The da Vinci Surgical System set-up.
The instruments are cable driven with 7 degrees of freedom and 360 degrees of rotation of the tip of the instruments (Figure 16.2). The three-dimensional image is displayed above the hands of the surgeon, giving the surgeon the perception of being in the surgical field.
Advantages
Compared with conventional thoracoscopic surgery, the da Vinci Surgical System has advantages (Table 16.1). One important benefit is the three-dimensional vision; the depth perception gives an improvement in the view over the cameras used in thoracoscopic surgery. The three-dimensional image is displayed above the surgeon’s hands, resulting in better hand-eye coordination and eliminating the fulcrum effect, making manipulation of the instruments much easier. The instruments also offer superior manoeuvrability with 7 degrees of freedom, 360 degrees of rotation of the tip of the instruments and elimination of physiologic tremors.
Disadvantages
Robotic surgery has a lot of advantages compared with thoracoscopic and conventional surgery, but it has also some disadvantages. In thoracoscopic surgery, there is reduction in touch sensation; in robotic surgery, however, there is an absence of touch sensation. Robotic surgery is also very expensive; there are high start-up costs and costs in training of the staff. Another disadvantage is the possibility of failure of the instruments of the da Vinci Surgical System. A survey of the MAUDE database showed that failures occurred in a number of robotic instruments in a short period, although some failures may go unreported[9].
Thoracic applications of robotic surgery
Lung cancer
Lung cancer is the main cancer worldwide whether considered in terms of incidence or mortality. More patients die of lung cancer than breast, colon and prostate cancer together[10]. Only patients with early stage lung cancer qualify for surgical resection. With the development of new screening tools like low-dose computed tomography (LDCT), it is possible that more early-stage lung cancers suitable for surgical resection will be diagnosed in the future.
VATS lobectomy was first described in the early 1990s, and ever since, multiple studies have been published. However, only three of these published studies are randomized, controlled trials comparing VATS lobectomy to thoracotomy. There is also a great variability in the techniques described so far. The variability exists in the surgical approach for the lobectomy itself, size of the utility incision thoracotomy, number of incisions and the use of rib spreading. Despite this variability, the studies published to date have shown that VATS lobectomy is safe and effective. It is a feasible technique for early-stage lung cancer and provides at least the same oncological results. In addition to this, it has been shown that VATS lobectomy is associated with lower rates of post-operative complications and shorter duration of hospitalization.
Despite these advantages, VATS lobectomy is not very widely used by thoracic surgeons. According to the Society for Thoracic Surgeons (STS) Database (voluntary database), in 2006, around 32% of lobectomies were performed through VATS[11]. The authors showed that the percentage of lobectomies performed by VATS in the STS Database has been increasing: 21.6% in 2004 and 28.6% in 2005. In the Nationwide Inpatient Sample Database (non-voluntary database in US), however, this number is as low as 6%[12], indicating the overall application of VATS lobectomies may be lower in nonacademic, smaller hospitals. The low application of VATS approach might be due to the limitations of VATS; it only has two-dimensional vision, hand-eye coordination is difficult, manoeuvrability is restricted and there is a steep learning curve. Robotic surgery might overcome these limitations. The use of robotic surgery for lobectomy is still in its infancy, so the literature is sparse. There are no published randomized, controlled trials comparing robotic lobectomy with VATS lobectomy.
Melfi et al. were in 2002 the first to report a series of robotic lobectomies, and they showed that it is safe and feasible[13]. Ever since, multiple series have been reported showing that robotic lobectomy is safe, feasible and has the same oncological results (Table 16.2). The early experiences with robotic lobectomy regarding chest tube drainage, morbidity, mortality, conversion rate and reasons for conversion are comparable with VATS[14–16].
| Authors | No. of patients | 30 days mortality, % | Follow-up, mos. | OC, % | OT, minutes | LOS, days |
|---|---|---|---|---|---|---|
| Melfi et al. 2004[21] | 23 | 4.3 | ― | 8.7 | 192 † | 5.0 † |
| Park et al. 2006[14] | 34 | 0 | ― | 12 | 218 * | 4.5 * |
| Melfi et al. 2008[22] | 107 | 0.9 | ― | 9.4 | 220 * | 5 † |
| Charagozloo et al. 2009[23] | 100 | 3.0 | 32 * | 0 | 216 † | 4.0 * |
| Veronesi et al. 2010[24] | 54 | 0 | ― | 13 | 236 * | 5.0 * |
| Augustin et al. 2011[25] | 26 | 3.8 | 27 * | 19 | 228 * | 11.0 * |
| Dylewski et al. 2011[26] | 154/200 | 3.0 ¶ | ― | 1.5 | 90 * | 3.0 * |
| Cerfolio et al. 2011[27] | 104/168 | 0 | ― | 7.7 | 132 * | 2.0 * |
| Jang et al. 2011[28] | 40 | 0 | ― | 0 | 240 * | 6.0 * |
| Veronesi et al. 2011[16] | 91 | 0 | 24 | 11 | 239 * | 5.0 * |
| Park et al. 2012[17] | 325 | 0.3 | 27 | 8.0 | 206 * | 5.0 * |
| Meyer et al. 2012[20] | 185 | 1.6 | ― | 1.6 | 211 † | 4.0 * |
The largest published series of robotic lobectomies is a multi-centre study by Park et al. The authors reported robotic lobectomies in 325 consecutive patients for early-stage non-small cell lung cancer (NSCLC) at three institutions[17]. The authors showed that robotic lobectomy for NSCLC was feasible and safe. The overall and stage-specific survival of robotic lobectomies for early-stage NSCLC was comparable with the reported series of (VATS) lobectomies in the literature[17,18]. With respect to the higher costs of robotic surgery related to purchase and maintenance of the technology, Park et al. reported that robotic surgery is more expensive than VATS but less expensive than open thoracotomy. This was mainly because of the longer hospitalization in patients who underwent open thoracotomy[19].
Meyer et al. showed in a recent paper that the learning curve for robotic lobectomies in surgeons experienced with VATS was 18 ± 3 cases based on operative time, mortality and the surgeon’s comfort[20].
An evaluation of the available literature shows that robotic surgery for lobectomies is comparable with the results in VATS lobectomies. However, additional research by prospective, randomized, controlled trials comparing VATS and robotic lobectomies is warranted to discern the differences between these two techniques.
Mediastinal surgery
Anterior mediastinum
In the anterior mediastinum, the most frequently found mediastinal mass is a thymoma. Thymomas and thymic carcinomas are rare tumours. Thymomas are frequently observed in patients with myasthenia gravis (MG). Up to 45% of the patients with a thymoma have MG, and in 10% of patients with MG, a thymoma is present[29]. The neurologist Oppenheim was the first who described the association between MG and the thymus[30]. The thymus gland plays a role in the complex pathogenesis of MG[31]. Therefore, thymectomy has been accepted as a standard treatment of MG for patients[32].
Myasthenia gravis (MG)
In 1936, Alfred Blalock was the first who performed a successful thymectomy by a median sternotomy in a patient with a mediastinal mass and MG[33]. Later, thymectomy by partial sternotomy, a transcervical approach, extended transcervical thymectomy, video-assisted thoracoscopic extended thymectomy and the transcervical subxyphoid-videothoracoscopic maximal thymectomy have been described[34,35]. Thymectomy has been reported as a possible treatment for nonthymomatous MG. Series comparing VATS with sternotomy in nonthymomatous MG have showed that in VATS thymectomy there is reduced operative blood loss, a shorter hospitalization and an equivalent MG remission rate[36]. Because of the heterogeneity in the surgical techniques described as VATS thymectomy, the evaluation and comparison of the studies are difficult.
On account of the lack of visualization, the unilateral procedure underwent several modifications; a bilateral approach, an addition cervical incision and an addition subxiphoid incision have been described.
Proponents of the robotic approach argue that it facilitates a total extended resection for MG by a minimal invasive approach more accurately than thoracoscopic surgery. In 2004, Bodner et al. were the first to report a series of 10 robotic thymectomies with an operative morbidity and mortality of 0% and a hospitalization of less than 3 days. Multiple small series have been reported ever since and have shown that robotic thymectomy for non-thymomatous MG is feasible, safe and can produce high cumulative complete remission rates[37–39].
Rückert et al. showed in a retrospective cohort with 79 thoracoscopic and 74 robotic thymectomies that the cumulative complete remission rate of MG is higher in the robotic group. After a follow-up of 42 months, the cumulative complete remission rate was 20.3% in the thoracoscopic group and 39.25% in the robotic group. It is postulated that the superior outcome of robotic thymectomy is due to a more complete mediastinal resection because of superior three-dimensional vision and an enlargement of the operation field by insufflation with CO2[40].
Thymomas
Minimally invasive surgery for a thymoma remains controversial. Despite advantages of less blood loss and shorter hospitalization, VATS thymectomy for thymomas is not widely used. A complete surgical resection with the resection margins free of tumour is the most important factor for the curative treatment of thymomas[41]. It is controversial whether with VATS this can be accomplished. Recurrences after resections of a thymoma, possible rupture of the capsule and seeding of the tumour during endoscopic manipulations are associated with the minimally invasive approach. Long-term oncological results are not available yet, and the prolonged learning curve is a secondary reason for the reserved attitude. In the literature, it is only recommended in highly selected patients with an early-stage thymoma[42]. A median sternotomy is the standard approach for advanced stage thymomas.
A thymectomy for a thymoma by a robotic approach might overcome the limitations of thoracoscopic thymectomy because of the three-dimensional vision and the manoeuvrability of the instruments. There are only a few studies published regarding the outcome of robotic thymectomies in patients with a thymoma (Table 16.3). Marulli et al. reported a multi-centre European study of 79 early-stage thymomas resected by robotic surgery. The authors indicated that robotic thymectomy is safe for early-stage thymomas with a low complication rate, shorter hospitalization and acceptable oncological outcome. There were no vascular injuries, no nerve injuries and no peri-operative mortality. However, these results should be interpreted with caution as the median follow-up was only 40 months[43].
| Authors | No. of patients | Masaoka stage I/II/III/IV | TS, cm | Follow-up, mos. | RR, % | OC, % | OT, minutes | LOS, days |
|---|---|---|---|---|---|---|---|---|
| Mussi et al. 2012[44] | 13 | 7/6/0/0 | 3.3 † | 14.5 * | 0 | 7.7 | 139 † | 4.0 † |
| Marulli et al. 2012[45] | 79 | 30/49/0/0 | 3.7 † | 51.7 † | 1.3 | 1.3 | 165 † | 4.4 † |
| Keijzers et al. 2014[46] | 37 | 20/13/3/1 | 5.1 † | 41 † | 2.7 | 10.4 | 149 † | 3.0 * |
TS, tumor size; RR, recurrence rate; OC, open conversion; OT, operative time; LOS, length of hospital stay.
