Optimal Use of Temporary Clip Application during Aneurysm Surgery - In Search of the Holy Grail

Transcarotid flow reversal for proximal control during cerebral aneurysm clip reconstruction: illustrative case

BACKGROUND

Paraclinoid aneurysms can pose an operative challenge during clip reconstruction, given the complex surrounding anatomy and the aneurysmal tendency to maintain turgor despite standard approaches to proximal control. This report demonstrates the use of intraoperative retrograde arteriovenous shunting with the transcarotid artery revascularization (TCAR) system to assist in the safe clip reconstruction of an irregular paraclinoid aneurysm.

OBSERVATIONS

A 33-year-old woman presented with perimesencephalic subarachnoid hemorrhage and was found to have an incidental 9-mm ophthalmic aneurysm. Coil embolization was not successful. During microsurgical clip reconstruction, the left common carotid artery was exposed to allow for proximal control as well as transcarotid arterial sheath placement. Flow reversal was instituted throughout the aneurysm dissection and clipping, with a visible softening of the aneurysm. Intraoperative angiography confirming successful clip reconstruction was performed utilizing the TCAR sheath. The case was complicated by the development of cerebrospinal fluid rhinorrhea postoperatively, requiring surgical repair. The patient has since made a complete recovery.

LESSONS

Transcarotid flow reversal utilizing the TCAR system has potential for use in the surgical treatment of paraclinoid aneurysms, as it may aid in softening the aneurysm for safer dissection and clip reconstruction, protect against aneurysm-associated emboli, and provide an avenue for intraoperative angiography. https://thejns.org/doi/10.3171/CASE24330.

Recurrent artery of Heubner aneurysms in focus: insights into occurrence and current treatment paradigms

INTRODUCTION

The recurrent artery of Heubner (RAH), also known as the medial striate artery, is the most clinically important perforator of the anterior cerebral artery. RAH aneurysm is relatively rare, with 11 cases found in the present literature review, but poses significant clinical challenges due to potential impact on cognitive and motor functions. This systematic review explored available case reports to comprehensively understand clinical presentation, diagnosis, management and outcome in RAH aneurysm.

MATERIALS AND METHODS

Following PRISMA guidelines, this systematic review extensively explored RAH aneurysms, covering demographics, symptoms, diagnosis, treatments and outcomes. Comprehensive searches on PubMed, Scopus, Google Scholar, and Science Direct employed keywords such as "recurrent artery of Heubner aneurysm" and "Heubner's artery."

RESULTS

After extensive screening, 9 qualifying studies were identified, with 11 patients diagnosed with rare RAH aneurysm. Median age was 55 years (standard deviation, 15.3 years), with 54.5% males. 45.5% of patients presented risk factors, including Moyamoya disease in 2 patients. The majority were classified as grade I/II on the Hunt and Hess (H&H) and World Federation of Neurological Societies (WFNS) systems. Aneurysms were predominantly located in the A1 segment, with a mean size of 4.7 mm. Treatments varied, with clipping being the most frequent (63.6%). The mortality rate was 18.2%. Clipping was associated with favorable outcomes but higher rates of infarction.

CONCLUSION

This analysis highlighted the various symptoms, therapy methods and outcomes of RAH aneurysm, with A1 being the predominant origin. Future research should explore potential genetic predisposition factors and novel therapeutic interventions to address gaps in our knowledge.

Rapid Ventricular Pacing for Clipping of Intracranial Aneurysms: A Single-centre Retrospective Case Series

OBJECTIVE

Multiple strategies exist to facilitate microdissection and obliteration of intracranial aneurysms during microsurgical clipping. Rapid ventricular pacing (RVP) can be used to induce controlled transient hypotension to facilitate aneurysm manipulation. We report the indications and outcomes of intraoperative RVP for clipping of ruptured and unruptured complex aneurysms.

METHODS

We completed a retrospective review of adult patients who underwent RVP-facilitated elective and emergent microsurgical aneurysm clipping by a single senior neurosurgeon between 2016 and 2023. Intraoperative RVP was performed at a rate of 150 to 200 beats per minute through a transvenous pacing wire and repeated as needed based on surgical requirements. Intraoperative procedural and pacing data and perioperative cardiac and neurosurgical variables were collected.

RESULTS

Forty patients were included in this study. The median (interquartile range) number of pacing episodes per patient was 8 (5 to 14), resulting in a median mean arterial pressure of 37 (30 to 40) mm Hg during RVP. One patient developed wide complex tachycardia intraoperatively, which resolved after cardioversion. Fifteen out of 36 (42%) patients who had postoperative troponin measurements had at least one troponin value above the 99th percentile upper reference limit. One patient had markedly elevated troponin with anterolateral ischemia in the context of massive postoperative intracranial hemorrhage. There were no other documented intraoperative or postoperative cardiac events.

CONCLUSIONS

This retrospective case series suggests that RVP could be an effective adjunct for clipping of complex ruptured and unruptured aneurysms, associated with transient troponin rise but rare postoperative cardiac complications.

Endoscopic clipping of an anterior communicating artery aneurysm

BACKGROUND

Anterior communicating artery aneurysms are most prone to rupture. Surgically, they are conventionally being managed by a pterional approach. Some neurosurgeons prefer a supraorbital keyhole approach in select cases. Fully endoscopic clipping of such aneurysms is seldom described.

METHOD

We clipped an antero-inferiorly directed anterior communicating artery aneurysm endoscopically via a supraorbital keyhole approach. The intraoperative aneurysmal rupture was also managed endoscopically. The patient made an excellent postoperative recovery without any neurological deficits.

CONCLUSION

Select cases of anterior communicating artery aneurysms can be clipped endoscopically using standard instruments and adhering to the basic principles of aneurysm clipping.

Adverse events associated with microsurgial treatment for ruptured intracerebral aneurysms: a prospective nationwide study on subarachnoid haemorrhage in Sweden

BACKGROUND

Adverse events (AEs) or complications may arise secondary to the treatment of aneurysmal subarachnoid haemorrhage (SAH). The aim of this study was to identify AEs associated with microsurgical occlusion of ruptured aneurysms, as well as to analyse their risk factors and impact on functional outcome.

METHODS

Patients with aneurysmal SAH admitted to the neurosurgical centres in Sweden were prospectively registered during a 3.5-year period (2014-2018). AEs were categorised as intraoperative or postoperative. A range of variables from patient history and SAH characteristics were explored as potential risk factors for an AE. Functional outcome was assessed approximately 1 year after the bleeding using the extended Glasgow Outcome Scale.

RESULTS

In total, 1037 patients were treated for ruptured aneurysms, of which, 322 patients were treated with microsurgery. There were 105 surgical AEs in 97 patients (30%); 94 were intraoperative AEs in 79 patients (25%). Aneurysm rerupture occurred in 43 patients (13%), temporary occlusion of the parent artery >5 min in 26 patients (8%) and adjacent vessel injury in 25 patients (8%). High Fisher grade and brain oedema on CT were related to increased risk of AEs. At follow-up, 38% of patients had unfavourable outcome. Patients suffering AEs were more likely to have unfavourable outcome (OR 2.3, 95% CI 1.10 to 4.69).

CONCLUSION

Intraoperative AEs occurred in 25% of patients treated with microsurgery for ruptured intracerebral aneurysm in this nationwide survey. Although most operated patients had favourable outcome, AEs were associated with increased risk of unfavourable outcome.

Predictive value of neurophysiological monitoring during posterior communicating artery aneurysm clipping for postoperative neurological deficits

Objective

This study aimed to evaluate the diagnostic effect of intraoperative neurophysiological monitoring in identifying intraoperative ischemic events and predicting postoperative neurological dysfunction during PCoA aneurysm clipping, as well as to explore the safe duration of intraoperative temporary clipping of the parent artery.

Methods

All 71 patients with PCoA aneurysm underwent craniotomy and aneurysm clipping. MEP and SSEP were used for monitoring during operation to evaluate the influence of MEP/SSEP changes on postoperative neurological function. Receiver operating characteristic (ROC) curve analysis was used to calculate optimal duration of intraoperative temporary clipping.

Results

Patients with intraoperative MEP/SSEP changes were more likely to develop short-term and long-term neurological deficits than those without MEP/SSEP changes (P < 0.05). From the ROC curve analysis, the safe time from the initiation of temporary clipping during the operation to the early warning of neurophysiological monitoring was 4.5 min (AUC = 0.735, 95%CI 0.5558-0.912). Taking 4.5 min as the dividing line, the incidence of short-term and long-term neurological dysfunction in patients with temporary clipping >4.5 min was significantly higher than that in patients with temporary clipping ≤4.5 min (P = 0.015, P = 0.018).

Conclusion

Intraoperative MEP/SSEP changes are significantly associated with postoperative neurological dysfunction in patients with PCoA aneurysms. The optimal duration of temporary clipping of the parent artery during posterior communicating aneurysm clipping was 4.5 min under neurophysiological monitoring.

Temporary vessel occlusion in cerebral aneurysm surgery guided by direct cortical motor evoked potentials

BACKGROUND

Temporary clipping is an important tool in the vascular neurosurgeon's armamentarium. We routinely utilize intraoperative neurophysiological monitoring (IONM) for complex brain aneurysm surgery cases, relying on direct cortical motor evoked potential (DCMEP) alerts to guide the duration of temporary clipping. Previous studies have argued for relatively short and intermittent temporary clipping strategies. In this study, we sought to assess the maximal permissive temporary clipping time during complex aneurysm surgery. To do this, we assessed patient outcome in relation to temporary clip duration guided by DCMEP.

METHODS

We queried our prospectively collected neuromonitoring database for anterior circulation aneurysm cases where temporary clipping was utilized by a single cerebrovascular surgeon between 2018 and 2021. Operative and IONM reports were reviewed. Patients in whom the duration of temporary clipping could not be determined were excluded. The operative strategy permissively allowed continuous temporary clipping as long as no neuromonitoring alerts were encountered. Maximal permissive parent artery occlusion time (Clip_max) was recorded as the longest duration of tolerated temporary vessel clipping without decrement in DCMEP.

RESULTS

A total of 41 complex anterior circulation aneurysm clipping cases met criteria for this study. The mean Clip_max for all cases was just over 19 min and did not differ between ruptured and unruptured aneurysms. Initial alert times were not found to be predictive of final permissive temporary clip duration after re-perfusion. In 100% (41/41) of cases, the aneurysm was completely clip occluded without residual on catheter angiogram. Stable or improved modified Rankin Score was achieved in 98% (40/41) of cases at 3-month follow-up.

CONCLUSIONS

This study demonstrates that using DCMEP can facilitate relatively long but safe temporary clipping durations in complex anterior circulation aneurysm surgery. In the endovascular era with only a limited subset of technically challenging aneurysms needing open surgical treatment, extended permissive temporary clipping guided by DCMEPs can significantly enhance a surgeon's ability to achieve excellent technical and clinical outcomes.