title: Pioneering Robotic Liver Surgery in Germany: First Experiences with Liver Malignancies.
abstract: BACKGROUND
  Minimally invasive liver surgery is growing worldwide with obvious benefits for the treated patients. These procedures maybe improved by robotic techniques, which add several innovative features. In Germany, we were the first surgical department implementing robotic assisted minimally invasive liver resections.
  
  
  METHODS
  Between June 2013 and March 2015, we performed robotic based minimally invasive liver resections in nine patients with malignant liver disease. Five off these patients suffered from primary and four from secondary liver malignancies. We retrospectively analyzed the perioperative variables of these patients and the oncological follow up.
  
  
  RESULTS
  Mean age of the patients was 63 years (range 45-71). One patient suffered from intrahepatic cholangiocellular, four from hepatocellular carcinoma, and four patients from colorectal liver metastases. In six patients, left lateral liver resection, in two cases single segment resection, and in one case minimally invasive guided liver ablation were performed. Five patients underwent previous abdominal surgery. Mean operation time was 312 min (range 115-458 min). Mean weight of the liver specimens was 182 g (range 62-260 g) and mean estimated blood loss was 251 ml (range 10-650 ml). The mean tumor size was 4.4 cm (range 3.5-5.5 cm). In all cases, R0 status was confirmed with a mean margin of 0.6 cm (range 0.1-1.5 cm). One patient developed small bowel fistula on postoperative day 5, which could be treated conservatively. No patient died. Mean hospital stay of the patients was 6 days (range 3-10 days). During a mean follow up of 12 months (range 1-21 months), two patients developed tumor recurrence.
  
  
  CONCLUSIONS
  Robotic-based liver surgery is feasible in patients with primary and secondary liver malignancies. To achieve perioperative parameters comparable to open settings, the learning curve must be passed. Minor liver resections are good candidates to start this technique. But the huge benefits of robotic-based liver resections should be expected in extended procedures beyond minor liver resections with the currently available technology.
authors.affiliation: Department of Surgery and Liver Center, University Hospital Erlangen , Erlangen , Germany.
authors.forename: Roland S
authors.initials: RS
authors.lastname: Croner
authors.affiliation: Department of Surgery and Liver Center, University Hospital Erlangen , Erlangen , Germany.
authors.forename: Aristotelis
authors.initials: A
authors.lastname: Perrakis
authors.affiliation: Department of Surgery and Liver Center, University Hospital Erlangen , Erlangen , Germany.
authors.forename: Maximillian
authors.initials: M
authors.lastname: Brunner
authors.affiliation: Department of Surgery and Liver Center, University Hospital Erlangen , Erlangen , Germany.
authors.forename: Klaus E
authors.initials: KE
authors.lastname: Matzel
authors.affiliation: Department of Surgery and Liver Center, University Hospital Erlangen , Erlangen , Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Hohenberger
keywords: HCC; colorectal cancer; liver malignancy; liver resection; minimally invasive; robotic