Bullous disease of the lung. Physiologic improvement after surgery

Incidence and outcomes of surgical resection for giant pulmonary bullae--a population-based study

BACKGROUND

Giant pulmonary bullae (GPB) are rare and there is little information on incidence, long-term prognosis, and outcome of treatment.

OBJECTIVES

To assess the incidence of GPB in the Icelandic population and to evaluate the outcome of surgical treatment.

METHODS

Twelve consecutive patients (11 males; mean age 60 ± 15.7 years) underwent resection for GPB in Iceland between 1992 and 2009. All were heavy smokers and had bullae occupying > 30% of the involved lung. There were 8 bilateral and 3 unilateral bullectomies and one lobectomy. Pulmonary function tests were performed preoperatively, and at one month and 5.4 years postoperatively. Age-standardized incidence rate (ASR) was calculated, complications and operative mortality were registered, and overall survival was estimated. Mean follow-up time was 8.2 years.

RESULTS

The ASR for GPB was 0.40 and 0.03 per 100,000 per year for men and women, respectively. There was no operative mortality, but prolonged air leakage (75%) and pneumonia (17%) were the most common postoperative complications. One month postoperatively, mean FEV1 increased from 1.0 ± 0.48 L (33% predicted) to 1.75 ± 0.75 L (57.5% predicted) (p < 0.01), but FVC remained unchanged. RV decreased from 3.9 ± 0.8 L (177% predicted) to 3.0 ± 1.0 L (128% predicted) (p < 0.05), but TLC and DLCO did not change after operation. At long-term follow-up the FEV1 and FVC had declined to near-baseline values. Five-year and 10-year survival were 100% and 60%, respectively.

CONCLUSIONS

The ASR of GPB in Iceland was 0.21 per 100,000 per year. In this small series, bullectomy was found to be a safe procedure that significantly improved pulmonary function. The functional improvement then declined over time. Prolonged air leakage was a common postoperative complication that prolonged hospital stay.

New simple classification for operated bullous emphysema

OBJECTIVES

Optimal results in bullectomy depend on both the size of the resected bulla volume and the reexpansion of the adjacent collapsed healthy pulmonary parenchyma. We hypothesized that the bigger the bulla is compared with residual volume, the greater are the possible benefits. We suggested a new prognostic classification according to bulla volume and its relationship with residual volume.

METHODS

We retrospectively reviewed 121 patients with emphysematous bulla (>200 mL) who, from 1996 to 2006, underwent unilateral single (n = 64), unilateral multiple (n = 16), bilateral 1-stage (n = 9), and bilateral 2-stage (n = 32) bullectomies. Bulla volume and residual volume were measured by computed tomography and body plethysmography, respectively. Six-month postoperative decrement of residual volume values and their persistence below the baseline for 5 years were considered primary outcomes. Logistic regression was used to select significant variables. The receiver operating characteristic curve was used to identify the cutoff point for a possible classification system.

RESULTS

There was no postoperative mortality. Significant postoperative improvements in respiratory function were found and correlated with bulla size. Residual volume improved in 75 patients (62%) and persisted in 20 patients (35% of the patients followed for > 5 years). Logistic regression selected bulla/residual volume ratio as the most predictive variable for both outcomes (P < .0001). The best cutoff individuated by the receiver operating characteristic curve analysis was 20% to achieve a high probability of residual volume improvement and 30% to minimize residual volume recurrence.

CONCLUSIONS

Bullectomy provides good results, but more significant and long-lasting improvements are achievable with a greater ratio bulla/residual volume: scant for less than 20%, good but temporaneous for 20% to 30%, and good and long-lasting results for more than 30%.

Elective surgery for giant bullous emphysema: a 5-year clinical and functional follow-up

BACKGROUND

So far, very few studies in the literature have reported data on the long-term follow-up of patients who have undergone surgery for giant bullous emphysema (GBE), and much still needs to be known on the late fate of these patients.

AIMS

To evaluate patients who have undergone elective surgery due to GBE, early and late mortality following surgery, the early and late reappearance of bullae, and the early and late modifications of clinical and functional data.

SUBJECTS AND METHODS

Forty-one consecutive patients (36 men; mean [+/- SD] age, 48.4 +/- 14.8 years) who underwent elective surgery for GBE were enrolled in a prospective study, and were studied both before and after undergoing bullectomy for a 5-year-follow-up period. Analyses were performed on the whole population and on two subgroups of patients who were divided on the basis of the absence of underlying diffuse emphysema (group A; n = 23) or the presence of underlying diffuse emphysema (group B; n = 18).

RESULTS

The early mortality rate was 7.3% (within the first year), and the late mortality rate was 4.9% (overall mortality rate at 5 years, 12.2%; mortality rate in group B, 27.8%). Bullae did not reappear and residual bullae did not become enlarged in any patients at the site of the bullectomy. During the follow-up, the dyspnea score was reduced significantly soon after bullectomy and up to the fourth year of follow-up; intrathoracic gas volume also was reduced significantly (average, 0.7 L). The same was true for the FEV1 percent predicted and the FEV1/vital capacity ratio, which kept increasing until the second year; then, from the third year of follow-up these values were reduced, yet remained above the prebullectomy values until the fifth year of follow-up. When considered separately, the patients in group B appeared to be the most impaired, clinically and functionally (eg, FEV1 showed a similar significant increase up to the second year in both groups after surgery, while a different mean annual decrease was appreciable from the second to the fifth year of follow-up: group A, 25 mL/year; group B, 83 mL/year. Furthermore, patients in group B were the only ones who contributed to the mortality rate, on the whole showing a behavior similar to that of patients who had undergone lung volume reduction surgery.

CONCLUSIONS

In patients with GBE who were enrolled in the study prospectively and were investigated yearly during a 5-year-follow-up period, elective surgery appears to have been fairly safe, and allowed clinical and functional improvement for at least 5 years. Better results may be expected in patients without underlying diffuse emphysema.

Giant bullous lung disease: evaluation, selection, techniques, and outcomes

Patient selection remains one of the most important aspects of successful surgery for bullous disease. Operation is indicated for patients who have incapacitating dyspnea with large bullae that fill more than 30% of the hemithorax and result in the compression of healthy adjacent lung tissue. Operation is also indicated for patients who have complications related to bullous disease such as infection or pneumothorax. Patients who have bullous disease in the presence of diffuse lung disease (emphysematous or nonemphysematous) should be evaluated on an individual basis and surgery should be performed on patients in whom even a small increase in pulmonary function might be of major benefit. Smoking cessation and outpatient pulmonary rehabilitation are required of all patients preoperatively. Patients should undergo PFTs including lung volumes by whole body plethysmography, spirometry, diffusion capacity, and arterial blood gas. CT remains the most important preoperative evaluation because it is useful assessing the extent of bullous disease and the quality of the surrounding lung tissue. The authors favor a minimally invasive technique through VATS whenever possible because it might allow for a quicker recovery and might be associated with less pain than is seen following thoracotomy. Modified Monaldi-type drainage procedures are also effective, especially in high-risk patients who cannot tolerate excisional procedures. Special care must be taken to avoid sacrifice of any potentially functional lung tissue. Lobectomies should be avoided whenever possible. The best results are seen in limited resections of large bullae that spare all surrounding functional pulmonary parenchyma. Postoperative complications are minimized through aggressive tracheobronchial toilet and vigorous chest physiotherapy. Adequate pain control in maintained throughout the postoperative period, initially by way of epidural infusion of morphine or fentanyl and later through oral opioids. Early ambulation and pulmonary rehabilitation also help minimize complications.

Lung volume reduction surgery for emphysema

There has been dramatic resurgence of interest in surgical treatment of emphysema, particularly "lung volume reduction" procedures. Recent studies have demonstrated improvements in pulmonary function, lung mechanics, exercise tolerance, and quality of life in selected patients following volume reduction procedures. However, considerable uncertainty remains regarding overall benefit, optimal patient selection, operative techniques, and duration of response. This summarizes current approaches to lung volume reduction surgery, available clinical outcome information, selection criteria, and physiologic mechanisms of response, and discusses the potential role for surgical volume reduction in treatment of emphysema. Recent data appear to support the efficacy of bilateral staple lung volume reduction surgery in patients with severe symptomatic heterogeneously distributed emphysema. Further studies will be needed to determine relative value of different operative techniques and benefit in patients with other clinical presentations.

Reduction pneumoplasty for giant bullous emphysema. Implications for surgical treatment of nonbullous emphysema

A review of the literature on reduction pneumoplasty for giant bullous emphysema was undertaken to identify current criteria for this surgical treatment and in the hope of obtaining insights into evaluating reduction pneumoplasty for nonbullous emphysema. Twenty-two retrospective case series, published since 1950, were retrieved by a computer search of the literature and a search of the Index Medicus prior to 1966. Reduction pneumoplasty is most effective when bullae are larger than one third of a hemithorax with evidence of compression of adjacent lung tissue and an FEV1 of less than 50% predicted; the presence of emphysema in nonbullous lung and the amount of compression are best judged by CT. The rationale for reduction pneumoplasty for nonbullous emphysema is supported by the similar early functional changes after reduction pneumoplasty for bullous and nonbullous-improvement of blood gas values and lung mechanics. A single study showing that decline of lung function after surgery for bullous emphysema was less in those who stopped smoking than in those who continued to smoke supports the need for preoperative and maintained smoking cessation in patients receiving reduction pneumoplasty. After 4 decades, the duration of improvement in lung function, whether worsening of emphysema occurs in remaining lung, and late morbidity and mortality after reduction pneumoplasty for bullous emphysema are not well defined. A registry with an unoperated-on comparison group could more rapidly accumulate such data after reduction pneumoplasty for nonbullous emphysema.

Prediction of postoperative performance status in patients with giant bulla

To predict the postoperative improvement in performance status after bullectomy, preoperative pulmonary function and dyspneic grade were evaluated in 20 patients with giant bulla. The patients were divided into two groups, based on postoperative performance status: group 1 consisted of 15 patients with improved status after surgery; and group 2 of five patients with worsened status after temporary improvement. To determine correlation with the groups, preoperative functional measurements such as %VC, FEV1%, MMF, PEFR, RV/TLC, delta N2, LCI, and PNCD were then analyzed by the multivariate statistic method; results of delta N2 and FEV1% showed significant correlation with the groups. Prediction of the groups based on the two measurements agreed with the actual results except in one patient. These results show that postoperative improvement in performance status of patients with giant bulla can be predicted on the basis of preoperative pulmonary function.

Functional indications for bullectomy of giant bulla

Nineteen patients with giant bulla were followed for more than 1 year after bullectomy. They were divided into two groups according to their postoperative symptoms. Group 1 consisted of 16 patients who had no problems in their postoperative clinical course, while Group 2 included 3 patients who complained of severe dyspnea at 5 to 6 years of follow-up. Prior to operation, the forced expiratory volume in 1 sec over vital capacity (FEV1%) was 66.8 +/- in Group 1 and 27.6 +/- 5.4% in Group 2. Differences in preoperative and postoperative FEV1% were statistically significant within Group 1 and between the two groups. Postoperative FEV1% (Y) correlated significantly with preoperative FEV1% (X) (Y = 0.74X + 25.4; r = 0.836; p less than 0.001). Thus, we were able to predict the postoperative FEV1% from the preoperative value. Regional ventilation over volume was computed from the washout curve of xenon 133 after reaching equilibrium with rebreathing in a closed circuit (V/V dynamic). Group 2 had significantly lower regional ventilation over volume in all regions, both before and even after bullectomy, compared with normal subjects or Group 1 patients. Preoperative V/V dynamic was below 0.5 in all regions of Group 2. Furthermore, postoperative V/V dynamic (Y) correlated significantly with preoperative V/V dynamic (X) in the upper region (Y = 0.46X + 0.40; r = 0.638; p less than 0.02) and in the lower region (Y = 0.72X + 0.33; r = 0.869; p less than 0.001). We conclude that functional indications of bullectomy for giant bulla are that FEV1% should be greater than 40%, and that regional V/V dynamic should be greater than 0.5. On the other hand, symptomatic and functional improvement following bullectomy was reduced in patients whose FEV1% was less than 35% in whose V/V dynamic was remarkably disturbed in all regions of the involved hemithorax.

Current status of ventilation-perfusion imaging

The major clinical use of ventilation-perfusion (V/Q) scintigraphy is for the diagnosis of pulmonary embolism (PE). Accurate diagnosis of PE is essential since effective treatment is available but involves some risk to the patient. The scintigraphic characteristics of PE are segmental perfusion defects in lung that is normally ventilated and normal on the radiograph. The inherent shortcoming of perfusion scintigraphy is its lack of specificity. Combining a ventilation study with perfusion imaging improves the diagnostic specificity of lung scintigraphy. Xenon-133 is currently the most commonly used radionuclide for routine ventilation studies; a long washout technique is more sensitive than single-breath imaging when this radionuclide is used. We obtain preperfusion xenon-133 ventilation studies with a 4-min rebreathing equilibrium phase and a long 5-min washout phase to obtain maximum information. It is imperative that V/Q studies be interpreted with a current high quality chest radiograph. Interpretation of V/Q studies for PE is perhaps best done by assigning a probability diagnosis, since rarely is absolute specificity possible. This article details the criteria we use for these probability determinations.

Bullous emphysema. Progressive incremental exercise testing to evaluate candidates for bullectomy

Various tests of both function and anatomy have been used in patients being considered for surgical resection of giant pulmonary bullae. A young patient had an excellent response to removal of a large bulla in the right lung. In addition to roentgenographic evaluation, ventilation perfusion scanning, and routine preoperative pulmonary function studies, we performed progressive incremental exercise testing to determine both preoperative and postoperative ventilatory and cardiac measurements. We feel that progressive incremental exercise pulmonary function adds another dimension to the selection and follow-up of patients being considered for operative bullectomy.