End-to-end revascularization between the occipital Artery(OA) and the p1 segment of posterior inferior cerebellar Artery(PICA) for a patient with posterior circulation ischemia via a far-lateral approach:2-Dimensional Operative video

Vertebral artery （VA）Aneurysms involving the origin of the posterior inferior cerebellar artery (PICA) ,occasionally, induce cerebellum and brainstem infarction due to intraluminal thrombus and calcific VA stenosis. At times, vessel occlusion and revascularization is necessary for successful obliteration of these aneurysms.2 The occipital artery (OA) is often the preferred donor graft for lesions of the posterior fossa. Although most OA-PICA bypasses can be performed using the p3 segment as the recipient site for an end-to-side anastomosis, a more feasible alternative to conventional OA-p3 PICA bypass in cases of high-riding caudal loops , aberrant anatomy or p3 multiple perforators is to free the p1 PICA, transpose it away from the lower cranial nerves, and perform an end-to-end OA-p1 PICA bypass instead. This video captures the dissection of the OA using an orientational anterograde harvesting technique and the end-to-end anastomosis of the OA to the PICA at the p1 segment. This was performed in a 56-year-old man who presented with posterior circulation ischemia from a fusiform aneurysm with calcific vertebral artery stenosis located at the origin of the right PICA. The patient tolerated the procedure well and suffered no major complications related to the operation. He did experience some mild, posterior neck rigidity at the time of his 6-month follow-up, likely due to nerve injury that occurred while harvesting the OA. Overall, the patient remains in good neurologic status 1 year after the operation. The operation proved the feasibility of end-to-end bypass in OA-p1 PICA.

Bypass Surgery for Vertebral Artery and Posterior Inferior Cerebellar Artery Fusiform Aneurysms: Surgical Technique and Key Lessons

Fusiform vertebral artery (VA) aneurysms are challenging to treat due to their pathophysiology, morphology, and anatomic location.1,2 Endovascular treatments are considered to be a widely adopted safe option for this pathology.1 Open microsurgical treatment is considered for complex anatomy, important branch involvement, poor collateral flow, or failed endovascular therapy.3-7 This report aims to show the flow-replacement strategy and bypass technique for a VA aneurysm with complex anatomy and branch involvement. A 24-year-old man presented to our clinic with a bilateral fusiform VA aneurysm discovered during workup of progressive headaches. Further investigation revealed that the left-side aneurysm was mostly thrombosed and the posterior inferior cerebellar artery arose from the aneurysm dome with a fusiform enlargement within a few millimeters from the branching point. After evaluating all management options, the patient decided on surgical treatment of the left VA aneurysm. We performed an occipital artery to posterior inferior cerebellar artery end-to-side anastomosis distal to the fusiform enlargement, followed by trapping of the aneurysm and dome resection (Video 1). Antegrade flow to the distal VA was reestablished using a radial artery interposition graft, thus preventing any flow alterations that may cause growth or rupture of the contralateral aneurysm caused by increased hemodynamic stress if the ipsilateral VA flow is not preserved.8 After in-hospital physical rehabilitation, the patient was discharged with a modified Rankin Scale score of 1. The contralateral aneurysm is managed with serial imaging and treatment will ensue if there is clinical-radiologic evolution. The patient consented to the procedure and publication of his image.

Prevalence of anatomical variations at the suboccipital (V3) segment of the vertebral artery: a systematic review

BACKGROUND AND OBJECTIVE

A recent meta-analysis on the incidence of iatrogenic injury to the VA has revealed that patients with variant anatomy are more prone to iatrogenic injury. Therefore, this review is designed to investigate the incidence of variations in the suboccipital component of the vertebral artery in different population groups according to the available literature.

METHODS

This systematic review was conducted according to PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The review is based on a comprehensive and extensive search of PubMed, Google Scholar, and ResearchGate. The following search terms were used: "vertebral artery" AND "suboccipital segment" AND "anomalies/anatomical variations of the V3 segment." Reference lists of all extracted articles were also extensively searched for references to any further relevant publications.

RESULTS

A total of 17 papers met the inclusion criteria. The 17 studies corresponded to a total of 10,820 patients. A persistent first intersegmental artery was registered in 1.8% (197 out of 10,820) of the patients. Extradural PICA origin was observed in 1.6% (175 out of 10,820) of the patients. Fenestration was detected in 0.7% (72 out of 10,820) of the patients.

CONCLUSION

The authors summarize the incidence of vascular variation at the suboccipital segment of the VA in different population groups across the Asian, European, American, and African continents. Awareness of the extent of possible anatomical variation will help interpret radiographs, which will enhance the identification of vascular pathologies and reduce the risk of iatrogenic injury.

Treatment of Intracranial Vertebral Artery Dissecting Aneurysms Using Pipeline Embolization Devices : A Multicenter Cohort Study

PURPOSE

Intracranial vertebral artery dissecting aneurysm (IVADA) is a rare type of aneurysm with high morbidity and mortality. Recently, the application of pipeline embolization devices (PEDs) has been extended to IVADAs. Here, we aim to investigate the safety and effectiveness of PEDs for IVADAs.

METHOD

We retrospectively reviewed the PLUS database to identify patients who had IVADAs and were treated with PEDs from 2014 to 2019 at 14 centers across China. Data including patient and aneurysm characteristics, procedure details, angiographic and clinical results, relationship with the ipsilateral posterior inferior cerebellar artery (PICA), and patency of the PICA following PED coverage were analyzed.

RESULTS

In this study 52 consecutive patients with 52 IVADAs were included. The mean age was 52.33 years and 82.7% were male. With a median follow-up of 10.5 months, the complete occlusion rate was 93.8% (45/48) and no recurrence or in-stent stenosis was detected. The total postoperative complication rate and mortality were 11.5% and 1.9%, respectively. Complications occurred in 9.6% (5/52) of patients within 30 days after the operation, including ischemic stroke in 3 and hemorrhagic stroke in 2. Another patient suffered an ischemic stroke at follow-up, 78.8% (41/52) PICAs were covered by PEDs, 1 case (2.4%) had a functional disability due to PICA occlusion, while 39.0% (16/41) had reduced flow during follow-up but hardly caused any obvious neurological deficits. Patients with IVADA involving PICA had a trend towards more complications (66.7% vs. 51.1%; P = 1).

CONCLUSION

Treating IVADAs with PEDs may be a safe and effective option, with favorable clinical and angiographic outcomes; however, complications associated with this treatment should not be ignored.

REGISTRATION

http://www.

CLINICALTRIALS

gov . Unique identifier: NCT03831672.

Occipital artery-to-PICA bypass: how I do it

BACKGROUND

Posterior inferior cerebellar artery (PICA) aneurysms are uncommon, and their management is challenging because of the complex angioarchitecture of the PICA and the frequently nonsaccular aneurysm presentation. Endovascular therapy may not be feasible.

METHODS

We describe our technique of clip trapping with occipital artery (OA)-to-PICA bypass to treat a PICA aneurysm. Because the aneurysm affected the ipsilateral, dominant PICA, an OA-PICA bypass was chosen to ensure adequate flow and reduce risk to the contralateral PICA supply.

CONCLUSION

The OA-PICA anastomosis is a safe and effective method to successfully achieve flow preservation with bypass reconstruction and aneurysm trapping.

A posterior inferior cerebellar artery of C2 transverse foramen level origin that entered the spinal canal via the C1/2 intervertebral space demonstrated by computed tomography angiography

PURPOSE

To describe a case of a posterior inferior cerebellar artery (PICA) of C2 transverse foramen level vertebral artery (VA) origin that entered the spinal canal via the C1/2 intervertebral space.

CASE REPORT

A 48-year-old man with posterior neck pain underwent computed tomography (CT) angiography and selective left vertebral angiography. Arterial dissection was found at the distal V2 segment of the left VA on subtracted CT angiography. The left PICA arising from the VA at the level of C2 transverse foramen was identified on CT angiography with bone imaging. This PICA of extracranial origin entered the spinal canal via the C1/2 intervertebral space, just like a PICA of C1/2 level origin.

DISCUSSION

The origins of PICAs show several variations. PICAs originating at the extracranial C1/2 level VA are relatively rare, with a reported prevalence of approximately 1%. Our patient had a left PICA arising from the VA at the level of the C2 transverse foramen. No similar cases have been reported in the relevant English-language literature. We speculated that the proximal short segment of the PICA arising from the C1/2 level VA regressed incidentally and that the distal segment of the PICA was supplied by the muscular branch of the VA arising from the level of the C2 transverse foramen.

CONCLUSION

We reported the first case of PICA arising from the C2 transverse foramen level VA. CT angiography with bone imaging is useful for identifying a PICA arising from the extracranial VA.

Occipital artery-posterior inferior cerebellar artery bypass: a cadaveric feasibility study

PURPOSE

To demonstrate that occipital artery (OA)-p1 posterior inferior cerebellar artery (PICA) bypass can be an alternative for complex posterior circulation aneurysms.

METHODS

A far-lateral approach to craniotomy was performed on 20 cadaveric specimens, and the OA was obtained 'in-line.' Its length, diameter, and the number of p1/p2 and p3 segmental perforators were determined, and the relationship between the caudal loop and cerebellar tonsil position was also assessed. The distance between the PICA's origin and the cranial nerve XI (CN XI), the buffer length above the CN XI after dissection, the OA length required to complete the OA-p1/p3 PICA bypass, and the p1 and p3 segment diameters were all measured. A bypass training practical scale (TSIO) was used to evaluate the quality of the anastomosis.

RESULTS

All specimens underwent OA-p1 PICA end-to-end bypass and had favorable results for the TSIO score, 15 sides underwent OA-p3 PICA end-to-side bypass, and the other bypass protocols were less common. The buffer length above the CN XI after dissection, the distance between the PICA's origin and the CN XI, and the first perforator were all of sufficient length. The direct length of the OA needed to complete the OA-p1 PICA end-to-end bypass was significantly less than the available length and the OA-p3 PICA end-to-side bypass, with the OA matching the p1 segment diameter. The number of p1 perforators was less than that of p3, and the OA diameter was equal to that of the p1 segment.

CONCLUSION

OA-p1 PICA end-to-end bypass is a feasible alternative in cases in which p3 segment has high caudal loops or anatomic anomalies.

Microsurgical anatomical vascular study of the PICA-PICA bypass

OBJECTIVE

To assess the posterior inferior cerebellar artery (PICA)-PICA bypass possibility.

METHODS

Fifteen adult cadaver heads were used for surgical simulation, and the far-lateral approach was used to expose the surgical field. The bilateral PICA course, diameter, and perforators were observed and measured to evaluate the possibility of a PICA-PICA bypass.

RESULTS

The PICA-PICA bypass was performed in seven (46.7 %) of the 15 specimens; the procedure was performed easily in three specimens, a little difficult in two, and was difficult in two specimens because of the relationship between the tonsil and the short parallel length of the bilateral tonsillomedullary (p3) segment. In eight (53.3 %) of the 15 specimens, PICA-PICA bypass was not feasible for reasons including 1) the caliber of the bilateral p3 was unmatched for bypass, 2) the distance of bilateral p3 in the midline was > 7 mm, 3) the middle segment of p3 perforating direct arteries limited the buffer length, and 4) single caudal loops.

CONCLUSION

The possibility of PICA-PICA bypass was determined by the proximity of the bilateral p3, caliber match, and mobilization of the bilateral caudal loop due to the perforators. The difficulty of the PICA-PICA bypass mainly depends on the relationship between the cerebellar tonsil and the parallel length of the bilateral PICA in the midline.

Posterior inferior cerebellar artery originating from the posterior meningeal artery mimicking dural arteriovenous fistula

PURPOSE

Many variations in the origin of the posterior inferior cerebellar artery (PICA) have been reported. To our knowledge, only one case of a PICA originating from the posterior meningeal artery (PMA) has been reported.

METHODS

We describe a case with a PICA that was supplied retrograde from the distal segment of the PMA, mimicking a dural arteriovenous fistula on magnetic resonance angiography (MRA).

RESULTS

A 31-year-old man was admitted to our hospital with a sudden occipital headache and nausea. MRA showed a hyperplastic left PMA, continuing to an abnormal vessel that was suspicious for venous drainage. Digital subtraction angiography revealed the left PMA originated from the extradural segment of the vertebral artery and then connected to the left PICA near the torcula. The cortical segment of the PICA flowed retrograde, which appeared as venous reflux on MRA. A second PICA originated from the extradural segment of the left vertebral artery and perfused the tonsillomedullary and televelotonsillar segment of the left PICA territory.

CONCLUSION

We present an anatomical variant of the PICA mimicking a dural arteriovenous fistula. Digital subtraction angiography is useful for diagnosis of the cortical segment of the PICA flowing retrograde from the distal segment of the PMA because signal intensity in MRA of retrograde flow tends to decrease and diagnosis may be difficult. During endovascular treatment and open surgery, we should note that ischemic complications may occur due to the potential anastomosing channels between cerebral and dural arteries.

Hiccups before a Pulmonary Embolism Speak against This as a Cause

How to cite this article: Finsterer J. Hiccups before a Pulmonary Embolism Speak against This as a Cause. Indian J Crit Care Med 2023;27(3):228.

Midline Suboccipital Unilateral Trans-Cerebellomedullary Fissure Approach for Clipping of Ruptured VA-PICA Aneurysm: Two-Dimensional Operative Video

The vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm poses a technical challenge for microsurgical clipping due to its anatomical complexity, which requires dissection of lower cranial nerves. Endovascular treatment is regarded as a feasible first-line therapeutic option for VA-PICA aneurysm because it has an acceptable aneurysm occlusion rate and is less invasive. However, microsurgical clipping remains an effective treatment option. We present the case of a 62-year-old man who presented with subarachnoid hemorrhage (SAH) due to a ruptured VA-PICA aneurysm. Neuroradiologic examination revealed a 2-3 mm medially pointing left VA-PICA aneurysm with acute obstructive hydrocephalus due to massive SAH in the posterior cranial fossa. As the patient had acute obstructive hydrocephalus and a relatively small aneurysm, we selected clipping over endovascular treatment. Because the aneurysm was located close to the midline and anterolateral to the medulla oblongata, we approached it from the midline. A midline suboccipital craniotomy, C1 laminectomy, and drilling of the left condylar fossa were performed; a unilateral cerebellomedullary fissure opening was added; and the aneurysm was clipped. Postoperative neuroradiologic examinations revealed complete obliteration of the aneurysm. As shown in this video, unilateral cerebellomedullary fissure opening combined with adequate removal of the condylar fossa provides a wide operative field in the cerebellomedullary cistern while avoiding strong retraction of the cerebellum. We believe that this technique makes VA-PICA aneurysm clipping safe and successful. Patient consent was obtained to perform the surgery and to publish the surgical video (Video 1).

Acute dysphagia: A rare initial symptom of lateral medullary syndrome: A case report

Introduction and importance

A unique etiology of stroke, lateral medullary syndrome (LMS), is a consequence of posterior inferior cerebellar artery or vertebral artery thromboembolic conditions. LMS patients present particularly with ipsilateral hyperalgesia, ipsilateral ataxia, and Horner's syndrome. Our case signifies that neurogenic origin should always be considered in the absence of local causes of dysphagia. Early diagnosis could prevent LMS complications, including neurological disabilities. A scarcity of research related to dysphagia in LMS, and its outcomes exists. Therefore, the objective is to investigate the clinical course in a patient afflicted with severe dysphagia following a diagnosis of (LMS). This would encourage further research, thus improving management and treatment strategies.

Case presentation

We report a case of a 45-year-old male, a smoker for 20 years, who presented with a single, unique complaint of acute dysphagia for 9 days. According to our knowledge, this is among very few reported cases of LMS with dysphagia being the rare initial complaint. The neurological issues associated with dysphagia gradually improved with the administration of antiplatelet; clopidogrel and lipid-lowering drug; rosuvastatin and the patient was discharged. Atypical presentation in LMS could be supported by the presence of lateral medullary infarct which was confirmed by MRI (Magnetic Resonance Imaging).

Clinical discussion

Dysphagia is a common complaint in multiple gastrointestinal (GI) settings. However, in cases where the GI causes are excluded, as described here, diagnosis of LMS becomes tough.

Conclusion

The diagnosis of LMS was queried owing to the presentation of the single most important common symptom, with no other characteristic manifestations of LMS.

Common trunk anomaly of the anterior and posterior inferior cerebellar artery in hemifacial spasm

BACKGROUND

The common trunk anomaly of the anterior and posterior inferior cerebellar artery (APC) is a variant artery that causes a hemifacial spasm (HFS). The anatomical characteristics include a large diameter of the trunk and the existence of the bifurcation near the facial nerve root entry zone (REZ). Despite APC being encountered at a constant rate in microvascular decompression (MVD), the anatomical and technical issues of transposing APC have not been entirely focused on yet.

METHODS

We reviewed our 68 cases with APC involvement. Patient background, radiological findings, and operative video recordings were reviewed retrospectively. The location of the bifurcation of APC and the distribution of perforators were investigated. Surgical outcomes were assessed in the long term.

RESULTS

APC involvement was diagnosed preoperatively in all cases by careful observation with MRI. Three-dimensional images determined the anatomical characteristics of APC and depicted the relationship with the facial nerve. All patients had a bifurcation close to the root entry zone that was required to transpose, including the common trunk and the distal branches, to achieve sufficient decompression. While adequate transposition from the REZ was accomplished in most cases, it was difficult to complete transposition due to short perforators in 6 patients (8.8%), resulting in interposition. Fifty-three patients (77.9%) became spasm free immediately after surgery, 66 patients (97.1%) were after 6 months, and all patients (100%) became spasm free within a year. Spasm-free status was maintained during the follow-up period (4.7 years) in all patients except one in whom facial spasm recurred 2 years after the initial surgery.

CONCLUSIONS

Transposing the common trunk with the bifurcation and distal branches contributes to obtaining favorable surgical outcomes in APC-related HFS.

Comparison of Parent Artery Occlusion and Stent-Assisted Treatments in Ruptured Vertebral Artery Dissecting Aneurysms

OBJECTIVE

To assess clinical outcomes of ruptured vertebral artery dissecting aneurysms, focusing on comparing parent artery occlusion (PAO) with stent-assisted treatments, and to identify risk factors for unfavorable outcomes and postprocedural complications.

METHODS

This retrospective review included 36 ruptured vertebral artery dissecting aneurysms treated between February 2009 and April 2020. Treatment modalities included PAO without stent and stent-assisted treatments. Stent-assisted treatments included PAO with posterior inferior cerebellar artery (PICA) stenting and stent-assisted coiling. Univariate and multivariate analyses were conducted to evaluate risk factors for unfavorable outcomes and postprocedural complications.

RESULTS

Patients were treated with PAO only (24, 66.7%), PAO with PICA stenting (4, 11.1%), and PAO with stent-assisted coiling (8, 22.2%). There were only fusiform aneurysms with PICA involvement in the PAO with PICA stenting group. In the stent-assisted coiling group, 4 aneurysms incorporated PICA, and 4 aneurysms involved dominant vertebral artery. Old age (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.01-1.56, P = 0.044) and poor Hunt-Hess grade (OR = 537.99, 95% CI = 6.73-42994.1, P = 0.005) were significantly associated with unfavorable clinical outcomes after a mean follow-up of 37.5 ± 32.8 months. Fusiform dilatation shape (OR = 15.97, 95% CI = 1.52-167.38, P = 0.021) and PICA involvement (OR = 13.71, 95% CI = 1.29-145.89, P = 0.030) were independent risk factors for ischemic complications.

CONCLUSIONS

Unfavorable clinical outcomes were significantly related to old age and poor Hunt-Hess grade. There were no significant differences between treatment groups in clinical outcomes or ischemic complications. Stent-assisted treatments might be effective and safe methods for ruptured vertebral artery dissecting aneurysms.

Angioarchitecture of the Normal Lateral Spinal Artery and Craniocervical Junction Arteriovenous Fistula Using Contrast-enhanced Cone-beam CT

BACKGROUND AND PURPOSE

The lateral spinal artery (LSA) perfuses the dorsolateral part of the spinal cord at the craniocervical junction (CCJ). We analyzed the angioarchitecture of the normal LSA and CCJ arteriovenous fistula (AVF).

METHODS

The first study included 26 patients with a cerebral aneurysm of the posterior circulation. Using slab maximum intensity projection (MIP) images from three-dimensional rotational angiography (3D-RA) and contrast-enhanced cone-beam CT (CE-CBCT), we analyzed the origin of the LSA, its anastomosis with the posterior inferior cerebellar artery (PICA), the point where it reaches the spinal cord, and the visualized range. In the second study, we analyzed the angioarchitecture and treatment results of 7 CCJAVF lesions treated in our department between 2016 and 2021.

RESULTS

We visualized the normal LSA for all patients. In 23 patients with an intradural origin PICA, all LSAs originated from the C1 or C2 radicular artery, and 8 patients had an anastomosis with the PICA. In three patients with a C1 level origin PICA, all LSAs originated from the PICA. All LSAs reached the dorsolateral part of the spinal cord. The mean visualized range of the LSA was 27.4 mm. The LSA was involved in five of seven CCJAVF lesions (71%). There was one lesion with a spinal infarction after LSA embolization. Other lesions were treated by direct interruption of the AVF, and the ASA and LSA were preserved.

CONCLUSION

This is the first report that visualized the LSA's normal anatomy using slab MIP images from 3D-RA and CE-CBCT. Knowledge of LSA anatomy is critical to avoid complications during the treatment of CCJAVF.

Symptomatic ischemic complications following endovascular treatment of vertebral artery dissecting aneurysms

PURPOSE

The aim of this study is to investigate the clinical and radiological features related to the symptomatic ischemic complications of vertebral artery dissecting aneurysm (VADA) following endovascular treatment (EVT).

METHODS

The clinical and radiological features of 127 VADAs, which were treated in a single tertiary institute between September 2008 and December 2020, were retrospectively reviewed. We defined a thrombosed aneurysm as being one which the thrombus was in the aneurysm in magnetic resonance imaging (MRI). Symptomatic ischemic complication was defined as a case in which acute infarction was confirmed on diffusion weighted image after EVT with associated clinical symptoms. Univariate and multivariate analyses were executed to demonstrate the associations between symptomatic ischemic complication and characteristics of VADA.

RESULTS

The rate of symptomatic ischemic complication was 13.4% (17 of 127). The thrombosed aneurysms were observed in 24.4% (31 of 127) and posterior inferior cerebellar artery (PICA) involvement was shown in 38.6% (49 of 127). Multivariate logistic regression analysis demonstrated that thrombosed aneurysms (odds ratio [OR] = 8.54, 95% confidence interval [CI] 1.98-36.87, p = 0.004) and PICA involvement (OR = 4.26, 95% CI 1.03-17.68, p = 0.046) were significantly associated with symptomatic ischemic complications following EVT.

CONCLUSION

This study showed that the VADAs with intra-aneurysmal thrombose and PICA involvement may be independent risk factors for symptomatic ischemic complications following EVT. Therefore, when the thrombosed VADAs with PICA involvement are observed, practitioners may consider close postoperative monitoring for early detection of ischemic complications.

Surgical and Endovascular Treatment of Saccular Posterior Inferior Cerebellar Artery Aneurysms: Systematic Review and Meta-Analysis

OBJECTIVE

The optimal treatment modality for saccular aneurysms of the posterior inferior cerebellar artery (PICA) remains unclear. A previous meta-analysis on the topic included a heterogenous study population, limiting the conclusions that can be drawn from its results. The aim of this study was to perform a systematic review and meta-analysis to compare outcomes of microsurgical and endovascular treatment (EVT) of these aneurysms.

METHODS

A search of 4 online databases was performed for studies describing the management of saccular PICA aneurysms. The primary outcome was complete aneurysm occlusion. Data were also collected on neurologic outcomes, cranial nerve palsies, and requirement for re-treatment. A random effects model was used for calculation of pooled proportions. Our protocol was registered with PROSPERO (CRD42021232784).

RESULTS

A total of 17 studies were included in the final analysis, reporting the treatment outcomes of 455 aneurysms, with a mean follow-up of 20 months. The pooled occlusion rates were 94.8% (95% confidence interval [CI] 90.6%-97.8%) for surgical treatment and 69.1% (95% CI 55.0%-81.7%) for EVT. Pooled rates of good neurologic outcome (modified Rankin scale score ≤2, Glasgow Outcome Scale score ≥4) at last follow-up were 78.1% (95% CI 67.4%-87.1%) for surgery and 77.6% (95% CI 67.9%-86.0%) for EVT.

CONCLUSIONS

This meta-analysis demonstrates that in the treatment of saccular PICA aneurysms, microsurgical clipping results in superior angiographic outcomes, similar functional outcomes, but higher rates of lower cranial nerve palsy compared with EVT. Further studies are required to assess the duration and severity of cranial nerve palsies following surgical treatment, and long-term aneurysm occlusion and the requirement for re-intervention following EVT.

Occipital Artery-Posterior Inferior Cerebellar Artery (PICA) Bypass for the Treatment of a Ruptured Fusiform Aneurysm of the Left PICA: 2-Dimensional Operative Video

Posterior inferior cerebellar artery (PICA) aneurysms are usually complex to treat because of their deep location, frequent entanglement with the lower cranial nerves, the presence of perforating arteries to the brainstem, and their often dissecting or fusiform morphology.¹ These aneurysms can require revascularization of the PICA.² The length and size of the occipital artery (OA) make it an excellent donor.^3,4 Video 1 shows the technical nuances of an OA-PICA bypass for the treatment of a ruptured fusiform aneurysm of the left PICA. The patient is a 34-year-old male presenting with an abrupt headache and confusion (Hunt and Hess grade III and World Federation Neurology Surgeons grade II). Computed tomography of the brain revealed hydrocephalus and subarachnoid hemorrhage (Fisher IV) and digital subtraction angiography revealed a fusiform aneurysm on the tonsillomedullary segment of the left PICA. Given the dissecting nature of this aneurysm and the fact that it was ruptured, we felt it would be safer to be prepared to perform revascularization and to secure the aneurysm using an open surgical approach.⁵ There were no complications associated with this procedure. The patient remained neurologically intact, and imaging showed good flow through the bypass and no evidence of stroke. OA-PICA bypass is a useful strategy to treat ruptured fusiform PICA aneurysms since it avoids sacrificing the PICA and the use of dual-antiplatelet therapy. This video is one of the few videos published on OA-PICA bypass.^6,7 It explains the technical aspects, open and endovascular alternatives, and rationale for this procedure.

Microsurgical Treatment for a Ruptured Posterior Inferior Cerebellar Artery Aneurysm: A 3-Dimensional Surgical Video and Anatomic Landmarks Review

Aneurysms are the most frequent issue for the posterior inferior cerebellar artery (PICA). PICA aneurysms account for 1.4% to 4.5% of all intracranial aneurysms.^1-3 Although the majority of PICA aneurysms arise from their junction with the vertebral artery, they can be found in any of 5 segments.^4,5 Although PICA is more prone to form nonsaccular aneurysms than other intracranial arteries, ruptured aneurysms are usually saccular.⁶ Nearly all PICA aneurysms are located intracranially, above the foramen magnum. Extracranial PICA aneurysms are rare, with few reports in literature.⁷ Microsurgical clipping remains a good treatment alternative for these aneurysms. Higher risk of rerupture has even been reported with embolization of the distal PICA aneurysm with parent artery preservation.⁸ Here we present the case of a 64-year-old male patient who presented right after a thunderclap headache, followed by a temporary loss of consciousness and disorientation. He was diagnosed with a modified Fisher 4 and Hunt and Hess 2 subarachnoid hemorrhage and found to have a partially thrombosed left PICA saccular aneurysm of the caudal loop just below the foramen magnum. The lesion was approached via a midline suboccipital craniotomy with C1 laminectomy. Microsurgical clipping of the aneurysm was performed without any complications (Video 1). Postoperatively, the patient was discharged without neurologic deficits. We present the first surgical video of the necessary steps in order to perform a microsurgical clipping of an extracranially located caudal loop PICA aneurysm through a midline suboccipital craniotomy with C1 laminectomy.

Foramen Magnum Meningioma-The Attainment of the Intra-Arachnoidal Dissection: 2-Dimensional Operative Video

Ventral foramen magnum meningiomas are a forbidding lesion. The stake is so high with a risk of devastating paralysis and respiratory failure. Careful preoperative clinical and radiological evaluation is necessary to implement the best treatment plan. Successful surgical intervention depends on paying high attention to minute details throughout the case, from intratracheal intubation to extubation. The neural head-on-neck position is critical to avoid further medullary compression at intubation and positioning.1 Extensive neurophysiological monitoring, including somatosensory, motor, brainstem evoked potential, and cranial nerves, during the positioning and throughout the case, is extremely helpful to detect early signs of dysfunction.1 To expose and access ventral tumors, partial condyle resection and vertebral artery transposition are invaluable techniques.2,3 Preservation and minute manipulation of the vital neurovascular structures at this junction that includes the medullar, anterior spinal artery, posterior inferior cerebellar artery, vertebral junction perforators, and lower cranial nerves are essential for good outcomes. This is achieved by microsurgical intra-arachnoidal dissection under high magnification and after debulking the tumor to establish that plane.1,3,4 The demonstration of this technique is the purpose of this article. We demonstrate these surgical tenets applied to the resection of a large ventral foramen magnum meningioma extending from the midclivus to the C3 vertebral body level in a 54-yr-old female presenting with swallowing difficulties. The patient consented to the surgical intervention and the publication of her images. Image at 1:38 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.

Ruptured aneurysm arising at anterior spinal artery as the collateral circulation with bulbar artery supply to posterior inferior cerebellar artery treated by proximal occlusion and occipital artery-posterior inferior cerebellar artery bypass: a case report and literature review

The cases of aneurysms arising from collateral vessels that supply the posterior inferior cerebellar artery (PICA) are so exceptionally rare that there is no consensus on the optimal treatment. In this report, a patient was presented with subarachnoid hemorrhage caused by a fusiform aneurysm on the right anterior spinal artery, which formed an anastomosis network with bulbar artery and the vessels supplying to the right PICA. We chose to perform proximal occlusion on the anterior spinal and bulbar arteries, using occipital artery-PICA bypass. Our case was the first where proximal occlusion was used concurrently with vascular reconstruction to treat a ruptured aneurysm of collateral vessels supplying to PICA.

How I do it? Posterior inferior cerebellar artery-intracranial vertebral artery reimplantation bypass and trapping of dissecting aneurysm involving the proximal posterior inferior cerebellar artery

BACKGROUND

Proximal posterior inferior cerebellar artery (PICA) aneurysms are surgically challenging due to the high variability in the anatomy of the PICA origin, their deep-seated nature, and their entanglement with the lower cranial nerves. Direct or reconstructive clipping may not be achievable if the aneurysm is large, or dissecting, or exhibits atherosclerosis or calcification.

METHOD

We present a case of a proximal PICA lateral medullary segment (P2) aneurysm that was successfully cured by trapping the aneurysm and reconstructing the PICA using the PICA-intracranial vertebral artery (PICA-V4) via end-to-side reimplantation bypass with the far lateral approach.

CONCLUSION

This case demonstrates the feasibility and safety of PICA-V4 reimplantation bypass, especially if the origin of the PICA is highly seated and the intracranial VA, or V4 segment, is long enough and well-exposed supra or under hypoglossal nerves.

Occipital Artery -Posterior Inferior Cerebellar Artery Bypass Combined with Aneurysm Trapping for a Recurrent Ruptured Vertebral Artery-Posterior Inferior Cerebellar Artery Aneurysm: Two-Dimensional Operative Video

Vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm is challenging owing to its variable anatomy and interference of lower cranial nerves. A recurrent ruptured VA-PICA aneurysm was successfully treated by occipital (OA)-PICA bypass with aneurysm trapping (Video 1). Informed consent was obtained from the patient. A ruptured right VA aneurysm was found in a 47-year-old man and treated by endovascular treatment. Follow-up angiography at 1 month revealed aneurysm recurrence with migration of endovascular materials. The patient was placed in a park-bench position for the far-lateral approach. A J-shaped incision was used for craniotomy. A 1-piece myocutaneous flap was raised, and the OA was skeletonized in a distal-to-proximal fashion. After craniotomy, the VA-PICA aneurysm with endovascular material inside was located under the vagoaccessory triangle. The tonsillomedullary segment or P3 of the PICA was robust and long enough as the recipient candidate for anastomosis. A linear arteriotomy was performed on the recipient artery, and an end-to-side OA-PICA bypass was achieved. Occlusion of the aneurysm was achieved by placing permanent clips on the VA proximal and distal to the aneurysm and the PICA next to the aneurysm sac without occluding the perforator. The postoperative course was uneventful with bypass patency. We believe this case demonstrates the surgical tenet of OA-PICA bypass for VA-PICA aneurysm.

A rare case of ruptured intracranial aneurysm arising from the retro-mastoid branch of the occipital artery

Background:

Aneurysms of the occipital artery (OA) are rare, with few cases published in the literature. The pathophysiology is unknown, and the presentation is variable. We present a case of a ruptured intracranial aneurysm arising from a branch of the OA.

Case Description:

A 36-year-old male with a history of ankylosing spondylitis presented with altered mental status after an assaulted. On examination, he was intubated, with a Glasgow coma scale of 9, and imaging of the head and neck revealed a subdural hematoma of the posterior fossa and the cervical spine. The patient underwent suboccipital craniectomy and C1-5 laminectomy with the evacuation of the subdural hematoma. Postoperative cerebral angiography showed an intracranial aneurysm arising from the retromastoid branch of the OA on the left side. Furthermore, the parent vessel of the aneurysm supplied the left lower half of the cerebellar hemisphere. The aneurysm and the parent vessel were embolized using platinum coils. The patient tolerated the procedure well, and magnetic resonance imaging of the brain showed a minor left-sided cerebellar infarct, which was asymptomatic. The patient was discharged home with a modified Rankin scale of 2. There were no outpatient follow-up data available because the patient lost to follow-up.

Conclusion:

Intracranial OA aneurysms are extremely rare with no clear consensus concerning the management of these aneurysms. They can be treated using endovascular and or open surgical techniques depending on the aneurysm characteristics, patient condition, rupture status, and others.

Twin Giant Intracranial Aneurysms

Giant aneurysms of the intracranial vertebral artery and posterior inferior cerebellar artery are challenging to treat as they often necessitate direct sacrifice of the diseased segment, which is thought to carry high morbidity due to brainstem and cerebellar stroke. Here, we report images of twin giant aneurysms of the left posterior inferior cerebellar artery at the brainstem and cerebellopontine angle region in a young child.

The Glossopharyngo-Cochlear Triangle-Part II: Case Series Highlighting the Clinical Application to High-Riding Posterior Inferior Cerebellar Artery Aneurysms Exposed Through the Extended Retrosigmoid Approach

BACKGROUND

Use of the far lateral transcondylar (FL) approach and vagoaccessory triangle is the standard exposure for clipping most posterior inferior cerebellar artery (PICA) aneurysms. However, a distal PICA origin or high-lying vertebrobasilar junction can position the aneurysm beyond the vagoaccessory triangle, making the conventional FL approach inappropriate.

OBJECTIVE

To demonstrate the utility of the extended retrosigmoid (eRS) approach and a lateral trajectory through the glossopharyngo-cochlear triangle as the surgical corridor for these cases.

METHODS

High-riding PICA aneurysms treated by microsurgery were retrospectively reviewed, comparing exposure through the eRS and FL approaches. Clinical, surgical, and outcome measures were evaluated. Distances from the aneurysm neck to the internal auditory canal (IAC), jugular foramen, and foramen magnum were measured.

RESULTS

Six patients with PICA aneurysms underwent clipping using the eRS approach; 5 had high-riding PICA aneurysms based on measurements from preoperative computed tomography angiography (CTA). Mean distances of the aneurysm neck above the foramen magnum, below the IAC, and above the jugular foramen were 27.0 mm, 3.7 mm, and 8.2 mm, respectively. Distances were all significantly lower versus the comparison group of 9 patients with normal or low-riding PICA aneurysms treated using an FL approach (P < .01). All 6 aneurysms treated using eRS were completely occluded without operative complications.

CONCLUSION

The eRS approach is an important alternative to the FL approach for high-riding PICA aneurysms, identified as having necks more than 23 mm above the foramen magnum on CTA. The glossopharyngo-cochlear triangle is another important anatomic triangle that facilitates microsurgical dissection.

Cerebellar artery infarction with sudden hearing loss and vertigo as initial symptoms: A case report

BACKGROUND

Sudden hearing loss (SHL) is associated with serious systematic conditions such as neoplasms, vascular events, autoimmune diseases, infections, and iatrogenic injury. Some authors report that SHL can be an early warning sign of impending vertebrobasilar ischemic stroke. It is important to distinguish stroke from benign disease.

CASE SUMMARY

A 48-year-old male patient presented with SHL and vertigo as first symptoms. Diffusion-weighted imaging revealed high signal intensity in the left posterior inferior cerebellar artery territory of the cerebellar hemisphere and high signal intensity in the right pons and bridge cerebellar arm, confirming that the patient had cerebral infarction. Treatment with antiplatelet drugs, steroid anti-inflammatory drugs, and neurotrophic nerve therapy promoted blood circulation and removed blood stasis, and the symptoms of the patient were significantly improved.

CONCLUSION

SHL and vertigo could be the initial symptoms of vertebrobasilar ischemic stroke.

Mechanical thrombectomy for acute occlusion of the posterior inferior cerebellar artery: A case report

BACKGROUND

Mechanical thrombectomy (MT) has been demonstrated to be useful for the treatment of ischemic stroke in patients with large vessel occlusions. However, recanalization by MT is not recommended for distal vessels such as second-order branches of the middle cerebral artery and posterior inferior cerebellar artery (PICA). Because of the small size and tortuosity of these arteries, the risks of using the available endovascular devices outweigh the benefits of treatment. However, MT appears to be effective in patients with primary distal vessel occlusion in eloquent areas, those with a high National Institutes of Health Stroke Scale score, and those ineligible for recombinant tissue plasminogen activator therapy. Here, we report the use of MT for treating acute occlusion of the PICA using a direct-aspiration first-pass technique (ADAPT).

CASE SUMMARY

In this case, the patient received acute occlusion of the PICA with ADAPT when right internal carotid artery stenting was performed.

CONCLUSION

With the introduction of advanced endovascular devices, MT may now be a feasible treatment for acute occlusion of the PICA.

Challenges in Using the Posterior Inferior Cerebellar Artery for Revascularization of the Anterior Inferior Cerebellar Artery: A Microsurgical Anatomic Study

BACKGROUND

A bypass is usually required to prevent ischemia during the treatment of anterior inferior cerebellar artery (AICA) aneurysms. The intracranial (IC)-to-IC bypass provides several advantages over the extracranial-to-IC bypass in the posterior fossa. However, there are only 2 case reports about AICA revascularization with the posterior inferior cerebellar artery (PICA). We aimed to investigate the microsurgical anatomical challenges for PICA to AICA anastomosis.

METHODS

Ten cadaveric heads injected with colored silicone were inspected on both sides using a lateral transcondylar approach. After the donor and recipient arteries were examined from the posterior side, neurovascular contents of the posterior fossa were excised and the origin, course, and variations of both arteries were investigated from the anterior view. The diameters of the AICA and PICA segments and the intersegment distance were measured.

RESULTS

PICA variations and posteromedial origins from the vertebral artery were identified in 8 of the 20 right and 6 of the 20 left sides, and the first segment of the PICA was not present in 7 sides. Furthermore, in 18 sides, the PICA was trapped between the lower cranial nerves and dentate ligaments. Therefore the donor artery could not be brought closer than 1 cm to the recipient artery in 19 sides. Moreover, AICA variations were identified in 6 sides, and in 12 sides, the diameter of the recipient artery was <1 mm.

CONCLUSIONS

The mostly PICA-related issues made PICA-to-AICA anastomosis unfeasible in all cadaveric heads included in the study.

Ascending pharyngeal artery-posterior inferior cerebellar artery anastomosis via the jugular foramen: a case report and literature review

The posterior inferior cerebellar artery (PICA) rarely arises from the cavernous segment of the internal carotid artery (ICA) and is called persistent trigeminal artery variant. The PICA also can arise from the cervical segment of the ICA, and it enters the posterior fossa via the hypoglossal canal, where it is called persistent hypoglossal artery variant. Using magnetic resonance angiography (MRA), we diagnosed a 79-year-old man with a PICA arising from the ascending pharyngeal artery and passing through the medial side of the jugular foremen pars vascularis. Only six cases of this variation have been reported previously in the English language literature. To identify this variation on MRA, the careful observation of source images is useful. Recognizing this variation is important in order to avoid ischemic cerebellar complications during neck surgery and endovascular therapy.

Anatomical Study of the Posterior Spinal Artery Branches to the Medulla Oblongata

BACKGROUND

The posterior spinal arteries (PSAs), branches of the intracranial segment of the vertebral artery or posterior inferior cerebellar artery, run bilaterally along the spinal cord and are integral to the blood supply primarily to the posterior one third of this structure. However, a less well-described distribution of the PSAs is their supply to the posterior medulla. The purpose of this study is to examine the medullary branches of the PSA anatomically.

METHODS

We conducted a cadaveric study to evaluate for branches of the PSA supplying the medulla oblongata.

RESULTS

All 14 sides had medullary branches arising from the PSAs. The average number of branches supplying the medulla oblongata on each side was 6. Most of these branches traveled laterally to anastomose with medullary branches arising from the anterior spinal artery. Additionally, lateral and ascending branches were noted.

CONCLUSIONS

Physicians who interpret imaging of the craniocervical junction, in particular arteriograms, should be aware of ascending medullary branches arising from the anterior spinal artery. Additionally, neurosurgeons operating this region must be careful in dissecting over the posterior medulla and manipulating the cerebellar tonsils, as in telovelar approaches to the fourth ventricle, in order to avoid iatrogenic injury to these vessels. Additionally, variable stroke patterns involving the vertebral artery or posterior inferior cerebellar artery might include ischemia to the medulla oblongata via PSA branches, and this anatomy should be kept in mind by interventionalists, radiologists, and neurologists alike.

Posterior Circulation Aneurysms: A Critical Appraisal of a Surgical Series in Endovascular Era

The advent of the endovascular era has apparently decreased the role of microneurosurgery for many of the posterior circulation aneurysms. This study consists of a critical appraisal of a retrospective surgical series regarding posterior circulation aneurysms, targeted to define whether microneurosurgery still has a role for some of these. In 28 years, 157 aneurysms were surgically treated, 98 of which ruptured. The Average patient age was 56.7 ± 14.2 years, while in hemorrhagic cases, the mean Hunt-Hess score was 2.17 ± 0.8. Basilar tip, vertebral artery and proximal posterior inferior cerebellar artery were the most frequently involved sites. The treatment consisted of 128 clippings, 19 trappings, 7 wrappings, and 3 bypasses. A total exclusion was achieved in 88.5% of the aneurysms. An average follow-up of 67.1 ± 61.3 months proved no recurrences. The best results were observed in patients <65 years old who harbored small-to-regular aneurysms of the basilar tip, distal cerebellar arteries, or vertebral artery.Clipping proved to be a definitive and durable treatment for a large part of posterior circulation aneurysms, whereas bypass allows for treating aneurysms not amenable for coiling, stenting, or clipping. The present study confirms that microneurosurgery continues to have a paramount role within neurovascular pathology.

Study of the Anatomical Features of the Offending Arteries Involved in Glossopharyngeal Neuralgia

BACKGROUND

The anatomic features of the posterior inferior cerebellar arteries (PICAs) and the anterior inferior cerebellar arteries (AICAs) as offending arteries involved in glossopharyngeal neuralgia (GPN) are important to dictate the best surgical approach.

OBJECTIVE

To study and classify the anatomic features of the offending arteries.

METHODS

All clinical data and surgical videos from 18 GPN cases that were surgically treated during the past 10 yr were retrospectively reviewed.

RESULTS

Among these 18 patients, the offending arteries involved were the PICA in 12 (66.7%), AICA in 4 (22.2%), and both PICA and AICA in 2 (11.1%). The PICA were then classified into the following groups based on their anatomic features: type I: the PICA formed an upward loop at the level of the glossopharyngeal nerve and passed between the glossopharyngeal and vestibulocochlear nerves; type II: the PICA formed an upward loop at the level of the glossopharyngeal nerve and passed between the glossopharyngeal and vagus nerves or between the rootlets of the vagus nerve; and type III: the PICA passed between the glossopharyngeal and vestibulocochlear nerves without forming a loop. The AICA had only one running pattern.

CONCLUSION

The offending arteries involved in GPN, mainly the PICA and/or AICA, were classified into 4 different types based on their anatomic features.

Revascularization of the Posterior Inferior Cerebellar Artery Using the Occipital Artery: A Cadaveric Study Comparing the p3 and p1 Recipient Sites

BACKGROUND

Revascularization of the posterior inferior cerebellar artery (PICA) is typically performed with the occipital artery (OA) as an extracranial donor. The p3 segment is the most accessible recipient site for OA-PICA bypass at its caudal loop inferior to the cerebellar tonsil, but this site may be absent or hidden due to a high-riding location.

OBJECTIVE

To test our hypothesis that freeing p1 PICA from its origin, transposing the recipient into a shallower position, and performing OA-p1 PICA bypass with an end-to-end anastomosis would facilitate this bypass.

METHODS

The OA was harvested, and a far lateral craniotomy was performed in 16 cadaveric specimens. PICA caliber and number of perforators were measured at p1 and p3 segments. OA-p3 PICA end-to-side and OA-p1 PICA end-to-end bypasses were compared.

RESULTS

OA-p1 PICA bypass with end-to-end anastomosis was performed in 16 specimens; whereas, OA-p3 PICA bypass with end-to-side anastomosis was performed in 11. Mean distance from OA at the occipital groove to the anastomosis site was shorter for p1 than p3 segments (30.2 vs 48.5 mm; P < .001). Median number of perforators on p1 was 1, and on p3, it was 4 (P < .001).

CONCLUSION

Although most OA-PICA bypasses can be performed using the p3 segment as the recipient site for an end-to-side anastomosis, a more feasible alternative to conventional OA-p3 PICA bypass in cases of high-riding caudal loops or aberrant anatomy is to free the p1 PICA, transpose it away from the lower cranial nerves, and perform an end-to-end OA-p1 PICA bypass instead.

Anomalous origin of the posterior inferior cerebellar artery from the jugular branch of the ascending pharyngeal artery: A case report

The posterior inferior cerebellar artery usually arises from the vertebral artery and has several variants. The posterior inferior cerebellar artery originating from the jugular branch of ascending pharyngeal artery has rarely been reported. A 63-year-old woman underwent cerebral magnetic resonance imaging and magnetic resonance angiography; the latter incidentally revealed an anomalous origin of the posterior inferior cerebellar artery. We report and discuss the neuroimaging findings in a patient with this anomaly. Determining the origin of the posterior inferior cerebellar artery is an important factor in planning surgical and endovascular treatment strategies for skull base disorders.

Coiling for a saccular aneurysm on the caudal channel in double origin of the posterior inferior cerebellar artery

BACKGROUND

Double origin of the posterior inferior cerebellar artery (DOPICA) is a rare cranial imaging finding with an incidence of 0.36-6% reported in various retrospective studies. Aneurysms on a DOPICA are even rarer.

CASE DESCRIPTION

A 34-year-old women hospitalised for subarachnoid haemorrhage showed a ruptured aneurysm arising from the caudal channel of the DOPICA. Endovascular treatment was selected, and the aneurysm was successfully and completely embolised using two coils.

CONCLUSIONS

To date, a total of three previous saccular aneurysms of the DOPICA itself have been reported, all of which were treated using endovascular methods. Our case is the first report of a ruptured saccular aneurysm arising from the non-branching segment of the caudal channel of the DOPICA.

A Case Report of Pediatric Geniculate Neuralgia Treated with Sectioning of the Nervus Intermedius and Microvascular Decompression of Cranial Nerves IX and X

BACKGROUND

Classic geniculate neuralgia (GN) is a rare condition characterized by lancinating pain centered in the ear and not involving the throat. To the best of our knowledge, no case of pediatric GN has been reported in the English literature.

CASE PRESENTATION

We present the first reported case of successfully treated GN in a child via an endoscopic approach. The patient was a 9-year-old boy who presented with a 1-year history of lancinating right ear pain. Neuroleptics resulted in a short-lived improvement in symptoms, but with significant side effects. Extensive evaluation by multiple specialties did not reveal a cause for his pain. Imaging disclosed a tortuous loop of the right posterior inferior cerebellar artery abutting cranial nerves IX and X but no other abnormalities. The patient underwent an endoscopic microvascular decompression of cranial nerves IX and X, and sectioning of the nervus intermedius through a right retromastoid craniotomy. Postoperatively, the patient reported complete resolution of his symptoms that persisted at 3 months of follow-up. At the 5-year follow-up, the patient maintained pain relief and was developing normally.

CONCLUSION

GN can affect the pediatric population. In carefully selected patients with consistent clinical and radiographic presentation, sectioning of the nervus intermedius and microvascular decompression of the lower cranial nerves can be an effective treatment.

Vertebral artery and posterior inferior cerebellar artery aneurysms: Results of microsurgical treatment of eighty patients

Background

The choice of surgical approaches and options for the microsurgical vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms repair remains controversial.

Methods

A retrospective analysis of the clinical, surgical, and angiographic data of 80 patients with VA and PICA aneurysms treated from 2012 to 2018 was performed.

Results

The aneurysms were saccular in 50 cases (62.5%) and fusiform in 30 cases (37.5%). The median suboccipital craniotomy was the most common approach (73.8%). Retrosigmoid craniotomy was performed in 25% of patients. There were the following types of microsurgical operations: neck clipping (61.25%), clipping with the artery lumen formation (13.75%), trapping (10%), proximal clipping (5%), and deconstruction with anastomosis (10%). Fifty-seven (71.3%) patients were discharged without worsening of the clinical signs after surgery. The most common postoperative neurological disorder was palsy of IX and X cranial nerve revealed in 14 (17.5%) patients. No fatal outcomes or patients in vegetative state were identified. The complete occlusion of PICA and VA aneurysms according angiography was in 77 (96.3%) cases.

Conclusion

Microsurgical treatment is an effective method for VA and PICA aneurysms. The majority of VA and PICA aneurysms do not require complex basal approaches. A thorough preoperative planning, reconstructive clipping techniques, and anastomoses creation, as well as patient selection based on the established algorithms and consultations with endovascular surgeons, may reduce the number of complications and increase the rate of complete microsurgical occlusion in VA and PICA aneurysms.

Far-Lateral Craniotomy for Posterior Inferior Cerebellar Artery to Occipital Artery Bypass: 2-Dimensional Operative Video

Posterior inferior cerebellar artery (PICA) aneurysms are infrequent compared with other intracranial aneurysms and are more commonly distal in origin (35% of PICA aneurysms are distal vs 6.5% of other aneurysms). This makes PICA aneurysms a surgical challenge that requires careful consideration of the patient's angiographic anatomy and perfusion needs before deciding on the appropriate intervention. This patient had a highly calcified left PICA p2 segment aneurysm, which was not favorable for endovascular intervention. An end-to-side anastomosis of the occipital artery to the p3 PICA segment was performed. This anastomosis was achieved with 11-0 suture. A permanent clip was then placed along the vertebral artery occluding both the proximal PICA and the aneurysm. Indocyanine green angiography was performed to demonstrate bypass and PICA patency. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Sumo-Associated Traumatic Vertebral Artery Dissection Precipitating Subarachnoid Hemorrhage in Association with Bifid Origins of the Posterior Inferior Cerebellar Artery

BACKGROUND

Traumatic vertebral artery dissection (tVAD) is frequently accompanied by cerebellar infarction, but subarachnoid hemorrhage (SAH) is rare.

CASE DESCRIPTION

We report a unique case of tVAD precipitating SAH, from which the patient fully recovered, most likely because of the protective effects of an anomalously duplicated posterior inferior cerebellar artery (PICA) origin. A 17-year-old Sumo wrestler experienced a brief loss of consciousness after an attack by an opponent to his neck. Head computed tomography imaging demonstrated diffuse posterior fossa SAH; cerebral angiography demonstrated left vertebral artery (VA) occlusion, which was thought to be most likely attributable to tVAD. Angiography revealed distal PICA reconstitution, supplied by collateral arterial flow from the meningeal branch of the proximal ipsilateral VA. An external ventricular drain was placed acutely for treatment of SAH-induced hydrocephalus; however, the patient had an otherwise uneventful course, and remained without clinical evidence of ischemic infarct. A repeat imaging confirming a probable duplicated PICA origin from the VA, distal to the tVAD-associated thrombosis.

CONCLUSIONS

Of particular interest, the patient's abnormal anatomy may have been a mixed blessing, with a more fragile bifid PICA potentially underlying the unexpected development of SAH, whereas the sister branch simultaneously spared him a potentially catastrophic infarction via arterial collateralization.

Posterior Inferior Cerebellar Artery Infarction Originating at C1-2 after C1-2 Fusion

Vertebral artery injuries associated with C1 lateral mass screw insertion rarely occur during C1-2 fusion. The posterior inferior cerebellar artery (PICA) is uncommonly located at the C1 lateral mass insertion position. A 71-year-old woman with atlanto-axial subluxation and cord compression underwent C1-2 fusion. Sixth nerve palsy and diplopia were detected postoperatively, and decreased consciousness occurred on postoperative day 4. Brain magnetic resonance image (MRI) and computed tomography (CT) revealed PICA infarction. In the preoperative CT angiography, the PICA originated between the C1 and C2 level. In the postoperative CT scan, the PICA was not visible. The patient was treated conservatively for two weeks and recovered. PICA originating between the C1 and C2 level comprises 1.1–1.3% of cases. Therefore, vertebral artery anomalies should be evaluated prior to C1-2 fusion to prevent vessel injuries.

Isolated left vertebral artery and its consequences for aortic arch repair

A left vertebral artery (LVA) originating directly from the aortic arch is the second most common supra-aortic branching anomaly. This isolated LVA can also terminate in the posterior inferior cerebellar artery without contributing to the circle of Willis, limiting treatment options, especially in cases with an incomplete circle. Here, we describe our consideration of the treatment options for a 79-year-old patient with a large distal aortic arch aneurysm combined with an isolated LVA and incomplete circle of Willis that may endanger adequate (intraoperative) cerebral perfusion.

Rare Case of Concurrent Glossopharyngeal and Trigeminal Neuralgia, in Which Glossopharyngeal Neuralgia was Possibly Induced by Postoperative Changes Following Microvascular Decompression for Trigeminal Neuralgia

BACKGROUND

Glossopharyngeal neuralgia (GPN) and trigeminal neuralgia (TN) can result from mechanical stimulation of the glossopharyngeal nerve (GPNv) and trigeminal nerve (TNv) by blood vessels. TN can cause severe pain in the orofacial region, whereas GPN manifests as pain in the tongue, throat, tonsil, and ear. Although these 2 neuralgias can occur concurrently, concurrence of recurrent TN and GPN that develops postoperatively has not been previously described.

CASE DESCRIPTION

A 68-year-old male complained of right glossalgia and pain in the pharynx radiating to the right auricular area. The patient had previously undergone microvascular decompression (MVD) for right TN. Medication and intraoral xylocaine spray did not relieve the symptoms. An oral surgeon was unable to find any disease related to the glossalgia. The anesthesiologist pointed out that the symptoms could be from partial recurrence of the TN because the patient also complained of pain in the inferior alveolus. Magnetic resonance angiography indicated that the right GPNv seemed to be compressed by the right posterior inferior cerebellar artery (PICA); hence, MVD for both GPN and TN was performed. Intraoperatively, the right PICA was found to be adherent to the GPNv because of the thickened arachnoid membrane and was subsequently detached. The TNv was also examined, but only a Teflon ball was found, which was detached from the TNv. The GPN disappeared postoperatively, although TN persisted after the second operation.

CONCLUSIONS

GPN can result from adhesions between the GPNv and arachnoid membrane following previous MVD.

Ruptured PICA aneurysms: presentation and treatment outcomes compared to other posterior circulation aneurysms. A Swiss SOS study

BACKGROUND AND PURPOSE

Aneurysms of the posterior inferior cerebellar artery (PICA) are relatively uncommon and evidence is sparse about patients presenting with ruptured PICA aneurysms. We performed an analysis of the Swiss SOS national registry to describe clinical presentation, treatment pattern, and neurological outcome of patients with ruptured PICA aneurysms compared with other ruptured posterior circulation (PC) aneurysms.

METHODS

This was a retrospective analysis of anonymized data from the Swiss SOS registry (Swiss Study on Aneurysmal Subarachnoid Hemorrhage; 2009-2014). Patients with ruptured PC aneurysms were subdivided into a PICA and non-PICA group. Clinical, radiological, and treatment-related variables were identified, and their impact on the neurological outcome was determined in terms of modified Rankin score at discharge and at 1 year of follow-up for the two groups.

RESULTS

Data from 1864 aneurysmal subarachnoid hemorrhage patients were reviewed. There were 264 patients with a ruptured PC aneurysm. Seventy-four PICA aneurysms represented 28% of the series; clinical and radiological characteristics at admission were comparable between the PICA and non-PICA group. Surgical treatment was accomplished in 28% of patients in the PICA group and in the 4.8% of patients in the non-PICA group. No statistically significant difference was found between the two groups in terms of complications after treatment. Hydrocephalus requiring definitive shunt was needed in 21.6% of PICA patients (p = 0.6); cranial nerve deficit was present in average a quarter of the patients in both PICA and non-PICA group with no statistical difference (p = 0.3). A more favorable outcome (66.2%) was reported in the PICA group at discharge (p < 0.05) but this difference faded over time with a similar neurological outcome at 1-year follow-up (p = 0.09) between both PICA and non-PICA group. The Kaplan-Meyer estimation showed no significant difference in the mortality rate between both groups (p = 0.08).

CONCLUSIONS

In the present study, patients with ruptured PICA aneurysms had a favorable neurological outcome in more than two thirds of cases, similar to patients with other ruptured PC aneurysms. Surgical treatment remains a valid option in a third of cases with ruptured PICA aneurysms.

Treatment of intracranial vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery origin

Background

Vertebral artery dissecting aneurysm (VADA) involving the origin of the posterior inferior cerebellar artery (PICA) is a complex disease entity in which the dual goals of preventing future rebleeding and maintaining perfusion of the lateral medulla must be considered. We present an illustrative case and review the literature surrounding treatment strategies.

Case Description

We report a patient presenting with extensive subarachnoid hemorrhage due to rupture of an intracranial VADA involving the PICA origin. After consideration of the patient's cerebral vasculature and robustness of collaterals, a flow-diverting stent was placed with angiographic resolution of the lesion and maintenance of antegrade PICA flow. Ultimately, the patient experienced a contralateral intraparenchymal hemorrhage leading to death. Review of the literature identified 124 cases of VADA involving the PICA origin described over the past decade. The methods of surgical and endovascular treatment of these cases were reviewed, with particular focus on the rationale of treatment, outcomes, and complications.

Conclusion

Numerous treatment options for VADA involving PICA have been reported with different risk and benefit profiles. Flow-diverting stents appear to offer the most favorable balance of securing the aneurysm and avoiding medullary infarction, but the risks and optimal anti-thrombotic treatment strategy are incompletely understood. In select cases, in which the surgical risk is low or in which the anatomy is favorable (e.g., nondominant parent vessel or robust collateral circulation in the involved territories), parent artery trapping with or without microsurgical revascularization can be considered.

Occipital Artery Harvesting and Anastomosis to P3 Segment of Posterior Inferior Cerebellar Artery: Operative Video

Aneurysms involving the origin of the posterior inferior cerebellar artery (PICA) have a greater incidence of fusiform morphology, intraluminal thrombi, and wall calcifications. At times, a complex treatment strategy with vessel occlusion and revascularization using a bypass graft is necessary for successful obliteration of these aneurysms. The occipital artery (OA) is often the preferred donor graft for lesions of the posterior fossa because of its proximity to the target recipient vessels. However, dissection of an OA can be challenging, given its anatomically tortuous path and the presence of thick surrounding muscles. This video captures the dissection of the OA using an unconventional, "inside-out" harvesting technique and the end-to-side anastomosis of the OA to the PICA at the p3 segment. This was performed in a 58-year-old man who presented with a subarachnoid hemorrhage (Hunt and Hess grade IV) from a ruptured fusiform aneurysm located at the origin of the right PICA. Major steps in Video 1 during this case include 1) dissection and harvesting of the OA using the "inside out" technique, 2) placement of 2 temporary clips occluding the PICA and isolating the P3 segment, 3) end-to-side OA-P3 anastomosis, and 4) removal of the temporary clips and confirmation of the PICA's patency using intraoperative indocyanine green. Due to the potential for infarction of the brainstem, the patient was started on dual antiplatelet therapy postoperatively. The patient tolerated the procedure well and suffered no major complications related to the operation or from being placed on dual antiplatelet therapy. He did experience some mild, posterior neck pain and rigidity at the time of his 3-month follow-up, likely due to nerve injury that occurred while harvesting the OA. Overall, the patient remains in good neurologic status 1 year after the operation. Complex fusiform aneurysms at the origin of PICA can be successfully treated via an OA-PICA bypass.

Staged, Combined Management of Ruptured Vertebral Artery Dissecting Aneurysms Involving the Posterior Inferior Cerebellar Artery: Report of 4 Cases and Review of the Literature

BACKGROUND

Ruptured vertebral artery dissecting aneurysms (VADAs) involving the posterior inferior cerebellar artery (PICA) are the most difficult to treat among variations of VADAs but require prompt treatment. The major challenge is to preserve the PICA while occluding the aneurysm. Despite advances in the management of ruptured VADAs involving the PICA, each treatment, whether it is combined or not, is associated with a significant degree of risk.

CASE DESCRIPTION

This study presents 4 cases of ruptured VADAs involving the PICA that were successfully treated using a staged, combined method. Embolization of the rupture point in the acute stage was followed 3-4 weeks later by occlusion of the proximal vertebral artery (VA) and PICA origin after occipital artery-PICA bypass in the chronic stage.

CONCLUSIONS

Although it is sometimes very difficult to determine the exact rupture point of VADAs, ruptures tend to occur at distal segments of a dissecting aneurysm presenting as bleb. Also, when planning a trapping of the VA, careful examination of angiography is needed to assess the contralateral VA and rupture point. Our staged and combined strategy may provide another valuable treatment option for treating VADAs involving the PICA with special emphasis on the safety and efficacy in our method.

Thrombotic Aneurysm of Posterior Inferior Cerebellar Artery

BACKGROUND

Spontaneous thrombosis of an intracranial aneurysm is rare but is common in fusiform or large cystic aneurysms, which result in subarachnoid hemorrhage after rupture. This case reports a 47-year-old woman with subarachnoid hemorrhage who developed spontaneous thrombosis of an aneurysm due to rupture of the posterior inferior cerebellar aneurysm.

CASE DESCRIPTION

The patient was admitted to the hospital with history of sudden headache and vomiting for 3 days. According to early imaging findings, she was initially diagnosed as having a cavernous hemangioma with hemorrhage in the left cerebellum, but according to the intraoperative pictures and postoperative pathologic results, the diagnosis was an aneurysm with thrombosis.

CONCLUSIONS

This case represents a rare but important complication of ruptured intracranial aneurysm, which can be easily misdiagnosed or ignored. It should be given great attention and considered in patients with subarachnoid hemorrhage who are negative for imaging examinations.

Double Origin of the Posterior Inferior Cerebellar Artery: Anatomic Case Report

BACKGROUND

Double origin of the posterior inferior cerebellar artery (DOPICA) is rare. It has important clinical implications especially in cases of aneurysms of the vertebral artery (VA) or the posterior inferior cerebellar artery (PICA). Several radiologic reports of this variant exist. However, no anatomical illustration of this rarity exists in the literature. This brief report provides the first anatomic illustration of this important variation of the vertebrobasilar system.

CASE DESCRIPTION

A cadaveric specimen was prepared for dissection. A far lateral craniotomy was performed on the right side. While exploring the right cerebellomedullary cistern, two separate origins of PICA were found from the vertebral artery (VA) as the caudal and rostral trunks that joined to form the distal PICA trunk at the tonsillomedullary segment. Microscopic and endoscopic illustrations are provided.

CONCLUSIONS

To the best of the authors' knowledge, this is the first anatomic report on the DOPICA. Cadaveric illustration of this variant helps with understanding its anatomical relationship with adjacent neurovascular structures of the cerebellomedullary cistern including the perforating arteries and the lower cranial nerves.