— You are performing open heart surgery. Most often, patients develop stenomediastinitis after such operations. Can you expand on this complication a bit?
– Stenomediastinitis is an inflammation followed by infection of the soft tissues of the sternum bone and anterior chest wall. It may be called a sternum abscess. The lesion can be either local or affect the entire sternum, ribs and soft tissues.
In 99% of cases, this complication develops only after open cardiac interventions. The specificity of the complication is due to the fact that during the operation, the sternum is cut longitudinally to access the heart. For operations on other organs, such access is practically not used.
According to statistics, the mortality rate in case of a complication can reach about 40%. If we talk about the incidence of stenomediastinitis, then in Russia there are no official statistics. In world practice, the infection develops in up to 7% of cases, that is, in every 10-15 patients of the cardiac surgeon. It should be noted that in about one in five patients with stenomediastinitis, massive destruction of the sternum is extremely rare.
Why does this complication occur? With
– If we are considering a classic bone injury, the bone must be firmly attached and not infected for fusion during treatment. The sternum is also a bone, we attach it with special fixers.
But there is an anatomical feature in this area – the person breathes, the chest moves, while breathing in, half of the cut sternum tries to scatter to the sides.
The mobility of the bones further increases the vital activity of the patient: he can take something in his hand, lean on it or lie on his side. This mobility increases postoperative inflammation. With such a constant trauma, the wound we try to close opens and bacteria penetrate there. Postoperative inflammation intensifies, and a purulent lesion of the surgical intervention site may develop.
– How are patients treated with such a complication?
– The classical method assumes that all the sutures in the wound are removed, after which they are washed with antiseptics. Bacteriological cultures are taken from the patient and antibiotics are prescribed according to the results. All this takes from 3-4 weeks to several months. After two sterile grafts, the bone is reattached and the wound is sutured. The history of limiting loads, maintaining chest stability is back. There are cases of repeated traumatic decomposition of the half of the sternum. Treatment starts over.
If the condition is neglected, most of the anterior chest wall will gradually rot. Then the affected tissue and bone areas are completely removed and the wound is cleaned.
– It seems like a hopeless situation – is there no way that can definitely save the patient from this complication?
We started looking for alternative approaches. Immediately after the first signs of a problem appear, we surgically remove the bony and soft tissues of the sternum from biofilm (bacterial plaque). After that, we straighten the bone and then necessarily cover this area with a biologically well-nourished tissue either from the inner surface of the chest or from the outer surface of the chest.
For comparison: With the usual treatment method, the patient stays in the clinic for about two months. We were able to reduce this time to three weeks and the number of attacks decreased.
– What kind of biological tissue do you cover the wound with?
– There are several options: This is a large omentum taken from the abdomen. In other words, we still need to cut the stomach from the diaphragm from there, and move some of the adipose tissue to the chest with many veins. We can also take nearby muscle fibers. These are the large pectoral muscles. If it cannot be removed, we move the rectus abdominis and the most extreme option is to move the back muscles, which are carried under the skin by their own veins, towards the anterior chest.
– You resort to this treatment method in cases that do not start. However, if the sternum has already rotted, then what?
“Unfortunately, 50% of patients come to us already in a state where everything is not so good, about 30% with a severe inflammatory reaction, and 13% with full-fledged sepsis with dysfunction of some organs.
When the case starts we have to remove the bone and it can no longer be a hard fix. Then we replace this bone with muscles. Muscle tissue has one peculiarity: over time it grows well and becomes fibrous, becoming rather rigid, like a tendon. In addition, the muscles are well supplied with blood, and the antibiotics of our choice penetrate directly to the site of infection.
— Are there any restrictions on such transactions?
– No, but we cannot immediately operate on all patients with stenomediastinitis. We need 3 to 5 days for analysis to understand which bacteria is affecting a particular patient. We prescribe antibiotics empirically until we get these results. We select them based on statistics based on the frequency of bacterial formation. We get this disease in more than 50% of cases, and if we don’t, we change antibiotics before surgery. Otherwise, there may be a relapse of the disease.
– This complication occurs due to incision of the chest. But now there are endovascular surgical methods without opening the chest. According to intravenous surgeons, almost all heart surgeries can be performed with this method. Shouldn’t the number of stenomediastinitis cases decrease with the introduction of this method?
— If we confine ourselves to the heart region, then there are many situations where endovascular surgery is still underpowered or significantly limited. For example, heart transplantation, stenting of mitral and tricuspid valves, hypertrophic cardiomyopathy. At the moment, I was the one who randomly listed the problems that could not be solved without open surgery.
Even if we’re talking about coronary heart disease, endovascular surgery cannot help in a third of cases. Basically, this is a multi-vessel lesion of the coronary arteries. Either doctors are technically unable to access the affected area, or the cost of endovascular treatment and the risk of death outweigh the risks of open surgery.
Cost is one of the main problems of endovascular surgery, so there are much less such surgeries than open surgeries, except for coronary heart disease, where most patients can be treated with endovascular methods. For example, the aortic valve I mentioned costs 1.5 million rubles. The valve installed by heart surgeons costs 100-150 thousand rubles.
— One of your studies talks about hybrid surgeries that use both methods. Are these operations more effective?
– They were introduced in an institution with my participation: this is the City Clinical Hospital named after SS Yudin.
Hybrid surgery is the most advanced approach available today for the treatment of diseases of the lower extremity arteries. For example, if the iliac arteries are damaged, it is technologically impossible to place a stent there when the atherosclerotic plaque passes into the deep femoral artery. The hybrid approach allows us to open access for the endovascular surgeon.
Such operations are not more effective, but less traumatic. This is a small incision, a quick operation, less anesthesia and a short recovery time compared to open surgery.
– Last year you published a study that resulted in the development of an application for risk stratification of postoperative complications. Can you explain this?
— The application is used in the treatment of patients with atherosclerosis. This is a disease that affects all the vessels of the body. Surgeons always have the question, which of the treatment modalities is better to recommend for a particular patient. Everything gets worse when there are other concomitant diseases.
In the study, we obtained a statistical analysis of which types of operations and in which state of the body we experience certain complications. We turned these statistics into a calculator: we enter the patient’s data into the app and get recommendations about possible interventions and their sequence. The software helps the surgeon choose the operation with the least number of complications.
While this practice is not widely adopted, it is currently being tested to evaluate its effectiveness.
What are your goals for the next 5-10 years?
– The first task is to take care of logistics so that patients with stenomediastinitis are not “abandoned”. We develop clear recommendations for surgeons on how to deal with such a complication.
Speaking of myself, I would like to deal with another infectious problem in cardiovascular surgery – this is infection of synthetic vessels.
When the veins are operated with open method, bacteria can also contaminate their walls and suppuration occurs. If the wall of the vein rots, the person will bleed heavily and die quickly.
The number of such patients is small, but there is a big problem in this country. According to statistics, this complication occurs in slightly less than 1% of patients who underwent surgery with the use of synthetic prostheses.