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.

Renal, Cardiac, and Autonomic Effects of Catheter-Based Renal Denervation in Ovine Heart Failure

A growing number of clinical studies suggest that in heart failure renal denervation (RDN) has beneficial effects on the autonomic control of the heart. There is also experimental evidence that surgical RDN improves sodium handling and clearance in heart failure. The aim of this study was to determine the effects of catheter-based RDN on the sympathetic and parasympathetic control of the heart, and salt and water handling capacity of the kidneys, in sheep with established heart failure. A randomized, controlled study was conducted in 10 sheep with heart failure (ejection fraction<40%) induced by rapid ventricular pacing. Sheep underwent either bilateral RDN using the Symplicity denervation system or sham denervation and were studied 1 and 6 weeks after RDN. In established ovine heart failure, at 6 weeks after catheter-based RDN, heart rate significantly decreased, estimates of resting and maximal parasympathetic control of heart rate increased, and cardiac sympathetic nerve activity decreased. Compared with sham denervation, there was an increase in the resting sodium and water excretion 6 weeks after catheter-RDN and an improved ability of the kidneys to excrete a nonhypertensive saline load. After catheter-based RDN, renal norepinephrine levels were reduced by 70% compared with sham denervation. In established heart failure, RDN induced a beneficial shift in both arms of the autonomic nervous control of the heart and improved the ability of the kidneys to excrete sodium and water. Thus, effective catheter-based RDN may be beneficial to both the heart and kidneys in heart failure.

Rapid ventricular pacing for flow control during transarterial Onyx embolization of tentorial dural arteriovenous fistulas

We report transarterial Onyx embolization with flow control using rapid ventricular pacing (RVP) in a middle-aged male patient with tentorial dural arteriovenous fistulas (TDAVFs). The patient completed angiographic obliteration in one session without any complications, and the 6-month postangiographic obliteration follow-up showed no evidence of residual or recurrent dural arteriovenous fistulas. RVP may be a novel treatment option of flow control to facilitate the embolic agent penetrating into the venous side and to achieve complete cure in transarterial embolization of TDAVFs.

Factors associated with a high or low implantation of self-expanding devices in TAVR

Objectives Optimizing valve implantation depth (ID) plays a crucial role in minimizing conduction disturbances and achieving optimal functional integrity. Until now, the impact of intraprocedural fast (FP) or rapid ventricular pacing (RP) on the implantation depth has not been investigated. Therefore, we aimed to (1) evaluate the impact of different pacing maneuvers on ID, and (2) identify the independent predictors of deep ID. Methods 473 TAVR patients with newer-generation self-expanding devices were retrospectively enrolled and one-to-one propensity-score-matching was performed, resulting in a matching of 189 FP and RP patients in each cohort. The final ID was analyzed, and the underlying functional, anatomical, and procedural conditions were evaluated by univariate and multivariate analysis. Results The highest ID was reached under RP in severe aortic valve calcification and valve size 26 mm. Multivariate analysis identified left ventricular outflow (LVOT) calcification [OR 0.50 (0.31–0.81) p = 0.005*], a “flare” aortic root [OR 0.42 (0.25–0.71), p = 0.001*], and RP (OR 0.49 [0.30–0.79], p = 0.004*) as independent highly preventable predictors of a deep ID. In a model of protective factors, ID was significantly reduced with the number of protective criteria (0–2 criteria: − 5.7 mm ± 2.6 vs. 3–4 criteria − 4.3 mm ± 2.0; p < 0.0001*). Conclusion Data from this retrospective analysis indicate that RP is an independent predictor to reach a higher implantation depth using self-expanding devices. Randomized studies should prove for validation compared to fast and non-pacing maneuvers during valve delivery and their impact on implantation depth. Trail registration Clinical Trial registration: NCT01805739. Graphic abstract Study design: Evaluation of the impact of different pacing maneuvers (fast ventricular pacing—FP vs. rapid ventricular pacing—RP) on implantation depth (ID). After one-to-one-propensity-score-matching, independent protective and risk factors for a very deep ID beneath 6 mm toward the LVOT (< − 6 mm) were identified. Stent frame pictures as a courtesy by Medtronic®. AVC aortic valve calcification.

Safety and feasibility of retrograde INOUE-BALLOON for balloon aortic valvuloplasty without rapid ventricular pacing during transcatheter aortic valve replacement

Rapid ventricular pacing (RVP) is commonly employed during transcatheter aortic valve replacement (TAVR); however, frequent TAVR is associated with worse prognoses. The retrograde INOUE-BALLOON® (IB) allows balloon aortic valvuloplasty (BAV) without RVP. The aim of this study was to evaluate the feasibility of retrograde IB for TAVR preparation. The study population included 178 consecutive patients (mean age, 84 ± 5 years; male, 47%) who underwent retrograde BAV before prosthetic valve replacement via the transfemoral approach. Patients were divided into a retrograde IB group without RVP (n = 74) and a conventional balloon (CB) group with RVP (n = 104). The primary endpoint was prolonged hypotension after BAV (reduced systolic pressure < 80 mmHg for over 1 min or vasopressor drug requirement). The incidence of prolonged hypotension after BAV was significantly lower in the IB group compared with the CB group (4% vs. 16%, p = 0.011). Balloons were able to penetrate and expand the aortic valve in both groups. RVP was used less for total TAVR in the IB group compared with the CB group. The aortic valve area-index after BAV was not significantly different between the two groups (0.72 ± 0.14 cm2/m2 vs. 0.71 ± 0.12 cm2/m2; p = 0.856). Multivariate analysis demonstrated that IB use was associated with avoidance of prolonged hypotension (OR, 0.27 [0.059–0.952]; p = 0.041). In conclusion, BAV using retrograde IB without RVP is both safe and feasible. More stable hemodynamics were achieved using retrograde IB by avoiding RVP during TAVR.

Role of Reduced Sarco-Endoplasmic Reticulum Ca2+-ATPase Function on Sarcoplasmic Reticulum Ca2+ Alternans in the Intact Rabbit Heart

Sarcoplasmic reticulum (SR) Ca2+ cycling is tightly regulated by ryanodine receptor (RyR) Ca2+ release and sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) Ca2+ uptake during each excitation–contraction coupling cycle. We previously showed that RyR refractoriness plays a key role in the onset of SR Ca2+ alternans in the intact rabbit heart, which contributes to arrhythmogenic action potential duration (APD) alternans. Recent studies have also implicated impaired SERCA function, a key feature of heart failure, in cardiac alternans and arrhythmias. However, the relationship between reduced SERCA function and SR Ca2+ alternans is not well understood. Simultaneous optical mapping of transmembrane potential (Vm) and SR Ca2+ was performed in isolated rabbit hearts (n = 10) using the voltage-sensitive dye RH237 and the low-affinity Ca2+ indicator Fluo-5N-AM. Alternans was induced by rapid ventricular pacing. SERCA was inhibited with cyclopiazonic acid (CPA; 1–10 μM). SERCA inhibition (1, 5, and 10 μM of CPA) resulted in dose-dependent slowing of SR Ca2+ reuptake, with the time constant (tau) increasing from 70.8 ± 3.5 ms at baseline to 85.5 ± 6.6, 129.9 ± 20.7, and 271.3 ± 37.6 ms, respectively (p &lt; 0.05 vs. baseline for all doses). At fast pacing frequencies, CPA significantly increased the magnitude of SR Ca2+ and APD alternans, most strongly at 10 μM (pacing cycle length = 220 ms: SR Ca2+ alternans magnitude: 57.1 ± 4.7 vs. 13.4 ± 8.9 AU; APD alternans magnitude 3.8 ± 1.9 vs. 0.2 ± 0.19 AU; p &lt; 0.05 10 μM of CPA vs. baseline for both). SERCA inhibition also promoted the emergence of spatially discordant alternans. Notably, at all CPA doses, alternation of SR Ca2+ release occurred prior to alternation of diastolic SR Ca2+ load as pacing frequency increased. Simultaneous optical mapping of SR Ca2+ and Vm in the intact rabbit heart revealed that SERCA inhibition exacerbates pacing-induced SR Ca2+ and APD alternans magnitude, particularly at fast pacing frequencies. Importantly, SR Ca2+ release alternans always occurred before the onset of SR Ca2+ load alternans. These findings suggest that even in settings of diminished SERCA function, relative refractoriness of RyR Ca2+ release governs the onset of intracellular Ca2+ alternans.

Thrombectomy and Clip Occlusion of a Giant, Stent-Coiled Basilar Bifurcation Aneurysm: 3-Dimensional Operative Video

Giant basilar apex aneurysms are associated with significant therapeutic challenges.1–6 Multiple techniques exist to treat giant basilar apex aneurysms, including direct clipping, stent-assisted coil embolization, and proximal occlusion with bypass revascularization.7–9 Hypothermic circulatory arrest was a useful adjunct for surgical repair of these aneurysms but has been abandoned because of associated risks.10,11 Rapid ventricular pacing can achieve similar aneurysm softening with minimal risks and assist in clip occlusion. This case illustrates clip occlusion of a giant, partially thrombosed, previously stent-coiled basilar apex aneurysm in a 15-yr-old boy with progressive cranial neuropathies and sensorimotor impairment. Although a wire was placed preoperatively for ventricular pacing, it was not needed during the procedure. Patient consent was obtained. A right-sided orbitozygomatic craniotomy transcavernous approach with anterior and posterior clinoidectomies was performed. The basilar quadrification was dissected, and proximal control was obtained. After aneurysm trapping, the aneurysm was incised and thrombectomized using an ultrasonic aspirator. Back-bleeding from the aneurysm was anticipated, and ventricular pacing was ready, but back-bleeding was minimal. With the coil mass left in place, stacked, fenestrated clips were applied in a tandem fashion to occlude the aneurysm neck. Indocyanine green videoangiography confirmed occlusion of the aneurysm and patency of parent and branch arteries. The patient was at a neurological baseline after the operation, with improvement in motor skills and cognition at 3-mo follow-up. This case demonstrates the use of trans-sylvian-transcavernous exposure, rapid ventricular pacing, and thrombectomy amid previous coils and stents to clip a giant, thrombotic basilar apex aneurysm. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Complete flow control using transient concurrent rapid ventricular pacing or intravenous adenosine and afferent arterial balloon occlusion during transvenous embolization of cerebral arteriovenous malformations: case series

BackgroundThere are no reports that describe complete flow control using concurrent transient rapid ventricular pacing or intravenous (IV) adenosine and afferent arterial balloon flow arrest to aid transvenous embolization of cerebral arteriovenous malformations (AVM). We describe our experience with the use of this technique in patients undergoing transvenous AVM embolization.MethodsConsecutive patients in whom transvenous embolization was attempted at our institute between January 2017 and July 2019 were included. Anatomical AVM features, number of embolization stages, technique of concurrent transient rapid ventricular pacing and afferent arterial balloon flow arrest, complications, and clinical and radiological outcomes were recorded and tabulated.ResultsTransvenous AVM embolization was attempted in 12 patients but abandoned in two patients for technical reasons. Complete embolization was achieved in 10 patients, five of whom had infratentorial AVMs. All 10 had a single primary draining vein. Rapid ventricular pacing was used in nine cases; IV adenosine injection was used in one case to achieve cardiac standstill. Complete AVM nidus obliteration was achieved with excellent neurologic outcome in nine cases, with transvenous embolization alone in two cases, and with staged transarterial followed by transvenous embolization in the others. Two patients developed hemorrhagic complications intraprocedurally. One patient was managed conservatively and the other operatively with AVM excision and hematoma evacuation; both made an excellent recovery without any neurologic deficits at 3 months.ConclusionComplete flow control using concurrent transient rapid ventricular pacing with afferent arterial balloon flow arrest technique is safe and feasible for transvenous embolization of select AVMs.