Hydatid Disease of the Lung Dr Mohammad sadra nazari Qazvin Univercity Of Medical Scince GENERAL SERGEON

PATHOPHYSIOLOGY INTRANCE WAYS OF PARAZITE TO LUNG 1) Those embryos whose diameter does not exceed 0.3 mm may pass through the sinus capillaries of the liver ;;.to the pulmonary capillaries. 2) alternative pathway of the parasites’ entrance into the lung is the lymphatic circulation.

PATHOPHYSIOLOGY  lung in 10% to 30% of the patients.  Pulmonary echinococcosis most frequently occurs in the right and both lower lobes,  75% to 90% of these cysts are solitary, whereas involvement of both lungs occurs in 2% to 30%.  Children are more likely to develop pulmonary rather than hepatic echinococcal cysts. develop More rapidly in the lungs of children than those of adults,  Younger patients have larger cysts owing to their greater tissue elasticity.

PATHOPHYSIOLOGY  Large pulmonary hydatid cysts are critical because they pose a higher risk of rupture.  The cysts growmore rapidly in the lungs than in other organs, mainly because of the negative pressure and the great elasticity.  Doughter cyst a rare findig in Pulmonary echinococcosis.  The hydatid cyst is filled with hydatid fluid, which is colorless, odorless, and sterile, resembling crystal-clear water. the pressure of the fluid ranges from 21 to 61 cm H2O. It contains antigenic elements that may cause anaphylactic phenomena when the cyst ruptures.

PATHOPHYSIOLOGY  During the growth period, it may rupture spontaneously or during coughing, sneezing, or anyother cause of increased intrathoracic pressure, or after injury during diagnostic thoracentesis.  Calcification of the cyst in the lung is rare.  It resembles an eggshell, is limited in the adventitia.  A calcified lung cyst is almost always in communication with the bronchial tree and is probably infected.

CLINICAL MANIFESTATIONS  depends on whether the cysts are intact or ruptured.  Intact or simple cysts of the lung produce no characteristic symptoms.  depend on their site and size.  Small peripherally located cysts are usually asymptomatic,whereas large central cyst with symptoms of compression of adjacent organs.

CLINICAL MANIFESTATIONS  If the patient is symptomatic,  the first complaint is often a nonproductive cough;  some patients, particularly those with centrally located cysts, may have blood-streaked sputum.  Some patients complain of a acute chest pain or present with a sensation of pressure in the chest.  During infancy, the hydatid cyst maydisturb growth. a bulge in the ipsilateral chest may also be observed.

Frontal (A) and lateral (B) preoperative and postoperative chest radiographs of a 5-year-old boywith a giant left-lower-lobe hydatid cyst producing chest deformity.

CLINICAL MANIFESTATIONS Rupture of the cyst Rupture of the cyst may occur spontaneously or as a result of trauma or anthelminthic therapy. Rupture of the cyst into an adjacent bronchus may be manifested by vigorous coughing and expectoration of sputum consisting of: 1)mucous hydatid fluid 2)fragments of the laminated membrane,

 In addition, the patient may a severe hypersensitivity reaction, generalized rash, high fever, pulmonary congestion, and severe bronchospasm.  the intrabronchial rupture of the cyst with sudden and severe dyspnea, which may lead to suffocation and death.  The diagnosis of rupture when the parasites elements are found during microscopic examination of the sputum. CLINICAL MANIFESTATIONS Rupture of the cyst

Rupture of the cyst into the pleural cavity is a severe but infrequent complication. It occurred in 5% of the patiens. The symptoms are usually moderate; dry cough, chest pain, moderate dyspnea, generalized malaise, and fever. These relatively mild clinical manifestations result from preexisting pleural adhesions, which prevent the dissemination of the cyst’s contents into the whole pleural space

CLINICAL MANIFESTATIONS Rupture of the cyst  In some patients, without preexisting pleural adhesions,  intrapleural rupture with an acute and dramatic clinical picture consisting of intense chest pain, persistent cough, severe dyspnea, and even cyanosis, shock, and suffocation.  symptoms of generalized urticaria, intense pruritus, and severe anaphylactic shock can occur, even leading to death.  The symptoms is accompanied localized or generalized hydropneumothorax.  Rupture of an infected cyst causes hydatid empyema.

DIAGNOSIS chest radiograph  Diagnosis in the asymptomatic patient based on suspicion resulting from an unexpected finding on routine chest radiographs.  Radiographically, the cyst appears as a homogeneous spherical opacity with definite edges (Fig.).  change from a spherical to an oval shape may be observed only during deep inhalation (Escudero–Nemerow sign).

Routine frontal chest radiograph showing a small peripheral hydatid cyst in the left upper lung field.

DIAGNOSIS chest radiograph  The radiologic picture depends mainly on the size and location of the cyst. A small cyst may difficult to recognize until it grows large enough on the chest radiograph.  A cyst may cause distal bronchial obstruction, manifested as atelectasis and pneumonitis beyond the cyst.  Centrally located cysts may compress the bronchovascular structures, presenting a depression or indentation at the site of pressure, the so-called notch sign.

DIAGNOSIS chest radiograph  Most cysts present as a solid mass in the right lower lobe. solitary lesions in approximately 60% of cases and multiple unilateral or bilateral lesions in 20% to 50% of cases.  Also, a patient with lung hydatidosis should be investigated for associated liver cysts.

DIAGNOSIS chest radiograph The radiographic pleural manifestations in the acute stage of rupture of a cyst : vary from loculated hydropneumothorax to nonloculated partial, complete, or tension hydropneumothorax.

DIAGNOSIS Computed tomography (CT)  Computed tomography (CT), particularly to the early discovery of coexistent small cysts in the lung and existing rupture of the cyst.  CT scanning with contrast may demonstrate mediastinal cysts.  Also, CT scanning in the follow-up of patients who have had resection or evacuation of a hydatid cyst of the lung.

DIAGNOSIS Magnetic resonance imaging  Magnetic resonance imaging may show detached membranes, local host reactions, or communications between the cyst and the bronchial tree in the case of ruptured cysts.  also show regression of the cyst during chemotherapy with albendazole.  Ultrasonography and echocardiography are two methods for evaluation of hepatic or pericardial–cardiac cysts.

DIAGNOSIS laboratory  The laboratory diagnosis is complementary to the clinical and radiologic methods.  Eosinophilia occurs in 20% to 34% of patients.  Because Eosinophilia is also observed in many other diseases,the test has limited diagnostic value.  Casoni’s intradermal reaction and Weinberg’s complement fixation test were widely used in the past. no recommended because of their variable sensitivity and limited specificity.

DIAGNOSIS laboratory many serologic tests are being proposed today. include the indirect immunofluorescence assay and the direct hemagglutination test. Immunoelectrophoresis or counterimmunoelectrophoresis with antigen 5. ELISA especially Igg.

DIAGNOSIS laboratory  the diagnosis in 80% to 94% of hepatic hydatidosis cases and in the 65% of pulmonary cases.  seronegativity cannot exclude hydatidosis.  False-negative results are obtained when the cysts are calcified.  Serologic tests do not replace imaging methods. confirm the hydatid origin of a cyst.

DIAGNOSIS Bronchoscopy can lead to the definitive diagnosis of a ruptured hydatid cyst of the lung in the bronchial tree. The finding of laminate membrane and hooklets in the bronchial aspirates confirms the diagnosis.

TREATMENT medical  The treatment is essentially surgical.  albendazole (ABZ) and mebendazole (MBZ), exert a direct effect on the wall of the cyst.  factors influencing the efficacy of benzimidazoles correlate inversely with the size and age of the parasite, calcification of the cyst wall, and pericystic fibrosis.  68% to 70% of patients response to chemotherapy, but the cure 25% to 34%.

TREATMENT medical The more common adverse events of patients treated with ABZ according to WHO guidelines are hepatotoxicity, neutropenia, and alopecia. chemotherapyis indicated in: A. patients who cannot tolerate surgery, B.those with numerous cysts in two or more organs, and C.when complete removal of the cysts is impossible.

TREATMENT medical  Chemotherapy can also be given postoperatively to prevent recurrence of a cyst that has ruptured during surgery.  the optimal duration of preoperative and postoperative chemotherapy is unknown.  therapy should begin approximately 4 days before surgery and be continued for 1 to 3 months.

TREATMENT medical  The recommended dose for ABZ is 10 to 15 mg/ kg per day or 400 mg twice a day in cycles of 1 month, with a 2-week interval between cycles.  three cycles are usually required.

TREATMENT Surgical Surgery is the main therapeutic modality for pulmonary hydatidosis. The objective of surgical treatment is: 1. eradicate the parasite, 2. prevent intraoperative rupture of the cyst and dissemination. 3. eliminate the residual cavity. 4. preserving the maximum amount of lung tissue.

TREATMENT Surgical  first choice of treatment lung-sparing operations such as enucleation or pericystectomy with or without capitonnage of the pericystic space.  Unnecessary resection of the lung must be avoided because the compressed lung is usually healthy and reexpands after excision of the cyst.

TREATMENT Surgical  Segmental resection is indicated for: large simple cysts that almost completely occupy the involved segment.  The principal indications for lobectomy are: 1.large cysts involving > 50% of the lobe, 2.cysts with severe pulmonary suppuration not responding to preoperative treatment, 3.multiple cysts, 4. sequelae of hydatid disease such as pulmonary fibrosis, bronchiectasis, or severe hemorrhage.  Pneumonectomy is rarely indicated only when the whole lung is involved in the disease process.

TREATMENT Surgical  Bilateral lung cysts should be resected in one or two stages (Fig.) the lung with the larger cyst or more numerous cysts should be approached first.  In a patient with a lung cyst > 4 or 5 cm in one lung and a ruptured cyst in the other lung, the intact cyst should be removed first in order to prevent its rupture. The contralateral lesions are then resected 2 to 4 weeks after the first operation.  three cysts, one in each lung and one in the liver. The left hydatid cyst was removed first. Six weeks later, the cysts from the right lung and liver were treated.

TREATMENT Surgical Frontal chest radiograph shows two intact, in each lung. Both were enucleated by separate thoracotomies at a 2-month interval. Frontal chest radiograph shows three cysts, one in each lung and one in the liver. The left hydatid cyst was removed first. Six weeks later, the cysts from the right lung and liver were treated.

TREATMENT surgical

COMPLICATED CYSTS After the acute period,  the rupture of a cyst into the pleura be treated urgently using an operation that eliminates the hydatid elements.  Complicated cysts cause significant pleura thickening and parenchymal damage ;  therefore more radical procedures, segmentectomy, and lobectomy.

PROGNOSIS  Postoperative complications are influenced by the size and number of cysts and the type of operation.  most common complications were pleural infection of the patients and prolonged air leakage.  The recurrence rate is also very low.  98.3% of the surviving patients were free of hydatid disease 18 years after the operation.

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