Alain Branchereau

Coxiella burnetii Infection of Aneurysms or Vascular Grafts: Report of Seven Cases and Review

The most frequent clinical presentation of chronic Q fever is endocarditis, although infections of aneurysms and vascular prostheses have also been described. We report seven new cases of Coxiella burnetii infection of aneurysms or vascular grafts. We also review the literature and compare our cases with the six previously reported cases. This study demonstrated the lack of specific symptoms associated with this disease. Moreover, prospectively, in an attempt to reevaluate the incidence of Q fever-associated vascular infection, we systematically searched for C. burnetii infections in 163 patients with aortic aneurysms or vascular grafts who underwent vascular surgery. Microbiological testing included standard culture, Q fever serology, cell culture, and polymerase chain reaction amplification of C. burnetii DNA from biopsy specimens of aneurysms or vascular grafts. A microorganism was isolated from 25 patients, including C. burnetii in two cases; both of these patients had serological titers consistent with chronic Q fever. Both patients had nonspecific clinical features, and thus their infections would have probably remained undiagnosed without our systematic testing. Therefore, since the incidence of C. burnetii vascular infection is probably underestimated, we suggest that C. burnetii serology be routinely carried out in cases of unexplained febrile illness, pain, or weight loss in patients with a history of underlying vascular disease.

Homocysteine induces synthesis of a serine elastase in arterial smooth muscle cells from multi-organ donors

OBJECTIVES In heart transplant recipients with diffuse coronary arteriopathy, we have previously demonstrated the prevalence of elevated homocysteinemia, also known as an independent risk factor for myocardial infarction and stroke. In hyperhomocysteinemic mini-pigs we also observed early detectable pathologic changes in the elastic laminae. We hypothesized that homocysteine causes premature breakdown in the arterial elastic fibers by activation of the elastolytic activities. METHODS We examined the effect of homocysteine on elastase-like production by smooth muscle cells from sub-inguinal arteries of multi-organ donors (23.4 +/- 3.4 yr, n = 8). The freshly isolated cells were incubated for 0-72 h with homocysteine (0-250 microM), in the presence or absence of specific protease inhibitors. RESULTS Homocysteine was devoid of a direct effect, but after 18 h incubation the elastase-like activities increased by 5-6-fold in the extracellular medium. The enzymes were characterized as serine proteases. Incubation of cells with a nucleic acid synthesis inhibitor (actinomycin D) or a protein synthesis inhibitor (cycloheximide) suppressed the enzyme induction. CONCLUSIONS This is the first report of serine protease induction by homocysteine in vascular smooth muscle cells. The process may require protein synthesis and account for the early alterations of the arterial elastic structures in heart transplant recipients, and in other hyperhomocysteinemic patients, as well.

Morphologic assessment of abdominal aortic aneurysms by spiral computed tomographic scanning

PURPOSE The aim of this study was to seek a relationship between the morphologic features of abdominal aortic aneurysms and the feasibility of endoaortic grafting. METHODS Between June 1995 and January 1996, 86 patients were prospectively studied with contrast-enhanced spiral computed tomographic scans, which provided 35 parameters concerning the aorta and iliac arteries. Four groups were established according to the diameter of abdominal aortic aneurysms: group A, 40 to 49 mm, 36 patients; group B, 50 to 59 mm, 26 patients; group C, 60 to 69 mm, 10 patients; and group D, greater than 70 mm, 14 patients. RESULTS There was a correlation between the diameter and length of the aneurysm (p < 0.0001) and between aneurysm diameter and length of the proximal neck (p < 0.001). Presence of a proximal neck or a distal neck was more frequent in groups A and B than in groups C and D (p < 0.01). The feasibility of endovascular grafting was estimated at between 50% and 61.6% and was higher in groups A and B than in groups C and D (p < 0.01). CONCLUSIONS This study has shown an inverse relationship between the diameter of the aneurysm and the length of the aortic neck (correlation coefficient, -0.3640, p < 0.001). The diameter of an aneurysm was the most useful of the 31 parameters measured in predicting the feasibility of endoaortic grafting, estimated at 71% for aneurysms less than 60 mm in diameter and 37.5% for aneurysms greater than 60 mm in diameter (p < 0.01).

Effects of cryopreservation on the viscoelastic properties of human arteries.

The purpose of this study was to use our newly developed mock circulation loop to determine the effects of cryopreservation on the common carotid artery (CCA) and the superficial femoral artery (SFA). Fourteen healthy arteries (7 CCA and 7 SFA) harvested from multiple organ donors between the ages of 18 and 35 years were tested before and after cryopreservation at −140° C using dimethyl sulfoxide and the vapor phase of liquid nitrogen. Mean storage time was 4.2 months. The mock pulse rate was 60 beats/min and the following four systolic/diastolic pressures settings were used: 50/110, 80/140, 110/170, and 140/200 mm Hg. Simultaneous measurements of intra-arterial pressure and external arterial diameter were made using an intra-arterial pressure sensor and external piezoelectric sensors. Measured data were used to calculate pulsatility, volumetric compliance, stiffness, midwall radial arterial stress, Youngs modulus, and the incremental modulus. After SFA cryopreservation, no significant changes were observed. Conversely, CCA cryopreservation led to a significant decrease in compliance and pulsatility and a significant increase in stiffness. Youngs modulus, the incremental modulus, and midwall radial arterial stress did not change significantly. A clearcut decrease in hysteresis was observed after cryopreservation in the CCA. No evidence of structural changes was detected on light and scanning electron microscopy. Baseline findings in this study were consistent with classification of the CCA as an elastic artery and the SFA as a muscular artery. Cryopreservation had no effect on the viscoelastic properties of muscular arteries (SFA). Cryopreservation affected only values related to the cylindrical shape of the elastic arteries (CCA). It had no effect on values related to wall structure.

Politeal artery entrapment syndrome

We report 15 examples of popliteal artery entrapment syndrome observed in 11 patients. The anatomical causes were as follows: in one case, the popliteal artery presented an aberrant course medially to the medial head of the gastrocnemius muscle. In 5 cases, there was a small fibrous band linking the medial head of the gastrocnemius muscle to the lateral condyle and crossing behind the popliteal artery; in 5 cases this anomaly was also found in association with an abnormally high and/or internal insertion of the medial head of gastrocnemius muscle. In the last 4 cases, there was a muscular insertion anomaly associated with muscular hypertrophy causing arterial compression. Arteriography performed in the 11 patients showed evocative signs of the diagnosis in all cases where the artery was patent. Two popliteal arteries were occluded. CT scan and MRI examination of the popliteal fossa enabled us to define the muscular origin of the popliteal compression. All of the patients were operated upon; two received a reversed saphenous bypass and all of the others were treated by liberation of the popliteal artery and/or vein by a posterior approach. Follow-up in all patients at long term showed good prognosis. All of the patients were able to take up their previous physical activities without sequelae. Our review of the literature, which is based on 374 cases of popliteal artery entrapment observed in 280 patients, made it possible to define the frequency of the various anomalies observed, their symptoms and the different therapeutic possibilities. The multiple anatomical classifications as well as the arterial and muscular embryology are also described.

Aorfix stent graft for abdominal aortic aneurysms reduces the risk of proximal type 1 endoleak in angulated necks : Bench-test study

Neck angulation (NA) is an important risk factor for type 1 proximal endoleaks following stenting of abdominal aortic aneurysms. The Aorfix (Lombard Medical, Oxon, UK) is a new flexible stent graft designed to overcome this issue. The aim of this study was to compare the endoleak flow rate (EFR) in relation to NA between the Aorfix and other manufactured stent grafts. A flow model with silicone proximal and distal necks was used. EFRs corresponding to 10 neck angles between 0 and 70° were measured. Eight stent grafts were tested: Aorfix, Ancure (Guidant, Indianapolis, IN), Powerlink (Endologix, Irvine, CA), AneuRx (Medtronic, Sunnyvale, CA), Excluder (W.L. Gore & Associates, Flagstaff, AZ), Zenith and Zenith-Flex (Cook Inc., Bloomington, IN), and Lifepath (Edwards Lifesciences, Irvine, CA). For all stent grafts except the Aorfix, the EFR was greater than at baseline for NA ≥ 30° (p < .01). The EFR at NA ≥ 30° was lower with the Aorfix compared with the other stent grafts (p < .01). NA had no influence on the EFR with the Aorfix. The Aorfix may decrease the incidence of proximal type 1 endoleak in patients with a severely angulated aortic neck.

Simultaneous Reconstruction of Infrarenal Abdominal Aorta and Renal Arteries

From 1980 to 1990, 48 (4.7%) of 1,002 patients underwent elective aortic reconstruction and simultaneous renal artery reconstruction. Forty-five men and three women (mean age: 66.5 years) had 59 renal artery lesions (51 stenoses, six occlusions, one dysplasia, and one aneurysm) associated with 20 infrarenal aortic aneurysms and 28 aortoiliac occlusive lesions. One nephrectomy and 58 renal artery reconstructions were performed (35 prosthetic bypasses, 11 vein bypasses, six direct reimplantations, five transaortic endarterectomies, and one resection of an intrahilar aneurysm followed by autotransplantation). Operation was always indicated for the aortic lesions. Indication for renal artery repair was hypertension in 33 cases (17 associated with renal insufficiency) and one with isolated renal insufficiency. In the remaining 14 cases, surgery was deemed preventive. One patient died (2%). There were 12 nonfatal complications two of which were kidney failures requiring chronic extrarenal epuration. Routine follow-up arteriograms showed four postoperative renal artery occlusions. Mean follow-up was 35.8 months. Four patients were lost to follow-up; 10 died secondarily. Five year survival was 72.1±19.1%. Secondary patency of renal artery reconstruction was 89.5±9.4% at five years. Late results were favorable in 45% of patients with hypertension and in 39% of patients with renal insufficiency. Mortality in simultaneous aortic and renal artery reconstruction is not superior to that of isolated infrarenal aortic surgery.

Open surgical reconstruction of the internal carotid artery aneurysm at the base of the skull

OBJECTIVES Aneurysms of the internal carotid artery (ICA) at the base of the skull are uncommon dangerous lesions whose management remains unclear. The aim of this retrospective study is to report a standardized surgical technique of ICA reconstruction with long-term results. METHODS Between 1988 and 2005, 13 patients (11 men; age 18 to 76 years, mean 42.6 years) underwent lateral skull base approach with cervical-to-petrous carotid artery bypass for repair of ICA aneurysms. Principal elements of the technique were: partial resection of the parotid gland without rerouting of the facial nerve; luxation of mandibula; drilling of the bone. RESULTS The 13 patients had unilateral aneurysm of the ICA at the base of the skull. Four aneurysms were of atherosclerotic origin; six fibromuscular dysplasia; two post-traumatic; one cause was undetermined. The mean diameter of the aneurysms was 12 mm (range, 7-21 mm). Twelve patients were symptomatic: six presented neurological events (four strokes, two transient ischemic attack [TIA]); two retinal events; three compressive symptoms (two Horners syndrome and one paralysis of the glossopharyngeal nerve); one patient presented a visible pulsatile mass in the neck. One patient was asymptomatic. There were no post-operative deaths, one TIA, 13 transient palsies of the lower facial nerve, and one transient palsy of accessory nerve. Palsy of cranial nerves was partial and disappeared within a mean of 5.6 months (range, 1-10 months). The postoperative angiogram showed patency in all but one case (one asymptomatic thrombosis). During follow-up (mean, 152 months), there was one unrelated death, one focal epileptic seizure, and one controlateral TIA. In November 2008, duplex showed patency of all 11 grafts (one death, one thrombosis). At 10 years, the survival, cumulative stroke-free survival, ipsilateral stroke-free, and patency rates was were 90.9%, 100%, 100%, and 92.3%. CONCLUSION Venous graft bypass from the cervical-to-petrous ICA can be performed safely with such an approach and produces durable satisfactory results.

The albumin-coated knitted dacron aortic prosthesis: A clinical study

Between June 1987 and January 1989, a total of 123 albumin-coated, knitted Dacron aortic prosthetic grafts were used in 120 patients. The aim of this study was to determine the degree of graft impermeability to blood as well as short - and medium-term patency of the graft material. Patients were grouped as follows: group I (64 patients), operation for chronic aortoiliac obliteration; group II (45 patients), operation for abdominal aortic aneurysm; group III (14 patients), operation on the thoracic aorta. Ninety-one bifurcated and 32 albumin-coated grafts were inserted. Abnormal bleeding was seen in five cases but did not lead to any adverse clinical consequences and stopped spontaneously. In group I there were two instances of early thromboses thought to be due to hemodynamic compromise, which were successfully treated surgically. In group III, two patients had early thrombosis due to coagulation disorders. These were treated by thrombectomy and medical therapy. One hundred and fourteen patients (95%) were followed for a mean of 8.2 months (range 1–18 months). Three late complications related to the prosthesis were observed: one patient had a false aneurysm occurring at month 14 and was corrected surgically. Two other patients experienced thrombosis of their graft treated by extraanatomical bypasses. Primary patency at the end of the follow-up period was 93% while secondary patency was 98%. There were no early or late infectious complications. We conclude that albumin-coated Dacron prosthesis is a reliable material for aortic replacement. Intraoperative loss of blood is reduced and short-and medium-term patency is comparable to those of uncoated aortic prosthetic material.

Use of descending thoracic aorta for lower limb revascularisation

From November 1984 to May 1991, descending thoracic aorta to femoral artery bypass was used to revascularise 51 lower limbs in 27 patients. There were 25 men and 2 women with a mean age of 60.2 years. There were four primary indications because of inability to use the abdominal aorta, and 23 secondary indications for late failure of a previous lower limb revascularisation: two aorto-prosthetic false aneurysms, nine infected aorto-bifemoral bypasses and 12 occluded grafts. Three deaths and one paraplegia occurred during the postoperative period, and three prosthetic occlusions and one popliteal embolism were successfully treated. During follow up (6-72 months) five deaths and three graft occlusions were observed; at 5 years, the cumulative life expectancy was 61.8 +/- 26.8%, and the cumulative secondary graft patency was 72.6 +/- 24.7%. One prosthetic infection and one ureteric fistula occurred and both were successfully treated. Thoracic aorta to femoral artery bypass is a simple extra-anatomic technique which can be used in cases of failure of a previous aorta to lower limb reconstruction. The haemodynamic results are good, and late results are better than axillo-femoral or bifemoral bypass.