Thoracoscopy, video-assisted thoracic surgery (VATS), medical thoracoscopy (MT), and pleuroscopy are minimally invasive procedures that provide access to the pleural space. They differ only in the approach to anesthesia. In this review, the focus is on diagnostic MT.
VATS is performed by a surgeon in the operating room, typically with single lung ventilation, three entry ports, and rigid instruments. Stapled lung biopsy, resection of pulmonary nodules, lobectomy, pneumonectomy, esophagectomy, and pericardial windows are performed with VATS, in addition to guided parietal pleural biopsy, drainage of pleural effusion or empyema, and pleurodesis ( Table 17.1 ). MT on the other hand is conducted by a pulmonologist in an endoscopy suite under local anesthesia and moderate sedation. MT allows biopsy of the parietal pleura under direct visualization with good accuracy. In addition, it facilitates therapeutic interventions such as fluid drainage, guided chest tube placement, and pleurodesis. Practitioners in Europe perform MT sympathectomy for essential hyperhidrosis and lung biopsy for diffuse lung disease.
|Where||Operating room (OR)||Endoscopy suite or OR|
|Anesthesia||General anesthesiaDouble-lumen intubationSingle lung ventilation||Local anesthesiaConscious sedationSpontaneous respiration|
|Indications||Parietal pleural biopsy, pleurodesis, decortication, stapled lung biopsy, lung nodule resection, lobectomy, pneumonectomy, pericardial window, esophagectomy, lung||Parietal pleural biopsy, pleurodesis, chest tube placement under direct visualization|
In 1910 Hans Christian Jacobaeus, a Swedish internist, described examination of the thoracic cavity with a rigid cystoscope attached to an electric lamp as “thorakoscopie.” He later advanced the technique to include lysis of pleural adhesions by galvanocautery, also known as the Jacobaeus operation, to facilitate collapse of the tuberculous lung because at that time there was no effective antituberculous therapy. At a presentation to the American College of Surgeons, Jacobaeus opined that “in making a differential diagnosis between tumors and pleurisy of other origin, thoracoscopy is of no small value.” He was a strong advocate for thoracoscopic-guided biopsies in the evaluation of pleural effusions of unknown etiology and applied thoracoscopy as a diagnostic and therapeutic tool.
Historically, rigid instruments such as stainless steel trocars and telescopes were central to the technique. Rigid thoracoscopy requires a cold xenon light source, an endoscopic camera attached to the eyepiece of the telescope, a video monitor, and recorder ( Fig. 17.1 ). The 0-degree telescope is useful for direct viewing while the oblique (30- or 50-degree) and periscope (90-degree) telescopes provide a panoramic view of the pleural cavity. Selection of trocars of varying sizes (5–13 mm in diameter) and made of disposable plastic or reusable stainless steel, as well as rigid telescopes of different angles of vision, depends on the operator’s preference and patient consideration. A large trocar that accommodates a larger telescope with better optics improves the quality of examination; however, compression of the intercostal nerve during manipulation of the trocar can cause greater discomfort, especially if MT is conducted under local anesthesia and moderate sedation. A 7-mm trocar, 0-degree viewing 4-mm or 7-mm telescope, and 5-mm optical forceps will often allow for effective pleural biopsy without the need for a second port and frequently is often the initial approach used for rigid thoracoscopy.
Tassi and Marchetti reported excellent views of the pleural space using a 3.3-mm telescope for a group of patients with small loculated pleural effusions that were inaccessible to standard-sized instruments. Two 3.8-mm trocars were used: one for a 3.3-mm telescope and the other for a 3-mm biopsy forceps. Diagnostic yield of 93.4% was comparable with that achieved using conventional 5-mm biopsy forceps.
The flex-rigid pleuroscope represents an advance in the field of MT as it is fashioned like a bronchoscope, making it easier to learn for physicians who have previously mastered bronchoscopy. The autoclavable flex-rigid pleuroscope (LTF 160 or 240, Olympus, Tokyo, Japan) has a handle and a shaft that measures 7 mm in outer diameter and 27 cm in length. The proximal 22 cm is rigid, whereas the distal 5 cm is flexible with two-way angulation (160 degrees up and 130 degrees down). It has a 2.8-mm working channel that can accommodate biopsy forceps, needles, cryo- and electrosurgical accessories ( Fig. 17.2 ), as well as interfaces with existing processors (CV-160, CLV-U40) and light sources (CV-240, EVIS-100 or 140, EVIS EXERA-145 or 160) made by the same manufacturer available in most endoscopy units at no additional cost. The procedure is typically performed in the bronchoscopy suite using local anesthesia and moderate sedation. A single 1-cm skin incision to accommodate the disposable flexible trocar is required to perform flex-rigid pleuroscopy. The flex-rigid pleuroscope is also equipped with narrow band imaging (NBI), a technology that highlights mucosal abnormalities and vascular patterns associated with malignancy. NBI can aid in the detection and biopsy of early pleural lesions.
The only contraindication is the lack of pleural space due to adhesions. However, Marchetti and colleagues have demonstrated that MT can be safely performed by trained practitioners in patients without pleural effusions over sites where lung sliding is observed on thoracic ultrasound (US). Since MT is performed under moderate sedation in spontaneously breathing patients with partial or near-total lung collapse, the patient must not have hypoxia unrelated to pleural effusion, unstable cardiovascular status, bleeding diathesis, refractory cough, or allergy to medications that are administered during MT.
History and physical examination are vital components of any preoperative evaluation. The entry site is selected after careful review of chest radiographs (CXR), decubitus films, US imaging, and computed tomography (CT). Prior to MT 200 to 300 mL of fluid is aspirated from the pleural cavity using a needle, angiocatheter, thoracentesis catheter, or Boutin pleural puncture needle. A pneumothorax is induced by opening the needle to air until stable equilibrium is achieved. Air causes the lung to collapse away from the chest wall to facilitate trocar insertion. The operator may choose to do MT directly with US imaging, which has been shown to reduce access failure as well as the need for iatrogenic pneumothorax.
Benzodiazepines (midazolam) combined with opioids (demerol, fentanyl, morphine) provide good analgesia and sedation. Meticulous administration of local anesthesia to the epidermis, aponeurosis, intercostal muscles, and parietal pleura at the entry site ensures patient comfort during manipulation of the thoracoscope.
There is increasing utilization of propofol in recent years to enhance patient comfort during talc poudrage. Propofol use, however, requires monitoring by anesthesiologists in many countries. In patients who received propofol titrated according to comfort, 64% developed hypotension, of which 9% required corrective measures. When propofol was compared against midazolam, more hypoxemia (27% vs. 4%) and hypotension (82% vs. 40%) were observed in the propofol group, which led to the authors’ conclusion that propofol should not be the first choice of sedation for MT.
Good pain control for talc poudrage was achieved by combining opioids, benzodiazepines, and anesthetizing the pleura with up to 250 mg of 1% lidocaine by spray catheter. Preoperative anesthesia should be individualized according to the patient’s general condition and expectations; however, physicians must be aware of potential adverse events associated with anesthetic drugs and be ready to manage them.
The patient is positioned in the lateral decubitus position with the affected side up. Continuous monitoring of the electrocardiogram, blood pressure, and pulse oximetry is performed throughout the procedure. Although the site of entry depends on the location of effusion or pneumothorax, hazardous sites such as the anterior chest where the internal mammary artery courses, axilla with lateral thoracic artery, infraclavicular area with subclavian artery, and diaphragm should be avoided. A single port between the fourth and seventh intercostal spaces of the chest wall and along the midaxillary line is preferred for diagnostic MT. A second port may be necessary to facilitate adhesiolysis, drainage of complex fluid collections, lung biopsy, or sampling of pathologic lesions located around the first entry site. Double port access may be necessary if rigid instruments are used, particularly around the posterior and mediastinal aspects of the hemithorax that are inaccessible due to partial collapse of lung, or when the lung parenchyma is adherent to the chest wall.
A single port will often suffice for the flex-rigid pleuroscope as its flexible tip allows easy maneuverability within a limited pleural space and around adhesions. A chest tube is inserted at the end of diagnostic MT and residual air is aspirated. The tube is removed as soon as the lung has reexpanded, and the patient may be discharged after a brief observation period in the recovery area. If talc poudrage or lung biopsy is performed, the patient is hospitalized for a period of monitoring, chest tube drainage, and to optimize pain control.
Thoracoscopic-Guided Biopsy of Parietal Pleura
|Clinical Scenario||Type of Procedure|
|Diagnostic thoracoscopy for indeterminate, uncomplicated pleural effusion where suspicion of mesothelioma is not high||Flex-rigid pleuroscopy a or use of rigid telescopes under local anesthesia|
|Trapped lung with radiographically thickened pleura||Rigid optical biopsy forceps a or flex-rigid pleuroscopy with flexible forceps performing multiple bites over the same area to obtain specimens of sufficient depth or use of flexible forceps, IT knife a , or cryobiopsy a|
|Mesothelioma is suspected||Rigid optical biopsy forceps a or flex-rigid pleuroscopy with IT knife a or cryobiopsy a|
|Pleuropulmonary adhesions||Fibrous: rigid optical biopsy forceps a or flex-rigid pleuroscopy with electrocautery accessoriesThin, fibrinous: flex-rigid pleuroscopy with flexible forceps|
|Empyema, split pleural sign, loculated pleural effusion||Rigid instruments (VATS) a or conversion to thoracotomy for decortication|
|Pneumothorax with bulla or blebs||Rigid instruments (VATS) a for staple bullectomy|
It is desirable to perform biopsy of the parietal pleura over a rib to avoid the neurovascular bundle ( Fig. 17.3 ). The forceps probe for the rib, grasp the overlying parietal pleura, and tear the pleura off, moving roughly parallel to and along the wall rather than “grab and pulling” perpendicular to the wall. Specimens obtained with the rigid forceps are larger than those obtained with the Abrams or Cope needle. Biopsies using the flex-rigid pleuroscope are smaller since they are limited by the size of the flexible forceps, which in turn depends on the diameter of the working channel. The flexible forceps also lack the mechanical strength necessary to obtain deep pleural specimens, which might pose a challenge if mesothelioma is suspected. This problem can overcome by taking multiple biopsies (8–12) of the abnormal area as well as several “bites” of the same area to obtain more representative tissue.
Comparative studies show no difference in diagnostic yield between biopsies by flexible and rigid forceps even in mesothelioma if pleural biopsies could be successfully performed. Full-thickness parietal pleural biopsies can be obtained with the insulated tip (IT) diathermic knife during flex-rigid pleuroscopy. In one study, the reported diagnostic yields were 85% and 60% with IT knife and flexible forceps, respectively. The IT knife was notably useful when smooth, thickened parietal pleura was encountered, of which nearly half were malignant mesothelioma. Cryobiopsy is another method that achieves bigger specimens and better preserved cellular architecture and tissue integrity.
Management of Hemorrhage
The principal danger is hemorrhage from inadvertent biopsy of an intercostal vessel. External finger compression of the intercostal space over the bleeding site is the first intervention while another access port is made. The physician then uses two entry sites to examine and cauterize tissues at the same time. Direct pressure with gauze mounted on forceps can be applied from the inside to also tamponade the bleeding site. Connecting the chest tube to underwater seal can also reexpands the lung, serving to tamponade the bleeding site. If the bleeding does not cease with the aforementioned measures, thoracic surgery consultation is warranted. Surgical options include ligating the bleeding vessels with endoclips, enlarging the incision to facilitate repair, or even thoracotomy.
Thoracoscopic Talc Poudrage
Since malignant pleural effusion (MPE) tends to recur unless the primary tumor is chemosensitive, chemical pleurodesis plays an integral role in management of recurrent MPE. Recurrence prevention by chemical pleurodesis is also a primary goal for secondary spontaneous pneumothorax. Chemical pleurodesis is performed via instillation of sclerosant through intercostal tube or small-bore catheter or via talc poudrage during thoracoscopy. Thoracoscopic talc poudrage is performed after fluid aspiration and pleural biopsy, and can be administered by various delivery devices such as talc spray atomizer or bulb syringe, where talc is administered via the trocar without visualization but sprayed in different directions within the pleural space ( Fig. 17.4 ).