Impact of removing OPTN region from vascularized composite allograft allocation.

On 6/18/2020, the Organ Procurement and Transplantation Network (OPTN) implemented new policy replacing OPTN region with a 500 nautical mile (NM) circle around the donor hospital for the purpose of vascularized composite allograft (VCA) allocation. We used OPTN data to assess deceased donor VCA transplants in the 3 years pre- (6/19/2017-6/17/2020) vs. post-implementation (6/18/2020-6/17/2023). A total of 19 deceased donor VCA transplants were performed pre-policy (10 uterus, 3 bilateral upper limb, 1 unilateral upper limb, 3 face, 1 abdominal wall and 1 penis), and 11 post-policy (4 uterus, 1 bilateral upper limb, 2 face, 1 trachea, 2 abdominal wall, and 1 bilateral upper limb and face). Median distance from donor hospital to transplant hospital increased from 70 NM (range: 0-524 NM) pre-policy to 119 NM (range: 0-464 NM) post-policy. The majority of transplants in both policy eras were within 500 NM of the donor hospital [89.5% (N = 17/19) vs. 100% (N = 11/11)] and most remained within the same OPTN region as the donor hospital [68.4% (N = 13/19) vs. 90.9% (N = 10/11)]. Although it is difficult to draw strong conclusions about the policy's impact due to the low transplant volume and timing of implementation relative to the COVID-19 pandemic, data in the 3 years post-implementation suggest that 500 NM circles were a reasonable replacement for OPTN region in VCA allocation. The OPTN will continue to review data to monitor the policy's impact and inform future changes to VCA allocation, such as the transition to continuous distribution, a points-based framework expected to replace the current framework.

Impact of removing donation service area and region from pancreas allocation.

On March 15, 2021, the Organ Procurement and Transplantation Network (OPTN) replaced donation service area (DSA) and OPTN region as units of pancreas (PA) allocation with a 250 nautical mile (NM) circle with proximity points. We analyzed OPTN data for kidney-pancreas (KP) and PA candidates, transplants, and donors in the 2 years pre-policy (March 16, 2019, to March 14, 2021) and post-policy (March 15, 2021, to March 14, 2023). As expected, more transplants occurred at hospitals outside the recovering organ procurement organization's DSA post-policy (KP: 32.1% vs 57.3%, P < .001; PA: 61.6% vs 69.3%, P = .09), but the majority stayed within 250 NM (KP: 79.7% vs 85.0%, P < .001; PA: 55.4% vs 61.5%, P = .19). Median preservation time increased from 9.5 to 10.3 hours for KP (P < .001); there was little change for PA (8.5 vs 8.6 hours; P = .99). There were no statistically significant differences in 1-year posttransplant patient mortality or graft failure after implementation for KP (mortality: 3.6% vs 3.2%, P = .60; kidney graft failure: 4.9% vs 5.0%, P = .95; PA graft failure: 9.5% vs 8.9%, P = .65) or PA (mortality: 1.7% vs 2.2%, P = .72; PA graft failure: 12.2% vs 12.6%, P = .88). The removal of DSA and OPTN region from PA allocation has resulted in broader distribution with minimal impact on preservation time or posttransplant outcomes.

OPTN/SRTR 2022 Annual Data Report: Vascularized Composite Allograft.

This year's chapter on vascularized composite allograft (VCA) encompasses reviews of data collected from 2014 (when VCA was included in the Final Rule) through 2022. The present Annual Data Report shows that the number of VCA recipients in the United States continues to be small and has remained consistent from the prior report. The data continue to be limited by sample size, with trends persistently demonstrating a predominance of White males in the young/middle-aged population as both donors and recipients for nonuterus VCA transplants, and White women younger than 35 years as the predominant recipients of uterus transplant. Similar to the 2021 report, there were only eight failed uterus grafts and one failed nonuterus VCA graft reported from 2014 through 2022. Standardization of definitions of success and failure as well as outcome measures for the different VCA types remain unmet needs in VCA transplantation.

OPTN/SRTR 2021 Annual Data Report: Vascularized Composite Allograft.

Year 2020 marked the first OPTN/SRTR Annual Data Report that included a chapter on vascularized composite allograft (VCA), which encompassed reviews of data collected between 2014 (when VCA was included in the Final Rule) and 2020. The present Annual Data Report shows that the number of VCA recipients in the United States continues to be small and trended downward in 2021. While data continue to be limited by sample size, trends continue to show a predominance in White, young/middle-aged, male recipients. Similar to the 2020 report, eight uterus and one non-uterus VCA graft failures were reported from 2014 through 2021. Critical to advancement of VCA transplantation will be the standardization of definitions, protocols, and outcome measures for the different VCA types. Like intestinal transplants, it is likely that VCA transplants will be concentrated and performed at referral transplant centers.

Acute stressor effects on cognitive flexibility: mediating role of stressor appraisals and cortisol.

Acute stressor experiences may influence cognition, possibly through actions of cognitive flexibility, which comprises the ability to modify cognitive and behavioral strategies in response to changing environmental demands. In the present investigation, we examined the effects of an acute psychosocial stressor (the Trier Social Stress Test) on a specific form of cognitive flexibility, namely that of set-shifting, which was assessed by the Berg's Card Sorting Task (BCST). Among undergraduate students, the stressor promoted better performance on the BSCT relative to that evident among nonstressed individuals, including a reduction of perseverative (an index of enhanced set-shifting) and non-perseverative errors. They also required fewer trials to learn the first sorting category, reflecting augmented acquisition of an attentional set, but did not differ in the ability to maintain a set. Moreover, increased cortisol levels specifically mediated the enhancing effects of the acute stressor on set-shifting, but not the ability to acquire and maintain an attentional set. However, this enhancing effect was minimized among individuals who appraised the stressor as being uncontrollable. These data indicate that an acute, social-evaluative stressor can facilitate certain forms of cognitive flexibility, such as set-shifting. The present investigation also highlights the value of focusing on psychological and physiological mediators in determining the impact of stressful experiences on cognitive functioning. Lay summary A brief social stressor (public speaking) can have an enhancing effect on mental flexibility, and this seems to be related to the stress hormone, cortisol. This cognitive enhancing effect, however, might be minimized if a stressful situation is perceived as beyond a person's control.