Surgery for Non-Neoplastic Disorders of the Chest: a Clinical Update

Lung and heart-lung transplantations are now considered as effective treatment for highly selected patients with end-stage lung or heart-lung disease. Although the survival rates have improved dramatically in recent years, the development of chronic rejection is still the major cause of late death after transplantation. Histologically chronic rejection is manifested by bronchiolitis obliterans (BO), with a gradual decline in pulmonary function tests and quality of life, eventually leading to respiratory insufficiency and recurrent infections with Gram-negative bacteria and fungi. A lot of research efforts have been put into the detection of possible risk factors for BO and unravelling the pathophysiology of BO. Several key cytokines and growth factors have now been identified. Since the histological diagnosis of chronic rejection remains difficult, a clinical grading system has been proposed, determined as bronchiolitis obliterans syndrome, divided into four, and more recently, five categories, depending on the severity of airflow obstruction. This chapter aims to review the current knowledge on the pathology, the aetiology (e.g. risk factors) and the pathophysiology of chronic rejection after heart-lung and lung transplantation.

Infection and chronic rejection are the major causes of mortality and morbidity in lung allografts. The host for lung transplantation is frequently colonised with multiresistant bacterial organisms as a consequence of their primary disease; therefore, irrespective of immunosuppression, the host is at risk of infection. The cytomegolavirus appears to be an important risk factor for fungal and bacterial super infection, and possibly for acute vascular rejection, which in themselves may all contribute to the risk of bronchiolitis obliterans syndrome (BOS). The precise role of bacterial infection in the development of BOS remains unclear; much of this relates to a current lack of standardisation of the definition of infection.

Ischaemia-reperfusion-induced lung Injury (IRI) remains an important problem after lung transplantation occurring in 10–20% of the recipients with a significant impact on clinical outcome. IRI has been identified as the main cause of primary graft failure resulting in a post-transplant mortality of 2–5%. This syndrome occurs within 72 h after transplantation and is characterised by impaired gas exchange, fluid loss via endotracheal tube and chest drains, pulmonary infiltrates on chest radiographs, elevated pulmonary vascular resistance, decreased pulmonary compliance, and diffuse alveolar damage on biopsy. Risk factors that have been identified are related to the donor, the preservation, the transplant procedure, and the recipient. Better understanding of the complex pathophysiological mechanism of this insult has marked the last decade. A myriad of molecular and cellular events occurs during ischaemia and reperfusion resulting in endothelial and epithelial cell dysfunction. This knowledge has resulted in new strategies to prevent and to treat IRI although randomised clinical trials to demonstrate an improvement are often lacking. Most publications are limited to personal experience and case series.

After more than 10 yrs of research, extra-cellular type preservation solutions such as low-potassium dextran glucose or Perfadex® and Celsior® have now been introduced, clinically replacing the intra-cellular type solutions such as modified EC and UW. This has resulted in an improved initial graft function and an improved early outcome. The technique of retrograde flush, where the preservation solution is administered via the left atrial appendage or via the pulmonary veins and drained through the pulmonary artery, is another strategy applied by many transplant teams nowadays. Most surgeons have adopted a technique of controlled reperfusion by slowly releasing the pulmonary artery clamp in order to gradually increase blood flow through the cold graft over a 10‐min period. Initial reperfusion with leukocyte-filtered blood, mixed with a crystalloid solution, has also been reported to be beneficial. Controlled ventilation with a low tidal volume or ventilation delayed until the cold graft has re-warmed (32°C) after the onset of reperfusion, may also be important.

Inhaled nitric oxide has been useful, clinically, to treat established IRI because it can improve ventilation/perfusion mismatch and decrease pulmonary artery pressures without affecting systemic pressures. On the basis of experimental evidence, some centres routinely use an infusion of prostaglandin (PG)E₁ during the postoperative period after lung transplantation, whereas others reserve PGE₁ infusion for the treatment of severe IRI. Experimental studies have found that exogenous surfactant-therapy can improve pulmonary function after lung transplantation, especially when given already in the donor. In cases of life threatening reperfusion oedema, the use of extracorporeal membrane oxygenation (ECMO) has been described as a successful, but ultimate treatment strategy. Weaning of the ECMO support is possible in 60–80% of the patients. In other patients, ECMO may ultimately serve as a bridge to retransplantation. However, this final option for early graft failure is controversial because of the poor results and should,therefore, be very restricted.

Surgical treatment of emphysema was designed to improve subjective dyspnoea, respiratory function and quality of life in severely disabled patients. Three surgical options are currently employed, namely bullectomy, lung volume reduction surgery (LVRS) and lung transplantation.

Bullectomy is indicated in presence of giant bullae occupying more than one half of the hemithorax with compression of relatively healthy lung tissue.

LVRS entails nonanatomical resections of severely diseased emphysematous areas of the lungs and is performed in severely disabled patients with hyperinflation, heterogeneous distribution of destruction prevailing in the upper lobes, a forced expiratory volume in one second (FEV1) >20% predicted and a normal carbon dioxide arterial tension. LVRS, can be performed by open or thoracoscopic approaches, in unilateral or bilateral fashion and have been shown to offer prolonged functional benefit with acceptable mortality.

Patients with lower FEV1, hypercapnia, and associated pulmonary hypertension are candidates for lung transplantation. Emphysema, especially in the context of α1-antitrypsin deficiency, is currently one of the most common indications for lung transplantation, accounting for ∼45% of cases worldwide. Single-lung transplantation is simpler and shorter than the bilateral transplantation, and there is less frequent need for cardiopulmonary bypass. Yet, it could potentially extend the availability of donor organs. These advantages have to be weighed against bilateral sequential lung transplantation procedure characteristics, which include an improved pulmonary function and the ability to use marginal lung donors as compared with single-lung transplantation.

In conclusion, in properly selected patients, bullectomy, LVRS and lung transplantation can offer prolonged functional benefit and satisfactory long-term survival. Nonetheless, since they are invasive options with a risk of both mortality and morbidity, they are directed only at patients who remain symptomatic despite optimal medical treatment.

Chronic obstructive pulmonary disease (COPD) is one of the most common causes of death both in Europe and in the USA. At the most advanced phases of the disease, when symptoms become disabling, the quality of life for these patients is extremely compromised. During the last 50 yrs various surgical procedures have been proposed to relieve dyspnoea and improve quality of life: costochondrectomy, pneumoperitoneum, glomectomy and many others. Early results were often encouraging but no sustained good results were obtained. All of these procedures were eventually abandoned.

At the present time, only resection of giant bullae and lung transplantation have shown substantial beneficial effect. Surgical bullectomy has been employed successfully to improve lung function in patients with bullous emphysema for more than four decades; single- and bilateral-lung transplantations are now considered a viable therapeutic option for a selected group of patients with end-stage emphysema.

Lung volume reduction has been recently rediscovered; it results in a significant but temporary functional improvement with palliation of dyspnoea and amelioration of quality of life. Also this surgical procedure can now be safely proposed for a selected group of patients with emphysema, with some limitations that are still debated in the literature.

More recently, other experimental endoscopic procedures have been described; two of them seem more promising: the airway bypass and the endoscopic lung-volume reduction.

Surgery for suppurative lung disease is often technically demanding and the patient may have an increased operative risk because their general health status has mostly suffered from the infectious disease status. Thoracic aspergillosis is by far the most common fungal disease of the lung and the pleura, requiring surgical care in Western Europe. For a long time, only the saprophytic aspergilloma has received surgical interest, but in the last decade it has become clear that surgical management may also improve the outcome of selected patients with invasive aspergillosis. Patients with bronchiectasis should be considered for surgery when the disease is localised and when they present with haemoptysis and/or recurrent infections with failure of medical treatment and poor compliance to this treatment. The basic principle of surgery in multidrug-resistant tuberculosis is to remove all cavitary disease after the antibiotic regimen has already been given for a 3‐month period; the operation has a curative intent and prevents spreading of these multidrug-resistant mycobacteria in the community. Pneumonectomy for destroyed lung is mostly indicated because of recurrent infections; it remains a distressing problem which may be regarded as one of the most serious challenges in general thoracic surgery.

The treatment of parapneumonic effusions (PPE) and empyema must always include antibiotics, which is sufficient in the early pleuritis sicca stage and in the exsudative stage. The fibrinopurulent stage also needs pleural space drainage in almost all cases also. The authors'current treatment approach, which has achieved a success rate of ∼90% on >440 patients, consists in drainage via double-lumen trocar catheter allowing simultaneous irrigation. Sometimes insertion of the tube is combined with medical thoracoscopy. Intrapleural fibrinolytic therapy is used over 5–6 days on average. In the authors' experience, the majority of fibrinopurulent effusions/empyemas can be managed successfully by nonsurgical treatment; the latter becomes necessary only when medical treatment fails or in the later organisational stage of empyema.

Management of tracheobronchial ruptures after blunt thoracic trauma requires a good knowledge of original mechanisms and of immediate or secondary physiological consequences of these lesions. An urgent and precise endoscopic diagnosis is mandatory. Immediate surgical treatment is the rule, taking into account, however, the schedule of other surgical repairs in case of polytrauma. The technical problems of surgical repair are nowadays overcome and prognosis mainly depends on the initial control of respiratory failure and complications.