Understanding Spatial Relationship of Saphenous Nerve and Great Saphenous Vein in the Lower Leg Region: A Systematic Review and Meta-analysis

The anatomical relationship between saphenous nerve (SN) and the great saphenous vein (GSV) should be taken into account to avoid injuries to the SN during surgical harvesting of the GSV.The relationship of SN with GSV is highly variable in the lower leg region and there is no comprehensive dataset available on the positioning and distance of the SN with GSV in the lower leg region.The main goal of our study was to analyze the positioning and distance of GSV with SN in the lower leg region.A systematic literature search using PRISMA guidelines was performed in databases such as MEDLINE, PubMed, SciELO, and Cochrane reviews using search terms such as "Saphenous nerve" "Great saphenous vein" "distance" AND "lower leg region", which yielded 1248 article links.Of the fourteen studies that met the inclusion criteria comprising 592 lower limbs are in a range of 26-101 years age.Our pooled analysis revealed that the distance of SN with GSV in the lower third of the leg using a random effects model with Hartung-Knapp adjustment was 0.27 cm (95 % CI; 2 =0.0049), indicating a relatively consistent anatomical proximity between these two structures.However, substantial heterogeneity was observed among the studies (I 2 = 97.6%,Q=254.3,p < 0.0001), suggesting significant variability in the reported distances.With regards to positioning of the SN with GSV, pooled estimate of our study revealed that the SN lies anterior to GSV in 31.4% cases, and in 33.1 % cases posterior to it.The predominance of SN lying deep to GSV aligns with 35.5 %, reflecting vulnerability of SN in surgical interventions of the GSV.Our data gives more representative values on the spatial relationship of SN with GSV in the lower leg region, and this information would be of great advantage for surgeons to avoid injury to the SN which can lead to sensory disturbances in the lower leg region and even the SN neuroma.