Morphometric analysis of the popliteal artery for endovascular treatment.

This study intended to determine the precise diameter of the popliteal artery in patients at risk for popliteal aneurysms. Accurate sizing is necessary to develop devices for endovascular treatment of popliteal aneurysms. Fifty-four patients with abdominal aortic aneurysms (AAAs) had computed tomography (CT) scans of the popliteal arteries. Age- and gender-matched control subjects were measured by ultrasound. NIH Image was used to measure the minor diameter at the adductor hiatus (proximal) and femoral condyles (midpopliteal artery). There were 4 unsuspected popliteal aneurysms (7.4%). The proximal popliteal artery was ectatic in these patients: 13.4 +/- 5.2 mm. Proximal and midpopliteal arteries were significantly larger in the other patients with AAAs compared with controls: 9.6 +/- 1.8 mm vs 7.9 +/- 1.1 mm at the hiatus (p<0.001) and 10.2 +/- 2 mm vs 7.9 +/- 0.9 mm at the condyles (p<0.001). The popliteal artery was focally larger in patients with AAAs without popliteal aneurysms. The popliteal artery was larger in men compared with women; 9.8 +/- 1.8 mm vs 8.8 +/- 1.9 mm at the hiatus (p=0.024) and 10.5 +/- 1.9 mm vs 9.0 +/- 2.4 mm at the condyles (p=0.005). The proximal popliteal artery was 2 mm larger in patients at risk for popliteal aneurysms and 5 mm larger in patients with popliteal aneurysms compared to controls. Focal ectasia of the midpopliteal artery was common. Planning for endovascular treatment of popliteal aneurysms must incorporate this striking enlargement.

Is bilateral ultrasound scanning of the legs necessary for patients with unilateral symptoms of deep vein thrombosis?

PURPOSE: The purpose of this study was to determine the necessity of bilateral lower-extremity venous duplex ultrasound scanning in patients with unilateral symptoms of deep vein thrombosis (DVT). PATIENTS AND METHODS: A retrospective review of 1080 bilateral venous duplex scans was performed. Patients were randomly selected from a total of 7922 studied between May 1998 and May 2000. Data on patient age, sex, comorbidity, and the reason for ultrasound scan were compiled. Forty percent (435/1080) of patients presented with unilateral symptoms of lower-extremity DVT. This group was further analyzed according to their status as inpatients or outpatients. RESULTS: DVT was diagnosed in 26.9% (117/435) of the patients. Of the inpatients found to have DVT, the thrombus was confined to the symptomatic leg in 23.8% (38/159), thrombus was present just in the asymptomatic leg in 8/159 (5.0%), and thrombus was found in both legs in 8/159 (5.0%). In the outpatient group, thrombus was confined to the symptomatic leg in 21.0% (58/276) and found in both legs in 1.8% (5/276). None of the 276 outpatients had DVT isolated in the asymptomatic leg. CONCLUSION: Routine bilateral lower-extremity venous duplex studies are not necessary in outpatients presenting with unilateral symptoms. In many outpatients, a single-limb study will suffice. If a patient is found to have a DVT on the symptomatic side, then we believe that a bilateral study is indicated. We do believe that routine bilateral scanning of inpatients remains justified. This algorithm may save technician time and increase vascular laboratory efficiency.

The effect of hospital vascular operation capability on outcomes of lower extremity arterial bypass graft procedures.

BACKGROUND: The purpose of this study was to determine whether hospitals with a high capability for vascular operations have lower rates of inpatient mortality, major complication, and major amputation with lower extremity arterial bypass (LEAB) procedures than do less well-equipped hospitals after controlling for hospital procedure volume and patient characteristics. METHODS: Admissions of 16,422 northern Illinois residents to Illinois hospitals for aortoiliac (AI) or distal bypass operations during 1993 to 1999 were analyzed. Hospitals were considered to have a high capability for vascular operations if they had cardiac surgical facilities and either an accredited blood flow laboratory, general surgical residency, or fellowship training in vascular surgery. Logistic regression was used to model the effect of hospital capability on mortality after controlling for hospital LEAB procedure volume, operation level, severity of illness, age, sex, and emergent admission. RESULTS: Sixteen of 98 Illinois hospitals with 34.4% of the sample patients, including 8 of 18 hospitals with more than 40 admissions for LEAB procedures annually, were classified as having high surgical capability. Hospitals classified as having high versus low capability had lower mortality (2.8% vs 3.7%; P =.003) and amputation rates (4.6% vs 4.9% [not significant]) but higher major complication rates (9.8% vs 8.5%; P =.006). CONCLUSIONS: Mortality outcomes for LEAB procedures were superior at high capability hospitals, even after controlling for patient characteristics, disease severity, and LEAB volume. Hospital complication rates were not correlated with mortality rates and may not be a meaningful measure of quality of care.

Mesenteric venous thrombosis: a changing clinical entity.

OBJECTIVE: Mesenteric venous thrombosis (MVT) and its clinical spectrum have become better defined following improvements in diagnostic imaging. Historically, MVT has been described as a morbid clinical entity, but this may not necessarily be true. Often, an underlying disease process that predisposes a patient to MVT can be found and potentially treated. This study was designed to evaluate the diagnostics and management of MVT and to review long-term results of treatment. PATIENTS: Thirty-one patients in whom MVT was diagnosed between 1985 and 1999 were retrospectively reviewed. Survivors were contacted for follow-up. There were 15 men and 16 women. Ages ranged from 22 to 80 years (mean, 49.1 years). Thirteen patients had documented hypercoagulability, 10 had a history of previous abdominal surgery, 6 had a prior thrombotic episode, and 4 had a history of cancer. MVT presented as abdominal pain (84%), diarrhea (42%), and nausea/vomiting (32%). Computed tomography (CT) was considered diagnostic in 18 (90%) of 20 patients who underwent the test. CT diagnosed MVT in 15 (100%) of 15 patients presenting with vague abdominal pain or diarrhea. Angiography demonstrated MVT in only five (55.5%) of nine patients. RESULTS: Seven of 31 patients died within 30 days (< 30-day mortality rate, 23%). Twenty-two patients (72%) were initially treated with heparin. Nine patients were not heparinized: four of them died, and two were later given warfarin sodium (Coumadin). Of the 31 patients, only one received lytic therapy. Three patients became symptom free without anticoagulation. Ten patients (32%) underwent bowel resection. Overall, 19 (79%) of 24 survivors were treated with long-term warfarin therapy. Long-term follow-up was obtained in 24 patients (mean, 57.7 months). Twenty-one (88%) of 24 survived in follow-up. CONCLUSION: The diagnosis of MVT should be suspected when acute abdominal symptoms develop in patients with prior thrombotic episodes or a documented coagulopathy. CT scanning appears to be the primary diagnostic test of choice. Anticoagulation is recommended. If diagnosed and treated early, MVT is not likely to progress to gangrenous bowel. Recent mortality rates for MVT are lower than previously published, perhaps because of earlier diagnosis and aggressive treatment or possibly because we now readily diagnose a more benign form of the disease, which is due to widespread use of CT scanning.

Staged embolization and operative treatment of multiple visceral aneurysms in a patient with fibromuscular dysplasia--a case report.

The importance of following a prioritized sequential approach to patients with complex multianeurysm disease cannot be overemphasized. The following patient with multiple visceral aneurysms first had coil embolization of bilateral renal artery aneurysms and then operative excision of her remaining splenic artery aneurysms to minimize the potential morbidity of a larger operation. This case also demonstrates the potential for following levels of specific degradative enzymes associated with aneurysmal disease (matrix metalloproteinase-9 (MMP-9) in this case) preoperatively and postoperatively and in long-term follow-up to monitor for disease recurrence.

Screening and surveillance for abdominal aortic aneurysms: who needs it and when.

Early detection of abdominal aortic aneurysms potentially can save many lives by preventing aneurysm rupture. Screening programs, however, have yet to be proven as an efficient means of accomplishing this goal and improving overall life expectancy. Until more information is available, selective high-risk screening may be the only viable option. Recently, 2 large prospective studies have better defined the utility of screening programs and have provided guidelines for the safe nonoperative management of small aneurysms. Using ultrasound surveillance, these can be followed up at 3- to 12-month intervals, depending on their size, with operative intervention reserved for aneurysms that enlarge rapidly, become symptomatic, or reach 5.5 cm in diameter.

Bedside vena cava filter placement guided with intravascular ultrasound.

OBJECTIVE: The purpose of this study was to report a feasibility trial approved by the Institutional Review Board for insertion of inferior vena cava (IVC) filters with intravascular ultrasound (IVUS) guidance in the intensive care unit. METHODS: Between October 1998 and May 2000, 26 patients (15 men, 11 women; age range, 22-86 years; mean, 55 years) were enrolled. Eight patients (31%) underwent prophylactic filter placement, and 18 patients (69%) had venous thromboembolism (deep venous thrombosis = 16, pulmonary embolism = 2) with contraindications to anticoagulation. A single groin puncture was used for IVUS and filter placement. Location of major branch veins, thrombosis, and caval diameter were readily demonstrated without the use of radiocontrast agents. Mapping of the IVC permitted assessment of ideal filter location. Postprocedure radiographs (23 of 26) were obtained to document filter position. Seventeen of 26 had follow-up lower extremity duplex studies. RESULTS: Twenty-four (92%) of 26 patients underwent successful filter deployment. The two other patients had filters subsequently placed by means of traditional fluoroscopic techniques. One femoral vein insertion site thrombosis resolved after a month. One patient experienced symptomatic caval thrombosis thought to be caused by thrombus trapping 55 days after the procedure. No pulmonary emboli occurred after filter placement. One patient's death was unrelated to vena cava filter placement. The hospital charge for bedside filters was $3623 compared with $4165 (P =.281) for fluoroscopic placement. CONCLUSION: Bedside insertion of an IVC filter with IVUS guidance is feasible and may be an effective alternative in the intensive care unit. No additional costs were incurred in this small series. Protocol refinements should reduce the incidence of complications. The results of this study support the need for further evaluation comparing it with standard techniques.