Accuracy Assessment for Computer-assisted Surgical Interventions of the Liver (CALS)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01474694
Recruitment Status : Completed
First Posted : November 18, 2011
Last Update Posted : November 26, 2015
Information provided by:
University Hospital Inselspital, Berne

November 15, 2011
November 18, 2011
November 26, 2015
October 2011
December 2013   (Final data collection date for primary outcome measure)
TRE, measuring the error in the prediction of a surgical target location when using the navigation system. [ Time Frame: 12 months ]
Same as current
Complete list of historical versions of study NCT01474694 on Archive Site
1.Identification of suitable landmarks for registration [ Time Frame: 15 months ]
Same as current
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Accuracy Assessment for Computer-assisted Surgical Interventions of the Liver
Accuracy Assessment for Computer-assisted Surgical Interventions of the Liver: A Prospective, Non Randomized Study
Preoperative image-guided data correlates with the actual intraoperative reality. Computer-assisted preoperative planning combined with intraoperative mapping of even very small lesions allows for improved accuracy during complete oncological resection / ablation. In the short- and long-term this possibly results in better patient outcome.


The aim of this study is to analyze the available accuracy of a computer-assisted approach to liver surgery and microwave ablation. The term 'computer-assisted' refers to 1) using 3D models of patient anatomy for extended orientation during the planning of the intervention and 2) using an image guidance system (similar to a GPS in a car) that allows for precise targeting of desired anatomical structures (e.g. intrahepatic tumor, bile ducts / vasculature) in the setting of successfully treating liver malignancies. Furthermore, we would like to demonstrate, that image guided open liver surgery is technically feasible, whenever the correlation between preoperative image-guided data and the intraoperative setting can be achieved with a known accuracy.

Eventually, this technology, like in other surgical domains, will lead to successively implemented technical guiding functionalities that could potentially improve patient outcome.


To date, first systems (CE marked medical devices) are available that have been specifically developed for image-guided open liver surgery. The systems tracks positions of surgical instruments in or near the target organs and visualizes the instruments position in correlation to patients medical image data (i.e. 3D-CT) on the computer screen. Surgeons benefit from a view to a virtual scene (on a computer screen) in which CT images, together with models of the vascular structures, tumors and organ boundaries, are intuitively visible. The surgeon can see the moving instrument, just like the movement of a car can be seen in a GPS system


In patients requiring extensive surgery (eg. extended right hemihepatectomy), accurate calculations of the remaining liver volume are essential to avoid postoperative liver failure with potentially serious postoperative complications or even death, resulting from an inadequate remaining liver volume (ie "small-for-size syndrome"). In high-risk liver resections, use of computer programs, such as MeVis (MeVis Medical Solutions Inc.), provide the surgeon with accurate preoperative information, allowing him / her to judge the feasibility of the planned surgical resection based on preoperative liver volume analysis and evaluation of the planned resection line in relation to essential structures (ie. major vessels / bile ducts).

Observational Model: Case-Only
Time Perspective: Prospective
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Probability Sample
patients that are still considered unresectable at the time point of presentation
Adult Liver Cancer
Other: Abdominal surgery
The patient is placed in a supine position and standard laparotomy (either via subcostal, midline or inverted hockey-stick incision) is performed. After mobilization of the liver, surgical swabs are packed around the organ to prevent unnecessary movement of the liver during the acquisition of the landmarks and the subsequent surgical procedure
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*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Same as current
December 2013
December 2013   (Final data collection date for primary outcome measure)

Inclusion Criteria:

  • 1.Written informed consent
  • 2.Male patients and non-pregnant, non-lactating females aged ≥18 years of age (negative serum/urine pregnancy test result at screening)
  • 3.Patients must be candidates for surgical liver resection and/or MWA (at least one anatomical segment) of primary or metastatic liver cancer. The liver tumors must be present on preoperative imaging study (CT and/or MRI).

Exclusion Criteria

  • 1.Any condition which, in the judgment of the clinical investigator or his designee, might increase the risk to the subject or decrease the chance of obtaining satisfactory data to achieve the objectives of the study.
  • 2.A mental condition rendering the patient unable to provide informed consent.
  • 3.Patients with hereditary hematological / coagulation disorders unrelated to their liver disease or cirrhosis of the liver classified as Child's B or C.
Sexes Eligible for Study: All
18 Years and older   (Adult, Senior)
Contact information is only displayed when the study is recruiting subjects
Eureka 6201/5/Ae
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Not Provided Vanessa Banz/ Prof. Dr. med.Daniel Candinas, Bern University Hospital
University Hospital Inselspital, Berne
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Principal Investigator: Vanessa Banz, Dr. med. Bern University Hospital
Principal Investigator: Daniel Candinas, Prof. Dr. med. Bern University Hospital
University Hospital Inselspital, Berne
November 2015