lungmalformationcongenital pulmonaryairwaymalformations.pptx

Lung malformations

1. Congenital pulmonary malformations in children Presenter Dr. Faheem ul Hassan Andrabi M Ch resident Moderator Dr. Aejaz A. Baba Associate professor Pediatric Surgery SKIMS

2. Congenital lung malformation Highlights Definition Embryology of lung Clasification of lung malformations Bronchogenic cyst Ccam

3. Congenital lung malformation Pulmonary malformations are also called congenital anomalies of the primitive foregut Represent broad spectrum abnormalities with a common origin at some point of the embryological development of the foregut / lung.

4. Congenital lung malformation These anomalies are detected in most of cases in infants and children Asymptomatic cases can be diagnosed in adults . Use of prenatal ultrasound has seen a large increase in the diagnosis of these anomalies

5. Classification 1. Abnormal lung with normal vasculature congenital lobar hyperinflation bronchial atresia, bronchial cyst 2. Abnormal vasculature and normal lung arteriovenus malformation

6. Classification 3. Both parenchyma and vascular abnormalities pulmonary sequestration hypogenetic lung syndrome

7. Embryological development Development of lung has 5 stages Embryonic stage Pseudoglandular stage Canalicular stage Terminal sac period Alveolar period

8. Embryological development Embryonic phase (3-7 weeks) Begins with the formation of the respiratory diverticulum from the ventral wall of the primitive foregut. Around 33 days of gestation, the distal end of the respiratory diverticulum bifurcates into two buds (left and right primary bronchi )

9. Embryological development

10. Embryological development Pseudoglandular phase (5-17 weeks): Segmental and sub-segmental bronchi are formed through a series of divisions Repeated branching forms upto terminal bronchioles No respiratory bronchioles and alveoli are present

11. Embryological development Canalicular phase (17-24 weeks) The diameter of the tube increases Respiratory bronchioles and alveolar ducts develop. airspaces are being canalized and approximated by a network of capillaries.

12. Embryological development Saccular phase (25-36 weeks) Primitive alveoli are formed By 26 weeks the alveoli have become vascularised

13. Embryological development Alveolar phase (36 weeks - childhood) It is the lung maturation period Pneumocytes (I and II) increase in number increase the surfactant production. Alveoli have well developed epithelial-endothelial contact

14. Embryological development

15. Pathogenesis It's difficult and in most of cases confusing to understand the pathogenesis of lung malformations. The proposed theories are defective foregut budding and differentiation. airway obstruction with secondary pulmonary dysplastic changes.

16. Types of broncopulmonary malformations Bronchogenic Cysts Congenital pulmonary airway malformation Pulmonary sequestration Bronchial atresia Congenital lobar hyperinflation

17. Bronchogenic Cysts Bronchogenic cysts develop from the abnormal budding of tracheal diverticulum or ventral portion of foregut They are mostly situated in the mediastinum (70%) Paraesophageal Paratracheal Perihilar and intraparenchymal (predominantly in lower lobes). Rarely they may appear in the neck, pericardium or abdominal cavity.

18. Bronchogenic Cysts Bronchogenic cysts are classified primarily into intrapulmonary and mediastinal types Mediastinal is further classified by Maier into 5 types Type I ( paratracheal ), Type II (bronchial bifurcational ), Type III ( hilar ), Type IV ( paraesophageal ) and Type V others

19. Bronchogenic Cysts It is usually unilocular, Has usually no communication with the bronchial tree and Is filled with clear mucous secretion. It is almost always closely attached to major airways or the esophagus by dense fibrous tissue

20. Bronchogenic Cysts Most bronchogenic cysts are asymptomatic and are found incidentally. The symptoms are generally caused by compression of the trachea, bronchi or esophagus, leading to wheezing, coughing stridor, dyspnea, and dysphagia. Atelectasis

21. Bronchogenic Cysts The clinical course of the cyst is strongly influenced by the presence or absence of communication with the parent bronchia. Non-communicating cysts cause symptoms by local compression but in most of the cases are asymptomatic.

22. Bronchogenic Cysts On the other hand a cyst-bronchial communication can cause two complications tension cyst and infection A tension cyst is a rapidly expanding cyst which causes acute distress and needs immediate intervention

23. Bronchogenic Cysts Cyst infection is more frequent for the intrapulmonary cysts They may present with Fever Cough sputum or even hemoptysis . Infections are recurrent and have poor response to treatment

24. Bronchogenic Cysts Spontaneous pneumothorax is rare. Malignancy although rare but has been reported in longstanding Bronchogenic cysts

25. Prenatal ultrasound anechoic lesion with posterior acoustic enhancement in fetal thorax

26. Chest Radiograph Well-defined mass of water density in right upper lobe (arrow)

27. Chest Radiograph CXR showing B. cyst with AFL. Air-fluid levels may be present when there is bronchial communication.

28. CT Scan CT Scan shows cystic lesion with AFL in right upper lobe

29. MRI rounded and well defined left paraspinal lesion (coronal and axial view)

30. Histologically Histologically, bronchogenic cysts are thin walled, lined with bronchial epithelium, and filled with mucus . They can be single or multiple and are white or pinkish .

31. Bronchogenic Cysts Differential diagnoses Foreign body Bronchial stenosis Lobar emphysema congenital pulmonary airway malformation, pneumatocele , lung abscess, pneumonia Hydatic cyst

32. Bronchogenic Cysts Treatment options include 1. Evacuations through percutaneous or transbronchial needle aspirations 2. complete or partial resection by thoracoscopical or open surgery

33. Bronchogenic Cysts Treatment Needle aspiration is required in case of a tension cyst that expands rapidly and can lead to death by acute cardiorespiratory embarrassment. Otherwise the cyst should be surgically removed.

34. Bronchogenic Cysts Treatment For intrapulmonary cysts the excision options are segmentectomy , lobectomy or simple cyst removal . Extrapulmonary cysts can be removed by thoracoscopic surgery.

35. Bronchogenic Cysts Treatment The precise vascular supply to these lesions is difficult to determine. Both extra- and intrapulmonary bronchogenic cysts are supplied by numerous small branches. Therefore special attention should be paid during the dissection of the cyst.

36. Bronchogenic Cysts Treatment When cyst is adherent to a vital structure (trachea, main vessels, heart). can be partially resected and cyst epithelium destroyed with electrocautery to prevent recurrence or malignant degeneration.

37. Congenital pulmonary airway malformation CCAM

38. Congenital pulmonary airway malformation CPAM CCAM is characterized by an “ adenomatoid ” increase of terminal bronchioles that form cysts of various sizes. It is the most commonly diagnosed lung malformation in prenatal period Accounts for about 25% of all congenital bronchopulmonary malformations .

39. CPAM Incidence between 1/25000 and 1/35000. These malformations are characterized 1: by an abnormal branching of immature bronchioles , with a lack of normal alveolar development. 2: hamartomatous proliferation of cysts which resemble bronchioles (airways without cartilage)

40. CPAM Pathogenesis The cause of CCAM is unknown but the error occurs around sixth week of gestation in the pseudoglandular stage of lung development. The proposed theories of pathogenesis are increased cell proliferation and markedly decreased apoptosis increased platelet-derived growth factor (PDGF) gene expression FGF-10 (fibroblast growth factor) over expression in the proximal tracheobronchial tree during the Pseudoglandular stage of lung development.

41. CPAM Pathogenesis CCAM usually arises from one lobe of the lung, with the lower lobes being the most common site. Bilateral lung involvement is rare. CCAM lesions have an equal left- and right-sided incidence.

42. CPAM Usually communicates with the normal tracheobronchial tree. Most CPAM derive their blood supply from the pulmonary artery. drain via the pulmonary veins .

43. CPAM Pathogenesis CCAM is distinguished from other lesions and normal lung by following histological features (1) polypoid projections of the mucosa, (2) an increase in smooth muscle within cyst walls, (3) an absence of cartilage (4) the presence of mucus-secreting cells , and (5) the absence of inflammation.

44. CPAM Pathogenesis While the CCAM portion of the lung does not participate in normal gas exchange. But there are connections to the tracheobronchial tree which can lead to air-trapping , and respiratory distress in the newborn period.

45. CPAM Presentation Clinical presentation is variable. About 10% become symptomatic during fetal life The large mass can 1: restrict lung growth 2: produce mediastinal shift 3: cardiovascular compromise and 4: vena cava obstruction leading to non-immune hydrops fetalis (HF).

46. CPAM Presentation 60% of patients become symptomatic within one month of life . another 10% between one and six months and 15 % by adolescence

47. CCAM Presentation The key symptom in neonatal period is the respiratory distress. Outside of the neonatal period recurrent pulmonary infections are the presenting features of CCAM

48. CCAM Stocker’s classification ( according to the cysts size) Stocker defined three types of CCAM based on cyst size, 1: Single or multiple cysts, > 2 cm , lined by pseudostratified columnar epithelium 2: Single or multiple cysts <2 cm . Cuboidal or columnar epithelial lining 3: Predominantly solid lesions, with small (under 0.5 cm) cysts, lined by cuboidal epithelium However, this categorization has little clinical relevance

49. Graphic representation of the congenital pulmonary airway malformation (CPAM)

50. Type I Originates from Bronchi/bronchioles characterized by cysts measuring over 2 cm. It is present in 50-70 % of cases and has the best prognosis. usually diagnosed in neonatal period

51. Type I Early radiographs may demonstrate a water density mass if the cysts are filled with retained fetal lung fluid . Mass effect can cause contralateral mediastinal shift , inversion of the ipsilateral hemidiaphragm and atelectasis of the ipsilateral and contralateral lung.

52. Type I It is essential to take the X-ray with an in situ nasogastric tube in order to avoid being diagnosed as a diaphragmatic hernia

53. Type I Chest radiograph: large multicystic lesion in the right lung associated with significant mass effect and mediastinal shift .

54. Type II Originates from bronchioles Contains cysts less than 2 cm in diameter Account for about 10-15% This type is associated with other congenital malformations (congenital heart disease, pulmonary sequestration, renal agenesis) Tumor degeneration (rhabdomyosarcoma and pulmonary blastoma) may occur

55. Type II Chest radiograph: ill-defined mass on right upper lobe with small radiolucencies inside , findings that are compatible with a type II CPAM.

56. Type III Originates from bronchioles/alveoli Bulky mass composed of multiple tiny, microscopic cysts resembling bronchi that involves the entire lobe. Adenomatous hyperplasia with polypoid arrangement of mucosal epithelium.

57. Type III Autopsy photograph showing the abnormally enlarged left lung containing multiple, small cysts. Type III

58. CCAM Antenatal diagnosis Antenatal diagnosis is made by ultrasound scan US of the fetus shows a large cystic mass in the thorax

59. CCAM Antenatal diagnosis Antenatal USG may show Polyhydramnios - Due to esophageal compression Fetal hydrops -From venocaval obstruction and cardiac compression Ascites

60. CCAM CT helps in confirming the diagnosis , characterization of the lesion, and to document the involved lobe or segment Intravenous contrast media must be used to define the presence of any systemic arterial vessels supplying the lesion CT also helps to diagnose other associated congenital malformations

61. Coronal (A) and sagittal (B) CT images of a CPAM: right upper lobe mass, formed by multiple cysts

62. CT: CCAM in the right lower lobe, solid mass with multiple small cysts

63. CCAM Other diagnostic means include (MRI) and Bronchoscop y. One of the most recent developments in the area is virtual bronchoscopy (VB). VB is a non-invasive three-dimensional (3D) technique that uses multidetector CT -generated image. It can evaluate the airways down to the sixth- to seventh-generation bronchial subdivisions

64. CCAM Appearance of CCAM on virtual bronchoscopy

65. Differential diagnoses Congenital lobar emphysema Bronchogenic cyst Bronchopulmonary sequestration Prior infection with pneumatocele formation Diaphragmatic hernia

66. Treatment The natural history of antenatal diagnosed CCAM is difficult to determine accurately spontaneous resolution in utero of an antenatally diagnosed CCAM is reported to occur in up to 15% of patients .

67. Treatment Although largely silent during fetal life there are certain cases when fetal intervention is required like: mediastinal shift lung hypoplasia. Cardiovascular compression presence of HF

68. Treatment In order to help predict whether a fetus may be at risk of hydrops , Crumbleholme et al. proposed sonographic CPAM volume ratio (CVR) CVR= (CPAM Length × Height × Width × 0.52)/head circumference.

69. Treatment A CVR >1.6 predicts fetal hydrops in 75% of patients. postnatal intubation was required in 88% of patients with CVR of >1.6, and survival was only 53%.

70. Treatment The optimal type of fetal intervention is still a debated subject. Treatment options include: Fetal surgical resection Cyst -amniotic shunting Thoracentesis And steroid therapy .

71. Treatment Cyst-amniotic shunting may be the treatment of choice for macrocystic CCAM with HF. while microcystic CCAM requires surgical resection. Termination of pregnancy should be considered in cases of insufficient pulmonary tissue to support life after birth

72. Treatment After birth management is dictated by the clinical status of the new-born. Prompt surgical resection should be performed in symptomatic newborn with respiratory distress. In asymptomatic patients delaying resection until infancy is reasonable and allows somatic growth that may facilitate the ease of pulmonary resection.

73. Treatment Surgical resection of CCAM lesions is necessary even for asymptomatic patients in order to: prevent infection and avoid malignant transformation of the lesion

74. Treatment Excision of the CCAM is accomplished by Lobectomy segmentectomy and Pneumonectomy in certain cases The usual intervention is lobectomy via thoracotomy or thoracoscopical approach. Lobectomy is preferred because of potential early air-leak after segmentectomy and long-term complications after pneumonectomy

75. Treatment Thoracoscopy provides few advantages over thoracotomy: lower pain, better postoperative pulmonary mechanics. Moreover up to 30% of neonates develop scoliosis after thoracotomy.

76. Complications of surgery Early complications include: Sepsis Air leaks with pneumothorax, Bronchopleural fistula, Wound infections. Later complications and sequelae are Incomplete excision, asthma, pneumonia

77. Prognosis Prognosis depends of several factors such as: cyst volume the presence of complications during fetal life the presence and severity of early respiratory distress. Histological type (type I has the best prognosis) microcystic lesions involve a relatively large amount of lung tissue

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