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Dive into the research topics where J. Leonel Villavicencio is active.

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Featured researches published by J. Leonel Villavicencio.


Journal of Vascular Surgery | 2007

Primary chronic venous disorders

Mark H. Meissner; Peter Gloviczki; John J. Bergan; Robert L. Kistner; Nick Morrison; Felizitas Pannier; Peter J. Pappas; Eberhard Rabe; Seshadri Raju; J. Leonel Villavicencio

Primary chronic venous disorders, which according to the CEAP classification are those not associated with an identifiable mechanism of venous dysfunction, are among the most common in Western populations. Varicose veins without skin changes are present in about 20% of the population while active ulcers may be present in as many as 0.5%. Primary venous disorders are thought to arise from intrinsic structural and biochemical abnormalities of the vein wall. Advanced cases may be associated with skin changes and ulceration arising from extravasation of macromolecules and red blood cells leading to endothelial cell activation, leukocyte diapedesis, and altered tissue remodeling with intense collagen deposition. Laboratory evaluation of patients with primary venous disorders includes venous duplex ultrasonography performed in the upright position, occasionally supplemented with plethysmography and, when deep venous reconstruction is contemplated, ascending and descending venography. Primary venous disease is most often associated with truncal saphenous insufficiency. Although historically treated with stripping of the saphenous vein and interruption and removal of major tributary and perforating veins, a variety of endovenous techniques are now available to ablate the saphenous veins and have generally been demonstrated to be safe and less morbid than traditional procedures. Sclerotherapy also has an important role in the management of telangiectasias; primary, residual, or recurrent varicosities without connection to incompetent venous trunks; and congenital venous malformations. The introduction of ultrasound guided foam sclerotherapy has broadened potential indications to include treatment of the main saphenous trunks, varicose tributaries, and perforating veins. Surgical repair of incompetent deep venous valves has been reported to be an effective procedure in nonrandomized series, but appropriate case selection is critical to successful outcomes.


Journal of Vascular Surgery | 1989

Abnormalities of lymphatic drainage in lower extremities: A lymphoscintigraphic study

Paul Steven Collins; J. Leonel Villavicencio; Sue H. Abreu; Edward R. Gomez; James A. Coffey; Cass Connaway; James M. Salander; Norman M. Rich

Chronic lower-leg edema in patients with venous disorders was studied by means of lymphoscintigraphy. Lymphatic patterns of flow were evaluated prospectively in 26 patients with technetium 99m antimony trisulfide colloid injected subcutaneously in the interdigital web spaces on the feet. Most patients in this study had postphlebitic syndrome, and all of these patients had abnormal lymphoscintigraphic flow patterns. Nine had evidence of lymphatic obstruction, and one had an enhanced flow pattern. Three patients had veins used for distal arterial bypass, and all these veins showed decreased lymphatic flow. Two patients with Klippel-Trenaunay syndrome (congenital varicose veins associated with limb elongation, a capillary nevus, and an abnormal deep venous system) had obstruction to lymphatic flow, and two others had normal and enhanced patterns. Normal studies were seen in four of five patients who had veins used for coronary artery bypass grafting. The finding of decreased lymphatic flow in patients appears to be the result of the length of time from an episode of deep venous thrombosis, the occurrence and number of episodes of cellulitis and lymphangitis, and mobilization of the vein for use in distal arterial bypass surgery. This study shows that the edema attributed previously to primary venous disorders may have a significant lymphatic component. The degree of lymphatic obstruction can be determined by lymphoscintigraphy with technetium-labeled antimony trisulfide colloid.


Journal of Vascular Surgery | 2003

Microthrombectomy reduces postsclerotherapy pigmentation: multicenter randomized trial

Anke H. Scultetus; J. Leonel Villavicencio; Tzu-Cheg Kao; David L. Gillespie; Gary D Ketron; Mark D. Iafrati; Emmanouil Pikoulis; Sandra Eifert

OBJECTIVE Postsclerotherapy pigmentation occurs in nearly 30% of patients. Hemosiderin, from degradation of the venous thrombus, is the possible cause. The hypothesis that early removal of the thrombus may eliminate or decrease the incidence of pigmentation has not been proved or documented. The objective of this study was to investigate the effects of early microthrombectomy on incidence of postsclerotherapy pigmentation. MATERIAL AND METHODS This multicenter, randomized, controlled study involved 101 patients with varicose veins (100 women, 1 man; mean age, 46 years [range, 25-68 years]). Patients were divided into two groups, with veins 1 mm or less in diameter (group 1, n = 50) or veins 3 mm or less in diameter (group 2, n = 51). Group 1 was treated with Sotradecol (STD) 0.25%, and group 2 with STD 0.50%. In each patient, an area of varicosities was selected and divided into halves. One half was randomized to microthrombectomy and the other half served as control. Microthrombectomy was performed 1 to 3 weeks after treatment in the randomized half. Standard photographs were obtained before and 16 weeks after treatment, and were evaluated by three independent reviewers who were blinded to treatment assignments. Each reviewer received an identical set of pretreatment and posttreatment 10 x 15-cm color photographs of the study area, and completed a scoring sheet. Average of the scores was used to evaluate primary (pigmentation) and secondary (overall clinical improvement) end points. The paired t test and chi-square test were used for statistical analysis. RESULTS In group 1, microthrombectomized areas had statistically significant less pigmentation (P =.0047) and better overall clinical improvement scores (P =.0002) compared with the control side. In group 2 there was no significant difference between the two areas, but patients reported significant relief of pain and inflammation associated with postsclerotherapy thrombophlebitis. CONCLUSION In veins 1 mm or smaller, microthrombectomy reduced pigmentation and improved overall clinical results. In veins 3 mm or smaller, statistical significance was not achieved, but thrombectomy resulted in faster resolution of the postsclerotherapy pain and inflammation. On the basis of these results, microthrombectomy after sclerotherapy is recommended.


Vascular | 2009

Endovascular Management of Takayasu Arteritis: Is It a Durable Option?:

Byung-Boong Lee; James Laredo; Richard F. Neville; J. Leonel Villavicencio

Interim outcome of endovascular management of Takayasu arteritis (TA) was determined retrospectively to assess the efficacy of angioplasty and/or stenting in 24 patients with 35 lesions in the chronic inactive stage. The renal (n = 16), subclavian/innominate (n = 11), and carotid (n = 5) arteries and abdominal aorta (n = 3) were treated. Twenty-six lesions achieved excellent to good target lesion revascularization with no residual or only minimal residual stenosis, whereas five had a moderate result. Thirty lesions achieved satisfactory hemodynamic correction. Restenosis was observed in 8 lesions treated with angioplasty alone (n = 18) and in 3 lesions treated with angioplasty and stenting (n = 17). All recurrent stenoses underwent successful reintervention without significant complication. Treatment of inactive stage TA lesions with angioplasty alone or with angioplasty and stenting results in excellent to good clinical improvement in the majority of patients (follow-up at 46.8 months). Endovascular therapy is a durable treatment option in patients with chronic inactive stage TA.


Surgical Clinics of North America | 1991

Deep Venous Thrombosis and Pulmonary Embolism

Alfred V. Persson; Robert J. Davis; J. Leonel Villavicencio

All surgical patients are at risk for the development of deep venous thrombosis and subsequent pulmonary embolism or postphlebitic syndrome. The evolution of ultrasonographic imaging has increased the awareness of prevention, diagnosis, and treatment of deep venous thrombosis. Duplex imaging and Doppler color flow imaging have made the diagnosis of deep venous thrombosis relatively simple, painless, inexpensive, and definitive. These procedures have gained acceptance by both patients and physicians. Several risk factors have been identified that increase the chance of the development of deep venous thrombosis. These factors include a history of deep venous thrombosis, presence of a malignant process, increasing age, cigarette smoking, obesity, prolonged bed rest, and general anesthesia. The greater the number of risk factors, the more aggressive prophylaxis should be. Means of prophylaxis have improved, and surgeons now generally agree that some form of prophylaxis is required. Heparin and intermittent compression devices appear to be equally effective in preventing deep venous thrombosis. The addition of venous monitoring in high-risk patients permits immediate identification of the presence of deep venous thrombosis. During the last decade, the treatment of patients with deep venous thrombosis has changed little. Heparin followed by warfarin remains the treatment of choice. A small group of patients receive fibrinolytic therapy for deep venous thrombosis. Although the incidence of postoperative deep venous thrombosis has decreased during the last decade, it remains a significant complication.


Journal of Vascular Surgery | 1992

Maffucci's syndrome (hemangiomatosis osteolytica): A report of four cases

Paul Steven Collins; Whay Han; Larry R. Williams; Norman M. Rich; John F. Lee; J. Leonel Villavicencio

Maffuccis syndrome is a congenital nonfamilial syndrome combining dyschondroplasia, (enchondromatosis) and hemangiomatosis. It is a rare disease; only 200 cases have been reported throughout the world in the past 140 years. Over the past 20 years, four patients have been admitted with signs and symptoms consistent with Maffuccis syndrome. Three were children ages 3, 7, and 9 years. The fourth was 23 years old. Two were male and two female. All had hemangiomas at birth, and all had skeletal deformities and enchondromas. All complained of pain and heaviness of the involved extremity. Three patients had the arterial inflow evaluated with arteriograms, and one had magnetic resonance imaging. Two also had venograms. Two patients had excision of their hemangiomas, and one had sclerotherapy and compression therapy. All had bone biopsies performed. None of the enchondromas or the soft tissue lesions had undergone sarcomatous transformation.


Seminars in Vascular Surgery | 2002

Congenital vascular malformations: When and how to treat them

J. Leonel Villavicencio; Anke H. Scultetus; B.B. Lee

Congenital vascular malformations may involve arterial, venous, and lymphatic structures, can present in a variety of forms, and present many diagnostic and therapeutic challenges. Two-thirds of all congenital vascular malformations are predominantly venous, and their management will be emphasized in this article, because of the focus of this issue. The majority of the venous malformations are asymptomatic and should be treated conservatively. However, the clinical presentation of venous malformations associated with lymphatic anomalies is variable, and management may be more challenging. The diagnosis and management of arteriovenous malformations is straightforward. Selective catheter-directed embolization of the feeding arteries, occasionally followed by tumor excision, is the treatment of choice. Hemangiomas often will grow rapidly and then begin to regress. When they produce troublesome symptoms and are well localized, they should be excised. Deeply seated or diffuse malformations require a complete diagnostic evaluation to select the most appropriate time and type of intervention. Both our own experience and that of others can provided some basis for therapeutic recommendations in treating the different vascular malformations.


Vascular Surgery | 1997

Popliteal Venous Aneurysm Leading to Massive Pulmonary Embolus in a Child: A Case Report and Literature Review

Robert E. Carlin; Daniel J. McGraw; Elefterios S. Xenos; J. Leonel Villavicencio

Popliteal venous aneurysms are rarely reported but represent a known source for pulmonary emboli. Early diagnosis with prompt excision of the aneurysm and venous reconstruction eliminate the embolic source and prevent long-term sequelae of venous stasis. The authors present the case of a twelve-year-old girl with Klippel-Trenaunay syndrome who presented with a massive pulmonary embolus. Magnetic resonance angiography defined a saccular aneurysm of the popliteal vein, which was confirmed by contrast venography. The patient underwent resection of the venous aneurysm and lateral venorrhaphy. This is the twenty-sixth report in the English-language literature of pulmonary embolism originating from a popliteal venous aneurysm, and the youngest patient to date.


Journal of Vascular Surgery | 1994

Primary varicose veins of the upper extremity: A report of three cases

Harold J. Welch; J. Leonel Villavicencio

Primary varicose veins of the upper extremity are extremely rare. We present three cases and discuss cause, diagnosis, and treatment. Three patients, a 23-year-old man, a 31-year-old woman, and a 39-year-old man, were referred with symptomatic varicose veins of the arm. None of the patients had lower extremity varicosities. Diagnosis was made by physical examination, noninvasive and invasive procedures, and excluded vascular malformations. Surgical treatment, similar to that for lower extremity varicose veins, entailed ligation and stripping of the varicose veins. Ligation and stripping were performed and successfully eliminated the varicosities with prevention of recurrence with a mean follow-up of 17 months. Although primary varicose veins of the upper extremity are extremely rare, they can be readily diagnosed and successfully treated, similar to lower extremity varicose veins. Although not proven, the cause is likely identical to lower extremity varicose veins. Excellent functional and cosmetic results can be obtained with surgical treatment.


World Journal of Surgery | 2005

The Military Medical School of Mexico: A Tradition of Excellence

J. Leonel Villavicencio; Daniel M. Merrill; Norman M. Rich

It is a historical fact that warfare and surgery have been linked together as far back as military history has been recorded. In the 18th century, the tendency of most armies to dismiss their medical services at the end of every major conflict resulted in higher mortality at the beginning of the next war. This became evident in the French and British Armies during the Battle of Waterloo. These countries went to great efforts to mobilize their civilian reserve physicians, only to discover that more than half of the medical personnel declined to serve. The scarcity of physicians and the inexperience of those caring for the wounded resulted in a high casualty rate. The current armed conflicts throughout the world with their high number of victims are living evidence of the need for preparedness of the military medical personnel. In this article, we review the systems of military medical education in several countries, and offer the example of the Escuela Medico Militar (Military Medical School) of Mexico, a prestigious source of military medical physicians for the Mexican armed forces.

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Norman M. Rich

Uniformed Services University of the Health Sciences

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Anke H. Scultetus

Uniformed Services University of the Health Sciences

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Seshadri Raju

University of Mississippi Medical Center

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John J. Bergan

University of California

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