Chronic lung allograft pathology lesions in two rat strain combinations.

BACKGROUND: Chronic lung allograft dysfunction remains an obstacle to long-term survival after lung transplantation. Two phenotypes have been described: obliterative bronchiolitis and restrictive allograft syndrome. Preclinical models are essential to analyze chronic lung allograft dysfunction pathophysiology. METHODS: Orthotopic lung transplants from 38 Lewis into Fischer 344 (Lew→F344) and 67 Brown-Norway into Lewis (BN→Lew) rats were performed in our center in the last decade. We carefully reviewed and quantified all grafts with chronic rejection (40 cases) (18 Lew→F344, 22 BN→Lew) with the aim to investigate if histological changes of chronic lung allograft dysfunction could be also detected in rat grafts. RESULTS: All animals showed human reminiscent histological lesions. Early chronic rejection lesions were detected in BN→Lew. End-stage chronic rejection with features of obliterative bronchiolitis was observed in 33% of Lew→F344; end-stage with restrictive allograft syndrome chronic rejection in 67% and 80% of Lew→F344 and BN→Lew, respectively. BN→Lew showed higher grades of endotheliitis, vascular fibrosis, and lower grades of lymphoid aggregates than Lew→F344 (P=0.007, P=0.043, P=0.004, respectively). CONCLUSIONS: Chronic rejection lesions in rat lung allografts mimic those in humans. The frequent occurrence of restrictive allograft syndrome-like lesions in BN→Lew may be related to a higher degree of mismatch in this strain combination. These animal models could allow future mechanistic studies to better understand chronic lung allograft dysfunction pathogenesis.

Vein Suturing Results in Worse Lung Graft Outcomes Compared to the Cuff Method.

BACKGROUND: The rat orthotopic lung transplant model is not widely used yet because of the complexity of the procedure, in particular, venous anastomosis. Here, we performed a rat orthotopic lung transplantation using either the suture (ST) or cuff (CT) method for vein anastomosis. OBJECTIVES: To compare the vein ST and CT techniques in terms of operative time, success, recipient survival, and early histological outcomes was the objective of this study. METHODS: A total of 24 left lung transplants in rats were performed. Twelve syngeneic (Lewis to Lewis) and 12 allogeneic (Brown-Norway to Lewis) lung transplants were performed using either the vein ST or the CT procedure. Arterial and bronchial anastomoses were performed with the CT technique. Graft histological damage was evaluated 3-7 days post-transplant in all rat lungs. RESULTS: The surgical success rate was 75% in both the ST and CT groups. Failures related mainly to vein bleeding (n = 2 in the ST group) and thrombosis (n = 1 in the ST group; n = 2 in the CT group). Total ischemia time was longer in the ST group (122 ± 25 min in ST group vs. 83 ± 10 min in CT group, mean ± SD), due to prolonged warm ischemia time (60 ± 12 min in the ST group vs. 21 ± 5 min in the CT group, mean ± SD), reflecting the time required to complete the vein ST procedure. The prolonged warm ischemia time resulted in significantly higher vascular inflammation in syngeneic grafts (2.3 ± 1.2 ST group vs. 0 in the CT group, mean ± SD) and in increased severity of ischemia/reperfusion injury and acute graft rejection (3.6 ± 0.4 in the ST group vs. 2.6 ± 0.4 in the CT group, mean ± SD) in allogeneic lung transplants. CONCLUSIONS: The vein ST technique is a more time-consuming procedure than the CT method and the prolonged anastomosis time has a deleterious impact on transplant outcomes. These findings suggest that warm ischemia time - one of the modifiable transplant factors - should be considered a major risk factor in lung transplantation, particularly in the setting of donation after cardiac death.

Acquired tracheoesophageal fistula repair, due to prolonged mechanical ventilation, in patient with double incomplete aortic arch.

We report a case of the repair of an acquired benign tracheoesophageal fistula (TEF) after prolonged mechanical invasive ventilation. Patient had an unknown double incomplete aortic arch determining a vascular ring above trachea and esophagus. External tracheobronchial compression, caused by the vascular ring, increasing the internal tracheoesophageal walls pressure determined by endotracheal and nasogastric tubes favored an early TEF development. The fistula was repaired through an unusual left thoracotomy and vascular ring dissection. TEFs are a heterogeneous group of diseases affecting critically ill patients. Operative closure is necessary to avoid further complications related to this condition. Pre-operative study is mandatory to plan an adequate surgical approach.

Lung ultrasound as a monitoring tool in lung transplantation in rodents: a feasibility study.

BACKGROUND: Orthotopic lung transplantation in rats has been developed as a model to study organ dysfunction, but available tools for monitoring the graft function are limited. In this study, lung ultrasound (LUS) is proposed as a new non-invasive monitoring tool in awake rodents. METHODS: LUS was applied to native and graft lung of six rats after left orthotopic transplantation. Rats were monitored with LUS while awake, patterns identified, images evaluated with a scoring system, intra- and inter-rater agreement was assessed and examination times analyzed. RESULTS: A total of 78 clips were recorded. The median quality score of LUS was 3.66/4 for left hemithorax and 3.71/4 for native right side. The intra-rater agreement was 0.53 and 0.65 and the inter-rater agreement was 0.61 (P<0.01). Median time to complete the examination was 233.0 seconds (IQR 142) for both lungs, lowered from 254.0 seconds (IQR 129.5) (first trimester of study) to 205.5 seconds (IQR 88.5) (second trimester of the study). Significant findings on LUS were confirmed on pathological examination. CONCLUSIONS: LUS in awake rodents without shaving has been shown to be both feasible and safe and the images collected were of good quality and comparable to those obtained in anesthetized rats without bristles.

Thoracoscopic wedge resection in single-lung patients.

BACKGROUND: The thoracoscopic approach has become a standard procedure in the field of lung resections. However, its advantage in single-lung patients has not yet been well studied. We describe a series of successful thoracoscopic wedge resections in patients presenting with lung cancer after contralateral pneumonectomy. METHODS: Eight patients, with a previous pneumonectomy (5 right and 3 left) for lung cancer, underwent resection for a suspicious neoplasm on the remaining lung. All lesions were detected in the asymptomatic phase during regular follow-up after pneumonectomy based on repeated computer tomography (CT). Only single peripheral lesions less than 2 cm were eligible for wedge resection were eligible for surgery. Video-assisted thoracoscopic, margin-free tumor wedge resections, were performed during apnea windows with the lung in a deflated position. RESULTS: All patients were treated by a wedge resections smaller than a single segment. Only one patient needed a mini-thoracotomy conversion to accomplish a safe margin-free resection. Median total surgical operative time was 37 minutes. There were no postoperative deaths, while morbidity was 12.5%. CONCLUSIONS: Thoracoscopic surgery represents a feasible surgical option in selected patients after contralateral pneumonectomy, with careful preoperative assessment and using short apnea windows in good collaboration with anesthesiologists. Histological definition, made possible by the surgical-procedure, gives patients the possibility to eventually undergo further targeted therapies. Randomized prospective trials are necessary to assess the best management of peripheral small lung nodules in single-lung patients, in particular to define which patients can benefit from a surgical approach.

Comparing robotic and trans-sternal thymectomy for early-stage thymoma: a propensity score-matching study.

OBJECTIVES: Minimally invasive techniques seem to be promising alternatives to open approaches in the surgical treatment of early-stage thymoma, although there are controversies because of lack of data on long-term results. The aim of the study was to evaluate the surgical and oncological results after robotic thymectomy for early-stage thymoma compared to median sternotomy. METHODS: Between 1982 and 2017, 164 patients with early-stage thymoma (Masaoka I and II) were operated on by median sternotomy (108 patients) or the robotic approach (56 patients). Duration of surgery, amount of blood loss, complications, duration of chest drainage, postoperative hospital stay, oncological results and total costs were retrospectively evaluated. Data were analysed also after propensity score matching. RESULTS: Compared to the trans-sternal group, robotic thymectomy had significantly longer average operative times (P < 0.001) but less intraoperative blood loss (P = 0.01), less perioperative complications (P = 0.03), shorter time to chest drainage removal and hospital discharge (P < 0.001). The median expense for the trans-sternal approach was significantly higher than the cost of the robotic procedure (P < 0.001), mainly due to longer hospitalization. From an oncological point of view, there were no differences in thymoma recurrence, although follow-up of the trans-sternal group was significantly longer (P < 0.001). Data were confirmed after propensity score matching. CONCLUSIONS: Robotic thymectomy for early-stage thymoma is a technically safe and feasible procedure with low complication rate and shorter hospital stay compared to the trans-sternal approach. Cost analysis revealed lower expenses for the robotic procedure due to the reduced hospital stay. The oncological outcomes seemed comparable, but longer follow-up is needed.

Surgery for T4 lung cancer invading the thoracic aorta: Do we push the limits?

BACKGROUND: Few investigators have described en bloc resection of non-small cell lung cancer (NSCLC) invading the aorta. AIM OF STUDY: Analysis of outcome and prognostic factors for en bloc resections of NSCLC invading the aorta. METHODS: Thirty-five patients (27 males, 8 females; mean age 63 ± 8.6 years) were operated between 1994 and 2015 in four European Centers. HISTOLOGY: 12 (34.3%) squamous cell carcinoma, and 6 (17.1%) undifferentiated/large cell carcinoma. The site of aortic infiltration was the descending thoracic aorta in 24 (68.6%) patients, the aortic arch in 9 (25.7%), and the aortic arch and supraortic trunks in 2 (5.7%). RESULTS: Lung resection consisted of pneumonectomy in 19 (54.3%) patients and lobectomy in 16 (45.7%). Aortic resection management was undertaken by endograft positioning (37.1%), subadventitial dissection (37.1%), cardiopulmonary/aorto-aortic bypass (17.2%), and direct clamping (8.6%). A tubular graft replacement was carried out in five cases, a synthetic patch repair in 6. Mortality was 2.9%, morbidity 37.1%. Patients undergoing pneumonectomy had a significantly higher morbidity rate compared with lobectomy (52% vs 18.7%; P = 0.003), although patients managed with aortic endografting had a lower complication rate. Median overall and disease-free survival rates were 31.3 and 22.2 months, respectively. Gender and site of aortic infiltration were independent prognostic factors. CONCLUSIONS: Resection of NSCLC combined with an infiltrated aorta is a challenging procedure that can be performed with reasonable morbidity and mortality in highly selected patients.

Identification of miRNAs Potentially Involved in Bronchiolitis Obliterans Syndrome: A Computational Study.

The pathogenesis of Bronchiolitis Obliterans Syndrome (BOS), the main clinical phenotype of chronic lung allograft dysfunction, is poorly understood. Recent studies suggest that epigenetic regulation of microRNAs might play a role in its development. In this paper we present the application of a complex computational pipeline to perform enrichment analysis of miRNAs in pathways applied to the study of BOS. The analysis considered the full set of miRNAs annotated in miRBase (version 21), and applied a sequence of filtering approaches and statistical analyses to reduce this set and to score the candidate miRNAs according to their potential involvement in BOS development. Dysregulation of two of the selected candidate miRNAs-miR-34a and miR-21 -was clearly shown in in-situ hybridization (ISH) on five explanted human BOS lungs and on a rat model of acute and chronic lung rejection, thus definitely identifying miR-34a and miR-21 as pathogenic factors in BOS and confirming the effectiveness of the computational pipeline.

An Unusual Cause of Thoracic Outlet Syndrome.

Thoracic outlet syndrome (TOS) is a condition arising from compression of the subclavian vessels and/or brachial plexus. Many factors or diseases may cause compression of the neurovascular bundle at the thoracic outlet. We describe the case of a 41-year-old woman with TOS who presented with vascular venous symptoms. Chest computed tomography (CT) scan showed a cystic mass at the level of cervico-thoracic junction, located between the left subclavian artery and vein, which appeared compressed. The cystic mass was removed through a cervical approach and it was found to be a cyst arising from the thoracic duct compressing and anteriorly dislocating the left subclavian vein. After surgery symptoms promptly disappeared.

Robotic-assisted thymectomy: current perspectives.

Thymectomy is the cornerstone in the treatment of thymic tumors and an accepted option for the management of myasthenia gravis. Different surgical approaches have been described, but the gold standard is represented by median sternotomy. In the last two decades, the development of minimally invasive surgery has led to an increased acceptance of thymectomy, especially for benign diseases. Robotic thymectomy seems a further step in the development and evolution of minimally invasive approaches. Since its introduction, different authors described their experience with robotic thymectomy, both for nonthymomatous myasthenia gravis and for thymic tumors. Available data show that robotic thymectomy may be considered a safe and feasible operation. In patients with nonthymomatous myasthenia, robotic thymectomy is effective and the long-term results are encouraging. The role of robotic thymectomy in patients affected by thymoma is still under evaluation, but the intermediate results seem promising both in terms of surgical and oncologic outcomes.

Safe resection of the aortic wall infiltrated by lung cancer after placement of an endoluminal prosthesis.

BACKGROUND: Few investigators have reported the results of combined resection of lung cancer infiltrating the thoracic aorta; only anecdotal accounts of off-label use of thoracic aortic endografts to facilitate resection of such tumors have been published. In this paper, we describe our experience using this innovative approach in terms of technical details and outcomes. METHODS: We retrospectively reviewed data on 9 patients (6 men and 3 women, median age 61 years) with preoperatively suspected thoracic aorta neoplastic invasion, who were operated on after positioning of an endograft and underwent en bloc tumor resection including the aortic wall. RESULTS: All but one cancer were non-small cell lung carcinomas; 4 patients received neoadjuvant chemotherapy, and 7 received adjuvant therapy. Aortic endografting was performed 2 to 17 days before resection of the tumor in 7 patients and as part of a one-stage procedure in 2 patients. The proximal end of the stent graft was deployed in the aortic arch (n = 1) or the descending aorta (n = 8). Lung resections were left pneumonectomies in 4 patients and left lower lobectomies in 5. Five patients underwent additional buttressing of the aortic defect using a synthetic patch (n = 2) or the omentum (n = 3). No cardiopulmonary bypass was required. At the last follow-up, 3 patients had evidence of tumor recurrence (one local and two distant). No endograft-related complications were detected. CONCLUSIONS: Thoracic aortic endografting allowed safe en bloc resection of tumors invading the aortic wall, avoiding the need for extracorporeal circulatory support. Such an extended indication for thoracic aortic endografts seems promising and should be considered for selected oncologic cases.

Early and late outcome after surgical treatment of acquired non-malignant tracheo-oesophageal fistulae.

OBJECTIVES: Tracheo-oesophageal fistula (TOF) is a rare, life-threatening condition. We report our results of surgical treatment and evaluation of the outcome of acquired non-malignant TOF. METHODS: Twenty-five patients (aged 49 ± 21 years) with TOF were operated on between 2001 and 2011. Tracheo-oesophageal fistula was due to prolonged intubation/tracheostomy (84%), was secondary to other surgery (8%) or trauma (4%) or was idiopathic (4%). The tracheal defect was 2.4 ± 1.3 cm long and was associated with tracheal stenosis in seven (28%) patients. Surgical treatment consisted of direct suturing of the oesophageal defect in two layers (or end-to-end oesophageal resection and anastomosis in one case) associated with tracheal suturing (n = 15; 60%), tracheal resection and anastomosis (n = 8; 32%) or covering of a large tracheal defect by an intercostal muscle flap or by a resorbable patch with muscle apposition (n = 2; 8%). The surgical approach was cervicotomy (n = 14; 56%), cervicotomy plus median sternotomy or split (n = 6; 24%), thoracotomy (n = 4; 16%) or cervicotomy plus sternal spit plus thoracotomy (n = 1; 4%). In 18 (72%) cases a muscular flap was used and in six (24%) a protective tracheostomy was performed. RESULTS: No perioperative deaths occurred. Morbidity occurred in eight (32%) patients; none of them required a second surgical look. At median follow-up of 41 months, the outcome was excellent or good for 22 patients (88%), two (8%) are still dependent on jejunostomy and tracheostomy for neurological diseases and one (4%) is under mechanical ventilation for end-stage respiratory failure. CONCLUSIONS: Surgical treatment of TOF is associated with good results in terms of control of acute symptoms and long-term outcome, particularly concerning oral intake and spontaneous breathing.

Iterative optimization of an ESI IT mass spectrometer using regular simplex and a multivariate target function representing the S/N ratio.

Standard automatic tuning for mass spectrometry usually exploits a one-variable-at-a-time approach. This method suffers from important drawbacks: the target function selected for optimization improves the signal of a single channel or a pool of channels without considering noise; the interactions between the parameters are not evaluated. The optimization of the experimental settings of an ESI IT mass spectrometer is carried out here by a multivariate procedure exploiting a target function representing the S/N ratio calculated by principal component analysis and a regular simplex optimization algorithm. A preliminary feasibility study was performed since the target function must be sensitive to the changes in the experimental conditions applied during the iterative tuning and be free from drifts. The feasibility study was carried out to evaluate: the presence of memory effects; the size of the variations in the S/N ratio; the number of scans needed to generate a reliable S/N ratio; the concentration of the multi-standard mixture to use during tuning; the experimental duration required to achieve S/N stability when the experimental settings are modified. The feasibility study led to the identification of the best protocol to accomplish the tuning, while simplex optimization allowed the S/N ratio to be improved by about 70% with respect to the default conditions suggested by the manufacturer.

Prevention of extubation failure in high-risk patients with neuromuscular disease.

BACKGROUND: A substantial proportion of patients with neuromuscular disease (NMD) who undergo positive pressure ventilation via endotracheal intubation for acute respiratory failure fail to pass spontaneous breathing trials and should be considered at high risk for extubation failure. In our study, we prospectively investigated the efficacy of early application of noninvasive ventilation (NIV) combined with assisted coughing as an intervention aimed at preventing extubation failure in patients with NMD. METHODS: This study is a prospective analysis of the short-term outcomes of 10 patients with NMD who were treated by NIV and assisted coughing immediately after extubation and comparison with the outcomes of a population of 10 historical control patients who received standard medical therapy (SMT) alone. The participants were composed of 10 patients with NMD who were submitted to NIV and assisted coughing after extubation (group A) and 10 historical control patients who were administered SMT (group B), who were admitted to a 4-bed respiratory intensive care unit (RICU) in a university hospital. Need for reintubation despite treatment was evaluated. Mortality during RICU stay, need for tracheostomy, and length of stay in the RICU were also compared. RESULTS: Significantly fewer patients who received the treatment protocol required reintubation and tracheostomy compared with those who received SMT (reintubation, 3 vs 10; tracheostomy, 3 vs 9; P = .002 and .01, respectively). Mortality did not differ significantly between the 2 groups. Patients in group A remained for a shorter time in the RICU compared with group B (7.8 ± 3.9 vs 23.8 ± 15.8 days; P = .006). CONCLUSIONS: Preventive application of NIV combined with assisted coughing after extubation provides a clinically important advantage to patients with NMD by averting the need for reintubation or tracheostomy and shortening their stay in the RICU; its use should be included in the routine approach to patients with NMD at high risk for postextubation respiratory failure.

Determination of perfluorochemicals in biological, environmental and food samples by an automated on-line solid phase extraction ultra high performance liquid chromatography tandem mass spectrometry method.

A rapid on-line solid phase extraction ultra high performance liquid chromatography tandem mass spectrometry method was developed for the identification and quantitation of nine perfluorinated compounds in matrices of environmental, biological and food interest. Pre-treatment, solid phase extraction, chromatographic and mass detection conditions were optimised, in order to apply the whole methodology to the analysis of different matrices. Particular attention was devoted to the evaluation of matrix effect and the correlated phenomena of ion enhancement or suppression in mass spectrometry detection. LOD and LOQ range from 3 to 15ngL(-1) and from 10 to 50ngL(-1), respectively. Method detection limits (MDLs) were also calculated for each kind of matrix. The recovery, evaluated for each analyte, does not depend on analyte concentration in the explored concentration range: average R¯% values are always greater than 82.9%. In the whole, the results obtained for samples of river waters, blood serum, blood plasma, and fish confirm the ubiquitous presence of perfluorinated compounds, as recently denounced by many sources.

Automated online solid phase extraction ultra high performance liquid chromatography method coupled with tandem mass spectrometry for determination of forty-two therapeutic drugs and drugs of abuse in human urine.

The study deals with a fast (analysis times of around 11 min) simultaneous identification and quantification in human urine of 42 drugs (21 therapeutic and 21 of abuse), through an automated online solid phase extraction ultra high performance liquid chromatography method coupled with tandem mass spectrometry (SPE UHPLC-MS/MS). In the method validation, particular attention was devoted to the matrix effect, through matrix-matched calibration in blank urine, suitably diluted. For all the abuse drugs investigated, the limit of quantitation (LOQ) values are lower than the legal threshold concentration levels, making the method suitable for routine control. The whole procedure was applied in the analysis of urine of patients positive to the I level screening test.

A new on-line solid phase extraction high performance liquid chromatography tandem mass spectrometry method to study the sun light photodegradation of mono-chloroanilines in river water.

The study investigates the natural photodegradation pathway of mono-chloroanilines in river waters, with the aim to identify the predominant photoproducts formed. At this purpose a new sensitive on-line SPE HPLC-MS/MS method has been developed with LOQ values equal or lower than the legal threshold concentration levels allowed for mono-chloroanilines in waters. The degradation processes of o-, m- and p-chloroaniline have been investigated subjecting their solutions, prepared both in ultrapure and in river water, to sun light irradiation simulated by a solar box system. The SPE HPLC-MS/MS methodology allowed to evaluate the degradation kinetics, to identify the predominant photodegradation products and to propose the chemical structures. Two photoproducts (aniline and 3-aminophenol), for which standards are available, have also been quantified.