Patients planning to undergo mediastinoscopy should have a complete history and physical examination. It is important to know if the patient had previous interventions in the neck and in the mediastinum, i.e. cervicotomy for goitre or neck tumours and tracheostomy, laryngectomy or median sternotomy for mediastinal or heart diseases. These rarely contraindicate mediastinoscopy, but the surgeon should be aware of them. Neck flexibility should be checked, too, because it is important to properly insert the mediastinoscope. Complete blood count and biochemistry, as well as coagulation tests, should be available before the operation. For those patients with high or moderate risk for thromboembolism (patients with a mechanical heart valve, atrial fibrillation or venous thrombosis), bridging anticoagulation is recommended with therapeutic doses of subcutaneous low-molecular-weight heparin 5 days before the operation. Regarding the perioperative antiplatelet therapy , it is recommended to stop aspirin and clopidogrel 5–7 days prior to surgery and restart within 24 h after surgery, except for doses of 100 mg of aspirin that do not need to be stopped [27].

Chest x-rays, CT of the chest and PET scans are necessary to identify the target areas in the mediastinum and should be available at the time of the operation. Although mediastinoscopy should be as complete as possible in all cases, if the surgeon knows the location of the abnormal lymph nodes or the site where the tumour contacts the mediastinum, these areas are not likely to be missed. The patient should be seen by an anaesthesiologist to assess the risk associated with general anaesthesia and should be informed of the most frequent complications (left recurrent laryngeal nerve palsy, pneumothorax) and of the rare but potentially fatal ones (bleeding, tracheobronchial and oesophageal perforation), as well as of the potential need for blood transfusion. The patient is required to sign an informed consent form.

Under general anaesthesia and oro-tracheal intubation, the patient is positioned in the supine decubitus. A double-lumen oro-tracheobronchial tube may be necessary if additional procedures are planned. For standard intercostal thoracoscopy or for mediastino-thoracoscopy, for which opening of the mediastinal pleura to reach the pleural space is required during mediastinoscopy, selective single-lung ventilation is needed to inspect the pleural space properly. The patient’s shoulders are raised with a long sand cushion. This allows some hyperextension of the neck and exposure of a long segment of the intrathoracic trachea, especially in young patients. The patient’s head is allowed to rest on a circular rubber pillow to prevent displacement during the operation. In addition to the EKG leads and the blood pressure cuff, a pulse metre is fixed in one right-hand finger to control the occlusion of the innominate artery that may occur during mediastinoscopy, when excessive pressure is exercised on the artery with the mediastinoscope against the anterior chest wall. Pressure is easily relieved by repositioning the mediastinoscope (Fig. 24.3).

An operative field is prepared and draped from the mandible, cranially, to the xiphoid, caudally, and from nipple to nipple, laterally. An extra drape is positioned caudal to the sternal notch to cover the sternum. In case median sternotomy is needed during mediastinoscopy, this drape can be quickly removed.

The surgeon either stands or sits at the head of the patient, depending on the moment of the operation. The assistant and the scrub nurse stand on the right. The television monitor, if the procedure is performed with a video-mediastinoscope, is positioned at the patient’s feet, slightly on the left.

A 5-cm collar incision is performed as close to the sternal notch as possible. After incising the skin, subcutaneous tissue and platysma, the avascular midline is incised, and the paratracheal muscles are dissected and separated laterally. Although this is a low-neck incision, sometimes the thyroid gland can be found covering the trachea. By blunt dissection and finger retraction, the thyroid gland can be pulled cranially to allow the insertion of the mediastinoscope. The pretracheal fascia is intimately attached to the trachea. It is hold with dissection forceps and incised with scissors. The fascia is further separated from the trachea by finger dissection: the index finger is inserted into the fascial opening, and the finger is carried caudally tearing most of the length of the pretracheal fascia.

Contrary to other endoscopies performed in virtual cavities, i.e. the pleural cavity (pleuroscopy), the peritoneum (laparoscopy) or a joint (arthroscopy), there is no mediastinal space as such. A space must be created in the upper mediastinum by finger dissection. In addition to creating an adequate mediastinal space, palpation allows the surgeon to feel the size, consistency and degree of attachment of mediastinal lymph nodes, mediastinal tumours or bronchogenic carcinomas with direct mediastinal contact or invasion.

Palpation must be systematic, and the anatomical landmarks must be recognized. In the typical case, after inserting the distal phalange of the index finger, the pulsation of the innominate artery can be felt. In young patients, when the neck is hyperextended, the innominate artery may become cervical and may be seen after completing the cervical incision. In older patients, the innominate artery may be located more caudally, if the neck cannot be hyperextended, or more cranially if the aortic arch is elongated. In all these circumstances, care must be taken not to injury it in these initial manoeuvres. Following the course of the innominate artery on the left, the aortic arch can be felt. Then, the finger is passed more distally behind the aortic arch. By palpation, the tracheal cartilages can be felt. Close to the carina, they are disrupted, as the trachea separates into the two main bronchi.

After creating a peritracheal space by finger palpation, the mediastinoscope is inserted into the upper mediastinum. At this point, the exploration is performed more comfortably if the surgeon sits on a chair. The height of the operating table and of the chair has to be regulated to relieve tension at the surgeon’s shoulders and elbows.

From top to bottom, the pulsation of the innominate artery is seen first. The pulsation of the ascending aorta is seen on the left. More caudally, at the level of the right tracheobronchial angle, the azygos vein can be identified. The fatty tissue of the right paratracheal space has to be dissected to find the azygos vein. This landmark is important because, according to the new regional lymph node map, nodes caudal to the inferior rim of the azygos vein are coded as right hilar nodes, or 10R, although they are anatomically located in the mediastinum [1]. If the dissection is carried out more distally on the right, the whole length of the right main bronchus can be seen and, in some patients, even the origin of the right upper lobe bronchus. Over the right main bronchus, the right pulmonary artery is found, usually the distal end of the exploration on the right. Over the subcarinal space, the prolongation of the pretracheal fascia has to be torn to reach the subcarinal nodes. The right pulmonary artery crosses in front of them, and the oesophagus is behind. Care must be taken not to injure these structures. If the integrity of the oesophagus is questionable, a naso-oesophageal tube can be inserted and air injected into it. With the subcarinal space flooded with saline, an air leak will be evident if there is an oesophageal perforation. In more than 3000 mediastinoscopies, we have inserted a naso-oesophageal tube once, only, to rule out oesophageal perforation. On the left, it is important not to injure the recurrent laryngeal nerve that runs along the left paratracheal margin. The left tracheobronchial angle can be identified and, distal to it, the left pulmonary artery, marking the end of the exploration on the left. Nodes caudal to its upper rim are now coded as left hilar nodes, or 10L [1].

Lymph node biopsies for lung cancer staging must be systematically taken to obtain the maximal benefit from the exploration. Ideally, the taking of biopsies should start on the contralateral side to the tumour to rule out N3 disease. Macroscopically abnormal nodes should be sent for frozen section examination, and if nodal involvement is identified, mediastinoscopy may be terminated unless the patient is in a protocol that requires more information on the extent of nodal disease. Then, the subcarinal and the ipsilateral paratracheal nodes are biopsied. If the nodes are not removed entirely, the initial biopsies of each lymph node are ideal to examine the involvement of the nodal capsule and the extranodal tumour invasion. Each complete node or all the biopsies from one node are kept in a different container and properly labelled according to the present nodal nomenclature [1]. This makes the counting of the removed and involved nodes much easier and reliable. Whenever possible, it is better to remove the entire nodes to avoid missing micrometastases and increase the sensitivity of the exploration. Mediastinal lymph nodes are embedded in the peritracheal fatty tissue. Exploration of this fatty tissue with the dissection-suction-coagulation device allows the surgeon to identify them and free them from their surrounding. Sometimes, fragments of lymph nodes or whole small lymph nodes are suctioned during dissection. In this case, it is recommendable to filter the contents of the suction container to retrieve the suctioned lymph nodes or their fragments for pathological examination.

Mediastinoscopy allows the surgeon to reach the cervical nodes at the sternal notch, the superior and inferior paratracheal nodes on both sides, the subcarinal nodes and the right and left hilar nodes. However, the superior paratracheal nodes are hidden by the mediastinoscope when it is inserted and are not easy to identify. They are better explored and biopsied in the open fashion at the time of cervicotomy. The European Society of Thoracic Surgeons (ESTS) guidelines require biopsies from, at least, one right and one left inferior paratracheal nodes and one subcarinal node for an acceptable mediastinoscopy in clinical practice. In addition, the superior paratracheal and hilar stations should be explored, if there is imaging suspicion of nodal involvement. For cancers of the left lung, exploration of the subaortic and para-aortic nodes is also required, either by left parasternal mediastinotomy, extended cervical mediastinoscopy or left thoracoscopy [19] (Fig. 24.4).

The use of the dissection-suction-coagulation cannula minimizes bleeding during dissection of peritracheal tissue. Mediastinal lymph nodes usually are dark blue or black because of their anthracotic content. The azygos vein or a partially visualized superior vena cava may resemble lymph nodes. In case of doubt, especially if the standard mediastinoscope is used, a puncture test should be performed. If blood is seen along the glass suction tube, the needle should be removed and the bleeding site gently pressed with gauze for haemostasis. During this manoeuvre, care must be taken not to puncture through the trachea, because perforation of the endotracheal cuff is possible and already has been described [28]. All biopsy sites should be checked before closure . Coagulation of biopsied lymph nodes or peritracheal fatty tissue is enough to control bleeding. Control of bleeding from the bronchial arteries in the subcarinal space, especially those running in front of the left main bronchus, should be tried first with gauze packing and coagulation. If bleeding persists, clipping of the bronchial artery may be necessary. The gauze used for packing must be removed through the mediastinoscope to minimize tumour seeding in the cervical incision. Tumour cell dissemination during mediastinoscopy is possible. Cytological analyses of mediastinal lavage fluid have shown that tumour cells can be identified before and after taking biopsies, although long follow-up periods are needed to understand their prognostic value [29]. Major bleeding is an uncommon complication that may occur in 0.4% of procedures and may come from the azygos vein , the pulmonary arteries, the innominate artery—the most common sites of serious bleeding—the superior vena cava and the aorta. Packing and median sternotomy or thoracotomy, depending on the location of bleeding, is the usual procedure of haemorrhage control [30]. The glass cannula for puncture test may be connected to a syringe to puncture and aspirate lymph nodes. This is especially useful when the nodes are fixed to vessels. In this case, pulling or taking biopsies from the nodes may injure the attached vessel. The aspirate is then sent for cytological examination.

The paratracheal muscles are not sutured to the midline. This facilitates remediastinoscopy , if it is needed. The incision is closed in two layers: platysma and subcutaneous tissue together with 2-0 continuous absorbable suture and skin with 3-0 absorbable intradermal suture. Drainage is not necessary. The wound is dressed with gauze that can be removed in 24 h.

The patient is awakened and extubated in the operating room and sent to recovery room till the patient is fully conscious and the vital constants are normal and stable. Then the patient is transferred to the normal ward or to the outpatient surgery room. Oral intake is started 6 h after the operation. The patient can be discharged on the same day, if an outpatient surgery programme is active in the hospital, or the next day. The admission rate after outpatient mediastinoscopy for all indications ranges from 1 to 4%, and the main reasons are supraventricular arrhythmias, pneumothorax, bleeding from bronchial artery or late end of the operation [31]. Postoperative chest x-rays are not necessary unless something unusual has occurred during (opening of the mediastinal pleura or bleeding) or after surgery (fever, dyspnoea or chest pain).

Intraoperative complications are infrequent, ranging from 0.6 to 3.7% [32, 33]. The occlusion of the innominate artery and bleeding from the most common sites have been described above. Other complications are wound infection, pneumothorax, mediastinitis, left recurrent laryngeal nerve palsy, oesophageal perforation, bronchial injury, chylomediastinum, haemothorax and incisional metastasis [34–39]. Mortality is below 0.5% [4, 40, 41].

Subaortic and para-aortic nodal stations cannot be reached with mediastinoscopy. Left parasternal mediastinotomy, performed over the second or third intercostal space, facilitates the exploration of this area but requires an additional incision and very often the removal of a costal cartilage [42, 43]. In 1987, Ginsberg et al. [44] reported their experience in extended cervical mediastinoscopy as a staging procedure for cancers of the left upper lobe, using the approach first described by Specht in 1965 [45]. To stage cancers of the left lung, after mediastinoscopy has been completed and from the same cervical incision, a passage is created by finger dissection over the aortic arch, between the innominate artery and the left carotid artery, either in front or behind the left innominate vein. Once the fascia between these two vessels is torn with the finger, the finger can be advanced easily over the aortic arch. Then, the mediastinoscope is inserted, and the lymph nodes in the subaortic station can be explored and biopsied. By moving the mediastinoscope medially, the para-aortic nodes also can be explored, although differentiating between subaortic and para-aortic nodes is not easy because mobilization of the mediastinoscope is limited by the bony structures of the chest wall. Extended cervical mediastinoscopy does not allow the surgeon to palpate the subaortic space well. If palpation is needed to differentiate between mere contact and tumour invasion in this area, then parasternal mediastinotomy is a much better approach. The parasternal incision allows the surgeon to inspect the subaortic space directly, but the mediastinoscope can also be used to facilitate the exploration. Additionally, a small rib spreader can be inserted to widen the operative field. Bimanual palpation from the collar incision and from the parasternal incision is useful to explore the integrity of the aortic arch (Fig. 24.5). Access to the pericardium, pleural space and lung is also possible from this incision. Right parasternal mediastinotomy is useful to assess the superior vena cava, the azygos vein, the right pulmonary artery, the right superior pulmonary vein and the right anterior mediastinal nodes [46].