title: Laparoscopic liver resection for posterosuperior and anterolateral lesions-a comparison experience in an Asian centre.
abstract: BACKGROUND
  Minimally invasive surgery has been one of the recent developments in liver surgery, laparoscopic liver resection (LLR) was initially performed for benign lesions at easily accessible locations. As the surgical techniques, technology and experience improved over the past decades, LLR surgery had evolved to tackle malignant lesions, major resections and even in difficult locations without compromising safety and principles of oncology. It was also shown to be beneficial in cirrhotic patients. We describe our initial experience with LLR in a population with significant proportion having cirrhosis, emphasising our approach for lesions in the posterosuperior (PS) segments of the liver (segments 1, 4a, 7, and 8).
  
  
  METHODS
  A review of patients undergoing LLR in single institution from 2006 to 2015 was performed from a prospective surgical database. Clinicopathological, operative and perioperative parameters were analyzed to compare outcomes in patients who underwent LLR for PS vs. anterolateral lesions (AL).
  
  
  RESULTS
  LLR was performed in consecutive 197 patients, with a mean age of 60 years. The indications for resection were hepatocellular carcinoma (HCC) (n=105; 53%), colorectal cancer liver metastasis (n=31; 16%), other malignancies (n=19; 10%) and benign lesions (n=42; 21%). A significant proportion had liver cirrhosis (25.9%). More females underwent surgery in the AL group and indications for surgery were similar between both groups. Major liver resection was performed more frequently for the PS group than for the AL group (P<0.001) and significantly more PS resections was performed in our latter experience (P=0.02). The mean operative time and the conversion rate were significantly greater in the PS group than in the AL group (P≤0.001 and 0.03, respectively). However, the estimated blood loss (EBL), rate of blood transfusion and mean postoperative stay were similar in the two groups (P=0.04, 0.88 and 0.92, respectively). The overall 90-day morbidity and mortality rate was 21.3% and 0.5% respectively, with no differences between the two groups. Surrogates of difficulty such as operative time, blood loss, conversion and outcomes e.g., morbidity and mortality, were similar in patients who underwent PS resections with or without cirrhosis.
  
  
  CONCLUSIONS
  LLR in selected patients is technically feasible and safe including cirrhotic patients with lesions in the PS segments.
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Jin Yao
authors.initials: JY
authors.lastname: Teo
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Juinn Huar
authors.initials: JH
authors.lastname: Kam
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Chung Yip
authors.initials: CY
authors.lastname: Chan
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Brian K P
authors.initials: BK
authors.lastname: Goh
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Jen-San
authors.initials: JS
authors.lastname: Wong
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Victor T W
authors.initials: VT
authors.lastname: Lee
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Peng Chung
authors.initials: PC
authors.lastname: Cheow
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Pierce K H
authors.initials: PK
authors.lastname: Chow
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: London L P J
authors.initials: LL
authors.lastname: Ooi
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Alexander Y F
authors.initials: AY
authors.lastname: Chung
authors.affiliation: 1 Department of Hepatopancreatobiliary and Transplantation Surgery, Singapore General Hospital, Singapore ; 2 Duke-NUS Graduate Medical School, Singapore ; 3 Division of Surgical Oncology, National Cancer Center Singapore, Singapore ; 4 Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Ser Yee
authors.initials: SY
authors.lastname: Lee
keywords: Laparoscopic liver resection (LLR); colorectal cancer liver metastasis; hepatocellular carcinoma (HCC); posterosuperior (PS) and anterolateral lesions (AL)