Role of innovative 3D printing models in the management of hepatobiliary malignancies

Table 1 Report of studies referring to 3D printing applications in liver diseases

Authors[REF], year	Study type	Field of application	Imaging tools	Outcome
Zein et al[19], 2013	Case series	PP	CT and MRI	Accurate in providing liver volume and size
				measurement
Takagi et al[20], 2014	Case report	PP, TP	CT	Reported reproducibility of the model and possible future aid to surgical procedures
Igami et al[21], 2014	Case report	PP	CT	Helpful in preoperative planning. Detects small tumors invisible with intraoperative US
Watson[36], 2014	Case series	ET	CT and MRI	Ability of creating patient-simulated 3D printed
				liver models at low cost
Baimakhanov et al[22], 2015	Case report	PP (transplantation)	CT	Helpful in preoperative planning and surgical training
Xiang et al[23], 2015	Case report	PP (hepatectomy for tumor)	CT	Helpful in preoperative planning
Dhir et al[33], 2015	Cohort study	ET, TP	MRCP	Accurate understanding liver anatomy
Souzaki et al[24], 2015	Case report	PP	CT	Assists surgical planning understanding of the anatomy
Soejima et al[25], 2016	Case report	PP	CT	Useful for small infants or neonates Realistic liver graft that is helpful in optimizing the procedure
Leng et al[26], 2016	Case report	PP	CT	Could be useful in reducing radiation dose and detecting small liver lesions
Kong et al[35], 2016	RCT, Cohort study	ET, TP	CT	Αnatomy teaching and significantly improved knowledge
Kong et al[34], 2016	RCT, Cohort study	ET, TP	CT	Τeaching of hepatic segments
Burdall et al[41], 2016	Cohort study	TP	CR, MRI	Scored 5.6/10 for fidelity, 6.2/10 for complexity and 7.36/10 for usefulness. All would suggest it and think it is reproducible
Takao et al[42], 2016	Case series	TP	CT	High accuracy of 3D
Koganemaru et al[45], 2016	Case report	PP	CT	Successful embolization and follow-up markers
Javan et al[37], 2016	Case series	ET	CT	Useful in comprehending difficult anatomical structures
Witowski et al[12,27], 2017	Case report	PP, ET	CT	Useful for planning procedures like hepatic resection and for educational purposes.
Kuroda et al[15], 2017	Case series	PP	CT	Successful resection
Madurska et al[28], 2017	Case report	PP	CT, MRI	Anatomical structures and lesions were clearly demonstrated
Oshiro et al[29], 2017	Case report	PP	CT	The surgical procedure was easier, and the visibility of small tumors was improved
Perica et al[17,30], 2017	Case report	PP	CT	Possible benefit in preoperative planning and intraoperative guidance
Andolfi et al[31], 2017`	Case report	PP ET, PE	VR	Clearer observations of the relationship between the mass and blood vessels
Trout et al[46], 2017	Case series	PP	CT, MRI	A new technique to standardize hepatic sectioning was used
Weng et al[47], 2017	Case report	PP, TP	CT, MRI	Positive comments from relatives and experts
Choi et al[43], 2017	Cohort study	TP	CT, US	No significant difference in tumor size was found between the CT images and 3D model measured with US
Bücking et al[44], 2017	Case series	TP	CT	High accuracy in fidelity
Igami et al[32], 2017	Case report	PP	CT	The 3D printed model was useful in determining the resection line
Yang et al[48], 2018	Cohort study	PE	CT	Parental understanding of basic liver anatomy
Li et al[38], 2018	RCT	ET	CT	The 1st group, trained with the 3D printed model
Yang et al[39], 2018	RCT	ET	CT	Better understanding liver anatomy
Javan et al[40], 2018	Case report	ET	CT, MRI	Abscess drainage, artery embolization, and catheter placement procedures were well-exhibited
Tang et al[49], 2018	Case report	VR	CT	Navigation was effective, although stability in tracking was not satisfactory

3D: Three-dimensional; PP: Preoperative planning; ET: Education and training; PE: Patient education; TP: Evaluation of technical properties; RCT: Randomized controlled trial; CT: Computed tomography; MRI: Magnetic resonance imaging; LDLT: Living donor liver transplantation; MRCP: Magnetic resonance cholangiopancreatography; VR: Virtual reality; AR: Augmented reality; 2D: Two-dimensional; US: Ultrasound.

Table 2 Cross-tabulation of the study characteristics

Field of application	Type of study				Sum
	Case report	Case series	Cohort studies	RCT
Preoperative planning	13	2	0	0	15
ET	3	2	1	4	10
TP	0	2	5	0	7
Other	4	1	1	0	6
Sum	20	7	7	4

ET: Education and training; TP: Evaluation of technical properties; RCT: Randomized controlled trial. Five of the studies belong to more than one application group, and they display different study types for each application, thus belonging to more than one cell.