Adenosine-induced cardiac arrest and EEG changes in patients with thoracic aorta endovascular repair

Low-dose adenosine-induced transient asystole during intracranial aneurysm surgery

Background

Few studies have evaluated the adenosine dose that induces cardiac arrest during intracranial aneurysm surgery. We present our experiences with adenosine-induced transient asystole (AiTA) during intracranial aneurysm surgery and dosage recommendations.

Methods

We retrospectively reviewed the medical records of all patients who underwent intracranial aneurysm surgery between July 2016 and December 2018. Patients who experienced AiTA during intracranial aneurysm surgery were included in the study.

Results

Our study included nine intracranial aneurysm surgeries performed in eight patients. Thirteen episodes of AiTA were reported. Five of these were performed to facilitate bleeding control due to intraoperative aneurysm rupture (IAR), and adenosine doses were 9 mg (0.20 mg/kg), 12 mg (0.25 mg/kg), 12 mg (0.26 mg/kg), 18 mg (0.34 mg/kg), and 18 mg (0.39 mg/kg), resulted in transient asystole for 12, 14, 9, 44, and 18 s, respectively. For episodes without IAR, adenosine doses ranging from 6 to 18 mg (0.11-0.39 mg/kg) caused asystole for 8-33 s. In five episodes without IAR, low-dose adenosine (lower than 0.2 mg/kg) was used and caused asystole ranging from 8 to 12 s. Postoperatively, two patients had elevated cardiac troponin T levels but normal electrocardiograms.

Conclusion

AiTA can facilitate the clipping of intracranial aneurysms at low-risk of serious cardiac complications. An adenosine dose of 0.2-0.4 mg/kg is safe and effective in both IAR and non IAR situations. In non IAR cases, we propose that low-dose AiTA is an option to facilitate aneurysm clipping. A starting dose of 6 mg or 0.1-0.2 mg/kg can adequately induce brief asystole by softening the aneurysmal sac during clip application.

What Is the Best Method to Achieve Safe and Precise Stent-Graft Deployment in Patients Undergoing TEVAR?

Thoracic endovascular aortic repair (TEVAR) for aortic pathologies requires sufficient landing zone of ideally more than 25 mm for safe anchoring of the stent-graft and prevention of endoleaks. In the aortic arch and at the thoracoabdominal transition, landing zone length is usually limited by the offspring of the major aortic side-branches. Exact deployment of the stent-graft to effectively use the whole length of the landing zone and to prevent occlusion of one of the side-branches is key to successful TEVAR. There are numerous techniques described to lower blood pressure and to reduce or eliminate aortic impulse to facilitate exact deployment of stent-grafts including pharmacologic blood pressure lowering, adenosine-induced asystole, inflow occlusion, and rapid pacing. Aim of this review was to assess the current literature to identify which of the techniques is best suited to prevent displacement and allow for precise placement of the stent-graft and safe balloon-molding.

Adenosine-induced Flow Arrest to Facilitate Intracranial Complex Aneurysm Clip Ligation: Review of the Literature

Complex intracranial aneurysms (CIAs) rank high among the most technically demanding neurosurgical pathologies. Microsurgery and clip ligation can be challenging in CIAs as 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 for CIAs. We reviewed the literature and PubMed advanced search showed 13 results of adenosine-induced flow arrest to facilitate intracranial complex aneurysm clip ligation which included three independent case reports and ten cases in a case series from 1999 to May 2016. Few case series have described the use of adenosine in intracranial aneurysm surgery. Satisfactory aneurysm decompression was achieved in all cases, and all aneurysms were clipped successfully. We recommend that adenosine cardiac arrest is a relatively novel method for decompression of intracranial aneurysms to facilitate clip application. With appropriate safety precautions, it is a reasonable alternative method when temporary clipping of proximal vessels is not desirable or not possible.

Rapid ventricular pacing for clip reconstruction of complex unruptured intracranial aneurysms: results of an interdisciplinary prospective trial

OBJECTIVE

To date, treatment of complex unruptured intracranial aneurysms (UIAs) remains challenging. Therefore, advanced techniques are required to achieve an optimal result in treating these patients safely. In this study, the safety and efficacy of rapid ventricular pacing (RVP) to facilitate microsurgical clip reconstruction was investigated prospectively in a joined neurosurgery, anesthesiology, and cardiology study.

METHODS

Patients with complex UIAs were prospectively enrolled. Both the safety and efficacy of RVP were evaluated by recording cardiovascular events and outcomes of patients as well as the amount of aneurysm occlusion after the surgical clip reconstruction procedure. A questionnaire was used to evaluate aneurysm preparation and clip application under RVP.

RESULTS

Twenty patients (mean age 51.6 years, range 28–66 years) were included in this study. Electrode positioning was easy in 19 (95%) of 20 patients, and removal of electrodes was easily accomplished in all patients (100%). No complications associated with the placement of the pacing electrodes occurred, such as cardiac perforation or cardiac tamponade. RVP was applied in 16 patients. The mean aneurysm size was 11.1 ± 5.5 mm (range 6–30 mm). RVP proved to be a very helpful tool in aneurysm preparation and clip application in 15 (94%) of 16 patients. RVP was used for a mean duration of 60 ± 25 seconds, a mean heart rate of 173 ± 23 bpm (range 150–210 bpm), and a reduction of mean arterial pressure to 35–55 mm Hg. RVP leads to softening of the aneurysm sac facilitating its mobilization, clip application, and closure of the clip blades. In 2 patients, cardiac events were documented that resolved without permanent sequelae in both. In every patient with successful RVP (n = 14) a total or near-total aneurysm occlusion was documented. In the 1 patient in whom the second RVP failed due to pacemaker electrode dislocation, additional temporary clipping was required to secure the aneurysm, but was not as sufficient as RVP. This led to an incomplete clipping of the aneurysm and finally a remnant on postoperative digital subtraction angiography. A pacemaker lead dislocation occurred in 3 (19%) of 16 patients, but intraoperative repositioning requires less than 20 seconds. Outcome was favorable in all patients according to the modified Rankin Scale.

CONCLUSIONS

To the best of the authors’ knowledge this is the first prospective interdisciplinary study of RVP use in patients with UIAs. RVP is an elegant technique that facilitates clip reconstruction in complex UIAs. The safety of the procedure is good. However, because this procedure requires extensive preoperative cardiological workup of the patient and an experienced neurosurgery and neuroanesthesiology team with much cerebrovascular expertise, actually it remains reserved for selected elective cases and highly specialized centers.

Clinical trial registration no.: NCT02766972 (clinicaltrials.gov)

A Case of High-dose Adenosine Usage for Anterior Communicating Artery Aneurysm Clip Ligation: What is the Dose Limit for a Resistant Response?

Intraoperative adenosine is used to induce asystole to facilitate clip ligation of intracranial aneurysms. Typically, 5–10 mg doses are used per administration and approximately 30 mg is used for a given case. An obvious concern with using adenosine is that the patient can remain in asystole or that prolonged hypotension can result in cerebral or cardiovascular ischemia. The upper limit of adenosine administration remains unclear. We present a case of a patient with a large anterior communicating artery aneurysm requiring large doses of adenosine, far exceeding previously reported cases. The patient received a 90 mg dose of adenosine to achieve 5 s of asystole as well as 30 s of hypotension that facilitated vessel dissection and clip application. Moreover, in order to successfully clip his aneurysm, he received a total of 744 mg of adenosine. After each administration of adenosine, his heart rate and blood pressure returned to baseline without the need for chest compressions or other interventions. He tolerated the procedure and had a good neurological outcome. This case is the first report of using such a high dose of adenosine in intracranial aneurysm surgery and suggests that more aggressive administration of adenosine during aneurysm clipping is feasible. Transient hypotension, as seen in this report, can provide surgeons the crucial moments they need to safely secure an aneurysm from circulation.

A new technique of in vivo synchrotron radiation coronary microangiography in the rat

BACKGROUND

Previously, in our laboratory, synchrotron radiation coronary microangiography (SRCA) using Langendorff-perfused rat hearts could visualize a coronary artery of 50 µm in diameter. However, in vivo rat SRCA poses the problem of compromised temporal resolution due to the rapid heart rate of rats.

PURPOSE

To establish a simple method of in vivo rat SRCA with bradycardia induced by intravenous injection of adenosine triphosphate disodium hydrate (ATP).

MATERIAL AND METHODS

SRCA was performed at the Photon Factory of the High Energy Accelerator Research Organization (Tsukuba, Japan). Eight male Wistar rats were anesthetized. A catheter for injecting the contrast material was inserted into the carotid artery. Temporary bradycardia was induced by an intravenous bolus injection of 5 mg of ATP, and SRCA was performed immediately thereafter.

RESULTS

After ATP administration, the average heart rate decreased from 388 to 73 beats per minute. As a result, we could detect a coronary artery as small as 45 µm in diameter.

CONCLUSION

Our SRCA system which has a high resolution of 9 µm per pixel could detect a coronary artery as small as 45 µm in diameter in the in vivo rat.

Finger-Thumb Technique for Elephant Trunk Retrieval

In this report we present a brief video illustrating the "Finger-Thumb Technique" that we have used extensively at our institution for elephant trunk retrieval during second stage elephant trunk procedures. Although only safe in experienced hands, this technique is a viable option in the arsenal of a cardiothoracic surgeon, especially in cases when proximally surrounding a massively enlarged aorta is unappealing.

Endovascular approaches and perioperative considerations in acute aortic dissection

Aortic dissections remain complicated management issues both in the acute setting and in the chronic setting. Acute problems revolve around malperfusion syndromes or rupture, whereas chronic issues progress from the development of aneurysms in the residual dissected aorta. Endovascular approaches to dealing with these difficult situations are being used more frequently to treat acute issues in type B dissections and prevent secondary complications in type A dissections that may require significant intervention in the future. This article discusses the endovascular approaches employed in the care of acute dissections with particular attention toward the anesthetic considerations involved in these challenging cases.

Intra-arterial mitoxantrone delivery in rabbits: an optical pharmacokinetic study

BACKGROUND

Several human studies have demonstrated the feasibility of intra-arterial delivery of mitoxantrone in systemic malignancies. Computational models predict that an intra-arterial bolus injection of mitoxantrone during transient cerebral hypoperfusion will enhance brain tissue drug deposition in comparison with injections during normal blood flow.

OBJECTIVE

To assess whether transient reduction in cerebral blood flow would enhance the delivery of mitoxantrone. This is accomplished by obtaining real-time measurements of mitoxantrone concentrations in brain tissues by using a novel optical pharmacokinetics technique, based on reflectance spectroscopy.

METHODS

The blood-brain barrier of anesthetized rabbits was disrupted by intracarotid injection of mannitol (8 mL, 25% over 40 seconds). Thereafter, animals received 3 mg of mitoxantrone injection during normal perfusion (n = 5) or cerebral hypoperfusion that was induced by contralateral arterial occlusion and systemic hypotension (n = 8).

RESULTS

Cerebral hypoperfusion significantly decreased the cerebral blood flow, allowing a longer exposure time of the drug. It was determined that therapeutic concentrations of mitoxantrone were achieved in both groups; however, hypoperfusion did not increase the tissue concentrations of mitoxantrone after 20 minutes.

CONCLUSION

These results demonstrate the effective delivery of mitoxantrone by the intra-arterial route, after blood-brain-barrier disruption, but the predicted benefits of flow reduction for improving intra-arterial deposition of mitoxantrone was not evident.

Endovascular repair of thoracic aortic injury: current thoughts and technical considerations

Thoracic aortic traumatic injury is a highly morbid event. Mortality and paraplegia rates after emergent open repair remain high. Now, however, thoracic aortic endografting for trauma (TAET) is commonly used. It is appealing due to reduction of operative stress for the multiply injured trauma victim. This minimizing of stress and risk is secondary to avoidance of thoracotomy, single-lung ventilation, aortic cross-clamping, and the more complex anesthetic techniques required. Early and midterm results from TAET delineate improved outcomes, yet access and aortic constraints continue to challenge TAET. Questions regarding longer-term durability of endografts in younger patients remain unanswered. Broader application of TAET within endovascular programs is challenged by appropriate imaging, operating suite inventories, and the logistics and personnel required for TAET. Currently developed thoracic endograft devices are not ideal for TAET due to platform size and graft diameter. This is changing, however, as new modifications have been developed and trials are ongoing. In light of these collective factors, the management paradigm for traumatic aortic injury is beginning to favor TAET.

Transient Adenosine-Induced Asystole During the Surgical Treatment of Anterior Circulation Cerebral Aneurysms: Technical Note

BACKGROUND:

Transient adenosine-induced asystole is a reliable method for producing a short period of relative hypotension during surgical and endovascular procedures. Although the technique has been described in the endovascular treatment of brain arteriovenous malformations, aortic aneurysms, and posterior circulation cerebral aneurysms, little description of its use in anterior circulation aneurysms is available.

OBJECTIVE:

To assess the benefits of adenosine-induced transient asystole in complex anterior circulation aneurysms, to describe our experience in selected cases, and to provide the first experience of the use of adenosine in anterior circulation aneurysms.

METHODS:

The adenosine-induced cardiac arrest protocol allows us to titrate the duration of cardiac arrest on the basis of individual patient responses. The operative setup is the same as with all aneurysm clippings, with the addition of the placement of transcutaneous pacemakers as a precaution for prolonged bradycardia or asystole. Escalating doses of adenosine are given to determine the approximate dose that results in 30 seconds of asystole. When requested by the surgeon, the dose of adenosine is administered for definitive dissection and clipping. We present 6 cases in which this technique was used.

RESULTS:

The use of transient adenosine-induced asystole provided excellent circumferential visualization of the aneurysm neck and safe clip application. All patients did well neurologically and suffered no evidence of perioperative cerebral ischemia or delayed complication from the use of adenosine itself.

CONCLUSION:

Transient adenosine-induced asystole is a safe and effective technique in select circumstances that may aid in safe and effective aneurysm clipping. Along with the traditional techniques of brain relaxation, skull base approaches, and temporary clipping, adenosine-induced asystole facilitates circumferential visualization of the aneurysm neck and is another technique available to cerebrovascular surgeons.

Adenosine: an old drug newly discovered

Over decades, anesthesiologists have used intravenous adenosine as mainstay therapy for diagnosing or treating supraventricular tachycardia in the perioperative setting. More recently, specific adenosine receptor therapeutics or gene-targeted mice deficient in extracellular adenosine production or individual adenosine receptors became available. These models enabled physicians and scientists to learn more about the biologic functions of extracellular nucleotide metabolism and adenosine signaling. Such functions include specific signaling effects through adenosine receptors expressed by many mammalian tissues; for example, vascular endothelia, myocytes, hepatocytes, intestinal epithelia, or immune cells. At present, pharmacological approaches to modulate extracellular adenosine signaling are evaluated for their potential use in perioperative medicine, including attenuation of acute lung injury; renal, intestinal, hepatic and myocardial ischemia; or vascular leakage. If these laboratory studies can be translated into clinical practice, adenosine receptor-based therapeutics may become an integral pharmacological component of daily anesthesiology practice.

Adenosine-induced Cardiac Standstill to Facilitate Endovascular Embolisation of Cerebral Arteriovenous Malformations in Children

This report describes three children, aged eight to 11 years, with high-flow cerebral arteriovenous malformations who underwent interventional neuroradiological procedures involving glue (N-butyl cyanoacrylate) embolisation under general anaesthesia. The procedure was facilitated by relative hypotension induced by esmolol infusion and intravenous adenosine boluses. To allow controlled deposition of N-butyl cyanoacrylate into the arteriovenous malformations, glue injection was synchronised with the onset of adenosine-induced brief cardiac standstill. This resulted in satisfactory obliteration of the arteriovenous malformations nidus in all cases. The haemodynamic modulations, including the adenosine-induced brief cardiac standstill, was noted to not affect the BIS values in our patients. All patients had satisfactory obliteration of their arteriovenous malformations and had good neurological outcomes at one-year follow-up.

Vascular clamp-assisted clipping of thick-walled giant aneurysms

OBJECTIVE

The prognosis of giant aneurysms remains poor despite recent advances in microneurosurgery. Thick-walled and partially calcified giant aneurysms with an atheromatic base are difficult to clip safely. Special techniques allowing reshaping of the base and ensuring the stability of clips are often needed. We present our experience with direct clipping of thick-walled giant aneurysms with the aid of the DeBakey cardiovascular clamp (Aesculap, Tuttlingen, Germany).

METHODS

Eighty-two patients with a giant aneurysm (>/=25 mm) were treated actively at the Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland, between 1997 and 2007. The vascular clamp technique was used in 8 of 50 patients in whom direct clipping was performed. The remaining patients were treated with bypass and trapping, trapping only, proximal occlusion, coiling, or explorative surgery.

RESULTS

The vascular clamp (DeBakey in 5 cases, Crile forceps [Medicon Medizin-Technik, Tuttlingen, Germany] in 2 cases, and Halsted-Mosquito forceps [Medicon Medizin-Technik, Tuttlingen, Germany] in 1 case) was used in 7 saccular middle cerebral artery aneurysms and 1 fusiform basilar bifurcation aneurysm. Two patients had postoperative infarctions, 1 attributable to occlusion of perforators by a clip and the other caused by clips sliding down the calcified base, occluding a major branch. Six patients had no neurological sequelae, 1 patient had transient upper limb paresis, and the patient with the occluded major branch died.

CONCLUSION

The DeBakey vascular clamp is helpful in assisting direct clipping of thick-walled giant aneurysms with a partially calcified atheromatic base. Some practical features of this instrument require further refinement.

Monitoring the quality of cardiopulmonary resuscitation

PURPOSE OF REVIEW

Numerous recent reports have described limitations in the quality of cardiopulmonary resuscitation. Thus, there has been increasing interest in the techniques available to monitor quality. This review focuses on the major publications since the review published by the International Liaison Committee on Resuscitation in 2005. Some key articles published prior to this time period have also been included.

RECENT FINDINGS

A number of devices can monitor various components of the quality of cardiopulmonary resuscitation. End-tidal CO2 measurement assists in confirming placement of endotracheal tubes, correlates with cardiac output and detects the return of spontaneous circulation. Turbine flow-meters monitor respiratory rate and tidal volume. Transthoracic impedance monitoring measures respiratory rate, and may assist in confirmation of endotracheal tube placement. A new mechanical device (CPREzy) and a new defibrillator/monitor allow estimation of depth (and rate) of compressions. Ventricular-fibrillation waveform analysis may facilitate better timing of defibrillation. Echocardiography detects conditions that may impair the quality of cardiopulmonary resuscitation.

SUMMARY

Many options are available to monitor the quality of cardiopulmonary resuscitation. Some have significant limitations, and others are only readily available in hospital. The use of the information from this more intensive monitoring promises to improve outcomes of cardiopulmonary resuscitation.

High-dose adenosine-induced asystole assisting accurate deployment of thoracic stent grafts in conscious patients

Adenosine has been used to induce asystole and assist deployment of endoluminal grafts. However, application of high-dose adenosine in conscious patients has not been described. In this prospective study, we administered high-dose adenosine in patients undergoing thoracic stent grafting. Asystole duration in relationship to the dosage of adenosine, safety, and side effect profiles was investigated. All patients who underwent thoracic stent grafting between 1998 and 2006 were the potential study subjects. They received monitored anesthesia care and local anesthesia unless contraindicated. Adenosine was given via rapid intravenous bolus immediately prior to the deployment of the stent graft. Every patient received a dose of 36 mg. If needed, a second dose of 18 mg was given. Duration of asystole was recorded after each administration. Patients' vital signs before and after administration were also documented. Side effect profiles were collected intra- and postoperatively. A total of 46 patients received adenosine (34 men, 12 women). Mean age was 60.4 +/- 17.5 years. American Society of Anesthesiologists scores were II in one patient (2%), III in six patients (13%), and IV in 39 patients (85%). Eighteen patients received a single dose of 36 mg adenosine, 15 were given a second dose of 18 mg, and 13 received nonstandard dosages. Asystole durations were 18.8 +/- 8.8 and 11.6 +/- 5.5 sec for 36 and 18 mg, respectively. Technical success was achieved in all cases. The differences achieved statistical significance (p = 0.0009). There were no severe cardiac or pulmonary complications. High-dose adenosine can be given safely in conscious patients. The dose-response was predictable and reproducible. The dosages used in our study induce sufficient duration of asystole, which ensured accurate deployment of thoracic stent grafts.