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Decellularized tissues and organs represent a suitable option for tissue engineering when specific scaffolds are needed. However, the optimal conditions to completely remove all the cellular components and minimally affect the biochemical and structural properties of the extracellular matrix are still to be found. For this aim, bioreactors could be an alternative means to dynamically treat the biological samples, automatically controlling all the variables involved in the process and speeding up the entire procedure in order to deal with a suitable scaffold within a limited time period. This paper presents the characterization of rat tracheae decellularized in dynamic conditions, implementing a detergent-enzymatic method, previously considered. Only 6 cycles were enough to generate a tracheal matrix that was histologically and structurally similar to the native one. The network of collagen, reticular and elastic fibers was well preserved, such as the epithelial cilia, the luminal basement membrane and the main matrix components. The elastin content decreased, even if not significantly, after the decellularization protocol. Mechanical properties of the treated tissues were slightly affected by the procedure, and were partially recovered after crosslinking with genipin, a naturally-derived agent. The use of bioreactors could enhance the decellularization procedure of tissues/organs, but a careful selection of the processing parameters is needed in order to prevent large modifications compared to the native condition.

The development of tracheal scaffolds fabricated based on electrospinning technique by applying different ratios of polyethylene terephthalate (PET) and polyurethane (PU) is introduced here. Prior to clinical implantation, evaluations of biomechanical and morphological properties, as well as biocompatibility and cell adhesion verifications are required and extensively performed on each scaffold type. However, the need for bioreactors and large cell numbers may delay the verification process during the early assessment phase. Hence, we investigated the feasibility of performing biocompatibility verification using static instead of dynamic culture. We performed bioreactor seeding on 3-dimensional (3-D) tracheal scaffolds (PET/PU and PET) and correlated the quantitative and qualitative results with 2-dimensional (2-D) sheets seeded under static conditions. We found that an 8-fold reduction for 2-D static seeding density can essentially provide validation on the qualitative and quantitative evaluations for 3-D scaffolds. In vitro studies revealed that there was notably better cell attachment on PET sheets/scaffolds than with the polyblend. However, the in vivo outcomes of cell seeded PET/PU and PET scaffolds in an orthotopic transplantation model in rodents were similar. They showed that both the scaffold types satisfied biocompatibility requirements and integrated well with the adjacent tissue without any observation of necrosis within 30 days of implantation.

Summary Background In 2008, the first transplantation of a tissue-engineered trachea in a human being was done to replace an end-staged left main bronchus with malacia in a 30-year-old woman. We report 5 year follow-up results. Methods The patient was followed up approximately every 3 months with multidetector CT scan and bronchoscopic assessment. We obtained mucosal biopsy samples every 6 months for histological, immunohistochemical, and electron microscopy assessment. We also assessed quality of life, respiratory function, cough reflex test, and production and specificity of recipient antibodies against donor human leucocyte antigen. Findings By 12 months after transplantation, a progressive cicatricial stenosis had developed in the native trachea close to the tissue-engineered trachea anastomosis, which needed repeated endoluminal stenting. However, the tissue-engineered trachea itself remained open over its entire length, well vascularised, completely re-cellularised with respiratory epithelium, and had normal ciliary function and mucus clearance. Lung function and cough reflex were normal. No stem-cell-related teratoma formed and no anti-donor antibodies developed. Aside from intermittent bronchoscopic interventions, the patient had a normal social and working life. Interpretation These clinical results provide evidence that a tissue-engineering strategy including decellularisation of a human trachea, autologous epithelial and stem-cell culture and differentiation, and cell-scaffold seeding with a bioreactor is safe and promising. Funding European Commission, Knut and Alice Wallenberg Foundation, Swedish Research Council, ALF Medicine.

The clinical outcome of transplantations of bioartificial tissues and organs depends on the presence of living cells. There are still no standard operative protocols that are simple, fast and reliable for confirming the presence of viable cells on bioartificial scaffolds prior to transplantation. By using mathematical modeling, we have developed a colorimetric-based system (colorimetric scale bar) to predict the cell viability and density for sufficient surface coverage. First, we refined a method which can provide information about cell viability and numbers in an in vitro setting: i) immunohistological staining by Phalloidin/DAPI and ii) a modified colorimetric cell viability assay. These laboratory-based methods and the developed colorimetric-based system were then validated in rat transplantation studies of unseeded and seeded tracheal grafts. This was done to provide critical information on whether the graft would be suitable for transplantation or if additional cell seeding was necessary. The potential clinical impact of the colorimetric scale bar was confirmed using patient samples. In conclusion, we have developed a robust, fast and reproducible colorimetric tool that can verify and warrant viability and integrity of an engineered tissue/organ prior to transplantation. This should facilitate a successful transplantation outcome and ensure patient safety.

Background. We prospectively evaluated a clinical and endoscopic score, the tracheal endoscopic clinical score (TECS), developed as a disease-specified outcome measure in adult patients undergoing operation for subglottic stenosis. We also performed a retrospective chart review to identify preoperative and intraoperative risk factors for worse TECS. Methods. The TECS includes endoscopic (vocal cord and glottic function, anastomotic healing, and patency) and interview (respiration, voice, swallow) variables, and was administered at 6-month follow-up. Endoscopic and subjective domains were weighted to obtain a continuous TECS index ranging from 0 (best) to 1 (worse). The TECS and preoperative variables relationships were evaluated by univariate and multivariate analysis. Results. We collected data (January 2009 to December 2010) from 30 patients (mean age, 48.3 19 years) undergoing subglottic resection and primary reconstruction. Stenosis etiology was postintubation (n 8), idiopathic (n 2), tracheostomy (n 18), and malignant (n 2). Surgery included Pearson operation with (n 7) or without (n 23) a Liberman-Mathisen cricoplasty. Mean length of resected trachea was 30.5 13.5 mm, and mean hospital stay was 7.4 days. Mortality rate was 1 patient (3.3%). The univariate analysis showed positive correlation between 6-month TECS and degree of stenosis (McCaffrey and Cotton scale 0 to 4) stage 4, tracheostomy or T-tube at surgery, bottleneck-type transition stenosis, and resection length. At multivariate analysis, the presence of tracheostomy, bottleneck-type transition stenosis and resection length were indicators of worse postoperative functional result. Conclusions. The TECS seems to be a valid and simple instrument to identify preoperative variables predicting worse results and to assess postoperative outcome. Validation on larger series is necessary. (Ann Thorac Surg 2012;94:1065‐72) © 2012 by The Society of Thoracic Surgeons

ObjectiveOur objective was to investigate the capacity of a pumpless extracorporeal lung membrane (iLA) (Novalung; Novalung GmbH, Hechingen, Germany) to provide adequate respiratory support and the impact on morbidity/mortality during complex airway reconstruction.MethodsOnly patients unable to be ventilated via conventional intubation were eligible for the study. A larynx mask or orotracheal tubes were placed above the airway defect and the iLA was attached via femoral vessels (arteriovenous), providing extracorporeal gas exchange, apneic hyperoxygenation, and total tubeless airway reconstruction. Haptoglobulin, plasmin–antiplasmin complex, P-selectin activation, and interleukin 6 were measured before, during, and after iLA use and 72 hours postoperatively.ResultsFifteen consecutive patients (age, 42 ± 17 years) underwent elective (n = 7) or emergency (n = 8) reconstruction of the airway owing to a variety of disorders or defects. The iLA was left in place for 185 ± 61 minutes, diverted 1.70 ± 0.48 L/min of the cardiac output, and provided an arteriovenous carbon dioxide removal and oxygen transfer of 173 ± 94 and 144 ± 83 mL/min, respectively. The arterial oxygen tension/inspired oxygen fraction (314 ± 31 mm Hg), and arterial carbon dioxide tension (40 ± 6 mm Hg) remained stable throughout the entire operations. The following procedures were performed: redo slide tracheoplasties (n = 3), redo tracheoesophageal fistula repair (n = 1), sleeve lobectomies (n = 2), main carina reconstructions (n = 7), and anastomotic stenting and myocutaneous coverages (n = 2). Three patients required prolonged (9 ± 2 days) postoperative iLA support. Two (13%) patients died during the hospital stay. The use of iLA was associated with significant (P

We investigated whether decellularized pig tracheas could regenerate in vivo, without being recellularized before transplantation, using the own body as bioreactor. Decellularized pig tracheal scaffolds were intraoperative conditioned with mononuclear cells and growth and differentiation factors. During the postoperative period, the in situ regeneration was boosted by administering bioactive molecules to promote peripheral mobilization and differentiation of stem/progenitor cells and ultimately the regenerative process. Results revealed, after 2 weeks, a nearly normal trachea, with respiratory epithelium and a double-banded cartilage but without any mechanical differences compared to the native tissue. The growth factor administration resulted in a mobilization of progenitor and stem cells into the peripheral circulation and in an up-regulation of anti-apoptotic genes. Isolated stem/progenitor cells could be differentiated in vitro into several cell types, proving their multipotency. We provide evidence that the own body can be used as bioreactor to promote in vivo tissue engineering replacement. Moreover, we demonstrated the beneficial effect of additional pharmaceutical intervention for an improved engraftment of the transplant.

Bioengineered tissues created for transplant will be expected to survive and contribute to function over the lifetime of the individual. To evaluate potential intrinsic changes and degradation of the extracellular matrix of decellularized human tissue scaffolds, human decellularized tracheas were evaluated over a one year period in vitro . Human tracheas were decellularized and stored for one year in phosphate-buffered saline at 4 °C in the presence of antibiotics and anti-mycotics, and their structural, mechanical, and angiogenic properties compared to baseline values. Results showed that stored human decellularized tracheas were increasingly degraded resulting in a loss of extracellular matrix architecture – in particular of collagenous and elastic fiber structure –and decreased mechanical and angiogenic properties. The mechanical alterations of the extracellular matrix but not the deterioration and microstructure were not improved by using a natural cross-linking agent. These findings demonstrate that human decellularized tracheas, stored for one year in phosphate-buffered saline solution at 4 °C, would not meet the demands for a tissue engineering matrix and likely would not yield a suitable graft for lifelong implantation. The degradation phenomenon observed in vitro may be further enhanced in vivo , having clinical relevance for tissues that will be transplanted long-term and this should be carefully evaluated in pre-clinical settings.

Recent technical advances in the domains of anesthesia, cardiovascular and thoracic surgery, and synthetic materials manufacturing coupled with more oncological extended tumor indications have unlocked the door to the surgical treatment of pulmonary, mediastinal, or other rare tumors involving intrathoracic vessels. In 1987, Dartevelle et al1 first described a consecutive and large series of patients with mediastinal or lung malignancies and superior vena cava (SVC) involvement treated with SVC resection by using polytetrafluoroethylene tubular grafts for reconstruction. Open surgery requires a high level of technical expertise and vigilant attention to patient selection and perioperative management to minimize complications, which are reported even in highly specialized centers.1,2 During the past decade, operative mortality for these procedures has ranged between 0% and 7.7%, with long-term patency rates of about 70%-100%.3-9 However, proper patient selection is critical for clinical success. We will outline the role of surgery for selected patients with locally advanced but completely resectable non-small cell lung cancers (NSCLC) or mediastinal tumors (MT) involving invading the SVC and/or the innominate vein (IV).

ObjectiveWe sought to determine the relative contributions of epithelial cells and mesenchymal stem cell–derived chondrocytes to the survival of tissue-engineered airway transplants in pigs.MethodsNonimmunogenic tracheal matrices were obtained by using a detergent-enzymatic method. Major histocompatibility complex–unmatched animals (weighing 65 ± 4 kg) were divided into 4 groups (each n = 5), and 6 cm of their tracheas were orthotopically replaced with decellularized matrix only (group I), decellularized matrix with autologous mesenchymal stem cell–derived chondrocytes externally (group II), decellularized matrix with autologous epithelial cells internally (group III), or decellularized matrix with both cell types (group IV). Autologous cells were recovered, cultured, and expanded. Mesenchymal stem cells were differentiated into chondrocytes by using growth factors. Both cell types were seeded simultaneously with a dual-chamber bioreactor. Animals were not immunosuppressed during the entire study. Biopsy specimens and blood samples were taken from recipients continuously, and animals were observed for a maximum of 60 days.ResultsMatrices were completely covered with both cell types within 72 hours. Survival of the pigs was significantly affected by group (P < .05; group I, 11 ± 2 days; group II, 29 ± 4 days; group III, 34 ± 4 days; and group IV, 60 ± 1 days). Cause of death was a combination of airway obstruction and infection (group I), mainly infection (group II), or primarily stenosis (group III). However, pigs in group IV were alive, with no signs of airway collapse or ischemia and healthy epithelium. There were no clinical, immunologic, or histologic signs of rejection despite the lack of immunosuppression.ConclusionsWe confirm the clinical potential of autologous cell– and tissue-engineered tracheal grafts, and suggest that the seeding of both epithelial and mesenchymal stem cell–derived chondrocytes is necessary for optimal graft survival.

ObjectiveWe sought to bioengineer a nonimmunogenic tracheal tubular matrix of 6 cm in length and test its structural, functional, and immunologic properties in vitro and in vivo.MethodsTwelve-centimeter tracheal segments were harvested from Yorkshire boars. Half of each segment was subjected to a detergent–enzymatic method (containing sodium deoxycholate/DNase lavations) of decellularization for as many cycles as needed, and the other half was stored in phosphate-buffered saline at 4°C as a control. Bioengineered and control tracheas were then implanted in major histocompatibility complex–unmatched pigs (allograft) or mice (xenograft) heterotopically for 30 days. Structural and functional analysis and immunostaining were performed after each detergent–enzymatic method cycle and transplantation.ResultsCompared with control tracheas, bioengineered matrices displayed no major histocompatibility complex class I and II antigens after 17 detergent–enzymatic method cycles, without significant (P > .05) differences in their strain ability (rupture force, 56.1 ± 3.3 vs 55.5 ± 2.4 N; tissue deformation at 203% ± 13% vs 200% ± 8% or 12.2 ± 0.8 vs 12 ± 0.5 cm; and applied maximum force, 173.4 ± 3.2 vs 171.5 ± 4.6 N). Thirty days after implantation, significantly (P < .01) smaller inflammatory reactions (392 vs 15 macrophages/mm2 and 874 vs 167 T lymphocytes/mm2) and P-selectin expressions (1/6 vs 6/6) were observed in both the xenograft and allograft models with bioengineered matrices compared with those seen with control tracheas. There was no development of anti-pig leukocyte antigen antibodies or increase in both IgM and IgG content in mice implanted with bioengineered tracheas.ConclusionsBioengineered tracheal matrices displayed similar structural and mechanical characteristics to native tracheas and excite no immune response to 30 days when implanted as allografts or xenografts. This method holds great promise for the future of tissue-engineered airway replacement.

Chronic thromboembolic pulmonary hypertension (CTEPH), which has a natural history with low long-term survival, is increasingly being diagnosed. Pulmonary endarterectomy (PE) is the treatment of choice, which can be curative. This technique consists of a true endarterectomy through a midline sternotomy with extracorporeal circulation and periods of hypothermic circulatory arrest. The following procedures should be performed before surgery: transesophageal echocardiogram, ventilation-perfusion pulmonary scintigraphy, right cardiac catheterism, pulmonary angiography and helicoidal computed tomography. Surgery should be indicated in CTEPH as soon as the diagnosis is made, before arteriopathy develops in the non-obstructed regions and CTEPH becomes severe. The only absolute contraindication to PE is the presence of obstructive or restrictive, severe underlying pulmonary disease. There are no inaccessible grades of embolic obstruction, or grade of right ventricular failure or level of pulmonary vascular resistance (PVR) that are inoperable. However, prognosis worsens with greater preoperative pulmonary pressure and greater postoperative PVR. Mortality in PE is 4-10% and the main cause of postoperative death is the persistence of high pulmonary pressures and PVR, followed by reperfusion edema, which requires prolongation of mechanical ventilation, the use of pulmonary vasodilators and, sometimes, extracorporeal respiratory support. In the long-term, 75% of patients undergoing PE show good functional results and half recover adequate exercise tolerance. Pulmonary transplantation is an alternative for patients unsuitable for PE, although with worse results and greater mortality.

Background The purpose of this study was to evaluate the long-term clinical and immunologic outcome of cryopreserved arterial allograft (CAA) revascularization of intrathoracic vessels invaded by malignancies. Methods Since January 2002, consecutive patients whose intrathoracic vessels were invaded by malignancies were operated on and revascularizion made using human lymphocyte antigen (HLA)– and ABO-mismatched CAAs. Immunologic studies were performed preoperatively, and 1, 3, 6, 12, and 24 months postoperatively. Postoperative oral anticoagulation therapy was not given. Results Twenty-six patients aged 53.1 ± 15 years with a nonsmall-cell lung cancer (n = 10), invasive mediastinal tumors (n = 7), pulmonary artery sarcoma (n = 3), laryngeal (n = 2), or other rare lung neoplasms (n = 4) underwent operation. Cardiopulmonary bypass was used in 10 cases (38%), and all resections were pathologically complete. Revascularization was either for venous (n = 12) or arterial (n = 14) vessels, and a total of 30 allografts revascularized the superior vena cava (n = 6), pulmonary artery (n = 7), innominate vein (n = 3) or artery (n = 2), ascendent (n = 4) or descending (n = 1) aorta, and subclavian vein (n = 3) or artery (n = 4). Hospital morbidity and mortality were 50% (n = 13) and 3.8% (n = 1), respectively, all CAA unrelated. With a median follow-up of 18 months (range, 3 to 60+), 5-year survival and allograft patency were 84% and 95%, respectively. Preoperative anti-HLA antibodies were detected in 2 patients (7.7%) and a postoperative anti-HLA antibody response, clinically irrelevant, in 1 of 24 patients (4%). Conclusions Revascularization of intrathoracic venous and arterial vessels in patients with malignancies using HLA- and ABO-mismatched CAA is technically feasible and clinically attractive because of no infection risk and postoperative anticoagulation, and excellent long-term survival, patency, and nonimmunogeneicity.

A small experimental animal model of postobstructive pulmonary hypertension (PH) providing insights in the physiopathology of this disease was developed.Male Lewis rats were anesthetized and aleatory manipulated via a left thoracotomy with (group I, n = 10) or without (group II, n = 10) ligation of the left pulmonary artery. Animals were followed for 2 weeks and then sacrificed. Hemodynamic parameters and blood gases were recorded at baseline and 2 weeks after surgical procedure.Group I animals developed a significant (P0.01) PH (mean pulmonary artery pressure, 32 +/- 6 versus 16 +/- 2 mm Hg; pulmonary vascular resistance, 46 +/- 3 versus 21 +/- 2 mm Hg/mL/min; reduction of cardiac output, 75 +/- 3 versus 105 +/- 4 mL/min), compared to group II animals, and had a significant (P0.01) worse gas exchange (partial arterial pressure of O(2): 91 +/- 3 versus 439 +/- 24 mm Hg; partial arterial pressure of CO(2): 54 +/- 3 versus 42 +/- 2 mm Hg, on a fraction of inspired oxygen of 1.0), right ventricle hypertrophy (ventricle to left ventricle/septum ratio, 0.56 +/- 0.04 versus 0.45 +/- 0.04, P0.02) and less tolerance test (immobility time, 123 +/- 11 versus 61 +/- 8 s, P0.01) than group II animals. Histologically, ligated lungs showed postobstructive pulmonary vasculopathic abnormalities and bronchial-pulmonary artery hypertrophy, and the contralateral lung had initial signs of small vessel arteriopathy.The experimental model generated here successfully reproduced a PH morphologically and functionally similar to clinical postembolic PH and might be used for evaluating the physiopathology of postobstructive PH.

The purpose of this study was to evaluate the feasibility of integrating an artificial, pumpless extracorporeal membrane ventilator (Novalung) to near static mechanical ventilation and its efficacy in patients with severe postresectional acute respiratory distress syndrome (ARDS) unresponsive to optimal conventional treatment.Indications were severe postresectional and unresponsive acute respiratory distress syndrome, hemodynamic stability, and no significant peripheral arterial occlusive disease or heparin-induced thrombocytopenia. Management included placement of the arteriovenous femoral transcutaneous interventional lung-assist membrane ventilator, lung rest at minimal mechanical ventilator settings, and optimization of systemic oxygen consumption and delivery.Among 239 pulmonary resections performed between 2005 and 2006, 7 patients (2.9%) experienced, 4 +/- 0.8 days after 5 pneumonectomies and 2 lobectomies, a severe (Murray score, 2.9 +/- 0.3) acute respiratory distress syndrome unresponsive to 4 +/- 2 days of conventional therapy. The interventional lung-assist membrane ventilator was left in place 4.3 +/- 2.5 days, and replaced only once for massive clotting. During this time, 29% +/- 0.3% or 1.4 +/- 0.36 L/min of the cardiac output perfused the device, without hemodynamic impairment. Using a sweep gas flow of 10.7 +/- 3.8 L/min, the device allowed an extracorporeal carbon dioxide removal of 255 +/- 31 mL/min, lung(s) rest (tidal volume, 2.7 +/- 0.8 mL/kg; respiratory rate, 6 +/- 2 beats/min; fraction of inspired oxygen, 0.5 +/- 0.1), early (24 hours) significant improvement of respiratory function, and reduction of plasmatic interleukin-6 levels (p0.001) and Murray score (1.25 +/- 0.1; p0.003). All but 1 patient (14%) who died of multiorgan failure were weaned from mechanical ventilation 8 +/- 3 days after removal of the interventional lung-assist membrane ventilator, and all of them were discharged from the hospital.The integration of this device to near static mechanical ventilation of the residual native lung(s) is feasible and highly effective in patients with severe and unresponsive acute respiratory distress syndrome after pulmonary resection.

Primary tumours of the trachea can be benign or malignant and account for fewer than 0.1% of tumours. However, they are a diagnostic and therapeutic challenge. Benign tumours are usually misdiagnosed as asthma or chronic lung disease, and can delay diagnosis for months or years. Because of their rapid growth and onset of haemoptysis, malignant tumours are often diagnosed earlier than benign tumours and patients thus often present with locally advanced disease. Inappropriate treatment is an equally frustrating issue. Modern techniques for tracheal surgery-laryngotracheal, tracheal, or carinal resection-combined with radiotherapy, can be offered curatively with low perioperative risks. Nevertheless, the low numbers of patients undergoing resection and the associated poor survival in epidemiological studies over the past two decades have shown that surgery is rarely considered outside referral centres, with radiotherapy or another form of local treatment (eg, endotracheal stents, debridement, brachytherapy) generally preferred. The liberal use of these other techniques should be avoided because surgery has the potential to cure all patients with benign and low-grade tumours and most patients with malignant primary tracheal tumours, and other techniques are usually palliative at best.

Objective We sought to grow in vitro functional smooth muscle cells, chondrocytes, and respiratory epithelium on a biologic, directly vascularized matrix as a scaffold for tracheal tissue engineering. Methods Ten- to 15-cm–long free jejunal segments with their own vascular pedicle were harvested and acellularized from donor pigs (n = 10) and used as a vascular matrix. Autologous costal chondrocytes, smooth muscle cells, and respiratory epithelium and endothelial progenitor cells were first cultured in vitro and then disseminated on the previously acellularized vascular matrix. Histologic, immunohistologic, molecular imaging, and Western blotting studies were then performed to assess cell viability. Results The endothelial progenitor cells re-endothelialized the matrix to such an extent that endothelial cell viability was uniformly documented through 2-(18F)-fluoro-2′-deoxyglucose positron emission tomography. This vascularized scaffold was seeded with functional (according to Western blot analysis) smooth muscle cells and successfully reseeded with viable ciliated respiratory epithelium. Chondrocyte growth and production of extracellular cartilaginous matrix was observed as soon as 2 weeks after their culture. Conclusions The fundamental elements for a bioartificial trachea were successfully engineered in vitro in a direct vascularized 10- to 15-cm–long bioartificial matrix. Future experimental work will be directed to give them a 3-dimensional aspect and a biomechanical profile of a functioning trachea.

Recent anesthetic and surgical advances have remarkably reduced the frequency of airway complications after tracheobronchial resections, yet the end-to-side reimplantation of a main, lobar, or intermedius bronchus onto the trachea or the side of the contralateral main bronchus still represents a major technical challenge with high anastomotic morbidity and procedure-related mortality.1 We present the results of a simplified anastomotic technique for end-to-side reimplantation of the lobar or intermedius bronchus onto the trachea or contralateral main bronchus after extensive bronchial sleeve resections or carinal lobectomy.

Objective: We describe a Pearson-type technique and evaluate its results for postintubation subglottic stenosis. Methods: Forty-five patients underwent a partial cricoidectomy with primary thyrotracheal anastomosis, and 5 underwent simultaneous repair of a tracheoesophageal fistula as well. Twenty-four (53%) patients were referred to us after initial conservative (n = 21) or operative (n = 3) management. There were 27 cuff lesions, 7 stomal lesions, and 11 at both levels. The upper limit of the stenosis was 1.5 cm (range, 1-2.5 cm) below the cords, and the subglottic diameter was reduced by 60% in 38 (84%) of the patients. The length of airway resection ranged from 2 to 6 cm (median, 3 cm). Despite 23 thyrohyoid or suprahyoid releases, 8 anastomoses were under tension. Results: Thirty-seven (82%) patients were extubated after the operation (n = 30) or within 24 hours (n = 7). Six patients required postoperative airway stenting (median, 5.5 days). Early (

Objective: This retrospective study was designed to confirm that aggressive pulmonary resection can provide effective long-term palliation of disease for patients with pulmonary aspergilloma. Methods and results: From 1959 to 1998, 84 patients underwent a total of 90 operations for treatment of pulmonary aspergilloma in the Marie-Lannelongue Hospital. The mean follow-up period was 9 years, and 83% of the patients were followed up for 5 years or until death, if the latter occurred earlier. The median age was 44 years. The most common indications were hemoptysis (66%) and sputum production (15%). Fifteen patients (18%) had no symptoms. Tuberculosis and lung abscess were the most common underlying causes of lung disease (65%). The procedures were 70 lobar or segmental resections, 8 cavernostomies, and 7 pneumonectomies. Five thoracoplasties were required after lobectomy (3 patients) or pneumonectomy (2 patients). The operative mortality rate was 4%. The major complications were bleeding (23 patients), prolonged air leak (31 patients), respiratory failure (10 patients), and empyema (5 patients). The actuarial survival curve showed 84% survival at 5 years and 74% survival at 10 years. During the first 2 years, death was related to the surgical procedure and the underlying disease. In contrast, 85% of the survivors had a good late result. Conclusion: Lobar resection in both the symptomatic and the asymptomatic patients was conducted in low-risk settings. For patients whose condition is unfit for pulmonary resection, cavernostomy may need to be undertaken despite the high operative risk. The better survival rate in this study may have been due to the selection of patients with better lung function and localized pulmonary disease. (J Thorac Cardiovasc Surg 2000;119:906-12)

Objective: We evaluated the outcome of different surgical techniques for postintubation tracheoesophageal fistula. Methods: Thirty-two consecutive patients aged 51 ± 23 years had tracheoesophageal fistulas resulting from a median of 30 days of mechanical ventilation via endotracheal (n = 12) or tracheostomy (n = 20) tubes. Tracheoesophageal fistulas were 2.5 ± 1.2 cm long and were associated with a tracheal (n = 10) or subglottic (n = 3) stenosis in 13 patients. Results: All but 3 patients were weaned from respirators before repair. All operations were done through cervical incisions and included direct division and closure (n = 9), esophageal diversion (n = 3), muscle interposition (n = 6), or, more recently, tracheal or laryngotracheal resection and anastomosis with primary esophageal closure (n = 14). Nine thyrohyoid and two supralaryngeal releases reduced anastomotic tension. Twenty-three patients (74%) were extubated after the operation (n = 16) or within 24 hours (n = 7), and 7 required a temporary tracheotomy tube. One postoperative death (3%) was associated with recurrent tracheoesophageal fistula. Seven complications (22%) included recurrent tracheoesophageal fistula (n = 1), delayed tracheal stenosis (n = 2), dysphagia (n = 2), and recurrent nerve palsy (n = 2). Complications necessitated reoperation (n = 1), dilation (n = 2), definitive tracheostomy (n = 1), Montgomery T tubes (n = 1), and Teflon injection of the vocal cords (n = 1). Twenty-nine patients (93%) had excellent (n = 24) or good (n = 5) anatomic and functional long-term results. Complications have been less common (7% vs 38%) and long-term results better (93% vs 65%) recently with tracheal or laryngotracheal resection and anastomosis with primary esophageal closure as compared with previous procedures. Conclusions: Postintubation tracheoesophageal fistula is usually best treated with tracheal or laryngotracheal resection and anastomosis with primary esophageal closure even in the absence of tracheal damage. (J Thorac Cardiovasc Surg 2000;119:268-76)

A 47-year-old man was admitted with recurrent autolimited bleeding arising from a cervical tracheostoma made 2 years earlier during a total laryngectomy. Stomal recurrence of the past laryngeal cancer invading the neighboring innominate artery was diagnosed by angiographic computer tomography and bronchoscopic biopsies. The malignant tracheostoma-innominate fistula was approached through an extended transversal supraclavicular incision, bilateral hemiclaviculectomy, and manubriectomy. It was treated with an anterior mediastinal tracheostomy with omental major transposition, right latissimus dorsi myocutaneous flap for tissue coverage, and brachiocephalic artery rerouting with cadaveric homograft. The patient was discharged on postoperative day 14 after an uneventful postoperative course.

Resume La principale cause d'echec des thrombo-endarteriectomies pulmonaires est l'insuffisance de la desobstruction des branches distales des arteres pulmonaires. Le but de cette etude est de souligner l'interet de l'angioscopie videoassistee comme aide a une endarteriectomie plus etendue et plus efficace. L'intervention est faite par sternotomie mediane, sous circulation extracorporelle en hypothermie profonde, et la dissection est limitee a la mobilisation totale de la veine cave superieure. L'endarteriectomie, toujours bilaterale, est faite a travers une arteriotomie longitudinale des arteres pulmonaires droite et gauche. Un endoscope rigide de 5 mm de diametre, introduit dans l'artere pulmonaire, guide l'endarteriectomie des branches les plus distales inaccessibles a la vue. De janvier 1996 a decembre 1997, 48 patients atteints d'hypertension arterielle pulmonaire postembolique grave sur le plan fonctionnel (deux stade II de la NYHA, 28 stade III et 18 stade IV) et sur le plan hemodynamique (pression arterielle pulmonaire moyenne: 53 ± 13 mmHg, index cardiaque: 2,16 ± 0,5 L/min/m 2 , resistances vasculaires pulmonaires totales: 1152 ± 414 dynes·s −1 ·cm 5 ) ont beneficie de cette intervention. Dans les suites operatoires, six patients sont decedes: quatre du fait d'une endarteriectomie insuffisante, un par hemorragie alveolaire et un par arret cardiaque hypoxique. Les 42 patients vivants ont eu une amelioration significative des parametres hemodynamiques (pression arterielle pulmonaire moyenne: 30 ± 9 mmHg, index cardiaque: 2,78 ± 0,5 L/min/m 2 , resistances vasculaires pulmonaires totales: 484 ± 159 dynes·s −1 cm 5 ). Quarante patients ont eu un excellent resultat fonctionnel postoperatoire (24 stade I et 16 stade II). Deux patients n'ont pas ete ameliores et sont restes au stade III, l'un d'eux est en attente de transplantation. La videoangioscopie a permis d'ameliorer la qualite de la thromboendarteriectomie et d'elargir les indications de cette chirurgie restauratrice aux patients les plus graves qui etaient auparavant candidats a une transplantation cardiopulmonaire.

Objective: Our objective was to study lung hyperacute rejection in the pig-to-human xenotransplantation combination. Methods: Pig lungs were harvested and continuously ventilated and perfused ex vivo, using a neonatal oxygenating system, with either xenogeneic unmodified human blood ( n = 6) or autogeneic pig blood ( n = 6). Results: Autoperfused lungs displayed normal hemodynamics, oxygen extraction (arteriovenous oxygen difference), and histologic characteristics throughout the 3-hour study period. By contrast, xenoperfused lungs displayed, within 30 minutes, severe pulmonary hypertension and abolishment of arteriovenous oxygen difference culminating in massive pulmonary edema, hemorrhage, and lung failure after 115 ± 44.2 minutes of reperfusion. Within 30 minutes, the human blood showed a significant drop of anti-αGal immunoglobulin M and G xenoreactive antibodies (enzyme-linked immunosorbent assay) and complement activity, consumption of clotting factors, and hemolysis; total circulating human immunoglobulins remained substantially normal. Histologically, lungs perfused with human blood were congestive and showed alveolar edema and hemorrhage and multiple fibrin and platelet thrombi obstructing the small pulmonary vessels (arterioles, capillaries, and venules) but not large (segmental or lobar) pulmonary vessels. On immunohistologic examination, deposits of human immunoglobulin M and (C1q and C3) proteins were observed on the alveolar capillaries. Conclusions: This pig-to-human xenograft model suggests that the pig lung perfused with human blood has an early and violent hyperacute rejection that results in irreversible pulmonary dysfunction and failure within approximately 150 minutes of reperfusion. (J Thorac Cardiovasc Surg 1997;114: 315-25)

Objective: Our goal was to investigate the effects of slide tracheoplasty on tracheal growth in newborn piglets. Methods: Slide tracheoplasty was performed on normal trachea (n = 6) and a model of tracheal stenosis resembling that seen in infants (n = 6). After division of the trachea at its midportion between the second cartilaginous ring above and the right upper lobe takeoff below (around 23 rings), the proximal and distal segments were incised vertically on opposite anterior and posterior surfaces and reconstructed together. Results: The reconstructed tracheas lengthed and their cross-sectional areas enlarged linearly at a rate of 0.94 cm per month and 1.55 mm2/kg, respectively, as the piglets grew over a 6-month period from 4.7 ± 0.6 to 64.4 ± 5.7 kg (± standard deviation). Growth was not different between the two studied groups. There was no narrowing or late restenosis. The mean anastomotic cross-sectional area was overall 1.63 ± 0.28 times larger (range 1.2 to 2.7) than the cross-sectional area of the unreconstructed trachea. When the animals were put to death, all tracheal lumina were completely lined with normal respiratory epithelium and all layers were histologically intact; anastomotic trachealis muscles contracted less (p < 0.001) but relaxed similarly to those muscles lining normal tracheas. Tracheal blood supply was macroscopically and microscopically normal in both groups; however, newborn piglets had an almost twofold increased number of intramural capillary vessels as opposed to adult pigs (p < 0.001). Conclusions: Results suggest that slide tracheoplasty is not limited by the length of stenosis, provides a permanent enlargement of the cross-sectional airway diameter, does not compromise tracheal vascular supply, and does not impair tracheal growth as somatic growth continues. (J Thorac Cardiovasc Surg 1997;113:558-66)

Background. Our objective was to study the maximal preservation time of directly revascularized tracheal allografts in immunosuppressed piglets. Methods. Donor grafts were flushed with Euro-Collins solution (65 mL/kg at 4°C) by simultaneous inferior thyroid artery and bronchial artery perfusion through a 15-cm aortic segment and heterotopically implanted on their own vascular pedicle after 3 (group 1), 6 (group 2), 15 (group 3), and 24 (group 4) hours of static storage in Euro-Collins solution at 4°C (n = 5 each). The animals were observed for 4 weeks after transplantation and then sacrificed. Histologic evaluation of the tracheal allografts was routinely done using specimens from open biopsies. Results. The overall length of tracheal grafts was 12.4 ± 0.6 cm, and this variable was not significantly different between the four groups. Graft exocrine (mucous secretion) function began 1.3 ± 0.5 days after transplantation in groups 1 through 3 but was absent in all group 4 grafts ( p p p Conclusions. These results demonstrate that tracheal allografts may be safely preserved for as long as 15 hours and that longer periods of ischemia are likely to result in irreversible allograft damage.

coding the human or species specific NIS genes. NIS function in transduced MSC was first validated in vitro; NIS expressing MSC (MSC_NIS) from multiple species concentrated high levels of I-125 with no side effects. The sensitivity of cell detection was determined by transplanting a known number of MSC_NIS subcutaneously into mice. We can reliably detect 2x105 MSC_NIS in mice using the newly acquired U-SPECT II machine. Canine MSC derived from the bone marrow were surprisingly robust; viable cells were still detected (albeit lower numbers) at day 28 in the athymic mice. In contrast, NIS signals from adipose tissue derived rat or human MSC disappeared by day 7 post transplantation. Using PET imaging and F18-TFB, sensitivity of imaging could be significantly improved to detect lower numbers of cells. We are currently evaluating the use of NIS for tracking natural killer cells and transplanted hemapoietic stem cells and results will be presented.

We investigated the impact of new biological prognostic factors is in 28 patients receiving a median of two courses of cisplatin-based chemotherapy with (n = 14) or without (n = 14) radiation and operation for stage IIIB (T4) non-small cell lung cancer (NSCLC). After induction therapy, 5 patients had a complete and 21 a partial response; 2 had a stable disease. A complete resection was made in 26 patients (93%). Five patients (18%) had their primary tumour and involved vestiges completely sterilized. In the remaining 23, the majority of the tumours showed abnormalities in the p53 gene expression (56%), harboured proliferating cells (91%) and induced angiogenesis (91%). Peritumoural blood and lymphatic vessel invasion (PBLVI) by tumour emboli was observed in 6 tumours. With a median follow-up of 25 months, overall 3-year survival was 48%; disease-free survival (DFS) has not been reached yet. The only significant factor influencing DFS in multivariate analysis was PBLVI by tumour cells; PBLVI-positive patients had a significantly higher likelihood ratio (P = 0.000001) of developing metastasis than their PBLVI-negative counterparts. This study documents the prognostic implication of PBLVI by tumour cells in T4 NSCLC.

Individuals with long-lasting ankylosing spondylitis (AS, Bechterew disease) are at increased risk for developing fractures as the fused spine often becomes osteoporotic. These bony protuberances may compress all elements lying in front of them and induce a soft-tissue inflammation to the extent that it causes irreversible dysphagia, especially at the level of the cervical spine. We describe here the decompression of the entire visceral mass of the median thoracic aperture by a simple manubriectomy in an AS patient with refractory dyspnea and dysphagia.

A macrosurgical technique of thyrotracheal harvesting and direct revascularization with and without venous drainage in a heterotopic thyrotracheal and immunosuppressed allograft in the pig model is described. Harvesting included en bloc cervicothoracic exenteration of the aortic arch and its supraortic trunks, anterior vena cava, jugular veins, subclavian vessels, thyroid gland, cervicothoracic trachea, and esophagus. This technique conserves the tracheal arterial supply provided by either the right or left subclavian artery, directly or indirectly via the inferior thyroid artery, and venous return provided by the anterior vena cava, directly or indirectly via the descending cervical vein. In recipients, implantation included (1) arterial end-to-end anastomoses of the proximal and postscalenic stumps of donor's subclavian artery to the proximal and prescalenic stumps of recipient's subclavian artery; (2) end-toside venous anastomosis of the donor's anterior vena cava to the recipient's brachiocephalic venous trunk; and (3) heterotopic implantation of the proximal and distal orifices of the grafted trachea into the neck. Ten adult Large White pigs underwent direct revascularization of a thyrotracheal allograft with ( n = 6, group 1) and without ( n = 4, group 2) venous drainage. All grafts of group 2 exhibited a venous infarction, extensive inferior thyroid artery thrombosis, and ischemic and suppurative thyrotracheal necrosis 1 to 2 days after transplantation. In group 1, the length of the grafted trachea and number of rings were 9.75 + 1.5 cm and 22.1 ± 3.3, respectively; ischemic time was 236.3 ± 338.3 minutes. Group 1 pigs were put to death 4 ( n = 4) and 3 ( n = 2) weeks after transplantation. All tracheal grafts had histologically normal airway epithelium; isolated areas of necrotic ischemia of the chorion and submucosa lasted for the first 7 days after transplantation but disappeared after epithelial regeneration. Premortem angiograms showed that all vascular anastomoses were patent. Grafts were histologically normal at postmortem examinations and all but one had no rejection. This large animal model demonstrates that long tracheal allografts might be transplanted by means of this direct revascularization and venous drainage technique.

En bloc double lung transplantation with bilateral bronchial anastomoses was successfully performed in three patients with complete situs inversus and end-stage Kartagener's syndrome. Dextrocardia was not a technical problem for institution of cardiopulmonary bypass, but a large azygos vein draining the systemic venous return was systematically preserved. The major technical difficulty was restoration of airway continuity, because patients with situs inversus have an inverse direction and length of the main stem bronchi. The right and left main bronchi of the recipients were approached in the aortocaval sinus and transected approximately at 1.5 cm from the carina. The donor right main stem bronchus was divided at its origin and the donor left main stem bronchus was divided proximal to the upper lobe takeoff. The different bronchial angulation was not an obstacle, and airway continuity was reestablished twice with an end-to-end anastomosis and once with a telescopic technique. Because of the midline position of the left atrium and pulmonary artery, the anastomoses with the respective recipient's structures were made as in patients with situs solitus. One patient required a right lower lobectomy because the position of the right side of the heart interfered with lobar expansion. One patient died of obliterative bronchiolitis 36 months after the operation. The remaining two are alive and doing well after 48 and 6 months, respectively. (J THORAC CARDIOVASC SURG 1994;108:86-91)

We have attempted to identify a biologic rationale for the local aggressiveness and late treatment failure of rejected non-small cell lung cancer involving the thoracic inlet. Tumor specimens from 28 patients who underwent a new transcervical approach were analyzed for the expression of tumor proliferative activity, suppressor-gene p53, intranimoral and peritumoral blood vessel invasion by tumor cells, the presence and degree of angiogenesis (induction of new capillaries and venules), and other biologic variables. Eighty-nine percent of the neoplasms were moderately or poorly differentiated, 89% expressed either an intermediate or high proliferate activity, 39% showed p53 aberrations, 71% exhibited induction of angiogenesis, and 39% had tumors that were positive for blood vessel invasion. With a median follow-up time of 3.5 years (range, 8 to 145+ months), the overall projected 5-year survival was 29% and the median disease-free interval was 23 months. Results of univariate and multivariate analysis of survival and the disease-free interval identified the degree of angiogenesis (density less than 1 versus more than 1 and number of neovessels less than 6 versus more than 6) as the only independent and significant predictors of the disease-free interval. Patients whose tumor showed a density of angiogenesis of 1 or greater and a number of neovessels of 6 or greater faced a significantly ( p = 0.0001) higher relative risk of suffering systemic recurrence of their primary tumor than did their low-risk counterparts. Results demonstrate that angiogenesis significantly correlates with late treatment failure (metastasis), and this is acquired at a critical density and number of vessels.

Despite the development of several lung transplantation procedures, the most advantageous for pulmonary hypertension remains controversial. Between 1986 and February 1992, 30 patients with end-stage primary pulmonary hypertension (n = 24), chronic pulmonary embolism (n = 4), and hystiocytosis X (n = 2) underwent heart-lung (n = 21), double lung (n = 8), or single lung (n = 1) transplantation. Indications for double lung transplantation were similar to those for heart-lung transplantation, and the preoperative clinical and hemodynamic parameters were not significantly different between the two groups. There were no intraoperative deaths, but two reoperations were needed for pleural hematoma. Five early deaths were related to graft failure (two heart-lung transplantations), mediastinitis (one heart-lung transplantation), multiorgan failure (one double lung transplantation), and aspergillosis (one double lung transplantation). There was a similar improvement in early (days 0 and 2) and late (6 months postoperatively) right-sided hemodynamic function in patients undergoing heart-lung and double lung transplantation. Three double lung transplant recipients had early and reversible left ventricular-failure. The early postoperative course of the one patient who had single lung transplantation was characterized by severe pulmonary edema, left ventricular failure, and persistent desaturation and later on by moderate pulmonary hypertension and an important ventilation/perfusion mismatch. The pulmonary function results were also similar in the heart-lung and double lung transplantation groups. The overall projected 2- and 4-year survivals were 49% and 41%, respectively, and were not significantly different between the heart-lung and double lung recipients. Results demonstrate that heart-lung and double lung transplantation are equally effective in obtaining early and durable right-sided hemodynamic and respiratory improvement and similar respiratory function. In patients with pulmonary hypertension, double lung transplantation should be preferred to single lung transplantation because of the critical postoperative course and the uncertain long-term results of single lung transplantation.

We describe an original anterior transcervical-thoracic approach required for a safe exposure and radical resection of non-small-cell lung cancer that has invaded the cervical structures of the thoracic inlet. Through a large L-shaped anterior cervical incision, after the removal of the internal half of the clavicle, the following steps may be performed: (1) dissection or resection of the subclavian vein; (2) section of the anterior scalenus muscle and resection of the cervical portion of the phrenic nerve, if invaded; (3) exposure of the subclavian and vertebral arteries; (4) dissection of the brachial plexus up to the spinal foramen; (5) section of invaded ribs; and (6) en bloc removal of chest wall and lung tumor, either directly or through an extension of the cervical incision into the deltopectoral groove. An additional posterior thoracotomy may be required for resection of the chest wall below the second rib. Between 1980 and 1991, 29 patients underwent radical en bloc resection of the inlet tumor, chest wall (ribs 1 and 2), and underlying lung, either through the anterior transcervical approach alone (n = 9) or with an additional posterior thoracotomy (n = 20). The inferior root of the brachial plexus, either alone (n = 11) or with the phrenic nerve (n = 4), was involved and resected in 15 patients (52%). Twelve patients (41%) had a vascular involvement that included the subclavian artery alone (n = 3); subclavian artery and subclavian vein (n = 3); subclavian artery, subclavian vein, and vertebral artery (n = 2); subclavian artery and vertebral artery (n = 1); subclavian vein alone (n = 1); vertebral artery alone (n = 1), or subclavian artery and vertebral artery (n = 1). The subclavian artery was revascularized either with a prosthetic replacement (n = 7) or an end-to-end anastomosis (n = 2), and the median graft patency was 18.5 months (range, 6 to more than 73 months); only 1 patient had postradiotherapy graft occlusion in the revascularized artery 6 months after operation. We performed 14 wedge resections, 14 lobectomies, and 1 pneumonectomy. There were no operative or hospital deaths. Postoperative radiotherapy (median, 56 Gy) was given to 25 (86%) patients, either alone (n = 14) or in combination with adjuvant systemic chemotherapy (n = 11). With a median follow-up time of 2.5 years, overall 2- and 5-year survivals were 50% and 31%, respectively. This transcervical-thoracic approach affords a safe exposure and radical resection of non-small-cell lung cancer involving the thoracic inlet and results in encouraging long-term survival.

Although primary or metastatic nonbrondiogenic tumors infrequently arise in or involve the thoracic outlet, they represent a major surgical challenge because of their tendency to encapsulate outlet structures. Fourteen patients with a histologically proven primary (n = 8) or metastatic (n = 6) nonbronchogenic outlet tumor were treated by an anterior transcervical approach, including an L-shaped cervicotomy extended into the deltopectoral groove, resection of the internal half of the clavicle, and, in the case of tumor involvement, resection of the jugular and subclavian veins, phrenic nerve, subclavian artery, brachial plexus, and ribs. All patients underwent a radical resection. Tumors extended to bony (usually the first rib), muscular (usually the anterior scalenus muscle), and nerve (usually the phrenic nerve) outlet structures in 8,10, and 7 patients, respectively, Ten patients had involvement of outlet vessels: 6 had simple ligature (n = 5) or wedge resection (n = 1) of the subclavian vein and related branches, 1 had revascularization of both the subclavian vein by an end-to-end anastomosis and the subclavian artery by a ringed polytetrafluoroethylene graft, 1 had revascularization of the subclavian artery alone, and 2 had revascularization between the left brachiocephalic vein and superior vena cava (ringed polytetrafluoroethylene graft). Follow-up venograms showed complete patency of the anastomoses. There was one postoperative death (7%) due to multiorgan system failure. Other complications were mild and short-lasting. With a median follow-up of 3.4 years, all patients but 1 (who had systemic progression) are alive and disease free 3 to 127 months postoperatively. Radical resection of primary or metastatic nonbronchogenic outlet tumors and encouraging long-term survival can be achieved using the technique presented.

S egmentectomy has been recommended as the surgical standard for the management of isolated, large pulmonary arteriovenous (AV) fistula, with minimal morbidity and mortality and low recurrence rates. However, segmentectomy removes some normal lung parenchyma,1 and this may contribute to an increase in postoperative pulmonary vascular resistance.2 We describe a lung-saving operation including a simple fistulectomy for an isolated, large pulmonary AV fistula.

Tracheoesophageal fistulas resulting from a Mycobacterium tuberculosis infection are uncommon. We describe a patient with such a lesion that had the radiologic and clinic appearance of a malignant tracheoesophageal fistula. Use of an anterior cervical approach with one-stage esophageal repair along with tracheal resection and anastomosis allowed definitive diagnosis and treatment of this life-threatening complication.

Adapting a silicone tracheal safe T-tube is a simple method to guarantee upper airway permeability. Its making and availability ease offers a cheap and valid option to avoid the complications of the tracheostomy tube.