Protamine Reduces Bleeding Complications without Increasing the Risk of Stroke after Carotid Endarterectomy: A Meta-analysis

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

Predictors of prolonged length of stay after elective carotid revascularization

OBJECTIVE

Postoperative day-one discharge is used as a quality-of-care indicator after carotid revascularization. This study identifies predictors of prolonged length of stay (pLOS), defined as a postprocedural LOS of >1 day, after elective carotid revascularization.

METHODS

Patients undergoing carotid endarterectomy (CEA), transcarotid artery revascularization (TCAR), and transfemoral carotid artery stenting (TFCAS) in the Vascular Quality Initiative between 2016 and 2022 were included in this analysis. Multivariable logistic regression analysis was used to identify predictors of pLOS, defined as a postprocedural LOS of >1 day, after each procedure.

RESULTS

A total of 118,625 elective cases were included. pLOS was observed in nearly 23.2% of patients undergoing carotid revascularization. Major adverse events, including neurological, cardiac, infectious, and bleeding complications, occurred in 5.2% of patients and were the most significant contributor to pLOS after the three procedures. Age, female sex, non-White race, insurance status, high comorbidity index, prior ipsilateral CEA, non-ambulatory status, symptomatic presentation, surgeries occurring on Friday, and postoperative hypo- or hypertension were significantly associated with pLOS across all three procedures. For CEA, additional predictors included contralateral carotid artery occlusion, preoperative use of dual antiplatelets and anticoagulation, low physician volume (<11 cases/year), and drain use. For TCAR, preoperative anticoagulation use, low physician case volume (<6 cases/year), no protamine use, and post-stent dilatation intraoperatively were associated with pLOS. One-year analysis showed a significant association between pLOS and increased mortality for all three procedures; CEA (hazard ratio [HR],1.64; 95% confidence interval [CI], 1.49-1.82), TCAR (HR,1.56; 95% CI, 1.35-1.80), and TFCAS (HR, 1.33; 95%CI, 1.08-1.64) (all P < .05).

CONCLUSIONS

A postoperative LOS of more than 1 day is not uncommon after carotid revascularization. Procedure-related complications are the most common drivers of pLOS. Identifying patients who are risk for pLOS highlights quality improvement strategies that can optimize short and 1-year outcomes of patients undergoing carotid revascularization.

An international, multispecialty, expert-based Delphi Consensus document on controversial issues in the management of patients with asymptomatic and symptomatic carotid stenosis

OBJECTIVE

Despite the publication of various national/international guidelines, several questions concerning the management of patients with asymptomatic (AsxCS) and symptomatic (SxCS) carotid stenosis remain unanswered. The aim of this international, multi-specialty, expert-based Delphi Consensus document was to address these issues to help clinicians make decisions when guidelines are unclear.

METHODS

Fourteen controversial topics were identified. A three-round Delphi Consensus process was performed including 61 experts. The aim of Round 1 was to investigate the differing views and opinions regarding these unresolved topics. In Round 2, clarifications were asked from each participant. In Round 3, the questionnaire was resent to all participants for their final vote. Consensus was reached when ≥75% of experts agreed on a specific response.

RESULTS

Most experts agreed that: (1) the current periprocedural/in-hospital stroke/death thresholds for performing a carotid intervention should be lowered from 6% to 4% in patients with SxCS and from 3% to 2% in patients with AsxCS; (2) the time threshold for a patient being considered "recently symptomatic" should be reduced from the current definition of "6 months" to 3 months or less; (3) 80% to 99% AsxCS carries a higher risk of stroke compared with 60% to 79% AsxCS; (4) factors beyond the grade of stenosis and symptoms should be added to the indications for revascularization in AsxCS patients (eg, plaque features of vulnerability and silent infarctions on brain computed tomography scans); and (5) shunting should be used selectively, rather than always or never. Consensus could not be reached on the remaining topics due to conflicting, inadequate, or controversial evidence.

CONCLUSIONS

The present international, multi-specialty expert-based Delphi Consensus document attempted to provide responses to several unanswered/unresolved issues. However, consensus could not be achieved on some topics, highlighting areas requiring future research.

Temporal Trends and Contemporary Regional Variation in Management of Patients Undergoing Carotid Endarterectomy

INTRODUCTION

The purpose of this study is to investigate regional variation and temporal trends in seven quality metrics amongst CEA patients: discharge on antiplatelet after CEA; discharge on statin after CEA; protamine administration during CEA; patch placement at conventional CEA site; continued statin usage at the time of most recent follow-up; continued antiplatelet usage at the time of most recent follow-up; and smoking cessation at the time of long term follow up.

METHODS

There are 19 de-identified regions within the VQI database in the United States. Patients were placed into one of three temporal eras based on the time of their CEA: 2003-2008; 2009-2015; and 2016-2022. We first investigated temporal trends across the seven quality metrics for all regions combined on a national basis. The percentage of patients in each time era with the presence/absence of each metric was identified. Chi-squared testing was performed to confirm statistical significance of the differences across eras. Next, analysis was performed within each region and within each time metric. We separated out the 2016-2022 patients within each region to serve as the status of each metric application in the most modern era. We then compared the frequency of metric non-adherence in each region utilizing Chi-squared testing.

RESULTS

There was statistically significant improvement in achievement of all seven metrics between the initial 2003-2008 era and the modern 2016-2022 era. The most marked change in practice pattern was noted for lack of protamine usage at surgery (decreased from 48.7% to 25.9%), discharge home postoperatively without statin (decreased from 50.6% to 15.3%), and lack of statin usage confirmed at time of most recent long term follow up (decreased from 24% to 8.9%). Significant regional variation exists across all metrics (P < .01 for all). Lack of patch placement at the time of conventional endarterectomy ranges from 1.9% to 17.8% across regions in the modern era. Lack of protamine utilization ranges from 10.8% to 49.7%. Lack of antiplatelet and statin at the time of discharge varies from 5.5% to 8.2% and 4.8% to 14.4% respectively. Adherence to the various measures at the time of most recent follow up are more tightly aligned across regions with ranges of: 5.3% to 7.5% for lack of antiplatelet usage; 6.6% to 11.7% lack of statin utilization; and 13.3 to 15.4% for persistent smoking.

CONCLUSIONS

Prior studies and societal initiatives on CEA documenting the beneficial effects of patch angioplasty, protamine use at surgery, smoking cessation, antiplatelet utilization and statin compliance have positively impacted adherence to these measures over time. In the modern 2016-2022 era the widest regional variation is noted in patch placement, protamine utilization and discharge medications allowing individual geographic areas to identify areas for potential improvement via internal VQI administrative feedback.

Perprocedural Heparinization in Non-cardiac Arterial Procedures: The Current Practice in the Netherlands

PURPOSE

Heparin is the most widely-used anticoagulant to prevent thrombo-embolic complications during non-cardiac arterial procedures (NCAP). Unfortunately, there is a lack of evidence and consequently non-uniformity in guidelines on perprocedural heparin management. Detailed insight into the current practice of antithrombotic strategies during NCAP in the Netherlands is important, aiming to identify potential optimal protocols and local differences concerning perprocedural heparinization.

MATERIALS AND METHODS

A comprehensive online survey was distributed electronically to vascular surgeons of every hospital in the Netherlands in which NCAP were performed. Data were collected from September 2020 to October 2021.

RESULTS

The response rate was 90% (53/59 hospitals). During NCAP, all surgeons generally administered heparin before arterial clamping. In 74% (39/54) of hospitals, a single heparin dosing protocol was used for all types of patients and vascular procedures. In 40%, there was no uniformity in heparin dosing between vascular surgeons. Depending on the procedure, a fixed bolus heparin, predominantly 5000 IU, was administered in 73% to 93%. In the remaining hospitals (7%-27%), a bodyweight-based heparin protocol was used, with an initial dose of 70 or 100 IU/kg. A minority (28%) monitored the effect of heparin in patients using the activated clotting time add (ACT) after activated clotting time. Target values varied between 180 and 250 seconds or 2 times the baseline ACT.

CONCLUSION

This survey demonstrates considerable variability in perprocedural heparinization during NCAP in the Netherlands. Future research on heparin dosing is needed to harmonize and optimize heparin dosage protocols and contemporary guidelines during NCAP, and thereby improve vascular surgical care and patient safety.

CLINICAL IMPACT

This survey demonstrated persisting intra- and inter-hospital variability in perprocedural heparinization during non-cardiac arterial procedures (NCAP) in the Netherlands. The observed variability in heparinization strategies highlights the need for high quality evidence on perprocedural anticoagulation strategies. This is needed in order to harmonize and optimize heparin dosage protocols and contemporary guidelines and thereby improve vascular surgical patient care. Based on the current results, an international survey will be conducted by the authors to gain additional insight into the antithrombotic strategies used during NCAP, aiming to harmonize anticoagulation protocols worldwide.

Vascular Quality Initiative assessment of compliance with Society for Vascular Surgery clinical practice guidelines on the management of extracranial cerebrovascular disease

OBJECTIVES

Compliance with Society for Vascular Surgery (SVS) clinical practice guidelines (CPGs) is associated with improved outcomes for the treatment of abdominal aortic aneurysm, but this has not been assessed for carotid artery disease. The Vascular Quality Initiative (VQI) registry was used to examine compliance with the SVS CPGs for the management of extracranial cerebrovascular disease and its impact on outcomes.

METHODS

The 2021 SVS extracranial cerebrovascular disease CPGs were reviewed for evaluation by VQI data. Compliance rates by the center and provider were calculated, and the impact of compliance on outcomes was assessed using logistic regression with inverse probability-weighted risk adjustment for each CPG recommendation, allowing for clustering by the center. Our primary outcome was a composite end point of in-hospital stroke/death. As a secondary analysis, compliance with the 2021 SVS carotid implementation document recommendations and associated outcomes were also assessed.

RESULTS

Of the 11 carotid CPG recommendations, 4 (36%) could be evaluated using VQI registry data. Median center-specific CPG compliance ranged from 38% to 95%, and median provider-specific compliance ranged from 36% to 100%. After adjustment, compliance with 2 of the recommendations was associated with lower rates of in-hospital stroke/death: first, the use of best medical therapy (antiplatelet and statin therapy) in low/standard surgical risk patients undergoing carotid endarterectomy for >70% asymptomatic stenosis (event rate in compliant vs noncompliant cases 0.59% vs 1.3%; adjusted odds ratio: 0.44, 95% confidence interval: 0.29-0.66); and second, carotid endarterectomy over transfemoral carotid artery stenting in low/standard surgical risk patients with >50% symptomatic stenosis (1.9% vs 3.4%; adjusted odds ratio: 0.55, 95% confidence interval: 0.43-0.71). Of the 132 implementation document recommendations, only 10 (7.6%) could be assessed using VQI data, with median center- and provider-specific compliance rates ranging from 67% to 100%. The impact of compliance on outcomes could only be assessed for 6 (4.5%) of these recommendations, and compliance with all 6 recommendations was associated with lower stroke/death.

CONCLUSIONS

Few SVS recommendations could be assessed in the VQI because of incongruity between the recommendations and the VQI data variables collected. Although guideline compliance was extremely variable among VQI centers and providers, compliance with most of these recommendations was associated with improved outcomes after carotid revascularization. This finding confirms the value of guideline compliance, which should be encouraged for centers and providers. Optimization of VQI data to promote evaluation of guideline compliance and distribution of these findings to VQI centers and providers will help facilitate quality improvement efforts in the care of vascular patients.

Protamine use in transcarotid arterial revascularization

OBJECTIVE

The literature suggests that heparin reversal with protamine in transcarotid arterial revascularization (TCAR) decreases postoperative bleeding complications without an increase in stroke or death. However, the dosing of protamine in TCAR has not yet been evaluated. We aimed to evaluate our experience with intraoperative heparin reversal with protamine.

METHODS

This was a single-center, retrospective, observational study that evaluated the heparin and protamine doses used during TCAR. All adult patients who underwent TCAR between 9/1/2019 and 4/2/2021 were included. Demographic data was obtained from the Vascular Quality Initiative and protamine/heparin doses were obtained from a chart review. Multivariate logistic regression models were used to assess the association between the protamine/heparin dose ratio and other variables.

RESULTS

Sixty-two patients were included. The average protamine/heparin dose ratio used was 0.96 ± 0.12 mg/U; seven had a ratio less than 0.8 mg/U, and one was greater than 1.2 mg/U. Two patients experienced bleeding complications, which were managed non-operatively. No patient with a protamine/heparin ratio greater than 0.8 mg/U had postoperative bleeding. Postoperative bradycardia was observed in 32.3% of patients and hypotension in 35%, with 19% requiring vasopressors. No relationship was identified between the protamine/heparin ratio and bleeding, bradycardia, or hypotension. No 30-day myocardial infarction, stroke or death occurred.

CONCLUSIONS

We identified a near 1:1 ratio of a protamine/heparin dosing regimen for the reversal of heparin during TCAR, with postoperative bleeding complications similar to those reported in the literature. However, patients who received a lower protamine/heparin ratio did not experience bleeding complications. In the era of protamine shortages, a future larger-scale study is needed to evaluate the impact of a lower protamine dose on postoperative complications.

Carotid endarterectomy with saphenous vein patch angioplasty: a single-center experience

BACKGROUND

When performing a conventional CEA it is recommended the use of patch angioplasty (PA), since previous meta-analyses have shown PA to be superior to primary closure (PRC) in terms of stroke and restenosis rates. Different materials patches can be employed although none of them has been proved to be superior. Although autologous veins are potentially more resistant to immediate thrombosis as well as infection, cons may be represented by patch rupture and late dilatation. Aim of this study is to evaluate immediate and long-term results of CEA with saphenous vein patch angioplasty (SVPA) in a single-center experience.

METHODS

A retrospective study was performed analyzing all patients undergoing CEA with SVPA at our institution from January 2012 to March 2020. CEA was performed in symptomatic patients with 50-99% carotid stenosis degree or asymptomatic patients with 70-99% stenosis degree. Exclusion criteria were critical limb ischemia, varicose disease, unavailability of saphenous veins, vein diameter <3.5 mm. All CEAs were performed under general anesthesia with routine shunting. Primary endpoints were perioperative stroke, death, carotid thrombosis and hematoma requiring surgery rates. Secondary endpoints included the rate of recurrent stenosis >70%, patch aneurysm/rupture/infection at follow-up.

RESULTS

Overall, 488 interventions were performed on 461 patients. Most patients were male (77.8%) with a mean age of 71.2±8.3 years. Thirty-day mortality and stroke rates were 0.4% and 1.2% respectively. Carotid thrombosis occurred in five patients (1%). Five patients (1%) developed a surgical site hematoma requiring surgical drainage. At a mean follow-up of 34.4±25.8 months 12 restenoses (2.5%) were detected. Five-year freedom from restenosis rate was 96.7%. Restenosis at follow-up was more frequent in patients who had contralateral carotid stenosis (P=0.019). Two patients (0.4%) developed carotid patch aneurysmal degeneration at a mean follow-up of 78.7 months. No infection nor patch disruption were detected.

CONCLUSIONS

CEA with SVPA resulted safe and effective in terms of early and late results. The perioperative complications rates we recorded were quite similar to those reported by other larger reviews and meta-analyses.

A Stepwise Haemostasis Intraoperative Protocol Driven Reduction of Haematoma Rate Following Symptomatic Carotidendarterectomy

INTRODUCTION

Carotid endarterectomy (CEA) for symptomatic stenosis reduces further stroke risk. Post-CEA haematoma increases the risk of complications including stroke. There are few studies considering protocols aimed at reducing post-CEA haematoma rates. Presented are the outcomes of a protocol developed to reduce this surgical complication.

METHOD

The protocol was implemented in 112 consecutive CEA. It involves stepwise additional measures to ensure haemostasis before wound closure. Attention to bleeding points is followed by light compression for 10 min. Protamine is then given if haemostasis has not been achieved. If after 20 min the problem persists Tranexamic acid is given. Following a further 20 min if haemostasis is not yet achieved a platelet transfusion is undertaken. Haematoma rates, return to theatre for post-operative haematoma and other complications were compared with 100 consecutive pre-protocol introduction CEA cases.

RESULTS

Of 112 CEA patients, 19 received protamine, 8 protamine and tranexamic acid. One case required platelet transfusion. Neck haematoma rate fell from 10 to 3 cases (P = .02, OR: 0.25 [95% CI .07-.94]), of which returned to theatre for haematoma evacuation fell from 6 to 1 case (P = .03, OR: 0.14 [95% CI .02-1.19]). 30 day stroke and death rate reduced from 5% to 1.8% (P = .11, OR: 0.35 [95% CI .07-1.82]).

CONCLUSION

The stepwise haemostasis intraoperative protocol can reduce post-CEA haematoma rates.

Intravenous thrombolysis in acute ischemic stroke after antagonization of unfractionated heparin with protamine: case series and systematic review of literature

Background and aims

Intravenous thrombolysis (IVT) is standard of care for disabling acute ischemic stroke (AIS) within a time window of ⩽ 4.5 h. Some AIS patients cannot be treated with IVT due to limiting contraindications, including heparin usage in an anticoagulating dose within the past 24 h or an elevated activated prothrombin time (aPTT) > 15 s. Protamine is a potent antidote to unfractionated heparin.

Objectives

The objective of this study was to investigate the safety and efficacy of IVT in AIS patients after antagonization of unfractionated heparin with protamine.

Methods

Patients from our stroke center (between January 2015 and September 2021) treated with IVT after heparin antagonization with protamine were analyzed. National Institutes of Health Stroke Scale (NIHSS) was used for stroke severity and modified Rankin Scale (mRS) for outcome assessment. Substantial neurological improvement was defined as the difference between admission and discharge NIHSS of ⩾8 or discharge NIHSS of ⩽1. Good outcome at follow-up after 3 months was defined as mRS 0-2. Safety data were obtained for mortality, symptomatic intracerebral hemorrhage (sICH), and for adverse events due to protamine. Second, a systematic review was performed searching PubMed and Scopus for studies and case reviews presenting AIS patients treated with IVT after heparin antagonization with protamine. The search was limited from January 1, 2011 to September 29, 2021. Furthermore, we conducted a propensity score matching comparing protamine-treated patients to a control IVT group without protamine (ratio 2:1, match tolerance 0.2).

Results

A total of 16 patients, 5 treated in our hospital and 11 from literature, [65.2 ± 13.1 years, 37.5% female, median premorbid mRS (pmRS) 1 (IQR 1, 4)] treated with IVT after heparin antagonization using protamine were included and compared to 31 IVT patients [76.2 ± 10.9 years, 45% female, median pmRS 1 (IQR 0, 2)]. Substantial neurological improvement was evident in 68.8% of protamine-treated patients versus 38.7% of control patients (p = 0.028). Good clinical outcome at follow-up was observed in 56.3% versus 58.1% of patients (p = 0.576). No adverse events due to protamine were reported, one patient suffered sICH after secondary endovascular thrombectomy of large vessel occlusion. Mortality was 6.3% versus 22.6% (p = 0.236).

Conclusion

IVT after heparin antagonization with protamine seems to be safe and, prospectively, may extend the number of AIS patients who can benefit from reperfusion treatment using IVT. Further prospective registry trials would be helpful to further investigate the clinical applicability of heparin antagonization.

Effect of Chronic Antiplatelet and Anticoagulant Medication in Neck Haematoma and Perioperative Outomes After Carotid Endarterectomy

OBJECTIVES

A retrospective analysis of neck haematoma, stroke and mortality after symptomatic and asymptomatic carotid endarterectomy (CEA) was conducted, in order to determine the most appropriate perioperative medication for these patients. Thirty-day outcomes of moderate and severe neck bleeding were also investigated.

METHODS

Patients undergoing CEA in a Vascular Surgery department were analysed (2015-2019). Pre-procedure antithrombotic medication (from the 5-days prior to surgery) was identified. End point predictors were identified by univariate and multivariable analyses and adjusted for confounders.

RESULTS

A total of 304 CEA were included. Almost half of the included patients (49.67%) were under low-dose aspirin, 17.55% other single antiplatelet agent, 12.59% dual antiplatelet therapy, 8.61% anticoagulation and 10.92% no antithrombotic therapy. There was 8.22% rate of important haematoma, including 4.93% severe (requiring surgical exploration) hematomas and a 30-day all-stroke incidence of 2.94% in symptomatic and 1.79% asymptomatic patients (p=.51). When compared to aspirin, severe haematoma was more prevalent with single clopidogrel or triflusal (RR 4.25, p=.11), dual antiplatelet group (RR 11.84, p=.002) and anticoagulation (RR 8.604, p=.02). Dual antiaggregation and anticoagulation did not confer post-operative stroke protection compared to single aspirin in either symptomatic or asymptomatic patients. Non-significant higher intra-hospital mortality was noted in no medication, dual antiplatelet and anticoagulation groups in contrast to aspirin. Severe neck bleeding was associated with increased congestive heart failure (9.26-fold, p=.03) and longer hospital stay (11.20±24.69 days versus 3.18±4.79 with no bleeding, p<.001), with a tendency for higher hospital readmission at 30-days (4.66-fold, p=.13). Mortality and stroke rates were similar.

CONCLUSIONS

Double antiaggregation and anticoagulation did not confer better perioperative outcomes after elective CEA in our study. These regimens were associated with increased risk of neck haematoma, especially severe bleeding, with similar rates of neurologic events in both symptomatic and asymptomatic patients and no mortality benefit. Monotherapy with aspirin appears to be the safest perioperative antithrombotic regimen for elective CEA.

Staged Versus Synchronous Carotid Endarterectomy and Coronary Artery Bypass Grafting: A Meta-Analysis and Systematic Review

BACKGROUND

There are several treatment options for patients with concomitant carotid and coronary artery disease, and it is difficult to identify an optimal treatment strategy that has consensus. Here, we performed a meta-analysis to compare the early and long-term outcomes of staged and synchronous carotid endarterectomy and coronary artery bypass grafting approaches.

METHODS

We performed a meta-analysis that compared staged and synchronous carotid endarterectomy and coronary artery bypass grafting approaches between July 1976 and September 2021. PubMed, EMBASE, and the Cochrane Library were systematically searched for related articles.

RESULTS

Nineteen studies were identified with a total of 39,269 and 30,066 patients in the synchronous and staged groups, respectively. Early mortality was lower in the staged group than in the synchronous group (odds ratio OR 1.256, 95% confidence interval CI 1.006-1.569, P= P < 0.05, I² = 54.5%), and stroke rates were significantly higher in the synchronous group (OR 1.356, 95% CI 1.232-1.493, P < 0.05, I² = 33.3%). The rate of myocardial ischemia was significantly higher in the staged group than in the synchronous group (OR 0.757, 95% CI 0.635-0.903, P < 0.05, I² = 51.5%), and this meta-analysis also showed a significantly higher risk of transient ischemic attacks (TIAs) in the synchronous group (OR 1.335, 95% CI 1.055-1.688, P < 0.05, I² = 0.00%). The secondary outcomes, including the rate of reoperation, were significantly lower for the staged procedure than for the synchronous procedure (OR 1.177, 95% CI 1.052-1.318, P < 0.05, I² = 4.2%), and the rate of wound infection was significantly higher in the synchronous group than in the staged group (OR 0.457, 95% CI 0.403-0.519, P < 0.05, I² = 0.0%). There was no significant difference in the rate of cardiac arrhythmia between the two groups (OR 0.544, 95% CI 0.265-1.117, P > 0.05, I² = 12.7%). There was also no statistical significance in the long-term results regarding the incidence of stroke, myocardial ischemia, and mortality between the synchronous and staged groups (P > 0.05).

CONCLUSIONS

Patients treated with the synchronous approach had a significantly higher risk of early mortality, stroke, TIA, wound infection, and reoperation and a lower risk of myocardial ischemia than those treated with the staged approach. There was no significant difference in the long-term results between the 2 groups.

Anesthetic management of carotid endarterectomy: an update from Italian guidelines

BACKGROUND AND AIMS

In order to systematically review the latest evidence on anesthesia, intraoperative neurologic monitoring, postoperative heparin reversal, and postoperative blood pressure management for carotid endarterectomy. The present review is based on a single chapter of the Italian Health Institute Guidelines for diagnosis and treatment of extracranial carotid stenosis and stroke prevention.

METHODS AND RESULTS

A systematic article review focused on the previously cited topics published between January 2016 and October 2020 has been performed; we looked for both primary and secondary studies in the extensive archive of Medline/PubMed and Cochrane library databases. We selected 14 systematic reviews and meta-analyses, 13 randomized controlled trials, 8 observational studies, and 1 narrative review. Based on this analysis, syntheses of the available evidence were shared and recommendations were indicated complying with the GRADE-SIGN version methodology.

CONCLUSIONS

From this up-to-date analysis, it has emerged that any type of anesthesia and neurological monitoring method is related to a better outcome after carotid endarterectomy. In addition, insufficient evidence was found to justify reversal or no-reversal of heparin at the end of surgery. Furthermore, despite a low evidence level, a suggestion for blood pressure monitoring in the postoperative period was formulated.

A Meta-Analysis of Using Protamine for Reducing the Risk of Hemorrhage During Carotid Recanalization: Direct Comparisons of Post-operative Complications

Background: Protamine can decrease the risk of hemorrhage during carotid recanalization. However, it may cause severe side effects. There is no consensus on the safety and efficacy of protamine during surgery. Thus, we conduct a comprehensive review and meta-analysis to compare the differences between the protamine and the no-protamine group.

Method: We systematically obtained literature from Medline, Google Scholar, Cochrane Library, and PubMed electronic databases. All four databases were scanned from 1937 when protamine was first adopted as a heparin antagonist until February 2021. The reference lists of identified studies were manually checked to determine other eligible studies that qualify. The articles were included in this meta-analysis as long as they met the criteria of PICOS; conference or commentary articles, letters, case report or series, and animal observation were excluded from this study. The Newcastle-Ottawa Quality Assessment Scale and Cochrane Collaboration’s tool are used to assess the risk of bias of each included observational study and RCT, respectively. Stata version 12.0 statistical software (StataCorp LP, College Station, Texas) was adopted as statistical software. When I2 &lt; 50%, we consider that the data have no obvious heterogeneity, and we conduct a meta-analysis using the fixed-effect model. Otherwise, the random-effect model was performed.

Result: A total of 11 studies, consisting of 94,618 participants, are included in this study. Our analysis found that the rate of wound hematoma had a significant difference among protamine and no-protamine patients (OR = 0.268, 95% CI = 0.093 to 0.774, p = 0.015). Furthermore, the incidence of hematoma requiring re-operation (0.7%) was significantly lower than that of patients without protamine (1.8%). However, there was no significant difference in the incidence of stroke, wound hematoma with hypertension, transient ischemic attacks (TIA), myocardial infarction (MI), and death.

Conclusion: Among included participants undergoing recanalization, the use of protamine is effective in reducing hematoma without increasing the risk of having other complications. Besides, more evidence-based performance is needed to supplement this opinion due to inherent limitations.

To drain or not to drain following carotid endarterectomy: a systematic review and meta-analysis

INTRODUCTION

A postoperative neck hematoma can be a life-threatening complication after carotid endarterectomy necessitating urgent surgical decompression to avoid airway compromise. The practice of routine incisional drain placement is variable with few published studies evaluating the "to drain versus not to drain" approach. We conducted a systematic review and meta-analysis of the safety and efficacy of neck drain placement for prevention of neck hematoma requiring re-exploration for decompression.

EVIDENCE ACQUISITION

This study is a systematic review and meta-analysis performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pooled odds ratios with 95% confidence intervals were calculated for the outcome of surgical re-exploration for neck decompression among patients receiving or not receiving wound drainage.

EVIDENCE SYNTHESIS

We identified 5 studies for inclusion, comprising 48,297 patients with 19,832 (41.1%) patients receiving a drain after carotid endarterectomy. Patients in the drain group had a significantly higher re-exploration rate after carotid endarterectomy compared to those who did not receive a drainage (OR=1.24, 95% CI: 1.03-1.49; P=0.02) with no heterogeneity (I²=0%).

CONCLUSIONS

Routine drain placement does not offer complete protection against neck hematoma development and may give the surgeon a false sense of security in wound drainage. Thus, we conclude that drain placement following carotid endarterectomy should be selective, not routine.

Surgical Technique for Carotid Endarterectomy: Current Methods and Problems

Over the last 60 years, many reports have investigated carotid endarterectomy (CEA) and techniques have thus changed and improved. In this paper, we review the recent literature regarding operational maneuvers for CEA and discuss future problems for CEA. Longitudinal skin incision is common, but the transverse incision has been reported to offer minimal invasiveness and better cosmetic effects for CEA. Most surgeons currently use microscopy for dissection of the artery and plaque. Although no monitoring technique during CEA has been proven superior, multiple monitors offer better sensitivity for predicting postoperative neurological deficit. To date, data are lacking regarding whether routine shunt or selective shunt is better. Individual surgeons thus need to select the method with which they are more comfortable. Many surgical techniques have been reported to obtain distal control of the internal carotid artery in patients with high cervical carotid bifurcation or high plaque, and minimally invasive techniques should be considered. Multiple studies have shown that patch angioplasty reduces the risks of stroke and restenosis compared with primary closure, but few surgeons in Japan have been performing patch angioplasty. Most surgeons thus experience only a small volume of CEAs in Japan, so training programs and development of in vivo training models are important.

Protamine Induced Anaphylactic Shock after Peripheral Vascular Surgery

Anaphylactic reactions to protamine are quite rare and almost exclusively reported during cardiac surgery. In this report, we illustrate a rare case of protamine reaction after peripheral vascular surgery a couple of months after cardiac surgery and how the patient survived this critical complication.

Haematomas after carotid endarterectomy can be reduced by direct pressure to the neck postoperatively

Introduction A recognised complication of carotid endarterectomy (CEA) is postoperative haematoma, which can threaten the airway. Previous studies have looked at medical methods of preventing this complication. This study aims to evaluate the impact of simple direct pressure postoperatively on the development of haematoma. Materials and methods From 2011 to 2016, 161 consecutive CEA were performed by a single surgeon or trainee under supervision. After 80 operations, the postoperative technique was altered, with additional pressure being applied by the surgeon to the skin incision from completion of suturing until each patient was awake in the recovery room. The rates of postoperative haematoma and other complications were compared between the pre- and post-intervention groups, as well as grade of surgeon, urgency of operation and antiplatelet/anticoagulant use. Results Post-carotid haematomas were eliminated in the post-intervention group (0/81); in the pre-intervention group 7/80 patients developed haematoma (P < 0.05). There were no significant differences in urgency of surgery, antiplatelet/anticoagulant use, grade of surgeon or other complications (stroke: 2/80 vs 0/81 P < 0.05), suggesting that this was not a learning curve effect. Discussion The results suggest that applying direct pressure helps to reduce oozing, provides time to monitor and identify additional bleeding and protects the wound from excessive strain that may be caused by coughing while the patient wakes up. We advise that the lead surgeon should apply such pressure to ensure precise and focal targeting, for maximum effect. Conclusion During recovery from CEA, focused and prolonged pressure by the operating surgeon is a highly effective method of reducing haematoma.

Competitive Antagonism of Anesthetic Action at the γ-Aminobutyric Acid Type A Receptor by a Novel Etomidate Analog with Low Intrinsic Efficacy

BACKGROUND

The authors characterized the γ-aminobutyric acid type A receptor pharmacology of the novel etomidate analog naphthalene-etomidate, a potential lead compound for the development of anesthetic-selective competitive antagonists.

METHODS

The positive modulatory potencies and efficacies of etomidate and naphthalene-etomidate were defined in oocyte-expressed α1β3γ2L γ-aminobutyric acid type A receptors using voltage clamp electrophysiology. Using the same technique, the ability of naphthalene-etomidate to reduce currents evoked by γ-aminobutyric acid alone or γ-aminobutyric acid potentiated by etomidate, propofol, pentobarbital, and diazepam was quantified. The binding affinity of naphthalene-etomidate to the transmembrane anesthetic binding sites of the γ-aminobutyric acid type A receptor was determined from its ability to inhibit receptor photoaffinity labeling by the site-selective photolabels [H]azi-etomidate and R-[H]5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl) barbituric acid.

RESULTS

In contrast to etomidate, naphthalene-etomidate only weakly potentiated γ-aminobutyric acid-evoked currents and induced little direct activation even at a near-saturating aqueous concentration. It inhibited labeling of γ-aminobutyric acid type A receptors by [H]azi-etomidate and R-[H]5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl) barbituric acid with similar half-maximal inhibitory concentrations of 48 μM (95% CI, 28 to 81 μM) and 33 μM (95% CI, 20 to 54 μM). It also reduced the positive modulatory actions of anesthetics (propofol > etomidate ~ pentobarbital) but not those of γ-aminobutyric acid or diazepam. At 300 μM, naphthalene-etomidate increased the half-maximal potentiating propofol concentration from 6.0 μM (95% CI, 4.4 to 8.0 μM) to 36 μM (95% CI, 17 to 78 μM) without affecting the maximal response obtained at high propofol concentrations.

CONCLUSIONS

Naphthalene-etomidate is a very low-efficacy etomidate analog that exhibits the pharmacology of an anesthetic competitive antagonist at the γ-aminobutyric acid type A receptor.