Provenance in Organ Transplant Management Applications: Application Scenario Summary

Overview

Treatment of patients through the transplantation of organs or tissue is one of the most complex medical processes currently carried out. This complexity arises not only from the difficulty of the surgery itself but also from a wide range of associated processes, rules and decision making which accompany any such surgery. Depending on the country where a particular transplant is being carried out procedures and the level of electronic automation of information / decision making may vary significantly. However, it is recognized worldwide that ICT solutions which increase the speed and accuracy of decision making can have a very significant positive impact on patient care outcomes.

Live organ transplants in particular present challenges since they often must occur in a very short time (from 6 to 72 hours depending on the organ), involve many individuals or different medical entities and require complex decision making throughout the process. New types of information system to support the information flow in Organ Transplant Management (OTM) processes now being studied in Spain and elsewhere in Europe will eventually make it possible to:

• Share information immediately between all the actors in a transplant case (from donors to recipients, decision makers, medical teams and families).

• Provide decision support through sophisticated case data, protocol enforcement and highlighting of possible matches.

• Speed up and automated data capture by all parties.

Each of these has the potential to significantly improve decision making, speed up reaction times and ultimately improve patient care outcomes. However, as with any medical information system great care must be taken to ensure that system procedures, protocols and data storage follow strict guidelines laid down by law and medical practice – this includes numerous challenges in which the provenance of data and outcomes is a key issue.

The following sections give a brief overview of a generic OTM information systems and the type of provenance questions which could be usefully asked in these applications.

OTM Application summary

In general terms, transplantation operations are divided into two broad classes, each with significantly different characteristics:

1. Live organ transplants (heart, lung, intestine, liver, pancreas, kidney): In this case, the item being implanted is a live internal organ such as a heart, lung or similar. In general such organs deteriorate rapidly between when they become available and implantation (becoming useless in less than 24hours in some cases1) – creating significant time pressure on transplantation. Furthermore cases normally arise with a waiting list of patients waiting for a suitable organ and a donation being made at a given moment in time meaning that the organ then must be assigned to one of the waiting patients (or none if no good matches are found).
2. Tissue transplants: In this type of transplant the item being transplanted is a tissue such as a cornea, skin, bone or something similar. In general such transplants are carried out by matching the requirements of an incoming recipient with pieces available for transplant from large collections of relevant tissues known as “tissue banks” - making decision making a “1 recipient to one of many possible donors” matching problem. Tissues can be stored for much longer periods of time than organs and such transplants are carried out with far less urgency.

The problems are therefore different in structure and challenges, furthermore the provenance issues may be somewhat different (in the organ case there is concern about whether the right recipient was chosen, in the tissue case concern whether or not the right piece for implantation was used). For this reason the use case used in the project focuses only on the organ transplantation case, leaving tissue cases for potential future exploration.

The organ transplant process involves the following major actors (as well as a number of auxiliary actors):

• Donor: person donating the organ or organs in a particular case. The individual must be associated with an available medical history (otherwise transplant cannot take place).

• Recipient: person or persons being operated upon (successfully or unsuccessfully) to implant the donated organ. Associated with a particular medical history and a particular possible implantation center.

• Recipient Waiting List: ordered list of individuals who may act as potential recipients if an organ becomes available (grouped by the type of organ they required).

• Retrieval Team: medical personnel (surgeon, nurses, technicians, etc.) carrying out the retrieval of an organ from the donor. Associated with a particular retrieval site.

• Implant Team: medical personnel (surgeon, nurses, technicians, etc.) carrying out the implantation of an organ in the recipient. Associated with a particular implantation site.

• Duty Transplant Surgeon: individual physician/surgeon on duty at the retrieval or implantation center.

Consultant Transplant Surgeons (experts): individual(s) other than the duty surgeon who may be consulted by the duty surgeon during any given case. Associated with one or more retrieval/implantation centers.

• Remote retrieval site: location where the retrieval takes place if this location is not a hospital or suitably equipped retrieval center.

• Retrieval center: hospital coordinating / carrying out the retrieval of an organ – either at the hospital itself or at a remote retrieval site.

• Implantation center: hospital carrying out the implantation of an organ.

• Post operation care center: hospital or medical center looking after the patient in post-operation care.

• Immunology center: specialist medical center performing blood and other analyzes of organs in order to determine matches in key indicators (HLA analysis and cross-matching). This step is normally skipped in the case of everything except kidney transplants since because of the extreme urgency of the transplants (the analysis of everything except blood type may not improve success rates more than a quick transplant).

• Regional and National Organ Transplant Authorities (OTA): regulatory and oversight body for all transplants in a given region (and subsequently national level). Associated with a number of retrieval / implantation centers. The OTA center also acts as the coordinating point to find recipients if local recipients are not available.

The activities of the individuals and organizations are governed by several authorities during the transplantation process. In particular the duty transplant surgeon takes initial responsibility for coordinating the process, the Regional and national Authorities take charge of assignment of organs to potential recipient and retrieval/implantation teams manage the medical process of the actual operation (in most cases the same team carries out both steps).

• A typical sequence in outline occurs as follows:

• A donor becomes available.

• The donor is assessed for potential donations by the duty transplant surgeon and his/her team.

• Data from medical records and these examinations is passed to the immunology center to carry out potential matching tests and to the Organ Transplant Authority to begin the search for a match.

• After making a national check for extremely urgent cases, the OTA begins a round robin process of all potential regional following established matching criteria. Hospital with potential recipients in order decide whether or not an organ could be assigned to one of their patients.

• Immunology results are used to inform this process where available.

• Once a decision is made, urgent arrangements are made for the recipient to be contacted and prepared.

• Medical procedure and accompanying logistics are prepared.

• In most cases a team from the center at which the recipient will have the organ implanted will travel to the center where the extraction will take place to perform the extraction and subsequently return with the organ to the implantation site.

• The implantation surgery is follows by post care and monitoring of outcomes.

• In the case where the donor is also alive, post care is continued for both patients.

Information is gathered, stored and accessed throughout the entire process in the form of reports filed by medical staff/administrators responsible for each step and the information flow between authorities (such as descriptions of available donor material). Information from more static sources such as lists of potential recipients is also accessed (in each potential implantation center). The information is:

• Stored in a distributed manner spanning the medical centers involved in the process

• Is managed by a range of authorities (individual hospitals or the OTA) depending on the data.

• Is created on the fly during the OTM process and consulted at execution time (immunology and patient examination reports for example feed into the OTAs decision making).

Current application development is making extensive use of Web Services infrastructures to put in place to automate both the software components deployed at each site but also the information flow between them.

Provenance questions

As well as generic logging functions carried out by system components, the OTM application requires more advanced analysis of the outcomes of organ transplantation cases: both in terms of results generated by the software systems and in terms of records of events which occurred in the real world. Requirements for analysis come both from legal requirements (such as the Real Decreto 2070/1999/30th December: regulating activities related to the procurement and clinical usage of human organs and tissues and other Spanish law for systems to be deployed in Spain) and clinical good practice. The following example provenance questions are a sample of what would be of high value:

A: Domain Specific Provenance questions:

1. Check a given set of decisions in a case against the established rules to ensure that it is conformant. These rules may or may not be automatically enforced by the transplant management software – however in the general case many of the will not be. This provenance question is a post-hoc check as to whether rules were followed. [Asked by Transplant Authority, Families, 3rd parties]
2. Derive a trace of the arguments, contributing factors and intermediate results which lead to a particular decision. [Asked by Transplant Authority, Families, 3rd parties, Physicians]
3. Derive aggregate information across many cases such as the %age of incidents of a certain type, success rates by center, etc. [Asked by Transplant Authority, researchers, physicians]
4. Truth maintenance for “next best candidate” or other dynamic information. Advanced functionality: meaning that the system could be used to keep up to date pre-calculated lists of recipients ready for an incident. This is a type of result which may need to be modified as underlying data changes. [Asked by transplant system itself, physicians]

B: Generic Provenance:

1. Extraction of an entire case-trace: gather all the records related to one incident into a single case-file. [Asked by physicians, families, patients]
2. Identify all individual users related to an incident [Asked by physicians, Organ Transplant Authority, 3rd parties (legal challenges)]
3. Replay service execution flow / verify this against template workflows and/or rules governing procedures (Sophistication may vary). [Asked by physicians, organ transplant authority, 3rd parties (legal challenges)]
4. (Possibly) Identify abstract derivation process of the result – based on some shared high level notions of the types of actions / content logged (e.g. Having a standard view of what is an assertion, what is a decision etc.) and what follows what.

Provenance Project Plans

The OTM application is being modeled in conjunction with the Spanish National Government FIS Carrel project which is being carried out jointly between Hospital St. Pau i Santa Creu and UPC in Barcelona Spain.

-- StevenWillmott - 15 May 2005
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