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  • Waste Not, Want Not: Determining the Fate of the Marginal Liver Allograft

    Dr. John SealJohn Seal, MD
    Transplant Surgeon
    Ochsner Health System

    The primary goal of liver transplantation is to reduce mortality and significant morbidity associated with end stage liver disease and hepatocellular carcinoma. To that end, the current allocation system in the United States is designed to prioritize patients with the highest risk of death as estimated by the MELD scoring system. However, significant variability in the quality of donor organs complicates this process. The presence of extended criteria donor (ECD) features such as advanced age, abnormal liver function tests, steatosis, and donation-after-circulatory death can negatively impact early allograft function and overall graft survival. Many transplant surgeons avoid or very selectively use these grafts in the highest MELD patients out of concern for early organ dysfunction not well tolerated by sicker patients. In the environment of severe organ shortage, transplant centers are left with the onerous task of balancing the risk of death on the waitlist versus the potential risks associated with expanded criteria allografts.  Each organ offer prompts the questions: Will this liver work in my sickest patient? If not, will it work in any of my listed patients? And, if it will only work in my lowest MELD patients, am I really offering a survival benefit?

    For the past several years, our center has adopted an aggressive approach to organ utilization based on the hypothesis that the potentially deleterious effects of marginal features can be minimized through careful patient selection and minimization of cold ischemia time. Recipient selection is focused on limiting surgical complexity to facilitate a rapid hepatectomy with minimal blood loss. We carefully consider the patient’s overall functional status and co-morbidities to help predict an adequate physiologic reserve to support hemodynamic stability during clamp and reperfusion periods. During the transplant evaluation process, patients are assigned a score of surgical risk to facilitate recipient selection when an ECD offer is received. The second key principle, minimization of cold ischemia time, is more complex—it requires robust logistics and communications with procurement coordinators as well as an OR staff and anesthesia team able to mobilize quickly and on short notice. We also have a routine practice of having two attending surgeons available for every case. By executing these details well, we can avoid the cumulative effects of even small delays in the process that can add hours to cold ischemia time.

    While the upper limit of recipient selection for ECD is easier to define (high MELD, ICU, frail, etc.), the lower limit is less clear. In keeping with the priorities of the allocation system, we approach each offer systematically working our way down the list of potential recipients from high MELD score to low. Our goal is to transplant the graft into the most appropriate patient with the highest MELD on the list. A majority of the recipients of imported grafts at our center have MELD scores between 18-25, a range where the survival benefit from transplantation is clear. For the lowest MELD patients (<18), we focus on patients with a disease burden that is not reflected in their MELD score such as marked ascites, debilitating encephalopathy, or early stage HCC tumors waiting to accrue exception points. Also, it is important to consider the MELD history of the patient, including prior episodes of increased MELD suggesting instability in the degree of compensation and likelihood of progressive liver disease in the future.

    What does it mean for a graft to “work”? Defining the terms of early allograft dysfunction is critical to evaluating the performance of ECD grafts. Since 2012, we have observed no significant difference in graft or patient survival comparing imported ECD grafts with standard donors, with both categories at or above expected. Certainly we have seen higher rates of elevated AST/ALT (>2000) in the ECD grafts, but typically it is transient and normalizes by the time of discharge from the hospital. At our center we put more weight on the markers of synthetic and metabolic function of the graft, namely INR, bilirubin, and lactate in the early post-transplant period. Using post-transplant MELD as a marker of graft function1, we see no difference in early graft function with ECD grafts.

    We believe nearly every donor liver offers a potential survival benefit for some listed patient. Accordingly, we have invested resources and experience to optimize outcomes using ECD grafts and to identify suitable recipients to achieve a survival benefit.  Currently in the United States, the distribution of aggressive centers and donor liver utilization varies significantly between regions.2,3 As we strive for parity in organ allocation across regions, some emphasis should be placed on the lack of uniformity in utilization. We should also continue to invest in the development of better diagnostics for graft assessment, including normothermic machine perfusion systems4 and metabolomic/proteomic approaches to biomarker discovery5. But in the meantime, the challenge is to employ donor-recipient matching strategies to optimize utilization of the non-perfect graft within an allocation system that prioritizes our sickest patients.

    References

    1. Wagener G, Raffel B, Young AT, Minhaz M, Emond J. Predicting early allograft failure and mortality after liver transplantation: the role of the postoperative model for end-stage liver disease score. Liver Transplant Off Publ Am Assoc Study Liver Dis Int Liver Transplant Soc. 2013 May;19(5):534–42.

    2. Garonzik-Wang JM, James NT, Van Arendonk KJ, Gupta N, Orandi BJ, Hall EC, et al. The aggressive phenotype revisited: utilization of higher-risk liver allografts. Am J Transplant Off J Am Soc Transplant Am Soc Transpl Surg. 2013 Apr;13(4):936–42.

    3. Goldberg DS, French B, Lewis JD, Scott FI, Mamtani R, Gilroy R, et al. Liver transplant center variability in accepting organ offers and its impact on patient survival. J Hepatol. 2015 Nov 25;

    4. Ravikumar R, Jassem W, Mergental H, Heaton N, Mirza D, Perera MTPR, et al. Liver transplantation after ex vivo normothermic machine preservation: a Phase 1 (first-in-man) clinical trial. Am J Transplant Off J Am Soc Transplant Am Soc Transpl Surg. 2016 Jan 11;

    5. Cortes M, Pareja E, García-Cañaveras JC, Donato MT, Montero S, Mir J, et al. Metabolomics discloses donor liver biomarkers associated with early allograft dysfunction. J Hepatol. 2014 Sep;61(3):564–74.

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  • Should Pediatric Transplantation Have Separate Fellowship Surgical Requirements?

    Dr. Amy GalloAmy E. Gallo, MD
    Assistant Professor of Surgery (Abdominal Transplantation)
    Stanford University Medical Center

    Low case volume is being associated with worse surgical outcomes, and transplantation is not an exception to this finding (1,2). As programs continue to be scrutinized by regulatory bodies to meet outcome measures, there have been fewer programs in the United States committed to pediatric transplantation.  While the American Society of Transplant Surgeons has established surgical volume requirements for liver, kidney, pancreas, and small bowel for fellowship training program accreditation, there are no fellowship requirements specific to pediatric transplantation. Assuming that each organ requires specific individual training requirements—because of complexity of the underlying disease and technical variation—it can be argued that pediatric solid organ transplantation calls for vastly different medical and surgical approaches from those of the adult counterparts and, therefore, should have its own fellowship requirements per solid organ.

    In addition, the UNOS Pediatric Transplant Committee has recently gained momentum on a motion to improve the quality and safety of pediatric transplantation. By the current OPTN Bylaws, the primary surgeon and primary physician in a pediatric transplant program are not required to have pediatric training or experience. The Pediatric Transplant Committee identified that OPTN data from 1995-2010 showed significantly better unadjusted Kaplan-Meier graft and patient survival for kidney, liver, and heart recipients from 1995-2010 at higher volume centers. Higher volume centers were defined differently for each organ:  12 for kidney, 18 for livers, 8 for hearts, and 4 for lungs, respectively. Over the period from 1/1/05-7/31/14, 65.5% of kidney and 58.0% of liver programs performing pediatric transplants met these criteria. The proposal by the UNOS Pediatric Transplant Committee requires that each transplant center have a primary pediatric transplant surgeon who meets the current Bylaws for a Primary Surgeon in addition to having performed 12 pediatric kidneys or 18 pediatric livers and participated for at least 2 years in organ-specific pediatric transplantation care. This proposal was presented to the Membership and Professional Standards Committee (MPSC) in September 2015. The MPSC is supportive of the proposal overall with the caveat that there be at least one qualifying program in each region by the time the requirements take effect.

    If pediatric requirements are accepted, mandating similar volume criteria for surgical fellowship (performing 12 kidneys and 18 livers for pediatric certification) would convey the technical and management differences that exist in pediatric transplantation. Currently in the 119 modules the transplant fellows are required to complete in the ASTS Academic Universe, only 2 are specific to pediatric transplantation.

    With certification targets in place, applicants interested in pediatric transplantation can seek out programs that will satisfy the requirements.  Graduates of these programs may pave the way to a better understanding of these pediatric differences following completion of their training. They can embark on job opportunities that reflect their strengths or look to continue training with their deficits more clearly defined. That is not to say that someone with no pediatric fellowship training could not consider pediatrics as a job career, but like many graduates without pancreatic or intestine training, the understanding is that they will not lead a program without senior expertise and further exposure.

    What continues to set transplant surgeons apart from other surgical fields is their lifelong commitment to patients, the reason that many of us chose the field. Setting fellowship requirements in pediatric transplantation might emphasize to trainees that performing a transplant on children means understanding and commanding issues unique to this patient population, such as the impact of psychomotor development as well as psychosocial issues, bone disease, inherited and sporadic syndromes, metabolic diseases, urologic anomalies, the effects of life-long immunosuppression, non-adherence particularly amongst adolescents, post-transplant lymphoproliferative disorders, and anatomic considerations (3,4). Embracing this knowledge allows us to advance the field of pediatric transplantation and reinforce our commitment to take care of such a fragile patient population.

    Bibliography

    1: Rana A, Pallister Z, Halazun K, Cotton R, Guiteau J, Nalty CC, O'Mahony CA, Goss JA. Pediatric Liver Transplant Center Volume and the Likelihood of Transplantation. Pediatrics. 2015 Jul;136(1):e99-e107. doi:10.1542/peds.2014-3016. Epub 2015 Jun 15. PubMed PMID: 26077479.

    2: Schold JD, Buccini LD, Goldfarb DA, Flechner SM, Poggio ED, Sehgal AR. Association between kidney transplant center performance and the survival benefit of transplantation versus dialysis. Clin J Am Soc Nephrol. 2014 Oct 7;9(10):1773-80. doi: 10.2215/CJN.02380314. Epub 2014 Sep 18. PubMed PMID:25237071; PubMed Central PMCID: PMC4186511.

    3. Davis ID, Bunchman TE, Grimm PC, Benfield MR, Briscoe DM, Harmon WE, Alexander SR, Avner ED. Pediatric renal transplantation: indications and special considerations. A position paper from the Pediatric Committee of the American Society of Transplant Physicians. Pediatr Transplant. 1998 May;2(2):117-29.Review. PubMed PMID: 10082443.

    4.  McDiarmid SV. Liver transplantation. The pediatric challenge. Clin Liver Dis. 2000 Nov;4(4):879-927. Review. PubMed PMID: 11232362.

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  • Uncompensated Work in Transplantation

    Dr. Christine Hwang Christine Hwang, MD
    Assistant Professor, Surgery
    UT Southwestern Medical Center

    In most specialties of general surgery, surgeons have a set schedule and patients are seen at regular intervals in clinic and scheduled for elective cases. Relative value units (RVUs) are generated in a predictable fashion, both in clinic and in the operating room.

    Transplant surgery is quite the opposite. We see our patients in evaluation, but the procurements and transplants occur at unpredictable times, and transplant activity waxes and wanes. When we do receive organ offers, it is not uncommon for multiple recipients to be evaluated for the same organ offer. This translates into going through several potential recipients’ charts, then admitting potential recipients, with only the possibility of transplantation.

    In the ideal situation, one of those potential recipients will receive the organ, which will allow for RVU generation, but there are times where nobody will receive the organ, and the work of evaluating each potential recipient is wasted. This work will not generate any RVUs except for at best reimbursement for seeing a patient to perform a history and physical.

    There are models in surgery where one is reimbursed for being on call, and in addition to that, any activity and RVU generation when being on call is compensated. This model extends into the call schedule for ancillary staff, such as OR staff, who are paid to take call and receive additional compensation if called in. Unfortunately, there is no such model in transplant surgery.

    In our field, we perform many other activities without any or minimal RVU compensation. Procurement activity is a perfect example of work without RVU compensation.  There is no RVU value associated with procurement activity. In general, most procurements take about 3 hours. There is also the travel time to the donor hospital and back to the transplant center, which is usually a couple of hours each way. Delays are not uncommon, where the procurement may be bumped for an undisclosed amount of time for an emergency at the donor hospital or waiting for other teams to arrive. These delays can add several hours to the process. All the time associated with a procurement can easily take 8 hours, or the time one puts in a “regular” working day. Finally, if the organ is procured and ultimately not used, there is no fee paid for the procurement.  It is interesting to note that some institutions have assigned an RVU value to procurement activity1.

    Likewise, backtable preparation of the organ, despite having a charge, also does not generate any RVU activity, unless a complex vascular reconstruction is involved. Some backtable activity can be simple enough, but the activity takes time and skill to perform and in some instances is critical in performing the transplant. A backtable reconstruction of the arterial system of a liver can be quite complex and can significantly simplify the arterial anastomosis in the recipient; the CPT code for arterial reconstruction, 47147, will generate only 7 RVUs. To put that into perspective, a laparoscopic appendectomy, 44970, will generate 9.45 RVUs.

    In an era where RVUs are increasingly viewed and equated to productivity, lack of recognition of work performed by transplant surgeons in the form of RVUs can become troublesome. As noted above, much of our work as transplant surgeons is not accounted for in work RVU activity. Some centers have adopted the strategy to have co-surgeons be involved in a liver transplant, which would allow for 125% of charges to be generated, rather than an assistant fee, which would be 110%. A virtual RVU system has been suggested2 by Abouljoud et al.

    It is again reasonable to have such a system account for this discrepancy in work performance; the other option is that transplant surgeons should work toward having their activities and work accounted for properly. This is not to ask for higher pay, but simply to receive credit for the work that we perform.

    1. https://www.aamc.org/download/105928/data/
    2. Abouljoud M, Whitehouse S, Langnas A et al. Compensating the transplant professional: time for a model change. Am J Transplant 2015 Mar; 15(3):601-5.
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