Vascular

The purpose of this review article is to summarize our published experience with the use of the superficial femoral-popliteal vein (SFPV) to replace infected aortic prostheses. The SFPV has proven to be resistant to infections of all types and has shown no signs of degeneration over the long term. Since SFPV bypass and prosthetic graft excision are performed as a single stage, operative times are extensive. Therefore, it may not be appropriate for the sickest patients with severe medical comorbidities. Nevertheless, the operation has been associated with gratifyingly low mortality and amputation rates that are far better than published rates associated with graft excision and extra-anatomic bypass. It is particularly suited to patients with complex aortofemoral graft reconstructions who cannot undergo extra-anatomic revascularization for technical reasons. The venous sequella of SFPV harvest are minimal. These data and those from three other centers support the conclusion that graft excision and replacement with SFPV is an excellent alternative for treatment of aortic graft infections.

For the 48th meeting of the International Society for Cardiovascular Surgery, North American Chapter in June 2000. we were asked to organize a presentation with the title displayed above. We welcomed this opportunity because the phrase ‘growing the practice’ literally means giving greater service to underserved patients with vascular disorders. Underserved individuals with vascular disorders include those with nonatherosclerotic arterial disorders, patients with lymphedema, and individuals with a variety of venous disorders including venous insufficiency. The majority of these conditions are not surgical, but venous insufficiency commands attention because its treatments are interventional. Therefore, this presentation will discuss prevalence of venous insufficiency, a unifying concept of its pathophysiology, how treatment may be selected, what the new technology provides, and then a description of coding issues and whether or not interventions are actually worthwhile from the point of view of the patient.

The surgical outcome of infectious abdominal aortic aneurysms was evaluated based on the preoperative presence or absence of systemic inflammatory response syndrome (SIRS). Nine patients were divided into two groups according to the criteria for SIRS such as body temperature, heart rate, respiratory rate, and white blood cell count. In the group with SIRS, rupture and impending rupture of aneurysms occurred in three of the four patients (75%). All aneurysms were resected with a small part as a remnant; two in situ and two extraanatomic reconstructions were performed. Three patients died after surgery: one after in situ (cerebral infarction) and two after extraanatomic reconstruction (sepsis and multiple organ failure). In the group without SIRS, closed en bloc resection in two patients and resection of the aneurysm with a small part as a remnant in three patients were performed. In situ reconstruction in all patients and omentum wrapping in two patients were performed. One of the five patients died of massive hematemesis 70 days after surgery. The overall mortality rate was 75% in the group with SIRS versus 20% in the group without SIRS. The surgical outcome of infectious abdominal aortic aneurysm depends upon the severity of underlying infection. A possibility exists that SIRS is a useful indicator for predicting the surgical outcome of patients.

The purpose of this study was to apply decision analysis to an established practice in vascular trauma diagnosis. While exclusion arteriography has resulted in an increase in positive surgical explorations, no formal analysis that determined either the cost-effectiveness of exclusion arteriography or the cost-effectiveness ratio has been reported in the literature. We created a decision model that compared exclusion arteriography and surgical exploration, the standard used prior to the development of extremity arteriography. The decision model used predominantly literature derived estimates for the prevalence of arterial injuries and the accuracy, complications, outcomes and costs of both arteriography and exploration. Exclusion arteriography is cost-effective. This finding is robust to changes in the major model variables. Compared to surgical exploration, exclusion arteriography is a superior strategy by dominance (more effective and costs less). Therefore, a cost-effectiveness ratio cannot be calculated. Under the base case assumption of 28% prevalence of arterial injury requiring operation, exclusion arteriography saves about $2000 and adds 0.3 quality adjusted life years (QALY) for each patient. Decision analysis can be successfully applied to problems in vascular trauma diagnosis.

This paper describes vascular ultrasound surveillance after endovascular intervention for occlusive iliac artery disease. There were 105 patients who had 198 procedures in 155 limbs, consisting of 110 balloon dilatations and 88 stentings. The patients were referred to the vascular diagnostic service by several surgeons. All procedures had been considered to be initially technically successful. Colour-Doppler duplex ultrasound studies were performed shortly before and at serial intervals after operation to determine patency rates. Univariate life table analysis showed 69% primary and 96% assisted primary patency at four years. Primary patency rates at four years were significantly worse for stentings (60%) compared to balloon dilatations (71%) (P<0.05). Maximum peak systolic velocities (PSV) were recorded from the treated arteries. Receiver operating characteristics curves showed that PSV >300 cm/s was most accurate for predicting technical failure. Haemodynamic success rates at four years were 72% for PSV >300 cm/s. Results for procedures that were initially successful indicate that long-term primary patency rates for iliac endovascular intervention are acceptable and that assisted primary patency rates are excellent.

Carotid endarterectomy with patch angioplasty is a durable procedure for prevention of recurrent neurological symptoms and stroke. However, no definitive study has demonstrated a clear benefit of one class of the patch material over another. The aim of this study was to evaluate the clinical outcome of carotid endarterectomy with bovine pericardium patch in comparison with autologous vein patch. One hundred and twenty-two carotid endarterectomies were performed using patch closure of the arteriotomy with bovine pericardium (61 cases) and autologous vein (61 cases) between September 1995 and June 1999. Though this is not a double-blind type randomized comparative study, effort was made to achieve a 1:1 ratio in sequence with a few exceptions such as non-available veins at time of surgery or for future use. In bovine pericardium patch closure group, the mean total operating time was significantly shorter than autologous vein closure group (P<0.01), but the mean carotid clamping time was similar in both groups, regardless of the use of shunt. The incidence of postoperative local complications including groin wound was less in bovine pericardium patch closure group. The patients were followed with duplex scans in one month post-CEA and 6 months interval thereafter. During the follow-up period, three patients developed non-critical stenosis (two in bovine and one in vein patch), and one aneurysmal dilation occurred in vein patch group. The incidence of restenosis was similar in both groups. Although this is a preliminary report, it is concluded that the results of carotid angioplasty using bovine pericardium compare favorably with autologous vein.

Reports on phenindione toxicity have limited its use as an oral anticoagulant. Our aim was to evaluate its risks in pregnant women. Thirty-one pregnancies in 29 women with mitral (±aortic) St. Jude mechanical valves were followed-up prospectively. Eighteen patients received phenindione. Eleven patients (37.9%) received in addition to phenindione 225 mg dipyridamole, which was given in three doses. The target INR was 2.5–3.5 in the former and 2–2.5 in the latter treatment. A fortnight before delivery, intravenous heparinotherapy was substituted. There were no maternal complications, apart from a single postpartum hemorrhage (3.2%). After the deliveries the results were: 26 mature babies (83.9%). 3 premature babies (9.7%) and 2 cases of stillbirth (6.4%). Outcome was dose related; being 57.2±20.9 mg/day for mature babies and 82.5±11.2 mg/day for prematures and stillbirths (P=0.016). Phenindione provided safe and effective anticoagulation during pregnancy. A larger study is necessary to confirm the relationship between the dosage and outcome.

We have recently shown that continuous coronary perfusion with warm blood enriched with the ultra-short acting ß-blocker Esmolol (ES) improves functional and structural myocardial protection during coronary artery surgery as compared with conventional cardioplegia (CP). The purpose of the present study was to compare both myocardial protection techniques in terms of patient outcome. We retrospectively analyzed the charts of 150 consecutive patients subjected to coronary artery surgery using the ES-technique; 150 patients matched for age, gender, preoperative left ventricular function, history of renal failure, and history of neurological symptoms undergoing surgery with conventional CP during the same time period served as control group. There were no significant differences between both groups with respect to perioperative myocardial infarction rate, need for positive inotropic medication, need for mechanical circulatory support, duration of mechanical ventilation, duration of intensive care unit stay, time of mobilization, postoperative renal failure, cardiac arrhythmias, neurological symptoms, infections or in-hospital mortality. ES-patients were less frequently readmitted to the intensive care unit (ES: 3/150; 2.2% [95% confidence interval: 0–4.2%] vs CP: 13/150; 8.7% [4.2–13.2%]; P= 0.010) and total hospital stay was shorter (ES: 12.3±14.8 days [95% CI: 11.5–13.0] vs CP: 13.5±3.8 [12.9–14.1] days; P= 0.0013), thus saving 159 patient days on the normal ward. Procedural costs were less for the ES-technique (US$ 60 per patient) as compared to the cardioplegia technique (US$ 120 per patient). These data suggest that myocardial protection using the ES-technique does not improve clinical outcome in patients subjected to routine coronary artery surgery, but may save costs.

Preoperative profiles, postoperative complications, and the early and late results in 32 patients 80 yrs of age and older (elderly group) who underwent coronary artery bypass grafting were compared with those in patients under 80 yrs of age (control group). In the elderly group, the prevalence of patients with preoperative creatinine clearance (Ccr.) <50 1/day (34.4%), unstable angina pectoris (78.1%) and left main trunk disease (40.1%) was significantly higher than those in the control group. The incidences of arrhythmia and intensive care unit(ICU) syndrome were also significantly higher in the elderly group than in the control group, however, there was no death due to these complications. In the elderly group, one patient (3.1%) died in the hospital due to low cardiac output syndrome (LOS), while three patients (2.4%) of the control group died in the hospital. As for the long-term results, the 5-yr survival rates for the elderly group and the control group were 82.6% and 85.2%, respectively, and the effectiveness of surgery was remarkable, with improved postoperative activity in 96.9% of the elderly group. These findings indicate that although the elderly patients have higher risks by undergoing surgery and have a disadvantage in the rate of postoperative complications, the postoperative improvement in activity and survival rate can be similar to those in the younger patients.

Neovascularisation is a prominent feature of long-term aortocoronary saphenous vein bypass grafts but mechanisms involved in the formation of neovessels have not been previously studied. Vascular Endothelial Growth Factor (VEGF) is an important angiogenic factor that induces migration and proliferation of endothelial cells, enhances permeability and modulates thrombogenecity. This study investigated the expression of VEGF in aortocoronary saphenous vein bypass grafts. Aortocoronary saphenous vein bypass grafts with angiographic luminal stenosis of >75% were explanted from 14 patients at redo coronary artery bypass grafting. The grafts demonstrated two distinct forms of graft occlusion: four out of the 14 graft occlusions (29%) resulted from severe hyperplastic transformation of the intima complicated by thrombi attached to the degenerating liminal endothelium; the remaining graft occlusions (71%) were due to the development of atherosclerotic lesions associated with mural thrombosis. Hiperplastically altered intimal segments were practically free of neovascularisation while atherosclerotic-like lesions contained neovessels irregularly distributed throughout. Intimal neovessels were located exclusively in microzones enriched with VEGF-expressing cells and, furthermore, neovascular endothelial cells themselves also displayed VEGF immunopositivity. Double-immunostaining revealed that in areas of neovascularisation, the vast majority macrophages (CD68+) expressed VEGF. Some CD68+ foam cells that surrounded branches of neovascularisation were also VEGF-positive. These findings suggest that VEGF expressed by neovascular endothelial cells and by macrophages may act as a local regulator of endothelial cells functions and may induce intimal neovascularisation in aortocoronary saphenous vein bypass grafts affected by atherosclerosis.

Anastomotic quality of coronary artery bypass grafting is directly associated with peri-operative and long-term clinical results. In this study, we investigated a cut-off value for intra-operative flow measurement. This value could be of use to a surgeon in determining the anastomotic quality of grafts. Intra-operative transit-time flow variables (mean flow, pulsatility index, % efficiency, fast Fourier transformation (FFT) of the flow curve) and the 2-week post-operative angiographic findings were examined in 66 coronary artery bypass grafts, including 33 internal thoracic arteries. There were significant differences between patent and non patent grafts in all of the intra-operative flow parameters. Only the FFT ratio, the ratio of powers of the fundamental frequency and its first harmonic, could be utilized as a cut-off value to distinguish patent from non patent grafts. All stenotic or occluded grafts showed an intra-operative FFT ratio of <1.0, while all patent grafts yielded a ratio of >1.0. Based upon these results, we concluded that power spectral analysis of flow measurement might be useful for intra-operative differential diagnosis of the anastomotic quality in coronary artery bypass grafting.

Hypertension is a known risk factor in heart disease. It can lead to pressure overload and hypertrophy of the left ventricle. The aim of this study is to examine the effect of hypertension on the operative and early postoperative outcome after aortic valve surgery using the retrograde cardioplegia.

All the data of all the patients who had aortic valve surgery in our department were retrospectively examined during the period from January 1994 until April 1996 and received retrograde blood cardioplegia. 397 patients were included in this study. 213 of them had arterial hypertension, as preoperatively diagnosed by the referring cardiologist. There were 163 females and 234 males. 142 were above 70 yr of age. 22 patients had an ejection fraction (EF) ≤0.4 and in 168 patients the LVEDP was >15 mmHg. Hypertension alone proved to be no risk factor. Decreased EF in hypertensive patients leads to an increase in the occurrence of prolonged ICU-stay, low cardiac output and neurological complications. Hypertension alone does not increase the risk of operative and early postoperative aortic valve surgery.

Patients requiring urgent surgical revascularization due to unstable coronary artery disease are usually pretreated with multiple antithrombotic drugs. The perioperative risks of this type of treatment were investigated in 123 patients who underwent emergency coronary artery bypass grafting (CABG) at our institution.

Eighty-two patients (group A) received heparin and acetylsalicylic acid solely and 41 patients (group B) received additionally ADP-receptor antagonists (82.9%), glycoprotein IIb/IIIa inhibitors (12.2%) or thrombolysis (14.6%) preoperatively. Both groups were similar regarding demographic data and overall clinical status. Preoperative coagulation parameters and intraoperative characteristics were comparable. Blood loss via chest tubes was not significantly different between groups. Transfusion of red blood cells and fresh frozen plasma were slightly, but not significantly increased in group B. Transfusion of pooled platelets was low in general and similar in both groups. Re-exploration rate, medium intensive care unit and hospital stay as well as perioperative mortality were comparable.

Excessive antithrombotic pretreatment seems to bear no additional risk in emergency CABG and may be beneficial in this setting.