Video-assisted thoracic surgery has considerably improved the care of the thoracic surgical patient. Patients are able to leave the hospital sooner and experience less pain with equal oncologic outcomes when compared with open surgery. Nonintubated thoracic surgery has more recently been applied in the management of both benign and malignant pleural effusions. This article provides the general thoracic surgeon a detailed description on how to manage pleural effusions using video-assisted thoracoscopic surgery in a nonintubated patient. Surgical techniques and pearls are also presented.
Key points
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Nonintubated video-assisted thoracic surgery is a useful approach in the management of pleural effusions.
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Both simple and complex effusions are amenable to video-assisted thoracic surgery via a nonintubated approach.
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Techniques from conventional video-assisted thoracoscopic surgery are directly applicable in the nonintubated patient setting.
Pleural effusions
The pleura is a serous membrane composed of pleural mesothelial cells arranged in 2 layers that line the surface of the lung (visceral pleura) and the internal surface of the thoracic cavity (parietal pleura). These 2 layers of pleura are continuous with each other at the hilum, giving rise to the fluid-filled pleural cavity. Pleural fluid within this space promotes apposition of the lungs and the chest wall during respiration and lubricates opposing surfaces of the parietal and visceral pleura to facilitate rapid transmission of forces from the chest wall to the lungs during inspiration and expiration with minimal friction.
Most pleural fluid is produced as an ultrafiltrate by the parietal pleura and the production of pleural fluid changes based on the hydrostatic, colloid, and tissue pressures within the pleural space and on the permeability of the pleural membrane. The high capillary pressure associated with the systemic capillaries supplying the parietal pleura as compared with the intrapleural negative pressure produces a pressure gradient favoring filtration into the pleural space. In contrast, low-pressure pulmonary circulation supplies the visceral pleura, producing a much less significant pressure gradient. Pleural fluid is subsequently reabsorbed by the lymphatic stomata of the parietal pleura that open directly into the pleural space, which can increase the drainage flow rate by up to 20 times in response to increased production of pleural fluid.
Under normal physiologic conditions, pleural fluid production is well balanced with the rate of absorption so as to maintain a low volume of fluid within this space, typically ranging between 0.1 and 0.2 mL/kg of pleural fluid per pleural cavity. Maintaining pleural fluid volume within this range is critical to ensure appropriate respiratory function and mechanical coupling of the lung and chest wall. Disturbance in this careful fluid balance results in fluid accumulation within the pleural space ultimately causing pleural effusion development and respiratory dysfunction, as increases in pleural fluid decrease the amount of force transmitted between the thoracic wall and lung. Pathologic accumulation of fluid within the pleural space may result from a pathologic decrease in the rate of pleural fluid reabsorption by the lymphatic system, a substantial increase in flow from the systemic vessels as a result of increased capillary endothelial permeability, and/or widening of the hydrostatic-oncotic pressure gradient favoring pleural fluid filtration into the pleural space.
Pleural effusions are most often classified according to their protein composition as either transudative or exudative based on the criteria of Light and colleagues. Transudative effusions are protein-poor effusions that most often result from alterations in Starling mechanisms that ultimately favor ultrafiltration of plasma and result in fluid overload, most commonly seen in congestive heart failure (increased hydrostatic pressure) and cirrhosis (decreased oncotic forces). Conversely, exudative effusions are rich in protein that most often are the result of increased capillary permeability and/or impaired lymphatic drainage due to local proliferative (eg, malignancy) or inflammatory (eg, parapneumonic effusions) processes ( Fig. 1 ).
Clinically, this distinction is of vital importance, as most transudative effusions result from systemic diseases that cause alterations in cardiac, renal, or hepatic function, whereas exudative effusions indicate a local pathologic process and require further workup to definitely exclude an underlying malignancy. A malignant pleural effusion is defined by presence of neoplastic cells within the pleural space as a result of either a primary pleural malignancy or invasion of the pleura by metastatic neoplastic cells following hematogenous, lymphatic, or contiguous spread. Most malignant pleural effusions are exudates and they most often develop as a result of tumor-induced lymphatic obstruction and/or tumor-induced increases in microvascular permeability. Malignant pleural effusions are important clinically because they indicate a very poor prognosis, correlating with an overall survival of 3 to 12 months after diagnosis, and often lead to debilitating symptoms.
Management of pleural effusions
Thoracostomy Tube and Talc Slurry Instillation
Tube thoracostomy is a minimally invasive, low-cost bedside procedure. It is well tolerated in patients who are deemed inappropriate candidates for video-assisted thoracoscopic surgical (VATS) procedures. Talc slurry can be instilled through the tube, also as a bedside procedure to achieve pleurodesis. Although this procedure is inexpensive and placement of the tube is simple, thoracostomy tubes do not allow for direct visualization of the pleural cavity. Because of lack of visualization, complete drainage may not be obtained. Furthermore, blind placement of talc for pleurodesis is not optimal and may lead to lower rates of pleurodesis compared with video-assisted procedures in which direct visualization is obtained. In addition, the lack of visualization increases the chance that there may be a need for additional procedures for drainage. Patient satisfaction has been shown to be lower for bedside tube placement because the patient is awake and there is reported to be a higher amount of pain because this procedure is not done with intravenous sedation but only using local anesthetic. A disadvantage of this procedure is that patients may likely go home with a chest tube in place that may have to remain in place for a longer period than those who have a VATS procedure.
Thoracentesis
This is a minimally invasive and cost-effective modality of treating pleural effusions. It is an outpatient procedure with low risk of complications. Thoracentesis has a less important role in treating recurrent pleural effusions, as it does not prevent recurrence. There is no pleurodesis associated with this procedure, and because most of these effusions will recur, this method is not a definitive treatment method. In addition, a tissue biopsy is usually not obtained with this procedure, making it a less desirable procedure than VATS, which can provide both diagnostic and therapeutic value.
Long-Term Indwelling Pleural Catheter
Placement of a long-term indwelling pleural PleurX catheter (CareFusion Corporation, San Diego, CA), is an overall well-tolerated procedure. It is a minimally invasive, cost-effective, outpatient method for treatment of recurrent pleural effusions and involves more patient control over the drainage of their effusions. The indwelling catheter is associated with a higher rate of complications, including catheter clogging, infections, and chronic pain at the catheter site. These complications create the need for additional procedures. This method does not allow for obtaining any tissue for diagnosis nor does it facilitate the instillation of any form of chemical for pleurodesis. Table 1 outlines the advantages and disadvantages of various options to treat pleural effusions.
| Treatment Method | Advantages | Disadvantages |
|---|---|---|
| Thoracoscopic chemical talc pleurodesis | Minimally invasive, can be outpatient Direct visualization, immediate and complete drainage High diagnostic yield of biopsy High pleurodesis rate Increased patient satisfaction | More costly than other methods Inpatient hospitalization May require tube thoracostomy following procedure |
| Tube thoracostomy and talc slurry | Minimally invasive Outpatient | Pain associated with indwelling tube May require inpatient hospitalization |
| Thoracentesis | Minimally invasive Outpatient | No pleurodesis achieved following procedure Frequent need for additional procedures |
| Long-term indwelling pleural catheter | Minimally invasive Outpatient | Chronic indwelling catheter Higher risk of infection Need for repeated drainage |
| Pleurectomy | High diagnostic yield of biopsy High pleurodesis rate | Invasive procedure Requires inpatient hospitalization |
Nonintubated video-assisted thoracoscopic surgery
Our group has published a report previously on this topic and has outlined patient selection, preparation, and technique.
Patient Selection and Preparation
In our prospectively maintained database, the cohort of patients we operated on have had large pleural effusions, pleural-based masses, early or midstage empyemas, or multiple lung nodules. Advanced age is not a contraindication nor is weight, as our group has performed nonintubated VATS (NIVATS) on patients weighing in excess of 150 kg ( Fig. 2 ). Furthermore, most patients are American Society of Anesthesiologists physical status classes 3 and 4. Extensive comorbidities are similarly not an absolute contraindication; however, this often requires consultation with the anesthesia provider preoperatively. Moreover, with the rotation of surgical technologists and circulating nurses, clear communication of anticipated steps and potential concerns between surgical team and operating room (OR) personnel also may facilitate a safe operation.
