Трансплантация легких: спасение и новые возможности

Surgical procedure in which a patient's diseased lungs are partially or totally replaced

Lung transplantation, or pulmonary transplantation, is a surgical procedure in which one or both lungs are replaced by lungs from a donor. Donor lungs can be retrieved from a living or deceased donor. A living donor can only donate one lung lobe. With some lung diseases, a recipient may only need to receive a single lung. With other lung diseases such as cystic fibrosis, it is imperative that a recipient receive two lungs. While lung transplants carry certain associated risks, they can also extend life expectancy and enhance the quality of life for those with end stage pulmonary disease.

Before 2005, donor lungs within the United States were allocated by the United Network for Organ Sharing on a first come, first served basis to patients on the transplant list. This was replaced by the current system, in which prospective lung recipients of age of 12 and older are assigned a lung allocation score or LAS, which takes into account various measures of the patient's health. The new system allocates donated lungs according to the immediacy of need rather than how long a patient has been on the transplant list. Patients who are under the age of 12 are still given priority based on how long they have been on the transplant waitlist. The length of time spent on the list is also the deciding factor when multiple patients have the same lung allocation score. Patients who are accepted as good potential transplant candidates must carry a pager with them at all times in case a donor organ becomes available. These patients must also be prepared to move to their chosen transplant center at a moment's notice. Such patients may be encouraged to limit their travel within a certain geographical region in order to facilitate rapid transport to a transplant center.

A lobe transplant is a surgery in which part of a living or deceased donor's lung is removed and used to replace the recipient's diseased lung. In living donation, this procedure requires the donation of lobes from two different people, replacing a lung on each side of the recipient. Donors who have been properly screened should be able to maintain a normal quality of life despite the reduction in lung volume. In deceased lobar transplantation, one donor can provide both lobes.

Many patients can be helped by the transplantation of a single healthy lung. The donated lung typically comes from a donor who has been pronounced brain dead.

Certain patients may require both lungs to be replaced. This is especially the case for people with cystic fibrosis, due to the bacterial colonization commonly found within such patients' lungs; if only one lung were transplanted, bacteria in the native lung could potentially infect the newly transplanted organ.

Some respiratory patients may also have severe cardiac disease which would necessitate a heart transplant. These patients can be treated by a surgery in which both lungs and the heart are replaced by organs from a donor or donors. A particularly involved example of this has been termed a "domino transplant" in the media. First performed in 1987, this type of transplant typically involves the transplantation of a heart and lungs into recipient A, whose own healthy heart is removed and transplanted into recipient B.

While the surgical details will depend on the type of transplant, many steps are common to all these procedures. Before operating on the recipient, the transplant surgeon inspects the donor lung(s) for signs of damage or disease. If the lung or lungs are approved, then the recipient is connected to an IV line and various monitoring equipment, including pulse oximetry. The patient will be given general anesthesia, and a machine will breathe for him or her. It takes about one hour for the pre operative preparation of the patient. A single lung transplant takes about four to eight hours, while a double lung transplant takes about six to twelve hours to complete. A history of prior chest surgery may complicate the procedure and require additional time. Intraoperatively, lung transplantation can be performed with the use of extracorporeal membrane oxygenation, cardiopulmonary bypass (heart lung machine) or without any mechanical circulatory support. Intraoperative mechanical circulatory support can be required due to severe pulmonary hypertension, haemodynamic instabilty or inabilty to tolerate one lung ventilation. In the case of a sequential transplant the recipient's lung with the poorest lung functions is collapsed, the blood vessels tied off, and cut at the corresponding bronchi. The new lung is then placed and the blood vessels reanastomosed (reconnected). To make sure the bronchial anastomosis is satisfactory before transplanting the other a bronchoscopy is performed.

Immediately following the surgery, the patient is placed in an intensive care unit for monitoring, normally for a period of a few days. The patient is put on a ventilator to assist breathing. Nutritional needs are generally met via total parenteral nutrition, although in some cases a nasogastric tube is sufficient for feeding. Chest tubes are put in so that excess fluids may be removed. Because the patient is confined to bed, a urinary catheter is used. IV lines are used in the neck and arm for monitoring and giving medications. There may be a number of side effects following the surgery. Because certain nerve connections to the lungs are cut during the procedure, transplant recipients cannot feel the urge to cough or feel when their new lungs are becoming congested. They must therefore make conscious efforts to take deep breaths and cough in order to clear secretions from the lungs. Their heart rate responds less quickly to exertion due to the cutting of the vagus nerve that would normally help regulate it. They may also notice a change in their voice due to potential damage to the nerves that coordinate the vocal cords. However, there are no detailed guidelines on how exercise should be performed in this type of population. Certain medications may also have nephrotoxic or other potentially harmful side effects. Other medications may also be prescribed in order to help alleviate these side effects. There is also the risk that a patient may have an allergic reaction to the medications. Close follow up care is required in order to balance the benefits of these drugs versus their potential risks. Chronic rejection, meaning repeated bouts of rejection symptoms beyond the first year after the transplant surgery, occurs in approximately 50% of patients. Such chronic rejection presents itself as bronchiolitis obliterans, or less frequently, atherosclerosis. + Survival rate after a lung transplant 1 year survival 5 years survival 10 years survivalLung transplant 83.6% 53.4% 28.4%Heart lung transplant 73.8% 46.5% 28.3%
Transplanted lungs typically last three to five years before showing signs of failure. A 2019 cohort study of nearly 10,000 lung transplant recipients in the US demonstrated significantly improved long term survival using sirolimus + tacrolimus (median survival 8.9 years) instead of mycophenolate mofetil + tacrolimus (median survival 7.1 years) for immunosuppressive therapy starting at one year after transplant. Since sirolimus is not administered until at least 3–12 months after transplant, these median survival estimates were conditional on surviving 1 year post transplant. As lung transplantation has improved since the late 20th century with advancements in perioperative management, surgical technique and postoperative rehabilitation, 5 year survival has increased even up to 60 70%.