Vein Specialist Newsletter: Rare Venous Conditions, Sept 2022

Table of Contents

Message from the Editor: Pontch, Rosie, and Zebras
Steve Elias, MD, Editor-in-Chief

Membership Matters

Membership Drive 2022: Recruit a New AVF Member Today!
Mona Li, MD, Chair of AVF Membership Committee

Venous For All: Together in DEI
Karem Harth, MD, MHS, RPVI and Anil Hingaroni, MD

Odds & Ends of Venous Disease

Peripheral Venous Aneurysms
Thomas W. Wakefield, MD, and Peter F. Lawrence, MD

Portal Vein Aneurysms
Mary Binko, MS, and Eric Hager, MD

IVC Cross-section and Hydration
David M. Williams, MD, and Andrea Obi, MD

The Iceberg Phenomenon that is Klippel-Trénaunay Syndrome (KTS)
Michael Dalsing, MD, MBA, DFAVF 

Common Dermatologic Diseases that Masquerade as Venous Pathology
Margaret Mann, MD, FAAD

Pediatric Thrombosis: Not Just Miniature Adults!
Joann Lohr, MD, FACS, RVT, CWSP

The Underreported Morbidity of Mesenteric Venous Thrombosis
Elizabeth Andraska, MD, MSc, and Natalie Sridharan, MD

When is DVT not Just a DVT?
Chandu Vemuri, MD and Robert Beaulieu, MD, MSE

Publications and Hoofbeats
Ruth L. Bush, MD, JD, MPH

International Corner

AVF Representation Across the Globe

Swiss Society of Phlebology Highlights: Diversity in Phlebology
Jürg Hafner, Dominik Heim, Jürg Traber

Copyright © 2022 by The American Venous Forum. All rights reserved.

EDITOR-IN-CHIEF
Steve Elias, MD 

EXECUTIVE EDITOR
John Forbes, MBA 

MANAGING EDITOR
Allie Woodward 

PUBLICATION DESIGNER
Christine Rataj 

Message from the Editor: Pontch, Rosie, and Zebras

Steve Elias, MD
Editor-in-Chief, Vein Specialist

Do we really need ice cream for dogs? Our human ice cream isn’t good enough for them? My dog has no issue. He’ll eat our ice cream. Ben & Jerry think differently. When you run out of humans to sell your ice cream to, you figure out the next demographic. In Ben & Jerry’s case, it is dogs. There are 76 million dogs and 56 million cats and 3,000 zebras in the United States. Clearly, the ice cream sellers are not going after zebras. We won’t see zebra-specific ice cream any time soon, although this issue of Vein Specialist is about venous zebras.

Cat ice cream is probably next. As far as I’m concerned, this is a pure marketing ploy. My wife and I have had many dogs throughout our marriage. We gave them a spoonful of human ice cream when we were eating some. They liked it. They didn’t have GI upset. Ben & Jerry think that this is a real doggie problem, GI upset.

Do dogs really need ice cream–human or doggie? If you never give them ice cream, they will never know what they’re missing. My experience has been that dogs will eat almost anything; well maybe not asparagus, mushrooms, or peas. But a lot of humans won’t eat them either. Do we really need Ben & Jerry’s Doggie Dessert ice cream in 2022? There are some humans with elevated BMIs who don’t really need it either. It is not an essential nutrition staple. It is a treat. It’s all about perspective.

Go to the Ben & Jerry’s website. They almost convinced me that my Corgi needed their sunflower butter based doggie ice cream. Breaking news… they say humans can eat it, too. Wow. What will your friends think as you lick either Pontch’s Mix or Rosie’s Batch doggie ice cream? Pontch and Rosie are Ben & Jerry’s dogs. When Pontch and Rosie create human ice cream maybe they’ll name it Ben’s Dream and Jerry’s Joy. Ludicrous.

In this issue of Vein Specialist we decided to go a little off the beaten path, (Clearly, Ben & Jerry are way off.) We have dedicated this issue to venous zebras: the unusual, uncommon pathologies that are the odds and ends of our specialty. Some of us rarely see them and some of us may never see them. We have 2 articles about aneurysms – portal and peripheral. DVT in unusual places or people is discussed by Chandu Vemuri and Joann Lohr – mesenteric veins and pediatric population. Margaret Mann, our resident dermatology person, talks about some dermatologic conditions that can mimic venous skin findings. Michael Dalsing’s article discusses that the skin components of KTS are merely the tip of the iceberg. Finally, our last venous zebra is David Williams and Andrea Obi’s article about IVC morphology/problems and hydration.But that’s not all. Members make AVF what it is. We have welcomed a lot of new members this past year, but we always need to grow. Read the article by our Membership Committee Chairman, Mona Li. Many monetary benefits are available to you for recruiting new members. See the ad for our BAM (“Become A Member”) campaign. “Venous for All” is the title of the article by our Diversity, Equity, and Inclusion (DEI) Committee members Karem Harth and Anil Hingorani. They give a good snapshot of where we are and where we intend to go. DEI is no zebra, but rather one of the horses you think about when you hear AVF hoofbeats.

Now that we have brought your attention to venous zebras, ever wonder what zebras eat? We know that dogs crave ice cream according to the marketing people at Ben & Jerry’s. They didn’t make ice cream for zebras because zebras aren’t picky eaters. In fact, they’ll eat almost anything green: grass, leaves, asparagus, peas, and perhaps money. Maybe Ben & Jerry just need to create a green ice cream for our Vein Specialist zebras? Until this issue I didn’t much think about zebras. I have a few other things that I need to think about: wife, four children, grandchildren, a job, and–most important–what Doggie Dessert type of ice cream I should bring home for our dog. And I thought decision making when treating patients with venous disease was tough at times! Ben & Jerry take it to a new level. This issue exposed you to some zebras in our vein world. And even though many of us don’t encounter zebras over the course of our professional lives, we hope this issue will help you when you do. Regarding your dogs, just give them a teaspoon of real human ice cream and call it a day. Ben & Jerry’s be damned.

Membership Drive 2022: Recruit a New AVF Member Today!

Mona Li, MD
Chair, AVF Membership Committee

As the AVF embarks on a new membership campaign, I began to reflect on how I became a member of the American Venous Forum.

As a general surgeon, I had the opportunity to begin my career in venous disease with the Division of Vascular Surgery at the University of Rochester in Rochester, NY in 2006. At that time, this division already operated a free-standing vein clinic. The person I credit as my main mentor, Dr Jeffrey Rhodes, encouraged me to train with them to learn the latest minimally invasive techniques for superficial venous disease. Dr Rhodes introduced me to the American Venous Forum, and I have been a member since 2007.

In 2011, when I was on faculty at the University of Cincinnati, Dr.George “Mickey” Meier directed me to the AVF Fellows and Early Career Course to further enhance my venous disease education and ultrasound skills. I followed their advice to become a member and to take advantage of all the benefits that this society provides for those who have an interest in venous and lymphatic disease.

While I can certainly espouse the enormous list of educational, career, and practice-enhancing perks of membership, the camaraderie, friendships, and new mentors that I have met through membership in the AVF have been the most gratifying benefits. Being surrounded by like-minded practitioners and researchers from around the world who share the same vision and purpose in advancing the care of patients with venous and lymphatic disease and increasing awareness of the clinical importance of our field is truly invaluable and worthwhile aspect of membership in this remarkable society.

As Chair of the Membership Committee this year, I want you to reflect on why you are a member of the American Venous Forum, and how you can pass on all the same benefits and rewarding relationships you have received from the AVF to a fellow physician who shares the same commitment to venous and lymphatic disease.

AVF member benefits include but are not limited to:

• • • Free online access to Journal of Vascular Surgery: Venous and Lymphatic Disorders
    • Reduced registration fees to AVF’s Annual Meeting and other educational programs
    • Reduced costs of selected educational publications in AVF’s online store ShopAVF
    • Free access to Venous Online® for recorded content and educational programs
    • Access to AVF Exchange, AVF’s private discussion board
    • Inclusion in VitaDox, an online resource for patients to find a vein specialist
    • Access to AVF’s Career Center to learn about new opportunities as a vein specialist

If you recruit a new physician member during the months of October and November 2022, you will receive a special bonus for your efforts. Be a mentor and recruit a fellow physician to join the AVF today! The Membership Committee and I thank you for your time and consideration.

Venous For All: Together in DEI

Karem Harth, MD, MHS, RPVI
Member, AVF Early Career Committee
Member, AVF DEI Committee

Anil Hingaroni, MD
Member, AVF Newsletter Committee
Member, AVF DEI Committee

The AVF core values include those of Diversity, Equity, and Inclusion. The commitment to understanding, accepting, respecting, and encouraging all ideas, people, and actions will advance AVF priorities and goals and elevate all aspects of society. Our newly developed ad hoc Diversity, Equity, and Inclusion (DEI) Committee will actively implement and create actionable goals in line with DEI principles. Research that is sensitive to DEI matters is of paramount importance to better understand all populations in an unbiased way. Internal reflection, we believe, will be a catalyst to the process of making meaningful strides in the DEI space. Looking at these data represents an important shift in our priorities and will elevate our society and its mission. To this end, we share voluntary survey results from our membership and report the make-up of our current committees and leadership.

AVF Membership
Our commitment and efforts in the DEI space, importantly, start with our membership as reflected in many areas including representation and role modeling by our AVF leaders, interest in venous disease by physicians and trainees, and how effective we are in demonstrating our inclusivity. These are just some of the ways our membership reflects on us and our actions. In 2021, the AVF performed a voluntary survey of our membership. The self-reported results provide a view of our membership, areas of opportunity, and the makeup of the global venous community as it exists and that we can build upon.

Per our recent member survey sent to 815 members, 75% of AVF members who responded are male and 23% are female, while 2% preferred not to say. Sexual orientation was predominantly heterosexual/straight (91%), with 1% gay/lesbian and 8% preferring to not disclose. 58% of AVF membership identifies as Caucasian, Non-Hispanic. Global representation of our AVF membership was 18% and included 45 different countries. 19% of our members (155/815) are trainees, 4% are allied health professionals, 2.3% are affiliates, and the remaining are physicians (74%).

AVF Committees
AVF committees play critical roles in the success, growth, and representation of our society. AVF supports 22 active committees with 194 volunteer positions filled by 118 active AVF members. Across all committees, 62% of the members are men and 38% are women. Of the active AVF members, 57% are men and 43% are women.

Each of these committees is chaired by a selected AVF member. Chairs of these 22 committees are 64% men and 36% women. In committees chaired by men, 28% of the committee members were women; while in committees chaired by women, 54% of the members were women. Among the 22 committees, 9 committees have equal numbers of men and women members.

Gender balance in specific committees was noted as a factor that will have an impact in the current and future image of the AVF. These committees in particular include mission advancement, digital media, annual program, patient education, membership, research, early career, DEI, and document oversight. We want to encourage engagement and participation and thus we highlight areas where we can be purposeful in our elections and sponsorships. From our 22 committees, those that have been identified as having an opportunity to improve gender-based diversity include international committee, ethics committee, bylaws committee, strategic planning committee, distinguished fellows (selection) committee, nominating committee, finance committee, and executive committee.

The CORE VALUES VEINS emphasizes Diversity, Equity, and Inclusion. As we reflect on these initial data, we want to thank those who voluntarily contributed to this survey as well as our leadership for openly sharing the data with our group and readers. Our membership, committee, and leadership survey provides an important “first look” at our make-up. Future updates to these data will allow us to monitor progress and serve as a surrogate for meaningful impact and change in our DEI efforts. Importantly, they highlight limitations and knowledge gaps in our data that we need to prioritize as we move forward. Our voices will be better heard and represented when we can improve on other important demographic variables not addressed by our current surveys. We need to better understand presence of under-represented minorities, various ethnicities, and LGBTQ groups, to name a few. Promoting equity and diversity starts with Inclusivity, which requires us to cultivate a culture and climate of non-judgment and open conversation. We will build momentum through the process of identifying our strengths and limitations. By increasing awareness, we will cultivate an ideal DEI platform – Venous for All.

Peripheral Venous Aneurysms

Thomas W. Wakefield, MD
Past AVF President
University of Michigan

Peter F. Lawrence, MD
Past AVF President
UCLA Medical Center

Venous aneurysms increase the risk for venous thromboembolism (VTE) and pulmonary embolism (PE) and can lead to the development of chronic venous insufficiency (CVI). A venous aneurysm is defined as a vein that measures 1.5-2.0 times the size of the normal vein below or above the aneurysm and can be either fusiform or saccular. The most common locations for peripheral venous aneurysms are popliteal, iliofemoral, and upper extremity/jugular. In a single center study, 3 (~30%) patients presented with DVT or PE; 3 (~30%) had limb pain or swelling; and 40% were asymptomatic (1). The mean size of popliteal venous aneurysms was 2.6 times the normal proximal and/or distal vein. Of asymptomatic patients who were observed, 3 ultimately underwent surgical repair due to size or symptoms.
In a multicenter study of venous aneurysms from the low frequency disease consortium with a median follow-up of 27 months, 8 patients with popliteal venous aneurysms (20%) presented with DVT/PE; 13 (33%) presented with pain; and the remainder were discovered incidentally (2). Patients presenting with DVT or PE had larger aneurysms than those presenting without VTE (3.8cm vs 2.5cm, p=0.003). Additionally, aneurysm morphology (saccular versus fusiform) was associated with thromboembolism (30% vs 9%, p=0.046) as was thrombus burden, which was determined by duplex ultrasound and/or cross-sectional imaging, with an estimate of intravascular thrombus measuring > 25% (45% vs 3%) being associated with DVT or PE. Because large lower extremity venous aneurysms and saccular aneurysms with thrombus >25% lumen involvement were more likely to present with thromboembolic complications, they deserve operative intervention.

Half of all patients treated for popliteal and iliofemoral venous aneurysms combined underwent immediate intervention, whereas the remainder of patients were managed with observation and an antithrombotic regimen. In the medically managed cohort, the incidence of DVT was 5% for popliteal venous aneurysms, but 33% for observed iliofemoral venous aneurysms. For upper extremity aneurysms, only 1 medically treated patient developed pain and 1 demonstrated growth. Thirty-nine patients (59%) ultimately underwent surgical intervention, with the most common indication for surgery being absolute size. Nine patients underwent a procedure for DVT/PE and 11 for pain or extremity swelling. The most common operation was aneurysmorrhaphy in 21 patients (54%), followed by excision and ligation in 14 patients (36%), and interposition bypass grafting in 5 patients (13%).Postoperative hematoma in anticoagulated patients requiring re-intervention was the most common complication, present in 3 popliteal vein repairs and 1 iliofemoral vein repair. Since postoperative hematoma is the most common complication, the technique of closed plication is often preferred to open plication for popliteal venous aneurysms (and iliofemoral venous aneurysms) if no thrombus is present in the aneurysm, as anticoagulation is unnecessary from the viewpoint of the surgery (3).

In conclusion, surgical intervention for lower extremity venous aneurysms is indicated to reduce the risk of VTE and need for continued anticoagulation, with popliteal venous aneurysms > 2.5cm and all iliofemoral aneurysms considered for repair. Plication (Figure 1) is the preferred procedure when there is no intraluminal thrombus because postoperative anticoagulation is not required. Upper extremity aneurysms do not carry a significant risk of VTE and warrant treatment primarily for symptoms.

Figure 1. Plication of popliteal vein aneurysm, in this case with two rows of plication sutures. Modified from Beaulieu et al.3 Figure by RJ Beaulieu. Used with permission.

References
1. Patel R, Hanish S, Baril D, Woo K, Lawrence P. Contemporary management of lower extremity venous aneurysms. J Vasc Surg Venous Lymphat Disord. 2019;7:860-864. doi:10.1016/j.jvsv.2019.06.017
2. Patel R WK, Woo K, Wakefield TWW, et al. Contemporary management and outcomes of peripheral venous aneurysms – a multi-institutional study. J Vasc Surg Venous Lymphat Disord. 2022 Aug 5:S2213-333X(22)00326-2. doi: 10.1016/j.jvsv.2022.06.011. Epub ahead of print. PMID: 35940449
3. Beaulieu RJ, Boniakowski AM, Coleman DM, Vemuri C, Obi AT, Wakefield TW. Closed plication is a safe and effective method for treating popliteal vein aneurysm. J Vasc Surg Venous Lymphat Disord. 2021; 9:187-92. doi:10.1016/j.jvsv.2020.04.026

Portal Vein Aneurysms

Mary Binko, MS
University of Pittsburgh

Eric Hager, MD
University of Pittsburgh
Chair, AVF Digital Media Committee
Member, AVF Newsletter Committee

From time to time we receive referrals for portal vein aneurysms, but we do not have consensus recommendations to guide our management of these patients. Due to the rarity of venous aneurysms, our current understanding is based on case reports and series as well as systematic reviews. However, portal vein aneurysms are increasingly reported as an incidental finding on imaging, thus urging us to develop a better understanding of this venous aneurysm.

Portal vein aneurysms occur at any age without male or female predominance. Venous aneurysms form due to degeneration and weakening of the vein wall resulting in aneurysmal dilation diagnosed on ultrasound or computerized tomography (Figure 1). This can lead to nonlaminar blood flow resulting in thrombosis or increased wall stress and spontaneous rupture.

The etiology of portal vein aneurysms is acquired or congenital. The most common acquired etiology is liver disease (26-28.3%) and portal hypertension (30.8-32%) (1). However, many patients without liver disease develop portal vein aneurysms. Case reports have described the presence of portal vein aneurysm in the fetus, which supports an underlying congenital origin. Developmental abnormalities in the vitelline and umbilical veins, which form the portal venous system, lead to portal vein aneurysms (2).

No consensus guidelines have been published on the management of portal vein aneurysms. The natural history, including their shape and rate of growth, is poorly understood. In an analysis of 53 patients, 94% of aneurysms remained stable without interval growth over a mean of 21.15 months (3). Consequently, patients with small aneurysms without interval growth on serial imaging are managed conservatively. Several indications for surgical intervention include size, rapid interval growth, symptoms, and complications. The diameter at which intervention is indicated remains unclear due to our incomplete understanding of the natural history of these aneurysms and the size at which risk of rupture outweighs the surgical risks. A size of 3 cm has been suggested as an indication for intervention (4). The most common symptoms leading to intervention are abdominal pain (44.7%) and GI bleeding (7.3%).3 Complications are rare, including thrombosis, rupture, or compression of nearby structures, including the common bile duct, duodenum, and inferior vena cava (1,3).

The presence of portal hypertension influences the selection of operative technique as patients with portal hypertension receive portosystemic shunts for venous decompression, splenectomy, or liver transplant (1). Aneurysmorrhaphy or aneurysmectomy is the preferred operative technique for patients without liver disease and thrombectomy when thrombosis is present. Although open surgical intervention remains the standard of care, a role for endovascular intervention in the treatment of portal vein aneurysm may exist. A hybrid approach using laparotomy and catheter-directed thrombectomy was utilized recently for a case of aneurysm thrombosis (5).

Figure 1. A.) 4.3 x 3 cm fusiform portal vein aneurysm in an asymptomatic patient in A, axial; B.) sagittal; and C.) coronal orientation.

 

References
1. Laurenzi A, et al. Portal vein aneurysm: what to know. Dig Liver Dis.2015; 47: 918-23. doi:10.1016/j.dld.2015.06.003
2. Gallego C, et al. Congenital and acquired anomalies of the portal venous system. Radiographics. 2002; 22:141-59.doi:10.1148/radiographics.22.1.g02ja08141
3. Sfyroeras GS, et al. Visceral venous aneurysms: clinical presentation, natural history and their management: a systematic review. Eur J Vasc Endovasc Surg. 2009; 38:498-505. doi:10.1016/j.ejvs.2009.05.016
4. Moreno JA, et al. Extrahepatic portal vein aneurysm. J Vasc Surg. 2011; 54:225-6,.doi:10.1016/j.jvs.2010.05.113
5. Gorolay V, et al. Asymptomatic thrombosis of extrahepatic portal vein aneurysm necessitating hybrid operative repair. Vascular. 2021; 29:762-66. doi:10.1177/1708538120976977

IVC Cross-section and Hydration

David’s M. Williams, MD
University of Michigan

Andrea Obi, MD
Chair, AVF Research Committee
Member and Past Chair, AVF Digital Media Committee 

Unlike the length of the human vein, the cross-section of a vein is not a fixed dimension. The relevance of intravascular ultrasound (IVUS) measurement of venous cross-section has been emphasized by vascular surgeons in the context of matching stent diameter to the anatomically compressed vein or to the pre-thrombotic native state of the thrombosed vein.1 Ultrasound monitoring of IVC and hepatic vein cross-section in response to fluid status or right heart pressure has also been found useful in monitoring congestive heart failure (CHF).2,3 The reliability of a single sample of venous cross-section has not been widely discussed, especially in the context of a single measurement to determine stent size. This short case report illustrates the importance of fluid status on venous cross-section.

The patient was a 56-year-old man referred to us for removal of a Guenther-Tulip IVC filter placed because of several thromboembolic episodes 10 years earlier. He was found to have the G20210A mutation. Anticoagulation was discontinued after 1 year, and the patient on aspirin only had no recurrence over the intervening years. He had no varicose veins in his legs or abdomen. He had no limitation to his activities of daily living. He walked 30 minutes 3-5 days weekly with no discomfort or limb swelling. After an attempt to remove the IVC filter failed, a CT was obtained, and the patient was referred for filter removal and possible IVC reconstruction.

Baseline CT shortly after filter placement showed normal caliber IVC at the level of the filter apex (Figure 1A). CT after failed retrieval 8 years later showed marked narrowing of the IVC at the level of the filter apex (Figure 1B). On the day of filter extraction 3 months later, the patient’s creatinine was 1.6 (baseline 1.3), so he was given 2 liters of lactated Ringer’s. Right trans saphenous iliocavogram after the crystalloid infusion (Figure 2A) showed normal caliber IVC and coaxial filter with no stricture or collateral flow. The IVC filter apex was free in the IVC lumen, and the filter was removed uneventfully using 12 Fr endobronchial forceps through a 16 Fr sheath. Post-extraction cavogram showed excellent flow with no stricture or contrast extravasation (Figure 2B).

This case illustrates the remarkable change in IVC caliber due to fluid status of the patient. Although we do not have biochemical markers of the patient’s fluid status at the time of exams, the CTs show small caliber suprarenal IVC at the time of failed extraction (Fig 3A) compared to normal caliber IVC after crystalloid infusion (Fig 3B) just prior to successful extraction. Unfortunately, we do not have a creatinine level at the time of the baseline CT, but we presume the change in IVC caliber was due entirely to the added 2 liters of crystalloid he received just before the venogram. Although hydration’s role is not rare in these cases, the factitious role hydration status can play in imaging is often not appreciated yet deserves attention and elaboration.4

Figure 1. CT shows normal IVC and filter apex several days after implantation (A) and contracted IVC several days after initial failed extraction (B) 8 years later.

Figure 2. Cavogram after crystalloid infusion before (A) and (B) after filter retrieval show normal caliber IVC without stricture or contrast extravasation.

Figure 3. From the same exams as in Figure 1 above, axial CT slices show normal caliber suprarenal IVC several days after implantation (A) and contracted IVC several days after initial failed extraction (B).

References
1. Raju, S. Ten lessons learned in iliac venous stenting. Endovasc Today. 2016;15:40-44.
2. Albani S, Mesin L, Roatta S, et al. Inferior vena cava edge tracking echocardiography: a promising tool with applications in multiple clinical settings. Diagnostics (Basel). 2022; 12:427.
3. De Vecchis R, Baldi C. Inferior vena cava and hemodynamic congestion. Res Cardiovasc Med. 2015; 4:e28913. doi: 10.5812/cardiovascmed.28913v2. PMID: 26436075; PMCID: PMC4588705
4. Eisenstat RS, Whitford AC, Lane MJ, Katz DS. The “flat cava” sign revisited: what is its significance in patients without trauma? Am J Roentgen. 2002; 178:21-25.

The Iceberg Phenomenon that is Klippel-Trénaunay Syndrome (KTS)

Michael Dalsing, MD, MBA, DFAVF
AVF Past President
Professor Emeritus, Division of Vascular Surgery
Indiana University School of Medicine

Below the obvious stripes of this venous zebra (iceberg tip) –port-wine stain skin tattooing, varicose veins, and enlarged and sometimes longer leg –lie important hidden anatomic abnormalities (hidden iceberg) that help explain symptom severity and best treatments.

Klippel-Trénaunay Syndrome (KTS) is classified (Hamburg classification) as a predominantly venous defect of the truncular form (signifying the inability to proliferate after removal) presenting with aplasia, obstruction, or dilation.The signs, symptoms, and disease progression can be quite different for each person and range from leg pain, swelling, and hyperpigmentation to variceal bleeding, superficial/deep venous thrombosis, ulceration, and limb length discrepancy with soft tissue, muscle, joint, and bone involvement. As the patient perceives increasing disability, the doctor seeks more understanding of the underlying pathology.

A venous duplex