title: Total anatomical laparoscopic liver resection of segment 4 (S4), extended S4, and subsegments S4a and S4b for hepatocellular carcinoma.
abstract: BACKGROUND
  When a tumor is located in segment 4 (S4), it is preferable to perform only limited resection of S4, even in laparoscopic surgery. Here we describe anatomical laparoscopic S4, subdivision of S4 (S4a and S4b), and extended S4 segmentectomy for hepatocellular carcinoma (HCC), using the Glissonian pedicle transection method for each, and evaluate the feasibility of laparoscopic liver resection (LLR) for tumors located in S4.
  
  
  METHODS
  Among 417 patients who underwent LLR for malignant tumors between March 2003 and February 2014, we performed retrospective analysis of the clinical and perioperative outcomes of 10 patients who underwent anatomical liver resection for tumors located in the S4 area of the liver.
  
  
  RESULTS
  Total laparoscopic anatomic liver resection (S4, extended S4, and S4a and S4b segmentectomies) were performed in 10 patients. There was no open conversion or postoperative mortality. The mean operation time was 316.5 minutes (range, 175-460 minutes), and mean estimated blood loss was 592 mL (range, 100-1600 mL). An intraoperative transfusion was necessary in 2 (20%) of the 10 patients. All patients had negative resection margins. Three patients (30%) had postoperative complications (intraabdominal fluid collection). The mean postoperative hospital stay was 7.7 days (range, 3-13 days). The median follow-up period was 18 months. Intrahepatic recurrence occurred in 2 (20%) of the 10 patients, which was managed by radiofrequency ablation with transarterial chemoembolization in 1 patient and by transarterial chemoembolization alone in the other patient.
  
  
  CONCLUSIONS
  Total laparoscopic anatomical S4, extended S4, or S4a or S4b segmentectomy is a feasible procedure for HCC. The Glissonian pedicle transection method is an effective technique for rapid and safe control and subdivision of the S4 pedicle that facilitates anatomical laparoscopic S4, extended S4, and S4a and S4b segmentectomy.
authors.affiliation: Department of Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine , Seoul, Korea.
authors.forename: Young Ki
authors.initials: YK
authors.lastname: Kim
authors.forename: Ho-Seong
authors.initials: HS
authors.lastname: Han
authors.forename: Yoo-Seok
authors.initials: YS
authors.lastname: Yoon
authors.forename: Jai Young
authors.initials: JY
authors.lastname: Cho
authors.forename: Woohyung
authors.initials: W
authors.lastname: Lee
mesh_terms: D000368:Aged; D001201:Ascites / Q000209:etiology; D016063:Blood Loss, Surgical; D006528:Carcinoma, Hepatocellular / Q000601:surgery*; D005260:Female; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects / Q000379:methods*; D007902:Length of Stay; D008113:Liver Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000628:therapy*; D018365:Neoplasm, Residual; D061646:Operative Time; D012189:Retrospective Studies