Intraoperative Assessment of Coronary Resistances: A New Quality Marker and Potential Tool to Predict Early Graft Failure after Coronary Artery Bypass Grafting?

Intraoperative assessment of graft patency is pivotal for successful coronary revascularization. In the present study we aimed to propose a new, easy to perform tool to assess anastomotic quality intraoperatively, and to investigate its potential reliability in predicting early graft failure. Intraoperative graft flowmetry of 63 consecutive patients undergoing CABG were prospectively collected. Transit time flowmetry and its derivatives were recorded. Coronary resistances were calculated according to Hagen–Poiseuille equation both during cardioplegic arrest and after withdrawal from cardiopulmonary bypass. Angiographic evidence of graft occlusion at follow-up was cross-checked with intraoperative recordings. After a mean follow-up of 10.4 ± 6.0 months, 22 grafts were studied, and occlusion was documented in five (22.7%). Occluded grafts showed lower flows and higher resistances recorded during aortic cross-clamping. Coronary resistances, recorded during aortic cross-clamping, greater than 2.0 mmHg/mL/min, showed a sensitivity of 80% and a specificity of 100% to predict graft failure. We propose the routine recording of coronary resistances during aortic cross-clamping as an additional tool to overcome the acknowledged limitation of TTF to predict graft occlusion at 1 year.

Outcomes of Repair of Total Graft Detachment following Descemetʼs Membrane Endothelial Keratoplasty

Objective To present the outcomes of attempts to salvage total graft detachment following Descemetʼs membrane endothelial keratoplasty (DMEK). Methods A search of the electronic medical records of two tertiary medical centers for all patients who underwent DMEK yielded six cases of postoperative total graft detachment (2.54%). Graft salvage was attempted in all cases using repeated intracameral graft staining, unfolding, and reattachment to the stroma under 20% hexafluoride gas. Results In all cases, a free-floating totally detached graft was identified in the anterior chamber shortly after surgery. Salvage surgery resulted in a central, well-oriented, and fully attached graft. In three cases, the primary graft failed, and in two, the corneas cleared at first but failed after 2 months and 1 year respectively. In one case, the cornea remained clear during 1 year of follow-up but had a very low endothelial cell density. Conclusion Reattachment of fully detached DMEK graft is technically possible, but graft manipulation during the primary and secondary operations is likely to damage the endothelial cells, resulting in primary or early graft failure. If graft salvage is attempted, the probability of primary or early graft failure should be discussed with the patient, and expectations should be tempered accordingly.

Prediction model for early graft failure after liver transplantation using aspartate aminotransferase, total bilirubin and coagulation factor

This study was designed to build models predicting early graft failure after liver transplantation. Cox regression model for predicting early graft failure after liver transplantation using post-transplantation aspartate aminotransferase, total bilirubin, and international normalized ratio of prothrombin time was constructed based on data from both living donor (n = 1153) and deceased donor (n = 359) liver transplantation performed during 2004 to 2018. The model was compared with Model for Early Allograft Function Scoring (MEAF) and early allograft dysfunction (EAD) with their C-index and time-dependent area-under-curve (AUC). The C-index of the model for living donor (0.73, CI = 0.67–0.79) was significantly higher compared to those of both MEAF (0.69, P = 0.03) and EAD (0.66, P = 0.001) while C-index for deceased donor (0.74, CI = 0.65–0.83) was only significantly higher compared to C-index of EAD. (0.66, P = 0.002) Time-dependent AUC at 2 weeks of living donor (0.96, CI = 0.91–1.00) and deceased donor (0.98, CI = 0.96–1.00) were significantly higher compared to those of EAD. (both 0.83, P < 0.001 for living donor and deceased donor) Time-dependent AUC at 4 weeks of living donor (0.93, CI = 0.86–0.99) was significantly higher compared to those of both MEAF (0.87, P = 0.02) and EAD. (0.84, P = 0.02) Time-dependent AUC at 4 weeks of deceased donor (0.94, CI = 0.89–1.00) was significantly higher compared to both MEAF (0.82, P = 0.02) and EAD. (0.81, P < 0.001). The prediction model for early graft failure after liver transplantation showed high predictability and validity with higher predictability compared to traditional models for both living donor and deceased donor liver transplantation.

Rebubbling and graft failure in Descemet membrane endothelial keratoplasty: a prospective Dutch registry study

AimsTo identify risk factors for rebubbling, and early graft failure after Descemet membrane endothelial keratoplasty (DMEK).MethodsIn this prospective registry study, all consecutive DMEK procedures registered in the Netherlands Organ Transplant Registry were assessed (n=752). Univariable and multivariable analysis was performed using logistic regression. The effect of rebubbling on endothelial cell density was analysed using a linear mixed model.Results144 of 752 (19%) eyes underwent rebubbling. Rebubbling was successful in 101 eyes (70%). In eyes that underwent rebubbling, the graft failure rate was significantly higher than eyes that did not undergo rebubbling (30% vs 9%, respectively; OR: 4.28, 95% CI 2.72 to 6.73, p<0.001). In multivariable analysis, independent risk factors for rebubbling were surgical complication (OR: 2.28, 95% CI 1.20 to 4.33, p=0.012) and older recipient age (OR: 1.04 (per increase of 1 year), 95% CI 1.01 to 1.07, p=0.003). Risk factors for developing graft failure within 3 months were transplant before 2016 (OR: 3.32, 95% CI 1.87 to 5.90, p<0.001), and surgical complication (OR: 2.93, 95% CI 1.42 to 6.04, p=0.004). Throughout the study period, rebubbling and early graft failure were inversely related. Eyes that underwent rebubbling showed significantly lower endothelial cell densities at 3, 6 and 12 months compared with eyes that did not undergo rebubbling (all p<0.001).ConclusionsThis Dutch registry study identified independent risk factors for DMEK graft detachment leading to rebubbling, namely recipient age and surgical complication, and early graft failure, namely transplantation before 2016 and surgical complication. Rebubbling was associated with significantly higher endothelial cell loss in the first year after surgery.

Compatible Donor and Recipient Pairs’ Perspectives on Participation in Kidney Paired Donation Programs: A Mixed-Methods Study

Background: Compatible pair participation in kidney paired donation (KPD) may increase the likelihood of finding suitable matches for all registered pairs. Retrospective studies have shown variable enthusiasm for participating in KPD in compatible pairs. Objective: The study objective was to gather potential living donor (PLD) and transplant candidate (TC) perspectives on compatible pair participation in KPD. Design: Surveys and qualitative interviews. Setting: Three transplant programs in Canada: Centre hospitalier de l’Université de Montréal in Montreal (Québec), Vancouver General Hospital, and St. Paul’s Hospital in Vancouver (British Columbia). Patients: Both PLDs and TCs undergoing evaluation for donation/transplantation between 2016 and 2018 at 3 transplant programs in Canada. Methods: Descriptive statistical analysis was performed for the results of the survey and thematic and content analysis method was used for the content of the qualitative interviews. Results: A total of 116 PLDs and 111 TCs completed surveys and an additional 18 PLDs and 17 TCs underwent semi-directed interviews. Of those surveyed, 61.2% of PLDs and 76.6% of TCs reported a willingness to participate in KPD as a compatible pair. The possibility of a more optimally matched kidney for the TC and policies ensuring prioritization of the TC for repeat transplantation in the event of early graft failure increased willingness to participate in KPD. Major concerns expressed during the interviews included the desire to retain the emotional bond of directed donation, the fear of chain breaks or donor reneging, delays in transplantation, and additional travel associated with participation in KPD. Limitation: The limitations of this study are that it was conducted in only 3 Canadian transplant programs and that the interviews and surveys were in French and in English. As a consequence, the results may not be reflective of the views of individuals not living in these 2 provinces and from ethnic minority populations. Conclusion: Most of the compatible PLDs and TCs surveyed were willing to participate in KPD. Ensuring timely transplantation and a more optimal match for TCs and offering a policy of reciprocity to ensure timely repeat transplantation for compatible recipients if their allograft fails post KPD transplant may further increase compatible pair participation in KPD.