Jonathan Woodson

Predictive Value of Reactive Hyperemia for Cardiovascular Events in Patients With Peripheral Arterial Disease Undergoing Vascular Surgery

Objective— Reactive hyperemia is the compensatory increase in blood flow that occurs after a period of tissue ischemia, and this response is blunted in patients with cardiovascular risk factors. The predictive value of reactive hyperemia for cardiovascular events in patients with atherosclerosis and the relative importance of reactive hyperemia compared with other measures of vascular function have not been previously studied. Methods and Results— We prospectively measured reactive hyperemia and brachial artery flow-mediated dilation by ultrasound in 267 patients with peripheral arterial disease referred for vascular surgery (age 66±11 years, 26% female). Median follow-up was 309 days (range 1 to 730 days). Fifty patients (19%) had an event, including cardiac death (15), myocardial infarction (18), unstable angina (8), congestive heart failure (6), and nonhemorrhagic stroke (3). Patients with an event were older and had lower hyperemic flow velocity (75±39 versus 95±50 cm/s, P=0.009). Patients with an event also had lower flow-mediated dilation (4.5±3.0 versus 6.9±4.6%, P<0.001), and when these 2 measures of vascular function were included in the same Cox proportional hazards model, lower hyperemic flow (OR 2.7, 95% CI 1.2 to 5.9, P=0.018) and lower flow-mediated dilation (OR 4.2, 95% CI: 1.8 to 9.8, P=0.001) both predicted cardiovascular events while adjusting for other risk factors. Conclusions— Thus, lower reactive hyperemia is associated with increased cardiovascular risk in patients with peripheral arterial disease. Furthermore, flow-mediated dilation and reactive hyperemia incrementally relate to cardiovascular risk, although impaired flow-mediated dilation was the stronger predictor in this population. These findings further support the clinical relevance of vascular function measured in the microvasculature and conduit arteries in the upper extremity.

A prospective, randomized trial of Unna's boot versus Duoderm CGF hydroactive dressing plus compression in the management of venous leg ulcers

Leg ulcers caused by chronic venous insufficiency plague an estimated 500,000 Americans, but there have been few improvements in conservative treatment in this century, and Unnas boot continues to be a mainstay of therapy. A recent report suggests that Duoderm CGF dressing provides greater patient comfort and enhanced compliance, but Duoderm alone (without compression) resulted in slower healing compared with Unnas boot. We enrolled 30 patients (30 ulcers) in a clinical trial to compare Duoderm CGF plus compression (Coban wrap) to Unnas boot. No significant difference was observed between the two groups with respect to age, sex, initial ulcer area, ulcer duration, or extent of venous insufficiency by duplex scan. Eight of 16 ulcers (50%) in the Duoderm group healed completely versus 6 of 14 ulcers (43%) in the Unnas boot group (p = 0.18). Healing rates (square centimeters per week) correlated significantly with initial ulcer area and initial ulcer perimeter for both groups but best correlated with initial ulcer perimeter (r = 0.88 with Duoderm, p less than 0.0001; r = 0.80 with Unnas boot, p less than 0.002). After adjusting for differences in initial ulcer perimeter, healing rates were significantly faster for patients on Duoderm than patients on Unnas boot during the first 4 weeks of therapy (0.384 +/- 0.059 cm2/wk/cm perimeter for Duoderm versus 0.135 +/- 0.043 cm2/wk/cm perimeter for Unnas boot; p = 0.002). At 12 weeks patients on Duoderm again appeared to heal faster than those on Unnas boot, although the result did not reach statistical significance (0.049 +/- 0.007 cm2/wk/cm perimeter for Duoderm versus 0.020 +/- 0.017 for Unnas boot, p = 0.11).(ABSTRACT TRUNCATED AT 250 WORDS)

The role of air plethysmography in monitoring results of venous surgery

The development of an objective, noninvasive method to assess the hemodynamic effects of venous surgery has long been awaited. Previous methods used to evaluate the results of surgery for varicose veins and venous stasis ulceration have been limited in their quantitative assessment. Now, by use of air plethysmography (APG), we can accurately quantify the effectiveness of corrective venous surgery. Twenty-five extremities that had evidence of venous insufficiency were examined with use of APG before and after venous surgical procedures. Surgery was directed at specific sites of venous incompetence as defined by physical examination and high-resolution duplex imaging. Twenty-one extremities underwent ligation and stripping of the greater saphenous vein. In these patients, APG showed an improvement in venous reflux as demonstrated by a decrease in the venous filling index from 6.6 +/- 0.7 ml/sec to 1.8 +/- 0.3 ml/sec (p = 0.0001) and venous volume from 177.1 +/- 14.5 ml to 139.2 +/- 8.9 ml (p = 0.0008). In addition, these patients showed a mild improvement in calf muscle pump function as noted by an improvement in ejection fraction from 45.8 +/- 2.0% to 50.8% +/- 2.5% (p = 0.07). The residual volume fraction decreased from 45.0% +/- 3.4% to 42.0% +/- 3.7%, a difference that was not statistically significant (p = 0.4). Four extremities with grade III chronic venous insufficiency underwent popliteal vein valve transplantation with use of an autogenous axillary vein valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional outcomes in limb salvage vascular surgery

BACKGROUND The crisis in health care brings a new focus to defining successful outcomes of medical treatments. The surgical literature has been criticized for not assessing functional outcomes in addition to technical success. METHODS We evaluated the functional outcomes of limb salvage surgery over 3 years in 38 patients 65 years of age and older with limb-threatening ischemia. The RAND-36-Item Health Survey 1.0 was used as a health assessment tool. RESULTS In spite of an 80% limb salvage rate, only 58% of patients survived 3 years and only 25% survived with the index limb and were able to walk. The RAND scores of patients whose limbs were amputated did not significantly differ from those of patients whose surgery was successful. CONCLUSION Functional outcome goals need to be better defined for patients who need limb salvage vascular operations to enhance the quality of care given these patients and to be in concert with emerging health policy.

Contrast-enhanced moving-table MR angiography: prospective comparison to catheter arteriography for treatment planning in peripheral arterial occlusive disease.

PURPOSE Prospective comparison of contrast-enhanced moving-table magnetic resonance (MR) angiography to catheter arteriography in endovascular and surgical treatment planning in patients with peripheral arterial occlusive disease. MATERIALS AND METHODS Thirteen patients scheduled for catheter arteriography for lower extremity arterial occlusive disease underwent contrast-enhanced moving-table MR angiography immediately prior to arteriography. A treatment plan was determined by the vascular surgeon, based on MR angiography, who was blinded to the catheter arteriogram. The treatment plan determined by the MR angiogram was compared to the final treatment plan, which was based on the catheter arteriogram and intraluminal pressure measurements. RESULTS Treatment plans based on MR angiography and catheter arteriography were identical in 10 of 13 patients (71%). For identifying lesions resulting in intervention, MR angiography had sensitivity of 100% and a positive predictive value of 92%. MR angiography had a treatment specific predictive value of 88% for each lesion identified, and 95% for lesions identified in patients evaluated for claudication. If treatment plans were based on MR angiography only, 46% of patients would have avoided catheter arteriography. CONCLUSION Contrast-enhanced moving-table MR angiography may be an effective alternative to catheter arteriography in endovascular and surgical treatment planning in selected patients with peripheral arterial occlusive disease, but larger studies are necessary to confirm this.

Endovascular management of the popliteal artery: comparison of atherectomy and angioplasty.

Purpose: Symptomatic atherosclerotic disease of the popliteal artery presents challenges for endovascular therapy. We evaluated the technical success, complications, and midterm outcomes of atherectomy and angioplasty involving the popliteal segment. Methods: We conducted a retrospective review of outcomes of popliteal artery intervention using atherectomy or angioplasty performed between 2003 and 2008. Results: A total of 56 patients (36% women, age 72.8 ± 12.2 years, 77% critical limb ischemia) underwent popliteal atherectomy (n = 18) or angioplasty (n = 38). These patients had similar clinical characteristics, TransAtlantic Intersociety Consensus (TASC)/ TASC II classification, mean lesion length, and runoff scores. We observed a trend toward higher rates of technical success defined as <30% residual stenosis after atherectomy compared to angioplasty (94% vs 71%, P = .08). While angioplasty was associated with a higher frequency of arterial dissection (23% vs 0%, P = .003), atherectomy was associated with a higher rate of thromboembolic events (22% vs 0%, P = 0.01). Adjunctive stenting was used more frequently following angioplasty compared to atherectomy (45% vs 6%, P = .005). Thrombolysis was used to treat embolization in 4 patients in the atherectomy group. The improvement in the ankle-brachial index (ABI) was similar between the 2 treatment groups. Primary patency of the popliteal artery at 3, 6, and 12 months was 94%, 88%, and 75% in the atherectomy group and 89%, 82%, and 73% in the angioplasty group (P = not significant [NS]). There were no significant differences in limb salvage and freedom from reintervention at 1 year between the atherectomy and angioplasty groups. Conclusions: Our experience with popliteal artery endovascular therapy indicates a distinct pattern of procedural complications with atherectomy compared to angioplasty but similar midterm patency, limb salvage, and freedom from intervention.

Role of Arteriography for Blunt or Penetrating Injuries in Proximity to Major Vascular Structures: An Evolution in Management

Over a 14-month period at Boston City Hospital, 93 consecutive patients who had received a blunt or penetrating extremity injury in proximity to a major vascular structure were evaluated. All patients were totally asymptomatic and underwent arteriography for proximity as a sole indication. Twenty-seven patients (27%) were found to have abnormal arteriograms. Muscular branches of the profunda femoris artery were the most frequently injured arteries (28%). Arterial spasm (41%) was the most common radiographic finding. All patients were managed nonoperatively and followed closely by serial pulse examinations. Follow-up arteriography or duplex scanning was used in isolated cases. No patients in this study required operative intervention based on arteriographic findings. No patients have subsequently required operative intervention for delayed arterial abnormalities. Based on these findings we believe the use of arteriography for asymptomatic injuries in proximity to major vascular structures is unwarranted.

Impact of a critical pathway on postoperative length of stay and outcomes after infrainguinal bypass.

PURPOSE To determine the effect of a critical pathway on postoperative length of stay and outcomes after infrainguinal bypass. METHODS A critical pathway for care of patients after infrainguinal bypass was introduced in December 1995 to coordinate postoperative care at our institution. We compared care of 67 consecutively treated patients before institution of the pathway with care of 69 consecutively treated patients with the critical pathway in place. Data collection was done by means of chart review. Univariate analyses were used to identify differences between prepathway and postpathway patients and to identify factors influencing postoperative length of stay. Multivariate analysis was used to identify factors that influenced length of stay and to examine the effect of use of the pathway after adjusting for other factors. RESULTS Patients on the pathway were similar to prepathway controls with respect to comorbid illnesses, vascular risk factors, indications for surgical treatment, type of conduit, and type of operation. Factors associated with longer postoperative stays included distal anastomoses to tibial rather than popliteal vessels (p = 0.02), preexisting cardiac disease (p = 0.005), postoperative complications (p = 0.0003), lower preoperative hematocrit (p = 0.01), and elevated preoperative creatinine level (p = 0.006). Overall, pathway patients had somewhat shorter postoperative lengths of stay (median value 7 days; range 2 to 29 days) than prepathway patients (median value 6 days; range 2 to 35; p = 0.01), and the two groups had similar frequencies of postoperative complications, readmission, and 6-month mortality. However, patients on the pathway were more likely to be discharged to an intermediate-care facility rather than directly home. After 12 patients with extraordinarily prolonged postoperative stays were excluded, multivariate analysis indicated that pathway patients had significantly shorter postoperative stays (p = 0.001). However, the difference was not significant if patients with extraordinarily long postoperative stays were included in the analysis (p = 0.28). CONCLUSION Use of a critical pathway was associated with a modest decrease in postoperative length of stay for most patients. This was accomplished without an adverse effect on readmission, complication, or mortality rates. However, the decrease in stay may have been achieved primarily by discharging more patients to intermediate-care facilities. The pathway did not appear to have any effect when the subset of patients with extraordinarily long stays because of complex medical problems was included.

Multiple mycotic pseudoaneurysms due to Yersinia enterocolitica: report of a case and review of the literature.

The etiology of mycotic aneurysms is variable but most often includes streptococci, staphylococci,Salmonella, andPseudomonas infections.Yersinia enterocolitica is an organism that has been infrequently associated with vascular infections. We report a case of two ruptured mycotic pseudoaneurysms occurring in the same patient in the superficial femoral artery and the infrarenal abdominal aorta only 10 days apart. The literature is reviewed, and the clinical findings and pathology are discussed. The unique problem of multiple mycotic aneurysms developing at different times as a result ofYersinia bacteremia suggests the need to monitor these patients longitudinally and evaluate multiple sites on the arterial tree to detect occult pseudoaneurysms and prevent late death from rupture.

The Management of Traumatic Aortic Tear in the Multiply-Injured Patient

Patients with traumatic aortic tears and severe life-threatening associated injuries require early and expeditious evaluation and treatment in order to improve survival. Diagnostic and treatment priorities, however, are not clearly established in this subset of patients. The purpose of this retrospective analysis was to help identify successful diagnostic and treatment priorities in this group of patients. Between 1979–1989 the medical records of all patients sustaining blunt chest trauma resulting in a traumatic aortic tear were reviewed. There were 11 patients with multiple injuries and this diagnosis was treated at Boston University Medical Center. Five patients had diagnostic peritoneal lavage or an exploratory laparotomy prior to a thoracotomy. Four patients had only a thoracotomy. Two patients in this series had a thoracotomy prior to treatment of suspected intraabdominal injuries. One of these two patients died. Our overall survival rate was 82%. This series suggests that the management sequence in patients with coexistent injuries should include treatment of severe associated injuries prior to treatment of the aortic injury and that initial treatment of traumatic aortic tears is appropriate if there is no evidence of severe life-threatening trauma.