Improving Pancreas Graft Utilization Through Importation
Running Head: Utilization of Imported Pancreata
Here we investigate whether using imported pancreata is a feasible strategy to address regional wait time disparities.
An observational retrospective cohort of 26 patients who received a local or imported pancreas transplant at Montefiore Medical Center was assessed. Wait times of this cohort were compared to other patients in Region 9. Using internal financial data, the cost effectiveness of this strategy was evaluated.
Imported pancreata (n=10) had significantly longer cold ischemia times (CIT) and peak lipase (PL) levels compared local pancreata (n=16); (CIT 827 vs. 497 minutes; p=0.001, PL 563 vs. 157 u/L; p=0.023). However, there was no difference in graft or patient survival. The median wait time at our center was 547 days versus 932 days for Region 9 (p = 0.16). The median wait time was significantly lower for SPK transplants at our center (518 days, n=21) compared to Region 9 (1001 days, n=65) p=0.038. Despite concerns over increased cost of importation, lower standard acquisition costs assessed by non-regional organ procurement organizations provided a favorable financial incentive for importation.
In the face of declining pancreas donors, using imported pancreata may be a cost effective strategy to increase organ utilization and shorten wait times in disadvantaged regions.
Organ acceptance, organ procurement, Organ Procurement and Transplantation Network (OPTN), organ procurement organization
Jay A. Graham, MD, MBA, FACS
Albert Einstein College of Medicine
Montefiore-Einstein Center for Transplantation
111 E. 210th Street, Rosenthal 2, Bronx NY 10467.
Telephone: 718-920-4928; FAX: 718-547-4773.
Tighter glucose control afforded by pancreatic transplantation can abrogate the progression of diabetic secondary complications such as nephropathy, neuropathy, retinopathy and peripheral vascular disease.(1, 2) Additionally, pancreatic transplantation engenders improved patient quality of life by maintaining durable insulin independence and offers increased long-term survival.(3, 4) As such, beta cell replacement either through simultaneous pancreas kidney (SPK) transplant, pancreas after kidney (PAK) transplant and pancreas transplant alone (PTA) has arisen a means to redress some of the devastating consequences of diabetes.(5)
Despite these benefits, since the peak of 2004 in which 1484 pancreas transplants were performed, there has been a 30% decline over the past 10 years in the United States.(5-8) Fewer transplant referrals, improvement in patient-centered diabetes management, a proportional rise in donor after cardiac death (DCD) donation and increased allograft discard rates are all thought to be factors in this pancreatic transplant denouement.(9-12)
Decreasing numbers of active patients on the waitlist (937 active patients in 2013, with a high of 2067 patients in 2002) seem to mirror this reality.(8, 13) While the reasons for the decline are likely multivariate, perhaps these trends suggest a conservatism and risk aversion that seem to have consolidated as the driving sentiment. Largely predicated on historical outcomes of pancreas transplantation, these views are not in-line with the reality of improved surgical techniques and medications.(14) To this point, in one the largest retrospective studies to date, Morath et al demonstrated that SPK provides superior survival in type 1 diabetic patients with ESRD.(15) Despite efforts to provide a cohesive vision for the benefits of pancreas transplantation all “politics remain local” and the narrative of significant morbidity attributed to pancreas transplantation has been hard to change.
Recognizing this incongruity of thought and buoyed by the aforementioned improved outcomes, our center decided to expand our criteria to include out-of-region donors. While this expansion of available grafts via importation facilitated programmatic growth, admittedly this strategic change was forced by excessive wait times in our region.
Although the national median time to transplant is under 2 years, there remains a wide disparity across donor service areas. This regional inequity is particularly pronounced in Region 9, where Montefiore Medical Center (MMC) is located, which is comprised of four donor service areas. Given that Region 9 is in the lowest quintile for organs recovered per donor (2.89 organs/donor) and in the lower third tertile for overall donation per 100 eligible deaths, it is unsurprising that waiting times are higher.(16)
As a result of this disparity in wait times, in 2014 MMC began identifying out of region donors with favorable characteristics for pancreatic graft procurement as a means of improving pancreas transplant rates among our patients. To date, we have performed 10 import pancreas transplants (38% of our total transplant volume), with outcomes equivalent to local donors.
However, utilization of import pancreas grafts requires a considerable increase in logistics, since commercial flights to transport organs would exceed safe cold ischemia times. In addition, importing pancreas grafts requires a reliance on procuring surgeons who may be unknown to the receiving center, so that the mechanisms and language of communicating suitability must be carefully protocoled. While necessary, this approach is antithetical to many centers that have typically adopted clinical protocols that restrict pancreas utilization to local donors procured by the center’s own surgical team to guard against injuries from perceived non-standardized and nuanced procurement techniques. Here we examine and evaluate our center’s experience with importation of pancreas grafts from outside of these four local donor service areas (Region 9) to better understand this practice.
An area of great interest was the financial impact of importation. Obviously, a series of new charges regarding transportation logistics raised some programmatic concerns. Focused on shortening wait times, we had petitioned for dispensation associated with increased cost. Surprisingly, in our analysis we found that importation facilitated favorable economics with a concomitant decrease in wait times as compared to our region.
Materials and Methods
This study is retrospective review of patients who received pancreas allografts after January 1, 2014. The cohort consisted of 26 patients with Type 1 diabetes that were ≥18 years old and received either a primary local or imported SPK or PAK at The Montefiore Einstein Center for Transplantation in Bronx, NY. Only 1 patient, who received an imported PAK, was a re-transplant in this cohort. The patient had a previous SPK complicated by thrombus resulting in pancreas graft loss in 2011. No patients in this cohort were part of HLA-0 mismatch or highly sensitized patient (HSP) allocation programs. Eight imported pancreata were flown to Teterboro Airport, NJ (home airport) using private aviation. One SPK and 1 PAK were imported from nearby regions using ground transportation.
All grafts were implanted in recipients utilizing the same classical technique with the pancreas on the right with the tail placed inferiorly toward the pelvis and the kidney on the left. Systemic venous and enteric drainage were preformed. Immunosuppressive regimens consisted of induction with 4 doses of rabbit antithymocyte globulin (Thymo) (1.5mg/kg/dose), and intravenous methylprednisolone followed by taper. A calcineurin inhibitor, typically tacrolimus, an inosine monophosphate dehydrogenase inhibitor, and oral corticosteroid were the backbone of the maintenance regimen.
Patient charts were reviewed to collect cold ischemic times (CIT), recipient peak amylase (PA), recipient peak lipase (PL), age, hemoglobin A1c (HgbA1c), length of stay (LOS), complications as well as graft and patient survival. Donor characteristics age, cause of death, kidney donor profile index (KDPI) and body mass index (BMI) were collected from DonorNet®. Wait times from listing to transplant were also assessed in this cohort and subsequently compared to UNOS data obtained from the Organ Procurement Transplant Network (OPTN) database (Star Files ending September 2016).
MMC patients were compared to other centers in Region 9 using the OPTN database from January 1, 2014 to September 1, 2016. Notably, when evaluating these groups, MMC patients were removed from the Region 9 dataset. Wait time was calculated using the UNOS Qualifying date subtracted from the date of actual transplant.
Standard Acquisition Cost (SAC) fees and transportation costs for patients transplanted at MMC were gathered from an internal cost-center database. These charges were subdivided by organ; pancreas and kidney. Means were generated and compared between local and imported SPKs and PAK separately. For imported organs mean aviation charges were also calculated. Aviation charges did not include the 2 imported organs that had been driven for the out-of-region OPO.
When comparing the OPTN database to the MMC patients, wait times had a skewed distribution with a large range and therefore medians were compared for this data set. Since the distribution of wait times was nonparametric, a Mann-Whitney test with a 95% confidence interval was utilized for comparison.
For MMC patients, the mean of each variable was used to compare local versus imported pancreata. Variables were compared using a two-tailed student t-test. Levene’s test was used to determine if equal or unequal variances were used for the t-test. Analysis was performed using IBM SPSS Statistics version 24. Graphs were generated using GraphPad Prism version 7.
This study was approved by The Albert Einstein College of Medicine Internal Review Board.
Imported pancreata have similar donor characteristics and outcomes as compared to local allografts.
Since 2014, there have been a total of 26 patients who receive a pancreas allograft, 16 local DSA and 10 import pancreata. Of the 16 local pancreas allografts, 12 were SPKs and 4 PAKs. Among the 10 pancreas transplants in the import group there were 9 SPKs and 1 PAK. The mean recipient age for a local allograft was 39.4 years v. a mean age of 35.9 years in the import allograft group (p = 0.37).
Donor characteristics between local and imported grafts showed no significant difference in age or BMI (Table 1). Local grafts had an average donor age of 24.3 v. 22.2 imported (p=0.36) and BMI averages were 24.5 and 25.7 respectively (p=0.33). KDPI, which takes into account multiple donor variables, was also used as an indicator of overall donor quality. KDPI averages were 18.9 and 24.9 (p=0.35) for local and imported groups respectively.
Additionally, the 3 variables, CIT, recipient PA, and recipient PL, were evaluated for the local and imported pancreata (Figure 1). Imported pancreata had significantly longer CITs than the local pancreata with mean times of 827 minutes and 497 minutes respectively (p=0.001). The mean recipient PA level in local grafts was 203 u/L and trended lower than the mean imported level of 304 u/L, but these values did not reach statistical significance (p=0.19). The mean recipient PL was 157 u/L in patients with local grafts and 563 u/L in imported grafts reaching statistical significance (p=0.023); which was suggestive of increased ischemia reperfusion injury (IRI).
Post-operative complications and length of stay did not differ between groups
Patients in the local group stayed an average of 9.4 days in-house as compared to an average LOS of 11.5 days for the import group (p=0.36). Notably, 2 patients in the local group experienced non-occlusive splenic vein thrombosis (SVT) treated with anti-coagulation therapy with a concomitant non-occlusive super mesenteric artery thrombus in 1 patient. Gastrointestinal bleeding at the staple line required a re-operation in another patient. It is noteworthy that there were 5 reported cases of acute rejection seen in the local group (1 kidney alone rejection). Resolution followed in all but 1 patient with PAK who had chronic rejection refractory to multiple T-cell depletion regimens. Ultimately, this resulted in a graft loss 363 days following transplant. No grafts have been lost in the import group to date. There was 100% patient survival in both cohorts.
Similar complications were seen in the import group in which 2 patients had non-occlusive SVTs again treated with anticoagulation. There was also a patient who had a peri-pancreatic abscess that was treated with CT guided drainage. Lastly, 1 patient had an episode of acute rejection of the pancreas that resolved after appropriate treatment. Urinary tract infections (UTI) and wound infections were common in both groups (Table 1).
Recipients of imported pancreata are not disadvantaged with regards to tighter glucose control post-operatively
The mean follow-up time from discharge after pancreas transplantation for the local and import groups was 590 days (range 129-1118 days) and 615 days (range 118-1023 days) respectively. Patients’ HgbA1c was monitored post transplantation at approximately the 3 month, 6 month and 1 year mark. The mean 3-month post transplantation HgbA1c was not significantly different between the two groups; local group (n= 16) was 5.78% and import group (n=9) was 5.16 % (p=0.06). Mean HgbA1c at the 6-month mark was also found to be not significantly different; local group (n=13) was 5.72% and import group (n=5) was 5.60% (p=0.63). Lastly, at 1 year, there was again no significant difference in mean HgbA1c the mean local group (n=10) had a mean of 6.30% of the import group (n=7) was 6.17% (p=0.87).
UNOS Data: Montefiore Medical Center patients have shorter wait times compared to the standard in Region 9
Wait times of MMC patients versus patients in other regions were compared (Figure 2A). Within Region 9, median wait times of transplanted patients at MMC were compared to the median wait times of Region 9 (Figure 2B). Frequency distributions of wait times were generated and large ranges were present. MMC wait times ranged from 127 days to 2425 days. Meanwhile, Region 9 ranged from 1 day to 5151 days. The median wait time at MMC for all pancreas transplantations was 547 days in comparison to a median of 932 days for Region 9 (Figure 2B). MMC’s total cohort of pancreas transplant recipients seemed to have a lower wait time, but the difference was not statistically significant (p=0.16). However, when assessing wait times for SPK and PAK separately, MMC SPK patients had a significantly lower median wait time of 518 days compared to Region 9, which had a median wait time of 1001 days (MMC, n=21; Region 9, n=65; p=0.038). Contrastingly, when comparing PAK patients between MMC and Region 9 there was no difference; median wait time for MMC PAK transplants (median= 671 days, n=5) and Region 9 (median=772 days, n=35) p=0.78.
Cost Analysis: Utilizing import pancreata reduces organ standard acquisitions costs
The assessment of the SAC fees for local and import pancreas and kidney allografts was evaluated internally from the cost-report. The SAC fees for kidney and pancreas were itemized separately. For patients receiving a SPK from organs procured locally (n=12), the average organ acquisition cost per pancreas allograft was $50,250 ($49,500-$52,500) and average cost per kidney allograft was $42,667 ($40,000 – $45,000) (Table 2). In contrast, the cost per imported organs for SPK recipients (n=9) proved to be significantly lower than the local group. In this group, the average pancreas allograft cost was $41,098 ($35,700 – 47,630) and the average kidney allograft cost was $32,833 ($27,000 – $40,500). Notably, in SPK patients the amount saved per acquisition of an imported pancreas as compared to a local pancreas was an average of $9,152. The average amount saved per kidney when comparing import versus a local allograft was $9,834. Additionally, in PAK patients the amount saved per acquisition of pancreas was $7,625 for an imported (n=1) versus local (n=4) grafts.
Overall when assessing patients who received an SPK, imported pancreata offered a significant average cost reduction of $18,986, due to combined charge synergy of the kidney and pancreas. It is this opportunity cost that has allowed us to use private aviation to import organs. Notably, the average SPK aviation costs were $21,630 ($12,775-$39,200), though flight charges were not received for 3 patients (Table 2).
OPTN regional disparity in wait times is a well-recognized phenomenon of the current allocation system. Concerns centered on this geographic inequity have arisen due to widespread differences in wait times in varied donor service areas across disparate organ systems.(17-19) Efforts to offer redress for this issue have often been in the form of retrospective analysis or theoretical models.(20) In so far as actual policy, geographic immunity offered to HLA 0-mismatched or highly sensitized patients has given priority to a limited cohort of kidney transplant recipients. Otherwise there has been relatively little done to facilitate actual organ sharing amongst donor service areas.
UNOS has previously attempted to address this issue. Share 35 arose as means to encourage organ sharing for the sickest liver transplant recipients, but only allows for intra-regional utilization.(21) Despite this shortcoming, the Share 35 policy attempted to apply equipoise vis-à-vis efficacy and equality. No such system currently exists for either kidney or pancreas transplant recipients. As such, wait times are markedly different between regions. This is particularly pronounced in pancreas transplant recipients as demonstrated in from our findings. Notably, Region 9 has the longest wait times with 932 median days.
Recognizing the disparate wait times between OPTN regions, our strategy of pancreata importation is advantageous as our wait times (546.5 median days at MMC) more closely resemble regions from where we import. As such, this approach has allowed a reduction in the total wait times at MMC (local and import recipients). This effect is particularly evident in SPK patients transplanted at MMC who have a median wait time of 518 days as compared to Region 9 (1001 median days).
However, a reduction in shortened wait times did not come at the expense of organ quality. Rather, stringent donor selection criteria applied to both groups resulted in no difference in donor characteristics. It is unclear why such excellent organs were declined by local OPOs. This availability may be due to the UNOS policy change in 2014 favoring pancreatic transplant. In an effort to increase utilization, this pancreas allocation policy change allowed potential SPK recipients to take priority over kidney alone recipients. While this allocation scheme applies locally, the OPO may allocate pancreata and combine kidney down the PA/KP match run to national candidates, when local candidates have been exhausted.
As such, our center has been fortunate to receive pristine organs when other centers back-out. However, pancreas importation does result in increased CITs, which can be worrisome. Extended CITs have been associated with longer hospital stays and increased 1-year patient mortality.(22) In our local OPO, donor tissue is provided in advance to allow for crossmatch prior to procurement. This shortens our CIT for local pancreata substantially. Imported allografts are mainly transported via private aviation in an effort to maintain relatively short CITs. However, due to time constraints and local policies, not all out-of-region OPOs offer tissue for pre-recovery crossmatch. Since we do not transplant based on virtual cross match alone, the organs and tissue simultaneously arrive and we wait for either flow cytometry solid phase assays or complement dependent cytotoxic mixed lymphoid reactions to assess the predetermined immunologic response (4-6 hours to complete). Expectedly, this increases CIT of imported organs prior to implantation. In our experience, utilization of private aviation rather than commercial airlines is required to achieve acceptable CIT for imported organs. Additionally, early involvement of the both center and on-site transplant coordinators allows for careful coordination of private aviation in order to reduce CIT. Depending upon the availability of planes, the point of origin or destination is used to charter a flight. The flight plan is made according to the donor time. All attempts are made to have the plane ready for departure 2 hours after this time to minimize standby flight cost and CIT.
Importantly, despite imported pancreata having significantly longer mean CIT than the locally acquired pancreata, the 14 hour mean CIT of the imported group is still relatively short in terms of standards for pancreas transplantation.(23) Our CIT is 2 hours above the desired 12 hour cutoff for optimum graft survival, but well below the upper limit of 24 hours, at which point graft failure increases by 2.2 fold. While the mean CIT of 827 min for import pancreata is within the accepted norm, increased recipient peak lipase in this group (563 u/L) as compared to recipients of local pancreata (157 u/L) does highlight the correlation between CIT and IRI. However, we have had no incidence of primary non-function (PNF). Moreover, the only graft loss was a PAK patient in the local pancreas cohort with resumption of insulin on day 363 due to refractory chronic rejection despite multiple T-cell depletion regimens. To date we have had 100% patient survival and this is in line with other groups that performed pancreas transplants using imported allografts.(24) While there is a selection bias given our lower risk donor pool, the shorter CIT may also contribute to these favorable outcomes.
Understandably, despite our promising clinical outcomes, financial concerns were raised as it related to pancreata importation. However, mean SAC fees for imported PAK pancreata were $41,000 compared to local pancreata SAC fees of $48,625. As such, imported pancreata yield an average $7,625 cost savings/PAK pancreas. This cost saving is even more pronounced for import versus local SPK recipients, where imports resulted in a cost saving of $18,986/SPK (Table 2). Importantly, this cost reduction represents retained earnings from diagnosis-related group (DRG) reimbursement. However, these retained earnings are a sunk cost given the mean cost of private aviation $21,630.
As such, it is our practice to fly organs only if the pancreas and kidney are being offered so as to offset the cost of aviation. While this study is limited by a small sample size, this difference in cost between imported SAC fee savings and aviation ($2,644) is likely marginal with increasing volumes. However, system based efforts to decrease transportation cost can facilitate maximization of reimbursement.
At present there is no concerted effort to consolidate the process of flight transport. Perhaps, collaboration with other regional centers can increase the leverage when negotiating contracts with private aviation companies so as to lessen expenses. Lastly, if geographically feasible, ground transportation likely represents the best opportunity for definitive cost control. Two imported grafts, 1 SPK and 1 PAK, were driven from nearby out-of-region OPOs allowing us to retain the savings of out-of-region SAC fees without the additional aviation charge.
The obvious benefits of this strategy are conferred to the patient in form of reduced wait times and to the transplant center in the form of favorable economics. Importantly, there is also a financial gain for statewide and federal entitlement programs. According to The American Diabetes Association the average total medical cost for an individual diagnosed with diabetes in the United States is $13,700 per year, with $7,900 being attributed to diabetes. As such, the average daily cost for medical expenditure to treat diabetes amounts to $21.64/day. Given that MMC had a median wait time 385 days less than Region 9 (difference in median wait time = Region 9: 932 days – MMC: 547 days respectively), pancreata importation imparts cost savings when compared to the region as a whole. Multiplying this average cost by the difference in wait times, pancreas transplantation at MMC saved an average of $8,331.40 ($21.64 x 385 days) in reduced diabetic cost per patient.
According to the United States Renal Data System, the total fee for service expenditure for hemodialysis was $87,945 per person per year ($240.95/day). Given that patients at our center are transplanted more than a year earlier that others in Region 9 (difference in median wait time = 385 days), $92,766 of Medicare spending are sparred. This reduction represents yet another advantage to the use of imported allografts.
Region 9, which encompasses New York State and Western Vermont, has long been plagued with long wait times due to a donor shortage. Efforts to service this region have resulted in an import rate approaching 70% in many transplant centers for kidney alone and PAK. According to the latest Scientific Registry of Transplant Recipients (SRTR) report (7/1/2015 – 6/30/2016) in Region 9, 77.8% of PAKs are imported (n=18). Conversely only 29.4% of SPKs are imported (n=35). However, our center’s import rate for this time period was 60% for SPK patients. In all likelihood, this discrepancy in import rates between Region 9 and our center explains the significant difference in wait times.
Though we highlight our positive experience with imported pancreata and the benefits offered, this strategy is not without risk. Our team does not travel for recovery of imported pancreata, rather imported grafts are always procured by ACIN certified surgeons in the local OPO. Often times, pancreas allografts are procured by surgeons not known to the program. Though we do not routinely demand pictures, surgeon-to-surgeon communication is paramount so as to render the best organ assessment possible. Nevertheless, this practice still necessitates a thorough examination of the imported graft on the back-table upon arrival. Two transplants were cancelled due to procurement injuries discovered during back table preparation: transection of the inferior pancreaticoduodenal artery from a high division on the superior mesenteric artery (SMA) in one case, and transection of an extra-pancreatic splenic vein, which was mistaken for the coronary vein, in a second case. Notably, the kidneys were reallocated and the pancreata were discarded. Though our center was responsible for the cost of transportation of both organs into our OPO, the SAC fees for the kidneys were paid by the accepting center, while the pancreas SAC fees were a write-off for the donor OPO.
Despite these risks, transplant centers faced with declining pancreas transplant rates for their patients may wish refine their strategy to identify out-of-region donors. Here we show that in a highly selected group of import pancreata that longer CIT does not seem to adversely affect outcomes when compared to pancreata procured locally. Moreover, utilization of imported pancreas allografts may allow transplant centers to decrease wait times for their patients without a significant decline in graft outcomes or patient survival. Finally, a careful assessment of the out-of-region SAC fees may provide a map of where to focus importation efforts to minimize financial burden and redouble our commitment to growing pancreas transplantation.
Table 1. Recipient and donor characteristics.
|Type||Recipient Age||Recipient ABO||Donor Age||Cause of Death||Donor BMI||KDPI||Donor Region||LOS||Complications||Rejection|
|SPK||33||O||25||IVDA||22||5||9||7||Non-obstructive thrombus of SMA & SVT, recurrent UTI||AR|
|Type||Recipient Age||Recipient ABO||Donor Age||Cause of Death||Donor BMI||KDPI||Donor Region||LOS||Complications||Rejection|
|SPK||34||B||20||Asphxia||27||30||2||15||Non-occlusive splenic vein thrombosis, recurrent UTIs||⎯|
|SPK||52||B||33||ICH||30||36||8||14||DGF & Wound infection||⎯|
|PAK||37||O||23||GSW||23||19||1||8||Non-occlusive venous thrombosis, recurrent UTIs||⎯|
Table 2. Average costs for local versus imported pancreas transplants at Montefiore Medical Center.
|n||Kidney SAC||Pancreas SAC||SPK SAC||Aviation|
Figure 1. Local SPK and PAK compared to Imported SPK and PAK transplants. Mean Cold ischemic time, recipient peak amylase and recipient peak lipase.
Figure 2A. Comparison of median qualification days prior to transplant for patients at Montefiore Medical Center versus all 11 UNOS regions. Region 1: Median=633, n=55; Region 2: Median=571, n=237; Region 3: Median=446.5, n=458; Region 4: Median=495.5, n=200; Region 5: Median=586, n=362; Region 6: Median=603, n=68; Region 7: Median=522, n=416; Region 8: Median=220, n=187; Region 9: Median=932, n=100; Region 10: Median=334, n=325; Region 11: Median=456.5, n=212; Montefiore: Median=546.5, n=26.
Figure 2B. Comparison of median qualification days prior to transplant for patients at Montefiore Medical Center versus UNOS region 9. Breakdown of total surgeries (SPK & PAK), only PAK, and only SPK surgeries. Total: Region 9: Median=932, n=100; Montefiore: Median=547, n=26; p=0.16. SPK: Region 9: Median=1001, n=65; Montefiore: Median=518, n=21; p value= 0.038. PAK: Region 9: Median=772, n=35; Montefiore: Median=671, n=5; p value=0.78.
CIT –Cold ischemic time
IRI –Ischemia reperfusion injury
PA – peak amylase
PAK –Pancreas after kidney
PL –peak lipase
SAC –standard acquisition cost
SPK –Simultaneous pancreas kidney
SVT –Splenic vein thrombosis
1. Control TD, Group CTR. The Effect of Intensive Treatment of Diabetes on the Development and Progression of Long-Term Complications in Insulin-Dependent Diabetes Mellitus. New England Journal of Medicine. 1993;329(14):977-86. PubMed PMID: 8366922.
2. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Diabetes Study (UKPDS) Group. Lancet. 1998 Sep 12;352(9131):837-53. PubMed PMID: 9742976.
3. Fioretto P, Steffes MW, Sutherland DE, Goetz FC, Mauer M. Reversal of lesions of diabetic nephropathy after pancreas transplantation. The New England journal of medicine. 1998 Jul 09;339(2):69-75. PubMed PMID: 9654536.
5. Pondrom S. The AJT Report. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2015 Apr;15(4):851-2. PubMed PMID: 25801862.
7. Gruessner AC, Gruessner RW. Declining numbers of pancreas transplantations but significant improvements in outcome. Transplantation proceedings. 2014 Jul-Aug;46(6):1936-7. PubMed PMID: 25131075. Epub 2014/08/19. eng.
8. Israni AK, Zaun D, Rosendale JD, Snyder JJ, Kasiske BL. OPTN/SRTR 2012 Annual Data Report: deceased organ donation. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2014 Jan;14 Suppl 1:167-83. PubMed PMID: 24373172.
9. Loss J, Drewitz KP, Schlitt HJ, Loss M. Accept or refuse? Factors influencing the decision-making of transplant surgeons who are offered a pancreas: results of a qualitative study. BMC Surgery. 2013 10/23 01/28/received 10/15/accepted;13:47-. PubMed PMID: PMC4016525.
10. Morrissey PE, Monaco AP. Donation after circulatory death: current practices, ongoing challenges, and potential improvements. Transplantation. 2014 Feb 15;97(3):258-64. PubMed PMID: 24492420. Epub 2014/02/05. eng.
11. Siskind E, Akerman M, Maloney C, Huntoon K, Alex A, Siskind T, et al. Pancreas transplantation from donors after cardiac death: an update of the UNOS database. Pancreas. 2014 May;43(4):544-7. PubMed PMID: 24632550. Epub 2014/03/19. eng.
12. Singh SK, Kim SJ. Epidemiology of Kidney Discard from Expanded Criteria Donors Undergoing Donation after Circulatory Death. Clinical journal of the American Society of Nephrology : CJASN. 2016 Feb 05;11(2):317-23. PubMed PMID: 26668028. Pubmed Central PMCID: PMC4741045. Epub 2015/12/17. eng.
13. Kandaswamy R, Stock PG, Gustafson SK, Skeans MA, Curry MA, Prentice MA, et al. OPTN/SRTR 2015 Annual Data Report: Pancreas. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2017 Jan;17 Suppl 1:117-73. PubMed PMID: 28052606.
14. Thai NL, Abu-Elmagd K, Khan A, Bond G, Basu A, Tom K, et al. Pancreatic transplantation at the University of Pittsburgh. Clinical transplants. 2004:205-14. PubMed PMID: 16704151. Pubmed Central PMCID: 3032528.
15. Morath C, Zeier M, Dohler B, Schmidt J, Nawroth PP, Schwenger V, et al. Transplantation of the type 1 diabetic patient: the long-term benefit of a functioning pancreas allograft. Clinical journal of the American Society of Nephrology : CJASN. 2010 Mar;5(3):549-52. PubMed PMID: 20093348.
16. Israni AK, Zaun D, Bolch C, Rosendale JD, Schaffhausen C, Snyder JJ, et al. OPTN/SRTR 2015 Annual Data Report: Deceased Organ Donation. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2017 Jan;17 Suppl 1:503-42. PubMed PMID: 28052608.
17. Yeh H, Smoot E, Schoenfeld DA, Markmann JF. Geographic inequity in access to livers for transplantation. Transplantation. 2011 Feb 27;91(4):479-86. PubMed PMID: 21200366. Pubmed Central PMCID: 3772346.
18. Davis AE, Mehrotra S, McElroy LM, Friedewald JJ, Skaro AI, Lapin B, et al. The extent and predictors of waiting time geographic disparity in kidney transplantation in the United States. Transplantation. 2014 May 27;97(10):1049-57. PubMed PMID: 24374790.
19. Kobashigawa JA, Johnson M, Rogers J, Vega JD, Colvin-Adams M, Edwards L, et al. Report from a forum on US heart allocation policy. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2015 Jan;15(1):55-63. PubMed PMID: 25534656.
20. Davis AE, Mehrotra S, Kilambi V, Kang J, McElroy L, Lapin B, et al. The effect of the Statewide Sharing variance on geographic disparity in kidney transplantation in the United States. Clinical journal of the American Society of Nephrology : CJASN. 2014 Aug 07;9(8):1449-60. PubMed PMID: 24970871. Pubmed Central PMCID: 4123391.
21. Murken DR, Peng AW, Aufhauser DD, Jr., Abt PL, Goldberg DS, Levine MH. Same Policy, Different Impact: Center-Level Effects of Share 35 Liver Allocation. Liver transplantation : official publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society. 2017 Apr 13. PubMed PMID: 28407441.
22. Finger EB, Radosevich DM, Bland BJ, Dunn TB, Chinnakotla S, Sutherland DE, et al. Comparison of recipient outcomes following transplant from local versus imported pancreas donors. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2012 Feb;12(2):447-57. PubMed PMID: 22070451.
23. Rudolph EN, Dunn TB, Sutherland DER, Kandaswamy R, Finger EB. Optimizing outcomes in pancreas transplantation: Impact of organ preservation time. Clinical transplantation. 2017 Jun 21. PubMed PMID: 28636074.
24. Fridell JA, Mangus RS, Hollinger EF, Milgrom ML, Taber TE, Mohler E, et al. No difference in transplant outcomes for local and import pancreas allografts. Transplantation. 2009 Sep 15;88(5):723-8. PubMed PMID: 19741472.