Does the presence of thyroid cancer increase the risk of venous thromboembolism in patients undergoing thyroidectomy?

Vascular events in patients with head and neck cancer: A systematic review and meta-analysis

OBJECTIVE

To assess the incidence of vascular events in patients with head and neck cancer.

REVIEW METHODS

Primary studies identified through April 2023. Meta-analysis was performed.

RESULTS

There were 146 studies included in the systematic review. Rates of events were collected in the overall group, those with chemoprophylaxis, and those that underwent surgery, radiation, or chemotherapy. Of 1 184 160 patients, 4.3% had a vascular event. Radiation therapy had highest risk of overall events and stroke when compared to surgery and chemotherapy. Chemotherapy had a higher risk of stroke and overall events when compared to surgery.

CONCLUSIONS

Vascular events occur in 4%-5% of patients with head and neck cancer. Our data does not support the use of routine anticoagulation. Patients undergoing radiation therapy had the highest frequency of events.

Implementation of a Novel Protocol for Preventing Venous Thromboembolism in Otolaryngology Patients

OBJECTIVE

Venous thromboembolism (VTE) is a preventable cause of postoperative morbidity and mortality. The Caprini risk assessment model (CRAM) is a validated tool for estimating the risk for postoperative VTE. Previous studies demonstrated a low risk of VTE among otorhinolaryngology-head and neck surgery (ORL-HNS). Hence, our objective was to modify the CRAM-based protocol to be applicable for otolaryngology patients and assess protocol efficacy and safety.

STUDY DESIGN

Observational pilot study conducted on ORL-HNS patients undergoing surgery.

SETTING

University-affiliated tertiary care center.

METHODS

We constructed a modified protocol based on the CRAM and previous reports in the ORL-HNS literature using a reduced postoperative anticoagulation regimen. Primary end point was symptomatic VTE up to 3 months after surgery. Main secondary outcome was postoperative bleeding.

RESULTS

A total of 508 patients were enrolled. Of them, 48% underwent head and neck surgery, 18% direct laryngoscopy and transoral robotic surgery, 15% endoscopic sinus surgery, and 11% otology surgery. Adherence to the protocol was 79%. Mean follow-up time was 115 days (range, 30-448 days). Only 1 patient developed deep vein thrombosis, and none developed pulmonary embolism. Two patients had major bleeding not related to the use of anticoagulation.

CONCLUSIONS

Our novel CRAM-based protocol appears to be efficacious and safe for VTE prevention in otolaryngology. A larger-scale study is required to validate these findings.

LEVEL OF EVIDENCE

Level 2b.

Does antithrombotic prophylaxis worsen early outcomes of total thyroidectomy? - a retrospective cohort study

Background

Currently, there is no strong evidence on the effectiveness and safety of pharmacological antithrombotic prophylaxis in thyroid surgery. The aim of this study was to establish whether the prophylactic use of low-molecular-weight heparin (LMWH) could negatively affect the early outcomes of patients undergoing total thyroidectomy.

Methods

Data from patients submitted to total thyroidectomy between February 2013 and October 2017 were retrospectively collected and analysed. Only patients with indication to antithrombotic prophylaxis according to current guidelines were included in the study. Eligible cases were divided into two groups, which corresponded to two distinct periods of our surgical practice: Group A, which included 178 consecutive patients who were submitted to antithrombotic prophylaxis with LMWH, and Group B, which included 348 consecutive patients who did not receive prophylaxis. Primary endpoints were the incidence of post-operative cervical haematomas (POCH) and thromboembolic events. Secondary endpoint was the length of postoperative hospital stay. Statistical analysis was performed by using Student’s t test for continuous variables and Chi-square test for categorical variables. A P value of less than 0.05 was considered statistically significant.

Results

The two groups of patients were comparable in terms of age, gender, thyroid disease, duration of surgery, and weight of the thyroid gland. Overall, no thromboembolic events were registered. The comparative analysis of the other outcome measures, showed no significant differences between the two groups (POCH: 2 cases (1.12%) in Group A vs 8 cases (2.30%) in Group B - p 0.349; Postoperative hospital stay: 2.90 ± 0.86 days in Group A vs 2.89 ± 0.99 days in Group B - p 0.908).

Conclusions

Data from this study do not support or contraindicate the use of antithrombotic prophylaxis in thyroid surgery. However, since thyroidectomy is a closed-space procedure, and even modest bleeding may quickly result in airway compression and death by asphyxia, mechanical prophylaxis should be preferred to LMWH whenever possible.

Trial registration

ISRCTN ISRCTN12029395. Registered 05/02/2018 retrospectively registered.

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.

Systematic Review and Meta-Analysis of Unplanned Reoperations, Emergency Department Visits and Hospital Readmission After Thyroidectomy

BACKGROUND

Unplanned reoperation, emergency department (ED) visits, and hospital readmission following thyroid operations usually arise due to complications and are a source of frustration for both surgeons and patients. With the aim of providing insight important for the development of patient quality care improvement initiatives, the primary objective of this review was to evaluate the available literature systematically in order to determine the contemporary rates of reoperation, readmission, and ED visits following thyroid operations. A secondary study objective was to determine if there were any practices that showed promise in reducing the occurrence of these undesirable postoperative events.

METHODS

This systematic review was conducted in accordance with the Preferred Reporting of Items for Systematic Reviews and Meta-Analyses protocols. Twenty-two studies were included in the systematic review. Meta-analysis was performed to obtain the weighted-pooled summary estimates of rates of reoperations, ED visits, and unplanned hospital readmission. Jackknife sensitivity analyses were performed for each data set. Finally, in order to detect the risk of publication bias and the small-study effect, funnel plot analysis was performed.

RESULTS

The pooled rate estimate for reoperation was very low (0.6% [confidence interval (CI) 0.3-1.1%]). This was subject to publication bias because smaller studies tended to report lower rates of reoperation. The pooled rate of ED visits was 8.1% [CI 6.5-9.8%], while the pooled rate of hospital readmission from 19 studies was 2.7% [CI 2.1-3.4%]. Neck hematoma was the most common reason for reoperation, while postoperative hypocalcemia was the most common reason for hospital readmission.

CONCLUSIONS

ED visits and hospital readmission after thyroidectomy are common, and there are several practices that can reduce their occurrence. Routine postoperative calcium and vitamin D supplementation may reduce rates of postoperative hypocalcemia, and avoiding postoperative hypertension may decrease the risk of neck hematoma development and the need for reoperation. Older age, thyroid cancer, dependent functional status, higher ASA score, diabetes, chronic obstructive pulmonary disease, steroid use, hemodialysis, and recent weight loss increase the risk of hospital readmission after thyroid surgery. By further identifying risk factors for reoperation, ED visits, and readmission, this review may assist practitioners in optimizing perioperative care and therefore reducing patient morbidity and mortality after thyroid operations.

Thrombosis in Thyroid Cancer

BACKGROUND

The number of studies on venous thromboembolism (VTE) and thyroid cancer is very scarce and existing data are contradictory. This paper reviews VTE in thyroid cancer.

METHODS

The following words were used for a comprehensive literature review using MEDLINE database: Blood coagulation factors; thyroid hormones; blood coagulation tests; venous thromboembolism; receptors thyroid hormone; hemostasis; fibrinolysis; bleeding; blood coagulation disorders; thyroid neoplasms; Thyroid cancer, papillary; Thyroid cancer, follicular; Thyroid carcinoma, anaplastic; Thyroid cancer, Hurthle cell; Familial medullary thyroid carcinoma; venous thrombosis; Pulmonary embolism; Blood coagulation factors. The studies, which include any changes in hemostasis and thyroid cancer were included and reviewed.

RESULTS

Although few studies have shown a possible increase in VTE occurrence in thyroid cancer in patients ≥ 60 years old and in proximity to cancer diagnosis, other studies could not find any difference compared to general population. New thyroid cancer classification excluding common subtype(s) with benign nature, may affect the results of the future studies on association of VTE and thyroid cancer.

CONCLUSIONS

Prospective studies on the occurrence of VTE in various types and severities of thyroid cancer and in different age groups are warranted, as the results would affect clinical practice on the necessity of usage of anticoagulants in some thyroid cancer groups.

The effect of hyperthyroidism on procoagulant, anticoagulant and fibrinolytic factors

Several coagulation and fibrinolytic parameters appear to be affected by thyroid hormone excess;however, the net effect on the haemostatic system remains unclear. We aimed to update our previous review and systematically summarise and meta-analyse the data by assessing the effects of thyrotoxicosis on the coagulation and fibrinolytic system in vivo. Data sources included MEDLINE (2006–2012), EMBASE (2006–2012), and reference lists. The sources were combined with our previous search containing studies from 1980–2006. Eligible studies were all observational or experimental studies. Two investigators independently extracted data and rated study quality. Weighted mean proportion and 95% confidence intervals were calculated and pooled using a fixed and a random-effects model. A total of 29 articles consisting of 51 studies were included, as in several articles more than one study was described. We included four intervention (before and after treatment in hyperthyroid patients), five cross-sectional (hyperthyroid subjects and euthyroid controls), and four experimental (before and after use of thyroid hormone in euthyroid subjects) medium/high quality studies for meta-analysis. We found that thyrotoxicosis shifts the haemostatic balance towards a hypercoagulable and hypofibrinolytic state with a rise in factors VIII and IX, fibrinogen, von Willebrand factor, and plasminogen activator inhibitor-1. This was observed in endogenous and exogenous thyrotoxicosis, and in subclinical as well as overt hyperthyroidism. We conclude that both subclinical and overt hyperthyroidism induce a prothrombotic state, which is therefore likely to be a risk factor for venous thrombosis.

Evaluation of a Standardized Risk-Based Venous Thromboembolism Prophylaxis Protocol in the Setting of Thyroid and Parathyroid Surgery

BACKGROUND

An elevated odds ratio for venous thromboembolism (VTE) prompted development of a Caprini risk assessment and risk-based prophylaxis protocol for all general surgery patients. This system includes pre- and postoperative prophylactic heparin as well as extended courses of low molecular weight heparin for high-risk patients. This study evaluated the safety of this chemoprophylaxis program in thyroid and parathyroid surgery.

STUDY DESIGN

A retrospective review was conducted of all general surgery patients undergoing thyroid or parathyroid operations after implementation of the Caprini prophylaxis protocol. Descriptive statistics were performed to evaluate bleeding complications, risk score categories, and chemoprophylaxis.

RESULTS

Of 1,012 consecutive patients, 72% were determined to be at low/moderate risk for VTE, 26% were high risk, and 2% were highest risk. Only 29% of eligible high/highest-risk patients actually received extended prophylaxis after discharge. Fifteen patients (1.5%) developed wound hematomas that required evacuations, 12 of them within 24 hours of the index operation. Among patients who developed bleeding complications, 5 (33%) had Caprini scores indicating low/moderate-risk for VTE, and 10 (67%) were in the high/highest-risk categories. Only 1 patient developed a delayed hematoma that required a return to the hospital for evacuation. One patient developed a VTE complication.

CONCLUSIONS

Although the incidence of VTE is quite low for patients undergoing thyroid and parathyroid operations, the Caprini prophylaxis protocol identifies a subset of high-risk patients who may benefit from extended VTE prophylaxis without the likelihood of added harm. Conversely, Caprini scores might also select low-risk patients who require no chemoprophylaxis, possibly reducing risks of hemorrhage.

Left lower limb may be a forbidden region for indwelling needle during operation

INTRODUCTION

Information about the incidence and risk factors of venous thromboembolism (VTE) after thyroid operation is limited. This study aimed to analyze the incidence and risk factors of postoperative VTE in patients who had undergone thyroid surgery.

MATERIALS AND METHODS

A prospective, multi-center cohort study was performed from June 2013 to June 2015 in 3 hospitals throughout South Central China. We analyzed 5029 patients who had undergone thyroid operation and received no VTE prophylaxis postoperatively. For the diagnosis of deep vein thrombosis (DVT), bilateral whole-leg ultrasound was conducted in patients with a high pretest probability of DVT. Lung ventilation/perfusion scintigraphy, pulmonary angiography, or helical computed tomography was implemented in patients suspected to have pulmonary embolism (PE).

RESULTS

DVT was diagnosed in 18 patients (0.36%). No patient was diagnosed with PE. Binomial logistic regression analysis revealed that age and left lower limb intraoperative venous access (IVA) were significant risk factors for DVT. The incidence of DVT increased as the number of risk factors increased.

CONCLUSIONS

VTE is uncommon in patients who have undergone thyroid surgery. The left lower limb was not an appropriate insertion site IVA. Pharmacologic thromboprophylaxis was not mandatory, particularly in those patients without risk factors.