Keyhole Approach and Neuroendoscopy for Cerebral Aneurysms

The role of surgery for optic pathway gliomas in the era of precision medicine

Optic pathway gliomas (OPGs) represent a unique subset of brain tumours that primarily affect the paediatric population. Traditionally, these tumours are managed conservatively due to their location to and association with vital structures. This article explores the evolving role of surgery in the management of OPGs, particularly in the context of advancements in precision medicine. The advent of targeted therapy, especially for tumours with specific genetic alterations, such as BRAF V600E mutations, has revolutionized the treatment landscape, offering new avenues for patient-specific therapy. However, surgery still plays a crucial role, especially for debulking in cases of hydrocephalus or when standard therapies are ineffective. Advances in surgical techniques, including neuronavigation, endoscopic approaches, and intraoperative neurophysiological monitoring, have enhanced the safety and efficacy of operative interventions. Despite these developments, the complexity of OPGs necessitates a multidisciplinary approach, focusing on long-term outcomes and quality of life. Future research is needed to further elucidate the role of surgery in an era increasingly dominated by molecular genetics and targeted therapies.

Effects of Scalp Nerve Block on the Quality of Recovery after Minicraniotomy for Clipping of Unruptured Intracranial Aneurysms : A Randomized Controlled Trial

OBJECTIVE

This study compared the quality of recovery (QoR) after minicraniotomy for clipping of unruptured intracranial aneurysms (UIAs) between patients with and without scalp nerve block (SNB).

METHODS

Patients were randomly assigned to the SNB (SNB using ropivacaine with epinephrine, n=27) and control (SNB using normal saline, n=25) groups. SNB was performed at the end of surgery. To assess postoperative QoR, the QoR-40, a patient-reported questionnaire, was used. The QoR-40 scores were measured preoperatively, 1-3 days postoperatively, at hospital discharge, and 1 month postoperatively. Pain and intravenous patient-controlled analgesia (IV-PCA) consumption were evaluated 3, 6, 9, and 12 hours and 1-3 days postoperatively.

RESULTS

All QoR-40 scores, including those measured 1 day postoperatively (primary outcome measure; 155.0 [141.0-176.0] vs. 161.0 [140.5-179.5], p=0.464), did not significantly differ between the SNB and control groups. The SNB group had significantly less severe pain 3 (numeric rating scale [NRS]; 3.0 [2.0-4.0] vs. 5.0 [3.5-5.5], p=0.029), 9 (NRS; 3.0 [2.0-4.0] vs. 4.0 [3.0-5.0], p=0.048), and 12 (NRS; 3.0 [2.0-4.0] vs. 4.0 [3.0-5.0], p=0.035) hours postoperatively. The total amount of IV-PCA consumed was significantly less 3 hours postoperatively in the SNB group (2.0 [1.0-4.0] vs. 4.0 [2.0-5.0] mL, p=0.044).

CONCLUSION

After minicraniotomy for clipping of UIAs, SNB reduced pain and IV-PCA consumption in the early postoperative period but did not improve the QoR-40 scores.

Prognostic Risk Factors of One-stage Surgical Clipping in aSAH Elderly Patients with MIAs

OBJECTIVE

To discuss the prognostic factors affecting the prognosis of 1-stage surgical clipping in aneurysmal subarachnoid hemorrhage (aSAH) elderly patients with multiple intracranial aneurysms (MIAs).

MATERIALS AND METHODS

A total of 84 elderly patients with aSAH who had MIAs and underwent 1-stage surgical clipping were retrospectively analyzed. Follow-up was conducted with patients 30 days after discharge using the Glasgow Outcome Scale (GOS). A GOS score of 1 to 3 was defined as a poor outcome, and a GOS score of 4 to 5 was defined as a good outcome. General information (gender, age, size of aneurysm, location of rupture of the responsible aneurysm, H-H grade, CT characteristics of aSAH, number of subarachnoid hemorrhages, operation opportunity, postoperative complications, and intraoperative rupture) and complications（cerebral infarction, hydrocephalus, electrolyte disturbance, and encephaledema）were recorded. Univariate analysis and multivariate regression analysis were used to analyze factors that may affect outcomes.

RESULTS

Univariate analysis showed that the number of SAH events ( P =0.005), intraoperative rupture ( P =0.048) and postoperative complications ( P =0.002) were associated with the prognosis of aSAH elderly patients with MIAs undergoing 1-stage surgery. Multivariate analysis showed that the number of SAH events (odds ratio [OR] 4.740, 95% confidence interval [CI] 1.056 to 21.282, P =0.042) and postoperative complications (OR 4.531, 95% CI 1.266 to 16.220, P =0.020) were independently associated with the prognosis of aSAH elderly patients with MIAs undergoing 1-stage surgery.

CONCLUSIONS

The number of SAH events and postoperative complications are independent risk factors for the prognosis of aSAH elderly patients with MIAs undergoing 1-stage surgery. These factors contribute to the timely treatment of potentially related patients.

Purely Endoscopic Keyhole Approach for Resection of a Frontal Falx Dural Arteriovenous Fistula: A Technical Note

OBJECTIVE

Dural arteriovenous fistulas (DAVFs) in the falx cerebri are rare. This study presents a case of DAVF in the frontal falx cerebri that was successfully resected using a purely endoscopic keyhole microsurgical technique.

METHODS

A 69-year-old male patient presented to the emergency department with an acute onset seizure. His condition was diagnosed as a DAVF in the frontal falx cerebri with multiple fistula points. A purely endoscopic resection was performed under neuronavigation. Postoperative angiography and clinical follow-up were performed after 10 days and 3 months, respectively.

RESULTS

The DAVF was satisfactorily observed and resected using a purely endoscopic keyhole microsurgical technique, with no deterioration of neural functions or major vessel ruptures. Postoperative angiogram revealed complete obliteration of the DAVF and no recurrent epilepsy during the clinical follow-up.

CONCLUSIONS

Supported by sufficient preoperative evaluation and meticulous manipulation,a purely endoscopic minimally invasive resection is feasible and safe for DAVF, with the advantages of close observation and panoramic view.

Keyhole Approach for Clipping Anterior Circulation Aneurysms: Clinical Outcomes and Technical Note

Purpose: Keyhole craniotomy is a minimally invasive approach for the treatment of anterior circulation aneurysm. In this study, we evaluated the benefits and value of the keyhole approach by analyzing the surgical results in 235 patients with anterior circulation aneurysm treated by the keyhole approach and identifying lessons learned from addressing various complications in this approach.

Patients and Methods: This was a retrospective study in a single institution of 235 surgical patients with 248 anterior circulation aneurysms who had the supraorbital keyhole approach (SKA) or pterional keyhole approach (PKA) between January 2016 and January 2021. The modified Rankin Scale (mRS) was used to measure long-term results during follow up.

Results: All 235 patients' aneurysms were fully clamped and have not recurred. Among them, 31 (13.2%) had intraoperative aneurysm rupture, 8 (3.4%) had cerebral vascular spasm, and 4 (1.7%) had intraoperative brain edema. There were seven (3.0%) cases of postoperative infection, eight (3.4%) cases of postoperative cerebral infarction, one (0.4%) case of postoperative hematoma, and two (0.8%) patients had some form of cognitive impairment after surgery. Follow up after surgery demonstrated that 189 out of the 235 patients (80.4%) had favorable outcomes (mRS score 0–2), and 43 (18.3%) had poor outcomes (mRS from 3–5). There were three deaths (1.28%).

Conclusions: The keyhole approach has a quick postoperative recovery, a mild postoperative response, and a good surgical outcome. Our findings indicate that the keyhole approach is a safe and effective surgical method for the treatment of anterior circulation aneurysm.

Treatment outcomes of 1-stage clipping of multiple unruptured intracranial aneurysms via keyhole approaches

OBJECTIVE

Complete exclusion of multiple unruptured intracranial aneurysms (UIAs) in one session of intervention may be ideal. However, such situations are not always feasible in terms of treatment modalities and outcomes. The authors aimed to analyze their experience with 1-stage clipping of multiple UIAs.

METHODS

Medical records between March 2013 and December 2018 were retrospectively reviewed, and 111 1-stage keyhole approaches in 110 patients with 261 multiple UIAs were ultimately included in this study. Clinical and radiological outcomes were analyzed, as well as postoperative complications up to 1 month after the surgery and their risk factors.

RESULTS

Keyhole approaches included unilateral supraorbital in 87 operations (78.4%), bilateral supraorbital in 12 (10.8%), and others in 12. The mean operative duration was 169.6 minutes (range 80-490 minutes). The highest numbers of aneurysms clipped at once were 2 (73.9%) and 3 (18.9%). Complete exclusion and residual neck of the clipped aneurysms were achieved in 89.3% and 7.3%, respectively. There was no significant difference between pre- and postoperative 1-month neurological states (p = 0.14). The permanent morbidity rate was 1.8% (n = 2), and there were no deaths. Postoperative transient neurological deterioration (TND) with no radiological and electrophysiological abnormalities occurred in 8 operations (7.2%). Hypertension was the only significant risk factor for postoperative TND (adjusted odds ratio 17.03, 95% confidence interval 1.99-2232.24, p = 0.01).

CONCLUSIONS

One-stage clipping of multiple UIAs via keyhole approaches showed satisfactory treatment outcomes with a low permanent morbidity. Patients with chronic hypertension had a high risk of postoperative TND.

Clinical application of 3D virtual and printed models for cerebrovascular diseases

OBJECTIVE

Three-dimensional (3D) printing techniques are rapidly advancing in the medical industry and in clinical practice. We aimed to evaluate the usefulness of 3D virtual and printed models of 6 representative cerebrovascular diseases using the software we developed.

METHODS

Six cases consisted of 4 intracranial aneurysms (IAs) including complex ones with intrasaccular thrombosis, large size and a skull base location; 1 cavernous malformation in the pons; and 1 arteriovenous malformation in the parietal lobe. The 3D modeling process was performed retrospectively in 3 cases and prospectively in 1 IA. Segmentation of raw data and rendering and modification for 3D virtual models were processed mostly automatically.

RESULTS

Most intracranial structures were satisfactorily made, including the skull, brain, vessels, thrombus, tentorium and major cranial nerves. Based on 3D modeling, surgical plan was changed in 1 prospective IA case. However, it was still difficult to discriminate small vessels and cranial nerves, to feel a realistic tactile sense and to directly perform presurgical simulations, such as dissection, removal, clipping and microanastomosis.

CONCLUSIONS

The 3D modeling was thought to be very helpful in experiencing the operative views from various directions in advance, in selecting an appropriate surgical approach, and in educating physicians and patients. With advancements in radiological resolution, processing techniques and material properties, 3D modeling is expected to simulate real brain tissues more closely.

The Keyhole Approach in Anterior Circulation Aneurysm - Current Indication and Limitation with Review of Literature

Introduction:

The keyhole approach has been an emerging technique for cerebral aneurysm surgery in the past two decades. The preoperative simulation and tailored-made approach for each patient make feasible to clip many cerebral aneurysms via keyhole approach. In our study, we reviewed the previous experiences of the keyhole approach, related specifically for anterior circulation aneurysm.

Material and Methods:

The comprehensive literature review was performed on PubMed, Google Scholar, ScienceDirect, and various neurosurgery and neurology journals. Then, each manuscript's reference list was reviewed for the potential relevant article. The data of total 17 articles, which met our inclusion criteria included for the final review.

Results:

It was found that the anterior communicating artery, middle cerebral artery, and internal carotid- posterior communicating aneurysms were the most common locations treated by keyhole approach. The size of an aneurysm was <10 mm in most of the studies. Many studies treated multiple aneurysms by single keyhole approach.

Conclusion:

The keyhole approach has shown benefit in term of satisfactory aneurysmal occlusion rate, short operative time, less blood loss, short hospital stay, and good overall surgical outcome.

Surgical Obliteration of Anterior Cranial Fossa Dural Arteriovenous Fistulas via Unilateral High Frontal Craniotomy

BACKGROUND

Surgical obliteration is generally recommended for anterior cranial fossa dural arteriovenous fistulas (ACF DAVFs) because of a high risk of bleeding and the difficulty of endovascular approaches. Surgical obliteration is generally performed via a frontobasal craniotomy; however, it is slightly excessive over the target fistula. Here, we present 2 cases of ACF DAVFs treated with small craniotomy without frontal sinus involvement and a review of the related literature.

METHODS

We present 2 cases including a 63-year-old woman who presented with a right-sided ACF DAVF that was fed by both ethmoidal arteries and drained into the right cortical veins (case 1) and a 59-year-old man with right-sided unruptured multiple aneurysms and a left-sided ACF DAVF that was fed by the right ethmoidal artery and drained into the left cortical veins (case 2).

RESULTS

Case 1 underwent surgical obliteration via a right high frontal craniotomy. Case 2 was simultaneously treated with surgical clipping of the multiple aneurysms via a right lateral supraorbital craniotomy and surgical obliteration of the ACF DAVF via a left high frontal craniotomy. These 2 patients had no neurologic deficits, and complete obliteration of all the lesions was confirmed on cerebral angiography.

CONCLUSIONS

Constructing a small corridor and a deep working distance in unilateral small high frontal craniotomy may be a slightly unusual approach; however, it is thought to provide sufficient space and a range of microscopic views that facilitate surgical manipulation without requiring extensive bone work.

Application of Indocyanine Green Videoangiography in Aneurysm Surgery: Evidence, Techniques, Practical Tips

Establishing blood vessel patency in neurovascular surgery is an essential component in treating cerebrovascular disorders. Given the difficulty in confirming complete obliteration of the aneurysm sac, ICG videoangiography has emerged as an intraoperative tool that provides neurosurgeons immediate feedback on the status of vessel flow, allowing for surgical modifications to be made without delay. ICG initially emerged as a tool for assessing hepatic, cardiac, and retinovascular function. It is an inert compound with a high affinity for plasma proteins and fluorescence properties making it the ideal candidate for assessment of vessel patency in neurovascular procedures. Requiring only a bolus peripheral vein injection and integration of a near-infrared imaging device into the surgical microscope, ICG can be visualized without disrupting operating room workflow or the surgical field. Quick response time, high-spatial resolution, and low complication rates are features of ICG videoangiography that prove advantageous when compared to the gold standard intra- and postoperative digital subtraction angiography (DSA). Despite this, ICG is not without limitations, specifically in the setting of atherosclerotic vessels, giant, and complex aneurysms. Additionally, there are instances where DSA may prove superior in detecting vessel stenosis and outflow obstruction, prompting the recommendation of ICG as an adjunct to, rather than complete replacement of DSA. In this article, the authors provide a brief overview of the biochemical properties and historical origins of ICG viedoangiography in addition to discussing its current application in aneurysm surgery.

[Value of 640-slice 3D CT angiography plus 3D printing for improving surgeries for intracranial aneurysms]

OBJECTIVE

To evaluate the value of 640-slice 3D CT angiography (3D-CTA) plus 3D printing for improving the outcomes of surgeries for intracranial aneurysms.

METHODS

Sixty patients with intracranial aneurysm were randomly divided into trial group (n=30) and control group (n=30). The control group received routine surgery, and the simulation models of the intracranial aneurysm in trial group was printed using a 3D printer using the imaging data from 3D-CTA. Using the simulation model, the surgery was designed and planned before operation (including surgical approaches and placement of clips) and simulation surgery was also conducted. The coincidence rates between preoperative and intraoperative findings of the intracranial aneurysms on 3D-CTA were compared. CT scan was performed at 1 and 3 days after the operation to detect potential cerebral infarction or bleeding associated with the operation; CTA was performed both at the same time and at 3-6 months after the operation to detect stenosis, occlusion and aneurysm clipping. The patients were followed up for 3-6 months to assess the outcomes using Glasgow Outcome Scale (GOS).

RESULTS

The preoperative 3D-CTA findings were basically consistent with the intraoperative findings in all the 60 patients. Nine patients in the control group and 2 patients in the trial group had short-term adverse operation events; 11 patients in control group and 4 patients in trial group had long-term adverse events; 18 patients in control group and 25 patients in trial group had good neurologic function. The incidences of short-term and long-term adverse events associated with the operation was significantly lower in the trial group than in the control group (χ²=5.364, P=0.021; χ²=4.841, P=0.028), and the outcomes were significantly better in the trial group than in the control group (χ²=4.633, P=0.031).

CONCLUSION

The simulation model of intracranial aneurysm is helpful to improve the quality of surgery and patients outcomes.