Thoracic Duct Leak Repair
A direct repair can be considered when the leak has been clearly identified. The site of the leak may be determined preoperatively by placement of right- or left-sided thoracostomy tubes or by the appearance of a milky-white drainage from a neck incision. The traditional approach for a leak in the pleural cavity is a muscle-sparing posterolateral thoracotomy. If the patient has had a recent thoracotomy, the prior incision is reopened either fully or in part with the adjunctive use of thoracoscopy if possible. On the right side, the course of the duct is inspected between the aorta and azygos vein along the spine (Fig. 133-2). The duct crosses into the left chest at the level of the fifth or sixth vertebral body.
Exposure of thoracic duct for direct repair by means of a muscle-sparing posterolateral thoracotomy approach.
Before incision, up to 1 L or more of heavy cream is administered enterally. A limited posterolateral thoracotomy is performed, sparing the serratus muscle. The chest is entered through the fifth interspace, although for leaks localized to the upper chest a fourth interspace incision can be used. Alternatively, a sixth or seventh interspace incision can be used for leaks localized to the lower chest. Magnifying loops may be helpful in identifying the thoracic duct and the site of leak. A search is conducted along the predicted course of the duct. If the leak is not found, further inspection of all midline operative sites is performed (i.e., sites of mediastinal nodal dissection, aortic surgery, etc.). Near-infrared fluorescence imaging is an up-and-coming modality in visualizing thoracic duct flow and site of leak in a porcine model that should eventually have clinical applications.23
The easiest, most secure method of repair is to use a pledgeted fine suture (i.e., 4-0 polypropylene). If a large duct has been interrupted, clips to either side of the duct may be applied, although this method may be less secure than direct suture ligation. The site of repair should be observed before and after repair for several minutes to ensure cessation of the chyle leak. A tissue sealant also can be used in conjunction with repair or ligation, but should not be relied on as the sole treatment.
Thoracoscopy is sometimes used to identify the site of leak and to guide the location of a minithoracotomy utility port (Fig. 133-3). A 5-mm camera can be inserted in the midaxillary line at approximately the seventh interspace. An additional 10-mm port is placed in the anterior axillary line at approximately the fifth or sixth interspace, and a grasping instrument is used to draw the lung forward. Alternatively, a fan retractor can be used. If the leak is not found, an additional posterior port can be placed behind and inferior to the tip of the scapula and the camera moved to this location. A figure-of-eight heavy silk stitch can be placed in the central tendon near the esophageal hiatus and passed out through the 5-mm port to retract the diaphragm inferiorly and expose the course of the thoracic duct near the diaphragm. Again, direct repair (other than clipping) of a fine thoracic duct can be difficult when following a purely thoracoscopic approach, and a minithoracotomy (i.e., video-assisted thoracic surgery [VATS]) incision placed directly over the leak can simplify the repair.
Ideal port placement for direct repair with VATS (i.e., thoracoscopy to identify the site of leak and to guide the location of a minithoracotomy utility port). This also may be used for simple mass suture ligation.
Mass ligation of the duct can be performed by thoracotomy, VATS, or even entirely by a thoracoscopic approach. In this region, between the diaphragmatic hiatus and the point where the thoracic duct passes over the spine to the left chest, the path of the duct is consistent in nearly all patients, even though the duct itself may have a plexiform configuration (see Fig. 133-1, inset C). A serratus-sparing sixth interspace thoracotomy incision is made, and the lung is retracted forward. The diaphragm is retracted inferiorly. The esophagus, or neoesophagus, is retracted anteriorly. Just above the aortic hiatus, the course of the thoracic duct can be visualized between the aorta and azygos vein overlying the spine. The pleura is incised over the edge of the aorta and over the edge of the spine. Several techniques may be used. A large, blunt right-angled clamp is passed under the duct alongside the aorta, onto the surface of the spine, and out again medial to the azygos vein, and a large suture (e.g., 0 silk) is tied around the tissues (Fig. 133-4). Large metal clips can be used instead, and others have even tried a TA stapler or LigaSure (Valley Lab, Denver, CO) device.24,25
Technique for simple mass suture ligation of a thoracic duct leak in the right chest.
Alternatively, a size 0 stitch or a smaller, pledgeted stitch could be used to encompass all the tissues between the aorta and azygos vein along the spine. The EndoStitch (Covidien, Mansfield, MA) can also be used. Occasionally, the suture, ligature, or clip may tear or pull through the duct, creating a new leak. Hence the ligation should be inspected carefully for several minutes to verify the integrity of the repair. In addition, the area of original leak should be inspected to ensure that it has fully sealed. One method of knot-tying that is very helpful in avoiding the pulling through of the suture that can be associated with hand-tying in this tight, low space is use of the Ti-Knot (LSI Solutions, Victor, NY) technique. With this device, the suture is placed in similar fashion, either passed under the bundled mass of tissue opened with a clamp or following suture ligature placement, but then the knot is tied down using the device which pulls the sutures through a short metal tie down clip that is crimped tight over the tissue as the surgeon pulls down tension with the instrument.
Thoracoscopic or VATS mass ligation can be performed as described for repair, with the utility incision placed at approximately the eighth interspace, centered over the posterior axillary line. Suture ligation or passage of a large tie around the ductal area can be performed as described earlier, especially with use of the EndoStitch and Ti-Knot. Regardless of surgical access technique, all fibrinous debris should be removed from the chest, and if there is any fibrin peel on the lung, it must be decorticated before closure to ensure complete lung reexpansion. A posteriorly directed drainage tube(s) should be placed.
Properly placed thoracostomy drainage tubes are important for continued control of chest drainage and pleural apposition. In theory, fatty foods should not interfere with the patient's recovery once the ductal injury has been controlled, and the diet can be advanced as tolerated. If there is concern regarding the effectiveness of the repair, it may be prudent to keep the patient on a low-fat oral diet and/or with elemental tube feedings. Total parenteral nutrition should be discontinued when the patient is able to achieve full oral intake. The chest tube drainage amount and character should be recorded and monitored closely. The chest tubes can be removed when the drainage is clear and less than 200 mL/day after resumption of a full-fat diet. Chest radiography should be followed to rule out residual effusion not controlled by thoracostomy drainage.