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Abstract

To improve current data systems for institutional decision-making, the Adult Liver Transplant Registry was established at the Hospital Italiano de Buenos Aires, Argentina. This article describes its design and implementation and reports on the outcomes for patients transplanted since its January 2020 launch. A multidisciplinary team designed the registry by identifying key variables from a literature review while considering balance between data depth and feasibility. Rigorous quality control measures were enforced, including monthly audits and staff training. Benchmark indicators for post-transplant outcomes were established. As of November 2023, the registry included 136 transplants. Its implementation and maintenance were straightforward, with no significant difficulties encountered. Cirrhosis was the predominant indication (77%) for transplant. Only one living donor transplantation was performed. Post-transplant results generally aligned with benchmarks, but rates of biliary complications slightly exceeded the recommended thresholds. The one-year post-transplant survival rate was 87%. The successful registry implementation provides a robust framework for research, treatment management, and patient care enhancement within a liver transplant unit.

Keywords

Patient registry Liver transplantation Transplant Outcomes Registry Design Benchmark Indicators Patient Care Improvement Quality Control Measure

Introduction

Liver transplantation is the treatment of choice for several liver diseases, most commonly cirrhosis.¹ The first liver transplant in Argentina was performed in 1988 at the Hospital Italiano de Buenos Aires. Over the past few decades, the number of liver transplants in Argentina has consistently increased year on year, reaching 7116 liver transplants in December 2023.^2–4

In 2002, the National Procurement Agency in Argentina (INCUCAI) introduced an online database known as SINTRA.⁵ The aim of this system was to facilitate real-time access to waitlist information and streamline the collection of data related to organ procurement and transplantation processes. To this end, essential structured data is to be collected and, up-to-date information on transplant activity provided. However, SINTRA only compiles basic information on the pre-transplantation process and postoperative outcomes, and lacks more in-depth data. While all transplant centres have to provide information on procurement and transplantation systematically, INCUCAI does not impose any requirements on the quality of the data submitted, rendering it insufficient for decision-making purposes at a liver transplant program level. Therefore, each liver transplant centre collects and analyses its own data for research and management purposes. This is typically done in an unstructured manner, sourced from medical records and administrative databases, and so the information is often incomplete. Although some centres collect data prospectively, there is often a lack of systematic record-keeping and quality control measures. Moreover, the data predominantly focus on the perioperative period, and so quality information on long-term survival and clinical and surgical events are absent.

High-quality data are essential for improving patient care, to improve waitlist priority criteria, assist in the planning of the transplantation, and help predict patient outcomes. They can also provide indicators for evaluating and monitoring the safety of medical practices, as well as the quality and efficiency of liver transplant programs. However, this can only be achieved if there is a minimum requirement for data collection, which can then be systematically analysed and compared to benchmarks. However, implementing a project that obtains impactful data is challenging.

Given their systematic data collection and methodical design, patient registries are a possible solution to these challenges. Patient registries are organized systems that use observational methods to collect pre-defined clinical data efficiently from a large number of individuals under normal conditions, for a specific disease or procedure, at a given moment.^6,7 The main challenge for registries is ensuring data quality and so their design must incorporate mechanisms to guarantee a high standard.

Up to January 2023, the liver transplant unit at the Hospital Italiano de Buenos Aires, had performed over 1500 liver transplantations. In January 2020, we initiated the Adult Liver Transplant Registry at this hospital, which prospectively included all adult patients considered for liver transplantation and who underwent transplant evaluation. The purpose of this article is to describe the design and implementation of the registry and report results from a subgroup of patients that underwent liver transplantation since the registry was launched.

Methods

Registry design

In Argentina, the INCUCAI, is responsible for organ transplant distribution, based on the model of end-stage liver disease (MELD)-Na scoring system. Candidates ≥18 years can be allocated a liver transplant on the basis of ‘adult emergency status’ (i.e., similar to Adult 1A [high priority] in the USA), or, a calculated MELD-Na score, or, an exception MELD score. Adult emergency status is assigned provided specific criteria are fulfilled that include, fulminant liver failure, primary non-function, or hepatic artery thrombosis.

The Hospital Italiano de Buenos Aires has over 780 beds and 57 operating rooms and performs approximately 45,000 surgical procedures annually. The Adult Liver Transplant Registry was designed to provide up-to-date information at this hospital that could be used for research, management, and patient care improvements. To achieve this, the registry prospectively collected pre-transplant and peri-transplant characteristics, as well as short- and long-term post-transplant outcomes. The project was approved by an independent ethical review board (Comité de Ética de Protocolos de Investigación; approval number 5412). Participation in the registry was voluntary and certified through an informed consent process. The registry was designed and led by two transplant team members, a surgeon, and a hepatologist, both trained in research methodology and with prior experience in patient registries.

The database was built using Research Electronic Data Capture (REDCap) and was designed with structured visits that represented every part of the patient trajectory, from pre-transplant evaluation to post-transplant follow-up (Figure 1). Each visit has a REDCap form designed by a multidisciplinary core group. The selection and definition of the registry’s variables were based on an extensive revision of the literature. The multidisciplinary group thoroughly discussed the variables to be included with the goal of striking a balance between capturing all relevant information and maintaining the feasibility of recording high-quality data. Priority was given to variables that were not systematically recorded in the electronic medical record and would, therefore, be challenging and prone to misclassification if collected in an unstructured manner.

Figure 1.

Description of the registry’s structured visits representing every part of the patient trajectory, from pre-transplant evaluation to post-transplant follow-up.

A data entry flowchart was developed to outline the process for data collection, and assignment of tasks for different individuals/teams (Figure 2). Tutorials for data entry were created and distributed, and the team leader of each specific form was responsible for training medical staff in the respective team on how to enter patient information correctly.

Figure 2.

Data entry flowchart that shows the process for data collection, and assignment of tasks for different groups. CRF, clinical record form.

Quality control and benchmarks

During the first year after implementation of the registry, the two administrators had regular meetings to review the registry’s completeness and evaluate its data quality. To accomplish this, they created a STATA ‘do-file’ analysis script to uncover inconsistencies and ensure the completeness of specific variables. Subsequently, they automated the process, running the script on a monthly basis. Any inconsistencies or missing data were promptly communicated to the relevant team leader. Additionally, when investigators used data from the registry, they were required to report any inconsistencies they found to the administrators.

Specific indicators were established to report the program’s results and to compare results with benchmarks set by experts.⁸ For each indicator, a proposed benchmark was set determined by the 75th percentile based on median values from a group of liver transplant centres for that particular indicator.⁸

The indicators were:

Operative time: time in hours from incision to closure. The suggested benchmark is ≤6 hours.

Intraoperative blood transfusions: red blood cells (RBCs) units transfused during surgery and during the first 24 hours postoperatively. The benchmark is ≤3 RBCs units.

Reoperation: Any open or percutaneous surgical intervention that requires general anaesthesia to correct a condition or complication associated with the liver transplantation until discharge, death, or re-transplantation. The benchmark is ≤30 of all transplant procedures.

Postoperative renal replacement therapy (RTT): at least one session of RRT for acute kidney injury (AKI) until discharge, death, or re-transplantation. The benchmark is ≤8% of all transplant procedures.

Intensive Care Unit (ICU) stay: duration of ICU stay estimated from transplant day (patients who die or are retransplanted within the first 7 days are excluded). The benchmark is ≤4 days.

Hospital stay: duration of hospitalization from transplant day until hospital discharge, re-transplantation, or death (patients who die or are retransplanted within 18 days are excluded). The benchmark is <18 days.

Biliary complications before discharge: percentage of patients with biliary stenosis, biloma, or biliary fistula that are detected in the postoperative period before discharge, re-transplantation, or death, regardless of the need for surgical or endoscopic intervention. The benchmark is <12% of all transplant procedures.

Hepatic artery thrombosis before discharge: percentage of patients with thrombosis of the hepatic artery confirmed by angiography or intraoperatively, diagnosed before discharge, death, or re-transplantation. The benchmark is <4% of all transplant procedures.

One-year post-transplant survival: all causes of death are considered from the time of transplant up to 365 days. The benchmark is ≥91% of all transplant procedures.

Statistical analysis

Statistical analysis was performed using STATA software (version 14.2, StataCorp LLC, Texas, USA). Categorical variables were reported as absolute numbers and percentages. Numerical variables are reported as median and interquartile range (IQR). The Kaplan-Meier method was used to estimate post-transplant survival. For this analysis, patients entered the cohort the day they were transplanted and exited the cohort the day they died, were retransplanted, were lost to follow-up, or completed the follow-up (whichever occurred first).

Results

From initiation of the liver transplant registry on January 1 2020, until dataset closure on November 21 2023, 317 liver transplant evaluations were performed in adult patients, with 289 (91%) subsequently being listed for transplantation. During the same period, 137 liver transplantations were performed, involving 136 patients. One patient underwent two transplants but for clarity in this report only the primary liver transplant of this patient was considered. Only one living donor liver transplantation was performed.

Median age at the time of transplantation was 59.6 (IQR 41.8–63.6) years, and 80 (59%) patients were male (Table 1). Of the 136 patients, 68 (50%) lived in Buenos Aires, where the liver transplant centre is located; the remainder lived in different provinces. Half of the patients resided in areas more than 250 miles from the transplant centre, with some living distances exceeding 800 miles.

Table 1.

Characteristics of the study population at the time of the liver transplant.

Variable	All patientsn = 136
Sex, male	80 (59)
Age, years	59.6 (41.8–63.6)
BMI, mg/kg²	27.5 (23.3–32.0)
MELD-Na score	27 (24–31)
MELD exceptions	61 (45)
Patient disposition before transplant
Home	89 (66)
General ward	26 (19)
Intensive care unit	21 (15)
Vasopressors*	7 (5)
Mechanical ventilation*	11 (8)
Acute renal replacement therapy*	6 (4)
At least one acute vital support*	14 (10)
Simultaneous liver-kidney transplantation	10 (7)
Reason for transplantation
Decompensated Cirrhosis	85 (63)
Decompensated cirrhosis + HCC	18 (13)
Compensated cirrhosis + HCC	2 (2)
Acute liver failure	9 (7)
Biliary disease	6 (4)
Re-transplantation**	6 (4)
polycystic liver disease	5 (4)
Other	4 (3)
Other tumours	1 (1)
HCC^†	30 (22)
Hypertension	40 (29)
Dyslipidaemia	18 (13)
Diabetes	38 (28)
HIV	3 (2)
Portal vein thrombosis (confirmed during surgery)	27 (20)

Data are expressed as, n (%) or median (interquartile range).

*at transplantation.

**3 chronic rejection; 1 autoimmune hepatitis; 1 HCC; 1 other.

^†Includes the sum of known HCC before transplantation and incidental HCC.

Abbreviations: BMI: body mass index; HCC: hepatocellular carcinoma; HIV, Human immunodeficiency virus; MELD: model of end-stage liver disease.

With regard to comorbidities at the time of the transplantation, hypertension, diabetes, and dyslipidaemia were present in 40 (29%), 38 (28%), and 18 (13%) of the patients, respectively. Notably, 105 (77%) transplants were performed in patients with cirrhosis, whereas 9 (7%) were performed for acute liver failure. There were 6 (4%) cases of re-transplantation and 10 (7%) cases of simultaneous liver-kidney transplantation (Table 1).

Among the transplantations, 61 (45%) were conducted in patients with MELD exceptions. The median MELD-Na score at the time of liver transplantation was 27 (IQR 24–31). In addition, 21 (15%) patients were admitted to intensive care unit (ICU) at the time of transplantation (Table 1). Median duration from waitlist to liver transplantation was 102 (IQR 19–577) days.

Primary aetiologies of cirrhosis were metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol, autoimmune hepatitis (AIH), and primary biliary cirrhosis, collectively accounting for approximately 75% cases (Table 2).

Table 2.

Primary aetiologies of cirrhosis and acute liver failure (n =).

Aetiology	All patientsn = 114
Cirrhosis*	105
MASLD	30 (29)
Alcohol	27 (26)
Autoimmune hepatitis	14 (13)
Cryptogenic	9 (9)
Primary biliary cirrhosis	8 (8)
Hepatitis C virus	6 (6)
Primary sclerosing cholangitis	3 (3)
Hepatitis B virus	2 (2)
Secondary biliary cirrhosis	1 (1)
Other	5 (5)
Acute liver failure	9
Autoimmune hepatitis	4 (44)
Indeterminate	2 (22)
Wilson disease	1 (11)
Hepatitis B virus	1 (11)
Herpes simplex virus	1 (11)

*In cases of more than one aetiology the investigators selected the main cause.

Data are expressed as, n, or n (%).

MASLD, Metabolic dysfunction-associated steatotic liver disease.

Post-transplant results were compared to the benchmarks (Figure 3). Median operative time was 6.0 (IQR 5.3–7.1) hours, with a median requirement of 3 (IQR 1–6) units of RBC transfusion Before discharge, reoperation was necessary for eight patients (6%), while 20 patients (15%) required renal replacement therapy. Median ICU stay was 8 days (IQR 5–11) and median hospital stay was 16.5 days (IQR 13–25). Biliary complications were recorded in 19 patients (14%), and hepatic artery thrombosis occurred in 2 patients (2%) before discharge. One-year post-transplant survival was 87% (95% CI, 79–92%) (Figure 4).

Figure 3.

Post-transplant results are shown in comparison with benchmarks.

Figure 4.

Overall post-transplant two-year survival (n = 130). Six patients had missing data on follow up. One-year post-transplant survival was 87% (95% CI, 79–92%).

Discussion

This article describes the successful establishment and initial results from the implantation of a liver transplant registry at the Hospital Italiano de Buenos Aires, Argentina. After almost three years since its inception, our report confirms that the project can be sustained, and initial results provide valuable information to compare liver transplant outcomes from this centre with well-established benchmarks.

The registry provides valuable insights into the indications and aetiologies necessitating liver transplantation. Unsurprisingly, our analysis of data from the registry shows that cirrhosis was the primary indication for liver transplantation and accounted for 77% of all transplants. Notably, the percentage of patients with AIH was high at 13%, which is greater than reported rates for USA and Europe, where it typically accounts for <5% of liver transplant indications.^9,10 However, our finding is consistent with previous reports from Argentina, Chile, and Peru.^2,11–13

By contrast with a study from the USA that found only 7% of liver transplant recipients lived 250 miles or more from a transplant centre,¹⁴ we found that 50% of the recipients lived that distance from our hospital. This observation underscores the significant influence that geographic distance may have on transplantation outcomes. For example, proximity to the centre, particularly for patients in Buenos Aires, may translate to enhanced access to pretransplant care, timely evaluations, and close disease monitoring. Conversely, recipients residing in distant provinces may encounter challenges in accessing specialized care, which could possibly lead to potential delays in evaluations and inclusion in the transplant list. Moreover, financial constraints, limited social support, and heightened psychological stress can further exacerbate the impact of distance. While these findings support the implementation of telemedicine solutions, resource for these innovations lack comprehensive coverage and are not widely available within the healthcare-provided framework for liver transplant recipients in Argentina.

Interestingly, only one living donor liver transplantation has been performed at our centre since the registry was launched. This contrasts with data from the USA (Organ Procurement and Transplantation Network) that found 6% of transplants in adult recipients were performed using living donors.¹⁴ In addition, by contrast with data from the USA that reported 20% of liver transplants were performed in patients with MELD exceptions,¹⁴ the data from our registry showed that nearly half of our liver transplants were conducted in patients under that condition. Additionally, we noted that the median MELD-Na score at transplantation among patients without exceptions was 27, indicating severe liver disease. Moreover, a third of our patients were already in hospital at the time of transplantation and 10% required implementation of at least one acute vital support before transplantation, further emphasizing the severity of patients included our registry.

The background information the registry has collected is crucial in placing patient outcomes into perspective. For instance, several of the post-transplant metrics, such as operative time, RBC transfusion requirements, reoperation, hospital stay and hepatic artery thrombosis, were within the suggested benchmarks, indicating adherence to these important standards. However, 15% patients required renal replacement therapy which exceeds the ≤8% benchmark and biliary complications were noted in 14% patients before discharge, slightly exceeding the recommended benchmark of <12%, suggesting the need for a more detailed analysis of underlying factors contributing to these complications. Importantly, although relatively low at less than 2%, the incidence of hepatic artery thrombosis in our data is a critical concern despite falling within the benchmark range of <4%. Although median hospital stay at our centre (17 days) was within the 18 days benchmark, ICU stay at 8 days was far greater than the benchmark limit of ≤4 days. These results emphasize the importance of ongoing quality assessment and improvement initiatives within liver transplant programs, with the purpose of minimizing complications and enhancing patient outcomes. Moreover, the one-year post-transplant survival rate of 87%, while falling slightly below the benchmark of ≥91%, emphasizes the necessity for continual monitoring and creating strategies to optimize patient care and improve survival rates in the long term.

The registry’s strengths lie in the meticulous and structured approach that has been implemented for data collection on liver transplantation at the Hospital Italiano de Buenos Aires. Our report demonstrates that there has been a comprehensive and multidisciplinary effort to select important variables for the registry, and that the methodology has ensured data completeness, and a high integrity has been maintained by periodic checks and sophisticated analysis scripts. Structured REDCap forms have ensured a streamlined and organized data entry process and enhanced any future collaboration among other liver transplant programs. The emphasis on benchmarks, derived from expert recommendations, reflects a commitment to monitor program performance and align it with established standards. Additionally, the prospective nature, patient-centric approach, and focus on clinical utility underscore the registry’s value as a resource for research, treatment management, and patient care initiatives in liver transplantation.

However, despite its strengths, the registry has several limitations, including the relatively short duration of monitoring since inception, and potential for biases because of its single-centre nature. Continuous efforts to expand the dataset, enhance data quality, and validate findings against broader cohorts are essential to augment the registry’s usefulness for evidence-based decision-making and to improve patient care outcomes in liver transplantation. In addition, a limitation of this report is that we focused on specific outcomes of patients who underwent liver transplantation. Future research on the registry should explore patient outcomes from the initial evaluation through to transplantation to provide a more comprehensive understanding of the entire transplant selection process.

In conclusion, this report shows that implementation of the Adult Liver Transplant Registry at the Hospital Italiano de Buenos Aires has provided a comprehensive database for ongoing research, treatment management, and patient care enhancement within the liver transplant unit. Continuous efforts to expand the dataset, validate findings across diverse populations, and address biases are crucial. The strategic use of this registry, coupled with ongoing validation and expansion efforts, is poised to advance liver transplantation practices in Argentina. Nationwide collaboration will certainly increase its impact and promote uniformity in evidence-based practices.

Supplemental Material

sj-pdf-1-imr-10.1177_03000605241264232 - Supplemental material for The building of an institutional liver transplant registry: opportunities and challenges

Supplemental material, sj-pdf-1-imr-10.1177_03000605241264232 for The building of an institutional liver transplant registry: opportunities and challenges by Sebastián Marciano, Jorge Carlos Martínez Morales, Camila Juana, Martin de Santibañes, Juan Pekolj, Eduardo de Santibañes, Mariela Francisconi, Jimmy Walker Uño Tala, Leandro Daniel Burgos Pratx, Adrian Gadano and Victoria Ardiles in Journal of International Medical Research

Footnotes

Acknowledgments

The authors express their gratitude to the patients who participated in the registry and their relatives. Additionally, the authors wish to extend their thanks to the Department of Research and the Medical Affairs Department at the Hospital Italiano Buenos Aires for their guidance, encouragement, and valuable input, which significantly enhanced the quality of this project.

Declaration of conflicting interests

The authors declare there are no conflicts of interest.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

ORCID iD

Sebastián Marciano

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