Abstract and Introduction
Purpose of review Medical thoracoscopy, also known as pleuroscopy, has been utilized by chest physicians for more than a century. Despite this, it has only recently re-emerged as an important tool for interventional pulmonologists to diagnose and treat pleural diseases. The purpose of this review is to critically assess the recent literature related to medical thoracoscopy, specifically as it pertains to its safety and feasibility as an outpatient procedure.
Recent findings Recent data have reaffirmed the clinical utility of medical thoracoscopy and suggest that it can be safely performed in an outpatient setting. A single-center study of 51 patients published in the past year described both the feasibility and safety of outpatient medical thoracoscopy. This study highlights the notion that the majority of patients do not require hospital admission after a routine diagnostic thoracoscopy in the absence of talc poudrage. Another study this year described the successful use of chest physician-directed ultrasound-guided cutting needle biopsy when medical thoracoscopy was not technically possible.
Summary The contribution of medical thoracoscopy in the diagnosis and management of pleural diseases is increasingly recognized. Evidence supports the routine practice of medical thoracoscopy on an outpatient basis in experienced centers.
Pleural diseases account for nearly 25% of diagnoses seen by pulmonologists.[1,2] Despite this, they often represent some of the most difficult diagnostic and management dilemmas. Pleural effusions are the most common of this group, with nearly 1.5 million identified annually in the United States. In addition, the burden of pleural diseases is increasing, owing to an aging and increasingly fragile patient population. A thorough history and physical examination combined with pleural fluid analysis will point to a cause in approximately 75% of cases. Therefore, a substantial number of pleural effusions will require further investigations.
Options have traditionally included closed (blind) or image-guided pleural biopsies,[4–6] which typically require the identification of focal pleural abnormalities, or surgical approaches such as video-assisted thoracoscopic surgery (VATS), which also offer the possibility of definitive treatment of the pleural effusion at the expense of the need for general anesthesia and a hospital stay. Medical thoracoscopy offers the advantages of a minimally invasive procedure while simultaneously allowing for therapeutic interventions, and is therefore ideally positioned as a valuable alternative to surgery for the diagnosis of unexplained exudative pleural effusions. The main impediments to the widespread adoption of medical thoracoscopy by pulmonologist in the United States have been the lack of standardized training opportunities and the misconception of medical thoracoscopy as an invasive procedure requiring hospitalization.
Increasing concerns over ever-expanding healthcare costs have in the past decade led to a transition of care from inpatient to outpatient procedures. Traditionally, thoracic procedures have not typically been considered suitable for the outpatient setting given the anatomic complexity of these interventions associated with potentially life-threatening complications, occasional prolonged postoperative recovery, and the need for a negative pressure pleural drainage system. Although talc insufflation generally requires hospitalization, increasing utilization of tunneled indwelling pleural catheters (TIPC) in the outpatient setting has facilitated reconsideration of medical thoracoscopy as an outpatient procedure, which was shown to be well tolerated in a recently published study. The purpose of this review is to describe and discuss the safety and practicality of outpatient medical thoracoscopy.
Patient Selection and Evaluation
Medical thoracoscopy is surprisingly well tolerated by even chronically ill and frail patients who might otherwise be poor candidates for general anesthesia. Absolute contraindications to medical thoracoscopy include absence of a pleural space, chronic hypoxemia (need for >2 l/min of supplemental oxygen via nasal canula) and hypercapnic respiratory failure (PaCO2 >50 mmHg). Moderate-to-severe sleep apnea should also be considered a contraindication as patients are not typically intubated during medical thoracoscopy, increasing the risk of hypercapnic respiratory failure. Furthermore, the use of positive airway pressure would prevent adequate lung atelectasis and interfere with optimal inspection of the pleural space. Absence of anesthesia and surgical backup should also be considered absolute contraindications. Other contraindications mirror those of other outpatient procedures, which are as follows:
Absence of a pleural space
Severe baseline hypoxia or hypercapnia
Inadequate facility (inexperienced team, no thoracic surgeon or anesthesia local)
Inability to tolerate sedation
Lack of informed consent
Cardiopulmonary disease that might make patient unable to tolerate a pneumothorax
A detailed history and careful physical examination should be routinely performed, with attention to chest X-ray and computed tomography scans, electrocardiography, and blood work (Table 1). The medication list should be thoroughly reviewed, including over-the-counter medications, to mitigate the bleeding risk.
We recommend that all patients have a thoracic ultrasound performed prior to the procedure to examine the pleural space. Although the majority of medical thoracoscopies are performed in the presence of a pleural effusion, medical thoracoscopy can occasionally be performed in the absence of any fluid. A recent study by Marchetti et al. describes a series of medical thoracoscopy performed to evaluate 29 patients with concerning pleural disease in the absence of effusion. They based their entry point on the presence of a sliding sign on ultrasound and were able to access the pleural space in all instances without complication. Even in patients with a pleural effusion, confirming the presence of a sliding sign is an important skill needed to identify a well tolerated trocar entry point, as after having positioned the patient in the lateral decubitus, the pleural effusion will often disappear from view as it layers dependently.
During the initial patient evaluation, patients should also receive education for tunneled indwelling pleural catheter (TIPC) management if applicable. We also suggest obtaining informed consent for both the medical thoracoscopy and TIPC during this visit. Specifically, we advise patients that although the procedure is generally well tolerated, there is a 5% chance of requiring admission after the procedure in our experience. Consequently, we also advise patients to plan to stay local overnight after the procedure and an emergency contact phone number is provided.
Generous local injection of lidocaine in all layers (epidermis, aponeurosis, intercostal muscle, and parietal pleura) is essential and will reduce the need for intravenous sedation. The parietal pleural is richly innervated, and we routinely use direct ultrasound visualization to carefully anesthetize this region. Intravenous benzodiazepines (midazolam) combined with opioids (usually fentanyl) are the preferred method of moderate sedation. In a review of 51 patients who underwent outpatient medical thoracoscopy at our institution, the average doses of midazolam and fentanyl administered were 4.1 mg and 164 μg, respectively, doses similar to those received during routine bronchoscopy examination. Propofol has been studied as a possible alternative agent for medical thoracoscopy because of its faster onset and shorter duration of action. Grendelmeier et al. assessed 90 consecutive patients undergoing medical thoracoscopy who were randomly allocated to intravenous propofol or midazolam. They found that the mean lowest oxygen saturation during the procedure was significantly lower in the propofol group as compared with the midazolam group (93 ± 6 vs. 96 ± 3%, P = 0.007). Patients randomized to propofol also showed more episodes of hypoxemia (27 vs. 4%, P = 0.007) and hypotension (82 vs. 40%, P < 0.0001). It is our opinion that given the track record of safety and efficacy of the midazolam/fentanyl combination, propofol should be discouraged as a first-line agent in this setting. Intrapleural lidocaine administered via a spray catheter may be a useful adjunct before talc poudrage pleurodesis. Continuous monitoring should include pulse oximetry, capnometry, heart rate, and blood pressure.
Medical thoracoscopy is typically performed in an endoscopy suite or operating room. The patient is positioned in the lateral decubitus position facing the proceduralist. This allows easy access of the posterior inferior parietal pleura, a favorable biopsy site for early metastatic seeding. The typical procedure table setup is shown in Fig. 1. We always use an ultrasound with a sterile probe cover to reconfirm our entry site after patient positioning and generally use direct ultrasound guidance for anesthesia. We typically induce a pneumothorax with a Boutin Trocar (Novatech, La Ciotat, France), unless a large pleural effusion is present, in which case direct entry into the pleural space by blunt dissection is possible. Spontaneous breathing results in negative intrathoracic pressures entraining air into the pleural space, with a whistling sound usually clearly audible by the proceduralists. After the pneumothorax has been induced, a 1 to 1.5-cm incision is made, parallel to the intercostal space, followed by blunt forceps dissection into the pleural space. Then, a disposable flexible trochar (Olympus MAJ-1058) is inserted. Although rigid thoracoscopes may offer a slightly improved diagnostic yield, we prefer using the semi-rigid scope (Olympus LTF-160) as we have found its use more comfortable in awake patients, as its improved maneuverability results in less compression of the rib periosteum and intercostal nerve compared with the rigid thoracoscope (Fig. 2). The pleural space is then thoroughly inspected, followed by parietal pleural biopsies. Six to eight biopsies are generally obtained.
Typical setup of table. Top half: Tunneled indwelling pleural catheter supplies. Bottom half, from left to right: Flexible trocar, Boutin stylet and catheter, scalpel, lidocaine (2), sterile ultrasound cover, chlorhexidine sponges.
If entry into the pleural space is not possible, pulmonologist-led ultrasound-guided closed pleural biopsies can be safely performed. Hallifax et al. reviewed a series of 50 ultrasound-guided cutting needle biopsies performed on patients with negative fluid cytology, 13 of which were performed after failed thoracoscopy, and were successful in obtaining adequate tissue in 47/50 (94%).
As a pneumothorax must be induced to perform a medical thoracoscopy, all patients will need some form of air evacuation postprocedurally. We advocate using small to medium-bore pigtail drains (8.5–10.2 French) through a different entry site under direct visualization, which in our experience are very effective. These are connected to suction at -20 cmH2O for 1 h, followed by a chest X-ray to confirm lung re-expansion. A very small residual pneumothorax may occasionally be seen; however, in the absence of an air leak, the drain may safely be removed. The patient is discharged once he or she has satisfied the requirements of our institution's postanesthesia care discharge scoring system (Fig. 3).
A physician experienced with medical thoracoscopy should be available to answer phone calls in the first day after the procedure, so appropriate call scheduling must be taken into consideration. All patients should be contacted the day after the procedure to ensure there are no issues. We suggest a return nursing visit 8–10 days after the procedure.
Safety and Management of Hemorrhage
Prolonged air leak
Surgical site infection
Seeding of chest wall from malignancy, primarily mesothelioma
One fatality was reported in a large series of 8000 patients. However, this often-quoted study suffered from serious methodological flaws and a more recent review reported a mortality rate of 0.34% [95% confidence interval (CI) 0.19–0.54%). Interestingly, after exclusion of procedures during which talc pleurodesis was performed, there were no deaths reported (of 2421 procedures). In fact, it should be noted that more than half of the reported deaths were from a single randomized controlled study of surgical thoracoscopy (rather than medical thoracoscopy) using nongraded talc, which has previously been associated with potentially life-threatening episodes of respiratory failure. Nonetheless, serious complications can occur as illustrated by a recent case report.
Major complications occur in 1.8% of the cases (95% CI 1.4–2.2%). The major risk of pleural biopsies is hemorrhage, which can be mitigated by avoiding biopsies of the apical and anterior parietal pleura, given the presence of major arteries (subclavian artery and internal mammary arteries, respectively). Biopsies should be preceded by palpation of the rib with closed forceps, and performed in a peeling fashion by grasping the pleura over the rib. In spite of these precautions, hemorrhage may rarely occur, and a systematic and stepwise approach to bleeding control is essential. First, immediate external pressure should be applied over the bleeding site by firmly pressing externally over the site. Electrocautery forceps should then be used to cauterize the bleeding site. Additionally, a second port of entry can be performed to apply direct pressure with gauze with rigid forceps. If the above measures fail, or if the bleeding is copious, a large bore chest tube should be immediately inserted and placed on suction to tamponade the bleeding, and surgical backup should be contacted immediately. A clear plan of action delineating the optimal sequence of interventions to effectively deal with such rare but potentially life-threatening complications in the outpatient setting is absolutely crucial to ensure patient safety and the long-term success of a medical thoracoscopy program.
Evidence Supporting Practice of Outpatient Medical Thoracoscopy
We recently reported our initial experience with the feasibility and safety of outpatient thoracoscopy at Mayo Clinic as part of a multidisciplinary program. In this series, 51 patients underwent medical thoracoscopy in an endoscopy suite under moderate sedation with intravenous midazolam and fentanyl. The indication for medical thoracoscopy was undiagnosed lymphocytic exudative effusion in 86.3% of patients. A TIPC was placed in 74.5% of patients; the remaining 12 patients had pigtail catheters (10–14 French) that were removed prior to dismissal following radiographic confirmation of lung re-expansion and absence of air leak. The only complication was a single pneumothorax ex-vacuo that was subsequently managed by surgical decortication. Talc insufflation was not used during medical thoracoscopy in any of these cases.
TIPCs provide the benefit of outpatient placement, but potential drawbacks include cost, required patient and/or provider maintenance efforts, and a substantial infectious risk over time. Therefore, an ideal solution may be to combine the more rapid pleurodesis seen with talc insufflation during medical thoracoscopy with the ability to manage drainage as an outpatient allowed by TIPCs. In an editorial, Folch and Santacruz described medical thoracoscopy with talc poudrage and TIPC placement. Postprocedurally, the TIPC was placed on suction for 4–12 h followed by same day discharge. They achieved pleurodesis in 7/8 patients at a median of 16 days, In support of this idea, a recent retrospective study looked at 22 patients who underwent TIPC placement and were found to have complete lung re-expansion at 3 days postprocedurally after daily drainage. They were treated by talc instillation followed by daily drainage of TIPC as an outpatient. Using this technique, patients were reassessed at 14 days and achieved pleurodesis in 92% of cases. The combination of TIPC and talc instillation (with medical thoracoscopy or without medical thoracoscopy) may eventually become the method of choice, but we feel further study is warranted before we can make this recommendation.
Outpatient Thoracoscopic Surgery
VATS usually consists of three surgical ports for adequate triangulation of instruments, and is traditionally done in the operating room under general anesthesia, with double lumen intubation and single lung ventilation. However, VATS may also be safely performed on an outpatient basis. There are reports detailing satisfactory outcomes after outpatient mediastinoscopy, thoracic sympathectomy, and lung biopsy. Ghosh-Dastidar et al. reported experience with 31 patients who underwent ambulatory VATS. Importantly, for those who underwent surgery for pleural effusions with biopsies and talc poudrage, a single port was used. Patients were discharged with an ambulatory chest drain. There were no complications noted in this group.
The use of a single entry port, spontaneous breathing, and no endotracheal tube are often cited as advantages of medical pleuroscopy. However, this distinction is arbitrary. For instance, Katlic and Facktor reported their results from 353 patients who underwent VATS operations, chiefly for pleural disease, including 383 total operations. There were 244 cases performed for pleural biopsy with or without talc. For pleural disease, they used one port for most cases. There are other reports of single-port VATS.[26,27] Indeed, there is increasing overlap between medical thoracoscopy and single-port VATS for pleural-based procedures.
Curr Opin Pulm Med. 2015;21(4):357-362. © 2015 Lippincott Williams & Wilkins