Monocentric, Retrospective Study on Infectious Complications within One Year after Solid-Organ Transplantation at a Belgian University Hospital

The epidemiology, diagnostic methods and management of infectious complications after solid-organ transplantation (SOT) are evolving. The aim of our study is to describe current infectious complications in the year following SOT and risk factors for their development and outcome. We conducted a retrospective study in adult SOT recipients in a Belgian university hospital between 2018 and 2019. We gathered demographic characteristics, comorbidities leading to transplantation, clinical, microbiological, surgery-specific and therapeutic data concerning infectious episodes, and survival status up to one year post-transplantation. Two-hundred-and-thirty-one SOT recipients were included (90 kidneys, 79 livers, 35 lungs, 19 hearts and 8 multiple organs). We observed 381 infections in 143 (62%) patients, due to bacteria (235 (62%)), viruses (67 (18%)), and fungi (32 (8%)). Patients presented a median of two (1-5) infections, and the first infection occurred during the first six months. Nineteen (8%) patients died, eleven (58%) due to infectious causes. Protective factors identified against developing infection were obesity [OR [IC]: 0.41 [0.19-0.89]; p = 0.025] and liver transplantation [OR [IC]: 0.21 [0.07-0.66]; p = 0.007]. Risk factors identified for developing an infection were lung transplantation [OR [IC]: 6.80 [1.17-39.36]; p = 0.032], CMV mismatch [OR [IC]: 3.53 [1.45-8.64]; p = 0.006] and neutropenia [OR [IC]: 2.87 [1.27-6.47]; p = 0.011]. Risk factors identified for death were inadequate cytomegalovirus prophylaxis, infection severity and absence of pneumococcal vaccination. Post-transplant infections were common. Addressing modifiable risk factors is crucial, such as pneumococcal vaccination.

A multicentre outcome analysis to define global benchmarks for donation after circulatory death liver transplantation

BACKGROUND & AIMS

The concept of benchmarking is established in the field of transplant surgery; however, benchmark values for donation after circulatory death (DCD) liver transplantation are not available. Thus, we aimed to identify the best possible outcomes in DCD liver transplantation and to propose outcome reference values.

METHODS

Based on 2,219 controlled DCD liver transplantations, collected from 17 centres in North America and Europe, we identified 1,012 low-risk, primary, adult liver transplantations with a laboratory MELD score of ≤20 points, receiving a DCD liver with a total donor warm ischemia time of ≤30 minutes and asystolic donor warm ischemia time of ≤15 minutes. Clinically relevant outcomes were selected and complications were reported according to the Clavien-Dindo-Grading and the comprehensive complication index (CCI). Corresponding benchmark cut-offs were based on median values of each centre, where the 75^th-percentile was considered.

RESULTS

Benchmark cases represented between 19.7% and 75% of DCD transplantations in participating centres. The 1-year retransplant and mortality rates were 4.5% and 8.4% in the benchmark group, respectively. Within the first year of follow-up, 51.1% of recipients developed at least 1 major complication (≥Clavien-Dindo-Grade III). Benchmark cut-offs were ≤3 days and ≤16 days for ICU and hospital stay, ≤66% for severe recipient complications (≥Grade III), ≤16.8% for ischemic cholangiopathy, and ≤38.9 CCI points 1 year after transplant. Comparisons with higher risk groups showed more complications and impaired graft survival outside the benchmark cut-offs. Organ perfusion techniques reduced the complications to values below benchmark cut-offs, despite higher graft risk.

CONCLUSIONS

Despite excellent 1-year survival, morbidity in benchmark cases remains high. Benchmark cut-offs targeting morbidity parameters offer a valid tool to assess the protective value of new preservation technologies in higher risk groups and to provide a valid comparator cohort for future clinical trials.

LAY SUMMARY

The best possible outcomes after liver transplantation of grafts donated after circulatory death (DCD) were defined using the concept of benchmarking. These were based on 2,219 liver transplantations following controlled DCD donation in 17 centres worldwide. Donor and recipient combinations with higher risk had significantly worse outcomes. However, the use of novel organ perfusion technology helped high-risk patients achieve similar outcomes as the benchmark cohort.

Biliary cast syndrome after liver transplantation: A cholangiographic evolution study

BACKGROUND AND AIM

The aim of this study is to describe the cholangiographic features and endoscopic management of biliary cast syndrome (BCS), a rare specific ischemic cholangiopathy following liver transplantation.

METHODS

Patients with biliary complications were identified from prospectively collected database records of patients who underwent liver transplantation at the Erasme Hospital from January 2005 to December 2014. After excluding patients with hepatico-jejunostomy or no suspicion of stricture, cholangiograms obtained during endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance imaging were systematically reviewed. Biliary complications were categorized as anastomotic (AS) and non-AS strictures, and patients with BCS were identified. Clinical, radiological, and endoscopic data were reviewed.

RESULTS

Out of 311 liver transplantations, 14 cases were identified with BCS (4.5%) and treated with ERCP. Intraductal hyperintense signal on T1-weighted magnetic resonance and a "duct-in-a-duct" image were the most frequent features of BCS on magnetic resonance imaging. On initial ERCP, 57% of patients had no stricture. Complete cast extraction was achieved in 12/14, and one of these had cast recurrence. On follow-up, 85% of the patients developed biliary strictures that were treated with multiple plastic stents reaching 60% complete stricture resolution, but 40% of them had recurrence. After a median follow-up of 58 months, BCS patients had lower overall and graft survival (42.9% and 42.9%) compared with non-AS (68.8% and 56.3%) and AS (83.3% and 80.6%), respectively.

CONCLUSIONS

Particular magnetic resonance-cholangiographic and ERCP-cholangiographic features of BCS have been identified. Outcomes for BCS are characterized by high complete cast extraction rates, high incidence of secondary strictures, and poorer prognosis.

Intraoperative hypotension during liver transplant surgery is associated with postoperative acute kidney injury: a historical cohort study

Background

Acute kidney injury (AKI) occurs frequently after liver transplant surgery and is associated with significant morbidity and mortality. While the impact of intraoperative hypotension (IOH) on postoperative AKI has been well demonstrated in patients undergoing a wide variety of non-cardiac surgeries, it remains poorly studied in liver transplant surgery. We tested the hypothesis that IOH is associated with AKI following liver transplant surgery.

Methods

This historical cohort study included all patients who underwent liver transplant surgery between 2014 and 2019 except those with a preoperative creatinine > 1.5 mg/dl and/or who had combined transplantation surgery. IOH was defined as any mean arterial pressure (MAP) < 65 mmHg and was classified according to the percentage of case time during which the MAP was < 65 mmHg into three groups, based on the interquartile range of the study cohort: “short” (Quartile 1, < 8.6% of case time), “intermediate” (Quartiles 2–3, 8.6–39.5%) and “long” (Quartile 4, > 39.5%) duration. AKI stages were classified according to a “modified” “Kidney Disease: Improving Global Outcomes” (KDIGO) criteria. Logistic regression modelling was conducted to assess the association between IOH and postoperative AKI. The model was run both as a univariate and with multiple perioperative covariates to test for robustness to confounders.

Results

Of the 205 patients who met our inclusion criteria, 117 (57.1%) developed AKI. Fifty-two (25%), 102 (50%) and 51 (25%) patients had short, intermediate and long duration of IOH respectively. In multivariate analysis, IOH was independently associated with an increased risk of AKI (adjusted odds ratio [OR] 1.05; 95%CI 1.02–1.09; P < 0.001). Compared to “short duration” of IOH, “intermediate duration” was associated with a 10-fold increased risk of developing AKI (OR 9.7; 95%CI 4.1–22.7; P < 0.001). “Long duration” was associated with an even greater risk of AKI compared to “short duration” (OR 34.6; 95%CI 11.5-108.6; P < 0.001).

Conclusions

Intraoperative hypotension is independently associated with the development of AKI after liver transplant surgery. The longer the MAP is < 65 mmHg, the higher the risk the patient will develop AKI in the immediate postoperative period, and the greater the likely severity. Anesthesiologists and surgeons must therefore make every effort to avoid IOH during surgery.

Myeloid tumor necrosis factor and heme oxygenase-1 regulate the progression of colorectal liver metastases during hepatic ischemia-reperfusion

The liver ischemia-reperfusion (IR) injury that occurs consequently to hepatic resection performed in patients with metastases can lead to tumor relapse for not fully understood reasons. We assessed the effects of liver IR on tumor growth and the innate immune response in a mouse model of colorectal (CR) liver metastasis. Mice subjected to liver ischemia 2 days after intrasplenic injection of CR carcinoma cells displayed a higher metastatic load in the liver, correlating with Kupffer cells (KC) death through the activation of receptor-interating protein 3 kinase (RIPK3) and caspase-1 and a recruitment of monocytes. Interestingly, the immunoregulatory mediators, tumor necrosis factor-α (TNF-α) and heme oxygenase-1 (HO-1) were strongly upregulated in recruited monocytes and were also expressed in the surviving KC following IR. Using TNF^flox/flox LysM^cre/wt mice, we showed that TNF deficiency in macrophages and monocytes favors tumor progression after IR. The antitumor effect of myeloid cell-derived TNF involved direct tumor cell apoptosis and a reduced expression of immunosuppressive molecules such as transforming growth factor-β, interleukin (IL)-10, inducible nitric oxyde synthase (iNOS), IL-33 and HO-1. Conversely, a monocyte/macrophage-specific deficiency in HO-1 (HO-1^flox/flox LysM^cre/wt ) or the blockade of HO-1 function led to the control of tumor progression post-liver IR. Importantly, host cell RIPK3 deficiency maintains the KC number upon IR, inhibits the IR-induced innate cell recruitment, increases the TNF level, decreases the HO-1 level and suppresses the tumor outgrowth. In conclusion, tumor recurrence in host undergoing liver IR is associated with the death of antitumoral KC and the recruitment of monocytes endowed with immunosuppressive properties. In both of which HO-1 inhibition would reinforce their antitumoral activity.

Hepatocarcinoma Induces a Tumor Necrosis Factor-Dependent Kupffer Cell Death Pathway That Favors Its Proliferation Upon Partial Hepatectomy

Partial hepatectomy (PH) is the main treatment for early-stage hepatocellular carcinoma (HCC). Yet, a significant number of patients undergo recursion of the disease that could be linked to the fate of innate immune cells during the liver regeneration process. In this study, using a murine model, we investigated the impact of PH on HCC development by bioluminescence imaging and flow cytometry. While non-resected mice were able to control and reject orthotopic implanted Hepa1-6 hepatocarcinoma cells, resected liver underwent an increased tumoral proliferation. This phenomenon was associated with a PH-induced reduction in the number of liver-resident macrophages, i.e., Kupffer cells (KC). Using a conditional ablation model, KC were proved to participate in Hepa1-6 rejection. We demonstrated that in the absence of Hepa1-6, PH-induced KC number reduction was dependent on tumor necrosis factor-alpha (TNF-α), receptor-interacting protein kinase (RIPK) 3, and caspase-8 activation, whereas interleukin (IL)-6 acted as a KC pro-survival signal. In mice with previous Hepa1-6 encounter, the KC reduction switched toward a TNF-α-RIPK3–caspase-1 activation. Moreover, KC disappearance associated with caspase-1 activity induced the recruitment of monocyte-derived cells that are beneficial for tumor growth, while caspase-8-dependent reduction did not. In conclusion, our study highlights the importance of the TNF-α-dependent death pathway induced in liver macrophages following partial hepatectomy in regulating the antitumoral immune responses.

The lack of selection criteria for surgery in patients with non-colorectal non-neuroendocrine liver metastases

BACKGROUND

The benefit of surgery in patients with non-colorectal non-neuroendocrine liver metastases (NCRNNELM) remains controversial. At the population level, several statistical prognostic factors and scores have been proposed but inconsistently verified. At the patient level, no selection criteria have been demonstrated to guide individual therapeutic decision making. We aimed to evaluate potential individual selection criteria to predict the benefit of surgery in patients undergoing treatment for NCRNNELM.

METHODS

Data for 114 patients undergoing surgery for NCRNNELM were reviewed. In this population, we identified an early relapse group (ER), defined as patients with unresectable recurrence < 1 year postoperatively who did not benefit from surgery (N = 28), and a long-term survival group (LTS), defined as patients who were recurrence-free ≥ 5 years postoperatively and benefited from surgery (N = 20). Clinicopathologic parameters, the Association Française de Chirurgie (AFC) score, and a modified 4-point Clinical Risk Score (mCRS) (excluding CEA level) were analyzed and compared between LTS and ER groups.

RESULTS

The majority of patients were female and a majority had an ASA score ≤ 2 at the time of liver surgery. The median age was 55 years. Almost half of the patients (46%) presented with a single-liver metastasis. Intermediate- and low-risk AFC scores represented 40% and 60% of the population, respectively. Five- and 10-year overall survival (OS) and disease-free survival (DFS) rates were 56% and 27%, and 30% and 12%, respectively. Negative prognostic factors were the size of liver metastases > 50 mm and delay between primary and NCRNNELM <24 months for OS and DFS, respectively. AFC score was not prognostic while high-risk mCRS (scores 3-4) was predictive for the poorer OS. The clinicopathologic parameters were similar in the ER and LTS groups, except the presence of N+ primary tumor, and the size of liver metastases was significantly higher in the ER group.

CONCLUSION

In patients with resectable NCRNNELM, no predictive factors or scores were found to accurately preoperatively differentiate individual cases in whom surgery would be futile from those in whom surgery could be associated with a significant oncological benefit.

The metabolic clinical risk score as a new prognostic model for surgical decision-making in patients with colorectal liver metastases

BACKGROUND AND OBJECTIVES

Selection for surgery in patients with colorectal liver metastases (CRLM) remains inaccurate. We evaluated if CRLM baseline metabolic characteristics, assessed by [18]F-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸ FDG-PET/CT), could predict postoperative outcomes.

METHODS

In a retrospective series of patients undergoing surgery for CRLM, we defined two groups: the long-term survival (LTS) and early relapse (ER) groups, where the postoperative recurrence-free survivals were ≥5 years or <1 year, respectively. We analyzed the patients in whom baseline ¹⁸ FDG-PET/CT was available. Clinicopathologic parameters, clinical risk score (CRS), and baseline ¹⁸ FDG-PET/CT characteristics were compared between LTS and ER groups. A metabolic CRS (mCRS) was implemented, adding one point to the standard five-point CRS when the highest tumor standardized uptake values (SUV_max )/normal liver mean SUV (SUV_mean(liver) ) ratios were >4.3, defining low- and high-risk mCRS by scores of 0 to 2 and 3 to 6, respectively.

RESULTS

From a series of 450 patients operated for CRLM (mean follow-up of 58 months), we included for analysis 23 and 30 patients in the LTS and ER groups, respectively. Clinicopathologic parameters and CRS were similar in the LTS and ER groups. Median SUV_max /SUV_mean(liver) ratios were higher in ER vs LTS patients (4.2 and 2.8, P = .008, respectively). mCRS was increased in ER patients (P = .024); 61% of LTS patients had low-risk mCRS and 73% of the ER patients had high-risk mCRS (P = .023).

CONCLUSIONS

¹⁸ FDG-PET/CT characteristics combined with traditional CRS may represent a new tool to improve selection for surgery in patients with CRLM.

Extended time interval between diagnosis and surgery does not improve the outcome in patients operated for resection or ablation of breast cancer liver metastases

BACKGROUND

Breast cancer liver metastases (BCLM) is considered a systemic disease with poorly defined selection criteria for surgery and little evidence for the appropriate timing of surgery.

METHODS

Postoperative outcomes of patients operated for BCLM were retrospectively reviewed and compared based on the timing of surgery, with the early surgery (ES) group treated ≤12 months after BCLM diagnosis, and late surgery (LS) group operated >12 months after diagnosis.

RESULTS

Seventy-two patients with BCLM underwent liver surgery, including 37 and 35 in the ES and LS groups, respectively. Demographic and preoperative characteristics were similar between the groups, except that multifocal liver disease was more frequent in the LS group (p = 0.008). The LS group had a morbidity rate of 38%, compared to 11% in the ES group (p = 0.015). No postoperative deaths occurred. In the whole cohort, median progression-free (PFS) and overall survival (OS) were 19 and 50 months, respectively, and 1-, 3- and 5-year PFS and OS were 63%, 41%, 24% and 93%, 66%, 43%, respectively, with no significant difference observed between the ES and LS groups. Multivariate analysis revealed that breast cancer progesterone receptor negativity (HR = 3.34, p = 0.03) and a size of LM > 40 mm (HR = 3.11, p = 0.01) were significant negative prognostic factors for PFS. Only a size of LM > 40 mm (HR = 2.79, p = 0.008) was significantly associated with shorter OS.

CONCLUSION

A prolonged preoperative observational period does not improve long-term outcomes after liver surgery in patients with resectable BCLM, suggesting that early management can safely be proposed to those patients, with good oncological outcomes.

Histological growth pattern as a potential marker of oligometastatic disease in patients operated for colorectal liver metastases

e15093

Background: The identification of oligometastatic profile in patients with resectable colorectal liver metastases (CRLM) would represent a major progress to improve selection for surgery. Currently, in the absence of biomarkers, the most reliable method to identify oligometastatic (OLM) and non-oligometastatic (NOLM) tumors relies on the oncological outcome after metastases-targeted surgery. The histological growth pattern (HGP) of CRLM, defined as desmoplastic (dHGP) or replacement (rHGP), has recently been shown to have prognostic value. We analyzed HGP in a series of patients operated for CRLM, characterized as OLM in case of prolonged postoperative recurrence-free survival (RFS) or NOLM in case of rapid postoperative relapse. Methods: In 357 patients operated for CRLM, we identified OLM patients as those with RFS≥5 years (N = 64), and NOLM patients as those with RFS < 1 year (N = 77). Clinicopathologic and surgical parameters were analyzed. In each CRLM, HGP was assessed in archival H&E stained tissue sections, according to international consensus guidelines. Proportions of rHGP and dHGP were determined in each metastasis. In case of multiple metastases, the mean HGP was calculated in each patient. Patients were categorized as pure (> 95% rHGP or dHGP) or dominant phenotypes (> 50% rHGP or dHGP, of the entire tumor-liver interface). Results: Preoperative characteristics of primary tumor and CRLM, and surgical data were identical in OLM and NOLM groups. In a first set of analyses, HGP was determined in 39 OLM and 52 NOLM patients. Pure dHGP was observed in 54.3% of OLM and 17.3% of NOLM patients (p = 0.001). Pure rHGP was similarly distributed among OLM and NOLM groups. Sixty-nine% of the OLM patients displayed a dHGP-dominant phenotype, whereas 57.7% of the NOLM patients presented with a rHGP-dominant phenotype (p = 0.02). Conclusions: These results confirm the potential prognostic value of HGP in patients operated for CRLM. dHGP, associated with angiogenesis and inflammation, could represent a (surrogate) marker for oligometastatic progression, whereas rHGP appears strongly associated with rapid postoperative relapse.

Previous bariatric surgery increases postoperative morbidity after sleeve gastrectomy for morbid obesity

OBJECTIVES

Sleeve gastrectomy (SG) has been used as the first step of a staged malabsorptive procedure for high-risk patients. More recently SG was proposed as an stand alone procedure in the treatment of morbidly obese patients. The aim of this study is to analyze perioperative outcome of morbid obese patients after SG.

METHODS

301 patients, 201 women and 100 men, undergoing SG were retrospectively analyzed. SG was performed by 17 surgeons all member of the Club Coelio. The mean BMI was 44.7kg/m2 (27.4-70.3 kg/m2). 34 patients (11.3%) of our series had SG as revisional surgery. These revisional procedures consisted of 32 conversions from gastric banding, 1 conversion from vertical gastroplasty (VBG) and 1 from transoral endoscopic gastroplasty. Among the 32 patients that had revisional SG after a gastric banding, 13 bands were removed at least 3 months before the revisional SG and 19 bands were removed during the SG procedure. Endpoints were perioperative morbidity and mortality and potential risk factors for complications, mainly per or postoperative bleeding or leakage.

RESULTS

Overall mortality was 0% and morbidity was 10.3%. Perioperative bleeding occurred in 10 patients (3.3%), leakage in 12 patients (4%) patients and stenosis in 3 patients (1%). The risk of leakage was significantly higher after revisional bariatric surgery and in case of gastric perforation during surgery (p = 0.0001). Previous gastric banding is also associated with a higher risk of postoperative bleeding (p = 0.0006).

CONCLUSIONS

SG can be safely performed but patients and surgeons must be aware of a higher risk of postoperative complications when SG is proposed as a revisional surgery.

Protective effect of quercetin on ischemia/reperfusion-induced gastric mucosal injury in rats

This study was designed to determine the gastroprotective properties of quercetin in ischemia/reperfusion-induced gastric mucosal injury and the involvement of endogenous prostaglandins in this process. Oral pretreatment of rats with quercetin (100 mg x kg(-1)) 30 min before surgery significantly decreased the length of gastric mucosal lesions. However, lower doses of quercetin (25 and 50 mg x kg(-1)) only slightly decreased the gastric mucosal injury. Intraperitoneal application of indomethacin (5 mg x kg(-1)) had no effect in control (sham-operated) animals, but significantly worsened gastric injury in non-treated animals after ischemia/reperfusion. Furthermore, indomethacin only slightly reversed protective effect of quercetin. Non-treated animals showed a marked decrease in adherent mucus after ischemia/reperfusion. On the other hand, application of quercetin prevented this significant decrease even in animals pretreated with indomethacin. It can be concluded that antioxidant properties of quercetin and its mucus protective effect might be the main factors responsible for its protective effect against ischemia/reperfusion-induced gastric mucosal injury.