Anatomical Presentation and Functional implication of Venous Valves in Facial Vein
Facial veins have in the past been declared to be devoid of valves. However, recent studies have shown that there are venous valves in facial veins. Most of the venous valves are found in the tributaries of the angular vein. In contrast, venous valves are found the superior ophthalmic vein. Two of the ophthalmic vein tributaries also have venous valves. Venules are small veins that join to form veins and the formed veins join to make even bigger veins. Veins have thin muscle coat. The veins on the face contain valves within. The venous valves are made up of thin folds of tunica intima that forms a flap like cusp. These valves point towards the heart and prevent retrograde flow of blood. Thus, venous valve facilitates venous return. Venous valves on the face break hydrostatic column of blood into segments. The valves remain open while in a normal resting scenario only closing when there is muscle activity. This retrograde flow must be sufficient to co-apt the cusps completely. The study of the anatomical presentation and functional implication of venous valves is significant because it refutes claims that nonexistence of venous valves cause infections in the face.
In, “Ophthalmic and facial valves is not valve less”, the study shows for the first time the existence of valves in two tributaries of the ophthalmic vein and the ophthalmic vein itself (Zhang & Springer, 2010). There were no venous valves in the inferior ophthalmic vein. The research identified 17 venous valves in the tributaries of the facial vein. However, no venous valves were found in the angular vein. According to Zhang and Springer (2010), facial vein tributaries had valves. According to this research, the venous valves in facial veins determined the blood flow in facial veins. Zhang and Springer concluded that the absence of veins was not responsible for facial infection but the communication between cavernous sinus and facial vein, and the blood flow direction.
In contrast with Zhang, Black and Smith argues that facial veins do not have valves and the cross-connection between the superficial and deep veins thus causing infection if the face (Black and Smith, 2012). A facial infection spreads to the cavernous sinus through communication of the angular, supraorbital and superior ophthalmic veins. According to Black and Smith (2012), the facial vein is 6-8mm and thus too thin to contain valves. Similar to Zhang, Black and Smith notes that there exists a communication amid the pterygoid plexus and facial vein through the facial vein. Venous determine the role of microvenous valves in veins in relation the prevention of skin changes. According to Vincent et al., (2011), microvenous valves exist in smaller valves like those in the face. These valves are not fully functional and only serve to optimize flow in their current locations.
Philip et al., (2014) claims that the venous valves in the face have smaller diameters. Regardless of their size, this study suggests that the interconnected nature of small veins like those in the face prevents valves from functioning properly. According to Jinkins (2000), the facial veins do not have valves. The facial vein drains the angular vein (the facial vein uppermost segment), the pterygoid venous plexus through the innermost facial vein and other smaller facial veins. The main trunk of the facial vein drains inferiorly into the retromandibular vein or the internal jugular vein. According to Chung (2005), the convergence of the supratrochlear and supraorbital veins forms the angular vein. Chung holds it that facial veins do not have the capacity to hold venous valves due to their small size.
Past studies have concluded that facial veins lack valves. The reason for this conclusion was because the small size of facial veins indicated the non-presence of venous valves. However, these allegations are false since recent studies by Zhang and Springer proved otherwise. In an experiment that involved 13 angular and facial veins harvested form adults, 75% of the veins had valves present. Past studies have indicated that the lack of valves in facial veins has allowed for two-way movement of blood. Researchers have explained that the lack of venous valves in facial veins is responsible for superficial infection of the face. However, recent studies show that venous valves are present in both ophthalmic veins and tributaries of angular veins. There is need for extensive research on facial veins as the only research that affirms the presence of venous valves in facial valves in the study by Zhang. There is a research gap about the presence of valves in facial veins. According to Zhang, venous valves in the facial veins determine the blood flow in the face. Though Zhang has done a commendable work in his research, there is still need for more information regarding the structure and functions of the venous valves in facial veins. Studies have also suggested that small veins have micro valves which are not functional. Facial veins have venous valves but their function is not yet clearly defined.
Black, E., & Smith, B. C. (2012). Smith and Nesi’s ophthalmic plastic and reconstructive surgery. New York: Springer
Chung, K. W. (2005). Gross anatomy. Philadelphia: Lippincott Williams & Willkins.
Jinkins, J. R. (2000). Atlas of neuroradiologic embryology, anatomy, and variants. Philadelphia: Lippincott Williams & Wilkins
Phillips M.N., Jones G.T., van Rij AM, Zhang M. (2004) “Micro-venous valves in the superficial veins of the human” Clin Anat: 17: 55-60.
Vincent, J.R. et al. (2011) “Failure of microvenous valves in small superficial veins is a key to the skin changes of venous insufficiency” 54 (6): 62-69. Journal of Vascular Surgery.
Zhang, J.; Stringer, M. D. (2010). “Ophthalmic and facial veins are not valveless”. Clinical & Experimental Ophthalmology. 38 (5): 502–510.