Key Points
Question
Do patients receiving aspirin before undergoing thyroid surgery experience increased bleeding complications?
Findings
In this cohort study of 570 adults undergoing thyroid surgery, aspirin use was not associated with an increased risk of blood loss. The association between aspirin use and complications of hematoma or recurrent laryngeal nerve injury was inconclusive because of the small sample size and infrequent events.
Meaning
The results suggest that patients receiving aspirin may expect to undergo thyroid surgery without experiencing clinically meaningful increased bleeding complications, although further investigation is warranted.
Abstract
Importance
No evidence exists to direct the management of preoperative aspirin (acetylsalicylic acid) use in patients undergoing thyroid surgery. Nevertheless, a considerable number of patients interrupt receiving aspirin therapy during the preoperative period to minimize bleeding complications despite the increased risk of experiencing major adverse cardiac events.
Objective
To determine whether aspirin therapy continued preoperatively increases bleeding complications in patients undergoing thyroid surgery.
Design, Setting, and Participants
Retrospective analysis of a consecutive sample of 570 patients, aged 18 to 100 years, who underwent thyroid surgery for benign and malignant disease from January 1, 2010, to December 31, 2015, by a single surgeon at a tertiary referral hospital center in New Orleans, Louisiana.
Exposures
Patients receiving aspirin therapy and patients not receiving aspirin therapy (aspirin naive) preoperatively.
Main Outcomes and Measures
Comparison of estimated blood loss, substantial blood loss, operative hematoma, nonoperative hematoma, and recurrent laryngeal nerve injury.
Results
Of 570 patients who underwent thyroid surgery, 106 (18.6%) were performed in patients receiving aspirin; of these, 23 (21.7%) were men and 105 (99.1%) were older than 45 years. Those receiving aspirin therapy displayed a 14.4-year difference in age (95% CI, 11.6-17.1). The aspirin group displayed a 20.3% absolute increase (95% CI, 9.3-30.7) in African American patients. Aspirin therapy was not associated with a statistically significant or clinically meaningful increase in intraoperative blood loss (2.5 mL; 95% CI, –0.4 to 5.3). Aspirin therapy was associated with a statistically significant increase in total hematoma formation (3.3%; 95% CI, 0.4-9.0), but the results were inconclusive. Aspirin therapy was not associated with a statistically significant increase in recurrent laryngeal nerve injury (2.6%; 95% CI, –1.1 to 8.6), but the results were inconclusive.
Conclusions and Relevance
These results suggest that aspirin therapy can be maintained prior to thyroid surgery without increased intraoperative bleeding. Further research with a larger sample size and more outcome events are required to make definitive conclusions regarding the association between aspirin use and complications, including hematoma and recurrent laryngeal nerve injury.
This cohort study assesses whether continued preoperative aspirin use preoperatively is associated with increased bleeding complications among patients undergoing thyroid surgery.
Introduction
When patients receiving antiplatelet medication undergo elective otolaryngologic surgery, both patients and physicians must decide whether to stop therapy preoperatively and risk a possible life-threatening thromboembolic event or to continue therapy and risk an intraoperative hemorrhage and associated complications. Multiple guidelines outline the management of preoperative antiplatelet therapy based on a stratification risk of hemorrhage vs thrombosis complications, but the literature examining the effects of cessation or continuation of antiplatelet therapy for specific noncardiac procedures is lacking. There is no universal consensus about how antiplatelet therapy for elective otolaryngologic procedures should be treated. Nevertheless, the preoperative cessation of antiplatelet therapy is still routinely practiced for these surgical procedures. The same holds true for thyroid surgery, where a successful procedure relies on the surgeon performing precise tissue dissection through narrow operating fields. Those surgeons who routinely withhold aspirin and other antiplatelet and/or anticoagulant medications preoperatively often fear increased bleeding, which may limit exposure of tissue during the operation and result in complications, such as recurrent laryngeal nerve (RLN) injury and hematoma formation.
The aim of this retrospective cohort study was to compare the incidence of bleeding complications between patients who underwent thyroid surgery while receiving aspirin therapy with those patients naive to aspirin therapy. We hypothesized that aspirin therapy would have no significant association with bleeding complications during thyroid surgery, including intraoperative blood loss, postoperative hematoma formation, and RLN injury.
Methods
Study Design and Patient Population
This retrospective cohort study included consecutive patients 18 years or older who underwent thyroid surgery performed by a single surgeon (E.K.) at a tertiary referral hospital center between January 1, 2010, and December 31, 2015. The present study was approved by the institutional review board at the Tulane University School of Medicine in New Orleans, Louisiana. Patient informed consent was waived by the Tulane University School of Medicine given the absence of patient-identifying information.
Thyroid surgery procedures included total thyroidectomy, thyroid lobectomy, completion thyroidectomy, parathyroidectomy, and central neck dissection. No patient was excluded on the basis of thyroid disease. Diseases treated included nodular hyperplasia, multinodular goiter, Hashimito thyroiditis, Graves disease, follicular adenoma, Hurthle cell neoplasm, papillary carcinoma, follicular carcinoma, medullary carcinoma, and hyperparathyroidism. Patients undergoing either robotic or endoscopic procedures were excluded.
Primary Outcome Measures
Intraoperative blood loss, hematoma formation, and RLN injury were measured as primary outcomes. Estimated blood loss was defined as the intraoperative blood loss as determined from a review of the operative report of the primary surgeon. A substantial blood loss was defined as more than 10 mL of intraoperative blood loss. The presence or absence of RLN injury was measured postoperatively for every patient (with or without dysphonia) by assessing vocal fold mobility via physician-directed, flexible fiberoptic laryngoscopy.
Temporary RLN injury was defined as vocal fold immobility that resolved spontaneously within 1 year from the date of surgery. Permanent RLN injury was defined as vocal fold immobility lasting longer than 1 year postoperatively.
Hematoma was defined as the development of a tender, tense, and discolored neck swelling. Clotted or collected blood was expressed or aspirated when the diagnosis was unclear. Nonoperative hematoma was defined as a hematoma treated conservatively (by observation or the expression or aspiration of blood from the wound), whereas operative hematoma described a hematoma necessitating surgical exploration. Total postoperative hematoma includes operative and nonoperative hematomas.
Stratification
Patients were divided into 2 groups: patients receiving aspirin therapy (aspirin group) and patients not receiving aspirin therapy (aspirin-naive group). Patients receiving aspirin and other antiplatelet and/or anticoagulant medications were included in the aspirin group.
Statistical Analysis
All collected information was recorded in a secure electronic database with strict control and supervision for data entry and access. All statistical analysis was performed using SAS, version 9.3 (SAS Institute Inc). The Fisher exact test was used for comparing categorical variables and the unpaired, 2-tailed t test was used for comparing continuous variables. Raw group differences, including comparison of means and comparison of proportions, were calculated for effect sizes and 95% CIs where appropriate. Logistic regression modeling was applied in testing for confounders and in estimating the odds ratio (OR) and 95% CI, where appropriate. The level of statistical significance was set as 2-sided α = .05.
Results
Patient Characteristics
Of 570 patients undergoing thyroid surgery who met the inclusion criteria, 464 (81.4%) were aspirin naive, while 106 (18.6%) were receiving aspirin. Of patients receiving aspirin, 23 (21.7%) were men and 105 (99.1%) were older than 45 years. Regarding the dosage of aspirin, 95 (89.6%) were receiving aspirin, 81 mg/d, and the remaining 11 patients (10.4%) were receiving aspirin, 325 mg/d. Most of the patients in the aspirin group (97 of 106 [91.5%]) were receiving aspirin alone, whereas other patients (9 [8.5%]) were receiving aspirin in combination with other antiplatelets and/or anticoagulants (aspirin and clopidogrel bisulfate [4 (3.8%)], aspirin and warfarin sodium [4 (3.8%)], and aspirin, clopidogrel, and warfarin [1 (0.9%)]) (Table 1).
Table 1. Characteristics and Bleeding Complications of Patients in the Aspirin-Naive Group vs the Aspirin Group.
| Characteristic | Aspirin-Naive Group (n = 464) | Aspirin Group (n = 106) | Effect Size (95% CI)a |
|---|---|---|---|
| Demographic and Medical | |||
| Age, mean (SD), y | 49.7 (13.8) | 64.1 (9.1) | 14.4 (11.6 to 17.1) |
| Age ≥45 y, No. (%) | 296 (63.8) | 105 (99.1) | 35.4 (29.3 to 40.0) |
| Male, No. (%) | 91 (19.6) | 23 (21.7) | 2.1 (−6.3 to 11.8) |
| Race/ethnicity, No. (%) | |||
| African American | 186 (40.1) | 64 (60.4) | 20.3 (9.3 to 30.7) |
| White | 225 (48.5) | 37 (34.9) | 13.6 (2.7 to 23.7) |
| Asian | 15 (3.2) | 1 (0.9) | 2.3 (−2.1 to 4.5) |
| Other | 38 (8.2) | 4 (3.8) | 4.4 (−1.6 to 8.4) |
| BMI, mean (SD) | 30.3 (7.7) | 31.2 (8.2) | 0.9 (−0.7 to 2.6) |
| BMI ≥25, No. (%) | 299 (64.4) | 75 (70.8) | 3.6 (−6.4 to 12.4) |
| Tobacco use, No. (%) | |||
| Ever | 33 (7.1) | 11 (10.4) | 3.1 (−2.7 to 10.9) |
| Current | 79 (17.0) | 27 (25.5) | 8.1 (−0.7 to 18.0) |
| Alcohol use, No. (%) | 145 (31.2) | 36 (34.0) | 1.7 (−8.2 to 12.4) |
| Clopidogrel bisulfate use, No. (%) | 0 | 5 (4.7) | 4.72 (1.4 to 10.7) |
| Warfarin sodium use, No. (%) | 15 (3.2) | 5 (4.7) | 1.49 (−2.3 to 7.6) |
| TSH, mean (SD), mIU/L | 2.3 (7.6) | 1.9 (2.7) | −0.4 (−1.9 to 1.1) |
| Nodule size, mean (SD), cm | 2.6 (1.7) | 2.6 (1.7) | −0.0 (−0.3 to 0.4) |
| Benign pathology results, No. (%) | 302 (65.1) | 76 (71.7) | 6.61 (−3.9 to 16.1) |
| Procedure, No. (%) | |||
| Total thyroidectomy | 104 (22.4) | 9 (8.5) | 13.9 (6.0 to 20.0) |
| Thyroid lobectomy | 289 (62.3) | 72 (67.9) | 5.6 (−5.1 to 15.5) |
| Completion thyroidectomy | 42 (9.0) | 13 (12.3) | 3.2 (−3.1 to 11.4) |
| Parathyroidectomy | 26 (5.6) | 11 (10.4) | 4.8 (−0.9 to 12.4) |
| Neck dissection | 3 (0.6) | 1 (0.9) | 0.3 (−1.2 to 4.5) |
| Bleeding Complications | |||
| EBL, mean (SD), mL | 11.4 (5.8) | 13.9 (28.7) | 2.5 (−0.4 to 5.3) |
| SBL, No. (%) | 54 (11.6) | 14 (13.2) | 1.6 (−5.1 to 10.0) |
| RLN injury, No. (%) | |||
| Temporary | 10 (2.2) | 5 (4.7) | 2.6 (−1.1 to 8.6) |
| Permanent | 0 | 0 | NA |
| Hematoma, No. (%) | |||
| Total postoperative | 2 (0.4) | 4 (3.8) | 3.3 (0.4 to 9.0) |
| Nonoperative | 2 (0.4) | 3 (2.8) | 2.4 (−0.1 to 7.6) |
| Operative | 0 | 1 (0.9) | 0.9 (−0.3 to 5.1) |
Abbreviations: BMI, body mass index (calculated as the weight in kilograms divided by height in meters squared); EBL, estimated blood loss; NA, not applicable; RLN, recurrent laryngeal nerve; SBL, substantial blood loss (EBL >10 mL); TSH, thyroid-stimulating hormone.
Effect size calculated using raw group differences, including comparison of means and comparison of proportions where appropriate.
Those receiving aspirin therapy displayed a 14.4-year difference in age (95% CI, 11.6-17.1). The aspirin group displayed a 20.3% absolute increase (95% CI, 9.3-30.7) in African American patients. Patients receiving aspirin underwent total thyroidectomy less frequently, corresponding to a 13.9% absolute difference (95% CI, 6.0-20.0). Sex, body mass index, thyroid-stimulating hormone levels, smoking history, alcohol use, anticoagulant use, dominant nodule size, and pathology results (benign vs malignant) were similar between the 2 groups (Table 1).
Primary Outcome Measures
Estimated Blood Loss
Based on the difference of means, patients taking aspirin experienced a 2.5-mL difference in estimated blood loss (95% CI, −0.4 to 5.3) (Table 1). The absolute difference of 2.5 mL is not statistically significant; the upper bound result of the 95% CI suggests there is no clinically meaningful difference. This is a conclusively negative finding.
Substantial Blood Loss
The rate of substantial blood loss in the aspirin-naive group was 54 of 464 patients (11.6%) vs 14 of 106 (13.2%) in the aspirin group for a difference of 1.6% (95% CI, −5.1 to 10.0). The absolute difference of 1.6% is not statistically significant; the upper bound results of the 95% CI suggest there is no clinically meaningful difference. This is a conclusively negative finding. On logistic regression, aspirin therapy increased the risk of substantial blood loss (OR, 1.2; 95% CI, 0.6-2.2).
RLN Injury
The rate of temporary RLN injury in the aspirin-naive group was 10 of 464 (2.2%) vs 5 of 106 (4.7%) in the aspirin group for a difference of 2.6% (95% CI, −1.1% to 8.6%). The absolute difference of 2.6% is not statistically significant; the upper bound result of the 95% CI suggests a clinically meaningful difference. This is an inconclusive finding. On logistic regression, aspirin therapy increased the risk of temporary RLN injury (OR, 2.2; 95% CI, 0.7-6.7). There were no cases of permanent RLN injury in either group (Table 1).
Hematoma
The rate of a total postoperative hematoma in the aspirin-naive group was 2 of 464 patients (0.4%) vs 4 of 106 (3.8%) in the aspirin group for a difference of 3.3% (95% CI, 0.4-9.0). The difference of 3.3% is statistically significant, but the small number of events leads to imprecision of the estimate. This is an inconclusive finding. On logistic regression, aspirin use significantly increased the risk of a total postoperative hematoma (OR, 9.1; 95% CI, 1.6-50.1).
The rate of a nonoperative hematoma in the aspirin-naive group was 2 of 464 patients (0.4%) vs 3 of 106 (2.8%) in the aspirin group for a difference of 2.4% (95% CI, –0.1 to 7.6). The difference of 2.4% is not statistically significant, and the upper bound of the CI was not clinically significant. On logistic regression, however, aspirin use significantly increased the risk of a total nonoperative hematoma (OR, 6.7; 95% CI, 1.1-40.8).
Only 1 of 106 patients (0.9%) receiving aspirin therapy developed an operative hematoma. None of the patients developed an operative hematoma in the aspirin-naive group (Table 1).
The small number of patients with a total postoperative hematoma (n = 6) precluded statistical analysis to identify hematoma risk factors (ie, univariate analysis).
Of the 6 patients who developed hematomas, 6 (100%) were older than 45 years, 5 (83.3%) were female, 4 (66.7%) were African American, and 4 (66.7%) were receiving aspirin therapy. Of the 6 patients who developed total postoperative hematoma, all had undergone thyroid lobectomy, the mean (SD) nodule size was 3.4 (1.2) cm, and 5 patients (83.3%) had benign pathology results (Table 2).
Table 2. Characteristics of 6 Patients With Total Postoperative Hematoma.
| Characteristic | No. (%) |
|---|---|
| Demographic and Medical | |
| Age, mean (SD), y | 57 (9.9) |
| Age ≥45 y | 6 (100) |
| Male | 1 (16.7) |
| Race/ethnicity | |
| African American | 4 (66.7) |
| White | 2 (33.3) |
| Asian | 0 |
| Other | 0 |
| BMI, mean (SD) (n = 5) | 31.1 (10.3) |
| BMI ≥25 (n = 5) | 2 (40.0) |
| Tobacco use | |
| Ever | 0 |
| Current | 2 (33.3) |
| Alcohol use | 2 (33.3) |
| Aspirin usea | 4 (66.7) |
| Clopidogrel bisulfate use | 0 |
| Warfarin sodium use | 0 |
| TSH, mean (SD), mIU/L | 1.6 (0.9) |
| Nodule size, mean (SD), cm | 3.4 (1.2) |
| Benign pathology results | 5 (83.3) |
| Procedureb | |
| Thyroid lobectomy | 6 (100) |
| Bleeding Complications | |
| EBL, mean (SD), mL | 11.7 (2.6) |
| SBL, No. (%) | 2 (33.3) |
| RLN injury, No. (%) | |
| Temporary | 1 (16.7) |
| Permanent | 0 |
Abbreviations: BMI, body mass index (calculated as the weight in kilograms divided by height in meters squared); EBL, estimated blood loss; RLN, recurrent laryngeal nerve; SBL, substantial blood loss (EBL >10 mL); TSH, thyroid-stimulating hormone.
All 4 patients were receiving a dosage of 81 mg/d.
Other procedures included central neck dissection, parathyroidectomy, total thyroidectomy, and complete thyroidectomy.
Discussion
Given that 25% of middle-aged and elderly adults receive aspirin (18.6% in our study population), otolaryngologists frequently perform surgical procedures for patients receiving aspirin therapy. No evidence-based guidelines exist regarding preoperative use of aspirin therapy, yet most otolaryngologists routinely advise patients to stop receiving aspirin therapy before surgical procedures. Some physicians cancel surgical procedures if patients have received aspirin preoperatively, which jeopardizes health care efficiency and incurs undue medical costs. We hypothesized that aspirin use does not increase major bleeding complications in patients undergoing thyroid surgery.
In this retrospective cohort study of aspirin use and bleeding complications during thyroid surgery, our results suggest neither a statistically nor clinically significant association between aspirin use and intraoperative blood loss. However, the results for the association of aspirin with RLN injury and hematoma are inconclusive because of the small sample size and number of outcome events and do not rule out the possibility of increased rates of RLN injury and hematoma with aspirin use. Additional studies with larger sample sizes are required to answer these questions.
Safety of Continuing Aspirin in Noncardiac Surgery
The literature examining the association of antiplatelet therapy with noncardiac procedures is limited. Authors supporting the safe continuation of aspirin during noncardiac procedures cite a reduced risk of major adverse cardiac events without increased bleeding complications in those patients receiving aspirin. On the other hand, the Burger et al meta-analysis of 49 590 patients reported an increased frequency of bleeding complications (median, 1.5; interquartile range, 1.0-2.5) in patients receiving aspirin during noncardiac procedures. However, they emphasized that aspirin therapy did not affect the risk of postoperative morbidity or mortality. They concluded that aspirin should be held preoperatively “only if low-dose aspirin may cause bleeding risks with increased mortality or sequels comparable with the observed cardiovascular risks after aspirin withdrawal.”(p399) Similarly, patients receiving aspirin therapy in our study who experienced a nonoperative hematoma did not experience any increased morbidity or mortality.
Safety of Aspirin in Otolaryngologic Surgery
Several studies support the safe continuation of aspirin therapy during various otolaryngologic and other surgical procedures anatomically related to the head and neck, including cataract surgery, vitreoretinal surgery, dental osteotomy, cutaneous surgery, in-office laryngologic procedures, and microlaryngeal surgery. Nevertheless, scarce evidence and contradictory guidelines offer no general consensus for preoperative management of aspirin therapy in otolaryngologic surgery.
Aspirin and Hematoma in Thyroid Surgery
The association between aspirin and hematoma in patients undergoing thyroid surgery remains controversial. Few studies report an association between antiplatelet therapy and hematoma, including the review by Campbell et al of 207 postthyroidectomy patients with hematomas that reported antiplatelet use as an independent risk factor for operative hematoma (OR, 2.1; 95% CI, 1.1-4.1). The grouping of all patients receiving aspirin, warfarin, clopidogrel, nonsteroidal anti-inflammatory medications, or low-molecular-weight heparin limits the use of their findings. Moreover, the increased rate of operative hematoma in the study was largely driven by patients actively receiving clopidogrel, warfarin, or low-molecular-weight heparin more than aspirin use.
Some authors dispute the association of aspirin therapy with hematoma formation. Lang et al found no correlation between antiplatelet therapy and operative hematoma, but all 22 patients in their study stopped antiplatelet therapy preoperatively. Likewise, Leyre et al reported on 70 patients and Burkey et al reported on 42 patients and found no increased risk of operative hematoma with preoperative antiplatelet use. However, it is unclear how many of their patients were actively using these medications at the time of the operation.
The findings of our study may prove useful for both patient and physician when deciding whether to withhold or to continue aspirin therapy before thyroid surgery. Regarding the association between aspirin and operative hematoma, no conclusion could be made from our study because of the small sample size (n = 1). The 0.9% incidence of operative hematoma in the aspirin group compares favorably with the documented 0.6% to 2.0% incidence of operative hematoma after thyroid surgery, supporting our hypothesis that aspirin does not increase major bleeding complications in patients undergoing thyroid surgery. Further research with a larger sample size and more outcome events are needed to investigate our findings and the safety of continuing aspirin and other antiplatelet and/or anticoagulation therapy in patients undergoing thyroid surgery. Ultimately, the management of perioperative aspirin therapy should involve a multidisciplinary approach until conclusive evidence-based guidelines are created.
Limitations
Limitations of the study include a small sample size and a retrospective study design. In lieu of the recently established surgeon volume–outcome association for thyroidectomy, it may be inappropriate to extrapolate our findings to those surgeons who do not routinely perform thyroidectomies.
The difference in mean age between the aspirin group and the aspirin-naive group (mean, 64.1 vs 49.7 years) warrants discussion, particularly because multiple studies have reported older age as an independent risk factor for hematoma. Dehal et al report age 41 to 65 years (reference group, 18-40 years) as a risk factor for developing hematoma after thyroid surgery (OR, 1.4; 95% CI, 1.1-1.6). Godballe et al similarly report age greater than 50 years (reference group, <50 years) as a risk factor for postthyroidectomy hemorrhage (OR, 1.5; 95% CI, 1.2-2.0). Weiss et al report an increased risk of hematoma starting at age 45 years (OR, 1.4; 95% CI, 1.1-2.0) compared with the reference group of patients aged 18 to 29 years. Although most authors would agree that increasing age is a risk factor for hematoma, the lack of consensus on which age constitutes such a risk precludes any meaningful conclusions related to our study.
A higher percentage of African American patients in the aspirin group (60.4%) compared with the aspirin-naive group (40.1%) may confound bleeding complication rates. This finding is especially true because previous studies have identified African American race as an independent risk factor for hematoma formation following thyroid surgery, including Dehal et al (OR, 1.5; 95% CI, 1.2-1.7) and Weiss et al (OR, 1.4; 95% CI, 1.2-1.6), who both use the term white as the reference population. Although the etiology is not understood, one can postulate that health care disparities involving racial minorities may be a contributing factor for increased complications in this population.
The difference in procedures performed between the 2 groups is difficult to interpret since the extent of thyroid resection (hemithyroidectomy vs total thyroidectomy) and its effect on neck hematoma is inconsistent. Several studies showed an increased risk of bleeding when total thyroidectomy is performed compared with partial thyroidectomy However, other studies report that the extent of thyroidectomy was not associated with the rate of hematoma formation.
Conclusions
Our results suggest that aspirin therapy can be continued before thyroid surgery without increasing intraoperative bleeding. Our study findings are inconclusive regarding the association of aspirin use with hematoma formation and RLN injury. Preoperative aspirin therapy management should involve a multidisciplinary approach until conclusive evidence-based guidelines are created. Further research involving larger sample sizes is required.
References
- 1.Burger W, Chemnitius JM, Kneissl GD, Rücker G. Low-dose aspirin for secondary cardiovascular prevention—cardiovascular risks after its perioperative withdrawal versus bleeding risks with its continuation—review and meta-analysis. J Intern Med. 2005;257(5):399-414. [DOI] [PubMed] [Google Scholar]
- 2.Collet JP, Montalescot G, Blanchet B, et al. Impact of prior use or recent withdrawal of oral antiplatelet agents on acute coronary syndromes. Circulation. 2004;110(16):2361-2367. [DOI] [PubMed] [Google Scholar]
- 3.Ferrari E, Benhamou M, Cerboni P, Marcel B. Coronary syndromes following aspirin withdrawal: a special risk for late stent thrombosis. J Am Coll Cardiol. 2005;45(3):456-459. [DOI] [PubMed] [Google Scholar]
- 4.Iakovou I, Schmidt T, Bonizzoni E, et al. Incidence, predictors, and outcome of thrombosis after successful implantation of drug-eluting stents. JAMA. 2005;293(17):2126-2130. [DOI] [PubMed] [Google Scholar]
- 5.Schouten O, van Domburg RT, Bax JJ, et al. Noncardiac surgery after coronary stenting: early surgery and interruption of antiplatelet therapy are associated with an increase in major adverse cardiac events. J Am Coll Cardiol. 2007;49(1):122-124. [DOI] [PubMed] [Google Scholar]
- 6.Sharma AK, Ajani AE, Hamwi SM, et al. Major noncardiac surgery following coronary stenting: when is it safe to operate? Catheter Cardiovasc Interv. 2004;63(2):141-145. [DOI] [PubMed] [Google Scholar]
- 7.CAPRIE Steering Committee A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). Lancet. 1996;348(9038):1329-1339. [DOI] [PubMed] [Google Scholar]
- 8.Chapman TW, Bowley DM, Lambert AW, Walker AJ, Ashley SA, Wilkins DC. Haemorrhage associated with combined clopidogrel and aspirin therapy. Eur J Vasc Endovasc Surg. 2001;22(5):478-479. [DOI] [PubMed] [Google Scholar]
- 9.Moore M, Power M. Perioperative hemorrhage and combined clopidogrel and aspirin therapy. Anesthesiology. 2004;101(3):792-794. [DOI] [PubMed] [Google Scholar]
- 10.Bélisle S, Hardy JF. Hemorrhage and the use of blood products after adult cardiac operations: myths and realities. Ann Thorac Surg. 1996;62(6):1908-1917. [DOI] [PubMed] [Google Scholar]
- 11.Thurston AV, Briant SL. Aspirin and post-prostatectomy haemorrhage. Br J Urol. 1993;71(5):574-576. [DOI] [PubMed] [Google Scholar]
- 12.Kapetanakis EI, Medlam DA, Boyce SW, et al. Clopidogrel administration prior to coronary artery bypass grafting surgery: the cardiologist’s panacea or the surgeon’s headache? Eur Heart J. 2005;26(6):576-583. [DOI] [PubMed] [Google Scholar]
- 13.Lecompte T, Hardy JF. Antiplatelet agents and perioperative bleeding. Can J Anaesth. 2006;53(6)(suppl):S103-S112. [DOI] [PubMed] [Google Scholar]
- 14.Chassot PG, Delabays A, Spahn DR. Perioperative antiplatelet therapy: the case for continuing therapy in patients at risk of myocardial infarction. Br J Anaesth. 2007;99(3):316-328. [DOI] [PubMed] [Google Scholar]
- 15.Douketis JD, Berger PB, Dunn AS, et al. The perioperative management of antithrombotic therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition). Chest. 2008;133(6)(suppl):299S-339S. [DOI] [PubMed] [Google Scholar]
- 16.Llau JV, Lopez-Forte C, Sapena L, Ferrandis R. Perioperative management of antiplatelet agents in noncardiac surgery. Eur J Anaesthesiol. 2009;26(3):181-187. [DOI] [PubMed] [Google Scholar]
- 17.Servin F. Low-dose aspirin and clopidogrel: how to act in patients scheduled for day surgery. Curr Opin Anaesthesiol. 2007;20(6):531-534. [DOI] [PubMed] [Google Scholar]
- 18.Broad L, Lee T, Conroy M, et al. Successful management of patients with a drug-eluting coronary stent presenting for elective, non-cardiac surgery. Br J Anaesth. 2007;98(1):19-22. [DOI] [PubMed] [Google Scholar]
- 19.Schlitt A, Jámbor C, Spannagl M, Gogarten W, Schilling T, Zwissler B. The perioperative management of treatment with anticoagulants and platelet aggregation inhibitors. Dtsch Arztebl Int. 2013;110(31-32):525-532. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Sylvester DC, Coatesworth AP. Antiplatelet therapy in ENT surgery: a review. J Laryngol Otol. 2012;126(4):331-336. [DOI] [PubMed] [Google Scholar]
- 21.Chassot PG, Marcucci C, Delabays A, Spahn DR. Perioperative antiplatelet therapy. Am Fam Physician. 2010;82(12):1484-1489. [PubMed] [Google Scholar]
- 22.Savage JR, Parmar A, Robinson PJ. Antiplatelet drugs in elective ENT surgery. J Laryngol Otol. 2012;126(9):886-892. [DOI] [PubMed] [Google Scholar]
- 23.Weiss A, Lee KC, Brumund KT, Chang DC, Bouvet M. Risk factors for hematoma after thyroidectomy: results from the nationwide inpatient sample. Surgery. 2014;156(2):399-404. [DOI] [PubMed] [Google Scholar]
- 24.Campbell MJ, McCoy KL, Shen WT, et al. A multi-institutional international study of risk factors for hematoma after thyroidectomy. Surgery. 2013;154(6):1283-1289. [DOI] [PubMed] [Google Scholar]
- 25.Shahar E, Folsom AR, Romm FJ, et al. Patterns of aspirin use in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study. Am Heart J. 1996;131(5):915-922. [DOI] [PubMed] [Google Scholar]
- 26.Oscarsson A, Gupta A, Fredrikson M, et al. To continue or discontinue aspirin in the perioperative period: a randomized, controlled clinical trial. Br J Anaesth. 2010;104(3):305-312. [DOI] [PubMed] [Google Scholar]
- 27.Bass E, Gill P. Report into “on the day cancellations” for plastic surgery in patients who failed to stop their medication. BMJ Qual Improv Rep. 2014;3(1):u204762.w2037. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Fayed A, Elkouny A, Zoughaibi N, Wahabi HA. Elective surgery cancelation on day of surgery: an endless dilemma. Saudi J Anaesth. 2016;10(1):68-73. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Assia EI, Raskin T, Kaiserman I, Rotenstreich Y, Segev F. Effect of aspirin intake on bleeding during cataract surgery. J Cataract Refract Surg. 1998;24(9):1243-1246. [DOI] [PubMed] [Google Scholar]
- 30.Ryan A, Saad T, Kirwan C, Keegan DJ, Acheson RW. Maintenance of perioperative antiplatelet and anticoagulant therapy for vitreoretinal surgery. Clin Exp Ophthalmol. 2013;41(4):387-395. [DOI] [PubMed] [Google Scholar]
- 31.Hanken H, Tieck F, Kluwe L, et al. Lack of evidence for increased postoperative bleeding risk for dental osteotomy with continued aspirin therapy. Oral Surg Oral Med Oral Pathol Oral Radiol. 2015;119(1):17-19. [DOI] [PubMed] [Google Scholar]
- 32.Dhiwakar M, Khan NA, McClymont LG. Surgical resection of cutaneous head and neck lesions: does aspirin use increase hemorrhagic risk? Arch Otolaryngol Head Neck Surg. 2006;132(11):1237-1241. [DOI] [PubMed] [Google Scholar]
- 33.Otley CC. Continuation of medically necessary aspirin and warfarin during cutaneous surgery. Mayo Clin Proc. 2003;78(11):1392-1396. [DOI] [PubMed] [Google Scholar]
- 34.Fritz MA, Peng R, Born H, et al. The safety of antithrombotic therapy during in-office laryngeal procedures-a preliminary study. J Voice. 2015;29(6):768-771. [DOI] [PubMed] [Google Scholar]
- 35.Francis DO, Dang JH, Fritz MA, Garrett CG. Antiplatelet and anticoagulation therapy in microlaryngeal surgery. Laryngoscope. 2014;124(4):928-934. [DOI] [PubMed] [Google Scholar]
- 36.Lang BH, Yih PC, Lo CY. A review of risk factors and timing for postoperative hematoma after thyroidectomy: is outpatient thyroidectomy really safe? World J Surg. 2012;36(10):2497-2502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Leyre P, Desurmont T, Lacoste L, et al. Does the risk of compressive hematoma after thyroidectomy authorize 1-day surgery? Langenbecks Arch Surg. 2008;393(5):733-737. [DOI] [PubMed] [Google Scholar]
- 38.Burkey SH, van Heerden JA, Thompson GB, Grant CS, Schleck CD, Farley DR. Reexploration for symptomatic hematomas after cervical exploration. Surgery. 2001;130(6):914-920. [DOI] [PubMed] [Google Scholar]
- 39.Chen E, Cai Y, Li Q, et al. Risk factors target in patients with post-thyroidectomy bleeding. Int J Clin Exp Med. 2014;7(7):1837-1844. [PMC free article] [PubMed] [Google Scholar]
- 40.Rosato L, Avenia N, Bernante P, et al. Complications of thyroid surgery: analysis of a multicentric study on 14,934 patients operated on in Italy over 5 years. World J Surg. 2004;28(3):271-276. [DOI] [PubMed] [Google Scholar]
- 41.Rosenbaum MA, Haridas M, McHenry CR. Life-threatening neck hematoma complicating thyroid and parathyroid surgery. Am J Surg. 2008;195(3):339-343. [DOI] [PubMed] [Google Scholar]
- 42.Adam MA, Thomas S, Youngwirth L, et al. Is there a minimum number of thyroidectomies a surgeon should perform to optimize patient outcomes? Ann Surg. 2017;265(2):402-407. doi: 10.1097/SLA.0000000000001688 [DOI] [PubMed] [Google Scholar]
- 43.Dehal A, Abbas A, Hussain F, Johna S. Risk factors for neck hematoma after thyroid or parathyroid surgery: ten-year analysis of the nationwide inpatient sample database. Perm J. 2015;19(1):22-28. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Godballe C, Madsen AR, Pedersen HB, et al. Post-thyroidectomy hemorrhage: a national study of patients treated at the Danish departments of ENT Head and Neck Surgery. Eur Arch Otorhinolaryngol. 2009;266(12):1945-1952. [DOI] [PubMed] [Google Scholar]
- 45.Hurtado-López LM, Zaldivar-Ramirez FR, Basurto Kuba E, et al. Causes for early reintervention after thyroidectomy. Med Sci Monit. 2002;8(4):CR247-CR250. [PubMed] [Google Scholar]
