Donor Selection and Prophylactic Strategy for Venous Thromboembolic Events in Living Donors of Liver Transplantation Based on Results of Thrombophilia Screening Tests

Safety and efficacy of extended thrombophilia screening directed venous thromboembolic events (VTE) prophylaxis in live liver donors: do we really need extended thrombophilia screening routinely?

Background and aims

The study aimed to determine the prevalence of hereditary thrombophilia, and stratify its severity among live liver donors in Pakistan. Also, the authors evaluated the safety and efficacy of thrombophilia profile testing directed venous thromboembolic events (VTE) prophylaxis while balancing bleeding risk and the need for routine thrombophilia testing before live liver donation among living donor candidates.

Materials and methods

Protein S (PS), protein C (PC), anti-thrombin (AT) III, and anti-phospholipid antibody panel (APLA) levels were measured in 567 potential donor candidates. Donors were divided into normal, borderline and high-risk groups based on Caprini score. The safety endpoints were VTE occurrence, bleeding complications or mortality.

Results

Among 567 donors, 21 (3.7%) were deficient in protein C, and 14 (2.5%) were deficient in anti-thrombin-III. IgM and IgG. Anti-phospholipids antibodies were positive in 2/567 (0.4%) and 2/567 (0.4%), respectively. IgM and IgG lupus anticoagulant antibodies were positive in 3/567 (0.5%) and 3/567 (0.5%), respectively. VTE events, bleeding complications and postoperative living donors liver transplantation-related complications were comparable among the three donor groups (P>0.05). One donor in the normal donor group developed pulmonary embolism, but none of the donors in either borderline or high-risk group developed VTE. The mean length of ICU and total hospital stay were comparable. No donor mortality was observed in all donor groups.

Conclusions

Due to thrombophilia testing directed VTE prophylaxis, VTE events were comparable in normal, borderline and high-risk thrombophilia donor groups, but more evaluations are required to determine the lower safe levels for various thrombophilia parameters including PC, PS and AT-III before surgery among living donor candidates.

An international survey of venous thromboembolic events and current practices of peri-operative VTE prophylaxis after living donor hepatectomy

BACKGROUND

Venous thromboembolic complications are an uncommon but significant cause of morbidity & mortality after live donor hepatectomy . The precise incidence of these events and the current practices of centers performing living donor liver transplantation worldwide are unknown.

METHODS

An online survey was shared amongst living donor liver transplantation centers containing questions regarding center activity, center protocols for donor screening, peri-operative thromboembolic prophylaxis and an audit of -perioperative venous thromboembolic events after live donor hepatectomy in the previous five years (2016-2020).

RESULTS

Fifty-one centers from twenty countries completed the survey. These centers had cumulatively performed 11500 living donor liver transplants between 2016-2020. All centers included pre-operative l assessment for thromboembolic risk amongst potential liver donors in their protocols. Testing for inherited prothrombotic conditions was performed by 58% of centers. Dual-mode prophylaxis was the most common practice (65%), while eight and four centers used single mode or no routine prophylaxis respectively. Twenty (39%) and 15 (29%) centers reported atleast one perioperative deep venous thrmobosis or pulmonary embolism event respectively. There was one donor mortality directly related to post-operative pulmonary embolism. Overall incidence of deep venous thrombosis and pulmonary embolism events was 3.65 and 1.74 per 1000 live donor hepatectomies respectively. Significant variations in center practices and incidence of thromboembolic events was identified in the survey primarily divided along world regions. 75% of participating centers agreed on the need for clear international guidelines.

CONCLUSION

Venous thromboembolic events after live donor hepatectomy are an uncommon but important cause of donor morbidity. There is significant variation in practice among centers. Evidence-based guidelines regarding risk assessment, and peri-operative prophylaxis are needed.

Living donor liver transplant candidate and donor selection and engagement: Meeting report from the living donor liver transplant consensus conference

INTRODUCTION

Living donor liver transplantation (LDLT) is a promising option for mitigating the deceased donor organ shortage and reducing waitlist mortality. Despite excellent outcomes and data supporting expanding candidate indications for LDLT, broader uptake throughout the United States has yet to occur.

METHODS

In response to this, the American Society of Transplantation hosted a virtual consensus conference (October 18-19, 2021), bringing together relevant experts with the aim of identifying barriers to broader implementation and making recommendations regarding strategies to address these barriers. In this report, we summarize the findings relevant to the selection and engagement of both the LDLT candidate and living donor. Utilizing a modified Delphi approach, barrier and strategy statements were developed, refined, and voted on for overall barrier importance and potential impact and feasibility of the strategy to address said barrier.

RESULTS

Barriers identified fell into three general categories: 1) awareness, acceptance, and engagement across patients (potential candidates and donors), providers, and institutions, 2) data gaps and lack of standardization in candidate and donor selection, and 3) data gaps regarding post-living liver donation outcomes and resource needs.

CONCLUSIONS

Strategies to address barriers included efforts toward education and engagement across populations, rigorous and collaborative research, and institutional commitment and resources.

Practice patterns of the medical evaluation of living liver donors in the United States

Living donor liver transplantation (LDLT) can help address the growing organ shortage in the United States, yet little is known about the current practice patterns in the medical evaluation of living liver donors. We conducted a 131-question survey of all 53 active LDLT transplant programs in the United States to assess current LDLT practices. The response rate was 100%. Donor acceptance rate was 0.33 with an interquartile range of 0.33-0.54 across all centers. Areas of high intercenter agreement included minimum age cutoff of 18 years (73.6%) and the exclusion of those with greater than Class 1 obesity (body mass index, 30.0-34.9 m/kg 2 ) (88.4%). Diabetes mellitus was not an absolute exclusion at most centers (61.5%). Selective liver biopsies were performed for steatosis or iron overload on imaging (67.9% and 62.3%, respectively) or for elevated liver enzymes (60.4%). Steatohepatitis is considered an exclusion at most centers (84.9%). The most common hypercoagulable tests performed were factor V Leiden (FVL) (88.5%), protein C (73.1%), protein S (71.2%), antithrombin III (71.2%) and prothrombin gene mutation (65.4%). At 41.5% of centers, donors were allowed to proceed with donation with FVL heterozygote status. Most programs discontinue oral contraceptive pills at least 28 days prior to surgery. At most centers, the need for cardiovascular ischemic risk testing is based on age (73.6%) and the presence of one or more cardiac risk factors (68.0%). Defining areas of practice consensus and variation underscores the need for data generation to develop evidence-based guidance for the evaluation and risk assessment of living liver donors.

What is the optimal prophylaxis against postoperative deep vein thrombosis in the living donor to avoid complications and enhance recovery? - A systematic review of the literature and expert panel recommendations

BACKGROUND

Deep venous thrombosis (DVT) prophylaxis is often employed to prevent the potentially serious complication of pulmonary embolism (PE). However, little data exist regarding the optimal DVT prophylaxis strategy for living donors undergoing hepatectomy for living donor liver transplantation. Here we present our consensus statement on DVT prophylaxis for living donors undergoing hepatectomy.

OBJECTIVES

To identify the optimal DVT prophylaxis strategy, which reduces, risk of complications in living liver donors, and enhances recovery.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Of interest was the impact of DVT prophylaxis or lack of prophylaxis on living donors undergoing hepatectomy and subsequent rates of DVT, PE, and hemorrhagic complications.

PROSPERO ID

CRD42021260720 RESULTS: The review of the literature identified three studies, which directly addressed thrombogenesis following living donor hepatectomy. All studies were observational in nature without randomization into treatments. The rate of DVT-PE in unscreened living donors with chemoprophylaxis was 5%. Furthermore, thromboelastography of living donors demonstrated sustained hypercoagulability for 50% of donors 10 days postoperatively. In line with CHEST (The American College of Chest Physicians) guidelines of chemoprophylaxis for surgical procedures with 3% or greater risk of DVT-PE, we conclude that a minimum of 10 days of postoperative chemoprophylaxis with unfractionated heparin or low-molecular weight heparin is recommended for patients undergoing living donor hepatectomy. The quality of evidence (QOE) for these recommendations based on the GRADE criteria is low, with a Grade of Recommendation of Strong.

CONCLUSIONS

Chemoprophylaxis for DVT following living donor hepatectomy is associated with reduced adverse thrombotic events, (Quality of Evidence; Low | Grade of Recommendation; Strong).

Hypercoagulability on thromboelastography after living donor hepatectomy-The true side of the coin

Background and Aims:

Coagulation dynamics after donor hepatectomy are complex. Having complete knowledge of the actual changes in the coagulation status during donor hepatectomy is important to prevent complications such as pulmonary embolism, deep vein thrombosis, and bleeding. Hence, the present study aimed to study the coagulation dynamics following open donor hepatectomy both by thromboelastography (TEG) and conventional coagulation tests (CCT).

Methods:

A total of 50 prospective liver donors were included. TEG and CCT [activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalised ratio (INR), fibrinogen, and platelet counts] were performed for each patient before surgery (baseline), on postoperative day (POD) 0, 1, 2, 3, 5, and 10.

Results:

TEG showed hypercoagulability in 28%, 38%, 30%, 46%, 42%, and 48% patients; in contrast INR showed hypocoagulability in 58%, 63%, 73%, 74%, 20%, and 0% patients on POD 0,1,2,3,5, and 10, respectively. Patients demonstrating hypercoagulability on TEG had significantly decreased reaction time (P = 0.004), significantly increased maximum amplitude (P < 0.001), and alpha angle value (P < 0.001). Postoperatively, INR, PT, and aPTT values increased significantly, while platelets and fibrinogen levels decreased significantly when compared to their baseline values. There was no coagulation-related postoperative complication in any of the patients.

Conclusion:

Hypercoagulability after donor hepatectomy is common. TEG showed hypercoagulability and did not show any hypocoagulability as suggested by the CCT. In patients undergoing donor hepatectomy, CCT may not reflect the actual changes incoagulation status and tests such as TEG should be performed to know the correct nature of changes in coagulation following donor hepatectomy.

Clinical Features and Long-Term Outcomes of Living Donors of Liver Transplantation Who Developed Psychiatric Disorders

BACKGROUND In the field of living donor liver transplantation (LDLT), it is important to ensure donor's psychological well-being. We report on clinical features and long-term outcomes of LDLT donors who developed psychiatric disorders after their donor operations. Additionally, we compare patient backgrounds, as well as surgical and perioperative aspects between LDLT donors with and without postoperative psychiatric complications. MATERIAL AND METHODS Between November 1998 and March 2018, we identified 254 LDLT donors at our hospital. Among these, we investigated those who had newly developed psychiatric complications and required psychiatric treatment after donor operation. RESULTS The median duration of follow-up was 4 years. Sixty-five donors were lost to follow-up. Eight donors (3.1%) developed postoperative psychiatric complications, including major depressive disorder in 4, panic disorder in 2, conversion disorder and panic disorder in 1, and adjustment disorder in 1. The median duration from donor surgery to psychiatric diagnosis was 104.5 days (range, 12 to 657 days) and the median treatment duration was 18 months (range, 3 to 168 months). Of those, 3 donors required psychiatric treatment over 10 years, and 4 donors remained under treatment. The duration of hospital stay after donor operation was significantly longer and perioperative complications with Clavien classification greater than grade IIIa were more frequent in donors with psychiatric complications than in those without psychiatric complications (P=0.02 and P=0.006, respectively). CONCLUSIONS Accurate diagnosis and appropriate treatment for psychiatric disorders by psychiatrists and psychologists are important during LDLT donor follow-up. Minimization of physiological complications might be important to prevent postoperative psychiatric complications in LDLT donors.

Pulmonary Embolism in a Donor of Living Donor Liver Transplantation

Pulmonary embolism (PE) is a rare but potentially fatal complication that may develop in a living liver donor. Here, we report a case of non-massive PE diagnosed by elevated serum D-dimer levels and successfully treated using anticoagulant therapy. A 57-year-old man underwent extended left hepatectomy as a living liver donor. His past medical history included hypertension and dyslipidemia which required medication and a history of smoking. Mechanical prophylactic measures for venous thromboembolism, including intermittent pneumatic compression and elastic stocking, were used; however, no pharmacological prophylaxis was used. Although the patient ambulated on postoperative day (POD) 1, he developed hypoxia. Serum D-dimer level was elevated to 29.3 ng/mL on POD 2. Enhanced computed tomography revealed small peripheral PEs in the branches of the right upper, right middle, and left lower lobes without deep vein thrombosis. Intravenous heparin was initiated followed by warfarin. The thrombi resolved completely by POD 13, following which warfarin was continued for 3 months. As of 25 months after donation, the patient remains well without recurrence of PE. Early diagnosis and treatment of postoperative PE are critical for preventing mortality of liver donors.