[Cardiac compression of hydatid origin]

INTRODUCTION

Cardiac hydatid disease is uncommon and occurs in 0.5 to 2% of patients with hydatidosis. Isolated intrapericardial hydatid cystic disease is extremely rare.

OBSERVATION

We report the case of a young woman with cardiac compression due to multiple primary intrapericardial hydatid cysts. Since 1 year, she had gradual general health deterioration including dyspnoea, sweats and weight loss of 8kg. A widening of the mediastinum was observed on chest X-ray. The CT-scan, echocardiography and the dynamic IRM showed multiple mediastinal cysts with mass effect on the heart and main pulmonary artery. The size of the main pulmonary artery was reduced to 5 mm in diameter and the right upper pulmonary vein was nearly closed by posterior cysts. The right and left ventricular ejection fractions were estimated at about 34%. A complete resection of the cysts was performed by sternotomy. The surgical procedure was technically difficult because of major local inflammatory process. The postoperative outcome after an initial pulmonary embolism event was finally favourable.

CONCLUSION

Hydatidosis can lead to severe cardiac involvement. These rare forms of hydatid cystic disease must be known even in non endemic regions by surgeons because of increasing mobility of the world's population.

[Evolution of species: Lung cancer evolution over one third of a century]

INTRODUCTION

Management of non-small cell lung cancer (NSCLC) is getting better and results on long-term survival have improved. We reviewed the modifications observed in surgery over a 32-year time period.

PATIENTS AND METHOD

Data of 6105 patients who underwent surgery from 1979 to 2010 were analyzed over three equal time-periods: gender, age, type of surgery, histology, pTNM, tobacco addiction, comorbidity and time periods.

RESULTS

Age, number of females and high-risk patients with comorbidity (including the history of a previous cancer) increased with time periods. Number of exploratory thoracotomy (7.7 % to 1.6 %) and pneumonectomy (48 % to 18 %) decreased. Number of wedge resection (0.5 % to 6 %) and lobectomy (42 % to 64 %) increased. Rates of the other types of resection were unchanged. Neoadjuvant treatments accounted for more than 20 % of patients in the last time period. Postoperative mortality (4 %) did not vary but non-lethal complication rates increased (16.9 % to 27.7 %). Global 5-year survival rates dramatically increased with time going from 37.4 % to 49.8 % (P<10(-6)). Survival improvement was observed in the different components of the pTNM and whatever the type of treatment. However, survival was affected by increasing age and multiplication of comorbidities but without impairing the general better outcome trend.

CONCLUSION

NSCLC itself, its diagnostic and therapeutic management, and patient's characteristics evolved with time. Survival improved in most studied prognosis factors. Time period factor was of paramount importance and might be included in research dealing with NSCLC.

[Lung cancer measuring 1cm or less: A miniature subset requiring surgery]

INTRODUCTION

Lung cancer measuring 1cm or less has an apparently very good outcome. However, the characteristics permitting their oncological management are unappreciated.

PATIENT AND METHOD

We reviewed 187 patients with such a cancer (145 men and 42 women, mean age 60.2years) and studied the type of surgery performed, the pTNM, and the histological features.

RESULTS

Surgery (19 wedge-resections, 12 segmentectomies, 136 lobectomies, 20 pneumonectomies) was complete (R0) in 97.3%. The tumors, each precisely defined among 98 adenocarcinomas (52.4%), 83 squamous cell carcinomas (44.4%), and 6 others, measured 1mm to 10mm:<5mm (n=41), 6 to 9mm (n=43), and 10mm (n=103). There were 161 pT1 (86.1%), 22 pT2 (11.8%) and 4 pT3; 148 pN0 (79.6%), 18 pN1 (9.7%) and 20 pN2 (10.7%). pN1 and pN2 were present in tumors<5mm (12/41, 29.3%) as well as in the others (26/146, 17.8% P=0.11). Histological examination frequently discovered visceral pleura involvement (tumors:<5mm 12.2% (5/41), 6 to 9mm 7% (3/43), 10mm 13.6% (14/103), P=0.53) and lympho-vascular invasion (12.9%). Five-year survival rate (66.4%) was adversely influenced by age, type of resection, pN and histological features. The survival rate was not better in tumor<5mm.

CONCLUSION

Surgical resection allows the local control of lung cancers<1cm and their complete histological study, a key issue in the therapy of the future, which renders surgery an absolute must even in very small tumors.

[Life threatening haemoptysis associated with partial abnormal pulmonary venous return and pulmonary arterial hypertension]

A 73-year-old man with chronic respiratory insufficiency was referred to the intensive care unit because of life threatening haemoptysis and hypoxemia. The patient was in respiratory failure with pulmonary arterial hypertension. The bleeding was issuing from the left inferior lobe. A small arterio-venous fistula was suspected on tomodensitometry. Arterial embolization was contraindicated because of diffuse vascular disease. A left inferior lobectomy was performed. The left superior pulmonary vein was draining into the brachiocephalic vein forming a partial anomalous pulmonary venous return. An anatomic restoration of the venous return to the left atrium was performed. The postoperative course was uneventful. No recurrence of haemoptysis was observed, after 9-month follow-up the vascular anastomosis was patent. Despite the pulmonary vascular bed reduction following lobectomy, echocardiography showed a globally mild improvement of cardiac status that might be attributed to right heart preload amelioration.

[Clinical and paraclinical prognostic factors in non-small cell lung cancer surgery]

INTRODUCTION

Lung cancer prognosis is mainly based on the TNM, histology and molecular biology. Our aim was to analyze the prognostic value of certain clinical and paraclinical variables.

PATIENTS AND METHODS

We studied among 6105 patients operated on, divided during 3 time-periods (1979 to 2010), the following prognostic factors: type of surgery, pTNM, histology, age, sex, smoking history, clinical presentation, and paraclinical variables.

RESULTS

Postoperative mortality was 4% (243/6105), rate of complications was 23.3% (1424/6105). The 5-year overall survival was 43.2% and 10-year was 27%. Best survival was observed after complete resection (R0) (P<10(-6)), lobectomy (P<10(-6)), lymph node dissection (P=0.0006), early pTNM stages (P<10(-6)), absence of a solid component in adenocarcinoma. Other pejorative factors were: male gender (P=10(-5)), age (P=0.0000002), comorbidity (P=0.016), history of cancer (P<10(-5)), postoperative complications (P=0.0018), FEV lower than 80% (P=0.0000025), time-periods (P<10(-6)). All these factors were confirmed by multivariate analysis, except gender. Smoking was not poor prognostic factor in univariate analysis (P=0.09) but became significant in the multivariate one (P=0.013).

CONCLUSION

Medical and human factors, and the general physiological state, play an important role in prognosis after surgery. We do not know their exact meaning and, like studies on chemotherapy, they justify special research.

[Place of limited resections and prognostic factors in non-small lung cancer]

INTRODUCTION

Results of surgery for non-small-cell lung cancer (NSCLC) are poorer after limited resection, wedge and segmentectomy, than after lobectomy. Guidelines recommend avoiding wedge-resection, which new techniques (radiofrequency ablation and cyberknife) tend to replace. This work aimed to study the wedge-resection carcinological value.

PATIENTS AND METHODS

NSCLC without previous other cancer history and neoadjuvant therapy measuring less than 31 millimetres and operated from 1980 to 2009 were reviewed. Analyzed variables were: location, gender, age, FEVS, type of resection, histology, pT and pN.

RESULTS

There were 66 wedge-resections (10.9%), 32 segmentectomies (5.3%), 507 lobectomies (83.8%), nine postoperative deaths (1.5%), 136 complications (22.5%), 557 complete resections (R0=92%); 72.2% of NSCLC upper lobe location (437/605). Age was more advanced in wedge-resection and segmentectomy, FEVS lower and NSCLC most often a squamous cell pN0 and pStage I carcinoma than in lobectomy. Lymphadenectomy was not performed in half the wedge-resections. Five-year survival rates were poorer after wedge-resection: 50% versus segmentectomy 59.8% (P=0.09), and lobectomy 66% (P=0.0035), but the number of recurrences was similar. Multivariate analysis demonstrated that age, FEVS, type of surgery and lymphadenectomy, pN in pTNM were the only prognosis factors.

CONCLUSION

Wedge-resection is less carcinological than segmentectomy when the patient-status and NSCLC location allow performing the latter, but more than the new techniques, because of its pathological yield, when the patient-status and nodule peripheral location allow wedging.

[Lung cancer surgery and cirrhosis]

INTRODUCTION

Lung cancer is the leading cause of death by cancer and cirrhosis is the fourteenth, all causes included. Surgery increases postoperative risks in cirrhotic patients. Our purpose was to analyze this point in lung cancer surgery.

METHODS

We collected, among 7162 patients, the data concerning those operated for lung cancer (n=6105) and compared patients with hepatic disease (n=448) to those presenting other medical disorder (n=2587). We analyzed cirrhotic patients' characteristics (n=49).

RESULTS

Five-year survival of patients with hepatic disease was lower (n=5657/6105): 35.3% versus 43.8% for patients with no hepatic disease, P=0.0021. Survival of cirrhotic patients was not statistically different from the one of patients with other hepatic disorder, but none survived beyond 10 years (0% versus 26.4%). Surgery in cirrhotic patients consisted in one explorative thoracotomy, three wedges resections, two segmentectomies, 33 lobectomies and 10 pneumonectomies. Postoperative mortality (8.2%; 4/49) was not different for patients without hepatic disease (4.2%; 239/5657) (P=0.32), as well as the rate of complications (40.8%; 20/49 and 24.8%; 1404/5657, P=0.11). Only one postoperative death was associated to a hepatic failure. Multivariate analysis pointed age, histological subtype of the tumour and stage of disease as independent prognosis factors.

CONCLUSION

When cirrhosis is well compensated, surgical resection of lung cancer can be performed with acceptable postoperative morbidity and satisfactory rates of survival. Progressive potential of this disease is worse after five years.

[Pneumonectomy for benign disease: indication and factors affecting the postoperative course]

Pneumonectomy for benign disease is rare but may generate more postoperative morbimortality than when performed for lung cancer. We questioned this assessment and retrospectively reviewed 1436 pneumonectomies and 54 completions of which 82 and 10 performed for benign disease (5.7% and 18.5%, respectively): left n=65 and right n=27. Indications were: post-tuberculosis destroyed lung (n=37), aspergilloma (n=18), bronchiectasis (n=19), infection (n=5), congenital malformations (n=5), inflammatory pseudotumor (n=3), trauma (n=2), post-radiation (n=2) and mucormycosis (n=1). Pneumonectomy consisted of 48 standard and 44 pleuro-pneumonectomies. Stump coverage by flaps was performed in 66.3% (61/92). Complications occurred in 21.7% (20/92) and postoperative deaths in 7.6% (7/92, of which 5 with fungal infections), which was not different than what was observed in lung cancer. There was no difference in fistula formation and mortality regarding the side, the type of resection and the protective role of stump coverage. Considering patients with fungal infections versus others, mortality was 26.3% (n=5/19) and 2.7% (n=2/74), respectively (P=0.0028). Pneumonectomy for benign disease achieves cure with acceptable mortality and morbidity. However, presence of fungal infection should raise the attention for possibility of increased postoperative risks.

[Mucoepidermoid tracheo-bronchial tumors in adulthood. A series of 22 cases]

INTRODUCTION

Mucoepidermoid tumours (TME) are rare tumours arising from the submucosal glands of the tracheobronchial tree. The majority of these tumours develop in a benign fashion but some of them are malignant. The latter can be easily mistaken for adenosquamous carcinomas.

PATIENTS AND METHOD

We have reviewed 22 patients suffering from TME observed over a period of 25 years. Two arose from the trachea and 20 from the cartilaginous bronchi; 12 of these tumours had macroscopic and histological criteria of low-grade malignancy, 4 had macroscopic and 6 macroscopic and microscopic criteria of high grade malignancy.

RESULTS

Prognosis of the latter was very poor and no survival observed after 6 years follow-up, a behavior similar to that observed in non-small cell lung carcinomas and adenosquamous carcinomas.

CONCLUSION

The best treatment of these orphan tumours remains surgery.

[Lung cancer surgery in a single-lung]

INTRODUCTION

The diagnosis of a second lung cancer in a patient with a previous medical history of lung cancer is no longer a rarity. Also, it is possible to observe a new location in a patient who underwent pneumonectomy in the past. Surgery remains the best treatment. Our objective was to overview this subject.

PATIENTS AND METHODS

Among 5611 patients operated in our institution, 186 (3.3%) had metachronous cancer and 17 had previous pneumonectomy (0.7% of pneumonectomies and 0.2% of NSCLC treated in our department). The procedure was diagnostic and therapeutic in 88% of cases (n=15).

RESULTS

There were 16 males and 1 female, mean age was 62.5-years. All were smokers (11 were former smokers) and 6 had other medical history. Mean FEV was 52% (range 35-95%). Types of resection were 2 lobectomies, 4 segmentectomies, and 11 wedge resections. There were no postoperative deaths, but two complications. Histological subtype of the first and second cancer was the same in 11 patients. All patients were pN0 after second surgery. The long-term survival (median 33 months) was 35.3% at 5-years and 14.1% at 10-years. Two patients treated with pneumonectomy for their first cancer were pN2. Patients who underwent upper right lobectomy for treatment of their second cancer survived longer than 5-years.

CONCLUSION

Surgical resection for lung cancer on single-lung is associated with acceptable morbidity and mortality. Prolonged survival can be achieved in selected patients.

[Lung cancer surgery in solid organ transplanted patients]

BACKGROUND

The incidence of lung cancer is reputed to be higher and prognosis worse in solid organ transplant recipients than in the general population. Our purpose was to review the results of surgery in this group of patients.

METHODS

We retrospectively reviewed 49 male and 6 female patients; mean aged 60.6 years (38-85). Transplanted organ was heart (n = 37), kidney (n=12), liver (n = 5) and both-lungs (n = 1); 48 patients had smoking habits and 42 heavy comorbidities (76.4%). Lung cancer was diagnosed during surveillance (78.2%, n = 43) or because of symptoms (21.8%, n = 12). We reviewed TNM and other main characteristics, among them histology (squamous-cell-carcinoma n = 23, adenocarcinomas n = 24, others n = 8).

RESULTS

Surgery consisted of: exploratory thoracotomy (n = 2), wedge resections (n = 6), segmentectomy (n = 1), lobectomy (n = 42), pneumonectomy (n = 4). Postoperative mortality was 7.4% (n = 4) and complication rate 34.5% (n = 19). Five-year survival rate was 46.4% (65.4% for stage I patients, n = 25). Among the 35 dead patients during follow-up, 14 died of their lung cancer (40%). Two had been re-operated from another lung cancer: one after 3 and 8 years who survived 16 years, and the other after 2 years who survived 70 months.

CONCLUSIONS

Surgery results are good and postoperative events acceptable despite theoretically increased risks. This also supports performing a close follow-up of transplanted patients and particularly those with smoking history in view of detecting lung cancer appearing at an early stage.

[Place and role of the pleura in non-small cell lung cancer dissemination]

INTRODUCTION

The pleural involvement (PLI) in non-small cell lung cancer (NSCLC) has a poor prognosis, even though it might be very heterogeneous.

PATIENTS AND METHODS

A multicentric retrospective descriptive study was performed over 2329 patients who were operated for NSCLC between 1979 and 2010. The patients with PLI were classified in P(Parietal)PLI and V(visceral)PLI and then each subdivided : VPLI to peripheric (VPLI-P) and fissural (VPLI-F) and PPLI to mediastinal (PPLI-M) and costal (PPLI-C). Characteristics and survival were compared between the subgroups as well as with patients without PLI (WPLI, n=1439).

RESULTS

The sex-ratio was 2.8 (males: n=1713). The PLI patients were significantly younger, with a less sex-ratio, less R0 resections (96% versus 98.7%, P=0.000076), and less N0 (60% vs 70%, P<10(-6)) as their 5-year survival (45.7% vs 55.5%, P<10(-6)). The PLI was related to the size of NSCLC (P<10(-6)) and N2 involvement (P=0.0020). It was less frequent after neoadjuvant treatment (36.2% vs 39.1% P=0.03). In the VPLI-F or PPLI-M, pneumonectomies were more frequent (P<10(-6)). In VPLI-P (n=196/561), there were more pN1 and pN2 (P=0.0065) with a 5-year survival of 42.9% vs 54.4%, P=0.013. In multivariate analysis, the PLI was not an independent prognostic factor contrary to age, sex, type of resection, pT and pN.

CONCLUSION

The pleura play a major role in NSCLC dissemination. Its involvement affects pN, the type of surgical resection and justifies the use of neoadjuvant treatment.

[Place of bilobectomy in pulmonary oncology and prognostic factors in NSCLC]

INTRODUCTION

Bilobectomy may be performed for different reasons and lung tumors. There are still controversies regarding the results of this procedure. We reviewed our experience of bilobectomy to evaluate the particularities of this resection.

METHODS

The clinical files of patients operated on for lung tumors in two French centers between 1980 and 2009 were prospectively recorded and retrospectively analyzed. The characteristics, management, pathology, and survival after right-sided resections for non-small cell lung cancer (NSCLC) were then compared.

RESULTS

During the study period, 3280 right-sided resections were performed, including 235 bilobectomy (7%), for NSCLC in 192 cases (82%). Lower-middle lobectomy (LML) represented 60% of bilobectomy, with carcinoid tumors and squamous cell carcinoma being more frequent in this group. Upper-middle lobectomy (UML) represented 40% of bilobectomy, with less postoperative complications and mortality in this group. In N0-NSCLC, the rate of postoperative mortality and 5-year survival rates after bilobectomy (4.7% and 46.1%, respectively) were intermediate between lobectomy (2.7% and 52.6%) and pneumonectomy (9.6% and 31.7%, P<10(-6) for both comparisons). There was no significant difference in 5-year survival rates according to the type of bilobectomy and the performance of any induction therapy.

CONCLUSION

Bilobectomy is associated with acceptable in-hospital mortality and encouraging 5-year survival rates despite an increased incidence of postoperative complications. Approximation in survival of UML and pneumonectomy and of LML and lobectomy may be due to differences in histologic features with different fissure extension and interlobar node involvement.

[Lymphatics and lung transplantation. A review]

The role of lymph circulation in lung transplantation (LTx) has not really been studied since the first animal models, which allowed the development of solid organ transplantations. However, the oedema observed in the grafts immediately after LTx often remains unpredictable and unexplained. Although it is an integral part of the entity called "primary graft failure". Despite its multifactor aspects making the interpretation difficult, the possibility of a change in the lymph circulation is proposed to explain an oedema occurrence. The animal models focusing on this point were mainly developed in small bowel transplantation because of interesting similarities with LTx. The analysed criteria were the consequences of lymphatic vessels interruption as well as their regeneration modalities after LTx. These studies also analysed the role of lymphatic vessels in the rejection induction, the local immune response and the occurrence of obliterative bronchiolitis. This review allowed analysing the studies, which approached the lymphatic vessel issue in transplantation.

[Impact of induction therapies on pathology and outcome after surgical resection of non-small lung cancer: a 30-year experience of 859 patients]

The management of localized non-small cell lung cancer (NSCLC) has been modified over the last decades, with induction therapies being increasingly recommended as a prerequisite to surgical resection. However, the relative impact of chemo- and chemoradiotherapy on tumours' pathology and patients' survival is still discussed.

METHODS

We set a retrospective study including every patient who underwent surgical resection for NSCLC in 2 French centres from 1980 to 2009. We then compared the tumours' pathology and patients' survival according to the use of induction chemotherapy (group 1) or induction chemoradiotherapy (group 2).

RESULTS

There were 733 patients in group 1 and 126 patients in group 2. In group 1, 669 patients (91%) had platinum-based chemotherapy, for 2 to 3 cycles in 564 cases (77%). In group 2, chemoradiotheray was concomitant in 68 patients (54%), and sequential in 58 patients (46%). As compared with group 1, group 2 was characterized by younger age (mean 59.8±9.5 vs 56.4±9.6, respectively, P<.001), a higher rate of tumours deemed unresectable before induction treatment (25% vs 44%, P<.001), and a higher proportion of T4 (25% vs 44%, P<.001) or N2 diseases (56% vs 69%, P=.005). The type of resection, postoperative complications, and postoperative mortality were not significantly different between groups. On final pathologic report, as compared with group 1, there were more N0 and N1 disease in group 2 (N0: 43% vs 58%, P=.002; N1: 22% vs 10%, P=.002) while the rate of N2 disease was comparable (34% vs 32%, P=ns). The median, 5-, and 10-year survivals were 28 months, 35%, and 21% for group 1, and 29 months, 36%, and 23% for group 2, respectively (P=ns).

CONCLUSION

As compared with induction chemotherapy, induction chemoradiotherapy was performed in more advanced NSCLC, and resulted in better downstaging, similar postoperative course, and comparable long-term outcome after surgical resection.

[Diaphragmatic palsy and dysfunction: from physiology to surgery]

The clinical presentations of diaphragm dysfunctions vary according to etiologies and unilateral or bilateral diseases. Elevation of the hemidiaphragm from peripheral origins, the most frequent situation, requires a surgical treatment only in case of major functional impact. Complete morphological and functional analyses of the neuromuscular chain and respiratory tests allow the best selection of patients to be operated. The surgical procedure may be proposed only when the diaphragm dysfunction is permanent and irreversible. Diaphragm plication for eventration through a short lateral thoracotomy, or sometimes by videothoracoscopy, is the only procedure for retensioning the hemidiaphragm. This leads to a decompression of intrathoracic organs and a repositioning of abdominal organs without effect on the hemidiaphragm active contraction. Morbidity and mortality rates after diaphragm plication are very low, more due to the patient's general condition than to surgery itself. Functional improvements after retensioning for most patients with excellent long-term results validate this procedure for symptomatic patients. In case of bilateral diseases, very few bilateral diaphragm plications have been reported. Some patients with diaphragm paralyses from central origins become permanently dependent on mechanical ventilation whereas their lungs, muscles and nerves are intact. In patients selected by rigorous neuromuscular tests, a phrenic pacing may be proposed to wean them from respirator. Two main indications have been validated: high-level tetraplegia above C3 and congenital alveolar hypoventilation from central origin. After progressive reconditioning of the diaphragm muscles following phrenic pacing at thoracic level, more than 90% of patients can be weaned from respirator within a few weeks. This weaning improves the quality of life with more physiological breathing, restored olfaction, better sleep and better speech. The positive impact of diaphragm stimulation has also been evaluated in other degenerative neurological diseases, particularly the amyotrophic lateral sclerosis. For either central or peripheral diaphragm dysfunctions, a successful surgical treatment lies on a strict preoperative selection of patients.

[Lymphatic spread of lung cancer: anatomical lymph node chains unchained in zones]

Lung cancer is characterized by its lymphophilia. Its metastatic spread mainly occurs by tumor cells lymphatic drainage into the blood circulation. Initially, the lymph node TNM classification was based on clinical and therapeutic considerations, particularly concerning N2 involvement. The goals were to avoid futile exploratory thoracotomies without lung resection, to provide more accurate data from mediastinoscopy, and to take into account the radiation therapy fields. Since 1997, the international lymph node classification was more used to analyse the disparities within N1 and N2 groups. However, this attempt did not succeed in clarifying the lymphatic metastazing process, and was not progressing any more. Anatomy not being considered, it did not permit to grasp the anatomical and physiological significances of N2 and N3 involvement. In effect, this classification is now confined in zones and is lacking the anatomical and physiological descriptions that characterise the lymphatic pathways draining the lungs and their tumoral pathology. The stations proposed in numbers in cartographies should have gained in accuracy and in prognostic value if they had been expressed in their anatomical counterparts.

[Lung cancer with heart failure--a cardiac and thoracic surgeon's collaboration]

Surgical resection is a validated therapeutic option for selected cases of pulmonary tumors invading the important mediastinal structures (caval vein, atrium, aorta or supra-aortic trunks). Here, we present a patient with a necrosed pulmonary tumor invading the left atrium, causing cardiac insufficiency. A complete surgical resection under extracorporeal circulation was performed by the thoracic and cardiac teams. Admitted in a bed-ridden state, the patient was discharged completely rehabilitated on postoperative day 13. He survived 1 year at home with a good quality of life.

[Pleural lymphatics and effusions]

The pleural lymphatic system has a great absorption capacity. Its most known function is fluid resorption. The pleura which cover the lungs (visceral pleura), the mediastinum, diaphragm and thoracic wall (parietal pleura) are formed by a mesothelial cell layer (mesothelium). This permeable layer is in direct contact with the vascular endothelium. The mesothelium is based over a connective tissue (interstitium) containing the blood and lymphatic vessels. The primary lymphatic vessels drain interstitium but are also in direct contact with pleural space by the stoma or openings, situated in the lower parts of parietal pleura, i.e: diaphragm, over lower ribs and mediastinum but not existing in the adjacent visceral pleura. In addition, a part of interstitial pulmonary fluid entered in the pleural cavity by passing the visceral pleura would be absorbed by these openings. The resorption process is active and directly related to the function of smooth muscles of lymphatic vessels. Besides resorption, we must emphasize that this "pumping" activity is permanent and the origin of negative pressure (the pleural void) in pleural cavity, a unique property. The other resorbed elements are molecules, bacterial and cellular debris, cells, red blood and cancer cells.

[Lung volume reduction surgery for emphysema and bullous pulmonary emphysema]

The improvement of respiratory symptoms for emphysematous patients by surgery is a concept that has evolved over time. Initially used for giant bullae, this surgery was then applied to patients with diffuse microbullous emphysema. The physiological and pathological concepts underlying these surgical procedures are the same in both cases: improve respiratory performance by reducing the high intrapleural pressure. The functional benefit of lung volume reduction surgery (LVRS) in the severe diffuse emphysema has been validated by the National Emphysema Treatment Trial (NETT) and the later studies which allowed to identify prognostic factors. The quality of the clinical, morphological and functional data made it possible to develop recommendations now widely used in current practice. Surgery for giant bullae occurring on little or moderately emphysematous lung is often a simpler approach but also requires specialised support to optimize its results.