How I do it: left posterior cerebral artery P1-2 segment dissecting aneurysm distal clipping via an A1-RAG-P2 bypass

BACKGROUND

Posterior cerebral artery (PCA) P1-2 segment dissecting aneurysms are difficult because regular craniectomy aneurysm clipping or intravascular interventional therapy is not applicable.

METHOD

We report distal clipping of a PCA P1-2 segment dissection aneurysm with an anterior cerebral artery (ACA) A1-radial artery graft-PCA P2 bypass.

CONCLUSION

This case demonstrates the value of an ACA-RAG-PCA bypass in the therapy of a PCA dissecting aneurysm.

Superficial temporal artery lengthening technique to prevent postoperative wound complications in direct revascularization to the anterior cerebral artery for Moyamoya disease

BACKGROUND

Neurocognitive dysfunctions or psychomotor symptoms of Moyamoya disease may improve after direct revascularization to the anterior cerebral artery (ACA). However, long-distance harvest of the frontal branch of the superficial temporal artery (STA) is needed to reach the cortical ACA, frequently resulting in postoperative wound complications. To solve this problem, we devised a novel method (STA lengthening technique). In this study, we compared the STA lengthening technique and the conventional method regarding postoperative wound complications.

METHODS

Twenty-five patients who underwent STA-ACA direct bypass from December 2016 to October 2021 were retrospectively reviewed, and postoperative wound complications were recorded. Magnetic resonance angiography was performed to evaluate the patency of the bypass to the ACA and postoperative development of collaterals to the skin flap.

RESULTS

Thirty-eight hemispheres (new method [n = 12] vs. conventional method [n = 26]) were treated. Wound complications occurred in 12 surgeries (46%) of the conventional method, and none (0%) of the new method. The anastomosis with the cortical ACA was patent in all surgeries. Postoperative development of collaterals to the skin flap was confirmed after all surgeries (100%) in the new method, whereas after only five surgeries (20%) in the conventional method.

CONCLUSION

The STA lengthening technique can enable to preserve the collateral circulation to the skin flap postoperatively, resulting in good wound healing.

Revascularization to the ACA: effectiveness and variation of the STA-RAG-A3 bonnet bypass

BACKGROUND

The effectiveness of bypass surgery in patients with atherothrombotic ischemia in the anterior cerebral artery (ACA) domain remains unclear. In this study, three cases with ischemia in the ACA territory underwent revascularization surgery using superficial temporal artery (STA)-radial artery graft (RAG)-A3 (pericallosal artery) bonnet bypass. Herein, we discuss the effectiveness and variations of this approach.

METHODS

Among 182 consecutive patients with atherothrombotic ischemic stroke admitted to the NTT Medical Center, Tokyo, from April 2017 to May 2021, three patients with hemodynamic insufficiency in the extensive ACA territory beyond the recent infarct area were treated using STA-RAG-A3 bonnet bypass.

RESULTS

One patient with bilateral severe cerebral blood flow (CBF) deficiency required additional A3-A3 and STA-middle cerebral artery single bypass in conjunction with STA-RAG-A3 bypass. There were no complications associated with the surgical procedure. The patients' hemodynamic study results and neurocognitive performances improved dramatically after surgery.

CONCLUSION

Our results suggest the efficacy of STA-RAG-A3 bypass for atherothrombotic ACA ischemia. However, because the number of cases was too small to generalize our results, more cases and thorough pre- and postoperative hemodynamic studies are necessary to prove the validity of the approach.

Retractorless combined pterional and interhemispheric approach to achieve proximal control in pericallosal artery aneurysm: how I do it

BACKGROUND

Pericallosal artery aneurysms differ from other cerebral aneurysms for the difficulty in establishing proximal vascular control during surgical clipping. A frontomedial craniotomy with combined pterional and interhemispheric approach allows obtaining a better proximal control.

MATERIALS AND METHODS

We present our surgical technique to achieve a proximal vessel control in pericallosal artery aneurysm clipping using a combined pterional and interhemispheric approach through frontomedial craniotomy. This surgical technique is illustrated by an intraoperative video.

CONCLUSION

Proximal control for pericallosal artery aneurysm clipping can be challenging. In selected cases, a single craniotomy allows performing two approaches and obtaining a safer proximal control for surgical clipping.

In Situ Side-to-Side Pericallosal-Pericallosal Artery and Callosomarginal-Callosomarginal Artery Bypasses for Complex Distal Anterior Cerebral Artery Aneurysms: A Technical Note

BACKGROUND

Despite surgical and endovascular technical improvements over the last decades, the treatment of complex aneurysms of the distal anterior cerebral artery (ACA) is very challenging for both vascular neurosurgeons and interventional neuroradiologists. Furthermore, the interpersonal anatomic variability requires, most of the time, a tailored planning.

OBJECTIVE

To describe a novel technique of bypasses in the territory of ACA to protect the brain territory distal to the aneurysm.

METHODS

A 53-yr-old male with a large complex fusiform aneurysm of the left distal A2 segment of the ACA, involving the origin of the callosomarginal and pericallosal arteries, was judged not suitable for a single procedure (endovascular or neurosurgical). Two side-to-side bypasses were performed in a single surgery to connect the pericallosal and callosomarginal arteries of both sides, distally to the aneurysm. Subsequently, an endovascular embolization of the aneurysm was achieved with coils.

RESULTS

The patency of the microanastomoses, performed in the anterior interhemispheric fissure, was positively evaluated intraoperatively with indocyanine green and fluorescein videoangiography. The aneurysm sac, together with proximal A2 segment, was completely occluded with platinum coils. At the last follow-up, computed tomography angiography confirmed the patency of both bypasses, without any sign of aneurysm recanalization. The patients never complained of any focal neurological deficits or worsening of clinical status.

CONCLUSION

We present an elegant and innovative solution to completely protect the distal ACA territory in cases of complex aneurysm involving the origin of both callosomarginal and pericallosal arteries.

Treatment of a Fusiform Anterior Cerebral Artery Aneurysm With an A3-A3 Bypass: 2-Dimensional Operative Video

Distal anterior cerebral artery (ACA) aneurysms remain a relatively rare and challenging entity for both open microsurgical and endovascular treatments. These lesions provide a significant surgical challenge because of the narrow interhemispheric surgical field, limited proximal control, common fixation of the aneurysm to the adjacent cingulate gyrus, and possible involvement of an unpaired azygos A2. These challenges result in a known association between distal ACA aneurysms and higher operative morbidity. This video demonstrates indirect obliteration of a prior ruptured fusiform right A2 aneurysm utilizing an A3-to-A3 side-to-side anastomotic bypass with aneurysm trapping. An anterior interhemispheric approach was used for exposure of bilateral ACAs, arteriotomies, microanastomosis, and trapping of the aneurysmal right A2 segment. Postoperatively, the patient's neurological status returned to baseline, and imaging demonstrated evidence of bypass patency with no residual filling of the fusiform aneurysmal segment. This video verifies the feasibility and efficacy of the A3-to-A3 anastomotic bypass for treatment of distal ACA aneurysms. 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.

Surgical treatment of traumatic distal anterior cerebral artery aneurysm: a report of nine cases from a single centre

BACKGROUND

Traumatic distal anterior cerebral artery (dACA) aneurysm is rare and can be easily neglected and misdiagnosed in patients with trauma. The aim of this study was to explore the radiologic characteristics of and therapeutic strategies for traumatic dACA aneurysm and to improve our understanding of unusual complications after trauma.

METHODS

The clinical data of nine cases of traumatic dACA aneurysm from our neurosurgical department from July 1, 2010, to July 1, 2018, were retrospectively analysed.

RESULTS

All 9 patients had a history of brain trauma. The initial computed tomography scan immediately after trauma showed subarachnoid haemorrhage in 8 cases. Among these cases, delayed intracranial haemorrhage occurred in 7 cases. The average interval between injury and diagnosis was 13.67 ± 9.43 days. All 9 cases were confirmed as traumatic dACA aneurysm by computed tomography angiography (CTA) and/or digital subtraction angiography. According to Lehecka's classification system, traumatic dACA aneurysm located in the A3 and A4 segment was found in 3 and 6 cases, respectively. Surgical treatment was performed in 8 cases, including neck clipping, with or without wrapping in 3 cases, trapping in 4 cases, aneurysm excision and suturing in 1 case and conservative treatment in 1 case. Three patients required a ventriculoperitoneal shunt due to severe hydrocephalus. According to the Glasgow Outcome Scale scoring system, good recovery was achieved in 4 cases, moderate disability in 2 cases, severe disability in 1 case, and death in 2 cases.

CONCLUSION

Traumatic dACA aneurysm is a rare complication of brain trauma. Delayed intracranial haemorrhage and the sudden deterioration of neurologic function were the typical characteristics in patients with traumatic dACA aneurysm. CTA is the first-line screening modality for patients who present with intracerebral haemorrhage in the corpus callosum after trauma, particularly for patients who are older, in a poorer or critical condition. When the aneurysm is located in the A4 segment or involves a small branch, surgical trapping is the preferred definitive therapy to prevent further growth and disastrous bleeding. Early diagnosis and prompt treatment could help to improve clinical outcomes.

Combined Pterional Transsylvian and Bifrontal Interhemispheric Approach to Ruptured Subcallosal and Pericallosal Brain Arteriovenous Malformation with Skeletonization of the Entire A2 ACA Segment

A 39-year-old man presented with a large left paramedian frontal lobe intracerebral hemorrhage. Computed tomography angiography and magnetic resonance imaging revealed a tangle of vessels arising from the anterior cerebral arteries (ACAs) and dilated draining veins entering the superior sagittal sinus. Angiography confirmed a Spetzler-Martin grade 3, supplemented 2 arteriovenous malformation (AVM) with predominant supply from branches of the left ACA with superficial and deep drainage (Video 1). The case illustrates an unusual cerebrovascular pathology involving the entire A2 ACA segment. The AVM extended from the A1/2 junction along the entire A2 segment past the genu of the corpus callosum (A3 segment). A combined pterional transsylvian and bifrontal interhemispheric approach was performed. The proximal sylvian fissure and opticocarotid cistern were opened to expose the A1/2 junction. Once proximal control was obtained, the hematoma was evacuated to define the lateral border of the AVM. The interhemispheric fissure was then opened to identify the draining vein and the distal pericallosal arteries. The interhemispheric approach also defined the medial border of the AVM. The A2 ACAs were then skeletonized from the AVM from the A1/2 junction to the pericallosal arteries. Aneurysm clips were used to interrupt large AVM feeders from the A2 arteries, which avoids cautery and heat transmission to the parent vessel. Once the AVM was disconnected and skeletonized from the A2s, the draining vein was clipped and the nidus was removed. Indocyanine green angiography confirmed patency of the A2s and pericallosal arteries. Postoperative angiography demonstrated no residual shunting, and the patient was discharged in good condition.

Modified encephalo-duro-periosteal-synangiosis (EDPS) for the revascularization of anterior cerebral artery territory in moyamoya disease: A single-center experience

OBJECTIVES

Anterior cerebral artery (ACA) territory, a crucial area of intellectual development in children, is frequently involved in the progress of moyamoya disease (MMD). However, revascularization surgeries for this area are not as established as surgeries for middle cerebral artery (MCA) territory. This study aimed to describe our experience and study the effect of revascularizing ACA territory with periocranium and dural leaflets, which is referred to as 'encephalo-duro-periosteal-synangiosis (EDPS)'.

PATIENTS AND METHOD

Fourteen hemispheres of 9 MMD patients who had undergone EDPS from November 2015 till July 2017 in our hospital were retrospectively included. Clinical characteristics and procedure-related information were recorded. Cerebral perfusion was evaluated by computed tomography perfusion (CTP). Absolute and relative (r) CTP parameters of ROIs in ACA territory at the level of centrum semiovale and middle basal ganglia were calculated. Preoperative and postoperative parameters were compared.

RESULTS

All EDPS procedures were technically successful with no postoperative complications. The mean operating time was 75.00 ± 22.53 min per hemisphere. Postoperative absolute cerebral blood flow (CBF), rCBF were significantly increased and absolute time to peak (TTP), rTTP, absolute mean transit time (MTT) were significantly reduced in ACA territory at centrum semiovale level (P = 0.002, 0.045, 0.007, 0.005 and 0.039 respectively). Improved outcomes were achieved in five patients, stabilization in three and one patient had deterioration out of intracerebral hemorrhage during follow-up.

CONCLUSION

EDPS is a simple but effective technique to revascularize ACA territory for MMD. EDPS significantly improved cerebral blood perfusion of frontal lobe in the majority of patients without increasing procedure-related risks.

[Combination of infraoptic anterior cerebral artery with an aneurysm of the ACA-AcomA complex. Case study and literature review]

The infraoptic anterior cerebral artery (ACA) is an abnormal vessel that usually is a bifurcation of the intradural part of the internal carotid artery (ICA) or near the site of discharge of the ophthalmic artery, which passes under the ipsilateral optic nerve and penetrates between the optic nerves into the prechiasm cistern, reaching the ACA-AcomA complex. The infra-optic ACA is an extremely rare anomaly, but it may be of great clinical significance in surgery of the arteries of the anterior sections of the Willis circle. The article describes the case of a combination of infra-optical ACA with an aneurysm of the ACA-AcomA complex. This observation is of interest both from the viewpoint of the rarity of the considered pathology and the associated increased risk of the formation of intracranial aneurysms.

STA-ACA bypass using the ipsilateral free STA graft as an interposition graft and A3-A3 anastomosis for treatment of bilateral ACA steno-occlusive ischemia

BACKGROUND

Anterior cerebral artery (ACA)-related ischemia is a rare entity in patients with atherosclerosis. Some surgical treatments are reported to date.

METHOD

We present the modification of intracranial-intracranial and intracranial-extracranial bypasses for symptomatic bilateral ACA steno-occlusive disease. The A3-A3 bypass followed by the superficial temporal artery-ACA bypass using the ipsilateral free superficial temporal artery graft is useful without harvesting of the radial artery.

CONCLUSION

Bilateral ACA steno-occlusive induced ischemia can be treated with tailored bypass procedures.

Retrograde Snare-Assisted Rescue via Anterior Communicating Artery for Lost Access During Multiple Overlapping Pipeline Embolization Device Placement

BACKGROUND

The Pipeline embolization device (PED; ev3, Irvine, California, USA) has been used to divert flow away from an aneurysm sac. The risk of complications may increase for flow diversion with giant aneurysms because these cases may require multiple overlapping PEDs, which makes the technique highly complex.

CASE DESCRIPTION

We report a rescue technical strategy for lost access during multiple overlapping PED placement for a giant, fusiform cavernous aneurysm.

CONCLUSIONS

By using the collateral circulation as an alternative rescue route, intraprocedural loss of distal access may be salvaged.

Rescue bypass for the treatment of pseudoaneurysm on the distal anterior cerebral artery: a case report of vertical side-to-side anastomosis of the distal callosomarginal artery-pericallosal artery

Pseudoaneurysm on the distal anterior cerebral artery (ACA) is rare but potentially fatal. It usually cannot be treated with typical treatment modalities. A 47-year-old female patient was diagnosed with a ruptured aneurysm on the pericallosal artery (PerA). During surgical exploration, it was found to be a pseudoaneurysm and could not be treated with clipping. We performed surgical trapping of the involved segment of the proximal PerA followed by side-to-side anastomosis between the ipsilateral PerA and the callosomarginal artery. The patient recovered without any neurologic deficit. This new method of anastomosis could be an alternative option.

Assessing the Role of Preoperative Embolization in the Surgical Management of Cerebral Arteriovenous Malformations

BACKGROUND

Preoperative embolization is established as an advantageous adjunct in multimodality treatment of cerebral arteriovenous malformations (AVMs). However, the benefit of preoperative embolization in AVMs with favorable surgical risk profile is debatable, because it has yet to be supported by evidence in comparative studies. In this study, we assessed outcome of surgically treated patients in a comparative setting.

METHODS

Our institutional AVM database of retrospectively and prospectively collected data between 1990 and 2015 was reviewed. Patients with complete clinical data who underwent surgical resection for AVMs were included. We performed a 1:1 ratio propensity score match for baseline variables that differed between patients with or without preoperative embolization. Differences in surgical risk and outcomes were evaluated between these 2 groups.

RESULTS

AVM size, eloquence, deep drainage, middle cerebral artery feeder, and ruptured presentation differed significantly between the 2 groups. Forty-eight patients without preoperative embolization were matched to 48 with embolization, with no significant differences in baseline variables or AVM characteristics between the 2 groups. We found no significant differences in AVM obliteration and postoperative modified Rankin Scale (mRS) score between embolized and nonembolized patients, respectively. Change in mRS score from preoperative score was also not significant, although more embolized patients had a decline in mRS score. Secondary outcome measures including duration of surgery (P = 0.172), intraoperative bleeding (P = 0.280), duration of hospitalization (P = 0.368), and postoperative symptoms were also similar between both groups.

CONCLUSIONS

Our data do not support substantial benefit of preoperative embolization for patients with a favorable surgical risk profile. Because of risks and costs with this intervention, the prudent use of preoperative embolization should be individually considered.

[Surgical management of proximal anterior cerebral artery (A1) aneurysms]

OBJECTIVE

To review our experience in surgical management of proximal anterior cerebral artery (A1) aneurysms in 23 patients.

METHODS

Between January, 2004 and December, 2014, 23 patients (1.6%) with A1 aneurysms diagnosed by CTA or DSA were treated surgically. The "3H" therapy was adopted for postoperative prevention of cerebrovascular spasm. All the patients were followed up and examined with cerebrovascular CTA at 6, 12, 48 and 60 months after the operation with their Glasgow Outcome Scale score recorded.

RESULTS

The patients consisted of 15 men and 8 women with an age range of 16 to 72 years (mean 51.3 years). The average diameter of the aneurysms was 5.8 mm, ranging from 3.2 to 9.7 mm. Twenty-two saccular aneurysms were found in these patients; 21 patients presented with SAH and two had vascular malformation. All the A1 aneurysms were managed through the pterional approach, and the mean postoperative Glasgow Outcome Scale score was 4.8.

CONCLUSION

Thorough analysis of the angiographic data is essential for the diagnosis and treatment of A1 aneurysms. Preservation of the perforators and prevention of aneurysm rupture are critical during the surgery. Full exposure of the Sylvian fissure and temporary occlusion of the parent artery ensures safe and effective dissection of A1 aneurysms.

Predicting the necessity of anterior communicating artery division in the bifrontal basal interhemispheric approach

Background

The anterior communicating artery (ACoA) often limits surgical exposure in the anterior interhemispheric approach. Although division of the ACoA has been proposed occasionally, it is rarely practiced, and criteria for such a surgical maneuver remain unknown. Our purpose was to identify key factors that allow for predicting the necessity of controlled ACoA division in the bifrontal basal interhemispheric approach.

Method

Twenty-two consecutive patients who underwent surgery via the bifrontal basal interhemispheric approach for removal of various pathologic brain lesions were examined. First, tumors were dichotomized into central and lateral lesions. Next, three tumor parameters were compared between cases with and without ACoA division in each, the central and lateral lesion groups, respectively: tumor volume, tumor depth (defined as distance between the ACoA and posterior tumor margin) and tumor laterality angle (defined as the geometric angle between the lateral tumor margin and sagittal midline).

Results

Tumor volume was not related in a statistically significant manner to ACoA division in both the central (P = 0.06) and lateral (P = 0.13) lesion groups, respectively. However, tumor depth was significantly correlated with ACoA division in the central lesion group (P = 0.01), whereas in the lateral lesion group, the tumor laterality angle showed a significant correlation with ACoA division (P = 0.04).

Conclusions

Our results suggest that controlled ACoA division may be required in central lesions with a depth of 38 mm or more and in lateral lesions with an angle of 23 degrees or more as defined in this study. Two key factors were thus identified that may predict the necessity of controlled ACoA division before surgery.

The outcome of a surgical protocol based on ischemia overprotection in large and giant aneurysms of the anterior cerebral circulation

Aiming to define the optimal treatment of large and giant aneurysms (LGAs) in the anterior circulation, we present our surgical protocol and patient outcome. A series of 42 patients with intracavernous LGAs (n = 16), paraclinoid (C2) LGAs (n = 17), and peripheral (middle cerebral artery—MCA or anterior cerebral artery—ACA) LGAs (n = 9) were treated after bypass under motor evoked potential (MEP) monitoring. Preoperatively, three categories of ischemic tolerance during internal carotid artery (ICA) occlusion were defined on conventional angiography: optimal, suboptimal, and insufficient collaterals. Accordingly, three types of bypass: low flow (LFB), middle flow (MFB) and high flow (HFB) were applied for the cases with optimal, suboptimal, and insufficient collaterals, respectively. Outcome was evaluated by the Glasgow Outcome Scale (GOS). All patients had excellent GOS score except one, who suffered a major ischemic stroke immediately after surgery for a paraclinoid lesion. Forty-one patients were followed up for 87.1 ± 40.1 months (range 13–144 months). Intracavernous LGAs were all treated by proximal occlusion with bypass surgery. Of paraclinoid LGA patients, 15 patients had direct clipping under suction decompression and other 2 patients with recurrent aneurysms had ICA (C2) proximal clipping with HFB. MEP monitoring guided for temporary clipping time and clip repositioning, observing significant MEP changes for up to 6 min duration. Of 9 peripheral LGAs patients 7 MCA LGAs had reconstructive clipping (n = 4) or trapping (n = 3) with bypass including LFB in 3 cases, MFB in 1 and HFB in 1. Two ACA LGAs had clipping (n = 1) or trapping (n = 1) with A3-A3 bypass. The applied protocol provided excellent results in intracavernous, paraclinoid, and peripheral thrombosed LGAs of the anterior circulation.

Ophthalmic artery originating from the anterior cerebral artery: anatomo-radiological study, histological analysis, and literature review

The ophthalmic artery has an anomalous origin in 2-3 % of cases and rarely arises from the anterior cerebral artery. Herein, we provide the first anatomical, radiological, and histological description of such an anomalous origin, together with a literature review. During the anatomical dissection of an 81-year-old Caucasian male, the absence of the right ophthalmic artery in its usual location was evident from an endonasal transsphenoidal perspective. The specimen was then studied in detail, through multiple dissections, corrosion casting, high-resolution CT, and histological analysis. The English literature on anomalous origins of the ophthalmic artery was reviewed, together with reported associated pathologies. Anatomo-radiological analysis documented that the right ophthalmic artery arose from the inferior surface of A1 tract of the anterior cerebral artery (A1) and passed over the optic nerve in its subarachnoid tract. A meningo-ophthalmic artery was evident on the same side and reached the orbit through the superior orbital fissure. Histological examination of both internal carotid artery (ICA) walls documented a significantly decreased thickness of the tunica media and adventitia on the side of the anomalous ophthalmic artery, with a significantly different content of collagen types I and III. The literature review documented an association of aneurysms and anomalous ophthalmic arteries. To the best of our knowledge, this is the first anatomical report that includes a radiological and arterial wall analysis of a persistent ventral ophthalmic artery. The latter provides histological data that support the clinical evidence of a higher association of aneurysms with anomalous origins of the ophthalmic artery.

Results of Clipping Surgery for Aneurysmal Subarachnoid Hemorrhage in Elderly Patients Aged 90 or Older

BACKGROUND

The number of elderly patients with aneurysmal subarachnoid hemorrhage (SAH) is increasing. Although advanced age is one of the recognized risk factors for poor outcome, conservative treatment for aneurysmal subarachnoid hemorrhage cannot provide satisfactory outcome in elderly patients. The aim of this study is to assess the outcome in patients aged 90 or older, for whom ruptured aneurysms were treated by clipping.

METHODS

We retrospectively reviewed the medical records of non-traumatic SAH patients who were hospitalized at the Chiba Neurosurgical Clinic between 2004 and 2013. Of the 702 patients, 8 patients (1.1 %) were aged 90 or older. Of them, four underwent clipping surgery and the other four died or were managed conservatively. Their preoperative conditions were evaluated with the World Federation of Neurosurgical Societies Grading Scale of SAH, and the Fisher classification was used to assess the bleeding severity. The location of the ruptured aneurysm was determined by three-dimensional computed tomographic angiography or cerebral angiography. The Glasgow Outcome Scale evaluation was assigned at discharge.

RESULTS

Four patients (four female, all WFNS grade 1), aged 90 or older, underwent clipping surgery. Fisher classification was three in two patients and four in the other two. Location of the ruptured aneurysm was internal carotid artery in two, anterior communicating artery in one, and posterior inferior cerebellar artery in one patient. Two of these four patients had a favorable outcome.

CONCLUSIONS

We propose that advanced age alone does not exclude suitable surgical clipping in patients with aneurysmal rupture in the tenth decade of life.

The extended endoscopic endonasal transplanum transtuberculum approach to the anterior communicating artery complex: anatomic study

BACKGROUND

When performing a transplanum transtuberculum approach, dealing with the anterior communicating artery (ACoA) complex is inevitable. The aim of this study is to provide quantitative anatomical information regarding the ACoA complex and its bony and neural relationships, when exposed through this approach.

METHOD

The endoscopic endonasal transplanum transtuberculum approach was performed on ten human cadaver heads. In each specimen, radiological studies were performed. A three-dimensional model of the approach was reconstructed. Measured parameters were: exposure of the vessels; distance between the proximal anterior cerebral artery (A1) and the optic chiasm; dimension of the bone opening. The feasibility to perform clip placement was graded as "possible" or "not possible".

RESULTS

Dimension of bone opening varied from 88 to 53 mm(2). The ACoA was exposed for 3 mm ± 2 mm, A1 for 17 mm ± 9 mm, the distal anterior cerebral artery (A2) for 12 mm ± 3 mm, the recurrent artery of Heubner (RAH) for 16 mm ± 4 mm. Clip placement was possible on the ACoA, A2, and distal segment of A1 in all cases, and on the proximal segment of A1 in one instance. The distance between A1 and the optic chiasm measured 9 mm ± 2 mm.

CONCLUSIONS

The ACoA, A2, and the distal segment of A1 can be visualized and controlled through the transplanum transtuberculum approach. The relationship between A1, gyrus rectus, and optic chiasm is the main determinant for the exposure and control of the vessel. The olfactory nerve can represent a surgical landmark for the identification of the A1 origin. The whole course of the RAH can be visualized trough this approach.

[A3-A3 side-to-side anastomosis combined with endovascular intervention in recurrent complex anterior artery aneurysm: a case report and literature review]

A 28-year-old female patient was admitted to the Second Affiliated Hospital, Zhejiang University School of Medicine, with sudden headache and vomiting for 1 day. CT scan conducted at emergency revealed subarachnoid hemorrhage, whereas digital subtraction angiography demonstrated a wide-neck aneurysm located at A1 segment of the left anterior cerebral artery. The aneurysm was totally coiled using stent assistance, which, however, was recanalized at 3 month follow-up. This patient was then subjected to aneurysm and parent artery occlusion after bypass of the bilateral A3 segments, who recovered well and discharged without ischemic complications.

Microsurgical efficacy and safety of a right-hemispheric approach for unruptured anterior communicating artery aneurysms

OBJECTIVE

We investigated the effectiveness of a right hemispheric surgical approach in treating unruptured anterior communicating artery aneurysms.

METHODS

Between January 2005 and June 2012, 305 patients with anterior communicating artery (Acom) aneurysms were treated using the pterional approach. Among them, 113 who underwent microsurgery with an unruptured Acom aneurysm were enrolled in this study. Every patient was evaluated with digital subtraction angiography preoperatively and CT scans were taken several times postoperatively. Surgical outcomes and complications were evaluated at discharge using the Glasgow Outcome Scale and at 6 months after surgery with CT angiography.

RESULTS

Enrolled patients included 55 males and 58 females with a mean age of 56.3 years (range: 30-75 years). The mean diameter of the aneurysm was 5.8mm (range: 1.9-24.1). Left A1 dominancy was found in 71 patients (62.8%) whereas right A1 dominancy was found in 20 patients (17.7%), and right pterional craniotomies were performed in 92 patients (81.4%) while left pterional craniotomies were performed in 21 patients (18.6%). Complete clip application was achieved in 94.9% of patients (74 of 78) in right-side approach group but in only 81.3% of patients (13 of 16) in left-side approach group. Despite a left A1 dominancy and approached from the right, more than 90% of the patients had an excellent outcome at discharge (GOS 5) and more than 90% a complete aneurysm clipping at the 6-month follow-up CT angiography although it was not statistically significant.

CONCLUSION

Microsurgical clipping of the unruptured Acom aneurysm through a right-side surgical approach showed favorable postoperative clinical and anatomical outcomes, especially aneurysms smaller than 10mm.

[Microsurgical anatomy of perforating branches of anterior communicating artery]

INTRODUCTION

The anterior communicating artery (ACoA) gives perforating branches to the optic chiasma, the hypothalamus and the corpus callosum. Perforating branches are variable (number, direction). Nevertheless, their knowledge is crucial during surgery of this area to spare injuries leading to ischemic post-operative complications.

OBJECTIVE

The objective was to update the anatomical knowledge about perforating branches of the ACoA.

METHODS

The study was led on a series of seven brains taken from human cadavers. An injection of latex neoprene was performed for every case. The region of interest was observed under operating microscope. Were examined: the length of the ACoA, its diameter, its orientation, its configuration and perforating branches (number and areas).

RESULTS

Three cases on five presented with an anatomical variation at the level of the ACoA. The average length of AcoA was 2.1 millimeters (min: 2, max: 2.2). The average diameter of the ACoA was 1.67 mm (min: 1.1, max: 2.1). The average number of perforating branches was 4.2 (min: 2, max: 6). The presence of a median artery of the corpus callosum seemed to correlated with a low number of perforating branches. Branches supplying the optic chiasma seemed to be more numerous.