Management of Established Small-for-size Syndrome in Post Living Donor Liver Transplantation: Medical, Radiological, and Surgical Interventions: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) following living donor liver transplantation is a complication that can lead to devastating outcomes such as prolonged poor graft function and possibly graft loss. Because of the concern about the syndrome, some transplants of mismatched grafts may not be performed. Portal hyperperfusion of a small graft and hyperdynamic splanchnic circulation are recognized as main pathogenic factors for the syndrome. Management of established SFSS is guided by the severity of the presentation with the initial focus on pharmacological therapy to modulate portal flow and provide supportive care to the patient with the goal of facilitating graft regeneration and recovery. When medical management fails or condition progresses with impending dysfunction or even liver failure, interventional radiology (IR) and/or surgical interventions to reduce portal overperfusion should be considered. Although most patients have good outcomes with medical, IR, and/or surgical management that allow graft regeneration, the risk of graft loss increases dramatically in the setting of bilirubin >10 mg/dL and INR>1.6 on postoperative day 7 or isolated bilirubin >20 mg/dL on postoperative day 14. Retransplantation should be considered based on the overall clinical situation and the above postoperative laboratory parameters. The following recommendations focus on medical and IR/surgical management of SFSS as well as considerations and timing of retransplantation when other therapies fail.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS).

METHODS

A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India.

RESULTS

It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion.

CONCLUSIONS

Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

HDR-based CRISPR/Cas9-mediated Knockout of PD-L1 in C57BL/6 Mice

The immune-inhibitory molecule programmed cell death ligand 1 (PD-L1) has been shown to play a role in pathologies such as autoimmunity, infections, and cancer. The expression of PD-L1 not only on cancer cells but also on non-transformed host cells is known to be associated with cancer progression. Generation of PD-L1 deficiency in the murine system enables us to specifically study the role of PD-L1 in physiological processes and diseases. One of the most versatile and easy to use site-specific gene editing tools is the CRISPR/Cas9 system, which is based on an RNA-guided nuclease system. Similar to its predecessors, the Zinc finger nucleases or transcription activator-like effector nucleases (TALENs), CRISPR/Cas9 catalyzes double-strand DNA breaks, which can result in frameshift mutations due to random nucleotide insertions or deletions via non-homologous end joining (NHEJ). Furthermore, although less frequently, CRISPR/Cas9 can lead to insertion of defined sequences due to homology-directed repair (HDR) in the presence of a suitable template. Here, we describe a protocol for the knockout of PD-L1 in the murine C57BL/6 background using CRISPR/Cas9. Targeting of exon 3 coupled with the insertion of a HindIII restriction site leads to a premature stop codon and a loss-of-function phenotype. We describe the targeting strategy as well as founder screening, genotyping, and phenotyping. In comparison to NHEJ-based strategy, the presented approach results in a defined stop codon with comparable efficiency and timelines as NHEJ, generates convenient founder screening and genotyping options, and can be swiftly adapted to other targets.

The value of intraoperative dynamic liver function test ICG in predicting postoperative complications in patients undergoing staged hepatectomy: a pilot study

PURPOSE

To assess the predictive value of intraoperative indocyanine green (ICG) test in patients undergoing staged hepatectomy.

METHODS

We analyzed intraoperative ICG measurements of future liver remnant (FLR), preoperative ICG, volumetry, and hepatobiliary scintigraphy in 15 patients undergoing associated liver partition and portal vein ligation for staged hepatectomy (ALPPS). Main endpoints were the correlation of intraoperative ICG values to postoperative complications (Comprehensive Complication Index (CCI®)) at discharge and 90 days after surgery, and to postoperative liver function.

RESULTS

Median intraoperative R15 (ICG retention rate at 15 min) correlated significantly with CCI® at discharge (p = 0.05) and with CCI® at 90 days (p = 0.0036). Preoperative ICG, volumetry, and scintigraphy did not correlate to postoperative outcome. ROC curve analysis revealed a cutoff value of 11.4 for the intraoperative R15 to predict major complications (Clavien-Dindo ≥ III) with 100% sensitivity and 63% specificity. No patient with R15 ≤ 11 developed major complications.

CONCLUSION

This pilot study suggests that intraoperative ICG clearance determines the functional capacity of the future liver remnant more accurately than preoperative tests. This may further reduce the number of postoperative liver failures, even if it means intraoperative abortion of hepatectomy in individual cases.

FOLFIRINOX or Gemcitabine-based Chemotherapy for Borderline Resectable and Locally Advanced Pancreatic Cancer: A Multi-institutional, Patient-Level, Meta-analysis and Systematic Review

BACKGROUND

Pancreatic cancer often presents as locally advanced (LAPC) or borderline resectable (BRPC). Neoadjuvant systemic therapy is recommended as initial treatment. It is currently unclear what chemotherapy should be preferred for patients with BRPC or LAPC.

METHODS

We performed a systematic review and multi-institutional meta-analysis of patient-level data regarding the use of initial systemic therapy for BRPC and LAPC. Outcomes were reported separately for tumor entity and by chemotherapy regimen including FOLFIRINOX (FIO) or gemcitabine-based.

RESULTS

A total of 23 studies comprising 2930 patients were analyzed for overall survival (OS) calculated from the beginning of systemic treatment. OS for patients with BRPC was 22.0 months with FIO, 16.9 months with gemcitabine/nab-paclitaxel (Gem/nab), 21.6 months with gemcitabine/cisplatin or oxaliplatin or docetaxel or capecitabine (GemX), and 10 months with gemcitabine monotherapy (Gem-mono) (p < 0.0001). In patients with LAPC, OS also was higher with FIO (17.1 months) compared with Gem/nab (12.5 months), GemX (12.3 months), and Gem-mono (9.4 months; p < 0.0001). This difference was driven by the patients who did not undergo surgery, where FIO was superior to other regimens. The resection rates for patients with BRPC were 0.55 for gemcitabine-based chemotherapy and 0.53 with FIO. In patients with LAPC, resection rates were 0.19 with Gemcitabine and 0.28 with FIO. In resected patients, OS for patients with BRPC was 32.9 months with FIO and not different compared to Gem/nab, (28.6 months, p = 0.285), GemX (38.8 months, p = 0.1), or Gem-mono (23.1 months, p = 0.083). A similar trend was observed in resected patients converted from LAPC.

CONCLUSIONS

In patients with BRPC or LAPC, primary treatment with FOLFIRINOX compared with Gemcitabine-based chemotherapy appears to provide a survival benefit for patients that are ultimately unresectable. For patients that undergo surgical resection, outcomes are similar between GEM+ and FOLFIRINOX when delivered in the neoadjuvant setting.

Are patients with hepatocellular carcinoma and portal vein tumour thrombosis candidates for liver transplantation?

In this debate, the authors consider whether patients with hepatocellular carcinoma (HCC) and portal vein tumour thrombosis are candidates for liver transplantation (LT). The argument for LT in this context is based on the premise that, following successful downstaging treatment, LT confers a much greater clinical benefit in terms of survival outcomes than the available alternative (palliative systemic therapy). A major argument against relates to limitations in the quality of evidence for LT in this setting - in relation to study design, as well as heterogeneity in patient characteristics and downstaging protocols. While acknowledging the superior outcomes offered by LT for patients with portal vein tumour thrombosis, the counterargument is that expected survival in such patients is still below accepted thresholds for LT and, indeed, the levels achieved for other patients who receive transplants beyond the Milan criteria. Based on the available evidence, it seems too early for consensus guidelines to recommend such an approach, however, it is hoped that with higher quality evidence and standardised downstaging protocols, LT may soon be more widely indicated, including for this population with high unmet clinical need.

Controversy Over Liver Transplantation or Resection for Neuroendocrine Liver Metastasis: Tumor Biology Cuts the Deal

BACKGROUND

In patients with neuroendocrine liver metastasis (NELM), liver transplantation (LT) is an alternative to liver resection (LR), although the choice of therapy remains controversial. In this multicenter study, we aim to provide novel insight in this dispute.

METHODS

Following a systematic literature search, 15 large international centers were contacted to provide comprehensive data on their patients after LR or LT for NELM. Survival analyses were performed with the Kaplan-Meier method, while multivariable Cox regression served to identify factors influencing survival after either transplantation or resection. Inverse probability weighting and propensity score matching was used for analyses with balanced and equalized baseline characteristics.

RESULTS

Overall, 455 patients were analyzed, including 230 after LR and 225 after LT, with a median follow-up of 97 months [95% confidence interval (CI): 85-110 months]. Multivariable analysis revealed G3 grading as a negative prognostic factor for LR [hazard ratio (HR)=2.22, 95% CI: 1.04-4.77, P =0.040], while G2 grading (HR=2.52, 95% CI: 1.15-5.52, P =0.021) and LT outside Milan criteria (HR=2.40, 95% CI: 1.16-4.92, P =0.018) were negative prognostic factors in transplanted patients. Inverse probability-weighted multivariate analyses revealed a distinct survival benefit after LT. Matched patients presented a median overall survival (OS) of 197 months (95% CI: 143-not reached) and a 73% 5-year OS after LT, and 119 months (95% CI: 74-133 months) and a 52.8% 5-year OS after LR (HR=0.59, 95% CI: 0.3-0.9, P =0.022). However, the survival benefit after LT was lost if patients were transplanted outside Milan criteria.

CONCLUSIONS

This multicentric study in patients with NELM demonstrates a survival benefit of LT over LR. This benefit depends on adherence to selection criteria, in particular low-grade tumor biology and Milan criteria, and must be balanced against potential risks of LT.

An International Expert Delphi Consensus on Defining Textbook Outcome in Liver Surgery (TOLS)

OBJECTIVE

To reach global expert consensus on the definition of TOLS in minimally invasive and open liver resection among renowned international expert liver surgeons using a modified Delphi method.

BACKGROUND

Textbook outcome is a novel composite measure combining the most desirable postoperative outcomes into one single measure and representing the ideal postoperative course. Despite a recently developed international definition of Textbook Outcome in Liver Surgery (TOLS), a standardized and expert consensus-based definition is lacking.

METHODS

This international, consensus-based, qualitative study used a Delphi process to achieve consensus on the definition of TOLS. The survey comprised 6 surgical domains with a total of 26 questions on individual surgical outcome variables. The process included 4 rounds of online questionnaires. Consensus was achieved when a threshold of at least 80% agreement was reached. The results from the Delphi rounds were used to establish an international definition of TOLS.

RESULTS

In total, 44 expert liver surgeons from 22 countries and all 3 major international hepato-pancreato-biliary associations completed round 1. Forty-two (96%), 41 (98%), and 41 (98%) of the experts participated in round 2, 3, and 4, respectively. The TOLS definition derived from the consensus process included the absence of intraoperative grade ≥2 incidents, postoperative bile leakage grade B/C, postoperative liver failure grade B/C, 90-day major postoperative complications, 90-day readmission due to surgery-related major complications, 90-day/in-hospital mortality, and the presence of R0 resection margin.

CONCLUSIONS

This is the first study providing an international expert consensus-based definition of TOLS for minimally invasive and open liver resections by the use of a formal Delphi consensus approach. TOLS may be useful in assessing patient-level hospital performance and carrying out international comparisons between centers with different clinical practices to further improve patient outcomes.

A randomized-controlled trial of ischemia-free liver transplantation for end-stage liver disease

BACKGROUND & AIMS

Ischemia-reperfusion injury (IRI) has thus far been considered as an inevitable component of organ transplantation, compromising outcomes, and limiting organ availability. Ischemia-free organ transplantation is a novel approach designed to avoid IRI, with the potential to improve outcomes.

METHODS

In this randomized, controlled clinical trial, recipients of livers from donors after brain death were randomly assigned to receive either an ischemia-free or a 'conventional' transplant. Primary end point was the incidence of early allograft dysfunction. Secondary end points included complications related to graft IRI.

RESULTS

65 out of 68 randomized patients underwent transplants and were included in the analysis. 32 patients received ischemia-free liver transplantation (IFLT), and 33 received conventional liver transplantation (CLT). Early allograft dysfunction occurred in 2 (6%) randomized to IFLT and in 8 (24%) randomized to CLT (difference, -18%; 95% CI, -35% to -1%; P=.044). Post-reperfusion syndrome occurred in 3 (9%) randomized to IFLT and in 21 (64%) randomized to CLT (difference, -54%; 95% CI, -74% to -35%; P < .001). Non-anastomotic biliary strictures diagnosed with protocol magnetic resonance cholangiopancreatography at 12 months were observed in 2 recipients (8%) randomized to IFLT and in 9 recipients (36%) randomized to CLT (difference, -28%; 95% CI, -50% to -7%; P = .014). The comprehensive complication index at one year after transplantation was 30.48 (95% CI, 23.25-37.71) in the IFLT group vs 42.14 (95% CI, 35.01-49.26) in the CLT group (difference, -11.66; 95% CI, -21.81 to -1.51; P = .025).

CONCLUSIONS

Among patients with end-stage liver disease, IFLT, compared with conventional approach, significantly reduced complications related to ischemia reperfusion injury.

CLINICAL TRIAL REGISTRATION

Chictr.org. ChiCTR1900021158 IMPACT AND IMPLICATIONS: Ischemia reperfusion injury has thus far been considered as an inevitable event in organ transplantation, compromising outcomes and limiting organ availability. Ischemia-free liver transplantation is a novel approach of transplanting donor livers without interruption of blood supply. We showed that in patients with end-stage liver disease, ischemia-free liver transplantation, compared with conventional approach led to reduced complications related to ischemia reperfusion injury in this randomized trial. This new approach is expected to change the current practice in organ transplantation improving transplant outcomes, increasing organ utilization, while providing a clinical model to delineate the impact of organ injury on alloimmunity.

Surgical Approach, Challenges, and Resolutions for Uterus Transplantation in Rats

Uterine transplantation (UTx) is a new approach for treating women with absolute uterine factor infertility (AUFI). An estimated 3%-5% of women suffer from AUFI. These women were deprived of the option to have children until the advent of UTx. The clinical application of UTx was driven by experimental studies in animals, and the first successful UTx was achieved in rats. Given their physiological, immunological, genetic, and reproductive characteristics, rats are a suitable model system for such transplants. In particular, their short gestation period is a clear advantage, as the usual endpoint of experimental UTx is successful pregnancy with live birth. The biggest challenge for rat models remains the small anatomy, which requires advanced microsurgical skills and experience. Although UTx has led to pregnancy in the clinic, the procedure is not established and requires continuous experimental optimization. Here, a detailed protocol is presented, including essential troubleshooting for rat UTx, which is expected to make the entire procedure easier to grasp for those without experience in this type of microsurgery.

Right-sided ALPPS after preoperative emergency embolization of the right hepatic artery: case report with a favorable anatomy

In patients with extensive colorectal liver metastases (CRLM) and insufficient future liver remnant (FLR) a faster and more effective FLR augmentation than portal vein embolization is the associating liver partition and portal vein ligation in staged hepatectomy (ALPPS). Before ALPPS, the presence of arterial blood supply to the subsequently resected hemiliver must be ensured. We present a case with neoadjuvant-treated CRLM and insufficient FLR who developed a large intrahepatic hematoma after liver biopsy. For continuous bleeding, the right hepatic artery was embolized. Fortunately, an accessory right hepatic artery arising from the superior mesenteric artery was present, which enabled the ALPPS procedure to be performed. After ALPPS, the patient did not experience liver failure. The case exemplifies that preoperative evaluation of the vascular supply of the liver is of paramount importance in advanced hepatic surgery such as ALPPS.

A multicenter randomized-controlled trial of hypothermic oxygenated perfusion (HOPE) for human liver grafts before transplantation

BACKGROUND & AIMS

Machine perfusion is a novel method intended to optimize livers before transplantation. However, its effect on morbidity within a 1-year period after transplantation has remained unclear.

METHODS

In this multicenter controlled trial, we randomly assigned livers donated after brain death (DBD) for liver transplantation (LT). Livers were either conventionally cold stored (control group), or cold stored and subsequently treated by 1-2 h hypothermic oxygenated perfusion (HOPE) before implantation (HOPE group). The primary endpoint was the occurrence of at least one post-transplant complication per patient, graded by the Clavien score of ≥III, within 1-year after LT. The comprehensive complication index (CCI), laboratory parameters, as well as duration of hospital and intensive care unit stay, graft survival, patient survival, and biliary complications served as secondary endpoints.

RESULTS

Between April 2015 and August 2019, we randomized 177 livers, resulting in 170 liver transplantations (85 in the HOPE group and 85 in the control group). The number of patients with at least one Clavien ≥III complication was 46/85 (54.1%) in the control group and 44/85 (51.8%) in the HOPE group (odds ratio 0.91; 95% CI 0.50-1.66; p = 0.76). Secondary endpoints were also not significantly different between groups. A post hoc analysis revealed that liver-related Clavien ≥IIIb complications occurred less frequently in the HOPE group compared to the control group (risk ratio 0.26; 95% CI 0.07-0.77; p = 0.027). Likewise, graft failure due to liver-related complications did not occur in the HOPE group, but occurred in 7% (6 of 85) of the control group (log-rank test, p = 0.004, Gray test, p = 0.015).

CONCLUSIONS

HOPE after cold storage of DBD livers resulted in similar proportions of patients with at least one Clavien ≥III complication compared to controls. Exploratory findings suggest that HOPE decreases the risk of severe liver graft-related events.

IMPACT AND IMPLICATIONS

This randomized controlled phase III trial is the first to investigate the impact of hypothermic oxygenated perfusion (HOPE) on cumulative complications within a 12-month period after liver transplantation. Compared to conventional cold storage, HOPE did not have a significant effect on the number of patients with at least one Clavien ≥III complication. However, we believe that HOPE may have a beneficial effect on the quantity of complications per patient, based on its application leading to fewer severe liver graft-related complications, and to a lower risk of liver-related graft loss. The HOPE approach can be applied easily after organ transport during recipient hepatectomy. This appears fundamental for wide acceptance since concurring perfusion technologies need either perfusion at donor sites or continuous perfusion during organ transport, which are much costlier and more laborious. We conclude therefore that the post hoc findings of this trial should be further validated in future studies.

Consensus recommendations on how to assess the quality of surgical interventions

Postoperative complications represent a major public health burden worldwide. Without standardized, clinically relevant and universally applied endpoints, the evaluation of surgical interventions remains ill-defined and inconsistent, opening the door for biased interpretations and hampering patient-centered health care delivery. We conducted a Jury-based consensus conference incorporating the perspectives of different stakeholders, who based their recommendations on the work of nine panels of experts. The recommendations cover the selection of postoperative outcomes from the perspective of patients and other stakeholders, comparison and interpretation of outcomes, consideration of cultural and demographic factors, and strategies to deal with unwarranted outcomes. With the recommendations developed exclusively by the Jury, we provide a framework for surgical outcome assessment and quality improvement after medical interventions, that integrates the main stakeholders' perspectives.

Delivering Safe Surgical Care While Simultaneously Caring for Patients With COVID-19; Assessment of Patient Selection, Volume and Outcomes in a Tertiary Care Hospital

Objectives: Compare patient selection and postoperative outcomes after surgical treatment for gastrointestinal disorders before and during the SARS-CoV-2 pandemic.

Methods: We assessed gastrointestinal surgeries conducted at a tertiary center from 2017–2021 for differences in patient populations and procedures before (up to February 2020) and during the pandemic (March 2020 to December 2021). We analyzed mortality, Intensive Care Unit (ICU) length of stay, admission to ICU and postoperative complications for complex procedures using descriptive statistics and regression models.

Results: 7309 procedures were analyzed, showing a caseload reduction in March and October 2020, but no statistical evidence for fewer overall procedures overall. Population characteristics differed with lower Body Mass Indices in 2020 and 2021, more patients smoking and with diabetes treated in 2020. There was no increased mortality, ICU length of stay and in 1,144 complex procedures assessed low overall morbidity at 90 days postoperative.

Conclusion: Delivering surgical care while treating patients for COVID-19 in the same hospital was safe. Healthcare officials should consider continuing surgical care during future health crises as consequences of limiting surgical treatment for gastrointestinal disorders may be fatal for patients.

Revival of associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma: An international multicenter study with promising outcomes

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma has been considered to be contraindicated due to the initial poor results. Given the recent reports of improved outcomes, we aimed to collect the recent experiences of different centers performing associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma to analyze factors related to improved outcomes.

METHODS

This proof-of-concept study collected contemporary cases of associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma and analyzed for morbidity, short and long-term survival, and factors associated with outcomes.

RESULTS

In total, 39 patients from 8 centers underwent associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma from 2010 to 2020. The median preoperative future liver remnant volume was 323 mL (155-460 mL). The median future liver remnant increase was 58.7% (8.9% -264.5%) with a median interstage interval of 13 days (6-60 days). Post-stage 1 and post-stage 2 biliary leaks occurred in 2 (7.7%) and 4 (15%) patients. Six patients (23%) after stage 1 and 6 (23%) after stage 2 experienced grade 3 or higher complications. Two patients (7.7%) died within 90 days after stage 2. The 1-, 3-, and 5-year survival was 92%, 69%, and 55%, respectively. A subgroup analysis revealed poor survival for patients undergoing additional vascular resection and lymph node positivity. Lymph node-negative patients showed excellent survival demonstrated by 1-, 3-, and 5-year survival of 86%, 86%, and 86%.

CONCLUSION

This study highlights that the critical attitude toward associating liver partition and portal vein ligation for staged hepatectomy for perihilar cholangiocarcinoma needs to be revised. In selected patients with perihilar cholangiocarcinoma, associating liver partition and portal vein ligation for staged hepatectomy can achieve favorable survival that compares to the outcome of established surgical treatment strategies reported in benchmark studies for perihilar cholangiocarcinoma including 1-stage hepatectomy and liver transplantation.

Implementation and validation of a novel instrument for the grading of unexpected events in paediatric surgery: Clavien-Madadi classification

BACKGROUND

Inconsistent definitions of complications and unexpected events have limited accurate analysis of surgical outcomes. Perioperative outcome classifications currently used for adult patients have limitations when used for children.

METHODS

A multidisciplinary group of experts modified the Clavien-Dindo classification to increase its utility and accuracy in paediatric surgery cohorts. Organizational and management errors were considered in the novel Clavien-Madadi classification, which focuses on procedural invasiveness rather than anaesthetic management. Unexpected events were prospectively documented in a paediatric surgery cohort. Results of the Clavien-Dindo and Clavien-Madadi classifications were compared and correlated with procedure complexity.

RESULTS

Unexpected events were prospectively documented in a cohort of 17 502 children undergoing surgery between 2017 and 2021. The results of both classifications were highly correlated (ρ = 0.95), although the novel Clavien-Madadi classification identified 449 additional events (organizational and management errors) over the Clavien-Dindo classification, increasing the total number of events by 38 per cent (1605 versus 1158 events). The results of the novel system correlated significantly with the complexity of procedures in children (ρ = 0.756). Furthermore, grading of events > grade III according to the Clavien-Madadi classification showed a higher correlation with procedure complexity (ρ = 0.658) than the Clavien-Dindo classification (ρ = 0.198).

CONCLUSION

The Clavien-Madadi classification is a tool for the detection of surgical and non-medical errors in paediatric surgery populations. Further validation in paediatric surgery populations is required before widespread use.

Hypoxia, a Targetable Culprit to Counter Pancreatic Cancer Resistance to Therapy

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, and it is a disease of dismal prognosis. While immunotherapy has revolutionized the treatment of various solid tumors, it has achieved little success in PDAC. Hypoxia within the stroma-rich tumor microenvironment is associated with resistance to therapies and promotes angiogenesis, giving rise to a chaotic and leaky vasculature that is inefficient at shuttling oxygen and nutrients. Hypoxia and its downstream effectors have been implicated in immune resistance and could be contributing to the lack of response to immunotherapy experienced by patients with PDAC. Paradoxically, increasing evidence has shown hypoxia to augment genomic instability and mutagenesis in cancer, suggesting that hypoxic tumor cells could have increased production of neoantigens that can potentially enable their clearance by cytotoxic immune cells. Strategies aimed at relieving this condition have been on the rise, and one such approach opts for normalizing the tumor vasculature to reverse hypoxia and its downstream support of tumor pathogenesis. An important consideration for the successful implementation of such strategies in the clinic is that not all PDACs are equally hypoxic, therefore hypoxia-detection approaches should be integrated to enable optimal patient selection for achieving improved patient outcomes.

Normalization of lipid oxidation defects arising from hypoxia early posthepatectomy prevents liver failure in mouse

Surgical liver failure (SLF) develops when a marginal amount of hepatic mass is left after surgery, such as following excessive resection. SLF is the commonest cause of death due to liver surgery; however, its etiology remains obscure. Using mouse models of standard hepatectomy (sHx) (68%, resulting in full regeneration) or extended hepatectomy (eHx) (86%/91%, causing SLF), we explored the causes of early SLF related to portal hyperafflux. Assessing the levels of HIF2A with or without oxygenating agent inositol trispyrophosphate (ITPP) indicated hypoxia early after eHx. Subsequently, lipid oxidation (PPARA/PGC1α) was downregulated and associated with persisting steatosis. Mild oxidation with low-dose ITPP reduced the levels of HIF2A, restored downstream PPARA/PGC1α expression along with lipid oxidation activities (LOAs), and normalized steatosis and other metabolic or regenerative SLF deficiencies. Promotion of LOA with L-carnitine likewise normalized the SLF phenotype, and both ITPP and L-carnitine markedly raised survival in lethal SLF. In patients who underwent hepatectomy, pronounced increases in serum carnitine levels (reflecting LOA) were associated with better recovery. Lipid oxidation thus provides a link between the hyperafflux of O₂-poor portal blood, the metabolic/regenerative deficits, and the increased mortality typifying SLF. Stimulation of lipid oxidation-the prime regenerative energy source-particularly through L-carnitine may offer a safe and feasible way to reduce SLF risks in the clinic.

Observations and findings during the development of a subnormothermic/normothermic long-term ex vivo liver perfusion machine

BACKGROUND

Ex situliver machine perfusion at subnormothermic/normothermic temperature isincreasingly applied in the field of transplantation to store and evaluateorgans on the machine prior transplantation. Currently, various perfusionconcepts are in clinical and preclinical applications. Over the last 6 years ina multidisciplinary team, a novel blood based perfusion technology wasdeveloped to keep a liver alive and metabolically active outside of the bodyfor at least one week.

METHODS

Within thismanuscript, we present and compare three scenarios (Group 1, 2 and 3) we werefacing during our research and development (R&D) process, mainly linked tothe measurement of free hemoglobin and lactate in the blood based perfusate. Apartfrom their proven value in liver viability assessment (ex situ), these twoparameters are also helpful in R&D of a long-term liver perfusion machine and moreover supportive in the biomedical engineering process.

RESULTS

Group 1 ("good" liver on the perfusion machine) represents the best liver clearance capacity for lactate and free hemoglobin wehave observed. In contrast to Group 2 ("poor" liver on the perfusion machine), that has shown the worst clearance capacity for free hemoglobin. Astonishingly,also for Group 2, lactate is cleared till the first day of perfusion andafterwards, rising lactate values are detected due to the poor quality of theliver. These two perfusate parametersclearly highlight the impact of the organ quality/viability on the perfusion process. Whereas Group 3 is a perfusion utilizing a blood loop only (without a liver).

CONCLUSION

Knowing the feasible ranges (upper- and lower bound) and the courseover time of free hemoglobin and lactate is helpful to evaluate the quality ofthe organ perfusion itself and the maturity of the developed perfusion device. Freehemoglobin in the perfusate is linked to the rate of hemolysis that indicates how optimizing (gentle blood handling, minimizing hemolysis) the perfusion machine actually is. Generally, a reduced lactate clearancecapacity can be an indication for technical problems linked to the blood supplyof the liver and therefore helps to monitor the perfusion experiments.Moreover, the possibility is given to compare, evaluate and optimize developed liverperfusion systems based on the given ranges for these two parameters. Otherresearch groups can compare/quantify their perfusate (blood) parameters withthe ones in this manuscript. The presented data, findings and recommendations willfinally support other researchers in developing their own perfusion machine ormodifying commercially availableperfusion devices according to their needs.

Safety and Efficacy of Robotic vs Open Liver Resection for Hepatocellular Carcinoma

Importance

Long-term oncologic outcomes of robotic surgery remain a hotly debated topic in surgical oncology, but sparse data have been published thus far.

Objective

To analyze short- and long-term outcomes of robotic liver resection (RLR) for hepatocellular carcinoma (HCC) from Western high-volume centers to assess the safety, reproducibility, and oncologic efficacy of this technique.

Design, Setting, and Participants

This cohort study evaluated the outcomes of patients receiving RLR vs open liver resection (OLR) for HCC between 2010 and 2020 in 5 high-volume centers. After 1:1 propensity score matching, a group of patients who underwent RLR was compared with a validation cohort of OLR patients from a high-volume center that did not perform RLR.

Main Outcomes and Measures

A retrospective analysis was performed of prospectively maintained databases at 2 European and 2 US institutions of patients who underwent RLR for HCC between January 1, 2010, and September 30, 2020. The main outcomes were safety and feasibility of RLR for HCC and its oncologic outcomes compared with a European OLR validation cohort. A 2-sided P < .05 was considered significant.

Results

The study included 398 patients (RLR group: 125 men, 33 women, median [IQR] age, 66 [58-71] years; OLR group: 315 men, 83 women; median [IQR] age, 70 [64-74] years), and 106 RLR patients were compared with 106 OLR patients after propensity score matching. The RLR patients had a significantly longer operative time (median [IQR], 295 [190-370] minutes vs 200 [165-255] minutes, including docking; P < .001) but a significantly shorter hospital length of stay (median [IQR], 4 [3-6] days vs 10 [7-13] days; P < .001) and a lower number of admissions to the intensive care unit (7 [6.6%] vs 21 [19.8%]; P = .002). Incidence of posthepatectomy liver failure was significantly lower in the RLR group (8 [7.5%] vs 30 [28.3%]; P = .001), with no cases of grade C failure. The 90-day overall survival rate was comparable between the 2 groups (RLR, 99.1% [95% CI, 93.5%-99.9%]; OLR, 97.1% [95% CI, 91.3%-99.1%]), as was the cumulative incidence of death related to tumor recurrence (RLR, 8.8% [95% CI, 3.1%-18.3%]; OLR, 10.2% [95% CI, 4.9%-17.7%]).

Conclusions and Relevance

This study represents the largest Western experience to date of full RLR for HCC. Compared with OLR, RLR performed in tertiary centers represents a safe treatment strategy for patients with HCC and those with compromised liver function while achieving oncologic efficacy.