Subxiphoid VATS thymectomy
Subxiphoid uniportal VATS has gained interest among the thoracic surgeons because its potential reduction of postoperative intercostal pain. There is still a lack of quality evidence to support this minimally invasive novel approach, but probably thymectomy has become the procedure most commonly performed by this approach. Here I describe the technique and some potential tips.
First of all, select strictly the patient: avoid obese patients or patients with previous cardiac or thoracic surgical procedures. Second, select the case: start with miastenia gravis thymectomy or small thymomas to decrease the potential difficult of a new surgical approach.
Place the patient in supine decubitus, with the legs in mild abduction. Surgical incision can be performed transverse (I prefer) or longitudinal.
Dissect soft tissues until you get to the xiphoid process, and then remove it if necessary or keep it if small. Then bluntly dissect with your finger the retroxiphoid space, and then place the soft tissue wound retractor.
Subxiphoid thymectomy has been described with the use of CO2. I strongly recommend CO2 insuflation because it makes easier the procedure, it gently dissects soft retrosternal tissues and collapses both lungs even though the patient is under bipulmonar ventilation. How to insufflate CO2 with a soft tissue retractor? There are some commercial devices that have designed a lid for the retractor where the thoracoscopic ports can be placed and sealed. I will explain here an easier home-made system I watched in a video from a Taiwanese surgeon: after placing the sof tissue retractor, take a sterile glove and attach it wrapping the retractor; then cut one tip of a finger, insert the 11 mm valvulated port and seal it with a silk suture. Start CO2 insufflation and you will see the glove inflating and the mediastinal retrosternal space getting wider. Then cut two more tips of fingers and place 5 mm ports sealed with silk sutures for instrumental handling.
I first dissect the thymus and mediastinal fat pad from the sternum and open both mediastinal pleuras to visualize both lungs and phrenic nerves.
Then carry on the dissection from the incision upwards, dissecting the thymus and fat pad from the pericardium and great vessels. Try to dissect form the superior vena cava and identify the innominate vein. Then continue the thymectomy in a conventional way, dividing thymic veins, dissecting both superior horns and completing the thymectomy.
Through this approach you get a really awesome view of the thymus, the anterior mediastinum, both pleural cavities and phrenic nerves.
I recommend the use of retrosternal lifter because makes easier the procedure in the innominate dissection stage. Specimen removal thorugh the supxiphoid incision is usually not difficult unless huge thymomas.
Main concerns about this approach are related to instrument crashing through the incision: it should be highlighted than conventional thoracoscopic thymectomy with 3 ports is much easier for handling, and with uniportal subxiphoid you need more experience for both the surgeon and the assistant. You have to cross instruments and place the thoracoscope in the less disturbing position, but it can be safely performed.
Patients experience really little pain and cosmetic results are excellent, but we still need randomized comparative studies and large-size prospective series to ellucidate if there is a real benefit for patients in postoperative pain, and if the procedure is as safe as conventional thoracoscopic thymectomy.