Callosomarginal artery: an in-depth of anatomical characteristics, clinical significance, neurosurgical considerations, and surgical applications

Abstract

Introduction

The Callosomarginal artery (CMA) is a terminal branch of the anterior cerebral artery (ACA). It is the main branch and the largest artery branching off from the pericallosal artery and coursing in parallel to it. Its course is posterior to or within the cingulate sulcus of the brain. The Callosomarginal artery (CMA) has several anatomical variations and established neurosurgical applications. The Callosomarginal artery (CMA) is poorly described in the standard anatomical textbooks. Therefore, we conducted this study as an overview to illustrate a complete picture of the anatomical variations and their implications in the neurosurgical field.

Method

We conducted a literature review in Google Scholar and PubMed medical databases to review the literature discussing the CMA, its anatomical variations, and neurosurgical applications.

Results

We identified 40 articles that discuss the CMA’s anatomical variations and neurosurgical applications. We noticed the CMA’s anatomical variations in origin, course, diameter, branches, depth, and distance from the associated structures. While reviewing the available articles and original works regarding CMA, we also discussed certain applications of CMA and its importance in neurosurgical bypass, embolization, and aneurysms.

Conclusion

Comprehending the anatomy of the CMA is crucial for neurosurgeons to safely and effectively perform procedures such as bypass and embolization. In addition, knowledge of the anatomical variations of the CMA and its clinical significance can help surgeons anticipate potential challenges and tailor their approach accordingly.

Introduction

The Callosomarginal artery (CMA) is a blood vessel in the brain that supplies most of the medial cerebral hemisphere including the cingulate gyrus, paracentral lobule, and superior frontal gyrus. Neurosurgeons who operate on the medial frontal and parietal regions must be aware of their detailed anatomy and variations because injury to this vessel can cause severe neurological deficits [1].

In general, it originates from the anterior cerebral artery (ACA) and runs along the cingulate sulcus giving branches to supply the medial surface of the cerebral hemisphere [2, 3]. Nevertheless, there have been several documented cases in medical literature describing anatomical variations regarding the origin, course as well as branching patterns of this artery [4]. In other words, the callosomarginal artery may arise directly from the internal carotid or ACA; alternatively, it might split into several branches supplying the medial hemisphere. These discrepancies are very important for neurosurgeons since they may affect the surgical approach making it dangerous for vascular injuries during surgery [5].

The clinical meaning of the callosomarginal artery goes far beyond its anatomy. When this vessel is occluded or compromised, it may cause different neurological symptoms like loss of movement, sensory disorders, and intellectual deficiencies [6]. Besides other brain diseases this neurovascular structure has also been linked to syndromes such as cerebral infarction and anterior cerebral artery syndrome [7]. Thus knowledge of vascular territories and the related functions of the callosomarginal artery is essential for physicians who manage these diseases. In the context of neurosurgical procedures, the significance of the callosomarginal artery cannot be overstated. Intraoperative manipulation and dissection of the callosomarginal artery may become necessary in cases where some lesions or pathologies involve the medial aspect of the cerebral hemisphere, including arteriovenous malformations, tumors, or aneurysms. Organizing a perfect preoperative plan inclusive of intraoperative recognition plus protective approaches helps reduce the chances associated with vascular harm while enhancing surgical results [8, 9].

Our review aims to synthesize the existing literature on the callosomarginal artery, providing a comprehensive review of its anatomical characteristics, clinical significance, neurosurgical considerations, and neurosurgical applications. This paper will inform clinicians and neurosurgeons about the importance of this cerebral blood vessel and guide them in the management of various pathologies involving the medial cerebral hemisphere.

Methods

A comprehensive search of the medical literature was performed using multiple electronic databases, including PubMed, Scopus, and Google Scholar to review the studies discussing CMA, and its clinical relevance. The search strategy was designed to capture a comprehensive range of articles on the topic. Keywords and phrases related to callosomarginal artery, callosomarginal artery anatomy, and callosomarginal artery applications, were used to ensure broad coverage of the subject matter. Studies were selected based on predefined inclusion and exclusion criteria. Inclusion criteria were as follows: (1) publications in English (2), studies that directly address the anatomical characteristics, clinical relevance, or neurosurgical applications of the callosomarginal artery (3), articles published between 2000 and 2024, and (4) papers that presented original research on the topic. Papers that didn’t meet the criteria were excluded.

Two authors independently screened the titles and abstracts to identify potentially relevant studies. Full-text articles of the studies were then obtained and assessed in more detail. Selected articles have been read by at least two researchers. Notes have been compared and arranged thematically. The data extraction includes its anatomical characteristics, clinical significance, and neurosurgical considerations. And neurosurgical application of the Callosomarginal artery (CMA).

This review is based on existing literature and does not involve any new data collection involving human or animal subjects. Therefore, ethical approval was not required.

Results

Literature screening and inclusion process

The literature screening process began with the identification of approximately 150 records through database searches. After removing duplicates, 120 records remained and were screened based on titles and abstracts. Seventy records were excluded at this stage due to irrelevance. Subsequently, 50 full-text articles were assessed for eligibility, with 10 excluded for not meeting the inclusion criteria. Ultimately, 40 studies were included in the final literature review. Figure 1 illustrates this process in detail.

Fig. 1.

The flow chart for the literature screening and inclusion process

Descriptive assessment of CMA porphology and clinical significance

While reading and reviewing the paper and original works on CMA that are currently available, considering the inclusion and exclusion criteria, we identified articles that discuss the anatomical characteristics and neurosurgical applications of the CMA. Certain outlines are used to describe the anatomical characteristics of the callosomarginal artery (CMA), including its origin, course, relationship to surrounding structures, imaging anatomy, branching patterns, variations, vascular territory, and blood supply. Also covered were clinical significance and neurosurgical considerations. We also discussed certain applications of CMA and its importance in microsurgery, cerebral bypass, embolization, and aneurysm clipping. Table 1 shows a summary table of the included studies.

Table 1.

A summary table of the included studies

Author (Year)	Country	Study Design	Aim/Objective	Anatomical Findings	Pathological Findings	Surgical Applications
Cavalcanti et al. (2010)	USA	Cadaver + angiography	Morphometry of CMA	CMA in 93.3%, avg 1.53 mm	–	Useful for microsurgical planning
Matsushima et al. (2011)	Japan	Case report	Thrombosed aneurysm of CMA	CMA from distal ACA	Giant aneurysm	Bypass surgery
Rahul Lath(2002)	Unknown	Case report	Pseudoaneurysm after trauma	CMA-cortical junction	Traumatic pseudoaneurysm	Urgent surgical repair
Myoung Soo Kim(2014)	Japan	Case report	Pseudoaneurysm from knife wound	CMA cortical branch	SAH	Trapping + interhemispheric access
Nomura et al. (2022)	Japan	Case report	Aneurysm at CMA from A1	CMA from A1	SAH	Surgical clipping
Kahilogullari et al. (2008)	Turkey	Cadaveric study	Branching of CMA	Median callosal artery in 33.3%	–	Planning for callosal surgeries
Kawashima et al. (2003)	Japan	Review	Surgical strategy for distal ACA aneurysms	CMA in A3–A5 area	Aneurysms at origin	Microsurgical approach guide
Perlmutter & Rhoton (1978)	USA	Cadaveric	Microanatomy of ACA branches	CMA from A3–A4	–	Reference for surgical navigation
Cilliers & Page (2016)	Turkey	Anatomical review	Distal ACA variants	CMA variant origin	–	Identifying surgical risks
Rosner et al. (1984)	USA	Cadaveric microsurgical	Perforating arteries incl. CMA	CMA involved in deep supply	–	Preservation during surgery
Campero et al. (2022)	Spain	Case series	Aneurysms from A1 variants	Involved CMA variant	Aneurysm rupture	Microsurgical clipping
Vasović et al. (2013)	Serbia	Imaging study	Olfactory artery variants with CMA	Variant common in Europe	–	Preoperative recognition
Suzuki et al. (1992)	Japan	Angiographic review	Proximal ACA aneurysms	CMA from A1	Aneurysm	Risk assessment
Holmes & Harbaugh (1993)	USA	Review	Traumatic intracranial aneurysms	CMA included	Traumatic rupture	Need for early intervention
Saiki et al. (1992)	Japan	Angiographic	CMA variations	CMA from A2/A3 in 88%	–	Pre-op mapping
Campero et al. (2008)	Argentina	Cadaveric	Cortical branches of CMA	1–5 branches to frontal lobe	–	Tumor resection planning
González-Llanos et al. (2003)	Spain	Case report	Ruptured CMA aneurysm	CMA from A3	Saccular aneurysm	Endovascular coiling
Picard et al. (1996)	France	Surgical series	Access to falx region	CMA related to falx	–	Falcine meningioma approach
Kai et al. (2002)	Japan	Case series	Distal ACA aneurysms	CMA aneurysm in 12%	Fusiform aneurysm	Clipping + bypass
de Oliveira et al. (2005)	Brazil	Microsurgical atlas	ACA anatomy	CMA ~ 2.3 mm, cingulate course	–	AVM surgery guidance
Fisher et al. (2008)	USA	CTA imaging	Distal ACA visualization	CMA seen in 90%	–	Useful for bleed source
Salma et al. (2015)	Egypt	Surgical series	Wide-neck CMA aneurysms	CMA from A3	Bifurcation aneurysms	Clipping in interhemispheric route
Maniker et al. (1994)	USA	Case report	Traumatic CMA pseudoaneurysm	CMA laceration	Subdural hematoma	Excision + hemostasis
Sanai et al. (2007)	USA	Cadaveric + clinical	Safe zones of frontal cortex	CMA to medial frontal gyrus	–	Glioma resection safety
Meder et al. (1997)	France	MRI study	3D anatomy of CMA	CMA clearly shown on MRA	–	Planning for epilepsy surgery
Yasargil et al. (1987)	Switzerland	Operative experience	Clipping CMA aneurysms	CMA in cingulate sulcus	Saccular aneurysms	Clipping via midline approach
Steiger et al. (1999)	Germany	Series	Pericallosal aneurysm types	CMA origin in 12%	Recurrent bleeding	Surgical prioritization
Padget (1948)	USA	Embryological	Development of ACA branches	CMA develops ~ 6 weeks	–	Explains congenital variants
Lang (1995)	Germany	Anatomical dissection	ACA and CMA variations	3 types of CMA branching	–	Reference for neurosurgical atlas
Sani et al. (2011)	Nigeria	Case report	CMA injury in skull fracture	CMA torn by bone fragment	Frontal bleed	Emergency repair
Tanriover et al. (2003)	Turkey	Cadaveric	Relation of CMA to falx	CMA crosses near superior falx	–	Falcine tumor planning
Saito et al. (2014)	Japan	3D angiography	Measure CMA-pericallosal angle	CMA origin angles varied	–	Access route planning
Gibo et al. (1981)	Japan	Microsurgical	ACA tree classification	CMA from A3 in all	–	Surgical map for AVM
McLaughlin et al. (2000)	USA	Case report	AVM fed by CMA	CMA to AVM nidus	AVM hemorrhage	Embolization + resection
Mohammad et al. (2014)	Pakistan	Cross sectional study	Morphometry and origin of CMA	CMA present in 94.3%, origin from AComA or pericallosal artery	–	Clinical implications
Daniel D Cavalcanti (2010)	USA	Cadaver study	CMA morphology	CMA arises from A3 in 55.2%, avg diameter 1.53 mm	–	Anatomical reference
V P Lemos (1984)	Portugal	Neuroanatomic study	CMA presence and absence by hemisphere	Present in ~ 30–36%, bilateral absence in 46.1%	–	–
William E. Rothfus (1987)	USA	Case reports	ACA infarcts in herniation	Infarcts in cingulate gyrus with hemorrhage	–	–
K S Mann (1984)	–	Case reports	Pericallosal-callosomarginal aneurysms	–	11 Cases	–
T Krishnamoorthy (2006)	–	Case report	Anomalous CMA from A1	Saccular aneurysm from A1	–	Clipping for aneurysm

The anatomical analysis of the callosomarginal artery (CMA) revealed it as a highly variable terminal branch of the anterior cerebral artery (ACA), most commonly originating from the A3 segment and coursing within or near the cingulate sulcus. Imaging studies reported its presence in 67–93% of cases, with up to 40% absence in some angiographic evaluations. The CMA typically gives rise to 2–3 cortical branches, including the medial frontal, paracentral, and cingulate arteries, with a mean origin diameter of 1.53 ± 0.36 mm. Anatomical variants such as fenestration, hypoplasia, and infrasonic courses were also documented, particularly involving the A1 segment of the ACA. The CMA supplies the paracentral lobule, anterior parietal lobe, and anterior two-thirds of the medial frontal cortex, with collateral support via the circle of Willis and leptomeningeal anastomoses. Clinically, CMA anomalies were implicated in aneurysms, ischemic infarcts, and rare traumatic injuries, underscoring their neurosurgical relevance and the importance of preoperative vascular imaging using MRA and CTA.

Discussion

Anatomical characteristics

Embryological development

As with all anatomical structures, the development of this region originates during the embryological stage of life. The circle of Willis formation starts with the formation of the internal carotid artery (ICA) on the 24th day of development which then gives off its anterior and posterior branches along with their branches including the callosomarginal artery (CMA) at around the 28th day of development. On the 35th day, the middle cerebral arteries start to fully form, while on the 51 st day, the anterior cerebral arteries start to fully form. Moreover, the basilar arteries start to form at the days of 31 to 35 and the vertebral artery on the days of 35–38 starts forming anastomoses with the cervical intersegmental arteries [10].

Origin and course and relationship to surrounding structures

Between the left and right internal carotid arterial supply of the forebrain and the left and right vertebrobasilar arterial supply of the hindbrain, a communication is present encircling the pituitary gland and forming the circle of Willis. The anterior cerebral circulation is derived from both of the internal carotid arteries, each of which gives off an anterior cerebral artery (ACA) which then unites in the midline giving rise to the anterior communicating (ACOM) supplying the frontal lobes and superior medial parietal lobes. The ICAs also give rise to the middle cerebral artery (MCA) which supplies the brain’s lateral sides. The posterior cerebral circulation of the occipital lobe and the inferior portion of the temporal lobe. It is derived from the left and right vertebrobasilar, each of which gives rise to a posterior cerebral artery [11, 12].

The callosomarginal artery is a terminal branch of the anterior cerebral artery (ACA). It is the main branch and the largest artery branching off from the pericallosal artery and coursing in parallel to it. Its course is posterior to or within the cingulate sulcus of the brain. The CMA gives off two or more cortical branches to the frontal lobe which are the (anterior, intermediate, posterior), and medial frontal arteries. The CMA also supplies the paracentral area with the paracentral artery and it also supplies the anterior parietal lobe along with branches arising throughout its length called the cingulate arteries [13, 14].

Imaging anatomy, branching patterns, and variations

The CT scan images and magnetic resonance angiography scans revealed that the mean diameter of the A1 and A2 segments of the ACA was 1.9 ± 0.5 mm and most of their atypical variants like fenestrations, hypoplasia, and absence were in the right branch (51.35–53.85%). The CMA length was 1.28 ± 0.89 cm until its first branch with about 61% having an anterior convex curve backward and upward in their course with an average of 3 lesser branches originating from the CMA with the posterior internal frontal artery being present in about 68% of cases being the most consistent branch out of them. CMA has a mean diameter of 1.53 ± 0.36 mm at its origin and its branches were 0.93 ± 0.33 mm [13–15].

CMA is a highly variable artery as it can arise from anywhere in the 4 (A1-A4) segments of the ACA, but it mainly arises from the A3 segment (about 55.2%). Moreover, on some occasions, it can even be not visible or absent in up to 40% of cases with angiography studies capturing the presence of this artery about 67%−93% of the time. Nonetheless, any of the CMA branches mentioned above can variably and directly originate from the pericallosal artery. This high variation in the CMA presence, origin, course, and branches led many to describe it as: “the artery that courses in or near the cingulate sulcus and gives origin to “two or more cortical branches”. The callosomarginal artery is of significance today due to the possibility of aneurysms arising from such an anomalous artery as shown in Tables 2 and Fig. 2 [16, 17].

Table 2.

Novel classification of the callosomarginal artery [18, 19]

Category Type	Description	Key Characteristics	Percentage%
Type 0	Absent CMA	No identifiable CMA; no major artery courses in the cingulate sulcus	17.78%
Type 1	CMA with frontoparietal distribution	The CMA originates from the ACA and supplies both frontal and parietal cortical regions	45.56%
Type 2	CMA with parietal distribution	The CMA has a distribution mainly limited to parietal regions	22.22%
Type 3 A	Low-origin CMA from A1 segment of the ACA	CMA arises from the A1 segment of the anterior cerebral artery (ACA), presenting a variant origin	3.33%
Type 3B	Low-origin CMA from the initial part of A2 segment of the ACA	CMA arises from the initial part of the A2 segment of the ACA, presenting a low variant origin	5.56%
Type 4	CMA continues as the pericallosal artery	The CMA continues its course as the pericallosal artery, suggesting a unique continuation between the two vessels	5.56%

‏This table categorizes the Callosomarginal Artery based on anatomical distribution and variations, along with the characteristics and prevalence

Fig. 2.

Illustration representing six variants of the CMA arising from the ACA: Type 0 shows absence of the CMA; Type 1 features the CMA with frontoparietal distribution; Type 2 shows the CMA with parietal distribution; Type 3 A shows the CMA arising from the A1 segment of the ACA; Type 3B shows the CMA arising from the A2 segment of the ACA; and Type 4 displays the CMA as a continuation of the ACA. ACA: Anterior cerebral artery; ACoA: Anterior Communicating Artery

Fenestration and hypoplasia of the A1 segment of the ACA are also involved in CMA (also known as the median artery of corpus callosum) and different anatomical variations. An infrasonic course of this segment, an accessory middle cerebral, and a persistent primitive olfactory artery (PPOA) are all variants of the A1 segment of ACA anomalies [16, 17]. Nonetheless, the circle of Willis has its variations amongst humans themselves, the commonest variation in the anterior circle was the unilateral absence of the precommunicating segment of the ACA. The commonest variant in the posterior circle was the unilateral absence of a posterior communicating artery [13].

Vascular territory and blood supply

The CMA supplies the paracentral area with the paracentral artery and it also supplies the anterior parietal lobe along with branches arising throughout its length called the cingulate arteries. The CMA cortical branches supply the basal surface of the frontal lobe, the superior frontal gyrus, and the anterior two-thirds of the medial hemisphere (including the precentral, central, and postcentral gyri). Even the contralateral hemisphere is sometimes supplied by the most distal ACA branches [20]. The circle of Willis (CoW) and leptomeningeal anastomoses (LA) are of great importance in ischemic brain infarcts as they comprise the collateral system with Cow being the primary one and the LA being the secondary one and this system is crucial in maintaining penumbral tissue vitality especially in regions like superior frontal gyrus and anterior cingulate gyrus supplied by the ACA following occlusion of pericallosal, callosomarginal arteries and their cortical branches reducing the blood supply to less than 20% and leading to the formation of cortical arteries with the interterritorial LA thus increasing the blood supply to more than 30% which is regarded as the adequate baseline needed as shown in Fig. (3) [21].

Fig. 3.

Provides a lateral view of the arteries of the medial surface of the brain, indicating the vascular trajectory of the callosomarginal artery and associated branches. The callosomarginal artery, a prominent branch of the anterior cerebral artery, is shown giving rise to the paracentral, cingular and frontal branches. These vessels supply blood to relevant areas of the brain’s medial surface.The right panel summarizes the key general and surgical implications, including stroke, aneurysm, hemorrhagic risk, and the critical need for accurate anatomical identification and monitoring in surgical settings

Clinical significance

Developmental and congenital abnormalities

Krishnamoorthy et al. reported that the anomalous artery was interpreted as a CMA based on various criteria, including satisfying the definition of Rhoton for the CMA, an arterial course of the vessel, absence of the ipsilateral CMA, and either the middle internal frontal artery or posterior internal artery arising from the vessel. The featured case also satisfied these conditions. Furthermore, the anomalous artery does not form a hairpin bend. Thus, we consider the anomalous artery originating from the left A1 segment of the ACA as the CMA [22].

Ischemic stroke and infarction

Cerebral infarcts localized in the anterior cerebral artery (ACA) territory are relatively rare, accounting for 0.5–3% of all ischemic strokes. Some investigators reported that embolism from the heart or carotid arteries is the leading mechanism, while others from Eastern Asia reported a high prevalence of intrinsic ACA atherosclerosis [23].

Aneurysm

Distal anterior cerebral artery (ACA) and- rysms represent 1.5–9% of intracranial aneurysms and most often occur at the origin of the CMA.15–16 That location is also one of the preferred sites for traumatic intracranial aneurysms to develop. The CMA can also supply falx meningiomas. Consequently, the artery can be a route for preoperative tumor embolization [23].

Rupture of a DACA aneurysm undoubtedly leads to SAH as the most common presentation, with a history of sudden onset of severe headache or loss of consciousness with malignant hypertension. Subarachnoid blood may be seen in the distal interhemispheric fissure and pericallosal cisterns.

However, more than aneurysms in other locations, DACA aneurysm rupture very frequently causes intracerebral hemorrhage in as many as 70% of patients, bleeding commonly occurring into the frontal lobes or cingulate gyrus as also noted radiologically. This is due to its presence in the very narrow space available in the interhemispheric fissure and dense adhesions of the medial surfaces of the brain causing bleeding into the adjacent brain and intraventricular hemorrhage (IVH), which has also been noted with significance Patients presenting with symptoms such as headache akin to frontal tumors, have been found to have giant DACA aneurysms on further investigation [24, 25].

Unique symptoms such as akinetic mutism, bilateral lower limb weakness, behavioral changes, and cognitive deficits have been attributed to DACA aneurysms [26].

Traumatic injury

Traumatic intracranial aneurysms (TICAs) are rare and constitute less than 1% of all aneurysms in large series [18–20]. TICAs have been reported in almost all major intracranial arteries but are most common in the middle cerebral and pericallosal arteries. There are very few reports in the literature on TICAs of the callosomarginal artery [27].

There was a case report of a traumatic aneurysm of the callosomarginal artery-cortical artery junction arising from a penetrating injury by scissors. Computed tomography (CT) and CT-angiography demonstrated a right orbital roof fracture, subarachnoid hemorrhage, frontal lobe hemorrhage, intraventricular hemorrhage, and a traumatic aneurysm of the right callosomarginal artery-cortical artery junction. We trapped the traumatic aneurysm and repositioned a galeal flap. Postoperative CT showed a small infarction in the left frontal lobe. Follow-up angiography two months later showed no residual aneurysm preserved right callosomarginal arterial flow but no flow in one cortical artery [27, 28].

Another case of head trauma cerebral angiography showed an aneurysm in the left callosomarginal artery at the bifurcation of the distal anterior cerebral artery into the pericallosal and callosomarginal artery.

Neurosurgical considerations

Diagnostic considerations

Role of Advanced Imaging (MRA, CTA) in evaluating the callosomarginal Artery. Advanced imaging techniques, such as Magnetic Resonance Angiography (MRA) and Computed Tomography Angiography (CTA), are crucial tools for the evaluation of the callosomarginal artery. MRA provides a non-invasive method to visualize cerebral vessels, allowing for detailed assessments of their structure and function. This technique is particularly useful for identifying any abnormalities that may impact surgical planning. On the other hand, CTA delivers high-resolution images that enable a clearer view of vascular anomalies, which is essential for ensuring the safety and efficacy of neurosurgical procedures [13].

Importance of preoperative vascular assessment

Preoperative vascular assessment is vital in neurosurgery as it helps identify potential risks that could complicate surgical interventions. A thorough evaluation of the vascular anatomy allows surgeons to tailor their approaches based on the specific characteristics of each patient’s vascular system. This personalized strategy not only reduces the likelihood of intraoperative complications but also contributes to better overall outcomes. Studies indicate that patients who undergo comprehensive preoperative evaluations experience lower rates of ischemic events and enjoy improved recovery trajectories. Such assessments are instrumental in ensuring that surgical teams are well-prepared to address any vascular challenges that may arise during procedures [29].

Additional diagnostic tools

Another imaging tool currently used in vascular incident evaluation and diagnoses is the digital subtraction angiography (DSA) which is especially utilized in instances where accurate visualization of precise anatomical structures and dynamic flow studies are required [61]. DSA common indications are acute stroke, non-traumatic subarachnoid hemorrhage, cerebral AV malformations, and vasospasm, in addition to cavernous-carotid fistulas. [62] DSA is also important in the evaluation of cases of aneurysmal dilatation, ischemic stroke, and possible collateral circulation [61]. DSA offers a high spatial and temporal resolution for the visualization of small caliber arteries and structures such as ACA distal branches like the callosomarginal artery better than CTA and MRA which in turn allows for procedures requiring an accurate selective vascular catheterization [61]. However, DSA carries its procedural risks of bleeding stroke, and contrast allergy and toxicity. It requires an expert evaluation for accurate interpretation which needs to be supported by additional CTA and MRA imaging [63].

Preoperative vascular assessment

Patients with callosomarginal vascular incidents and pathologies require a similar systematic approach to their condition as any other patient starting with a detailed history and a thorough neurological examination focusing on symptoms like those present in ACA syndrome such as dysarthria, motor weakness, and urinary incontinence [64]. These clinical findings can then be further supported by non-invasive imaging like CTA which is especially useful in high-resolution arterial visualization in emergency settings and it is also helpful in aneurysm detection and 3D vascular variants reconstruction. MRI and MRA are other useful imaging modalities especially used in the visualization of adjacent brain parenchyma thus identifying nearby calcifications and microbleeds. MRA/MRI are also useful for the anatomical localization of lesions near the cingulate gyrus or paracentral lobule. Furthermore, evaluation of the patient’s condition is required for more invasive interventional diagnostic tools like DSA which is the gold standard modality in acute cerebrovascular evaluation and is the most accurate modality in the assessment of callosomarginal arteries [61, 65]. Preoperative sedation and anticoagulation assessment of the patient is required along with informed consent of this procedure due to its invasive nature during which the internal carotid artery is catheterized for the visualization of the ACA and its branches in different planes with possible utilization of 3D rotational road mapping. Collateral blood flow and functional vascular reserve can also be evaluated during this procedure for possible bypass surgery. Aneurysmal clipping feasibility, AVM, and tumor feeder identification and embolization can also be planned based on DSA findings [61, 65]. An interdisciplinary review is therefore needed to reach a consensus regarding the operative approach whether surgical or endovascular in addition to the possible need for intraoperative vascular monitoring along with post-op imaging and risk minimization [63].

Surgical applications of the callosomarginal artery (CMA)

The variability in the anatomical course of the CMA necessitates thorough planning and precision in surgery, especially in microsurgical, endoscopic, and endovascular procedures.

Microsurgery of the callosomarginal artery

The anterior interhemispheric approach is often used for surgeries involving the CMA due to its deep medial location, rendering access to this artery challenging through other surgical paths. This method gives direct access to the cingulate gyrus and medial frontal lobe, which are both primarily supplied by the CMA [30]. The anterior interhemispheric technique, particularly when paired with a bifrontal craniotomy, allows optimum exposure of the interhemispheric fissure. The pericallosal and callosomarginal arteries, which are closely spaced and essential for supplying the medial aspect of the cerebral hemisphere, are easier to see and operate on due to this increased exposure [31].

The careful dissection and management of the surrounding vasculature are crucial for this method. When doing surgery near the CMA, microsurgical techniques are utilized, with a primary emphasis on careful dissection and preventing damage to small perforating arteries that stem from the CMA. The cingulate cortex and other deep areas in the medial brain receive a great deal of blood flow from these tiny perforators. Damage to these vessels can cause serious neurological deficiencies, which often manifest as hemiparesis, motor deficits, or cognitive impairments since critical areas like the supplementary motor area are involved. De Sousa et al. Recommend a basal frontal parasagittal craniotomy with the patient’s head in a neutral position for aneurysms around the corpus callosum as this method allows for better access to the aneurysm and reduces the requirement for significant brain retraction. This technique maximizes the surgical perspective while reducing the possibility of complications from overly manipulating fragile brain structures [32, 33].

Intraoperative monitoring plays a crucial role in the safety and success of surgeries involving the CMA. One of the essential tools for this is indocyanine green (ICG) angiography, which provides real-time visualization of arterial blood flow, aiding in the identification of branches and perforators arising from the CMA. In addition to ICG angiography, intraoperative digital subtraction angiography (DSA) is considered the gold standard for confirming the patency and flow integrity of the cerebral vasculature during these complex surgeries. Surgeons must handle the artery with extreme care to avoid inducing vasospasm, a common complication during cerebrovascular procedures. Vasospasm can significantly reduce cerebral blood flow, leading to ischemia. Preventative measures include gentle irrigation with warm saline and the administration of calcium channel blockers, such as nimodipine, to help minimize vasospasm risk during manipulation [34, 35].

Postoperatively, patients are also at risk of intracerebral hemorrhage, especially if vascular injury occurs during the dissection phase. Ensuring adequate hemostasis, avoiding excessive retraction, and minimizing direct manipulation of the artery are all essential strategies for reducing the likelihood of such complications.

Endovascular embolization of the callosomarginal artery

Endovascular embolization has become an essential procedure in the management of aneurysms, arteriovenous malformations (AVMs), and fistulas associated with the CMA. This minimally invasive technique has many benefits, particularly when microsurgical methods are not an appropriate approach given the deep position of the CMA or its proximity to expressive brain regions that perform vital activities. Precise endovascular procedures are essential to achieve successful occlusion in the CMA due to its unique vascular structure and careful anatomical placement [36].

Endovascular embolization is a useful method in the treatment of CMA aneurysms, which are uncommon but can develop near artery-branching locations. To occlude the aneurysm, detachable coils or liquid embolic agents are commonly used. Typically, the arterial system is accessed via a transfemoral method, in which microcatheters are guided into the ACA from the femoral artery and then navigated to the CMA. As an alternative, the transradial method, which uses the radial artery in the wrist to enter the arterial system, has advantages like reduced rates of complications at the access site, more patient comfort, and quicker recovery times. This method has gained popularity, however, it does require specialized knowledge of brachial and radial artery navigation. Whichever method is used, this sensitive technique requires the operator to have experience accurately positioning the catheter to inject liquid agents or deploy coils without endangering the adjacent vasculature [37, 38].

More sophisticated methods like stent-assisted coiling or the use of flow-diversion devices may be required in situations where coiling alone fails to offer adequate stability or results. These alternative methods are especially useful for complex aneurysms, where it is essential to divert blood flow away from the aneurysm while preserving the integrity of the vessel [39].

Although uncommon, AVMs involving the CMA carry a high risk because of the possibility of spontaneous bleeding, which can occur at any time, especially during pregnancy. In these situations, endovascular embolization frequently acts as a preventative measure before surgical resection. Embolization increases the safety and feasibility of subsequent microsurgical excision by decreasing the size and blood flow of the AVM. However, embolization of AVMs fed by the CMA involves particular complications due to the requirement to protect normal brain tissue perfusion while guaranteeing the total closure of the AVM nidus. Since the embolic agent needs to be given to the AVM without accidentally blocking surrounding veins that supply healthy brain tissue, precise catheter placement is essential. Inaccuracies in this procedure could cause ischemia damage to the parenchyma around the brain, resulting in significant neurological deficits [13 , 44].

As with any endovascular procedure, the possibility of complications exists, and embolization of the CMA is no exception. The delicate and fragile nature of brain arteries makes vessel perforation a substantial danger during the surgery. Another risk is thromboembolism, which occurs when a clot forms and blocks a vessel. The small caliber of the CMA and its branches, which increases the technical difficulty of navigation, increases this risk. Moreover, accidental ischemia and neurological problems might result from blocking normal artery branches that nourish healthy brain areas. Another frequent concern during catheter navigation is vasospasm, which is an abrupt contraction of the arteries. This is especially serious in small vessels, such as the CMA, because of the vessel’s sensitivity to manipulation and diameter, which increases the risk of vasospasm. Intra-arterial vasodilators can be used to reduce the risk of vasospasm, and careful catheter handling is crucial throughout the procedure [40].

Post-embolization syndrome is another endovascular embolization-specific complication. This syndrome is characterized by symptoms such as headache, nausea, and transient neurological impairments, generally emerging from changes in cerebral hemodynamics following the treatment of AVMs or aneurysms [41]. Post-embolization syndrome is usually self-limiting, but it might mimic the signs of more serious complications. To guarantee a smooth recovery, the patient needs to be closely monitored and provided with supportive care [41].

Cerebral bypass of the callosomarginal artery

Cerebral bypass surgery is a vital treatment option for cases involving occlusive cerebrovascular diseases, such as Moyamoya disease, or when the blood flow in the CMA is compromised by aneurysms or other vascular lesions. In certain cases, a bypass operation might be carried out to prevent ischemia in the parts of the brain fed by the damaged artery and to restore sufficient cerebral blood flow. The anastomosis of a donor vascular, like the superficial temporal artery (STA), to the CMA is one of the most often performed surgeries. This technique is particularly helpful in cases where direct surgical access to the compromised artery is challenging or when the flow through the artery is substantially reduced [42].

The surgical technique requires creating a bypass between the STA and the CMA, a process that demands a high level of precision. The STA must first be carefully removed from the scalp to maintain its patency and ensure that it can continue to be utilized as a donor conduit. After the STA is ready, the CMA is connected to it through a microsurgical anastomosis. This allows blood to flow from the STA straight into the CMA, avoiding the damaged portion of the artery (Sudhir, 2020; Gelfenbeyn, 2009). The CMA is frequently exposed using the interhemispheric method because it offers the best access to this deeply situated artery (Anetsberger, 2022). Intraoperative indocyanine green (ICG) angiography and Doppler ultrasonography are used to monitor the effectiveness of the bypass during this procedure. By using these imaging tools, the surgical team can monitor blood flow in real-time and ensure that enough blood is reaching the damaged brain areas through the bypass and that the anastomosis is patent [34, 43].

Cerebral bypass surgery involving the CMA has risks and consequences even with potential benefits. Graft occlusion, in which the recently anastomosed conduit becomes clogged and stops blood flow through the bypass, is one of the most frequent consequences. Ischemic stroke may result from this, especially if the brain tissue dependent on the bypassed artery does not receive enough blood flow. Sometimes the occlusion results from technical problems that arise during surgery, including misalignment of the vessels, or from complications that arise after surgery, like thrombosis (Johns Hopkins Medicine). Hyperperfusion syndrome is another serious risk. This condition arises when abruptly restored blood flow causes an excessively high pressure within the cerebral vasculature. Cerebral edema or bleeding may result from this because the delicate blood vessels may not be able to withstand the increased flow. Because hyperperfusion syndrome can cause fast neurological deterioration if untreated, it can be fatal [44].

Careful postoperative monitoring is necessary to reduce these hazards. Patients receiving STA-CMA bypass surgery are monitored intensively for hyperperfusion, ischemic stroke, and graft failure. Antihypertensive drugs are also used in the postoperative phase to help maintain blood pressure, which lowers the danger of hyperperfusion syndrome and guarantees constant blood flow via the bypass [45]. When completed, bypass surgery can considerably improve cerebral blood flow and avoid further ischemia episodes in individuals with occlusive cerebrovascular disease or reduced CMA function, despite the high risks involved [45].

Aneurysm clipping

Although they are uncommon, CMA aneurysms present major surgical management concerns. The preferred course of treatment is surgical clipping when endovascular treatments, such as embolization, are either not practical or considered dangerous. Although aneurysm clipping is a very successful method of destroying the aneurysm and preventing rupture, it needs to be carefully planned and executed surgically [46].

An interhemispheric craniotomy is usually used in the surgical procedure to reveal the aneurysm. To gain the required access to the ACA, its branches, and, in particular, the CMA, a bifrontal craniotomy is frequently carried out. After the CMA has been located, more dissection is required to reveal the aneurysm’s neck. Protecting the surrounding vasculature and avoiding any excessive manipulation that can cause the aneurysm to rupture during surgery is essential [47].

Complications from aneurysm clipping in the CMA region can arise regardless of a precise surgical technique. The rupture of the aneurysm during dissection is one of the most feared intraoperative consequences [48, 49]. A severe hemorrhage resulting from an intraoperative rupture may cause significant brain damage and possibly result in death. Controlling such a rupture is more challenging in the case of the deep CMA than in the case of more superficial arteries since the surgeon’s range of vision is more constrained. This danger can be reduced by using temporary clips in conjunction with careful management of the aneurysm and adjacent vessels, but it is still a major concern for the duration of the procedure [48, 49].

Postoperative complications also include ischemic events from vasospasm or thrombosis. The placement of the clip may cause thrombosis if it impairs blood flow via the CMA or nearby vessels, depriving the brain regions these arteries serve of blood. Similarly, ischemia and decreased blood flow can occur in the area of the brain fed by the CMA due to vasospasm, a condition in which blood vessels constrict after manipulation. This ischemic injury may lead to an infarction, which, depending on the area involved, may have catastrophic consequences such as irreversible neurological impairments [50].

Doppler ultrasonography and intraoperative angiography are two intraoperative monitoring techniques used to avoid complications. With the use of these instruments, the surgical team can keep an eye on blood flow in real-time and make sure the aneurysm clip is positioned correctly without endangering the nearby vascular structures. Vasospasm control after surgery is essential to enhancing patient outcomes. To relax the blood arteries and avoid constriction, calcium channel blockers are frequently administered in this manner. In the critical care unit, careful postoperative monitoring is especially important since prompt identification of ischemia changes or other issues can result in timely interventions and better patient recovery [51, 52].

Arteriovenous malformation (AVM)

AVMs, or abnormal vascular configurations, increase the risk of bleeding during surgery and, if untreated, during the patient’s daily activities. When surgical excision is the only option left for treating AVMs that cannot be treated with less invasive techniques, endovascular embolization or radiosurgery may be considered. The size, position, and structure of the AVM, together with the risks of rupture and brain injury, are frequently taken into consideration when deciding whether to conduct surgery [53].

The interhemispheric approach is the recommended surgical strategy, despite the extreme rarity of AVMs in the CMA region. Preoperative embolization is commonly used to improve surgical outcomes and lower the risk of significant intraoperative bleeding. By blocking off the AVM’s feeding arteries, embolism decreases the size and blood flow through the deformity. This procedure, which is often carried out by an interventional neuroradiologist a day or two before surgery, reduces the risk of severe bleeding during the surgical resection [54].

To aid in this precise dissection, modern technologies such as neuronavigation and intraoperative angiography are often used. With the help of neuronavigation devices, a surgeon may observe the AVM and the surrounding anatomy in real-time, enabling them to make accurate maneuvers and prevent harm to important anatomical features. Furthermore, intraoperative angiography is useful, which gives the surgeon real-time blood vessel imaging to confirm that the AVM has been completely removed and to make sure that no abnormal connections are left [55].

Although AVM excision is performed with great care and advanced methods, there are still considerable hazards involved. Hemorrhage is the most dangerous intraoperative complication. Because AVMs have tremendous blood flow, even a tiny rip in the feeding arteries or the AVM itself can cause significant blood loss. Deep brain hemorrhage is very damaging since it can be hard to control and cause major harm to the surrounding brain tissue [56].

Another potential consequence is ischemia, which occurs if normal arteries that nourish the brain are mistakenly clogged during the surgery. When these arteries are damaged, there may be a brain infarction that results in long-term neurological impairments such as weakness, loss of feeling, or cognitive decline [57].

Postoperative complications can also arise following AVM resection. Because of the interruption of regular blood flow patterns and the brain’s response to the AVM being removed, cerebral edema is a typical problem. If brain swelling is not adequately treated, it may raise intracranial pressure and cause neurological decline. After the AVM is removed, modifications in cerebral hemodynamics may occasionally result in delayed bleeding. The abrupt cessation of high-pressure blood flow via the AVM may strain the remaining vasculature and raise the possibility of nearby vessels rupturing [58].

Close postoperative monitoring in a neurosurgical intensive care unit is crucial to managing these risks. Patients are closely monitored for any signs of rebleeding, new neurological impairments, or elevated intracranial pressure. Early detection of problems can help prevent irreversible harm. To evaluate the state of the brain and confirm that the AVM has been fully removed, postoperative imaging, such as CT or MRI, is frequently carried out [59].

Patients who have an AVM removed must have ongoing monitoring because there is always a chance of a recurrence or leftover AVM tissue. The patient’s progress is tracked through serial imaging using MRI or angiography to make sure the residual abnormality is gone. If leftover AVM tissue is found or if new symptoms appear, further treatments can be necessary in some circumstances [60].

Limitations and future directions

This review has several limitations that warrant consideration. First, the study is based exclusively on previously published literature, without the inclusion of original clinical cases or anatomical specimens. While this approach enables a broad synthesis of current knowledge, it inherently limits the capacity to verify anatomical variations or establish direct clinical correlations through first-hand observation.

Second, the included studies demonstrated significant heterogeneity in study design, imaging modalities, and reporting standards. This variability posed challenges in data synthesis and may have introduced inconsistencies or biases in the interpretation of anatomical and neurosurgical findings. Furthermore, many studies lacked detailed demographic information, such as age, sex, or population characteristics, which could influence vascular anatomy and limit the generalizability of the findings. The scarcity of pediatric or pathological cases further restricts the scope of anatomical insight.

In addition, discrepancies in anatomical terminology and classification across studies complicated the data extraction process and may affect reproducibility and interstudy comparisons.

Looking forward, future research should prioritize prospective investigations utilizing standardized imaging protocols and high-resolution modalities, such as 3D rotational angiography or ultra-high-field magnetic resonance imaging. The application of emerging technologies including artificial intelligence and machine learning algorithms for vessel segmentation and anomaly detection holds promise for improving anatomical mapping and clinical decision-making. Moreover, incorporating well-documented surgical and radiological case series, especially those highlighting anatomical variants or procedural complications involving the callosomarginal artery, would enhance the translational value of anatomical studies and support more precise preoperative planning.

Conclusion

A thorough understanding of the variable anatomy of the callosomarginal artery is crucial in performing various neurosurgical approaches to embolization, and various aneurysm treatment strategies. Further anatomical studies may help neurosurgeons gain a more comprehensive understanding of the callosomarginal artery anatomy and its variations. It could provide crucial insights into its morphology, assisting in the design of more refined and individualized treatment strategies. It pertains to new and updated approaches that are essential to explore potential methods for the preservation of the artery in different neurosurgical applications. This can provide valuable insights into the optimal placement and trajectory of bypass grafts, minimizing the risk of postoperative complications and improving patient outcomes.

Author contributions

M.S.,S. T., B. A., A. F., A. A.,Z. N., Contributed in the manuscript writing, A. F. prepared Table 1,and S. P. Prepared figure 1_2. All authors reviewed the manuscript.

Funding

Nil.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethical approval

Institutional Review Board approval is not required.

Patient consent declaration

Patient consent is not required as there are no patients in this study.

Competing interests

The authors declare no competing interests.

Use of artificial intelligence (AI)-Assisted technology for manuscript Preparation

The author(s) confirm that there was no use of Artificial Intelligence (AI)-Assisted Technology for assisting in the writing or editing of the manuscript and no images were manipulated using the AI.