Carotid artery reconstruction for infected carotid patches.

OBJECTIVES: Infected carotid prosthetic patches (ICPP) are a rare but catastrophic complication of carotid endarterectomy (CEA). Prevention and appropriate surgical management is essential. We report our experience of carotid artery reconstruction for ICPP. DESIGN: Single-center retrospective study. METHODS: 10-year review of the surgical treatment of ICPP. RESULTS: Twelve patients presented with patch infection following CEA. Three patients presented acutely with an expanding hematoma, eight with chronic complications (abscess/discharging sinus n = 5, carotid pseudoaneurysm n = 3). Mean age was 75 years. Replacement conduits included superficial femoral artery (n = 6), cadaveric homograft (n = 3), long saphenous vein (n = 2) and one patient had primary closure. Five patients had muscle flaps fashioned for carotid artery protection. Operative complications included hypoglossal nerve injury (1 patient), superficial skin infection (2 patients) and one patient was returned to the operating room for a neck haematoma. Five surgical specimens were culture positive for: Staphylococcus aureus (n = 3), Corynebacterium propionibacterium (n = 1) and Streptococcus anginous (n = 1). There were no 30-day mortalities. Mean hospital stay was 6 days. Median follow-up was 16 months (range 3-108 months). CONCLUSION: Carotid artery reconstruction in a contaminated wound represents a significant surgical challenge. Unlike previous reports that used venous conduits, this is the first series where cadaveric or autologous arterial conduits were preferred. Arterial conduits achieved durable short term follow-up.

Autologous peripheral blood CD133+ cell implantation for limb salvage in patients with critical limb ischemia.

We report the safety and feasibility of autologous CD133+ cell implantation into the lower extremity muscles of patients with critical limb ischemia, whose only other option was limb amputation. Nine patients participated in the study: seven patients suffering from arteriosclerosis obliterans, one with thromboangiitis obliterans (Buerger's disease) and one with thromboembolic disorder. Autologous PBSC were collected after the administration of G-CSF (10 mcg/kg/day). CD133+ cells were selected using the CLINIMACS cell separation device and were injected i.m. without earlier cryopreservation using a 22-gauge needle into multiple sites 3 cm apart in the gastrocnemius/soleus muscle, or depending on clinical circumstances, in the foot or quadriceps muscle, or both, of the involved leg. There were no complications from either leukapheresis or injection. Stem cell injection prevented leg amputation in seven of the nine patients. In this small cohort of patients with end-stage critical limb ischemia, quality of life (Short Form-36) physical component score improved significantly at 3 (P=0.02) and 6 (P=0.01) months, but not at 1 year (P=0.08). There was a trend towards the improvement in pain-free treadmill walking time (P=0.13) and exercise capacity (P=0.16) at 1 year. Lower extremity limb salvage was achieved for seven of the nine treated patients.

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.

Leg symptoms in peripheral arterial disease: associated clinical characteristics and functional impairment.

CONTEXT: Persons with lower-extremity peripheral arterial disease (PAD) are often asymptomatic or have leg symptoms other than intermittent claudication (IC). OBJECTIVE: To identify clinical characteristics and functional limitations associated with a broad range of leg symptoms identified among patients with PAD. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study of 460 men and women with PAD and 130 without PAD, who were identified consecutively, conducted between October 1998 and January 2000 at 3 Chicago-area medical centers. MAIN OUTCOME MEASURES: Ankle-brachial index score of less than 0.90; scores from 6-minute walk, accelerometer-measured physical activity over 7 days, repeated chair raises, standing balance (full tandem stand), 4-m walking velocity, San Diego claudication questionnaire, Geriatric Depression Score Short-Form, and the Walking Impairment Questionnaire. RESULTS: All groups with PAD had poorer functioning than participants without PAD. The following values are for patients without IC vs those with IC. Participants in the group with leg pain on exertion and rest (n = 88) had a higher (poorer) score for neuropathy (5.6 vs 3.5; P<.001), prevalence of diabetes mellitus (48.9% vs 26.7%; P<.001), and spinal stenosis (20.8% vs 7.2%; P =.002). The atypical exertional leg pain/carry on group (exertional leg pain other than IC associated with walking through leg pain [n = 41]) and the atypical exertional leg pain/stop group (exertional leg pain other than IC that causes one to stop walking [n = 90]) had better functioning than the IC group. The group without exertional leg pain/inactive (no exertional leg pain in individual who walks

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.

Transplanting a kidney with a renal artery aneurysm--a case report and literature review.

As a rare postoperative complication, renal artery aneurysm has been reported in 0.95% of kidney transplants. A renal artery aneurysm was repaired prior to transplantation of the kidney.

Postoperative and amputation-free survival outcomes after femorodistal bypass grafting surgery: findings from the Department of Veterans Affairs National Surgical Quality Improvement Program.

PURPOSE: A noncardiac surgery risk model was used as a means of analyzing variations in postoperative mortality and amputation-free survival for older veterans undergoing femorodistal bypass grafting surgery. METHODS: A prospective cohort study was undertaken in 105 Veterans Affairs (VA) hospitals at the time of index operation from 1991 to 1995. Each patient was linked to subsequent hospitalizations, major amputation surgery, and survival through 1999. Logistic regression and proportional hazards models were used as a means of developing risk indices on the basis of risk factors from the VA National Surgical Quality Improvement Program. A total of 4288 male veterans 40 years or older underwent artificial, vein, or in situ bypass grafting surgery at the femoral to tibial level. The main outcome measures were 30-day postoperative mortality and amputation-free survival. RESULTS: Approximately half of all patients had undergone an earlier revascularization or amputation at any level for vascular disease. The 30-day postoperative mortality rate was 2.1% and varied greatly between mortality risk index quartiles (0.6%-5.2%). In a median 44.3 months of follow-up, surviving patients had 17,694 subsequent VA hospitalizations, 1147 patients (26.7%) underwent subsequent major amputation, and 1913 patients (44.6%) died. The overall survival probability was 88% at 1 year and 63% at 5 years; 1- and 5-year (any sided) limb salvage rates were 87% and 74%, respectively, for patients who underwent a femoropopliteal bypass grafting procedure, compared with 77% and 63%, respectively, for patients who underwent a tibial bypass grafting procedure. When amputation and death were combined as end points, amputation-free survival probability rates at 1, 3, and 7.5 years were 74%, 56%, and 29%, respectively. Patients with the best 20% survival risk scores had observed mean survival probability rates 30% higher than patients in the poorest 20% of survival risk. CONCLUSION: Risk indices derived from the preoperative workup may be of use to clinicians in assessing and communicating risk and prognosis. Risk-adjustment of outcomes is critical for evaluating future disease management initiatives for patients with advanced peripheral arterial disease.

Postoperative and late survival outcomes after major amputation: findings from the Department of Veterans Affairs National Surgical Quality Improvement Program.

BACKGROUND: A surgical risk model is used to analyze postoperative mortality and late survival for older veterans who underwent above- or below-knee amputations in 119 Veterans Affairs (VA) hospitals from 1991 to 1995. METHODS: Preoperative medical conditions and laboratory values abstracted by the VA National Surgical Quality Improvement Program were linked to subsequent hospitalization and survival through 1999. Logistic regression and proportional hazards models were used to develop risk indexes for postoperative mortality and long-term survival. RESULTS: Thirty-day postoperative mortality was 6.3% for 1909 below-knee and 13.3% for 2152 above-knee amputees. Mortality varied greatly between the lowest-highest risk index quartiles (0.8%-18.4% for below-knee amputation and 2.3%-31.1% for above-knee amputation). Surviving patients had 10,827 subsequent VA hospitalizations during a median 32-month follow-up. Survival probabilities for below- and above-knee amputees were 77% and 59% at 1 year, 57% and 39% at 3 years, and 28% and 20% at 7.5 years. The lowest quartile of survival risk had a 61% five-year survival compared with 14% for the highest-risk quartile. CONCLUSION: A generic surgical risk model can be of use in stratifying prognosis after major amputation. The heavy burden of hospital use by these patients suggests the need for better disease management for this high-risk, high-cost patient population.

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.

Gait alterations associated with walking impairment in people with peripheral arterial disease with and without intermittent claudication.

OBJECTIVES: To describe gait alterations associated with impaired walking endurance in patients with and without lower-extremity peripheral arterial disease (PAD) and determine whether the Caltrac accelerometer provides a valid measure of physical activity in PAD. DESIGN: Cross-sectional. SETTING: Academic medical center. PARTICIPANTS: PAD (n = 40) and non-PAD patients (n = 22) from two Chicago hospitals. MEASUREMENTS: Participants underwent measurement of the ankle brachial index (ABI), leg length, and 6-minute walk. Steps per minute and step length were measured during the first and last 100 feet of the 6-minute walk. Participants wore a Caltrac accelerometer, sensitive to vertical acceleration, during the 6-minute walk and for 7 continuous days. RESULTS: Five PAD participants (13%) and one non-PAD participant (5%) ceased walking before the end of 6 minutes. Among the remaining participants, distance walked in 6 minutes was more highly related to walking velocity during the last 100 feet of the walk than walking velocity during the first 100 feet. ABI was associated significantly with cadence (20.77 steps/minute per unit ABI, P <.001) but not step length (10.12 centimeters/unit ABI, P =.08). ABI was associated significantly with 6-minute walk distance (493 feet/unit ABI, P =.018), but this association disappeared completely after adjustment for step length and cadence. We found no difference in accelerometer scores between PAD and non-PAD participants over a fixed distance of 800 feet (7.34 vs 7.17 activity units, P =.789). However, scores were significantly different after 7 days (730.8 vs 1,485.0 activity units, P =.003). CONCLUSION: Walking performance in PAD patients who completed 6 minutes of walking was largely determined by a decline in walking velocity rather than slower initial walking velocity. ABI was more closely associated with cadence than step length. Future studies should assess the effect of exercise programs and revascularization on cadence and step length in PAD.

Murine aortic aneurysm produced by periarterial application of calcium chloride.

A murine abdominal aortic aneurysm model was developed by applying calcium chloride periarterially. A 13.6 mEq/10 ml calcium chloride solution was applied to the abdominal aorta of nine mice. Three mice were randomly selected at the end of the first, second, and third weeks postoperatively, and their vessel diameters were measured. The vessel diameter at the end of the first week postoperatively was 0.39 +/- 0.03 mm (mean +/- SD) pretreatment and 0.41 +/- 0.03 mm posttreatment (5.3% increase, P > 0.05). The vessel diameter at the end of the second week postoperatively was 0.48 +/- 0.03 mm pretreatment and 0.78 +/- 0.20 mm posttreatment (64% increase, P < 0.05). The vessel diameter at the end of the third week postoperatively was 0.57 +/- 0.14 mm pretreatment and 1.16 +/- 0.43 mm posttreatment (110% increase, P < 0.05). Nine other murine abdominal aortas were treated with sodium chloride, and their vessel diameters were measured in similar 7-day intervals. No measurements in this group were statistically significant when comparing pretreatment to posttreatment vessel diameters. A larger number of inflammatory infiltrates was observed in the intima and media layers of calcium-chloride-treated mice. Underlying mechanisms for this model include disrupting the elastic network within the media by calcium precipitations and activating the inflammatory response. We conclude that periarterial application of calcium chloride is a convenient and reliable model for creating abdominal aortic aneurysms in mice.

Surgical management of abdominal aortic aneurysm.

Abdominal aortic aneurysms (AAA) are increasingly common in the aging population. While the etiology of abdominal aortic aneurysms is unknown, there is growing evidence that suggests an immune response. The majority of AAA are asymptomatic and when treated are standard open surgical procedures. The overall mortality rate is 5% or less. The current recommendations for the treatment of aneurysms are based on diameter: diameters exceeding 5 cm in good-risk younger patients should be treated. Aortic aneurysms tend to enlarge over time with a growth-rate between 0.2 and 0.4 mm per year. Once rupture occurs mortality is estimated to exceed 75%, with half of the patients dying prior to arriving at the hospital and the remaining one-half following surgical correction. Recently, minimally invasive techniques have been developed to treat AAA in high-risk patients. These techniques involve the use of covered stented grafts. Current clinical investigations are underway both in this country and in Europe, which have yielded promising results. However, long-term complications are unknown. Currently, aortic aneurysms are best treated with open surgical management.

Carotid endarterectomy: characterization of recent increases in procedure rates.

INTRODUCTION: Recent increases in the rate of carotid endarterectomies (CEAs) have been attributed to results of clinical trials demonstrating efficacy when CEA is performed in centers of excellence. Subsequent population-based data suggest that trial results may not be matched in the community. This study was undertaken to characterize trends in CEA procedure rates after the dissemination of trial data and to describe any change in patient outcomes with population-based data from a single state. METHODS: Hospital administrative data on CEAs from 1992 to 1996 (n = 45,744) were obtained for the state of Florida. Annualized CEA rates per 100, 000 Florida residents were analyzed to determine trends in patient age, sex, admission type, size of hospital beds, ownership type and teaching status, and annual hospital and surgeon CEA volume. Outcomes were examined to track trends in complication rates. RESULTS: The annual number of CEA procedures increased 74% from 63.7 per 100,000 residents per year to 110.8 per 100,000 residents per year between 1992 and 1996. A single large increase occurred during the second half of 1994 when CEAs increased 73.5% from 16.6 per 100, 000 residents per quarter to 28.8 per 100,000 residents per quarter after a clinical alert on benefits to CEAs in asymptomatic patients. Over 5 years, there were significant trends toward more nonemergent admissions, and more procedures were performed in high-volume hospitals and by high-volume surgeons. Procedure rates in both women and very elderly patients increased more than 70%, which was in step with younger patients and men. The incidence of inpatient stroke and death declined over the 5-year period, whereas the rate of perioperative myocardial infarction remained constant. CONCLUSIONS: Experience from Florida indicates that CEA rates increased as results of the Asymptomatic Carotid Artery Study disseminated. Trial results have been broadly interpreted to include women and very elderly patients. More patients are being referred to busier hospitals and to high-volume surgeons, which should continue to result in better patient outcomes.

Transrectal ultrasound assessment of murine aorta and iliac arteries.

Recent research in arterial aneurysm formation has focused on animal model development. Mice are an ideal experimental organism due to their short life cycle, prolific progeny, and extensively studied genome. Most experiments require the sacrifice of the mice to observe and assess any morphological changes. Noninvasive or minimally invasive imaging is limited due to the relatively small size of the structures. The development of such a technique, therefore, is especially useful for allowing repeated measurement without sacrificing the mice. We introduce a novel technique of imaging and measuring the aorta, the aorta/inferior vena cava complex, and the right and the left common iliac artery/vein complex by the use of an intravascular ultrasound catheter. The catheter is inserted through the anus and rectum and into the sigmoid and left colon, where the aorta can be observed to fluctuate at approximately 500 beats/min. The aortic bifurcation can also be observed. The diameters of the aorta and the inferior vena cava were measured first with the transrectal ultrasound technique and then with direct visualization upon laparotomy for 10 mice. This revealed a percentage error between 13.7 and 14.2% for this novel technique. Fifteen more sets of vessel measurements were also made with 8 male and 7 female mice. The results demonstrated a correlation between vessel size and body weight in male but not female mice and suggested an intersex difference in vessel growth rate. We conclude that transrectal ultrasound is a useful tool in imaging and measuring the murine aorta and its bifurcation.