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Guidance for procedures to mark kidney laterality

June 2, 2015

Summary and goals

Over the past several years, there have been multiple documented (and likely many more undocumented) cases of switched kidney laterality occurring as part of the procurement and organ transportation process. For this document, switched laterality is defined as receipt of a kidney laterality other than the one expected by the recipient center and documented as being sent by the procuring center. This error is typically discovered when the kidney is received at the recipient transplant center. In some of these instances, kidneys were discarded due to the laterality error. Multiple OPOs have instituted process changes to prevent switched laterality errors, and anecdotal and formal input from those OPOs suggest that such process changes are cost effective and efficacious. However, processes to prevent switched kidney laterality vary from OPO to OPO, and mechanisms to prevent this potentially important occurrence have not been implemented by all OPOs. The goals of this document are to define the problem and provide guidance on, and support for, more aggressive and uniform OPO-based process improvements aimed at ensuring laterality accuracy before the kidney is shipped to the transplanting center.


As part of the Electronic Tracking and Transport (ETT) project, Northwestern University conducted a Failure Modes Effects and Criticality Analysis (FMECA) on the current deceased donor organ procurement process. The results ranked the incorrect marking of kidney laterality as the third highest ranking failure. As of June 2014, a total of 21 cases of incorrect marking of kidney laterality occurring since 2012 had been self-reported to UNOS. Anecdotal reports from OPO staff and surgeons suggest that this number is underreported. In at least three of the reported cases, one or both of the kidneys involved were unable to be transplanted due at least in part to the switched laterality error. The relevance of this issue is heightened by the increase in regional and national sharing with implementation of the new kidney allocation system in December 2014.

The consequences of incorrect marking

The consequences of incorrectly labeled laterality range from the annoyance created by not receiving the expected kidney, to increased cold ischemia time, to a sentinel event when the received kidney cannot be used for the intended (or any) recipient.


UNOS safety data regarding errors in laterality is currently voluntarily submitted by the OPTN members and likely suffers from substantial underreporting bias. Cases are identified by UNOS staff’s manual review of submitted narratives describing each event. As previously mentioned a total of 21 cases of incorrect marking of laterality had been self-reported to UNOS from 2012 through June 2014. The errors involved packaging, shipping and/or labeling problems. Both donor kidneys were successfully transplanted in 16 (76%) of cases, and at least one kidney was discarded in 5 of the 21 reported cases of switched laterality. These discards were due to the wrong kidney, from the correct donor, being shipped to the accepting center. In these cases, the donors’ kidneys had significantly different biopsy findings or pump parameters, indicating a significant difference in anticipated organ quality based on laterality.

Six OPOs were contacted by phone to solicit information about their processes for marking kidney laterality. Five of them had experienced a laterality error, and one had a near-miss error identified at time of organ packaging. As a result, each had implemented policy driven processes to prevent future errors. These policies had been in place from one to four years, and none of the OPOs experienced errors in kidney laterality after process improvement.

The surveyed OPOs instituted various processes to prevent switched laterality errors, including placing a silk tie or umbilical tape on the distal ureter, or placing color-coded vessel loops in the perinephric fat. Most OPOs required that the identifying placement be done in situ, and all required that at least the left kidney be identified by their defined process.

Quality checks implemented by the various OPOs include:

  • taking pictures of each organ and its identifying marker
  • visual crosscheck and documentation of the marking by a second staff member
  • calling out organ identification and/or marking laterality before moving the organ to the backtable
  • calling a time out to check the labeling before packaging
  • requirement that only one organ be packaged at a time

Additionally, one OPO sterilizes UNOS organ labels so that they can be placed at a defined location on the backtable, and another uses differently shaped basins for the two kidneys. At one OPO, the Quality Department audits documentation of the laterality marking process, and in another OPO, recovering surgeons sign an agreement to uphold the defined laterality practice when recovering organs.

Recommended guidance

To ensure that transplant centers receive kidneys of expected laterality, all OPOs should define a specific formal process to ensure the consistent and accurate marking of kidney laterality. While this guidance promotes a consistent approach nationally, it allows for definition of OPO-specific practices.

Marking laterality

  1. Kidney laterality should be marked during the recovery surgery. It is recommended that each OPO work with its local recovery surgeons to define the supplies that will be used to physically mark laterality, and where the marking will be placed on the kidney. For example, the OPO may choose to have surgeons place a silk tie, prolene suture or umbilical tape on a pre-defined anatomical location such as distal ureter or distal renal vein.
  2. The marking should clearly identify the left kidney. If an OPO already utilizes a system in which both kidneys are marked, it should ensure its laterality marking process will clearly and quickly enable a receiving transplant center to know which kidney has been received.
  3. It is recommended that the marking be placed in situ.

Pre-Packaging Confirmation of Kidney Laterality

  1. It is recommended that each OPO incorporate a mechanism to crosscheck that laterality marking is accurate before the kidney is packaged.
  2. Practices such as utilizing a second staff member to confirm and document correct laterality marking, calling a time out to ensure that laterality marking is correct, creating a practice in which one organ is examined and packaged at the backtable at a time have been successfully incorporated by several OPOs.
  3. Additional quality checks may include post-case chart audits to confirm that correct procedure was completed and documented.