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.

Benchmarks in colorectal surgery: multinational study to define quality thresholds in high and low anterior resection

BACKGROUND

Benchmark comparisons in surgery allow identification of gaps in the quality of care provided. The aim of this study was to determine quality thresholds for high (HAR) and low (LAR) anterior resections in colorectal cancer surgery by applying the concept of benchmarking.

METHODS

This 5-year multinational retrospective study included patients who underwent anterior resection for cancer in 19 high-volume centres on five continents. Benchmarks were defined for 11 relevant postoperative variables at discharge, 3 months, and 6 months (for LAR). Benchmarks were calculated for two separate cohorts: patients without (ideal) and those with (non-ideal) outcome-relevant co-morbidities. Benchmark cut-offs were defined as the 75th percentile of each centre's median value.

RESULTS

A total of 3903 patients who underwent HAR and 3726 who had LAR for cancer were analysed. After 3 months' follow-up, the mortality benchmark in HAR for ideal and non-ideal patients was 0.0 versus 3.0 per cent, and in LAR it was 0.0 versus 2.2 per cent. Benchmark results for anastomotic leakage were 5.0 versus 6.9 per cent for HAR, and 13.6 versus 11.8 per cent for LAR. The overall morbidity benchmark in HAR was a Comprehensive Complication Index (CCI®) score of 8.6 versus 14.7, and that for LAR was CCI® score 11.9 versus 18.3.

CONCLUSION

Regular comparison of individual-surgeon or -unit outcome data against benchmark thresholds may identify gaps in care quality that can improve patient outcome.

Transplantation of a human liver following 3 days of ex situ normothermic preservation

Current organ preservation methods provide a narrow window (usually <12 hours) to assess, transport and implant donor grafts for human transplantation. Here we report the transplantation of a human liver discarded by all centers, which could be preserved for several days using ex situ normothermic machine perfusion. The transplanted liver exhibited normal function, with minimal reperfusion injury and the need for only a minimal immunosuppressive regimen. The patient rapidly recovered a normal quality of life without any signs of liver damage, such as rejection or injury to the bile ducts, according to a 1-year follow up. This inaugural clinical success opens new horizons in clinical research and promises an extended time window of up to 10 days for assessment of viability of donor organs as well as converting an urgent and highly demanding surgery into an elective procedure.

Machine perfusion in liver transplantation

Although liver transplantation is a true success story, many patients still die awaiting an organ. The increasing need for liver grafts therefore remains an unsolved challenge to the transplant community. To address this, transplant donor criteria have been expanded and, for example, more liver grafts with significant steatosis or from donors with circulatory death are being used. These marginal grafts, however, carry an increased risk of graft-associated complications, such as primary nonfunction, delayed graft function, or late biliary injuries. Therefore, reliable assessment of graft viability before use is essential for further success. To achieve this, machine liver perfusion, a procedure developed more than 50 years ago but almost forgotten at the end of the last century, is again of great interest. We describe in this review the clinical most applied machine perfusion techniques, their mechanistic background, and a novel concept of combining immediate organ assessment during hypothermic oxygenated perfusion, followed by an extended phase of normothermic machine perfusion, with simultaneous ex situ treatment of the perfused liver. Such a new approach may allow the pool of usable livers to dramatically increase and improve outcomes for recipients.

The essential requirements for an HPB centre to deliver high-quality outcomes

The concept of a centre approach to the treatment of patients with complex disorders, such as those with hepato-pancreato-biliary (HPB) diseases, is widely applied, although what is needed for an HPB centre to achieve high-quality outcomes remains unclear. We therefore conducted a literature review, which highlighted the paucity of information linking centre structure or process to outcome data outside of caseloads, specialisation, and quality of training. We then conducted an international survey among the largest 107 HPB centres with experts in HPB surgery and found that most responders work in 'virtual' HPB centres without dedicated space, assigned beds, nor personal. We finally analysed our experience with the Swiss HPB centre, previously reported in this journal 15 years ago, disclosing that budget priorities set by the hospital administration may prevent the development of a fully integrated centre, for example through inconsistent assignment of the centre's beds to HBP patients or removal of dedicated intermediate care beds. We propose criteria for essential requirements for an HPB centre to deliver high-quality outcomes, with the concept of "centre of reference" limited to actual, as opposed to virtual, centres.

Vascular injury during cholecystectomy: A multicenter critical analysis behind the drama

BACKGROUND

The management of a vascular injury during cholecystectomy is still very complicated, especially in centers not specialized in complex hepatobiliary surgery.

METHODS

This was a multi-institutional retrospective study in patients with vascular injuries during cholecystectomy from 18 centers in 4 countries. The aim of the study was to analyze the management of vascular injuries focusing on referral, time to perform the repair, and different treatments options outcomes.

RESULTS

A total of 104 patients were included. Twenty-nine patients underwent vascular repair (27.9%), 13 (12.5%) liver resection, and 1 liver transplant as a first treatment. Eighty-four (80.4%) vascular and biliary injuries occurred in nonspecialized centers and 45 (53.6%) were immediately transferred. Intraoperative diagnosed injuries were rare in referred patients (18% vs 84%, P = .001). The patients managed at the hospital where the injury occurred had a higher number of reoperations (64% vs 20%, P ˂ .001). The need for vascular reconstruction was associated with higher mortality (P = .04). Two of the 4 patients transplanted died.

CONCLUSION

Vascular lesions during cholecystectomy are a potentially life-threatening complication. Management of referral to specialized centers to perform multiple complex multidisciplinary procedures should be mandatory. Late vascular repair has not shown to be associated with worse results.

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.

How to Establish Benchmarks for Surgical Outcomes?: A Checklist Based on an International Expert Delphi Consensus

OBJECTIVE

To define a standardized methodology for establishing benchmarks for relevant outcomes in surgery.

SUMMARY BACKGROUND DATA

Benchmarking is an established tool to improve quality in industry and economics, and is emerging in assessing outcome values in surgery. Despite a recent 10-step approach to identify such benchmark values, a standardized and more widely agreed-on approach is still lacking.

METHODS

A multinational web-based Delphi survey with a focus on methodological requirements for establishing benchmarks for surgical outcomes was performed. Participants were selected among internationally renowned specialists in abdominal, vascular, and thoracic surgery. Consensus was defined as ≥70% agreement and results were used to develop a checklist to establish benchmarks in surgery.

RESULTS

Forty-one surgical opinion leaders from 19 countries and 5 continents were involved. Experts' response rates were 98% and 80% in rounds 1 and 2, respectively. Upon completion of the final Delphi round, consensus was successfully achieved for 26 of 36 items covering the following areas: center eligibility, validation of databases, patient cohort selection, procedure selection, duration of follow-up, statistical analysis, and publication requirements regarding center-specific outcomes.

CONCLUSIONS

This multinational Delphi survey represents the first expert-led process for developing a standardized approach for establishing benchmarks for relevant outcome measures in surgery. The provided consensual checklist customizes the methodology of outcome reporting in surgery and thus improves reproducibility and comparability of data and should ultimately serve to improve quality of care.

Long-term outcomes of transplant kidneys donated after circulatory death

BACKGROUND

Donation after circulatory determination of death (DCD) represents up to 40% of used kidney grafts. While studies have shown similar outcome compared to donation after brain death (DBD) on the short- and mid-term, no data on long-term outcomes exist.

METHODS

We retrospectively analyzed patients transplanted at our institution between January 1985 and March 2000. All DCD recipients were matched one-to-one with patients transplanted with DBD grafts during this period according to sex, age, and year of transplantation, and followed-up until December 2020. During this period, 1133 kidney transplantations were performed, 122 of which with a DCD graft.

RESULTS

Median graft survival after 35-years follow-up was 23 years (277 months; CI 182 -372) in DBD, and 24.5 years (289 months; CI 245 - 333) in DCD (P = 0.65; HR = 0.91). Delayed graft function occurred in 47 patients in the DCD group compared to 23 in the DBD group (P < 0.001), albeit without significant long-term outcome difference in graft or patient survival. We could not show any difference in graft function, in terms of creatinine levels (133 µmol/l vs. 119 µmol/l), proteinuria (370 mg/24h vs. 240 mg/24h), nor GFR slope (-0.6 ml/min/year vs. -0.3 ml/min/year) between the two groups for grafts surviving more than 20 years.

CONCLUSIONS

This is the first study to show similar graft survival and function in DCD kidneys compared to DBD after 35 years follow-up. DCD grafts are a valuable resource and can be utilized in the same way as DBD grafts.

Neoadjuvant Therapy for Resectable Pancreatic Cancer: A New Standard of Care. Pooled Data From 3 Randomized Controlled Trials

OBJECTIVE

The aim of this study was to pool data from randomized controlled trials (RCT) limited to resectable pancreatic ductal adenocarcinoma (PDAC) to determine whether a neoadjuvant therapy impacts on disease-free survival (DFS) and surgical outcome.

SUMMARY BACKGROUND DATA

Few underpowered studies have suggested benefits from neoadjuvant chemo (± radiation) for strictly resectable PDAC without offering conclusive recommendations.

METHODS

Three RCTs were identified comparing neoadjuvant chemo (± radio) therapy vs. upfront surgery followed by adjuvant therapy in all cases. Data were pooled targeting DFS as primary endpoint, whereas overall survival (OS), postoperative morbidity, and mortality were investigated as secondary endpoints. Survival endpoints DFS and OS were compared using Cox proportional hazards regression with study-specific baseline hazards.

RESULTS

A total of 130 patients were randomized (56 in the neoadjuvant and 74 in the control group). DFS was significantly longer in the neoadjuvant treatment group compared to surgery only [hazard ratio (HR) 0.6, 95% confidence interval (CI) 0.4-0.9] (P = 0.01). Furthermore, DFS for the subgroup of R0 resections was similarly longer in the neoadjuvant treated group (HR 0.6, 95% CI 0.35-0.9, P = 0.045). Although postoperative complications (Comprehensive Complication Index, CCI®) occurred less frequently (P = 0.008), patients after neoadjuvant therapy experienced a higher toxicity, but without negative impact on oncological or surgical outcome parameters.

CONCLUSION

Neoadjuvant therapy can be offered as an acceptable standard of care for patients with purely resectable PDAC. Future research with the advances of precision oncology should now focus on the definition of the optimal regimen.

Defining Global Benchmarks in Elective Secondary Bariatric Surgery Comprising Conversional, Revisional, and Reversal Procedures

OBJECTIVE

To define "best possible" outcomes for secondary bariatric surgery (BS).

BACKGROUND

Management of poor response and of long-term complications after BS is complex and under-investigated. Indications and types of reoperations vary widely and postoperative complication rates are higher compared to primary BS.

METHODS

Out of 44,884 BS performed in 18 high-volume centers from 4 continents between 06/2013-05/2019, 5,349 (12%) secondary BS cases were identified. Twenty-one outcome benchmarks were established in low-risk patients, defined as the 75th percentile of the median outcome values of centers. Benchmark cases had no previous laparotomy, diabetes, sleep apnea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, thromboembolic events, BMI> 50 kg/m2 or age> 65 years.

RESULTS

The benchmark cohort included 3143 cases, mainly females (85%), aged 43.8 ± 10 years, 8.4 ± 5.3 years after primary BS, with a BMI 35.2 ± 7 kg/m2. Main indications were insufficient weight loss (43%) and gastro-esophageal reflux disease/dysphagia (25%). 90-days postoperatively, 14.6% of benchmark patients presented ≥1 complication, mortality was 0.06% (n = 2). Significantly higher morbidity was observed in non-benchmark cases (OR 1.37) and after conversional/reversal or revisional procedures with gastrointestinal suture/stapling (OR 1.84). Benchmark cutoffs for conversional BS were ≤4.5% re-intervention, ≤8.3% re-operation 90-days postoperatively. At 2-years (IQR 1-3) 15.6% of benchmark patients required a reoperation.

CONCLUSION

Secondary BS is safe, although postoperative morbidity exceeds the established benchmarks for primary BS. The excess morbidity is due to an increased risk of gastrointestinal leakage and higher need for intensive care. The considerable rate of tertiary BS warrants expertise and future research to optimize the management of non-success after BS.

Normal width of the linea alba, prevalence, and risk factors for diastasis recti abdominis in adults, a cross-sectional study

Aim

The prevalence and definition of diastasis recti abdominis (DRA) is under debate. This retrospective cross-sectional study evaluated the interrectal distance and the prevalence of DRA in computed tomography (CT) in an asymptomatic population.

Materials and methods

Patients undergoing CT scans for suspected appendicitis or kidney stones from 01/2016 to 12/2018 were screened retrospectively to participate. A study population with equal distribution according to gender and age (18–90 years) was generated (n = 329 patients) and the interrectal distance was measured at six reference points.

Results

DRA (defined as > 2 cm at 3 cm above the umbilicus) was present in 57% of the population. The 80th percentile of the interrectal distance was 10 mm at the xiphoid (median 3 mm, 95% confidence interval (CI) 0–19 mm), 27 mm halfway from xiphoid to umbilicus (median 17 mm, 95% CI 0–39 mm), 34 mm at 3 cm above the umbilicus (median 22 mm, 95% CI 0–50 mm), 32 mm at the umbilicus (median 25 mm, 95% CI 0–45 mm), 25 mm at 2 cm below the umbilicus (median 14 mm, 95% CI 0–39 mm), and 4 mm halfway from umbilicus to pubic symphysis (median 0 mm, 95% CI 0–19 mm). In the multivariate analysis, higher age (p = 0.001), increased body mass index (p < 0.001), and parity (p < 0.037) were independent risk factors for DRA, while split xiphoid, tobacco abuse, and umbilical hernia were not.

Conclusion

The prevalence of DRA is much higher than commonly estimated (57%). The IRD 3 cm above the umbilicus may be considered normal up to 34 mm. To avoid over-treatment, the definition of DRA should be revised.

Repeated hepatectomy after ALPPS for recurrence of colorectal liver metastasis: the edge of limits?

BACKGROUND

Repeated liver resections for the recurrence of colorectal liver metastasis (CRLM) are described as safe and have similar oncological outcomes compared to first hepatectomy. Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is performed in patients with conventionally non-resectable CRLM. Repeated resections after ALPPS has not yet been described.

METHODS

Patients that underwent repeated liver resection in recurrence of CRLM after ALPPS were included in this study. The primary endpoint was morbidity and secondary endpoints were mortality, resection margin and survival.

RESULTS

Thirty patients were included in this study. During ALPPS, most of the patients had classical split (60%, n = 18) and clearance of the FLR (77%, n = 23). Hepatic recurrence was treated with non-anatomical resection (57%, n = 17), resection combined with local ablation (13%, n = 4), open ablation (13%, n = 4), segmentectomy (10%, n = 3) or subtotal segmentectomy (7%, n = 2). Six patients (20%) developed complications (10% minor complications). No post-hepatectomy liver failure or perioperative mortality was observed. One-year patient survival was 87%. Five patients received a third hepatectomy.

CONCLUSION

Repeated resections after ALPPS for CRLM in selected patients are safe and feasible with low morbidity and no mortality. Survival seems to be comparable with repeated resections after conventional hepatectomy.

Attenuation of peripheral serotonin inhibits tumor growth and enhances immune checkpoint blockade therapy in murine tumor models

[Figure: see text].

The Impact of Neoadjuvant Treatment on Survival in Patients Undergoing Pancreatoduodenectomy with Concomitant Portomesenteric Venous Resection: An International Multicenter Analysis

OBJECTIVE

The aim of this study was to evaluate whether neoadjuvant therapy (NAT) critically influenced microscopically complete resection (R0) rates and long-term outcomes for patients with pancreatic ductal adenocarcinoma who underwent pancreatoduodenectomy (PD) with portomesenteric vein resection (PVR) from a diverse, world-wide group of high-volume centers.

SUMMARY BACKGROUND DATA

Limited size studies suggest that NAT improves R0 rates and overall survival compared to upfront surgery in resectable and borderline resectable pancreatic cancer (R/BR-PDAC) patients.

METHODS

This multicenter study analyzed consecutive patients with R/BR-PDAC who underwent PD with PVR in 23 high-volume centers from 2009 to 2018.

RESULTS

Data from 1192 patients with PD and PVR were collected and analyzed. The median age was 68 [interquartile range (IQR) 60-73] years and 52% were males. Some 186 (15.6%) and 131 (10.9%) patients received neoadjuvant chemotherapy (NAC) alone and neoadjuvant chemoradiotherapy (NACRT), respectively. The R0/R1/R2 rates were 57%, 39.3%, and 3.2% in patients who received NAT compared to 46.6%, 49.9%, and 3.5% in patients who did not, respectively (p=0.004). The 1-, 3-, and 5-year OS in patients receiving NAT was 79%, 41%, and 29%, while for those that did not it was 73%, 29%, and 18%, respectively (p<0.001). Multivariable analysis showed no administration of NAT, high tumor grade, lymphovascular invasion, R1/R2 resection, no adjuvant chemotherapy, occurrence of Clavien-Dindo grade 3 or higher postoperative complications within 90 days, preoperative diabetes mellitus, male sex and portal vein involvement were negative independent predictive factors for OS.

CONCLUSION

Patients with PDAC of the pancreatic head expected to undergo venous reconstruction should routinely be considered for NAT.

Synthesis of coagulation factors during long-term ex situ liver perfusion

Robust viability assessment of grafts during normothermic liver perfusion is a prerequisite for organ use. Coagulation parameters are used commonly for liver assessment in patients. However, they are not yet included in viability assessment during ex situ perfusion. In this study, we analysed coagulation parameters during one week ex situ perfusion at 34℃. Eight discarded human livers were perfused with blood-based, heparinised perfusate for one week; perfusions in a further four livers were terminated on day 4 due to massive ongoing cell death. Coagulation parameters were well below the physiologic range at perfusion start. Physiologic levels were achieved within the first two perfusion days for factor V (68.5 ± 35.5%), factor VII (83.5 ± 26.2%), fibrinogen (2.1 ± 0.4 g/L) and antithrombin (107 ± 26.5%) in the livers perfused for one week. Despite the increased production of coagulation factors, INR was detectable only at 24h of perfusion (2.1 ± 0.3) and prolonged thereafter (INR > 9). The prolongation of INR was related to the high heparin level in the perfusate (anti-FXa > 3 U/mL). Intriguingly, livers with ongoing massive cell death also disclosed synthesis of factor V and improved INR. In summary, perfused livers were able to produce coagulation factors at a physiological level ex situ. We propose that single coagulation factor analysis is more reliable for assessing the synthetic function of perfused livers as compared to INR when using a heparinised perfusate.

Tumor Oxygenation by Myo-Inositol Trispyrophosphate Enhances Radiation Response

PURPOSE

Tumor hypoxia is a major limiting factor for successful radiation therapy outcomes, with hypoxic cells being up to 3-fold more radiation resistant than normoxic cells; tumor hypoxia creates a tumor microenvironment that is hostile to immune response. Thus, pharmaceutical-induced tumor oxygenation before radiation therapy represents an interesting method to enhance the efficacy of radiation therapy. Myo-inositol trispyrophosphate (ITPP) triggers a decrease in the affinity of oxygen to hemoglobin, which leads to an increased release of oxygen upon tissue demand, including in hypoxic tumors.

METHODS AND MATERIALS

The combined treatment modality of high-dose bolus ITPP with a single high-dose fraction of ionizing radiation (IR) was investigated for its mechanics and efficacy in multiple preclinical animal tumor models in immunocompromised and immunocompetent mice. The dynamics of tumor oxygenation were determined by serial hypoxia-oriented bioimaging. Initial and residual DNA damage and the integrity of the tumor vasculature were quantified on the immunohistochemical level in response to the different treatment combinations.

RESULTS

ITPP application did not affect tumor growth as a single treatment modality, but it rapidly induced tumor oxygenation, as demonstrated by in vivo imaging, and significantly reduced tumor growth when combined with IR. An immunohistochemical analysis of γH2AX foci demonstrated increased initial and residual IR-induced DNA damage as the primary mechanism for radiosensitization within initially hypoxic but ITPP-oxygenated tumor regions. Scheduling experiments revealed that ITPP increases the efficacy of ionizing radiation only when applied before radiation therapy. Irradiation alone damaged the tumor vasculature and increased tumor hypoxia, which were both prevented by combined treatment with ITPP. Interestingly, the combined treatment modality also promoted increased immune cell infiltration.

CONCLUSIONS

ITPP-mediated tumor oxygenation and vascular protection triggers immediate and delayed processes to enhance the efficacy of ionizing radiation for successful radiation therapy.

FDG-PET/CT: novel method for viability assessment of livers perfused ex vivo

PURPOSE

Ex vivo liver machine perfusion is a promising option to rescue marginal liver grafts mitigating the donated organ shortage. Recently, a novel liver perfusion machine that can keep injured liver grafts alive for 1 week ex vivo was developed and reported in Nature Biotechnology. However, liver viability assessment ex vivo is an unsolved issue and the value of 18F-fluorodeoxyglucose (FDG)-PET/CT for such purpose was explored.

MATERIALS AND METHODS

Discarded two human and six porcine liver grafts underwent FDG-PET/CT for viability assessment after 1 week of ex vivo perfusion. PET parameters [standardized uptake value (SUV)max, SUVmean, SUVpeak and total lesion glycolysis] were compared between hepatic lobes and between porcine and human livers. The prevalence of FDG-negative organ parts was recorded. The estimated effective radiation dose for PET/CT was calculated.

RESULTS

All organs were viable with essentially homogeneous FDG uptake. Of note, viability was preserved in contact areas disclosing the absence of pressure necrosis. Four porcine and two human organs had small superficial FDG-negative areas confirmed as biopsy sites. Total lesion glycolysis was significantly higher in the right hepatic lobe (P = 0.012), while there was no significant difference of SUVmax, SUVmean and SUVpeak between hepatic lobes. There was no significant difference in FDG uptake parameters between porcine and human organs. The estimated effective radiation dose was 1.99 ± 1.67 mSv per organ.

CONCLUSION

This study demonstrates the feasibility of FDG-PET/CT for viability assessment of ex vivo perfused liver grafts after 1 week.