Bleeding in liver surgery: prevention and treatment

Low Versus High Blood Pressure Targets in Critically Ill and Surgical Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

Hypotension is associated with adverse outcomes in critically ill and perioperative patients. However, these assumptions are supported by observational studies. This meta-analysis of randomized controlled trials aims to compare the impact of lower versus higher blood pressure targets on mortality.

DATA SOURCES

We searched PubMed, Cochrane, and Scholar from inception to February 10, 2024.

STUDY SELECTION

Randomized trials comparing lower versus higher blood pressure targets in the management of critically ill and perioperative settings.

DATA EXTRACTION

The primary outcome was all-cause mortality at the longest follow-up available. This review was registered in the Prospective International Register of Systematic Reviews, CRD42023452928.

DATA SYNTHESIS

Of 2940 studies identified by the search string, 28 (12 in critically ill and 16 in perioperative settings) were included totaling 15,672 patients. Patients in the low blood pressure target group had lower mortality (23 studies included: 1019/7679 [13.3%] vs. 1103/7649 [14.4%]; relative risk 0.93; 95% CI, 0.87-0.99; p = 0.03; I2 = 0%). This corresponded to a 97.4% probability of any increase in mortality with a Bayesian approach. These findings were mainly driven by studies performed in the ICU setting and with treatment lasting more than 24 hours; however, the magnitude and direction of the results were similar in the majority of sensitivity analyses including the analysis restricted to low risk of bias studies. We also observed a lower rate of atrial fibrillation and fewer patients requiring transfusion in low-pressure target groups. No differences were found in the other secondary outcomes.

CONCLUSIONS

Based on pooled randomized trial evidence, a lower compared with a higher blood pressure target results in a reduction of mortality, atrial fibrillation, and transfusion requirements. Lower blood pressure targets may be beneficial but there is ongoing uncertainty. However, the present meta-analysis does not confirm previous findings and recommendations. These results might inform future guidelines and promote the study of the concept of protective hemodynamics.

Efficacy and safety of terlipressin infusion during liver surgery: a protocol for systematic review and meta-analysis

INTRODUCTION

Liver disease causes 2 million deaths annually, accounting for 4% of all deaths worldwide. Liver surgery is one of the effective therapeutic options. Bleeding is a major complication during liver surgery. Perioperative bleeding and allogeneic blood transfusion may deteriorate the prognosis. Terlipressin (TP), a synthetic analogue of the antidiuretic hormone, may reduceblood loss during abdominal surgery. Several clinical centres have attempted to use TP during liver surgery, but the evidence for its effectiveness in reducing blood loss and the need for allogeneic blood transfusion, as well as its safety during the perioperative period, remains unclear. The aim of this systematic review and meta-analysis is to evaluate the efficacy and safety of TP in reducing blood loss and allogeneic blood transfusion needs during liver surgery.

METHODS AND ANALYSIS

We will search PubMed, EMBASE, the Cochrane Library and Web of Science for studies on perioperative use of TP during liver surgery from inception to July 2023. We will limit the language to English, and two reviewers will independently screen and select articles. The primary study outcomes are estimated blood loss and the need for allogeneic blood transfusion. Secondary outcomes include operating time, intensive care unit stay, length of stay, intraoperative urine output, acute kidney injury rate, postoperative complications, hepatic and renal function during follow-up, and TP-related adverse effects. We will include studies that met the following criteria: (1) randomised controlled trials (RCTs), cohort studies or case-control studies; (2) the publication time was till July 2023; (3) adult patients (≥18 years old) undergoing elective liver surgery; (4) comparison of TP with other treatments and (5) the study includes at least one outcome. We will exclude animal studies, case reports, case series, non-original articles, reviews, paediatric articles, non-controlled trials, unpublished articles, non-English articles and other studies that are duplicates. We will use Review Manager V.5.3 software for meta-analysis and perform stratification analysis for the study quality of RCTs based on the Jadad score. For cohort or case-control studies, the study quality will be analysed based on Newcastle-Ottawa Scale scores. Grading of Recommendations, Assessment, Development and Evaluation will be used to assess confidence in the cumulative evidence. For primary outcomes, we will conduct subgroup analyses based on meta-regression. We will also perform leave-one-out sensitivity analyses to evaluate the effect of each individual study on the combined results by removing the individual studies one by one for outcomes with significant heterogeneity. The protocol follows the Cochrane Handbook for Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols guidelines.

ETHICS AND DISSEMINATION

This study is a secondary analysis of existing data; therefore, it does not require ethical approval. We will disseminate the results through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42023450333.

Stage-by-stage analysis of the effect of blood transfusion on survival after curative hepatectomy for hepatocellular carcinoma-a retrospective study

OBJECTIVE

This study is to examine the impact of perioperative (intraoperative/postoperative) blood transfusion on the outcomes of curative hepatectomy for hepatocellular carcinoma. Hepatectomy is a well-established curative treatment for hepatocellular carcinoma, and blood transfusion cannot always be avoided in treating the disease.

METHODS

A retrospective study of patients having curative hepatectomy for hepatocellular carcinoma from January 2010 to December 2019 at a single center was conducted. The patients were stratified by their disease stage. Patients with and without perioperative blood transfusion were matched by propensity-score matching and compared for each disease stage. Univariate and multivariate analyses were performed to identify prognostic factors for overall survival for each stage.

RESULTS

A total of 846 patients were studied. Among them, 125 received perioperative blood transfusion and 720 did not. Patients with blood transfusion had worse disease-free and overall survival. After stratification and matching, the ratios of transfusion to non-transfusion were 33:165 (stage 1), 28:140 (stage 2), and 45:90 (stage 3). Perioperative blood transfusion was associated with a higher incidence of postoperative complications in all three disease stages (p = 0.004/0.006/0.017), and hence longer hospitalization (p < 0.001 in all stages), but had no significant impact on hospital mortality (p = 0.119/0.118/0.723), 90-day mortality (p = 0.259/0.118/0.723), disease-free survival (p = 0.128/0.826/0.511), or overall survival (p = 0.869/0.122/0.122) in any disease stage. Prognostic factors for overall survival included tumor size, tumor number, alpha-fetoprotein level, and postoperative complication of grade ≥ 3A.

CONCLUSION

Perioperative blood transfusion was associated with a higher incidence of complications but had no significant impact on survival after curative hepatectomy for hepatocellular carcinoma.

Effectiveness of a thrombin-gelatin flowable for treating severe liver bleeding: an experimental study

BACKGROUND

Current scientific evidence has pointed out the relevance of hemostatic products for improving clinical outcomes in liver trauma, including increased survival rates and reductions in bleeding-related complications. The purpose of this study was to compare the use of the gelatin-thrombin flowable (Flowable) versus the standard technique of Packing in a new experimental liver injury model.

METHODS

Twenty-four swine were prospectively randomized to receive either Flowable or standard packing technique. We used a novel severe liver injury model, in which the middle and left suprahepatic veins were selectively injured, causing an exsanguinating hemorrhage. The main outcome measure was the percentage of lost blood volume.

RESULTS

The median total percentage of total blood volume per animal lost, from injury to minute 120, was significantly lower in the Flowable group (15.2%; interquartile range: 10.7-46.7%) than in the Packing group (64.9%; Interquartile range: 53.4-73.0%) (Hodges-Lehmann median difference: 41.1%; 95% CI: 18.9-58.0%, p = 0.0034). The 24-hour survival rate was significantly higher in the Flowable group (87.0%) than in the Packing group (0.0%) (Hazard ratio (HR) 0.08; 95% confidence interval 0.102 to 0.27; p < 0.0001). Mean-arterial pressure was significantly lower at minute 60 and 120 in the Flowable group than in the packing group (p = 0.0258 and p = 0.0272, respectively). At minute 120, hematocrit was higher in the Flowable than in the packing group (Hodges-Lehmann median difference: 5.5%; 95%CI: 1.0 to11.0, p = 0.0267). Finally, the overall-surgical-procedure was significantly shorter with Flowable than with Packing (Hodges-Lehmann median difference: 39.5 s, 95% CI: 25.0 to 54.0 s, p = 0.0004).

CONCLUSIONS

The use of the Flowable was more effective in achieving hemostasis, reducing blood loss, and improving survival rates than standard packing in a severe porcine-liver bleeding model.

Injectable Hydrogels Including Magnetic Nanosheets for Multidisciplinary Treatment of Hepatocellular Carcinoma via Magnetic Hyperthermia

Relapse and unresectability have become the main obstacle for further improving hepatocellular carcinoma (HCC) treatment effect. Currently, single therapy for HCC in clinical practice is limited by postoperative recurrence, intraoperative blood loss and poor patient outcomes. Multidisciplinary therapy has been recognized as the key to improving the long-term survival rate for HCC. However, the clinical application of HCC synthetic therapy is restricted by single functional biomaterials. In this study, a magnetic nanocomposite hydrogel (CG-IM) with iron oxide nanoparticle-loaded mica nanosheets (Iron oxide nanoparticles@Mica, IM) is reported. This biocompatible magnetic hydrogel integrated high injectability, magnetocaloric property, mechanical robustness, wet adhesion, and hemostasis, leading to efficient HCC multidisciplinary therapies including postoperative tumor margin treatment and percutaneous locoregional ablation. After minimally invasive hepatectomy of HCC, the CG-IM hydrogel can facilely seal the bleeding hepatic margin, followed by magnetic hyperthermia ablation to effectively prevent recurrence. In addition, CG-IM hydrogel can inhibit unresectable HCC by magnetic hyperthermia through the percutaneous intervention under ultrasound guidance.

Intraoperative hypotension and postoperative outcomes: a meta-analysis of randomised trials

INTRODUCTION

Intraoperative hypotension is associated with adverse postoperative outcomes; however these findings are supported only by observational studies. The aim of this meta-analysis of randomised trials was to compare the postoperative effects permissive management with targeted management of intraoperative blood pressure.

METHODS

We searched PubMed, Cochrane, and Embase up to June 2023 for studies comparing permissive (mean arterial pressure ≤60 mm Hg) with targeted (mean arterial pressure >60 mm Hg) intraoperative blood pressure management. Primary outcome was all-cause mortality at the longest follow-up available. Secondary outcomes were atrial fibrillation, myocardial infarction, acute kidney injury, delirium, stroke, number of patients requiring transfusion, time on mechanical ventilation, and length of hospital stay.

RESULTS

We included 10 randomised trials including a total of 9359 patients. Mortality was similar between permissive and targeted blood pressure management groups (89/4644 [1.9%] vs 99/4643 [2.1%], odds ratio 0.88, 95% confidence interval [CI], 0.65-1.18, P=0.38, I2=0% with nine studies included). Atrial fibrillation (102/3896 [2.6%] vs 130/3887 [3.3%] odds ratio 0.71, 95% CI 0.53-0.96, P=0.03, I2=0%), and length of hospital stay (mean difference -0.20 days, 95% CI -0.26 to -0.13, P<0.001, I2=0%) were reduced in the permissive management group. No significant differences were found in subgroup analysis for cardiac and noncardiac surgery.

CONCLUSION

Pooled randomised evidence shows that a target intraoperative mean arterial pressure ≤60 mm Hg is not associated with increased mortality; nevertheless it is surprisingly associated with a reduced rate of atrial fibrillation and of length of hospital stay.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42023393725.

Early γGT and bilirubin levels as biomarkers for regeneration and outcomes in damaged bile ducts after liver transplantation

BACKGROUND

Early patient and allograft survival after liver transplantation (LT) depend primarily on parenchymal function, but long-term allograft success relies often on biliary-tree function. We examined parameters related to cholangiocyte damage that predict poor long-term LT outcomes after donation after brain death (DBD).

METHODS

Sixty bile ducts (BD) were assessed by a BD damage-score and divided into groups with "major" BD-damage (n = 33) and "no relevant" damage (n = 27) during static cold storage. Patients with "major" BD damage were further investigated by measuring biliary excretion parameters in the first 14 days post-LT (followed-up for 60-months).

RESULTS

Patients who received LT showing "major" BD damage had significantly worse long-term patient survival, versus grafts with "no relevant" damage (p = .03). When "major" BD damage developed, low bilirubin levels (p = .012) and high gamma-glutamyl transferase (GGT)/bilirubin ratio (p = .0003) were evident in the early post-LT phase (7-14 days) in patients who survived (> 60 months), compared to those who did not. "High risk" patients with bile duct damage and low GGT/bilirubin ratio had significantly shorter overall survival (p < .0001).

CONCLUSIONS

Once "major" BD damage occurs, a high GGT/bilirubin ratio in the early post-operative phase is likely indicator of liver and cholangiocyte regeneration, and thus a harbinger of good overall outcomes. "Major" BD damage without markers of regeneration identifies LT patients that could benefit from future repair therapies.

Phlebotomy resulting in controlled hypovolemia to prevent blood loss in major hepatic resections (PRICE-2): study protocol for a phase 3 randomized controlled trial

INTRODUCTION

Blood loss and red blood cell (RBC) transfusion in liver surgery are areas of concern for surgeons, anesthesiologists, and patients alike. While various methods are employed to reduce surgical blood loss, the evidence base surrounding each intervention is limited. Hypovolemic phlebotomy, the removal of whole blood from the patient without volume replacement during liver transection, has been strongly associated with decreased bleeding and RBC transfusion in observational studies. This trial aims to investigate whether hypovolemic phlebotomy is superior to usual care in reducing RBC transfusions in liver resection.

METHODS

This study is a double-blind multicenter randomized controlled trial. Adult patients undergoing major hepatic resections for any indication will be randomly allocated in a 1:1 ratio to either hypovolemic phlebotomy and usual care or usual care alone. Exclusion criteria will be minor resections, preoperative hemoglobin <100g/L, renal insufficiency, and other contraindication to hypovolemic phlebotomy. The primary outcome will be the proportion of patients receiving at least one allogeneic RBC transfusion unit within 30 days of the onset of surgery. Secondary outcomes will include transfusion of other allogeneic blood products, blood loss, morbidity, mortality, and intraoperative physiologic parameters. The surgical team will be blinded to the intervention. Randomization will occur on the morning of surgery. The sample size will comprise 440 patients. Enrolment will occur at four Canadian academic liver surgery centers over a 4-year period. Ethics approval will be obtained at participating sites before enrolment.

DISCUSSION

The results of this randomized control trial will provide high-quality evidence regarding the use of hypovolemic phlebotomy in major liver resection and its effects on RBC transfusion. If proven to be effective, this intervention could become standard of care in liver operations internationally and become incorporated within perioperative patient blood management programs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03651154 . Registered on August 29 2018.

Implantable Sandwich-like Scaffold/Fiber Composite Spatiotemporally Releasing Combretastatin A4 and Doxorubicin for Efficient Inhibition of Postoperative Tumor Recurrence

Tumor recurrence is a critical conundrum in the postoperative therapy, on account of severe bleeding with disseminated tumor cells, residual tumor cells, and the rich nutrient and oxygen supply transported to tumors by the abundant blood vessels. Biodegradable drug-loaded implants, inserted in the resection cavity right away upon the surgery, possess bleeding prevention and efficient chemotherapeutic capabilities, considered to be a promising strategy to efficiently inhibit the recurrence of the solid tumor. Here, we developed a sandwich-like composite consisting of the combretastatin A4 (CA4)-loaded 3D-printed scaffold and doxorubicin (DOX)-loaded electrospun fiber (Scaffold-CA4@Fiber-DOX), presenting hemostatic, chemotherapeutic, and antibacterial potencies. The lyophilized 3D-printed scaffold with a porous structure rapidly absorbed and clotted the blood cells and disseminated tumor cells to prevent bleeding and tumor metastasis. Subsequently, the preferentially released CA4 from the scaffold disrupted the microtubules of the vascular endothelial cell, resulting in vascular deformation and consequent insufficient nutrient supply to the solid tumor. The sustained release of DOX from the sandwiched electrospun fiber dramatically inhibited the peripheral tumor cell proliferation. This all-in-one multifunctional implant system, combining efficient vascular disruption and chemotherapy, provides a promising strategy for postoperative tumor therapy.

In situ Thermal-Responsive Magnetic Hydrogel for Multidisciplinary Therapy of Hepatocellular Carcinoma

Current surgical single modality treatments for hepatocellular carcinoma (HCC) were restricted by recurrence, blood loss, significant trauma, and poor prognostic. Although multidisciplinary strategies for HCC treatment have been highly recommended by the clinical guidelines, there was limited choice of materials and treatments. Herein, we reported an in situ formed magnetic hydrogel with promising bioapplicable thermal-responsiveness, strong adhesion in wet conditions, high magnetic hyperthermia, and biocompatibility, leading to efficient HCC multidisciplinary treatment including postoperative treatment and transarterial embolization therapy. In vivo results indicated that this hydrogel could reduce the postoperative recurrence rate. The hemostatic ability of the thermal-responsive hydrogel was further demonstrated in both the liver scratch model and liver tumor resection. Computed tomography imaging suggested that the hydrogel could completely embolize the arterial vessels of rabbit liver tumor by vascular intervention operation, which could serve as multidisciplinary responsive materials to external magnetic field and body temperature for HCC treatment.

Tranexamic acid versus placebo to reduce perioperative blood transfusion in patients undergoing liver resection: protocol for the haemorrhage during liver resection tranexamic acid (HeLiX) randomised controlled trial

INTRODUCTION

Despite use of operative and non-operative interventions to reduce blood loss during liver resection, 20%-40% of patients receive a perioperative blood transfusion. Extensive intraoperative blood loss is a major risk factor for postoperative morbidity and mortality and receipt of blood transfusion is associated with serious risks including an association with long-term cancer recurrence and overall survival. In addition, blood products are scarce and associated with appreciable expense; decreasing blood transfusion requirements would therefore have health system benefits. Tranexamic acid (TXA), an antifibrinolytic, has been shown to reduce the probability of receiving a blood transfusion by one-third for patients undergoing cardiac or orthopaedic surgery. However, its applicability in liver resection has not been widely researched.

METHODS AND ANALYSIS

This protocol describes a prospective, blinded, randomised controlled trial being conducted at 10 sites in Canada and 1 in the USA. 1230 eligible and consenting participants will be randomised to one of two parallel groups: experimental (2 g of intravenous TXA) or placebo (saline) administered intraoperatively. The primary endpoint is receipt of blood transfusion within 7 days of surgery. Secondary outcomes include blood loss, postoperative complications, quality of life and 5-year disease-free and overall survival.

ETHICS AND DISSEMINATION

This trial has been approved by the research ethics boards at participating centres and Health Canada (parent control number 177992) and is currently enrolling participants. All participants will provide written informed consent. Results will be distributed widely through local and international meetings, presentation, publication and ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT02261415.

[Perioperative risk factors of bleeding in extensive liver resections]

OBJECTIVE

To study the risk factors of severe blood loss in extensive liver resections, consequences of hemorrhagic problems and their correction.

MATERIAL AND METHODS

The study included 374 patients. Group 1 comprised 282 patients (118 men and 164 women aged 54.1±0.7 years) who underwent surgery between 2000 and 2012. Group 2 included 92 patients (34 women and 58 men aged 53.6±1.3 years) operated on for the period 2013-2019.

RESULTS

Technical equipment for mobilization and dissection of hepatic parenchyma has fundamentally changed for the period 2013-2019. This processes reduced blood loss by more 50% and consumption of donor blood components (red blood cells by 2.8 times, FFP by 1.8 times). Compression of hepatoduodenal ligament (Pringle maneuver) and tumor type did not affect intraoperative blood loss. Neoplasms over 10 cm increased blood loss. An increase in the number of resected segments by 2 times contributed to increase of blood loss by 2.7 times. Body mass index >25 kg/m² was also associated with higher blood loss.

A Bionic Nano-Band-Aid Constructed by the Three-Stage Self-Assembly of Peptides for Rapid Liver Hemostasis

Critical challenges remain in trauma emergency and surgical procedures involving liver bleeding, particularly in perforating wounds that cannot be pressed and large wounds that cannot be sewn. Self-assembling peptide hydrogels are particularly attractive due to their intrinsic biocompatibility and programmability. Herein, we develop a nano-band-aid (NBA) through a three-stage self-assembly strategy of two functionalized peptides, which were first coassembled into nanofibers and then woven to a meshlike network driven by Ca²⁺. Then, catalyzed by blood coagulation factor XIIIa (FXIIIa), NBA underwent a third stage, self-assembly into a densely compacted physical barrier to stop and control the bleeding. As expected, NBA rapidly and efficiently stopped the bleeding in rat liver scratches while effectively reducing the inflammation around the wound and promoting the wound healing. This bionic self-assembly strategy will provide a clinically potential peptide-based treatment for fatal liver bleeding and reinvigorate efforts to develop self-assembling peptide hydrogels as hemostatic agents.

The Association between Prognostic Nutritional Index (PNI) and Intraoperative Transfusion in Patients Undergoing Hepatectomy for Hepatocellular Carcinoma: A Retrospective Cohort Study

BACKGROUND

PNI is significantly associated with surgical outcomes; however, the association between PNI and intraoperative transfusions is unknown.

METHODS

This study retrospectively analyzed 1065 patients who underwent hepatectomy. We divided patients into two groups according to the PNI (<44 and >44) and compared their transfusion rates and surgical outcomes. We performed multivariate logistic and Cox regression analysis to determine risk factors for transfusion and the 5-year survival. Additionally, we found the net reclassification index (NRI) to validate the discriminatory power of PNI.

RESULTS

The PNI <44 group had higher transfusion rates (adjusted odds ratio [OR]: 2.20, 95%CI: 1.06-4.60, p = 0.035) and poor surgical outcomes, such as post hepatectomy liver failure (adjusted [OR]: 3.02, 95%CI: 1.87-4.87, p < 0.001), and low 5-year survival (adjusted OR: 1.68, 95%CI: 1.17-2.24, p < 0.001). On multivariate analysis, PNI <44, age, hemoglobin, operation time, synthetic colloid use, and laparoscopic surgery were risk factors for intraoperative transfusion. On Cox regression analysis, PNI <44, MELD score, TNM staging, synthetic colloid use, and transfusion were associated with poorer 5-year survival. NRI analysis showed significant improvement in the predictive power of PNI for transfusion (p = 0.002) and 5-year survival (p = 0.004).

CONCLUSIONS

Preoperative PNI <44 was significantly associated with higher transfusion rates and surgical outcomes.

Meta-analysis of the effect of the pringle maneuver on long-term oncological outcomes following liver resection

Hepatic pedicle clamping reduces intraoperative blood loss and the need for transfusion, but its long-term effect on survival and recurrence remains controversial. The aim of this meta-analysis was to evaluate the effect of the Pringle maneuver (PM) on long-term oncological outcomes in patients with primary or metastatic liver malignancies who underwent liver resection. Literature was searched in the Cochrane Central Register of Controlled Trials (CENTRAL), Medline (via PubMed), and Web of Science databases. Survival was measured as the survival rate or as a continuous endpoint. Pooled estimates were represented as odds ratios (ORs) using the Mantel–Haenszel test with a random-effects model. The literature search retrieved 435 studies. One RCT and 18 NRS, including 7480 patients who underwent liver resection with the PM (4309 cases) or without the PM (3171 cases) were included. The PM did not decrease the 1-year overall survival rate (OR 0.86; 95% CI 0.67–1.09; P = 0.22) or the 3- and 5-year overall survival rates. The PM did not decrease the 1-year recurrence-free survival rate (OR 1.06; 95% CI 0.75–1.50; P = 0.75) or the 3- and 5-year recurrence-free survival rates. There is no evidence that the Pringle maneuver has a negative effect on recurrence-free or overall survival rates.

Safety Evaluation of Human Cord-Lining Epithelial Stem Cells Transplantation for Liver Regeneration in a Porcine Model

We investigated the safety of using umbilical cord-lining stem cells for liver regeneration and tested a novel method for stem cell delivery. Stem cells are known by their ability to repair damaged tissues and have the potential to be used as regenerative therapies. The umbilical cord's outer lining membrane is known to be a promising source of multipotent stem cells and can be cultivated in an epithelial cell growth medium to produce cell populations which possess the properties of both epithelial cells and embryonic stem cells-termed cord-lining epithelial cells (CLEC). Hepatocytes are epithelial cells of the liver and their proliferation upon injury is the main mechanism in restoring the liver. Earlier studies conducted showed CLEC can be differentiated into functioning hepatocyte-like cells (HLC) and can survive in immunologically competent specimens. In this study, we chose a porcine model to investigate CLEC as a treatment modality for liver failure. We selected 16 immune competent Yorkshire-Dutch Landrace pigs, with a mean weight of 40.5 kg, for this study. We performed a 50% hepatectomy to simulate the liver insufficient disease model. After the surgery, four pigs were transplanted with a saline scaffold while seven pigs were transplanted with a HLC scaffold. Five pigs died on the surgical table and were omitted from the study analysis. This study addressed the safety of transplanting human CLEC in a large animal model. The transplant interfaces were evaluated and no signs of cellular rejection were observed in both groups.

Efficacy of pro- and anticoagulant strategies in plasma of patients undergoing hepatobiliary surgery

BACKGROUND

In vitro efficacy of pro- and antihemostatic drugs is profoundly different in patients with compensated cirrhosis and in those who have cirrhosis and are critically ill.

OBJECTIVES

Here we assessed the efficacy of pro- and anticoagulant drugs in plasma of patients undergoing hepato-pancreato-biliary (HPB) surgery, which is associated with unique hemostatic changes.

METHODS

We performed in vitro analyses on blood samples of 60 patients undergoing HPB surgery and liver transplantation: 20 orthotopic liver transplantations, 20 partial hepatectomies, and 20 pylorus-preserving pancreaticoduodenectomies. We performed thrombin generation experiments before and after in vitro addition of fresh frozen plasma (FFP), prothrombin complex concentrate (PCC), recombinant factor VIIa (rFVIIa), low molecular weight heparin (LMWH), unfractionated heparin, dabigatran, and rivaroxaban.

RESULTS

We showed that patients undergoing HPB surgery are in a hypercoagulable state by thrombin generation testing. FFP and rFVIIa had minimal effects on thrombin generation, whereas PCC had a more pronounced procoagulant effect in patients compared with controls. Dabigatran showed a more pronounced anticoagulant effect in patients compared with controls, whereas rivaroxaban and LMWH had a decreased anticoagulant effect in patients.

CONCLUSION

We demonstrate profoundly altered in vitro efficacy of commonly used anticoagulants, in patients undergoing HPB surgery compared with healthy controls, which may have implications for anticoagulant dosing in the early postoperative period. In the correction of perioperative bleeding complications, PCCs appear much more potent than FFP or rFVIIa, and PCCs may require conservative dosing and caution in use in patients undergoing HPB surgery.

Blood Markers of Portal Hypertension Are Associated with Blood Loss and Transfusion Requirements during Orthotopic Liver Transplantation

There is increasing evidence that portal hypertension plays a major role in bleeding risk during orthotopic liver transplantation (OLT). We investigated the association between preoperative blood levels of von Willebrand factor (VWF) and soluble CD163 (sCD163), which are established markers of portal hypertension, and blood loss and transfusion requirements during OLT. We measured levels of VWF and sCD163 in preoperative serum samples of 168 adult patients undergoing a primary OLT between 1998 and 2012. Preoperative levels of VWF and sCD163 correlated with the model of end-stage liver disease (MELD) score (r = 0.414, p < 0.001 and r = 0.382, p < 0.001, respectively). Patients with high VWF or sCD163 levels (VWF and sCD163 levels above the median) had a substantially increased risk of needing red blood cell transfusion compared with patients with low VWF or sCD163 levels (VWF and sCD163 levels below the median) (odds ratio 3.5 [95% confidence interval, CI 1.7-7.0] and 2.3 [95% CI 1.1-4.5], respectively). Blood loss was highest in patients with both high VWF or sCD163 levels and a high preoperative international normalized ratio. Elevated blood levels of markers of portal hypertension are associated with increased blood loss and transfusion requirements during OLT and support the notion that portal hypertension is an important contributor to perioperative blood loss.

[Blood-saving technologies in extensive liver resections]

The researches devoted to blood-saving technologies in extensive liver resections are analyzed in the manuscript. Resection of three and more liver segments is effective method of surgical treatment of various focal liver lesions. Surgical (anatomical resection with hilar glissonean access, Pringle maneuver, modern technical equipment, etc.), anesthesiological (reduction of central venous pressure, hemostatic agents) and transfusion (autologous blood donation, transfusion, cell saver, etc.) methods contribute to prevention and reduction of blood loss. Intraoperative measures for blood loss prevention should include adequate surgical incision and liver mobilization, precise techniques of parenchymal dissection (for example, cavitation surgical aspirator-destructor), use of clip applicators and local or systemic hemostatic agents.

Guidelines on the use of liver biopsy in clinical practice from the British Society of Gastroenterology, the Royal College of Radiologists and the Royal College of Pathology

Liver biopsy is required when clinically important information about the diagnosis, prognosis or management of a patient cannot be obtained by safer means, or for research purposes. There are several approaches to liver biopsy but predominantly percutaneous or transvenous approaches are used. A wide choice of needles is available and the approach and type of needle used will depend on the clinical state of the patient and local expertise but, for non-lesional biopsies, a 16-gauge needle is recommended. Many patients with liver disease will have abnormal laboratory coagulation tests or receive anticoagulation or antiplatelet medication. A greater understanding of the changes in haemostasis in liver disease allows for a more rational, evidence-based approach to peri-biopsy management. Overall, liver biopsy is safe but there is a small morbidity and a very small mortality so patients must be fully counselled. The specimen must be of sufficient size for histopathological interpretation. Communication with the histopathologist, with access to relevant clinical information and the results of other investigations, is essential for the generation of a clinically useful report.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

Haemostatic Efficacy of Topical Agents During Liver Resection: A Network Meta-Analysis of Randomised Trials

BACKGROUND

Hepatic resection carries a high risk of parenchymal bleeding both intra- and post-operatively. Topical haemostatic agents are frequently used to control bleeding during hepatectomy, with multiple products currently available. However, it remains unknown which of these is most effective for achieving haemostasis and improving peri-operative outcomes.

METHODS

A systematic review and random-effects Bayesian network meta-analysis of randomised trials investigating topical haemostatic agents in hepatic resection was performed. Interventions were analysed by grouping into similar products; fibrin patch, fibrin glue, collagen products, and control. Primary outcomes were the rate of haemostasis at 4 and 10 min.

RESULTS

Twenty randomized controlled trials were included in the network meta-analysis, including a total of 3267 patients and 7 different interventions. Fibrin glue and fibrin patch were the most effective interventions for achieving haemostasis at both 4 and 10 min. There were no significant differences between haemostatic agents with respect to blood loss, transfusion requirements, bile leak, post-operative complications, reoperation, or mortality.

CONCLUSIONS

Amongst the haemostatic agents currently available, fibrin patch and fibrin glue are the most effective methods for reducing time to haemostasis during liver resection, but have no effect on other peri-operative outcomes. Topical haemostatic agents should not be used routinely, but may be a useful adjunct to achieve haemostasis when needed.

Transfusional optimization in liver transplant using viscoelastic test guided therapy

BACKGROUND

Assess the reduction of packed red blood cells (PRBCs) transfusion in liver transplantation (LT) after the introduction of the thromboelastometry as intraoperative coagulation monitor.

METHODS

We conducted a retrospective cohort study (n=92), randomized into two groups: groupA (control), in whom transfusion therapy was based on conventional laboratory tests (CLT), and groupB (ROTEM), whose blood transfusion was performed as protocolized algorithms, guided by thromboelastometry (ROTEM). We analyzed packed red blood cells (PRBCs) units, transfused units of fresh frozen plasma (FFP), platelets units, fibrinogen and tranexamic acid. We used the chi square test for the comparison of proportions and Student's t test to compare means when the distribution was normal. Otherwise, Mann-Whitney U test was performed.

RESULTS

In groupA 84.8% of patients required transfusion of PRBCs, with a median (IQR) of 4 (1.5-6), compared with 67.4% in groupB with a median (IQR) of 2 (0-4) (P<.05). We also found differences in the following variables: FFP transfusion rate was 84.8% with a median (IQR) of 5 (2-12) IU in groupA and 56.5% (median (IQR) of 1 (0-4.5) in B (P<.001) and in the fibrinogen administration, that was 6.5% in groupA and 34.8% in groupB (P<.01). Backward stepwise logistic regression model showed associations between the clamping time, the preoperative hemoglobin, the portal hypertension (PHT) and being or not in the treatment group and the need for perioperative transfusion. We didn't find significant differences in the incidence of complication during the early postoperative period between the two groups.

CONCLUSIONS

The introduction of thromboelastometry (ROTEM) measurements in hemostatic therapy algorithms reduces the transfusion rate of FFP and PRBCs during liver transplantation. The using of ROTEM derived thresholds leads to detecting higher requirements of fibrinogen compared to conventional laboratory tests.

The safety and efficacy of hypovolemic phlebotomy on blood loss and transfusion in liver surgery: a systematic review and meta-analysis

BACKGROUND

Hypovolemic phlebotomy (HP) is a novel intervention that involves intraoperative removal of whole blood (7-10 mL/kg) without volume replacement. The subsequent central venous pressure (CVP) reduction is hypothesized to decrease blood loss and the need for blood transfusion. The objective was to conduct a systematic assessment of the safety and efficacy of HP on blood loss and transfusion in the liver surgery literature.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases were searched. Outcomes of interest included blood loss, allogenic red blood cell transfusion, postoperative adverse events, and CVP change. A qualitative synthesis and meta-analysis were performed as appropriate.

RESULTS

Four cohort studies, one case series, and three randomized controlled trials involving 2255 patients were included. Meta-analysis of studies involving liver resections for any indication (n = 6) found no difference in transfusion (OR 0.38, p = 0.12) or incidence of adverse events with HP compared to non-use. Pooling of studies involving liver resections for an underlying pathology (n = 4) revealed HP was associated with significant reduction in transfusion (OR 0.25, p = 0.03) but no differences in blood loss (-173 mL, p = 0.17).

CONCLUSION

This review suggests HP is safe and associated with decreased transfusion in patients undergoing liver surgery. It supports further investigation.

Phlebotomy resulting in controlled hypovolaemia to prevent blood loss in major hepatic resections (PRICE-1): a pilot randomized clinical trial for feasibility

BACKGROUND

Major liver resection is associated with blood loss and transfusion. Observational data suggest that hypovolaemic phlebotomy can reduce these risks. This feasibility RCT compared hypovolaemic phlebotomy with the standard of care, to inform a future multicentre trial.

METHODS

Patients undergoing major liver resections were enrolled between June 2016 and January 2018. Randomization was done during surgery and the surgeons were blinded to the group allocation. For hypovolaemic phlebotomy, 7-10 ml per kg whole blood was removed, without intravenous fluid replacement. Co-primary outcomes were feasibility and estimated blood loss (EBL).

RESULTS

A total of 62 patients were randomized to hypovolaemic phlebotomy (31) or standard care (31), at a rate of 3·1 patients per month, thus meeting the co-primary feasibility endpoint. The median EBL difference was -111 ml (P = 0·456). Among patients at high risk of transfusion, the median EBL difference was -448 ml (P = 0·069). Secondary feasibility endpoints were met: enrolment, blinding and target phlebotomy (mean(s.d.) 7·6(1·9) ml per kg). Blinded surgeons perceived that parenchymal resection was easier with hypovolaemic phlebotomy than standard care (16 of 31 versus 10 of 31 respectively), and guessed that hypovolaemic phlebotomy was being used with an accuracy of 65 per cent (20 of 31). There was no significant difference in overall complications (10 of 31 versus 15 of 31 patients), major complications or transfusion. Among those at high risk, transfusion was required in two of 15 versus three of nine patients (P = 0·326).

CONCLUSION

Endpoints were met successfully, but no difference in EBL was found in this feasibility study. A multicentre trial (PRICE-2) powered to identify a difference in perioperative blood transfusion is justified. Registration number: NCT02548910 ( http://www.clinicaltrials.gov).

Improved hemostasis with major hepatic resection in the current surgical era

BACKGROUND

Major hepatic resection, predominantly performed for oncologic intent, is a complex procedure with the potential for severe intraoperative hemorrhage. The current surgical era has the ability to improve hemostasis throughout the performance of major hepatic resections which decreases blood transfusions and the detrimental effects associated with transfusion. We evaluated hemostasis and outcomes in the current surgical era of performing hepatic resections.

METHODS

Utilizing the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database all major hepatic resections performed between 2012 and 2016 were analyzed in regards to hemostasis. Hemostasis was evaluated by the need for and magnitude of blood transfusions. Additional perioperative variables (including operative time, length of hospital stay, and mortality rates) were analyzed to assess for outcomes with hemostasis. The NSQIP results were compared to previous publications involving major hepatic resections to detect improvement in hemostasis and outcomes in the current surgical era.

RESULTS

A total of 22777 major hepatic resections met the inclusion criteria for analysis in the NSQIP database. An additional 21198 cases were compiled within the selected publications for comparative analysis. The transfusion rate in the current surgical era was 13.3% versus 38.7% in the previous era (P = 0.0001). When a transfusion was required in the current surgical era there was a two-fold reduction in the number of units transfused (1.5 U vs. 3.8 U, P = 0.0001). Statistically significant improvements in operative time and length of hospital stay were presented within the current surgical era (P = 0.0001). When a transfusion was required there was an increased relative risk score of 7 for mortality (4.9% vs. 0.7%, P = 0.0001), however, improvement in mortality rates did not reach statistical significance across surgical eras (1.3% vs. 4.0%, P = 0.0001).

CONCLUSIONS

The conduction of major hepatic resection in the current surgical era is more hemostatic. Correlated with improved hemostasis are better outcomes for both clinical and financial endpoints. These findings should encourage continued and increased performance of major hepatic resections.

In vivo photoacoustic imaging of major blood vessels in the pancreas and liver during surgery

Abdominal surgeries carry considerable risk of gastrointestinal and intra-abdominal hemorrhage, which could possibly cause patient death. Photoacoustic imaging is one solution to overcome this challenge by providing visualization of major blood vessels during surgery. We investigate the feasibility of in vivo blood vessel visualization for photoacoustic-guided liver and pancreas surgeries. In vivo photoacoustic imaging of major blood vessels in these two abdominal organs was successfully achieved after a laparotomy was performed on two swine. Three-dimensional photoacoustic imaging with a robot-controlled ultrasound (US) probe and color Doppler imaging were used to confirm vessel locations. Blood vessels in the in vivo liver were visualized with energies of 20 to 40 mJ, resulting in 10 to 15 dB vessel contrast. Similarly, an energy of 36 mJ was sufficient to visualize vessels in the pancreas with up to 17.3 dB contrast. We observed that photoacoustic signals were more focused when the light source encountered a major vessel in the liver. This observation can be used to distinguish major blood vessels in the image plane from the more diffuse signals associated with smaller blood vessels in the surrounding tissue. A postsurgery histopathological analysis was performed on resected pancreatic and liver tissues to explore possible laser-related damage. Results are generally promising for photoacoustic-guided abdominal surgery when the US probe is fixed and the light source is used to interrogate the surgical workspace. These findings are additionally applicable to other procedures that may benefit from photoacoustic-guided interventional imaging of the liver and pancreas (e.g., biopsy and guidance of radiofrequency ablation lesions in the liver).

The validity of central venous to arterial carbon dioxide difference to predict adequate fluid management during living donor liver transplantation. A prospective observational study

BACKGROUND

To assess the validity of central and pulmonary veno-arterial CO₂ gradients to predict fluid responsiveness and to guide fluid management during liver transplantation.

METHODS

In adult recipients (ASA III to IV) scheduled for liver transplantation, intraoperative fluid management was guided by pulse pressure variations (PPV). PPV of ≥15% (Fluid Responding Status-FRS) indicated fluid resuscitation with 250 ml albumin 5% boluses repeated as required to restore PPV to < 15% (Fluid non-Responding Status-FnRS). Simultaneous blood samples from central venous and pulmonary artery catheters (PAC) were sent to calculate central venous to arterial CO₂ gap [C(v-a) CO2 gap] and pulmonary venous to arterial CO₂ gap [Pulm(p-a) CO2 gap]. CO and lactate were also measured.

RESULTS

Sixty seven data points were recorded (20 FRS and 47 FnRS). The discriminative ability of central and pulmonary CO₂ gaps between the two states (FRS and FnRS) was poor with AUC of ROC of 0.698 and 0.570 respectively. Central CO₂ gap was significantly higher in FRS than FnRS (P = 0.016), with no difference in the pulmonary CO₂ gap between both states. The central and Pulmonary CO₂ gaps are weakly correlated to PPV [r = 0.291, (P = 0.017) and r = 0.367, (P = 0.002) respectively]. There was no correlation between both CO₂ gaps and both CO and lactate.

CONCLUSION

Central and the Pulmonary CO₂ gaps cannot be used as valid tools to predict fluid responsiveness or to guide fluid management during liver transplantation. CO₂ gaps also do not correlate well with the changes in PPV or CO.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03123172 . Registered on 31-march-2017.

Hypovolemic phlebotomy in liver surgery is associated with decreased red blood cell transfusion

BACKGROUND

Perioperative red blood cell (RBC) transfusion is associated with poor outcomes in liver surgery. Hypovolemic phlebotomy (HP) is a novel intervention hypothesized to decrease transfusion requirements. The objective of this study was to examine this hypothesis.

METHODS

Consecutive patients who underwent liver resection at one institution (2010-2016) were included. Factors found to be predictive of transfusion on univariate analysis and those previously published were modeled using multivariate logistic regression.

RESULTS

A total of 361 patients underwent liver resection (50% major). HP was performed in 45 patients. Phlebotomized patients had a greater proportion of primary malignancy (31% vs 18%) and major resection (84% vs 45%). Blood loss was significantly lower with phlebotomy in major resections (400 vs 700 mL). Nadir central venous pressure was significantly lower with HP (2.5 vs 5 cm H₂O). On multivariate logistic regression, HP (OR 0.20, 95% CI 0.068-0.57, p = 0.0029), major liver resection (OR 2.91, 95% CI 1.64-5.18, p = 0.0003), preoperative hemoglobin < 125 g/L (OR 6.02, 95% CI 3.44-10.56, p < 0.0001), and underlying liver disease (OR 2.24, 95% CI 1.27-3.95, p = 0.0051) were significantly associated with perioperative RBC transfusion.

CONCLUSION

Hypovolemic phlebotomy appears to be strongly associated with a reduction in RBC transfusion requirements in liver resection, independent of other known risk factors.

Sandwich-Like Fibers/Sponge Composite Combining Chemotherapy and Hemostasis for Efficient Postoperative Prevention of Tumor Recurrence and Metastasis

Intraoperative bleeding is an essential factor leading to the earliest recurrence and tumor metastasis frequently seen after resection of solid tumors. Local drug delivery implants show the unique advantages on postoperative cancer therapy. Herein, a sandwich-like cisplatin-loaded fibers/sponge composite (CFSC) combining chemotherapy and hemostasis is constructed. The obtained implantable CFSC is able to simultaneously stop bleeding and absorb disseminated tumor cells after tumor resection. More importantly, sustained released cisplatin can kill local residual tumor cells as well as those concentrated in the CFSC, which significantly inhibits local tumor recurrence and distant tumor metastasis on the subcutaneous postoperative recurrence model and metastasis models. This dual functional implant strategy with low toxicity to healthy organs may inspire new aspects for efficient postoperative cancer therapy.

A Systematic Review and Meta-Analysis Comparing Liver Resection with the Rf-Based Device Habib™-4X with the Clamp-Crush Technique

Liver cancer is the sixth most common cancer and third most common cause of cancer-related mortality. Presently, indications for liver resections for liver cancers are widening, but the response is varied owing to the multitude of factors including excess intraoperative bleeding, increased blood transfusion requirement, post-hepatectomy liver failure and morbidity. The advent of the radiofrequency energy-based bipolar device Habib™-4X has made bloodless hepatic resection possible. The radiofrequency-generated coagulative necrosis on normal liver parenchyma provides a firm underpinning for the bloodless liver resection. This meta-analysis was undertaken to analyse the available data on the clinical effectiveness or outcomes of liver resection with Habib™-4X in comparison to the clamp-crush technique. The RF-assisted device Habib™-4X is considered a safe and feasible modality for liver resection compared to the clamp-crush technique owing to the multitude of benefits and mounting clinical evidence supporting its role as a superior liver resection device. The most intriguing advantage of the RF-device is its ability to induce systemic and local immunomodulatory changes that further expand the boundaries of survival outcomes following liver resection.

A Prospective, Randomized, Phase III Study to Evaluate the Efficacy and Safety of Fibrin Sealant Grifols as an Adjunct to Hemostasis as Compared to Cellulose Sheets in Hepatic Surgery Resections

BACKGROUND

Local hemostatic agents have a role in limiting bleeding complications associated with liver resection.

METHODS

In this randomized, phase III study, we compared the efficacy and safety of Fibrin Sealant Grifols (FS Grifols) with oxidized cellulose sheets (Surgicel®) as adjuncts to hemostasis during hepatic resections. The primary efficacy endpoint was the proportion of patients achieving hemostasis at target bleeding sites (TBS) within 4 min (T₄) of treatment application. Secondary efficacy variables were time to hemostasis (TTH) at a later time point if re-bleeding occurs and cumulative proportion of patients achieving hemostasis by time points T₂, T₃, T₅, T₇, and T₁₀.

RESULTS

The rate of hemostasis by T₄ was 92.8% in the FS Grifols group (n = 163) and 80.5% in the Surgicel® group (n = 162) (p = 0.01). The mean TTH was significantly shorter (p < 0.001) in the FS Grifols group (2.8 ± 0.14 vs. 3.8 ± 0.24 min). The rate of hemostasis by T₂, T₅, and T₇ was higher and statistically superior in the FS Grifols group compared to Surgicel®. No substantial differences in adverse events (AE) were noted between treatment groups. The most common AEs were procedural pain (36.2 vs. 37.7%), nausea (20.9 vs. 23.5%), and hypotension (14.1 vs 6.2%).

CONCLUSIONS

FS Grifols was safe and well tolerated as a local hemostatic agent during liver resection surgeries. Overall, data demonstrate that the hemostatic efficacy of FS Grifols is superior to Surgicel® and support the use of FS Grifols as an effective local hemostatic agent in these surgical procedures.

Intensive Care of Pulmonary Complications Following Liver Transplantation

Chronic liver disease has been associated with pulmonary dysfunction both before and after liver transplantation. Post-liver transplantation pulmonary complications can affect both morbidity and mortality often necessitating intensive care during the immediate postoperative period. The major pulmonary complications include pneumonia, pleural effusions, pulmonary edema, and atelectasis. Poor clinical outcomes have been known to be associated with age, severity of liver dysfunction, and preexisting lung disease as well as perioperative events related to fluid balance, particularly transfusion and fluid volumes. Delineating each and every one of these pulmonary complications and their associated risk factors becomes paramount in guiding specific therapeutic strategies.

Current practices in perioperative blood management for patients undergoing liver resection: a survey of surgeons and anesthesiologists

BACKGROUND

Development of intraoperative techniques and blood management strategies in liver resection, and the multidisciplinary nature of perioperative transfusion decision making, creates an opportunity for practice variation. The aim of this study was to describe the current practices in perioperative blood management and explore differences between surgeons and anesthesiologists.

STUDY DESIGN AND METHODS

A Web-based survey was developed, piloted, and circulated to Canadian liver surgeons and anesthesiologists. The survey focused on management of preoperative anemia, blood conservation strategies, estimation of blood loss, and transfusion decision making in a multidisciplinary setting.

RESULTS

A total of 198 physicians received the survey, with 117 responding (59%). Most responding surgeons (67%) perform more than 20 liver resections per year, while most responding anesthesiologists (90%) take part in fewer than 20. Anesthesiologists most commonly stated that preoperative anemia is managed by someone else (38%), while surgeons most commonly reported "no specific treatment" (45%). The most common intraoperative blood conservation technique used is administration of antifibrinolytics (63% used them at least occasionally). The most important factor for anesthesiologists when deciding on an intraoperative transfusion was hemoglobin value (47%); for surgeons, it was patient hemodynamics (33%). Compared to when they started their career, 60% of respondents felt that they were less likely to transfuse a patient now.

CONCLUSION

The results of our survey provide insights into current transfusion practice and decision making in liver resection, including a comparison between anesthesiologist and surgeon transfusion behavior. Management of preoperative anemia, increased use of intraoperative blood conservation techniques, and improved communication between providers were identified as targets for quality improvement.

Postoperative complications in cirrhotic pediatric deceased donor liver transplantation: Focus on transfusion therapy

Intraoperative transfusions seem associated with patient death and graft failure after PLTx. A retrospective analysis of recipients' and donors' characteristics and transplantation data in a cohort of patients undergoing PLTx from 2002 to 2009 at the Bergamo General Hospital was performed. A two-stage hierarchical Cox proportional hazard regression with forward stepwise selection was used to identify the main risk factors for major complications. In addition, propensity score analysis was used to adjust risk estimates for possible selection biases in the use of blood products. Over the 12-year period, 232 pediatric cirrhotic patients underwent PLTx. One-year patient and graft survival rates were 92.3% and 83.7%, respectively. The Kaplan-Meier shows that the main decrease in both graft and patient survival occurs during the first months post-transplantation. At the same time, it appears that most of the complications occur during the first month post-transplantation. One-month and 1-year patient complication-free survival rates were 24.8% and 12.1%, respectively. Our study shows that intraoperative red blood cells and platelet transfusions are independent risk factors for developing one or more major complications in the first year after PLTx. Decreasing major complications will improve the health status and overall long-term patient survival after pediatric PLTx.

A new index predicts early allograft dysfunction following living donor liver transplantation: A propensity score analysis

OBJECTIVE/AIM

The aim of this study was to identify a new index to predict early allograft dysfunction following living donor liver transplantation.

METHODS

The study enrolled 260 adult living donor liver transplantation recipients. Postoperative laboratory variables were assessed for their association with the prevalence of early allograft dysfunction using the inverse probability of treatment weighting and propensity-score matching (n=93 pairs) analysis.

RESULTS

Forty-seven recipients (18.1%) developed early allograft dysfunction. In multivariable analysis, the alanine aminotransferase and gamma-glutamyl transpeptidase levels on postoperative day 1 were independent predictors of early allograft dysfunction. The alanine aminotransferase to gamma-glutamyl transpeptidase ratio (AGR) was developed. All cases were divided into two groups (Group 1 [AGR≥8.47, n=103] and Group 2 [AGR<8.47, n=157]). AGR≥8.47 (OR 10.345, 95%CI 4.502-23.772, p<0.001), hepatorenal syndrome (OR 3.016, 95%CI 1.119-8.125, p=0.029), and graft to recipient weight ratio <0.8% (OR 2.155, 95%CI 1.004-4.624, p=0.049) were independent risk factors for early allograft dysfunction. The prevalence of early allograft dysfunction was higher in group 1 (after adjusting for inverse probability of treatment weighting [n=39; 37.9% vs n=8; 5.1%] and propensity-score matching [n=33; 35.5% vs n=2; 2.2%]) than that in group 2 (p<0.001).

CONCLUSIONS

The postoperative AGR is a practical index for predicting early allograft dysfunction after living donor liver transplantation.

Pathogenesis, prevention, and management of bleeding and thrombosis in patients with liver diseases

Patients with liver diseases may develop alterations in all components of the hemostatic system. Thrombocytopenia, low levels of coagulation factors and inhibitors, low levels of fibrinolytic proteins, and increased levels of endothelial-derived proteins such as von Willebrand factor are all part of the coagulopathy of liver disease. Due to concomitant changes in pro- and antihemostatic drivers, the net effects of these complex hemostatic changes have long been unclear. According to current concepts, the hemostatic system of patients with liver disease is in an unstable balance, which explains the occurrence of both bleeding and thrombotic complications. This review will discuss etiology and management of bleeding and thrombosis in liver disease and will outline unsolved clinical questions. In addition, we will discuss the role of intrahepatic activation of coagulation for progression of liver disease, a novel paradigm with potential consequences for the general management of patients with liver disease.

Comparison of TachoSil and TachoComb in patients undergoing liver resection-a randomized, double-blind, non-inferiority trial

Background

This study aimed to demonstrate the noninferior efficacy of TachoSil vs. TachoComb in Japanese patients undergoing liver resection and to assess the safety of TachoSil vs. TachoComb in these patients.

Methods

This randomized, double-blind, noninferiority study (JapicCTI-090684) involved participants scheduled for liver resection/living donors (age ≥ 20 years). TachoSil or TachoComb (1:1 allocation ratio) was applied to control persistent exudative bleeding after primary hemostasis during liver resection/removal for donation. The primary outcome was hemostasis 5 min after study treatment application. The 95% confidence interval (CI) for the difference in the proportion of participants with hemostasis 5 min after application of TachoSil/TachoComb was determined; noninferiority of TachoSil was indicated if the lower limit of the CI was ≥−14%. Adverse events (AEs) were recorded.

Results

All participants in the efficacy analysis (TachoSil: 54/54, 100%; TachoComb: 54/54, 100%) achieved hemostasis 5 min after study treatment application. Therefore, TachoSil was noninferior to TachoComb. All participants experienced ≥1 AE; however, none discontinued because of an AE. Most (≥97.8%) AEs were mild or moderate in severity.

Conclusions

These findings confirm the safety profile and noninferior hemostatic efficacy of TachoSil compared with TachoComb.

Central Venous Pressure Drop After Hypovolemic Phlebotomy is a Strong Independent Predictor of Intraoperative Blood Loss During Liver Resection

BACKGROUND

Intraoperative hypovolemic phlebotomy (HP) has been suggested to reduce central venous pressure (CVP) before hepatectomy. This study aimed to analyze the impact of CVP drop after HP on intraoperative blood loss and postoperative renal function.

METHODS

A retrospective review of a prospective database including 100 consecutive patients (43 males and 57 females; mean age, 65 years; range 23-89 years) undergoing liver resection with HP was performed. The primary outcome variable was estimated blood loss (EBL), and the secondary outcome was postoperative serum creatinin (Scr). A multivariate linear regression analysis was performed to identify predictors of intraoperative blood loss.

RESULTS

The median CVP before blood salvage was 8 mmHg (range 4-30 mmHg). The median volume of hypovolemic phlebotomy was 400 ml (range 200-1000 ml). After HP, CVP decreased to a median of 3 mmHg (range -2 to 16 mmHg), resulting in a median CVP drop of 5.5 mmHg (range 2-14 mmHg). The median EBL during liver resection was 165 ml (range 0-800 ml). The median preoperative serum creatinin (Scr) was 0.82 g/dl (range 0.5-1.74 g/dl), and the postoperative Scr on day 1 was 0.74 g/dl (range 0.44-1.68 g/dl). The CVP drop was associated with EBL (P < 0.001). There was no significant impact of CVP drop on postoperative Scr.

CONCLUSION

A CVP drop after HP is a strong independent predictor of EBL during liver resection. The authors advocate the routine use of HP to reduce perioperative blood loss and transfusion rates in liver surgery. As a predictive tool, CVP drop might help surgeons decide whether a laparoscopic approach is safe.

Major liver resection, systemic fibrinolytic activity, and the impact of tranexamic acid

BACKGROUND

Hyperfibrinolysis may occur due to systemic inflammation or hepatic injury that occurs during liver resection. Tranexamic acid (TXA) is an antifibrinolytic agent that decreases bleeding in various settings, but has not been well studied in patients undergoing liver resection.

METHODS

In this prospective, phase II trial, 18 patients undergoing major liver resection were sequentially assigned to one of three cohorts: (i) Control (no TXA); (ii) TXA Dose I - 1 g bolus followed by 1 g infusion over 8 h; (iii) TXA Dose II - 1 g bolus followed by 10 mg/kg/hr until the end of surgery. Serial blood samples were collected for thromboelastography (TEG), coagulation components and TXA concentration.

RESULTS

No abnormalities in hemostatic function were identified on TEG. PAP complex levels increased to peak at 1106 μg/L (normal 0-512 μg/L) following parenchymal transection, then decreased to baseline by the morning following surgery. TXA reached stable, therapeutic concentrations early in both dosing regimens. There were no differences between patients based on TXA.

CONCLUSIONS

There is no thromboelastographic evidence of hyperfibrinolysis in patients undergoing major liver resection. TXA does not influence the change in systemic fibrinolysis; it may reduce bleeding through a different mechanism of action. Registered with ClinicalTrials.gov: NCT01651182.

Safety and feasibility of phlebotomy with controlled hypovolemia to minimize blood loss in liver resections

BACKGROUND

Liver resection can be associated with significant blood loss and transfusion. Whole blood phlebotomy is an under-reported technique, distinct from acute normovolemic hemodilution, the goal of which is to minimize blood loss in liver operation. This work sought to report on its safety and feasibility and to describe technical considerations.

METHODS

Consecutive patients who had an elective liver resection and concurrent phlebotomy between 2013 and 2016 were examined prospectively. Formal Inclusion and exclusion criteria were defined a priori. All surgical indications were allowed. All procedures were carried out with a stated goal of low central venous pressure anesthesia (<5 cm H₂O). The target phlebotomy volume was 7-10 mL/kg of patient body weight. The removed blood was not replaced by intravenous fluid. Removed blood was returned back to the patient after parenchymal transection. Safety end points were examined. A historic cohort (2010-2014) of major resections was included for comparison.

RESULTS

A total of 37 patients underwent liver resection with phlebotomy (86% major) and 101 without. Half had metastatic colorectal cancer. The median phlebotomy volume was 7.2 mg/kg (4.7-10.2), yielding a median drop in central venous pressure of 3 cm H₂O (0-15). Median blood loss was 400 vs 700 mL (P = .0016), and the perioperative transfusion rate was 8.1% vs 32% (P = .0048). There was no difference between the 2 groups in overall complications, mortality, intensive care admission, duration of stay, or end-organ ischemic complications.

CONCLUSION

Whole blood phlebotomy with controlled hypovolemia prior to liver resection seems to be safe and feasible. Comparative studies are required to determine its effectiveness.

A multicentre, prospective, randomized, controlled trial comparing EVARREST™ fibrin sealant patch to standard of care in controlling bleeding following elective hepatectomy: anatomic versus non-anatomic resection

BACKGROUND

This multicentre, randomized clinical trial assessed the safety and effectiveness of the EVARREST™ Fibrin Sealant Patch (FP) in treating parenchymal bleeding following anatomic and non-anatomic liver resections.

METHODS

One hundred and two patients were stratified according to the type of hepatic resection (anatomic/non-anatomic), and randomized (1:1) after identification of an appropriate bleeding site, to FP vs Standard of Care (SoC, manual compression ± topical haemostat). The primary endpoint was haemostasis at 4 min from bleeding site identification with no re-bleeding requiring re-treatment.

RESULTS

The FP was superior in achieving haemostasis at 4 min (96%, 48/50) to SoC (46%, 24/52; p < 0.001). Stratification for resection type showed treatment differences for primary endpoint for anatomic (24/25 FP vs 13/23 SoC; p = 0.001) and non-anatomic liver resections (24/25FP vs 11/29 SoC; p < 0.001). Adverse events related to the study procedure were reported in 40/50 patients (80%) in the FP group and 43/52 patients (83%) in the SoC group. One (2%) adverse event (infected intra-abdominal fluid collection) was possibly related to study treatment.

CONCLUSION

This clinical trial confirms that the FP is safe and highly effective in controlling parenchymal bleeding following hepatectomy regardless of the type of resection. ClinicalTrials.gov NCT01993888.

Blood loss and outcomes after resection of colorectal liver metastases

BACKGROUND

The influence of intraoperative blood loss (IBL) on long-term outcomes of patients undergoing liver resection for colorectal cancer liver metastases (CRLM) remains not well defined.

MATERIALS AND METHODS

A total of 433 patients who underwent curative-intent hepatic resection for CRLM between 2000 and 2013 at Johns Hopkins were identified. Demographics, IBL data, and long-term outcomes were collected and analyzed. Clinicopathologic predictors of IBL and the association of IBL and outcomes were assessed.

RESULTS

The median patient age was 54 y (interquartile range, 44-64), most patients were male (58.9%; n = 255). At surgery, the median IBL was 400 mL (range, 10-5100 mL). Two-hundred eighty-seven patients (66.3%) had an IBL of >250 mL. Factors associated with increased IBL (>250 mL) on multivariate analysis were male sex (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.68-4.09; P < 0.001), tumor size >3 cm (OR, 1.88; 95% CI, 1.18-2.99; P = 0.008), and major hepatic resection (OR, 3.08; 95% CI, 1.92-4.92; P < 0.001). At a median follow-up time of 30.6 mo, the median survival times were 70.5, 56.4, and 36.9 mo for IBL <250, 250-1000, and >1000 mL, respectively (P = 0.004). IBL >250 mL remained an independent prognostic factor of overall survival in multivariate analysis (hazard ratio, 1.41; 95% CI, 1.01-1.97; P = 0.04) after adjusting for other factors including the receipt of blood transfusion.

CONCLUSIONS

The magnitude of IBL during CRLM resection was related to biologic characteristics of the tumor and the extent of surgery. Increased IBL during CRLM resection was an independent prognostic factor for worse patient survival. Furthermore, a dose-response relationship between increasing IBL and worsening survival was evident.

Ex vivo addition of fibrinogen concentrate improves the fibrin network structure in plasma samples taken during liver transplantation

BACKGROUND

Optimal hemostatic management during orthotopic liver transplantation (OLT) remains a challenge. The cause of bleeding during OLT is multifactorial, and may include hemostatic imbalance. Fibrinogen concentrates are increasingly being used to control perioperative bleeding during OLT. However, administration is based on arbitrary thresholds of fibrinogen levels. Importantly, studies on fibrin clot structure during OLT are lacking.

OBJECTIVE

We determined the hemostatic efficacy of fibrinogen concentrate in correcting the fibrin structure.

METHODS

Plasma samples taken at various times during OLT from 15 patients and 15 healthy controls were spiked with 1 g L(-1) fibrinogen concentrate or saline. Turbidity, fibrin fiber density and permeability of the fibrin clots were assessed.

RESULTS

Clotting rate and turbidity were significantly decreased at the start of surgery, and decreased even further during surgery. Addition of fibrinogen significantly increased the clotting rate and turbidity at all time points, but did not normalize it. Fibrin density was significantly reduced after reperfusion as compared with the density at the start of surgery and in healthy controls. Fibrin density improved significantly after addition of fibrinogen in samples taken at the start of surgery and after reperfusion. The severely impaired polymerization and decreased density after reperfusion were accompanied by significantly increased permeability of the clot as compared with the start of surgery and in controls, which was completely restored after addition of fibrinogen.

CONCLUSIONS

Ex vivo addition of fibrinogen concentrate during OLT substantially improves the structural properties of the fibrin clot, which, particularly after reperfusion, shows hypocoagulable features. These data support the use of fibrinogen concentrate to control bleeding complications during OLT.

Affinity purification of aprotinin from bovine lung

An affinity protocol for the purification of aprotinin from bovine lung was developed. To simulate the structure of sucrose octasulfate, a natural specific probe for aprotinin, the affinity ligand was composed of an acidic head and a hydrophobic stick, and was then linked with Sepharose. The sorbent was then subjected to adsorption analysis with pure aprotinin. The purification process consisted of one step of affinity chromatography and another step of ultrafiltration. Then purified aprotinin was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis, trypsin inhibitor activity, gel-filtration, and thin-layer chromatography analysis. As calculated, the theoretical maximum adsorption (Qmax ) of the affinity sorbent was 25,476.0 ± 184.8 kallikrein inactivator unit/g wet gel; the dissociation constant of the complex "immobilized ligand-aprotinin" (Kd ) was 4.6 ± 0.1 kallikrein inactivator unit/mL. After the affinity separation of bovine lung aprotinin, reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis and gel-filtration chromatography revealed that the protein was a single polypeptide, and the purities were ∼ 97 and 100%, respectively; the purified peptide was also confirmed with aprotinin standard by gel-filtration chromatography and thin-layer chromatography. After the whole purification process, protein, and bioactivity recoveries were 2.2 and 92.6%, respectively; and the specific activity was up to 15,907.1 ± 10.2 kallikrein inactivator unit/mg.

The effect of ferric chloride on superficial bleeding

Background:

Controlling superficial bleeding, despite all the progress in surgical science, is still a challenge in some settings.

Objectives:

This study assesses the hemostatic effects of ferric chloride and compares it with the standard method (suturing technique) to control superficial bleeding.

Materials and Methods:

In this animal model study, 60 male Wistar rats were used. An incision, 2 cm long and 0.5 cm deep was made on rat skin and the hemostasis time was recorded using ferric chloride at different concentrations (5%, 10%, 15%, 25%, and 50%) and then using a control (i.e. control of bleeding by suturing). The skin tissue was examined for pathological changes. Finally, the obtained data were entered into SPSS (ver. 16) and analyzed using Kruskal-Wallis test, Mann-Whitney, Kolmogorov-Smirnov, and Wilcoxon signed ranks test.

Results:

The hemostasis time for the ferric chloride concentration group was significantly less than for the control group (P < 0.001).

Conclusions:

Ferric chloride may be an effective hemostatic agent to control superficial bleeding in rats.