Thrombotic Ringed Polytetrafluoroethylene Graft With Infection After Living-Donor Liver Transplantation.

BACKGROUND: The safety of the living donor in living-donor liver transplantation (LDLT) is always the first priority, meanwhile, the graft-to-recipient weight ratio (GRWR) and the anatomy of the liver allograft must also not be compromised in order to warrant tranplatation success. When it comes to the allograft of the right lobe of the liver without the middle hepatic vein (R-M), the outflow and adequate drainage for the territory of middle hepatic vein (MHV) is one critical concern. Despite publications in some high-volume transplant centers on the positive results of using expanded polytetrafluoroethylene (ePTFE) grafts to substitute those of autologous veins, complications related to the ePTFE graft have not been well discussed. METHODS: From July 2012 to June 2016, 129 adult patients who underwent living donor liver transplantation in Taipei Veterans General Hospital were analyzed. There were 3 cases of adjacent organ erosion with gas bubbles in the lumen of an ePTFE graft, including gastrointestinal (GI) tract penetration in 2 out of the first 15 cases that used the venous graft of ringed expanded polytetrafluoroethylene (rPTFE). The patient survival rate during this period was compared and radiological findings of rPTFE function and clinical signs of erosion with infection were also examined to raise the concerns of safety as well as early detection of complications of rPTFE. RESULTS: The overall 1-year patient survival rate was 90%, of which the right lobe wih MHV (R+M) group was 93.5% and the R-M group was 91.9%. For the mean of GRWR, the R+M group was 1.05 ± 0.19 and R-M group was 1.19 ± 0.27, while those who needed reconstruction with vein grafts was 0.96 ± 0.11. Among the R-M group, 24 out of 88 cases (27.3%) needed reconstruction of MHV tributaries. Of the 24 cases, 15 cases were done with rPTFE and the 1-year patient survival rate of the rPTFE group was 73%, which is significantly worse (P = .008) than the non-rPTFE (89%) and non-reconstructed (97%) groups. The mean GRWR is significantly higher (P = .001) in the non-reconstructed group (1.19 ± 0.27) than in the rPTFE (0.99 ± 0.11) and non-rPTFE (0.94 ± 0.11) groups. The venous grafts patency rate between the different graft types is no different, and there is also significance in warm ischemic time (P = .009) between the non-reconstructed (49 ± 15), rPTFE (81 ± 51), and non-rPTFE (56 ± 18) groups in the mean minutes. CONCLUSION: In cases of fever of unknown cause in patients receiving LDLT with rPTFE graft, a regular computed tomography (CT) scan with contrast and gas bubbles within the graft lumen is the best way for early detection of graft related infection and suspicious GI tract penetration. To decrease the risks of tissue reaction induced by ePTFE graft in LDLT, omentum patches or other inert agents can be introduced as a buffer between the graft and adjacent organs, especially the GI tracts. However, research in material science shall be explored to solve the problem in the future.

Comparison of Two Devices for Intraoperative Portal Venous Flow Measurement in Living-Donor Liver Transplantation: Transit Time Ultrasound and Conventional Doppler Ultrasound.

BACKGROUND: Intraoperative portal venous flow measurement provides surgeons with instant guidance for portal flow modulation during living-donor liver transplantation (LDLT). In this study, we compared the agreement of portal flow measurement obtained by 2 devices: transit time ultrasound (TTU) and conventional Doppler ultrasound (CDU). METHODS: Fifty-four recipients of LDLT underwent intraoperative measurement of portal flow after completion of vascular anastomosis of the implanted partial liver graft. Both TTU and CDU were used concurrently. Agreement of TTU and CDU was assessed by intraclass correlation coefficient using a model of 2-way random effects, absolute agreement, and single measurement. A Bland-Altman plot was applied to assess the variability between the 2 devices. RESULTS: The mean, median, and range of portal venous flow was 1456, 1418, and 117 to 2776 mL/min according to TTU; and 1564, 1566, and 119 to 3216 mL/min according to CDU. The intraclass correlation coefficient of portal venous flow between TTU and CDU was 0.68 (95% confidence interval, 0.51-0.80). The Bland-Altman plots revealed an average variation of 4.8% between TTU and CDU but with a rather wide 95% confidence interval of variation ranging from -57.7% to 67.4%. CONCLUSIONS: Intraoperative TTU and CDU showed moderate agreement in portal flow measurement. However, a relatively wide range of variation exists between TTU and CDU, indicating that data obtained from the 2 devices may not be interchangeable.

Isolated Crystalloid Podocytopathy With Focal Segmental Glomerulosclerosis in Renal Allograft: An Unusual Presentation of Post-Transplant Monoclonal Gammopathy of Renal Significance-A Case Report.

BACKGROUND: Monoclonal gammopathy of renal significance denotes a spectrum of hematologic disorders that cause direct or indirect renal damage. CASE PRESENTATION: A 51-year-old man had received a living-donor kidney transplant from his wife in 2008. He had gradual increased proteinuria 4 years later. His renal biopsy results revealed cytoplasmic crystalloid inclusions in the podocytes. No crystalloid inclusion was found in other renal cells. Despite that immunofluorescent examination failed to show light-chain deposition, the serum immuno-electrophoresis revealed monoclonal immunoglobulin-Gκ. Bone marrow biopsy showed interstitial infiltration of plasma cells of approximately 10%. A follow-up renal biopsy was performed in 2016. Light microscopy showed focal segmental glomerulosclerosis. The immunofluorescent examination remained negative for light chain, but κ-light chain could be demonstrated after antigen retrieval. Similar to previous biopsy results, cytoplasmic inclusions were found only in podocytes without involving other renal cells. CONCLUSIONS: To the best of our knowledge, this is the first report of monoclonal gammopathy of renal significance presenting as isolated crystalloid podocytopathy in the allograft kidney. The mechanism of preferential podocyte deposition of crystalloid immunoglobulin remains unclear. The inherent features of crystalloid podocytopathy may mislead the pathologic diagnosis.

How to Improve the Positive Predictive Value of Urinary Decoy Cell Surveillance for Polyomavirus BK-Associated Nephropathy in Kidney Transplant Patients.

BACKGROUND: Polyomavirus BK-associated nephropathy (BKVN) has been a serious problem after kidney transplantation. Detection of urinary decoy cells (UDCs) and assessment of polyomavirus BK nucleic acids by polymerase chain reactions (PCRs) are currently used, noninvasive tests. PCRs have better positive predictive value (PPV) but higher cost and lower accessibility. This study investigated ways to improve the PPV of UDCs for BKVN prediction. METHODS: From 2000 to 2013, kidney transplant recipients with sustained UDCs for more than half a month and who had received allograft biopsies were enrolled. We analyzed the PPV of UDCs for BKVN with 2 variables: (i) the percentage changes in serum creatinine (SCr) levels and (ii) the duration of sustained UDCs by receiver operating characteristic (ROC) curve analysis; we predicted the percentage changes in SCr levels with the corresponding PPV using a linear regression model. RESULTS: BKVN was diagnosed in 26 of 68 enrolled patients. The percentage changes in SCr levels significantly deteriorated in the BKVN group during 1-2 months of UDC positivity. According to ROC curve analysis, percentage changes in SCr levels had a significant discriminating power for BKVN during 1-1.5 month, and if the percentage changes in SCr levels were >19%, the PPV of UDCs for BKVN was 50%. CONCLUSIONS: An UDC surveillance program is a judicious strategy to predict BKVN in kidney transplant patients, particularly when graft renal function shows deterioration after 1 month of UDC positivity.

Incidence and Risk Factors for Tuberculosis After Liver Transplantation in an Endemic Area: A Nationwide Population-Based Matched Cohort Study.

Morbidity and mortality from tuberculosis (TB) are high in Taiwan. We conducted a nationwide population-based matched cohort study using data retrieved from the Taiwan's National Health Insurance Research Database to determine the impact of TB after liver transplantation (LT). During 2000-2011, we identified 3202 liver transplant recipients and selected subjects from the general population matched for age, sex, and comorbidities on the same index date of recognition of LT with a 1:10 ratio. The data were analyzed using Cox proportional hazards models. Compared to the matched cohort, liver transplant patients had a higher risk for TB (adjusted HR 2.25, 95% CI 1.65-3.05, p < 0.001), and those with TB showed higher mortality (HR 2.27, 95% CI 1.30-3.97, p = 0.004). Old age (HR 2.64, 95% CI 1.25-5.54, p = 0.011) and mammalian target of rapamycin inhibitors (mTORis) (HR 3.09, 95% CI 1.68-5.69, p < 0.001) were significant risk factors for TB in LT; mTORis were also associated with mortality after adjusting for confounders (HR 2.13, 95% CI 1.73-2.62, p < 0.001). Therefore, regular surveillance of TB and treatment of latent TB infection in high-risk patients after LT are important, especially in TB-endemic areas.

Extracorporeal membrane oxygenation as treatment for acute respiratory failure and subsequent pneumothorax caused by Pneumocystis jirovecii pneumonia in a kidney transplant recipient.

Acute respiratory failure (ARF) accompanied by pneumothorax caused by Pneumocystis jirovecii pneumonia (PJP) is often fatal. We present our experience using extracorporeal membrane oxygenation as treatment for ARF and subsequent pneumothorax caused by PJP in a kidney transplant recipient.

Hepatic venous congestion after living donor liver transplantation: quantitative assessment of liver stiffness using shear wave elastography--a case report.

We report a 49-year-old right lobe liver transplant recipient, who developed a significant anastomotic stenosis of the right hepatic vein shortly thereafter. Shear wave elastography (SWE) was applied to investigate liver stiffness quantitatively. It showed increased stiffness in the anterior compared with the posterior segment of right lobe graft. The stenotic right hepatic venous anastomosis was then managed by angioplasty with stent placement. SWE after angioplasty showed a gradual decrease in stiffness of the anterior segment, which was almost equal to the posterior segment at 2 weeks thereafter. Our experience suggested that SWE may be a noninvasive tool to assess alterations in liver stiffness secondary to hepatic venous congestion after liver transplantation.

Early postoperative spectral Doppler parameters of renal transplants: the effect of donor and recipient factors.

BACKGROUND: The objective of this study was to explore the donor and recipient factors related to the spectral Doppler parameters of the transplant kidney in the early posttransplantation period. METHODS: This retrospective study included 76 patients who underwent renal transplantation assessed using Doppler ultrasonography (US) on the first postoperative day. We compared spectral Doppler parameters (peak systolic velocity [PSV] and resistive index [RI]) of the segmental artery of the transplant kidney according to the type of renal transplant, level of serum creatinine (SCr) of donor prior to organ donation, and donor/recipient age. RESULTS: RI was significantly higher in deceased-donor kidney transplantation (DDKT) as compared with living-donor kidney transplantation (LDKT; 0.73 ± 0.10 vs 0.66 ± 0.11; P = .007). In the DDKT recipients, multivariate analysis showed donor SCr was the only factor affecting PSV (P = .023), whereas recipient age was the only factor affecting RI (P = .035). In the LDKT recipients, multivariate analysis showed recipient age was the only factor affecting both PSV (P = .009) and RI (P = .018). CONCLUSION: Spectral Doppler parameters in the early posttransplantation period are related to the type of renal transplant, donor renal function, and recipient age. These factors should be taken into consideration when interpreting the results of spectral Doppler US.

Results of kidney transplantation from high-terminal creatinine donors and the role of time-zero biopsy.

BACKGROUND: Deceased-donor kidney transplantation (DDKT) from high-terminal creatinine donors is associated with lower graft survival. These kidneys may be considered for discarding, worsening the organ shortage crisis. Using time-zero biopsy for histologic evaluation of these kidneys, we identified those organs eligible for transplantation, seeking to achieve better graft utility with comparable outcomes. METHODS: From April 2004 to April 2008, 55 patients underwent DDKT. A time-zero biopsy was used to examine glomerulosclerosis, interstitial fibrosis, tubular atrophy, and arteriolar narrowing. A scoring system was used to determine a discard. RESULTS: Twenty-five patients received DDKT from donors whose terminal creatinine levels were >2.0 mg/dL (high terminal creatinine, HTC group) and 30 from donors whose terminal creatinine levels were <2.0 mg/dL (low terminal creatinine, LTC group). Patients who accepted kidneys from HTC donors had shorter waiting times (P = .011) but a higher incidence of delayed graft function after transplantation (P < .001). Nonetheless, 5-year graft survival rates were similar between the two groups. CONCLUSIONS: With a time-zero biopsy for histologic evaluation, kidneys recovered from high-terminal creatinine donors can be transplanted to overcome the organ shortage while achieving reasonable graft survival.

Changes in mitochondrial respiratory enzyme activity after ischemia-reperfusion injury in living-donor liver transplantation.

BACKGROUND: Ischemia-reperfusion (I-R) injury plays an important role in the immediate graft function in living-donor liver transplantation (LDLT). There is growing evidence that mitochondria play a pivotal role in I-R injury. Our aim was to evaluate changes in mitochondrial respiratory enzyme activities after I-R injury in LDLT. METHODS: Specimens from 8 donor recipient pairs enrolled in this study were obtained from the donor livers before harvest (before I-R injury) and after vascular anastomosis in the recipient (after I-R injury). Histidine-tryptophan-ketoglutarate solution was used to perfuse the organ during the cold ischemic period between harvesting and transplantation. We correlated changes in mitochondrial respiratory enzyme complex activity (succinate cytochrome c reductase [SCCR]; NADH cytochrome c reductase [NCCR]) after I-R injury with clinical data and graft status. RESULTS: NCCR and SCCR activities did not uniformly decrease after I-R injury. Two of 8 recipients experienced graft dysfunction after transplantation. The decrease in neither NCCR nor SCCR activity correlated with graft dysfunction in these 2 patients. Among the clinical factors, grafts from older donors tended to show decreased NCCR activity after I-R injury. CONCLUSIONS: In this study, changes in mitochondrial respiratory enzyme activity failed to predict the severity of I-R injury in LDLT. The organ preservation solution may play a protective role on mitochondrial respiratory enzymes during I-R injury.

Use of an adenosine triphosphate assay, and simultaneous staining with fluorescein diacetate and propidium iodide, to evaluate the effects of cryoprotectants on hard coral (Echinopora spp.) oocytes.

The objective was to examine the effects of cryoprotectants on oocytes of hard corals (Echinopora spp.) to obtain basic knowledge for cryopreservation procedures. Oocytes were exposed to various concentrations of cryoprotectants (0.25 to 5.0M) for 20 min at room temperature (25 degrees C). Two tests were used to assess ovarian follicle viability: fluorescein diacetate (FDA)+propidium iodide (PI) staining, and adenosine triphosphate (ATP) assay. Both FDA+PI staining and ATP assay indicated that cryoprotectant toxicity to oocytes increased in the order methanol, dimethyl sulfoxide (DMSO), propylene glycol (PG), and ethylene glycol (EG). The no observed effect concentrations for Echinopora spp. oocytes were 1.0, 0.5, 0.25, and 0.25 M for methanol, DMSO, PG, and EG, respectively, when assessed with FDA+PI. The ATP assay was more sensitive than FDA+PI staining (P<0.05). Oocyte viability after 1.0M methanol, DMSO, EG, or PG treatment for 20 min at room temperature assessed with FDA+PI tests and ATP assay were 88.9+/-3.1% and 72.2+/-4.4%, 66.2+/-5.0% and 23.2+/-4.9%, 58.9+/-5.4% and 1.1+/-0.7%, and 49.1+/-5.1% and 0.9+/-0.5%, respectively. We inferred that the ATP assay was a valuable measure of cellular injury after cryoprotectant incubation. The results of this study provided a basis for development of protocols to cryopreserve coral oocytes.