Current status of minimally invasive liver surgery for cancers

Table 1 Summary of current status of minimally invasive liver surgery for cancers

Disease	Backgrounds of disease and liver for surgery	Status of minimally invasive liver resection
HCC	Chronically injured background of liver[1,2]: (1) Deteriorated liver function–postoperative morbidity; and (2) Multicentric carcinogenesis–repeated treatments	Established/applied with some merit to most cases[21,29]: Advantages in LR of LC patients[30,31] and repeat LR[30,34] by laparoscopic specific “caudal approach”[26-28]
	Anatomical resection[6]	Under discussion and development: (1) Small anatomical resection using Glissonian approach[40,42], ICG-guided approach[39], hepatic vein-guided approach[38]; and (2) Robot for long-range dissection of major vessels?
CRCLM	Combination treatments with chemotherapy[3]: (1) Multiple bilateral tumors–TSH[10], ALPPS[11]; and (2) Injured liver–fragility from steatosis[15], easy bleeding form congestion[16,17]	Established/applied to many cases[20,23]: Advantages of better hemostasis[20,29] by pneumoperitoneum/optimal visualization
	Parenchymal sparing resection[12,14]	Under discussion and development: (1) LLR with TSH[43], ALPPS[44]–possible in experienced centers; (2) ICG-guided tumor identification[39,45]; and (3) Robot for handling the fragile liver?
BTC	Spreading invasion along Glissonian pedicle[4], LN metastases and direct invasion to liver parenchyma: (1) Extended LR of normal liver–PTPE[8]; (2) Lymphadenectomy; and (3) Bile duct (vasculature) resection/reconstruction-Needs of setting tumor free resection line and reconstruction of small bile duct orifice	Developing and possible in specialized center[24]: (1) Lymphadenectomy and bile duct (vasculature) resection/reconstruction in specialized center[24,51]; and (2) Difficulties in setting tumor free resection line and reconstruction of small bile duct orifice: Well simulated robot-assisted procedure?

HCC: Hepatocellular carcinoma; CRCLM: Liver metastasis of colorectal carcinoma; BTC: Biliary tract carcinomas; LR: Liver resection; LLR: Laparoscopic liver resection; LC: Liver cirrhosis; ICG: Indocyanine green; TSH: Two-stage hepatectomy; ALPPS: Associating liver partition or portal vein embolization for staged hepatectomy; PTPE: Percutaneous transhepatic portal embolization; LN: Lymph node.