Perioperative management of a neurosurgical patient requiring antiplatelet therapy

Preoperative evaluation of coagulation status in neuromodulation patients

OBJECTIVE

The incidence of hemorrhage in patients who undergo deep brain stimulation (DBS) and spinal cord stimulation (SCS) is between 0.5% and 2.5%. Coagulation status is one of the factors that can predispose patients to the development of these complications. As a routine part of preoperative assessment, the authors obtain prothrombin time (PT), partial thromboplastin time (PTT), and platelet count. However, insurers often cover only PT/PTT laboratory tests if the patient is receiving warfarin/heparin. The authors aimed to examine their experience with abnormal coagulation parameters in patients who underwent neuromodulation.

METHODS

Patients who underwent neuromodulation (SCS, DBS, or intrathecal pump implantation) over a 9-year period and had preoperative laboratory values available were included. The authors determined abnormal values on the basis of a clinical protocol utilized at their practice, which combined the normal ranges of the laboratory tests and clinical relevance. This protocol had cutoff values of 12 seconds and 39 seconds for PT and PTT, respectively, and < 120,000 platelets/μl. The authors identified risk factors for these abnormalities and described interventions.

RESULTS

Of the 1767 patients who met the inclusion criteria, 136 had abnormal preoperative laboratory values. Five of these 136 patients had values that were misclassified as abnormal because they were within the normal ranges at the outside facility where they were tested. Fifty-one patients had laboratory values outside the ranges of our protocol, but the surgeons reviewed and approved these patients without further intervention. Of the remaining 80 patients, 8 had known coagulopathies and 24 were receiving warfarin/heparin. The remaining 48 patients were receiving other anticoagulant/antiplatelet medications. These included apixaban/rivaroxaban/dabigatran anticoagulants (n = 22; mean ± SD PT 13.7 ± 2.5 seconds) and aspirin/clopidogrel/other antiplatelet medications (n = 26; mean ± SD PT 14.4 ± 5.8 seconds). Eight new coagulopathies were identified and further investigated with hematological analysis.

CONCLUSIONS

New anticoagulants and antiplatelet medications are not monitored with PT/PTT, but they affect coagulation status and laboratory values. Although platelet function tests aid in a subset of medications, it is more difficult to assess the coagulation status of patients receiving novel anticoagulants. PT/PTT may provide value preoperatively.

Perioperative dual antiplatelets management for ventriculoperitoneal shunt operation in patients with hydrocephalus after stent-assisted coil embolization of the ruptured intracranial aneurysm

OBJECTIVE

Ventriculoperitoneal shunt (VPS) surgery is sometimes necessary in patients who present with symptomatic hydrocephalus after undergoing stent-assisted coil embolization of ruptured intracranial aneurysms. However, there are no guidelines for the perioperative management of VPS using dual antiplatelet therapy (DAPT) and balancing between the thromboembolic and hemorrhagic complications. Studies regarding discontinuation of DAPT and its substitution with a less potent drug for reducing the risk of hemorrhage have been previously attempted; however, the sample size in these studies was small. This study investigates the safety and feasibility of ibuprofen bridging therapy with discontinuation of DAPT for five days in patients who have recently received a neurovascular stent and require VPS.

METHODS

Forty-one patients, who were administered DAPT after neurovascular stent placement and later underwent VPS, were retrospectively enrolled. Patients were divided into two groups based on the perioperative DAPT therapy: (1) Bridge: discontinuing DAPT and substituting it with ibuprofen 600 mg bid for five days, and (2) Continue: maintaining DAPT during surgery. The groups were compared and risk factors for hemorrhagic complication were investigated.

RESULTS

On comparison analysis, no ischemic complications were observed in both groups; however, hemorrhagic complications were significantly higher in the continue than in the bridge group (p = 0.004). On multivariate logistic regression analysis, "ibuprofen bridging" was identified as a significant factor negatively associated with hemorrhagic complications (p = 0.019).

CONCLUSION

"Ibuprofen bridging therapy with discontinuation of DAPT for 5 days" is a potential treatment strategy for patients having recently undergone neurovascular stent placement and are scheduled for VPS surgery.

Postoperative Antiplatelet Therapy in the Treatment of Complex Basilar Apex Aneurysms Implementing Hunterian Ligation and Extracranial-to-Intracranial Bypass: Review of the Literature with an Illustrative Case Report

Large broad-based basilar artery (BA) apex aneurysms involving multiple arterial origins are complex lesions commonly not amenable to direct clipping or endovascular management. BA proximal (Hunterian) occlusion with extracranial-to-intracranial bypass is a supported strategy if 1 or both posterior communicating arteries are small. Hunterian ligation risks sudden aneurysm thrombosis and thromboembolism in the perforator-rich BA apex. There currently exist no guidelines for antiplatelet and anticoagulant therapy after Hunterian ligation for complex BA apex aneurysm treatment. We present a literature review and an illustrative case of an 18-year-old man who presented with progressive headaches and was found to have a large unruptured BA apex aneurysm involving the origins of the bilateral superior cerebellar and posterior cerebral arteries. Given the small posterior communicating arteries and complexity of the aneurysm, proximal BA occlusion with unilateral superficial temporal artery-to-superior cerebellar artery bypass was recommended. Despite antiplatelet treatment with acetylsalicylic acid before and after operation, the patient experienced acute ischemia of the brainstem and cerebellum and an embolic left temporal lobe infarct. The patient received dual antiplatelet therapy starting on postoperative day 6, after which he experienced no new infarcts and made a significant neurologic recovery. The current evidence suggests that proximal BA occlusion in complex BA apex aneurysm cases is thrombogenic and can be especially dangerous if thrombosis occurs suddenly in aneurysms without pre-existing intraluminal thrombus. Dual antiplatelet therapy during the first postoperative week presents a possible strategy for reducing the risk of ischemia due to sudden aneurysm thrombosis.

Low-dose acetylsalicylic acid and bleeding risks with ventriculoperitoneal shunt placement

OBJECTIVE Ventriculoperitoneal (VP) shunt placement is a common procedure for the treatment of hydrocephalus following diverse neurosurgical conditions. Most of the patients present with other comorbidities and receive antiplatelet therapy, usually acetylsalicylic acid (ASA). Despite its clinical relevance, the perioperative management of these patients has not been sufficiently investigated. The aim of this study was to compare the peri- and postoperative bleeding complication rates associated with ASA intake in patients undergoing VP shunt placement. METHODS Of 172 consecutive patients undergoing VP shunt placement between June 2009 and December 2015, 40 (23.3%) patients were receiving low-dose ASA treatment. The primary outcome measure was bleeding events in ASA users versus nonusers, whereas secondary outcome measures were postoperative cardiovascular events, hematological findings, morbidity, and mortality. A subgroup analysis was conducted in patients who discontinued ASA treatment for < 7 days (n = 4, ASA Group 1) and for ≥ 7 days (n = 36, ASA Group 2). RESULTS No statistically significant difference for bleeding events was observed between ASA users and nonusers (p = 0.30). Cardiovascular complications, surgical morbidity, and mortality did not differ significantly between the groups either. Moreover, there was no association between ASA discontinuation regimens (< 7 days and ≥ 7 days) and hemorrhagic events. CONCLUSIONS Given the lack of guidelines regarding perioperative management of neurosurgical patients with antiplatelet therapy, these findings elucidate one issue, showing comparable bleeding rates in ASA users and nonusers undergoing VP shunt placement.

[Neurosurgery in a patient on dual antiplatelet therapy. Case report and the review of the literature]

INTRODUCTION

A neurosurgical intervention in a patient on dual antiplatelet therapy is a serious challenge for both the neurosurgeon and anesthesiologist..

MATERIAL AND METHODS

The article describes a clinical case of a successful urgent neurosurgical intervention (ventriculoperitoneostomy for obstructive hydrocephalus caused by a large meningioma of the posterior surface of the petrous pyramid) in a patient on dual antiplatelet therapy (DAT) due to a recently placed coronary stent..

CONCLUSION

Given a high risk of coronary stent thrombosis, the surgery was performed in the presence of ongoing DAT. There were no intracranial hemorrhagic complications, but subcutaneous hemorrhagic complications developed. The article discusses the features of managing similar patients whose number is growing.

Effects of Perioperative Acetyl Salicylic Acid on Clinical Outcomes in Patients Undergoing Craniotomy for Brain Tumor

OBJECTIVE

To evaluate the safety of continuing acetyl salicylic acid (ASA) in patients undergoing brain tumor resection. Many patients are on antiplatelet agents that are withheld before elective neurosurgical procedures to reduce bleeding risk. Cessation of ASA in patients with cardiovascular disease is associated with a known increased risk of thrombotic events, especially in patients with coronary stents.

METHODS

The medical records of patients who underwent surgical resection of a brain tumor at the University of Florida from 2010 to 2014 were evaluated. The patients were separated into groups based on preoperative ASA use and whether or not it was stopped before surgery. Patients were evaluated for thrombotic complications, postoperative hemorrhage, estimated blood loss, length of hospital stay, and discharge disposition.

RESULTS

Of the 452 patients analyzed, 368 patients were not on chronic ASA therapy, 55 patients had their ASA discontinued before surgery, and 28 patients were continued on ASA perioperatively. The patients on preoperative ASA were comparable on all collected demographic variables. There were no statistical differences detected between the groups for outcomes including bleeding complications, need for reoperation, or thrombotic complications.

CONCLUSIONS

In this analysis, perioperative low dose ASA use was not associated with increased risk of perioperative complications.

Aspirin allergy desensitization in cerebrovascular disease. A report of two cases, literature review and management guide for the neurointerventionalist

Aspirin (ASA) is the mainstay of treatment in cerebrovascular and systemic vascular disease. ASA hypersensitivity can pose a challenge to achieving optimum medical management prior to and after neurointerventional treatment. Desensitization to ASA is well described in the allergy and cardiovascular literature, but there are no similar discussions specific to neurointervention. The purpose of our study was to describe our experience with ASA hypersensitivity management and review the relevant literature. Two cases of patients with symptomatic cerebrovascular disease requiring neurointervention who were successfully desensitized to their ASA hypersensitivity prior to treatment are described. The subsequent literature is reviewed. Several ASA desensitization protocols exist and have been proven to successfully treat ASA hypersensitivity and allow for ASA therapy to be safely initiated. We describe several previously published protocols. ASA desensitization is a safe and simple way to manage ASA hypersensitivity. We provide comprehensive management guidelines for the neurointerventionalist engaging in ASA desensitization.

Risk of hemorrhagic complication associated with ventriculoperitoneal shunt placement in aneurysmal subarachnoid hemorrhage patients on dual antiplatelet therapy

Object

The use of an intracranial stent requires dual antiplatelet therapy to avoid in-stent thrombosis. In this study, the authors sought to investigate whether the use of dual antiplatelet therapy is a risk factor for hemorrhagic complications in patients undergoing permanent ventriculoperitoneal (VP) shunt for hydrocephalus following aneurysmal subarachnoid hemorrhage (aSAH).

Methods

Patients were given 325 mg acetylsalicylic acid and 600 mg clopidogrel during the coil/stent procedure, and they were maintained on dual antiplatelet therapy with acetylsalicylic acid 325 mg daily and clopidogrel 75 mg daily during hospitalization and for 6 weeks posttreatment. Patients underwent placement of VP shunt at a later time during initial hospitalization, usually between 7 and 21 days following aSAH. Postoperative CT scans obtained in each study patient were reviewed for hemorrhages related to placement of the VP shunt.

Results

A total of 206 patients were admitted to the University of Iowa Hospitals and Clinics with aSAH between July 2009 and October 2010. Thirty-seven of these patients were treated with a VP shunt for persistent hydrocephalus. Twelve patients (32%) had previously undergone stent-assisted coiling and were on dual antiplatelet therapy with acetylsalicylic acid and clopidogrel. The remaining 25 patients (68%) had undergone surgical clipping or aneurysm coiling and were not receiving antiplatelet therapy at the time of surgery.

Four cases (10.8%) of new intracranial hemorrhages associated with VP shunt placement were observed. All 4 hemorrhages (33%) occurred in patients on dual antiplatelet therapy for stent-assisted coiling. No new intracranial hemorrhages were observed in patients not receiving dual antiplatelet therapy. The difference in hemorrhagic complications between the 2 groups was statistically significant (4 [33%] of 12 vs 0 of 25, p = 0.0075]). All 4 hemorrhages occurred along the tract of the ventricular catheter. Only 1 hemorrhage (1 [8.3%] of 12) was clinically significant as it resulted in occlusion of the proximal shunt catheter and required revision of the VP shunt. The patient did not suffer any permanent morbidity related to the hemorrhage. The remaining 3 hemorrhages were not clinically significant.

Conclusions

This small clinical series suggests that placement of a VP shunt in patients on dual antiplatelet therapy may be associated with an increased, but low, rate of symptomatic intracranial hemorrhage. It appears that in patients who are poor candidates for open surgical clipping and have aneurysms amenable to stent-assisted coiling, the risk of symptomatic hemorrhage may be an acceptable trade-off for avoiding risks associated with discontinuation of antiplatelet therapy. The authors' results are preliminary, however, and require confirmation in larger studies.