Minimally invasive heart surgery - a look through the keyhole


The human heart is often described as an engine that quietly and unobtrusively drives the body and mind. The high-performance motor beats heart about three billion times in the course of a lifetime and pumps about 18 million liters of blood through the body. This precision machine is usually not noticed until it stumbles. Heart attacks, cardiac arrhythmias and the constriction of coronary arteries make the diseases of the heart still the number one cause of death in Germany.

Technical progress enables "buttonhole surgery"

One of the enormous medical advances of recent decades in the treatment of heart disease is minimally invasive surgery, also known as keyhole surgery or buttonhole surgery.

This technique is used in cardiac surgery in the majority of cardiac centers in Germany.

Bypass surgery: minimally invasive heart surgery

About 80 percent of all minimally invasive procedures on the heart are bypass surgeries that restore the heart's oxygen supply.

The surgeon dispenses with this technique on the wide opening of body cavities. He operates instead with a so-called endoscope and extremely miniaturized instruments through mini-cuts - as through a keyhole.

The endoscope is a tube-shaped or tubular instrument that uses an optical system to make the images of the inside of the body visible to the doctor on the outside. In addition, a small camera can transmit the images to a monitor.

Especially in the field of heart surgery, this technique is much more comfortable for patients than conventional methods: In a conventional bypass surgery, the sternum must be severed. It then takes up to eight weeks for this artificially induced bone fracture to heal again - including pain and movement restrictions.

Lower load but higher monitoring effort

For patients, minimally invasive procedures are less stressful than conventional heart surgery. You will recover faster, stay in the intensive care unit for a shorter time and be able to leave the clinic sooner. For anesthesiologists and cardiac surgeons, however, such interventions represent a much greater challenge because the monitoring of the circulatory system during beating heart surgery must be particularly close-knit.

In a conventional bypass operation, the heart is connected to a heart-lung machine and the heart itself "shut down". Although this technique is mature and can take over the function of the heart and lungs for a limited time, but the total burden on the body is very large. The aim of minimally invasive cardiac surgery is therefore not only a small wound area, but also the renunciation of the heart-lung machine.

During manipulation of the beating heart, the circulation must be monitored as closely as possible and accurately. Recent developments in the combination of medicine and electronics have led to intelligent monitoring methods that further reduce the risk and burden of cardiac surgery.

MIDCAB - the direct route to the coronary arteries

With a minimally invasive surgery on the coronary vessels (MIDCAB = Minimally Invasive Direct Coronary Artery Bypass), one or two, sometimes three constricted coronary arteries can be re-perfused by the connection with a healthy artery.

This is how the procedure works:

  • A 3 to 4 cm incision is made over the heart into the 4th intercostal space.
  • Now, under direct vision or after an endoscope (metallic light guide) with camera has been introduced, the left inner thoracic artery visited and exposed.
  • The pericardium is opened and the very often narrowed anterior vessel branch shown.
  • A stabilizer makes it possible to immobilize the operating area in the area of ​​the vessel connection.
  • The clogged vessel is wrapped with a sling and tied for a short time after a drug has been injected to keep the blood fluid. Up to 20 minutes of such a vessel interruption are usually well tolerated by the heart muscle without oxygen deficiency signs.
  • Then the surgeon connects the narrowed ligated coronary vessel with the internal mammary artery.
  • Subsequently, all vascular occlusions are released again.
  • A wound discharge leads the developing wound secretions in the thorax to the outside.

Good results achieved with MIDCAB

Very good results have been achieved so far with this method: 96 to 98 percent of the new vascular connections are still open after 1 year, and with the MIDCAB technique, a multiple bypass is also possible. But since the MIDCAB operation has only been around for a few years, there are hardly any longer observation periods.

By comparison, with conventional bypass up to 90 percent of the new vascular connections are still open after 15 years - at least if an artery was used as a donor vessel.

Surgeon and robot as a well-rehearsed team

Professor Friedrich Wilhelm Mohr of the Heart Center Leipzig was the world's first surgeon in 1998 to perform a heart surgery without standing directly at the treatment table. He conducted surgical instruments and a tiny camera inserted into the body through eight-to-ten-millimeter incisions through a keyhole several feet away.

For several years, the operation robot "Da Vinci" conquers the operating rooms of the cardiac surgeons. The heart surgeons operate on the beating heart with the robot, make bypasses, replace heart valves and repair defective heart septa. In general surgery, the robot is only gradually being used. The "Da Vincis" are now in numerous university clinics and other major clinics, where they are used, inter alia, for urological procedures.

How does "Da Vinci" work?

The robot system "Da Vinci" consists of two essential components: the control console and the robot arms. The surgeon sits at the console and steers with two joysticks the electronic robot arms on which the (interchangeable) surgical instruments are located. In front of him he has a high-resolution 3-D video image showing the surgical field in 20- to 30-fold magnification.

The surgeon's hands rest beneath the monitor and use the instruments with the same flexibility as open surgery. Even better: the translation of the movements from the console to the instruments is jitter-free and can be adjusted individually. For example, if the surgeon turns his hand ten centimeters, the instruments move only one centimeter. In this way, the surgeon can work much more accurately and attach even the finest sutures without complications.

The surgeon is not superfluous by the robot. On the contrary, he sits away from the patient, but leaves the system at no time the control. The robot supports the surgeon and helps him to achieve more precision.

... and man remains human

Minimally invasive procedures are currently holding high hopes, even if the costs for a surgical robot are high. On the other hand, developments in the areas of medicine, biology and electronics are leading to ever-better control and monitoring methods that make complicated procedures easier and more controllable.
However, the risk factor human remains uncontrollable: malnutrition, smoking, alcohol, stress and a lack of exercise are still the main causes of heart disease - regardless of how well the consequences can be ironed out later.




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