Interesting cases of lung hernias

Lung hernias for a radiologist, thoracic radiology, chest posters, chest radiology, abr, acr, STR,lung,hernia, society of thoracic radiology

1. Lung Hernia Chiemelie Ebeledike, MS3 Clint Walters, MD PGY3 Resident Radiology Jayanth H. Keshavamurthy, MD Norman B. Thomson, MD William B. Bates, MD

2. Financial Disclosures None to disclose for all authors

3. Background Lung herniation is an extension of lung tissue into chest wall through a rib cage defect in bony thorax rare More likely to occur when etiology causes increase in intrathoracic pressure or decrease in chest wall resistance Classified as congenital vs acquired Congenital cases make up <20% of cases Diaphragm or Rib/intercostal hypoplasia/agenesis Acquired cases classified as T raumatic (52%) spontaneous (30%) Trauma- most common cause Surgery- inadequate postoperative closure of rib cage, chest tube drainage Spontaneous (30%) Vigorous coughing, sneezing, strenuous exercise or lifting heavy objects, wind instruments (muscle defect usually present) Pathologic Neoplasm, infection/inflammatory process Chronic steroid use Herniation can be Thoracic- chest wall Cervical- apices, defective Sibson’s fascia Abdominal- diaphragm (least likely due to physiologically high intra-abdominal pressures)

4. Discussion Presentation Usually asymptomatic Point tenderness, crepitus, SOB, paroxysmal cough, subcutaneous mass in neck or chest wall on PE (may very with Valsalva/respiratory cycle) Hemoptysis if strangulation present Diagnose Chest CT, helical CT (diagnostic procedure of choice) Shows location and size of lesion, evidence of associated defects, gives information about thoracic and pleural space, indicates need for surgery in case of strangulation CXR – Oblique/tangential views more helpful Complications Strangulation I ncarceration Pneumothorax May resolve spontaneously S urgical repair- Severe or large hernias, presence of narrow neck created by broken costae, increase in hernia size reduce lung volume, repair skeletal defect, prosthetic mesh reinforcement Open or VATS technique Not routine for cervical/supraclavicular hernias no matter how severe Conservative management with serial radiographic follow up.

5. Apical Lung Hernia Defect in the supra-pleural membrane (Sibson’s fascia ) Can occur as congenital defect in neck muscles or fascia Almost always resolve spontaneously Acquired form in adults-rare More common with penetrating injury or chest wall disease (spontaneous) Common scenario is elderly persons, chronic cough or emphysema leading to weakened and stretched deep cervical fascia Reported in wind instrument players, weightlifters

6. Case 48-year-old female with severe COPD requiring multiple hospitalizations History of Right Pneumothorax, requiring pleurodesis Presents to ED for worsening dyspnea, respiratory failure.

7. Apical Lung Hernia Multiple Axial CT images demonstrate herniation of a lung bulla through the left Sibson’s fascia seen as a left paratracheal hypoattenuating mass continuous with the lung parenchyma.

8. Apical Lung Hernia Coronal and Sagittal reconstructions demonstrate herniation of a lung bulla through Sibson’s fascia

9. Intercostal lung hernia Results from decreased thoracic wall resistance, abnormally high intrathoracic pressure or a combination of both Spontaneous type is uncommon Frequently occur parasternally Absent external intercostal muscle Posteriorly, paraspinal muscles provide extra protection in deficiency of internal intercostal muscle Arise more commonly from penetrating injury vs blunt injury Costal fractures, direct sternal injury, clavicle-sternal/costal-sternal dislocation Can be due to instrumentation such as chest tube drainage If traumatic, presentation might immediately follow injury, or occur months to years after Rx is surgical repair in presence of Pain, incarceration and strangulation with resultant hemoptysis

10. Case 55-year-old male smoker >40 pack year Hx significant for HTN O steoarthritis ( heavy osteoarthritis of thoracic spine, femoro -acetabular osteoarthritis) Recent CXR obtained for lung cancer screen

11. Mild U ntreated C hronic Traumatic H ernia Normal CT obtained prior to trauma CT obtained after trauma chronic posterior right 9 th rib fracture Initial scout view of low dose CT lung cancer screening Multiple old fractures involving the right 7th, 8th, 9th and 10th ribs posteriorly

12. Mild Untreated Chronic Traumatic Hernia CT obtained after trauma in lung windows demonstrates a moderate sized posterolateral right intercostal hernia adjacent to previously demonstrated rib fracture

13. Case 68-year-old male involved in a motor vehicle accident S ustained multiple rib fractures with subcutaneous emphysema. CT scan of the chest revealed right lung herniation into the chest wall anteromedially with overlying subcutaneous emphysema. R etained hemothorax requiring evacuation was also present.

14. Anterior Traumatic Lung Hernia CT of the chest demonstrates small anterior intercostal lung hernia after trauma

15. Acute Traumatic Lung Hernia with Repair Chest CT in bone window showing anterior rib fracture AP chest Radiograph demonstrates multiple coils overlying the right hemithorax after lung hernia repair Surgical repair Reduction of right lung hernia with wedge resection of denuded tissue and evacuation of retained hemothorax . Bovine pericardial patches positioned onto anteromedial right chest wall, excluding the area of defect, to prevent further herniation.

16. Case 68-year-old male H istory of ischemic cardiomyopathy and placement of left ventricular epidural pacing leads via a previous left thoracotomy incision for biventricular pacing. Referred for swelling in his left anterolateral chest area particularly with Valsalva and coughing and localized chest symptoms. CT scan of the chest revealed a large left lung hernia through the intercostal space into the left chest wall.

17. Lung Herniation Through Mini-thoracotomy Defect After AICD Placement CT obtained prior to AICD placement - normal CT obtained 1 year after AICD placement - mild herniation of left lung parenchyma through mini-thoracotomy defect

18. Lung Herniation Through Mini-thoracotomy Defect After AICD Placement CT obtained 1.5 years after AICD placement - large herniation of lung parenchyma through mini-thoracotomy defect with significant inflammatory change in herniated lung Surgical repair Left thoracotomy with reduction of hernia and excision of hernia sac was performed with pericardial patch repair of intercostal defect

19. Case 45-year-old female with incidental lung nodule finding on CXR Hx of partial resection of right posterior 6 th rib

20. Pseudo-Lung Nodule Nodular 2.5 cm density in the right mid-lung

21. Pseudo-Lung Nodule Extrapleural fat inward herniation secondary to prior right posterior sixth rib partial resection

22. Congenital Diaphragmatic Hernia Congenital defect of diaphragm May be identified with routine prenatal US (24 wks ) Abdominal viscera herniates into chest Pulmonary hypoplasia (decrease in bronchial and pulmonary arterial branching) Increased risk of persistent pulmonary hypertension (PPHN ) Presents in neonates with a range of mild to severe respiratory distress in first few days of life depending on degree of hypoplasia Associated findings Cardiac anomalies Adrenal insufficiency

23. Learning Points Lung hernias are usually caused by high intrathoracic pressure or decreased resistance of thoracic wall Important to consider in patients with lung swelling or intermittent mass (neck, chest wall or abdomen) with increased intrathoracic pressure Pertinent history can assist in identification, classification and treatment Physical exam and radiographic imaging may be normal Need to examine and image during a valsalva maneuver for adequate diagnosis. Knowledge of presentation may avoid complications from instrumentation such as subclavian venous catheter insertion Conservative management or surgical repair for local compression sxs, incarceration or cosmetic reasons

24. References/Suggested Reading Bhalla M, Leitman BS, Forcade C, Stern E, Naidich DP, McCauley DI. Lung hernia: radiographic features.  AJR Am J Roentgenol . 1990;154:51-53 . Bloss RS, Aranda JV, Beardmore HE. Congenital diaphragmatic hernia: pathophysiology and pharmacologic support. Surgery 1981; 89:518 . Clark AJ, Hughes N, Chisti F. Traumatic extrathoracic lung herniation.  Br J Radiol . 2009;82:e82-e84 . Deshmukh , Swati, and Karen Horton. "Case in Point-Lung Hernia." American College of Radiology . N.p ., 21 Aug. 2012. Web. 30 Sept. 2015. Getzoff A, Shaves S, Carter Y, Foy H. Traumatic lung herniation.  AJR Am J Roentgenol . 1999;172:1032 . Jastrow , Kenneth M et al. “Posterior Lung Herniation after a Coughing Spell: A Case Report.”  Cases Journal  2 (2009): 86.  PMC . Web. 30 Sept. 2015. Weissberg D, Refaely Y. Hernia of the lung.  Ann Thorac Surg . 2002;74:1963-1966.

25. Presenting Author Chiemelie Ebeledike, MS3 [email protected]