Assessment of behavioral determinants influencing success of supervised exercise therapy in patients with intermittent claudication: A cross sectional survey.

BACKGROUND: Supervised exercise therapy is the first step in treatment of intermittent claudication. However, adherence to supervised exercise therapy is low. Limited access and reimbursement issues are known reasons, though lack of motivation is often leading. Behavioral determinants influencing motivation and thus adherence to supervised exercise therapy remain to be investigated. In this study we sought to determine which behavioral determinants would be of influence on the long-term adherence of supervised exercise therapy. METHODS: 200 patients, newly diagnosed with peripheral arterial disease Rutherford classification II-III, were sent a questionnaire to assess motivation and behavior with regard to supervised exercise therapy. The questionnaire was constructed using the I-CHANGE model for explaining motivational and behavioral change. Baseline characteristics were acquired from medical records. Alpha Cronbach's was calculated to test reliability of the questionnaire. RESULTS: 108 (54%) patients returned their questionnaire. A total of 79% patients followed supervised exercise therapy. Patients who increased their walking distance after supervised exercise therapy have significantly greater knowledge (p = 0.05), positive attitude (p = 0.03) and lower negative attitude (p = 0.01). Patients with a higher self-efficacy remained significantly more active after participating in supervised exercise therapy (p = 0.05). CONCLUSION: Increasing the determinants knowledge, attitude and self-efficacy will improve adherence to supervised exercise therapy and result in delayed claudication onset time.

Contrast Induced Nephropathy and Long-term Renal Decline After Percutaneous Transluminal Angioplasty for Symptomatic Peripheral Arterial Disease.

OBJECTIVE/BACKGROUND: Administration of iodinated contrast media during endovascular procedures for peripheral arterial disease (PAD) may cause contrast induced nephropathy (CIN). The aim of the present study was to establish the incidence of CIN after these procedures and to study its association with long-term loss of kidney function, cardiovascular events, and death. METHODS: Consecutive patients first presenting with symptomatic PAD (Rutherford classification II-VI) who were treated with an endovascular procedure were included in this prospective observational cohort study. CIN was defined as >25% increase of serum creatinine concentration from baseline at 5 days after the intervention. RESULTS: Some 337 patients were included with a mean estimated glomerular filtration rate (eGFR) of 67 mL/minute. Thirteen percent (95% confidence interval [CI] 9-16) of these patients developed CIN after endovascular interventions for PAD. One year after treatment, eGFR was reduced by 12.4 mL/minute (95% CI 8.6-16.2) in patients with CIN compared with 6.2 mL/minute (95% CI 4.9-7.0) in patients without acute kidney injury (p < .01). After correction for potential confounders, CIN was associated with a 7.8 mL/minute (95% CI 4.5-11.0) reduction of eGFR at 1 year after endovascular intervention (p < .01). Furthermore, patients with CIN were at increased risk of long-term cardiovascular events and mortality. CONCLUSION: Exposure to iodinated contrast media during endovascular procedures for symptomatic PAD frequently results in CIN. Patients with CIN are at increased risk of long-term loss of renal function, cardiovascular events, and death.

Endothelial cells (ECs) for vascular tissue engineering: venous ECs are less thrombogenic than arterial ECs.

Primary endothelial cells (ECs) are the preferred cellular source for luminal seeding of tissue-engineered (TE) vascular grafts. Research into the potential of ECs for vascular TE has focused particularly on venous rather than arterial ECs. In this study we evaluated the functional characteristics of arterial and venous ECs, relevant for vascular TE. Porcine ECs were isolated from femoral artery (PFAECs) and vein (PFVECs). The proliferation rate was comparable for both EC sources, whereas migration, determined through a wound-healing assay, was less profound for PFVECs. EC adhesion was lower for PFVECs on collagen I, measured after 10 min of arterial shear stress. Gene expression was analysed by qRT-PCR for ECs cultured under static conditions and after exposure to arterial shear stress and revealed differences in gene expression, with lower expression of EphrinB2 and VCAM-1 and higher levels of vWF and COUP-TFII in PFVECs than in PFAECs. PFVECs exhibited diminished platelet adhesion under flow and cell-based thrombin generation was delayed for PFVECs, indicating diminished tissue factor (TF) activity. After stimulation, prostacyclin secretion, but not nitric oxide (NO), was lower in PFVECs. Our data support the use of venous ECs for TE because of their beneficial antithrombogenic profile.

Abdominal aortic aneurysms with high thrombus signal intensity on magnetic resonance imaging are associated with high growth rate.

OBJECTIVES: A layer of intraluminal thrombus is commonly observed in abdominal aortic aneurysms (AAAs). The purpose of this study was to investigate whether AAAs with high thrombus signal intensity (SI) at T1-weighted (T1w) magnetic resonance imaging (MRI) exhibit a faster aneurysm growth rate. METHODS: This was a prospective follow-up study. Patients with a small AAA underwent MRI examinations at 6 month intervals. Aneurysm thrombus and psoas muscle SI at the point of maximal diameter on T1w images were measured and expressed as a ratio (thrombus SI/muscle SI). Based on these measurements, patients were categorized into three groups: AAA with relative thrombus SI above (group A) and below (group B) the mean relative thrombus SI of 1.20. Patients with AAA without thrombus constituted group C. Eight patients were scanned twice within 2 weeks to investigate scan-rescan reproducibility. Aneurysm growth rates were expressed as the change in maximal cross sectional area (cm(2)). RESULTS: A total of 35 patients (m/f: 26/9; age 72 ± 7 years; AAA maximal diameter 4.9 ± 0.5 cm) were included. Mean aneurysm growth rate for patients in group A (n = 11, 1.87 cm(2)/0.5 year) was two-fold higher than group B (n = 17, 0.78 cm(2)/0.5 year, p = .005) and eight-fold higher than group C (n = 7, 0.23 cm(2)/0.5 years, p = .004) at 6 months' follow-up. At 12 months' follow-up, the mean aneurysm growth rate remained significantly higher in group A (n = 7, 3.03 cm(2)/year) than groups B (n = 10, 1.63 cm(2)/year, p = .03) and C (n = 7, 0.73 cm(2)/year, p = .004). The reproducibility for thrombus SI measurements was found to be high with a coefficient of variation of 6.2%. Aneurysm maximal cross-sectional area at baseline was not significantly different for the three groups. CONCLUSIONS: Abdominal aortic aneurysms with high thrombus SI on T1w MR images are associated with higher aneurysm growth rates.

CTA with fluoroscopy image fusion guidance in endovascular complex aortic aneurysm repair.

OBJECTIVES: To evaluate the effect of intraoperative guidance by means of live fluoroscopy image fusion with computed tomography angiography (CTA) on iodinated contrast material volume, procedure time, and fluoroscopy time in endovascular thoraco-abdominal aortic repair. METHODS: CTA with fluoroscopy image fusion road-mapping was prospectively evaluated in patients with complex aortic aneurysms who underwent fenestrated and/or branched endovascular repair (FEVAR/BEVAR). Total iodinated contrast material volume, overall procedure time, and fluoroscopy time were compared between the fusion group (n = 31) and case controls (n = 31). Reasons for potential fusion image inaccuracy were analyzed. RESULTS: Fusion imaging was feasible in all patients. Fusion image road-mapping was used for navigation and positioning of the devices and catheter guidance during access to target vessels. Iodinated contrast material volume and procedure time were significantly lower in the fusion group than in case controls (159 mL [95% CI 132-186 mL] vs. 199 mL [95% CI 170-229 mL], p = .037 and 5.2 hours [95% CI 4.5-5.9 hours] vs. 6.3 hours (95% CI 5.4-7.2 hours), p = .022). No significant differences in fluoroscopy time were observed (p = .38). Respiration-related vessel displacement, vessel elongation, and displacement by stiff devices as well as patient movement were identified as reasons for fusion image inaccuracy. CONCLUSION: Image fusion guidance provides added value in complex endovascular interventions. The technology significantly reduces iodinated contrast material dose and procedure time.

Spinal cord function monitoring during endovascular treatment of thoracoabdominal aneurysms: implications for staged procedures.

AIM: Spinal cord ischemia is a well-known complication in the treatment of thoracoabdominal aneurysms (TAAA). Despite the fact that endovascular treatment of TAAA is less invasive, spinal cord ischemia rate is not reduced if compared to open repair. METHODS: We report the results of our experience of spinal cord function monitoring by measuring motor evoked potentials (MEP) during endovascular treatment of TAAA type II and III. Depending on the level of the MEPs the decision is made whether to stage the procedure or not. We treated ten patients according to this protocol. RESULTS: In two patients, MEPs decreased 50% or more and procedures were staged. Both experienced no neurological complications after first and second procedure. No MEPs decrease was seen during the second procedures. One of the other eight patients had a temporary right lower leg pararesis. CONCLUSION: In conclusion we state that our first experience demonstrates the value of assessing spinal cord function during extensive endovascular TAAA repair with subsequent strategies to prevent paraplegia.

Plasma levels of matrix metalloproteinase-9: a possible diagnostic marker of successful endovascular aneurysm repair.

OBJECTIVE: The aim of the study was evaluating the diagnostic value of plasma matrix metalloproteinase- (MMP)-2 and -9 and tissue inhibitor of MMP-1 (TIMP-1) for endoleak detection after endovascular aneurysm repair (EVAR). REPORT: Consecutive EVAR patients (n = 17) with endoleak and matched controls without endoleak (n = 20) were prospectively enrolled. Increased levels of MMP-9 were observed in patients with endoleak (P < 0.001). Regression analysis showed no significant influence of age, sex or abdominal aortic aneurysm (AAA) size. The receiver operating characteristic (ROC) curve of plasma MMP-9 levels showed that a cut-off value of 55.18 ng ml(-1) resulted in 100% sensitivity and 96% specificity with an AUC value of 0.988 (P < 0.001) to detect endoleak. CONCLUSIONS: Plasma MMP-9 levels appear to discriminate between patients with and without an endoleak with high sensitivity and specificity.

Differential protein expression in serum of abdominal aortic aneurysm patients - a proteomic approach.

OBJECTIVE: The aim of the study is to investigate the differential expression of proteins in serum of abdominal aortic aneurysm (AAA) patients in relation to aneurysm size (D(max)) and progression. METHODS: Two-dimensional differential in-gel electrophoresis (2D-DIGE) together with tandem mass spectrometry (MS/MS) was used to analyse the serum proteome from patients with small (D(max) 30-54 mm) AAA, either stable (increase D(max) <5 mm year⁻¹; n = 8) or progressive (increase D(max) ≥5 mm year⁻¹; n = 8), and large (D(max) ≥ 55 mm; n = 8) AAA. The identified proteins were quantitatively validated in a larger population (n = 80). RESULTS: Several proteins were differentially expressed in serum of small stable, small progressive and large AAA. Three validated proteins (immunoglobulin G (IgG), α1-antitrypsin (α1-AT) and Factor XII activity) showed strong correlation with D(max). Size combined with either Factor XII activity or α1-antitrypsin had minimal effect on the prognostic value in predicting aneurysm progression compared with size alone (area under the curve (AUC), 0.85; 95% confidence interval (CI), 0.73-0.97; p < 0.001 and AUC, 0.85; 95% CI, 0.72-0.98; p < 0.001 vs. AUC, 0.83; 95% CI, 0.71-0.96; p < 0.001, respectively). CONCLUSION: The present study indicates that both Factor XII and α1-antitrypsin are found in increased amounts in the serum of patients with expanding AAA. However, combination of either Factor XII or α1-antitrypsin with aneurysm diameter had little effect on prediction of aneurysm progression versus diameter alone.

Blocking the saphenofemoral junction during ultrasound-guided foam sclerotherapy-- assessment of a presumed safety-measure procedure.

OBJECTIVES: Ultrasound-guided foam sclerotherapy (UGFS) is a technique in which a mixture of sclerosing drug and gas is used to treat varicose veins. Several authors have demonstrated transient systemic effects after UGFS. These effects are not well understood but probably originate from a systemic distribution of the sclerosing foam. Therefore, safety measures have been developed to prevent foam from flowing into the deep venous system. The aim of the study is to evaluate whether blockage of the saphenofemoral (SF) junction by either manual compression or surgical ligation prevents microbubbles from leaking into the deep venous circulation. METHODS: To detect the distribution of microbubbles, radioactive pertechnetate (99mTcO4-) was added to the foam solution. Initially, in vitro trials were performed in the laboratory to investigate the effect of 99mTc on foam stability. The time taken for foam to liquefy was measured for foam alone and for the mixture with 99mTc. In subsequent research, eight varicose great saphenous veins (GSVs) were treated by UGFS. In three patients, this treatment was preceded by surgical ligation of the SF junction. In three patients, the groin was manually compressed during UGFS. In two patients, UGFS was performed without compression of the groin. RESULTS: In vitro, 99mTc did not influence foam stability; after 2.6 min all foam had reduced to liquid, regardless of whether 99mTc had been added or not. In vivo trials showed that all patients showed a decrease in the cumulative amount of 99mTc detected in the GSV following polidocanol-99mTc mixture injection. However, the decrease of radioactivity was slightly reduced when compression or ligation of the SF junction was performed. CONCLUSIONS: Blocking the SF junction during UGFS using either manual compression or ligation does not prevent, but may reduce the flow of foam into the femoral vein.

Open repair for ruptured abdominal aortic aneurysm and the risk of spinal cord ischemia: review of the literature and risk-factor analysis.

OBJECTIVES: Spinal cord ischemia after open surgical repair for rAAA is a rare event. We estimated the current incidence and tried to identify risk factors. We also report a new case. METHODS: Group A consisted of 10 reports on open repair for rAAA from 1980 until 2009. Only series of ≥100 patients were considered to estimate the incidence. Thirty three case reports from 1956 until 2009 were identified (group B). Case reports from group B were not encountered in group A. Group B patients were stratified according to the type of neurological deficit as described by Gloviczki (type I complete infarction and type II infarction of the anterior two third). RESULTS: Group A consisted of 1438 patients. In group A 86% were male with a mean age of 72.1 years. The incidence of post-operative paraplegia was 1.2% (range 0-2.8%). In-hospital mortality was 46.9%. Of the 33 patients of group B were 86% male with a mean age of 68.0 years. Most patients developed a type I (42%) or type II (33%) deficit. In-hospital mortality was 51.6%. No significant differences between different types were encountered. CONCLUSION: Spinal cord ischemia after ruptured AAA is a rare complication with an incidence of 1.2% (range 0-2.8%).

The influence of wall stress on AAA growth and biomarkers.

OBJECTIVES: This study investigated the relation between abdominal aortic aneurysm (AAA) wall stress, AAA growth rate and biomarker concentrations. With increasing wall stress, more damage may be caused to the AAA wall, possibly leading to progression of the aneurysm and reflection in up- or downregulation of specific circulating biomarkers. Levels of matrix metalloproteinase-9, tissue inhibitor of matrix metalloproteinase-1, C-reactive protein and alpha 1-antitrypsin were therefore evaluated. METHODS: Thirty-seven patients (maximum AAA diameter 41-55mm) with two, three or four consecutive computed tomography angiography (CTA) scans were prospectively included. Diameter growth rate in mm/year was determined between each pair of two sequential CTA scans. AAA wall stress was computed by finite element analysis, based on the first of the two sequential CTA scans only (n=69 pairs). Biomarker information was determined in 46 measurements in 18 patients. The relation between AAA diameter and wall stress was determined and the AAA's were divided into three equally sized groups (relative low, medium and high stress). Growth rate and biomarker concentrations were compared between these groups. Additionally, correlation coefficients were computed between absolute wall stress, AAA growth and biomarker concentrations. RESULTS: A relative low AAA wall stress was associated with a lower aneurysm growth rate. Growth rate was also positively related to MMP-9 plasma concentration (r=0.32). The average MMP-9 and CRP concentrations increased with increasing degrees of relative wall stress, although the absolute and relative wall stress did not correlate with any of the biomarkers. CONCLUSION: Although lower relative wall stress was associated to a lower AAA growth rate, no relation was found between biomarker concentrations and wall stress. Future research may focus on more and extensive biomarker measurements in relation to AAA wall stress.

Initial stress and nonlinear material behavior in patient-specific AAA wall stress analysis.

Rupture risk estimation of abdominal aortic aneurysms (AAA) is currently based on the maximum diameter of the AAA. A more critical approach is based on AAA wall stress analysis. For that, in most cases, the AAA geometry is obtained from CT-data and treated as a stress free geometry. However, during CT imaging, the AAA is subjected to a time-averaged blood pressure and is therefore not stress free. The aim of this study is to evaluate the effect of neglecting these initial stresses (IS) on the patient-specific AAA wall stress as computed by finite element analysis. Additionally, the contribution of the nonlinear material behavior of the AAA wall is evaluated. Thirty patients with maximum AAA diameters below the current surgery criterion were scanned with contrast-enhanced CT and the AAA's were segmented from the image data. The mean arterial blood pressure (MAP) was measured immediately after the CT-scan and used to compute the IS corresponding with the CT geometry and MAP. Comparisons were made between wall stress obtained with and without IS and with linear and nonlinear material properties. On average, AAA wall stresses as computed with IS were higher than without IS. This was also the case for the stresses computed with the nonlinear material model compared to the linear material model. However, omitting initial stress and material nonlinearity in AAA wall stress computations leads to different effects in the resulting wall stress for each AAA. Therefore, provided that other assumptions made are not predominant, IS cannot be discarded and a nonlinear material model should be used in future patient-specific AAA wall stress analyses.

Patient-specific AAA wall stress analysis: 99-percentile versus peak stress.

OBJECTIVE: Biomechanically, rupture of an Abdominal Aortic Aneurysm (AAA) occurs when the stress acting on the wall due to the blood pressure, exceeds the strength of the wall. Peak wall stress estimations, based on CT reconstruction, may be prone to observer variation. This study focuses on the robustness and reproducibility of AAA wall stress assessment and the relation with geometrical features of the AAA. METHODS: The AAAs of twenty patients were reconstructed by three operators. Both the peak and 99-percentile stress were used for intra- and inter-operator variability using the intraclass correlation coefficient (ICC). A regression analysis was performed to relate the stress parameters with the maximum diameter. Outliers were analyzed by their geometrical characteristics. RESULTS: The intra-operator ICC was 0.73-0.79 for the peak stress and 0.94 for the 99-percentile stress. The inter-operator ICC was 0.71 for the peak stress and 0.95 for the 99-percentile stress. A significant linear relation with the diameter was found only for the 99-percentile stress. CONCLUSIONS: The 99-percentile stress is more reproducible than peak wall stress. A significant relation between wall stress and diameter was found. Other geometrical features had no statistical relation with high stress.

Thoracoabdominal aortic aneurysm repair in patients with marfan syndrome.

OBJECTIVE: We assessed the surgical outcome of descending thoracic aortic aneurysm repair (DTAA) and thoracoabdominal aortic aneurym (TAAA) repair in patients with Marfan syndrome. METHODS: During a six year period, 206 patients underwent DTAA and TAAA repair. In 22 patients, Marfan syndrome was confirmed. The median age was 40 years with a range between 18 and 57 years. The extend of the aneurysms included 6 DTAA (1 with total arch, 2 with distal hemi-arch), 11 type II TAAA (2 with total arch, 3 with distal hemi-arch), 4 type III and one type IV TAAA. All patients suffered from previous type A (n=6) or type B (n=16) aortic dissection and 15 already underwent aortic procedures like Bentall (n=7) and ascending aortic replacement (n=8). All patients were operated on according to the standard protocol with cerebrospinal fluid drainage, distal aortic and selective organ perfusion and monitoring motor evoked potentials. In patients undergoing simultaneous arch replacement (via left thoracotomy), transcranial Doppler and EEG assessed cerebral physiology during antegrade brain perfusion. In four patients circulatory arrest under moderate hypothermia was required. RESULTS: In-hospital mortality did not occur. Major postoperative complications like paraplegia, renal failure, stroke and myocardial infarction were not encountered. Mean pre-operative creatinine level was 125mmol/L, which peaked to a mean maximal level of 130 and returned to 92mmol/L at discharge. Median intubation time was 1.5 days (range 0.33-30 days). Other complications included bleeding requiring surgical intervention (n=1), arrhythmia (n=2), pneumonia (n=2) and respiratory distress syndrome (n=1). At a median follow-up of 38 months all patients were alive. Using CT surveillance, new or false aneurysms were not detected, except in one patient who developed a visceral patch aneurysm six years after open type II repair. CONCLUSION: Surgical repair of descending and thoracoabdominal aortic aneurysms provides excellent short- and mid-term results in patients with Marfan syndrome. In this series, a surgical protocol with cerebrospinal fluid drainage, distal aortic and selective organ perfusion and monitoring motor evoked potentials resulted in low morbidity and absent mortality. These outcomes of open surgery should be considered when discussing endovascular aneurysm repair in Marfan patients.

[Peripheral artery disease: clinical and cost comparison between duplex ultrasonography and contrast-enhanced magnetic resonance angiography--a multicenter randomized trial]. / De kosten en de effecten van magnetischeresonantieangiografie en duplexechografie bij patiënten met perifeer arterieel vaatlijden: een multicentrische gerandomiseerde studie.

OBJECTIVE: To determine the clinical and economic consequences of replacing duplex ultrasonography (DUS) by contrast-enhanced magnetic resonance angiography (CE-MRA) for the initial diagnostic work-up of patients with peripheral artery disease (PAD). DESIGN: Randomised multicentre study. METHOD: In the period from January 2002 to August 2003, consecutive patients with PAD were randomly assigned to CE-MRA or DUS. The primary outcome measure was the costs. Secondary outcome measures included the confidence with which the specialist could take a therapeutic decision on the basis of the imaging study, the change in disease severity, and the change in quality of life (QOL) assessed during 6 months of follow-up. In addition, all costs of imaging, therapeutic interventions and outpatient visits were calculated. RESULTS: After 6 months of follow-up the data on 352 patients were analysed. Use of CE-MRA reduced the number of additional vascular-imaging procedures by 42% ((69-40)/69) and the specialists felt more confident about their therapeutic decisions. The diagnostic costs of all imaging studies taken together were Euro 167,- higher, on average, in the CE-MRA group (p < 0.001). However, after 6 months of follow-up, no statistically significant differences were found between the two groups with regard to the change in disease severity, the QOL, or the total costs (p > 0.05). CONCLUSION: Based on these findings, a specialist that replaces DUS by CE-MRA will feel more confident about taking a therapeutic decision and will feel less need for additional imaging. However, the diagnostic costs were higher with CE-MRA.

[Findings in 67 patients with recurrent or persistent symptoms after implantation of a disc prosthesis for low back pain]. / Bevindingen bij 67 patiënten met recidiverende of persisterende klachten na het plaatsen van een discusprothese wegens lage rugpijn.

OBJECTIVE: To determine the symptoms in patients who presented with persistent or recurrent backache or leg pain after implantation of an artificial disc prosthesis. DESIGN: Descriptive. METHOD: During the past II years in the Maastricht University Hospital (n=65) and the Utrecht University Medical Centre (n=2), 67 patients were seen with persistent or recurrent backache or leg pain in whom, an average of 53 months previously, one or more SB Charité-III lumbar-disc prostheses had been implanted elsewhere. The results were evaluated. RESULTS: The most prominent findings were: migration of the prosthesis (n=6); subsidence into the vertebra (n=35); disc degeneration at one or more neighbouring levels (n=34) and arthrosis of facet joints (n=24). In 9 cases, rupture of the metal wire around the polyethylene core was observed and in 5 cases there were radiological signs of polyethylene wear. Re-operation (spondylodesis) was generally unsatisfactory if the prosthesis was left in place. In 21 patients, the prosthesis was removed; all specimens showed polyethylene wear or rupture. CONCLUSION: Published results are mostly case series and suffer from observer bias; moreover, the benefits are moderate. Given the uncertain role ofdisc degeneration in patients with chronic backache, the real risk of complications and the uncertain advantages, the implantation ofa disc prosthesis is difficult to defend.

Endovascular treatment of traumatic rupture of the thoracic aorta.

BACKGROUND: Traumatic rupture of the thoracic aorta is a life-threatening event. Open surgical repair is the 'gold standard', but is associated with high mortality and morbidity rates. Endovascular repair is emerging as a potentially safer alternative. METHODS: A systematic review was performed of all published literature on this subject, including the authors' own experience. Using Sumsearch, PubMed and cross-references, all published reports up to January 2006 were identified, and analysed for injuries, perioperative morbidity, mortality, operating time, hospital stay and follow-up. RESULTS: A total of 284 patients were identified. Reported mortality rates range from 0 to 6 per cent. The procedure-related mortality rate is about 1.5 per cent. Some 6.7 per cent of all procedures were complicated by endoleak and the overall procedure-related morbidity rate was 14.4 per cent. These results are promising compared with those of open repair, but individual experience is limited and there may be some publication bias. CONCLUSION: Endovascular repair of traumatic rupture of the thoracic aorta seems to reduce morbidity and mortality in patients with multiple trauma. Ideally, both devices and experienced personnel should be available in trauma centres.

Recipient hemodynamics during non-heart-beating donor kidney transplantation are major predictors of primary nonfunction.

Non-heart-beating donor (NHBD) kidneys may substantially expand the donor pool, but many transplant centers are reluctant to use these kidneys because of the relatively high incidence of primary nonfunction (PNF). In heart-beating donor kidneys, intravascular fluid depletion during transplant surgery is associated with delayed graft function (DGF). Therefore, we studied the effect of the recipients' hemodynamic status on the outcome of 177 NHBD kidney transplantations. Independent statistically significant predictors of PNF were average central venous pressure (CVP) below 6 cmH(2)O (adjusted odds ratio (AOR) 3.1 (95% CI: 1.4-7.1), p=0.007), average systolic blood pressure below 110 mmHg (AOR 2.6 (95% CI: 1.1-5.9), p=0.03) and pre-operative diastolic blood pressure below 80 mmHg (AOR 2.4 (95% CI: 1.0-5.9), p=0.05). Donor characteristics were not independently associated with PNF (p>0.10). In a subgroup analysis of 56 paired kidneys, 29% of the recipients with the lower CVP of the pair experienced PNF compared with 11% of their counterparts with higher CVP (p=0.09). Our study indicates that recipient hemodynamics during transplant surgery are major predictors of PNF. Therefore, improving recipient hemodynamics by expansion of the intravascular volume is expected to enhance the results of NHBD kidney transplantations and may enlarge the donor pool by increasing the acceptance of NHBD kidneys.

Surgical repair of thoracoabdominal aortic aneurysms.

Morbidity and mortality following thoracoabdominal aortic aneurysm (TAAA) repair are tremendous. Preoperative assessment is essential in detecting cardiac and pulmonary risk factors in order to reduce cardiopulmonary complications. Paraplegia and renal failure are main determinants of postoperative mortality and therefore gained substantial attention during the last decades. Left heart bypass, cerebrospinal fluid (CSF) drainage and epidural cooling have significantly reduced paraplegia rate, however, this dreadful event still occurs in up to 25% of patients undergoing type II repair. Renal failure has been partly prevented by means of retrograde aortic perfusion and cooling but renal failure still remains a significant problem. We have evaluated the effects of protective measures aiming for reduction of paraplegia and renal failure. Monitoring motor evoked potentials (MEPs) is an accurate technique to assess spinal cord integrity during TAAA repair, guiding surgical strategies to prevent paraplegia. Selective volume- and pressure controlled perfusion is a technique to continuously perfuse the kidneys during aortic cross clamping and subsequent circulatory exclusion In patients with atherosclerotic thoracoabdominal aortic aneurysms, blood supply to the spinal cord depends on a highly variable collateral system. In our experience, monitoring MEPs allowed detection of cord ischemia, guiding aggressive surgical strategies to restore spinal cord blood supply and reduce neurologic deficit: overall paraplegia rate was less than 3%. We believe that these protective measures should be included in the surgical protocol of TAAA repair, especially in type II cases. Renal and visceral ischemia can be reduced significantly by continuous perfusion during aortic cross clamping in TAAA repair. Not only sufficient volume flow but also adequate arterial pressure appears to be essential in maintaining renal function.Obviously, endovascular modalities have been successfully applied in TAAA patients, the majority of which as part of hybrid procedures. Technological innovation will eventually cause a shift from open to minimal invasive surgical repair. At present, however, open surgery is considered the gold standard for TAAA repair, especially in (relatively) young patients and patients suffering from Marfan's disease.