Risk of stroke with temporary arterial occlusion in patients undergoing craniotomy for cerebral aneurysm

Vascular Repair for Iatrogenic Injury during Microsurgical Procedures: Clinical Investigation and Review of 18 Cases at a Single Institution

BACKGROUND

 Intracranial vascular injury (VI) due to surgery is a critical complication that can lead to serious neurologic deficits. To our knowledge, only a few review articles on VI during an operation have been published so far. We retrospectively investigated the type, cause, and measurement of VI during surgery at our institution.

METHODS

 Unexpected VI cases occurred in 18 of 2,228 craniotomy procedures, including 794 aneurysm clippings and 357 tumor resections. We investigated the causes and coping techniques of the VI cases, as well as their full details.

RESULTS

 There were six cases of aneurysm neck tear, one case of sylvian vein injury, and one case of superior trunk perforation during direct clipping. Regarding tumor resection procedures, nine cases of arterial injury and one case of cortical vein injury were extracted. Almost all VIs were caused by carelessness or basic manipulation mistakes. We repaired all these cases with simple placement of suture threads with or without pinch clips, flow alteration using bypass techniques, and in 16 cases no neurologic deficit or deterioration on imaging occurred; however, 3 patients were verified to have ischemic changes on postoperative imaging.

CONCLUSIONS

 Most VIs were directly caused by a simple error and carelessness of an operator or an assistant. Many of these injuries can be avoided if a basic set of rules are followed and remembered during the surgical procedure. However, the surgical procedure involves human work, and errors cannot be eradicated even upon maximum concentration levels. Neurosurgeons should be prepared for an eventual quick repair of an unexpected cerebral VI.

Role of temporary arterial occlusion in subarachnoid hemorrhage outcomes: a prospective cohort study

PURPOSE

Temporary arterial occlusion (TAO) is a widespread practice in the surgical treatment of intracranial aneurysms. This study aimed to investigate TAO's role during ruptured aneurysm clipping as an independent prognostic factor on short- and long-term outcomes.

METHODS

This prospective cohort included 180 patients with ruptured intracranial aneurysms and an indication of microsurgical treatment. Patients who died in the first 12 hours after admission were excluded.

RESULTS

TAO was associated with intraoperative rupture (IOR) (odds ratio - OR = 10.54; 95% confidence interval - 95%CI 4.72-23.55; p < 0.001) and surgical complications (OR = 2.14; 95%CI 1.11-4.07; p = 0.01). The group with TAO and IOR had no significant difference in clinical (p = 0.06) and surgical (p = 0.94) complications compared to the group that had TAO, but no IOR. Among the 111 patients followed six months after treatment, IOR, number of occlusions, and total time of occlusion were not associated with Glasgow Outcome Scale (GOS) in the follow-up (respectively, p = 0.18, p = 0.30, and p = 0.73). Among patients who underwent TAO, IOR was also not associated with GOS in the follow-up (p = 0.29).

CONCLUSIONS

TAO was associated with IOR and surgical complications, being the latter independent of IOR occurrence. In long-term analysis, neither TAO nor IOR were associated with poor clinical outcomes.

Robotic Arm-Protected Microsurgical Pericallosal and Middle Cerebral Artery Aneurysm Clipping: A Technical Note and Case Series

BACKGROUND

Managing intraoperative aneurysm rupture (IAR) during intracranial aneurysm clipping can be challenging given the excessive hemorrhage and limited field of view under the microscope for visualizing the proximal artery and safe temporary clipping.

OBJECTIVE

To describe the first known use of robotic arm for safeguarding IAR in microsurgical aneurysm clipping.

METHODS

A robotic arm was used to safeguard 3 microsurgical clipping cases (1 pericallosal and 2 middle cerebral artery) performed by a single surgeon. The device was installed onto the side rail of the operating table along with the clip applier attachment. After dissecting the cerebral artery segment proximal to the aneurysm, a temporary aneurysm clip was loaded and established at the appropriate segment before dissecting distally toward the aneurysm.

RESULTS

Setup for the robotic arm and temporary clip was simple, quick, precise, and without any unforeseen accommodations needed in all 3 instances. The temporary clip acted as an emergency gate and could be deployed either manually or remotely through a controller. IAR occurred in case 1, and the robotic-assisted temporary clip deployment achieved immediate hemostasis without complications. This method bypassed the need for significant suctioning, packing, and further exploration for safe temporary clipping. Case 2 and 3 demonstrated the feasibility for middle cerebral artery protection and ease of intraoperative readjustment.

CONCLUSION

This technical note highlights the feasibility and relative ease of using a robotic arm as a safeguard device, and it enables on-demand control of proximal blood flow and may enhance the safety of microsurgical aneurysm procedures.

Brain retraction injury after elective aneurysm clipping: a retrospective single-center cohort study

Background

BRI is estimated to occur in 10% of skull-base surgery and 5% of aneurysm surgery. These estimates are based on a few studies with unclear methodology. The purpose of this study is to assess the rate of BRI occurrence, its risk factors, and the association between BRI and postoperative focal neurological deficit in patients that underwent elective aneurysm surgery in a single institution.

Methods

All patients that underwent elective aneurysm surgery in a single tertiary center in the Netherlands were included. BRI was defined as cortical hypodensities in the surgical trajectory not matching areas of large arterial infarction. Risk ratios were calculated between BRI and (a) the use of temporary parent artery occlusion during clipping, (b) anterior communicating artery (ACom), and (c) middle cerebral artery (MCA) location of the aneurysm, (d) presence of mentioned CVA risk factors, (e) the clipping of > 1 aneurysm during the same procedure, and (f) new focal neurological deficit. Statistical analysis further included t-tests and binary logistical regression analysis on the correlation between age and BRI.

Results

BRI was identified postoperatively in 42 of the 94 patients included in this study. A new focal neurological deficit was found in 7 patients in the BRI group. A total of 5 patients had persisting symptoms at 3-month follow-up, of which 2 were caused by BRI. Increasing age is a risk factor for developing BRI.

Conclusions

The high rate of BRI and significant risk of new postoperative focal neurological deficit in our patients should be considered when counseling patients for elective aneurysm surgery.

Intra-operative cerebral blood flow assessment by indocyanine green video-angiography after temporary arterial occlusion in aneurysm surgery and its clinical implications: a prospective study

Objective

Indocyanine green video angiography (ICG-VA) is a routine while performing vascular surgery to assess patency of perforators, completeness of clipping and/or to assess patency of anastomosis. Its usefulness in assessing cerebral blood flow and perfusion is not well studied. This study is aimed to assess the cerebral blood flow and perfusion after temporary clipping and to correlate with the risk of ischemia.

Methods

Prospective analysis of intra-operative ICG-VA performed during temporary arterial occlusion in 38 patients from January 2014 to December 2018 was conducted. Co-relation with post-operative MR diffusion weighted imaging (MR DWI) in terms of vascular territory of interest within 48 hours of surgery was performed. Clinical outcome was assessed using modified Rankin Scale (mRS) score 1-month post-surgery.

Results

43 aneurysms in 38 patients clipped using ICG-VA were included in this study. No side effect of ICG dye was seen in any patients. The number of times temporary clips applied had a direct relationship to the delay in appearance of ICG in the surgical field which became statistically significant after application of 3rd temporary clip. Nine (23.7%) patients developed ischemia following the procedure confirmed by post-operative MR DWI and all the ischemic cases had visible decrease in ICG fluorescence post-temporary clipping.

Conclusions

No previous study had tried to assess the intraoperative cerebral blood flow and perfusion during temporary clipping of parent vessels during aneurysm surgery. The use of ICG-VA can be extended to assess perfusion in desired territory by merely assessing the degree of opacification.

Neuroprotective mechanisms of erythropoietin in a rat stroke model

Objective

This study was designed to investigate the indirect neuroprotective properties of recombinant human erythropoietin (rhEPO) pretreatment in a rat model of transient middle cerebral artery occlusion (MCAO).

Methods

One hundred and ten male Wistar rats were randomly assigned to four groups receiving either 5,000 IU/kg rhEPO intravenously or saline 15 minutes prior to MCAO and bilateral craniectomy or sham craniectomy. Bilateral craniectomy aimed at elimination of the space-consuming effect of postischemic edema. Diagnostic workup included neurological examination, assessment of infarct size and cerebral edema by magnetic resonance imaging, wet–dry technique, and quantification of hemispheric and local cerebral blood flow (CBF) by flat-panel volumetric computed tomography.

Results

In the absence of craniectomy, EPO pretreatment led to a significant reduction in infarct volume (34.83 ± 9.84% vs. 25.28 ± 7.03%; p = 0.022) and midline shift (0.114 ± 0.023 cm vs. 0.083 ± 0.027 cm; p = 0.013). We observed a significant increase in regional CBF in cortical areas of the ischemic infarct (72.29 ± 24.00% vs. 105.53 ± 33.10%; p = 0.043) but not the whole hemispheres. Infarct size-independent parameters could not demonstrate a statistically significant reduction in cerebral edema with EPO treatment.

Conclusions

Single-dose pretreatment with rhEPO 5,000 IU/kg significantly reduces ischemic lesion volume and increases local CBF in penumbral areas of ischemia 24 h after transient MCAO in rats. Data suggest indirect neuroprotection from edema and the resultant pressure-reducing and blood flow-increasing effects mediated by EPO.

Prevention of Back Bleeding During Carotid Endarterectomy: Analysis of Clamping Techniques

OBJECTIVE

Complete control of back bleeding during carotid endarterectomy (CEA) is important. We investigated the causes of back bleeding during CEA and techniques for the control of bleeding.

METHODS

A retrospective review was performed of 214 CEA procedures. We assessed the results of routine preoperative examinations, instruments used for arterial clamping (vessel loop and crude or bulldog clamps), and severity of carotid artery stenosis and arterial wall calcification. The study end point was incomplete control of back bleeding before arteriotomy. Factors associated with back bleeding were identified by univariate analysis. The culprit artery and intraoperative technique used in patients with back bleeding were also determined.

RESULTS

Transient back bleeding occurred in 19 CEA procedures (8.9%). Back bleeding was from the ascending pharyngeal artery in 9 cases, common carotid artery in 8 cases, and external carotid artery in 2 cases. Univariate analysis identified the following factors as being related to incomplete control of back bleeding: moderate carotid artery stenosis (20 mm thick) and use of bulldog clamps.

CONCLUSIONS

Transient back bleeding during CEA was uncommon, with the risk factors being severe carotid calcification and moderate carotid stenosis. Transient back bleeding was managed by clamping an undetected ascending pharyngeal artery or by additional clamping of the common carotid or external carotid artery. The vessel loop and crude were superior to the bulldog clamp for clamping the carotid artery.

Prediction of postoperative motor deficits using motor evoked potential deterioration duration in intracranial aneurysm surgery

OBJECTIVE

The study aimed to investigate the predictive value of motor evoked potential (MEP) deterioration duration for postoperative motor deficits in patients undergoing intracranial aneurysm surgery.

METHODS

Data from 587 patients were reviewed and 92 patients with MEP deterioration were enrolled. MEP deterioration duration was compared between patients with and without postoperative motor deficits. Receiver operating characteristic (ROC) curve analysis was performed to define the threshold value for predicting postoperative motor deficit risk. Additionally, the association between MEP deterioration duration and postoperative CT findings was explored.

RESULTS

Patients with postoperative motor deficits had a significantly longer MEP deterioration duration (p < 0.01). An MEP deterioration duration greater than or equal to 13 min was identified as an independent predictor of immediate (p < 0.01), short-term (p < 0.01), and long-term postoperative motor deficits (p < 0.05). There was no significant association between MEP deterioration duration and new CT abnormalities.

CONCLUSION

MEP deterioration duration could be used for predicting intracranial aneurysm surgical outcome.

SIGNIFICANCE

The study first proposed a threshold value of MEP deterioration duration (13 min) for predicting the risk of postoperative motor deficits in patients undergoing intracranial aneurysm surgery.

Microsurgical Clipping of a Giant Middle Cerebral Artery Aneurysm with Successful Postoperative Endovascular Mechanical Thrombectomy for Emergent Treatment of Large Vessel Occlusion

BACKGROUND

Giant intracranial aneurysms (>25 mm) are uncommon. These lesions typically manifest clinically due to mass effect, acute hemorrhage, or thromboembolic events. To minimize the risk of poor clinical outcome, detailed operative planning and a consideration of all neurosurgical and endovascular techniques are essential before proceeding with microsurgical clipping of ruptured giant aneurysms.

CASE DESCRIPTION

We describe a case involving a 15-year-old male with a ruptured giant middle cerebral artery aneurysm treated with microsurgical clipping. After clip application, poor distal flow was demonstrated intraoperatively, and emergent angiography demonstrated an M1 occlusion with thrombus. A salvage procedure using endovascular mechanical thrombectomy reestablished distal flow resulting in a good neurologic outcome.

CONCLUSIONS

To our knowledge, this is the first case report to describe microsurgical clipping of an aneurysm followed by successful postoperative endovascular mechanical thrombectomy.

The efficacy of microsurgery in the treatment of cerebral aneurysm rupture and its effect on NF-κB, MCP-1 and MMP-9

The clinical efficacy of microsurgical neck clipping for the treatment of cerebral aneurysm rupture and its effect on serum nuclear factor κ-light-chain-enhancer of activated β cells (NF-κB), monocyte chemoattractant protein-1 (MCP-1) and matrix metalloproteinase-9 (MMP-9) levels were investigated. A total of 56 patients with first occurrence of cerebral aneurysm rupture were enrolled from June 2015 to June 2016. These patients were divided into control (25 patients) and observation groups (31 patients) according to treatment received. The patients in the control group were treated with interventional embolization and extraventricular drainage, while the patients in the observation group were treated with microsurgical neck clipping. Serum NF-κB, MCP-1 and MMP-9 levels were measured by ELISA prior to the operation and at 6 h post-operation. Clinical effects were compared at the 6-month follow-up. There was no significant difference in the success rate of the operation between the two groups (p>0.05). The incidence of complications in the observation group was significantly lower than that in the control group (p<0.05). The Glasgow Outcome Scale score was significantly improved in the observation group (p<0.05) compared with the control group. Serum NF-κB, MMP-9 and MCP-1 were significantly decreased in both groups at 6 and 24 h after operation, but the observational group showed significantly lower levels for all three proteins than the control group (p<0.05). The application of early microsurgical neck clipping for the treatment of cerebral aneurysm rupture can reduce complications and improve clinical prognosis, and this may be related to a decrease in serum inflammatory response-related factors (NF-κB and MCP-1) and MMP-9.

Neuroprotective effects of erythropoietin pretreatment in a rodent model of transient middle cerebral artery occlusion

OBJECT.: There is an unmet clinical need to develop neuroprotective agents for neurosurgical and endovascular procedures that require transient cerebral artery occlusion. The aim in this study was to explore the effects of a single dose of recombinant human erythropoietin (rhEPO) before middle cerebral artery (MCA) occlusion in a focal cerebral ischemia/reperfusion model.

METHODS

Twenty-eight adult male Wistar rats were subjected to right MCA occlusion via the intraluminal thread technique for 60 minutes under continuous cortical perfusion monitoring by laser Doppler flowmetry. Rats were divided into 2 groups: control and treatment. In the treated group, rhEPO (1000 IU/kg intravenously) was administered 10 minutes before the onset of the MCA ischemia. At 24-hour reperfusion, animals were examined for neurological deficits, blood samples were collected, and animals were killed. The following parameters were evaluated: brain infarct volume, ipsilateral hemispheric edema, neuron-specific enolase plasma levels, parenchyma histological features (H & E staining), Fluoro-Jade-positive neurons, p-Akt and total Akt expression by Western blot analysis, and p-Akt-positive nuclei by immunohistochemical investigation.

RESULTS

Infarct volume and Fluoro-Jade staining of degenerating neurons in the infarct area did not vary between groups. The severity of neurological deficit (p < 0.001), amount of brain edema (78% reduction in treatment group, p < 0.001), and neuron-specific enolase plasma levels (p < 0.001) were reduced in the treatment group. Perivascular edema was histologically less marked in the treatment group. No variations in the expression or localization of p-Akt were seen.

CONCLUSIONS

Administration of rhEPO before the onset of 60-minute transient MCA ischemia protected the brain from this insult. It is unlikely that rhEPO pretreatment leads to direct neuronal antiapoptotic effects, as supported by the lack of Akt activation, and its benefits are most probably related to an indirect effect on brain edema as a consequence of blood-brain barrier preservation. Although research on EPO derivatives is increasing, rhEPO acts through distinct neuroprotective pathways and its clinical safety profile is well known. Clinically available rhEPO is a potential therapy for prevention of neuronal injury induced by transitory artery occlusion during neurovascular procedures.

The impact of temporary artery occlusion during intracranial aneurysm surgery on long-term clinical outcome: part I. Patients with subarachnoid hemorrhage

BACKGROUND

Temporary artery occlusion (TAO) during intracranial aneurysm surgery is an integral element in facilitating aneurysm dissection and clipping. Despite its significance, knowledge of effects of TAO on long-term clinical outcome is limited. The purpose of this study was to evaluate the impact of TAO in patients with subarachnoid hemorrhage (SAH) at one institution.

METHODS

Patients managed for an intracranial aneurysm were followed from January 2000 to July 2009. This study included a cohort of patients with a diagnosis of SAH who underwent TAO during aneurysm surgery. Risk factors known to affect outcome were considered. Effects of TAO time on long-term clinical outcome were evaluated using the Glasgow Outcome Scale (GOS) at last follow-up visit or hospital discharge. Analyses included descriptive statistics and binary logistic and ordinal logistic regression.

RESULTS

Inclusion criteria were met by 382 patients (74.3% female, age 52 years ± 13.5) with aneurysmal SAH. Mean follow-up was 39 months ± 57.3. Mean TAO time was 19.4 minutes ± 15.7. Of patients, 66% had a good outcome and made a complete recovery at last follow-up (GOS 5); 13% of patients were moderately disabled (GOS 4); and 27% of patients were severely disabled (GOS 3), were in a vegetative state (GOS 2), or had died (GOS 1). Overall, TAO time had no effect on overall long-term clinical outcome (P = 0.76). Higher Hunt and Hess grades (P < 0.001), Fisher computed tomography grades (P < 0.001), age (P < 0.001), larger size of aneurysm (P < 0.008), aneurysms of the posterior circulation (P = 0.044), and presence of clinical vasospasm (P < 0.001) were significantly associated with worse outcomes. On logistic regression analysis, the association between location of aneurysm (anterior vs. posterior circulation) and outcome disappeared.

CONCLUSIONS

Limited duration of TAO during aneurysm surgery did not affect long-term clinical outcome and appears to be safe in patients with aneurysmal SAH. Established SAH risk factors including Hunt and Hess grades, Fisher computed tomography grades, and presence of clinical vasospasm clearly correlated with long-term clinical outcomes.

Monitoring of brain oxygenation in surgery of ruptured middle cerebral artery aneurysms

Background:

The occurrence of brain ischemic lesions, due to temporary arterial occlusion or incorrect placement of the definitive clip, is a major complication of aneurysm surgery. Temporary clipping is a current technique during surgery and there is no reliable method of predicting the possibility of ischemia due to extended regional circulatory interruption. Even with careful inspection, misplacement of the definitive clip can be difficult to detect. Brain tissue oxygen concentration (PtiO₂) was monitored during surgery of middle cerebral artery (MCA) aneurysm presenting with subarachnoid hemorrhage (SAH), for detection of changes in brain oxygenation due to reduced blood flow, as a predictor of ischemic events, during temporary clipping and after definitive clipping.

Methods:

PtiO₂ was monitored during surgery of 13 patients harboring MCA aneurysms presenting with SAH, using a polarographic microcatheter (Licox, GMS, Kiel, Germany) placed in the territory of MCA.

Results

A decrease in PtiO₂ values was verified in every period of temporary clipping. Brain infarction occurred in 2 patients; in both cases, there was a decrease in PtiO₂ greater than 80% from basal value, a minimum value of less than 2 mmHg persisting for 2 or more minutes during temporary clipping, and an incomplete recovery of PtiO₂ after definitive clipping. In 2 patients, incomplete recovery of values after definitive clipping led to verification of inappropriate placement and repositioning of the clip.

Conclusion:

The results suggest that intraoperative monitoring of PtiO₂ may be a useful method of detection of changes in brain tissue oxygenation during MCA aneurysm surgery. Postoperative infarction in the territory of MCA developed in cases with an abrupt decrease of PtiO₂ and a very low and persistent minimum value, during temporary clipping, and an incomplete recovery after definitive clipping. Verification of clip position should be considered when there is an incomplete recovery or a persistent fall in PtiO₂ after definitive clipping.

Monitoring of brain tissue oxygenation in surgery of middle cerebral artery incidental aneurysms

Introduction:

The management of incidental unruptured aneurysms remains a matter of controversy; middle-sized or large anterior circulation incidental aneurysms, in young or middle age patients, should be considered for treatment. Surgical clipping is an accepted treatment for middle cerebral artery unruptured aneurysms. Ischemic events can occur even in cases of incidental aneurysm surgery. Since regional cerebral blood flow can be compromised due to temporary arterial clipping or to incorrect placement of defi nitive clip, we performed intra-operative monitoring of brain tissue oxygen concentration (PtiO₂), to detect changes in brain oxygenation due to reduced blood fl ow, eventually leading to ischemia, during surgery of middle cerebral artery incidental aneurysms.

Methods:

PtiO₂ monitoring was performed during surgery of eight patients harboring incidental MCA aneurysms, using a polarographic microcatheter (Licox, GMS – Kiel, Germany), placed in the temporal lobe on the side of the lesion, from dural opening to dural closure.

Results:

Basal values varied between 2.3 and 27.3 mmHg; these values are lower than those previously described in the literature as “normal” for uninjured brain or in cases of subarachnoid hemorrhage. In all patients, a significant decrease in PtiO2 was found in every period of temporary clipping of MCA. Post-operative infarction in the territory of middle cerebral artery occurred in one patient and, in that case, there was a persistent minimum value of 0.6 mmHg, without recovery after the placement of the definitive clip. In another patient, an incorrect placement of the definitive clip could be predicted by a decrease in PtiO₂ value.

Conclusions:

PtiO₂ monitoring during aneurysm surgery shows brain tissue perfusion in real time and there is a correlation between any episode of reduced blood flow to the affected vascular territory during surgery and a decrease of PtiO2 values. Unexpected low basal values were obtained in “uninjured” brain, with no influence from subarachnoid hemorrhage. The values of risk for brain infarction during temporary arterial occlusion still need further studies, but an incomplete recovery or a persistent fall in PtiO₂ values after definitive clipping should be considered as an indication for verification of the position of the clip.