Quality assessment of donor liver procurement surgery using an unadjusted CUSUM prediction model. A practical nationwide evaluation.

BACKGROUND: The aim of this study was to analyze the value of the unadjusted CUSUM graph of liver surgical injury and discard rates in organ procurement in the Netherlands. METHODS: Unadjusted CUSUM graphs were plotted for surgical injury (C event) and discard rate (C2 event) from procured livers accepted for transplantation for each local procurement team compared with the total national cohort. The average incidence for each outcome was used as benchmark based on procurement quality forms (Sep 2010-Oct 2018). The data from the five Dutch procuring teams were blind-coded. RESULTS: The C and C2 event rate were 17% and 1.9%, respectively (n = 1265). A total of 12 CUSUM charts were plotted for the national cohort and the five local teams. National CUSUM charts showed an overlapping "alarm signal." This overlapping signal for both C and C2, albeit a different time period, was only found in one local team. The other CUSUM alarm signal went off for two separate local teams, but only for C events or C2 events respectively, and at different points in time. The other remaining CUSUM charts showed no alarm signaling. CONCLUSION: The unadjusted CUSUM chart is a simple and effective monitoring tool in following performance quality of organ procurement for liver transplantation. Both national and local recorded CUSUMs are useful to see the implication of national and local effects on organ procurement injury. Both procurement injury and organ discard are equally important in this analysis and need to be separately CUSUM charted.

Real-time assessment of liver fat content using a filter-based Raman system operating under ambient light through lock-in amplification.

During liver procurement, surgeons mostly rely on their subjective visual inspection of the liver to assess the degree of fatty infiltration, for which misclassification is common. We developed a Raman system, which consists of a 1064 nm laser, a handheld probe, optical filters, photodiodes, and a lock-in amplifier for real-time assessment of liver fat contents. The system performs consistently in normal and strong ambient light, and the excitation incident light penetrates at least 1 mm into duck fat phantoms and duck liver samples. The signal intensity is linearly correlated with MRI-calibrated fat contents of the phantoms and the liver samples.

Accurate assessment of liver steatosis in animal models using a high throughput Raman fiber optic probe.

Due to the shortage of healthy donor organs, steatotic livers are commonly used for transplantation, placing patients at higher risk for graft dysfunction and lower survival rates. Raman Spectroscopy is a technique which has shown the ability to rapidly detect the vibration state of C-H bonds in triglycerides. The aim of this study is to determine whether conventional Raman spectroscopy can reliably detect and quantify fat in an animal model of liver steatosis. Mice and rats fed a methionine and choline-deficient (MCD) and control diets were sacrificed on one, two, three and four weeks' time points. A confocal Raman microscope, a commercial Raman (iRaman) fiber optic probe and a highly sensitive Raman fiber optic probe system, the latter utilizing a 785 nm excitation laser, were used to detect changes in the Raman spectra of steatotic mouse livers. Thin layer chromatography was used to assess the triglyceride content of liver specimens, and sections were scored blindly for fat content using histological examination. Principal component analysis (PCA) of Raman spectra was used to extract the principal components responsible for spectroscopic differences with MCD week (time on MCD diet). Confocal Raman microscopy revealed the presence of saturated fats in mice liver sections. A commercially available handheld Raman spectroscopy probe could not distinguish the presence of fat in the liver whereas our specially designed, high throughput Raman system could clearly distinguish lobe-specific changes in fat content. In the left lobe in particular, the Raman PC scores exhibited a significant correlation (R(2) = 0.96) with the gold standard, blinded scoring by histological examination. The specially designed, high throughput Raman system can be used for clinical purposes. Its application to the field of transplantation would enable surgeons to determine the hepatic fat content of the donor's liver in the field prior to proceeding with organ retrieval. Next steps include validating these results in a prospective analysis of human liver transplantation implant biopsies.

Simultaneous liver kidney transplantation: a medical decision analysis.

BACKGROUND: The use of simultaneous liver kidney transplantation has increased dramatically. When the liver and kidney are available from the same deceased donor, what is the best decision? There are two allocation options. In the combined allocation, both organs are allocated to a liver failure (end-stage liver disease [ESLD]) patient on dialysis leaving an end-stage renal disease (ESRD) patient on dialysis. In split allocation, the liver is allocated to the liver failure patient on dialysis and the kidney to the patient with ESRD. METHODS: A computerized medical decision analysis was performed using published US survival data. The two options were compared by examining differences in projected quality-adjusted life years (QALYs). RESULTS: Combined allocation was the best strategy (+0.806 QALYs) if liver transplant recipients on dialysis have proportionately worse survival compared with kidney failure alone patients on dialysis. However, because some patients with hepatorenal syndrome recover kidney function post-liver transplant alone (LTA), a second analysis incorporated the possibilities of being dialysis free. If the chance of recovery of renal function is 50% rather than 0%, the decision reversed. Here, the split allocation provided 1.02 more total QALYs than the combined allocation. CONCLUSIONS: This study demonstrates that simultaneous liver kidney transplantation is an excellent strategy in most patients with both ESLD and ESRD. However, allocating a kidney to a patient with ESLD, who has the potential to be dialysis free without a kidney transplant, does not maximize overall outcomes when all patients are considered.