Clinical Factors Associated With Failed Weaning From Intraoperative Extracorporeal Membrane Oxygenation Used During Lung Transplantation

Background: Extracorporeal membrane oxygenation (ECMO) promotes adequate oxygenation and hemodynamic stability during lung transplantation (LTx). However, some recipients cannot be weaned from ECMO following surgery. Thus, we evaluated the prognosis and risk factors of failed weaning from intraoperative ECMO during LTx.Methods: We retrospectively analyzed data from 274 patients receiving intraoperative ECMO during LTx. Risk factors were evaluated using logistic regression analyses.Results: Weaning failure occurred in 118 patients (43.1%). Intensive care unit stay was longer and mortality was higher in the failed weaning group than in the successful weaning group. The failed weaning group exhibited significantly older donor age, lower donor PaO2/FiO2 ratio, greater intraoperative transfusion volume, and longer operation time than the successful weaning group. Recipient age, body mass index, donor age, lower donor PaO2/FiO2 ratio, donor/recipient total lung capacity (TLC) ratio, greater intraoperative transfusion volume, and longer operation time were associated with weaning failure after adjustment. Conclusion: The failed weaning group showed a poor prognosis. Perioperative factors including donor age, donor PaO2/FiO2 ratio, donor/recipient TLC, operation time, and blood loss can predict postoperative ECMO weaning failure.

Predictors of Delayed Graft Function in Renal Transplantation

<b><i>Purpose:</i></b> This study aimed to analyze our data on delayed graft function (DGF) and to identify associated factors. <b><i>Methods:</i></b> This is a retrospective case-control study of all patients transplanted in our center over a period of 11 years (January 1, 2003, to December 31, 2014) comparing patients with immediate graft function (<i>n</i> = 332) to those with DGF (<i>n</i> = 165). DGF was defined as the need for hemodialysis within the first 7 days after transplantation. Donor and recipient characteristics as well as procedural factors were compared by univariate and multivariate logistic regression analyses. <b><i>Results:</i></b> Overall, 33% of patients had DGF. The rate of DGF declined from 2003 to 2011. In cases with DGF, donors and recipients were significantly older (<i>p</i> = 0.004 and <i>p</i> = 0.005, respectively), had longer cold ischemia times (<i>p</i> = 0.039), more revision surgeries (<i>p</i> &#x3c; 0.001), and more HLA mismatches (<i>p</i> = 0.001), especially in the DR locus (<i>p</i> = 0.002). Neither donor nor recipient gender, waiting time, nor CMV status had any influence. In multivariable analysis, significant risk factors were ischemia time and mismatches at the HLA-DR loci. <b><i>Conclusions:</i></b> DGF is a common complication in renal transplantation which occurred in 33% of our cases. Important factors identified were donor and recipient age, ischemia time, HLA mismatching, and revision surgery.

Prophylactic Peritoneal Fenestration during Kidney Transplantation Can Reduce the Type C Lymphocele Formation

Lymphocele is a common complication following kidney transplantation (KTx). We aimed to evaluate the preventive effect of peritoneal fenestration during KTx in reducing lymphocele. From January 2001, the data of all KTx were prospectively gathered in our digital data bank. From 2008, preventive peritoneal fenestration was performed as a routine procedure for all patients with KTx. Between 2001 and 2008, 579 KTx were performed without preventive peritoneal fenestration. To compare the results between with and without peritoneal fenestration, the same number of patients after 2008 (579 patients) was included in this study. The pre-, intra-, and postoperative data of the patients in these two groups were analyzed and compared, especially regarding the postoperative different types of lymphocele formation. The mean recipient age was 52.6 ± 13.8, and 33.7% of the patients were female. Type C lymphocele was significantly lower in the group with preventive fenestration (5.3% vs. 8.8%, p = 0.014 for 31/579 vs. 51/579). Peritoneal dialysis and implantation of the kidney in the left fossa were independently associated with a higher rate of type C lymphocele (OR 2.842, 95% CI 1.354–5.967, p = 0.006 and OR 3.614, 95% CI 1.215–10.747, p = 0.021, respectively). The results of this study showed that intraoperative preventive peritoneal fenestration could significantly reduce type C lymphocele.

Practice Patterns in the Acceptance of Medically Complex Living Kidney Donors with Obesity, Hypertension, Family History of Kidney Disease, or Donor-Recipient Age Discrepancy

Background To assess the practice patterns of the acceptance of medically complex living kidney donors (MCLKDs). Methods We distributed a survey to nephrologists and transplant surgeons (TS) across the world through major international transplant societies. The survey contained questions regarding obesity, abnormal blood glucose profile, mild hypertension, donor-recipient age discrepancy, or family history of kidney disease of unknown etiology. Results In total, 239 respondents from 29 countries (42% were nephrologists and 58% were TS).Most respondents would allow donations from obese donors, especially if they intended to lose weight but would be cautious if these donors had abnormal blood glucose or family history of diabetes mellitus. In hypertensive donors, future pregnancy plans mattered in decisions regarding the acceptance of female donors. Most respondents would allow young donors but would be more cautious if they had a future risk of hypertension or a family history of kidney disease of unknown etiology. They would also allow donations from an older person if prolonged waiting time was anticipated. We found multiple areas of consensus of practice among the diverse members of international transplant societies, with some interesting variations among nephrologists and TS. Conclusions This survey highlights the practice patterns of the acceptance of MCLKDs among the international community. In the absence of clear guidelines, this survey provides additional information to counsel kidney donors with these conditions.

Feature Importance of Acute Rejection among Black Kidney Transplant Recipients by Utilizing Random Forest Analysis: An Analysis of the UNOS Database

Background: Black kidney transplant recipients have worse allograft outcomes compared to White recipients. The feature importance and feature interaction network analysis framework of machine learning random forest (RF) analysis may provide an understanding of RF structures to design strategies to prevent acute rejection among Black recipients. Methods: We conducted tree-based RF feature importance of Black kidney transplant recipients in United States from 2015 to 2019 in the UNOS database using the number of nodes, accuracy decrease, gini decrease, times_a_root, p value, and mean minimal depth. Feature interaction analysis was also performed to evaluate the most frequent occurrences in the RF classification run between correlated and uncorrelated pairs. Results: A total of 22,687 Black kidney transplant recipients were eligible for analysis. Of these, 1330 (6%) had acute rejection within 1 year after kidney transplant. Important variables in the RF models for acute rejection among Black kidney transplant recipients included recipient age, ESKD etiology, PRA, cold ischemia time, donor age, HLA DR mismatch, BMI, serum albumin, degree of HLA mismatch, education level, and dialysis duration. The three most frequent interactions consisted of two numerical variables, including recipient age:donor age, recipient age:serum albumin, and recipient age:BMI, respectively. Conclusions: The application of tree-based RF feature importance and feature interaction network analysis framework identified recipient age, ESKD etiology, PRA, cold ischemia time, donor age, HLA DR mismatch, BMI, serum albumin, degree of HLA mismatch, education level, and dialysis duration as important variables in the RF models for acute rejection among Black kidney transplant recipients in the United States.

Higher levels of serum phosphorus are associated with coronary calcification post heart transplantation

Background A higher serum phosphorus level, although within the normal range has been linked to coronary artery and aortic calcification in the non-transplant population. Coronary calcification is mostly associated with donor-derived lesions, and is uncommon within the first years after heart transplantation. Purpose We aimed to investigate the association of phosphorus levels with plaque calcification after heart transplantation. Methods A total of 156 patients who underwent virtual histology intravascular ultrasound (VH-IVUS) studies for cardiac allograft vasculopathy (CAV) surveillance and had fasting serum phosphorus levels &lt;4.5 mg/dL, were included in the analyses. IVUS analyses were performed in the proximal left anterior descending artery, and plaque composition of dense calcium (DC) was evaluated using VH-IVUS, and presented as percent DC of total plaque volume. The patients were separated into 3 groups according to tertiles of serum phosphorus levels. Results Mean recipient and donor ages were 54±13 and 31±14 years, respectively. Mean serum phosphorus in recipients was 3.5±0.6 mg/dL, with median time after transplantation at the IVUS studies of 6 (3,10) years. There were no significant differences in %DC between phosphorus tertiles in patients who underwent IVUS within 6 years after transplantation (p=0.11, Fig. 1A). However, beyond 6 years after transplantation, we observed an incremental association between phosphorus levels and the extent of calcification (p=0.02, Fig. 1B). In this group, serum phosphorus levels significantly correlated with %DC (standardized β=0.29, P=0.008), and this correlation remained significant after adjustment for donor age, recipient age, and eGFR (standardized β=0.26, P=0.001). Conclusion Higher serum phosphorus levels were associated with a level-dependent increase in calcified coronary artery plaque in patients starting 6 years post heart transplant. Long-term exposure to higher serum phosphorus, even within the normal range, might promote plaque calcification after heart transplantation. FUNDunding Acknowledgement Type of funding sources: None.