الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 180 |  |  |
| | | from | 180 | | |
Abstract
Emphysema is pathologically defined as an abnormal permanent enlargement of air spaces distal to the terminal bronchioles, accompanied by the destruction of alveolar walls and without obvious fibrosis.
The risk factors thought to be responsible for the development of COPD are cigarette smoking, next are cigars and pipe smoke, occupational, inhalational, and environmental exposures, including biomass fuel cooking.
Severe AAT deficiency predisposes to unopposed elastolysis with the clinical sequelae of an early onset of pan-acinar emphysema. Deficiency of AAT is inherited as an autosomal codominant condition.
Most patients seek medical attention late in the course of their disease. Patients will adapt and modify their lifestyles in order to minimize dyspnea and ignore cough and mucus production.
Thoracic examination reveals a 2:1 increase in anterior to posterior diameter “barrel chest”, diffuse or focal wheezing, diffusely diminished breath sounds, hyperresonance upon percussion, prolonged expiration, and/or hyperinflation on chest radiographs.
Chest radiographs reveal signs of hyperinflation, High-resolution CT scanning is more sensitive than standard chest radiography. HRCT scanning is highly specific for diagnosing emphysema and outlines bullae that are not always observed on radiographs.
Various surgical approaches to improve symptoms and restore function in patients with emphysema have been described. These should be offered to carefully selected patients as they may provide great benefit.
Lung volume reduction surgery attempts to decrease hyperinflation by surgically resecting the most diseased parts of the lung. This improves airflow by increasing the elastic recoil of the remaining lung and the mechanical efficiency of the respiratory muscles to generate expiratory pressures.
Removal of giant bullae has been a standard approach in selected patients for many years. Removal of these bullae may result in expansion of compressed lungs and improvement of lung function.
There may be a role for therapeutic lobectomy for emphysema, even if this is only to reduce the in-patient morbidity and length of stay.
Lobectomy is indicated in patients with localized pulmonary interstitial emphysema in a small number of patients when spontaneous regression is not occurring and medical management has failed.
Lung transplantation provides improved quality of life and functional capacity but does not result in survival benefit.
The idea of LVR entails surgical resection of emphysematous portion of lung as a treatment for severe emphysema.
A good candidate for LVRS is someone who has stopped smoking for at least 4 months and has disabling emphysema despite complete compliance with optimum medical therapy. The patient must be able to participate in a pulmonary rehabilitation program prior to and after surgery.
The following groups of patients are not optimum candidates for LVRS: Patients with non-upper lobe emphysema and high exercise capacity; Patients with extremely poor pulmonary function.
Lung volume reduction surgery has been found to alleviate symptoms and improve survival rate in a subgroup of patients with heterogeneous emphysema but the risks of morbidity and mortality are excessive.
Non-anatomical resection involves removal of a diseased portion of lung without complete dissection of the anatomic segment or lobe of the lung and without removal of draining lymph nodes. The most commonly performed procedure is wedge resection.
The morbidity after a lesser lung resection (wedge resection) is minimal. Potential complications include either retention of secretions or pleural problems.
Lung volume reduction surgery can be done with a large incision that exposes the whole lung, or via video-assisted thoroscopy.
Postoperative complication included cardiac arrhythmia, pneumonia, readmission to ICU, and failure to wean patients from mechanical ventilation within 3 days of LVRS.
Bronchoscopic lung volume reduction (BLVR) has shed new lights on surgical treatment for patients with emphysema by using a range of modalities such as stents, valves, thermal vapor ablation, sealants and implants.
Endobronchial valves is among the most intensively investigated techniques. By valve insertion into the bronchial lumen, valves may allow one-way flow of secretions and air out of an occluded pulmonary segment during expiration but prevent any distal flow during inspiration.
Endobronchial-valve induced improvements in lung function, exercise tolerance, and symptoms at the cost of more frequent exacerbations of COPD, pneumonia, and hemoptysis.
Complications of EBV included severe COPD, pneumothorax, pneumonia, valve migration and atelectasis.
Biological agents aim to reduce lung volume by sealing off the most emphysematous areas. The rapidly polymerizing sealant is designed to work at the alveolar level. The mechanism involves atelectasis resorption from airway occlusion and subsequent remodeling.
Controlled doses of steam can produce massive inflmmatory responses resulting in lung volume reduction.
Airway bypass aims to create an extra-anatomic bronchial fenestration to deflate emphysematous lung parenchyma. This technique may depend on the presence of collateral ventilation.
Lung volume reduction nitinol coils with flexible sizes can be inserted into target lumens of bronchai under fluoroscopic guidance. The released coils can reshape themselves and bend multiple bronchai to reduce lung volume.