Core content for venous and Lymphatic Medicine: 2022 revision.

The core content for a medical specialty outlines the scope of the discipline as well as the categories of knowledge considered essential to practice in the field. It provides a template for the development of curricula for medical school, graduate, and postgraduate education, as well as for creating certification standards. Venous and Lymphatic Medicine (VLM) is a specialty that has benefitted from contributions from specialists from several medical disciplines. Optimally, the societies, boards, and residency review committees representing these disciplines would uniformly recognize the scope of VLM to develop education and assessment standards to allow training and identification of qualified practitioners. In order to inform the standard setting bodies and other stakeholders of the current scope of VLM, a task force of VLM experts from cardiology, dermatology, emergency medicine, general surgery, interventional radiology, vascular medicine, and vascular surgery was formed to revise a 2014 consensus document defining the core content of the specialty of VLM.

Endovenous laser ablation of varicose veins.

UNLABELLED: Readily available non-invasive diagnostic tests now allow physicians to accurately map out abnormal venous pathways and identify all sources of reflux. Minimally invasive alternatives to surgical removal of incompetent truncal veins have been developed with impressive RESULTS: Endovenous laser treatment can be performed in the office under local anesthesia and is associated with virtually no recovery period. Better understanding of the primary mechanism of energy transfer by direct contact between the laser fiber tip and vein wall has underscored the importance of vein emptying. Improved utilization of tumescent anesthesia has helped facilitate circumferential laser fiber to vein wall contact and virtually eliminated the incidence of heat-related complications. Further refinements in the technique and optimization of laser energy parameters have improved success rates of vein closure from 90% to nearly 100%. Compared to surgery, endovenous laser has also demonstrated lower rates of recurrence largely due to the absence of neovascularity. This review of endovenous laser treatment should validate this exciting technique as a scientifically acceptable option for eliminating truncal vein reflux. If measured by patient acceptance and satisfaction, endovenous laser and other minimally invasive methods have already supplanted traditional surgery as the treatment of choice for superficial venous insufficiency.

Thrombolysis for native arterial occlusions of the lower extremities: clinical outcome and cost.

INTRODUCTION: Intra-arterial thrombolysis is commonly used as the initial treatment of acute or subacute lower extremity ischemia. METHODS: To evaluate the efficacy and cost of thrombolysis, we retrospectively analyzed 100 consecutive cases (87 patients) in which intra-arterial lysis (urokinase) was used as the initial treatment for native arterial lower extremity occlusive disease. The mean age of patients was 67 years, 57% of the patients were male, and preexisting peripheral vascular disease was present in 74%. Presenting symptoms were limb-threatening ischemia (53%) and claudication (47%). Acute symptoms (< 2 weeks' duration) were present in 48%. RESULTS: The 30-day morbidity rate was 31%, and four patients died. Complications were significant bleeding (23%), ischemic stroke (1%), and renal failure with (2%) and without (2%) dialysis. Concomitant angioplasty was performed in 63%. Complete or significant lysis as demonstrated with angiography was achieved in 75% of iliac, 58% of femoropopliteal, and 41% of crural vessels (P <.001). Within 30 days of lysis, 9% of patients underwent major amputation and 20% surgical revascularization (in 3 patients the extent of revascularization was lessened by the lytic therapy). Amputation-free survival was 83% and 75% at 6 months and 2 years, respectively. Relief of ischemia (defined as relief of claudication or limb salvage without major surgical intervention) was achieved in only 70% and 43% of patients at 30 days and 2 years, respectively (Kaplan-Meier analysis; mean follow-up, 31 months). Patients with aortoiliac disease had significantly better outcomes than those with infrainguinal disease (P =.03). Duration or type of presenting symptoms did not predict outcome. The cost of the initial hospitalization per patient for thrombolysis was $18,490. CONCLUSION: Thrombolysis can be as or more costly than surgery and is associated with a suboptimal outcome in a significant number of patients. These data lead us to caution against a uniform policy of initial thrombolysis for patients who present with lower extremity ischemia.

Contrast-enhanced peripheral MR angiography from the abdominal aorta to the pedal arteries: combined dynamic two-dimensional and bolus-chase three-dimensional acquisitions.

UNLABELLED: Wang Y, Winchester PA, Khilnani NM, et al. Contrast-enhanced peripheral MR angiography from the abdominal aorta to the pedal arteries: Combined dynamic two-dimensional and bolus-chase three-dimensional acquisitions. Invest Radiol 2001;36:170-177. RATIONALE AND OBJECTIVES: To obtain reliable contrast-enhanced peripheral MR angiography for imaging peripheral vascular disease from the abdominal aorta to the pedal arteries. METHODS: A protocol consisting of contrast-enhanced, dynamic two-dimensional (2D) acquisition at the feet and calf and bolus-chase three-dimensional (3D) acquisition from the abdominal aorta to the calf was developed and applied in patients with peripheral vascular disease. The performance of this integrated protocol was assessed in 89 consecutive patients. RESULTS: The bolus-chase 3D acquisition was of diagnostic quality in 100% of the acquisitions in the abdomen, 96% in the thigh, and 43% in the calf. The poor quality of the calf acquisitions was due to insufficient spatial resolution, poor arterial signal, and venous contamination. Diagnostic-quality images were obtained in 100% of the dynamic 2D acquisitions of the calf and 98% of the feet. CONCLUSIONS: The combined dynamic 2D and bolus-chase 3D contrast-enhanced MR angiography technique provides diagnostic images of the entire lower extremity.

Anatomically tailored k-Space sampling for bolus-chase three-dimensional MR digital subtraction angiography.

The purpose of this study was to evaluate a variable k-space sampling method for bolus-chase three-dimensional magnetic resonance digital subtraction angiography in the arterial system from the abdomen to the calf. Imaging time was minimized by tailoring the acquisition according to the vascular anatomy of the station. For images obtained in 30 patients, results with the modified protocol were compared to those with the previously published protocol. For all stations, significant improvement (P <.001) was found with the modified protocol.

Fluoroscopic landmarks for optimal visualization of the proximal renal arteries.

PURPOSE: To accurately determine the in vivo orientation of the origin of the renal arteries from the aorta relative to a fluoroscopic bony landmark for optimal diagnostic arteriography and renal artery stent placement. MATERIALS AND METHODS: One hundred sixty abdominal computed tomography (CT) scans of patients in eight age groups (20-90 years) were reviewed to determine the angle of the origins of the renal arteries from the aorta relative to the long axis of the L-1 spinous process (L1SP). RESULTS: The right renal artery arises ventrally at an angle of 30 degrees (standard deviation [SD] = 15 degrees) from a plane orthogonal to the long axis of the L1SP. The left renal artery arises dorsally at an angle of 7 degrees (SD = 13 degrees) relative to the same plane. CONCLUSIONS: The optimal initial angle for angiographic evaluation of the origin of the renal artery and for renal artery stent placement is 30 degrees left anterior oblique (LAO) relative to the L1SP for the right renal artery and 7 degrees LAO for the left renal artery. Unfortunately, there is variability in the angle of the renal artery origins from the aorta which cannot be controlled for using this technique. In some patients, additional views will be necessary to optimally depict the origins of the renal arteries.

Comparison of two-dimensional MR digital subtraction angiography of the lower extremity with x-ray angiography.

PURPOSE: To perform a preliminary evaluation of the diagnostic accuracy of contrast-enhanced, two-dimensional (2D) magnetic resonance (MR) digital subtraction angiography (DSA) of the lower extremity by comparison with x-ray angiography (XRA). MATERIALS AND METHODS: Forty lower extremities in 22 patients were imaged at multiple levels with both XRA and 2D MR DSA. Images were retrospectively analyzed by three radiologists in a randomized blinded manner. Seventeen vascular segments were graded as an insignificant lesion, a significant lesion, or as an occlusion. With the use of segments well depicted with XRA as the gold standard, the sensitivity, specificity, and accuracy of 2D MR DSA, as compared with XRA, were evaluated. The McNemar-Stuart-Maxwell test was performed to determine the significance of any differences found. RESULTS: Three hundred eighty-three arterial segments were evaluated with both techniques. Three hundred one segments were well depicted with XRA. There was no significant difference between 2D MR DSA and XRA for assessing the degree of occlusive disease in these 301 segments (.25 < P < .5). The sensitivity, specificity, and diagnostic accuracy of 2D MR DSA were found to be 90%, 98%, and 93%, respectively. CONCLUSION: Two-dimensional MR DSA is an accurate method for assessing arterial lesions in the lower extremity.

In vitro evaluation of the relative thrombolytic efficiency of forced intrathrombic injections: saline versus urokinase.

PURPOSE: To compare the rates of thrombolysis produced by forced intrathrombic injections of saline versus urokinase, as well as automated versus manual injections of urokinase, with use of an in vitro model of a vascular occlusion. MATERIALS AND METHODS: The rates of thrombolysis produced by forced intrathrombic injections of saline and urokinase were compared in an in vitro radiometric model utilizing I-125-labeled thrombus. Similar experiments were performed to compare manual and automated injections of urokinase. The dissolution of the thrombus was quantitatively monitored with use of a scintillation detector. Averaged time activity data for each type of experiment were fit to exponential functions and half times of lysis calculated. The differences in the half times for the experiments being compared were evaluated for significance with use of the Student t test. RESULTS: The half times of lysis produced by forced intrathrombic injections of urokinase were substantially and significantly shorter than those produced by forced saline injections. The half time of lysis produced by automated injections was not significantly different than that produced by manual injections. CONCLUSIONS: Forced intrathrombic injections of urokinase produce faster and substantially more thrombolysis when compared with similarly administered saline. Also, for forced intrathrombic injections of lytic agents, an automated injector is an equivalent alternative to manual injections.

Timing algorithm for bolus chase MR digital subtraction angiography.

To acquire multiple longitudinal locations in the lower extremity after a single contrast injection, appropriate table translation and contrast injection are required. An approximate model based on constant bolus velocity was developed to describe the space-time course of a contrast bolus in the lower extremity. This model was verified in dynamic MR angiograms acquired in a group of patients using time-resolved 2D MR digital subtraction angiography (MRDSA). From this contrast bolus passage model, a timing algorithm for table translation and contrast injection was developed for bolus chase MRDSA, subsequently validated in bolus chase 2D MRDSA experiments. All targeted major peripheral arteries were well depicted in bolus chase 2D MRDSA using this timing algorithm and a single 15-ml contrast dose.

Distal lower extremity arteries: evaluation with two-dimensional MR digital subtraction angiography.

PURPOSE: To test the hypothesis that magnetic resonance (MR) digital subtraction angiography is superior to two-dimensional time-of-flight (TOF) MR angiography for demonstration of patent arteries in the distal lower extremity. MATERIALS AND METHODS: Thirty-seven lower extremities in 23 consecutive patients were imaged with two-dimensional TOF MR angiography and two-dimensional MR digital subtraction angiography. Images were interpreted in a randomized and blinded manner. Each lower extremity was subdivided into seven potential arterial segments. The number of digital arteries visualized was also determined. Overall image quality of MR digital subtraction and TOF angiograms was compared. The relative ability of MR digital subtraction angiography and TOF MR angiography to demonstrate patent arterial segments was assessed. RESULTS: MR digital subtraction angiography was significantly superior to TOF MR angiography for demonstration of patent arterial segments and digital arteries (P < .001). MR digital subtraction angiographic images were qualitatively superior to TOF images (P < .001). CONCLUSION: Two-dimensional MR digital subtraction angiography is superior to two-dimensional TOF MR angiography for help in identifying patent segments in the distal lower extremity.

Bolus-chase MR digital subtraction angiography in the lower extremity.

A bolus-chase magnetic resonance (MR) angiographic technique performed with a prototypic stepping table and coil holder and a 15-20-mL injection of contrast material was developed to depict the entire lower extremity. Image acquisition was synchronized with passage of the contrast medium bolus through the lower extremity. Ten subjects underwent the examination, which was performed in less than 1 minute. All major arteries were well demonstrated in all cases.