Defining incidence and risk factors of venous thromboemolism after hepatectomy

Does the Surgical Approach Affect the Incidence of Post-Hepatectomy Liver Failure in Cirrhotic Patients? An Analysis of the NSQIP Database

Background: The association between surgical approach and post-hepatectomy liver failure (PHLF) in cirrhotic patients is poorly understood. We hypothesize that patients will have similar rates of liver failure regardless of whether they undergo minimally invasive liver resection (MILR) or open liver resection (OLR) in major liver resections. In contrast, there will be lower rates of PHLF in patients undergoing minor hepatectomy via the MILR approach.Methods: Propensity score matching was used to analyze regression by matching the MILR to the OLR cohort. Patient demographics from the American College of Surgeons National Surgical Quality Improvement Program, including race, age, gender, and ethnicity, were matched. Chronic obstructive pulmonary disease, congestive heart failure, smoking, hypertension, diabetes, renal failure, dyspnea, dialysis dependence, body mass index, and American Society of Anesthesiologists (ASA) classification (>ASA III) were among the preoperative patient characteristics subject to matching. PHLF (Grade A vs B. vs C) was our primary outcome measure.Results: A total of 2129 cirrhotic patients were included in the study. In the minor hepatectomy group, patients undergoing an OLR were more likely to get discharged to a facility (7.0% vs 4.4%; P = .03), had greater hospital length of stay (5 vs 3 days; P = .02), and had a greater need for invasive postoperative interventions (10.7% vs 4.6%; P < .01). They were also noted to have higher rates of organ space superficial surgical infections (SSIs) (7.3% vs 3.7%; P = .003), Clostridium difficile infection (.9% vs .1%; P = .05), renal insufficiency (2.1% vs .1%; P < .01), unplanned intubations (3.1% vs 1.4%; P = .03), and Grade C liver failure (2.3% vs .9%; P = .03).Conclusion: A higher incidence of PHLF grade C was found in patients undergoing OLR in the minor hepatectomy group. Therefore, in cirrhotic patients who can tolerate minimally invasive approaches, MILR should be offered to prevent postoperative complications as part of their optimization plan.

Safety of postdischarge extended venous thromboembolism prophylaxis after hepatopancreatobiliary surgery

BACKGROUND

The risk of venous thromboembolism (VTE) after hepatopancreatobiliary (HPB) surgery is high. Extended postdischarge prophylaxis in this patient population has been controversial. This study aimed to examine the safety of postdischarge extended VTE prophylaxis in patients at high risk of VTE events after HPB surgery.

METHODS

Adult patients risk stratified as very high risk of VTE who underwent HPB operations between 2014 and 2020 at a quaternary care center were included. Patients were matched 1:2 extended VTE prophylaxis to the control group (patients who did not receive extended prophylaxis). Analyses compared the proportions of adverse bleeding events between groups.

RESULTS

A total of 307 patients were included: 103 in the extended prophylaxis group and 204 in the matched control group. Demographics were similar between groups. More patients in the extended VTE prophylaxis group had a history of VTE (9% vs 3%; P = .045). There was no difference in bleeding events between the extended VTE prophylaxis and the control group (6% vs 2%; P = .091). Of the 6 patients with bleeding events in the VTE prophylaxis group, 5 had gastrointestinal (GI) bleeding, and 1 had hemarthrosis. Of the 4 patients with bleeding events in the control group, 1 had intra-abdominal bleeding, 2 had GI bleeding, and 1 had intra-abdominal and GI bleeding.

CONCLUSION

Patients discharged with extended VTE prophylaxis after HPB surgery did not experience more adverse bleeding events compared with a matched control group. Routine postdischarge extended VTE prophylaxis is safe in patients at high risk of postoperative VTE after HPB surgery.

Efficacy and safety of patient-controlled epidural analgesia versus patient-controlled intravenous analgesia following open hepatectomy: A single-center retrospective study

Background

Postoperative analgesia is an essential component of enhanced recovery after surgery following abdominal surgery. Studies comparing the effectiveness of epidural analgesia with that of other analgesic modalities after liver surgery have reported inconsistent results. Consequently, the use of epidural analgesia for open hepatectomy is controversial.

Objective

The present single-center retrospective study aimed to compare the efficacy and safety of patient-controlled epidural analgesia (PCEA) and patient-controlled intravenous analgesia (PCIA) in adults undergoing open hepatectomy.

Methods

Patients who underwent open hepatectomy between January 2018 to December 2019 at Zhongshan Hospital, Fudan University were retrospectively analyzed. Propensity score matching was used to adjust baseline information between the PCEA and PCIA groups. The primary outcome measure was scores of the numeric rating scales (NRSs) for resting, exercise, and nocturnal pain at postoperative 24 h (postoperative day 1 [POD1]) and 48 h (POD2). The secondary outcome indicators included postoperative nausea and vomiting (PONV), hypotension, pruritus, respiratory depression, functional activity score (FAS), effective analgesic pump compression ratio, analgesic relief rate, discontinuation of the analgesic pump, reasons for discontinuation of the analgesic pump, and patient satisfaction with postoperative analgesia.

Results

The NRS scores of the PCEA group on POD1 were significantly lower than those of the PCIA group (P < 0.05). On POD2, the difference between the two groups was significant only for motion NRS scores (P < 0.05). The PCIA group had significantly more patients with lower FAS functional class than the PCEA group (P < 0.001). The effective analgesic pump compression ratio and the analgesic relief rate at 2 days after the surgery were lower in the PCEA group than in the PCIA group (P < 0.001). The incidence of pump discontinuation was higher in the PCEA group than in the PCIA group on POD2 (P = 0.044). Moreover, on POD1 and POD2, the PCEA group showed a higher incidence of pruritus and hypotension than the PCIA group (P < 0.001). Both groups showed no significant difference in PONV incidence.

Conclusion

In patients undergoing open hepatectomy, PCEA was more effective than PCIA in relieving moderate to severe pain on POD1. However, improving the safety and effectiveness of PCEA remains a challenge.

An international survey of venous thromboembolic events and current practices of peri-operative VTE prophylaxis after living donor hepatectomy

BACKGROUND

Venous thromboembolic complications are an uncommon but significant cause of morbidity & mortality after live donor hepatectomy . The precise incidence of these events and the current practices of centers performing living donor liver transplantation worldwide are unknown.

METHODS

An online survey was shared amongst living donor liver transplantation centers containing questions regarding center activity, center protocols for donor screening, peri-operative thromboembolic prophylaxis and an audit of -perioperative venous thromboembolic events after live donor hepatectomy in the previous five years (2016-2020).

RESULTS

Fifty-one centers from twenty countries completed the survey. These centers had cumulatively performed 11500 living donor liver transplants between 2016-2020. All centers included pre-operative l assessment for thromboembolic risk amongst potential liver donors in their protocols. Testing for inherited prothrombotic conditions was performed by 58% of centers. Dual-mode prophylaxis was the most common practice (65%), while eight and four centers used single mode or no routine prophylaxis respectively. Twenty (39%) and 15 (29%) centers reported atleast one perioperative deep venous thrmobosis or pulmonary embolism event respectively. There was one donor mortality directly related to post-operative pulmonary embolism. Overall incidence of deep venous thrombosis and pulmonary embolism events was 3.65 and 1.74 per 1000 live donor hepatectomies respectively. Significant variations in center practices and incidence of thromboembolic events was identified in the survey primarily divided along world regions. 75% of participating centers agreed on the need for clear international guidelines.

CONCLUSION

Venous thromboembolic events after live donor hepatectomy are an uncommon but important cause of donor morbidity. There is significant variation in practice among centers. Evidence-based guidelines regarding risk assessment, and peri-operative prophylaxis are needed.

Anesthesia in patients with chronic liver disease: An updated review

Anesthesia in chronic liver disease patients can be challenging because of the medications given or interventions performed and their effects on liver physiology. Also, the effects of liver disease on coagulation and metabolism should be considered carefully. This review focuses on anesthesia in patients with different chronic liver disease stages. A literature search was performed for Scopus and PubMed databases for articles discussing different types of anesthesia in patients with chronic liver disease, their safety, usage, and risks. The choice of anesthesia is of crucial importance. Regional anesthesia, especially neuroaxial anesthesia, may benefit some patients with liver disease, but coagulopathy should be considered. Regional anesthesia provides optimum intraoperative relaxation and analgesia that extends to the postoperative period while avoiding the side effects of intravenous anesthetics and opioids. Pharmacodynamics and pharmacokinetics of anesthetic medications must guard against complications related to overdose or decreased metabolism. The choice of anesthesia in chronic liver disease patients is crucial and could be tailored according to the degree of liver compensation and the magnitude of the surgical procedure.

Venous thromboembolism and bleeding after hepatectomy: role and impact of risk adjusted prophylaxis

Venous thromboembolism (VTE) occurs in 2-6% of post-hepatectomy patients and is associated with increased mortality and morbidity. The use of VTE risk assessment models in hepatectomy cases remains unclear. Our study aimed to determine the use and impact of Caprini guideline indicated VTE prophylaxis following hepatectomy. Hepatectomy cases performed during 2016-2021 were included. Caprini score and VTE prophylaxis were determined retroactively, and VTE prophylaxis was categorized as appropriate or inappropriate. The primary outcome was the receipt of appropriate prophylaxis, and secondary outcomes were postoperative VTE and bleeding. Statistical analyses included Fisher Exact test, Kruskal-Wallis, Pearson Chi-Square test, and multivariate regression models. R Statistical software was used for analysis. A p-value < 0.05 or 95% Confidence Interval (CI) excluding 1 was considered significant. A total of 1955 hepatectomy cases were analyzed. Patient demographics were similar between study cohorts. Inpatient, 30- and 90-day VTE rates were 1.28%, 0.56%, and 1.24%, respectively. By Caprini guidelines, 59% and 4.3% received appropriate in-hospital and discharged VTE prophylaxis, respectively. Inpatient VTE (4.5-fold) and mortality (9.5-fold) were lower in patients receiving appropriate prophylaxis. All discharged VTE and mortality occurred in patients not receiving appropriate prophylaxis. Inpatient, 30- and 90-day bleeding rates were 8.4%, 0.62%, and 0.68%, respectively. Appropriate prophylaxis did not increase postoperative bleeding. Increasing Caprini score inversely correlated with receiving appropriate prophylaxis (OR 0.38, CI 0.31-0.46) at discharge, and appropriate prophylaxis did not correlate with bleeding risk (OR 0.79, CI 0.57-1.12). Caprini guideline indicated prophylaxis resulted in reduced VTE complications without increasing bleeding risk.

Risk factors for hypercoagulability after laparoscopic hepatic haemangioma resection

Background

Laparoscopic hepatectomy with a small incision, light abdominal wall trauma and rapid postoperative recovery has been widely used in the surgical treatment of benign liver diseases. However, the occurrence of complications, such as deep-vein thrombosis, associated with laparoscopic techniques has raised concerns. This study aimed to investigate the factors influencing the development of a hypercoagulable state in patients following laparoscopic hepatic haemangioma resection.

Materials and Methods

Between 2017 and 2019, 78 patients to be treated by laparoscopic hepatic haemangioma resection were selected prospectively for the study. The differences in relevant clinical factors between patients with and without blood hypercoagulability at 24 h after surgery were compared, and the factors influencing the development of blood hypercoagulability after surgery were analysed.

Results

The study included 78 patients, split into the hypercoagulable group (n = 27) and nonhypercoagulable group (n = 51). Compared with patients who did not develop blood hypercoagulability, patients who did had significantly higher preoperative levels of fibrinogen (Fib), D-dimer (D-Di), fibrinogen degradation products (FDP), platelet count (PLT), low-density lipoprotein cholesterol (LDL-C) and history of hyperlipidaemia whereas high-density lipoprotein cholesterol (HDL-C) levels were significantly lower (P < 0.05.) in hypercoagulable group. Univariate and multifactorial logistic regression analyses showed that a history of hyperlipidaemia, Fib ≥3.83 g/L, D-Di ≥9.12 μg/ml, FDP ≥14.64 μg/ml, PLT ≥292 × 109/L, HDL-C ≥1.25 mmol/L and LDL-C ≥2.03 mmol/L was the most common independent risk factors for the development of a hypercoagulable state of blood in patients after laparoscopic hepatic haemangioma resection (P < 0.05).

Conclusion

For patients undergoing laparoscopic hepatic haemangioma resection, attention should be paid to the development of a hypercoagulable state in those with the risk factors described in this study.

Deep vein thrombosis after open hepatectomy or other major upper abdominal surgery in Taiwan: A prospective and cross-sectional study relevant to the issue of pharmacological thromboprophylaxis

BACKGROUD/PURPOSE

Venous thromboembolism, including deep vein thrombosis (DVT) and pulmonary embolism (PE), is an important complication in patients who underwent open hepatic surgery as well as other major upper abdominal surgery. This study aims to investigate the occurrence of postoperative DVT without pharmacological thromboprophylaxis in such cohorts in Taiwan.

METHODS

This is a prospective, cross-sectional cohort study conducted from March 2010 to December 2011. Patients who underwent major upper abdominal surgery, including open hepatectomy, were enrolled. Color duplex compression ultrasonography (CUS) was used to detect DVT. Symptomatic PE was excluded if there were no suggestive respiratory symptoms or sudden death. Relevant clinicopathological and surgical information of each patient was collected and analyzed.

RESULTS

195 patients (118 male and 77 female) were enrolled, with a median age of 63.6 years. The majority (169/195, 88.7%) were treated for active malignancy. Totally 147 patients received open hepatectomy. Only one asymptomatic and distal postoperative DVT event was identified by CUS, which occurred on a 73-year-old female patient who received a left lateral segmental hepatectomy for removing the advanced hepatocellular carcinoma (pathologic stage, T3aN0M0). No cases of symptomatic PE or sudden death were observed. No correlation between DVT and precipitating factor was demonstrated in our cohort.

CONCLUSION

Without pharmacological thromboprophylaxis, a low rate of postoperative DVT among patients undergoing open hepatectomy (0.7%, 1/147) or major upper abdominal surgery (0.5%, 1/195) in Taiwan was reported. A distinctively regional role of pharmacological thromboprophylaxis for hepatic surgery was also suggested by our data.

Evaluation of perioperative D-dimer concentration for predicting postoperative deep vein thrombosis following hepatobiliary-pancreatic surgery

PURPOSE

This study was performed to investigate the predictive value of the perioperative D-dimer concentration for the development of postoperative deep vein thrombosis (DVT) after hepatobiliary-pancreatic (HBP) surgery.

METHODS

The subjects of this retrospective study were 178 patients who underwent HBP surgery in our hospital between January, 2017 and December, 2021. The D-dimer concentration was measured preoperatively and on postoperative days (POD) 1, 3, and 5. Postoperative DVT was diagnosed based on compression ultrasonography in both lower limbs on POD 6 or 7.

RESULTS

Postoperative DVT developed in 21 (11.8%) of the 178 patients. The D-dimer concentration was significantly higher in the patients with than in those without postoperative DVT before surgery and on PODs 1, 3, and 5. The highest area under the curve of the D-dimer concentration for predicting DVT was 0.762 on POD 3. Multivariate analysis revealed that the D-dimer concentration on POD 3 was an independent predictive risk factor for postoperative DVT, along with the preoperative estimated glomerular filtration rate. Preoperative albumin and D-dimer concentrations were also identified as independent predictive factors of an increase in D-dimer concentration on POD 3.

CONCLUSIONS

The D-dimer concentration on POD 3 is a useful predictor of DVT after HBP surgery.

Unfractionated heparin or low-molecular-weight heparin for venous thromboembolism prophylaxis after hepatic resection: A meta-analysis

BACKGROUND

Two systematic reviews summarized the efficacy and safety of pharmacological prophylaxis for venous thromboembolism (VTE) after hepatic resection, but both lacked a discussion of the differences in the pharmacological prophylaxis of VTE in different ethnicities. Therefore, we aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) for VTE prophylaxis in Asian and Caucasian patients who have undergone hepatic resection.

METHODS

We searched PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data, and VIP databases for studies reporting the primary outcomes of VTE incidence, bleeding events, and all-cause mortality from January 2000 to July 2022.

RESULTS

Ten studies involving 4318 participants who had undergone hepatic resection were included: 6 in Asians and 4 in Caucasians. A significant difference in VTE incidence was observed between the experimental and control groups (odds ratio [OR] = 0.39, 95% confidence interval [CI]: 0.20, 0.74, P = .004). No significant difference in bleeding events and all-cause mortality was observed (OR = 1.29, 95% CI: 0.80, 2.09, P = .30; OR = 0.71, 95% CI: 0.36, 1.42, P = .33, respectively). Subgroup analyses stratified by ethnicity showed a significant difference in the incidence of VTE in Asians (OR = 0.16, 95% CI: 0.06, 0.39, P < .0001), but not in Caucasians (OR = 0.69, 95% CI: 0.39, 1.23, P = .21). No significant differences in bleeding events were found between Asians (OR = 1.60, 95% CI: 0.48, 5.37, P = .45) and Caucasians (OR = 1.11, 95% CI: 0.58, 2.12, P = .75). The sensitivity analysis showed that Ejaz's study was the main source of heterogeneity, and when Ejaz's study was excluded, a significant difference in VTE incidence was found in Caucasians (OR = 0.58, 95% CI: 0.36, 0.93, P = .02).

CONCLUSION

This study's findings indicate that the application of UFH or LMWH for VTE prophylaxis after hepatic resection is efficacious and safe in Asians and Caucasians. It is necessary for Asians to receive drug prophylaxis for VTE after hepatic resection. This study can provide a reference for the development of guidelines in the future, especially regarding the pharmacological prevention of VTE in different ethnicities.

Immediate and Delayed Complications of IVC Filters

OBJECTIVE

Inferior vena cava (IVC) filter placement has increased dramatically in the past two decades. However, literature supporting the efficacy of these devices has been limited and controversial. In the present study, we have evaluated the predictors and rates of technical complications after IVC filter insertion in a large national database.

METHODS

The Vascular Quality Initiative registry was explored (January 2013 to December 2020). Immediate complications were defined as venous injury requiring treatment, filter misplacement (failure to open, deployed >20 mm from intended site or in wrong vein, embolized to the heart), angulation >20°, and insertion site complications. Delayed complications were defined as migration, angulation >15°, fracture, caval and/or iliac thrombosis, filter thrombus, fragment embolization, and perforation. The Pearson χ² test was used to compare the baseline characteristics between the patients who had developed immediate and/or delayed complications and those who had not. The predictors of these complications were evaluated using multivariable logistic regression, Cox proportional hazard regression, and Kaplan-Meier survival analysis.

RESULTS

A total of 14,784 patients were included in the present analysis, with a median follow-up of 11 months (interquartile range, 4-16 months). The rate of immediate and delayed complications was 1.8% and 3.1%, respectively. Angulation (1.2%) was the most common immediate complication, and filter thrombosis (1.6%) was the most common delayed complication. Compared with the patients with no immediate complications, those with immediate complications were more likely to have had abnormal anatomy (6.0% vs 1.7%; P < .001) and a landing zone other than infrarenal (7.0% vs 4.2%; P = .02). Compared with their counterparts, those with delayed complications were less likely to have received statins (21.0% vs 29.5%; P = .006) and were more likely to have a family history of venous thromboembolism (8.0% vs 5.1%; P = .047). Logistic regression analysis revealed that renal vein visualization was associated a 50% reduction (adjusted odds ratio [aOR], 0.50; 95% confidence interval [CI], 0.27-0.92; P = .027) in the odds of immediate complications and female sex and abnormal anatomy were associated with a 41% (aOR, 1.41; 95% CI, 1.08-1.85; P = .013) and 244% (aOR, 3.44; 95% CI, 1.66-7.16; P < .001) increase in the odds of immediate complications, respectively. Immediate (P = .21) and delayed (P = .51) complications did not result in increased mortality.

CONCLUSIONS

The immediate and delayed IVC filter complication rates were 1.8% and 3.1%, respectively, but the occurrence of complications was not associated with increased mortality. Female sex was associated with an increase in the development of immediate complications. The incidence of immediate complications might be mitigated if advanced imaging were used for renal vein visualization before IVC filter deployment. Delayed complications might be avoided if IVC filter retrieval were performed in a timely fashion and institutional retrieval protocols were optimized.

Positive Patient Postoperative Outcomes with Pharmacotherapy: A Narrative Review including Perioperative-Specialty Pharmacist Interviews

The influence of pharmacotherapy regimens on surgical patient outcomes is increasingly appreciated in the era of enhanced recovery protocols and institutional focus on reducing postoperative complications. Specifics related to medication selection, dosing, frequency of administration, and duration of therapy are evolving to optimize pharmacotherapeutic regimens for many enhanced recovery protocolized elements. This review provides a summary of recent pharmacotherapeutic strategies, including those configured within electronic health record (EHR) applications and functionalities, that are associated with the minimization of the frequency and severity of postoperative complications (POCs), shortened hospital length of stay (LOS), reduced readmission rates, and cost or revenue impacts. Further, it will highlight preventive pharmacotherapy regimens that are correlated with improved patient preparation, especially those related to surgical site infection (SSI), venous thromboembolism (VTE), nausea and vomiting (PONV), postoperative ileus (POI), and emergence delirium (PoD) as well as less commonly encountered POCs such as acute kidney injury (AKI) and atrial fibrillation (AF). The importance of interprofessional collaboration in all periprocedural phases, focusing on medication management through shared responsibilities for drug therapy outcomes, will be emphasized. Finally, examples of collaborative care through shared mental models of drug stewardship and non-medical practice agreements to improve operative throughput, reduce operative stress, and increase patient satisfaction are illustrated.

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).

Incidence and Risk Factors of Venous Thromboembolism Following Hepatectomy for Colorectal Metastases: A Population-Based Retrospective Cohort Study

BACKGROUND

Incidence of venous thromboembolism (VTE) following hepatectomy for colorectal cancer (CRC) metastases is unclear. These patients may represent a vulnerable population due to increased tumour burden. We aim to identify the risk of VTE development in routine clinical practice among patients with resected CRC liver metastases, the associated risk factors, and its impact on survival.

METHODS

We conducted a population-based retrospective cohort study of Ontario patients undergoing hepatectomy for CRC metastases between 2002 and 2009 using linked universal healthcare databases. Multivariable logistic regression was used to estimate the association between patient characteristics and VTE risk at 30 and 90-days after surgery. Cox proportional-hazards regression was used to estimate the association between VTE and adjusted cancer specific (CSS) and overall survival (OS).

RESULTS

1310 patients were included with a mean age of 63 ± 11. 62% were male. 51% had one metastatic deposit. Major hepatectomy occurred in 64%. VTE occurred in 4% within 90 days of liver resection. Only longer length of stay was associated with VTE development (OR 6.88 (2.57-18.43), p <0.001 for 15-21 days versus 0-7 days). 38% of VTEs were diagnosed after discharge, comprising 1.52% of the total cohort. VTE was not associated with inferior CSS or OS.

CONCLUSIONS

Risk of VTE development in this population is similar to those undergoing hepatectomy for other indications, and to the risk following other cancer site resections where post-operative extended VTE prophylaxis is currently recommended. The number of VTEs occurring after discharge suggests there may be a role for extended VTE prophylaxis.

Safety of liver resection in patients receiving antithrombotic therapy: A systematic review of the literature

BACKGROUND

Little is unknown about the effect of chronic antithrombotic therapy (ATT) on bleeding complication during or after hepatectomy. In addition, the safety and effectiveness of chemical prevention for venous thromboembolism (VTE) is still controversial.

AIM

To clarify the effect of ATT on thromboembolism and bleeding after liver resection.

METHODS

Articles published between 2011 and 2020 were searched from Google Scholar and PubMed, and after careful reviewing of all studies, studies concerning ATT and liver resection were included. Data such as study design, type of surgery, type of antithrombotic agents, and surgical outcome were extracted from the studies.

RESULTS

Sixteen published articles, including a total of 8300 patients who underwent hepatectomy, were eligible for inclusion in the current review. All studies regarding patients undergoing chronic ATT showed that hepatectomy can be performed safely, and three studies have also shown the safety and efficacy of preoperative continuation of aspirin. Regarding chemical prevention for VTE, some studies have shown a potentially high risk of bleeding complications in patients undergoing chemical thromboprophylaxis; however, its efficacy against VTE has not been shown statistically, especially among Asian patients.

CONCLUSION

Hepatectomy in patients with chronic ATT can be performed safely without increasing the incidence of bleeding complications, but the safety and effectiveness of chemical thromboprophylaxis against VTE during liver resection is still controversial, especially in the Asian population. Establishing a clear protocol or guideline requires further research using reliable studies with good design.

Construction and Validation of a Nomogram for Predicting the Risk of Deep Vein Thrombosis in Hepatocellular Carcinoma Patients After Laparoscopic Hepatectomy: A Retrospective Study

Background

The incidence of deep vein thrombosis (DVT) in hepatocellular carcinoma (HCC) patients after laparoscopic hepatectomy (LH) is unclear, and there is no effective method for DVT risk assessment in these patients.

Methods

The data from the total of 355 consecutive HCC patients who underwent LH were included. A DVT risk algorithm was developed using a training set (TS) of 243 patients, and its predictive performance was evaluated in both the TS and a validation set (VS) of 112 patients. The model was then used to develop a DVT risk nomogram (TRN).

Results

The incidence of DVT in the present study was 18.6%. Age, sex, body mass index (BMI), comorbidities and operative position were independent risk factors for DVT in the TS. The model based on these factors had a good predictive ability. In the TS, it had an area under the receiver operating characteristic (AUC) curve of 0.861, Hosmer-Lemeshow (H-L) goodness of fit p value of 0.626, sensitivity of 44.4%, specificity of 96.5%, positive predictive value (PPV) of 74.1%, negative predictive value (NPV) of 88.4%, and accuracy of 86.8%. In the VS, it had an AUC of 0.818, H-L p value of 0.259, sensitivity of 38.1%, specificity of 98.9%, PPV of 88.9%, NPV of 87.4%, and accuracy of 87.5%. The TRN performed well in both the internal and the external validation, indicating a good clinical application value. The TRN had a better predictive value of DVT than the Caprini score (p < 0.001).

Conclusion

The incidence of DVT after LH was high, and should not be neglected in HCC patients. The TRN provides an efficacious method for DVT risk evaluation and individualized pharmacological thromboprophylaxis.

Pre- vs. postoperative initiation of thromboprophylaxis in liver surgery

BACKGROUND

Thromboprophylaxis protocols in liver surgery vary greatly worldwide. Due to limited research, there is no consensus whether the administration of thromboprophylaxis should be initiated pre- or postoperatively.

METHODS

Patients undergoing liver resection in Helsinki University Hospital between 2014 and 2017 were reviewed retrospectively. Initiation of thromboprophylaxis was changed in the institution in the beginning of 2016 from postoperative to preoperative. Patients were classified into two groups for analyses: thromboprophylaxis initiated preoperatively (Preop-group) or postoperatively (Postop-group). The incidences of VTE and haemorrhage within 30 days of surgery were compared between these groups. Patients with permanent anticoagulation were excluded.

RESULTS

A total of 512 patients were included to the study (Preop, n = 253, Postop, n = 259). The incidence of VTE was significantly lower in the Preop-group compared to the Postop-group (3 (1.2%) vs. 25 (9.7%), P = <.0001), mainly due to a lower incidence of pulmonary embolisms in the Preop-group (3 (1.2%) vs. 24 (9.3%), P < .0001). The rates of posthepatectomy haemorrhage within 30 days of surgery were similar (Preop 38 (15.0%) vs. Postop 36 (13.9%), p = .719).

CONCLUSION

Initiating thromboprophylaxis preoperatively may reduce the incidence of postoperative VTE without affecting the incidence of posthepatectomy haemorrhage in patients undergoing liver resection.

Risk of venous thromboembolism in patients with elevated INR undergoing hepatectomy: an analysis of the American college of surgeons national surgical quality improvement program registry

BACKGROUND

Patients undergoing hepatectomy can have elevated INR and may have venous thromboembolism (VTE) prophylaxis withheld as a result. We sought to examine the association between preoperative INR elevation and VTE following hepatectomy.

METHODS

Hepatectomies captured in the American College of Surgeons National Surgical Quality Improvement Program registry between 2007 and 2016 were analyzed. Univariable and multivariable models examined the effect of incremental increases in preoperative INR on 30-day VTE, perioperative transfusion, serious morbidity, and mortality, adjusting for potential confounders.

RESULTS

We included 25,220 elective hepatectomies (62.4% partial lobectomies, 10.1% left hepatectomies, 18.6% right hepatectomies, 9.2% trisegmentectomies). The median age of the patients was 60 years and 49% were male. INR was elevated in 3089 patients (12.2%): 1.1-1.2 in 8.1%, 1.2-1.4 in 3.3%, and 1.4-2.0 in 0.9%. Incremental elevations in INR were independently associated with increasing risk for postoperative VTE [odds ratio (OR) 1.15, 95% confidence intervals 1.01-1.31], perioperative transfusion [OR 1.35 (1.28-1.43)], serious morbidity [OR 1.35 (1.28-1.43)], and mortality [OR 1.76 (1.56-1.98)].

CONCLUSION

Elevation in preoperative INR was counter-intuitively associated with increased risk of both VTE and perioperative transfusion following hepatectomy. The role of perioperative thromboprophylaxis warrants further investigation to determine optimal care in patients with elevated preoperative INR.

Development and validation of a risk calculator for post-discharge venous thromboembolism following hepatectomy for malignancy

BACKGROUND

Post-discharge venous thromboembolism (VTE) chemoprophylaxis decreases VTEs following cancer surgery, however identifying high-risk patients remains difficult. Our objectives were to (1) identify factors available at hospital discharge associated with post-discharge VTE following hepatectomy for malignancy and (2) develop and validate a post-discharge VTE risk calculator to evaluate patient-specific risk.

METHODS

Patients who underwent hepatectomy for malignancy from 2014 to 2017 were identified from the ACS NSQIP hepatectomy procedure targeted module. Multivariable logistic regression identified factors associated with post-discharge VTE. A post-discharge VTE risk calculator was constructed, and predicted probabilities of post-discharge VTE were calculated.

RESULTS

Among 11 172 patients, 95 (0.9%) developed post-discharge VTE. Post-discharge VTE was associated with obese BMI (OR 2.29 vs. normal BMI [95%CI 1.31-3.99]), right hepatectomy/trisegmentectomy (OR 1.63 vs. partial/wedge [95%CI 1.04-2.57]), and several inpatient postoperative complications: renal insufficiency (OR 5.29 [95%CI 1.99-14.07]), transfusion (OR 1.77 [95%CI 1.12-2.80]), non-operative procedural intervention (OR 2.97 [95%CI 1.81-4.86]), and post-hepatectomy liver failure (OR 2.22 [95%CI 1.21-4.08]). Post-discharge VTE risk ranged from 0.3% to 30.2%. Twenty iterations of 10-fold cross validation identified internal validity.

CONCLUSIONS

Risk factors from all phases of care, including inpatient complications, are associated with post-discharge VTE following hepatectomy. Identifying high-risk patients may allow for personalized risk-based post-discharge chemoprophylaxis prescribing.

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.

Autophagy and Liver Diseases

Autophagy plays an important role in the physiology and pathology of the liver. It is involved in the development of many liver diseases such as α-1-antitrypsin deficiency, chronic hepatitis virus infection, alcoholic liver disease, nonalcoholic fatty liver disease, and liver cancer. Autophagy has thus become a new target for the treatment of liver diseases. How to treat liver diseases by regulating autophagy has been a hot topic.

Coagulation in liver surgery: an observational haemostatic profile and thromboelastography study

BACKGROUND

International normalized ratio (INR) is used as a marker of the haemostatic status following liver resection. However, the impact of liver resection on haemostasis is complex and beyond what can be measured by INR. This study aimed to prospectively assess haemostatic profile following liver resection and determine if INR measurement can safely guide post-operative thromboprophylaxis.

METHODS

In this prospective cohort study, patients undergoing liver resection had coagulation parameters (International normalised ratio (INR), prothrombin time (PT), activated partial thromboplastin time, fibrinogen, d-dimer, von Willebrand factor antigen, procoagulant activity of phospholipids and clotting factors II, VII, VIIIc, IX and X) and thromboelastogram parameters assessed perioperatively. Clinical follow-up assessed for thromboembolism and haemorrhage.

RESULTS

In the 41 patients included, INR was significantly (P < 0.0001) elevated post-operatively, and INR >1.5 was observed in seven of 41 (17.1%) on post-operative day 1 and one of 41 (2.4%) patients on post-operative day 3, respectively. Factor VII levels showed transient reduction but other factors, especially factors II and X, remained within normal range following liver resection. Thromboelastogram parameters remained normal or supranormal for all patients at all time points. One incident of post-hepatectomy haemorrhage occurred, despite a normal coagulation profile. Two patients suffered late pulmonary embolic episodes.

CONCLUSION

Post liver resection haemostasis is complex and poorly reflected by INR, which should not guide initiation of chemical thromboprophylaxis in the immediate post-operative period.

Venous thromboembolism in children undergoing surgery: incidence, risk factors and related adverse events

Background

Although less common in adults, venous thromboembolism (VTE) in children is a highly morbid, preventable adverse event. While VTE has been well studied among pediatric hospitalized and trauma patients, limited work has been done to examine postoperative VTE in children undergoing surgery.

Methods

Using data from National Surgical Quality Improvement Project Pediatric database (NSQIP-P) from 2012 to 2016, a retrospective cohort analysis was performed to determine the incidence of, and risk factors for, VTE in children undergoing surgery. Additionally, the relationships between VTE and other postoperative adverse outcomes were evaluated.

Results

Of 361 384 pediatric surgical patients, 378 (0.10%) were identified as experiencing postoperative VTE. After controlling for patient and surgical factors, we found that American Society of Anesthesiologists (ASA) class of II or greater, aged 16–18 years, non-elective surgery, general surgery (compared with several other surgical specialties), cardiothoracic surgery (compared with general surgery) and longer operative time were significantly associated with VTE in pediatric patients (p<0.001 for each comparison). Furthermore, a majority of adverse events were found to be associated with increased risk of subsequent VTE (p<0.001).

Conclusion

In a large pediatric surgical population, an incidence of postoperative VTE of 0.10% was observed. Defined patient and surgical factors, and perioperative adverse events were found to be associated with such VTE events.

Prophylactic Enoxaparin Adjusted by Anti-Factor Xa Peak Levels Compared with Recommended Thromboprophylaxis and Rates of Clinically Evident Venous Thromboembolism in Surgical Oncology Patients

BACKGROUND

Studies among populations at high risk of venous thromboembolism (VTE) have demonstrated that recommended doses for enoxaparin thromboprophylaxis are associated with high incidence of subprophylactic anti-factor Xa (anti-Xa) levels. This study examines the efficacy and safety of dose-adjusted enoxaparin guided by anti-Xa levels.

STUDY DESIGN

Patients undergoing abdominal cancer operation had dose adjustments based on peak anti-Xa levels to attain a target of >0.20 IU/mL were prospectively enrolled and compared with a historic cohort of patients receiving recommended thromboprophylaxis. Incidence of in-hospital VTE and major bleeding after changes in enoxaparin dosing were monitored.

RESULTS

The study population comprised 197 patients-64 patients in the prospective intervention group and 133 patients in the control group. Baseline characteristic were similar between the intervention and control groups, with the exception of the Caprini score (8.09 vs 7.26; p = 0.013). In the intervention group, 50 of 64 patients (78.1%) initially had subprophylactic peak anti-Xa levels. The VTE rates were lower in the intervention group than the control group (0% vs 8.27%; p = 0.018). There were no differences in major bleeding events (3.12% vs 1.50%; p = 0.597), rates of postoperative packed RBC transfusion (17.2% vs 23.3%; p = 0.426), or mean Hgb on discharge (9.58 vs 9.37g/dL; p = 0.414). Therapeutic anti-Xa levels correlated positively with age (65.7 vs 58.2 years; p = 0.022) and correlated negatively with operating room time (203 vs 281 minutes; p = 0.032) and BMI (25.3 vs 29.2 kg/m²; p = 0.037).

CONCLUSIONS

Thromboprophylactic enoxaparin 40 mg daily is often associated with subprophylactic peak anti-Xa levels. Dose adjustment based on anti-Xa levels increased the daily enoxaparin dose, resulting in a lower rate of in-hospital VTE without increased risk of bleeding.

Practice patterns of VTE chemoprophylaxis after discharge following hepatic and pancreatic resections for cancer: A survey of hepatopancreatobiliary surgeons

Patients with hepatopancreatobiliary (HPB) malignancies undergoing resection are prone to venous thromboembolism (VTE), and current guidelines recommend up to 28 days of chemoprophylaxis after major surgery. We sought to determine the practice patterns among HPB surgeons for use of chemoprophylaxis after discharge. A survey on VTE chemoprophylaxis after oncologic HPB operations was distributed to attending surgeons at the 18 HPB fellowship training programs in the United States and Canada. Of the HPB surgeons surveyed, 44 (44%) responded. VTE prophylaxis is used by 93% of respondants in the inpatient postoperative setting. Chemoprophylaxis after discharge for pancreaticoduodenenctomy and distal pancreatectomy is utilized by 45% and 39% of respondants, respectively. Of those who prescribe chemoprophylaxis after discharge, 79% and 88% prescribe it for the recommended 28 days after pancreaticoduodenectomy and distal pancreatectomy, respectively. Chemoprophylaxis after discharge for major and minor hepatectomy is utilized by 39% and 26% of respondents, respectively. Of those who prescribe chemoprophylaxis after discharge, 67% and 55% provide it for the recommended 28 days after major and minor hepatectomy, respectively. Despite documented prolonged postoperative thrombogenic risk, the use of chemoprophylaxis following discharge after pancreatic and liver resections for cancer was moderate among surveyed HPB surgeons.

Enhanced recovery after surgery in liver resection: current concepts and controversies

Enhanced recovery after surgery (ERAS) attenuates the stress response to surgery in the perioperative period and hastens recovery. Liver resection is a complex surgical procedure where the enhanced recovery program has been shown to be safe and effective in terms of postoperative outcomes. ERAS programs have been shown to be associated with lower morbidity, shortened postoperative stay, and reduced cost with no difference in mortality and readmission rates. However, there are challenges that are unique to hepatic resection such as safety after epidural catheterization and postoperative coagulopathy, intraoperative fluids and postoperative organ dysfunction, need for low central venous pressure to reduce blood loss, and non-lactate containing intravenous fluids. This narrative review briefly discusses these concerns and controversies and suggests revisiting some of the strong recommendations made by the ERAS society in light of the recent evidence.

Incidence, risk factors, and outcomes of venous thromboembolism after oncologic surgery: A systematic review and meta-analysis

BACKGROUND

The risk and prognosis of VTE associated with oncologic surgery need to be quantified to guide patient management. We aimed to examine the availability of data and to report the incidence of venous thromboembolism (VTE) in cancer patients after surgery, as well as the clinical outcomes of VTE following oncologic surgery.

METHODS

We searched multiple databases for terms related to VTE after oncologic surgery from inception to November 1, 2017. A random-effects meta-analysis was done to calculate the pooled incidence of VTE.

RESULTS

Of the 8611 citations identified, 136 studies including 1,481,659 patients met the eligibility criteria. The overall incidence of VTE was estimated to be 2.3% (95% CI 2.1-2.5). Bone and soft tissue cancer (10.6%, 95% CI 2.9-18.2) and lung cancer (8.1%, 95% CI 3.7-12.6) were associated with the highest and second highest risk of postoperative VTE, respectively. Age (standardized mean difference [SMD] = 0.46, 95% CI 0.40-0.53; I² = 93.8%), radiation (OR 1.29, 95% CI 1.03-1.62; I² = 34.6%), transfusion (OR 1.96, 95% CI 1.48-2.59; I² = 57.0%), and operative time (SMD = 1.12, 95% CI 1.07-1.16; I² = 100%) were possible risk factors for postoperative VTE. Patients with VTE versus those without had increased odds of all-cause fatal events (11.15, 95% CI 4.07-30.56; I² = 92.0%).

CONCLUSIONS

The risk of VTE after oncologic surgery remains high, and this risk varied according to the cancer type, study region, surgical location, and thromboprophylactic strategy. VTE is associated with increased mortality at the early stage of cancer surgery.

Efficacy and safety of pharmacological venous thromboembolism prophylaxis following liver resection: a systematic review and meta-analysis

BACKGROUND

Current guidelines recommend pharmacological prophylaxis for patients undergoing abdominal surgery for malignancy. Liver resection exposes patients to risk factors for venous thromboembolism, but there is a risk of bleeding. The aim of this study is to evaluate the evidence base supporting the use of pharmacological thromboprophylaxis in liver surgery.

METHODS

An electronic search was carried out for studies reporting the incidence of VTE following liver resection comparing patients receiving pharmacological prophylaxis with those who did not. The search resulted in 990 unique citations. Following the application of strict eligibility criteria 5 studies comprise the final study population.

RESULTS

Included studies report on 3675 patients undergoing liver resection between 1999 and 2013. 2256 patients received chemical thromboprophylaxis, 1412 had mechanical prophylaxis only and 7 received no prophylaxis. Meta-analysis revealed lower VTE rates in patients receiving chemical thromboprophylaxis (2.6%) compared to without prophylaxis (4.6%) (Dichotomous correlation test, odds ratio: 0.631 [95% Cl: 0.416-0.959], Fixed model, p = 0.030). Data regarding bleeding could not be pooled for meta-analysis, but chemical thromboprophylaxis was reported as safe in four studies.

CONCLUSION

This systematic review and meta-analysis of retrospective studies indicates that the use of perioperative chemical thromboprophylaxis reduces VTE incidence following liver surgery without an apparent increased risk of bleeding.

Retrospective analysis of post-operative coagulopathy after major hepatic resection at a tertiary care centre in Northern India

Background and Aims:

Hepatic resection is a major surgery associated with intraoperative massive fluid shifts, blood loss, haemodynamic instability and risk of development of post-hepatectomy liver failure. Hepatic resection predisposes the patient to coagulopathy as well as venous thrombosis. However, due to the development of deranged coagulation profile post-operatively, there is a dilemma in starting thromboprophylaxis. Our aim in this study was to determine the incidence of coagulopathy in patients undergoing major hepatectomy.

Methods:

In this retrospective study, we included 86 patients who had undergone major hepatectomy between January 2010 and December 2015 at our centre. Intraoperatively, we noted the number of liver segments resected, details of epidural catheter insertion, estimated blood loss, transfusion requirement and need for mechanical ventilation post-operatively. Trends of international normalised ratio (INR) and platelet values were recorded until post-operative day 5.

Results:

Of the 86 patients, 6 (7%) had an abnormal coagulation profile pre-operatively and 39 (45.34%) patients developed a derangement in their coagulation profile on 1^st post-operative day (POD). Platelet count was significantly lower and INR values were significantly higher than the pre-operative values on all 5 PODs. Sixty-seven (78%) patients had pre-operative epidural catheter insertion for post-operative pain management. Mechanical thrombophylaxis was used routinely.

Conclusions:

The incidence of post-operative coagulopathy in our patients who underwent major liver resection was 45.34%. Epidural catheters could be removed safely without transfusion between POD 5 and 7. There was no incidence of venous thrombosis or thromboembolism.

The Johns Hopkins Venous Thromboembolism Collaborative: Multidisciplinary team approach to achieve perfect prophylaxis

Venous thromboembolism (VTE) is an important cause of preventable harm in hospitalized patients. The critical steps in delivery of optimal VTE prevention care include (1) assessment of VTE and bleeding risk for each patient, (2) prescription of risk-appropriate VTE prophylaxis, (3) administration of risk-appropriate VTE prophylaxis in a patient-centered manner, and (4) continuously monitoring outcomes to identify new opportunities for learning and performance improvement. To ensure that every hospitalized patient receives VTE prophylaxis consistent with their individual risk level and personal care preferences, we organized a multidisciplinary task force, the Johns Hopkins VTE Collaborative. To achieve the goal of perfect prophylaxis for every patient, we developed evidence-based, specialty-specific computerized clinical decision support VTE prophylaxis order sets that assist providers in ordering risk-appropriate VTE prevention. We developed novel strategies to improve provider VTE prevention ordering practices including face-to-face performance reviews, pay for performance, and provider VTE scorecards. When we discovered that prescription of risk-appropriate VTE prophylaxis does not ensure its administration, our multidisciplinary research team conducted in-depth surveys of patients, nurses, and physicians to design a multidisciplinary patient-centered educational intervention to eliminate missed doses of pharmacologic VTE prophylaxis that has been funded by the Patient Centered Outcomes Research Institute. We expect that the studies currently underway will bring us closer to the goal of perfect VTE prevention care for every patient. Our learning journey to eliminate harm from VTE can be applied to other types of harm. Journal of Hospital Medicine 2016;11:S8-S14. © 2016 Society of Hospital Medicine.

Patient Adherence and Experience with Extended Use of Prophylactic Low-Molecular-Weight Heparin Following Pancreas and Liver Resection

BACKGROUND

Guidelines recommend 28 days venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) following major abdominal surgery for cancer. Overall adherence with these recommendations is poor, but little is known about feasibility and tolerability from a patient perspective.

METHODS

An institution-wide policy for routine administration of 28 days of post-operative LMWH following major hepatic or pancreatic resection for cancer was implemented in April 2013. Patients having surgery from July 2013 to June 2015 were approached to participate in an interview examining adherence and experience with extended duration LMWH.

RESULTS

There were 100 patients included, with 81.4 % reporting perfect adherence with the regimen. The most frequent reasons for non-adherence were that a healthcare provider stopped the regimen or because of poor experience with injections. Most patients were able to correctly recall the reason for being prescribed LMWH (82.6 %), and 78.4 % of patients performed all injections themselves. Over half the patients (55.7 %) did not find the injections bothersome.

CONCLUSION

Patients reported high adherence and a manageable experience with post-operative extended-duration LMWH in an ambulatory setting following liver or pancreas resection. These findings suggest that patient adherence is not a major contributor to poor compliance with VTE prophylaxis guidelines.

Alterations in coagulation following major liver resection

The international normalised ratio is frequently raised in patients who have undergone major liver resection, and is assumed to represent a potential bleeding risk. However, these patients have an increased risk of venous thromboembolic events, despite conventional coagulation tests indicating hypocoagulability. This prospective, observational study of patients undergoing major hepatic resection analysed the serial changes in coagulation in the early postoperative period. Thrombin generation parameters and viscoelastic tests of coagulation (thromboelastometry) remained within normal ranges throughout the study period. Levels of the procoagulant factors II, V, VII and X initially fell, but V and X returned to or exceeded normal range by postoperative day five. Levels of factor VIII and Von Willebrand factor were significantly elevated from postoperative day one (p < 0.01). Levels of the anticoagulants, protein C and antithrombin remained significantly depressed on postoperative day five (p = 0.01). Overall, the imbalance between pro- and anticoagulant factors suggested a prothrombotic environment in the early postoperative period.

Balance between von Willebrand factor and ADAMTS13 following major partial hepatectomy

BACKGROUND

Conventional coagulation tests are frequently prolonged after liver surgery, suggesting a postoperative bleeding tendency. At the same time, thrombotic complications following partial hepatectomy (PH) are not uncommon. Little is known about changes in the platelet adhesive protein von Willebrand factor (VWF) and its cleaving protease a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 (ADAMTS13) following a PH.

METHODS

Plasma samples were collected before and after PH and pylorus-preserving pancreaticoduodenectomy (PPPD), and from 24 healthy individuals. Plasma levels of VWF and ADAMTS13, VWF activity and VWF-dependent platelet adhesion were measured, and compared between the groups.

RESULTS

Median (i.q.r.) VWF levels increased more after PH (17 patients) than following PPPD (10), reaching the highest level on postoperative day (POD) 3 (570 (473-656) versus 354 (305-476) per cent respectively; P = 0·009). VWF levels remained raised on POD 30. A decrease in median (i.q.r.) ADAMTS13 activity was observed for both patient groups, reaching the lowest level on POD 7 (24 (16-32) versus 38 (23-66) per cent for PH and PPPD respectively; P = 0·049), and levels remained significantly reduced at POD 30. VWF activity was significantly higher on day 7 following PH compared with PPPD (median (i.q.r.) 517 (440-742) versus 385 (322-484) per cent respectively; P = 0·009), and remained increased at POD 30. VWF-dependent platelet adhesion under conditions of flow was increased until POD 30 in patients after PH and PPPD, but was more pronounced in the PH group.

CONCLUSION

There are changes in the balance between VWF and ADAMTS13 levels and activity in patients after both PH and PPPD. Changes in the VWF-ADAMTS13 axis were more pronounced and of longer duration after PH than following PPPD.

Venous Thromboembolism Prophylaxis in Liver Surgery

BACKGROUND

At a recently concluded Americas Hepato-Pancreato-Biliary Association Annual Meeting, a Clinical Practice Guidelines Conference Series was convened with the topic focusing on Venous Thromboembolism (VTE) Prophylaxis in Liver Surgery. The symposium brought together hepatobiliary surgeons from three continents as well as medical experts in hematology and coagulation.

METHODS

The content of the discussion included literature reviews, evaluation of multi-institutional VTE outcome data, and examination of practice patterns at multiple high-volume centers.

RESULTS

Literature review demonstrated that, within gastrointestinal surgery, liver resection patients are at particularly high-risk for VTE. Recent evidence clearly indicates a direct relationship between the magnitude of hepatectomy and postoperative VTE rates, however, the PT/INR does not accurately reflect the coagulation status of the post-hepatectomy patient. Evaluation of available data and practice patterns regarding the utilization and timing of anticoagulant VTE prophylaxis led to recommendations regarding preoperative and postoperative thromboprophylaxis for liver surgery patients.

CONCLUSIONS

This conference was effective in consolidating our knowledge of coagulation abnormalities after liver resection. Based on the expert review of the available data and practice patterns, a number of recommendations were developed.

Hypercoagulability following major partial liver resection - detected by thrombomodulin-modified thrombin generation testing

BACKGROUND

Conventional coagulation tests are frequently prolonged after liver surgery, suggesting a post-operative hypocoagulability. However, these tests are unreliable for assessment of the haemostatic status in these patients. In contrast, thrombin generation testing measures the true balance between pro- and anti-coagulant factors.

AIM

To study the perioperative coagulation status in patients undergoing hemi-hepatectomy using thrombin generation assays.

METHODS

We examined thrombin generation profiles in serial plasma samples taken from seventeen patients undergoing right hemi-hepatectomy. Results were compared to ten patients undergoing pancreatic resection and twenty-four healthy volunteers. In addition, we measured conventional coagulation tests and plasma levels of several haemostatic proteins.

RESULTS

Following liver resection, the endogenous thrombin potential (ETP) slightly decreased until post-operative day 7. However, in the presence of thrombomodulin, the ETP increased [from 542 nM*min (417-694) at baseline to 845 nM*min (789-1050) on post-operative day 3] to values higher than that in healthy subjects (558 nM*min (390-680); P < 0.001), which contrasts with substantially prolonged PT levels. Normal to decreased thrombin generation was observed following pancreatic resection. Thrombin generation was only slightly affected by thrombomodulin after hemi-hepatectomy, while thrombin generation in healthy subjects decreased profoundly upon addition of thrombomodulin. This hypercoagulability following liver resection may be explained by decreased levels of protein C, S, and antithrombin and by elevated levels of factor VIII.

CONCLUSIONS

Thrombin generation in the presence of thrombomodulin revealed hypercoagulability in patients following liver resection. These results support the recently advocated restrictive use of plasma during liver resection and the exploration of more extensive use of post-operative thrombosis prophylaxis.

Complications following hepatectomy

As the number of liver resections in the United States has increased, operations are more commonly performed on older patients with multiple comorbidities. The advent of effective chemotherapy and techniques such as portal vein embolization, have compounded the number of increasingly complex resections taking up to 75% of healthy livers. Four potentially devastating complications of liver resection include postoperative hemorrhage, venous thromboembolism, bile leak, and post-hepatectomy liver failure. The risk factors and management of these complications are herein explored, stressing the importance of identifying preoperative factors that can decrease the risk for these potentially fatal complications.

Venous thromboembolic prophylaxis after a hepatic resection: patterns of care among liver surgeons

INTRODUCTION

No consensus exists for post-hepatectomy venous thromboembolic (VTE) prophylaxis. Factors impacting VTE prophylaxis patterns among hepato-pancreato-biliary (HPB) surgeons were defined.

METHOD

Surgeons were invited to complete a web-based survey on VTE prophylaxis. The impact of physician and clinical factors was analysed.

RESULTS

Two hundred responses were received. Most respondents were male (91%) and practiced at academic centres (88%) in the United States (80%). Surgical training varied: HPB (24%), transplantation (24%), surgical oncology (34%), HPB/transplantation (13%), or no specialty (5%). Respondents estimated VTE risk was higher after major (6%) versus minor (3%) resections. Although 98% use VTE prophylaxis, there was considerable variability: sequential compression devices (SCD) (91%), unfractionated heparin Q12h (31%) and Q8h (32%), and low-molecular weight heparin (39%). While 88% noted VTE prophylaxis was not impacted by operative indication, 16% stated major resections reduced their VTE prophylaxis. Factors associated with the decreased use of pharmacologic prophylaxis included: elevated international normalized ratio (INR) (74%), thrombocytopaenia (63%), liver insufficiency (58%), large EBL (46%) and complications (8%). Forty-seven per cent of respondents wait until ≥post-operative day 1 (POD1) and 35% hold pharmacologic VTE prophylaxis until no signs of coagulopathy. A minority (14%) discharge patients on pharmacologic prophylaxis. While 81% have institutional VTE guidelines, 79% believe hepatectomy-specific guidelines would be helpful.

CONCLUSION

There is considerable variation regarding VTE prophylaxis among liver surgeons. While most HPB surgeons employ VTE prophylaxis, the methods, timing and purported contraindications differ significantly.

Efficacy of postoperative anticoagulation therapy with enoxaparin for portal vein thrombosis after hepatic resection in patients with liver cancer

BACKGROUNDS

Enoxaparin, low-molecular-weight heparin, has become a routine thromboprophylaxis in general surgery.

STUDY DESIGN

A retrospective cohort study was performed in 281 patients who underwent hepatic resections for liver cancers from 2011 to 2013. These patients were divided into two groups; an enoxaparin (-) group (n=228) and an enoxaparin (+) group (n=53). Short-term surgical results including venous thromboembolism (VTE) and portal vein thrombosis (PVT) were compared.

RESULTS

In the enoxaparin (+) group, the patients' age (65 vs. 69 years; p=0.01) and BMI (22.9 vs. 24.4; p<0.01) were significantly higher. According to the symptomatic VTE, symptomatic pulmonary embolism occurred in one patient (0.4%) in the enoxaparin (-) group, but the complication rate was not significantly different (p=0.63). The complication rate of PVT was significantly lower in the enoxaparin (+) group (10 vs. 2%; p=0.04). The independent risk factors for PVT were an operation time ≥ 300 minutes (Odds ratio 6.66) and non-treatment with enoxaparin (Odds ratio 2.49).

CONCLUSIONS

Postoperative anticoagulant therapy with enoxaparin could prevent PVT in patients who underwent hepatic resection for liver cancers.