The amount of mediastinal lymph nodes dissected in robot-assisted cervical esophagectomy-an experimental cadaver study.

Background: Transthoracic esophagectomy (TTE) is the preferred approach for curative esophageal cancer. However, concomitant single-lung ventilation limits its use in patients with compromised cardio-pulmonary function. Transhiatal esophagectomy (THE) grants two-lung ventilation yet offers a limited mediastinal lymphadenectomy and is only suitable for distal tumors. A promising alternative is robot-assisted cervical esophagectomy (RACE). Initial studies show its feasibility, yet, the mediastinal lymph node yield (LNY) is unknown. The aim of this study is to describe the accessibility of the lymph node stations (LNS) and to analyze to which extent the mediastinal LNS can be resected during the cervical phase of RACE. Methods: Experienced robotic upper-gastrointestinal (GI) surgeons performed cervical esophagectomy and mediastinal lymphadenectomy on 4 cadavers using a "da Vinci Xi" surgical system through a left cervical approach. Target LNS were 4R, 4L, 5 and 7, as defined by Naruke. Resected tissues were categorized as primary-esophagus and lymph nodes (LNs) resected through RACE- or secondary-residual LNs post-RACE- resected tissue and were analyzed by experienced pathologists. LNs were counted for every station. Results: Station 4R yielded a median of 16 LNs primarily and 12 secondarily; station 4L: 17 primarily, 0 secondarily; station 5: 4 primarily, 7 secondarily; and for station 7: 9 primarily and 5 secondarily. Conclusions: This study shows that the RACE procedure delivers a limited mediastinal lymphadenectomy. LNS 4L can be fully resected. Stations 4R, 5 and 7 could be partially resected. The RACE procedure may, however, be a viable alternative for patients who cannot undergo a TTE.