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Page 214 Stott et al. Art Int Surg 2023;3:207-16 https://dx.doi.org/10.20517/ais.2022.42

it originated from the first jejunal branch, the origin of the first jejunal artery was divided early in operation.
When comparing this to matched individuals who underwent surgery without the navigation system with
early division of the IPDA and those where the IPDA was not divided early, it was noted that the
augmented reality system allowed easy visualisation of the IPDA; however, use of the system had no
statistical impact on either operating time or intra-operative blood loss.

Abe et al. (2014) used image navigation surgery to improve the ability to achieve an R0 resection during
pancreaticoduodenectomy for PDAC in borderline resectable cases . They utilised 3D imaging
[15]
reconstruction to determine the dissection margins if the tumour abutted either the SMA or the coeliac axis.
They determined the “cutting line” required near the vessel that would achieve an R0 resection. This is the
line at which dissection takes place and this margin is then sent for frozen section perioperatively. If this is
positive, then the procedure did not proceed and the cancer was deemed inoperable.

Cinematic rendering technology could further revolutionise navigation surgery. It has been suggested that
this imaging technology could be integrated with modern virtual reality methods such as Hololens
(Microsoft). Similarly, integration of the technology would allow user integration of the data and allow a
[16]
better understanding and appreciation of complex vascular anatomy .

Use of virtual simulation and augmented reality navigation to guide venous resection and
reconstruction
Similar technology has been used during pancreaticoduodenectomy to guide venous resection and facilitate
types of venous reconstruction. Tang et al. (2021) described the use of augmented reality technology in
assisting the resection and reconstruction of the SMV in this situation . Here, standard preoperative CT
[17]
images of patients were taken with a slice thickness of 1.25 mm and this was reconstructed to 3D imaging
using the Iqqa-Liver software (EDDA Technology, USA). They used less sophisticated technology than that
described previously, but used printed QR codes that were placed in the operative field to represent the pre-
set points at the common bile duct, pancreatic head, and tail of the pancreas. These were then used as fixed
points to superimpose the 3D reconstructed images on the operative field utilising the X-Liver smartphone
app (Beijing Tsinghua Changgung Hospital, Beijing, China). The AR imaging was then utilised during the
procedure to determine the involvement of the SMV-PV confluence and determine the extent of the SMV,
PV and SV that required resection en bloc with the tumour. They suggest this benefit of the AR-guided
surgery enables surgeons to visualise key anatomical relationships ahead of the dissection of those structures
and allows operative decisions to be made ahead of time. Unfortunately, in their case series, they are unable
to comment on whether this improves perioperative or oncological outcomes compared with conventional
surgery, but they suggest this should be the aim of larger trials to determine the overall benefit of artificial
guided navigation surgery in pancreaticoduodenectomy.

Navigation systems in minimally invasive pancreatic surgery
The previous discussion has focussed on open oncological resection, mainly for borderline resectable PDAC
requiring better assessment of involved arteries, better attainment of an R0 resection, or for determining the
need for and reconstruction after venous involvement. Du et al. (2022) reported the development of an
intraoperative navigation system utilising a multi-modality fusion of a 3D virtual model and laparoscopic
[18]
real-time images during laparoscopic pancreatic surgery . 3D virtual modelling was achieved by machine
learning algorithms, including the Fisher Linear Discriminant and Graph-cut algorithms. This was then
loaded to a system with inbuilt navigation software. Two cases were assessed with the model and
development in preclinical tests: a laparoscopic pancreatoduodenectomy for distal cholangiocarcinoma and
a laparoscopic distal pancreatosplenectomy for a tail of pancreas tumour. Analysis was of surgeon
experience as well as operative time, blood loss, and transfusion requirement. They suggest that the model