Renal inflamm-aging provokes intra-graft inflammation following experimental kidney transplantation

Donor age is a major risk factor for allograft outcome in kidney transplantation. The underlying cellular mechanisms and the recipient's immune response within an aged allograft have yet not been analyzed. A comprehensive immunophenotyping of naïve and transplanted young versus aged kidneys revealed that naïve aged murine kidneys harbor significantly higher frequencies of effector/memory T cells, whereas regulatory T cells were reduced. Aged kidney-derived CD8⁺ T cells produced more IFNγ than their young counterparts. Senescent renal CD8⁺ T and NK cells upregulated the cytotoxicity receptor NKG2D and the enrichment of memory-like CD49a⁺ CXCR6⁺ NK cells was documented in aged naïve kidneys. In the C57BL/6 to BALB/c kidney transplantation model, recipient-derived T cells infiltrating an aged graft produced significantly more IFNγ, granzyme B and perforin on day 7 post-transplantation, indicating an enhanced inflammatory, cytotoxic response towards the graft. Pre-treatment of aged kidney donors with the senolytic drug ABT-263 changed the recipient-derived effector molecule profile to significantly reduced levels of IFNγ and IL-10 compared to controls. Graft function after ABT-263 pre-treatment was significantly improved 28 days post kidney transplantation. In conclusion, renal senescence also occurs at the immunological level (inflamm-aging) and aged organs provoke an altered recipient-dominated immune response in the graft.

Feasibility of robotic-assisted pancreatic resection in patients with previous minor abdominal surgeries: a single-center experience of the first three years

BACKGROUND

Robotic-assisted pancreatic surgery is limited to specialized high-volume centers and selected patient cohorts. Especially for patients with a history of previous abdominal surgeries, the standard procedure remains open surgery due to the fear of complications caused by abdominal adhesions.

METHODS

Clinical data of all consecutive patients undergoing robotic-assisted pancreatic surgery using the daVinci Xi system (Intuitive Surgical) at our center (Department of Surgery, Universitätsmedizin Berlin, Germany) were collected prospectively and further analyzed from October 2017 to October 2020. Prior abdominal surgeries were specified according to the surgical approach and localization. In univariate and multivariate analysis, baseline and perioperative parameters of patients with a history of prior abdominal surgeries (PS) were compared to those of patients with no history of prior abdominal surgeries (NPS).

RESULTS

Out of 131 patients undergoing robotic-assisted pancreatic surgery, 62 (47%) had a history of abdominal surgery. Previous procedures included most often appendectomy (32%) followed by gynecological surgery (29%) and cholecystectomy (27%). 24% of PS had received multiple surgeries prior to the robotic-assisted pancreatic resections. Baseline characteristics and comorbidities were comparable between the groups. We did not detect differences in the duration of surgery (262 min), conversion rates (10%), and postoperative complications between NPS and PS. Postoperative pancreatic fistula (POPF), postpancreatectomy hemorrhage (PPH), and in-house mortality showed no significant differences between the two groups. Multivariate analysis revealed male sex and high BMI as a potential predictive factor for severe postoperative complications. Other characteristics like the type of pancreatic resection, ASA, and underlying malignancy showed no difference in the multivariable analysis.

CONCLUSIONS

We propose robotic-assisted pancreatic surgery to be safe and feasible for patients with a history of minor prior abdominal surgery. Hence, each patient should individually be evaluated for a minimally invasive approach regardless of a history of previous operations.

Hepatic artery reconstruction using an operating microscope in pediatric liver transplantation-Is it worth the effort?

INTRODUCTION

In pediatric liver transplantation (pLT), hepatic artery thrombosis (HAT) is associated with inferior transplant outcome. Hepatic artery reconstruction (HAR) using an operating microscope (OM) is considered to reduce the incidence of HAT.

METHODS

HAR using an OM was compared to a historic cohort using surgical loupes (SL) in pLT performed between 2009 and 2020. Primary endpoint was the occurrence of HAT. Secondary endpoints were 1-year patient and graft survival determined by Kaplan-Meier analysis and complications. Multivariate analysis was used to identify independent risk factors for HAT and adverse events.

RESULTS

A total of 79 pLTs were performed [30 (38.0%) living donations; 49 (62.0%) postmortem donations] divided into 23 (29.1%) segment 2/3, 32 (40.5%) left lobe, 4 (5.1%) extended right lobe, and 20 (25.3%) full-size grafts. One-year patient and graft survival were both 95.2% in the OM group versus 86.2% and 77.8% in the SL group (p = .276 and p = .077). HAT rate was 0% in the OM group versus 24.1% in the SL group (p = .013). One-year patient and graft survival were 64.3% and 35.7% in patient with HAT, compared to 93.9% and 92.8% in patients with no HAT (both p < .001). Multivariate analysis revealed HAR with SL (p = .022) and deceased donor liver transplantation (DDLT) (p = .014) as independent risk factors for HAT. The occurrence of HAT was independently associated with the need for retransplantation (p < .001) and biliary leakage (p = .045).

CONCLUSION

In pLT, the use of an OM is significantly associated to reduce HAT rate, biliary complications, and graft loss and outweighs the disadvantages of delayed arterial perfusion and prolonged warm ischemia time (WIT).

Expression of MICA in Zero Hour Biopsies Predicts Graft Survival After Liver Transplantation

In search for novel biomarkers to assess graft quality, we investigated whether defined candidate genes are predictive for outcome after liver transplantation (LT).

Zero-hour liver biopsies were obtained from 88 livers. Gene expression of selected candidate markers was analyzed and correlated with clinical parameters as well as short and long-term outcomes post LT. Whereas both, the calculated Eurotransplant Donor-Risk-Index and the donor body mass index, had either a poor or no predictive value concerning serum levels indicative for liver function (ALT, AST, GGT, bilirubin) after 6 months, chronological donor age was weakly predictive for serum bilirubin (AUC=0.67). In contrast, the major histcompatibility complex class I related chain A (MICA) mRNA expression demonstrated a high predictive value for serum liver function parameters revealing an inverse correlation (e.g. for ALT: 3 months p=0.0332; 6 months p=0.007, 12 months 0.0256, 24 months p=0.0098, 36 months, p=0.0153) and proved significant also in a multivariate regression model. Importantly, high expression of MICA mRNA revealed to be associated with prolonged graft survival (p=0.024; log rank test) after 10 years of observation, whereas low expression was associated with the occurrence of death in patients with transplant related mortality (p=0.031). Given the observed correlation with short and long-term graft function, we suggest MICA as a biomarker for pre-transplant graft evaluation.

Transplantation programs facing lack of empirical evidence on SARS-CoV-2 vaccination: A society recommendation consensus update

BACKGROUND

Since phase III trials for the most prominent vaccines excluded immunocompromised or immunosuppressed patients, data on safety and efficacy of SARS-CoV-2 vaccines for recipients of solid organ transplantations are scarce.

AIMS

Our study offers a synthesis of expert opinions aligned with available data addressing key questions of the clinical management of SARS-CoV-2 vaccinations for transplant patients.

METHOD

An online research was performed retrieving available recommendations by national and international transplantation organizations and state institutions on SARS-CoV2 vaccination management for transplant recipients.

RESULTS

Eleven key statements were identified from recommendations by 18 national and international societies, and consensus for the individual statements was evaluated by means of the Society Recommendation Consensus score. The highest consensus level (SRC A) was found for prioritized access to vaccination for transplant patients despite anticipation of a weakened immune response. All currently authorized vaccines can be considered safe for transplant patients (SRC A). The handling of immunosuppressive medication, the timely management of vaccines, and other aspects were aligned with available expert opinions.

CONCLUSION

Expert consensus can be determined for crucial aspects of the implementation of SARS-CoV-2 vaccination programs. We hereby offer a tool for immediate decision-making until empirical data becomes available.

Perioperative Perfusion of Allografts with Anti-Human T-lymphocyte Globulin Does Not Improve Outcome Post Liver Transplantation-A Randomized Placebo-Controlled Trial

Due to the lack of suitable organs transplant surgeons have to accept unfavorable extended criteria donor (ECD) organs. Recently, we demonstrated that the perfusion of kidney organs with anti-human T-lymphocyte globulin (ATLG) prior to transplantation ameliorates ischemia-reperfusion injury (IRI). Here, we report on the results of perioperative ATLG perfusion in a randomized, single-blinded, placebo-controlled, feasibility trial (RCT) involving 30 liver recipients (LTx). Organs were randomly assigned for perfusion with ATLG/Grafalon^® (AP) (n = 16) or saline only (control perfusion = CP) (n = 14) prior to implantation. The primary endpoint was defined as graft function reflected by aspartate transaminase (AST) values at day 7 post-transplantation (post-tx). With respect to the primary endpoint, no significant differences in AST levels were shown in the intervention group at day 7 (AP: 53.0 ± 21.3 mg/dL, CP: 59.7 ± 59.2 mg/dL, p = 0.686). Similarly, exploratory analysis of secondary clinical outcomes (e.g., patient survival) and treatment-specific adverse events revealed no differences between the study groups. Among liver transplant recipients, pre-operative organ perfusion with ATLG did not improve short-term outcomes, compared to those who received placebo perfusion. However, ATLG perfusion of liver grafts was proven to be a safe procedure without the occurrence of relevant adverse events.

[COVID-19 Pandemic in Germany: The Current Situation in Thoracic Surgery]

BACKGROUND

The new COVID-19 pandemic has an impact on routine thoracic surgery. Various concepts and recommendations are being pursued to protect patients and hospital staff. However, the implementation of these recommendations may depend on the existing infrastructure, local conditions and in-house procedural instructions.

MATERIAL AND METHOD

Between 11th May and 26th May 2020, an anonymous online survey on the topic of COVID-19 was conducted among thoracic surgeons in Germany. The survey consisted of 16 questions on the local COVID-19 case numbers, protective measures, procedural instructions and treatment concepts. The results were summarised, descriptively analysed and discussed.

RESULTS

The response rate of 42.6% (n = 66), included replies from 23 (34.8%) specialised hospitals, 18 (27.3%) maximum care hospitals and 14 (21.2%) university clinics. COVID-19-positive patients were treated in 65 (99%) clinics and 37.9% of the clinics also performed surgery on COVID-19-positive patients. Nasopharyngeal swabs were the main instrument for COVID-19 patient testing (in 95.4% of the clinics). Test results influenced decisions on treatment in 71.2% of the clinics. In 59.1% of clinics, safety equipment was supplemented with FFP2 masks and eye protection during thoracic surgeries due to the COVID-19 pandemic.

DISCUSSION

Almost all thoracic surgeons reported that they had treated patients with COVID-19 and half of them also had performed surgery on COVID-19-positive patients. The applied procedural instructions as well as the effects of COVID-19 on treatment decisions and patient-doctor contact differed between the reporting clinics.

Treatment of Anti-HLA Donor-Specific Antibodies Results in Increased Infectious Complications and Impairs Survival after Liver Transplantation

Donor-specific anti-human leukocyte antigen antibodies (DSA) are controversially discussed in the context of liver transplantation (LT). We investigated the relationship between the presence of DSA and the outcome after LT. All the LTs performed at our center between 1 January 2008 and 31 December 2015 were examined. Recipients < 18 years, living donor-, combined, high-urgency-, and re-transplantations were excluded. Out of 510 LTs, 113 DSA-positive cases were propensity score-matched with DSA-negative cases based on the components of the Balance of Risk score. One-, three-, and five-year survival after LT were 74.3% in DSA-positive vs. 84.8% (p = 0.053) in DSA-negative recipients, 71.8% vs. 71.5% (p = 0.821), and 69.3% vs. 64.9% (p = 0.818), respectively. Rejection therapy was more often applied to DSA-positive recipients (n = 77 (68.1%) vs. 37 (32.7%) in the control group, p < 0.001). At one year after LT, 9.7% of DSA-positive patients died due to sepsis compared to 1.8% in the DSA-negative group (p = 0.046). The remaining causes of death were comparable in both groups (cardiovascular 6.2% vs. 8.0%; p = 0.692; hepatic 3.5% vs. 2.7%, p = 0.788; malignancy 3.5% vs. 2.7%, p = 0.788). DSA seem to have an indirect effect on the outcome of adult LTs, impacting decision-making in post-transplant immunosuppression and rejection therapies and ultimately increasing mortality due to infectious complications.

[Postdural puncture headache after neuraxial anesthesia: incidence and risk factors]

Hintergrund/Ziel der Arbeit

Der postpunktionelle Kopfschmerz (PKS) ist eine Komplikation nach rückenmarknahen Verfahren (RA) mit erheblichem Krankheitswert. Ziel der Untersuchung war es, die Inzidenz des PKS in 2 großen operativen Kollektiven zu untersuchen, mögliche Risikofaktoren zu identifizieren und den Einfluss auf die Krankenhausverweildauer zu untersuchen.

Material und Methoden

In einer retrospektiven Analyse des Zeitraums 2010–2012 wurden 341 unfallchirurgische (UCH) und 2113 geburtsmedizinische (GEB) Patient*innen nach Spinalanästhesie (SPA) analysiert. In der statistischen Auswertung (SPSS-23) kamen univariate Analysen mittels Mann-Whitney-U-, Chi²- und Student’s t‑Test sowie logistische Regressionsanalysen zur Anwendung.

Ergebnisse

Die Inzidenz des PKS betrug in der UCH-Gruppe 5,9 % und in der GEB-Gruppe 1,8 %. Patient*innen mit PKS in der UCH wiesen ein jüngeres Patientenalter (38 vs. 47 Jahre, p = 0,011), einen geringeren BMI (23,5 vs. 25,2, p = 0,037) sowie ein niedrigeres Köpergewicht (70,5 kg vs. 77 kg, p = 0,006) als Patient*innen ohne PKS auf. Dabei konnten das Alter mit einer „odds ratio“ (OR 97,5 % Konfidenzintervall [KI]) von 0,963 (97,5% KI 0,932–0,991, p = 0,015) und das Köpergewicht mit einer OR von 0,956 (97,5 % KI 0,920–0,989, p = 0,014) als unabhängige Risikofaktoren für die Entstehung eines PKS identifiziert werden. In der GEB wies die SPA eine höhere Inzidenz des PKS auf als die kombinierte Spinalepiduralanästhesie (CSE) (8,6 % vs. 1,2 %, p < 0,001). Dabei erwies sich das Verfahren mit einer OR von 0,049 (97,5 % KI 0,023–0,106, p < 0,001) als unabhängiger Risikofaktor für die Entstehung eines PKS. In beiden Gruppen war der PKS mit einem verlängerten Krankenhausaufenthalt assoziiert (UCH-Gruppe 4 vs. 2 Tage, p = 0,001; GEB-Gruppe 6 vs. 4 Tage, p < 0.0005).

Diskussion

Die Inzidenz des PKS nach SPA/CSE war in unserer Untersuchung in den beschriebenen Patientengruppen unterschiedlich, mit einem deutlich höheren Anteil in der UCH-Gruppe. Alter, Konstitution und Verfahren waren hinweisgebende Risikofaktoren eines PKS. In Anbetracht der funktionellen Einschränkungen (Mobilisation, Versorgung des Neugeborenen) und des verlängerten Krankenhausaufenthalts, sollten zukünftige Studien eine frühe Behandlung des PKS untersuchen.

Outcome after pediatric liver transplantation for staged abdominal wall closure with use of biological mesh-Study with long-term follow-up

Abdominal wall closure after pediatric liver transplantation (pLT) in infants may be hampered by graft-to-recipient size discrepancy. Herein, we describe the use of a porcine dermal collagen acellular graft (PDCG) as a biological mesh (BM) for abdominal wall closure in pLT recipients. Patients <2 years of age, who underwent pLT from 2011 to 2014, were analyzed, divided into definite abdominal wall closure with and without implantation of a BM. Primary end-point was the occurrence of postoperative abdominal wall infection. Secondary end-points included 1- and 5-year patient and graft survival and the development of abdominal wall hernia. In five out of 21 pLT recipients (23.8%), direct abdominal wall closure was achieved, whereas 16 recipients (76.2%) received a BM. BM removal was necessary in one patient (6.3%) due to abdominal wall infection, whereas no abdominal wall infection occurred in the no-BM group. No significant differences between the two groups were observed for 1- and 5-year patient and graft survival. Two late abdominal wall hernias were observed in the BM group vs none in the no-BM group. Definite abdominal wall closure with a BM after pLT is feasible and safe when direct closure cannot be achieved with comparable postoperative patient and graft survival rates.

Perioperative Pleural Drainage in Liver Transplantation: A Retrospective Analysis from a High-Volume Liver Transplant Center

BACKGROUND Pleural effusions represent a common complication after liver transplantation (LT) and chest drain (CD) placement is frequently necessary. MATERIAL AND METHODS In this retrospective cohort study, adult LT recipients between 2009 and 2016 were analyzed for pleural effusion formation and its treatment within the first 10 postoperative days. The aim of the study was to compare different settings of CD placement with regard to intervention-related complications. RESULTS Overall, 597 patients met the inclusion criteria, of which 361 patients (60.5%) received at least 1 CD within the study period. Patients with a MELD >25 were more frequently affected (75.7% versus 56.0%, P<0.001). Typically, CDs were placed in the intensive care unit (ICU) (66.8%) or in the operating room (14.1% during LT, 11.5% in the context of reoperations). In total, 97.0% of the patients received a right-sided CD, presumably caused by local irritations. Approximately one-third (35.4%) of ICU-patients required pre-interventional optimization of coagulation. Of the 361 patients receiving a CD, 15 patients (4.2%) suffered a post-interventional hemorrhage and 6 patients (1.4%) had a pneumothorax requiring further treatment. Less complications were observed when the CD was performed in the operating room compared to the ICU: 1 out 127 patients (0.8%) versus 20 out of 332 patients (6.0%); P=0.016. CONCLUSIONS CD placement occurring in the operating room was associated with fewer complications in contrast to placement occurring in the ICU. Planned CD placement in the course of surgery might be favorable in high-risk patients.

[High donor age for liver transplantation : Tackling organ scarcity in Germany]

BACKGROUND

Liver transplantation is the only curative treatment option for patients with end-stage liver disease; however, the 40% decline of available organ donors in recent years in Germany necessitates the optimization of available resources and possibly extending the criteria to older donors.

MATERIAL AND METHODS

All 2652 livers made available to the Charité Universitätsmedizin Berlin from 2010 to 2016 were retrospectively analyzed and the clinical outcome of 526 liver transplantations during this time frame were evaluated.

RESULTS

The median age of donors of transplanted organs increased from 49.3 years in 2010 to 57.3 years in 2016 (p = 0.02). Organs from donors ≥65 years were more frequently discarded than organs from younger donors (n = 344, 18.4% vs. n = 220, 28.1%; p = 0.005). Moreover, the older donors had higher rates of diabetes mellitus and hepatic steatosis. Organs from older donors had a higher donor risk index (2.8 vs. 2.2; p < 0.001) and were transplanted more often in patients with preserved liver function and hepatocellular carcinoma and liver cirrhosis (n = 121, 74.7% of indications). The 3‑year survival after liver transplantation from donors ≥65 and ≥80 years old was not significantly reduced in comparison to younger donors; however, there was an increased retransplantation rate (28.6%; p = 0.005) after transplantation of organs from donors ≥80 years old.

CONCLUSION

Despite conservative organ acceptance there were higher rates of retransplantation after transplantation from very old donors. In the light of an increasing scarcity of suitable organs this mandates caution and highlights the need for adequate assessment instruments for marginal donor organs before transplantation.

Deletion of the activating NK cell receptor NKG2D accelerates rejection of cardiac allografts

It has already been shown that neutralization of the activating NK cell receptor NKG2D in combination with co-stimulation blockade prolongs graft survival of vascularized transplants. In order to clarify the underlying cellular mechanisms, we transplanted complete MHC-disparate BALB/c-derived cardiac grafts into C57BL/6 wildtypes or mice deficient for NKG2D (Klrk1^-/- ). Although median survival was 8 days for both recipient groups, we detected already at day 5 posttransplantation significantly greater intragraft frequencies of NKp46⁺ NK cells in Klrk1^-/- recipients than in wildtypes. This was followed by a significantly greater infiltration of CD4⁺ , but a lesser infiltration of CD8⁺ T cell frequencies. Contrary to published observations, co-stimulation blockade with CTLA4-Ig resulted in a significant acceleration of cardiac rejection by Klrk1^-/- recipients, and this result was confirmed by applying a neutralizing antibody against NKG2D to wildtypes. In both experimental setups, grafts derived from Klrk1^-/- recipients were characterized by significantly higher levels of interferon-γ mRNA, and both CD4⁺ and CD8⁺ T cells displayed a greater capacity for degranulation and interferon-γ production. In summary, our results clearly illustrate that NKG2D expression in the recipient is important for cardiac allograft survival, thus supporting the hypothesis that impairment of NK cells prevents the establishment of graft acceptance.