ISKANDER AL GITHMI, M.D. L UNG V OLUME R EDUCTION S URGERY ( L V R S )

BACKGROUND Dr. Brantigan in 1957 was the first person to present the concept of LVRS. His concept, based on “Under normal circumstances, the elasticity of expanded lung is transmitted to the small airways which held opened by circumferential elastic pull”

In emphysema this elasticity and circumferential pull on the small airways are lost. He proposed “Resection of the most useless area and Down sizing the lung would help to restore the outward pull on the small airway”

In 1991, Wakabayashi and colleague reported using the carbon dioxide laser to shrink bullous areas of the lung via VATs. In 1995, Cooper and Associate a modification of Brantigan’s volume reduction operation, in which lung tissue was resected from both lungs via median sternotomy. He reported his initial 20 cases with no operative mortality and the operation produced an 82% mean increase in FEV 1.0 and significant improvement in 6 min. walking distance.

In 2001, Cooper and associate report 6 cases of endobronchial bypass procedure by creating extra-anatomic broncho- pulmonary passage and placing a stent. His concern? How long the stent stay open.

OVERVIEW EMPHYSEMA: is a condition of the lung characterized by abnormal permanent enlargement of airspace distal to the terminal bronchiole, accompanied by destruction of their wall in the absence of fibrosis.

PATHO PHYSIOLOGY Loss of elastic recol Expansion of rib cage and flattening the diaphragm Increase resting volume Inefficient respiratory muscle Increase work of breathing Dyspnea

PATIENT SELECTION NOT ALL PATIENTS BENEFIT FROM LVRS  Severe emphysema not reversible by medical treatment.  Poor exercise performance.  Marked hyperinflation.  Indication :

EXCLUSION CRITERIA  Advanced age, above 70 years  Paco 2 more than 55 mmHg.  Mean pulmonary artery pressure >35mmHg  Psychosocial unstable  Severe active infection: bronchiectasis, TB  Malignancy with life expectancy less than 2 years  Significant coronary artery disease not candidate for revascularization.

INCLUSION CRITERIA  Age less than 75 years  FEV 1.0 less than 35% of predicted value  TLC more than 125% of predicted value  RV/TLC more than 0.6  Vo 2 max. less than 12 ml/kg/min  Highly motivated and stably psychosocial patient.  Radiological evidence of heterogenous distribution of emphysema.

PATIENT EVALUATION  Initial screening: routine CXR PA and lateral.  Standard pulmonary function tests.  Extensive history and exam. On this basis 70% of applicants are turned down, due to a lack of distension or the presence of homogenous severe destruction throughout the lung.

FINAL EVALUATION  HRCT scan  Quantitative V/Q scan  Lung-volume measurement  Dobutamine echo cardiogram  6-minute walk test (140 m)

OUTCOME MEASURE PRIMARY MEASURES According to NETT study group - Survival - Maximum exercise capacity SURVIVAL is chosen as primary measure because… - It is clinically significant - It can be assessed early and quantified

OUTCOME MEASURE MAXIMUM EXERCISE IS CHOSEN BECAUSE - It is easier to standardize - More reproducable than 6 min walk test - There is no study document a consistent relationship between improvement in functional status and changes in pulmonary function.

SECONDARY MEASURES  Quality of life and specific symptoms: dyspnea  Pulmonary function and gas exchange  Radiologic studies… - CT scan to verify the presence of emphysema and to assess the severity of the disease.  6 Minute Walking Test: - to assess the exercise performance Source: JTCS 1999, 118

Does lung functions improve after LVRS? Source: JTCS 2002: 123:845  Konrad et al have reported 115 patients underwent LVRS.  Symptoms and lung functions were assessed before the operation and 3, 6 and every 6 months after the operation. CONCLUDE FEV1.0 peaks within 6 months post operative then decline in the fist year and slows down in succeeding years to baseline.

RELATION BETWEEN AGE AND CLINICAL OUTCOME

RELATION BETWEEN RADIOLOGICAL PATTERN AND CLINICAL OUTCOME

SURGICAL INTERVENTION LVRS performed by means of bilateral VATS or median sternotomy (buttressed or non buttressed with bovine peri cardium). Resection is directed to the target areas identified by means of analysis of the CT scan and perfusion scan as the lung and the lung zones with the most pronounced emphysematous alteration and greatest reduction in perfusion.

PATIENTS AT HIGH RISK OF DEATH AFTER LVRS A total of 1033 patients had been randomized by June Patients had FEVI < 20% of their predicted value and homogenous distribution of emphysema on CT scan or their DLCO < 20% of predicted value. The 30-days mortality rate after surgery was 16% as compared with the rate of 0% among 70 medically treated patients (P < 0.001). Concluded: Very low DLCO Very low FEV 1.0 Homogenous distribution of emphysema are at high risk of death after LVRS. Source: NEJM 345: 1075 – 1083 Oct. 2001

ISSUES AFTER L V R S

DEVELOPMENT OF PULMONARY HYPERTENSION Weg. et al reported that development of pulmonary hypertension may occur after LVRS. 9 Patients were involved in a prospective study with an average age of 64 years After LVRS (PA) systolic pressure rose to ± 12.4 mmHg but the changes in PAP did not correlate with the changes in symptoms. Source: AM.J. Respir. Crit Care, 1999

TAKE HOME MESSAGE  There are no long term data as yet.  LVRS improved the life of many patients.  We are still on a learning curve in predicting outcome after LVRS.