Awake Thoracic Surgery

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During the early twentieth century, thoracic surgery procedures were frequently attempted through local anesthesia, although the pneumothorax created after opening of the chest wall was deemed invariably fatal. During the ensuing decades, some surgeons started performing awake thoracic surgery procedures taking into account the experience matured during the World War I, which suggested that soldiers with severe open thoracic traumas could eventually survive.

In the 1940s, a multi-step analgesia protocol entailing multiple local blocks with Novocaine was developed in Russia. Using this technique, hundreds of major thoracic surgery procedures including major lung resections and esophagectomies, were carried out. Subsequently, Buckingham first reported on major surgery procedures using sole thoracic epidural anesthesia in awake patients.

The introduction of double-lumen tube ventilation in the 1950s led to the birth of modern thoracic surgery and general anesthesia with one-lung ventilation is still considered mandatory to allow accomplishment of more complex surgical procedures including lung resections.

Awake thoracic surgery fell into disuse until recent years when, thanks to the better knowledge of potential adverse effects of general anesthesia, some surgeons again started to investigate the possibility of performing thoracic surgery operation in awake patients

Awake thoracic surgery could not have been developed without the previous experience of pioneering thoracic surgeons. Moreover, continuing technological advances and the increased knowledge in cardiopulmonary physiology, are leading to a potentially revolutionary strategy capable of minimizing both surgical and anesthesiological trauma to eventually offer patients comprehensive non-invasive surgical management.

Surgical pneumothorax makes awake thoracic surgery procedures feasible. This iatrogenic event is followed by a complex cascade of physiologic changes in both lung ventilation and perfusion, as well as in mechanical interaction between lungs, pleural cavity, diaphragm and mediastinum.

In most instances, the newly developed intrapleural atmospheric pressure environment leads to a drop in lung volume, thus assuring an adequate space for easy surgical maneuvering. The extent of this effect, however, varies considerably and is related to the conditions of lung tissue, airways and pleural cavity.

During surgical pneumothorax, ventilation-to-perfusion mismatch increases shunt fraction. Mechanical changes may include mediastinal shifting towards the dependent ventilated lung, and paradoxical respiration with collapse of non-dependent lung during inspiration and expansion during exhalation, leading to alveolar hypoventilation and hypoxemia. Mediastinal shift and paradoxical respiration decrease the efficiency of spontaneous ventilation with re-breathing of exhaled gases. Hemodynamic changes include an increase in vascular resistance due to mechanical limitation to flow and hypoxemia, which accompanies collapse of the lung and may enhance this effect by inducing pulmonary vasoconstriction. Administration of oxygen can usually prevent hypoxemia but permissive hypercapnia can develop, particularly in patients with severe emphysema.

Hence, though well tolerated by the majority of patients, hypoxemia, hypercapnia and hypoventilation are all common findings during awake thoracic surgery and need to be carefully taken into account by physicians who decide to be involved in this novel surgical field.

Systemic response to surgery entails the activation of hormonal, metabolic and inflammatory pathways, and may affect postoperative outcome due to interaction with host’s immunity, metabolism, organ function, coagulation, and wound healing.

In recent years, we have being actively involved with video-assisted thoracoscopic surgery performed on spontaneously ventilating patients (awake VATS), with the use of just local- or locoregional anesthesia techniques. Amongst the expected advantages of this approach, an attenuation of postoperative response has been hypothesized, potentially contributing to a more physiological recovery. In particular, our recent observation has showed that avoidance of one-lung ventilation may result into attenuated release of stress hormones and systemic inflammation biomarkers including Creactive protein and interleukin-6 in patients undergoing awake videothoracoscopic procedure. In this chapter, we review the basic knowledge on systemic host response after surgery, whit particular reference to our most recent evidences in this setting.

The management of patients for thoracic surgical procedures remains challenging. Not only do patients present with a variety of comorbidites, but they are also subjected to surgical trauma with the requirement for one-lung ventilation and lateral decubitus position, while common intraoperative problems include proper isolation of the lungs utilizing a dual lumen endotracheal tube or bronchial blocker, the potential for dynamic pulmonary hyperinflation and hypoxia. The purpose of this review is to describe the main problems reported in the literature on managing general anesthesia in thoracic surgery, with the aim of choosing the best risk/benefit balance technique.

Mechanical ventilation can produce barotrauma, volotrauma, atelectrauma, and release of a variety of proinflammatory mediators (biotrauma), leading to the development of acute lung injury. Moreover, general anesthesia can lead to an increased risk of pneumonia, impaired cardiac performance, and neuromuscular problems in patients with myasthenia gravis.

Awake anesthesia with thoracic epidural technique, avoids endotracheal intubation, complications such as hypoxia due to double lumen endotracheal tube malposition, hyperinflation of the dependent lung, re-expansion pulmonary edema, and unilateral ventilator-induced lung injury.

In order to avoid the adverse effects of general anesthesia in patients undergoing thoracic surgery procedures and to allow surgical treatment for those patients considered at high-risk for general anesthesia because of their compromised medical conditions, some anesthesiological techniques can be employed to perform awake thoracic surgery.

In this chapter we describe three different anesthesiological techniques which can be performed successfully in this setting.

Our favourite technique is Thoracic Epidural Anesthesia (TEA), which can be chosen for most awake thoracic procedures. This technique offers a sympathetic block that decreases stress response to surgery, positively affecting the cardiovascular system, gastrointestinal function and postoperative pulmonary function. Furthermore, it provides excellent postoperative analgesia.

Thoracic paravertebral block is another technique that can offer effective intraoperative and postoperative management of surgical pain. It has a better side-effects profile and lower complication rate compared with TEA, but so far, it has not often been used as a sole anesthetic method for thoracic surgery.

Local anesthesia as a sole technique can also represent a valid method for minor thoracic surgery procedures.

The term Solitary Pulmonary Nodule (SPN) refers to a newly developed lung nodular lesion of unknown origin and up to 3 cm in diameter, which is completely surrounded by normal parenchyma without atelectasis or adenopathy.

Video-Assisted Thoracic Surgery (VATS) has been increasingly advocated as an ideal approach for management of peripheral SPN due the satisfactory results and negligible morbidity rates reported with this minimal invasive surgical option. General anesthesia with one-lung ventilation has been considered mandatory to accomplish a safe operation by VATS. However, this type of anesthesia should not be considered strictly necessary to accomplish simple pulmonary resection and can be associated with several adverse effects that can increase the procedure-related morbidity with a potential negative impact on hospital stay and overall costs.

We have employed VATS performed through sole thoracic epidural anesthesia in awake patients to resect undetermined lung nodules, solitary metastases and non-small-cell lung cancer in high-risk patients. Early results have been encouraging although the pros and cons of awake VATS pulmonary resections still need to be fully elucidated.

Lung Volume Reduction Surgery (LVRS) is now a well established procedure, which can considerably improve dyspnea, pulmonary function, exercise capacity, quality of life and survival in selected patients with severe emphysema, particularly when the upper lung lobes are predominantly involved. The standard operation entails unilateral or bilateral, staple non-anatomical resection of the most emphysematous lung tissue, carried out by median sternotomy or thoracoscopic approaches through general anesthesia and single-lung ventilation (resectional LVRS).

Operative mortality and morbidity of resectional LVRS have been higher than those observed following the majority of other thoracic surgery procedures. It seems reasonable to assume that, in anatomically and physiologically fragile subjects such as candidates to LVRS, determinants of operative mortality and morbidity may include not only the surgical trauma deriving from resection of emphysematous lung tissue, but also general anesthesia.

We have developed a non-resectional LVRS method that can be carried out through sole thoracic epidural anesthesia in fully awake patients. This technique has proved to offer lower morbidity and clinical benefits that paralleled those of resectional LVRS.

Lung biopsy has become progressively more important to achieve a definitive diagnosis in patients with Interstitial Lung Disease (ILD) who does not exhibit an easily recognizable clinicalradiological pattern.

Surgical biopsy has been accomplished via thoracotomy or Video-Assisted Thoracic Surgery (VATS), which is deemed to offer a lower morbidity, less pain and a shorter hospital stay.

Unfortunately, many ILD patients are considered at high-risk for surgical biopsy due to the need for general anesthesia, which can be poorly tolerated, particularly in patients with compromised respiratory function, pulmonary hypertension and/or immune-suppression.In order to avoid these generalanesthesia- related adverse effects, we have developed a VATS biopsy approach that is performed under thoracic epidural or local anesthesia in awake patients with spontaneous ventilation.

We believe that the introduction of awake VATS biopsy might lead to an easier acceptance of the surgical procedure by both patients and pneumologists and could widen the number of precise pathologic diagnoses, eventually resulting in more targeted therapeutic regimens.

Pleural Effusion (PE) is a common clinical condition, which can greatly affect patients’ quality of life. Etiology of PEs can be variable, although in over 70% of cases they prove to be malignant in nature. Video-Assisted Thoracoscopic Surgery (VATS) is now routinely employed for management of recurrent PE and allows a thorough exploration of the pleural cavity, accomplishment of gross multiple biopsies and, whenever required, pleurodesis to prevent recurrences. VATS is usually performed under general anesthesia although this type of anesthesia can be associated with several adverse effects, particularly in the presence of comorbidities such as advanced malignancy, cardiopathy and severe systemic diseases. For this reason, use of local anesthesia in spontaneously ventilating patients has been advocated and we also started a clinical program of VATS carried out through local or Thoracic Epidural Anesthesia (TEA) in fully awake, spontaneously ventilating patients. Awake VATS management of PE requires a single trocar access; it is easily performed and results in optimal patients tolerability, minimal hospitalization and satisfactory outcome.

Spontaneous Pneumothorax (SP) is a relatively common condition defined as the presence of air in the pleural space associated with lung collapse.

On an etiologic basis, pneumothorax is classified as spontaneous, traumatic and iatrogenic. The term “spontaneous” indicates that no mechanical injury is recognized as the causative mechanism whereas secondary SP occurs as an acute complication of an underlying lung disease.

The principal goal of treatment is to evacuate air from the pleural space and achieve lung reexpansion. Simple chest drainage is often employed as first line treatment, whereas bullectomy performed by Video-Assisted Thoracic Surgery (VATS) is widely adopted for treatment of recurrent SP. Pleurodesis by pleurectomy or talc insufflation is also commonly associated to bullectomy to reduce risks of recurrence.

VATS is usually carried out through general anesthesia and one lung ventilation, although use of this type of anesthesia can be associated with several adverse effects. Recently, VATS management of SP has been performed with satisfactory results by local anesthesia in spontaneously ventilating patients. In particular, we have began a clinical investigational program entailing VATS bullectomy and pleurectomy performed through sole Thoracic Epidural Anesthesia (TEA) in fully awake patients. In this chapter we describe technical features and results of this novel surgical approach.

Empyema thoracis is defined as the presence of purulent fluid within the pleural cavity. Despite proper management is still debated, widespread agreement exists amongst thoracic surgeons that an immediate surgery is more likely to result in favorable outcome than conservative treatment.

In recent years, the use of video-assisted thoracic surgery has gained acceptance as a valuable option in this setting, since satisfactory re-expansion of the trapped lung can be achieved in more than 90% of patients with a minimal surgical traumatism.

A further development in the field of minimally-invasive approach for empyema thoracis is represented by the renewed interest in videothoracoscopic operations performed in spontaneous ventilating patients, through local or locoregional anesthesia techniques. In our experience, awake videothoracoscopic decortication performed under thoracic epidural anesthesia proven feasible and well tolerated in most instances. In addition, conversion to thoracotomy was possible in more than 20% of patients without switching to general anesthesia.

In this chapter, we focus on clinical and technical aspect of this novel surgical approach, which could represent a reliable treatment tool especially in high-risk patients with early-stage empyema thoracis.

Recently, several major thoracic procedures performed in awake patients have been reported. In order to reduce the adverse effects of general anesthesia and the cost, Thoracic Epidural Anesthesia (TEA) has been employed to perform such awake thoracic surgery procedures. Awake procedure under TEA can be performed even in endoscopic thymectomy. The postoperative recovery is fast, and surgery can be performed on patients in whom general anesthesia is difficult. Herein we discuss awake thymectomy procedure and perioperative management for patients and describe the techniques in detail.

Anterior mediastinal masses can develop due to a number of conditions, most of which require prompt pathologic diagnosis to initiate appropriate treatment.

Diagnosis can be achieved by surgical and non-surgical methods but Video-Assisted Thoracic Surgery (VATS) through general anesthesia is frequently preferred due to its minimal invasiveness and optimal diagnostic yield. One limitation of VATS includes the need for general anesthesia and one-lung ventilation, which can induce life-threatening adverse effects, particularly in patients with bulky masses

In order to reduce general anesthesia-related operative risks, we employed a VATS biopsy approach performed by just thoracic epidural or local anesthesia in fully awake, spontaneously ventilating patients.

This surgical method allows a wide visual control of mediastinal compartments, an accurate assessment of the disease extension and achievement of multiple biopsy specimens from different sites of the mass, eventually resulting in excellent diagnostic yield. In addition, adequate surgical management of associated intrathoracic conditions including drainage of pleural-pericardial effusions or pleuralpulmonary biopsy is possible when necessary.

We believe that this novel and globally less invasive surgical option might thus be included within the framework of the most reliable methods currently available to achieve a rapid diagnosis and adequate surgical management in patients with undetermined anterior mediastinal masses.

Video-Assisted Thoracic Surgery (VATS) sympathectomy is a safe and effective procedure for treatment of facial, palmar and axillary hyperhidrosis. It can be more rarely used in other conditions. Awake thoracic surgery with epidural anesthesia and spontaneous ventilation has been employed to perform many surgical procedures including VATS sympathectomy.

This chapter describes the anatomy of the nerve with the most frequent abnormalities, the indications and contraindication for both sympathectomy and awake surgery, the method for awake anesthesia, a detailed step-by-step description of the surgical technique and postoperative management as well as an analysis of benefits and potential side-effects of awake VATS sympathectomy.

Patient selection, choice of the level of sympathectomy and adequate information about anesthesia and side effects of the operation are extremely important for the good result of the procedure.

Awake VATS sympathectomy may be considered a globally minimally invasive approach combining avoidance of general anesthesia-related adverse effects with maximum patient satisfaction.

Video-Assisted Thoracic Surgery (VATS) is usually performed with general anesthesia and endotracheal intubation. There are risks to such anesthesia and some operations may not require general anesthesia or intubation. Presently at our institution all stable patients with large unilateral pleural effusion, Stage I and II empyema, pericardial effusion with coexisting pleural effusion, diffuse lung disease, or multiple lung nodules are offered local anesthesia and sedation. No patient is excluded based on age or comorbidity.

Details of the technique are presented in this chapter. All operations are performed in the operating room with the patient in full lateral position.

Of 384 consecutive patients reported in 2010, no patient required intraoperative intubation or epidural or nerve block analgesia. No patient required conversion to thoracotomy. Diagnosis was achieved, without need for additional procedure, in all cases of biopsy; 2 patients (3% of 74) required a subsequent procedure for empyema. No patient had awareness or memory of the operation. There were 10 complications (3%) and no deaths due to operation.

VATS utilizing local anesthesia/sedation is well tolerated, safe, and valuable for an increasing number of indications.

Awake thoracic surgery procedures have now been successfully performed in early series with satisfactory results.

Potential advantages include short hospitalization and immediate resumption of daily life activities, even in functionally compromised patients, as well as a minor impact on postoperative immune function and hormone stress response.

So far, awake anesthesia has been mainly employed to perform simple surgical procedures. In this setting, we have preferred thoracic epidural anesthesia but local anesthesia and paravertebral blocks are also promising alternatives, which have been successfully used.

Future perspectives might include ambulatory awake thoracic surgery programs as well as standardization of more complex awake surgical procedures such as thymectomy and anatomical lung resections.

The rapidly growing clinical experience and the accomplishment of properly controlled studies will provide more answers regarding the advantages and limits of this intriguing novel surgical approach when dealing with the various proposed indications.

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