The visceral hybrid repair of thoraco-abdominal aortic aneurysms--a collaborative approach.

OBJECTIVE: To report the collaborative data of 3 major European Vascular Units using the 'visceral hybrid' procedure for thoraco-abdominal aortic aneurysms and dissections. METHODS: A consecutive series of 107 urgent and elective high-risk patients were included in a prospectively collected database. RESULTS: All stents involved the entire thoracic and abdominal aorta with left subclavian coverage in 19 and revascularisation in 12. The distal landing zone was in the infra-renal aorta in 75% and in the iliac artery in 25%. The 30-day mortality rate was 16/107 (14.95%). 13/107 (12.1%) of the patients suffered spinal cord ischaemia which was complete and permanent in 9/12 (8.4%). 4 patients (3.7%) required long term dialysis and a segment of gut infarction requiring resection occurred in 3 (2.8%). Most patients had visceral bypass grafting and aortic stent-grafting performed in one stage. In 18 patients the stenting was performed later. Three of these patients ruptured before the stenting procedure was undertaken. CONCLUSION: These early results of visceral hybrid repair for high-risk patients with complex thoraco-abdominal aortic aneurysms are encouraging, in a group of patients in whom fenestrated/branched stent-grafting is not an option and open surgery hazardous.

Surgical therapy of extracranial carotid artery aneurysms: long-term results over a 24-year period.

BACKGROUND: To evaluate long-term results of surgical therapy of extracranial carotid artery aneurysms (ECCA) and to provide a morphologic classification for individual surgical reconstruction techniques. PATIENT AND METHODS: This retrospective analysis includes 57 patients (43 male, mean age 61.9 years.) with 64 carotid reconstructions for ECCA between 1980 and 2004. In 29 (50.9%) of the patients there was found a cerebral ischemic event as an initial symptom (18 transient ischemic attacks, 11 strokes). In patients without cerebral events, the presenting symptom was pulsatile cervical mass in 19 and cranial nerve dysfunction in 3 cases. ECCA was morphologically stratified in Type I=isolated aneurysms of the internal carotid artery (n=25), Type II=aneurysms of the complete internal carotid artery with involvement of the bifurcation (n=8), Type III=aneurysms of the carotid bifurcation (n=20), Type IV=combined aneurysm of the internal and common carotid artery (n=5) and Type V=isolated aneurysm of the common carotid artery (n=6). RESULTS: Perioperative stroke rate was 1.6%. 4 patients suffered from transient ischemic attacks (6.3%). Permanent and transient cranial nerve injury rate was 6.3% and 20.3% respectively. After 5, 10, 15 and 20 years the actuarial survival was 90%, 77%, 65% and 57%. The ipsilateral stroke-free time was 96%, 96%, 93% and 87%, respectively. CONCLUSIONS: Surgical reconstruction of extracranial carotid aneurysms is a safe procedure with good long-term results. The risk of a permanent, perioperative cerebral neurological deficit is low, but there is a considerable risk of cranial nerve injury.

Spinal cord ischemia after endovascular repair of the descending thoracic aorta in a sheep model.

OBJECTIVES: Spinal cord ischemia remains a devastating complication after thoracic aortic surgery. The aim of this study was to investigate the pathophysiology of spinal cord ischemia after thoracic aortic endografting and the role of intercostal artery blood supply for the spinal cord in a standardized animal model. METHODS: Female merino sheep were randomized to either I, open thoracotomy with cross-clamping of the descending aorta for 50 min (n=7), II, endograft implantation (TAG, WL Gore & Ass.), (n=6) or III open thoracotomy with clipping of all intercostal arteries (n=5) . CT-angiography was used to assess completion of surgical protocol and assess the fate of intercostal arteries. Tarloy score was used for daily neurological examination for up to 7 days post-operatively. Histological cross sections of the lumbar, thoracic and cervical spinal cords were scored for ischemic damage after stained with Hematoxylin-Eosin, Klüver-Barrrera and antibodies. Exact Kruskall-Wallis-Test was used for statistical assessment (p<0.05). RESULTS: Incidence of paraplegia was 100% in group I and 0% in group II (p=0.0004). When compared to the endovascular group, there was a higher rate of histological changes associated with spinal cord ischemia in the animals of the control group (p=0.0096). Group III animals showed no permanent neurological deficit and only 20% infarction rate (p=0.0318 compared to group I). CONCLUSIONS: In sheep, incidence of histological and clinical ischemic injury of the spinal cord following endografting was very low. Complete thoracic aortic stent-grafting was feasible without permanent neurologic deficit. Following endovascular coverage or clipping of their origins, there is retrograde filling of the intercostal arteries which remain patent.

An unusual cause of peripheral artery embolism: floating thrombus of the thoracic aorta surgically removed.

Intraluminal mobile thrombus of the descending aorta are rare disorders. They are at high risk for peripheral embolism and therefore indication for treatment is mandatory. We report on a 54-year-old patient with peripheral arterial embolization who was treated by surgical thrombus removement by thoracotomy and staged peripheral bypass grafting. New diagnostic tools are presented, therapy and prognosis are discussed.

[Leiomyosarcoma of the inferior vena cava]. / Leiomyosarkom der V. cava inferior.

Leiomyosarcomas of the inferior vena cava are rare and the clinical symptoms unspecific. We report a case of leiomyosarcoma of the inferior vena cava in an 82-year-old woman presenting with weight loss and abdominal pain. Following elaborate preoperative examinations, surgical resection was performed and the inferior vena cava was reconstructed. Clinical signs, diagnosis, therapy, and prognosis are discussed.

Hybrid aortic procedures for endoluminal arch replacement in thoracic aneurysms and type B dissections.

The aim of this study was to report our clinical experience with and review current literature on endoluminal aortic hybrid techniques and to evaluate outcome in high-risk patients treated for complex aortic arch lesions combining conventional supra-aortic debranching bypasses with subsequent or staged thoracic endovascular grafting. Of 172 patients treated with thoracic endografts for different thoracic aortic pathologies within the last 8 years, the mid-aortic arch was involved in 25, i.e. at least the left common carotid artery had to be overstented and revascularized to provide a proper proximal landing zone. These debranching bypasses were performed as a simultaneous or a staged procedure. All patients were at high-risk and were excluded by cardiac surgeons as ineligible for conventional arch repair. After partial (n=16) or complete (n=9) supra-aortic transposition, 4 different commercially available endografts (80% TAG, WL Gore) were implanted transfemorally or via iliac conduit. Deployment success was 100% in 25 patients after simultaneous or staged supra-aortic transposition; in 32% an emergency procedure was performed due to contained rupture; in 36% more than 1 endograft system was implanted (2 in 20%, 3 in 8% und 4 in 8%). The overall perioperative thirty-day mortality was 5 of 25 (20%) due to interoperative proximal bare stent perforation (n=1), transfusion related acute lung injury (TRALI n=1), cardiac failure (n=1), embolic stroke (n=1) and pneumonia (n=1). The mean follow-up was 21 months. All endoleaks type I (n=3) were corrected with another endograft; the 2 endoleaks type II sealed spontaneously. The major adverse events were: prolonged ventilation in 5 (20%), temporary renal insufficiency with hemodialysis (n=2), bypass infection (n=1), without any complications (n=9). No cases of paraplegia were recorded. Hybrid aortic arch repair is technically challenging but feasible. This novel approach may be an alternative to standard open procedures in high-risk patients and emergency cases. However, the promising early results need to be confirmed by longer follow-up and larger series.

Do workshops improved the technical skill of vascular surgical trainees?

AIMS: Adjuncts to conventional surgical training are needed in order to address the reduction in working hours. This purpose of this study was to objectively assess the efficacy of workshop training on simulators. METHODS: Fifteen consecutive participants of the European Vascular Workshop in 2003 and 2004 were recruited to this study. Participants performed a proximal anastomosis on a commercially available abdominal aortic aneurysm simulator, were then given intensive training on sophisticated models for 3 days and re-assessed. Pre- and post-course procedures were videotaped and independently reviewed by three assessors (tapes were blinded and in random order). The operative end product was similarly assessed. Four measures of technical skill were used: generic skill, procedural skill; a five point technical rating of the anastomosis (assessed using validated rating scales) and procedure time. Non-parametric tests were used in the statistical analysis. RESULTS: The video assessment scores for aneurysm repair increased significantly following completion of the course (p=0.006 and p=0.004 for generic and procedural skill, respectively). End product assessment scores increased significantly post-course (p=0.001) and participants performed aneurysm repair faster following the course (p<0.05). Inter-observer reliability ranged from alpha=0.84-0.98 for the three rating scales pre- and post-course. CONCLUSION: Objective improvements in technical performance follow intensive workshop training. Participants' perform better, faster, and with an improved end product following the course. Such adjuncts to training play an important part in a focused integrated programme that addresses reduced work hours.

[Early transfer from intensive care does not influence clinical results of carotid endarterectomy]. / Limitierte Uberwachung nach Karotisthrombendarteriektomie. Frühverlegung aus der Uberwachungseinheit beeinflusst nicht das klinische Ergebnis.

The purpose of this prospective observational study was to examine the necessity of intensive care after carotid endarterectomy (CEA). In consideration of the neurological stage and comorbidities, morbidity and mortality after early transfer from the intensive care unit (ICU) were examined. The CEA patients were assigned preoperatively to short or long monitoring. Those with symptomatic stenosis ranking > or =2 (stroke within 6 weeks before surgery) and ischemic areas in cCT were observed overnight (long) in the ICU. Within 5.5 months, 100 consecutive patients had received 107 CEAs. Preoperatively, seven of these (6.54%) were assigned to ICU overnight monitoring. 14 patients (13%) needed postoperative over night ICU. We observed no perioperative stroke or mortality in the 107 consecutive CEAs. We could not detect any risk factor in preoperatively determining the length of postoperative ICU monitoring. This prospective, single center study showed that, after CEA, it is safe to monitor patients for only a short period (4-8 h) in the ICU. Morbidity and mortality after early transfer to the regular ward did not increase.

[Vascular surgery in the elderly]. / Gefässchirurgie im Alter.

The prevalence of vascular disease among the elderly population is high (approximately 20%). The morbidity and mortality of many vascular operations show no differences between the fit elderly and younger patients. A major problem is that the elderly are often not diagnosed and treated early enough to prevent emergency operations, which carry a much higher mortality. Many new surgical techniques, especially endovascular interventions, have made vascular surgery less invasive. These advances have increased the potential of life saving and prolonging vascular surgery that can be offered to all patients regardless of age. Risk-benefit analysis, especially in elderly patients, is a cornerstone of proper patient selection. The main goal of vascular surgery in the elderly is preservation of quality of life and independence. Surgery of a ruptured aneurysm is a life saving exception. Indications for treatment in the elderly remains an individual decision making process. Advanced age should not be considered as a limitation or contraindication for carotid, aneurysm and bypass surgery. Age is not a disease, it is just a chapter of life.

Surgical thrombectomy followed by intraoperative endovascular reconstruction for symptomatic ilio-femoral venous thrombosis.

OBJECTIVES: To evaluate the efficacy of surgical thrombectomy combined with endovascular reconstruction for acute ilio-femoral/caval venous thrombosis. METHODS: Twenty consecutive patients with acute, symptomatic ilio-femoral/-caval thrombosis underwent valve-preserving thrombectomy with immediate endovascular repair between October 1996 and October 2003. Thrombectomy was classified by intraoperative venography as: TYPE I=complete, TYPE II=partial, TYPE III=complete with stenosis other than thrombus, TYPE IV=permanent occlusion. TYPEs I and IV were excluded from this analysis because endovascular repair was not performed. RESULTS: Left-sided venous thrombosis predominated (90%). Lesions were located in the common iliac vein (85%), the external iliac vein (10%), and the inferior vena cava (5%). Three TYPE II lesions and 17 TYPE III lesions (11 spurs, one hypoplasia, one fibrosis, one haematoma, and three others) were diagnosed. Catheter-directed recanalisation (thrombectomy/thrombolysis) resolved TYPE II lesions in three patients. Balloon angioplasty (one patient), iliac stenting (15 patients [two with thrombolysis]), and caval stenting (one patient) were employed in TYPE III stenoses. No serious complication or death occurred. Mean follow-up was 21 months. Of 20 patients clinical results were excellent in 18 patients who maintained patency of their reconstructed iliac veins. Primary and secondary patency rates were 80 and 90%, respectively. CONCLUSIONS: Ilio-caval venous obstructions detected intraoperatively can be reconstructed in a one-stage combined procedure. The specific endovascular approach depends on the type of residual venous obstruction. Excellent mid-term results indicate that the proposed thrombectomy classification (TYPE I-IV) and treatment algorithm optimises the results in selected patients with symptomatic venous thrombosis.

[Surgical management of thoracic aortic lesions. Aneurysm, dissection and traumatic rupture]. / Chirurgische Therapie thorakaler Aortenläsionen. Aneurysma, Dissektion und traumatische Ruptur.

Surgical management of distinct thoracic aneurysmal lesions stands at the crossroads. Until recently, the only treatment options for thoracic aortic lesions were surgical repair or medical management. There is increasing evidence that endovascular therapy will be useful in treating thoracic aortic disease, possibly becoming the preferred approach. Endovascular surgery will affect the incidence of open thoracic aortic surgery not only by producing a lower mortality risk but also a significantly lower incidence of paraplegia. In designing adequate treatment options of complex and difficult-to-treat thoracic aortic lesions, novel three-dimensional imaging reconstructions are mandatory.

[Intraluminal mass lesions of the thoracic aorta]. / Intravasale Raumforderungen der thorakalen Aorta. Differenzialdiagnosen und risikoadapiertes Management der embolisierenden Läsionen.

Aortic intraluminal mass lesions of the thoracic aorta are rare disorders with a wide range of differential diagnoses. Generalized hypercoagulation or vascular endothelial disorders have been proposed as the main etiological factor. The risk of catheter-related thrombus development or embolization after interventional procedures is as high as 17%. Malignancies of the aorta are somewhat rare. In some cases, the specific source of the thrombus could not be determined. Mainly, intraluminal tumors of the thoracic aorta become evident through peripheral embolization. Modern diagnostic tools are able to identify the structure and location of intravascular formations. Therapy options are influenced, due to the heterogenic entity, by the individual risk to the patient and the pathology of the thrombus.

Are elevated homocysteine plasma levels related to peripheral arterial disease? Results from a cross-sectional study of 6880 primary care patients.

BACKGROUND: It is still unclear whether the strength of the association between elevated plasma homocysteine (HC) levels and peripheral arterial disease (PAD), coronary artery disease (CAD) and cerebrovascular disease (CVD) is similar. METHODS: Fasting homocysteine plasma levels were measured in 6880 unselected primary care patients aged 65 years or older. Presence of PAD was determined with the ankle brachial index, and both CAD and CVD were recorded according to patient history. RESULTS: Median homocysteine levels in the total sample (58.0% females, mean age 72.5 years, mean body mass index 27.3 kg m-2) differed between patients with and without PAD: 15.2 micro mol L-1 (95% confidence interval [CI] 14.8; 15.7, vs. 13.9 micro mol L-1 (CI: 13.8; 14.1; P < 0.001). Peripheral arterial disease prevalence moderately increased from 13.0% in the lowest HC quintile to 24.3% in the highest quintile (crude odds ratio [OR], 2.1 [CI: 1.7; 2.6]). The frequency of atherothrombotic manifestations in the patients' history increased nearly linearly across the homocysteine quintiles in the univariate analysis. However, the association diminished substantially after adjusting for known interfering variables: the ORs between the HC highest fifth vs. lowest fifth (adjusted for age, gender, smoking status, diabetes, hypertension lipid disorders, and estimated glomerular filtration rate levels) for PAD decreased to 1.4, for CAD to 1.0 (NS), and for CVD to 1.1. (NS). CONCLUSIONS: Elevated HC is only slightly more related to PAD than to CAD and CVD. After adjustment for known risk factors, the effect size is small, and an association can no longer be observed between homocysteine and CAD and CVD.

Graft patency and clinical outcome of femorodistal arterial reconstruction in diabetic and non-diabetic patients: results of a multicentre comparative analysis.

OBJECTIVE: in diabetic patients with critical limb ischaemia (CLI) an inferior success rate following infrainguinal bypass surgery is quite often suggested. The aim of this retrospective analysis was, therefore, to evaluate the graft patency and, particularly, the clinical outcome at 1 year in diabetic compared with non-diabetic patients. MATERIAL AND METHODS: two hundred and eleven patients (diabetics 94; non-diabetics 117) with femorodistal reconstruction for CLI were studied. Groups were comparable with regard to the Fontaine classification, the distribution of vascular risk factors, graft material, distal anastomosis site, and the angiographic runoff grading. RESULTS: diabetes did not adversely affect graft function. For diabetics and non-diabetics primary cumulative patency rate at 1 year was found to be 66 and 56%, respectively (p=0.10) and a virtually identical limb salvage rate of 85 and 83% was achieved (p=0.76). With regard to healing of ischaemic foot ulcers a trend against diabetics was noted with a healing rate of 81% compared to 96% in non-diabetics at 1 year (p=0.067); gangrenous foot lesions could be equally remedied in 94% and in 87% among patients with and without diabetes (p=0.44). The survival rate of diabetics, however, was significantly lower with 78% at 1 year compared with 95% in non-diabetic patients (p=0.0004). CONCLUSIONS: our preliminary results support the view that infrainguinal bypass grafting can be safely done even in diabetics. Despite increased mortality in this group, liberal indication for reconstructive vascular surgery seems to be justified by favourable patency rates and clinical outcome in selected patients.

Improvement of carotid blood flow after carotid endarterectomy--evaluation using intraoperative ultrasound flow measurement.

OBJECTIVES: to examine the relationship between the degree of extracranial internal carotid artery (ICA) stenosis and changes in the ipsilateral ICA blood flow after carotid endarterectomy (CEA). MATERIALS AND METHODS: in a prospective study we studied 51 patients with unilateral 60-99% ICA stenosis (median degree 84%, asymptomatic stenosis n = 13, symptomatic stenosis n = 38). The degree of ICA diameter stenosis was determined by ex-vivo plastination of the surgically removed atherosclerotic specimen and video-assessed planimetry. Intraoperative transit time ultrasound flow measurements of the carotid arteries were performed before and after CEA. Blood flow changes were assessed by mathematical approximations. Statistics were done by use of the Wilcoxon signed Rank test. RESULTS: common carotid artery (CCA) and ICA median blood flow increased after CEA from 370 and 130 ml/min to 450 and 282 ml/min, respectively (p <.001). The relative increase of ICA blood flow was 5% and 18% for 60-69% and 70-79% ICA stenosis (n.s.) but 70% and 247% for 80-89% and 90-99% stenosis (p <.001 each). Mathematical evaluation (fourth-polynomal function) determined a significant increase of carotid blood flow after CEA in ICA stenosis of > or =82.3%. CONCLUSIONS: in the absence of severe contralateral ICA occlusive disease a significant increase of ipsilateral ICA blood flow by CEA can be expected in patients with an ICA stenosis of > or =82.3% (linear degree of stenosis, ECST criteria).

The Carotid Surgery for Ischemic Stroke trial: a prospective observational study on carotid endarterectomy in the early period after ischemic stroke.

OBJECTIVE: The purpose of this study was to examine the safety of carotid endarterectomy (CEA) within 6 weeks after a nondisabling carotid-related ischemic stroke. Endpoints were the perioperative stroke or mortality rate and the incidence rate of cerebral bleedings. METHODS: This prospective observational multicenter trial was performed in community and university centers. One hundred sixty-four hospitalized patients with nondisabling carotid-related ischemic stroke were included. The patients were identified clinically with the modified Rankin scale (initial neurologic deficit grade >/= 2, n = 160). Four patients with evidence of ischemic territorial infarction on cerebral computed tomographic (CT) scan but no persisting functional deficit were also included. CEA was performed within 6 weeks after stroke. Neurologic examinations were performed initially, before surgery, 3 days after surgery, and 6 weeks after CEA. Worsening of more than 1 grade on the Rankin scale was considered as a new stroke or stroke extension. Unenhanced CT scans of the brain were performed before and after surgery. CT scans were evaluated blind to clinical patient data. Statistical analysis included univariate and multivariate analysis. RESULTS: The combined stroke or mortality rate within 30 days after CEA was 6.7%. Ten patients had a new ipsilateral stroke or stroke extension, and one patient died after surgery of a myocardial infarction. One patient (0.6%) had parenchymatous cerebral bleeding, and in 10 patients, hemorrhagic transformation within the preexisting ischemic infarction was detected but no infarct extension was observed. In the multivariate analysis, American Society of Anesthesiology (ASA) grades III and IV and decreasing age were significant predictors for an increased perioperative risk. Patients with a higher risk profile (ASA classification grades III and IV) had a high perioperative risk when CEA was performed within the first 3 weeks (14.6% versus 4.8% beyond 3 weeks). Patients without severe concomitant diseases (ASA grades I/II) had a low perioperative risk of 3.4% if CEA was performed within the first 3 weeks. CONCLUSION: Early CEA within 6 weeks after a carotid-related ischemic stroke can be performed with a perioperative stroke or mortality rate comparable with the results reported in the European Carotid Surgery Trial and the North American Symptomatic Carotid Endarterectomy Trial. The risk of parenchymatous bleeding is low. ASA grades III and IV and decreasing age were predictive of an increased perioperative risk, especially if CEA was performed within the first 3 weeks. Patients at low risk can undergo operation safely within the first 3 weeks. Individual patient selection in an interdisciplinary approach between neurologists, anesthesiologists, and vascular surgeons remains mandatory in these patients.

Perfusion-weighted magnetic resonance imaging in patients with carotid artery disease before and after carotid endarterectomy.

OBJECTIVE: The purpose of this study was to investigate the potential of perfusion-weighted magnetic resonance imaging for preoperative and postoperative evaluation of cerebral hemodynamics in patients undergoing carotid endarterectomy for carotid artery stenosis. METHODS: We examined 26 patients with angiographically proven stenoses (60%-99%) of the internal carotid artery preoperatively. Perfusion imaging studies were performed by bolus-tracking of a dosage of 0.2 mmol/kg body weight of gadolinium diethylenetriaminepentaacetic acid on a 1.5-T scanner using a T2*-weighted fast low-angle shot sequence. The observed signal intensities were converted pixel by pixel into concentration-time curves. In each patient, the hemispheres were compared and the difference between the normalized first moments (NFMs) and the percentage changes of the regional cerebral blood volume (CBV) were calculated. Three months postoperatively, perfusion-weighted magnetic resonance imaging was performed in 13 patients. RESULTS: In patients with <80% stenosis (n = 10), there was no significant alteration of NFM and regional CBV compared with the contralateral hemisphere (-0.16 +/- 0.7 s, +5.9 +/- 24.6%). In patients with stenoses >or=80% (n = 16), we found an increase in NFM ipsilateral to the stenosis of 1.2 +/- 0.92 s (P < .001) and an increase of CBV of 16.8 +/- 15.2% (P < .005). Three months postoperatively, perfusion parameters were normal in all 13 patients examined. CONCLUSIONS: Perfusion-weighted magnetic resonance imaging is well suited to evaluate the preoperative and postoperative hemodynamic changes in patients with carotid artery stenosis. This noninvasive, semiquantitative magnetic resonance technique could prove to be a valuable adjunct in identification of patients who might benefit from carotid endarterectomy.

[Aortic dissection--when operative treatment, when endoluminal therapy?]. / Die Aortendissektion--Wann operieren, wann endoluminal therapieren?

GOAL: To demonstrate the Heidelberg results of the previous 2 years in patients referred for acute aortic dissection. MATERIAL AND METHODS: 93 patients referred for acute aortic dissection were treated by cardiac surgery, vascular surgery and interventional radiology according to a novel therapeutic algorithm including stent-grafts and combined open and interventional procedures and conservative medical therapy when no malperfusion syndrome was present or patients were considered prohibitive for even minor surgical procedures. Stent-graft placements were done assisted by short term cardiac arrest to facilitate correct device deployment. RESULTS: 36 patients presented with type A and the other 57 with type B dissection. 32 of the A patients were operated and 20 of the B patients, respectively. 12 patients with B dissection were treated with stent-grafts. 3 required additional interventional therapy for organ malperfusion. The mortality was 0% in these 12 patients The overall mortality rate in the A group was close to 40% mainly as a result of postoperative organ malperfusion while it was 15% in the B group. In both groups mortality was highest in the respective untreated patient subgroup (3/4 and 8/37, respectively). The main mortality factor was visceral (mesenteric or liver) ischemia. Paraplegic complications occured in neither group. In 4 patients a combined approach applying cardiac surgery of the ascending aorta and endluminal stent-graft placement for the residual B dissection was successfully performed. In one patient this was done simultaneously. DISCUSSION: Acute aortic dissection of type A with or without valve involvement, coronary artery ischemia can be treated with high technical success rates. However, remaining distal aortic dissection associated with true lumen collapse and organ malperfusion is the main causative factor for clinical failures. Successful combination of open proximal aortic surgery with endoluminal treatment of residual B dissection encourages further use of this novel approach. Acute B type dissection appears to be effectively and safely treated by endoluminal approach in selected cases. Unsolved questions of this less invasive therapeutic approach focus mainly on the design of the proximal anchoring part of the devices.

[Post-traumatic dissection of the abdominal aorta]. / Die posttraumatische abdominelle Aortendissektion.

Dissections due to deceleration trauma are rarely limited to the infradiaphragmal aorta (only 2-3%) and are usually lethal. Here we report the unusual course of an abdominal aortic dissection with aneurysmatic enlargement of the false lumen. Based on diagnostic imaging, a therapeutic stent application was planned in order to close the entry and to prevent rupture. During the intervention sondation of the false lumen revealed that the left renal artery had a reentry. Due to the complexity of the entry-reentry situation of the left renal artery the intervention was not possible, and the patient had to undergo vascular surgery.

Characterization of renal parenchymal perfusion during experimental infrarenal aortic clamping and declamping with enhanced thermodiffusion electrodes.

Despite multiple previous experimental and clinical investigations, it has not been fully clarified until now whether infrarenal aortic cross-clamping (IRAC) induces a significant disturbance of renal parenchymal perfusion. Most renal cortical flow data collected thus far have been heterogenous because of inherent limitations of available measurement technology. The enhanced thermal diffusion (TD) electrode is a newly developed and previously validated prototype device that allows continuous quantification of parenchymal kidney perfusion after local probe implantation. We monitored renal perfusion during experimental IRAC with TD for the first time, thereby also evaluating the potential applicability of the method in clinical aortic surgery. IRAC (20 min) followed by sudden declamping was performed in pigs under general anesthesia (n = 14). Renal cortical blood flow (RCBF) was continuously quantified by TD, total aortic flow (TABF) and renal artery flow (RABF) were measured by ultrasonic flow probes, and parameters of systemic circulation were determined by Swan-Ganz catheter. Our results showed that kidney perfusion can be continuously quantified using TD electrodes during experimental aortic surgery in a porcine model. IRAC does not lead to a significant impairment of RCBF in young pigs as measured by TD. Renal perfusion appears to be predominantly pressure driven. Consequently, abrubt aortic declamping can bring about prolonged renal ischemia. Transfer of the TD method to RCBF monitoring during clinical aortic surgery appears to be feasible and should be investigated in selected cases.