The temporal pattern of postoperative coagulation status in patients undergoing major liver surgery

The link between high factor VIII to protein C ratio values and poor liver function after major hepatectomy

Our goal was to assess the coagulation profile in the immediate postoperative time after major liver surgery and its association with the liver function. Our hypothesis is that a decreased synthesis of the coagulation factor levels reflects an impaired liver synthesis following hepatic resection and will be associated with poor outcomes. This is a prospective, observational study recruiting consecutive patients scheduled for major liver resection in a tertiary hospital. Coagulation profile was assessed by conventional assays, viscoelastic assays and coagulation factor levels preoperatively and, on postoperative days 1, 2 and 6. Factor VIII to protein C (FVIII/PC) ratio has been used as a surrogate marker of hemostatic imbalance. Liver function was measured with conventional and indocyanine green (ICG) clearance tests, which were obtained preoperatively and on postoperative days 1 and 2. Sixty patients were recruited and 51 were included in the study. There is a clear increase in FVIII/PC ratio after surgery, which was significantly associated with low liver function, being more pronounced beyond postoperative day 2 and in patients with poorer liver function ( P  < 0.001). High FVIII/PC ratio values were significantly associated with higher postoperative morbidity, prolonged ICU and hospital stay and less survival ( P  < 0.05). High FVIII/PC ratio on postoperative day 2 was found to be predictor of posthepatectomy liver failure (PHLF; area under the ROC curve = 0.8129). Early postoperative high FVIII/PC ratio values are associated with low liver function, PHLF and poorer outcomes in patients undergoing major hepatic resection.

Peri-operative thrombophilia in patients undergoing liver resection for colorectal metastases

BACKGROUND

Routine chemical venous thromboembolism (VTE) prophylaxis for liver surgery remains controversial, and often delayed post-operatively due to perceived bleeding risk. This study asked whether patients undergoing hepatectomy for colorectal metastases (CRM) were at risk from VTE pre-operatively, and the impact of hepatectomy on that risk.

METHODS

Single-centre prospective observational cohort study of patients undergoing open hepatectomy for CRM, comparing pre-, peri- and post-operative haemostatic variables.

RESULTS

Of 336 hepatectomies performed October 2017-December 2019, 60 resections in 57 patients were recruited. There were 28 (46.7%) major resections, with median (interquartile range [IQR]) blood loss 150.0 (76.3-263.7) mls, no blood transfusions, post-operative VTE events or deaths. Patients were prothrombotic pre-operatively (high median factor VIIIC and increased thrombin generation velocity index), an effect exacerbated post-hepatectomy. Major hepatectomies had a significantly greater median drop in Protein C, rise in Factor VIIIC and von Willebrand Factor, versus minor resections (p = 0.001, 0.005, 0.001 respectively). Patients with parenchymal transection times greater than median (40 min), had significantly increased median (IQR) PMBC-TFmRNA expression [1.65(0.93-2.70)2ddCt], versus quicker transections [0.99(0.69-1.28)2ddCt, p = 0.020].

CONCLUSIONS

Patients with CRM are prothrombotic pre-operatively, an effect exacerbated by hepatectomy, particularly longer, complex resections, suggesting chemical thromboprophylaxis be considered early in the patient pathway.

Fibrinogen and albumin synthesis rates in major upper abdominal surgery

Plasma fibrinogen and albumin concentrations initially decrease after abdominal surgery. On postoperative days 3-5 fibrinogen concentration returns to the preoperative level or even higher, while albumin stays low. It is not known if these altered plasma concentrations reflect changes in synthesis rate, utilization, or both. In particular a low albumin plasma concentration has often been attributed to a low synthesis rate, which is not always the case. The objective of this study was to determine fibrinogen and albumin quantitative synthesis rates in patients undergoing major upper abdominal surgery with and without intact liver size. Patients undergoing liver or pancreatic resection (n = 9+6) were studied preoperatively, on postoperative days 1 and 3-5. De novo synthesis of fibrinogen and albumin was determined; in addition, several biomarkers indicative of fibrinogen utilization were monitored. After hemihepatectomy, fibrinogen synthesis was 2-3-fold higher on postoperative day 1 than preoperatively. On postoperative days 3-5 the synthesis level was still higher than preoperatively. Following major liver resections albumin synthesis was not altered postoperatively compared to preoperative values. After pancreatic resection, on postoperative day 1 fibrinogen synthesis was 5-6-fold higher than preoperatively and albumin synthesis 1.5-fold higher. On postoperative days 3-5, synthesis levels returned to preoperative levels. Despite decreases in plasma concentrations, de novo synthesis of fibrinogen was markedly stimulated on postoperative day 1 after both hemihepatectomies and pancreatectomies, while de novo albumin synthesis remained grossly unchanged. The less pronounced changes seen following hepatectomies were possibly related to the loss of liver tissue.

Post-hepatectomy venous thromboembolism: a systematic review with meta-analysis exploring the role of pharmacological thromboprophylaxis

PURPOSE

Patients undergoing hepatectomy are at moderate-to-high risk of venous thromboembolism (VTE). This study critically examines the efficacy of combining pharmacological (PTP) and mechanical thromboprophylaxis (MTP) versus only MTP in reducing VTE events against the risk of hemorrhagic complications.

METHODS

A systematic review of major reference databases was undertaken, and a meta-analysis was performed using common-effects model. Risk of bias assessment was performed using Newcastle-Ottawa scale. Trial sequential analysis (TSA) was used to assess the precision and conclusiveness of the results.

RESULTS

8 studies (n = 4238 patients) meeting inclusion criteria were included in the analysis. Use of PTP + MTP was found to be associated with significantly lower VTE rates compared to only MTP (2.5% vs 5.3%; pooled RR 0.50, p = 0.03, I² = 46%) with minimal type I error. PTP + MTP was not associated with an increased risk of hemorrhagic complications (3.04% vs 1.9%; pooled RR 1.54, p = 0.11, I² = 0%) and had no significant impact on post-operative length of stay (12.1 vs 10.8 days; pooled MD - 0.66, p = 0.98, I² = 0%) and mortality (2.9% vs 3.7%; pooled RR 0.73, p = 0.33, I² = 0%).

CONCLUSION

Despite differences in the baseline patient characteristics, extent of hepatectomy, PTP regimens, and heterogeneity in the pooled analysis, the current study supports the use of PTP in post-hepatectomy patients (grade of recommendation: strong) as the combination of PTP + MTP is associated with a significantly lower incidence of VTE (level of evidence, moderate), without an increased risk of post-hepatectomy hemorrhage (level of evidence, low).

Perioperative coagulation profile in major liver resection for cancer: a prospective observational study

Hepatectomy induced coagulation disturbances have been well studied over the past decade. Cumulative evidence supports the superiority of global coagulation analysis compared to conventional coagulation tests (i.e. PT or aPTT) for clinical decision making. Cancer, however, represents an acquired prothrombotic state and liver resection for cancer deserves a more thorough investigation. This prospective observational study was conducted to assess the perioperative coagulation status of patients undergoing major hepatectomies for primary or metastatic hepatic malignancy. Patients were followed up to the 10th postoperative day by serial measurements of conventional coagulation tests, plasma levels of coagulation factors and thrombin generation assay parameters. An abnormal coagulation profile was detected at presentation and included elevated FVIII levels, decreased levels of antithrombin and lag time prolongation in thrombin generation. Serial hematological data demonstrated increased vWF, FVIII, D-dimer, fibrinogen and decreased levels of natural anticoagulant proteins in the early postoperative period predisposing to a hypercoagulable state. The ratio of the anticoagulant protein C to the procoagulant FVIII was low at baseline and further declined postoperatively, indicating a prothrombotic state. Though no bleeding complications were reported, one patient experienced pulmonary embolism while under thromboprophylaxis. Overall, patients with hepatic carcinoma presenting for elective major hepatectomy may have baseline malignancy associated coagulation disturbances, aggravating the hypercoagulable state documented in the early postoperative period.

Severe Congenital Factor VII Deficiency with Normal Perioperative Coagulation Profile Based on ROTEM Analysis in a Hepatectomy

BACKGROUND Factor VII (FVII) deficiency is the most common autosomal-recessive bleeding disorder. FVII activity level (FVII: C) of 10-20% is often used as the threshold for administering activated recombinant FVII (rFVIIa) for patients undergoing major surgery. However, rFVIIa is expensive and carries the risk of a thromboembolic event, and thus should only be administered when truly indicated. CASE REPORT A 22-year-old woman with 8% FVII: C underwent a hepatectomy. Although there were no clinical signs of bleeding, peri-operative administration of rFVIIa was recommended by the hematologist (first dose at surgical incision, then 4 h later, then every 12 h until 48 h postoperatively). Intraoperatively, serials of ROTEM analysis were performed to evaluate the effect of rFVIIa administration. No significant effect of rFVIIa was seen on NATEM. Surgery was unremarkable, without any significant blood loss. The patient developed radial artery thrombosis 24 h postoperatively, the arterial line was removed, and rFVIIa was discontinued (PT: 14.6, FVII: C 36%). On POD 3, INR was elevated (3.15, FVII: C 3%). To correct INR, the patient was transfused 8 units of FFP, despite any signs of clinical bleeding. However, INR and FVII: C did not correct and the patient was discharged on POD 7 in a stable condition. CONCLUSIONS Even with FVII: C of 8%, the ROTEM analysis revealed a normal coagulation status. The administration of rFVIIa did not improve the already normal baseline coagulation profile, but rather potentially led to an accelerated coagulation or hypercoagulable state and may have led to the radial artery thrombosis. We endorse the use of viscoelastic testing for hemostasis assessment and factor replacement in congenital FVII deficiency.

Utility of viscoelastic coagulation testing in liver surgery: a systematic review

BACKGROUND

The objective of the current study was to summarize and evaluate all published evidence regarding viscoelastic testing in the field of liver surgery.

METHODS

A systematic search of the literature was performed using Medline/PubMed, Scopus, Cochrane Library Central, Google Scholar, and clinicaltrials.gov databases. The following keywords were used:"Thromboelastography", "Thromboelastometry", "Viscoelastic tests OR testing", "Sonoclot Devices", "Point-of-care tests OR testing", "Coagulation OR Haemostasis OR Hemostasis", "Liver OR Hepatic Surgery", "Cirrhosis."

RESULTS

A total of 12 studies analyzing 348 patients who underwent viscoelastic testing of coagulation during liver surgery for benign or malignant diseases were included; 7 (58.3%) studies reported on the use of thromboelastography (TEG), and 5 (41.7%) reported on rotational thromboelastometry (ROTEM). Viscoelastic testing (TEG and ROTEM) identified normo-, hyper- and hypo-coagulable status in 77% (n = 268/348), 18.4% (n = 64/348), and 4.6% (n = 16/348) of patients, respectively. In contrast, conventional coagulation tests indicated normo-coagulability in 111 patients (34.2% out of 325) and hypo-coagulability in 214 (65.8% out of 325) patients following liver resection. No patient (0% out of 291) experienced postoperative hemorrhage, whereas 5.8% (n = 17/291) experienced postoperative thromboembolic events.

CONCLUSIONS

Global viscoelastic testing may be a reasonable adjunct to conventional coagulation testing to provide a more robust assessment of the coagulation status of patients undergoing liver surgery.

Evaluation of selected parameters of the coagulation system during the perioperative period in patients undergoing endoscopic surgery of the paranasal sinuses

INTRODUCTION

The aim of the study was to evaluate selected parameters of the coagulation system during the perioperative period in patients undergoing endoscopic sinus surgery.

MATERIAL AND METHODS

The study involved 121 patients: group I - 42 patients who did not receive anticoagulatory or antiplatelet medications, qualified for endoscopic sinus surgery under total intravenous anaesthesia (TIVA); group II - 40 patients who received in the perioperative period low-molecular-weight heparins, qualified for endoscopic sinus surgery under TIVA; group III - 39 patients diagnosed according to a schedule, due to vertigo or loss of hearing. All the patients received a full laryngological examination and detailed audiological and otoneurological diagnostics, and examination of selected haemostatic parameters before the surgery/diagnostics.

RESULTS

The analysis of concentrations of coagulation parameters in groups I and II revealed a statistically significantly higher international normalized ratio value before surgery (I - 1.11; II - 1.08) and 48 h following surgery (I - 1.15; II - 1.10) in group I. The concentration of coagulation factor VII in the study patients was considerably higher in group I for all three measurements (481.93; 443.13; 486.02). The concentration of fibrinogen (coagulation factor I) was significantly lower in group I before surgery (3.2) and at 6 h after surgery (2.84). A significantly lower level of von Willebrand factor was found in group I before surgery (2.94). Comparing test results of groups I and III, who did not receive antiaggregants, statistically significant differences were observed in both tests for factors VII and VIII.

CONCLUSIONS

Concentrations of von Willebrand factor and prothrombin revealed statistically significant differences in between groups.

Postoperative initial 2-day blood pressure management facilitates the shrinkage of abdominal aortic aneurysm after endovascular aneurysm repair by reducing the incidence of type II endoleak

OBJECTIVE

The aim of this study was to evaluate the effect of initial 2-day blood pressure management (BPM) after endovascular aneurysm repair (EVAR) for the incidence of subsequent type II endoleak (T2E) and shrinkage of abdominal aortic aneurysm (AAA) sac diameter.

METHODS

We reviewed 136 patients who underwent EVAR for atherosclerotic AAA between July 2008 and July 2014 with one of three stent grafts (Excluder [W. L. Gore & Associates, Flagstaff, Ariz], Powerlink [Endologix Inc, Irvine, Calif], and Endurant [Medtronic Vascular, Santa Rosa, Calif]). Starting from 2013, the mean blood pressure of 76 participating patients (treatment group) was maintained at 75 to 90 mm Hg for the initial 48 hours after EVAR. The incidence of T2E at 7 days and AAA sac diameter 12 months after EVAR were evaluated using computed tomography scanning. The results so obtained were then compared with those of the control group composed of 60 consecutive patients who underwent EVAR before 2013.

RESULTS

The incidence of T2E at 7 days was significantly lower in patients who received treatment (treatment group, 19.7%; control group, 40.0%; P = .013), and AAA sac diameter at 12 months in the treatment group had a mean decrease of 5.1 mm compared with the mean 2.2 mm in the control group (P = .004). In multivariate regression analysis, BPM was significantly related to the reduction of incidence of T2E at 7 days (odds ratio, 0.31; P = .007) and a decrease in AAA sac diameter at 12 months (P = .005). In addition, although the use of Endurant had less effect, the use of Excluder under controlled blood pressure conditions improved the incidence of T2E from 80% to 23% compared with those under normal postoperative management (P = .001).

CONCLUSIONS

The initial 2-day postoperative BPM might have positive effects, such as lower incidence of T2E and facilitation of AAA sac shrinkage.

Repeated quantitative measurements of De Novo synthesis of albumin and fibrinogen

The possibility of using two different isotopomers, for the incorporation of isotopically labeled amino acids, was explored to enable longitudinal studies of de novo synthesis of two export liver proteins, albumin and fibrinogen. The agreement of the synthesis rates between the two different labels was evaluated along with the reproducibility of repeated experiments using different time intervals. Healthy volunteers were studied in a standardized fed state. Protocol A (n = 10) involved two measurements 48 hours apart. Protocol B (n = 6) involved three measurements at baseline and five hours and then seven days after the initial measurement. De novo synthesis of albumin and fibrinogen by the incorporation of D5-phenylalanine or D8-phenylalanine were measured using the flooding dose technique. Albumin and fibrinogen were isolated from plasma using standard techniques. Fractional and absolute synthesis rates were calculated. Repeated measurements employing the two isotoptomers showed good agreement for albumin fractional synthesis rate after 48 hours (p = 0.92) and after 7 days (p = 0.99), with a coefficient of variation of 5.9% when using the same isotopic label. For fibrinogen, the coefficient of variation for the fractional synthesis rate employing the same isotopic label was 16.6%. Repeated measurements after 48 hours and seven days showed less agreement although there was no statistical difference (P = 0.32 and P = 0.30 respectively). Repeated measurement after five hours showed a statistical significant difference for the fractional synthesis rate of fibrinogen (p = 0.008) but not for albumin (p = 0.12). Repeated measurements of albumin de novo synthesis more than 48 hours apart show acceptable agreement using either one or two different isotopic labels. For fibrinogen the larger intra-individual scatter necessitates larger study groups to detect changes in longitudinal studies. Repeated measurements within 48 hours need to be validated further.