Page 289 - Libro 2

17 — Venous Valvular Insufficiency Testing
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• Documentation of a dual femoral vein
• Patency and flow characteristics of the popliteal vein at one level, with color flow and spectral
Doppler waveforms
• Condition of calf veins in patients with localized
signs and symptoms showing risk for DVT or
chronic obstruction below the knee
• Flow characteristics in segmental levels of the saphenous veins including the GSV, AASV,
PASV, VOG, and SSV
• Flow characteristics of nonsaphenous veins
potentially associated with varicose veins or
pelvic source drainage
• Possible involvement of pelvic veins or veins
proximal to the groin
• Any unusual venous or nonvenous finding Documentation may be simplified during screen-
ing protocols and may have to be more complex de- pending on the objectives of pretreatment mapping protocols. Peritreatment protocols are dependent on the type of treatment and the specific objectives. Follow-up protocols are also dependent on the ob- jectives of the examination and intended treatment.
Screening for CVVI with US
The basic protocol includes image documentation of any anomaly of the femoropopliteal veins and a single documentation of the saphenous or nonsaphe- nous abnormality. The scans of the deep and super- ficial veins follow the pattern described previously but can be interrupted after the discovery of a single abnormality. The scan may also focus primarily on the region with the highest suspicion of an abnor- mality, for example, during the search of the source of obvious varicose veins.
DEFINITIVE DIAGNOSIS FOR CVVI WITH US
The protocol may vary depending on the objective of the test and the potential treatment. There are three common test objectives. The first is the selection of patients for thermal ablation of the GSV in the thigh. The protocol comprises a standard evaluation of the femoropopliteal veins and the GSV in the thigh. Ad- ditionally, (1) a limited evaluation of the GSV and SSV in the calf are performed, and (2) the calf deep veins may have to be studied depending on signs and symptoms.
The second is the examination of patients of a phlebology clinic with perioperative US capabilities. A complete examination included the femoropopli- teal, the saphenous veins, and nonsaphenous veins related to visible varicose veins. The infrapopliteal deep veins are examined as a function of signs and symptoms. Details of the exact location of reflux
sources and drainage points are not necessary because vein mapping is performed at the time of treatment.
The third type of objective is the examination of patients for limited or extensive stripping/ligation/ phlebectomy procedures. A complete examination includes a detailed drawing of refluxing and nonre- fluxing veins plus segments not visualized. Perforat- ing veins, sources, and drainage points are precisely located. Vertical and circumferential measurements are performed. Distance from the sole of the foot determines the vertical location. Distance from the tibial tuberosity, for example, determines the circum- ferential position of the venous finding. The physi- cian would then perform treatment based either on a paper drawing or on a mapping on the skin of the pa- tient. Some procedures may require measurements or skin marking very close to treatment day, often with the patient in the standing and operative position.
Saphenous sparing techniques, such as a CHIVA (French acronym for conservative and hemodynam- ic treatment of venous insufficiency in ambulatory care) procedure, may require additional information to determine the new flow pathways through the venous channels left open in the extremity.
Peritreatment US
The role of US in venous disease has expanded be- yond a diagnostic tool and is commonly used during treatments such as thermal and chemical ablation. During thermal ablation, US is often used to map the course of the vein being treated on the patient’s skin. The site of the venous incision is selected with US, and needles, introducers, guide wires, and la- ser or radio-frequency catheters are inserted under ultrasound guidance. The tip of the thermal abla- tion catheter is placed at an appropriate distance from the saphenofemoral junctions under direct US visualization. The introduction of the tumescent anesthesia is performed under ultrasound guidance. At the completion of the ablation procedure, US con- firms obstruction of the treated vein and the lack of deep venous thrombosis. US can also demonstrate local recanalization of the treated vein, tributaries approaching the treated vein with potential risk for recanalization, and other superficial veins, which may need subsequent, complementary procedures.
US during Chemical Ablation or Foam Sclerotherapy
There are a few simple, primary applications of US. Imaging of the vein is performed during needle inser- tion. US can follow the hyperechoic foam as it flows through the treated vein and can be used to warn the physician if the foam approaches a perforating vein, the saphenofemoral junction, or saphenopopliteal