Preoperative Fibrinogen Level and Bleeding in Liver Transplantation for End-stage Liver Disease: A Cohort Study.

BACKGROUND: Liver transplantation is a high-risk surgery associated with important perioperative bleeding and transfusion needs. Uncertainties remain on the association between preoperative fibrinogen level and bleeding in this population. METHODS: We conducted a cohort study that included all consecutive adult patients undergoing a liver transplantation for end-stage liver disease in 1 center. We analyzed the association between the preoperative fibrinogen level and bleeding-related outcomes. Our primary outcome was intraoperative blood loss, and our secondary outcomes were estimated perioperative blood loss, intraoperative and perioperative red blood cell transfusions, reinterventions for bleeding and 1-y graft and patient survival. We estimated linear regression models and marginal risk models adjusted for all important potential confounders. We used restricted cubic splines to explore potential nonlinear associations and reported dose-response curves. RESULTS: We included 613 patients. We observed that a lower fibrinogen level was associated with a higher intraoperative blood loss, a higher estimated perioperative blood loss and a higher risk of intraoperative and perioperative red blood cell transfusions (nonlinear effects). Based on an exploratory analysis of the dose-response curves, these effects were observed below a threshold value of 3 g/L for these outcomes. We did not observe any association between preoperative fibrinogen level and reinterventions, 1-y graft survival or 1-y patient survival. CONCLUSIONS: This study suggests that a lower fibrinogen level is associated with bleeding in liver transplantation. The present results may help improving the selection of patients for further studies on preoperative fibrinogen administration in liver transplant recipients with end-stage liver disease.

Intraoperative phlebotomies and bleeding in liver transplantation: a historical cohort study and causal analysis.

BACKGROUND: Liver transplantation is associated with major bleeding and red blood cell (RBC) transfusions. No well-designed causal analysis on interventions used to reduce transfusions, such as an intraoperative phlebotomy, has been conducted in this population. METHODS: We conducted a historical cohort study among liver transplantations performed from July 2008 to January 2021 in a Canadian centre. The exposure was intraoperative phlebotomy. The outcomes were blood loss, perioperative RBC transfusions (intraoperative and up to 48 hr after surgery), intraoperative RBC transfusions, and one-year survival. We estimated marginal multiplicative factors (MFs), risk differences (RDs), and hazard ratios by inverse probability of treatment weighting both among treated patients and the whole population. Estimates are reported with 95% confidence intervals (CIs). RESULTS: We included 679 patients undergoing liver transplantations of which 365 (54%) received an intraoperative phlebotomy. A phlebotomy did not reduce bleeding, transfusion risks, or mortality when estimated among the treated but reduced bleeding and transfusion risks when estimated among the whole population (MF, 0.85; 95% CI, 0.72 to 0.99; perioperative RD, -15.2%; 95% CI, -26.1 to -0.8; intraoperative RD, -14.7%; 95% CI, -23.2 to -2.8). In a subgroup analysis on 584 patients with end-stage liver disease, slightly larger effects were observed on both transfusion risks when estimated among the whole population while beneficial effects were observed on the intraoperative transfusion risk when estimated among the treated population. CONCLUSION: The use of intraoperative phlebotomy was not consistently associated with better outcomes in all targets of inference but may improve outcomes among the whole population. STUDY REGISTRATION: www. CLINICALTRIALS: gov (NCT04826666); registered 1 April 2021.

RéSUMé: CONTEXTE: La transplantation hépatique est associée à des saignements importants et à de multiples transfusions de globules rouges (GR). Aucune analyse causale bien conçue sur l'effet d'interventions servant à réduire les transfusions, comme une phlébotomie peropératoire, n'a été menée dans cette population. MéTHODE: Nous avons mené une étude de cohorte historique incluant toutes les transplantations hépatiques réalisées dans un centre canadien de juillet 2008 à janvier 2021. L'exposition d'intérêt était une phlébotomie peropératoire. Les critères d'évaluation étaient le saignement peropératoire, les transfusions de GR périopératoires (peropératoires et jusqu'à 48 heures après la chirurgie), les transfusions de globules rouges peropératoires et la survie à un an. Des facteurs multiplicatifs (FM), des différences de risque (DR) et des rapports de risques instantanés marginaux ont été estimés en utilisant une pondération par l'inverse de la probabilité de traitement parmi les patients traités et parmi l'ensemble de la population. Les effets estimés ont été rapportés avec des intervalles de confiance (IC) à 95 %. RéSULTATS: Nous avons inclus 679 transplantations hépatiques dont 365 (54 %) ont bénéficié d'une phlébotomie peropératoire. La phlébotomie n'a pas réduit les saignements, le risque de transfusion ou la mortalité lorsque ses effets ont été estimés parmi les patients traités, mais a réduit les risques de saignement et de transfusion lorsque ses effets ont été estimés parmi l'ensemble de la population (FM = 0,85 (IC 95 %, 0,72 à 0,99); DR périopératoire = −15,2 % (IC 95 %, −26,1 % à −0,8 %); DR peropératoire = −14,7 % (IC 95 %, −23,2 % à −2,8 %)). Dans une analyse de sous-groupe portant sur 584 patients atteints d'une hépatopathie terminale, des effets légèrement plus importants ont été observés sur les deux risques transfusionnels lorsqu'estimés dans l'ensemble de la population, tandis que des effets bénéfiques ont été observés sur le risque transfusionnel peropératoire lorsqu'estimés parmi les patients traités. CONCLUSION: L'utilisation de la phlébotomie peropératoire n'a pas été systématiquement associée à de meilleurs résultats dans toutes les populations cibles, mais semble améliorer les résultats lorsque les effets sont estimés dans l'ensemble de la population. ENREGISTREMENT DE L'éTUDE: www.ClinicalTrials.gov (NCT04826666); enregistrée le 1er avril 2021.

Postoperative outcomes in surgical COVID-19 patients: a multicenter cohort study.

BACKGROUND: Data on postoperative outcomes of the COVID-19 patient population is limited. We described COVID-19 patients who underwent a surgery and the pandemic impact on surgical activities. METHODS: We conducted a multicenter cohort study between March 13 and June 192,020. We included all COVID-19 patients who underwent surgery in nine centres of the Province of Québec, the Canadian province most afflicted by the pandemic. We also included concomitant suspected COVID-19 (subsequently confirmed not to have COVID-19) patients and patients who had recovered from it. We collected data on baseline characteristics, postoperative complications and postoperative mortality. Our primary outcome was 30-day mortality. We also collected data on overall surgical activities during this first wave and during the same period in 2019. RESULTS: We included 44 COVID-19 patients, 18 suspected patients, and 18 patients who had recovered from COVID-19 at time of surgery. Among the 44 COVID-19 patients, 31 surgeries (71%) were urgent and 16 (36%) were major. In these patients, pulmonary complications were frequent (25%) and 30-day mortality was high (15.9%). This mortality was higher in patients with symptoms (23.1%) compared to those without symptoms (5.6%), although not statistically significant (p = 0.118). Of the total 22,616 cases performed among participating centres during the study period, only 0.19% had COVID-19 at the time of surgery. Fewer procedures were performed during the study period compared to the same period in 2019 (44,486 cases). CONCLUSION: In this Canadian cohort study, postoperative 30-day mortality in COVID-19 patients undergoing surgery was high (15.9%). Although few surgeries were performed on COVID-19 patients, the pandemic impact on surgical activity volume was important. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04458337 .