Specialist commentator comments

Comments on this technology were invited from clinical specialists working in the field and relevant patient organisations. The comments received are individual opinions and do not represent NICE's view.

Six out of 8 of the specialist commentators said they were familiar with the technology, 1 of whom had used the device in a research setting.

Level of innovation

Most of the commentators agreed that the technology was a novel concept, although 1 commentator believed it was a variation of an existing modality (ICG-LiMON) for assessing liver function. One commentator noted that, although other quantitative measures of liver function are available, it is innovative in that it uses a single-breath test after injecting a diagnostic drug. Another commentator said that the technology is likely to be of prognostic value, but more data are needed before widespread implementation. Good tests for liver function capacity was highlighted by 1 of the commentators as an area of unmet need. Another specialist said that existing strategies lack accuracy and the selection of patients for surgery is based on a crude assessment of liver function. Two of the commentators were not aware of any competing technologies, while all other commentators identified plasma disappearance rate of indocyanine green (ICG-PDR) as an alternative to LiMAx. Hepatobiliary scintigraphy was also identified by 1 commentator, who noted that the scan can provide an estimation of future remnant liver function; which they stated was the most useful information for surgeons. One commentator thought that the technology provided similar information to ICG-PDR and that there is more experience of ICG-PDR in the UK.

Potential patient impact

Improved risk stratification, better patient selection for liver resection and transplant, and improved assessment of graft function after liver transplant were mentioned by commentators as potential benefits to patients. One commentator said that the technology could help avoid surgery in high-risk patients, while another said the technology could help identify patients who would be suitable for preoperative procedures aimed at improving liver remnant before surgery. The non-invasive nature of the test was also highlighted as a patient benefit by 1 commentator. Most of the specialists believe the technology has the potential to either change the current care pathway or improve clinical outcomes in the UK, although 4 noted that more data would be needed to support this. One commentator noted that the technology would always be part of a multiparametric assessment, so direct correlation between the test and clinical outcomes (morbidity, mortality and length of stay) may be difficult to determine. One commentator said that studies from a German centre have already shown a change in the care pathway after adoption of the technology. When commenting on the groups of people who would benefit most from the technology, 5 of the experts identified people with cirrhosis who are having liver resection. People being considered for major resection and those at high risk of complications were also mentioned. Another commentator thought that the test had the most benefit in identifying suitable transplant donor organs. One commentator thought that the group of patients who would benefit was not yet clearly defined.

Potential system impact

The commentators said the technology may assist surgical planning through improved risk stratification of people with liver disease. According to some of the specialists, there is the potential to reduce intensive care unit resource and hospital mortality by reducing post-operative liver failure, and may contribute to better intensive care unit use after surgery. One commentator said that the technology has the potential to help standardise national protocols for liver resection. Another commentator thought it may provide system benefits, mainly through helping to identifying donor organs with good liver function. One commentator did not think the test would have a wide effect on the healthcare system because mortality rates after surgery are low and most surgeries can be done safely. Most commentators thought LiMAx would be used as an add-on test to standard of care, with 1 commentator saying that it may replace ICG-PDR in some centres. One commentator said LiMAx would cost more than standard of care and another said it would be cost incurring in the short term. Three commentators said the technology has the potential to provide cost-savings but only if it leads to shorter hospital/intensive care stays for patients or reduces the risk of post-operative complications. Two commentators said the cost implications were unclear because of the lack of economic analyses, with 1 specialist adding that the technology should be cost neutral but further data are needed. One commentator thought that the technology could lead to an increase in surgery on high-risk patients and another specialist said that the test may lead to more portal vein embolisation procedures. Additional staff time and the need for staff resource to do the test, product-specific training need as well as logistical issues, such as the purchase, storage, transport and maintenance of equipment, were other factors thought to effect resource. One commentator said that the effect on resources was not yet clear but is expected to be very modest. Most of the specialists expect minimal or no changes to facilities or infrastructure to use the technology. Purchase of the LiMAx equipment and staff training were said to be the only other needs.

General comments

None of the commentators were aware of any safety concerns or regulatory issues. One commentator said that there is a potential risk of allergic reaction to methacetin but was not aware of any reports of this to date. All of the commentators said that the technology is not yet widely used in the UK but most were not aware of any major barriers to adoption. Three commentators thought the main issues for adoption surrounded the available evidence base, particularly the lack of evidence in an NHS setting. The cost of the technology was mentioned as another potential issue for adoption. Most commentators thought that UK NHS-based studies were needed, which could be via post-marketing studies after implementing the test. One commentator noted that LiMAx threshold values for risk stratification should to be validated in other centres before it can be used in clinical practice. One commentator said the technology could be used as a point-of-care test, both in the in-patient and outpatient setting but only in secondary or tertiary care. Two commentators thought the role of the technology in liver transplant was unclear from available evidence. One of the commentators added that it should be used with caution when assessing liver function after transplant but could potentially be used to assess organ-donor graft function. One commentator said that the test seems technically involved while all other commentators said there were no issues with the usability or the practical aspects of the technology. One commentator said the test is easy to use but is not convinced it has substantial advantages over ICG-PDR at present. Another specialist said that, based on regular use in Germany, the test appears to provide unique insight into the functional capacity of the liver.