Solitary fibrous tumours of the pleura: do we need a different perspective on malignancy?

OBJECTIVES

Solitary fibrous tumours of the pleura (SFTP) are historically considered to be benign soft tissue neoplasms. However, a clinical relevant number of these neoplasms have malignant histological features. The objective of this study was to evaluate the percentage of SFTP presenting unfavourable clinical behaviour in order to predict negative long-term outcome.

METHODS

A retrospective review of 74 patients treated at 4 hospitals between 1990 and 2013 was performed. The median follow-up was 10 years (range: 1-20 years). Risk of tumour recurrence and metastases (unfavourable clinical behaviour) with regard to histology using the Kaplan-Meier and Cox proportional hazards methods.

RESULTS

The mean age was 61 years (SD 12.75 years). There were 31 male patients (58%) and 43 female patients (42%). Tumour size ranged from 1 to 30 cm (mean 9.09 cm; SD 6.22 cm). Complete resection (R0) was achieved by minimally invasive thoracoscopic resection in 29% and thoracotomy in 57%; 25% of SFTPs showed histological evidence of malignancy, according to England criteria. Recurrence occurred in 21% and 10% of patients had metastases; 83% of patients with metastases and 39% of patients with recurrence died within 5 years. The median recurrence-free survival for histologically benign SFTP was not reached, compared to 8 years for malignant SFTP. The five-year overall survival rate was 84%. Mitotic rate ≥1/10 HPF, high cellularity, nuclear atypia, Ki-67 level >5% and poorly circumscribed (sessile) growth pattern were associated with poor long-term outcome.

CONCLUSIONS

Pathological differentiation of SFTP morphology into pedunculated, well circumscribed and poorly circumscribed (sessile) growth pattern is recommended. Due to the misleading classification into histologically benign and malignant, all unpedunculated SFTP should be classified as potentially aggressive. Lifelong follow-up is mandatory.

Long-Term Outcome of Chest Wall and Diaphragm Repair with Biological Materials

INTRODUCTION

 Chest wall and/or diaphragm reconstruction aims to preserve, restore, or improve respiratory function; conserve anatomical cavities; and upkeep postural and upper extremity support. This can be achieved by utilizing a wide range of different grafts made of synthetic, biological, autologous, or bioartificial materials. We aim to review our experience with decellularized bovine pericardium as graft in the past decade.

PATIENTS AND METHODS

 We conducted a retrospective analysis of patients who underwent surgical chest wall and/or diaphragm repair with decellularized bovine pericardium between January 1, 2012 and January 13, 2022 at our institution. All records were screened for patient characteristics, intra-/postoperative complications, chest tube and analgesic therapy duration, length of hospital stay, presence or absence of redo procedures, as well as morbidity and 30-day mortality. We then looked for correlations between implanted graft size and postoperative complications and gathered further follow-up information at least 2 months after surgery.

RESULTS

 A total of 71 patients either underwent isolated chest wall (n = 51), diaphragm (n = 12), or pericardial (n = 4) resection and reconstruction or a combination thereof. No mortality was recorded within the first 30 days. Major morbidity occurred in 12 patients, comprising secondary respiratory failure requiring bronchoscopy and invasive ventilation in 8 patients and secondary infections and delayed wound healing requiring patch removal in 4 patients. There was no correlation between the extensiveness of the procedure and extubation timing (chi-squared test, p = 0.44) or onset of respiratory failure (p = 0.27).

CONCLUSION

 A previously demonstrated general viability of biological materials for various reconstructive procedures appears to be supported by our long-term results.

Nickel contamination after minimally-invasive repair of pectus excavatum persists after bar removal

BACKGROUND

Minimally-invasive repair of pectus excavatum (MIRPE) has been shown to be associated with high release of trace metals into patient's body. The aim of our study was to analyze the kinetics of metal contamination after MIRPE and after bar removal.

METHODS

We prospectively assessed nickel and chromium changes in blood, urine, and local tissue in patients undergoing MIRPE with stainless-steel bar(s). Baseline samples were taken prior to surgery, further samples were taken at six defined time points until 30 months after bar removal. Clinical symptoms were evaluated at the time of every sample collection.

RESULTS

28 patients were included (mean age 16.4 years). At four weeks after MIRPE and persisting up to bar removal, we found significantly elevated trace metal levels in blood and urine. Tissue nickel and chromium levels were significantly elevated at the time of bar removal. After bar removal, the concentration of trace metal in urine and the concentration of chromium in plasma decreased gradually. In contrast, nickel levels in blood further increased. Five patients showed irritative symptoms after MIRPE, all symptomatic patients had elevated metal levels.

CONCLUSIONS

Following MIRPE, we found a rapid systemic increase of nickel and chromium. Our data indicate that trace metal release could cause irritative symptoms. The prolonged elevated systemic nickel levels beyond bar removal necessitate further investigations of the long-term side effects of MIRPE.

Surgical treatment of non-cystic fibrosis bronchiectasis in Central Europe

Background

Bronchiectasis is a mostly irreversible bronchial dilatation induced by the destruction of elastic and muscular fibers of the bronchial wall. Surgical treatment is usually reserved for focal disease, and whenever complications, like hemoptysis or secondary aspergilloma, arise. In this study, we report our experience and outcomes in surgical bronchiectasis management between 2016 and 2020.

Methods

We retrospectively searched our database for patients admitted for surgical treatment of bronchiectasis between 2016 and 2020. All records were screened for pre-surgical management. Age, gender, distribution of bronchiectatic lesions, type of surgery, perioperative complications, chest tube duration, length of hospital stay as well as 30-day-mortality were recorded, and a brief follow-up was made.

Results

A total of n=34 patients underwent pulmonary resection with bronchiectasis. Mean age on admission was 56.2±15.1 years and n=21 patients (62%) were female. In n=23 cases the right lung was affected, in n=9 cases the left side and in two cases both lungs. Indications for surgery included persistent major alterations after conservative therapy (n=9), massive hemoptysis (n=4), and full-blown “destroyed lobe” (n=7). All patients received anatomical lung resection (n=21 lobectomies, n=2 bilobectomies and n=11 segmentectomies), either by uniportal video assisted thoracoscopic surgery (n=28) or by lateral thoracotomy (n=6). Average length of hospital stay was 7.9±6.3 days; one patient died on POD 7 due to myocardial infarction.

Conclusions

In spite of a decreasing number of patients with bronchiectasis referred to surgery due to improvements in preventing and managing the disease, pulmonary resection still plays a significant role in treating this pathology in Central Europe. Surgery remains a viable approach for localized forms of bronchiectasis, and the only option in treating acute deterioration and complications like massive hemoptysis.

Analysis of pH and electrolytes in blood and ruminal fluid, including kidney function tests, in sheep undergoing long-term surgical procedures

BACKGROUND

The physiology of sheep as small ruminants is remarkably different from monogastric animals especially regarding the forestomach system. Using sheep for surgical procedures during scientific research thereby presents an exceptional setting for the anaesthetist. Long-term anaesthesia generally demands deprivation of food to reduce the risk of bloat in sheep. This might influence the energy and electrolyte balance. In horses and companion animals, close monitoring of mean arterial blood pressure, capnography and blood gas analysis are common procedures during long-term surgery. However, few data are available on reference ranges for blood gas in sheep and these cover only short periods of anaesthesia. To the authors' knowledge, there is no study available that includes the monitoring of electrolytes and pH in ruminal fluid and kidney function tests in sheep undergoing long term anaesthesia. Thereby, the aim of the present study was to gather data on blood parameters, and data on ruminal fluid and kidney function during long-term anaesthesia in sheep. Data were obtained from eight sheep undergoing the invasive surgical procedure of left pneumonectomy and auto-transplantation or isolated left lung perfusion. After a 19-h fasting period, the animals were administered xylazine and ketamine and then intubated and maintained in general anaesthesia under artificial ventilation using isoflurane in oxygen. Blood samples were evaluated during 9 h of anaesthesia; ruminal fluid and kidney function tests were evaluated during 7 h of anaesthesia.

RESULTS

Blood parameters such as electrolytes and partial pressure of carbon dioxide revealed few changes, yet blood glucose decreased and beta-hydroxybutyric acid increased significantly. All animals showed an elevated arterial pH and bicarbonate concentration despite artificial ventilation. In ruminal fluid, the pH significantly decreased and no significant changes in electrolytes occurred. Kidney function tests revealed no significant changes in any of the animals. However, fractional excretion of water and phosphate was slightly increased. One animal showed severe complications due to hypokalaemia.

CONCLUSION

Invasive surgery under long-term anaesthesia in sheep is possible without great imbalances of arterial pH and electrolytes. Nevertheless, potassium concentrations should be monitored carefully, as a deficiency can lead to life-threatening complications. The operated sheep tended not to develop metabolic acidosis and the mean kidney function could be maintained within the physiological range throughout anaesthesia. However, slight elevations in renal fractional water and phosphate excretion could suggest an early tubular reabsorption dysfunction. In ruminal fluid, acidification occurred, though no significant changes were observed in L- and D-lactate levels or in electrolyte concentrations. To our knowledge, the role of the rumen in storing fluids and balancing electrolytes in the blood has not yet been documented during anaesthesia. However, the importance of the rumen for fluid equilibrium in sheep indicates the necessity for routine monitoring and further research.

Developing a minimally-invasive anaesthesiological approach to non-intubated uniportal video-assisted thoracoscopic surgery in minor and major thoracic surgery

Background

Non-intubated uniportal video-assisted thoracoscopic surgery (niVATS) is a novel approach to major and minor lung resection. It benefits from a holistic anesthesiological concept with adequate pain relief and sedation in a minimal-invasive setup allowing thoracic procedures under spontaneous breathing. At present no anesthesiological gold standard for niVATS exists. The primary aim of our retrospective observational study was to evaluate feasibility and safety of minimally invasive niVATS for both minor and major pulmonary resections at our institution.

Methods

All 88 consecutive patients scheduled for niVATS minor or major thoracic procedures were included into the study. Anaesthesia was performed according to a departmental niVATS algorithm including both regional anaesthesia and sedation. Patient characteristics and early outcome data including intraoperative and postoperative findings were compared between groups. Prediction scores for postoperative complications (LAS VEGAS, ARISCAT, ThRCRI) were calculated and compared.

Results

No early mortality and a low overall morbidity rate of 28.4% were encountered. Conversion to orotracheal intubation was required in 6.8% of all cases. Postoperative pulmonary complications occurred in 15.9% of total cases and were lower than predicted by both LAS VEGAS and ARISCAT respectively. Cardiac complications were found in 1.1% and lower than predicted by ThRCRI. A persistent air leak occurred in 11.4% of total cases and was significantly higher in major resection. Postoperative chest tube duration and hospital length of stay in the major resection group exceeded times reported by other groups.

Conclusions

niVATS appears to be safe in both minor and major thoracic procedures. A minimally invasive anaesthesiological approach foregoing central iv lines, arterial blood pressure measurement and urinary catheterization is feasible. Our niVATS protocol appears to be a viable alternative for both minor and major thoracic procedures in selected patients.

Functional Pulmonary Magnetic Resonance Imaging for Detection of Ischemic Injury in a Porcine Ex-Vivo Lung Perfusion System Prior to Transplantation

RATIONALE AND OBJECTIVES

To evaluate the feasibility of multiparametric magnetic resonance imaging (MRI) of the lungs to detect impaired organ function in a porcine model of ischemic injury within an ex-vivo lung perfusion system (EVLP) prior to transplantation.

MATERIALS AND METHODS

Twelve pigs were anesthetized, and left lungs were clamped to induce warm ischemia for 3 hours. Right lungs remained perfused as controls. Lungs were removed and installed in an EVLP for 12 hours. Lungs in the EVLP were imaged repeatedly using computed tomography, proton MRI (¹H-MRI) and fluorine MRI (¹⁹F-MRI). Dynamic contrast-enhanced derived parenchymal blood volume, oxygen washout times, and ¹⁹F washout times were calculated. P_aO2 was measured for ischemic and normal lungs, wet/dry ratio was determined, histologic samples were assessed, and cytokines in the lung tissue were analyzed. Statistical analysis was performed using nonparametric testing.

RESULTS

Eleven pigs were included in the final analysis. Ischemic lungs showed significantly higher wet/dry ratios (p = 0.024), as well as IL-8 tissue levels (p = 0.0098). Histologic assessment as well as morphologic scoring of computed tomography and ¹H-MRI did not reveal significant differences between ischemic and control lungs. ¹⁹F washout (p = 0.966) and parenchymal blood flow (p = 0.32) were not significantly different. Oxygen washout was significantly prolonged in ischemic lungs compared to normal control lungs at the beginning (p = 0.018) and further prolonged at the end of the EVLP run (p = 0.005).

CONCLUSION

Multiparametric pulmonary MRI is feasible in lung allografts within an EVLP system. Oxygen-enhanced imaging seems to be a promising marker for ischemic injury, enabling detection of affected lung segments prior to transplantation.

Treatment of infected lungs by ex vivo perfusion with high dose antibiotics and autotransplantation: A pilot study in pigs

The emergence of multi-drug resistant bacteria threatens to end the era of antibiotics. Drug resistant bacteria have evolved mechanisms to overcome antibiotics at therapeutic doses and further dose increases are not possible due to systemic toxicity. Here we present a pilot study of ex vivo lung perfusion (EVLP) with high dose antibiotic therapy followed by autotransplantation as a new therapy of last resort for otherwise incurable multidrug resistant lung infections. Severe Pseudomonas aeruginosa pneumonia was induced in the lower left lungs (LLL) of 18 Mini-Lewe pigs. Animals in the control group (n = 6) did not receive colistin. Animals in the conventional treatment group (n = 6) received intravenous application of 2 mg/kg body weight colistin daily. Animals in the EVLP group (n = 6) had their LLL explanted and perfused ex vivo with a perfusion solution containing 200 μg/ml colistin. After two hours of ex vivo treatment, autotransplantation of the LLL was performed. All animals were followed for 4 days following the initiation of treatment. In the control and conventional treatment groups, the infection-related mortality rate after five days was 66.7%. In the EVLP group, there was one infection-related mortality and one procedure-related mortality, for an overall mortality rate of 33.3%. Moreover, the clinical symptoms of infection were less severe in the EVLP group than the other groups. Ex vivo lung perfusion with very high dose antibiotics presents a new therapeutic option of last resort for otherwise incurable multidrug resistant pneumonia without toxic side effects on other organs.

[The Patient with Chest Trauma: Surgical Management]

Even though isolated cases of penetrating chest wounds are exceptionally rare in Germany, chest trauma accounts for major morbidity and mortality in over 18 0000 multitrauma patients encountered every year. Injuries range from immediately fatal cardiac wounds and major vessel lacerations to intercostal bleeding, parenchymal damage, chronic haematothorax and secondary empyema. Placement of large-bore chest tubes constitutes a sufficient treatment for most of these pathologies. In select cases further treatment either by minimally invasive techniques (VATS) or conventional thoracotomy is warranted.

Pulmonary metastasectomy - A retrospective comparison of surgical outcomes after laser-assisted and conventional resection

INTRODUCTION

Indications and surgical techniques for pulmonary metastasectomy (PME) are controversially discussed issues. Laser-assisted surgery (LAS) is a recent innovation that has been advocated especially in patients with multiple pulmonary metastases (PM). However, there are hardly any studies comparing surgical outcomes after laser-assisted and conventional resection. The aim of the current study was to evaluate the value of LAS in a larger study population.

MATERIALS & METHODS

A retrospective analysis was completed on 178 consecutive patients undergoing 236 PMEs at a single center between 2010 and 2015. The main endpoint was survival. Statistical analysis was performed using the Kaplan-Meier method and survival rates were compared with the log rank test. Follow-up was done with special attention to the development of recurrent PM. Local relapse was defined as a recurrent metastasis in direct relation to the previously resected area according to CT scan comparisons.

RESULTS

LAS was performed on 256 metastases in 99 patients, non-laser-assisted surgery (NLAS) on 127 metastases in 79 patients. 5-year-survival rates were 69.3% in all patients, 65.7% after LAS and 73.6% after NLAS. There was no statistically significant survival difference after LAS or NLAS (p = 0.41). The rate of local relapse was 0.8% after LAS vs 3.1% after NLAS (p = 0.073).

CONCLUSION

Despite a larger number of negative predictors for survival in LAS patients, overall survival (OS) was similar in the compared groups. There was also a trend for a lower risk of local relapses after LAS. Therefore, LAS should be considered a promising method for PME.

A new era of thoracic oncology? Ex-vivo stereotactic ablative radiosurgery within Ex-vivo Lung Treatment System as a hybrid therapy for unresectable locally advanced pulmonary malignancies

The concept of oligometastases is the medical rationale for a local treatment of a limited number of metastatic tumor manifestations. Patients with pulmonary oligometastases are candidates for surgery or radiotherapy, however there are a number of technical issues that limit treatment. Technical issues relating to radiotherapy include organs at risk of irradiation, chest wall toxicity and decreased precision of tumor targeting because of breathing movements. Technical issues relating to surgery include loss of lung parenchyma and unresectability. We propose the hypothesis that ex-vivo radiosurgery as new hybrid technique in thoracic oncology has the capability to overcome these technical issues and will expand the medical spectrum in thoracic oncology. The proposed - highly complex - technique consists of surgical lung explantation, followed by stereotactic radiotherapy during ex-vivo perfusion followed by surgical re-implantation.

Porcine pulmonary auto-transplantation for ex vivo therapy as a model for new treatment strategies

OBJECTIVES

Lung auto-transplantation is the surgical key step in experiments involving ex vivo therapy of severe or end-stage lung diseases. Ex vivo therapy has become a clinical reality because of systems such as the Organ Care System (OCS) Lung, which is the only commercially available portable lung perfusion system. However, survival experiments involving porcine lung auto-transplantation pose special surgical and anaesthesiological challenges. This current study was designed to describe the development of surgical techniques and aneasthesiological management strategies that facilitate lung auto-transplantation survival surgery including a follow-up period of 4 days.

METHODS

Left pneumonectomy was performed in 12 Mini-Lewe miniature pigs. After ex vivo treatment of the harvested lungs within the OCS Lung for 2 h, the lungs were retransplanted into the same animal (auto-transplantation). Four animals were used to develop the optimal techniques and establish an experimental protocol. According to the final protocol, eight additional animals were operated. The follow-up period was 4 days.

RESULTS

There were four severe intraoperative surgical complications [anatomical variant of the superior vena cava (two times), a complication related to the bronchial anastomosis and a complication related to the pulmonary arterial anastomosis]. The major postoperative problems were hyperkalaemia, prolonged recovery from anaesthesia and pulmonary oedema after reperfusion. Establishment of the surgical technique showed that using a pericardial tube to facilitate the anastomosis of the thin left superior pulmonary vein should be considered to prevent thrombosis. However, routine use of the patch technique to construct venous and arterial anastomoses is not necessary. Furthermore, traction on the venous anastomoses can be avoided by performing the bronchial anastomosis first.

CONCLUSIONS

Lung auto-transplantation is a feasible experimental model for ex vivo therapy of lung diseases and is applicable for experimental questions concerning human lung transplantation.

[Ex situ tracheobronchoplastic operations using the organ care system]

First clinical experiences with the organ care system (OCS) in lung transplantation showed that this device allows perfusion and ventilation of the lungs under practically physiological conditions. Some pulmonary pathologies necessitate ex situ operations, e.g. to avoid pneumonectomy. The objective of this work was to investigate the feasibility of ex situ pulmonary surgery within the OCS.In the first procedure a large tracheobronchial leakage was covered with a pericardial patch. The procedure was authorized by the local committee of animal welfare. In the second surgery a replacement of the distal trachea using an aortic graft was performed after removal of the heart-lung segment from a pig from the slaughterhouse. The postoperative ventilation of both lungs was free of problems. The mean pressure of the pulmonary artery remained steady during the whole experiment. The setup to prevent lung edema was basically successful.Performing thoracic surgery with the OCS is feasible; however, this approach is reserved for very special indications. Further investigations to optimize technical details of the OCS setup for this purpose are necessary.

Magnetic resonance imaging of soft tissue infection with iron oxide labeled granulocytes in a rat model

OBJECT

We sought to detect an acute soft tissue infection in rats by magnetic resonance imaging (MRI) using granulocytes, previously labeled with superparamagnetic particles of iron oxide (SPIO).

MATERIALS AND METHODS

Parasternal infection was induced by subcutaneous inoculation of Staphylococcus aureus suspension in rats. Granulocytes isolated from isogenic donor rats were labeled with SPIO. Infected rats were imaged by MRI before, 6 and 12 hours after intravenous injection of SPIO-labeled or unlabeled granulocytes. MR findings were correlated with histological analysis by Prussian blue staining and with re-isolated SPIO-labeled granulocytes from the infectious area by magnetic cell separation.

RESULTS

Susceptibility effects were present in infected sites on post-contrast T2*-weighted MR images in all animals of the experimental group. Regions of decreased signal intensity (SI) in MRI were detected at 6 hours after granulocyte administration and were more pronounced at 12 hours. SPIO-labeled granulocytes were identified by Prussian blue staining in the infected tissue and could be successfully re-isolated from the infected area by magnetic cell separation.

CONCLUSION

The application of SPIO-labeled granulocytes in MRI offers new perspectives in diagnostic specificity and sensitifity to detect early infectious processes.

TissuePatch™ as a novel synthetic sealant for repair of superficial lung defect: in vitro tests results

Background

Controversies surrounding the efficacy of surgical sealants against alveolar air leaks (AAL) in lung surgery abound in the literature. We sought to test the sealing efficacy of a novel synthetic sealant, TissuePatch™ in an in vitro lung model.

Methods

The lower lobe of freshly excised swine lung (n = 10) was intubated and ventilated. A superficial parenchymal defect (40 × 25 mm) was created, followed by AAL assessment. After sealant application, AAL was assessed again until burst failure occurred. The length of defect was recorded to evaluate the elasticity of the sealant.

Results

Superficial parenchymal defects resulted in AAL increasing disproportionally with ascending maximal inspiratory pressure (Pmax). Multiple linear regression analysis revealed strong correlation between AAL and Pmax, compliance, resistance. After sealant application, AAL was sealed in all ten tests at an inspired tidal volume (TVi) of 400 ml, in nine tests at TVi = 500 ml, in seven at TVi = 600 ml and in five at TVi = 700 ml. The mean burst pressure was 42 ± 9 mBar. Adhesive and cohesive sealant failures were found in six and three tests respectively. The length of defect before sealant failure was 8.9 ± 4.9% larger than that at TVi = 400 ml, demonstrating an adequate elasticity of this sealant film.

Conclusions

TissuePatch™ may be a reliable sealant for alternative or adjunctive treatment for repair of superficial parenchymal defects in lung surgery. The clinical benefits of this sealant should be confirmed by prospective, randomised controlled clinical trials.

Abstrakt

Methode

Der Unterlappen von frisch entnommenen Schweinlungen (n = 10) wurde intubiert und beatmet. Eine pleurale Läsion (40 × 25 mm) wurde erstellt und APL mit steigendem inspiratorischem Tidalvolumen (TVi) untersucht. Nach Applikation von TissuePatch™ wurde APL auf die gleiche Weise gemessen bis zur Auftritt von Kleberbruch. Zur Untersuchung der Elastizität des Klebers wurde die Länge der pleuralen Läsion gemessen.

Ergebnis

Pleurale Läsion führte bei aufsteigendem maximalem inspiratorischem Druck (Pmax) zu überproportionalem Anstieg von APL. Multiple lineare Regressionsanalyse ergab eine starke Korrelation zwischen APL und Pmax, Lungencompliance sowie Widerstand. Nach der Applikation von Klebstoff wurde APL bei TVi = 400 ml in allen zehn Testen versiegelt, bei TVi = 500 ml in neun Testen, bei TVi = 600 ml in sieben und bei TVi = 700 ml in fünf Testen. Der mittlere Pmax, der zu Kleberbruch führte, betrug 42 ± 9 mBar. Bei den Versuchen wurden adhäsiver und kohäsiver Kleberbruch in jeweils sechs und drei Testen gefunden. Die Länge der pleuralen Läsion vor dem Kleberbruch war 8,9 ± 4,9% größer als die bei TVi = 400 ml.

Schlussfolgerung

Unsere Versuche zeigten eine zuverlässige Versiegelung von TissuePatch™ unter mechanischer Ventilation. Die klinische Nützlichkeit vom Kleber als unterstützende Maßnahme zur Prävention von alveolo-pleuralem Luftleck in Lungenchirurgie sollte durch prospektive, randomisierte kontrollierte klinische Studien bestätigt werden.

TissuePatch™ as a novel synthetic sealant for repair of superficial lung defect: in vitro tests results

BACKGROUND

Controversies surrounding the efficacy of surgical sealants against alveolar air leaks (AAL) in lung surgery abound in the literature. We sought to test the sealing efficacy of a novel synthetic sealant, TissuePatch™ in an in vitro lung model.

METHODS

The lower lobe of freshly excised swine lung (n = 10) was intubated and ventilated. A superficial parenchymal defect (40 × 25 mm) was created, followed by AAL assessment. After sealant application, AAL was assessed again until burst failure occurred. The length of defect was recorded to evaluate the elasticity of the sealant.

RESULTS

Superficial parenchymal defects resulted in AAL increasing disproportionally with ascending maximal inspiratory pressure (Pmax). Multiple linear regression analysis revealed strong correlation between AAL and Pmax, compliance, resistance. After sealant application, AAL was sealed in all ten tests at an inspired tidal volume (TVi) of 400 ml, in nine tests at TVi = 500 ml, in seven at TVi = 600 ml and in five at TVi = 700 ml. The mean burst pressure was 42 ± 9 mBar. Adhesive and cohesive sealant failures were found in six and three tests respectively. The length of defect before sealant failure was 8.9 ± 4.9% larger than that at TVi = 400 ml, demonstrating an adequate elasticity of this sealant film.

CONCLUSIONS

TissuePatch™ may be a reliable sealant for alternative or adjunctive treatment for repair of superficial parenchymal defects in lung surgery. The clinical benefits of this sealant should be confirmed by prospective, randomised controlled clinical trials. ABSTRAKT:

HINTERGRUND

Die Wirksamkeit von chirurgischen Klebstoffen zur Prävention von alveolo-pleuralem Luftleck (APL) ist trotz zunehmenden klinischen Anwendungen in Lungenchirurgie immer noch kontrovers diskutiert. Wir evaluierten die Abdichtungswirksamkeit von einem neuartigen synthetischen Kleber, TissuePatch™ mittels eines in vitro Lungenmodels. METHODE: Der Unterlappen von frisch entnommenen Schweinlungen (n = 10) wurde intubiert und beatmet. Eine pleurale Läsion (40 × 25 mm) wurde erstellt und APL mit steigendem inspiratorischem Tidalvolumen (TVi) untersucht. Nach Applikation von TissuePatch™ wurde APL auf die gleiche Weise gemessen bis zur Auftritt von Kleberbruch. Zur Untersuchung der Elastizität des Klebers wurde die Länge der pleuralen Läsion gemessen. ERGEBNIS: Pleurale Läsion führte bei aufsteigendem maximalem inspiratorischem Druck (Pmax) zu überproportionalem Anstieg von APL. Multiple lineare Regressionsanalyse ergab eine starke Korrelation zwischen APL und Pmax, Lungencompliance sowie Widerstand. Nach der Applikation von Klebstoff wurde APL bei TVi = 400 ml in allen zehn Testen versiegelt, bei TVi = 500 ml in neun Testen, bei TVi = 600 ml in sieben und bei TVi = 700 ml in fünf Testen. Der mittlere Pmax, der zu Kleberbruch führte, betrug 42 ± 9 mBar. Bei den Versuchen wurden adhäsiver und kohäsiver Kleberbruch in jeweils sechs und drei Testen gefunden. Die Länge der pleuralen Läsion vor dem Kleberbruch war 8,9 ± 4,9% größer als die bei TVi = 400 ml.

SCHLUSSFOLGERUNG

Unsere Versuche zeigten eine zuverlässige Versiegelung von TissuePatch™ unter mechanischer Ventilation. Die klinische Nützlichkeit vom Kleber als unterstützende Maßnahme zur Prävention von alveolo-pleuralem Luftleck in Lungenchirurgie sollte durch prospektive, randomisierte kontrollierte klinische Studien bestätigt werden.