Huang K, Hu HY, Chen K, Chen XY, Chen Z, Sun Y, Du CY, Chang GX, Fu H, Hu C, Xiao H, Lan X. Portal vein-based subsegmental classification of liver segment four for parenchyma-sparing laparoscopic resection: A retrospective study. World J Gastroenterol 2026; 32(44): 120736 [DOI: 10.3748/wjg.120736]
Corresponding Author of This Article
Xiang Lan, PhD, Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Youyi Road, Yuzhong District, Chongqing 400000, China. lanxiang_tmmu@163.com
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Surgery
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research-article
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Huang K, Hu HY, Chen K, Chen XY, Chen Z, Sun Y, Du CY, Chang GX, Fu H, Hu C, Xiao H, Lan X. Portal vein-based subsegmental classification of liver segment four for parenchyma-sparing laparoscopic resection: A retrospective study. World J Gastroenterol 2026; 32(44): 120736 [DOI: 10.3748/wjg.120736]
World J Gastroenterol. Nov 28, 2026; 32(44): 120736 Published online Nov 28, 2026. doi: 10.3748/wjg.120736
Portal vein-based subsegmental classification of liver segment four for parenchyma-sparing laparoscopic resection: A retrospective study
Kun Huang, Hai-Yang Hu, Kai Chen, Xing-Yu Chen, Zhu Chen, Yu Sun, Cheng-You Du, Gui-Xiong Chang, Hao Fu, Cong Hu, Heng Xiao, Xiang Lan
Kun Huang, Department of General Surgery, Mianyang Hospital of Traditional Chinese Medicine, Mianyang 621000, Sichuan Province, China
Hai-Yang Hu, Kai Chen, Xing-Yu Chen, Zhu Chen, Yu Sun, Cheng-You Du, Gui-Xiong Chang, Hao Fu, Cong Hu, Heng Xiao, Xiang Lan, Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400000, China
Co-first authors: Kun Huang and Hai-Yang Hu.
Co-corresponding authors: Heng Xiao and Xiang Lan.
Author contributions: Lan X and Xiao H designed the research study, revised the manuscript critically for important intellectual content and supervised the study and they contribute equally to this study as co-corresponding authors; Huang K and Hu HY developed the methodology and they contribute equally to this study as co-first authors; Chen K, Chen XY and Chen Z performed the investigation; Sun Y, Du CY, Chang GX, Fu H and Hu C collected and curated the data; Huang K performed the visualization and drafted the manuscript; and all authors have read and approved the final manuscript.
Supported by the 2024 University-Hospital Joint Innovation Fund of Chengdu University of Traditional Chinese Medicine, No. LH202402010.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of the First Affiliated Hospital of Chongqing Medical University (Approval No. 2025-460-01).
Informed consent statement: The requirement for informed consent was waived by the Ethics Committee of the First Affiliated Hospital of Chongqing Medical University due to the retrospective nature of the study.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: The data that support the findings of this study are available from the corresponding author upon reasonable request. Because the study involves patient imaging data and institutional operative records, restrictions apply to their public availability due to ethical and privacy considerations.
Corresponding author: Xiang Lan, PhD, Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Youyi Road, Yuzhong District, Chongqing 400000, China. lanxiang_tmmu@163.com
Received: March 10, 2026 Revised: April 8, 2026 Accepted: May 20, 2026 Published online: November 28, 2026 Processing time: 207 Days and 12.9 Hours
Abstract
BACKGROUND
Conventional cranial-caudal classification of hepatic segment 4 (S4) based on the falciform ligament does not fully reflect individual variation in portal inflow and may limit anatomical precision during parenchyma-sparing liver resection.
AIM
To characterize portal inflow variation in S4, develop a portal vein-based subsegmental classification, and assess its surgical applicability in laparoscopic parenchyma-sparing liver resection.
METHODS
This retrospective single-center study included 207 patients who underwent laparoscopic liver resection (LLR) between June 2021 and April 2024. Preoperative contrast-enhanced computed tomography, magnetic resonance imaging, and three-dimensional reconstruction were performed to define the portal inflow patterns of S4. Classification-guided laparoscopic parenchyma-sparing resection was assessed using intraoperative indocyanine green fluorescence. Detailed perioperative biochemical and pathological analyses focused on the type II subgroup. Exploratory comparative follow-up analysis was performed using Kaplan-Meier estimation and the log-rank test.
RESULTS
Intermediate branches crossing the falciform ligament were identified in 192 of 207 patients (92.8%). S4 was classified as type I (cranial-caudal, 120/207, 58.0%), type II (left-right, 78/207, 37.7%), or type III (scattered, 9/207, 4.3%). In the type II subgroup, postoperative liver enzymes increased transiently and recovered by postoperative day 5, and all analyzed patients achieved negative pathological margins. In the comparative follow-up dataset, the pathological distribution included 113 hepatocellular carcinomas, 38 colorectal liver metastases, 36 intrahepatic cholangiocarcinomas, and 20 benign lesions. During follow-up, 32 patients developed recurrence, and 5 died. The median follow-up duration was 22.0 (interquartile range: 17.0-27.0) months. Exploratory Kaplan-Meier analysis revealed no significant difference in overall survival (OS) or progression-free survival (PFS) between the novel and conventional groups (log-rank P = 0.22 and 0.21, respectively).
CONCLUSION
A portal vein-based classification of S4 may improve anatomical understanding and support individualized parenchyma-sparing LLR. The current data support anatomical plausibility and technical feasibility, while exploratory comparative analysis showed no significant difference in OS or PFS. Formal validation and broader long-term assessments remain necessary.
Core Tip: This study proposes a portal vein-based subsegmental classification of liver segment 4 (S4) derived from preoperative imaging and three-dimensional reconstruction. Intermediate branches crossing the falciform ligament were frequently identified, suggesting that the conventional boundary of S4 may not fully reflect its true portal territory. The proposed framework may support individualized parenchyma-sparing laparoscopic resection, particularly for type II anatomy. In the exploratory comparative follow-up dataset, no significant difference in overall survival or progression-free survival was observed between the novel and conventional groups. Formal validation remains necessary.
