing practice variation and unnecessary or harmful procedures.
Heart teams have evolved which will work in unison to combine interventional and less invasive surgeries and these hybrid procedures can be increasingly applied for coronary revascularisation, with minimally invasive or robotic surgery for left sided vessels and angioplasty for right sided blocks. A “hybrid room” where the catheterisation lab and operating room is combined, helps to perform both procedures in one sitting..
Valvular Heart Disease
Nonsurgical valve replacement procedures via catheters in cathlab are on the rise. The candidates for such procedures initially were the frail and elderly patients with multiple comorbidities. The future will see more of these devices being used in lower risk and younger patients. The transcatheter valve replacement procedure which was started for aortic valve is now being expanded to cater to other valves also. Once a transcatheter valve fails that problem also can be tackled without surgery by introducing another valve inside the first valve, called a “valve-in-valve” procedure.
Tissue valve usage will be on the rise making mechanical valves obsolete. Tissue valve durability is being improved with better tissue preparation and preservation techniques. The future may bring the ‘ideal’ custom made bioengineered valves from patients own stem cells which will reduce the need for mechanical valves that require obligate lifelong blood thinners (anticoagulants) which need constant monitoring and carries risk of bleeding.
Cardiac Transplantation and Mechanical Circulatory Support
With advances in organ preservation, transport, better immunosuppression, reduction of infections and monitoring for rejection without biopsy from heart, the results of heart transplant are getting better day by day. Currently the upper limit of storage time of heart (time elapsed when heart is arrested in donor till it starts getting supply from the recipient –‘ cold storage time’ is around 5 hrs. Techniques and technologies to harvest the heart and then cannulate and make it beat again by a sterile device will allow transport to distant places. The organ is then rearrested again in the recipient hospital and transplanted.
Patients with advanced heart failure who are functionally limited with symptoms at rest or minimal exertion, who require medications as continuous infusion to maintain blood pressure and patients awaiting heart transplant are candidates for Mechanical Circulatory Support (MCS). The current mechanical circulatory support device systems are more efficient, less bulky and more advanced with low complications. These devices can be used as bridge to transplant till suitable donor hearts are available or even as destination therapy. Short term and Long term devices are available. Temporary support is used to support patients through a high risk procedure till recovery or to provide time to assess prognosis and guide definitive treatment. Long term support devices support either one ventricle (Left Ventricular Assist Device – LVAD) or both ventricles (Biventricular Assist Devices – Bi VAD).The future focus of MCS will be to reduce infection, decrease clotting and bleeding complications, reduce the size of the devices and early implantation before the onset of organ failure.
Regenerative medicine in cardiovascular surgery holds great promise. The goal is to regenerate the myocardium with stem cells which can change the
current reliance on cardiac transplantation and MCS devices.
Minimal Access Surgery
Minimally Invasive Cardiac Surgery (MICS) or Keyhole Cardiac surgery is performed through a small incision, often using specialised surgical instruments. The surgery is performed between the ribs without need to cut the breast bone (sternum). The potential benefits include less blood loss, lower infection rates, reduced pain and trauma, faster recovery, shorter hospital time and quicker return to normal activities with smaller less noticeable scars. In robot-assisted heart surgery, the surgeon works from a remote console with magnified high definition 3 D view on a video monitor and the surgeon’s movements are translated precisely to the robotic arms at the operating table which moves similar to human wrist. A second surgeon and the surgical team assist at the operating table, changing surgical instruments attached to robotic arms. MICS holds great promise and in future about 80% of cardiac surgeries will be done via MICS.
Conclusion
The newer developments in cardiac surgery points to bright future. The heart team has been a patient-focused advance that allows the expertise of all the relevant cardiovascular specialists to consult and recommend the best evidence-based treatment plan for each patient. These newer strategies, albeit a bit more expensive provide value, extend life and relieve human suffering.
Dr. Shaji Palangadan
Consultant – Cardio Thoracic & Vascular Surgery
KIMS Hospital Trivandrum