Outcomes of normothermic machine perfusion of liver grafts in repeat liver transplantation (NAPLES initiative).

BACKGROUND: Retransplantation candidates are disadvantaged owing to lack of good-quality liver grafts. Strategies that can facilitate transplantation of suboptimal grafts into retransplant candidates require investigation. The aim was to determine whether late liver retransplantation can be performed safely with suboptimal grafts, following normothermic machine perfusion. METHODS: A prospectively enrolled group of patients who required liver retransplantation received a suboptimal graft preserved via normothermic machine perfusion. This group was compared with both historical and contemporaneous cohorts of patient who received grafts preserved by cold storage. The primary outcome was 6-month graft and patient survival. RESULTS: The normothermic machine perfusion group comprised 26 patients. The historical (cold storage 1) and contemporaneous (cold storage 2) groups comprised 31 and 25 patients respectively. The 6-month graft survival rate did not differ between groups (cold storage 1, 27 of 31, cold storage 2, 22 of 25; normothermic machine perfusion, 22 of 26; P = 0.934). This was despite the normothermic machine perfusion group having significantly more steatotic grafts (8 of 31, 7 of 25, and 14 of 26 respectively; P = 0.006) and grafts previously declined by at least one other transplant centre (5 of 31, 9 of 25, and 21 of 26; P < 0.001). CONCLUSION: In liver retransplantation, normothermic machine perfusion can safely expand graft options without compromising short-term outcomes.

Liver transplantation is a life-saving procedure for many different diseases. In the UK, one in 10 patients awaiting transplant have had a previous liver transplant. These retransplant operations are complex, and the general belief is that a good-quality donor liver graft is required for best outcomes. However, there is a significant shortage of good-quality organs for liver transplantation, so many patients awaiting retransplantation spend longer on the waiting list. This study investigated whether a new technology, called normothermic machine perfusion, could be used to preserve lower-quality donor livers and have successful outcomes for patients undergoing retransplantation. Traditionally, good-quality livers are preserved in an ice box and the study compared the outcomes of these two different approaches. The aim was to prove that normothermic machine perfusion improves access to transplantation for this group of patients, without compromising outcomes. A group of patients who underwent retransplantation and received a lesser-quality liver preserved with normothermic machine perfusion was compared with two groups of patients who had received a transplant with traditional ice-box preservation. The complications, graft, and patient survival of the former group was compared with those in the latter two groups who underwent liver retransplantation with better-quality liver grafts. The rate of survival and adverse surgical outcomes were comparable between the groups of patients who received a liver preserved via traditional ice-box preservation, and those who received a lesser-quality liver preserved via normothermic machine perfusion. Normothermic machine perfusion can potentially expand the number of suitable donor livers available for retransplant candidates.

Transarterial chemoembolization of hepatocellular carcinoma before liver transplantation and risk of post-transplant vascular complications: a multicentre observational cohort and propensity score-matched analysis.

BACKGROUND: Transarterial chemoembolization (TACE) in patients with hepatocellular cancer (HCC) on the waiting list for liver transplantation may be associated with an increased risk for hepatic artery complications. The present study aims to assess the risk for, primarily, intraoperative technical hepatic artery problems and, secondarily, postoperative hepatic artery complications encountered in patients who received TACE before liver transplantation. METHODS: Available data from HCC liver transplantation recipients across six European centres from January 2007 to December 2018 were analysed in a 1 : 1 propensity score-matched cohort (TACE versus no TACE). Incidences of intraoperative hepatic artery interventions and postoperative hepatic artery complications were compared. RESULTS: Data on postoperative hepatic artery complications were available in all 876 patients (425 patients with TACE and 451 patients without TACE). Fifty-eight (6.6 per cent) patients experienced postoperative hepatic artery complications. In total 253 patients who had undergone TACE could be matched to controls. In the matched cohort TACE was not associated with a composite of hepatic artery complications (OR 1.73, 95 per cent c.i. 0.82 to 3.63, P = 0.149). Data on intraoperative hepatic artery interventions were available in 825 patients (422 patients with TACE and 403 without TACE). Intraoperative hepatic artery interventions were necessary in 69 (8.4 per cent) patients. In the matched cohort TACE was not associated with an increased incidence of intraoperative hepatic artery interventions (OR 0.94, 95 per cent c.i. 0.49 to 1.83, P = 0.870). CONCLUSION: In otherwise matched patients with HCC intended for liver transplantation, TACE treatment before transplantation was not associated with higher risk of technical vascular issues or hepatic artery complications.

Lay Summary Patients with liver cancer may be treated with transarterial chemoembolization (TACE) during the period on the transplant waiting list. With TACE, chemotherapeutic coils are injected directly into the small arteries supplying the tumour, after which these vessels are closed. The aim of this therapy is to decrease the tumour size and slow down tumour growth. However, concerns are raised that manipulation of the main hepatic artery by TACE may cause damage to the artery itself. If this would result in problems during or after liver transplantation when the artery is connected to the artery supplying the donor liver, this may endanger the donor liver graft survival. The present study shows no increased risk in problems to connect the artery during liver transplantation after TACE treatment. Also, arterial complications after liver transplantation did not occur more frequently if patients had received TACE treatment. The authors therefore conclude that TACE treatment before liver transplantation could be considered a safe approach.

In Vitro Effects of Resin Infiltration on Enamel Erosion Inhibition.

Resin-based materials that show promising effects for preventing the progression of erosion have been studied. This in vitro study evaluated the effects of applying resin-based materials, including resin infiltration, on previously eroded enamel subjected to erosive challenges. The influence of enamel surface etching prior to application of the material was also studied. Bovine enamel blocks were immersed in hydrochloric acid (HCl), 0.01 M (pH 2.3), for 30 seconds in order to form a softened erosion lesion. The blocks were then randomly divided into nine groups (n=12) and treated as follows: C = control without treatment; Hel = pit & fissure resin sealant (Helioseal Clear); Adh = two-step self-etching adhesive system (AdheSe); Tet = two-step conventional adhesive system (Tetric N-bond); and Inf = infiltrant (Icon). The Helno, Adhno, Tetno, and Infno groups received the same materials without (or with no) surface conditioning. The depth of the material's penetration into softened erosion lesions was qualitatively analyzed using reflection and fluorescence confocal microscopy. After application of the materials, the blocks were immersed in HCl for two minutes; this step was followed by immersion in artificial saliva for 120 minutes four times a day for five days (erosive cycling). Both the enamel alteration and material thickness were analyzed using profilometry, and the results were submitted to Kruskal-Wallis and Dunn tests (p>0.05). Images from the confocal microscopy showed minimal penetration of Adh/Adhno and deep penetration of Inf/Infno into the erosive lesions. The groups Hel, Adh, Inf, Tetno, and Infno resulted in the formation of a layer of material over the enamel, which was effective in inhibiting the progression of erosion. In conclusion, the infiltrant, with or without etching, was able to penetrate and protect the enamel against dental erosion. The other resin-based materials, except for the two-step conventional adhesive, were able to penetrate and inhibit the progression of erosive lesions only when they were applied after enamel etching.