Venous Stasis Changes Research Articles

Magnetic resonance venography in the diagnosis and management of May-Thurner syndrome.

Isolated left lower extremity swelling secondary to left iliac vein compression was first described by McMurrich in 1908, and defined anatomically by May and Thurner in 1957 and clinically by Cockett and Thomas in 1965. The left iliac vein is usually located posterior to the right iliac artery and can be compressed between the artery and the fifth lumbar vertebrae. Symptoms include left lower extremity edema, pain, varicosities, venous stasis changes, and deep venous thrombosis. Evaluation of these patients historically included a venous duplex scan to rule out deep venous thrombosis and an abdominal computed tomography scan to rule out pelvic mass. This paper describes the use of magnetic resonance imaging and venography in the evaluation of patients with isolated left lower extremity swelling. A retrospective analysis of a series of 24 patients who presented with symptomatic left lower extremity edema was performed. Infrainguinal deep venous thrombosis and valvular reflux was evaluated by duplex scan. The presence of suprainguinal deep venous thrombosis and pelvic mass was evaluated by magnetic resonance imaging. Magnetic resonance imaging was used to define the anatomic characteristics of the May-Thurner syndrome. Patients identified with the syndrome were treated either conservatively with lower extremity compression and elevation or with angioplasty and stenting. Follow-up of this subset of patients was performed with clinical assessment of the resolution of their symptomatic lower extremity edema as well as quality of life assessments via phone interviews. Twenty-four patients were evaluated for isolated left lower extremity swelling. Seven patients had positive results on duplex scans for deep venous thrombosis. Magnetic resonance imaging results demonstrated 1/24 (4%) had a pelvic mass compressing the iliac vein; 2/24 (8%) patients had iliac vein thrombosis; 1/24 (4%) patients with a history of deep venous thrombosis demonstrated a long stenotic segment of the left iliac vein unrelated to its association with the right iliac artery; 9/24 patients (37%) had anatomic evidence of May-Thurner syndrome; and 2/24 patients (8%) had isolated left lower extremity swelling of unknown etiology. Five patients diagnosed with May-Thurner syndrome were treated conservatively with compression stockings and leg elevation. Four patients with May-Thurner syndrome underwent iliac vein angioplasty and stenting. Technical success was 100%. On clinical follow-up, the patients with May-Thurner syndrome have had improvement/resolution of their symptoms. There have been no complications from either therapy. May-Thurner syndrome is a clinical entity of left iliac vein compression by the right iliac artery, resulting in isolated left lower extremity swelling and may be a precipitating factor for iliofemoral deep venous thrombosis. Magnetic resonance imaging is the best modality for diagnosis of this entity as it can rule out the presence of pelvic masses and deep venous thrombosis while simultaneously demonstrating the anatomy characteristic of this syndrome.

Tourniquet-related Hypotension in Venous Stasis Ulcer Excision

Extremity tourniquets are widely used to achieve bloodless dissection in the surgical field. Excision of venous stasis ulcers (VSU) is aided by tourniquet use because of large dilated veins associated with venous stasis disease. We present 3 patients with hypotensive shock occurring 10 to 15 minutes after tourniquet release after excision of venous stasis ulcers. All patients had long histories of venous stasis changes and two-thirds had prior histories of deep vein thromboses and pulmonary embolism. Mean tourniquet inflation time was 34 minutes and there were electrocardiographic changes in two-third of the patients. All patients responded rapidly to standard resuscitation measures and in all 3 postoperative testing for pulmonary embolus and myocardial infarction was negative. Wound cultures revealed no organisms in 1 patient, mixed Gram-positive cocci in another, and greater than 10(5) Serratia marcescens in the third patient. Although small decreases in blood pressure and blood pH, and increases in blood lactate, PcO2, and creatinine phosphokinase, are normally associated with the use of extremity tourniquets, hypotensive shock has not been reported. The combined effect of tourniquet ischemia and venous stasis changes may cause hypotensive shock by (1) an endotoxic bolus upon tourniquet release, (2) pulmonary microembolization of platelet, fibrin, and leukocyte aggregates causing vasoactive substance release, and (3) synergistic effects of platelet-activating factor, a known mediator of endotoxic shock. The untoward events noted in these patients may be prevented by (1) proximal to distal dissection of the ulcer with initial ligation of large veins, (2) pretreatment with steroids and/or platelet-activating factor antagonists, and/or (3) slow release of the tourniquet.

Asymptomatic miniocclusions of the optic disc veins in glaucoma.

This study was done to document photographically the evolution of asymptomatic venous stasis changes of the optic disc in glaucoma, estimate their prevalence, and report the clinical findings. Asymptomatic venous miniocclusions were found to develop and occasionally disappear in the optic disc stereophotographs of nine patients with early to moderate glaucoma or ocular hypertension during a mean follow-up of 9 years. In the 1664 photographs examined, a prevalence of 3% was found. None of the patients had a history of retinal vein occlusion or venous stasis retinopathy. Progression of glaucomatous optic disc changes occurred in eight of nine patients. It is possible that asymptomatic miniocclusions are secondary to the changes at the bottom of the optic cup. The miniocclusions, which are easily missed if not looked for, may be an early indicator of glaucomatous progression of the optic disc cupping.

Variables associated with postoperative deep venous thrombosis: A prospective study of 411 gynecology patients and creation of a prognostic model

Deep venous thrombosis is a major complication following gynecologic surgery. Assessing a patient's risk of developing deep venous thrombosis is important for patient selection and in choosing appropriate prophylactic methods. Four hundred eleven patients undergoing major gynecologic surgery were evaluated prospectively. All known variables associated with deep venous thrombosis were recorded. Deep venous thrombosis was diagnosed by 125I fibrinogen leg counting of all patients. Univariate analysis of all variables identified the following to be significantly related (P less than .05) to postoperative deep venous thrombosis: a prior history of deep venous thrombosis, leg edema or venous stasis changes, venous varicosities, degree of preoperative ambulation, type of surgery, nonwhite race, recurrent malignancy, prior pelvic radiation therapy, age above 45 years, excessive body weight, intraoperative blood loss, and duration of anesthesia. A stepwise logistic regression analysis of these variables was performed. The following preoperative prognostic factors remained significant: type of surgery, age, leg edema, nonwhite patients, severity of venous varicosities, prior radiation therapy, and prior history of deep venous thrombosis. Duration of anesthesia was also important when intraoperative factors were considered in the analysis. Using these factors, a prognostic model was created and tested. The model resulted in a degree of concordance of 0.82 and allows one to evaluate the risks of postoperative deep venous thrombosis for an individual patient.