Morphology and function of preserved microvascular arterial grafts: an experimental study in rats

The aim of this study is to examine the morphology and function and small-caliber, arterial grafts after preservation in the University of Wisconsin solution (UW). Rat carotid arteries were stored in UW (n = 10) or in phosphate-buffered saline (PBS) (n = 10) for 1, 3, 7, and 14 days and were examined with light microscopy (LM) and scanning electron microscopy (SEM). Rat aortic preparations were stored in UW or PBS for 1 hour, 24 hours, 72 hours, 7 days, and 14 days and assessed for functional responses (stimulated contraction and endothelium-dependent relaxation). Segments (5 mm) of rat carotid arteries were stored in UW or PBS for 3 days, 7 days, and 14 days and orthotopically implanted as autografts and allografts. No immunosuppressive or anticoagulant agents were used. After 28 days of implantation, the grafts were assessed for patency and excised for LM and SEM. In UW, the endothelial layer remained intact up to 9 days of storage. In PBS, the endothelial layer showed deterioration after 1 day and was completely lost after 3 days. Functional responses were demonstrated to exist for as long as 7 days storage in UW. In PBS, no responses could be evoked after 24 hours storage. Autografts preserved in UW for 3 days (n = 6), 7 days (n = 6), and 14 days (n = 6) showed patency rates of 83.3%, 66.6%, and 66.6%, respectively, whereas patency rates of allografts were 66.6%, 33.3%, and 33.3%, respectively. Autografts stored in PBS for 3 days (n = 6), 7 days (n = 6), and 14 days (n = 6) showed patency rates of 33.3%, 33.3%, and 50%, respectively, whereas patency rates of allografts were 16.7%, 0%, and 33.3%, respectively. The UW preserved autografts showed normal morphology. All other groups showed vessel wall degeneration which in the allograft groups, were accompanied by lymphocellular infiltration. In conclusion, the endothelial layer and vessel wall of arteries are adequately preserved in UW. Functional responses are retained up to 14 days storage in UW, but, are lost after 24 hours storage in PBS. Autograft implantation studies accordingly show good performance of arterial segments preserved in UW, whereas allografts are subject to degradation as a result of rejection.     

Extrathoracic bypass procedures for proximal common carotid artery lesions

During a 10-year period ending in December 1991, 31 extrathoracic bypass procedures were performed in 29 patients for proximal common carotid artery atherosclerotic stenosis or occlusion. This included 16 men and 13 women, with a mean age of 63 years. Indications for surgery included transient ischemic attacks in 23 patients (79%), nonfocal symptoms in 4 patients (14%), and asymptomatic proximal common carotid artery stenosis associated with near-total occlusion of the internal carotid artery in 2 patients (7%). Severe proximal stenosis or complete occlusion of the common carotid artery was demonstrated angiographically in all cases. Subclavian-to-carotid bypass was performed in 26 cases and carotid-to-carotid bypass in 5 cases. Seventy-four percent of the bypass procedures were to the common carotid artery and 26% to the external carotid artery. Endarterectomy of the common carotid bifurcation was performed in conjunction with the bypass procedure in 13 cases and vertebral artery transposition in 2 other cases. Saphenous vein was used as the bypass conduit in 65% and prosthetic grafts in 35% of cases. There were no perioperative strokes or deaths in this series, and the mean postoperative hospital stay was 5 days. Follow-up ranged from 2 to 118 months (mean: 38.4 months). Graft occlusion occurred in two cases during the follow-up period (3-year patency rate: 90%), with recurrence of symptoms in one patient, which necessitated revision. Three patients had persistence or recurrence of symptoms despite patency of the graft, one other patient sustained a posterior circulation infarct, and there was one death unrelated to carotid vascular disease during the follow-up period. This experience shows that extrathoracic bypass procedures are safe and well tolerated for symptomatic proximal common carotid artery stenosis or occlusion. This method of reconstruction has excellent long-term patency and protection against further anterior circulation neurologic events.     

Vascular anastomosis using a biodegradable device with a heat-shrinking sleeve: a preliminary report

PURPOSE: The objective of this study is to present a simple mechanical anastomosis system capable of uniting vessels of differing diameters and to evaluate its applicability. MATERIALS AND METHODS: A new mechanical system for anastomosis of small vessels was used in 30 rabbits to join 100 sectioned carotid arteries and jugular veins. The system is resorbable and consists of a cuff and a shrinkable sleeve. To carry out the anastomosis, one vessel end is pulled through the cuff and everted over it. The second vessel end is then slipped over the everted vessel end and the cuff. A heat-shrinking sleeve is positioned over the site and shrunk to produce permanent fixation. RESULTS: The overall patency rate of the anastomoses was 96.6% in the arteries and 93.3% in veins. Microscopically, the intima-to-intima contact sites were bridged by an endothelial layer in the first postoperative weeks. CONCLUSION: Advantages of the system include a short insertion time, simple instrumentation, a high patency rate, and resorbability. However, the method requires additional vessel length for eversion, and it cannot be used for end-to-side anastomoses.     

Improved adherence of genetically modified endothelial cells to small-diameter expanded polytetrafluoroethylene grafts in a canine model

PURPOSE: A significant limitation to using genetically modified endothelial cells (ECs) to seed prosthetic grafts before implantation has been poor cell adherence to the graft lumen. Methodologic changes to improve cell adherence were evaluated in a canine carotid interposition graft model using 4 mm interior diameter expanded polytetrafluoroethylene. METHODS: ECs harvested from external jugular veins were grown in culture, with 80% of the cells from each culture transduced by incubation with an LXSN-type retroviral vector carrying a gene for human prourokinase and a neomycin resistance gene for selection in antibiotic G418. Control grafts had passive luminal coating with fibronectin and were seeded with transduced ECs immediately after G418 selection; these grafts were incubated for 2 days before implantation. Experimental grafts had fibronectin forcefully squeezed through the interstices and were seeded with ECs that had recovered in culture for 5 days after G418 selection; these grafts were incubated for 4 days before implantation. For each control (n = 9) and experimental (n = 12) graft, a graft prepared in the same fashion but seeded with the remaining autologous nontransduced cells was placed in the contralateral carotid artery. Grafts were explanted after 30 days and were evaluated for patency, thrombus-free surface area, and cell-free surface area. RESULTS: No significant differences in patency rates were seen between any groups. The thrombus-free surface area was improved for experimental grafts (90%) compared with control grafts (76%), but this improvement did not achieve statistical significance. The cell-free surface area for transduced cells on experimental grafts was 65% compared with 96% for control grafts (p = 0.021) and was comparable with that for nontransduced cells on both control grafts (62%) and experimental grafts (51%; p = 0.201). CONCLUSIONS: Adherence of genetically modified endothelial cells to small-diameter expanded polytetrafluoroethylene grafts in an in vivo physiologic flow model is significantly improved when cells have a more prolonged recovery from G418 selection, when the graft lumen is more uniformly coated with fibronectin before EC seeding, and when seeded grafts are left longer in culture before implantation to develop cell lining stability. The short-term patency rate of these seeded grafts is not affected by increased cell retention; long-term graft patency data and luminal healing require further evaluation.     

Surgical treatment of atherosclerotic lesions of subclavian artery: carotid-subclavian bypass versus subclavian-carotid transposition

BACKGROUND: The aim of this retrospective study is to analyze the short and long term results of two different surgical treatments in patients with subclavian lesions: common carotid-subclavian artery bypass (CSB) versus transposition of subclavian artery on the common carotid artery (SCT). METHODS: From 1981 until 1995, 40 non randomized patients with symptomatic subclavian steal underwent 20 CSBs and 20 SCTs. Risk factor rates were equally balanced in the two groups. Surgery was carried out routinely under general anesthesia, with electroencephalic continuous monitoring. Patency of revascularization was assessed by physical examination, brachial blood pressure determinations, ultrasound sonography and angiography whenever recurrence of symptoms developed or when the function of repair was in doubt. Patients were examined every year. In Spring 1996 (range 9-189 mos, average 7 years) a general clinical-instrumental follow-up was performed. RESULTS: In the short term (<30 days) mortality was 5%: one death (5%) for pulmonary embolism in a patient with CSB and one for myocardial infarction in a patient with SCT. The early thrombosis rate was 5% (1 CSB and 1 common carotid artery distal to a patent SCT). During follow-up 10 patients (25%) died and 6 were lost. The six-year actuarial patency rate was 100% for SCT and 66% for CSB. Moreover there were 3 thromboses of the vertebral artery homolateral to patent CSBs. CONCLUSIONS: In conclusions SCT should be considered the surgical technical choice for the treatment of proximal subclavian artery lesions.     

Importance of eliminating portal flow to produce large intrahepatic lesions with interstitial laser coagulation

The objective of this study was to determine the incidence of internal jugular vein thrombosis in patients undergoing free flap reconstruction and simultaneous neck dissection. Patients underwent Doppler ultrasound examination of their internal jugular veins on postoperative days 1 and 7 after functional neck dissection and free flap transfer. Long-term follow up was obtained at a minimum of 3 months. The incidence of internal jugular vein thrombosis in patients undergoing free flap reconstruction with simultaneous neck dissection is similar to that of patients undergoing just neck dissection. A significant number of these veins recanalize and have excellent long term patency. There does not seem to be a correlation between venous thrombosis and free flap survival.     

The investigation of chronic constipation for surgical management

Organic solvents, such as ethanol or dimethyl sulphoxide (DMSO), have been used in liquid embolic agents. To investigate the effects of these solvents on the cerebral blood vessels and cerebral tissue, we subjected Wistar rats weighing 250-300 g to internal carotid artery infusion of 0.2 ml diluted ethanol (10%, 40% or 70%) or anhydrous DMSO (100%). Some rats were sacrificed 5 min after the infusion and the remainder at 10 days. Rats injected with ethanol at high concentration or DMSO showed extensive exudation of Evans blue at the site of injection 5 min after infusion, together with full-thickness necrosis of the wall of vessels and swelling of brain cells. In contrast, rats injected with 10% or 40% ethanol solution showed necrosis of only the intimal layer and partial necrosis of the medial layer and no brain swelling was observed. These findings suggest that ethanol at low concentration can be used as a relatively safe solvent for liquid embolic substances.     

Usefulness of ultrasonographic techniques in catheterization of the internal jugular vein in patients with chronic heart failure

BACKGROUND: The right internal jugular vein as a route for right heart catheterization and continuous infusion of drugs is increasingly used in patients with heart failure. Although this approach has several advantages, a small but definite number of unsuccessful vein punctures and/or of complications have been reported. This prospective study was designed to evaluate the usefulness of ultrasound techniques for cannulating internal jugular vein in a series of 310 consecutive patients with chronic heart failure. METHODS: In all patients a duplex scanning of internal jugular veins was performed before the cannulation. A subgroup of 62 patients was selected for having a "difficult" cannulation according to the following criteria: previous failure of cannulating the vein (3 unsuccessful needle advances); neck abnormalities; severe emphysema and respiratory insufficiency. In these patients a Doppler-guidance system, which consisted of a miniature ultrasound Doppler transducer inserted in a standard 19 gauge needle, was used. The needle was advanced under the skin following the maximal audio signal of the venous flow. The following variables were considered: success rate, number of needle advances to cannulate the vein, time elapsed from local anesthesia and the insertion of the catheter, minor and major complications. RESULTS: Duplex scanning showed that in 14 patients (4.5%) the right internal jugular vein was occluded or severely narrowed. In all patients the left internal jugular vein, which showed a compensatory dilatation, was successfully cannulated. In 294 of the remaining 296 patients the position of the vein was anterior to the carotid artery at a depth of 4-27 mm below the skin. With respect of the triangle formed by the two heads of the sternocleidomastoid muscle, the vein was central in 35%, medial in 15% and lateral in 60% of cases. Based on duplex scanning ultrasound data, 285 patients underwent internal jugular vein cannulation, which was achieved at the first attempt in 74% and within 3 attempts in 87% of cases. Minor and major complications occurred in 4 (1.4%) and in 1 (0.3%) respectively. By the Doppler guidance system, the cannulation was successfully achieved in 79% of patients at the first attempt and in 98% of patients (61/62) within 3 attempts. In one patient an uneventful puncture of the carotid artery occurred. The time to perform the cannulation was not significantly different using the two approaches (conventional approach: 4.4 +/- 3 minutes; Doppler guidance system: 4.2 +/- 2). Overall the internal jugular vein was successfully cannulated in 307/310 patients (99%). CONCLUSIONS: Ultrasound techniques provide useful information which facilitates the cannulation of the internal jugular vein in patients with heart failure. The Doppler guidance method allows a rapid and safe cannulation of the vein even in cases that are difficult using the conventional approach.     

Differences in the erythrocyte aggregation level between veins and arteries of normolipidemic and hyperlipidemic individuals

The objectives of this study were to detect differences in the Doppler power backscattered by blood in vivo, and to identify factors affecting the backscattered power. The main hypothesis was that variations in the erythrocyte aggregation level between veins and arteries of normolipidemic and hyperlipidemic individuals can be detected with power Doppler ultrasound. Doppler measurements were performed at 5 MHz, with an Acuson 128 XP/10 system, over the carotid artery and jugular vein, external iliac artery and vein, common femoral artery and vein and popliteal artery and vein. Doppler signals were recorded at the center of each vessel to optimize the detection of erythrocyte aggregation, and processed off-line to obtain the backscattered power. The power of each recording was compensated for Doppler gain differences, tissue attenuation with depth and transmitted power variations occurring with pulse-repetition interval modifications. Results showed statistically stronger backscattered power in veins compared to arteries for the iliac, femoral and popliteal sites. In comparison with healthy subjects, stronger powers were observed in hyperlipidemic patients for the femoral and popliteal sites. Power differences were also found between peripheral measurements. On the other hand, no difference was observed between the power measured in the carotid artery and jugular vein for both groups of individuals. Multiple linear regression analyses were performed to identify factors affecting the backscattered power. Results showed a correlation (r) of 71.2% between the Doppler power in the femoral vein and the linear combination of two parameters: an erythrocyte aggregation index S10 measured with a laser scattering method, and the diameter of the vessel measured on B-mode images. Statistically significant linear correlation levels were also found between S10 and the Doppler power in various vessels. In conclusion, this study showed that power Doppler differences exist in vivo in large vessels between veins and arteries of normolipidemic and hyperlipidemic individuals. The Doppler power variations were also shown to be related to erythrocyte aggregation.     

Bacteria-specific lymphocyte proliferation in peripheral blood in reactive arthritis and related diseases

The inferior epigastric artery has been proposed as a suitable conduit for myocardial revascularization but its mid-term patency rate has not been assessed. A prospective clinical and angiographic study on the use of the inferior epigastric artery as an additional arterial conduit together with bilateral internal thoracic artery grafting was conducted in 38 patients. No deaths or major postoperative complications occurred. Twenty-three patients underwent repeat angiography after an average of 21.2 months. The left and right internal thoracic artery grafts patency rate was 95.6% (44/46), while inferior epigastric artery patency rate was 52.2% (12/23). By relating patency to the grafted coronary branch, the following results were obtained: 100% for the left anterior descending (3/3), right coronary (1/1) and ramus medianus (1/1); 40% (4/10) and 37.5% (3/8) for diagonals and obtuse marginals respectively. The low patency rates observed when the inferior epigastric artery is used on diagonals and obtuse marginals indicate that this vessel cannot be considered a suitable conduit for extensive application of arterial revascularization. We suggest that the inferior epigastric artery should only be used in patients presenting with contraindications to bilateral internal thoracic artery or right gastroepiploic artery grafting, or exhibiting unsuitable saphenous veins.     

Antiplatelet effect of FK633, a platelet glycoprotein IIb/IIIa antagonist, on thrombus formation and vascular patency after thrombolysis in the injured hamster carotid artery

The antithrombotic and restenosis-preventing effects of FK633, an inhibitor of platelet aggregation via binding to the glycoprotein (GP) IIb/IIIa receptor, were studied, IC50 value of FK633 against platelet aggregation ex vivo induced by 2.5 microM adenosine diphosphate (ADP) was 5.4 x 10(-7) M as determined using hamster platelet rich plasma. The inhibitory effect was also investigated in vivo on thrombus formation at the carotid arterial wall injured by a modified catheter. As a control, the left carotid artery was injured and the time required to develop a thrombotic occlusion (3.9 +/- 1.1 min, mean +/- S.E.M., n = 18) was determined. Then, the right carotid artery of the same animal was injured while a continuous intravenous (i.v.) infusion of FK633 was administered at doses of 0 (saline), 0.1, 0.3 or 1.0 mg/kg/h. The time to occlusion was dose-dependently prolonged. In a separate experiment, 10% of the total tPA dose (0.52 mg/kg) was injected into the injured artery as a bolus and the remaining was infused i.v. at a constant rate for 30 min. When FK633 (0.3 or 1.0 mg/kg/h) was infused together with tPA, late patency of the reperfused artery was much improved as compared with that of treatment with tPA alone. Bleeding time, measured at the end of the tPA infusion, was markedly prolonged when the higher dose of FK633 (1.0 mg/kg/h) was coadministered, however coadministration of the lower dose of FK633 (0.3 mg/kg/h) was almost without prolongation on the bleeding time, despite a significant effect on the vascular patency after thrombolysis. Next, neointima formation was evaluated 2 weeks after the vascular injury. When FK633 (0.3 mg/kg/h) was continuously infused i.v. by an implanted osmotic pump for 3, 7 or 14 days after the vascular injury, the neointimal area formation was significantly suppressed in the treatment groups for 7 or 14 days. These findings suggest that FK633 inhibits platelet activation in the injured artery and improves vascular patency after thrombolysis with tPA with a concomitant suppression of neointima formation.     

Schistocytosis and a thrombotic microangiopathy-like syndrome in hospitalized HIV-infected patients

Surgical repair of extremity venous injuries remains controversial. Literature supports both ligation and repair when analyzed for functional recovery. However, few studies review the natural history of venous repair for trauma. Twenty patients were prospectively enrolled in a protocol of immediate repair of major extremity veins. Simple venorraphy and complex reconstructions were performed at the discretion of the operative team. Patients were studied by contrast venogram on postoperative day 3 and 6 weeks after surgery. Patients with occluded repairs at 3 days received a 5-day course of intravenous anticoagulation and were discharged. Overall, patency at 3 days was 55 per cent and increased to 88 per cent at 6 weeks (P < 0.02). Lateral venorraphy and direct reapproximation had higher patency rates than complex repairs at 6 weeks (92% versus 50%; P < 0.05). All veins that were patent at 3 days remained patent (correlation coefficient 1.0). Repair of traumatized extremity veins carries minimal morbidity and has a high rate of early and eventual patency. Long-term anticoagulation in the face of early thrombosis is unnecessary.     

Mid-term results in coronary revascularization using the right gastroepiploic artery graft

We studied the mid-term results in 191 patients (including emergent operation in 27 patients) who have performed coronary artery bypass grafting (CABG) using the right gastroepiploic artery (REGA) for 74 months (mean follow up period was 37 months). We evaluated the postoperative results in terms of 1. mortality and survival rate, 2. graft angiography, 3. cardiac event free rate and 4. abdominal complications. We had operative death in 6 patients (3.1%) including 3 patients of emergent operations. Late deaths were found in 11 patients (5.9%): 2 patients were cardiac death and 9 were non-cardiac. The actual survival rates were 94.2% at one year, 90.0% at three years and 85.9% at five years. Early patency rate of the RGEA was 98.9% (n = 178). However flow competition between the RGEA and native coronary artery was seen in 42 patients (24.0%). Mid-term patency rate was 96.4% (n = 28). According to mid-term graft angiography, 1 patient improved and 5 patients got worse in comparison with early control. Cardiac event free rates were 98.2% at 1 year, 94.8% at 3 years and 92.7% at 5 years. Abdominal complications were observed in 5 patients (1 patient of bleeding from the RGEA, 1 of gastric perforation, 2 of bleeding from gastric ulcer and 1 of pyloric stenosis) at early period and in 7 patients (2 patients of incisional hernia and 5 of gastric cancer) at long-term period. Early and mid-term results of CABG using the RGEA were quite good. However, the RGEA had a tendency of flow competition against native coronary artery and a problem of gastric cancer after the operation.     

Carotid-subclavian bypasses (1985-1996)

A carotic-subclavian bypass is an extraanatomical reconstruction. It is one of the possibilities how to connect the ipsilateral common carotid and subclavian artery. The authors evaluate carotic-subclavian bypasses made during the past 11 years at the Second Surgical Clinic in Brno. In all twelve cases carotico-subclavian bypasses were involved, in none of the patients a subclavian-carotid bypass was involved or direct anastomosis. The author discusses in detail preoperative complaints, associated diseases, postoperative complaints. In his opinion absolute indications for surgery are neurological symptomatic affections even of one trunk, incl. subclavian steal syndrome. They indicate asymptomatic affections for surgery if at least two trunks are affected. The greatest pitfall of the operation is in their opinion the selection of the length and type of vascular prosthesis. They find that the interval patency rate 100% and the cumulative patency rate 85% evaluated by the method of "Life table analysis" with a standard error of patency rate of 9% are comparable with similar reports from abroad.     

Study of microvascular polyester prosthesis in rat carotid arteries

The implantation of a microvascular polyester prosthesis (MPP) (internal diameter 1 mm, length 10 mm) in the carotid arteries was studied in 48 Sprague-Dawley rats. The left carotid artery was resected to 7 mm in length and replaced with MPP by means of sleeve anastomoses. Postoperatively the patency was monitored with Doppler ultrasound at 24 and 72 hr, and at 1, 2, 3, 4, 8, and 12 weeks and was confirmed either by direct inspection intraoperatively or by angiography at the time of removal. At each monitoring time, all the thrombosed and some selected patent grafts were removed and prepared for scanning electron microscopy (SEM) study. The early patency rate was 100% within 24 hr, and the cumulative long-term patency rate was 77.1% at 12 weeks. Rapid and complete endothelial lining (EL) restoration was demonstrated 3 weeks after operation, which provided a smooth and nonthrombogenic surface, and contributed to the long-term patency. Ten of the 11 failed grafts occurred within 3 weeks, that is, before EL, due to thrombosis. These observations indicate that MPP can be successfully used as arterial conduits in rats, and an enhanced patency rate may be expected with the use of anticoagulants or endothelial cell seeding for prevention of early thrombosis.     

Xenogeneic iso-skin graft and mixed lymphocyte reaction studies using HLA-DP transgenic mice

With increased use of catheter intervention, candidates for coronary artery bypass grafting (CABG) have become more severely diseased. In the past 4 years with normothermic cardiopulmonary bypass technique, operative mortality was 1.5% (0.7% for elective and 5.6% for emergency) in 690 primary CABGs. The internal thoracic artery graft was used in 94% of the patients and the patency rate was 98%. The gastroepiploic artery was used in 565 patients since 1986 with 2.3% operative mortality and the patency rate was 96% in early and 92% in mid-term angiography. The inferior epigastric artery was used in 48 patients with 2% operative mortality and 90% patency rate. The radial artery was used in 105 patients with 0.9% operative mortality and patency rate was 88% at 1 postoperative year. Surgical result and angiographic patency of the graft are acceptably good while candidates of CABG have become more severely diseased. With use of arterial conduits, better long term outcome can be expected.     

Does multi-vessel disease of brain supplying arteries modify the procedure in carotid operations?

In a prospective evaluation 159 patients with carotid artery stenosis showed a multiple artery disease in 78 to 99% depending on the grade of cerebral artery insufficiency. Contralateral occlusion process could be detected in 15.7%, internal and common carotid artery occlusion in 16 patients (10%). 1595 patients picked out of the literature have been analyzed in respect of the natural history which showed a risk to develop a stroke in 4.5%/year. In further 1286 operated patients of other reports the morbidity and mortality rate ranged 4.5% and the risk of further neurologic events after operation was 2.4%/year. The use of an intraluminal shunt after thrombendarterectomy proved to be a good procedure to lower the morbidity and mortality rate without any intraoperative monitoring.     

Carotid and lower extremity arterial disease in patients with renal artery atherosclerosis

BACKGROUND: Atherosclerotic lesions of the carotid and lower extremity arteries may be associated with renal artery stenosis and influence the management of patients with renal artery disease. OBJECTIVE: To document the prevalence and clinical features of carotid and lower extremity arterial disease in patients with renal artery atherosclerosis. METHODS: An analysis of baseline data on 149 patients enrolled in a prospective natural history study of atherosclerotic renal artery stenosis. Patients with at least 1 abnormal renal artery by duplex scanning were eligible. Carotid artery disease was evaluated by duplex scanning, and ankle/brachial indices were used to assess the lower extremity arteries. Disease at each of the 3 arterial sites was classified as mild, moderate, or severe based on the extent of involvement on both sides. Serum urea nitrogen, creatinine, and lipid levels were also measured. RESULTS: Severe renal, carotid, or lower extremity arterial disease was present in 44%, 19%, and 21% of the patients, respectively. There was a trend for patients with increasing degrees of renal artery disease to have increasing degrees of carotid and lower extremity arterial disease. The prevalence of severe carotid artery disease increased from 7% in the mild renal artery group to 28% in the severe renal artery group. Clinical factors that were most predictive of severe disease were elevated apolipoprotein B levels for the renal arteries, high serum urea nitrogen or creatinine levels for the carotid arteries, and smoking for the lower extremity arteries. CONCLUSIONS: There was a strong association between severe renal artery atherosclerosis and severe carotid artery disease. Patients with renal artery disease also had a high prevalence of lower extremity arterial disease. In this patient population, screening for lower extremity arterial disease can be reserved for those with signs or symptoms of peripheral ischemia. Noninvasive carotid screening is justified in patients with renal artery disease to detect asymptomatic lesions that require either immediate surgical treatment or serial follow-up for disease progression.     

A review of 100 consecutive reconstructions of the distal vertebral artery for embolic and hemodynamic disease

PURPOSE: The aim of our study was to assess the outcome of distal vertebral artery (VA) reconstructions through a retrospective review conducted at a university-affiliated referral center. METHODS: One hundred consecutive distal VA reconstructions had been performed during a period of 14 years (98 patients) and included reversed saphenous vein bypass from the ipsilateral common, internal, or external carotid to the third portion of the VA at the C1-2 level (68 reconstructions) or the C0-1 level (4); transposition of the external carotid or its occipital branch to the VA (23); and transposition of the third portion of the VA onto the internal carotid artery (2). Other methods were used in 3 additional patients. Eighteen patients underwent concomitant carotid operations, and 1 patient underwent a concomitant subclavian transposition. Symptoms were present in 98% of patients and included vertebrobasilar ischemia (89%), vertebrobasilar plus hemispheric ischemia (7%), and hemispheric ischemia (2%). Two asymptomatic patients with bilateral carotid occlusions underwent operations to provide a single artery for cerebral perfusion (2%). Sixty-three lesions were atherosclerotic, 18 were dynamic bony compressions, and 14 were dissection, fibromuscular dysplasia, arteritis, or aneurysm. Five had miscellaneous anatomic indications. RESULTS: Stroke caused the four perioperative deaths that occurred. There was one occurrence of nonfatal hemispheric stroke. Routine postoperative arteriography identified 16 graft abnormalities; 11 patients underwent attempted revision. The introduction of the use of intraoperative angiography in 1990, halfway through the series, lowered the incidence of graft abnormalities from 28% to 4% and the incidence of perioperative death from 6% to 2%. Eighty-seven percent of patients had complete or significant resolution of symptoms. Follow-up ranged from 1 to 168 months (mean, 79 months). Ten patients were lost to follow-up. Twenty late deaths occurred; none were stroke related. Five reconstructions required late revision. The cumulative primary patency at 5 and 10 years was 75% +/- 6 and 70% +/- 7 (mean +/- SE), respectively; cumulative secondary patency was 84% +/- 5 and 80% +/- 6 at 5 and 10 years, respectively. Median survival was 107 months. CONCLUSIONS: Distal VA reconstruction provides excellent long-term patency and stroke protection. Intraoperative angiography is mandatory.     

Percutaneous transluminal angioplasty of iliac occlusions

Percutaneous transluminal angioplasty (PTA) has become an established treatment modality for iliac artery stenosis. PTA of iliac artery occlusions, however, remains a topic of controversy due to difficulties with mechanical recanalization, a lower patency rate and a higher complication rate than obtained after PTA of iliac artery stenosis. During a three year period, we performed 31 PTA's of iliac artery occlusions. The primary recanalization rate was 71% (22 occlusions). Stents were applied in 16 patients. The cumulated patency rates were 95% and 85% after one and six months respectively. There was one late reocclusion after two years. We found a tendency towards inferior patency in the longer occlusions (> or = 5cm). The complication rate was 10% due to three episodes of distal embolisation, all of which were successfully treated immediately with additional PTA and stenting. These results are in accordance with the results of international studies, and suggest that PTA is a useful alternative to surgical treatment of iliac artery occlusions, albeit long occlusions involving both the common and the external iliac artery should be excluded.