Advertisement

Thoracoscopic or Video-Assisted (VATS) Thymectomy 1

  • Stephen R Hazelrigg
    Correspondence
    Address correspondence to Stephen R. Hazelrigg, MD, Professor and Chairman, Division of Cardiothoracic Surgery, P.O. Box 19638, Springfield, IL 62794-9638 USA
    Affiliations
    Division of Cardiothoracic Surgery, Southern Illinois University School of Medicine, Springfield, IL, USA
    Search for articles by this author
      We began our experience with VATS (Video-Assisted Thoracic Surgery) thymectomy in 1992. This procedure evolved out of a larger VATS experience with lung and other thoracic procedures. We reported our experience in 33 thymectomies for myasthenia gravis and concluded that it was as effective as other approaches. The cosmetic benefit was also thought to be a positive impetus for earlier thymectomy.

      Surgical technique

      Figure thumbnail GR1
      1The patient is positioned in the full left lateral decubitus position and the table is flexed at 30°. A double lumen endotracheal tube is placed and single lung ventilation used. Typically, we use three port sites and a zero degree thoracoscope.
      Figure thumbnail GR2
      2All ports are placed anterior to the midaxillary line. The highest port is in the third to fifth ICS (intercostal space) and two other ports around the seventh ICS. In females, the port sites can be placed strategically over the submammary fold for cosmetic consideration.
      Figure thumbnail GR3
      3The scope is introduced and the entire hemithorax is examined. The right phrenic nerve is identified and carefully preserved throughout the dissection. In most cases, we do not place trocars but simply work through the incisions and use standard instruments such as ring forceps.
      Our dissection of the thymus gland begins at the right inferior pole over the pericardium. The mediastinal pleura is incised and the thymus can be lifted up and easily dissected off the pericardium.
      Figure thumbnail GR4
      4The thymus and mediastinal fat are then gently dissected to expose the superior vena cava and the brachiocephalic vein. There are several venous tributaries into the thymus and these must be dissected and clipped (endoclip, autosuture, U.S. Surgical Corp.) before transection. We find gentle traction on the gland and the use of Kitner’s or dental pledgets works well at exposing these structures. There are usually two or three venous tributaries and they can be avulsed quite easily if care is not taken.
      Figure thumbnail GR5
      5After controlling the vascular structures, dissection is carried behind the sternum. The gland is retracted with the sponge forceps. By then pulling the gland toward the right side, the left inferior horn can be identified. This is dissected completely up to the isthmus of the thymus, and bluntly off the left sided pleura. Much of this dissection can be performed bluntly and care must be taken not to injure the left phrenic nerve.
      Dissection of the superior horns of the thymus gland may be challenging. Arterial branches from the internal mammary arteries are identified and clipped as the dissection moves to the cervical area.
      Figure thumbnail GR6
      6Some retraction of the thymus inferiorly allows visualization during dissection of the superior poles. We pull down with moderate force on the superior poles and using a combination of blunt and sharp dissection the gland is completely freed. Bending the patient’s head forward may enhance exposure.
      Figure thumbnail GR7
      7The free thymus gland is placed in a specimen bag and removed through the most anterior trocar site. Following thymectomy, the mediastinum is inspected and any suspicious fatty tissue removed. The brachiocephalic vein should be skeletonized and the junction with the superior vena cava clearly visible.
      At completion the decision of whether to leave a chest tube is optional (assuming there was no injury to the lung). In most cases, we do not leave a drain but expand the lung with a soft catheter that is withdrawn after no air escapes with its end under water. The incisions are closed with subcuticular absorbable sutures.
      VATS thymectomy can be performed in several different ways. It can be done from either chest or in combination with a cervical approach. Reports of doing it with costal hooks to pull the chest forward have been described. Our preference has become a right thoracoscopic approach because it gives the best view of the venous anatomy and provides the most working space.

      Summary

      VATS thymectomy can be performed for myasthenia gravis with results comparable to sternotomy. It is cosmetically pleasing and generally patients are discharged within two days. There are no lifting restrictions or healing concerns such as exist with sternal incisions.
      Minimally invasive routes for resection of thymomas remain controversial. VATS resection has been described and is quite feasible for small tumors. The concern of drop metastases or compromise of oncologic results has caused most surgeons to use median sternotomy for these tumor resections.
      The completeness of thymic resection has been questioned. However, our comparison of 33 cases did not show any inferior results, in fact, 88% (29/33) showed clinical improvement. Our data analysis compared with nine published series performed by other approaches showed no difference in clinical outcomes based on the surgical approach. Thymectomy may be considered a more advanced VATS procedure and probably best done by those with moderate prior VATS experience.
      Thoracoscopic thymectomy provides better visualization than the cervical route and cosmetic superiority to sternotomy. As long as a complete thymic resection can be achieved then it is a viable surgical approach. By providing a minimally invasive approach VATS may lead to wider acceptance of earlier thymectomies by myasthenia gravis patients and their neurologists.