Risk factors and outcomes for delayed kidney graft function in simultaneous heart and kidney transplant recipients: A UNOS/OPTN database analysis.

There are no prior studies assessing the risk factors and outcomes for kidney delayed graft function (K-DGF) in simultaneous heart and kidney (SHK) transplant recipients. Using the OPTN/UNOS database, we sought to identify risk factors associated with the development of K-DGF in this unique population, as well as outcomes associated with K-DGF. A total of 1161 SHK transplanted between 1998 and 2018 were included in the analysis, of which 311 (27%) were in the K-DGF (+) group and 850 in the K-DGF (-) group. In the multivariable analysis, history of pretransplant dialysis (OR: 3.95; 95% CI: 2.94 to 5.29; p < .001) was significantly associated with the development of K-DGF, as was donor death from cerebrovascular accident and longer cold ischemia time of either organ. SHK recipients with K-DGF had increased mortality (HR: 1.99; 95% CI: 1.52 to 2.60; p < .001) and death censored kidney graft failure (HR: 3.51; 95% CI: 2.29 to 5.36; p < .001) in the multivariable analysis. Similar outcomes were obtained when limiting our study to 2008-2018. Similar to kidney-only recipients, K-DGF in SHK recipients is associated with worse outcomes. Careful matching of recipients and donors, as well as peri-operative management, may help reduce the risk of K-DGF and the associated detrimental effects.

Indeterminate-Depth Burn Injury-Exploring the Uncertainty.

In the management of indeterminate-depth burns (IDB), common challenges include the ability to predict time to healing and regenerative potential, risk of burn wound progression, and timing of excision. Several technologies exist to aid in determination of the depth of a burn injury, yet surgeons continue to rely on the naked eye-visual assessment-as the standard of care. Newer and improved imaging technologies are closing in on the goal of inexpensive, accurate, noninvasive modalities for depth determination. Likewise, management of IDB is becoming more sophisticated as newer wound healing technologies continue to be developed. By describing what is meant by "indeterminate" depth burns, and their associated challenges, we hope to stimulate interest in research to develop new therapies and management strategies. The ultimate goal is to treat IDB without the need for autografts.

Evolution of ischemia and neovascularization in a murine model of full thickness human wound healing.

Translation of wound healing research is limited by the lack of an appropriate animal model, due to the anatomic and wound healing differences in animals and humans. Here, we characterize healing of grafted, full-thickness human skin in an in vivo model of wound healing. Full-thickness human skin, obtained from reconstructive operations, was grafted onto the dorsal flank of NOD.Cg-KitW41J Tyr + Prkdcscid Il2rgtm1Wjl /ThomJ mice. The xenografts were harvested 1 to 12 weeks after grafting, and histologic analyses were completed for viability, neovascularization, and hypoxia. Visual inspection of the xenograft shows drying and sloughing of the epidermis starting at week four. By week 12, the xenograft appears healed but has lost 63.05 ± 0.24% of the initial graft size. There is histologic evidence of epidermolysis as early as 2 weeks, which progresses until week 4, when new epidermis appears from the wound edges. Epidermal regeneration is complete by week 12, although the epidermis appears hypertrophied. An initial increase of infiltrating immune mouse cells into the xenograft normalizes to baseline 6 months after grafting. Neovascularization, as evidenced by positive staining for the proteins human CD31 and alpha smooth muscle actin, is present as early as 2 weeks after grafting at the interface between the xenograft and the mouse tissue. CD31 and alpha smooth muscle actin staining increased throughout the xenograft over the 12 weeks, leading to greater viability of the tissue. Likewise, there is increased Hypoxia Inducible Factor 1-alpha expression at the interface of viable and nonviable tissue, which suggest a hypoxia-driven process causing early graft loss. These findings illustrate human skin wound healing in an ischemic environment, providing a timeline for use of full thickness human skin after grafting in a murine model to study mechanisms underlying human skin wound healing.

Discordance between histologic and visual assessment of tissue viability in excised burn wound tissue.

The regenerative capacity of burn wounds, and the need for surgical intervention, depends on wound depth. Clinical visual assessment is considered the gold standard for burn depth assessment but it remains a subjective and inaccurate method for tissue evaluation. The purpose of this study was to compare visual assessment with microscopic and molecular techniques for human burn depth determination, and illustrate differences in the evaluation of tissue for potential regenerative capacity. Using intraoperative visual assessment, patients were identified as having deep partial thickness or full thickness burn wounds. Tangential excisions of burn tissue were processed with hematoxylin and eosin to visualize tissue morphology, lactate dehydrogenase assay to ascertain cellular viability, and Keratin-15 and Ki67 to identify epidermal progenitor cells and proliferative capacity, respectively. RNA from deep partial and full thickness burn tissue as well as normal tissue controls were submitted for RNA sequencing. Lactate dehydrogenase, Keratin-15, and Ki67 were found throughout the excised burn wound tissue in both deep partial thickness burn tissues and in the second tangential excision of full thickness burn tissues. RNA sequencing demonstrated regenerative capacity in both deep partial and full thickness burn tissue, however a greater capacity for regeneration was present in deep partial thickness compared with full thickness burn tissues. In this study, we highlight the discordance that exists between the intraoperative clinical identification of burn injury depth, and microscopic and molecular determination of viability and regenerative capacity. Current methods utilizing visual assessment for depth of injury are imprecise, and can lead to removal of viable tissue. Additionally, hematoxylin and eosin microscopic analysis should not be used as the sole method in research or clinical determination of depth, as there are no differences in staining between viable and nonviable tissue.

Disposal of Unused Postoperative Opioids: A Real-World Demonstration of Surgeon-initiated Strategies Using an Activated Charcoal Bag System.

Excessive opioid prescribing following surgery creates a reservoir of unused medications available for diversion and abuse. We conducted a cohort study examining the impact of clinic-based, surgeon-initiated strategies using an activated charcoal bag (ACB) system on disposal of unused opioids. Among patients undergoing a variety of general surgery procedures, 67% of those with unused opioids disposed of them using the ACB. Our findings demonstrate practical ways to incorporate opioid disposal into surgical practice as a complement to judicious opioid prescribing.

Significant Improvement in Rat Kidney Cold Storage Using UW Organ Preservation Solution Supplemented With the Immediate-Acting PrC-210 Free Radical Scavenger.

Ischemia-reperfusion injury, including injury from warm- and cold-ischemia (CI) organ storage, remains a significant problem for all solid organ transplants. Suppressing CI damage would reduce delayed graft function and increase the donor organ pool size. PrC-210 has demonstrated superior prevention of damage in several preclinical studies as an immediate-acting free-radical scavenger. Here, we describe its profound efficacy in suppressing CI injury in a rat kidney model. METHODS: Kidneys in 300 gm Sprague-Dawley rats were perfused in situ with UW solution with or without added PrC-210 and then stored at 4°C in the same solution for 0 to 48 hours. When procured, kidney-activated caspase-3 level (a marker of cell death) was measured, and direct histological analysis of kidneys was performed to assess PrC-210 protective efficacy. In vitro analyses of PrC-210-conferred protection to isolated rat kidneys or naked DNA were also performed. RESULTS: A single 15 seconds in situ perfusion of kidneys with 20 mmol/L PrC-210 in UW solution resulted in significant reductions in (1) 30-hour CI-induced kidney-activated caspase level (P < 0.0001); activated caspase was reduced to levels not significantly different than control activated caspase levels seen in unperturbed kidneys, (2) 30-hour CI-induced renal Tubular Injury Scores (P = 0.0004) where brush border and tubular necrosis were markedly reduced, (3) PrC-210 conferred 100% protection against ·OH damage to naked DNA and isolated kidney mitochondria while current UW solution antioxidants were without protective effect. CONCLUSIONS: A single PrC-210-UW solution perfusion of rat kidneys upon removal from the rat profoundly reduced caspase and renal tubular injury in kidneys exposed to 30 hours of CI organ storage. These findings support further development of the PrC-210 molecule to suppress or to prevent ischemia-reperfusion injury in organ transplant and other ischemia-reperfusion injury settings.

Interpreting Outcomes in DCDD Liver Transplantation: First Report of the Multicenter IDOL Consortium.

BACKGROUND: In the United States, 5% of adult liver transplant recipients receive a graft donation after circulatory determination of death (DCDD). Concerns for ischemic cholangiopathy (IC), a disease of diffuse intrahepatic stricturing limits broader DCDD use. Single-center reports demonstrate large variation in outcomes. METHODS: Retrospective deidentified data collected between 2005 and 2013 were entered electronically by 10 centers via a Research Electronic Data Capture database. Our primary outcome was development of intrahepatic biliary strictures consistent with IC. RESULTS: Within 6 months post-DCDD transplant, 162 (21.8%) patients developed a biliary stricture, of which 88 (11.8%) exhibited intrahepatic structuring consistent with IC. Unadjusted 6-month IC rate among the 10 centers varied significantly (P = 0.006) from 6.3% to 25.9%. The only factor associated with increased risk of IC within 6 months was Roux-en-Y hepaticojejunostomy (vs duct-to-duct) (odds ratio, 3.06; 95% confidence interval, 1.52-6.16; P = 0.002). Graft failure by 6 months was more than 3 times higher for DCDD recipients with IC (odds ratio for IC, 3.36; 95% confidence interval, 1.95-5.79). CONCLUSIONS: This first report of the large combined experience with DCDD from the Improving DCDD Outcomes in Liver Transplant consortium demonstrates significant differences in IC among centers, the importance of biliary strictures as a risk factor for graft failure, and does not validate other risk factors for IC found in smaller studies.

Strategy for microbiome analysis using 16S rRNA gene sequence analysis on the Illumina sequencing platform.

Understanding the identity and changes of organisms in the urogenital and other microbiomes of the human body may be key to discovering causes and new treatments of many ailments, such as vaginosis. High-throughput sequencing technologies have recently enabled discovery of the great diversity of the human microbiome. The cost per base of many of these sequencing platforms remains high (thousands of dollars per sample); however, the Illumina Genome Analyzer (IGA) is estimated to have a cost per base less than one-fifth of its nearest competitor. The main disadvantage of the IGA for sequencing PCR-amplified 16S rRNA genes is that the maximum read-length of the IGA is only 100 bases; whereas, at least 300 bases are needed to obtain phylogenetically informative data down to the genus and species level. In this paper we describe and conduct a pilot test of a multiplex sequencing strategy suitable for achieving total reads of > 300 bases per extracted DNA molecule on the IGA. Results show that all proposed primers produce products of the expected size and that correct sequences can be obtained, with all proposed forward primers. Various bioinformatic optimization of the Illumina Bustard analysis pipeline proved necessary to extract the correct sequence from IGA image data, and these modifications of the data files indicate that further optimization of the analysis pipeline may improve the quality rankings of the data and enable more sequence to be correctly analyzed. The successful application of this method could result in an unprecedentedly deep description (800,000 taxonomic identifications per sample) of the urogenital and other microbiomes in a large number of samples at a reasonable cost per sample.