Lung volume reduction surgery


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Lung volume reduction surgery

  2. 2. LVRS BACKGROUND Lung volume reduction surgery (LVRS), or reduction pneumoplasty (also referred to as lung shaving or lung contouring), is performed on patients with severe emphysema in order to allow the remaining compressed lung to expand and thus improve respiratory function.  In advanced stages of emphysema there is a sequence of events that start with hyperinflation, followed by a reduction in diaphragmatic mobility, an increase in resting pleural pressures that intensifies expiratory muscle recruitment and reduces elastic recoil of the lungs. The medical treatment of this condition includes bronchodilators, costicosteroids, oxygen and the management of exacerbations and infections but it does not impact on survival
  3. 3. LVRS BACKGROUND The current options for the surgical treatment are surgical ablation of bulous disease (bullectomy), lung volume reduction surgery (LVRS) and lung transplantation. 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” He proposed “Resection of the most useless area and Down sizing the lung would help to restore the outward pull on the small airway”
  4. 4. LVRS BACKGROUND  Several decades later – Delarue and Dahan - unilateral thoracotomy approach - pulmonary haemodynamics.  1991 – Wakabayashi-unilateral parenchymal laser ablation by thoracoscopic approach. 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. 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.
  5. 5. LVRS BACKGROUND This was followed by randomized studies that demonstrated functional benefits and acceptable mortality in patients with low exercise capacity and upper lobe predominant heterogeneous disease (Ciccone, Meyers et al. 2003).  NETT RESEARCH GROUP Carried between January 1998 and July 2002 17hospitals, data coordinating center JHSPH Patients randomized to medical or surgery treatment Secondary end points included quality of life, pulmonary function, 6-min walk distance N Engl J Med 2001
  6. 6. What is Emphysema?  Permanent abnormal enlargement of the acini  Destruction of alveolar walls without obvious fibrosis ( Specifically, two things combined:
  7. 7. Two kinds of emphysema EMPHYSEMA TYPES Primary emphysema  1-2% of cases  Inherited lack of alpha-1 antitrypsin, a protective protein (inhibits neutrophil elastase) Secondary emphysema  Also caused by inability to inhibit proteolytic enzymes in the lungs  From inhaled toxins (e.g., cigarette smoke)  20% of smokers at risk Wayne McLaren…Former Marlboro Man Age 30…a robust young man Age 51…riding into the sunset
  8. 8. Bullous Emphesyma CENTRIACINAR EMPHYSEMA [ “Bullae are large dilated airspaces that bulge out from beneath the pleura.” Respiratory bronchioles in proximal portion of acinus are lost Alveoli distal to terminal bronchiole intact Occurs in smokers with chronic bronchitis Usually in upper lobes
  9. 9. PRINCIPLE  1. VENTILATION/PERFUSION MISMATCH Patients with end-stage emphysema have distended airspaces; these may be inadequately ventilated. These distended airspaces may continue to expand and compress adjacent, well-perfused alveoli, which then become similarly dysfunctional. Resection of such damaged lung would remove some component of the ventilation/perfusion mismatch and potentially allow reexpansion of adjacent alveoli
  10. 10. PRINCIPLE -2
  11. 11. AIRWAY RESISTANCE The combination of the loss of the driving force of elastic recoil and the reduced tethering effect leads to closure of terminal bronchioles earlier in the expiratory cycle than what would normally occur. Over time, these forces result in increased airway resistance and hyperinflation of the lung. LVR entails resection of hyperinflated and nonfunctional lung
  12. 12. PRINCIPE -3 Loss of elastic recol Expansion of rib cage and flattening the diaphragm Increase resting volume Inefficient respiratory muscle Increase work of breathing Dyspnea CHEST WALL & DIAPHRAGM
  13. 13. Chest Wall and Diaphraghm  Excision of nonfunctional hyperinflated lung will lead to a smaller overall lung volume. This provides the opportunity for the chest wall to shrink down to a less hyperexpanded position and the diaphragm to resume its more dome-like appearance. Theoretically this return of the chest wall and diaphragm to their more normal shape and position will restore some of the functional capacity and muscular strength, leading to greater volumes of air movement throughout the respiratory cycle
  14. 14. Chest radiographs obtained at TLC and FRC in one patient before (Pre-op) and at 6 months and 12 months after LVRS. Top six views: anteroposterior views.
  15. 15. HAEMODYNAMICS LVR would theoretically decrease the size of the lung within the chest cavity and, by decreasing airway resistance, would lead to a lowering of the intrathoracic pressure throughout the respiratory cycle.  It might therefore improve venous return, decrease pulmonary vascular resistance, and thus improve right heart output and overall cardiac index.  This was in part the pathophysiologic mechanism for improvement promoted by DeLarue13 and Dahan  LVR  Decrease size of lung within chest cavity  lowering of intrathoracic pressure  Improve venous return,decrease PVR  Improve right heart output &cardiac index
  16. 16. Hemodynamics
  17. 17. PRE OPERATIVE ASSESMENT CHEST X RAY HRCT scan Quantitative V/Q scan Lung-volume measurement/ PFT Maximal exercise testing-6-minute walk test (140 m)  CARDIOVASCULAR WORKUP
  18. 18. CHEST X RAY  Marked HYPER INFLATED lungs is noted with flattend and low diaphragm  Intercostal space becomes widen  A horizontal pattern of ribs  A long thin heart shadow  Decreased markings of lung peripheral vessels
  19. 19. . (A) Preoperative plain chest radiographs reveal marked emphysematous changes with bullae over the apical zones of both lungs that were more predominant on the right. (B) A follow-up chest radiograph 3 months after surgery shows a less flattened diaphragm and apparent lung marking over the right upper lung zone.
  20. 20. CT SCAN Document the presence of emphysema Rule out the presence of infiltrative processes/ occult lung cancer Presence of solitary nodule undetected on X- RAY HRCT – whether Emphysema is homogenous or heterogenous Upper lobe predominant or lower lobe predominant
  21. 21. Three major types of emphysema distribution were defined: markedly heterogeneous (upper panel), intermediately heterogeneous (middle panel), and homogeneous (lower panel).
  22. 22. HRCT shows diffuse emphysematous changes over both lungs, with bulla formation that predominates over both upper lung zones, indicating vanishing tissue in the upper lungs. (D) HRCT taken three months after surgery shows an apparent disappearance of bullae with more pronounced vasculature in the right lung but with little change to the left lung.
  23. 23. Ventillation & Perfusion scintigrams  significant lack of perfusion in the upper lobes  Persistent retention of gas in same region  Indicates heterogenous disease with severe involvement in upper lobe
  24. 24. Lung perfusion single positron emission computed tomography scan showing underperfused areas (darkened zones) in the right lower lobe lateral basal segment and in the anterior segment of the left upper lobe.
  25. 25. PULMONARY FUNCTION TEST  Optimal candidates are those with severe obstructive disease (forced expiratory volume in one second [FEV1] <40% predicted) without a significant restrictive component or reversible bronchoconstriction.  Plethysmography must demonstrate significantly increased total lung capacity (TLC) >120% predicted as well as elevated residual volume (RV) >150% predicted.  Initial testing also includes determination of resting arterial blood gases (PO2 and PCO2). The diffusing capacity (DLCO) is also measured and, proves to be an important parameter that can occasionally contraindicate surgical intervention.  Ideally, patients who are candidates for LVR have a PO2 >60, a PCO2 <55 mm Hg, and a DLCO >20% predicted.
  26. 26. Pulmonary function test
  27. 27. The BODE score Four factors predict increased risk of death:  BODY MASS INDEX  The degree of airflow obstruction (FEV1)  Dyspnea  Exercise tolerance (6 MW distance) -------------------------------------------------------  Patients with higher BODE score - are at higher risk of death  BODE index has a stronger ability to discriminate the probability of survival among patients than FEV1  The BODE score predicts hospitalization better than FEV1
  28. 28. Computation of the BODE score Variable Points on BODE Index 0 1 2 3 FEV1 % predicted > 65 50-64 36-49 <35 6MW distance m >350 250-349 150-249 < 149 MRC dyspnea scale 0-1 2 3 4 BMI > 21 < 21
  29. 29. CARDIO VASCULAR WORK UP  Doppler echocardiography is routinely used to rule out significant cardiomyopathy and valvular heart disease. Early in the clinical experience, Doppler echocardiography was utilized to try to identify those patients with pulmonary hypertension, because such patients were felt to have an elevated risk of mortality.  However, Fisher and coworkers documented relatively mediocre sensitivity (60%) and specificity (74%) when echocardiography was utilized in this fashion. Patients in whom pulmonary hypertension is suspected on the basis of signs, symptoms or radiographic findings should therefore undergo right heart catheterization to determine whether pulmonary pressures contraindicate LVR
  30. 30. PATIENT SELECTION NOT ALL PATIENTS BENEFIT FROM LVRS Severe emphysema not reversible by medical treatment. Poor exercise performance. Marked hyperinflation. Indication :
  31. 31. Patient selection The National Emphysema Treatment Trial (NETT) was a prospective, randomized, multicenter trial which compared the results of LVRS to medical therapy which showed that there were 3 groups of patients that tend to benefit from LVRS Group 1: Patients with predominantly upper lobe emphysema and low exercise capacity. These patients have improved survival and functional outcomes after LVRS compared to medical therapy. Group 2: Patients with predominantly upper lobe emphysema and high exercise capacity. These patients have improved functional outcomes after LVRS but no difference in survival compared to medical therapy. Group 3: Patients with non-upper lobe emphysema and low exercise capacity. These patients have improved survival after LVRS but no difference in survival compared to medical therapy.
  32. 32. INCLUSION CRITERIA History and physical examination; BMI ≤31.1 kg/m2 (men) or ≤32.3 kg/m2 (women) at randomization; stable on ≤20 mg prednisone (or equivalent) daily  Radiographic HRCT scan evidence of bilateral emphysema  Pulmonary function (pre-rehabilitation) FEV1≤45% predicted (≥15% predicted if ≥70 years);  TLC ≥100% predicted; RV ≥150% predicted  Arterial blood gas (pre-rehabilitation) PCO2 ≤60 mm Hg (Denver: PCO2≤55 mm Hg) PO2 ≥45 mm Hg (Denver: PO2 ≥30 mm Hg) on room air  Cardiac assessment Approval for surgery before randomization by cardiologist if any of the following are present: unstable angina; LVEF cannot be estimated from the echocardiogram; LVEF ≤45%; dobutamine-radionuclide cardiac scan indicates coronary artery disease or ventricular dysfunction; arrhythmia (≥5 PVCs per minute; cardiac rhythm, other than sinus; PACs at rest)
  33. 33. INCLUSION CRITERIA Surgical assessment Approval for surgery by pulmonary physician, thoracic surgeon, and anesthesiologist after rehabilitation and before randomization Exercise Post-rehabilitation 6-minute walk ≥140 meters; able to complete 3 minutes of unloaded pedaling in exercise tolerance test (before and after rehabilitation)  Consent Signed consent forms for screening, rehabilitation, and randomization  Smoking Plasma cotinine ≤13.7 ng/mL (or arterial carboxyhemoglobin ≤2.5% if using nicotine products); nonsmoking for 4 months before initial interview and throughout screening  Rehabiliation -Must complete pre-randomization assessments, rehabilitation program, and all post-rehabilitation and randomization assessments
  34. 34. Exclusionary Criteria  Previous operation Lung transplantation; LVRS; median sternotomy or lobectomy  Cardiovascular Arrhythmia that might pose a risk during exercise or training; resting bradycardia (<50 beats/min); frequent multifocal PVCs; complex ventricular arrhythmia; sustained SVT; history of exercise- related syncope; MI within 6 months and LVEF <45%; congestive heart failure within 6 months and LVEF <45%; uncontrolled hypertension (systolic >200 mm Hg, diastolic >110 mg Hg)  Pulmonary History of recurrent infections with clinically significant sputum production; pleural or interstitial disease that precludes surgery; clinically significant bronchiectasis; pulmonary nodule necessitating surgery; giant bulla (greater than one third the volume of the lung); pulmonary hypertension; peak systolic PPA ≥45 mm Hg (≥50 mm Hg in Denver) or mean PPA ≥35 mm Hg (≥38 mm Hg in Denver); (right heart catheterization is required to rule out pulmonary hypertension if peak systolic PPA on echocardiogram ≥ 45 mm Hg); requirement for ≥ 6 L oxygen to keep saturation 90% or greater with exercise  Radiographic CT evidence for diffuse emphysema judged unsuitable for LVRS  General Unplanned weight loss of <10% usual weight in 90 days before enrollment; evidence of systemic disease or neoplasia expected to compromise survival during 5-year period; 6-minute walk distance ≤140 meters after rehabilitation; any disease or condition that interferes with completion of initial or follow-up assessments; unwillingness or inability to complete screening or baseline data collection procedures
  35. 35. Lung Volume Reduction Surgery Parameter Favourable Unfavourable Clinical Age <75 yrs Age > 75–80 yrs Clinical picture consistent with emphysema Co-morbid illness which would increase surgical mortality Not actively smoking (>3–6 months) Clinically significant coronary artery disease Severe dyspnea despite maximal medical treatment including pulmonary rehabilitation Pulmonary hypertension (PA systolic >45, PA mean >35 mmHg) Requiring <20 mg prednisone•day-1 Severe obesity or cachexia Surgical constraints Previous thoracic procedure Pleurodesis Chest wall deformity Physiological FEV1 after bronchodilator <45% pred FEV1 <20% pred and D L,CO <20% pred Hyperinflation Decreased inspiratory conductance RV >150% TLC >100% pred Pa,O2 > 6 kPa (45 mmHg) Pa,CO2 < 8 kPa (60 mmHg) Post-rehabilitation 6-min walk >140 m Low post-rehabilitation maximal achieved cycle ergometry watts# Radiographical High-resolution computed tomography confirming severe emphysema, ideally with upper lobe predominance Homogeneous emphysema and FEV1 <20% pred Non-upper lobe predominant emphysema and high post-rehabilitation cycle ergometry maximal achieved wattage
  36. 36. Pulmonary Rehabilitation  Most programs insist on a 6- to 8-week course of pulmonary rehabilitation prior to LVR in order to optimize the patient's physical condition and thus avoid any unnecessary morbidity or mortality from the operation itself.  Rehabilitation comprises a number of elements, including nutritional counseling, psychosocial counseling, and skill training with regard to breathing strategies and management of anxiety.  The exercise component includes maneuvers to improve both strength and flexibility as well as to maximize lower- and upper-body aerobic capacity. This entails upper-body weight training as well as treadmill work with supplemental oxygen as necessary.
  37. 37. 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.
  38. 38. LVRS by Median Sternotomy  The procedure involves bilateral LVRS in one operation, aiming to reduce the total lung volumeby 30% and to reshape each lung to best adapt to its hemithorax.  The decision in favour of bilateral operation was predicated on the view that it would maximise the improvement in chest wall mechanics by allowing the sternum to return to a more normal position.  This avoids the problem of further hyperinflation of theremaining lung from disabling the operated lung if a unilateral procedure were used.  General anaesthesia is used with a left sided double- lumen tube to allow selective  ventilation of each lung.  An epidural catheter is inserted before operation to allow epidural anaesthesia and reduce the need for analgesics, which may cause respiratory depression in the postoperative period.
  39. 39. LVRS by Median Sternotomy  Median sternotomy is carried out to carefully preserve the pleural membranes so that mobilisation of the apical pleurae can be achieved to provide apical pleural tents after resection, so that the lung apices will be covered by pleura, the space above the pleura will fill with fluid and intrapleural air spaces will be avoided.  The most severely affected side is operated on first.  Ventilation to that lung is ceased and the pleural cavity is opened.  Absorption collapse occurs in the more normal lung parts  The worstaffected areas remain inflated. These observations are considered with the information from the CT and ventilation-perfusion scans, to decide on the most strategic areas for resection.  Resection of each lung is limited to 30% and the stapled resection line is shaped to tailor the lung to best fit the hemithorax.  Linear staplers with the staple blades lined by reinforcing strips of bovine pericardium have proved to be a most effective way to secure an airless staple line.  Air leaks are meticulously dealt with, the opposite lung is then reduced and both pleural cavities are drained with low-pressure suction. Immediate
  40. 40. LVRS by Bilateral Thoraco-Sternotomy – the “Clam-Shell” Incision  Whilst the median sternotomy approach has many advantages, particularly its avoidance of damage to the lateral chest wall, exposure of the posterior surface of the lung, and in particular, the lower lobes is difficult. The clam-shell incision is an inviting alternative that overcomes some of these problems
  41. 41. Video Assisted Thoracoscopic Surgery  The widespread current use of video-assisted thoracoscopy (VATS), owes much to the pioneering work of Wakabayashi and co-workers5, who used a VATS approach to ablate emphysematous bullae using carbon dioxide laser.  The use of laser techniques in non-bullous emphysema has been shown to be less effective than stapling in a prospective trial by McKenna and colleagues16. They compare 33 patients in whom Neodymium:YAG laser was used, with 39 patients in whom staplers were used.  Both groups were exposed to unilateral operation with low mortality, but the frequency of functional improvement was greater in the stapled group at 32.9% compared with 13.4% in the laser group
  42. 42. Non-LVRS Approaches to Volume Reduction  • Compression/banding devices  • Endobronchial sealants  • Endobronchial sealants/plugs  • Endobronchial fenestration with bypass  • Endobronchial valves – Spiration valve (IBV valve) – Emphasys valve (Zephyr)
  43. 43. BRONCHOSCOPIC LVRS  Performed in OT under general anesthesia  Patient intubated and FB is advanced through ET  Target segmental bronchus is visualised and a guidewire is inserted into the operating channel of bronchoscope to reach the desired segment.  Leaving the guidewire in place, the bronchoscope is withdrawn and the delivery catheter is passed on the guidewire.  After the removal of the latter the valve is delivered.  Between three and five valves  Postoperative hospital stay ~ 2 day
  44. 44. Unilateral Versus Bilateral Approach  Early during the modern evolution of LVR surgery, there was a controversy regarding whether to perform the procedure unilaterally or bilaterally.  Cooper8 and other investigators performing median sternotomy routinely performed simultaneous bilateral procedures. Those performing a thoracoscopic LVR surgery initially performed unilateral procedures. This rapidly evolved to a simultaneous bilateral thoracoscopic procedure, but—not surprisingly—it was clear from early results that the morbidity of a bilateral thoracoscopic procedure exceeded that of a unilateral procedure. Thus the question arose as to whether LVR should be done unilaterally, bilaterally in a sequential fashion, or in a simultaneous bilateral procedure.  Studies by McKenna and Argenziano suggested that a bilateral LVR surgery yielded significantly greater improvements in spirometric indices than did unilateral procedures. Interestingly, the former author noted no increased morbidity for the  Because of the improved spirometric and quality-of-life results following bilateral LVR, the bilateral approach has become the routine for most surgeons undertaking this intervention.  Unilateral approach- These include patients in whom one pleural cavity or the other will be obliterated by dense adhesions, such as those with a history of prior unilateral thoracotomy, empyema, or pleurodesis. The unilateral approach should also be entertained in those whose emphysema is asymmetric and primarily unilateral. For such patients, unilateral LVR can still provide significant benefit
  45. 45. Who benefits from LVRS Maximum  Many reports support the claim that improvement following LVRS is better in patients whose target areas are in the upper lobes than in patients with lower-lobe targets.  A high ratio of emphysema in the upper lobe to the lower lobe on CT or perfusion scan predicted short-term functional improvements well  Recently, it has been shown that LVRS yields a survival advantage for patients with both predominantly upper-lobe emphysema and low baseline exercise capacity, whereas it does not afford patients with non– upper-lobe emphysema and high exercise capacity the benefit.
  46. 46. 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 assessedbefore the operation and 3, 6 and every 6 months after the operation. CONCLUDE FEV1.0 peaks within 6 months postoperative then decline in the fist year and slows down in succeeding years to baseline.
  47. 47. PATIENTS AT HIGH RISK OF DEATH AFTER LVRS A total of 1033 patients had been randomized by June 2001. 69 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 FEV1.0 Homogenous distribution of emphysema are at high risk of death after LVRS. Source: NEJM 345: 1075 – 1083 Oct. 2001
  48. 48. ISSUES AFTER L V R S
  49. 49. 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 47.69 ± 12.4 mmHg but the changes in PAP did not correlate with the changes in symptoms. Source: AM.J. Respir. Crit Care, 1999
  50. 50. COMPLICATIONS  INTRAOPERATIVE  None 91%  Hypotension 0.4%  Arrhythmia 1.2%  Hypoxemia 2.2%  Cardiac arrest 0.4%  Uncontrolled air leak 1.0% Postoperative (within 30 d of surgery)  None 41.3%  Major pulmonary morbidity* 29.8%  Failure to wean 8.0%  Tracheostomy 8.2%  Pneumonia 18.2%  Reintubation 21.8%  Ventilation . 2 d 13.6%  Major cardiovascular morbidity* 20.0%  Arrhythmia requiring Rx 18.6%  Myocardial infarction 1.0%  Pulmonary embolus 0.8%  Reoperation for air leak 3.3%  Readmit to ICU 11.7%  Mediastinitis 0.6%  Sternal debridement 0.6%  Sepsis 2.5%  Epidural catheter complications 0.8%  Readmit to hospital 2.5%  Urinary retention
  51. 51. The National Emphysema Treatment Trial (NETT)
  52. 52. NETT Design  17 clinical centers  Randomized 1,218 patients to medical therapy or medical therapy plus LVRS  Screened 3,777  Pulmonary function  FEV1 15% to 45%  TLC >105%  RV > 150%  No significant cardiac disease or pulmonary HTN  No other pulmonary diseases present  Bilateral emphysema amenable to LVRS  Upper lobe predominant  Diffuse NETT Research Group Chest, 1999
  53. 53. Durability of LVRS Naunheim et al, Ann Thorac Surg 2006 UL/Low Exercise UL/high Exercise
  54. 54. Exercise performance all patients 10 watt improvement Months LVRS Medical Rx p value 6 28% 4% <0.001 12 22% 5% <0.001 24 15% 3% <0.001 NETT Research Group NEJM, 2003
  55. 55. Who should not get surgery? NETT Research Group NEJM, 2001
  56. 56. Video Assisted Thorascopy (VATS) vs Median Sternotomy (MS)  8 centers used MS  3 used VATS  6 randomized to either  Total patients: 359 MS vs 152 VATS  Randomized patients: 77 MS vs 71 VATS McKenna et al, J Thorac Cardiovasc Surg, 2004
  57. 57. VATS vs MS  30 day mortality  2.8% MS vs 2.0% VATS (p = 0.76)  90 day mortality  5.9% MS vs 4.6% (p = 0.67)  No mortality difference for randomized patients  Intra-operative hypoxemia more common in VATS (0.8% vs 5.3%)  No difference in days with air leak  Median hospital LOS of 10 d in MS vs 9 in VATS (p=0.01)  Randomized patients: 15d for MS vs 9d for VATS (p<0.001) McKenna et al, J Thorac Cardiovasc Surg, 2004
  58. 58. Most important lessons from NETT?  LVRS works!!  Interventions to improve survival  Smoking cessation  Oxygen  LVRS  LVRS improves  Oxygenation and oxygen requirements  Favorable alters breathing patterns  Reduces exacerbations
  59. 59. 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.