Thoracoscopy is a closed surgical technique that involves the use of a lighted telescope that is introduced into the thoracic cavity to diagnose or treat pathology. The basic technique is an old one, first described by Jacobaus in 1910. He reported using a cystoscope that was introduced into the pleural space to dissect adhesions in patients with pulmonary tuberculosis. This produced a complete pneumothorax, the primary treatment for the disease at that time. Because the optics were poor and as general inhalational anesthesia became less dangerous, open thoracotomy became more popular, and thoracoscopy became nearly obsolete. Gradually, optics and instrumentation for laparoscopic and thoracoscopic procedures improved, causing a concomitant push for minimally invasive procedures. This resulted in a revitalization of thoracoscopy as an alternative to open thoracotomy.
These endoscopic techniques were used little in children until the last two decades as optical telescopes and cameras have decreased in size and increased in quality. One of the first descriptions of thoracoscopy in children was in 1979, when Rodgers reported using the technique for diagnosis of diffuse pulmonary infiltrates in immunosUppressed children.1 Since then, thoracoscopy has been used for many diagnostic and therapeutic problems, including trauma, decortication of empyemas, resection of intrathoracic cysts, management of recurrent pneumothoraces, and diagnosis or treatment of parenchymal, mediastinal, and pleural tumors.
Thoracoscopy has many advantages over open thoracotomy. The 1-cm puncture wounds of thoracoscopy are much less painful than the large ribspreading incision of an open procedure. These small incisions often make it unnecessary to use a chest tube postoperatively when the lung parenchyma is not violated. Patients undergoing a closed procedure often can be discharged the same day, or certainly the day after the procedure, versus a 1-week hospitalization for open thoracotomy. Often, operating room time is decreased because of shorter closure time, adding to the decrease in the overall cost of thoracoscopy. Also, thoracoscopy usually results in decreased blood loss compared with an open thoracotomy. It is a safe procedure and can be converted easily to an open procedure if the diagnostic or therapeutic objectives cannot be accomplished in a closed manner.
Some Common Reported Indications for Thoracoscopy in the Pediatric Age Group
Possibly, the greatest advantage is the rapidity of healing small thoracoscopy wounds. This not only allows children to return rapidly to their previous activities, but also allows patients needing chemotherapy or radiation treatment to immediately resume their respective protocols.
As a result of miniaturization of fiberoptic systems and enhanced instrumentation, the indications for diagnostic and therapeutic use of thoracoscopy have multiplied. These have become so numerous that most open procedures have a corresponding closed technique (Table). Numerous applications for both benign and malignant disease have been described. Kapsenberg described thoracoscopy for lung biopsy in patients with diffuse changes on chest radiograph or with pleural effusions of unknown etiology.2 In a group of 1 1 5 patients, he reported no major complications, and positive pathology was obtained in 95%. These results are better than many series of percutaneous needle or transbronchial biopsy, and fewer complications are noted compared with open-lung biopsy. Even though thoracoscopy is an excellent technique for obtaining tissue, we have not realized a great advantage using thoracoscopy for patients with diffuse lung disease. For this problem, we use a small anterior minithoracotomy and stapler on the lingular segment. The small incision is minimally painful, and the procedure is as well tolerated as thoracoscopy. Thoracoscopy, though, is useful for diagnosing pathology in the posterior or apical areas of the lung not accessible to a minithoracotomy.
Thoracoscopy also has been used as a diagnostic tool in trauma patients. Adamthwaite recommended this technique in all patients with abnormal chest radiographs suggesting traumatic diaphragmatic hernia.3,4 This may become popular because these injuries are often difficult to diagnose on plain chest radiograph or computerized tomography (CT) scan. Thoracoscopy also has proved useful in penetrating trauma to determine trajectory of bullets entering the chest cavity and to remove knives and sharp objects from the thoracic cavity under direct vision.
Thoracoscopy has become useful not only in the diagnosis but also in the therapy of many benign diseases. The use of thoracoscopy in the treatment of patients with loculated pleural effusions or empyemas has been described.5 Moreover, we now believe that hospital stay can be significantly shortened by early thoracoscopy and decortication for patients with loculated fluid collections not responsive to thoracostomy drainage.
Tribble and his colleagues described five cystic fibrosis patients in whom thoracoscopy was used to lyse adhesions in patients with recurrent pneumothoraces.6 Talc was then dusted over the entire lung surface. No complications or recurrences developed. A similar use of thoracoscopy was described by Hejgaard and Olsen in a patient with a chylothorax.7 They first drained the chest, inspected the entire cavity, and then sclerosed with tetracycline.
Improvement in instrumentation and miniaturization has allowed pediatric surgeons to do a number of thoracoscopic procedures, such as removal of simple intrathoracic cysts, on infants.5,8 In addition, other procedures such as sympathetectomy have been described.9 Pericardiectomy and thymectomy also have become simple closed procedures. Thoracoscopic ligation of patent ductus arteriosa have been described, and cardiac surgeons are contemplating thoracoscopic coronary bypass surgery that is being studied on a bovine model.10
Thoracoscopy also has become popular for the pediatric oncology patient. As mentioned, one of the first descriptions of the use of the technique for lung biopsy in children was in the immunologically suppressed patient.1 Shortly thereafter, Rodgers reported 100% diagnostic accuracy in 42 immunocompromised children.11
Figure 1. This photograph shows the recently developed Thoracoport for use in thoracoscopy. Note the blunt trocar and the short length of the cannula, which is ideal for insertion through the chest wall. Photo courtesy of United States Surgical Co, Norwalk, Connecticut. Reprinted with permission from Lobe T, Schropp K1 eds. Pediatric Laparoscopy and Thoracoscopy. Philadelphia, Pa: WB Saunders Co; 1993. Copyright ® 1993 WB Saunders.
Figure 2. A single firing of the EndoGia stapler results in stapling and cutting. Three rows of air tight staples are placed on either side of the cut tissue. It is very useful for lung biopsies and segmental pulmonary resections.
Diagnosis and staging of intrathoracic neoplasia also has been described.11 It has become increasingly easy to biopsy parenchymal, pleural, and mediastinal tumors. Parenchymal lesions are easiest to remove if they are localized by computed tomographic scan and are peripheral in location. The one difficulty with thoracoscopy is that it is not possible to feel the lesion with the surgeons fingers, the major method for finding intraparenchymal lesions in an open thoracotomy. Some of this handicap is being overcome by an ultrasound device that is mounted on the end of an instrument and can be the surgeon's "finger" to find a specific lesion. Once located, the new endoscopic staplers have made biopsy or resection of pulmonary lesions safe and efficient.
There are few contraindications to beginning a diagnostic or therapeutic thoracic operation with thoracoscopy to determine if the procedure can be accomplished endoscopically. However, in patients with complete pleural symphysis secondary to diffuse tumor or previous sclerosis, it may be hazardous to perform a closed procedure. If it is impossible to establish and maintain an adequate pneumothorax, thoracoscopy then becomes difficult. In patients with a coagulopathy associated with sepsis or cancer chemotherapy, an open procedure may be preferable because of problems with hemostasis. Occasionally, size becomes a relative contraindication for a closed procedure. For example, a small infant who needs a stapled lung biopsy may not have a large enough chest cavity to accommodate the endoscopic stapler.
The equipment used for thoracoscopy is generally interchangeable with laparoscopic instruments. In the last few years, as the popularity of noninvasive procedures has escalated, the equipment supporting the basic instruments has become more specialized. Specifically, shorter instruments including telescopes, cannulas, retractors, staplers, and biopsy forceps are helpful in traversing the shorter distances encountered in thoracoscopic procedures.
The basic instrument used for thoracoscopy is a telescope and a cold light source. The telescope we have found to be the most useful for small pediatric patients is the 4-mm Storz instrument. As with all fiberoptic, Hopkins rod-lens systems (the most common optical telescope systems used today), the larger the diameter of the scope and fiber bundles, the better the optics. Unfortunately, with smaller children and infants, it is difficult to pass an endoscope much larger than 4 mm between the ribs. A standard 10-mm telescope (which is what is usually used in adults) gives better visualization but is hard to introduce in a child younger than 7 to 8 years of age. Also, the long length of the 10-mm scope makes its use awkward in children.
Other basic instruments for thoracoscopy include a cannula or port that will allow the telescope to pass through the chest wall. There are many different types. One of the first disposable instruments developed was a Surgiport (USSC, Norwalk, Connecticut), which is an airtight cannula through which a trocar fits. After the cavity is entered, the trocar is removed, leaving the hollow cannula. A more recent development was the Thoracoport (USSC, Norwalk, Connecticut), which has a blunt tip, is shorter, and is ideal for use in the chest (Figure 1).
One of the most valuable devices in our practice for thoracoscopic procedures is the EndoGia stapler (USSC, Norwalk, Connecticut) (Figure 2). This instrument leaves six airtight rows of staples and then cuts between. The major disadvantage for children is that it must be passed through a 12-mm port, which is not always possible in small children under 4 years of age. Overall, it is very useful for pediatric thoracoscopies in older children, and it has made closed lung biopsies, lobectomies, and pneumonectomies relatively easy.
Figura 3. This drawing depicts elevation of the right hemidiaphragm and liver following left main stem intubation with collapse of the right lung. Therefore, needle aspiration to ensure entry into the chest cavity should be performed at the level of the second or third intercostal space. Reprinted with permission from Rogers D, Philippe P, Lobe T1 et al. Thoracoscopy in children: an initial experience with an evolving technique. J Laparoendosc Surg. 1992;2:7-14. Copyright ® 1992.
The type of anesthesia is dependent on the diagnosis, the complexity of the procedure, and the skill of the anesthesiologist. Improvement in pediatric anesthesia techniques has enabled thoracoscopy to become a possibility in children as a complete pneumothorax is necessary to accomplish a successful closed operation. Three basic anesthetic techniques are possible. Local anesthesia with intercostal block has been advocated. It has the advantage of easily maintaining a pneumothorax because there is no positive pressure on either bronchus and it entails minimal risk. The disadvantage is that few pediatric patients will cooperate to make the procedure satisfactory for the surgeon or the patient.
General, intravenous, spontaneously breathing anesthesia is occasionally used in children. Its advantages are similar to local anesthesia with ease in establishing and maintaining a pneumothorax. Many anesthesiologists feel uncomfortable with this technique because it is difficult to obtain airway control, if necessary, as the patient is positioned in the decubitus position.
Difficulty in quickly intubating children younger than 3 years of age has prompted a preference for the third method, general inhalational anesthesia. As in a thoracotomy, most anesthesiologists feel comfortable with this technique; therefore, it is the most common method used not only for young children but also for all pediatric thoracoscopies. It has the disadvantage of greater difficulty for the surgeon to create and maintain a pneumothorax since the positive intrathecal pressure of an intubated patient opposes a complete pneumothorax. A double lumen endotracheal tube is preferred, allowing ventilation of either or both lungs. Selective intubation of the opposite mainstem bronchus with a cuffed endotracheal tube is necessary if the child is too small for a dual lumen tube. Flexible bronchoscopy may be a useful adjuvant to assure correct tube position after positioning the patient for the procedure. When selective intubation is not complete, the positive pressure in the lung is often a constant battle for the surgeon. Anesthesiologists experienced in adult thoracoscopy are gaining experience with endotracheal intubation using selective bronchial-blocking devices (resembling fogarty catheters) to decrease the ventilation of the ipsilateral lung.
The child is placed in the lateral decubitus position with the side of the pathology away from the table. After prepping, the patient is draped as widely as possible, in the event an open thoracotomy is required. Intercostal spaces are then identified and numbered. In the second or third space, a 21-ga or Veress needle, which has a blunt, retractable tip, is passed over the rib into the pleural space. Care is taken to aspirate to make sure the liver, spleen, or one of the pulmonary vessels has not been entered. It is actually quite easy to enter the liver or spleen since selective intubation may cause the ipsilateral lung to collapse before the pneumothorax is created, causing the diaphragm to be retracted high into the chest (Figure 3). Ten cc/kg of air is then slowly pushed into the pleural space, watching for any signs of tension pneumothorax.
Next, an incision no bigger than the port to be used is made in the skin in an interspace that will give the most direct view of the lesion. Blunt dissection with a hemostat is accomplished through the intercostal muscles until the pleura is seen. Carefully, dissection is continued until the pleura is opened and a hiss of air entering the pleural cavity is heard. The cannula is then gently passed into the pleural space followed by insertion of the telescope through the cannula. A meticulous survey of the entire chest cavity is performed, adding air if necessary.
At this point, if the endotracheal tube is properly positioned, a complete pneumothorax should be seen with complete deflation of the lung. If the lung remains inflated, and the anesthesiologist cannot reposition the endotracheal tube to allow the lung to deflate, low pressure insufflation with CO2 can be used, watching vital signs closely for deleterious effects of a controlled tension pneumothorax. An angled scope can be used to view areas not visible to the straight viewing scope. Additional cannulas must be placed in positions that will offer the best retraction or most direct angle for biopsy. Generally, three or four cannulas are required for most procedures including one for the telescope, one or two for graspers or retractors, and one for stapler/clip applier/ scissors.
Unfortunately, much more thought must be put into the placement of cannulas in children than in adults because the size of the instruments in relation to the size of the patients must be considered. Placement of ports may need to be close to the diaphragm in smaller children, just to be able to place the entire working end of an instrument into the thorax (eg, endoscopic stapler). Also, since it may be difficult to fit larger ports between ribs, it is necessary to determine where the largest port can be used most efficiently.
If the goal of the procedure is to obtain a diagnosis of pathologic tissue, the biopsy should be sent immediately for frozen section. In some settings, failure to obtain a diagnosis thoracoscopically should be an indication for opening the chest to obtain adequate tissue for diagnosis. If tissue resection is planned or if the biopsy is large, one of the cannula incisions can be enlarged, with little extra discomfort to the patient since the ribs are not being spread.
When the objectives of the operation have been met, the ports are removed. A chest tube may be placed and exteriorized through one of the cannula incisions. If biopsy of a mediastinal or pleural lesion was done, the chest tube can usually be removed once the skin incisions are closed with a single subcutaneous stitch, and the pneumothorax has been evacuated through the tube. While we often omit the tube thoracostomy when lung parenchyma is resected using the EndoGia stapler, the safer course may be to leave a chest tube in the pleural space overnight. This is particularly true if the patient is on a positive pressure ventilator.
Most of the complications described with thoracoscopy have been minimal. Tension pneumothorax may be observed as the original air or CO2 is introduced into the chest to create and maintain a pneumothorax. Air or CO2 embolism into the pulmonary vessels or the liver may be manifested by acute cardiovascular collapse as the pneumothorax is being created. The pneumothorax should be evacuated immediately using the needle. Unless there is massive embolism, as caused by the automatic insufflator, the patient usually does well with supportive treatment.
Because a pneumothorax must be created to introduce the telescope, the diaphragm is often elevated. This causes the subdiaphragmatic viscera, specifically the liver and spleen, to be at risk for injury from insertion of the insufflating needle or trocars. The best treatment for this complication is avoidance of injury by remembering how often these organs may be displaced.
Hemorrhage occasionally occurs during dissection and may appear quite brisk. This often can be remedied by laser coagulation or ligation of the bleeding vessel with an endoscopic clip. Rarely will the procedure need to be converted to an open thoracotomy.
The overall results of this relatively low-risk procedure have been excellent. In the American literature, diagnostic accuracy for thoracoscopic biopsy has been reported between 92% and 100%. 12·13 Little has been written in the pediatric literature over the last few years since thoracoscopy only recently has gained much popularity. We have recently detailed our initial experience with benign and malignant disease in children.5 There has not been a reported mortality directly due to this technique in children, and complications have all been minor. The most serious problem has been the need to convert to open thoracotomy.
The future of thoracoscopy in children depends to a large extent on the creation of new and better instruments. Already there have been lobectomies, pneumonectomies, and patent ductus arteriosus ligations using the thoracoscopic approach. As lasers, clip appliers, and staplers become increasingly sophisticated and smaller, and suturing techniques become more efficient, the possibilities for use in the pediatric population are as numerous as the number of open procedures.
1. Rodgers B, Moazam F1 Talbert J. Thoracoscopy: early diagnosis of interstitial pneumonitis in the immunologically suppressed child. Chest. 1979;75:126-130.
2. Kaspsenberg P. Thoracoscopic biopsy under visual control. Poumon Coeur. 1981:37:313-316.
3. Adamthwaite D. Diaphragmatic hernia presenting itself as a surgical emergency. injury. 1984:15:367-369.
4. Adamthwaite D. Traumatic diaphragmatic hernia. Surg Annu. 1983;15:73-97.
5. Rogers D, Philippe P, Lohe T, et al. Thoracoscopy in children: an initial experience with an evolving technique. J Laparoendosc Surg, 1992;2:7-14.
6. Tribble C, Seiden R, Rodgers B. Talc poudrage in the treatment of spontaneous pneumothoraces in patients with cvstic fibrosis. Ann Surg. 1986;204:677-680.
7. Hejgaard N, Olsen R Massive Gotham osteolysis of the right hemipelvis complicated by chylothorax: report of a case in a 9-year-old boy successfully treated by pleurodesis. J Pediatr Orthop. 1987;7:96-99.
8. Rodgers B, Harman P, Johnson A. Bronchopulmonary foregut malformations. The spectrum of anomalies. Ann Surg. 1986;203:517-524.
9. Kux M. Thoracic endoscopic sympathectomy in palmar and axillary hyperhidrosis. Arch Surg. 1978;113:264-266.
10. Labotde F, Noirhomme P, Karam J, Bâtisse A, Bourel P, Saint .Maurice Q A new video-assisted thoracoscopic surgical technique for interruption of patient 'ductus' arteriosus in infants and children. ) Thorac Cardiovase Surg. 1993;105:278-280.
11. Rodgers B. Thoracoscopy in children, ftiumon Coeur. 1981;37:301-306.
12. Rodgers B1 Ryckman F, Motuam F, Talbert J. Thoracoscopy for intrathoracic tumors. Ann Thorac Surg. 1981;31:414-420.
13. Ryckman FC, Rodgers BM. Thoracoscopy for intrathoracic neoplasia in children. Pediatric Surgery. 1982;17:521-524.
Some Common Reported Indications for Thoracoscopy in the Pediatric Age Group