Vascular Laboratory Studies Research Articles

An e-Health Approach to Managing Vascular Surgical Patients

The objective of this study was to investigate an e-health approach to managing patients presenting with vascular-type symptoms. A pilot study of a prospective cohort of patients referred from a single general practitioner practice of 5700 patients using electronic referral, assessment by a practice nurse, and teleconferencing facilities as an adjunct to normal referral and management practice was designed and conducted. Thirty-eight patients aged 30-93 years old (median 72 years) were enrolled in the study between March 2001 and July 2004. Twelve patients had leg ulceration and 12 complained of leg pain. The remainder had a range of symptoms potentially vascular in nature. All but 1 patient had an initial teleconsultation. This initial teleconsultation lasted a median of 11 minutes (interquartile range 9 minutes (min) 59 seconds (sec)-12 min 43 sec). For 10 patients this was their only contact with the hospital. One patient had teleconsultation follow-up only, 26 patients attended the hospital for vascular laboratory studies or angiography, and 8 of these went on to have radiological and/or surgical intervention. Three patients attended the outpatient department for follow up; all other follow-ups were managed via the teleclinic. Overall, 57 standard outpatient attendances in these patients were replaced by teleconsultations. Common vascular-type symptoms can be satisfactorily evaluated across a telelink with the aid of a practice nurse and baseline patient data transmitted electronically. Decisions can be made regarding the need for further investigation and attendance in outpatient clinic can be largely eliminated.

Appropriate Resource Utilization in Portable Noninvasive Vascular Studies: The Role of Disruptive Technology

Purpose Common reasons for avoiding portable noninvasive vascular laboratory (VL) studies include degraded study quality, repetitive stress injuries, the wear and tear of equipment, and inefficiency. We examined the efficiency of portable VL studies in the context of productivity and potential loss of revenue. Methods From January 2005 to March 2005, sonographers in the VL recorded the time required to conduct “in-lab” and portable studies with conventional full-size scanners. A blended average based on frequency of portable studies within different areas of the hospital was used to determine the additional time required to conduct a portable study. The sonographer also made a qualitative assessment on the necessity of the portable study in each case. Results The VL performed an average of 31 portable studies (18% of total studies) per week. On average, portable testing increased overall study time by 17.7 min per test and 1.8 h per day, resulting in 9.1 h of additional study time lost per week. The potential increase in study volume could result in incremental annual gross revenue of $41,204 to $77,258 for the VL. The sonographers estimated that 24% to 45% of portable procedures could have been conducted in the lab. Conclusions In addition to suboptimal imaging and sonographer/equipment wear and tear, the current practice of unrestricted portable tests performed with existing bulky equipment is economically inefficient. New “disruptive” technology, leading to high-quality bedside scanning and limiting portable studies to patients who genuinely need it, will allow for greater productivity, decrease wait time for elective outpatients, and generate incremental revenue for the VL.

The role of surgical revascularization in the management of diabetic foot wounds

Diabetic foot wounds affect an estimated 15% of all patients with diabetes. These wounds are typically multifactorial in origin. Neuropathy of the foot and impaired wound healing are frequently associated with peripheral arterial occlusive disease. These factors combine to contribute to the development of foot ulcers. Successful wound healing and limb salvage require prompt recognition and treatment. Assessment of arterial perfusion is imperative and may be accomplished by a combination of physical examination and noninvasive vascular laboratory studies. When associated with significant ischemia, diabetic foot ulcers require arterial revascularization to achieve wound healing.

A Case Study Demonstrating the Utility of Duplex Ultrasonography as the Sole Imaging Modality in the Surveillance and Repair of Lower Extremity Arterial Bypass Grafts

Introduction Traditionally, duplex ultrasonography has played a secondary role in the pre-operative assessment of lower extremity arterial bypass graft revision, being used more as a follow-up tool, with more expensive and invasive modalities being used primarily. This case demonstrates the accuracy and reliability of using duplex ultrasonography alone in the management of lower extremity bypass graft revision, as well as postoperative follow-up. Case Report A 76-year-old man was seen in the diagnostic vascular unit for 2-week postoperative assessment after a left common femoral artery (CFA) aneurysm repair. Five months previously he had undergone right lower extremity femoral-to-posteriortibia in situ bypass graft for superficial femoral artery occlusion and a popliteal artery aneurysm. Ankle brachial indices were performed at his 2-week follow-up and showed a significant decrease in the right ankle brachial index (ABI) from 0.79 to 0.41. A right lower extremity duplex ultrasonography was performed and revealed significantly decreased flow velocities within the graft secondary to an arteriovenous fistula (AVF) found at the midthigh. The patient was scheduled for ligation of the AVF to restore adequate flow to the right lower extremity. The right thigh AV fistula was marked with duplex ultrasonography immediately before surgery. An incision was made directly over the marked AVF site, and the vein graft was isolated, revealing a large posterior medial AV fistula. Postoperative ABIs were significantly increased to 0.85 on the right side. Conclusions This case demonstrates the usefulness, accuracy, and reliability of duplex ultrasonography in the management of lower extremity arterial bypass grafts. All preoperative decisions were made on the basis of noninvasive vascular laboratory studies.

Accreditation and credentialing in the vascular laboratory

The vascular diagnostic laboratory remains an integral component of the vascular surgeon's practice and has replaced many invasive techniques for the diagnosis and treatment plan of vascular disease. Although financial challenges have been leveled at the vascular laboratory, the actual number of laboratories continues to increase, suggesting a greater demand for vascular laboratory studies. With this, also comes the challenge of maintaining quality within each laboratory as well as ensuring a standard of quality for all laboratories nationwide. Credentialing and accreditation have been used for this purpose in nearly all areas of medicine and have provided a mechanism for assuring a minimum standard of competency. Over the last decade, similar mechanisms have been applied toward the vascular diagnostic laboratory, which likely have resulted in improved vascular diagnostic studies and overall care.

65-Year-Old Woman With Painful Leg Ulcers

65-Year-Old Woman With Painful Leg Ulcers

Lower‐extremity Doppler for Deep Venous Thrombosis—Can Emergency Physicians Be Accurate and Fast?

Clinical diagnosis of lower-extremity (LE) deep venous thrombosis (DVT) requires confirmation by an imaging study before committing the patient to anticoagulation therapy. Studies have shown that demonstrating compressibility of leg veins under ultrasound is accurate for ruling out DVTs when performed by vascular specialists. Although LE Doppler has become the preferred test for diagnosing DVTs, it is not always available 24 hours per day. To evaluate the accuracy and speed with which emergency physicians (EPs) could perform LE color duplex ultrasonography for the detection of DVT. Patients presenting to an urban community emergency department (ED) between August 1, 1998, and March 3, 1999, were enrolled into this prospective study. The EPs, who underwent brief and standardized training, scanned patients at high risk for DVT with leg pain, swelling, or both. Physicians performed color duplex ultrasound examinations with compression at the common femoral and popliteal veins. The time until completion of the ED scan was recorded with a standardized method. The vascular laboratory performed a complete duplex ultrasound examination within eight hours. One hundred twelve patients were enrolled in the study, with 34 positive for DVT. The median examination time was 3 minutes 28 seconds (95% CI = 2 min 45 sec to 4 min 2 sec; IQR 3 min 9 sec). Times ranged from 1:02 to 18:20 minutes. The ED results had a high correlation with vascular laboratory studies, giving a kappa of 0.9 and a 98% agreement (95% CI = 95.4% to 100%). Emergency physicians can perform LE duplex ultrasound examinations accurately and quickly.

Directional Atherectomy and Balloon Angioplasty for Lower Extremity Arterial Disease

This study was undertaken to evaluate the use of directional atherectomy, balloon angioplasty, and video angioscopy in highly selected patients with superficial and popliteal artery stenoses. Directional atherectomy and balloon angioplasty for superficial femoral and popliteal artery stenosis (> 80%) were performed in 96 limbs (88 patients) between 1990 and 1994. All procedures were performed by the authors with angioscopy and C-arm angiography. Society for Vascular Surgery/International Society for Cardiovascular Surgery (SVS/ISCVS) categorical classification of chronic limb ischemia and run off scoring was utilized pre- and postoperatively to assess outcome. The indicators for atherectomy were moderate claudication (category 2, 15% of limbs), severe claudication (category 3, 65%), ischemic rest pain (category 4, 12%), and tissue loss (category 5, 12%). Morbidity was 6.0% with no perioperative mortality. All technically and (angiographically) successfully treated patients demonstrated postoperative improvement. Clinical assessment, vascular laboratory studies (outcome criteria), and/or angiography were monitored at follow-up visits. Intraoperative failures occurred in 6% of limbs due to inability to pass a guide wire (3%), impacted atherectomy catheter (1%), or vessel perforation (2%). In the remaining 90 limbs, 23% failed due to either progression of disease (7.7%) or restenosis at the original site (15.3%). Seventy-one percent of limbs maintained their postoperative categorical improvement at a mean follow up of 24 months. Combining atherectomy and balloon angioplasty may be more durable than angioplasty or atherectomy alone. A long-term prospective study of the role of directional atherectomy and balloon angioplasty by vascular surgeons appears to be warranted utilizing SVS/ISCVS guidelines for lower extremity chronic ischemia categories, run-off score, and outcome criteria for patency.

Color Doppler ultrasonography by emergency physicians for the diagnosis of acute deep venous thrombosis.

To assess the feasibility of emergency physicians' (EPs') performing color-flow Doppler ultrasonographic vascular studies in the ED to diagnose deep venous thrombosis (DVT), after a modest training program. A retrospective observational review was performed of the performance of color-flow Doppler ultrasonographic vascular studies by EPs. Prior to the study period, venous Doppler studies were not available at off-hours. Two attending EPs were trained by the hospital's vascular laboratory by observing studies and then performing 25-30 studies successfully. They were then available to examine all patients presenting to the ED at off-hours who were suspected of having DVT. Patients were admitted or released from the ED based on the examination results. All patients were to have formal vascular laboratory studies the next day. The study was performed at a university hospital ED and evaluated all patients who underwent off-hour examinations from January 1993 to February 1994. The examiners were aware of the clinical scenario. Of 23 eligible patients, 15 completed the protocol with a follow-up next-day study. Based on the follow-up study, the ED examination was 100% sensitive (7 true positives) and 75% specific (6 true negatives). The 2 false-positive studies were for patients with old DVT. The 8 patients without follow-up studies were not included in the analysis, although 4 of these patients had negative studies and unremarkable clinical outcomes. These preliminary findings suggest that Doppler ultrasonographic studies of the lower extremity veins by EPs can be used to make admission decisions when formal studies are not available. Confirmatory studies should be performed. EPs may overread acute thrombosis in the setting of old venous disease. Issues of cost and logistics remain to be resolved.

Utility of routine carotid duplex screening in patients who have claudication.

The recently published Asymptomatic Carotid Atherosclerosis Study (ACAS) demonstrated the benefit of performing carotid endarterectomy in selected asymptomatic patients who have > 60% carotid stenoses. It therefore becomes clinically important to identify the subgroups of patients who have a sufficiently high incidence of high-grade carotid stenosis to warrant routine carotid duplex screening. To determine the incidence of asymptomatic carotid disease in patients who had a chief complaint of claudication, we evaluated 188 patients who had claudication and no history of cerebrovascular symptoms. After a complete history was taken and a physical examination performed, patients underwent standard lower-extremity noninvasive vascular laboratory studies and carotid duplex scanning. Carotid duplex findings were interpreted by the Strandness criteria. Associated atherosclerotic risk factors were assessed (patient age, male sex, diabetes, hypertension, smoking history, lipid levels, history of coronary artery disease, coronary or vascular surgery, and family history of cerebrovascular disease). Presence of a carotid bruit was also noted. Univariate analysis, logistic regression, and odds ratios were performed to identify subgroups of patients that had an increased incidence of significant carotid disease. Of the 188 patients with claudication who were screened, 8% had an internal carotid artery stenosis of 16% to 49%, 21.8% had a stenosis that exceeded 50%, and 2.7% had an occluded internal carotid artery. The presence of a carotid bruit on physical examination was predictive of a > or = 50% internal carotid artery stenosis (p = 0.027). The ankle-brachial index was highly predictive of the presence of carotid stenoses in an inverse relationship (p = 0.001). Patient age approached significance (p = 0.143). Patients older than 65 years of age who had claudication, an ankle-brachial index less than 0.7, and a carotid bruit had a 45% incidence of significant carotid disease. The atherosclerotic risk factors of male sex, diabetes, hypertension, hyperlipidemia, smoking history, coronary history, previous coronary or vascular surgical history, and family history were not predictive of the presence of a > 50% carotid stenosis. In patients who seek medical attention with the chief complaint of claudication and who have no cerebrovascular symptoms, there is a 24.5% incidence of a > 50% internal carotid artery stenosis or occlusion on duplex examination. Select subsets of these patients have upwards of a 45% incidence of significant asymptomatic carotid disease. All patients who seek medical attention with claudication should therefore undergo routine carotid duplex screening to detect asymptomatic high-grade stenosis.

Reversed vein graft stenosis: early diagnosis and management.

Conscientious surveillance of intrainguinal bypass grafts is mandatory to detect vein graft stenoses, which, if uncorrected, can lead to graft occlusion. It is now widely accepted that noninvasive vascular laboratory studies are the best way to detect these lesions. However, controversy still exists over treatment, specifically whether balloon angioplasty is an acceptable substitute for surgery (patch angioplasty or short jump grafts) in the treatment of these lesions. We have always favored balloon angioplasty as primary treatment and have summarized our experience with treating 72 stenotic reversed femoropopliteal and femorotibial vein grafts, which represent 12% of 521 bypass grafts performed at our institution. Prosthetic and in situ grafts are specifically excluded from this report, as well as occluded grafts, found to have stenotic lesions after lytic therapy. The most common stenotic lesion occurred within 4 cm of the proximal anastomosis (29/72 = 40%). The other sites were near the distal anastomosis (7/72 = 10%), and in the middle of the graft (15/72 = 12%). Eighty-one percent (58/72) of the lesions were treated initially by balloon angioplasty with a 31% recurrence. Twenty-nine percent of the 14 grafts treated surgically by vein patch angioplasty or short jump grafts experienced recurrence. Overall 61% (44/72) of the stenotic grafts were treated by balloon angioplasty alone. The 5-year life-table assisted primary patency after correction of the stenotic lesion was 61%. The patency of the grafts from the time of initial bypass surgery, however, was 80%. Location of the stenosis within the graft was a major determinant of patency. Lesions in the proximal graft, proximal anastomosis, and distal graft taken as a group had significantly better patency than the midgraft and distal anastomotic lesions (5-year patency, 65% vs 48%, p less than 0.001 log rank test). We continue to recommend balloon angioplasty as primary therapy for vein graft stenosis except for those occurring in the midgraft and distal anastomosis. Fortunately, this group accounts for only 36% of lesions seen with reversed veins. Recurrent stenosis after balloon angioplasty should be repaired surgically.

Reversed vein graft stenosis: Early diagnosis and management

Conscientious surveillance of intrainguinal bypass grafts is mandatory to detect vein graft stenoses, which, if uncorrected, can lead to graft occlusion. It is now widely accepted that noninvasive vascular laboratory studies are the best way to detect these lesions. However, controversy still exists over treatment, specifically whether balloon angioplasty is an acceptable substitute for surgery (patch angioplasty or short jump grafts) in the treatment of these lesions. We have always favored balloon angioplasty as primary treatment and have summarized our experience with treating 72 stenotic reversed femoropopliteal and femorotibial vein grafts, which represent 12% of 521 bypass grafts performed at our institution. Prosthetic and in situ grafts are specifically excluded from this report, as well as occluded grafts, found to have stenotic lesions after lytic therapy. The most common stenotic lesion occurred within 4 cm of the proximal anastomosis (29/72 = 40%). The other sites were near the distal anastomosis (7/72 = 10%), and in the middle of the graft (15/72 = 12%). Eighty-one percent (58/72) of the lesions were treated initially by balloon angioplasty with a 31% recurrence. Twenty-nine percent of the 14 grafts treated surgically by vein patch angioplasty or short jump grafts experienced recurrence. Overall 61% (44/72) of the stenotic grafts were treated by balloon angioplasty alone. The 5-year life-table assisted primary patency after correction of the stenotic lesion was 61%. The patency of the grafts from the time of initial bypass surgery, however, was 80%. Location of the stenosis within the graft was a major determinant of patency. Lesions in the proximal graft, proximal anastomosis, and distal graft taken as a group had significantly better patency than the midgraft and distal anastomotic lesions (5-year patency, 65% vs 48%, p less than 0.001 log rank test). We continue to recommend balloon angioplasty as primary therapy for vein graft stenosis except for those occurring in the midgraft and distal anastomosis. Fortunately, this group accounts for only 36% of lesions seen with reversed veins. Recurrent stenosis after balloon angioplasty should be repaired surgically.

Combined transluminal angioplasty and infrainguinal reconstruction in multilevel atherosclerotic disease

Patients with multilevel atherosclerotic disease represent a difficult surgical challenge. This report is a retrospective review of 46 patients who were treated using a combination of iliac transluminal angioplasty and infrainguinal reconstruction. There were 42 male and 4 female patients with an average age of 62 years (range: 40 to 74 years). Follow-up ranged from 1 month to 10 years (mean: 27.3 months). These patients had multiple health problems typical of patients with peripheral vascular disease, including coronary artery disease (67%), hypertension (61%), and diabetes mellitus (42%); 80% of the patients were smokers. Forty-one patients were treated for rest pain and/or tissue loss, while five were treated for incapacitating claudication. Forty-three patients had a combination of angioplasty and distal bypass, while 3 patients had a form of femoral endarterectomy. Iliac artery pressure gradients were reduced from 35.4 +/- 4 mm Hg preangioplasty to 0.6 +/- 0.3 mm Hg postangioplasty. The procedures were well tolerated with no mortality and four serious complications. Vascular laboratory studies showed an improvement in the mean ankle-brachial index from 0.35 +/- 0.03 preoperatively to 0.71 +/- 0.04 postoperatively (p less than 0.05). Life-table analysis revealed a 72% 5-year primary patency rate, with a 93% 5-year limb salvage. Eight patients required a secondary procedure to maintain limb salvage. Five patients underwent amputation, three due to early graft thrombosis and two due to late graft failure. We conclude that combined iliac angioplasty and infrainguinal reconstruction is a safe and effective method for managing the patient with severe multilevel atherosclerotic disease.

The Thoracic Outlet Syndrome Is Underrated

The thoracic outlet syndromes (TOS) are caused by congenital or developmental anatomic anomalies of musculoskeletal tissues that cause abnormal compression and irritation of the brachial plexus and subclavian vessels. The most obvious anomaly is a cervical rib, but this is found in only about 10% of patients with TOS. The other 90% who develop severe neuromuscular symptoms affecting the neck, shoulder, and upper extremity are found to have soft-tissue anomalies usually related to the middle and anterior scalene muscles. Although these anomalies have been carefully classified and reported, 1,2 only the surgical team can appreciate the remarkable anatomic variations that cause the severe neurovascular symptoms. Extensive (and expensive), sophisticated neuroelectric studies, magnetic resonance imaging scans, computed tomography scans, and vascular laboratory studies completely fail to demonstrate the anatomic variations of the soft tissues and the neurologic compression-irritation mechanisms that are the basic cause of the symptoms. 3,4 Thus, the physician

Thrombolytic Therapy of Axillary-Subclavian Venous Thrombosis-Reply

Patients with axillary-subclavian vein thrombosis often have a poor outcome when treated with intravenous heparin sodium and oral warfarin sodium. Four patients were therefore treated with thrombolytic therapy. Good initial and excellent long-term results were achieved. In follow-up that has ranged up to four years, these patients do not have the common complaints of edema, fatigue, cramping, or weakness seen after traditional anticoagulation. Patients have returned to their previous occupations and have normal arm function. Noninvasive Doppler vascular laboratory studies suggest continued patency of axillary veins. Thrombolytic therapy should be considered in the treatment of spontaneous axillary-subclavian vein thrombosis.

Percutaneous transluminal angioplasty: A suggested method for analysis of clinical, arteriographic, and hemodynamic factors affecting the results of treatment

Sixty-nine percutaneous transluminal angioplasties (PTAs) were performed in the iliac and the femoral arteries of 54 patients. The main factors that might affect the results were reviewed: associated diseases, severity of ischemic symptoms, location and type of lesions (stenosis or occlusion and their length), and presence of disease distal to the site dilated. The vascular status of the patients in our series was more severe than in most others. Improvement at follow-up (average 15 months) was maintained in 74% of 66 radiographically successful PTAs. Poor runoff was the only factor found to affect the outcome deleteriously. Intra-arterial pressure measurements performed during the procedure and vascular laboratory studies were most valuable in assessing immediate and long-term results. Wide variations in results of PTA published in the literature are due to differences in methods of selection, evaluation, and reporting. A plea is made for future presentations of PTA series in an analyzable and comparable way, including and correlating all relevant variables as in the model suggested by the present study.

Carotid artery disease following external cervical irradiation.

A retrospective study of 910 patients surviving at least five years after cervical irradiation for Hodgkin's disease, non-Hodgkin's lymphoma, or primary head an neck neoplasms showed the incidence of stroke following cervical irradiation was 63 of 910 patients (6.3%) during a mean period of observation of nine years. This represents a trend toward an increased risk for this population observed over the same period of time (p = 0.39). A prospective study of 118 similar patients currently living five years after cervical radiotherapy was performed to determine the incidence of carotid artery disease occurring as a consequence of neck irradiation. Abnormal carotid phonangiograms (CPA) were found in 25% of the patients and abnormal oculoplethysmographs (OPG) were found in 17%. These studies represent significant carotid lesions that are not expected in such a population. It is concluded that the carotid stenoses demonstrated are most likely a consequence of prior irradiation. Patients that are five-year survivors of cervical irradiation should have noninvasive vascular laboratory studies performed as part of their routine follow-up examinations in order to detect these carotid lesions while they are occult.

Carotid Endarterectomy: Emphasis on Necessity of Long-Term Postoperative Evaluation

Carotid endarterectomy remains an effec tive means of preventing a stroke in patients with extracranial carotid lesions. Although long-term patency may be assumed, the true incidence of recurrent pathology is not known. In the past, follow-up angiography has been performed only when recommended for recurrent symptoms and some postoper ative bruits. Four different pathologic condi tions found at the endarterectomized bifur cation site are discussed as are their treat ments. Long-term follow-up evaluation is strongly recommended. Angiography is in dicated for recurrent symptoms. Carotid bruits are difficult to evaluate on a yearly basis. Vascular laboratory studies are recom mended 4 months after surgery and then on a yearly basis. Hopefully, early and late res tenosis will be identified. An artery should be explored when symptoms and angiog raphic findings indicate recurrent pathology.