[Digital applications in prehabilitation before major visceral surgery procedures]. / Digitale Applikationen in der Prähabilitation vor großen viszeralchirurgischen Operationen.

BACKGROUND: Prehabilitation is of becoming of growing interest in the medical specialist societies, especially before major surgical procedures in older and frail patients. The body of evidence in steadily growing. OBJECTIVES: Are there good digital solutions for a remote prehabilitation program at home? METHODS: Narrative review of the evidence and current study activities in analogous and digital prehabilitation. RESULTS: Prehabilitation is becoming increasingly more important in the optimal preparation of patients before major surgical procedures. With the help of tailored programs patients can be improved and the risk of complications can be significantly lowered. With an optimal selection, this is not associated with a deterioration of the prognosis for patients with cancer during the intervention lasting for 3-6 weeks. There is still a lack of results and good evidence from well-designed trials for digital solutions. CONCLUSION: Prehabilitation can be safely implemented in the preparation of patients before major surgical procedures. Digital solutions are currently being developed and tested and could possibly increase the acceptance in the currently intensifying resource shortages.

Predictive value of a novel digital risk calculator to determine early patient outcomes after major surgery: a proof-of-concept pilot study.

BACKGROUND: A structured risk assessment of patients with validated and evidence-based tools can help to identify modifiable factors before major surgeries. The Protego Maxima trial investigated the value of a new digitized risk assessment tool that combines tools which can be easily used and implemented in the clinical workflow by doctors and qualified medical staff. The hypothesis was that the structured assessment and risk-grouping is predictive of short-term surgical quality reflected by complications and overall survival. METHODS: The Protego Maxima Trial was a prospective cohort analysis of patients undergoing major surgery (visceral, thoracic, urology, vascular and gynecologic surgeries) as key inclusion criterion and the absence of an acute or acute on chronically decompensated pulmo-cardiovascular decompensation. Patients were risk-scored with the software (The Prehab App) that includes a battery of evidence-based risk assessment tools that allow a structured risk assessment. The data were grouped to predefined high and low risk groups and aggregate and individual scores. The primary outcome was to validate the predictive value of the RAI score and the TUG for overall survival in the high and low risk groups. Secondary outcomes were surgical outcomes at 90-days after surgery (overall survival, Clavien-Dindo (CD) 1-5 (all complications), and CD 3-5 (major complications)). The study was carried out in accordance with the DIN ISO 14,155, and the medical device regulation (MDR) at Frankfurt University Hospital between March 2022 and January 2023. RESULTS: In total 267 patients were included in the intention to treat analysis. The mean age was 62.1 ± 12.4 years. Patients with a RAI score > 25 and/or a timed up and go (TUG) > 8 s had a higher risk for mortality at 90 days after surgery. The low-risk group predicted beneficial outcome and the high-risk group predicted adverse outcome in the ROC analysis (Area Under the Curve Receiver Operator Characteristics: AUROC > 0.800; p = 0.01). Risk groups (high vs. low) showed significant differences for 90-day survival (99.4% vs. 95.5%; p = 0.04) and major complications (16.4% vs. 32.4%; p < 0.001). CONCLUSION: The proof-of-concept trial showed that a risk assessment with 'The Prehab App' may be viable to estimate the preoperative risk for mortality and major complications before major surgeries. The overall performance in this initial set of data indicated a certain reliability of the scoring and risk grouping, especially of the RAI score and the TUG. A larger data set will be required to proof the generalizability of the risk scoring to every subgroup and may be fostered by artificial intelligence approaches. TRIAL REGISTRATION: Ethics number: 2021-483-MDR/MPDG-zuständig monocentric; The Federal Institute for Pharmaceuticals and Medical Devices/BfArM, reference number: 94.1.04-5660-13655; Eudamed: CIV-21-07-0307311; German Clinical Trial Registry: DRKS 00026985.

Liver regeneration after portal and hepatic vein embolization improves overall survival compared with portal vein embolization alone: mid-term survival analysis of the multicentre DRAGON 0 cohort.

BACKGROUND: The purpose of this study was to compare 3-year overall survival after simultaneous portal (PVE) and hepatic vein (HVE) embolization versus PVE alone in patients undergoing liver resection for primary and secondary cancers of the liver. METHODS: In this multicentre retrospective study, all DRAGON 0 centres provided 3-year follow-up data for all patients who had PVE/HVE or PVE, and were included in DRAGON 0 between 2016 and 2019. Kaplan-Meier analysis was undertaken to assess 3-year overall and recurrence/progression-free survival. Factors affecting survival were evaluated using univariable and multivariable Cox regression analyses. RESULTS: In total, 199 patients were included from 7 centres, of whom 39 underwent PVE/HVE and 160 PVE alone. Groups differed in median age (P = 0.008). As reported previously, PVE/HVE resulted in a significantly higher resection rate than PVE alone (92 versus 68%; P = 0.007). Three-year overall survival was significantly higher in the PVE/HVE group (median survival not reached after 36 months versus 20 months after PVE; P = 0.004). Univariable and multivariable analyses identified PVE/HVE as an independent predictor of survival (univariable HR 0.46, 95% c.i. 0.27 to 0.76; P = 0.003). CONCLUSION: Overall survival after PVE/HVE is substantially longer than that after PVE alone in patients with primary and secondary liver tumours.

Effect of Sarcopenia on the Increase in Liver Volume and Function After Portal Vein Embolization.

PURPOSE: Sarcopenia is associated with a decreased kinetic growth rate (KGR) of the future liver remnant (FLR) after portal vein embolization (PVE). However, little is known on the increase in FLR function (FLRF) after PVE. This study evaluated the effect of sarcopenia on the functional growth rate (FGR) after PVE measured with hepatobiliary scintigraphy (HBS). METHODS: All patients who underwent PVE at the Amsterdam UMC between January 2005 and August 2017 were analyzed. Functional imaging by HBS was used to determine FGR. Liver volumetry was performed using multiphase contrast computed tomography (CT). Muscle area measurement to determine sarcopenia was taken at the third lumbar level (L3). RESULTS: Out of the 95 included patients, 9 were excluded due to unavailable data. 70/86 (81%) patients were sarcopenic. In the multivariate logistic regression analysis, sarcopenia (p = 0.009) and FLR volume (FRLV) before PVE (p = 0.021) were the only factors correlated with KGR, while no correlation was found with FGR. 90-day mortality was similar across the sarcopenic and non-sarcopenic group (4/53 [8%] versus 1/11 [9%]; p = 1.000). The resection rates were also comparable (53/70 [75%] versus 11/16 [69%]; p = 0.542). CONCLUSION: FGR after PVE as measured by HBS appears to be preserved in sarcopenic patients. This is in contrast to KGR after PVE as measured by liver volumetry which is decreased in sarcopenic patients. LEVEL OF EVIDENCE: Level 3b, cohort and case control studies.

Assessment of liver function by gadoxetic acid avidity in MRI in a model of rapid liver regeneration in rats.

BACKGROUND: This animal study investigates the hypothesis of an immature liver growth following ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) by measuring liver volume and function using gadoxetic acid avidity in magnetic resonance imaging (MRI) in models of ALPPS, major liver resection (LR) and portal vein ligation (PVL). METHODS: Wistar rats were randomly allocated to ALPPS, LR or PVL. In contrast-enhanced MRI scans with gadoxetic acid (Primovist®), liver volume and function of the right median lobe (=future liver remnant, FLR) and the deportalized lobes (DPL) were assessed until post-operative day (POD) 5. Liver functionFLR/DPL was defined as the inverse value of time from injection of gadoxetic acid to the blood pool-corrected maximum signal intensityFLR/DPL multiplied by the volumeFLR/DPL. RESULTS: In ALPPS (n = 6), LR (n = 6) and PVL (n = 6), volumeFLR and functionFLR increased proportionally, except on POD 1. Thereafter, functionFLR exceeded volumeFLR increase in LR and ALPPS, but not in PVL. Total liver function was significantly reduced after LR until POD 3, but never undercuts 60% of its pre-operative value following ALPPS and PVL. DISCUSSION: This study shows for the first time that functional increase is proportional to volume increase in ALPPS using gadoxetic acid avidity in MRI.

Chemotherapy and Targeted Therapy Strategies in Patients with Unresectable or Borderline Resectable Metastatic Colorectal Cancer: Evidence for a Lack of Focus on Resection Rates.

BACKGROUND AND AIMS: Chemotherapy (CTx) with targeted therapy (TT) have increased the overall response rate (ORR) and improved survival in unresectable or borderline resectable metastatic colorectal cancer (mCRC). However, the resection rate is an endpoint with often suboptimal expert involvement. The aim was to investigate whether the improvements in ORR have translated to improved resection rates (RR). STUDY DESIGN: A systematic literature search was performed using the PICO process. STATISTICAL ANALYSIS: Odds ratios, and 95% confidence intervals (OR, 95% CI) were analyzed for ORR and RR using dichotomous values with the Mantel-Haenszel method. Progression-free survival (PFS) and overall survival (OS) were analyzed using the inverse-variance method and displayed as hazard ratios and 95% confidence intervals (HR, 95% CI). RESULTS: The literature search returned 469 records. Sixteen articles with 5724 patients were selected for analysis. The qualitative analysis revealed low and moderate risk of bias endpoints. Higher ORR was observed with CTx + TT versus CTx only (OR: 0.62 [95% CI 0.45; 0.82], p = 0.002) and with triplet CTx + TT versus doublet CTx + TT (OR: 0.61 [95% CI 0.46; 0.81], p < 0.001). PFS and OS were improved by use of TT (HR: 0.68-0.84; p < 0.001 to 0.04). The overall RR was low (< 15%) and did not improve in the same way as the other endpoints. CONCLUSION: The ORR and survival rates in unresectable and borderline resectable mCRC were improved by modern CTx and TT that did not translate into higher RR, mostly due to the lack of expert involvement.

E-AHPBA-ESSO-ESSR Innsbruck consensus guidelines for preoperative liver function assessment before hepatectomy.

BACKGROUND: Posthepatectomy liver failure (PHLF) contributes significantly to morbidity and mortality after liver surgery. Standardized assessment of preoperative liver function is crucial to identify patients at risk. These European consensus guidelines provide guidance for preoperative patient assessment. METHODS: A modified Delphi approach was used to achieve consensus. The expert panel consisted of hepatobiliary surgeons, radiologists, nuclear medicine specialists, and hepatologists. The guideline process was supervised by a methodologist and reviewed by a patient representative. A systematic literature search was performed in PubMed/MEDLINE, the Cochrane library, and the WHO International Clinical Trials Registry. Evidence assessment and statement development followed Scottish Intercollegiate Guidelines Network methodology. RESULTS: Based on 271 publications covering 4 key areas, 21 statements (at least 85 per cent agreement) were produced (median level of evidence 2- to 2+). Only a few systematic reviews (2++) and one RCT (1+) were identified. Preoperative liver function assessment should be considered before complex resections, and in patients with suspected or known underlying liver disease, or chemotherapy-associated or drug-induced liver injury. Clinical assessment and blood-based scores reflecting liver function or portal hypertension (for example albumin/bilirubin, platelet count) aid in identifying risk of PHLF. Volumetry of the future liver remnant represents the foundation for assessment, and can be combined with indocyanine green clearance or LiMAx® according to local expertise and availability. Functional MRI and liver scintigraphy are alternatives, combining FLR volume and function in one examination. CONCLUSION: These guidelines reflect established methods to assess preoperative liver function and PHLF risk, and have uncovered evidence gaps of interest for future research.

Liver surgery is an effective treatment for liver tumours. Liver failure is a major problem in patients with a poor liver quality or having large operations. The treatment options for liver failure are limited, with high death rates. To estimate patient risk, assessing liver function before surgery is important. Many methods exist for this purpose, including functional, blood, and imaging tests. This guideline summarizes the available literature and expert opinions, and aids clinicians in planning safe liver surgery.

A critical appraisal of the ISGLS definition of biliary leakage after liver resection.

PURPOSE: The International Study Group of Liver Surgery (ISGLS) defined post-hepatectomy biliary leakage as drain/serum bilirubin ratio > 3 at day 3 or the interventional/surgical revision due to biliary peritonitis. We investigated the definition's applicability. METHODS: A retrospective evaluation of all liver resections over a 6-year period was performed. ROC analyses were performed for drain/serum bilirubin ratios on days 1, 2, and 3 including grade A to C (analysis I) and grade B and C biliary leakages (analysis II) to test specific cutoff values. RESULTS: A total of 576 patients were included. One hundred nine (18.9%) postoperative bile leakages occurred (19.6% of the whole population grade A, 16.5% grade B/C). Areas under the curve (AUC) for analysis I were 0.841 (day 1), 0.846 (day 2), and 0.734 (day 3). The highest sensitivity (78% on day 1/77% on day 2) and specificity (78% on day 1/79% on day 2) in analysis I were obtained for a drain/serum bilirubin ratio of 2.0. AUCs for analysis II were similar: 0.788 (day 1), 0.791 (day 2), and 0.650 (day 3). The highest sensitivity (73% on day 1/71% on day 2) and specificity (74% on day 1/76% on day 2) in analysis II were detected for a drain/serum bilirubin ratio of 2.0 on postoperative day 2. CONCLUSION: Biliary leakages should be defined if the drain/serum bilirubin ratio is > 2.0 on postoperative day 2.

Resectability of bilobar liver tumours after simultaneous portal and hepatic vein embolization versus portal vein embolization alone: meta-analysis.

BACKGROUND: Many patients with bi-lobar liver tumours are not eligible for liver resection due to an insufficient future liver remnant (FLR). To reduce the risk of posthepatectomy liver failure and the primary cause of death, regenerative procedures intent to increase the FLR before surgery. The aim of this systematic review is to provide an overview of the available literature and outcomes on the effectiveness of simultaneous portal and hepatic vein embolization (PVE/HVE) versus portal vein embolization (PVE) alone. METHODS: A systematic literature search was conducted in PubMed, Web of Science, and Embase up to September 2022. The primary outcome was resectability and the secondary outcome was the FLR volume increase. RESULTS: Eight studies comparing PVE/HVE with PVE and six retrospective PVE/HVE case series were included. Pooled resectability within the comparative studies was 75 per cent in the PVE group (n = 252) versus 87 per cent in the PVE/HVE group (n = 166, OR 1.92 (95% c.i., 1.13-3.25)) favouring PVE/HVE (P = 0.015). After PVE, FLR hypertrophy between 12 per cent and 48 per cent (after a median of 21-30 days) was observed, whereas growth between 36 per cent and 67 per cent was reported after PVE/HVE (after a median of 17-31 days). In the comparative studies, 90-day primary cause of death was similar between groups (2.5 per cent after PVE versus 2.2 per cent after PVE/HVE), but a higher 90-day primary cause of death was reported in single-arm PVE/HVE cohort studies (6.9 per cent, 12 of 175 patients). CONCLUSION: Based on moderate/weak evidence, PVE/HVE seems to increase resectability of bi-lobar liver tumours with a comparable safety profile. Additionally, PVE/HVE resulted in faster and more pronounced hypertrophy compared with PVE alone.

Current trends in regenerative liver surgery: Novel clinical strategies and experimental approaches.

Liver resections are performed to cure patients with hepatobiliary malignancies and metastases to the liver. However, only a small proportion of patients is resectable, largely because only up to 70% of liver tissue is expendable in a resection. If larger resections are performed, there is a risk of post-hepatectomy liver failure. Regenerative liver surgery addresses this limitation by increasing the future liver remnant to an appropriate size before resection. Since the 1980s, this surgery has evolved from portal vein embolization (PVE) to a multiplicity of methods. This review presents an overview of the available methods and their advantages and disadvantages. The first use of PVE was in patients with large hepatocellular carcinomas. The increase in liver volume induced by PVE equals that of portal vein ligation, but both result only in a moderate volume increase. While awaiting sufficient liver growth, 20%-40% of patients fail to achieve resection, mostly due to the progression of disease. The MD Anderson Cancer Centre group improved the PVE methodology by adding segment 4 embolization ("high-quality PVE") and demonstrated that oncological results were better than non-surgical approaches in this previously unresectable patient population. In 2012, a novel method of liver regeneration was proposed and called Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS). ALPPS accelerated liver regeneration by a factor of 2-3 and increased the resection rate to 95%-100%. However, ALPPS fell short of expectations due to a high mortality rate and a limited utility only in highly selected patients. Accelerated liver regeneration, however, was there to stay. This is evident in the multiplicity of ALPPS modifications like radiofrequency or partial ALPPS. Overall, rapid liver regeneration allowed an expansion of resectability with increased perioperative risk. But, a standardized low-risk approach to rapid hypertrophy has been missing and the techniques used and in use depend on local expertise and preference. Recently, however, simultaneous portal and hepatic vein embolization (PVE/HVE) appears to offer both rapid hypertrophy and no increased clinical risk. While prospective randomized comparisons are underway, PVE/HVE has the potential to become the future gold standard.

Sarcopenia predicts reduced liver growth and reduced resectability in patients undergoing portal vein embolization before liver resection - A DRAGON collaborative analysis of 306 patients.

BACKGROUND: After portal vein embolization (PVE) 30% fail to achieve liver resection. Malnutrition is a modifiable risk factor and can be assessed by radiological indices. This study investigates, if sarcopenia affects resectability and kinetic growth rate (KGR) after PVE. METHODS: A retrospective study was performed of the outcome of PVE at 8 centres of the DRAGON collaborative from 2010 to 2019. All malignant tumour types were included. Sarcopenia was defined using gender, body mass and skeletal muscle index. First imaging after PVE was used for liver volumetry. Primary and secondary endpoints were resectability and KGR. Risk factors impacting liver growth were assessed in a multivariable analysis. RESULTS: Eight centres identified 368 patients undergoing PVE. 62 patients (17%) had to be excluded due to unavailability of data. Among the 306 included patients, 112 (37%) were non-sarcopenic and 194 (63%) were sarcopenic. Sarcopenic patients had a 21% lower resectability rate (87% vs. 66%, p < 0.001) and a 23% reduced KGR (p = 0.02) after PVE. In a multivariable model dichotomized for KGR ≥2.3% standardized FLR (sFLR)/week, only sarcopenia and sFLR before embolization correlated with KGR. CONCLUSION: In this largest study of risk factors, sarcopenia was associated with reduced resectability and KGR in patients undergoing PVE.

A Reproducible Intensive Care Unit-Oriented Endotoxin Model in Rats.

Sepsis and septic shock remain the leading cause of death in intensive care units. Despite significant improvements in sepsis management, mortality still ranges between 20 and 30%. Novel treatment approaches in order to reduce sepsis-related multiorgan failure and death are urgently needed. Robust animal models allow for one or multiple treatment approaches as well as for testing their effect on physiological and molecular parameters. In this article, a simple animal model is presented. First, general anesthesia is induced in animals either with the use of volatile or by intraperitoneal anesthesia. After placement of an intravenous catheter (tail vein), tracheostomy, and insertion of an intraarterial catheter (tail artery), mechanical ventilation is started. Baseline values of mean arterial blood pressure, arterial blood oxygen saturation, and heart rate are recorded. The injection of lipopolysaccharides (1 milligram/kilogram body weight) dissolved in phosphate-buffered saline induces a strong and reproducible inflammatory response via the toll-like receptor 4. Fluid corrections as well as the application of norepinephrine are performed based on well-established protocols. The animal model presented in this article is easy to learn and strongly oriented towards clinical sepsis treatment in an intensive care unit with sedation, mechanical ventilation, continuous blood pressure monitoring, and repetitive blood sampling. Also, the model is reliable, allowing for reproducible data with a limited number of animals in accordance with the 3R (reduce, replace, refine) principles of animal research. While animal experiments in sepsis research cannot easily replaced, repetitive measurements allow for a reduction of animals and keeping septic animals anesthetized diminishes suffering.

Simultaneous portal and hepatic vein embolization before major liver resection.

BACKGROUND: Regenerative liver surgery expands the limitations of technical resectability by increasing the future liver remnant (FLR) volume before extended resections in order to avoid posthepatectomy liver failure (PHLF). Portal vein rerouting with ligation of one branch of the portal vein bifurcation (PVL) or embolization (PVE) leads to a moderate liver volume increase over several weeks with a clinical dropout rate of 20-40%, mostly due to tumor progression during the waiting period. Accelerated liver regeneration by the Associating Liver Partition and Portal vein Ligation for Staged hepatectomy (ALPPS) was poised to overcome this limitation by reduction of the waiting time, but failed due increased perioperative complications. Simultaneous portal and hepatic vein embolization (PVE/HVE) is a novel minimal invasive way to induce rapid liver growth without the need of two surgeries. PURPOSE: This article summarizes published results of PVE/HVE and analyzes what is known about its efficacy to achieve resection, safety, and the volume changes induced. CONCLUSIONS: PVE/HVE holds promise to induce accelerated liver regeneration in a similar safety profile to PVE. The demonstrated accelerated hypertrophy may increase resectability. Randomized trials will have to compare PVE/HVE and PVE to determine if PVE/HVE is superior to PVE.

Regulatory myeloid cells paralyze T cells through cell-cell transfer of the metabolite methylglyoxal.

Regulatory myeloid immune cells, such as myeloid-derived suppressor cells (MDSCs), populate inflamed or cancerous tissue and block immune cell effector functions. The lack of mechanistic insight into MDSC suppressive activity and a marker for their identification has hampered attempts to overcome T cell inhibition and unleash anti-cancer immunity. Here, we report that human MDSCs were characterized by strongly reduced metabolism and conferred this compromised metabolic state to CD8+ T cells, thereby paralyzing their effector functions. We identified accumulation of the dicarbonyl radical methylglyoxal, generated by semicarbazide-sensitive amine oxidase, to cause the metabolic phenotype of MDSCs and MDSC-mediated paralysis of CD8+ T cells. In a murine cancer model, neutralization of dicarbonyl activity overcame MDSC-mediated T cell suppression and, together with checkpoint inhibition, improved the efficacy of cancer immune therapy. Our results identify the dicarbonyl methylglyoxal as a marker metabolite for MDSCs that mediates T cell paralysis and can serve as a target to improve cancer immune therapy.

[A Challenge: Colorectal Foreign Bodies]. / Kolorektale Fremdkörper ­ eine Herausforderung für Patient und Arzt.

BACKGROUND: Colorectal foreign bodies are commonly seen in the emergency department. A delayed consultation may be associated with a worse outcome. Despite a low-lying position, the extraction can be a challenge and has to be done under general anesthesia. Sharp or potentially dangerous foreign bodies should be excluded before extraction manoeuvres and complications have to be ruled out after the retrieval. METHOD: Data were retrospectively collected from 2002 to 2017. Overall 33 patients were included. In addition, a systematic search, employing the PRISMA criteria, was performed. The search was carried out on PubMed (1623), Cochrane Library (17) and Google Scholar (300). Case reports, papers not written in English and publications before 1980 were excluded. RESULTS: With an average delay of 33 h, patients admitted themselves to the emergency department. Attempts to remove foreign bodies in the emergency department were successful in 2 cases (6%). General anaesthesia was required in 31 (94%) patients. An emergency laparotomy was necessary in 3 cases (9%). No complications were noticed. CONCLUSION: A delayed consultation is not associated with a worse outcome. Complications should be ruled out by endoscopy. After a normal control, the patient can be discharged prematurely without further imaging.

Building a collaboration to improve surgical research through EORTC/ESSO 1409-CLIMB study: A prospective liver metastasis database with an integrated quality assurance program.

The challenges of conducting surgical oncology trials have resulted to low quantity and poor quality research [1,2]. Considering the definitive role of surgery to offer cure, immediate response to improve surgical research is needed [3]. The European Organization for Research and Treatment of Cancer (EORTC) and the European Society of Surgical Oncology (ESSO) share the vision to achieve excellent surgical research and care for cancer patients. Building on their complimentary expertise, they embarked on a pilot project to map out challenges and initiate a sustainable collaboration to advance cancer surgery research in Europe. This pilot project is EORTC-ESSO 1409 GITCG/ ESSO-01: A Prospective Colorectal Liver Metastasis Database with an Integrated Quality Assurance Program (CLIMB). This article will describe the challenges, milestones and vision of both organizations in setting up this collaboration.

Simultaneous hepatic and portal vein ligation induces rapid liver hypertrophy: A study in pigs.

BACKGROUND: Liver hypertrophy induced by partial portal vein occlusion (PVL) is accelerated by adding simultaneous parenchymal transection ("ALPPS procedure"). This preclinical experimental study in pigs tests the hypothesis that simultaneous ligation of portal and hepatic veins of the liver also accelerates regeneration by abrogation of porto-portal collaterals without need for operative transection. METHODS: A pig model of portal vein occlusion was compared with the novel model of simultaneous portal and hepatic vein occlusion, where major hepatic veins draining the portal vein-deprived lobe were identified with intraoperative ultrasonography and ligated using pledgeted transparenchymal sutures. Kinetic growth was compared, and the portal vein system was then studied after 7 days using epoxy casts of the portal circulation. Portal vein flow and portal pressure were measured, and Ki-67 staining was used to evaluate the proliferative response. RESULTS: Pigs were randomly assigned to portal vein occlusion (n = 8) or simultaneous portal and hepatic vein occlusion (n = 6). Simultaneous portal and hepatic vein occlusion was well tolerated and led to mild cytolysis, with no necrosis in the outflow vein-deprived liver sectors. The portal vein-supplied sector increased by 90 ± 22% (mean ± standard deviation) after simultaneous portal and hepatic vein occlusion compared with 29 ± 18% after PVL (P < .001). Collaterals to the deportalized liver developed after 7 days in both procedures but were markedly reduced in simultaneous portal and hepatic vein occlusion. Ki-67 staining at 7 days was comparable. CONCLUSION: This study in pigs found that simultaneous portal and hepatic vein occlusion led to rapid hypertrophy without necrosis of the deportalized liver. The findings suggest that the use of simultaneous portal and hepatic vein occlusion accelerates liver hypertrophy for extended liver resections and should be evaluated further.

N-acetylcysteine protects hepatocytes from hypoxia-related cell injury.

AIM OF THE STUDY: Hepatocyte transplantation has been discussed as an alternative to liver transplantation in selected cases of acute and chronic liver failure and metabolic diseases. Immediately after infusion of hepatocytes, hypoxia-related cell injury is inevitable. N-acetylcysteine (NAC) has been suggested to attenuate hypoxic damage. This study's objective was to evaluate NAC's protective effect in a model of hypoxia-related hepatocyte injury. MATERIAL AND METHODS: HepG2 cells were used as a model for hepatocytes and were cultured under standardized hypoxia or normoxia for 24 hours with or without NAC. Growth kinetics were monitored using trypan blue staining. The activation of apoptotic pathways was measured using quantitative real-time PCR for Bcl-2/Bax and p53. The proportions of vital, apoptotic and necrotic cells were verified by fluorescence activated cell sorting using annexin V-labelling. The expression of hypoxia inducible factor 1 (HIF-1) was measured indirectly using its downstream target vascular endothelial growth factor A (VEGF-A). RESULTS: After NAC, cell proliferation increased under both hypoxia and normoxia by 528% and 320% (p < 0.05), while VEGF-A expression decreased under normoxia by 67% and 37% (p < 0.05). Compared to cells treated without NAC under hypoxia, the Bcl-2/Bax ratio increased significantly in cells treated with NAC. This finding was confirmed by an increased number of vital cells in FACS analysis. CONCLUSIONS: NAC protects hepatocytes from hypoxic injury and ultimately activates anti-apoptotic pathways.

The meteorological influence on seasonal alterations in the course of acute appendicitis.

BACKGROUND: Several diseases, including acute appendicitis (AA), have been known to undergo seasonal variations. Changes in the incidence and course of AA are attributed to seasonal weather differences, but this connection remains unproven. METHODS: In this retrospective, single-center analysis, we analyzed daily meteorological data over an 8-year period. A connection of day-by-day meteorological data with 680 consecutive appendectomies was performed. Patients' characteristics, intraoperative findings, and outcome parameters were analyzed. Seasons were classified meteorologically as 3-month periods (winter, spring, summer, and autumn). RESULTS: Nonambient temperature (unusual warm or cold weather) is correlated with a higher rate of complicated (gangrenous or perforated) AA (P = 0.018). In summer and winter, days with nonambient temperatures were more frequent (P < 0.0001). A higher rate of complicated AA was seen during summer and winter (P = 0.009). In addition, patients operated on in summer and accordingly after warm days suffer more complications (P < 0.0001), especially more superficial surgical site infections (P < 0.048). CONCLUSIONS: The concordant observation of more complicated AA and complications after AA with meteorological data and calendric seasonal variations makes it most likely that temperature is a cofactor in complicated AA and contributes to the seasonal variations in AA. Although an increase in the microbiome of the skin during warm seasons might explain the increase in surgical site infection, the functional connection between warmer temperatures and AA complications remains unclear.