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.

The management of diabetic foot: a clinical practice guideline by the Society for Vascular Surgery in collaboration with the American Podiatric Medical Association and the Society for Vascular Medicine

Diabetes mellitus continues to grow in global prevalence and to consume an increasing amount of health care resources. One of the key areas of morbidity associated with diabetes is the diabetic foot. To improve the care of patients with diabetic foot and to provide an evidence-based multidisciplinary management approach, the Society for Vascular Surgery in collaboration with the American Podiatric Medical Association and the Society for Vascular Medicine developed this clinical practice guideline.

Clinical outcome after treatment of pelvic congestion syndrome: sense and nonsense.

Chronic pelvic pain accounts for approximately 10% of outpatient gynecologic visits and among the varied causes, pelvic congestion syndrome is second only to endometriosis in frequency. Manifestations may include pelvic pain, dyspareunia, dysuria, and dysmenorrhea as well as external varices and a number of psychosocial symptoms. Although a variety of treatments have been proposed-including pharmacologic ovarian suppression, hysterectomy with or without oophorectomy, and ovarian vein resection-transcatheter embolization is the least invasive and most efficacious management option. Complete or partial symptom improvement has been reported in 68.2-100% of patients and there has been a consistent reduction in visual analog pain scores after treatment. Based upon these results, recommendation of either pharmacotherapy or other surgical procedures is difficult to justify. However, it is also clear that 6-31.8% of patients do not get substantial relief from pelvic venous embolization. Potential explanations for an inadequate response to treatment include patient variability, procedural variability, and inadequate outcome measures. The latter are particularly important and future investigation should focus on the development of disease-specific quality of life measures as well as identifying those aspects of the procedure, such as choice of embolic agents and extent of embolization, associated with the best clinical outcomes.

Indications for platelet aggregation inhibitors after venous stents.

Iliofemoral venous obstruction may arise from either primary compressive lesions or may be secondary to an episode of deep venous thrombosis. Regardless of aetiology, these lesions, either alone or in association with more distal reflux, may be responsible for lower extremity pain, swelling, and ulceration. Conventional surgical procedures for the treatment of iliofemoral venous obstruction have largely been supplanted by endovascular approaches relying on the deployment of venous stents. Large series have reported good technical and clinical results from venous stenting, particularly for primary lesions. However, early stent occlusions and late re-stenosis do occur. Although most of these appear related to technical factors, there is likely a role for pharmacological adjuncts in maintaining stent patency. The use of anticoagulants and antiplatelet agents is largely based on the underlying pathophysiology and extrapolation from arterial interventions, which likely are significantly different with respect to their pathophysiology and natural history. Although lacking substantial evidence demonstrating efficacy, the use of adjunctive antiplatelet agents in stents placed for primary lesions and consideration of anticoagulation for high-risk post-thrombotic lesions appears to be reasonable.

What is the medical rationale for the treatment of varicose veins?

Varicose veins occur in up to one-third of Western populations and are associated with clinical manifestations ranging from asymptomatic, isolated varicose veins (C2 disease) to venous ulceration. While the development of less invasive treatment options, such as endovenous ablation and sclerotherapy, have been well accepted by patients they have led to increased utilization of scarce health-care resources. While few would argue with the treatment of acute complications such as superficial venous thrombosis and variceal haemorrhage, the role of interventional treatment in the management of lifestyle limiting symptoms and the prevention of disease progression may be debatable. Good-quality evidence does suggest that surgical management of varicose veins is associated with improved quality of life at costs below the thresholds of many Western health-care systems. However, the progression of isolated C2 disease to advanced chronic venous insufficiency occurs infrequently and the role of treatment to prevent such progression remains undefined at present.

Rationale and indications for aggressive early thrombus removal.

Randomized clinical trials have defined anticoagulation with unfractionated or low-molecular-weight heparin followed by warfarin as a standard therapy for acute deep venous thrombosis (DVT). Such treatment is highly effective in preventing recurrent venous thromboembolism with a low risk of bleeding, but provides imperfect protection against development of the post-thrombotic syndrome. Several strategies of early thrombus removal, including surgical venous thrombectomy, catheter-directed thrombolysis and pharmacomechanical thrombectomy have been developed with the goal of reducing the incidence of the post-thrombotic syndrome by restoring venous patency and preserving valvular function. Although clinical judgement and a consideration of the individual patient's medical condition and values are required, early thrombus removal strategies should be considered in selected patients with phlegmasia cerulea dolens and those with a first episode of acute iliofemoral thrombosis of less than 14 days duration.

Duplex follow-up of patients with DVT: does it have clinical significance?

Venous duplex ultrasonography is now the diagnostic test of choice for the diagnosis of deep venous thrombosis (DVT) at many institutions. In the research setting, the ability to serially evaluate thrombi localized to specific venous segments has shown the importance of recurrent thrombotic events and recanalization in the natural history of acute DVT. In addition, its availability and noninvasive nature have led increasingly to the use of serial venous ultrasound examinations in the clinical management of acute DVT. Unfortunately, there is little evidence to support the use of follow-up ultrasonography for many of these purposes. Based on the limited evidence available, follow-up ultrasound examinations appear to be warranted only in patients with isolated calf vein thrombosis and contraindications to conventional anticoagulation, patients with recurrent symptoms, and to establish a baseline after completion of therapy in patients at risk for recurrence. In contrast, the anticoagulant management of acute DVT should be guided by the results of clinical trials, and currently available evidence provides no basis for using ultrasonography to guide the duration of anticoagulation. Therefore, if therapy is based on guidelines derived from clinical trials, there are few indications for the noninvasive follow-up of DVT during anticoagulant treatment in the absence of new symptoms.

Impact of presenting physiology and associated injuries on outcome following traumatic rupture of the thoracic aorta.

We hypothesized that the predominant factor influencing outcome of traumatic rupture of the thoracic aorta (TRA) was the degree of shock on presentation and associated injuries. We reviewed our experience with TRA over a 15-year period. Patients were classified as "unstable" if presenting systolic blood pressure was <90 mm Hg or if it decreased to <90 mm Hg after admission. We determined the presence of closed head injury, cardiac risk factors, a preoperative acute lung injury (ALI). The influence of these factors on mortality, postoperative adult respiratory distress syndrome (ARDS), and paralysis was analyzed. One hundred thirty-six patients were admitted with TRA. One hundred twenty underwent operative repair with a mortality of 31 per cent. Operative mortality was significantly higher in unstable patients (62%) versus stable patients (17%, P = 0.001), in patients with cardiac risk factors (71%) versus those without (24%, P = 0.001), and in patients with preoperative free rupture (83%) with versus those without (19%, P = 0.001). Free rupture was the cause of hypotension in only 10 of 42 unstable patients, with the remainder being due to other causes. Preoperative ALI was associated with a marked increase in postoperative ARDS (47% with vs 9% without, P = 0.001) but not operative mortality. Mechanical circulatory support (MCS) was used in 59 cases, none of whom experienced paralysis, whereas eight of 61 operated on without MCS developed paralysis (P = 0.001). When logistic regression was applied the use of MCS was not determined to be statistically significant. However, preoperative instability was found to be a significant predictor of postoperative paralysis with the risk being increased 5.5 times (confidence interval 3.3-10). The predominant factor influencing mortality, postoperative ARDS, and paralysis was preoperative instability and associated injuries. In patients who are hypotensive, other injuries should take precedence over repair of TRA. Patients who are stable but who have cardiac or pulmonary risk factors may be better managed by a period of nonoperative management until their condition improves.

Markers of plasma coagulation and fibrinolysis after acute deep venous thrombosis.

OBJECTIVE: Plasma markers of coagulation and fibrinolysis have proved sensitive in the initial diagnosis of acute deep venous thrombosis (DVT). The purpose of this study was to examine the evolution and utility of measuring D-dimer and prothrombin fragment 1+2 (F 1+2) levels after an acute DVT. METHODS: Subjects with DVT confirmed by ultrasonography had quantitative plasma D-dimer and F 1+2 levels determined before anticoagulation. Ultrasound scan and coagulation studies were repeated at 3, 7, and 14 days; 1 month; and every 3 months for 1 year. RESULTS: Sixty-one patients with a median initial thrombus score of 3 (interquartile range, 2-7) were followed up for 266 days (interquartile range, 91.5-364 days). Initial D-dimer levels were elevated in 92.7% of patients and were associated with thrombus extent (P =.003), whereas F 1+2 levels were increased in 94.5% of patients and were lower in patients with isolated calf vein thrombosis (P =.001). Initial D-dimer (P =.002) and F 1+2 levels (P =.009) were significantly higher in the 26 (43%) patients with recurrent thrombosis during follow-up. Initial D-dimer levels of 2000 ng/mL or greater were predictive of recurrent events after both proximal and isolated calf vein thrombosis. Although interval increases in these markers had little value in detecting recurrent thrombotic events, D-dimer levels of 1000 ng/mL or greater and 500 ng/mL or greater had respective sensitivities of 89.3% and 100% in detecting early and late recurrences. Corresponding specificities were 35.6% and 53.9%. CONCLUSIONS: Initial D-dimer levels are determined by total thrombus load and remain elevated long after an acute DVT. F 1+2 levels are less sensitive to thrombus score and return to baseline more quickly. Initial levels of these markers may have some utility in predicting the risk of ultrasound scan-documented recurrences, whereas increased D-dimer levels are a sensitive but nonspecific marker of these events.

Deep venous thrombosis and superficial venous reflux.

OBJECTIVE: Although superficial venous reflux is an important determinant of post-thrombotic skin changes, the origin of this reflux is unknown. The purpose of this study was to evaluate the frequency and etiologic mechanisms of superficial venous reflux after acute deep venous thrombosis (DVT). METHODS: Patients with a documented acute lower extremity DVT were asked to return for serial venous duplex ultrasound examinations at 1 day, 1 week, 1 month, every 3 months for the first year, and every year thereafter. Reflux in the greater saphenous vein (GSV) and lesser saphenous vein (LSV) was assessed by standing distal pneumatic cuff deflation. RESULTS: Sixty-six patients with a DVT in 69 lower extremities were followed up for a mean of 48 (SD +/- 32) months. Initial thrombosis of the GSV was noted in 15 limbs (21.7%). At 8 years, the cumulative incidence of GSV reflux was 77.1% (SE +/- 0.11) in DVT limbs with GSV involvement, 28.9% (+/- 0.09%) in DVT limbs without GSV thrombosis, and 14.8% (+/- 0.05) in uninvolved contralateral limbs (P <.0001). For LSV reflux, the cumulative incidence in DVT limbs was 23.1% (+/- 0.06%) in comparison with 10% (+/- 0.06%) in uninvolved limbs (P =.06). In comparison with uninvolved contralateral limbs, the relative risk of GSV reflux for DVT limbs with and without GSV thrombosis was 8.7 (P <.001) and 1.4 (P =.5), respectively. The relative risk of LSV reflux in thrombosed extremities compared with uninvolved extremities was 3.2 (P =.07). Despite these observations, the fraction of observed GSV reflux that could be attributable to superficial thrombosis was only 49%. CONCLUSIONS: Superficial venous thrombosis frequently accompanies DVT and is associated with development of superficial reflux in most limbs. However, a substantial proportion of observed reflux is not directly associated with thrombosis and develops at a rate equivalent to that in uninvolved limbs.

Venous severity scoring: An adjunct to venous outcome assessment.

Some measure of disease severity is needed to properly compare the outcomes of the various approaches to the treatment of chronic venous insufficiency. Comparing the outcomes of two or more different treatments in a clinical trial, or the same treatment in two or more reports from the literature cannot be done with confidence unless the relative severity of the venous disease in each treatment group is known. The CEAP (Clinical-Etiology-Anatomic-Pathophysiologic) system is an excellent classification scheme, but it cannot serve the purpose of venous severity scoring because many of its components are relatively static and others use detailed alphabetical designations. A disease severity scoring scheme needs to be quantifiable, with gradable elements that can change in response to treatment. However, an American Venous Forum committee on venous outcomes assessment has developed a venous severity scoring system based on the best usable elements of the CEAP system. Two scores are proposed. The first is a Venous Clinical Severity Score: nine clinical characteristics of chronic venous disease are graded from 0 to 3 (absent, mild, moderate, severe) with specific criteria to avoid overlap or arbitrary scoring. Zero to three points are added for differences in background conservative therapy (compression and elevation) to produce a 30 point-maximum flat scale. The second is a Venous Segmental Disease Score, which combines the Anatomic and Pathophysiologic components of CEAP. Major venous segments are graded according to presence of reflux and/or obstruction. It is entirely based on venous imaging, primarily duplex scan but also phlebographic findings. This scoring scheme weights 11 venous segments for their relative importance when involved with reflux and/or obstruction, with a maximum score of 10. A third score is simply a modification of the existing CEAP disability score that eliminates reference to work and an 8-hour working day, substituting instead the patient's prior normal activities. These new scoring schemes are intended to complement the current CEAP system.

Venous thrombus stability during acute phase of therapy.

The purpose of this study was to use serial venous duplex scans to document the status of deep venous thrombi during the early phase of therapy for acute, deep-vein thrombosis (DVT). A total of 71 consecutive participants treated for a first episode of acute DVT were monitored for new venous thrombosis using serial venous duplex scans. An average of 4.6 duplex scans were performed per patient (range, three to seven) during the 3-week study period. The cumulative incidence of contiguous/non-contiguous extension of the DVT at 3 weeks was 26% (95% CI = 14% to 38%). Nine of the 15 (60%) occurrences were asymptomatic. None of the classical risk factors for DVT was significantly associated with the development of new thrombi. The fraction of time during which the level of anticoagulation was considered 'adequate' (international normalized ratio > or =2.0 and/or heparin concentration > or =0.2 IU/ml) was inversely associated with the risk of extension/new thrombi (p = 0.01, Cox proportional hazards analysis). It was concluded that: (1) the frequency of contiguous/non-contiguous extension of venous thrombosis detectable during the first 3 weeks of therapy was higher than previously reported; (2) the majority of the occurrences were asymptomatic; and (3) the risk of developing this complication was inversely associated with the level of anticoagulation achieved.

Catheter-directed thrombolysis for lower extremity deep venous thrombosis: report of a national multicenter registry.

PURPOSE: To evaluate catheter-directed thrombolysis for treatment of symptomatic lower extremity deep venous thrombosis (DVT). MATERIALS AND METHODS: From a registry of patients (n = 473) with symptomatic lower limb DVT, results of 312 urokinase infusions in 303 limbs of 287 patients (137 male and 150 female patients; mean age, 47.5 years) were analyzed. DVT symptoms were acute (< or = 10 days) in 188 (66%) patients, chronic (> 10 days) in 45 (16%), and acute and chronic in 54 (19%). A history of DVT existed in 90 (31%). Lysis grades were calculated by using venographic results. RESULTS: Iliofemoral DVT (n = 221 [71%]) and femoral-popliteal DVT (n = 79 [25%]) were treated with urokinase infusions (mean, 7.8 million i.u.) for a mean of 53.4 hours. After thrombolysis, 99 iliac and five femoral vein lesions were treated with stents. Grade III (complete) lysis was achieved in 96 (31%) infusions; grade II (50%-99% lysis), in 162 (52%); and grade I (< 50% lysis), in 54 (17%). For acute thrombosis, grade III lysis occurred in 34% of cases of acute and in 19% of cases of chronic DVT (P < .01). Major bleeding complications occurred in 54 (11%) patients, most often at the puncture site. Six patients (1%) developed pulmonary emboli. Two deaths (< 1%) were attributed to pulmonary embolism and intracranial hemorrhage. At 1 year, the primary patency rate was 60%. Lysis grade was predictive of 1-year patency rate (grade III, 79%; grade II, 58%; grade I, 32%; P < .001). CONCLUSION: Catheter-directed thrombolysis is safe and effective. These data can guide patient selection for this therapeutic technique.

Determinants of chronic venous disease after acute deep venous thrombosis.

PURPOSE: The purpose of this investigation was to evaluate the relationship between the presenting features of an acute deep venous thrombosis (DVT), the subsequent natural history of the thrombus, and the ultimate outcome as defined according to the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery reporting standards in venous disease. METHODS: Patients with an acute DVT were followed with serial clinical and ultrasound examinations. Thrombus extent within 7 venous segments was scored retrospectively according to the reporting standards (scores ranged from 0 to 3), and segmental reflux was scored as present (1) or not present (0). The initial and final thrombus scores, the rates of recanalization and rethrombosis, and the total reflux scores were then calculated from these grading scales and related to ultimate chronic venous disease (CVD) classification. RESULTS: Sixty-eight patients with an acute DVT in 73 limbs were followed for 18 to 110 months (mean, 55 +/- 26 months). At the completion of the follow-up period, 20 extremities (27%) were asymptomatic (class 0), 13 (18%) had pain or prominent superficial veins (class 1), 25 (34%) had manifested edema (class 3), 13 (18%) had developed hyperpigmentation (class 4), and 2 (3%) had developed ulceration (class 5). In a univariate analysis, CVD classification was correlated with the reflux score (P =.003) but not with the initial or final thrombus score or with the rate of recanalization or rethrombosis. In a multivariate model of features documented at presentation, only the tibial thrombosis score was a significant predictor of CVD classification (R2 =.06). Outcome was better predicted (R2 =.29) with a model that included variables defined during follow-up the final reflux score, the final popliteal score, and the rate of recanalization. CONCLUSION: The ability to predict the severity of CVD after an acute DVT is currently limited, although the natural history appears more important than the presenting features of the event. The extent of reflux, the presence of persistent popliteal obstruction, and the rate of recanalization are related to ultimate CVD classification, but other determinants remain to be identified.

Rupture in small abdominal aortic aneurysms.

BACKGROUND: The decision of whether to repair small abdominal aortic aneurysms (AAAs), which are those that are less than 5 cm in diameter, remains controversial. METHODS: We describe 161 consecutive patients who were seen at a single urban hospital with ruptured AAAs (rAAAs) and in whom aneurysm size was measured with ultrasound scanning, or rarely computed tomography, en route to the operating room. Eleven patients (6.8%) had AAAs that measured less than 5.0 cm. This group was compared with 150 patients who had rAAAs that were more than 5 cm. RESULTS: The mortality rates were similar in both of the groups 70% for small rAAAs versus 66% for large rAAAs. No significant differences were seen between the patients with small and large ruptured aneurysms with respect to the prevalence rates of hypertension (60% vs 50%) or of cardiac disease (20% vs 22%). However, the prevalence rate of obstructive lung disease was significantly different (64% vs 25%; P =.02) as was the rate of diabetes (28% vs 3%; P =.004). Five aneurysms were measured at exactly 5 cm. This suggests that approximately 10% of all aneurysms that rupture in this series do so at 5 cm or less. CONCLUSION: In view of the safety of elective repair as compared with the prohibitive risk associated with aneurysm rupture, patients who are at good risk with small AAA (between 4 and 5 cm) should be considered for elective aneurysm resection. For unclear reasons, obstructive lung disease and diabetes are associated with a significantly greater risk for rupture of small AAA. Patients with these risk factors should be given special consideration.

Gadolinium-enhanced three-dimensional MR angiography of the aorta and peripheral arteries: evaluation of a multistation examination using two gadopentetate dimeglumine infusions.

OBJECTIVE: Three-dimensional gadolinium-enhanced MR angiography is a rapid and accurate method that can at times image only a limited amount of anatomy during an examination. We evaluated a technique that doubled the anatomy imaged by obtaining two separate gadolinium-enhanced MR angiograms during a single examination. MATERIALS AND METHODS: Twenty-three patients referred for MR evaluation of aortic or peripheral vascular disease underwent two successive gadolinium-enhanced three-dimensional MR angiographic examinations during a single MR examination. An injection of 15 ml of gadopentetate dimeglumine was used for the first MR angiogram, and 25 ml was used for the second MR angiogram. The angiograms were quantitatively and qualitatively evaluated to determine the effect of residual gadolinium from the initial MR angiogram on the second angiogram. RESULTS: The two studies depicted either the entire aorta to the femoral arteries (n = 10) or the distal aorta to the popliteal arteries (n = 13). The total mean gadolinium dose was 0.245 mmol/kg per patient. An average of 15 min elapsed between injections. The value of arterial signal-to-noise ratio (mean, 48.8 versus 56.4) and artery-to-vein contrast-to-noise ratio (mean, 45.5 versus 49.0) increased between the first and second angiograms, respectively. Residual gadolinium elevated the values for venous signal-to-noise ratio (mean, 2.3 versus 7.2) and background-to-muscle signal-to-noise ratio (mean, 5.5 versus 10.1) on the second MR angiogram. Qualitative evaluation by three observers showed no significant differences in diagnostic usefulness or overall image quality between the first and second MR angiograms. CONCLUSION: The use of two low-dose gadolinium-enhanced three-dimensional MR angiograms during a single examination is a feasible approach to increase anatomic coverage when performing gadolinium-enhanced three-dimensional MR angiography of the aorta and peripheral vessels. Although background enhancement is slightly elevated on the second angiogram, such enhancement does not significantly change diagnostic usefulness or overall image quality.

Cilostazol has beneficial effects in treatment of intermittent claudication: results from a multicenter, randomized, prospective, double-blind trial.

BACKGROUND: Cilostazol is a new phosphodiesterase inhibitor that suppresses platelet aggregation and also acts as a direct arterial vasodilator. This prospective, randomized, placebo-controlled, parallel-group clinical trial evaluated the efficacy of cilostazol for treatment of stable, moderately severe intermittent claudication. METHODS AND RESULTS: Study inclusion criteria included age > or =40 years, initial claudication distance (ICD) on treadmill (12.5% incline, 3.2 km/h) between 30 and 200 m, and confirmation of diagnosis of chronic lower-extremity arterial occlusive disease. After stabilization and single-blind placebo lead-in, 81 subjects (62 male, 19 female) from 3 centers were randomized unequally (2:1) to 12 weeks of treatment with cilostazol 100 mg PO BID or placebo. Primary outcome measures included ICD and maximum distance walked (absolute claudication distance, or ACD). Secondary outcome measures included ankle pressures, subjective assessments of benefit by patients and physicians, and safety. Treatment and control groups were similar with respect to age, severity of symptoms, ankle pressures, and smoking status. Statistical analyses used intention-to-treat analyses for each of 77 subjects who had > or =1 treadmill test after initiation of therapy. Comparisons between groups were based on logarithms of ratios of ICD and ACD changes from baseline using ANOVA test at last treatment visit. The estimated treatment effect showed a 35% increase in ICD (P<0.01) and a 41% increase in ACD (P<0.01). There was no significant change in resting or postexercise ankle/brachial indexes. Patients' and physicians' subjective assessments corroborated the measured improvements in walking performance observed in the cilostazol-treated group. CONCLUSIONS: Cilostazol improved walking distances, significantly increasing ICD and ACD. The data suggest cilostazol is safe and well tolerated for the treatment of intermittent claudication.

Deep venous thrombosis in the trauma patient.

Despite improvements in trauma care and thromboembolism prophylaxis over the past 50 years, deep venous thrombosis (DVT) remains a source of morbidity and mortality in the injured patient. Pulmonary embolism may complicate the course of up to 6% of such patients, although the morbidity associated with late development of the postthrombotic syndrome remains poorly defined and perhaps underemphasized. Prolonged immobilization and venous injury contribute to the risk of venous thrombosis, and accumulating evidence suggests underlying imbalances between activated coagulation and fibrinolysis. Much investigative work has focused on identifying subpopulations, including older patients (30 to 40 years) and those with prolonged immobilization, pelvic and lower extremity fractures, spinal cord injury, major venous injury, central venous lines, significant blood requirements, and admission coagulopathy, who are at particular risk of developing DVT. Given the diverse underlying pathophysiologic factors, it is perhaps not surprising that the benefits of prophylactic measures have been imperfect and remain controversial. Both intermittent pneumatic compression and low-dose unfractionated heparin have limitations, although the low-molecular-weight heparins have promise for prophylaxis in this population. It has also been suggested that other measures, such as serial duplex ultrasound screening and prophylactic vena cava filters, may have a role in very high-risk patients and those who are not candidates for other means of prophylaxis. However, the precise role of these measures remains poorly defined and awaits prospective validation. An improved understanding of the operative risk factors may permit prophylactic therapy to be better tailored to the individual patient.

Early outcome after isolated calf vein thrombosis.

PURPOSE: The clinical significance of isolated calf vein thrombosis (CVT), particularly with respect to development of the postthrombotic syndrome, remains controversial. The purpose of this study was to define the early natural history of CVT in relation to persistent lower extremity symptoms, propagation, recanalization, and the development of valvular incompetence. METHODS: Over a 116-month period, 499 patients with acute deep venous thrombosis (DVT) were referred to our research laboratory, of whom 58 (12%) had thrombosis confined to the calf veins of at least one extremity. The lower extremities of 268 patients (29 with isolated CVT) were followed-up clinically and with duplex ultrasonography at intervals of 1 day, 7 days, 1 month, every 3 months for the first year, and yearly thereafter. RESULTS: Seventy percent of extremities with CVT were symptomatic at presentation. Although the prevalence of clinical signs and symptoms decreased to 29% by 1 month, 23% of patients had persistent pain, edema, or both at 12 months. In contrast, 9% of uninvolved extremities contralateral to a CVT and 54% of extremities with proximal DVT remained symptomatic at 1 year (p = 0.004). Recanalization proceeded rapidly such that the mean thrombus load was reduced by 50% at 1 month and to zero at 1 year. The prevalence of valvular incompetence progressively increased such that reflux was present in 24% of extremities at 1 year. Although its investigation was not a primary goal of this study, pulmonary embolism was diagnosed at presentation and during follow-up in 11% and 3% of patients, respectively. CONCLUSIONS: The natural history of CVT is complicated by persistent symptoms and the development of valvular incompetence in approximately one-quarter of patients. This potential for persistent lower extremity symptoms should be considered in evaluating the clinical relevance of isolated calf vein DVT.

Delayed abdominal closure in the management of ruptured abdominal aortic aneurysms.

BACKGROUND: Resuscitative measures associated with ruptured abdominal aortic aneurysm (rAAA) repair may result in massive edema of the bowel, retroperitoneum and abdominal wall. The resulting "abdominal compartment syndrome" may compromise abdominal closure and may be associated with respiratory, renal and cardiovascular deterioration. METHODS: The medical records of 23 patients surviving initial operative repair of a rAAA were retrospectively reviewed. Eight underwent delayed abdominal closure after early approximation with silastic sheets (n = 6) or of the skin only (n = 2). Ultimate outcome, as well as several pulmonary and cardiovascular parameters, were compared with patients undergoing standard primary fascial closure (n = 15). RESULTS: A trend toward improved survival was apparent in the group undergoing delayed abdominal wall closure. Significant improvements in oxygenation and mixed venous oxygen saturation were observed in these patients, and there were fewer late deaths due to multiple organ failure. No patient undergoing delayed abdominal closure developed a graft infection. CONCLUSIONS; As in massively resuscitated trauma victims, delayed laparotomy closure in rAAA patients may confer a physiologic and survival benefit.