Donor Proteinuria and Allograft Function in Kidney Transplantation: Short- and Long-Term Results From a Retrospective Cohort Study.

Donor proteinuria (DP) is a common but rarely evaluated aspect of today's kidney transplant allocation process. While proteinuria after kidney transplantation is a risk factor for impaired graft function and survival, the long-term effects of DP in kidney transplantation have not yet been evaluated. Therefore, this study aims to investigate the impact of DP on the long-term outcome after kidney transplantation. A total of 587 patients were found to be eligible and were stratified into two groups: (1) those receiving a graft from a donor without proteinuria (DP-) and (2) those receiving a graft from a donor with proteinuria (DP+). At 36 months, there was no difference in the primary composite endpoint including graft loss and patient survival (log-rank test, p = 0.377). However, the analysis of DP+ subgroups showed a significant decrease in overall patient survival in the group with high DP (p = 0.017). DP did not adversely affect patient or graft survival over 36 months. Nevertheless, this work revealed a trend towards decreased overall survival of patients with severe proteinuria in the subgroup analysis. Therefore, the underlying results suggest caution in allocating kidneys from donors with high levels of proteinuria.

Microporous Polylactic Acid Scaffolds Enable Fluorescence-Based Perfusion Imaging of Intrinsic In Vivo Vascularization.

In vivo tissue engineering (TE) techniques like the AV loop model provide an isolated and well-defined microenvironment to study angiogenesis-related cell interactions. Functional visualization of the microvascular network within these artificial tissue constructs is crucial for the fundamental understanding of vessel network formation and to identify the underlying key regulatory mechanisms. To facilitate microvascular tracking advanced fluorescence imaging techniques are required. We studied the suitability of microporous polylactic acid (PLA) scaffolds with known low autofluorescence to form axial vascularized tissue constructs in the AV loop model and to validate these scaffolds for fluorescence-based perfusion imaging. Compared to commonly used collagen elastin (CE) scaffolds, the total number of vessels and cells in PLA scaffolds was lower. In detail, CE-based constructs exhibited significantly higher vessel numbers on day 14 and 28 (d14: 316 ± 53; d28: 610 ± 74) compared to the respective time points in PLA-based constructs (d14: 144 ± 18; d28: 327 ± 34; each p < 0.05). Analogously, cell counts in CE scaffolds were higher compared to corresponding PLA constructs (d14: 7661.25 ± 505.93 and 5804.04 ± 716.59; d28: 11211.75 + 1278.97 and 6045.71 ± 572.72, p < 0.05). CE scaffolds showed significantly higher vessel densities in proximity to the main vessel axis compared to PLA scaffolds (200-400 µm and 600-800 µm on day 14; 400-1000 µm and 1400-1600 µm on day 28). CE scaffolds had significantly higher cell counts on day 14 at distances from 800 to 2000 µm and at distances from 400 to 1600 µm on day 28. While the total number of vessels and cells in PLA scaffolds were lower, both scaffold types were ideally suited for axial vascularization techniques. The intravascular perfusion of PLA-based constructs with fluorescence dye MHI148-PEI demonstrated dye specificity against vascular walls of low- and high-order branches as well as capillaries and facilitated the fluorescence-based visualization of microcirculatory networks. Fluorophore tracking may contribute to the development of automated quantification methods after 3D reconstruction and image segmentation. These technologies may facilitate the characterization of key regulators within specific subdomains and add to the current understanding of vessel formation in axially vascularized tissue constructs.

Quantification of Indocyanine Green Fluorescence Imaging in General, Visceral and Transplant Surgery.

Near-infrared (NIR) imaging with indocyanine green (ICG) has proven to be useful in general, visceral, and transplant surgery. However, most studies have performed only qualitative assessments. Therefore, a systematic overview of all studies performing quantitative indocyanine green evaluation in general, visceral, and transplant surgeries should be conducted. Free term and medical subject heading (MeSH) term searches were performed in the Medline and Cochrane databases until October 2022. The main categories of ICG quantification were esophageal surgery (24.6%), reconstructive surgery (24.6%), and colorectal surgery (21.3%). Concordantly, anastomotic leak (41%) was the main endpoint, followed by the assessment of flap perfusion (23%) and the identification of structures and organs (14.8%). Most studies examined open surgery (67.6%) or laparoscopic surgery (23.1%). The analysis was mainly carried out using manufacturer software (44.3%) and open-source software (15.6%). The most frequently analyzed parameter was intensity over time for blood flow assessment, followed by intensity alone or intensity-to-background ratios for structure and organ identification. Intraoperative ICG quantification could become more important with the increasing impact of robotic surgery and machine learning algorithms for image and video analysis.

Reducing the Risks of Esophagectomies: A Retrospective Comparison of Hybrid versus Full-Robotic-Assisted Minimally Invasive Esophagectomy (RAMIE) Approaches.

This retrospective analysis aimed to assess and compare the short-term perioperative outcomes and morbidity of hybrid and full-Robotic-Assisted Minimally Invasive Esophagectomy (RAMIE) surgical techniques. A total of 168 robotic-assisted Ivor Lewis esophagectomy procedures performed at Muenster University Hospital were included in the study, with 63 cases in the hybrid group and 105 cases in the full-robotic group. Demographic factors, comorbidities, and tumor stages showed no significant differences between the two groups. However, the full-RAMIE technique demonstrated superiority in terms of overall operative time, postoperative pain levels, and patient morphine consumption. Additionally, the full-RAMIE group exhibited better perioperative outcomes, with significantly shorter ICU stays and fewer occurrences of pneumonias and severe complications. While there was a trend favoring the full-RAMIE technique in terms of severe postoperative complications and anastomotic insufficiencies, further research is required to establish it as the gold standard surgical technique for Ivor Lewis esophagectomy.

Comparison of Fasciocutaneous and Muscle-based Free Flaps for Soft Tissue Reconstruction of the Upper Extremity.

Soft tissue free flap reconstruction of upper extremities has proven to be reliable and essential for limb salvage and function. Nevertheless, comparative data regarding flap outcome are still lacking. The present study aimed to compare procedural features and individual complication rates of different free flaps used for upper extremity reconstruction. METHODS: The authors evaluated retrospectively the results of 164 free flaps in 149 patients with upper extremity defects. Chart reviews were performed from April 2000 to June 2014, analyzing flap choices, complication, and success rate assessment for patients >18 years old, with a soft tissue defect of the upper extremity. Chosen flap types were classified as fasciocutaneous (including adipocutaneous) and muscle-based, respectively. We comparatively analyzed total flap loss, flap survival after microsurgical revisions, and susceptibility rates for thromboses rates and partial flap necrosis. RESULTS: Defect size was larger when muscle-based flaps were used (231 ± 38.6 versus 164 ± 13.7 cm2, P < 0.05). Outcome analysis revealed a tendency towards higher arterial thrombosis rates for muscle flaps (10.2% versus 4.3%) and venous thrombosis rates for fasciocutaneous flaps (2% versus 7%). Total flap loss (6.1% versus 7.8%) and flap survival after vascular revisions (75% versus 70.6%) showed comparable rates. Partial flap necrosis was generally higher in muscle-based flaps (22.4% versus 8.6%, P = 0.02) with impact on patients' hospital stay (37.2 ± 4.69 and 27.11 ± 1.62 days, n = 115, P = 0.01), while no differences in partial necrosis rates were noted in flaps larger than 300 cm2 (25% versus 10%, P = 0.55). There was a trend over time towards using fasciocutaneous-based flaps more frequently with a final overall percentage of 83.7% between 2012 and 2014. CONCLUSIONS: Microsurgical tissue transfer to the upper extremity is safe and reliable, but flap-type specific procedural and measures should be taken into consideration. Total flap loss as well as flap survival after microsurgical revisions are not altered between these flaps. They differ, however, in their susceptibilities for thromboses rates, partial flap necrosis and thus require individual risk stratification and flap placement.