Pathology of the pulmonary trunk

Birth defects - atresia, narrowing, messages between the pulmonary trunk and the aorta and others - see the heart diseases.
Damage to pulmonary trunk is not frequent (for example, at gunshot wounds); usually cause fatal blood loss. Sometimes you tackle the wounded, timely operirovat it and put seams on the wound of the vessel.
Thrombosis and embolism pulmonary trunk have the greatest practical importance. They are pretty common, especially in women. The age of patients is 50-60 years. Forecast heavy.
Etiology. The main source of embolism HP - clots in the deep veins of the pelvis and lower extremities with acute and chronic trombophlebitis, sometimes a blood clot right atrium and right ventricle in endocarditis, heart attack, aneurism of the heart. Emboli of the left heart chambers abdurasoul HP with congenital defects, atrial and ventricular septal, when patent arterial duct. Sometimes tromboembolia HP observed in cancer, atherosclerosis, hypertension, diabetes, polycythemia, in severe bone injury.
Acute obstruction of the pulmonary trunk may develop on 6-12-th day after operation into the thoracic and abdominal cavities, often in connection with postoperative thrombosis of the veins of the pelvis and lower limbs on the background of violations of the blood coagulation system (see Thrombosis, Embolism).
Pathological physiology. Embolus can completely block a HP or its branches all calibres; sometimes it does not cause the blockage, situated in the area of bifurcation of the pulmonary trunk or at a place of dividing its branches.
The syndrome embolism HP is determined by the degree of mechanical blockage of the pulmonary trunk or branches, reflex changes of blood circulation and breathing. Long believed that the blockage of the channel HP embolus is the only reason for the development of this syndrome, however, when studying a large clinical and experimental material installed discrepancy between the degree of mechanical closing pulmonary channel embolus and severity of the syndrome embolism HP Noted that the relatively small size of the pitch, which cannot serve as a significant obstacle to blood flow, often there is a severe embolism HP fatal. There are cases when the death occurred when events embolism pulmonary trunk, although none of its larger branches was not obturated.
Data centuries Parin about reflex pressure drop in a big circle at the irritation of the receptors of blood vessels HP (see Circulation) suggest that the collapse, which in these cases the cause of death, is the reaction to the irritation embolus receptors HP While embolus causes numerous reflex changes of blood circulation.
On the basis of data about the role of reflex factor in the development of the syndrome embolism pulmonary trunk for therapy were used gexametoni, pandemic and other ganglioblokirute funds. Pentamin used embolism in patients with HP in the amount of 100 mg intravenously. Patients in the first 15 minutes, and the rest after an hour was a decrease of pain in the chest, withdrawal symptoms of the fear of death, reducing shortness of breath. Some pain resumed, but were so weak that did not require more use of medicines. Gexametoni and pentamin were tested in experimental conditions. After prophylactic use of pentamin showed asymptomatic embolism or weak pathological response. Fatal cases were not even with the introduction of a large number of emboli.
Many studies suggest three important reflex shift that play a role in the development of the syndrome embolism HP 1. Reflex fall in blood pressure in the pulmonary caused by the reduction in vascular tone and inhibition of cardiac activity. 2. Reflex spasm those of the pulmonary arteries and arterioles, which are not themselves subject embolization. 3. Reflex shortness of breath, which, along with the reduction of blood flow through the lungs contributes to the deepening of hypoxia. The combination of these reflex reactions with mechanical closing of pulmonary vessels is the basis of the clinical syndrome embolism pulmonary trunk. Mechanical factor in the form of a fixation of the pitch in the pulmonary vessels is primary, and reflex factor is the result of the action of the pitch at their receptors, i.e. joins again. For very large dimensions of the pitch and complete blockage of the main trunk of mechanical factor determines the occurrence and outcome syndrome embolism, and reflex factor causes only part of the clinical picture. Minor dimensions of the pitch or multiple small emboli reflex factor, however, is crucial.

Fig. 2. Operation Trendelenburg: 1 - conducting rubber drainage sinus pericardii behind the pulmonary trunk and the cut wall; 2 - hole pulmonary trunk covered finger; 3 - removing the pitch of the pulmonary trunk when taut rubber drainage; 4 - the imposition of terminals and stitching holes.

The clinical picture. Acute tromboembolia pulmonary trunk is manifested in sudden shock or severe collapse. A characteristic pale skin, quickly resulting in cyanosis, particularly in the extremities, shortness of deep breathing. Sometimes cruel chest pain in epigastria. Sometimes vomiting.
The patient loses consciousness, pulse quickens (sometimes gallop rhythm), blood pressure drops to 60-70 mm even with the introduction vazopressornah funds. Found expansion of the heart to the right, and the focus of the second tone of the pulmonary trunk. The liver is enlarged veins in the neck blown up. ECG revealed signs of acute overflow and ischemia of the right heart, increased tooth's in the lead, the increase of Q-wave and the emergence of negative zubza T III lead (N. Y. Shvedov). Radiographically - strengthening transparency lung fields, expansion of the right border of the heart. Revealed a high content glutamicoxaloacetic transaminaz in blood. Death can occur in a few minutes, rarely, patients live a few hours. Sometimes there are short periods of improvement, which, however, are replaced by more serious picture. To differentiate have to myocardial infarction, brain hemorrhage, severe internal bleeding, pneumonia.
Surgical treatment - operation trendelenberg (F.Trendelenburg). Opening of the chest produce a vertical or semioval incision from II to V of the fins to the left of the sternum, repetiruyut II and III ribs. Cut through the pericardium. On the basis of the pulmonary trunk, put a tourniquet, longitudinally cut through the vessel. Embolus remove the clip, sucking or by "divania". The wound vessel sew (Fig. 2). Proposed to remove a blood clot from HP through a section of the right ventricle. Upper and lower hollow vein while squeeze. In the world literature are about 30 of successful operations Trendelenburg, including with the use of extracorporeal circulation.
N. M. Rzaev offered to produce sewing pulmonary trunk end in side wide vascular prosthesis and make embolectomy through it, without compression of large vessels. In case of trial, HP recommend to place the patient in the operating room, where it is required to conservative treatment and in the absence of effective to operate. Conservative measures, except for symptomatic include the use of anti - fibrinolizina (plazmin) and heparin.
Anticoagulants shows and after the operation to prevent rethrombosis. Their "appointed not earlier 9-14 hours after interventions to prevent bleeding.
Prevention tromboamboliy HP is timely detection and treatment of thrombosis of deep veins of the pelvis and lower extremities. In these patients, P. Zaitsev with the threat of thromboembolism HP recommends to bandage thrombosed veins - femoral, iliac, inferior caval. Important struggle with hypercoagulability.
Prevention of postoperative embolism and thrombosis pulmonary trunk: careful preparation of patients for operations, normalization of blood coagulation, non-traumatic and aseptique operation, active the behavior of patients after surgery (early rising), the fight against dehydration.