{"id":3278,"date":"2026-08-30T15:59:04","date_gmt":"2026-08-30T15:59:04","guid":{"rendered":"https:\/\/www.ijmhr.org\/IntJAnatRes\/?post_type=article&p=3278"},"modified":"2026-08-30T16:13:11","modified_gmt":"2026-08-30T16:13:11","slug":"ijar-2026-132","status":"publish","type":"article","link":"https:\/\/www.ijmhr.org\/IntJAnatRes\/IJAR.2026.132\/","title":{"rendered":"Exploring the Variations of the Cavernous Sinus Tributaries in the South African Population"},"content":{"rendered":"\n

Background<\/strong><\/h2>\n\n\n\n

The cavernous sinus (CS) is known as a frequent site of thrombosis, which is a process of formation of blood clots in vessels in response to an infection from the face or the orbit called cellulitis [1; 2]. Thrombosis of the CS can result in inflammation of the adjacent neurovascular structures, while diseases such as cavernous sinus thrombosis (CST), which are life-threatening, can result in the formation of blood clots in the CS [2]. The aetiology of these diseases could be as a result of an infection from the face, sinuses, orbital cellulitis, and pharyngitis, but they are predominantly found in patients with diabetes and thrombophilia [2]. These conditions are reported to predominantly affect women of reproductive age [2]. CST can cause long-term damage to the brain, eyes, and nerves, and without sufficient treatment, may lead to death [2].<\/p>\n\n\n\n

The CS is also a site of dural arteriovenous fistulae (dAVF), an abnormal connection between the internal or external carotid arteries, which results in the CS being fed by arteries [3]. This type of malformation is often as a result of traumatic brain injury, embryological defects, surgery, and\/or genetic conditions [3]. This condition is normally found unilaterally; however, the majority of females were found to possess bilaterality (90%, p = 0.043) of this condition. Although it is also found unilaterally in males (10%) [3].<\/p>\n\n\n\n

Among the life-threatening disorders affecting the CS is cerebral venous sinus thrombosis (CVST), a type of stroke normally found in women in their reproductive ages [4]. Although the exact aetiology of the disease is not known, it is found to affect women on oral contraceptives, during pregnancy, and in the peripartum period [5; 6]. Previous literature has documented the use of contraceptives in relation to CVST, and a significant association was obtained, which confirmed that females are the most vulnerable to this disease [4]. A systematic review study on the CVST in sub-Saharan Africa found a very high prevalence of women with CVST (58.6%) [6]. In a case series report of 210 patients, hemicraniectomy was successfully done in one patient (2.1%); meanwhile, ten percent of the patients died after the surgery, with 46.5% of the patients recovering either completely or partially [6].\u00a0<\/p>\n\n\n\n

Surgical interventions to these cerebral venous sinus diseases in the skull base have resulted in very high mortality and morbidity rates (10%) in sub-Saharan Africa [5,6]. This is owing to the intracranial bleeding caused by the rupture of veins during these surgical procedures [5-7].<\/p>\n\n\n\n

Endovascular embolisation has been the treatment of choice for this condition because it is safer and possesses low complication rates [3]. The access to the CS when performing the endovascular embolisation is through the inferior petrosal sinus (IPS), but if it is occluded, the point of access will be through the facial and ophthalmic veins [3]. Although the endovascular embolisation procedure is declared safe and presents fewer complications, it is important to note that the veins used in accessing the CS have numerous variations in their morphology and drainage patterns to the CS, thus making the procedure difficult [8].<\/p>\n\n\n\n

The CS receives communication from numerous para-cavernous sinus structures such as the superior and inferior ophthalmic veins [1; 9; 10].  The superior ophthalmic vein (SOV) runs between the optic nerve and the superior rectus muscle and exits the orbit via the superior orbital fissure to drain into the CS [11,12]. However, Tsutsumi et al<\/em>. [12] who observed the course of the SOV from distal to proximal using magnetic resonance angiography (MRA) found that morphological variations in terms of laterality were evident. The proximal segment of the SOV was found to be tortuous in seven percent of the population on the left side and in eleven percent of the population on the right [12].<\/p>\n\n\n\n

Furthermore, the inferior ophthalmic vein (IOV), which is located in the midorbit slightly superior to the inferior rectus muscle, was found to drain into the CS in two different patterns [11]<\/a>. The IOV either curved upwards laterally and infrequently medial to the optic nerve to join the third part of the SOV and then drained into the CS, or it drained directly into the CS, bypassing the SOV [11]. These observations were not compared according to sex, age and laterality.<\/p>\n\n\n\n

The sphenoparietal sinus (SPS) is known to receive blood from the superficial middle cerebral vein (SMCV) located in the lesser wing of sphenoid bone before it emptied into the CS [9]. They found the SPS to drain in three different patterns using Magnetic Resonance (MR) images and the patterns were classified into types, namely: Type A- drained into the anterior aspect of the CS; Type B- connected with the sphenoid emissary veins (SEV) or the pterygoid plexus; and Type C- the hypoplastic (underdeveloped) SPS drained into the anterior aspect of the CS.<\/p>\n\n\n\n

As mentioned above, the SMCV empties into the SPS [9]. However, different studies have noted variations in the drainage pattern of the SMCV [9; 13]. Suzuki and Matsumoto [13] observed seven different drainage patterns of the SMCV. Meanwhile, previous findings by Tanoue et al<\/em>. [9] in their study observed only four types: Type A- the SMCV drained into the SPS, Type B- entered the anterior aspect of the CS, Type C- connected to the SEVs to drain into the pterygoid plexus and Type D- emptied into the superior petrosal sinus\/transverse sinus. Type A was the most prevalent, followed by TypeB. Two percent of the subjects presented with mixed types [9].<\/p>\n\n\n\n

Although, there is existing literature regarding the variations of the CS tributaries, it is important to note that variations regarding the age, sex, laterality in the SA population remain undocumented. Also, the use of CT images to study the pattern and variations of these veins is highly recommended before transvenous embolisation is performed.  Therefore, the current study, using CT images aimed to report on the variable patterns of the CS tributaries in the SA population with comparison to sex, age, and laterality.<\/p>\n\n\n\n

Materials and Methods<\/strong><\/strong><\/h2>\n\n\n\n

Sample size:<\/strong> This was a retrospective analysis of 100 CT scans of adult individuals (56 males, 44 females). The left and right sides were assessed separately, amounting to a total of 200 sides. The CT images were obtained from a tertiary hospital, the Inkosi Albert Luthuli Central Hospital (IALCH) in Durban, Kwa-Zulu Natal, South Africa.<\/p>\n\n\n\n

Age classification and population:<\/strong> The CT images were of 13 years of age and above. The age categories were classified according to Biwasaka et al.<\/em> [14] as follows: <29, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89, and >89 years of age. The starting age was considered because the venous sinuses of the skull demonstrate their most significant growth between the ages of zero and seven years and typically reach adult size around five to ten years of age [15]. The diseases affecting the dural venous sinuses were also found to affect women in their reproductive ages (age \u2265 13 years) [4].<\/p>\n\n\n\n

Regarding population, due to the skewness of data in the CT sample, the White and the Indian sample groups were merged into one sample and were compared to the Black sample, \u2018Black SA vs. Other SA sample groups (Indian\/White SA)\u2019.<\/p>\n\n\n\n

The composition of the sample for the CT images were Black (71; 71%) and Indian\/White (29; 29%). (Note: Generally, the distribution of the SA population, Black SA makes up about 79.8%; White SA makes up about 8.7%, with Indian SA making up about 11.5%) [16,17].<\/p>\n\n\n\n

Materials<\/strong><\/p>\n\n\n\n

A total of 100 CT images from CT venograms and CT angiograms (with venous phase) were used in the study. The digital imaging and communications in medicine (DICOM) images were viewed and analyzed using syngo.plaza viewer software (version VB10). The morphology and drainage patterns of the veins were viewed in axial and sagittal planes.<\/p>\n\n\n\n

Scanning protocol<\/strong><\/p>\n\n\n\n

The CT images were acquired using Multi-Detector row CT(MDCT) Scanners (Lightspeed CT, GE Healthcare Medical System, Milwaukee, Wisconsin, USA, and SOMATOM Definition Flash CT Scanner, Siemens Healthineers, Forcheim, Germany, both of 1mm and 2 mm slice configuration, respectively). Acquisition number: 18; CS:.60; Exposure Time:285; KVP:120.00; X-ray tube Current:425; Feed: 46.00.<\/p>\n\n\n\n

Inclusion and exclusion criteria<\/strong><\/p>\n\n\n\n

The inclusion criteria for scans were as follows:<\/p>\n\n\n\n