The ongoing need to further increase the numbers of liver allografts that can be transplanted from deceased donors has stimulated ongoing endeavors around the world to understand where there may still be areas of untapped potential. In parallel, there has been an evolution in the management of liver injury secondary to blunt abdominal trauma. So, having an understanding of what may now be possible when it comes to both assessing and then transplanting the so-called injured liver is important. However, little has been published in the last decade on this particular subject except for a handful of case reports. Hence, you could be forgiven for thinking that there was nothing new on this particular front.
The comprehensive analysis from Seckler et al1 of the nationwide data held by the Cristal registry of the Biomedicine Agency in France from 2010 to 2018 provides some indication as to what is now happening in one region of the world. By specifically focusing on the subset of deceased donors with a history of liver trauma following the declaration of brain death in which organ recovery was being considered, some interesting results have been obtained. Importantly this approach facilitated subgroup analysis and comparison between the donors from where the liver was retrieved for the purpose of transplantation (n = 131) versus those from whom it was not (n = 153). Where possible, the degree of physical injury to the liver was obtained from data held on computerized tomographic (CT) scan imaging reports, using the American Association for the Surgery Trauma (AAST) system.2 In addition, it appears that, of the 142 liver allografts that were transplanted, 23 of these were split livers (16%), confirming that, in a subgroup of selected donors, splitting of the liver is a viable option.3
It is perhaps not surprising from this analysis that evidence of increasing degrees of liver injury, whether it be via biochemical measures or from abnormalities detected on CT scan, were associated with a lower likelihood of the liver being used for transplantation purposes. Despite data from CT scanning being only available for just under half of the donors in this particular study, along with limitations on how the CT scans had been previously reported, the results are informative. A reasonable proportion of the donor livers with either AAST grade 2 or 3 injuries were transplanted (46/67; 69%), whereas this was not the case for AAST grade 4 or 5 injury (0/11; 0%). The predilection of parenchymal injury to more likely be manifested in the right lobe of the liver is also evident from these data.4
Particularly informative are the results obtained from the subgroup analysis for the outcomes of the donors, in which a prior intervention was required in 20 (7%) to manage various sequelae of the liver trauma before organ donation became a consideration.5 Although the numbers are small, it is evident that the liver was then able to be transplanted from some of the donors who had either undergone a damage control laparotomy (8/15; 53%) or hepatic artery embolization (3/5; 60%). Before now, recovering the liver for the purposes of transplantation in these particular circumstances has only been described via case reports.4
Overall, the reported outcomes of transplanting these selected liver allografts are acceptable with 81% 1-y graft survival rate and 72% 5-y graft survival rate. Of note, in 13% of the transplant operative procedures, additional surgical measures were required to deal with manifestations of the trauma to the liver allograft either on the back table or during the transplant surgical procedure. As no other detail is provided for this particular subgroup, it is not known whether this was associated with the initial AAST grade of liver injury. Nevertheless, it serves as a reminder to transplant surgeons that vigilance is required when dealing with these particular scenarios.
As the authors point out, their study cohort represents the pool of organ donors in which organ recovery was considered but not the wider pool of all potential deceased donors with a history of liver trauma. Hence, it is possible that the potential donors with the worst liver trauma were excluded at an early stage following admission to the hospital, but it is also equally possible that some of them were excluded at a later stage. This is not a new problem in that comprehensive reporting on the outcomes of potential deceased donors with a history of blunt trauma remains a goal rather than an actual reality.6,7 This information gap can be addressed if more in the way of appropriate data are collected by donor registries on the potential organ donors who have sustained trauma, with further analysis and reporting then following. This will facilitate a greater understanding being gained as to what factors are contributing to the relevant decision making, including where there is practice variation. Nevertheless, this latest analysis should be of interest to the professionals who reside within the relevant stakeholder groups involved in the assessment and management of deceased donors along with their transplant counterparts. The question needs to be asked, Are we optimally using all of the liver allografts from deceased donors who have sustained blunt liver trauma?
Finally, what else might be able to assist with the assessment of these injured donor livers when there is uncertainty around whether they can be safely transplanted, allowing for the limited time frames once organ recovery is being contemplated? Machine preservation is emerging as a possible option that may facilitate the ongoing assessment/management of donor livers such that their subsequent transplantation then becomes a greater possibility.8 Use of Normothermic Machine Preservation may also facilitate splitting of a donor liver and/or management of a donor liver ex situ,9 providing an additional level of assessment that may also be of benefit in some settings. As to whether the injured liver might able to be fully “repaired” while undergoing Machine Preservation remains to be seen; however, it just might become a possibility in the not-too-distant future.
REFERENCES
1. Seckler F, Turco C, Mohkam K, et al. Liver transplantation using allografts with recent blunt trauma: a nationwide audit from the French Cristal Biomedicine Agency registry. Transplantation. doi: 10.1097/TP.0000000000004434
2. Coccolini F, Coimbra R, Ordonez C, et al.; WSES expert panel. Liver trauma: WSES 2020 guidelines. World J Emerg Surg. 2020;15:24.
3. Geenen IL, Sosef MN, Shun A, et al. Usage and outcomes of deceased donor liver allografts with preprocurement injury from blunt trauma. Liver Transpl. 2009;15:321–325.
4. Angrisani M, Colasanti M, Meniconi R, et al. Transplantation of a severely traumatized liver during the COVID-19 pandemic: a case report and review of the literature. Exp Clin Transplant. 2021;19:1232–1237.
5. Lada NE, Gupta A, Anderson SW, et al. Liver trauma: hepatic vascular injury on computed tomography as a predictor of outcome. Eur Radiol. 2021;31:3375–3382.
6. Israni AK, Zaun D, Gauntt K, et al. OPTN/SRTR 2020 annual data report: DOD. Am J Transplant. 2022;22(Suppl 2):519–552.
7. de Oliveira LB, Riccetto E, Boin IFSF. Prevalence and profile of discarded liver donors in a tertiary health service in Brazil from 2015 to 2018. Trans Proc. 2020;52:1251–1255.
8. Lascaris B, de Meijer VE, Porte RJ. Normothermic liver machine perfusion as a dynamic platform for regenerative purposes: what does the future have in store for us? J Hepatol. 2022;77:825–836.
9. Stephenson BTF, Bonney GK, Laing RW, et al. Proof of concept: liver splitting during normothermic machine perfusion. J Surg Case Rep. 2018;3:rjx218.
