Week 8 : INR and Cardio Thoracic

I spent this week briefly in Interventional Neuroradiology (INR) and Cardio Thoracic Department.

In INR I shadowed doctors evaluating artery-venous fistula in the brain by using fluoroscopy. The fistula was causing blood to flow from the artery back up through superior sinus (SS), causing pressure buildup in the brain. The doctors reached a conclusion to block section of the SS because, as the patient was young they concluded that the brain would develop other vessels to transport the SS venous blood out of the brain.

Figure 1: Superior Sinus in the brain (Source: http://www.slideshare.net/saeed45/venous-sinuses)

In Cardio Thoracic Department I was able to observe application of Robotics in performing surgery on a leaking mitral valve (Figure 2) (Thanks to Andrea De Micheli for taking me to these doctors who he was shadowing).

Figure 2: Mitral valve (Source: http://www.daviddarling.info/encyclopedia/M/mitral_regurgitation.html)

After placing the patient under anesthesia, Echo cardiogram was used to evaluate the status of the mitral valve (MV).  The Ultrasound Doppler was inserted in the esophagus and live images of the mitral valve were obtained and MV status evaluated.

Perfusion machine/pump was used to circulate the blood in the patient by bypassing the heart. Femur vein was accessed from the perfusion machine for venous blood and femur artery was accessed for arterial blood. The aorta was blocked by a balloon to stop blood circulation through the heart. The heart was then arrested by using Potassium solution through the coronal arteries which feed the heart muscles. At this moment the perfusion machine took over the heart’s function.

Prior to perfusion, four openings were made through the chest for the two robot arms (left and right), the camera, and the operation port, where stitches and the scissors could be passed.

The doctors accessed the MV by opening the left atrium.

During the procedure the surgeons first stitched up atrium appendage which was supposed to close after birth but was still open in this patient.

They then stitched two cords at A2 to the papillary muscles to repair MV leak. The surgeons then stitched together A3P3 to increase cooptation area. Finally, they put a ring around the MV, to decrease its circumference, by stitching through the annulus and the ring.

 Figure 3: Mitra valve anatomy (Source: http://www.mitralvalverepair.org/content/view/50/)

After the stitching, tests were done to evaluate the repair, by filling the ventricle with saline and see if there were any leaks. Then the heart was brought back to function by using pacemaker, and further leak tests and repair were done. Then some other tasks were carried out to restore the patient.

I was also able to shadow doctors performing repair of the aorta arch graft which was leaking. This was open chest surgery.