Thoracic duct injury

Introduction to thoracic duct injury Thoracic catheter injury is a penetrating injury or blunt trauma of the chest. The thoracic duct is located outside the pleura of the posterior chest wall. If the pleura is ruptured at the same time, the chyle directly flows into the pleural cavity to form the chylothorax. If the pleura is intact, the effluent from the effusion first accumulates. Extra-pleural, gradually increased, increased pressure, rupture of the pleura, spilling into the chest and then forming a chylothorax. The true incidence of traumatic chylothorax may be higher than reported, as many cases with only a small amount of chyle are difficult to detect and are absorbed early before the diagnosis is established. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of infection: non-infectious Complications: chylothorax, open neck injury

Causes of thoracic duct injury

(1) Causes of the disease

1. Neck and chest open injury neck, chest stab wound, bullet, shrapnel penetrating injury can cause chest tube injury, less common and often combined with more serious other damage, early cover is not easy to find.

2. Closed neck and chest injury: chest blunt contusion, blast injury, crush injury or severe cough can damage the thoracic duct, because the thoracic duct is relatively fixed in front of the spine, when the spine suddenly stretches excessively, or the spine fracture can Causes tear or rupture of the thoracic duct; inflammation, blood filariasis or tumor invasion caused by obstruction of the chest tube or excessive filling of the thoracic duct after a fat meal, chest closed injury or strenuous exercise, severe cough can cause the right tendon muscles to violently contract, Shear damage to the thoracic duct; in addition, the fracture of the clavicle, rib or spine fracture can also damage the thoracic duct.

3. Surgical injury: Surgical operation near the thoracic duct may damage the trunk and branches of the thoracic duct and lead to postoperative chylothorax. Postoperative chylothorax mainly occurs after neck and thoracic surgery. Due to the increase of cardiothoracic surgery, the thoracic duct is damaged. There have been many reports of chylothorax; in recent years, due to the deepening of the understanding of the anatomy of the thoracic duct, the surgical operation has improved, and the chest tube injury has a downward trend.

(two) pathogenesis

After the thoracic duct injury, it takes time to accumulate the leakage of the chyle, which can be asymptomatic at an early stage. Generally, after 3 to 4 days of trauma, the chylothorax gradually forms. In most cases, the pleural effusion is treated until the recovery. Diet, the lymph fluid accumulated in the thoracic cavity becomes white. Considering this disease, the patient suffers from malnutrition due to loss of fat and protein, and soon loses weight, loses weight, subcutaneous edema; loses 500-1000 ml of chyle every day, causing dehydration symptoms. Thirsty and oliguria, plasma protein decreases rapidly; a large number of chyle sputum accumulates lung and mediastinal organs, causing difficulty in breathing, hindering venous return, leading to jugular vein engorgement and decreased cardiac output, patients may have low fever, and chyle has antibacterial properties. In addition to multiple chest-penetration contamination, secondary infections are rare, and later, long-lasting chylothorax can cause fibrosis.

Thoracic catheter injury prevention

Thoracic catheter injury caused by surgery or other medical operations, chylothorax after surgery, chylotitis accounted for more than 90% of all thoracic duct injuries; therefore, attention must be paid to prevent iatrogenic injury of the thoracic duct, the surgeon must be familiar with the thoracic catheter Surgical anatomy, in the dangerous area that may cause chest tube injury, the operation should be careful, the separation of the tissue should be ligated; before suturing the incision, the tissue peeling surface should be carefully examined, with or without lymphatic leakage, if the suspected chyle leaks, it should Sew the leaked parts, and be alert to avoid damage to the thoracic duct during the following operations.

1. Esophageal cancer surgery: The most common operation with chylothorax is esophageal cancer resection, which has been detailed in the etiology section. When surgical separation is performed between the tumor bed and the aortic arch, all the severed tissues should be firmly ligated; Before carefully examining the peeling surface, suture the suspected leaking part; if necessary, perform a low-position prophylactic thoracic duct ligation.

2. Thoracic aortic surgery, patent ductus arteriosus closure, posterior mediastinal tumor surgery, thoracic sensory ganglionectomy, pleural stripping, hernia repair, aortic coarctation surgery.

3. In general chest surgery, such as left lung resection, should also be alert to the possibility of damage to the thoracic duct, sometimes away from the operation of the anatomy of the thoracic duct, can also damage the thoracic duct of its branch or variant.

4. Measures to prevent postoperative chylothorax during open heart surgery with sternal median incision:

1 When the thymus is separated, the cut tissue should be properly ligated;

2 When separating the ascending aorta, the superior and inferior vena cava, pay attention to the depth of the posterior lobes should not be too deep, so as not to damage the traversing thoracic duct or its branches;

3 postoperative diuretic and cardiac treatment to prevent hypercapnia.

5. Neck and supraclavicular lymphadenectomy, anterior oblique muscle surgery, thoracic outlet syndrome release left first rib resection, carotid artery, jugular vein surgery, etc., should pay attention to avoid damage to the cervical thoracic duct.

6. Others: such as central venous catheter caused by superior vena cava obstruction, esophageal varices injection of sclerosing agents and other operations can also cause chylothorax, should also pay due attention.

7. In the chest surgery for preventive thoracic duct ligation, if the thoracic duct injury is found, the chyle leaks out, or the thoracic duct injury is highly suspected, the thoracic duct can be ligated at a low position to prevent postoperative chylothorax. If there is no obvious damage to the thoracic duct The signs do not advocate ligation of the thoracic duct. Wang Yunjie summarized 72 cases of middle-stage esophageal cancer resection with preventive thoracic duct ligation. The incidence of chylothorax was 9.7% (7 cases), and the incidence of chylothorax in high ligation patients. Higher than the low ligation, the high ligation of the thoracic duct caused obstruction, and the pressure in the thoracic duct increased immediately after the operation; when eating a high-fat diet, the chyle flow increased, which led to the rupture of the thoracic duct and the chylothorax, so if there is no Suspicious lesions of the thoracic duct do not advocate prophylactic thoracic duct ligation, and should avoid high ligation.

Thoracic catheter injury complications Complications, chylothorax, chest and neck open injury

Chest catheter injury, after rupture, chyle leakage; if accumulated in the pleural cavity, it will cause chylothorax, accumulation in the mediastinum is mediastinal chyle swelling, accumulation in the neck or chest wall can form chest wall or neck chyle; if there is a wound If the outside world is connected, it can form a chyle. If it is not treated immediately, it will cause serious pathological problems.

1. chylothorax: a large amount of chyle leaking from the thoracic duct accumulates in the pleural cavity, first causing a large amount of chyle loss. If the chyle flow rate in the thoracic duct is calculated according to 2ml/min, the chyle solution can be lost 2000~3000ml per day. It has been reported that In a 6-month period, 158L of chyle solution was taken from a patient for repeated thoracentesis, and 500L was reached in 18 months. Such a large amount of body fluid loss, if not replenished in time, will inevitably lead to serious metabolic disorders, including severe dehydration, low sodium, and low Potassium, acidosis; severe dystrophies; low protein, low blood lipids; and various vitamin deficiency, decreased clotting factors, etc., a large number of lymphocytes lost and mainly T cells, can not be recycled back to the blood circulation; protein loss, massive loss of complement , can lead to decreased immunity.

A large volume of fluid in the pleural cavity, compressing the lung tissue, causing lung collapse, decreased lung capacity, reduced gas exchange; mediastinal shift, cardiac vascular compression, venous return blocked, resulting in a series of respiratory circulatory dysfunction, long-term chyle The precipitation of fibrin in the middle forms a large number of fiber clots, which can also seriously affect respiratory function.

The above-mentioned various obstacles need timely treatment and active supportive treatment; if the treatment is not timely, or support treatment failure, the above obstacles will be catastrophic, inevitably leading to death, chest surgery after chest surgery, for just major surgery For postoperative patients whose functions have been greatly affected, it is a very serious and difficult to treat complication.

The thoracic duct has a rich collateral circulation. The thoracic duct is ligated at any level. Generally, the proximal chyle leaks, the left chyle leaks, and the blood fat content decreases 3 hours after the ligation of the thoracic duct. It returns to normal after 16 days. The end internal pressure is temporarily raised to 6.67 kPa (50 mmHg). It gradually returns to normal with the opening and establishment of the collateral circulation. This process usually takes more than 15 days. If during this period, a large amount of high-fat diet is consumed, the chyle The formation of a large increase may also cause the ventral ventral thoracic duct to swell and rupture.

2. Mediastinal and extrapleural chyema: The chyle is accumulated in the mediastinum or extrapleural loose tissue, which can cause pressure on the big blood vessels and lungs of the heart, resulting in a series of respiratory circulatory dysfunction such as chest tightness, shortness of breath, chest pain, and difficulty in breathing. There is no obvious free body cavity outside the pleura, generally does not cause a large loss of chyle, but the accumulation of chyle is too much, it will break through the pleura and enter the chest, causing the chylothorax.

3. Cervical and thoracic soft tissue edema: one of the serious pathological phenomena after thoracic duct injury, mostly in the pleural extensive adhesions, or free pleural cavity after pleural exfoliation, severe damage to the thoracic duct, fracture with severe obstruction, chyle Patients who can not recirculate from the collaterals. At this time, the chyle is widely leaked in the intermuscular space of the chest wall and the loose tissue in the skin. In the chest wall and the neck, severe non-concave lymphedema is formed, which reduces the thoracic compliance and dyspnea. And can produce a variety of compression symptoms, resulting in head and neck upper extremity venous return disorder, forming a serious pathological state.

4. chyle external sputum: chyle leaks to the outside through the wound, more common in the open neck injury or surgery, accompanied by cervical thoracic duct injury, at this time, the wound has not healed for a long time and there is continuous leakage or leakage of chyle. According to the amount of leakage, it causes different pathophysiological disorders.

Symptoms of thoracic duct injury Common symptoms Chest pain increased heart rate, dyspnea, palpitation, shortness of breath, tachycardia, low blood pressure, low pleural effusion, systemic failure

1. Traumatic thoracic duct injury: Open thoracic trauma caused by chest tube injury often has serious and important organ damage at the same time, sometimes it is too late to save and die, sometimes covered in visceral injury after thoracotomy surgery, and chylothorax is found after operation. Only the diagnosis of thoracic duct injury is diagnosed. The thoracic duct laceration caused by closed injury is mostly above the diaphragm. The chyle is first accumulated in the posterior mediastinum and then into the pleural cavity. It is often the right chylothorax or the left side. Or bilateral chylothorax, so there is often an incubation period of several days or weeks after injury, sometimes as long as several months. Generally speaking, the shorter the incubation period, the more severe the damage of the thoracic duct; on the contrary, the degree of damage is lighter; In some cases, the mediastinal mastoid swelling can be self-healing. After the incubation period, the patient suddenly has shortness of breath, difficulty breathing, and even cyanosis, increased heart rate, weakened pulse, decreased blood pressure, and the like, and then a large amount of pleural effusion. The puncture fluid is initially a bloody liquid, and then gradually becomes a typical milky white chyle; after puncture, the patient is short of breath and dyspnea is relieved quickly, but not long after Like relapse, the need to repeatedly pumping fluid through the chest, the patient quickly consumed, developed progressive dehydration, electrolyte imbalance, malnutrition; the final result of systemic failure and death, but also because of extremely low body resistance and serious infections, sepsis and death.

2. Chest chest after chest surgery: The main clinical manifestations are abnormal increase of thoracic drainage after operation. Because the pleural fluid is immediately taken out, there is no obvious compression symptoms. Some patients have a large number of chests after the chest drainage tube is removed or after eating. The effusion, varying degrees of shortness of breath, palpitation, chest tightness, chest pain, tachycardia, low blood pressure and other pressure caused by breathing, circulatory dysfunction, severe patients can have shock performance; with the loss of pleural fluid increased, and supportive treatment Different conditions, can gradually show dehydration, low sodium, low potassium, acidosis and other symptoms of consumption, severe cases of death and death, usually after chest surgery, the chest drainage on the third day after surgery is still not less than 500ml, Except for other reasons, the vast majority of the merger is the chylothorax.

Thoracic catheter injury examination

The chyle is white, alkaline, and sterile. The lymphocyte count is increased, which is significantly higher than that of multinucleated cells. The protein content can reach 40-50g/L. Many refractable fat beads can be seen by microscopy. The upper layer is a yellow creamy fat layer. It can be clarified by adding diethyl ether, or the fat droplets can be found by Sudan III staining. The cell count is mainly lymphocytes, and the diagnosis of chylothorax can be established. For example, the chyle solution is placed in a test tube. After mixing with diethyl ether, the milky white liquid becomes a colorless liquid, and a layer of fat can be found floating on the liquid. The tea red test can further confirm the diagnosis. It can simultaneously perform pleural fluid and blood lipid test, if the cholesterol in the pleural fluid And the content of lipids in triacylglycerols significantly exceeds the amount in the blood, which can also help to establish the diagnosis of chyle.

Some special examination methods can be used as an auxiliary diagnosis method for trauma and postoperative chylothorax, but the operation is complicated, the clinical application is not convenient, and it is only applied in special cases.

1. Lymphatic angiography: The lower limb or spermatic lymphatic angiography can show the lumbar lymphatic vessels, the chyle pool, the walking and shape of the thoracic duct, which can help determine the location of the thoracic duct rupture in the chylothorax patient and the severity of the chyle leakage. Direct lymphatic angiography, first injection of dye mixture in the toe toe, commonly used dyes are 0.5% indigo carmine (indigecarmine) and 0.5% Evans blue (Evans blue), and then found blue dyed in the foot Lymphatic vessels, cut the skin, separate the lymphatic vessels, and use a fine needle (No. 25-27) for lymphatic vessel puncture. Inject the contrast agent (30% myodil or 37% ethiodol) 6-9 ml at a rate of 0.2 ml per minute. Immediately after the injection, the film was taken and the image of the lymphatic vessels was observed. After 16 to 24 hours, the lymph node image was observed.

2. Dye injection method: After the subcutaneous injection of the rouge blue dye in the thigh, the pleural fluid is continuously taken to check whether it is blue-stained. If blue dyeing can help determine the diagnosis of the chylothorax.

3. Radionuclide examination: 131I-labeled fat is taken orally, and then radioactive scanning is performed on the chest. The radioactivity count is significantly increased, and the diagnosis of chylothorax can also be confirmed.

Diagnosis and diagnosis of thoracic duct injury

When the patient was in the chest for a few days, the patient was diagnosed with severe dyspnea, and the pleural effusion was confirmed by X-ray chest radiography. The diagnostic chest was taken, the milky white liquid was withdrawn, and the microscope was removed. It should be highly suspected that the chylothorax can also be diagnosed by pleural effusion Sudan III staining.

In some pleural infections and neoplastic diseases, a large amount of turbid chyle-like pleural effusion, pseudo-chyle sputum, pseudo-chyle pleural effusion containing lecithin protein complex, milky appearance, mainly by cell degeneration Decomposed, but the cell denaturing material has a low fat content, Sudan III staining negative, specific gravity <1.012, there are a lot of cells in this pleural sediment, but the lymphocytes are less, the protein and cholesterol levels are lower than the real chyle, Some tuberculous pleurisy, pleural effusion of cholesterol pleurisy is also easy to be confused with chyle, but the fat content is low, can be identified by Sudan III staining, and it is rare after trauma and surgery.

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