Haemodynamic changes after intracisternal papaverine instillation during intracranial aneurysmal surgery

Intraoperative cerebral angiography reveals microsurgically occult sequelae of temporary clip application during elective cerebral aneurysm surgery

BACKGROUND

Temporary clipping (TC) is an essential adjunct in cerebral aneurysm (CA) surgery. Despite appearing insignificant to the surgeon under the microscope, TC may cause parent vessel injury. Intraoperative diagnostic cerebral angiography (ioDCA) is crucial for assessing aneurysm occlusion and parent vessel integrity. We aimed to assess sequelae of TC evident on immediate ioDCA.

METHODS

Elective CA clippings with ioDCA in a hybrid operating room from January 2020 to June 2023 were reviewed. Microsurgical and angiographic assessments were performed to identify post-TC parent vessel alterations. Outcomes were compared between TC and non-TC-groups.

RESULTS

Collectively, 107 patients underwent 111 craniotomies for clipping of 127 CAs. TC was used in 59/111 cases (53.2%) for treatment of 66/127 CAs (51.9%). CA size and neck were significantly larger in the TC group than in the non-TC group (p<0.001). Parent vessel vasospasm at the site of the previous temporary clip location was evident on 3D rotational angiography in 12/59 (20.3%) TC cases. Clip adjustment rates after ioDCA were similar between groups (TC 13.6% vs non-TC 8.2%, p=0.328). In the TC group compared with the non-TC group, the rates of symptomatic radiographic ischemia and functional decline at discharge were significantly higher (p=0.022 and p=0.045, respectively). However, functional status at follow-up was comparable (p=0.620).

CONCLUSIONS

TC during CA surgery can cause significant yet microsurgically occult vasospasm in the parent vessel, potentially contributing to symptomatic ischemia and early functional decline. Intraoperative angiography is crucial for detecting this issue, highlighting both its importance and the risks associated with TC.

Symptomatic cerebral vasospasm in the setting of carmustine wafer placement for glioblastoma: A case presentation and review of literature

Background:

Gliadel placement in glioblastoma resection, particularly with concurrent chemoradiation, has demonstrated an improvement in survival. There have been several reported adverse effects, some of which lend to significantly increased morbidity and mortality. With only two other cases described in literature, cerebral vasospasm secondary to carmustine-impregnated wafers is an extremely rare side effect.

Case Description:

We report the case of a 51-year-old female who presented with the left lower limb paresis 8 days after high-grade glioma resection provoked by carmustine wafer placement.

Conclusion:

We urge surgeons to reconsider placement of carmustine wafers in nations where the surgical resection cavity includes exposed large cerebral vasculature. We also propose the early identification of this devastating complication in the postoperative period by maintaining a high clinical suspicion and prompt utilization of computed tomography and digital subtraction angiography in the management and treatment of these patients accordingly.

Prolonged Intracisternal Papaverine Toxicity: Index Case Description and Proposed Mechanism of Action

BACKGROUND

Intracisternal papaverine (iPPV) is a vasodilator used for prophylaxis of intraoperative vasospasm during aneurysmal clipping. Postoperative side effects of iPPV include transient cranial nerve palsies, most commonly mydriasis owing to oculomotor nerve involvement, with rapid resolution.

METHODS

We critically reviewed current literature on the adverse effects of iPPV in aneurysmal surgery with a focus on oculomotor nerve involvement. We also present the index case of prolonged bilateral mydriasis secondary to iPPV irrigation toxicity and its putative underlying mechanism.

RESULTS

Papaverine toxicity occurs in the setting of its antimuscarinic action and blood-cerebrospinal fluid and blood-brain barrier compromise owing to acute subarachnoid hemorrhage and direct effect of papaverine. Our patient also experienced severe vasospasm and a minor stroke, both contributing to further blood-brain barrier disruption, and relatively acidic pH of the subarachnoid hemorrhage milieu.

CONCLUSIONS

We propose that these factors perpetuate phase dynamics of papaverine crystals and facilitate a sustained slow release of papaverine within the cisternal system. Were it indicated, 0.3% iPPV would reasonably diminish the risk for neurotoxicity.

Transient pupillary dilation following local papaverine application in intracranial aneurysm surgery

Isolated cases of transient pupillary changes after local intracisternal papaverine administration during aneurysm surgery have been reported. This study aimed to determine the prevalence and factors associated with this phenomenon. We assessed a total of 103 consecutive patients who underwent craniotomy for cerebral aneurysm clipping for the presence of postoperative pupillary dilation (mydriasis) after intracisternal papaverine administration. Univariate and multivariate logistic regression were conducted to evaluate the association of mydriasis with patient age, sex, duration of surgery, and aneurysm location. We observed either ipsilateral or bilateral pupillary dilation in the immediate postoperative period in nine out of 103 patients (8.7%). This phenomenon was not associated with patient age or sex. There was a trend towards positive correlation with aneurysms located at the anterior communicating artery (odds ratio 3.76, p=0.10), and a negative correlation with the duration of surgery (odds ratio 0.57, p=0.08). All pupillary dilation resolved within several hours, and the onset and resolution were consistent with the half-life of papaverine. To our knowledge, this represents the largest study of posteropative pupillary changes due to papaverine. The current findings are consistent with the small number of prior case reports of transient pupillary changes after papaverine administration and appear to reflect the local anesthetic action of papaverine on the oculomotor nerve.

The effect of irrigation of intracisternal papaverine on cerebral blood flow in subarachnoid hemorrhage

BACKGROUND

Despite different treatments, cerebral vasospasm is still the most important cause of death in patients after subarachnoid hemorrhage. This study was conducted to explore the effect of intracisternal washing with papaverine on cerebral blood flow.

MATERIALS AND METHODS

This study was performed on 40 patients and totally 120 arteries in 2010. Then, variations in cerebral blood flow before and after washing with papaverine were measured and analyzed.

RESULTS

Twenty (20) patients with aneurysm of the anterior communicating artery (ACOM) and 20 patients with aneurysm of the middle cerebral artery (MCA) were assessed. Mean blood flow before aneurysm and before washing in ACOM and MCA was 70.68 ± 14.8 cm/s and 65.66 ± 9.3 cm/s, respectively, which reached 23.25 ± 5.17 cm/s and 34.1 ± 4.7 cm/s, respectively after washing (P value = 0.016 and 0.024). Mean blood flow after aneurysm and before washing in ACOM and MCA was 95.12 ± 13.9 cm/s and 67.44 ± 15.16 cm/s, respectively, which reached 35.69 ± 6.2 cm/s and 38.01 ± 8.28 cm/s, respectively after washing (P value = 0.001 and 0.01).

CONCLUSION

Washing with papaverine significantly reduces cerebral blood flow and relieves vasospasm.

Transient bilateral brainstem dysfunction caused by topical administration of papaverine

Papaverine has been associated with transient cranial nerve dysfunction after topical application during craniotomy. The authors report similar dysfunction after the use of papaverine affected brainstem structures. Two patients undergoing craniotomy for clipping of an aneurysm experienced bilateral depression of cortical somatosensory evoked potentials to both median and tibial nerve stimulation after administration of papaverine. Arterial blood gas analysis, hemodynamic parameters, and anesthetic levels remained constant throughout these somatosensory evoked potential changes. In addition, intraoperative angiography and immediate postoperative CT imaging showed intact blood flow with complete exclusion of the aneurysm. Both patients recovered within 1-2 hours and had normal neurological examination findings after extubation. Topical papaverine use may be associated with direct effects on brainstem structures. The transient nature of those changes suggests that aggressive intervention may not be needed. Maneuvers to limit the spread of papaverine to basal cisterns should be considered.

Cardiac arrest after intracisternal papaverine instillation during intracranial aneurysm surgery. Case report

Cerebral vasospasm induced by aneurysmal subarachnoid hemorrhage is still a leading cause of morbidity and death. This 50-year-old man underwent surgery for aneurysm clipping. After the aneurysm was clipped, papaverine was instilled into the surgical area. Bradycardia, hypotension, and sinus arrest developed in the first minute after applying the papaverine. Thus, the authors concluded that the application of papaverine to the surgical area can result in fatal bradycardia and hypotension.

Osmotic-driven release of papaverine hydrochloride from novel poly(decane-co-tricarballylate) elastomeric matrices

Background: We have recently reported on the synthesis, characterization and biocompatibility of a novel family of visible-light photocrosslinked poly(diol-co-tricarballylate) elastomers intended for use in drug delivery and tissue engineering applications. In this work, the osmotic-driven controlled release of the water-soluble drug, papaverine hydrochloride, from poly(decane-co-tricarballylate) elastomeric cylindrical monoliths is reported. We also examined the influence of various parameters such as the degree of prepolymer acrylation, crosslinking density and the incorporation of osmotic excipients such as trehalose on the release kinetics of the drug. Results: The release rate of papaverine hydrochloride was found to decrease in dissolution media of higher osmotic activity as an indication of the predominant involvement of the osmotic-driven release mechanism from the elastomeric devices. The drug release rate was also found to be dependent on the degree of macromer acrylation. Furthermore, it was found that coformulating papaverine hydrochloride with trehalose increases the release rate without altering the linear nature of the drug release kinetics. Conclusions: A new delivery vehicle composed of biodegradable poly(decane-co-tricarballylate) elastomers was demonstrated to be a promising and effective matrix for linear, constant and controllable osmotic-driven release of drugs.

Evidence-based pharmacotherapy for cerebral vasospasm

INTRODUCTION

The vast amount of literature on the pharmaceutical treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage remains daunting. Optimal treatment regimens for patients can be obscured by studies not statistically powered to draw evidenced-based conclusions.

METHODS

In this chapter, we reviewed the English literature using the National Library of Medicine for studies regarding pharmacotherapies for the treatment of cerebral vasospasm. These studies were then categorized according to the US Preventative Services Task Force ranking system for evidence based medicine and reviewed each pharmacotherapy for its efficacy in the treatment of cerebral vasospasm.

RESULTS

Nimodipine (Nimotop), HMG Co-A reductase inhibitor (statins) and enoxaparin (Lovenox) were the only drugs with level-1 evidence available for the treatment of vasospasm from aneurysmal subarachnoid hemorrhage as defined by the US Preventative Services Task Force.

CONCLUSION

As the understanding of the pathophysiological mechanisms of vasospasm after aneurysmal subarachnoid hemorrhage evolves in the basic science laboratory, novel medications are being trialed in humans. However, significantly more work must be carried out in this area before we have an effective medical treatment that can prevent or reverse the devastating events of cerebral vasospasm.

Adverse effects of topical papaverine on auditory nerve function

BACKGROUND

Papaverine hydrochloride is a direct-acting vasodilator used to manage vasospasm during various neurosurgical operations. Transient cranial nerve dysfunction has been described in a few cases with topical papaverine. This study supports previous reports and provides neurophysiological evidence of an adverse effect on the auditory nerve.

METHODS

We conducted a retrospective review of 70 consecutive microvascular decompression operations and studied those patients who received topical papaverine for vasospasm. Topical papaverine was used as a direct therapeutic action to manage vasospasm in a total of 11 patients. The timing of papaverine application and ongoing operative events was reviewed relative to changes in neurophysiological recordings. Brainstem auditory evoked potentials (BAEPs) were routinely used to monitor cochlear nerve function during these operations.

FINDINGS

A temporal relationship was found between topical papaverine and BAEP changes leading to complete waveform loss. The average temporal delay between papaverine and the onset of an adverse BAEP change was 5 min. In 10 of 11 patients, BAEP waves II/III-V completely disappeared within 2 to 25 min after papaverine. Eight of these 10 patients had complete loss of BAEP waveforms within 10 min. One patient showed no recovery of later waves and a delayed profound sensorineural hearing loss. The average recovery time of BAEP waveforms to pre-papaverine baseline values was 39 min.

CONCLUSIONS

Topical papaverine for the treatment of vasospasm was associated with the onset of a transient disturbance in neurophysiological function of the ascending auditory brainstem pathway. The complete disappearance of BAEP waveforms with a consistent temporal delay suggests a possible adverse effect on the proximal eighth nerve. Recommendations to avoid potential cranial nerve deficits from papaverine are provided.

Aneurysmal subarachnoid haemorrhage and the anaesthetist

The anaesthetist may be involved at various stages in the management of subarachnoid haemorrhage (SAH). Thus, familiarity with epidemiological, pathophysiological, diagnostic, and therapeutic issues is as important as detailed knowledge of the optimal intraoperative anaesthetic management. As the prognosis of SAH remains poor, prompt diagnosis and appropriate treatment are essential, because early treatment may improve outcome. It is, therefore, important to rule out SAH as soon as possible in all patients complaining of sudden onset of severe headache lasting for longer than an hour with no alternative explanation. The three main predictors of mortality and dependence are impaired level of consciousness on admission, advanced age, and a large volume of blood on initial cranial computed tomography. The major complications of SAH include re-bleeding, cerebral vasospasm leading to immediate and delayed cerebral ischaemia, hydrocephalus, cardiopulmonary dysfunction, and electrolyte disturbances. Prophylaxis and therapy of cerebral vasospasm include maintenance of cerebral perfusion pressure (CPP) and normovolaemia, administration of nimodipine, triple-H therapy, balloon angioplasty, and intra-arterial papaverine. Occlusion of the aneurysm after SAH is usually attempted surgically ('clipping') or endovascularly by detachable coils ('coiling'). The need for an adequate CPP (for the prevention of cerebral ischaemia and cerebral vasospasm) must be balanced against the need for a low transmural pressure gradient of the aneurysm (for the prevention of rupture of the aneurysm). Effective measures to prevent or attenuate increases in intracranial pressure, brain swelling, and cerebral vasospasm throughout all phases of anaesthesia are prerequisite for optimal outcome.