Objective: Coursing the posterior thigh as a tributary or trunk projection of the small saphenous vein (SSV), the Giacomini vein's clinical significance in chronic venous disease (CVD) remains undetermined. This cross-sectional controlled study examined the prevalence, anatomy, competency status, and clinical significance of the Giacomini vein across the clinical spectrum of CVD in relation to the SSV termination.
Methods: One hundred eighty-nine consecutive subjects (301 limbs) with suspected CVD (109 men, 80 women; age, 18-87 years [median, 61 years]) underwent examination, clinical class (CEAP) stratification, and duplex ultrasound determination of the sites and extent of reflux >0.5 sec) and Giacomini vein's anatomy.
Results: A Giacomini vein was found in 70.4% of limbs (212 of 301; 95% confidence interval, 65%-75.6%). Extent, pattern, and sites of reflux in all named superficial and deep veins were evenly distributed in limbs with and without a Giacomini vein; perforator vein incompetence in thigh and calf was also balanced (all, P > .2). Giacomini vein had no effect ( P > .2) on SSV termination anatomy, displaying a similar prevalence in classes C(0-6) . In 212 limbs, either as a tributary or trunk projection of the SSV, the Giacomini vein ascended subfascially (n = 210) to the lower (8%; n = 17), middle (47.6%; n = 101), or upper (44.3%; n = 94) thigh, and terminated at the deep system (45.3%; n = 96) and/or perforated the fascia (64.2%; n = 136), to join the superficial system. Giacomini vein morphology was not affected by the SSV termination anatomy and CEAP clinical class. Incompetence was detected less often (P < .001) in the Giacomini vein (4.7%; n = 10 of 212) than in the saphenous trunks cumulatively (53.3%; n = 113 of 212). Yet the odds ratio of Giacomini incompetence was 11.94 (7 of 33 over 3 of 169) in the presence of SSV reflux, and 11.67 (6 of 23 over 4 of 179) when both the great saphenous vein (proximal, proximal plus distal) and SSV were incompetent.
Conclusion: Found in more than two thirds of limbs, the Giacomini vein has a complex anatomy that is linked vastly to the deep or superficial veins of the posteromedial thigh, but is unaffected by the anatomy of SSV termination and CEAP clinical class. Its presence proved insignificant to the extent, pattern, sites, and clinical severity of venous incompetence, yet the Giacomini vein was far less often susceptible to reflux than the saphenous trunks were. Routine Giacomini vein investigation is not justified in view of these findings. Investigation could be considered selectively in limbs with SSV incompetence, with or without great saphenous vein incompetence, supported by the high odds of concomitant Giacomini vein reflux.