Timing and nature of in-house postoperative events following uncomplicated elective endovascular aneurysm treatment

Clinical article

Full access

Object

Most patients with asymptomatic intracranial aneurysms treated with endovascular methods are closely observed overnight in an intensive care unit setting for complications, including ischemic and hemorrhagic stroke, cardiac dysfunction, and groin access complications. The purpose of this study was to analyze the timing, nature, and rate of in-house postoperative events.

Methods

Patients who underwent endovascular treatment or retreatment of unruptured cerebral aneurysms from March 2002 to June 2012 were identified from a prospective case log and their medical records were reviewed. The presentation, patient characteristics, aneurysm size and location, and method of endovascular treatment of each cerebral aneurysm were recorded. Patients with adverse intraprocedural events including perforation and thromboembolism were excluded from this analysis. Overnight postprocedural monitoring was performed in a neurological intensive care unit or postanesthesia care unit for all patients, with discharge planned for postoperative Day 1. Postprocedural events occurring during hospitalization were categorized as intracranial hemorrhage, ischemic stroke, groin hematoma resulting in additional treatment or prolonged hospital stay, retroperitoneal hematoma, and cardiac events. The time from the completion of the procedure to event discovery was recorded.

Results

A total of 687 endovascular treatments of unruptured cerebral aneurysms were performed. Nine treatments were excluded from our analysis due to intraprocedural events. Endovascular procedures included coiling alone, stent-assisted coiling, balloon-assisted coiling, balloon-assisted embolization with a liquid embolic agent, and placement of a flow diversion device with or without coiling. Twenty-seven treatments (4.0%) resulted in postprocedural complications: 3 intracranial hemorrhages, 6 ischemic strokes, 4 cardiac events, 5 retroperitoneal hematomas, and 9 groin hematomas. The majority (20 [74.0%]) of these 27 complications were detected within 4 hours from the procedure. These included 1 hemorrhage, 4 ischemic strokes, 4 cardiac events, 2 retroperitoneal hematomas, and 9 groin hematomas. All cardiac events and groin hematomas were detected within 4 hours. Four (14%) of the 27 complications were detected between 4 and 12 hours, 1 (3.7%) between 12 and 24 hours, and 2 (7.4%) more than 24 hours after the procedure. The complications detected more than 4 hours from the conclusion of the procedure included 2 minor intracranial hemorrhages causing headache and resulting in no permanent deficits, 2 mild ischemic strokes, and 3 asymptomatic retroperitoneal hematomas identified by falling hematocrit levels that required no further intervention or treatment.

Conclusions

The large majority of significant postprocedural events after uncomplicated endovascular aneurysm intervention occur within the first 4 hours; these events become less frequent with increasing time. Transfer to a floor bed after 4–12 hours for further observation is reasonable to consider in some patients.

Abbreviations used in this paper:DAPT = dual antiplatelet therapy; ICA = internal carotid artery; MCA = middle cerebral artery; POD = postoperative day.

Abstract

Object

Most patients with asymptomatic intracranial aneurysms treated with endovascular methods are closely observed overnight in an intensive care unit setting for complications, including ischemic and hemorrhagic stroke, cardiac dysfunction, and groin access complications. The purpose of this study was to analyze the timing, nature, and rate of in-house postoperative events.

Methods

Patients who underwent endovascular treatment or retreatment of unruptured cerebral aneurysms from March 2002 to June 2012 were identified from a prospective case log and their medical records were reviewed. The presentation, patient characteristics, aneurysm size and location, and method of endovascular treatment of each cerebral aneurysm were recorded. Patients with adverse intraprocedural events including perforation and thromboembolism were excluded from this analysis. Overnight postprocedural monitoring was performed in a neurological intensive care unit or postanesthesia care unit for all patients, with discharge planned for postoperative Day 1. Postprocedural events occurring during hospitalization were categorized as intracranial hemorrhage, ischemic stroke, groin hematoma resulting in additional treatment or prolonged hospital stay, retroperitoneal hematoma, and cardiac events. The time from the completion of the procedure to event discovery was recorded.

Results

A total of 687 endovascular treatments of unruptured cerebral aneurysms were performed. Nine treatments were excluded from our analysis due to intraprocedural events. Endovascular procedures included coiling alone, stent-assisted coiling, balloon-assisted coiling, balloon-assisted embolization with a liquid embolic agent, and placement of a flow diversion device with or without coiling. Twenty-seven treatments (4.0%) resulted in postprocedural complications: 3 intracranial hemorrhages, 6 ischemic strokes, 4 cardiac events, 5 retroperitoneal hematomas, and 9 groin hematomas. The majority (20 [74.0%]) of these 27 complications were detected within 4 hours from the procedure. These included 1 hemorrhage, 4 ischemic strokes, 4 cardiac events, 2 retroperitoneal hematomas, and 9 groin hematomas. All cardiac events and groin hematomas were detected within 4 hours. Four (14%) of the 27 complications were detected between 4 and 12 hours, 1 (3.7%) between 12 and 24 hours, and 2 (7.4%) more than 24 hours after the procedure. The complications detected more than 4 hours from the conclusion of the procedure included 2 minor intracranial hemorrhages causing headache and resulting in no permanent deficits, 2 mild ischemic strokes, and 3 asymptomatic retroperitoneal hematomas identified by falling hematocrit levels that required no further intervention or treatment.

Conclusions

The large majority of significant postprocedural events after uncomplicated endovascular aneurysm intervention occur within the first 4 hours; these events become less frequent with increasing time. Transfer to a floor bed after 4–12 hours for further observation is reasonable to consider in some patients.

Unruptured intracranial aneurysms are common: the prevalence of unruptured cerebral aneurysms in the general population is approximately 2.0%.16 Over the last decade, an increasing number of unruptured cerebral aneurysms have been treated using endovascular techniques. Analysis of the Nationwide Inpatient Sample demonstrates that from 1998 to 2007 there were 14,765 discharges for patients with an unruptured cerebral aneurysm.6 From 2002 to 2007, 61.7% of all treated unruptured aneurysms were managed with endovascular coil embolization, making it the predominant treatment option.6

Endovascular treatment of intracranial aneurysms is accompanied by risks related to a variety of complications, some of which may occur in a delayed fashion in the hours following completion of the procedure. These periprocedural complications include ischemic or hemorrhagic stroke, cardiac events, and access site complications (ischemic or hemorrhagic).2,3,8–10,13 There are few published data regarding the timing, nature, and frequency of these complications, however. Most prior studies have not made the distinction between intraprocedural complications and complications that were only detected after the procedure.9 In the present investigation, we sought to analyze the timing, rate, and nature of postoperative events in patients in whom the procedure was completed without apparent intraprocedural complications. These data may have important implications for defining acceptable postoperative monitoring for patients undergoing these procedures.

Methods

Patients who underwent elective endovascular treatment of unruptured cerebral aneurysms between March 2002 and June 2012 were identified from a prospective case log maintained for quality assurance purposes. Institutional review board approval was obtained for this retrospective review. Authors Arias and Patel reviewed procedure logs and hospital records for each admission.

Admissions for first-time treatment and treatment of recurrent aneurysms were included. The presentation, baseline patient characteristics, aneurysm size and location, and form of treatment of each cerebral aneurysm were recorded. All patients in whom treatment was initiated, including those with attempted but aborted procedures, were included. Patients with adverse intraprocedural events noted during the procedure, such as arterial perforation or thromboembolism, were excluded from this analysis.

All procedures were performed by 1 of 3 neurointerventional staff members and 1 of 2 neurointerventional fellows per year. Treatment with aspirin (325 mg per day) and clopidogrel (Plavix, Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership; 75 mg per day) was initiated at least 5 days prior to the procedure in anticipation of any possible intervention requiring temporary balloon occlusion or stent placement. All procedures were performed under general anesthesia, and in the majority of cases a 6.5-Fr sheath was placed in the right common femoral artery and routine diagnostic cerebral angiography was performed using a high-resolution biplane angiographic unit (Neurostar or Axiom Artis, Siemens). Systemic heparinization was initiated to maintain the activated clotting time at 250–350 seconds once the parent vessel harboring the aneurysm was catheterized. After the procedure, heparin was reversed. The femoral sheath was removed immediately following the procedure with closure of the arteriotomy with a mechanical closure device or manual compression at the discretion of the treating physician. All patients were monitored after the procedure in a neurological intensive care unit or a 24-hour postanesthesia care unit overnight, with discharge planned for the following morning.

All patients with unanticipated adverse events discovered or occurring after procedure completion and before hospital discharge were identified from chart review. Events were adjudicated based on review of these records as well as the results of imaging studies or laboratory results. Postprocedural events were categorized as intracranial hemorrhage (subcategorized as subarachnoid hemorrhage, intraparenchymal hemorrhage, and intraventricular hemorrhage), stroke, groin hematoma (if resulting in additional treatment or prolonged hospital stay), retroperitoneal hematoma, and cardiac events. The time from the completion of the procedure to event discovery was calculated. Procedure completion time was defined as the time recorded for the last angiographic image. Event discovery was determined based on chart review. Time of onset was recorded as the time that symptoms were recorded, or the time a diagnostic test that confirmed a postprocedural complication was ordered, which ever was earlier. For example, in a patient with a retroperitoneal hematoma, discovery time was recorded as the time when the first hematocrit was ordered if charting did not record symptom onset time. For each patient with a postoperative event, details regarding the treatment and outcome of the complication were collected for presentation in a vignette form.

Results

A total of 501 patients with unruptured cerebral aneurysms underwent 687 elective endovascular procedures between March 2002 and June 2012. Nine patients were excluded from our analysis due to intraprocedural events, for a total of 678 treatments in 492 patients who underwent routine postprocedural observation after an apparently uncomplicated procedure.

Most of the 492 patients were female (n = 402). Of the 678 procedures, 530 were first-time procedures, while 148 were performed on patients with aneurysms that recurred after previous open surgical or endovascular treatment. The patients' mean age (± SD) at the time of treatment was 56.5 ± 12.7 years. Endovascular procedures included coiling alone, stent-assisted coiling, balloon assisted coiling, Onyx HD 500 occlusion (eV3 Covidien Neurovascular), and Pipeline Embolization Device (eV3 Covidien Neurovascular). The aneurysm locations and types of treatment are shown in Table 1.

TABLE 1:

Summary of all cases of uncomplicated elective endovascular aneurysm treatment at our institution from March 2002 to June 2012*

VariableValue
total treatments678
 initial530
 retreatment148
individual patients492
 female402
 male90
mean age at treatment (± SD)56.5 ± 12.7
treatments by aneurysm location
 ACoA85
 basilar apex105
 ICA (other)156
 MCA28
 OphA111
 PCoA64
 PICA4
 posterior circulation (other)45
 SHA80
treatment types
 stent-assisted coiling242
 coil alone329
 balloon-assisted coiling59
 stent alone1
 Onyx HD18
 Pipeline29

ACoA = anterior communicating artery; ICA = internal carotid artery; MCA = middle cerebral artery; OphA = ophthalmic artery; PCoA = posterior communicating artery; PICA = posterior inferior cerebellar artery; SHA = superior hypophyseal artery. ICA (other) refers to branches or segments of the ICA other than the listed locations.

Twenty-seven (4.0%) of the 678 procedures resulted in postprocedural complications: 3 intracranial hemorrhages (1 intraventricular, 1 subarachnoid and intraventricular, and 1 intraparenchymal), 6 ischemic strokes, 4 cardiac events, 5 retroperitoneal hematomas, and 9 groin hematomas requiring treatment or prolonged observation. The majority (20/27 or 74.0%) of these complications were detected within 4 hours from the procedure. Four of the 27 complications (14.8%) were detected between 4 and 12 hours, 1/27 (3.7%) between 12 and 24 hours, and 2/27 (7.4%) more than 24 hours after the procedure (Table 2).

TABLE 2:

Complications detected after an uncomplicated elective endovascular aneurysm treatment and the hours to event discovery

EventHours to Event Discovery
<44–1212–24>24Total
intracranial hemorrhage10113
ischemic stroke42006
cardiac event40004
retroperitoneal hematoma22015
groin hematoma90009
total2041227

The complications detected within 4 hours included 1 intracranial hemorrhage, 4 ischemic strokes, 4 cardiac events, 2 retroperitoneal hematomas, and 9 groin hematomas. All cardiac events and groin hematomas were detected within 4 hours. Complications occurring or detected greater than 4 hours from the conclusion of the procedure consisted of 2 intracranial hemorrhages detected on head CT obtained for evaluation of headaches and resulting in no permanent deficits, 2 ischemic strokes with minor deficits requiring inpatient rehabilitation after discharge, and 3 clinically asymptomatic retroperitoneal hematomas found due to falling hematocrit levels leading to abdominal CT scans that required no further intervention or treatment. All 3 patients with clinically asymptomatic retroperitoneal hemorrhage were observed and remained stable without intervention. All complications are detailed in the following case descriptions and in Table 3.

TABLE 3:

Details of the 27 cases with postoperative events*

Case No.ComplicationEvent DiscoveryAge (yrs), SexPresenting SymptomsRepeat TreatmentAneurysm LocationSize (in mm)TreatmentComplication Requiring ProcedureLOS (days)Disposition
1ICH<4 hrs86, Mprior rupturenobasilar apex310stent assistno3rehab
2ICH12–24 hrs53, FHAnoACoA6coil aloneno5home
3ICH>24 hrs69, Fmass effectnoposterior circulation (other)22coil aloneno6home
4ischemic stroke<4 hrs65, FincidentalnoICA (other)7stent assistno4rehab
5ischemic stroke<4 hrs75, FincidentalnoICA (other)7coil aloneno6rehab
6ischemic stroke<4 hrs45, FincidentalnoMCA7coil aloneno5rehab
7ischemic stroke<4 hrs62, FincidentalnoPCoA5coil aloneno13SNF
8ischemic stroke4–12 hrs66, Fincidentalnoposterior circulation (other)6stent assistno3rehab
9ischemic stroke4–12 hrs65, MincidentalnoICA (other)4coil aloneno5rehab
10cardiac event<4 hrs56, FincidentalnoOphA5coil aloneno2home
11cardiac event<4 hrs73, FincidentalnoPCoA4balloon assistyes13home
12cardiac event<4 hrs72, FseizuresnoICA (other)11coil aloneno5home
13cardiac event<4 hrs61, Fmass effectnoACoAunknowncoil aloneyes6home
14retroper hematoma<4 hrs51, Fprior ruptureyesACoA6coil aloneno2home
15retroper hematoma<4 hrs56, FincidentalnoSHA5coil aloneyes9home
16retroper hematoma4–12 hrs57, FincidentalyesICA (other)4stent assistno4home
17retroper hematoma4–12 hrs46, FincidentalnoICA (other)4stent assistno3home
18retroper hematoma>24 hrs39, FHAyesbasilar apexresidualcoil aloneno3home
19groin hematoma<4 hrs73, FHAnoposterior circulation (other)8stent assistno5home
20groin hematoma<4 hrs58, FseizuresyesOphA20coil aloneno1home
21groin hematoma<4 hrs63, FHAnobasilar apex22stent assistno1home
22groin hematoma<4 hrs45, Fmass effectnoACoA7coil aloneno2home
23groin hematoma<4 hrs62, Fprior ruptureyesbasilar apexresidualcoil aloneno3home
24groin hematoma<4 hrs50, FHAnoSHA4stent assistno3home
25groin hematoma<4 hrs53, FincidentalnoICA (other)unknownstent assistno2home
26groin hematoma<4 hrs59, Fmass effectnobasilar apex30stent assistno2home
27groin hematoma<4 hrs54, Fincidentalnobasilar apex7coil aloneno2home

HA = headache; ICH = intracranial hemorrhage; LOS = length of stay; rehab = rehabilitation; retroper = retroperitoneal; SNF = skilled nursing facility.

Complications Detected Less Than 4 Hours Postprocedure

The intracranial hemorrhage occurred in an 86-yearold man who presented with coil compaction of a previously treated ruptured basilar tip aneurysm. He was receiving aspirin and clopidogrel prior to retreatment, and on the day of the procedure he was given an extra dose of 225 mg of clopidogrel and 325 mg of aspirin due to suboptimal platelet inhibition on testing performed the day prior. He underwent stent-assisted coil embolization without any intraprocedural events. Immediately after the procedure he was confused, and a head CT demonstrated a small amount of bilateral intraventricular hemorrhage. He was discharged to a rehabilitation facility with minimal physical impairment on postoperative day (POD) 3.

There were 4 patients with delayed ischemic stroke: a 45-year-old woman underwent successful coiling of a left middle cerebral artery (MCA) aneurysm. About 2 hours after the procedure she developed right upper-extremity weakness. Repeat angiography showed no abnormality but MRI demonstrated an acute cerebral infarction in a left MCA lenticulostriate territory. She was discharged to a rehabilitation facility with mild right upper- and lower-extremity weakness on POD 5.

A 62-year-old woman underwent uncomplicated left posterior communicating artery aneurysm coiling, but in the anesthesia recovery area, the patient was noted to have a left gaze preference and an 8-mm fixed and dilated right pupil. An emergent head CT demonstrated no abnormality. Subsequent MRI scans demonstrated infarction of the left posterior cerebral artery territory, including a small region of the posterior left thalamus. She required placement of a gastric feeding tube and was eventually discharged to a skilled nursing facility on POD 13. She was not following commands and had a left gaze preference and right-sided hemiparesis at discharge.

A 75-year-old woman underwent stent-assisted coil embolization of 2 left internal carotid artery (ICA) aneurysms. Immediately after the procedure she was slow to awaken, and then in the postanesthesia care unit was aphasic with right hemiparesis. Repeat angiography showed no stent-associated thrombus or any other acute abnormality, but MRI showed a low apparent diffusion coefficient in the posterior limb left internal capsule and left peritrigonal white matter, consistent with hyperacute stroke in the left anterior choroidal artery distribution. She was discharged to a rehabilitation facility on POD 6 with residual right lower-extremity weakness.

A 65-year-old woman underwent uncomplicated stent-assisted coil embolization of a right paraclinoid aneurysm. Immediately postoperatively she developed a left hemiparesis. Repeat angiography showed no acute abnormality, and MRI showed acute watershed infarcts in the right cerebral hemisphere. Small embolic infarcts were seen in the head of the right caudate nucleus, left frontal lobe, and both cerebellar hemispheres. She was discharged to a rehabilitation facility with no motor function in her left arm and weakness in her left leg on POD 4.

There were 4 cardiac events detected within 4 hours from procedure conclusion. The first involved a 72-yearold woman who underwent coiling of an ICA aneurysm and developed non–ST-segment elevation with peak troponin values of 16. Cardiac catheterization revealed severe 3-vessel disease. The patient was offered a coronary artery bypass graft, but she declined and indicated that she wished to have this procedure done at an institution closer to her home.

The second case involved a 73-year-old woman who underwent balloon-assisted coil embolization of a right posterior communicating artery aneurysm. Following this procedure, the patient became hypotensive and myocardial infarction was diagnosed. Cardiac catheterization revealed a severe stenosis of the left main coronary artery and high-grade lesion of the right coronary artery. A coronary artery bypass graft procedure was delayed due to the administration of clopidogrel during the procedure and was performed 3 days later.

The third case was a 56-year-old woman who underwent uneventful coiling of a left ICA aneurysm at the origin of the ophthalmic artery. Postoperatively, while in the postanesthesia recovery unit, she was noted to be in atrial fibrillation with her heart rate in the 110s to 120s. She was treated with metoprolol and her heart rhythm converted to normal sinus rhythm.

The fourth case was a 61-year-old woman who underwent coiling of an anterior communicating artery aneurysm. Postprocedure she developed transient asymptomatic first-degree heart block lasting seconds on 2 occasions. The heart block was determined to be due to vagal stimulation. The patient was monitored on telemetry. No further intervention was pursued.

There were 2 cases of retroperitoneal hematomas detected within the first 4 hours. The first case was a 51-year-old woman who underwent coiling of an anterior communicating aneurysm. She developed lower right quadrant abdominal pain subsequent to the procedure. A large pelvic hematoma was identified on pelvic CT. It was managed with observation.

The second case occurred in a 56-year-old woman who underwent coiling of a left ICA aneurysm. During the first few hours of her hospitalization, she described a popping sensation in her right groin. A hematoma subsequently developed and was evaluated by the vascular surgery service. The patient underwent an ultrasound and was discovered to have a retroperitoneal hematoma as well as a right femoral pseudoaneurysm. She was taken to the operating room by the vascular surgery team for primary repair of her pseudoaneurysm, which was performed without complication.

There were a total of 9 groin hematomas that required observation and extended length of stay by at least 1 day. All were detected within the first 4 hours, but none required any further intervention.

Complications Occurring Between 4 and 12 Hours Postprocedure

One ischemic stroke occurred in a 65-year-old man who underwent successful coiling of a left anterior choroidal artery aneurysm. Eight hours after the procedure, he developed slurred speech and right hemiparesis. Head CT and repeat cerebral angiography showed no acute abnormality, but an MRI demonstrated an early subacute infarction within the left anterior choroidal artery distribution. He was discharged to a rehabilitation facility with mild dysarthria and right facial and extremity weakness on POD 5.

The other ischemic stroke occurred in a 66-year-old woman with a history of seizures who underwent stent-coil embolization of a broad-based, saccular aneurysm arising from the distal right vertebral artery just distal to the posterior inferior cerebellar artery. That evening, she developed mild dysarthria and a subtle left upper-extremity pronator drift. MRI demonstrated a small focus of diffusion restriction in the right thalamus. She was discharged to a rehabilitation facility on POD 3.

Two patients were found to have retroperitoneal hematomas, and both were detected by abdominal CT due to falling hematocrit levels. Otherwise both were asymptomatic. They were observed and both discharged to home without consequence.

Complications Occurring Between 12 and 24 Hours Postprocedure

The 1 complication detected between 12 and 24 hours after the procedure was an intracranial hemorrhage. It occurred in a 53-year-old woman with an anterior communicating artery aneurysm with adequate platelet inhibition on aspirin and clopidogrel prior to treatment. She underwent successful coil embolization of the aneurysm, but on the morning of POD 1 she complained of persistent headache with nausea and emesis. A head CT demonstrated small amounts of hemorrhage in the subarachnoid spaces over the cerebral convexities and a small amount of hemorrhage layering in the occipital horns of the lateral ventricles with mild dilation of both temporal horns. She was observed and then discharged without any complications on POD 5.

Complications Detected More Than 24 Hours From Procedure Conclusion

One intracerebral hemorrhage was detected more than 24 hours after the procedure conclusion. A 69-yearold woman with a left superior cerebellar artery aneurysm was pretreated with aspirin and clopidogrel; however, the VerifyNow (Accumetrics) clopidogrel test prior to her procedure showed less than 2% inhibition, and she was therefore given a bolus oral dose of 60 mg of prasugrel. She underwent successful and uneventful coiling of the aneurysm. On POD 2 she developed severe occipital headache and nausea and vomiting, and a head CT demonstrated a 1.8 × 1.2–cm right cerebellar hemorrhage. Her symptoms resolved and she made a full recovery and was discharged to home on POD 9.

One retroperitoneal hematoma was found on POD 1 after workup due to falling hemoglobin level and mild abdominal pain. The patient was observed and discharged home without complication.

Discussion

The present study provides good evidence from a large single-center case series that severe complications requiring urgent management are rare after the first 4 hours following uncomplicated elective endovascular aneurysm treatment. Transfer to a less intensive care setting for further observation would be reasonable to consider in some cases, particularly after 12 hours postprocedure.

Timing of Postprocedural Complications

Few studies have focused on the timing of postprocedural complications and most have reported procedural and early postprocedural events in aggregate.2,3,8–10 Niskanen reported 6 procedural complications and no postoperative events in 53 patients with unruptured aneurysms undergoing endovascular treatment.9

Frequency of Complications

Prior publications have reported the procedural complications rates related to endovascular treatment of cerebral aneurysms.10,13 The most common complications are related to acute thromboembolic events and perforation of the aneurysm during treatment. Overall, the reported rate of thromboembolic complications ranges between 4.7% and 12.5%, while the rate of intraprocedural rupture of cerebral aneurysms is about 0.7% in patients with unruptured aneurysms and about 4.1% in patients with previously ruptured aneurysms.10 A few studies, such as the ATENA (Treatment by Endovascular Approach of Nonruptured Aneurysms) study,13 have focused on treatment of unruptured aneurysms only. The ATENA study demonstrated an overall rate of thromboembolic complications of 7.1% and an intraoperative rupture rate of 2.6% in 700 procedures. Adverse events associated with transient or permanent neurological deficit or death were encountered in 5.4% of cases. The 1-month morbidity and mortality rates were 1.7% and 1.4%, respectively.13 The timing of these events was not reported.

In our series of 678 treatments (excluding treatments with intraprocedural complications such as aneurysm rupture, wire perforations, and witnessed thromboembolic events) our total postprocedural complication rate was 4.0% (27 postprocedural complications in 678 cases). A postprocedural intracerebral hemorrhage was detected after 3 (0.4%) of 678 treatments, ischemic stroke after 6 (0.9%), cardiac event after 4 (0.6%), and retroperitoneal or groin hematomas that either required further treatment or resulted in increased length of stay were detected after 5 (0.7%) and 9 (1.3%), respectively.

There were a total of 3 intracerebral hemorrhages detected after the procedure, without any evidence of intraprocedural perforation or rupture. These occurred in 3 (0.4%) of 678 cases and represented 3 (11.1%) of our 27 postprocedural complications. The origin and nature of these hemorrhages are unclear.

One possible contributing factor for development of intracerebral hemorrhages is the use of antiplatelet therapy. Literature from the field of interventional cardiology suggests that adding aspirin and clopidogrel dual antiplatelet therapy (DAPT) to postprocedural management minimizes the risk of thromboembolic complications5 and is more benefcial than single-agent therapy with aspirin alone.7,17,18 As a result, DAPT with full-dose aspirin (325 mg orally daily) and clopidogrel (75 mg orally daily) has also been recommended for neurointerventional surgery.1,15 Prior studies in coil embolization procedures have demonstrated that symptomatic thromboembolic complications (transient ischemic attack or stroke within 60 days) occurred in 4 (16%) of 25 cases when no antiplatelet drugs were given, in 2 (2.3%) of 86 cases when antiplatelet drugs were administered only after embolization, and in 5 (1.9%) of 258 cases when antiplatelet drugs were administered before and after embolization.19

Our current practices reflect these observations. We tend to pretreat all of our patients with oral aspirin, 81 or 325 mg daily, unless contraindicated by an aspirin allergy. Since 1999, when clopidogrel became available, many patients also received clopidogrel for at least 3–5 days before their procedures. In a minority of cases, clopidogrel was given in loading doses of 300–450 mg immediately before procedures. Over the last decade we have begun to monitor preprocedural platelet inhibition levels, given reports in the cardiovascular literature that up to 50% of patients respond inadequately to clopidogrel and 5%–60% are resistant to aspirin.14 In a minority of cases, the patients were given loading doses of aspirin and/or clopidogrel immediately before procedures due to inadequate platelet inhibition on preprocedure testing. Patients treated after procedures were generally given aspirin permanently and clopidogrel for 30–60 days.19 In this series, 2 of the 3 patients with postprocedural hemorrhages were given boluses of aspirin and clopidogrel prior to the procedure due to inadequate platelet inhibition on preprocedure testing.

Symptomatic ischemic strokes occurred after 6 (0.9%) of our 678 procedures and represented 6 (22.2%) of our 27 postprocedural complications. Of these 6 ischemic strokes, 5 resulted in deficits requiring intensive inpatient rehabilitation at discharge, and in 1 case discharge to a skilled nursing facility was required.

Four of the 6 patients with ischemic strokes returned to the angiography suite for repeat angiograms to search for possible causes of their symptoms. All of these angiograms were normal, without evidence of thrombus or vessel occlusion. All 6 patients with strokes had evidence of diffusion restriction or infarction on MRI, in territories that were consistent with their symptoms.

The nature of these ischemic events is not entirely clear, as none of the patients had evidence of vessel- or coil/stent-associated thrombus on follow-up imaging. Thromboembolic events are a known complication of endovascular aneurysm treatment. The rates of thromboembolic complications in unruptured aneurysm treatment range between 3.7% and 6.9%.4,11 The source of these emboli may be the catheters and guidewires used during the procedure, the surface of the coils or stents left in the aneurysms and vessels, iatrogenic vessel dissection, or stagnation of blood within flow-diverters or vessels in vasospasm.10 Systemic heparinization is commonly used during procedures to reduce the occurrence of these events. Our patients generally receive systemic anticoagulation therapy with intravenous heparin during endovascular procedures (initial boluses of 70–100 U/kg followed by continuous infusions of 7–10 U/kg per hour). Activated clotting times on heparin are monitored and maintained at twice the baseline value at least, usually at or near 300 seconds, by administration of additional boluses or by adjusting infusion rates, as needed. Heparin is generally discontinued at the conclusion of the procedure.19

Previous studies have not revealed significant differences in the complication rate between balloon-assisted coiling and simple coil embolization.12 In our series, 4 of 6 ischemic strokes occurred in patients treated with simple coil embolization, and 2 of 6 ischemic strokes occurred in patients treated with stent-assisted coiling. There was no permanent coil protrusion from the aneurysm at the conclusion of the procedure in any of these cases. No postprocedural strokes occurred in patients undergoing balloon-assisted coiling or treatments using the Pipeline Embolization Device.

Retroperitoneal or groin hematomas that either required further treatment or resulted in increased length of stay were detected after 5 (0.7%) and 9 (1.3%) of 678 treatments, respectively. There is little consensus in the literature on the rates of these types of complications, as they are rarely reported and are frequently not detected unless patients are overtly symptomatic or the hemorrhage is significant enough to cause a detectable drop in hematocrit or require further treatment.

Nature of Complications

Our series indicates that most complications are detected within the first 4 hours following the procedure. Fewer complications were detected between 4 and 12 hours, and even fewer after 12 hours. The severity of the complications also correlates with time of detection. Half of the complications detected within the first hours required further treatment or resulted in deficits at discharge. In contrast, all of the patients with complications detected more than 12 hours after the procedure were discharged home without deficits.

Of the 20 events that were detected within 4 hours from the conclusion of the procedure, 10 were retroperitoneal or groin hematomas that were observed and required no further treatment. Another 2 events were transient cardiac issues (atrial fibrillation in 1 patient, and first-degree heart block in another) that required no further treatment. The remaining 8 events were 1 intraventricular hemorrhage in a patient who was eventually discharged to a rehabilitation facility, 4 ischemic strokes (3 of the patients were discharged to a rehabilitation facility and 1 to a skilled nursing facility), 2 cardiac events in patients who eventually required coronary artery bypass grafts, and 1 retroperitoneal hematoma with an associated femoral pseudoaneurysm that required surgical intervention.

The complications detected beyond 4 hours from the conclusion of the procedure were both rare (7 out of 678 procedures) and relatively minor. Between 4 and 12 hours, 2 patients had ischemic strokes; both patients were eventually discharged to a rehabilitation facility. Two other patients were found to have retroperitoneal hematomas, which were detected due to falling hematocrit levels, and both were observed and discharged home without consequence.

Only 3 complications were found beyond 12 hours after the procedure: 2 patients had intracerebral hemorrhages and were discharged without complication; 1 had a retroperitoneal hematoma and was observed and also discharged without complication. In our series, none of the complications that occurred after 4 hours after the procedure required intervention.

We acknowledge some limitations of this study. Our study design was a retrospective review that sought to detect all postprocedural complications; however, patients were identified from our quality assurance case log, which is prospective and unlikely to omit patients with adverse events. Detection of complications in this manner is highly dependent on an accurate, detailed, and complete medical record. Some complications may have been missed due to incomplete documentation. Furthermore, we depended on the presence of diagnostic tests to detect postprocedural complications. It is possible that some patients developed hemorrhagic or ischemic strokes that were not detected because they did not undergo postprocedural radiological imaging. Some retroperitoneal hematomas could have also been missed in a similar fashion. Cardiac events were dependent both on postprocedural symptoms and further investigations, such blood tests or electrocardiogram. We also limited our inclusion of groin hematomas only to those that caused a prolongation in hospital stay.

Our prospective database does not include follow-up data, and obtaining such data for all of our patients would be difficult. Furthermore, outcomes and long-term follow-up are beyond the scope of this paper, which focuses primarily on complications detected in the immediate postprocedural period.

Conclusions

These data provide useful and important information regarding the timing and nature of complications following uncomplicated endovascular treatment of patients with unruptured intracranial aneurysms. These findings have implications for postoperative monitoring. First, the large majority of complications occurred within the first 4 hours after awakening from general anesthesia. These patients require close observation and postanesthesia recovery unit staff should be aware of the nature of these complications, which include neurological, cardiac, and groin access problems. Second, beyond 4 hours, and certainly after 12, the risk of developing a clinically significant problem becomes much lower. It would be reasonable to consider transferring these stable patients to the floor if intensive-care beds were needed for other, more critically ill patients. These data are not sufficient to conclude that all patients should routinely be transferred to a floor environment 4 to 12 hours after an uncomplicated procedure. Further studies with greater numbers, as well as cost-benefit analyses, would be required to explore this more completely.

Disclosure

Dr. Derdeyn reports a consultant relationship with MicroVention, Inc., W. L. Gore and Associates, Silk Road, Inc., and Penumbra, Inc. and direct stock ownership in Pulse Therapeutics. Dr. Moran reports a consultant relationship with Covidien Neurovascular.

Author contributions to the study and manuscript preparation include the following. Conception and design: Derdeyn, Arias. Acquisition of data: Arias, Patel. Analysis and interpretation of data: Derdeyn, Arias, Patel. Drafting the article: Derdeyn, Arias, Patel, Dacey. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Derdeyn. Study supervision: Derdeyn.

Portions of this work were presented in oral paper form at the American Society of Neuroradiology Annual Meeting, San Diego, CA, May 25, 2013, and in poster form at the Congress of Neurological Surgeons Annual Meeting, San Francisco, CA, October 21, 2013.

References

  • 1

    Akbari SHReynolds MRKadkhodayan YCross DT IIIMoran CJ: Hemorrhagic complications after prasugrel (Effient) therapy for vascular neurointerventional procedures. J Neurointerv Surg 5:3373432013

  • 2

    Alshekhlee AMehta SEdgell RCVora NFeen EMohammadi A: Hospital mortality and complications of electively clipped or coiled unruptured intracranial aneurysm. Stroke 41:147114762010

  • 3

    Derdeyn CPCross DT IIIMoran CJBrown GWPilgram TKDiringer MN: Postprocedure ischemic events after treatment of intracranial aneurysms with Guglielmi detachable coils. J Neurosurg 96:8378432002

  • 4

    Gonzalez NMurayama YNien YLMartin NFrazee JDuckwiler G: Treatment of unruptured aneurysms with GDCs: clinical experience with 247 aneurysms. AJNR Am J Neuroradiol 25:5775832004

  • 5

    Kushner FGHand MSmith SC JrKing SB IIIAnderson JLAntman EM: 2009 Focused Updates: ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction (updating the 2004 guideline and 2007 focused update) and ACC/AHA/SCAI guidelines on percutaneous coronary intervention (updating the 2005 guideline and 2007 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation 120:227123062009. (Erratum in Circulation 121: e257 2010)

  • 6

    Lin NCahill KSFrerichs KUFriedlander RMClaus EB: Treatment of ruptured and unruptured cerebral aneurysms in the USA: a paradigm shift. J Neurointerv Surg 4:1821892012

  • 7

    Mehta SRYusuf SPeters RJBertrand MELewis BSNatarajan MK: Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study. Lancet 358:5275332001

  • 8

    Naggara ONWhite PMGuilbert FRoy DWeill ARaymond J: Endovascular treatment of intracranial unruptured aneurysms: systematic review and meta-analysis of the literature on safety and efficacy. Radiology 256:8878972010

  • 9

    Niskanen MKoivisto TRinne JRonkainen APirskanen SSaari T: Complications and postoperative care in patients undergoing treatment for unruptured intracranial aneurysms. J Neurosurg Anesthesiol 17:1001052005

  • 10

    Orrù ERoccatagliata LCester GCausin FCastellan L: Complications of endovascular treatment of cerebral aneurysms. Eur J Radiol 82:165316582013

  • 11

    Park HKHorowitz MJungreis CGenevro JKoebbe CLevy E: Periprocedural morbidity and mortality associated with endovascular treatment of intracranial aneurysms. AJNR Am J Neuroradiol 26:5065142005

  • 12

    Pierot LCognard CAnxionnat RRicolfi F: Remodeling technique for endovascular treatment of ruptured intracranial aneurysms had a higher rate of adequate postoperative occlusion than did conventional coil embolization with comparable safety. Radiology 258:5465532011

  • 13

    Pierot LSpelle LVitry F: Immediate clinical outcome of patients harboring unruptured intracranial aneurysms treated by endovascular approach: results of the ATENA study. Stroke 39:249725042008

  • 14

    Prabhakaran SWells KRLee VHFlaherty CALopes DK: Prevalence and risk factors for aspirin and clopidogrel resistance in cerebrovascular stenting. AJNR Am J Neuroradiol 29:2812852008

  • 15

    Qureshi AILuft ARSharma MGuterman LRHopkins LN: Prevention and treatment of thromboembolic and ischemic complications associated with endovascular procedures: Part I—Pathophysiological and pharmacological features. Neurosurgery 46:134413592000

  • 16

    Rinkel GJDjibuti MAlgra Avan Gijn J: Prevalence and risk of rupture of intracranial aneurysms: a systematic review. Stroke 29:2512561998

  • 17

    Smith SC JrFeldman TEHirshfeld JW JrJacobs AKKern MJKing SB III: ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention—summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 47:2162352006

  • 18

    Steinhubl SRBerger PBMann JT IIIFry ETDeLago AWilmer C: Early and sustained dual oral antiplatelet therapy following percutaneous coronary intervention: a randomized controlled trial. JAMA 288:241124202002

  • 19

    Yamada NKCross DT IIIPilgram TKMoran CJDerdeyn CPDacey RG Jr: Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms. AJNR Am J Neuroradiol 28:177817822007

If the inline PDF is not rendering correctly, you can download the PDF file here.

Article Information

Address correspondence to: Colin P. Derdeyn, M.D., 510 S. Kingshighway Blvd., St. Louis, MO 63110. email: derdeync@wustl.edu.

Please include this information when citing this paper: published online August 29, 2014; DOI: 10.3171/2014.7.JNS132676.

© AANS, except where prohibited by US copyright law.

Headings

References

1

Akbari SHReynolds MRKadkhodayan YCross DT IIIMoran CJ: Hemorrhagic complications after prasugrel (Effient) therapy for vascular neurointerventional procedures. J Neurointerv Surg 5:3373432013

2

Alshekhlee AMehta SEdgell RCVora NFeen EMohammadi A: Hospital mortality and complications of electively clipped or coiled unruptured intracranial aneurysm. Stroke 41:147114762010

3

Derdeyn CPCross DT IIIMoran CJBrown GWPilgram TKDiringer MN: Postprocedure ischemic events after treatment of intracranial aneurysms with Guglielmi detachable coils. J Neurosurg 96:8378432002

4

Gonzalez NMurayama YNien YLMartin NFrazee JDuckwiler G: Treatment of unruptured aneurysms with GDCs: clinical experience with 247 aneurysms. AJNR Am J Neuroradiol 25:5775832004

5

Kushner FGHand MSmith SC JrKing SB IIIAnderson JLAntman EM: 2009 Focused Updates: ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction (updating the 2004 guideline and 2007 focused update) and ACC/AHA/SCAI guidelines on percutaneous coronary intervention (updating the 2005 guideline and 2007 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation 120:227123062009. (Erratum in Circulation 121: e257 2010)

6

Lin NCahill KSFrerichs KUFriedlander RMClaus EB: Treatment of ruptured and unruptured cerebral aneurysms in the USA: a paradigm shift. J Neurointerv Surg 4:1821892012

7

Mehta SRYusuf SPeters RJBertrand MELewis BSNatarajan MK: Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study. Lancet 358:5275332001

8

Naggara ONWhite PMGuilbert FRoy DWeill ARaymond J: Endovascular treatment of intracranial unruptured aneurysms: systematic review and meta-analysis of the literature on safety and efficacy. Radiology 256:8878972010

9

Niskanen MKoivisto TRinne JRonkainen APirskanen SSaari T: Complications and postoperative care in patients undergoing treatment for unruptured intracranial aneurysms. J Neurosurg Anesthesiol 17:1001052005

10

Orrù ERoccatagliata LCester GCausin FCastellan L: Complications of endovascular treatment of cerebral aneurysms. Eur J Radiol 82:165316582013

11

Park HKHorowitz MJungreis CGenevro JKoebbe CLevy E: Periprocedural morbidity and mortality associated with endovascular treatment of intracranial aneurysms. AJNR Am J Neuroradiol 26:5065142005

12

Pierot LCognard CAnxionnat RRicolfi F: Remodeling technique for endovascular treatment of ruptured intracranial aneurysms had a higher rate of adequate postoperative occlusion than did conventional coil embolization with comparable safety. Radiology 258:5465532011

13

Pierot LSpelle LVitry F: Immediate clinical outcome of patients harboring unruptured intracranial aneurysms treated by endovascular approach: results of the ATENA study. Stroke 39:249725042008

14

Prabhakaran SWells KRLee VHFlaherty CALopes DK: Prevalence and risk factors for aspirin and clopidogrel resistance in cerebrovascular stenting. AJNR Am J Neuroradiol 29:2812852008

15

Qureshi AILuft ARSharma MGuterman LRHopkins LN: Prevention and treatment of thromboembolic and ischemic complications associated with endovascular procedures: Part I—Pathophysiological and pharmacological features. Neurosurgery 46:134413592000

16

Rinkel GJDjibuti MAlgra Avan Gijn J: Prevalence and risk of rupture of intracranial aneurysms: a systematic review. Stroke 29:2512561998

17

Smith SC JrFeldman TEHirshfeld JW JrJacobs AKKern MJKing SB III: ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention—summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 47:2162352006

18

Steinhubl SRBerger PBMann JT IIIFry ETDeLago AWilmer C: Early and sustained dual oral antiplatelet therapy following percutaneous coronary intervention: a randomized controlled trial. JAMA 288:241124202002

19

Yamada NKCross DT IIIPilgram TKMoran CJDerdeyn CPDacey RG Jr: Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms. AJNR Am J Neuroradiol 28:177817822007

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 254 254 35
PDF Downloads 121 121 8
EPUB Downloads 0 0 0

PubMed

Google Scholar