Comparing transforming growth factor-beta2, talc and bleomycin as pleurodesing agents in sheep

Mechanical and biological properties of poly-ε-caprolactone membrane for pleurodesis: A preclinical study in pigs

BACKGROUND/PURPOSE

Biomaterial implants are emerging as a treatment choice for pleurodesis; however, the optimal biomaterial and form for managing spontaneous pneumothorax, particularly post-video-assisted thoracic surgery, remain under investigation. This study evaluated the mechanical and biological properties of the poly-ε-caprolactone (PCL) membrane as a sclerosing agent for pleurodesis in Landrace pigs.

METHODS

Twenty-four Landrace pigs were split into two groups for mechanical abrasion and PCL membrane pleurodesis, with the latter group's PCL meshes inserted using video-assisted thoracic surgery. The mechanical and biological properties of the PCL membrane were assessed in pigs at three, six, and 12 months after the procedure. This assessment involved a range of techniques, such as the T-Peel test, macroscopic evaluation with a scoring scale, microscopic examination, and biomechanical and molecular weight analysis.

RESULTS

The PCL membrane group outperformed the traditional abrasion group, with stronger adhesions seen over longer implantation durations. This group also showed superior and more consistent results in both macroscopic and microscopic evaluations compared to the control group. The membrane-based method was easier and faster to perform than the control group's method, and importantly, no mortality occurred following membrane implantation.

CONCLUSION

This study is the pioneering effort to present long-term findings regarding the mechanical and biological properties of the PCL membrane in an in vivo animal model. The membrane demonstrated better adhesion ability than that of traditional abrasion and showed reassuring biocompatibility in both the pig model, suggesting its potential as treatment for patients with primary spontaneous pneumothorax. Further clinical studies are needed to support these observations.

Safety assessment of poly-ε-caprolactone in the treatment of primary spontaneous pneumothorax

Background/purpose

Biomaterial-based implants are gaining traction as an option for pleurodesis treatment, yet the search for the best biomaterial or the most suitable shape to handle spontaneous pneumothorax continues. This forward-looking research assessed the use of a poly-ε-caprolactone membrane for its safety when applied as a sclerosant in pleurodesis procedures in human patients.

Methods

From July 2017 to February 2018, we conducted a Phase I trial in which 10 patients with primary spontaneous pneumothorax were treated using video-assisted thoracoscopic surgery with a poly-ε-caprolactone membrane. These procedures encompassed bleb resection and mechanical pleurodesis through parietal pleura scrubbing. After resection, a 150 × 150 mm poly-ε-caprolactone membrane was applied to the apex. The primary outcome measures were the adverse events and laboratory outcomes.

Results

After surgery, we observed no cardiopulmonary-related adverse events or indications of systemic inflammation. Furthermore, no episodes of hypothermia or hyperthermia occurred. Chest radiographs showed no evident pneumonitis or effusion associated with tissue reactions. The average follow-up duration was 31.7 ± 17.7 months, during which two patients exhibited recurrence.

Conclusion

This study is the first to show the biocompatibility of poly-ε-caprolactone in humans, suggesting its potential as a treatment option for patients with primary spontaneous pneumothorax. Despite the relatively small number of patients, we maintain confidence in the reliability and safety profile of the PCL membrane, bolstered by its previously established efficacy in applications involving other organs. Phase II and phase III clinical studies are needed to support these observations.

Pleural Fluid Cytokine Levels at Baseline and Over Time are Associated With Time to IPC Removal: An Exploratory Study

BACKGROUND

The behavior of pleural fluid cytokine (PFCs) levels and their association with pleurodesis after indwelling pleural catheter (IPC) placement is unknown.

OBJECTIVE

A prospective exploratory study was conducted to obtain preliminary data on PFC levels after IPC placement.

METHODS

The PFC panel consisted of 4 cytokines [interleukin -8 (IL-8), vascular endothelial growth factor, total (but not activated) transforming growth factor betas, and basic fibroblast growth factor], measured across 5 time points (T0: insertion; T1: 24 to 48 h; T2: 72 to 96 h; T3: 1 wk; and T4: 2 wk). Profile plots were used to identify patterns of change of PFC levels. Correlation matrices for each PFC over time were computed, and area under the curve (AUC) categories were used to compare the cumulative incidence of IPC removal. Auto pleurodesis was defined as elective catheter removal because of decreased drainage within 90 days of insertion.

RESULTS

A total of 22 patients provided complete data. Except for IL-8, the majority of PFCs demonstrated strong positive correlations across measurement time points. Patients with high AUCs for IL-8, basic fibroblast growth factor, and vascular endothelial growth factor had a higher cumulative incidence of IPC removal by 90 days than did patients with low AUCs.

CONCLUSION

This is the first study to evaluate longitudinal changes of pleural cytokine levels with respect to the likelihood of IPC removal and provide early evidence that the cytokine profile may be associated with the outcome of pleurodesis induced by IPCs. However, this is an exploratory study and further studies are needed to assess if these findings can be validated in further studies.

Survivin is a negative prognostic factor in malignant pleural effusion

BACKGROUND

Survivin is a well-known member of the inhibitor of apoptosis family, and has been related to increased tumour aggressivity, both in tissue and in pleural fluid.

OBJECTIVES

In patients with malignant pleural effusion, we sought to investigate the changes in pleural fluid survivin concentrations induced by talc instillation into the pleural space. Those changes were also examined in relation to pleurodesis outcome and patient survival.

METHODS

We investigated 84 patients with malignant pleural effusion who underwent talc pleurodesis. Of them, 32 had breast cancer, 25 lung cancer and 27 had mesothelioma. Serial samples of pleural fluid were obtained before thoracoscopy (baseline) and 24 hours thereafter.

RESULTS

Survivin levels were successfully quantified in all pleural fluid samples, and they were significantly higher in samples obtained after thoracoscopic talc poudrage compared with baseline (P < .001). Patients with higher pleural fluid survivin levels at baseline had a significantly poorer pleurodesis outcome (P = .004). A 30 pg/mL cut-off for baseline survivin in pleural fluid predicted failure of pleurodesis with a 54% sensitivity and 79% specificity (P = .009). Moreover, median postpleurodesis survival of patients with baseline survivin levels ≥30 pg/mL was 4 months (range: 0.1-38), compared with 13 months (range: 0.1-259) in patients below that cut-off (P < .001).

CONCLUSION

Elevated pleural fluid survivin concentrations are useful to predict failure of pleurodesis and are associated with shorter survival in patients with malignant pleural effusion.

Intrapleural or intraperitoneal lobaplatin for treatment of patients with malignant pleural effusion or ascites

AIMS

To explore efficacy and side effects of intrapleural or intraperitoneal lobaplatin for treating patients with malignant pleural or peritoneal effusions.

METHODS

Patients in Jiangsu Cancer Hospital and Research Institute with cytologically confirmed solid tumors complicated with malignant pleural effusion or ascites were enrolled into this study. Lobaplatin (20-30 mg/m2) was intrapleurally or intraperitoneally infused for patients with malignant pleural effusion or ascites.

RESULTS

From 2012 to 2013, intrapleural or intraperitonea lobaplatin was administered for patients with colorectal or uterus cancer who were previous treated for malignant pleural effusion or ascites. Partial response was achieved for them. Main side effects were nausea/vomiting, and bone marrow suppression. No treatment related deaths occurred.

CONCLUSION

Intrapleural or intraperitoneal infusion of lobaplatin is a safe treatment for patients with malignant pleural effusion or ascites, and the treatment efficacy is encouraging.

Use of a drug eluting pleural catheter for pleurodesis

PURPOSE

Repeated administration of low-dose silver nitrate (SN) has been shown to be effective in creating pleurodesis. This study aimed to determine the effectiveness of a SN-eluting pleural catheter for pleurodesis.

METHODS

Catheters with a chitosan-SN-hyaluronic acid hydrogel coating designed to release SN over 14 days, or placebo uncoated catheters, were inserted in rabbit and lamb pleurodesis models. Pleurodesis was assessed at 28 days according to a 1-8 point scoring system and pleural fibrosis and inflammation assessed histologically on a 0-4 point scale.

RESULTS

In the rabbit model, pleurodesis scores were significantly increased in both the 24 mg and 50 mg SN catheters versus control animals as well as compared to the contralateral untreated pleural space (median-treated side scores were 5, 8, and 1, respectively, median score for contralateral side was 1 in all groups). In the lamb model, pleurodesis scores were significantly increased in both the 750 mg and 1000 mg catheter groups versus control animals as well as compared to the contralateral untreated pleural space (median-treated side scores were 7, 7, and 1, respectively, median score for contralateral pleural space was 1 in all groups). Catheters appeared well tolerated, although higher than expected mortality was seen in the 50 mg catheter rabbit group.

CONCLUSIONS

A catheter designed to deliver SN to the pleural space over 14 days appears to be effective in creating pleurodesis. Further investigations to determine in-vivo catheter pharmacokinetics, toxicity, dose and optimal coating methods are warranted.

Monoclonal anti-vascular endothelial growth factor antibody reduces fluid volume in an experimental model of inflammatory pleural effusion

BACKGROUND AND OBJECTIVE

Vascular endothelial growth factor (VEGF) is known to increase vascular permeability and promote angiogenesis. It is expressed in most types of pleural effusions. However, the exact role of VEGF in the development of pleural effusions has yet to be determined. The anti-VEGF mAb, bevacizumab, has been used in the treatment of cancer to reduce local angiogenesis and tumour progression. This study describes the acute effects of VEGF blockade on the expression of inflammatory cytokines and pleural fluid accumulation.

METHODS

One hundred and twelve New Zealand rabbits received intrapleural injections of either talc or silver nitrate. In each group, half the animals received an intravenous injection of bevacizumab, 30 min before the intrapleural agent was administered. Five animals from each subgroup were sacrificed 1, 2, 3, 4 or 7 days after the procedure. Twelve rabbits were used to evaluate vascular permeability using Evans's blue dye. Pleural fluid volume and cytokines were quantified.

RESULTS

Animals pretreated with anti-VEGF antibody showed significant reductions in pleural fluid volumes after talc or silver nitrate injection. IL-8 levels, vascular permeability and macroscopic pleural adhesion scores were also reduced in the groups that received bevacizumab.

CONCLUSIONS

This study showed that bevacizumab interferes in the acute phase of pleural inflammation induced by silver nitrate or talc, reinforcing the role of VEGF as a key mediator in the production of pleural effusions. The results also suggest that bevacizumab should probably be avoided in patients requiring pleurodesis.

The evolving role of interventional pulmonary in the interdisciplinary approach to the staging and management of lung cancer. Part III: diagnosis and management of malignant pleural effusions

The diagnosis and management of a malignant pleural effusion can be one of the most vexing problems faced by physicians and their patients. Lung cancer is the most common primary tumor of origin with a prognosis that is limited, but variable and correlated with performance status (PS). Therefore, with a poor PS and known advanced lung cancer, establishing whether or not an effusion is malignant might not be necessary. Conversely, identifiable subsets of patients will have a much better survival, and establishing a definitive diagnosis could be of critical importance. In the great majority of cases, a diagnosis can be determined by serial thoracenteses with or without closed pleural biopsy. However, thoracoscopy is increasingly being utilized and can expedite the workup by obviating the need for repeated thoracenteses and/or closed pleural biopsy, while in the same setting providing definitive palliative treatment. Although studies comparing diagnostic and treatment strategies are limited, we will present the available data with the intention of providing the practicing oncologist with a practical strategy for the diagnosis and management of malignant pleural effusions due to lung cancer. The interventional pulmonologist can play an important role from diagnosis to palliation, greatly facilitating the care of patients with malignant pleural effusions.

Surgical and other invasive approaches to recurrent pleural effusion with malignant etiology

With an increasing number of cancer survivors, the annual incidence of malignant pleural effusions has been rising in recent decades worldwide. Many patients with various forms of cancer develop malignant pleural effusions at some point in their life. Patients most commonly present with progressive dyspnea. These effusions are refractory and are associated with impaired quality of life for these patients. The main goals of management are evacuation of the pleural fluid and prevention of its re-accumulation. The therapy plan should consider the general health of the patients, their performance status, the presence of trapped lung, and the primary malignancy. However, there is no universally established, standard approach. Surgical options include thoracentesis, chest tube drainage, thoracoscopy followed by chemical and mechanical pleurodesis, Pleur-X catheter drainage, and pleurectomy. Chemical pleurodesis is the most common modality of therapy for patients with recurrent pleural effusion. For example, Talc is the most successful pleurodesis agent with similar equal to that of poudrage or slurry. Pleur-X catheter can reduce hospital stay and adds value to the treatment of patients with trapped lung, who are not appropriate candidates for pleurodesis. Furthermore, a mechanical pleurodesis has been shown to be effective particularly in pleural effusions with lower pH. This article reviews the surgical and other invasive options as well as their technical aspects in the management of recurrent malignant pleural effusions.

Who Gains Most? A 10-Year Experience With 611 Thoracoscopic Talc Pleurodeses

BACKGROUND

Thoracoscopic talc pleurodesis is a therapeutic option for recurrent pleural effusion.

METHODS

This retrospective study included 611 patients who underwent thoracoscopic talc pleurodesis between 1994 and 2003. We analyzed the risk factors, efficiency, outcome, follow-up, and survival, while taking into consideration primary disease and general condition.

RESULTS

The mean follow-up was 319 days (range, 31 to 1994). A total of 105 (17.2%) of 611 patients died within 30 days after treatment. Risk factors for death within 30 days included a Karnofsky index of less than 50%, a body mass index of less than 25 kg/m2, malignant disease, and male gender. Treatment was successful in 347 (68.6%) of 506 patients, and 451 (89.1%) reported an improvement in symptoms. Previous thoracic irradiation and a chest tube drainage time exceeding 10 days negatively influenced the outcome of pleurodesis. The survival rate was negatively influenced by a preoperative Karnofsky index of less than 60% and by malignant disease.

CONCLUSIONS

Patients with pleural effusion due to malignant disease gain from early pleurodesis. The most favorable outcome after talc pleurodesis was seen in women whose lungs were fully expandable, in patients whose Karnofsky index exceeded 60%, in patients whose body mass index was greater than 25 kg/m2, and in patients with benign disease.

Malignant pleural effusion, current and evolving approaches for its diagnosis and management

Malignant pleural effusion is a common and debilitating complication of advanced malignant diseases. This problem seems to affect particularly those with lung and breast cancer, contributing to the poor quality of life. Approximately half of all patients with metastatic cancer develop a malignant pleural effusion at some point, which is likely to cause significant symptoms such as dyspnea and cough. Evacuation of the pleural fluid and prevention of its re-accumulation are the main goals of management. Optimal treatment is controversial and there is no universally standard approach. Intervention options range from observation in the case of asymptomatic effusions through simple thoracentesis to more invasive methods such as chemical and mechanical pleurodesis, pleur-X catheter drainage, pleuroperitoneal shunting, and pleurectomy. The best results are reported with thoracoscopy and talc insufflation, with an acceptable morbidity. Development of novel methods to control malignant pleural effusion should be a high priority in palliative care of cancer patients. This article reviews the current, as well as, novel approaches that show some promise for the future. The aim is to identify the proper approach for each individual patient.

Pleurodesis is inhibited by anti-vascular endothelial growth factor antibody

STUDY OBJECTIVES

The intrapleural injection of transforming growth factor (TGF)-beta2 produces pleurodesis in rabbits associated with large pleural effusions. This study investigated whether anti-vascular endothelial growth factor (VEGF) antibody has any effect on the fluid production or the pleurodesis induced by TGF-beta2.

INTERVENTIONS AND MEASUREMENTS

Three groups of seven New Zealand white rabbits were administered TGF-beta2 5.0 microg intrapleurally. Two groups received anti-VEGF antibody (10 mg/kg and 25 mg/kg) IV 24 h before TGF-beta2 injection, and the third group received no antibody. The rabbits were killed at 2 weeks, and the macroscopic pleurodesis score was determined. The degree of pleural angiogenesis was assessed by immunohistochemical staining for factor VIII.

RESULTS

The administration of anti-VEGF antibodies had no significant effect on the pleural fluid volume or the characteristics of the fluid. The mean pleurodesis score of the seven rabbits in the control group (7.71 +/- 0.76) was significantly (p < 0.05) higher than that for seven rabbits in the low-dose treatment group (4.43 +/- 2.37) and the seven rabbits in the high-dose treatment group (4.57 +/- 2.36) [+/- ]. The percentage of pleural tissue demonstrating angiogenesis in the control group (4.87 +/- 0.43%) was significantly (p < 0.05) higher than that for the low-dose (2.94 +/- 0.68%) or high-dose (2.67 +/- 0.64%) antibody groups. When all rabbits were considered, there was a highly significant correlation between the pleural vascular density scores and the pleurodesis scores (r = 0.84, p < 0.01).

CONCLUSION

VEGF and angiogenesis appear to play a pivotal role in the production of a pleurodesis.

Pleural effusion

Pleural disease remains a commonly encountered clinical problem for both general physicians and chest specialists. This review focuses on the investigation of undiagnosed pleural effusions and the management of malignant and parapneumonic effusions. New developments in this area are also discussed at the end of the review. It aims to be evidence based together with some practical suggestions for practising clinicians.

Intrapleural Injection of Transforming Growth Factor-β Antibody Inhibits Pleural Fibrosis in Empyema

STUDY OBJECTIVES

Transforming growth factor (TGF)-beta is a cytokine that has been demonstrated to be an important modulator of inflammation and angiogenesis, as well as a potent stimulator of pleural fluid production and fibrosis. We previously demonstrated that rising levels of pleural fluid TGF-beta(1) correlate with pleural fibrosis in experimental empyema in rabbits. In this study, our hypothesis is that neutralization of TGF-beta with an intrapleural injection of a monoclonal antibody to TGF-beta will decrease pleural fibrosis in empyema.

DESIGN

Prospective, randomized, blinded study.

SETTING

Animal research laboratory.

SUBJECTS

Nineteen rabbits.

INTERVENTIONS

An empyema was induced in 19 rabbits by intrapleural injection of Pasteurella multocida. A panspecific monoclonal antibody to TGF-beta was injected into the pleural space on 2 subsequent concurrent days in nine rabbits. Ten rabbits received intrapleural injections of bacteria alone and served as controls. All animals were then killed on day 6. Immunohistochemistry, using the antibody to TGF-beta, was performed on pleural tissue specimens from the control rabbits.

MEASUREMENTS AND RESULTS

Immunohistochemistry revealed localization of TGF-beta to macrophages in the exudative material and the visceral pleura. After injection of the antibody to TGF-beta, the amount of purulent, exudative material in the pleural space of the nine experimental animals was markedly decreased at autopsy on day 6, relative to control animals. All markers of empyema and pleural fibrosis were also significantly decreased in the rabbits receiving intrapleural anti-TGF-beta.

CONCLUSIONS

TGF-beta localizes to macrophages in experimental empyema. Early intrapleural injection of an antibody to TGF-beta inhibits empyema formation and significantly decreases pleural fibrosis in experimental empyema.

Management of malignant pleural effusions

Malignant pleural effusion is a common clinical problem. Evacuation of the pleural fluid and prevention of its reaccumulation are the main aims of management. Pleurodesis should be attempted early, although considerable practice variations exist in the way it is performed. There is a lack of consensus among respiratory physicians worldwide on the optimal method and agent for pleurodesis. Talc remains the most commonly used pleurodesing compound in most countries. While talc produces a higher success rate than other compounds, it generates more side-effects. The association between talc and ARDS continues to be debated. Ambulatory small-bore pleural catheter drainage followed by intrapleural instillation of a pleurodesing agent is increasingly accepted as an alternative to conventional in-patient pleurodesis. Development of novel methods to control pleural fluid formation should be made a high priority in future pleural research.

Effect of neutralizing transforming growth factor beta1 on the immune response against Mycobacterium tuberculosis in guinea pigs

Transforming growth factor beta (TGF-beta) is a cytokine which has been shown to suppress the antimycobacterial immune responses of humans and experimental animals. In this study, the contributions of TGF-beta to cytokine production in vivo were investigated by using the established guinea pig model of tuberculous pleurisy. Mycobacterium bovis BCG-vaccinated guinea pigs were injected intrapleurally with heat-killed virulent Mycobacterium tuberculosis. Eight days following induction of an antigen-specific pleural effusion, guinea pigs were injected intrapleurally with anti-TGF-beta1 or isotype control antibody. The following day, pleural exudates were removed, and the fluid volume and characteristics of the infiltrating cells were determined. Pleural fluid was analyzed for total interferon (IFN) and tumor necrosis factor (TNF) protein levels by using appropriate bioassays. RNA from pleural effusion cells was examined to determine TGF-beta1, TNF-alpha, IFN-gamma, and interleukin-8 mRNA levels by using real-time PCR. Proliferative responses of pleural effusion lymphocytes were examined in response to concanavalin A and purified protein derivative (PPD) in vitro. Treatment with anti-TGF-beta1 resulted in decreased pleural fluid volume and decreased cell numbers in the pleural space along with an increased percentage of lymphocytes and a decreased percentage of neutrophils. The bioactive TNF protein levels in pleural fluid were increased in guinea pigs treated with anti-TGF-beta1, while the bioactive IFN protein concentrations were not altered. Expression of TGF-beta1 and TNF-alpha mRNA was significantly increased following TGF-beta1 neutralization. Finally, PPD-induced proliferative responses of pleural cells from anti-TGF-beta1-treated animals were significantly enhanced. Thus, TGF-beta1 may be involved in the resolution of this local, mycobacterial antigen-specific inflammatory response.

Influence of talc dose on extrapleural talc dissemination after talc pleurodesis

This study was designed to ascertain, in a rabbit model, extrapleural talc deposition and the related inflammatory response after talc slurry pleurodesis with two clinical doses, 200 and 50 mg/kg. Histopathologic evaluations revealed that whereas numerous rabbits receiving a high dose had talc in the ipsilateral (70%) and contralateral (55%) lung, mediastinum (90%), pericardium (30%), and liver (25%), a small number of animals treated with a low dose showed talc in the ipsilateral lung (10%) and mediastinum (20%) and none in the contralateral lung, pericardium, or liver. Hematologic and immunocytochemical analyses showed that a systemic inflammatory response develops shortly after pleurodesis with a high talc dose involving massive accumulation of neutrophils and macrophages in lung tissue. Zymography also revealed that the pulmonary expression of matrix metalloproteinases 2 and 9 was up-regulated in both lungs in a dose-dependent manner soon after talc instillation. Furthermore, microscopic examination of lung specimens revealed that the higher the dose of talc, the greater the development of both fibrotic visceral pleural thickening and foreign-body granulomas. These findings show pleurodesis with a high talc dose to be associated with an increased risk of extrapleural talc deposition, which may originate undesirable acute and chronic inflammatory responses.