The anatomy of the small saphenous vein: Fascial and neural relations, saphenofemoral junction, and valves

PurposeVaricose veins are a frequent burden, also in the small saphenous system. Yet its basic anatomy is not described consistently. We therefore investigated the fascial and neural relationships of the small saphenous vein (SSV) as well as the frequency and position of valves and the different junctional patterns, also considering the thigh extension.Materials and MethodsWe dissected the legs of 51 cadavers during the regular dissection course held in winter 2007 at Innsbruck Medical University, with a total of 86 SSVs investigable proximally and 94 SSVs distally.ResultsA distinct saphenous fascia is present in 93 of 94 cases. It starts with a mean distance of 5.1 cm (SD 1.2 cm) proximal to the calcaneal tuber, where the tributaries to the SSV join to form a common trunk. The neural topography at the level of the gastrocnemius muscle's origins shows the medial sural cutaneous nerve in 88% medially and in 12% laterally to the SSV, the tibial nerve in 64% medially and in 36% laterally, and the common fibular nerve in 98% medially and in 2% laterally to the vein. The saphenopopliteal junction (SPJ) resembled in about 37% type A (UIP-classification), 15% type B, and 24% type C. A total of 17% of specimens showed a venous web or star at the popliteal fossa and 6% had a doubled junction. A thigh extension could be demonstrated in about 84%. A most proximal valve was present in only 94% at a mean distance of 1.2 cm (SD 1.4 cm) to the SSVs orifice. A consecutive distal valve was only present in 65% with a mean distance of 5.1 cm (SD 2.3 cm).ConclusionTwo fascial points or regions can be described in the SSVs' course and its own saphenous fascia is demonstrated macroscopically in almost all cases. The neural topography is highly individual. The SPJ is highly individual where we found hitherto unclassified patterns in a remarkable number of veins. Venous valves are not as frequent as we supposed them to be. Furthermore, not all most proximal valves seem to be terminal valves.Clinical RelevanceOur study's aim is to support the basic understandings of the small saphenous system by providing exact anatomic data. This will help to understand physiology as well as pathophysiologic possibilities at the small saphenous system. On the other hand, our study especially can provide assistance for the vascular surgical approach at the popliteal fossa and also distally to the beginning of the trunk of the short saphenous vein itself

Impact of [¹⁸F]FDG PET/CT in the Assessment of Immunotherapy-Induced Arterial Wall Inflammation in Melanoma Patients Receiving Immune Checkpoint Inhibitors

We aimed to investigate the role of [18F]FDG positron emission tomography/computed tomography (PET/CT) in the early detection of arterial wall inflammation (AWI) in melanoma patients receiving immune checkpoint inhibitors (ICIs). Our retrospective study enrolled 95 melanoma patients who had received ICIs. Inclusion criteria were ICI therapy for at least six months and at least three [18F]FDG PET/CTs, including one pretreatment session plus two scans three and six months after treatment initiation. AWI was assessed using quantitative and qualitative methods in the subclavian artery, thoracic aorta, and abdominal aorta. We found three patients with AWI visual suspicion in the baseline scan, which increased to five in the second and twelve in the third session. Most of these patients’ treatments were terminated due to either immune-related adverse events (irAEs) or disease progression. In the overall population, the ratio of arterial-wall maximum standardized uptake value (SUVmax)/liver-SUVmax was significantly higher three months after treatment than the pretreatment scan in the thoracic aorta (0.83 ± 0.12 vs. 0.79 ± 0.10; p-value = 0.01) and subclavian artery (0.67 ± 0.13 vs. 0.63 ± 0.12; p-value = 0.01), and it remained steady in the six-month follow-up. None of our patients were diagnosed with definite clinical vasculitis on the dermatology follow-up reports. To conclude, our study showed [18F]FDG PET/CT’s potential to visualise immunotherapy-induced subclinical inflammation in large vessels. This may lead to more accurate prediction of irAEs and better patient management