Invasive Methods of Diagnosing Acute and Chronic Venous Disease David M. Williams The diagnosis of acute and chronic venous disease is usually made by compression ultrasound (US) of the extremities and by computed tomography (CT) or magnetic resonance imaging (MRI) in the chest, abdomen, and pelvis. Invasive contrast venography, including intravascular US (IVUS), is reserved for answering specific questions of venous anatomy or venous physiology, usually in the context of an endovascular or open surgical procedure. Intravascular Ultrasonography IVUS catheters are introduced into the venous system over guidewires, requiring either a 5-Fr sheath for imaging a field of view of approximately 24 mm diameter, or an 8-Fr sheath for a field of view of 60 mm. High-quality transcutaneous ultrasound imaging allows safe entry into many nonstandard venous access segments, including upper thigh femoral vein, greater saphenous vein, popliteal vein, posterior tibial vein, and brachial veins, with insertion of a 3-Fr catheter to answer specific but limited anatomic questions, or of a larger-caliber sheath to undertake venous interventions. Cannulation of these veins in many patients can proceed with relative safety even in the setting of international normalized ratios (INRs) in the range of 2.0 to 3.0, with the decision to do so resting on the purpose of the procedure and the ease of postoperative hemostasis. In general, even large-caliber (9-Fr sheath) access into the internal jugular or greater saphenous veins of fully coumadinized patients has been safe in our experience, with due attention to postoperative hemostasis and postural and weight-lifting restrictions. Intravascular ultrasound is unmatched in its comprehensive and sensitive demonstration of the cross section of a venous lumen. It is a common experience to demonstrate by IVUS a 50% or 75% cross-sectional narrowing in a venous channel that looks marginal or even acceptable by contrast venography. In a protracted venous recanalization, we find that the added expense of intravascular ultrasound is justified by its return of accurate and valuable anatomic information complementing the flow evaluation of contrast venography, leading to more consistent and more confident decisions regarding whether to stent or not stent or whether to add a flow-enhancing procedure such as venous thrombectomy or construction of an arteriovenous fistula to a recanalization procedure. Finally, IVUS is often necessary to answer specific and limited anatomic questions, such as whether a prophylactic filter contains postprocedural clot burden, whether the contralateral transfemoral guidewire is inside or outside an IVC stent, or to confirm the level of a known anatomic structure. Often IVUS can answer such limited anatomic questions conclusively without the incremental burden of contrast material or irradiation entailed by a contrast venogram. Contrast Venography Contrast venography through peripheral cannulas in a hand or foot vein or through percutaneous 5-Fr catheters allows imaging of veins varying from 0.5 mm to 30 mm in diameter. Correlation with fluoroscopic anatomy allows catheter manipulation to specific sites or interventional procedures to proceed, assisted by intermittent small-volume contrast injections to confirm underlying venous anatomy, to query whether the recanalizing catheter or needle has strayed from the venous system, or to assess response to therapy. Contrast injection following catheter placement or an interventional procedure allows estimates of venous flow and washout. In the study and treatment of venous malformations, contrast venography is used to confirm placement of a catheter within the malformation, estimate safe volumes of injection before spillage into the venous system, and, when mixed with the sclerosing agent, visualize ongoing treatment of the malformation. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease In-Situ Treatment of Aortic Graft Infection with Prosthetic Grafts and Allografts Treatment of Acute Upper Extremity Venous Occlusion Intraoperative Assessment of the Technical Adequacy of Carotid Endarterectomy Stay updated, free articles. Join our Telegram channel Join Tags: Current Therapy in Vascular and Endovascular Surgery Aug 25, 2016 | Posted by admin in CARDIOLOGY | Comments Off on Invasive Methods of Diagnosing Acute and Chronic Venous Disease Full access? Get Clinical Tree
Invasive Methods of Diagnosing Acute and Chronic Venous Disease David M. Williams The diagnosis of acute and chronic venous disease is usually made by compression ultrasound (US) of the extremities and by computed tomography (CT) or magnetic resonance imaging (MRI) in the chest, abdomen, and pelvis. Invasive contrast venography, including intravascular US (IVUS), is reserved for answering specific questions of venous anatomy or venous physiology, usually in the context of an endovascular or open surgical procedure. Intravascular Ultrasonography IVUS catheters are introduced into the venous system over guidewires, requiring either a 5-Fr sheath for imaging a field of view of approximately 24 mm diameter, or an 8-Fr sheath for a field of view of 60 mm. High-quality transcutaneous ultrasound imaging allows safe entry into many nonstandard venous access segments, including upper thigh femoral vein, greater saphenous vein, popliteal vein, posterior tibial vein, and brachial veins, with insertion of a 3-Fr catheter to answer specific but limited anatomic questions, or of a larger-caliber sheath to undertake venous interventions. Cannulation of these veins in many patients can proceed with relative safety even in the setting of international normalized ratios (INRs) in the range of 2.0 to 3.0, with the decision to do so resting on the purpose of the procedure and the ease of postoperative hemostasis. In general, even large-caliber (9-Fr sheath) access into the internal jugular or greater saphenous veins of fully coumadinized patients has been safe in our experience, with due attention to postoperative hemostasis and postural and weight-lifting restrictions. Intravascular ultrasound is unmatched in its comprehensive and sensitive demonstration of the cross section of a venous lumen. It is a common experience to demonstrate by IVUS a 50% or 75% cross-sectional narrowing in a venous channel that looks marginal or even acceptable by contrast venography. In a protracted venous recanalization, we find that the added expense of intravascular ultrasound is justified by its return of accurate and valuable anatomic information complementing the flow evaluation of contrast venography, leading to more consistent and more confident decisions regarding whether to stent or not stent or whether to add a flow-enhancing procedure such as venous thrombectomy or construction of an arteriovenous fistula to a recanalization procedure. Finally, IVUS is often necessary to answer specific and limited anatomic questions, such as whether a prophylactic filter contains postprocedural clot burden, whether the contralateral transfemoral guidewire is inside or outside an IVC stent, or to confirm the level of a known anatomic structure. Often IVUS can answer such limited anatomic questions conclusively without the incremental burden of contrast material or irradiation entailed by a contrast venogram. Contrast Venography Contrast venography through peripheral cannulas in a hand or foot vein or through percutaneous 5-Fr catheters allows imaging of veins varying from 0.5 mm to 30 mm in diameter. Correlation with fluoroscopic anatomy allows catheter manipulation to specific sites or interventional procedures to proceed, assisted by intermittent small-volume contrast injections to confirm underlying venous anatomy, to query whether the recanalizing catheter or needle has strayed from the venous system, or to assess response to therapy. Contrast injection following catheter placement or an interventional procedure allows estimates of venous flow and washout. In the study and treatment of venous malformations, contrast venography is used to confirm placement of a catheter within the malformation, estimate safe volumes of injection before spillage into the venous system, and, when mixed with the sclerosing agent, visualize ongoing treatment of the malformation. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Technical Aspects of Percutaneous Carotid Angioplasty and Stenting for Arteriosclerotic Disease In-Situ Treatment of Aortic Graft Infection with Prosthetic Grafts and Allografts Treatment of Acute Upper Extremity Venous Occlusion Intraoperative Assessment of the Technical Adequacy of Carotid Endarterectomy Stay updated, free articles. Join our Telegram channel Join
