Chapter 12

Thoracoscopy

Pyng Lee

Division of Respiratory and Critical Care Medicine, National University Hospital, Singapore.

Correspondence: Pyng Lee, Yong Loo Lin Medical School, National University of Singapore, Division of Respiratory and Critical Care Medicine, Dept of Medicine, National University Hospital, 1E Kent Ridge Road, NUHS Tower Block Level 10, Singapore 119228. E-mail: mdclp@nus.edu.sg

Thoracoscopy, VATS, medical thoracoscopy (MT) and pleuroscopy are minimally invasive procedures that provide access to the pleural space. They differ only in their approach to anaesthesia. In this chapter, our focus will be on diagnostic MT.

VATS is performed by a surgeon in the operating room using single-lung ventilation, three entry ports and rigid instruments. VATS is used for: stapled lung biopsy, resection of pulmonary nodules, lobectomy, pneumonectomy, oesphagectomy, pericardial windows, guided parietal pleural biopsy, drainage of pleural effusion or empyema, and pleurodesis [1, 2].

MT is conducted by a pulmonologist in an endoscopy suite; local anaesthesia and conscious sedation are used. MT allows biopsy of the parietal pleura under direct visualisation with good accuracy, and achieves fluid drainage, guided chest tube placement and pleurodesis [3]. In Europe, MT sympathectomy is used for essential hyperhidrosis, and lung biopsy is used for diffuse lung disease [4].

Table 1 provides a comparison of VATS and MT.

In 1910, Swedish internist Hans-Christian Jacobaeus 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 with galvanocautery, also known as the Jacobaeus operation, to collapse the tuberculous lung as part of anti-tuberculous therapy [5, 6]. At a presentation to the American College of Surgeons, Jacobaeus suggested that when “making a differential diagnosis between tumours and pleurisy of other origin, thoracoscopy is of no small value” [7]. He was a strong advocate of thoracoscopy-guided biopsies in the evaluation of pleural effusions of unknown aetiology, and applied thoracoscopy as a diagnostic and therapeutic tool [7].

Equipment

Rigid instruments

Historically, rigid instruments such as stainless steel trocars and telescopes are central to the technique (figure 1) [3–9]. Rigid thoracoscopy requires a cold xenon light source, an endoscopic camera attached to the eyepiece of the telescope, a video monitor and a recorder. The 0-degree telescope is used to provide a direct view of the pleural cavity; the oblique (30- or 50-degree) and periscope (90-degree) telescopes provide a panoramic view of the pleural cavity [8, 9]. Trocars of varying sizes (5–13 mm in diameter) and of either disposable plastic or reusable stainless steel, as well as rigid telescopes providing different angles of vision, can be used depending on the operator’s preference and patient considerations. Examination quality can be improved using a bigger trocar that accommodates a larger telescope with better optics. Compression of the intercostal nerve during manipulation of the trocar can increase discomfort, especially if MT is conducted under local anaesthesia and conscious sedation. The preferred instruments for rigid thoracoscopy are a 7-mm trocar, a 0-degree viewing 4-mm or 7-mm telescope, and 5-mm optical forceps [4, 8, 9].

Figure 1. Rigid trocars, telescopes and accessories.

In 2003, in a group of patients with small loculated pleural effusions that were inaccessible to standard-sized instruments, TASSI and MARCHETTI [10] reported excellent views of the pleural space using a 3.3-mm telescope. Two 3.8-mm trocars were used: one for a 3.3-mm telescope and the other for 3-mm biopsy forceps. The diagnostic yield of 93.4% was comparable with that achieved using conventional 5-mm biopsy forceps.

Flexi-rigid pleuroscope

The flexi-rigid pleuroscope represents an advance in the field of MT as it is fashioned like a bronchoscope thereby allowing the operator to scale up the learning curve quickly. The autoclavable flexi-rigid pleuroscope (LTF 160 or 240, Olympus, Tokyo, Japan) has a handle and a shaft that is 7 mm in outer diameter and 27 cm in length (figure 2a). The proximal 22 cm is rigid, while 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 (figure 2b–d), and that can interface 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 [3, 13, 14]. Flexi-rigid pleuroscopy is generally performed in the bronchoscopy suite on patients under local anesthesia and conscious sedation [3, 14]. A single 1-cm skin incision to accommodate the disposable flexible trocar is required to perform flexi-rigid pleuroscopy. The flexi-rigid pleuroscope is also equipped with NBI, a technology that highlights mucosal abnormalities and vascular patterns associated with malignancy. NBI can aid the detection and biopsy of early pleural lesions [3]. NBI is discussed further elsewhere in this Monograph [15].

Figure 2. a) Flexi-rigid pleuroscope (LTF 160 or 240; Olympus, Tokyo, Japan). Similar in handling to a flexible bronchoscope and compatible with an existing processor and light source. The working channel can accommodate accessories such as b) a spray catheter, c) an insulated-tip knife (Olympus) or d) a cryoprobe (Erbe, Tübingen, Germany). b) Reproduced and modified from [11] with permission. c) Reproduced and modified from [12] with permission. d) Reproduced with kind permission of Erbe.

Contraindications

The only contraindication is the lack of pleural space due to adhesions, although this can be overcome by enlarging the skin incision or digitally dissecting the lung away from the chest wall. MT requires special skills and should not be undertaken without proper training. MARCHETTI et al. [16] advanced the technique further by performing MT in patients without pleural effusion but with demonstrable lung sliding on thoracic ultrasound. As MT is performed in a spontaneously breathing patient under conscious sedation who has suffered partial or near-total lung collapse, it is important that the patient does not have hypoxia unrelated to pleural effusion, unstable cardiovascular status, bleeding diathesis, refractory cough or allergy to medications that are administered during MT.

Patient preparation

Taking a patient’s history and performing a physical examination are vital to any pre-operative evaluation. The entry site is selected after careful review of the chest radiograph, decubitus films, ultrasound and CT. Before MT takes place, 200–300 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 the air until stable equilibrium is achieved. Air causes the lung to collapse away from the chest wall, which aids trocar insertion. The operator may choose to perform MT directly with ultrasound, which has been shown to reduce access failure and diminish the need for iatrogenic pneumothorax [16, 17].

Anaesthesia

Benzodiazepines (midazolam) combined with opioids (demerol, fentanyl, morphine) provide good analgesia and sedation. Patient comfort during manipulation of the thoracoscope can be achieved through meticulous administration of local anaesthesia to the epidermis, aponeurosis, intercostal muscles and parietal pleura at the entry site [18].

In recent years, propofol has been increasingly used to enhance patient comfort during talc poudrage. However, in many countries, propofol use has to be monitored by anaesthesiologists. In patients who receive propofol titrated according to comfort, 64% develop hypotension, with 9% of these requiring corrective measures [19]. In a comparison of propofol and midazolam, increased hypoxaemia (27% versus 4%) and hypotension (82% versus 40%) were observed in the propofol group, leading the authors to conclude that propofol should not be the first choice of sedation for MT [20].

Good pain control for talc poudrage was achieved by combining opioids with benzodiazepines and anaesthetising the pleura with 250 mg of 1% lidocaine via spray catheter [21]. Pre-operative anaesthesia should be individualised according to the patient’s general condition and expectations; however, physicians must be aware of the potential adverse events associated with anaesthetic drugs and should be ready to manage them.

Technique

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 carried out throughout the procedure. Although the entry site depends on the location of the effusion or pneumothorax, hazardous sites (e.g. anterior chest where the internal mammary artery courses, axilla with lateral thoracic artery, infraclavicular area with subclavian artery, diaphragm) should be avoided. The preference for diagnostic MT is a single port between the fourth and seventh intercostal spaces of the chest wall and along the mid-axillary line. A second port might be necessary to facilitate adhesiolysis, drainage of complex fluid collections, lung biopsy or sampling of pathological lesions located around the first entry site. If rigid instruments are used, double port access may be necessary, 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 [4, 8].

When using the flexi-rigid pleuroscope, a single port would suffice as its flexible tip allows easy manoeuverability within a limited pleural space and around adhesions [13, 14, 21]. At the end of diagnostic MT, a chest tube is inserted and the air is aspirated. The tube is removed as soon as the lung has re-expanded, and the patient can be discharged after a brief period of observation in a recovery area [22]. If talc poudrage or lung biopsy has been performed, the patient should be hospitalised for a period of monitoring and chest tube drainage [4, 14].

Thoracoscopic guided biopsy of parietal pleura

It is preferable to perform biopsy of the parietal pleura over a rib in order to avoid the neurovascular bundle (figure 3). The forceps probe for the rib, grasp the overlying parietal pleura and tear, rather than “grabbing and pulling”. Specimens that are obtained with rigid forceps are larger than those achieved with the Abram’s or Cope needle. Biopsies performed using the flexi-rigid pleuroscope are small as 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 required to obtain pleural specimens of sufficient depth, which may pose a challenge if mesothelioma is suspected. This technical hitch can be overcome by taking multiple (eight to 12) biopsies of the abnormal area as well as several “bites” of the same area to obtain representative tissue.

Figure 3. Biopsy of parietal pleura using a) flexible forceps, b) rigid forceps, c) a cryoprobe and d) an insulated-tip knife.

Comparative studies show no difference in diagnostic yield between biopsies performed with flexible and rigid forceps, even in mesothelioma [23]. Full thickness parietal pleural biopsies can be obtained using the insulated-tip diathermic knife during flexi-rigid pleuroscopy. One study reported that the diagnostic yields using the insulated-tip knife and the flexible forceps were 85% and 60%, respectively. The authors noted that the insulated-tip knife was useful when smooth, thickened parietal pleura was encountered, of which nearly half were malignant mesothelioma [12]. Cryobiopsy is another method that achieves larger specimens and better preserves the cellular architecture and tissue integrity [24].

Management of haemorrhage

A principal danger is haemorrhage 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 should then use two entry sites to examine and cauterise tissues at the same time. Direct pressure with gauze mounted on the forceps can be applied from the inside; in addition, connecting the chest tube to underwater seal re-expands the lung, which tamponades the bleeding site. If the bleeding does not cease, the surgeon might have to ligate the bleeding vessels using endoclips, enlarge the incision to facilitate repair and even consider thoracotomy.

Thoracoscopic talc poudrage

Chemical pleurodesis has an integral role as malignant pleural effusion (MPE) tends to recur unless the primary tumour is chemosensitive. Prevention of recurrence using chemical pleurodesis is also a primary goal for secondary spontaneous pneumothorax. Chemical pleurodesis is performed via instillation of a sclerosant through an 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 using various delivery devices, such as a talc spray atomiser or a bulb syringe. Thoracoscopic talc poudrage is discussed further elsewhere in this Monograph [25].

Complications

Mortality from rigid thoracoscopy ranges 0.09–0.34% [26, 27]. Talc poudrage was associated with 0.69% mortality, and a trial conducted in the USA using non-graded talc contributed to nine out of 16 deaths [28].

Major complications (prolonged air-leak, haemorrhage, empyema, pneumonia and port site tumour growth) occur in 1.8%, while minor complications (subcutaneous emphysema, wound infection, fever, hypotension and cardiac arrhythmia) are observed in 7.3% of MT [28, 29].

A serious but rare complication associated with pneumothorax induction is air embolism (<0.1%) [26]. During MT, litres of pleural fluid can be removed with minimal risk of re-expanding pulmonary oedema due to the immediate equilibration of the pressures provided by air through the trocar into the pleural space. Fever that occurs after talc poudrage generally resolves within 48 h; in comparison, bronchopleural fistula that requires prolonged chest drainage and suction may occur after thoracoscopic lung biopsy for ILD. Wound infection, pneumonia and empyema can develop as a result of long-term tube drainage [28, 29]. In cases of mesothelioma, prophylactic radiotherapy should be carried out within 2 weeks of MT to prevent tumour growth at the incision site [30].

Complications associated with the flexi-rigid pleuroscope are rare. No mortality was reported in a recent meta-analysis of 755 patients who underwent flexi-rigid pleuroscopy [13, 31]; however, training in the proper techniques cannot be overemphasised. Table 2 describes the type of patient suitable for rigid or flexi-rigid pleuroscopy.

Stay updated, free articles. Join our Telegram channel

Join