Early and long-term results after reconstructive surgery in 42 children and two young adults with renovascular hypertension due to fibromuscular dysplasia and middle aortic syndrome.

OBJECTIVES: This retrospective study presents the early and late results of pediatric patients who underwent reconstructive surgery for renovascular hypertension (RVH) between 1979 and 2009. METHODS: From 1979 to 2009 44 patients (male 22; mean age 13±5.2 years, range 1-19 years; early childhood 7 [1-6 years], middle childhood 5 [7-10 years]; adolescents 32 [11-19 years]) with renovascular hypertension underwent surgery for abdominal aortic stenoses (n=6), renal artery stenosis (RAS) (n=25) or for combined lesions (n=13). Nineteen aortic stenoses (bypass/interposition 10/5, patch dilatation/thromboendarterectomy 2/2), 51 renal arteries (interposition 36, resection+reimplantation 13, patch dilatation/aneurysmorraphy 1 each), and 10 visceral arteries (resection+reimplantation 6, interposition 3, patch dilatation 1) were reconstructed. Each patient underwent duplex studies and if required intra-arterial digital subtraction angiography. Reoperations within 30 postoperative days were required in four (9%) of the patients for occlusion of four arteries (6%), achieving a combined technical success rate of 94%. RESULTS: After 114±81 months 36 patients were re-examined by duplex and magnetic resonance angiography (2 not surgery-related deaths 7/12 years postoperatively, 8 patients lived abroad). Twelve patients had required a second and three a third procedure. Hypertension was cured early/late postoperatively in 27%/56%, improved in 41%/44%, and remained unchanged in 32%/0%. Best late results were obtained in patients with isolated aortic disease and at the age of middle childhood. CONCLUSIONS: Reconstructive surgery for pediatric RVH yields good results at every age and every type of lesion. However, these children should be followed up closely and to avoid early cardiovascular disease and death in later life, surgery should not be delayed.

Renal artery revascularization after unsuccessful percutaneous therapy: a single centre experience.

PURPOSE: This retrospective review describes the long time effect of surgical revascularization after unsuccessful early or mid-term failure of percutaneous transluminal renal angioplasty (PTRA). METHODS: From January 1995 to January 2005, 60 out of 696 patients operated due to renal artery occlusive disease (17 fibromuscular dyplasia (FMD): mean age, 33.4 years; 43 atherosclerotic disease (ASD): mean age, 62.46 years) after unsuccessful PTRA underwent surgical revascularization for renal artery stenosis at our institution. The mean duration from failed PTRA to operation was 1.74 years. Out of the 68 renal arteries, 44 were pretreated with angioplasty alone (19, FMD; 25, ASD), and 24 were treated with PTRA and stent (all ASD). Operative management, response of renal function and hypertension as well as survival were compared to the literature. RESULTS: Fifty-nine per cent (n = 40) of the renal arteries were treated by transaortic thrombendarterectomy, 37% (n = 25) by bypass. Thirty-day and in-hospital mortality was 0% in all pretreated patients; after a mean of 4.16 years, it was 16.6% (only atherosclerotic). There was a significant decrease in systolic blood pressure values for all patients early after surgery as well as in follow-up. Creatinine remained stable in the patients with FMD, and there was an insignificant increase in creatinine level in the atherosclerotic patients. Hypertension was improved or healed in 32.5% of all pretreated patients, in cases with FMD in 54%, in atherosclerotic cases in 22.2%. Re-stenoses occurred in 26% of cases with FMD and in 18% of patients with atherosclerotic RAS. CONCLUSION: Surgical renal artery revascularization after failed PTRA is feasible and safe and systolic blood pressure can be lowered. The higher rate in re-stenoses in both the literature as well as in our own experience may be explained by the alterations in the renal artery after interventional treatment.

Successful surgical management of a recurrent leiomyosarcoma of the inferior vena cava.

The leiomyosarcoma of the inferior vena cava (IVC) is a rare malignant tumour of the venous system. The recurrence of the tumour after previous initial surgical resection is common and occurs in more than half of the patients. Surgical resection of a local recurrence is poorly described in the literature and the available data are restricted to a small number of cases. We report the case of a 62 year old woman, who was referred to our vascular surgical unit for recurrence of a leiomyosarcoma of the inferior vena cava, 35 months after diagnosis and initial surgical treatment. We performed an extensive local resection and circumferencial replacement of the IVC. 18 months after the second operation and adjuvant radiotherapy, the patient is in a very good physical condition and CT-scans show no evidence of tumour recurrence.

Surgical treatment for agenesis of the vena cava: a single-centre experience in 15 cases.

OBJECTIVE: Agenesis of the inferior vena cava (IVC) is a rare vascular malformation. Deep vein thrombosis (DVT) and bilateral pelvic thrombosis develop quite frequently, making surgical therapy necessary. PATIENTS AND METHODS: Between 1982 and 2006, 15 patients (nine male, six female, mean age 28 standard deviance 9 years) with agenesis of the IVC (IVCA) were treated surgically because of acute or subacute DVT. These patients underwent bilateral transfemoral ante- and retrograde thrombectomy of the iliofemoral and sometimes popliteal veins and replacement of the IVC with an external ring supported PTFE-graft. Bi- or unilateral arteriovenous fistulae were created in the femoral region. The fistulae were closed, on average, 8 months after trans-arterial venography was performed. These patients were examined clinically and by duplex ultrasound imaging during follow-up to assess graft patency and to allow CEAP classification. Patients were assessed for the development of post-thrombotic syndrome (PTS). RESULTS: No patient died during any part of their treatment or within 60 days. Primary patency of the venous reconstruction was 53%, secondary and long time follow-up patency was 83%. The mean duration of follow-up was 41 SD 12 months. Minor complications were observed in five cases (33%). PTS showed no progression during a follow-up of 41 SD 12 months in all patients. There was no change in the CEAP clinical stage during follow-up nor did any leg ulcer develop. CONCLUSION: A surgical approach to restore venous patency is effective and appears to prevent the deterioration of CVI over time.

[Occlusive aortic disease as coral reef aorta--experience in 80 cases]. / Der stenosierende Aortenprozess als Coral Reef Aorta--Erfahrungen in 80 Patienten.

BACKGROUND: Coral reef aorta (CRA) is described as rock-hard calcifications in the visceral part of the aorta. These heavily calcified plaques grow into the lumen and can cause significant stenoses, leading to malperfusion of the lower limbs, visceral ischaemia or hypertension due to renal ischaemia. PATIENTS/METHODS: From 1/1984 to 11/2008, 80 patients (26 m, 54 f, mean age 61.6, range 14 to 86 years) underwent treatment in the Department of Vascular Surgery and Kidney Transplantation, Heinrich-Heine-University Hospital for CRA. The present study is based on a review of patient records and prospective follow-up in our outpatient clinic. RESULTS: The most frequent finding was renovascular hypertension (n=33, 41.3%) causing headache, vertigo and visual symptoms. Intermittent claudication due to peripheral arterial occlusive disease was found in 35 cases (43.8%). 15 patients (18.8%) presented with chronic visceral ischaemia causing diarrhoea, weight loss and abdominal pain. 79 patients (98.7%) underwent surgery; in 73 (93.7%) aortic reconstruction was achieved with thromboendarterectomy, on an isolated suprarenal segment in 7 (9.3%), an infrarenal segment in 21 (26.6%), and the supra- and infrarenal aorta in 45 cases (60%). Desobliteration of renal arteries was performed in 47 (one-sided n=8, 10.1%; both arteries n=39, 49.4%); the aortic bifurcation was desobliterated in 37 (46.8%), extension into iliac arteries was necessary in 29 cases (one-sided n=4, 5.1%; both arteries n=25, 31.6%). The coeliac trunk was desobliterated in 43% (n=34), the superior mesenteric artery in 44.3% (n=35) and the inferior mesenteric artery in 20.3% (n=16). In 15 cases additional revascularisation (bypass, transposition, graft interposition) was necessary. Surgical access was via a left-sided thoracoabdominal incision in 56.4% (n=45) and via laparotomy in 41.8% (n=33). The 30-day lethality was 8.7% (n=7). Postoperative complications requiring corrective surgery occurred in 11 patients (13.9%). Almost ⅓ of the patients (n=19, 27.5%) returned for follow-up after a mean of 52.6 months (range 3 to 215 months). Of these, there was significant clinical and diagnostic improvement in 16 (84.2%) and 3 (15.8%) were unchanged. Impairment was not observed. CONCLUSION: In spite of the existing and improving surgical techniques for the treatment of CRA, procedures are challenging and should be performed in centres with expertise.

[Esophageal necrosis following endovascular treatment of a ruptured thoracal aortic aneurism: caused by mediastinal compartment syndrome]. / Osophagusnekrose nach endovaskulärer Versorgung eines rupturierten thorakalen Aortenaneurysmas : Folge eines mediastinalen Kompartments.

We report a case of acute esophageal necrosis after endovascular stenting for acute rupture of a thoracic aortic aneurysm into the mediastinum caused by mediastinal compartment syndrome and overstenting of intercostal arteries.

[Retrograde aortomesenteric loop bypass behind the left renal pedicle ("French bypass") in the treatment of acute and chronic mesenteric ischemia. Clinical experiences and long-term follow-up in 27 patients]. / Der retrograde aorto-mesenteriale Bypass mit links retrorenalem Verlauf ("französischer Bypass") bei der Behandlung der akuten und chronischen viszeralen Ischämie. Klinische Erfahrung und Langzeitverlauf bei 27 Patienten.

BACKGROUND: In 2001 Leschi et al. published a new method to improve perfusion of the superior mesenteric artery (SMA) in operative therapy of acute and chronic visceral ischemia. They presented a retrograde aorto-mesenteric bypass following an arcuate course behind the left renal pedicle. Due to the intricate correct anatomic description of this vascular reconstruction this loop bypass was named the "French bypass". PATIENTS AND METHODS: In our department 84 patients underwent surgery because of an acute or chronic visceral ischemia between January 2002 and December 2007. Out of these patients 27 received a "French bypass". The pre-, intra-, and postoperative data were collected from the patient hospital files retrospectively. The follow-up consisted of a review of the patient history and clinical findings in an outpatient setting, combined with a duplex sonography of the visceral arteries. RESULTS: The group of 27 patients had an average age of 55.0 years: (range: 29-81 years) and consisted of 21 women (78.6 %) and 6 men (21.4 %). The cardinal symptom of all patients was abdominal pain of variable intensities. 14 patients complained about an increased pain post ingestion (abdominal angina) and 12 patients about an involuntary loss of weight. Bypass material was autologous saphenous vein in 18 patients (66.7 %) and in 9 patients (33.3 %) an 8-mm ring-enforced PTFE prosthesis. Apart from 10 patients who only received the French bypass, we performed comprehensive visceral revascularisations in 12 patients. Overall hospital mortality was 18.5 %; 4 out of the 5 deceased patients had undergone surgery due to acute visceral ischemia. The mortality of patients with acute visceral ischemia was 30.8 % and of patients with chronic visceral ischemia 7.1 %. Eight patients had a revision before -discharge from hospital (surgery n = 6, interventional n = 2). Primary and secondary patencies of the bypasses of the surviving patients were 54.6 % (12 out of 22 patients) and 81.8 % (18 out of 22 patients), respectively. Concerning the end-point "freedom from abdominal complaints" 14 out of 27 patients (51.9 %) benefited after a mean follow-up of 38.9 months (range: 3-84 months), 7 patients each in the acute and chronic visceral ischemia group. CONCLUSIONS: The implantation of a "French bypass" represents a good option to reconstruct the SMA, combining the advantages of ante- and retrograde visceral bypasses. Furthermore this -bypass procedure allows to reconstruct distal segments of the -superior mesenteric artery in cases when long distance and peripheral stenosis impeded local thromendarterectomy. Perioperative morbidity and mortality are acceptable when the acute clinical situation is taken into account. The long-term benefit for the patients with regard to the prevention of intestinal ischemia and also the freedom from complaints is high.

[Development of neointimal matrix after incorporation of modern alloplastic prostheses: comparison between ePTFE and Dacron]. / Entwicklung neointimaler Matrix nach Einheilen moderner Prothesen: Vergleich zwischen ePTFE und Dacron.

BACKGROUND: In the therapy for peripheral arterial occlusive disease there remain inadequacies in the use of alloplastic material concerning thrombogenicity and biological compliance. In the 1960s, Sparks tried to combine the advantages of alloplastic prostheses with those of autologous reconstructions by using incorporated prostheses. No extensive myointimal hyperplasia was noted, but besides infections aneurysmatic dilatation were limiting factors in clinical practice. MATERIAL AND METHODS: The incorporation of modern alloplastic prostheses without connection to circulation concerning the thickness of neointima as well as the percentage of smooth muscle cells was examined in a dog model. RESULTS: The thickness of the neointima increased significantly in Dacron grafts with a peak on day 70 (p = 0.022), additionally a significantly greater percentage of smooth muscle cells was noted in Dacron grafts after 44 and 58 days (p = 0.008, p = 0.036). CONCLUSION: Due to the decreased thickness of the incorporating matrix as well as the lower percentage of smooth muscle cells, PTFE grafts should be preferred for peripheral arterial revascularisation.

[Paradigm shift in the therapy of Wilkie's syndrome. From bowel reconstruction to transposition of the superior mesenteric artery]. / Paradigmenwechsel in der Behandlung des Wilkie-Syndroms : Von der Darmumleitung zur Transposition der A. mesenterica superior.

The superior mesenteric artery syndrome--also known as Wilkie's syndrome or as arteriomesenteric obstruction of the duodenum--is a rare condition of upper intestinal obstruction in which the third part of the duodenum is compressed by the overlying, narrow-angled superior mesenteric artery against the posterior structures. It is characterized by early satiety, recurrent vomiting, abdominal distention, weight loss and postprandial distress. When nonsurgical management is not possible or the problem is refractory, surgical intervention is necessary. Usually a reconstruction of the intestinal passage is performed. We report the first case of successful transposition of the superior mesenteric artery into the infrarenal aorta in the therapy of Wilkie's syndrome.

[Ruptured abdominal aortic aneurysm : perioperative indicators for the clinical course following conventional open surgery]. / Rupturiertes Bauchaortenaneurysma : Perioperative Prädiktoren für den klinischen Verlauf nach konventioneller offener Behandlung.

OBJECTIVES: Ruptured abdominal aortic aneurysms (rAAA) still represent a life-threatening vascular disease, with high mortality despite improved diagnostic tools and perioperative patient management. The aim of this study was to reveal predictors of perioperative mortality and survival after open (conventional) rAAA repair. PATIENTS AND METHODS: We analyzed data from our department containing 67 patient histories and clinical notes which were collected between January 1984 and December 2004. The study patients underwent emergent surgery for rAAA. In these cases we defined 72 preoperative, 47 intraoperative, and 39 postoperative variables for further analysis. RESULTS: Our results indicate that the worst survival prognosis could be defined in patients with rAAA and aneurysmatic inclusion of the iliac arteries with concomitant prolonged shock who received an aorto-iliac bypass. For these patients we calculated a cumulative 30-day survival rate of 59.7% and 1-year survival of 43.3%. An influence of age and comorbidity on the mortality rate could not be proven. Furthermore the conclusion cannot be drawn that postoperative course was influenced by intra- vs retroperitoneal rupture localization. CONCLUSION: This study provides evidence that neither old patient age nor comorbidities influence the mortality of patients suffering from rAAA, for whom time-consuming case selection according to previous morbidities should therefore be omitted. Instead we recommend conventional surgical repair as soon as possible to maximize the chances of survival.

[The Klippel-Trenaunay syndrom associated with multiple visceral arteries aneurysms]. / Das Klippel-Trenaunay Syndrom bei gleichzeitigem Vorliegen von Viszeralarterienaneurysmen.

The Klippel-Trenaunay-syndrom (KTS) is a congenital angiodysplasia of venous vessels characterized by three main symptoms: cutanous vascular naevi, hyperthropy of a limb and varicosis or venous malformations. The coincidence of KTS and arterial malformations such as renal artery aneurysm has been described twice in the literature. We report the case study of a 40-years-old male patient with KTS and aneurysms of a renal artery, the splenic artery, the superior mesenteric artery and of a popliteal artery and popliteal vein. After documenting the diagnostic and therapeutic course we describe this case as it relates to the clinical literature. In the differential diagnosis of KTS two different syndroms have to be pointed out: the Servelle-Martorell-syndrom and the Frederick Parkes Weber-syndrom.

[Pulmonary embolism and deep vein thrombosis in the inferior vena cava affected by a rare anomaly]. / Embolisierende Thrombose bei Fehlbildung der V. cava inferior.

Persistent left-sided inferior vena cava (VCI) is a rare venous anomaly, its prevalence being estimated at 0.2-0.5%. Thrombotic occlusion of a VCI has been reported in only a few of these cases. We report the case of a 24-year old woman who suffered an acute thrombosis in a left-sided VCI and recurrent pulmonary embolism. After thrombectomy the course was uneventful. The diagnostic approach and the treatment strategy are discussed with reference to the literature.

[Indication for emergent revascularisation of acute carotid occlusion]. / Stellenwert der Revaskularisation eines akuten Karotisverschlusses.

BACKGROUND AND PURPOSE: We examined indications for emergent revascularisation of acutely occluded internal carotid artery (ICA) using current diagnostic methods. MATERIAL AND METHODS: From 1997 to 2006 we prospectively followed 34 consecutive patients undergoing emergency revascularisation due to acute extracranial ICA occlusion and acute ischaemic stroke within 72 h after symptom onset (mean 25) and within 36 h after admission (mean 16). Exclusion criteria were occlusion of the intracranial ICA or ipsilateral middle cerebral artery (MCA), ischaemic infarction of more than one third of the MCA perfusion area, or reduced level of consciousness. All patients underwent duplex sonography, cerebral CT, and/or MRI and angiography (MRA and/or DSA). We performed endarterectomy and thrombectomy of the ICA. RESULTS: Confirmed by postoperative duplex sonography at discharge, ICA revascularisation was successful in 30 (88%) of 34 cases. Postoperative intracranial haemorrhage was detected in two patients (6%) and perioperative reinfarction in one (3%). Compared to the preoperative status, 20 patients (59%) showed signs of clinical improvement by at least one point on the Rankin scale, ten patients (29%) remained stable, and two patients (6%) had deteriorated. The 30-day mortality was 6% (two patients). CONCLUSION: After careful diagnostic workup, revascularisation of acute extracranial ICA occlusion is feasible with low morbidity and mortality.

Renovascular disease: a review of diagnostic and therapeutic procedures.

The clinical importance of renovascular disease, atherosclerotic or of other origin, arises from the fact, that renal artery stenosis (RAS), if hemodynamically significant (> 70% diameter reduction), induces arterial hypertension, renal insufficiency or both. The prevalence of RAS rises with increasing age and with the presence of atherosclerosis of the aorta, carotid, coronary and peripheral arteries. Typical clinical symptoms, as uncontrolled hypertension or renal dysfunction in the absence of pathological urinary findings, are helpful to select patients for further screening methods: We see a prominent role of color duplex sonography as a screening procedure. Intra-arterial angiography remains gold standard for the diagnosis of RAS. The major problem in daily clinical practice is the differentiation between patients in which hypertension and kidney function can be improved or normalized by removal of RAS and those with ''fixed'' hypertension and irreversible kidney dysfunction and therefore to decide if it is worth while to perform invasive treatment as angioplasty or surgery. In this setting, the proof of hemodynamic significance is essential and is indicated especially when the stenosis has a diameter reduction of < 50-70% only. Methods proving a critical stenosis are intra-arterial measurement of the pressure gradient, measurement of differential renal vein renin and duplex sonography. In addition, predictors of treatment outcome should be considered. Studies analyzing if patients improve with blood pressure and kidney function after removal of RAS have shown that high grade stenosis and/or very high blood pressure indicate a good outcome. Further prognostic factors are the absence of parenchymal disease and/or positive functional test. In the presence of a critical stenosis in a patient with a clear clinical problem with hypertension and/or renal dysfunction a positive effect of invasive treatment seems warranted despite the risks that must be considered as well in angioplasty as in surgery. The selection for the type of invasive treatment requires a clarification of the treatment goals in the individual patient, the evaluation of the morphology and localization of the stenosis as the presence of other vascular disease (aortic aneurysm, peripheral artery disease etc.) and the assessment of the risk according to the type of intervention.

[Extracranial aneurysm of the carotid artery in a 12-year-old girl]. / Aneurysma verum der Arteria carotis im Kindesalter.

Extracranial aneurysms of the carotid artery in childhood are rare, and we found just nine cases described in the literature within the last 20 years. We report on the clinical appearance, diagnosis, and therapy of a carotid artery aneurysm in a 12-year-old girl and review the literature.

Intraaortic balloon pump counterpulsation after implantation of infrarenal and thoracoabdominal aortic protheses.

Highly complex vascular surgery interventions have nowadays become possible due to sophisticated operative techniques and modern intra- and postoperative anesthesiological strategies. Accordingly, the number of high risk vascular surgery interventions rises continuously and thus, the number of secondary complications after high risk interventions increases as well and requires likewise extraordinary treatment concepts. We report of a 68-year old patient who 6 months previously was operated on a ruptured abdominal aneurysm, before he was admitted to our institution for the treatment of a type IIIb (Crawford classification) thoracoabdominal aneurysm. Intraoperatively we implanted a 26 mm Dacron prosthesis which was anastomosed with the previously existing infrarenal graft. Postoperatively the patient suffered from a hemodynamically significant myocardial infarction and acute coronary catheter intervention was necessary. However, circulatory stability could not be reestablished by interventional measures and we therefore decided to implant the intraaortic balloon pump despite the presence of two synthetic aortic grafts. However, the chance of success of such a manoeuver as well as the effectiveness of intraprosthetic counterpulsation was unclear and our literature research undertaken to predict the risk of such a manouver was unsatisfactory. We therefore want to report this case and compile the literature dealing with perceptions and complications of intraaortic counterpulsation after the implantation of synthetic aortic prostheses, since such a treatment option comes to an increased clinical application in comparable constellations.

Chlamydia pneumoniae, herpes simplex virus and cytomegalovirus in symptomatic and asymptomatic high-grade internal carotid artery stenosis. Does infection influence plaque stability?

BACKGROUND: Current debates are focused on inflammatory processes in atherosclerotic lesions as a possible pathomechanism for destabilization and thrombembolism. In this prospective study the role of systemic and local infection in patients with high-grade internal carotid artery stenosis (ICA) was evaluated. PATIENTS AND METHODS: Serum antibody titers of 109 consecutive patients, who underwent surgery for ICA stenosis (asymptomatic n = 40, symptomatic n = 69) were prospectively measured for Chlamydia pneumoniae (Cpn) (IgA and IgG), Herpes simplex virus (HSV) (IgG, IgM) and Cytomegalovirus (CMV) (IgG, IgM) respectively. 53 carotis plaques of this group (asymptomatic n = 17, symptomatic n = 36) could be analyzed by polymerase chain reaction (PCR) for Cpn-, HSV- and CMV-DNA presence. RESULTS: Seropositivity was found in 61,5% for Cpn, 91,7% for HSV and 72,5% CMV respectively. No significant relation was found between symptomatic and asymptomatic patients as well as no difference was seen for presence of IgA antibodies against Cpn comparing both groups. Plaque-PCR revealed Cpn in 7 cases (13,2%), HSV in 2 cases (3,8%) and no CMV had been detected. Again, no significant relationship was found concerning symptomatic and asymptomatic patients. All 9 PCR-positive plaques displayed lesions of "complicated atherosclerosis" as central fibrous necrosis and calcification or plaque bleeding and surface thrombosis. CONCLUSIONS: Our results do not support the hypothesis that systemic Cpn, HSV or CMV- infection or evidence of Cpn-, HSV- or CMV-DNA in carotid plaques causes plaque destabilization and cerebral thromboembolism. Plaque infection could only be observed in cases with advanced atherosclerosis.

Expression of tissue factor in high-grade carotid artery stenosis: association with plaque destabilization.

BACKGROUND AND PURPOSE: The procoagulant protein tissue factor (TF) has been implicated in thromboembolic complications associated with advanced atherosclerosis. In this study, we investigated whether TF expression in high-grade stenoses of the internal carotid artery (ICA) is associated with clinical features of plaque destabilization and addressed the relationship between TF expression and plaque inflammation. METHODS: In 36 consecutive patients undergoing surgery for high-grade ICA stenosis, clinical evidence of plaque instability was provided by the recent occurrence of ischemic symptoms attributable to the stenosis and the detection of cerebral microembolism by means of transcranial Doppler ultrasound monitoring of the ipsilateral middle cerebral artery. Endarterectomy specimens were stained immunocytochemically for TF expression as well as macrophage (CD68) and T cell (CD3) infiltration. RESULTS: Morphologically, TF immunoreactivity was codistributed with plaque inflammation and predominantly localized to CD68+ macrophages. Accordingly, statistical analysis revealed a significant association of TF expression with plaque infiltration by macrophages (P<0.0001) and T cells (P=0.013). Plaques extensively stained for TF (median of TF+ total section area >40% in semiquantitative assessment) were more frequent in symptomatic (12/27) than in asymptomatic patients (1/9). Conversely, plaques exhibiting little TF expression (median of TF+ section area <20%) were more frequent in asymptomatic (3/9) than in symptomatic (1/27) patients (P=0.016). Likewise, we found a highly significant association of TF expression with the occurrence of cerebral microembolism (P=0.008). CONCLUSIONS: Induction of TF at sites of plaque inflammation may play an important role in the destabilization of high-grade ICA stenosis.

Influence of SIMV plus inspiratory pressure support on VA/Q distributions during postoperative weaning.

Since the introduction of synchronized intermittent mandatory ventilation (SIMV) several advantages have been attributed to this ventilatory mode, one of them being a more homogeneous distribution of ventilation and perfusion than during controlled mechanical ventilation (CMV). Up to now no data are available to confirm whether this is true when SIMV is used in combination with inspiratory pressure support (IPS). Therefore, we compared the influence of CMV and SIMV + IPS on the distributions of ventilation and perfusion in 9 patients undergoing weaning from postoperative mechanical ventilation. Continuous distributions of ventilation and perfusion were assessed using the multiple inert gas elimination technique (MIGET). SIMV + IPS did not induce any change in the hemodynamic or oxygenation parameters, in particular CI and PaO2 remained constant. Physiological dead space (VD/VT) increased, but PaCO2 remained unchanged due to increased minute ventilation (from 9.5 +/- 0.9 l.min-1 to 11.3 #/- 1.2 l.min-1). The perfusion distributions remained unaltered; there was no change in QS/QT nor in the perfusion of the low VA/Q lung regions. This result was underscored by the unchanged dispersion of the perfusion distribution (log SDQ). The increased VD/VT was caused by increased inert gas dead space (from 22.0 +/- 9.6 to 26.8 +/- 8.7%) which was accompanied by increased ventilation of lung regions with high VA/Q ratios (10 less than VA/Q less than 100) in 3 patients. These results show that in our group of patients partial removal of CMV together with pressure support assistance of spontaneous ventilation did not induce a clinically significant loss of the efficiency of the breathing pattern.(ABSTRACT TRUNCATED AT 250 WORDS)