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.

Efficacy and safety of adenosine, rapid ventricular pacing and hypothermia in cerebral aneurysms clipping: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Cerebral aneurysms in complex anatomical locations and intraoperative rupture can be challenging. Many methods to reduce blood flow can facilitate its exclusion from the circulation. This study evaluated the safety and efficacy of using adenosine, rapid ventricular pacing, and hypothermia in cerebral aneurysm clipping.

METHODS

Databases (PubMed, Embase, and Web of Science) were systematically searched for studies documenting the use of adenosine, rapid ventricular pacing, and hypothermia in cerebral aneurysm clipping and were included in this single-arm meta-analysis. The primary outcome was 30-day mortality. Secondary outcomes included neurological outcomes by mRs and GOS, and cardiac outcomes. We evaluated the risk of bias using ROBIN-I, a tool developed by the Cochrane Collaboration. OpenMetaAnalyst version 2.0 was used for statistical analysis and I2 measured data heterogeneity. Heterogeneity was defined as an I2 > 50%.

RESULTS

Our systematic search yielded 10,100 results. After the removal of duplicates and exclusion by title and abstract, 64 studies were considered for full review, of which 29 were included. The overall risk of bias was moderate. The pooled proportions of the adenosine analysis for the different outcomes were: For the primary outcome: 11,9%; for perioperative arrhythmia: 0,19%; for postoperative arrhythmia: 0,56%; for myocardial infarction incidence: 0,01%; for follow-up good recovery (mRs 0-2): 88%; and for neurological deficit:14.1%. In the rapid ventricular pacing analysis, incidences were as follows: peri operative arrhythmia: 0,64%; postoperative arrhythmia: 0,3%; myocardial infarction: 0%. In the hypothermia analysis, the pooled proportion of 30-day mortality was 11,6%. The incidence of post-op neurological deficits was 35,4% and good recovery under neurological analysis by GOS was present in 69.2%.

CONCLUSION

The use of the three methods is safe and the related complications were very low. Further studies are necessary, especially with comparative analysis, for extended knowledge.

Unstable ventricular tachycardia requiring defibrillation from rapid ventricular pacing during basilar apex aneurysm clipping

BACKGROUND

Controlled hypotension is an important tool in the open treatment of complex intracranial aneurysms. Of the available methodologies, rapid ventricular pacing (RVP) provides titratable, sustained hypotension with a relatively safe profile.

METHOD

We report the case of a 63-year-old woman who underwent a combined subfrontal and subtemporal approach for clipping of anterior communicating artery and basilar apex aneurysms. RVP was used during initial dissection of the basilar apex aneurysm and perforators but caused uncontrolled ventricular tachycardia requiring synchronized defibrillation. After restoration of hemodynamic stability, the aneurysm was uneventfully clipped.

CONCLUSION

Preparation for unstable cardiac arrhythmias is needed with RVP.

Rapid Ventricular Pacing as a Safe Procedure for Clipping of Complex Ruptured and Unruptured Intracranial Aneurysms

Surgical treatment of intracranial aneurysm requires advanced technologies to achieve optimal results. Recently, rapid ventricular pacing (RVP) has been described to be an elegant technique that facilitates clip reconstruction of complex unruptured intracranial aneurysm (uIA). However, there is also a growing need for intraoperative tools to ensure safe clip reconstruction of complex ruptured intracranial aneurysm (rIA). We conducted a retrospective analysis of 17 patients who underwent RVP during surgical reconstruction of complex aneurysms. Nine patients had uIA while eight patients underwent surgery for rIA suffering from consecutive subarachnoid hemorrhage (SAH). Hemodynamic data, critical events, laboratory results, and anesthesia-related complications were evaluated. No complications were reported concerning anesthesia induction and induction times were similar between patients exhibiting uIA or rIA (p = 0.08). RVP induced a significant decline of median arterial pressure (MAP) in both groups (p < 0.0001). However, median MAP before and after RVP was not different in both groups (uIA group: p = 0.27; rIA group: p = 0.18). Furthermore, high-sensitive Troponin T (hsTnT) levels were not increased after RVP in any group. One patient in the rIA group exhibited ventricular fibrillation and required cardiopulmonary resuscitation, but has presented with cardiac arrest due to SAH. Otherwise, no arrhythmias or complications occurred. In summary, our data suggest RVP to be feasible in surgery for ruptured intracranial aneurysms.

Adverse intraoperative events during surgical repair of ruptured cerebral aneurysms: a systematic review

Compared with endovascular techniques, clipping of ruptured cerebral aneurysms has been shown to associate with increased morbidity in several studies. Despite this, clipping remains the preferred option for many aneurysms. The objective of this study is to describe the reported adverse events of open repair of ruptured cerebral aneurysms and their impact on patient outcome. The PubMed, Embase and Cochrane databases were searched between June 1999 and June 2019 to identify original studies of at least 100 patients undergoing surgical repair of ruptured cerebral aneurysms and in which adverse event rates were reported. Thirty-six studies reporting adverse events in a total of 12,410 operations for repair of ruptured cerebral aneurysms were included. Surgical adverse events were common with 36 event types reported including intraoperative rupture (median rate of 16.6%), arterial injury (median rate of 3.8%) and brain swelling (median rate 5.6%). Only 6 surgical events were statistically shown to associate with poor outcomes by any author and for intraoperative rupture (the most frequently analysed), there was an even split between authors finding a statistical association with poor outcome and those finding no association. Even with modern surgical techniques, the technical demands of surgical aneurysm repair continue to lead to a high rate of intraoperative adverse events. Despite this, it is not known which of these intraoperative events are the most important contributors to the poor outcomes often seen in these patients. More research directed towards identifying the events that most drive operative morbidity has the potential to improve outcomes for these patients.

Adenosine-Assisted Clipping of Intracranial Aneurysms

BACKGROUND

Temporary parent vessel clip occlusion in aneurysm surgery is not always practical or feasible. Adenosine-induced transient cardiac arrest may serve as an alternative.

METHODS

All patients who underwent microsurgical clipping of intracranial aneurysms under adenosine-induced asystole performed by the author between September 2011 and July 2014 were retrospectively reviewed.

RESULTS

A total of 16 craniotomies were performed and 16 aneurysms were clipped under adenosine-induced asystole (in 8 basilar arteries, 7 internal carotid arteries, and 1 middle cerebral artery) in 14 patients (8 females, 6 males). Seven cases were elective and 7 were performed after subarachnoid hemorrhage. The patients' mean age was 54 years (range, 39-70 years). The indications for adenosine use were proximal control in narrow surgical corridors in 11 cases, aneurysm softening in 4 cases, and aneurysm rupture in 1 case. A single dose was used in 12 patients; 2 patients had multiple boluses. The median (range) total dose was 30 (18-60) mg. Adenosine induced bradycardia with concomitant arterial hypotension in all patients and the majority also had asystole for 5-15 s. Transient cardiac arrhythmias were noted in 1 patient (atrial fibrillation in need of electroconversion after two boluses).

CONCLUSION

Nine clinical scenarios were identified in which adenosine-induced temporary cardiac arrest and deep hypotension was an effective adjunct to temporary clipping during the microsurgical clipping of intracranial aneurysms.

Endovascular occlusion of pial arteriovenous macrofistulae, using pCANvas1 and adenosine-induced asystole to control nBCA injection

Background In large-caliber pial macrofistulae (pMF), the combination of high blood flow velocity and large efferent artery diameter makes control over the endovascular vessel occlusion difficult and may result in the inadvertent venous passage of occlusive devices or embolic agents. Case descriptions Patient 1: A 27-year-old man presented with headache and ataxia. An infratentorial pMF supplied by both superior cerebellar arteries with venous ectasia was found. The first treatment attempt using balloons and coils failed since the position of either device could not be controlled because of a distal diameter of the feeding artery of 8 mm. In a second session a pCANvas1 (phenox) was deployed at the level of the arteriovenous connection and adenosine-induced asystole allowed the controlled injection of nBCA/Lipiodol with partial occlusion of the pMF. A remaining arteriovenous shunt was occluded under asystole in a third session. The procedures were well tolerated, the patient returned to normal and DSA confirmed the occlusion of the fistula. Patient 2: A 13-year-old boy with hereditary hemorrhagic teleangiectasia presented with an intracerebral hemorrhage from an aneurysm of the left MCA. Twelve weeks after the aneurysm treatment a feeding MCA branch (diameter 4.5 mm) of a right frontal pMF was catheterized. The macrofistula was occluded by deployment of a pCANvas1, followed by the injection of nBCAl/Lipiodol under adenosine-induced asystole. Conclusion pCANvas1 and adenosine-induced asystole allow a controlled injection of nBCA/Lipiodol for the endovascular occlusion of high-flow pMF without venous passage of the embolic agent.

Adenosine-induced transient asystole

Cerebral aneurysms are an important health issue in the United States, and the mortality rate following aneurysm rupture, or SAH, remains high. The treatment of these aneurysms uses endovascular options which include coil placement, stent assistant coiling and, recently, flow diversion. However, microsurgical clipping remains an option in those aneurysms not suited for endovascular therapy. These are often the more complicated aneurysms such as in large, giant aneurysms or deep-seated aneurysms. Circumferential visualization of the aneurysm, parent vessels, branches, perforators, and other neurovascular structures is important to prevent residual aneurysms or strokes from vessel or perforator occlusion. Decompression of the aneurysm sac is often required and we believe that adenosine-induced transient asystole should be an important option for clipping of complex cerebral aneurysms.

Rapid ventricular pacing assisted hypotension in the management of sudden intraoperative hemorrhage during cerebral aneurysm clipping

Sudden intraoperative hemorrhage during intracranial aneurysm surgery from vascular injury or aneurysmal rupture has been known to dramatically increase the associated morbidity and mortality. We describe the first reported use of rapid ventricular pacing (RVP) assisted hypotension to control sudden intraoperative hemorrhage during intracranial aneurysm surgery where temporary arterial occlusion was not achievable.

Controversies in the anesthetic management of intraoperative rupture of intracranial aneurysm

Despite great advancements in the management of aneurysmal subarachnoid hemorrhage (SAH), outcomes following SAH rupture have remained relatively unchanged. In addition, little data exists to guide the anesthetic management of intraoperative aneurysm rupture (IAR), though intraoperative management may have a significant effect on overall neurological outcomes. This review highlights the various controversies related to different anesthetic management related to aneurysm rupture. The first controversy relates to management of preexisting factors that affect risk of IAR. The second controversy relates to diagnostic techniques, particularly neurophysiological monitoring. The third controversy pertains to hemodynamic goals. The neuroprotective effects of various factors, including hypothermia, various anesthetic/pharmacologic agents, and burst suppression, remain poorly understood and have yet to be further elucidated. Different management strategies for IAR during aneurysmal clipping versus coiling also need further attention.