Cavernous Venous Malformations Research Articles

The value of cryoablation in orbital surgery.

Aim of this article is to give an overview of the technical background and the advantages of modern devices for different applications of cryoablation in cranio-orbital neurosurgery.The treatment of orbital lesions is complicated by the complex and potentially inapparent anatomy due to retro-orbital fat. With the help of cryoprobes different well-defined lesions such as cavernous venous malformations can be safely and effectively removed thanks to the cryoadhesive effect. Their use has been described in several different approaches including traditional lateral or transcranial orbitotomy but also anterior transconjunctival as well as transnasal endoscopic approaches. Recently, single-use devices were introduced that allow the use of cryosurgery also without the need for large investment or service costs.

Radiologic Features of Well-circumscribed Orbital Tumors With Histopathologic Correlation: A Multi-center Study.

To delineate specific imaging characteristics of solitary fibrous tumors, schwannomas, cavernous venous malformations, and well-circumscribed orbital lymphoma. Patients undergoing excisional biopsy of solitary fibrous tumor, schwannomas, cavernous venous malformations, or well-circumscribed orbital lymphoma with preoperative MRIs available for review were identified at 3 academic centers in the United States and Australia. An exploratory statistical analysis was performed to identify important radiologic features, which were subsequently included in a random forest model. Histopathologic correlates were evaluated in representative cases. A total of 91 cases were included with a mean age of 52.9 ± 17.2 years. Nearly all solitary fibrous tumors were located in the anterior or mid orbit (87.5%) and they more commonly demonstrated intralesional heterogeneity on T2-weighted imaging (45.5%) ( p < 0.01). Compared with the other tumors, schwannomas tended to be intraconal (66.7%) and were often in the mid or posterior orbit (83.4%) ( p < 0.01). Cavernous venous malformations characteristically demonstrated progressive contrast enhancement (93.9%; p < 0.01). Most lesions in all 4 groups were hypointense on T1-weighted imaging (80%-100%; p = 0.14) and only well-circumscribed orbital lymphoma tended to also be hypointense on T2 (81.8%) ( p < 0.01). Finally, cases of lymphoma had significantly lower apparent diffusion coefficient ratios (0.9 ± 0.2) ( p < 0.001), while the other 3 groups were not significantly different from one another (cavernous venous malformations: 1.8 ± 0.4; schwannomas: 1.8 ± 0.5; and solitary fibrous tumor: 1.6 ± 0.6) ( p = 0.739). Key features that aid in the differentiation of these 4 tumors from one another include T2 intensity and homogeneity, early contrast-enhancement pattern, and ADC ratio.

Biological identity of orbital cavernous venous malformations.

Vascular anomalies comprise a wide spectrum of clinical manifestations related to disturbances in the blood or lymph vessels. They correspond to mainly tumors (especially hemangiomas), characterized by high mitotic activity and proliferation of the vascular endothelium, and malformations, endowed with normal mitotic activity and no hypercellularity or changes in the rate of cell turnover. However, the classifications of these lesions go beyond this dichotomy and consist various systems adapted for and by different clinical subgroups. Thus, the classifications have not reached a consensus and have historically caused confusion regarding the nomenclatures and definitions. Cavernous venous malformations of the orbit, previously called cavernous hemangiomas, are the most common benign vascular orbital lesions in adults. Herein, we have compiled and discussed the various evidences, including clinical, radiological, morphological, and molecular evidence that indicate the non-neoplastic nature of these lesions.

Incidence and Risk Factors for Poor Postoperative Visual Outcome After Excision of Orbital Cavernous Venous Malformations.

To determine the incidence and risk factors for poor postoperative visual outcome (PPVO) after removal of orbital cavernous venous malformations (OCVMs). Retrospective case-note and imaging review for patients undergoing excision of OCVMs, with estimation of odds-ratios (ORs) and relative risks (RRs) for visual loss in relation to the position of the mass, surgical approach, and patient factors. The 290 patients (179 female; 62%) presented at a mean age of 46.4 years: 243/287 (85%) OCVMs were intraconal, with 213/243 (88%) located freely in the posterior two-thirds of the orbit, and 30/243 (12%) wedged tightly in the apex. PPVO was observed in 6.9% (20/290) patients, solely after removal of intraconal lesions, Univariate analysis showed increased risk with preoperative relative afferent pupillary defect (RAPD) (14/107 [13%]; RR 2.9; P = 0.011), apical lesions (9/30 [30%]; RR 5.8; P < 0.001), situated below optic nerve (15/115 [13%]; RR 3.3; P = 0.007), fibrous masses (14/78 [18%]; RR 6.7; P = 0.005), or intraoperative diastolic blood pressure below 50mmHg (10/64 [16%]; RR 2.8; P = 0.007). Multivariate analysis found apical extension (OR 4.9; P = 0.036) and fibrous lesions (OR 10.0; P = 0.035) as strongest predictors for PPVO. The incidence of complete visual loss (no light perception) was 4.1% (12/290); half of these patients had preoperative acuity of counting fingers or worse, 8 (67%) had RAPD, 7 (58%) wedged apical lesions, and 8 (67%) were below the optic nerve. PPVO after excision of OCVMs can occur in up to 5% of "free" retrobulbar intraconal lesions and in approximately one-third of apical lesions.

Chorio-Retinal Folds Associated With Orbital Cavernous Venous Malformations.

To determine the incidence of clinically detectable chorio-retinal folds (CRFs) with orbital cavernous venous malformations (OCVMs) and their recovery. Retrospective case-note and imaging review, with estimation of odds ratios in relation to the position and volume of the mass. Records for 402 patients were reviewed, 83 (21%) having CRFs. The mean logarithm of minimum angle of resolution acuity was similar with or without CRFs (0.37 and 0.31, respectively; p = 0.46), but induced hyperopia was commoner with CRFs (76% vs. 12%; p < 0.001), exophthalmos greater (4.52 mm vs. 2.97 mm; p < 0.001), eye movement restriction commoner (37% vs. 21%; p = 0.004), and disc swelling more prevalent (42%, vs. 17%; p < 0.001). Orbital cavernous venous malformations with CRFs were almost all intraconal (98%; odds ratio 9.96; p = 0.002), and 93% (77/83) midorbital (odds ratio 6.02; p < 0.001). The median size with CRFs was twice that of those without (3.85 ml vs. 1.92 ml; p < 0.001), and two-thirds OCVMs with folds had volumes >2.5 ml ( p < 0.001). The OCVM was excised in 76 of 83 (92%) of CRF group and 213 of 319 (67%) of those without ( p < 0.001). The postoperative acuity was improved or unchanged in 67 of 76 (88%) eyes with folds, and 184 of 213 (83%) without CRFs ( p = 0.84). The proportion recovering an acuity within 1 Snellen line (or better than) the unaffected side was 80% with CRFs and 77% in their absence ( p = 0.63). Induced hyperopia persisted in 39% of all patients, with the mean being higher with CRFs (2.22D vs. 1.02D; p = 0.017). CRFs occur in ~25% of mid-intraconal OCVMs. Despite OCVM excision, 39% of operated patients retain significant residual hyperopia (54% if CRFs present before surgery), and 41% of such CRFs remain clinically detectable after surgery (with variable visual impairment). Earlier surgery might, therefore, be advisable in patients with CRFs and/or induced hyperopia.

When should one avoid operating on orbital cavernous venous malformations?

When should one avoid operating on orbital cavernous venous malformations?

A clinicopathological reappraisal of orbital vascular malformations and distinctive GJA4 mutation in cavernous venous malformations

Vascular anomalies are common orbital lesions, while variations in previous nomenclature might hamper robust characterization of their clinicopathological and genetic features. We reviewed and reclassified 92 orbital vascular lesions by the modified International Society for the Study of Vascular Anomalies (ISSVA) classification with reappraising clinicopathological parameters of 4 main types of vascular malformations, including orbital venous malformation 1 (OVM1, cavernous venous malformation), OVM2 (varix), OVM3 (infiltrating venous malformation), and arteriovenous malformation (AVM). GJA4, BRAF, and KRAS mutations were assessed by Sanger sequencing. There were 90 cases of vascular malformations, consisting of 60 OVM1 (67%), 13 AVM (14%), 8 OVM2 (9%), 8 OVM3 (9%), and 1 lymphatic-venous malformation (1%). The prevailing OVM1, histologically characterized by well-delineated borders and a uniform cavernous growth pattern, predominantly occurred in intraconal space (57%, P=.019) with an older median age (49 years) and female predilection (73%). OVM2, OVM3, and AVM exhibited differences in the distributions of patients' ages and lesion locations. Sizes of lesions were significantly correlated with periorbital and intraconal/extraconal locations (P<.001). OVM1 had the lowest rate of residual and recurrent diseases (3%). GJA4 mutations were identified in 75% (44/59) of OVM1 but not in OVM2/3 and AVM. No BRAF or KRAS mutations were detected. In conclusion, the modified ISSVA scheme enables meaningful classification of orbital vascular malformations by highlighting the molecular correlation between the distinct clinicopathological features and specific GJA4 mutation in OVM1, which implies OVM1 as a unique variant of venous malformation genetically akin to cutaneous and hepatic counterparts.

Pictorial Review of Cavernous Sinus Hemangiomas (Venous Malformations)

Cavernous venous malformations of the cavernous sinus are rare, benign tumors that account for 2%‐3% of all cavernous sinus lesions. An accurate pretreatment diagnosis is important due to the highly vascular nature of these lesions and the risk of major intraoperative hemorrhage. A shifting preference toward radiosurgery as a primary treatment, increasingly without a pretreatment biopsy, further underscores the need for an accurate imaging diagnosis. The aim of this pictorial review is to illustrate the imaging findings of cavernous sinus venous malformations on CT and MR imaging, the use of red blood cell scintigraphy as an adjunct imaging technique, relevant differential diagnoses, and management.Learning Objective: To describe the main imaging features of cavernous sinus venous malformations using CT, MR imaging, and red blood cell scintigraphy to differentiate them from other common lesions of the cavernous sinus

Somatic GJA4 gain-of-function mutation in orbital cavernous venous malformations

Orbital cavernous venous malformation (OCVM) is a sporadic vascular anomaly of uncertain etiology characterized by abnormally dilated vascular channels. Here, we identify a somatic missense mutation, c.121G > T (p.Gly41Cys) in GJA4, which encodes a transmembrane protein that is a component of gap junctions and hemichannels in the vascular system, in OCVM tissues from 25/26 (96.2%) individuals with OCVM. GJA4 expression was detected in OCVM tissue including endothelial cells and the stroma, through immunohistochemistry. Within OCVM tissue, the mutation allele frequency was higher in endothelial cell-enriched fractions obtained using magnetic-activated cell sorting. Whole-cell voltage clamp analysis in Xenopus oocytes revealed that GJA4 c.121G > T (p.Gly41Cys) is a gain-of-function mutation that leads to the formation of a hyperactive hemichannel. Overexpression of the mutant protein in human umbilical vein endothelial cells led to a loss of cellular integrity, which was rescued by carbenoxolone, a non-specific gap junction/hemichannel inhibitor. Our data suggest that GJA4 c.121G > T (p.Gly41Cys) is a potential driver gene mutation for OCVM. We propose that hyperactive hemichannel plays a role in the development of this vascular phenotype.

Pupillary Abnormalities After Excision of Orbital Cavernous Venous Malformations.

The aim of this study was to determine the incidence and recovery rate for pupillary abnormalities after excision of orbital cavernous venous malformations (OCVMs). Retrospective case-note and imaging review for patients with OCVMs, with an estimation of odds ratios (ORs) in relation to the position of the mass and surgical approach. The 287 included patients (176 female; 61%) presented at a mean age of 46.5 years: 243/287 (85%) OCVMs were intraconal, 253/287 (88%) located in the posterior two-thirds of the orbit, and 29/287 (11%) wedged tightly in the apex. Pupillary changes-varying from minor sectoral paresis (only evident on slit-lamp examination) to a marked mydriasis-were noted in 21% (60/287) of patients and were strongly associated with removal of intraconal (60/243 [25%]; p < 0.001), apical (14/29 [48%]; OR, 4.3; p < 0.001), inferior or inferotemporal (41/105 [39%]; OR, 5.5; p < 0.001) masses. Lateral approaches-either with (23/129; 18%) or without (30/71; 42%) osteotomy-were associated with 88% (53/60) of all abnormalities (OR, 4.1; p < 0.001). Where known, the abnormalities improved in 43/50 (86%), although 15/43 (35%) had a persistent tonic pupil. Pupillary abnormalities after excision of OCVMs can occur in up to a quarter of intraconal lesions-particularly those located inferotemporally or inferiorly-and in about a half of apical lesions. Lateral or inferolateral orbital approaches that disrupt the inferior intraconal fat appear to be associated with a higher risk. Most changes resolve or improve markedly, although a third of those affected may have a persistent tonic pupil.

Presenting Characteristics for Symptomatic, as Compared to Asymptomatic (assumed), Orbital Cavernous Venous Malformations.

To compare the characteristics for symptomatic and asymptomatic orbital cavernous venous malformations (OCVMs). A retrospective case-note review for patients with OCVMs was performed for demographics and presenting features. Four hundred and fourteen patients (258 female; 62%) presented at a mean age of 49.4 years and all were unilateral. Ninety-two (22%) asymptomatic OCVMs were found a decade later than 322 symptomatic patients (57.8 vs. 47.0 years; p < 0.001). Patients with symptomatic OCVMs had an average symptom duration of 3.3 years with the commonest being altered vision (57%), proptosis (55%), orbital ache (21%), and diplopia (13%). Visual obscurations were reported by 11% of symptomatic patients, whereas 30% had a hyperopic shift.Mean LogMAR was 0.39 for symptomatic OCVMs and 0.1 for asymptomatic ( p < 0.001), and a relative afferent pupillary defect was detected in 38% symptomatic and 7% asymptomatic patients ( p < 0.001). Mean relative exophthalmos was 3.9 mm in symptomatic patients and 1.5 mm in asymptomatic ( p < 0.001), but there was no correlation between age and exophthalmos. Symptomatic lesions had higher rates of nonaxial displacement (30% vs. 7%; p < 0.00001), more palpable masses (17% vs. 2%; p = 0.0001), and more impairment of motility (29% vs. 10%; p = 0.0024). Fundal abnormalities were noted in 63% of patients with symptomatic OCVMs, as compared to 26% of asymptomatic ( p < 0.0001). Symptomatic OCVMs may present with reduced visual function, either due to the globe or optic nerve compression, or proptosis. Asymptomatic (presumed) OCVMs- representing 22% of all OCVMs-are usually found a decade later than symptomatic lesions, and a few may have only mild functional impairment.

Prognosis Analysis and Clinical Features of Orbital Cavernous Venous Malformations With Refractory Insidious Onset.

ObjectiveThe present study aims to analyse the clinical presentation, treatment and prognosis of a group of patients with orbital cavernous venous malformation (OCVM) with an insidious onset.MethodThe clinical data of 35 patients with OCVM treated at our centre between 2003 and 2020 were retrospectively analysed. The OCVMs were classified as one of six types (I–VI) according to the orbital position of the tumour. The clinical characteristics, treatment methods and follow-up results were recorded.ResultsA total of 35 patients with OCVM under the optic nerve sheath in the orbital apex area or the common tendon ring (Types I and II) were included in the present study. In 20 cases (57.1%), patients were misdiagnosed with optic neuritis, and in 20 cases (57.1%), the tumour was not identified based on imaging. The presentation was acute or subacute in 23 cases (65.7%). All patients underwent surgery: transnasal surgery in 22 cases (62.9%) and craniotomy in 13 cases (37.1%). A total of 9 patients (25.7%) experienced postoperative complications, and 17 patients (48.6%) experienced vision improvement. The average patient age at first diagnosis was 43.3 ± 10.3 years, and the median follow-up period was 64.5 months. Overall, 14 patients (40%) experienced postoperative complications: postoperative blindness in 6 cases, postoperative vision loss in 8 cases and orbital apex syndrome in 7 cases.ConclusionPatients with Type I and Type II OCVMs are the most complex cases. They have an insidious onset and are associated with a high rate of misdiagnosis and missed diagnosis. Acute and subacute decreases in visual acuity are mainly caused by OCVM haemorrhage. The difficulty of surgical treatment and the poor prognosis of postoperative vision are characteristics of this tumour. Transnasal surgery and craniotomy can be used to remove OCVMs located in the common tendon ring or optic canal as well as those involving the intracranial area through the supraorbital fissure. Meanwhile, the orbital approach (orbitotomy) has proven to be an effective method of treating OCVMs not involving the deep orbital apex and intracranial area.

Machine Learning Based Non-Enhanced CT Radiomics for the Identification of Orbital Cavernous Venous Malformations: An Innovative Tool.

To evaluate the capability of non-enhanced computed tomography (CT) images for distinguishing between orbital cavernous venous malformations (OCVM) and non-OCVM, and to identify the optimal model from radiomics-based machine learning (ML) algorithms. A total of 215 cases of OCVM and 120 cases of non- OCVM were retrospectively analyzed in this study. A stratified random sample of 268 patients (80%) was used as the training set (172 OCVM and 96 non-OCVM); the remaining data were used as the testing set. Six feature selection techniques and thirteen ML models were evaluated to construct an optimal classification model. There were statistically significant differences between the OCVM and non-OCVM groups in the density and tumor location (P < 0.05), whereas other indicators were comparable (age, gender, sharp, P > 0.05). Linear regression (area under the curve [AUC] = 0.9351; accuracy = 0.8657) and Stochastic Gradient Descent (AUC = 0.9448; accuracy = 0.8806) classifiers, both of which coupled with the f test and L1-based feature selection method, achieved optimal performance. The support vector machine (AUC = 0.9186; accuracy = 0.8806), Random Forest (AUC = 0.9288; accuracy = 0.8507) and eXtreme Gradient Boosting (AUC = 0.9147; accuracy = 0.8507) classifier combined with f test method showed excellent average performance among our study, respectively. The effect of non-enhanced CT images in OCVM not only can help ophthalmologist to find and locate lesion, but also bring great help for the qualitative diagnosis value using radiomic- based ML algorithms.

Cavernoma in the medulla oblongata – Case presentation and review of the literature

Cerebral cavernous venous malformations (also called cavernous hemangiomas or cavernomas) are the third most common cerebral vascular malformations having an incidence of 0.4-0.8% in the general population and being diagnosed more frequently incidentally during an imaging procedure. Usually solitary, but cavernomas can also be present as multiple lesions with autosomal dominant inheritance pattern. We present a rare case and the MRI imaging of a type I Zabramski cavernoma that bled, localized in the medulla oblongata of a 41-year-old man, admitted with paresthesia of the right upper limb, very mild right hemiparesis and impaired fine motor movements of the right hand and intractable persistent hiccups.

Clinical Outcome and Technical Nuances After Resection of Orbital Cavernous Venous Malformations—A Single-Center Experience

Cavernous venous malformations (CVMs) represent the most common benign intraorbital lesions. Enlarging or symptomatic CVMs (progressive proptosis or visual disturbances) are treated by surgical resection. For this, a variety of different surgical approaches have been described. The aim of this study was to present a contemporary series of orbital CVMs treated via open microsurgical approaches. In this study, patients who underwent resection of orbital CVMs between 2002 and 2019 were included. Presenting symptoms were noted and neuro-ophthalmologic examinations performed pre- and postoperatively. For surgical resection, the location of the orbital CVM and its relation to the orbital anatomy led to decision-making for appropriate approaches. A comparison between anatomical location and surgical outcome was performed. Overall, 35 patients with orbital CVMs were included. Most common presenting symptoms were progressive proptosis (43%) and visual disturbances (34%). Most common location was the lateral quadrant (37%) followed by the superior quadrant (20%). A subfrontal craniotomy was performed in 40% of cases followed by a supraorbital craniotomy including the orbital rim in 34% of cases. For surgical excision, a cryo-probe was used in 30 patients, and complete resection was feasible in all cases. Location of a CVM within the superior quadrant was associated with improved postoperative recovery of visual acuity. No differences for clinical outcomes were observed depending on the surgical approach. Resection of orbital CVMs is indicated in patients with visual disturbances or progressive proptosis. In these, microsurgical approaches can be used with minimal morbidity for complete removal of these well-circumscribed lesions.

Risks and Benefits of Surgical Excision of Orbital Cavernous Venous Malformations (So-Called Cavernous Hemangioma): Factors Influencing the Outcome

To assess risks and benefits associated with surgical excision of orbital cavernous venous malformation and analyze factors influencing the outcome. Design: cohort study. Participants: 164 consecutive patients undergoing surgical removal of orbital cavernous venous malformation. Intervention: lateral or anterior orbitotomy. Outcome measures: visual acuity, visual field, pupillary function, ocular motility, and fundus examination. Influence of the mass volume and tumor location on the outcome was evaluated. The threshold value and risk group for the volume were evaluated using the receiver operating characteristic analysis; 8 orbital different quadrants, extraconal/intraconal position, and orbital apex extension were considered as variables to evaluate the location. Postoperatively overall visual acuity (p = 0.0084), visual field (p < 0.0001), diplopia (p < 0.0001), proptosis (p < 0.0001), ocular motility (p = 0.02), ptosis (p = 0.033), choroidal fold (p < 0.0001), disk edema (p = 0.0004) were significantly improved. The commonest location was the lateral quadrant (28%). Choroidal folds were associated with tumor greater than 1100 mm3 (p = 0.001). Visual loss occurred in 2 patients (1.2%) and tonic pupil in 5 (3%,) Visual deterioration was associated with the apical extension (p = 0.001). Pupil efferent defect was associated with lateral quadrant location (p = 0.011) and apical extension (p = 0.05). Surgical removal of orbital cavernous venous malformation is a useful treatment modality, particularly for large size tumors. Removal of cavernous venous malformations located at the lateral aspect of the orbit carries an increased risk of permanent tonic pupil. Postoperative blindness is rarely seen and is often associated with the apical extension. Tailoring the surgical approach, depending on the relative position to the optic nerve, may have an important bearing on outcome.

Intramuscular cavernous venous malformation of extraocular muscles. Fractionated stereotactic radiotherapy as a therapeutic alternative

Intramuscular cavernous venous malformations affecting extraocular muscles are extremely uncommon. Due to their location, complete resection could be difficult. A clinical case is presented of an inferior rectus muscle orbital cavernous malformation treated with fractionated stereotactic radiotherapy after post-surgical excision recurrence. The malformation responded to radiotherapy with a reduction in size and symptoms. Fractionated stereotactic radiotherapy is an alternative and effective treatment for cavernous venous malformations that are surgically challenging due to their radiotherapy sensitivity.

Malformación venosa cavernosa en musculatura extrínseca ocular. Radioterapia estereotáctica fraccionada como alternativa terapéutica

Intramuscular cavernous venous malformations affecting extraocular muscles are extremely uncommon. Due to their location, complete resection could be difficult.A clinical case is presented of an inferior rectus muscle orbital cavernous malformation treated with fractionated stereotactic radiotherapy after post-surgical excision recurrence. The malformation responded to radiotherapy with a reduction in size and symptoms.Fractionated stereotactic radiotherapy is an alternative and effective treatment for cavernous venous malformations that are surgically challenging due to their radiotherapy sensitivity.

Fractionated Stereotactic Radiotherapy for Cavernous Venous Malformations of the Orbital Apex.

The objective of this study was to investigate the efficacy and safety of fractionated stereotactic radiotherapy in the treatment of cavernous venous malformation of the orbital apex. The authors reviewed a prospective database from a single center of patients with cavernous venous malformation of the orbital apex who had treatment with fractionated stereotactic radiotherapy. The authors compared the symptoms, visual function and the size of the tumor pre- and posttreatment as well as reviewed the treatment details and the incidence of complications. Six patients received treatment with fractionated stereotactic radiotherapy for cavernous venous malformation involving the orbital apex. The median age was 48 (range, 32-63), and 50% were female. Patients received a dose of 45 to 50.4 Gy in 1.8 to 2 Gy fractions. Median follow up was 33 months (range, 18-66 months). The average tumor volume reduction at posttreatment imaging after 12 months was 63%. All lesions reduced in size postradiotherapy and remained controlled for the duration of follow up. All patients who had proptosis or a visual field defect had an improvement in the symptoms posttreatment. There were no complications of the treatment. Fractionated stereotactic radiotherapy appears to be a safe and effective management option for cavernous venous malformation of the orbital apex and leads to a sustained reduction of the volume of the lesion with associated improvement in symptoms and visual function.

Surgical Outcomes of Intraconal Cavernous Venous Malformation According to Their Location in Four Right-Angled Sectors.

The present study evaluated the surgical outcomes of intraconal cavernous venous malformation according to their location in 4 right-angled sectors. Data regarding the surgical method and approach, surgical outcome, and postoperative complications were retrospectively analyzed for 18 patients with intraconal cavernous venous malformations that were surgically treated at the authors’ center between March 2006 and May 2017. The lesion location was defined using 2 perpendicular lines connecting the optic disc and the 4 surrounding rectus muscles in the coronal plane, which resulted in the formation of 4 right-angled sectors (upper-outer quadrant, upper-inner quadrant, lower-inner quadrant, and lower-outer quadrant). Accordingly, there were 3, 3, 8, and 4 lesions in the upper-outer, upper-inner, lower-outer, and lower-inner quadrants, respectively. Ten patients received anterior orbitotomy and 8 received lateral orbitotomy. There were no recurrences during the follow-up period. All patients exhibited reduced proptosis after surgery. Vision improved in 4 patients and remained unchanged in 14. Five patients experienced ocular movement limitation (1 permanent and 4 temporary), 1 developed an inferomedial blowout fracture, 2 developed a temporary sensory deficit, and 1 developed temporary ptosis. The authors’ findings suggest that intraconal cavernous venous malformations most frequently occur in the lower-outer quadrant. Although most lesions can be removed via anterior orbitotomy, large lesions located near the orbital apex or on the orbital wall require lateral orbitotomy. Ocular movement limitation is a common complication and can become permanent in rare cases, necessitating close monitoring. Lesion location and surgical approach do not seem to influence the postoperative complication rate.