Intraoperative use of dextran is associated with cardiac complications after carotid endarterectomy

Bailout Distal Internal Carotid Artery Stenting after Carotid Endarterectomy: Indications, Technique, and Outcomes

BACKGROUND

Distal internal carotid artery (ICA) stenting may be employed as a bailout maneuver when an inadequate end point or clamp injury is encountered at the time of carotid endarterectomy (CEA) in a surgically inaccessible region of the distal ICA. We sought to characterize the indications, technique, and outcomes for this infrequently encountered clinical scenario.

METHODS

We performed a retrospective review of all patients who underwent distal ICA stenting at the time of CEA at our institution between September 2008 and July 2022. Procedural details and postoperative follow-up were reviewed for each patient.

RESULTS

Six patients were identified during the study period. All were male with an age range of 63 to 82 years. Five underwent carotid revascularization for asymptomatic carotid artery stenosis, and one patient was treated for amaurosis fugax. Three patients were on dual antiplatelet therapy preoperatively, whereas 2 were on aspirin monotherapy, and one was on aspirin and low-dose rivaroxaban. Five patients underwent CEA with patch angioplasty, and one underwent eversion CEA. The indication for stenting was distal ICA dissection due to clamp or shunt injury in 2 patients and an inadequate distal ICA end point in 4 patients. In all cases, access for stenting was obtained under direct visualization within the common carotid artery, and a standard carotid stent was deployed with its proximal aspect landing within the endarterectomized site. Embolic protection was typically achieved via proximal common carotid artery and external carotid artery clamping for flow arrest with aspiration of debris before restoration of antegrade flow. There was 100% technical success. Postoperatively, 2 patients were found to have a cranial nerve injury, likely occurring due to the need for high ICA exposure. Median length of stay was 2 days (range 1-7 days) with no instances of perioperative stroke or myocardial infarction. All patients were discharged on dual antiplatelet therapy with no further occurrence of stroke, carotid restenosis, or reintervention through a median follow-up of 17 months.

CONCLUSIONS

Distal ICA stenting is a useful adjunct in the setting of CEA complicated by inadequate end point or vessel dissection in a surgically inaccessible region of the ICA and can minimize the need for high-risk extensive distal dissection of the ICA in this situation.

Intraoperative Bivalirudin Use in Patient Undergoing Femoral Endarterectomy with Heparin-Induced Thrombocytopenia: Case Report and Review of the Literature

PURPOSE

To describe the intraoperative use of bivalirudin during lower extremity revascularization in the setting of heparin-induced thrombocytopenia (HIT).

CASE SUMMARY

A 65 year-old man presented with left common iliac, external iliac, and femoral artery occlusion necessitating revascularization with left femoral endarterectomy and common and external iliac stent angioplasty. Three months before the femoral endarterectomy, the patient was hospitalized for a coronary artery bypass procedure. During this admission, the patient tested positive for the presence of heparin-PF4 antibody complexes. With the patient's recent history of HIT, bivalirudin was selected as the optimal agent for intraoperative anticoagulation. Bivalirudin was administered as a 50 mg bolus, followed by a continuous infusion initiated at 1.75 mg/kg/hr. Repeated bivalirudin boluses were necessary to maintain an activated clotting time (ACT) necessary for the revascularization procedures and recurrent subacute thrombi despite appropriate ACT values.

DISCUSSION

Bivalirudin has been utilized for cardiopulmonary bypass and carotid endarterectomy (CEA), but data for dosing in lower extremity revascularization are lacking. As the risk for thrombosis with HIT continues for months after diagnosis, it is important to elucidate optimal dosing of non-heparin anticoagulant options, such as the direct thrombin inhibitor, bivalirudin. The absence of validated dosing strategies for bivalirudin can result in prolonged operative times, increased risk of bleeding, and inadequate anticoagulation.

CONCLUSION

Bivalirudin is an appropriate agent for intraoperative anticoagulation in lower extremity revascularization. However, further investigation into the optimal intraoperative bivalirudin dosing regimen is necessary.

Intraoperative Infusion of Dextran Confers No Additional Benefit after Carotid Endarterectomy but Is Associated with Increased Perioperative Major Adverse Cardiac Events

BACKGROUND

Intraoperative dextran infusion has been associated with reduction of an embolic risk in patients undergoing carotid endarterectomy (CEA). Nonetheless, dextran has been associated with adverse reactions, including anaphylaxis, hemorrhage, cardiac, and renal complications. Herein, we aimed to compare the perioperative outcomes of CEA stratified by the use of intraoperative dextran infusion using a large multiinstitutional dataset.

METHODS

Patients undergoing CEA between 2008 and 2022 from the Vascular Quality Initiative database were reviewed. Patients were categorized by use of intraoperative dextran infusion, and demographics, procedural data, and in-hospital outcomes were compared. Logistic regression analysis was utilized to adjust for differences in patients while assessing the association between postoperative outcomes and intraoperative infusion of dextran.

RESULTS

Of 140,893 patients undergoing CEA, 9,935 (7.1%) patients had intraoperative dextran infusion. Patients with intraoperative dextran infusion were older with lower rates of symptomatic stenosis (24.7% vs. 29.3%; P < 0.001) and preoperative use of antiplatelets, anticoagulants and statins. Additionally, they were more likely to have severe carotid stenosis (>80%; 49% vs. 45%; P < 0.001) and undergo CEA under general anesthesia (96.4% vs. 92.3%; P < 0.001), with a more frequent use of shunt (64.4% vs. 49.5%; P < 0.001). After adjustment, multivariable analysis showed that intraoperative dextran infusion was associated with higher odds of in-hospital major adverse cardiac events (MACE), including myocardial infarction [MI] (odds ratio [OR], 1.76, 95% confidence interval [CI]: 1.34-2.3, P < 0.001), congestive heart failure [CHF] (OR, 2.15, 95% CI: 1.67-2.77, P = 0.001), and hemodynamic instability requiring vasoactive agents (OR, 1.08, 95% CI: 1.03-1.13, P = 0.001). However, it was not associated with decreased odds of stroke (OR, 0.92, 95% CI: 0.74-1.16, P = 0.489) or death (OR, 0.88, 95% CI: 0.58-1.35, P = 0.554). These trends persisted even when stratified by symptomatic status and degree of stenosis.

CONCLUSIONS

Intraoperative infusion of dextran was associated with increased odds of MACE, including MI, CHF, and persistent hemodynamic instability, without decreasing the risk of stroke perioperatively. Given these results, judicious use of dextran in patients undergoing CEA is recommended. Furthermore, careful perioperative cardiac management is warranted in select patients receiving intraoperative dextran during CEA.

Contralateral Occlusion and Concomitant Procedures Drive Risk of Non-ipsilateral Stroke After Carotid Endarterectomy

OBJECTIVES

Stroke after carotid endarterectomy (CEA) has been assessed widely. However, factors enhancing non-ipsilateral stroke risk are poorly defined. The aim of this study was to identify drivers of 30 day non-ipsilateral stroke after CEA in the Vascular Quality Initiative (VQI) and assess long-term survival based on laterality of post-operative stroke.

METHODS

The VQI was queried between April 1, 2003, and March 31, 2017, for all CEA. Bilateral carotid procedures within 30 days were excluded. Thirty day non-ipsilateral strokes were identified. Factors were examined to discriminate between patients with and without non-ipsilateral stroke. Univariable analysis followed by multivariable logistic regression was performed. Kaplan-Meier and log rank methods were used to estimate and compare survival.

RESULTS

During this 14 year period, 80,230 CEA in 74,928 patients met the criteria. The average age was 70.3 ± 9.3 years. Most were male (48,506; 60%), Caucasian (73,967; 92%), smokers (60,543; 76%), and asymptomatic (43,074; 54%). Contralateral stenosis ≥70% was present in 8033 (10%) with 2239 (3%) having contralateral occlusion. In 491 (0.6%) patients, peri-operative non-ipsilateral stroke occurred. After characterising univariable associations, logistic regression identified independent drivers of non-ipsilateral stroke after CEA. Operative urgency (p = .001), symptomatic disease (p < .001) and contralateral occlusion (p = .001) were pre-operative drivers. Operative predictors included shunt use (p = .008), CEA with cardiac surgery (p = .013), and CEA with concomitant proximal ipsilateral endovascular intervention (p = .01). Use of dextran (p = .005) and anti-angiotensin therapy (p = .03) were protective. Reperfusion syndrome (p < .001), re-exploration (p < .001), myocardial infarction (p < .001), and intravenous treatment of hypotension (p < .001) or hypertension (p < .001) were post-operative correlates. Non-ipsilateral stroke 30 day mortality was less than ipsilateral stroke (6.1% vs. 10.3%; p = .007). Five year survival after non-ipsilateral stroke was 73%, and no different from ipsilateral stroke 76% (p = .16). Both were worse than without stroke (88%; p < .001).

CONCLUSION

Non-ipsilateral stroke after CEA is rare. Features driving risk surround global disease burden, combined procedures, and haemodynamic fluctuations. Contralateral occlusion independently increases non-ipsilateral stroke risk. Regardless of laterality or location, effects of stroke after CEA on long-term survival are similar.

Comparison of dextran and albumin on blood coagulation in patients undergoing major gynaecological surgery

Background

Hydroxyethyl starches have been withdrawn from the European market. In Sweden, dextran was the main colloid until 2000, when starches overtook the market. After the recent 6S-trial, it was suggested that dextran could be reinstituted, but concerns for greater coagulopathy, bleeding and anaphylaxis still remain. An experimental study from our department indicated that isovolemic substitution of dextran-70 did not derange the von Willebrand function more than albumin 5%, considering the fact that dextran is hyperoncotic in comparison to albumin 5% and, therefore, induces a greater plasma volume expansion and thereby a greater dilutional coagulopathy.

Methods

Eighteen patients undergoing major gynaecological surgery were assigned to receive either 5% albumin or 6% dextran-70 with 9 patients in each group. Standard coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and platelet count, viscoelastic coagulation test thromboelastometry (ROTEM) and the Multiplate platelet aggregation test were used to test for coagulation defects at different time points perioperatively. Blood loss, blood loss replacement data and haemodynamic parameters were retrieved from anaesthetic and postoperative charts. A local departmental fluid and transfusion/infusion protocol assured haemoglobin > 90 g/l and mean arterial pressure > 65 mmHg with Ringer’s acetate in addition to the colloid use.

Results

There were no differences in demographic data between the groups. The tissue factor-activated (EXTEM) clot-structure parameter ROTEM A10 was decreased significantly in the dextran group as compared to the albumin group after the infusion of 500 ml of either colloid solution. The PT and aPTT were significantly prolonged, and the platelet count decreased postoperatively in the dextran group, whereas albumin only deranged fibrinogen levels as compared to preoperative levels. There were no differences in Multiplate platelet aggregometry, amount of haemorrhage or transfusion of blood components between the groups.

Conclusions

Standard plasma-based coagulation tests, platelet count and whole blood viscoelastic clot structure are affected by 6% dextran-70 to a greater extent than by 5% albumin, but platelet aggregation is not. Future studies should use more advanced haemodynamic monitoring to assess isovolemic plasma volume expansion with dextran and whether this affects haemostasis to a lesser degree.

The need for treatment of hemodynamic instability following carotid endarterectomy is associated with increased perioperative and 1-year morbidity and mortality

OBJECTIVE

The objective of this study was to evaluate the outcomes of patients after carotid endarterectomy (CEA) who developed postoperative hypertension or hypotension requiring the administration of intravenous vasoactive medication (IVMED).

METHODS

We examined consecutive, primary elective CEA performed by 128 surgeons within the Vascular Study Group of New England (VSGNE) database (2003-2010) and compared outcomes of patients who required postoperative IVMED to treat hyper- or hypotension with those who did not. Outcomes included perioperative death, stroke, myocardial infarction (MI), congestive heart failure (CHF), hospital length of stay, and 1-year stroke or death. Propensity score matching was performed to facilitate risk-adjusted comparisons. Multivariable regression models were used to compare the association between IVMED and outcomes in unmatched and matched samples. Factors associated with use of IVMED in postoperative hypertension and hypotension were evaluated, and predictive performance of multivariable models was examined using receiver operating characteristic (ROC) curves.

RESULTS

Of 7677 elective CEAs identified, 23% received IVMED for treatment of either postoperative hypertension (11%) or hypotension (12%). Preoperative neurological symptomatic status (20%) was similar across cohorts. In the crude sample, the use of IVMED to treat postoperative hypertension was associated with increased 30-day mortality (0.7% vs 0.1%; P < .001), stroke (1.9% vs 1%; P = .018), MI (2.4% vs 0.5%; P < .001), and CHF (1.9% vs 0.5%; P < .001). The use of IVMED to treat postoperative hypotension was also associated with increased perioperative mortality (0.8% vs 0.1%; P < .001), stroke (3.2% vs 1.0%; P < .001), MI (2.7% vs 0.5%; P < .001), and CHF (1.7% vs 0.5%; P < .001), as well as 1-year death (5.1% vs 2.9%; P < .001) or stroke (4.2% vs 2.1%; P < .001). Hospital length of stay was significantly longer among patients who needed IVMED for postoperative hypertension (2.8 ± 4.7 days vs 1.7 ± 5.5 days; P < .001) and hypotension (2.8 ± 5.9 days vs 1.7 ± 5.5 days; P < .001). In multivariable analysis, IVMED for postoperative hypertension was associated with increased MI, stroke, or death (odds ratio, 2.6; 95% confidence interval [CI], 1.6-4.1; P < .001). Similarly, IVMED for postoperative hypotension was associated with increased MI, stroke, or death (odds ratio, 3.2; 95% CI, 2.1-5.0; P < .001), as well as increased 1-year stroke or death (hazard ratio, 1.6; 95% CI, 1.2-2.2; P = .003). Smoking, coronary artery disease, and clopidogrel (ROC, 0.59) were associated with postoperative hypertension requiring IVMED, whereas conventional endarterectomy and general anesthesia were associated with postoperative hypotension requiring IVMED (ROC, 0.58). The unitization of IVMED varied between 11% and 38% across VSGNE, and center effect did not affect outcomes.

CONCLUSIONS

Postoperative hypertension requiring IVMED after CEA is associated with increased perioperative mortality, stroke, and cardiac complications, whereas significant postoperative hypotension is associated with increased perioperative mortality, cardiac, or stroke complications, as well as increased 1-year death or stroke following CEA. The utilization of IVMED varied across centers and, as such, further investigation into this practice needs to occur in order to improve outcomes of these at-risk patients.