Unilateral normal perfusion pressure breakthrough after carotid endarterectomy: case report

Insight into the cerebral hyperperfusion syndrome following carotid endarterectomy from the national Vascular Quality Initiative

BACKGROUND

Cerebral hyperperfusion syndrome (CHS), characterized by severe ipsilateral headache, seizures, and intracranial hemorrhage, is a rare, poorly understood complication that can be fatal following carotid endarterectomy (CEA). The purpose of the study was to determine the factors associated with CHS as captured in the Vascular Quality Initiative.

METHODS

Analysis was conducted on 51,001 procedures captured from the CEA module of the Vascular Quality Initiative from 2003 to 2015. Preoperative, operative, and postoperative variables were considered for inclusion in logistic regression analyses to determine possible associations with CHS. The relative contribution of each variable to the overall model was determined using dominance analysis.

RESULTS

The mean age was 70.2 ± 9.4 years; there were 39.6% female patients, 93.1% of white race, with 29.6% of CEAs being performed for symptomatic status. The overall rate of CHS was 0.18% (n = 94), with 55.1% occurring in asymptomatic and 44.9% occurring in symptomatic patients with an associated mortality rate of 38.2%. Multivariable analysis including preoperative variables showed that female gender (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.09-2.51; P = .019), <1 month major ipsilateral stroke (OR, 5.36; 95% CI, 2.35-12.22; P < .001), coronary artery disease (OR, 1.77; 95% CI, 1.15-2.71; P = .009), and contralateral stenosis ≥70% (OR, 1.54; 95% CI, 1.00-2.36; P = .050) were independently associated with CHS and that <1 month major stroke was the most important contributor to the model. With the additional inclusion of operative and postoperative variables, female gender (OR, 1.75; 95% CI, 1.14-2.67; P = .010), <1 month ipsilateral major stroke (OR, 3.20; 95% CI, 1.32-7.74; P = .010), urgency (OR, 2.25; 95% CI, 1.38-3.67; P = .001), re-exploration (OR, 2.98; 95% CI, 1.27-6.97; P = .012), postoperative hypertension (OR, 4.09; 95% CI, 2.65-6.32; P < .001), postoperative hypotension (OR, 3.21; 95% CI, 1.97-5.24; P < .001), dysrhythmias (OR, 3.23; 95% CI, 1.64-6.38; P = .001), and postoperative myocardial infarction (OR, 2.84; 95% CI, 1.21-6.67; P = .017) were significantly associated with CHS, with postoperative blood pressure lability and cardiac complications having the strongest associations with CHS.

CONCLUSIONS

The risk of CHS was highest in female patients and in those with a recent major stroke, coronary artery disease, and contralateral stenosis ≥70%. In addition, in adjusting for operative and postoperative variables, CHS was most significantly associated with postoperative blood pressure lability and cardiac complications. These data lend insight into a high-risk population for this devastating complication.

Cerebral hemorrhage after endovascular treatment of bilateral traumatic carotid cavernous fistulae with covered stents

Bilateral traumatic carotid-cavernous fistulae (TCCFs) is rarely encountered neurovascular disease. For treatment of TCCF, detachable balloons have been widely used. Nowadays, transarterial and/or transvenous coil embolization with placement of covered stents is adopted as another treatment method. We experienced a patient with a bilateral TCCFs who was successfully treated with covered stents. However, cerebral hemorrhage occurred in the bed of previous infarction one day after treatment. Hyperperfusion syndrome was considered as a possible cause of the hemorrhage, so that barbiturate coma therapy was started and progression of hemorrhage was stopped. We emphasize that cerebral hyperperfusion hemorrhage can occur even after successful endovascular treatment of TCCF.

Case report: Aggressive blood pressure management for carotid endarterectomy hyperperfusion syndrome

PURPOSE

Cerebral hyperperfusion syndrome (CHS) is a rare but potentially devastating complication following cerebral revascularization. Management of CHS requires aggressive blood pressure control to prevent stroke and intracerebral hemorrhage. This case report documents a severe case of CHS, and outlines a successful outcome associated with aggressive blood pressure control.

CLINICAL FEATURES

A 67-yr-old gentleman, nine days post left carotid endarterectomy, required tracheal intubation and intensive care unit admission following seizures and acute right-sided weakness. A computed tomography scan and magnetic resonance imaging revealed significant vasogenic edema in the left middle cerebral artery territory, without evidence of infarction. The history and radiographic findings suggested CHS. As such, a systolic blood pressure target was set at 90-140 mmHg. This blood pressure parameter was lower than typically targeted following acute ischemic or hemorrhagic stroke. Rapid clinical improvements were seen by day five, and tight blood pressure control was maintained throughout. Repeat computed tomography and magnetic resonance imaging revealed improved edema and no evidence of infarct or hemorrhage.

CONCLUSION

Cerebral hyperperfusion syndrome is believed to occur following restoration of blood flow to a brain with impaired autoregulation due to chronic hypoperfusion. Massive brain edema and hemorrhage can result from higher pressures. Clinicians should be aware of this potential complication following cerebral revascularization procedures, and the importance of establishing blood pressure targets which are considerably lower than for other patients with similar clinical presentations.

Postoperative hyperperfusion in a patient with a dural arteriovenous fistula with retrograde leptomeningeal venous drainage: case report

OBJECTIVE AND IMPORTANCE

Hyperperfusion has been reported after carotid endarterectomy or stenting for stenosis of the internal carotid artery. Because few reports have examined postoperative hyperperfusion after treatment for dural arteriovenous fistulae (DAVFs), we present a case describing a patient who manifested this clinical entity.

CLINICAL PRESENTATION

The patient was a 63-year-old man with a DAVF in the left transverse sigmoid sinus with retrograde leptomeningeal venous drainage. He experienced slowly progressive disorientation lasting for several months. Preoperative single-photon emission computed tomography with (123)I-labeled N-isopropyl-p-iodoamphetamine revealed an area of hyperintensity on T2-weighted magnetic resonance imaging (MRI) scans that coincided with the hypoperfusion area; it was not increased after acetazolamide challenge. Complete DAVF obliteration was achieved by embolization, then sinus isolation. After treatment, he experienced frequent generalized convulsions that were terminated by 2-day barbiturate therapy.

INTERVENTION

On T2-weighted MRI scans obtained 3 days after surgery, the hyperintense area not only persisted but had expanded to the left parietal lobe. Moreover, a subcortical hyperintense lesion was recognized on T1-weighted MRI scans; this was considered to reflect cortical laminar necrosis. Single-photon emission computed tomography revealed hyperperfusion in the left parietal lobe; it changed to hypoperfusion a month after treatment.

CONCLUSION

In patients with DAVFs with preoperative findings of marked low perfusion and a poor perfusion reserve, postoperative study may reveal hyperperfusion on single-photon emission computed tomography or cortical laminar necrosis on MRI. This may be evidence of severe perfusion disturbance as a result of venous infarction. In these patients, careful blood pressure control and early treatment of seizures are important after DAVF treatment.

Intraoperative lidocaine injection into the carotid sinus during endarterectomy

OBJECT

Many surgeons inject a local anesthetic agent into the carotid sinus before carotid endarterectomy in an attempt to ameliorate perioperative hemodynamic instability. The purpose of this study is to analyze the effect of carotid sinus injection with lidocaine on perioperative hemodynamics and complications.

METHODS

The authors prospectively studied 92 patients in whom 100 consecutive carotid endarterectomies were performed by a single surgeon (eight procedures were bilateral). Patients were randomly assigned to one of two groups, in which either 0.5 ml of 1% lidocaine was injected into the carotid sinus nerve or no injection of lidocaine was administered before the arteriotomy. All patients were treated postoperatively according to a standard endarterectomy protocol. There were no significant differences between the two groups in the incidence of hypertension, hypotension, or the use of vasoactive medications in the operating room following restoration of carotid artery (CA) blood flow, in the recovery room, or in the intensive care unit.

CONCLUSIONS

Injection of lidocaine into the carotid sinus at the time of endarterectomy is not associated with a significant improvement in any hemodynamic factor, from the time of restoration of CA blood flow to postoperative Day 1.

Increased cerebral blood flow after brain arteriovenous malformation resection is substantially independent of changes in cardiac output

Brain arteriovenous malformation (BAVM) resection can result in an acute increase in cerebral blood flow (CBF) of unclear etiology. This observational study investigated the relationship between changes in CBF and cardiac output (CO) in patients undergoing microsurgical resection of BAVMs. In 20 patients undergoing a BAVM resection during an isoflurane-based anesthesia, we measured CBF and systemic cardiovascular parameters immediately before and after BAVM resection. CBF was measured on the hemisphere ipsilateral to the lesions and on the contralateral side, using intravenous cold 133Xe washout. Cardiac output was measured using thermodilution technique via a pulmonary artery catheter. There was an increase in global CBF after resection (25 +/- 8 versus 31 +/- 13 mL/100 g/min, preresection versus postresection, mean +/- SD, P =.002), ipsilateral CBF (25 +/- 8 versus 31 +/- 13 mL/100 g/min, P =.002), and contralateral CBF (24 +/- 7 versus 30 +/- 13 mL/100 g/min, P =.003). There was no change in CO, mean systemic arterial pressure, central venous pressure, or pulmonary artery diastolic pressure. The change in CBFGLOBAL was not correlated with changes in CO (r =.154, P =.517). BAVM resection resulted in global increases in CBF that was not substantially related to changes in CO or other systemic parameters.

Postoperative hyperperfusion in dural arteriovenous fistula associated with venous ischemia: case report

BACKGROUND

It is well known that carotid endarterectomy and extracranial-intracranial arterial bypass sometimes cause postoperative hyperperfusion, and vasoparalysis attributable to long-standing ischemia has been suggested as the cause. It is also well known that dural arteriovenous fistula (AVF) sometimes causes cerebral ischemia attributable to venous hypertension. However, there are few reports regarding the postoperative changes of regional cerebral blood flow (rCBF).

METHODS

We report a case of dural AVF of the left transverse/sigmoid sinuses, occurring in a 64-year-old man. Intraoperative transvenous embolization combined with transarterial embolization was performed, and the rCBF was measured pre- and postoperatively using 99mTc-hexamethyl-propylene amine oxime and single-photon emission computed tomography (SPECT).

RESULTS

Preoperative SPECT disclosed a marked rCBF reduction in the left temporal, parietal, and occipital lobes. Complete obliteration of the AVF was attained after the intraoperative transvenous embolization, without any neurological deterioration. However, postoperative SPECT demonstrated temporary hyperperfusion in these regions.

CONCLUSIONS

Sudden resolution of venous ischemia can lead to postoperative hyperperfusion, and pre- and post-treatment rCBF studies are important to prevent complications related to hyperperfusion.

Imaging studies of cerebral hyperperfusion after carotid endarterectomy. Case report

A case is reported of severe unilateral hemispheric edema and localized hemorrhage associated with seizures following endarterectomy of an ipsilateral high-grade carotid stenosis. Imaging studies including angiography, computerized tomography (CT), magnetic resonance imaging/angiography, and xenon-CT, suggested postoperative ipsilateral cerebral hyperperfusion. Cerebral hyperperfusion syndromes caused by a probable failure of vascular autoregulation are rare but potentially serious complications after endarterectomy. The literature on this type of complication is briefly reviewed, and the role of various imaging modalities in identification of the syndrome and in guiding management decisions is emphasized.

Pressure autoregulation is intact after arteriovenous malformation resection

The loss of autoregulatory control of cerebral perfusion to changes in perfusion pressure in tissue remote from an arteriovenous malformation (AVM) has been proposed as the mechanism underlying "normal perfusion pressure breakthrough." This study is the first direct test of this mechanism. Studies were performed during the resection of moderate to large AVMs in 25 patients undergoing 28 procedures under isoflurane anesthesia. Cerebral blood flow (CBF) was measured (xenon-133 method) in the hemisphere adjacent to the nidus before resection after dural exposure (pre), after AVM removal before dural closure at spontaneous systemic blood pressure (post), and, finally, with the mean arterial pressure increased by 20 mm Hg, using phenylephrine (post-BP). AVM resection resulted in a significant enhancement of perfusion in the adjacent hemisphere (30 +/- 2 vs. 25 +/- 1 ml/100g/min, P < 0.01), but no further increase of CBF occurred during increased perfusion pressure (30 +/- 2 ml/100g/min). One patient suffered a postoperative hemorrhage and another developed intraoperative brain swelling during the course of the resection that necessitated staging the procedure. These two patients had the highest increases in CBF, but intact pressure autoregulation. Preserved autoregulation to increased mean arterial pressure after resection does not support a hemodynamic mechanism for the observed increase in CBF from before the resection to after the resection. Pathological events, however, do appear to be related to increases in hemispheric perfusion.