Clifford M. Sales

Management of isolated soleal and gastrocnemius vein thrombosis

OBJECTIVE The ideal treatment for hospitalized patients with isolated gastrocnemius and/or soleal venous thrombosis is unclear. Recommendations range from watchful waiting to full-dose anticoagulation. This study examines the effectiveness of practice patterns at a single institution as measured by progression of thrombus. METHODS All consecutive inpatients with a duplex scan diagnosis of isolated gastrocnemius and/or soleal vein clot (no other thrombotic segments were identified) and where two consecutive duplex studies (Intersocietal Commission for the Accreditation of Vascular Laboratories laboratory) were available for review were included. Two study groups were identified. TX group included patients who received anticoagulation treatment (heparin [fractionated or unfractionated], heparin substitutes, or warfarin) and the NoTX group included those who did not receive anticoagulant. Demographic, risk factors, comorbidities, length of hospital and intensive care unit stay, ambulatory status, and underlying hypercoagulable states were recorded. Thrombus progression rate in the two groups was compared using the χ2 test. A multivariate logistic regression model was used to examine the effect of anticoagulation treatment as well as the above demographic and clinical factors on the risk of progression. RESULTS A total of 141 patients were included in the study, 76 of whom (54%) received anticoagulation. Forty-three patients (30%) had progression of their venous thrombosis: 33% (25/76) in the TX group and 28% (18/65) in the NoTX group (P=.50, by χ2 test). Results from multivariate logistic regression showed that treatment had no significant impact on outcome (Odds ratio=1.28, 95% confidence interval: 0.55-3.01; P=.57]. Patients with end-stage renal disease (6%), or stroke (13%) had significantly higher risk of progression (P<.05). None of the other clinical or demographic factors were significantly associated with the risk of progression. CONCLUSION The results speak to the lack of efficacy of anticoagulation in the management of gastrocnemius and/or soleal vein thrombosis in the hospitalized patient. When measured by thrombus progression, treating these patients without anticoagulation appears to be equally efficacious as subjecting patients to anticoagulant therapy. A prospective, randomized clinical trial will be an important step in fully addressing this clinical dilemma.

Natural history, duplex characteristics, and histopathologic correlation of arterial injuries in a canine model

The treatment of patients with penetrating extremity trauma in proximity to major arteries as well as the nonoperative treatment of clinically occult arterial injuries remain controversial. Duplex ultrasonography (DUS) has recently been advocated in this setting. We therefore studied experimentally induced arterial injuries in dogs to correlate the natural history, duplex findings, and histopathologic condition of different injuries and to help define criteria for operation. Fifty-two canine femoral and carotid arteries were randomized to have surgically created intimal flaps (n = 15), crush injuries (n = 15), or lacerations (n = 15) or to be controls (n = 7). An experienced sonographer, blinded to the presence or type of injury, evaluated the vessels every 10 days for 1 month. Histopathologic study was performed 1 month after injury when the arteries were retrieved. The sensitivity (96.5%), specificity (86.4%), and accuracy (95.1%) of DUS in evaluating arterial injuries at 1 month correlated well with histopathologic evaluation. All arteries subjected to crush injuries showed abnormal duplex findings. These findings correlated well with the histologic picture of severe injury (arterial wall thickness = 2.72 x +/- 0.23 x control; intramural hemorrhage, 93%; mural thrombus, 60%). DUS and histologic study revealed healing of intimal flaps in 27% of the arteries. Other intimal flaps deteriorated (stenoses, 47%; dilation, 13%; occlusion, 13%). Most lacerations (86%) revealed duplex evidence of healing within 10 days of injury. This was confirmed by histologic study at 1 month in 73% of lacerated arteries. This study confirms the accuracy of DUS in diagnosing various arterial injuries and shows that the natural history of these injuries varies with the mechanism of injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Saphenous vein angioscopy: A valuable method to detect unsuspected venous disease

PURPOSE The presence of preexisting saphenous vein lesions adversely affects graft patency. Despite careful preoperative venous duplex examination and meticulous intraoperative evaluation, clinically significant saphenous vein disease may remain undetected. We evaluated angioscopy as a means to better detect these vein lesions. METHODS Ninety saphenous vein remnants, obtained at bypass surgery, were perfusion fixed for subsequent angioscopic and histologic evaluation. The specimens were categorized by independent examiners on the basis of the angioscopic or light microscopic findings. Of the 90 vein remnants, 66 were normal by angioscopic criteria. Fifty-three (80%) of these angioscopically normal vein segments were normal histologically, and all 24 angioscopically abnormal saphenous vein remnants showed disease on microscopic examination. RESULTS Angioscopy correctly identified sclerotic vein segments (n = 20) by irregular white plaques, whereas postphlebitic veins (n = 3) demonstrated multiple lumens, fibrous strands, and thickened opaque valve cusps on angioscopic evaluation. Absence of an angioscopic lumen was confirmed histologically in occluded veins (n = 2). Angioscopy failed to identify thick-walled (n = 10) and varicose (n = 2) vein segments as abnormal; one sclerotic segment was normal angioscopically, thereby lowering the sensitivity of angioscopy. CONCLUSIONS Angioscopy detected unsuspected preexisting saphenous vein disease in five patients undergoing arterial reconstruction with saphenous vein. Because the use of angioscopy is a reliable means of prospectively assessing the vein for most preexisting lesions, its routine use may ultimately improve graft patency.

Prospective Study of the Value of Prebypass Saphenous Vein Angioscopy

BACKGROUND The patency of a saphenous vein graft is directly related to the quality of the vein harvested. Thus, appropriate evaluation of the vein before implanting it as a bypass graft may help identify those veins at high risk for early failure. Accordingly, we prospectively investigated whether prebypass angioscopic assessment of the saphenous vein could identify those vein grafts at particularly high risk of early failure. PATIENTS AND METHODS Thirty-two greater saphenous veins with a grossly normal appearance were evaluated angioscopically before their use as a bypass conduit. After modification of abnormal segments, all of the veins irrigated well and were used as bypass grafts. RESULTS Twenty-four patients were available for follow-up at 12 months. Seventeen (71%) had been prospectively classified as having angioscopically normal saphenous veins, while 7 were identified as having abnormal veins. The two groups did not differ significantly in demographics, cardiovascular risk factors, or indications for operative intervention. Twelve of the 17 (70%) normal veins were patent at 1 year; however, only 1 (14%) of the angioscopically abnormal vein grafts remained patent for 12 months (chi-square = 4.27; P = 0.039). CONCLUSION Angioscopic inspection of the saphenous vein, before insertion as a graft, allows for identification of unrecognized venous disease that portends early graft thrombosis. Exclusion of abnormal veins, based on an abnormal angioscopic appearance, may lead to improved results for lower-extremity revascularization procedures; this supports the value of vein-graft angioscopy.

Human Greater Saphenous Vein: Histologic and Ultrastructural Variation

This study describes the varied histologic features and ultrastructure of human saphenous veins obtained from patients undergoing infrainguinal arterial reconstruction. Portions of 30 remnant veins were fixed at arterial pressure (100 mmHg). Vein specimens were obtained from 13 men and 17 women, with a mean age of 70.2 years. Ten veins (33%) were from diabetic patients. Samples of fixed veins were prepared for light and electron microscopy. The luminal surface contained valves and redundant intimal folds at the site of ligated side branches. Microvalves were present at the orifices of several 1-mm vein tributaries. The endothelial cells lining the intima were often discontinuous and were aligned in a variable pattern. The thicknesses of the vein walls varied from 20 to 360 μm, with increased connective tissue matrix in the intima and medial layers of thick-walled veins. Some 10% of the veins demonstrated spindle cells in the intima; these cells had a smooth muscle cell phenotype and varied with respect to the degree of cellular differentiation. Regions of vein wall calcification were occasionally seen and were always present in association with a thickened vein intima. Variations in the structure of the saphenous vein from patients undergoing bypass surgery are common. The relationship between altered saphenous vein morphology and subsequent vein graft stenosis needs to be defined.

Misplacement of a vena cava filter into the spinal canal

We report the case of a 70-year-old male with a complication of misplacement of a vena cava filter into the spinal canal. This likely happened as a result of penetration of the wire and filter sheath through the iliac vein or vena cava into the retroperitoneum, vertebral foramina, and spinal canal at the level of L2 and L3. Due to the patients condition, the filter was not removed and no neurologic symptoms have occurred. This represents the first reported case of a filter deployment into the spinal canal. Although placement of vena cava filters is a relatively safe procedure, complications are seen commonly due to the large number of procedures performed. Spinal complications, however, are rarely reported. This is the first reported case of the inadvertent placement of a vena cava filter into the spinal canal.

Analysis of Balloon Dilatation of Human Vein Graft Stenoses

Controversy continues as to whether percutaneous transluminal angioplasty (PTA) or surgical revision is the ideal modality for the treatment of failing grafts. This prompted a histopathologic analysis of failing human vein graft segments subjected to ex vivo balloon dilatation to define variables responsible for the discrepant results. Fifteen vein graft lesions from 14 patients with failing infrainguinal bypasses were recovered after surgical excision. Each graft lesion was focal and uniform in length (2.1±0.3 cm). Rings sectioned from adjacent regions of each vein graft lesion before and after balloon inflation were processed for histologic study, photomicrography, and image analysis. Angioplasty balloon size was selected on the basis of preoperative arteriograms. Graft lesions were divided into three groups based on lesion thickness and the degree of fibrosis and cellularity seen on sections stained with Massons trichrome. The luminal area before angioplasty was not significantly different for the three groups (p>0.2). Vein grafts with thick intimas (group 1) had significantly less luminal dilatation after angioplasty as compared with less thick intimal lesions (groups 2 and 3;p<0.001). Those lesions with varying degrees of cellularity (groups 2 and 3) showed no significant differences in luminal diameter after angioplasty. However, the cellular lesions in group 2 consistently formed multiple intimal flaps that could produce PTA failures even with good luminal restoration. The varying histology of vein graft lesions and associated differences in intimal thickness and cellularity may be responsible for the inconsistent results following PTA. Estimates of wall thickness before angioplasty, particularly in the intimal area, may be helpful in evaluating which lesions might benefit most from PTA.

Fistula First clarifies its message

This material was prepared by the Mid-Atlantic Renal Coalition as part of the Fistula First Breakthrough Initiative Special Project, which is performed under contract HHSM-500-2006-NW005C, with the Centers for Medicare and Medicaid Services (CMS), an agency of the U.S. Department of Health and Human Services. The contents presented do not necessarily reflect CMS policy.