59 years old Mr. Rohtas was on his way to his office by Delhi’s Metro when he felt a gnawing pain in his chest. This was unlike any pain he might have suffered in the past and forced him to sit. He mentioned it to his fellow passengers; while one was a regular heart patient and offered his tablets to Rohtas others suggested he ought to be taken to the hospital. Staff at the Patel Nagar metro station helped him to his feet and he managed to talk to his son on the phone. They agreed that Rohtas must immediately reach the Super Speciality Sir Ganga Ram Hospital for all the facilities available there.
Metro Staff at Patel Nagar called PCR at 100 and a police car was waiting for him as he stumbled down the stairs. Lucky Mr. Rohtas was at the Sir Ganga Ram Hospital less than half an hour after he first felt pain. By this time the pain was tearing down his back; an additional pain also started in his left groin that was now tearing down his leg. For all that was wrong with him he maintained his composure, his family and friends also reached the hospital the same time as casualty doctors were examining him. Importantly the blood pressure in his right arm was 160/60, that in his left arm was 110/50; left groin pulse was absent along with all the pulses in the left thigh, leg and foot. Emergency treatment was started along with diagnostic tests. An immediate Echocardiogram; suggested that there was a complete tear in the wall of the aorta as well as sudden severe leakage from the aortic valve as it was torn off its attachments.
Senior Cardiac Surgeon Dr. Sujay Shad was informed of a patient with a distinct possibility of Acute Type A Aortic Dissection on Echo. An Acute Type A Aortic Dissection is without doubt the most lethal of all conditions. As you would see from the attached picture, there develops a tear within the wall of the Aorta. As the tear in the aortic wall progresses so does the patients pain; it starts in the front and then goes all the way to the back and the tummy. This patient’s left femoral artery that supplies blood to the left thigh and leg was cutoff prior to him reaching the Casualty itself. This was evident from the shooting pain from his left groin to his left leg; along with that the pulse on that side could not be felt. Any delay in surgery could tear off any of the remaining arteries of the body with devastating organ function loss. One could imagine loss of blood supply to the heart = heart attack or cardiac arrest; brain = stroke; spinal cord = paralysis below the waist; liver = liver failure; kidneys = kidney failure; intestines = gangrene, septicemia. The existing loss of blood supply to the left leg could allow production of enough biological poisons to reduce his chances of survival on an hourly basis. It is well known to all doctors that almost half the untreated patients with Acute Type A Aortic Dissection would die within a matter of 24 hours. Not only that there exists a linear risk of 2% deaths per hour during the first 25 hours.
Time is of the essence to help a patient survive this devastating illness; so orders were flying while Dr. Shad made his way to the emergency. CT department was advised to await arrival of this patient; Cardiac Operating Theatres were advised to keep one OT ready for this patient pending further investigations. As the patient was shifted to CT scan Dr. Shad got a brief chance to look at the patient and his family. They were informed of the gravity of the probable illness and that no efforts would be spared to ensure diagnosis and treatment without any delay.
In modern days a CT aortogram is the only investigation required preceding surgery in such patients. In the bygone times Cardiac Surgeons and Cardiologists would insist upon Coronary Angiography prior to such an operation; the complexity of anatomy as well as the inherent time delays with such a protocol lost many more patients than lives saved. CT aortogram was performed and reported within a half hour of the patient’s arrival to the emergency such is the speed of Doctors in the Emergency department as well as the organization of Sir Ganga Ram Hospital.
The CT Aortogram confirmed diagnosis of an Acute Type A Aortic Dissection and even before the blood bank was able to cross-match blood and blood products for this patient we shifted him to the operating theatre. Despite top speed diagnostic works, by the time this patient reached the Cardiac OT he was showing signs of an impending Cardiac arrest. He complained of further chest pain and started sweating.
To the teams comprising Senior Surgeons (Dr. S Shad and Dr. S Dubey) and Cardiac Anaesthetists (Dr. Arun Maheshwari and Dr. Rachna Gupta) this was an emergency like no other. Under a rapid sequence general anaesthetic with preparation to commence circulatory support at any given moment, the chest was opened in the midline. The Aorta was clearly breaking down its walls with blood oozing out from its surface.
Thrombus in Left Common Iliac Artery
Aortic Dissection all along the wall of mediately took over the patient’s circulation by using a heart lung machine, as well as using special protective drugs to stop and preserve the heart. With a plan to stop the heart lung machine also after the initial part of this operation, a heat exchanger is used to drop the patient’s temperature. Patient’s temperature was gradually brought down to 20 oC by the heart lung machine while Dr. Sujay Shad checked the damage inflicted by the aortic tear. The entire blood supply of the heart had by now been cut off (because the orifices of the coronary arteries were torn), the aortic valve was hanging folded away like a poorly kept curtain and the whole of the ascending part of the aorta was completely torn. The aortic valve was carefully removed preserving small islands of tissue around the origins of the coronary arteries to restore blood supply to the heart. A part of the ascending aorta was also removed while the final excision would take place later.
A composite Graft containing an aortic valve and a fabric tube is now sutured to the site of the aortic valve. Orifices are created at relevant positions onto the graft and the two main coronary arteries are very carefully sutured into the fabric graft.
This is when (at 20 oC temperature) all the blood is drained away from the patients body after administering special agents to protect the brain and the spinal cord. Now a final resection of the ascending aorta is completed. This leaves us looking into the origins of all the head and neck blood vessels and the distal aorta. The fabric tube of the composite graft is tailored to appropriate length and is sutured to the distal aorta. Once this part of the operation is complete, blood flow can be recommenced and patient is gradually re-warmed to 37 oC. Slowly the heart is allowed to pick up the load of circulation and finally we are able to separate the patient from the heart lung machine.
The most important part of such an operation is to ensure that there is no bleeding from any of the anastomoses. There is just too much excision and suturing to do especially when one is working against the clock and the tissues are inherently weak for suturing. To top all this a surgeon finds that with each completed anastomosis certain areas become hidden from view and should there be any leak from any site it could be fatal.
There are very few operations as satisfying as this one admits Dr. Shad, this patient came into the hospital desperately sick with fatality a whiskers breath away. It took a five hour operation, 120 minutes of cardiac arrest, some 27 minutes of absence of blood flow in the body, 2 units of blood transfusion and we had a healthy patient discharged from hospital 7 days later. He is looking forward to rejoining his duties in the Planning Commission soon.
- Aortic Dissection should be suspected if the chest pain is
- TEARING in nature
- Located in the dorsum
- Moves in location from proximal to distal
- Aortic Regurgitation murmur is present, or heart sounds are muffled in such a patient
- Differential blood pressure recordings in upper limbs are suggestive
- An absent pulse in such a patient is almost diagnostic
- Only investigation required is CT AORTOGRAPHY
- Operation must proceed immediately with Deep Hypothermic Circulatory Arrest
- Surgeon must ensure absence of bleeding at each anastomotic site