Statistical analysis of MCC-IMS data for two group comparisons-an exemplary study on two devices.

The Multi-capillary-column-Ion-mobility-spectrometry (MCC-IMS) technology for measuring breath gas can be used for distinguishing between healthy and diseased subjects or between different types of diseases. The statistical methods for classifying the corresponding breath samples typically neglects potential confounding clinical and technical variables, reducing both accuracy and generalizability of the results. Especially measuring samples on different technical devices can heavily influence the results. We conducted a controlled breath gas study including 49 healthy volunteers to evaluate the effect of the variables sex, smoking habits and technical device. Every person was measured twice, once before and once after consuming a glass of orange juice. The two measurements were obtained on two different devices. The evaluation of the MCC-IMS data regarding metabolite detection was performed once using the software VisualNow, which requires manual interaction, and once using the fully automated algorithm SGLTR-DBSCAN. We present statistical solutions, peak alignment and scaling, to adjust for the different devices. For the other potential confounders sex and smoking, in our study no significant influence was identified.

Cranial ultrasound and MRI at term age in extremely preterm infants.

OBJECTIVES: Conventional MRI at term age has been reported to be superior to cranial ultrasound (cUS) in detecting white matter (WM) abnormalities and predicting outcome in preterm infants. However, in a previous study cUS was performed during the first 6 weeks only and not in parallel to MRI at term age. Therefore, the aim of the present work was to study brain injuries in preterm infants performing concomitant cUS and MRI at full-term age. METHODS: In a population-based cohort of 72 extremely low gestational age infants paired cUS and conventional MRI were performed at term age. Abnormalities on MRI were graded according to a previously published scoring system. On cUS images the lateral ventricles, the corpus callosum, the interhemispheric fissure and the subarachnoidal spaces were measured and the presence of cysts, grey matter abnormalities and gyral folding were scored. RESULTS: Moderate or severe WM abnormalities were detected on MRI in 17% of infants and abnormalities of the grey matter in 11% of infants. Among infants with normal ultrasound (n=28, 39%) none had moderate or severe WM abnormalities or abnormal grey matter on MRI. All infants with severe abnormalities (n=3, 4%) were identified as severe on MRI and cUS. CONCLUSIONS: All severe WM abnormalities identified on MRI at term age were also detected by cUS at term, providing the examinations were performed on the same day. Infants with normal cUS at term age were found to have a normal MRI or only mild WM abnormalities on MRI at term age.

Vacuum assisted wound closure in postoperative periprosthetic groin infections: a new gold standard?

AIM: This study was designed to control the results of conservative treatment using vacuum assisted wound closure (VAWC) applied exclusively to cases of deep groin infections with involvement of alloplastic graft material. METHODS: During a 2 year period 10 patients with 11 deep inguinal infections involving alloplastic graft material were treated with supportive VAWC. Intraoperative management included extensive debridement, sartorius myoplastic and VAWC application. A retrospective case-note review was performed. Variables comorbidity, surgical management of the infection, microbiological results, complications and Doppler results were analysed. RESULTS: Six early graft infections (< 30 days after implantation) and 5 late infections were treated. In 3 cases (27.3%) the infected graft material was replaced by a silver-coated Dacron prosthesis. The mean duration of VAWC was 16+/-7.7 days; postoperative mean hospital stay was 25.3+/-8.5 days. Mean postoperative follow-up was 13.1 months with no procedure-related mortality. CONCLUSION: Even in the presence of synthetic vascular graft material, negative pressure therapy can greatly simplify challenging wound healing problems under maintenance of the alloplastic grafts. These preliminary results demonstrate the safety and effectiveness of VAWC for the treatment of deep alloplastic graft infections.

Antibiotics modulate the stimulated cytokine response to endotoxin in a human ex vivo, in vitro model.

BACKGROUND: Sepsis may lead to the suppression of stimulated cytokine release after Gram-negative stimuli, correlating with a fatal outcome. Treatment of sepsis includes adequate therapy with antibiotics. The aim of this study was to investigate the role of antibiotics in the modulation of the lipopolysaccharide (LPS)-stimulated cytokine response of human monocytes. METHODS: In this ex vivo, in vitro study, whole blood samples were taken from 10 healthy volunteers, stimulated with LPS in the presence or absence of various antibiotics (penicillin, amoxicillin, cefuroxime, ceftazidime, cefotaxime, piperacillin/tazobactam, imipenem/cilastatin, gentamicin, netilmicin, ciprofloxacin, vancomycin) and cultured for 24 h. Thereafter, tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were measured in the supernatants by enzyme-linked immunosorbent assay (ELISA). Furthermore, CD14 and HLA-DR expression on monocytes was assessed using flow cytometry. RESULTS: All cephalosporins decreased LPS-stimulated IL-10 release. Cefuroxime and cefotaxime also decreased the expression density of the LPS recognition molecule CD14 on monocytes. An increase in LPS-stimulated IL-10 release was observed with vancomycin. A suppression of LPS-stimulated TNF-alpha and IL-10 release was observed in the presence of ciprofloxacin. CONCLUSION: These results indicate a modulation of the expression density of CD14 on monocytes, together with a shift from a balanced to an inflammatory cytokine release pattern, by cefuroxime and cefotaxime. Vancomycin changes the response to an anti-inflammatory release pattern. After ciprofloxacin, a profound unresponsiveness of immune-competent cells to LPS stimulation is observed. Because of the critical role of a balanced innate immune response, these data may be of importance for the selection of antibiotics in septic patients.

[Standard procedures in hemodialysis shunt surgery]. / Standardverfahren in der Hämodialyse-Shuntchirurgie.

Native arteriovenous (AV) fistula are the first choice for primary hemodialysis access. It is essential to save as much vein as possible, and therefore distal AV shunts should be tried first. In patients with diabetes, primary brachiocephalic shunts are indicated and show better results than distal AV fistulae. The major complication of AV fistulae is shunt thrombosis. Immediate surgical repair is necessary, with the aim of preserving enough puncture sites to allow prompt continuation of the hemodialysis therapy. It is important to avoid central venous catheters, because these cause infectious complications more frequently. Shunt infections occur more often in polytetrafluoroethylene grafts than in native AV fistulae and represent a life-threatening situation for dialysis patients.

Carotid endarterectomy prior to major abdominal aortic surgery.

BACKGROUND: Major aortic surgery carries a high risk of stroke. Carotid artery occlusive disease (CAOD) has been identified as one of the contributing risk factors. Regarding the long-term prevention of stroke, carotid endartectomy (CEA) seems to be superior to the best medical treatment in patients with high-grade CAOD. However, the role of CEA prior to major aortic surgery has not been studied. DESIGN: Prospective study, observational design. SUBJECTS AND SETTING: 201 patients referred to a community hospital for major aortic surgery. INTERVENTION: The patients were non-invasively screened by continuous-wave and duplex Doppler ultrasonography for the presence of CAOD. In 41 patients with angiographically confirmed high-grade CAOD, CEA was performed prior to major aortic surgery. MAIN OUTCOME MEASURE: Combined mortality and major morbidity from CEA and abdominal aortic surgery. RESULTS: There was no mortality or morbidity related to CEA. Total perioperative mortality related to major aortic reconstruction was 3.5%. No new perioperative focal neurologic deficits occurred except for one fatal stroke in a patient in whom CEA had been judged not to be indicated. CONCLUSIONS: CEA can be performed safely prior to major aortic surgery resulting in excellent overall neurologic outcome in patients with high-grade CAOD. We propose that patients scheduled for major aortic surgery be screened for the presence of high-grade CAOD and that CEA be performed first, if indicated according to published guidelines.

Eversion endarterectomy versus open thromboendarterectomy and patch plasty for the treatment of internal carotid artery stenosis.

OBJECTIVE: in 1996 we changed our treatment for stenosis of the internal carotid artery (ICA) from open thromboendarterectomy and PTFE-patch plasty (TEA) to eversion endarterectomy (EEA). DESIGN: retrospective study. METHODS: a total of 475 EEAs of the ICA were performed between 2/96 and 11/96. These results were compared to the results of TEA carried out between 2/94 and 11/94 (n=388). RESULTS: clamping and operation time were significantly shorter for EEA. Neurological complications included transient ischaemic attacks in 1. 0% in the EEA group versus 1.3% after TEA (p=0.72), minor strokes (0. 6% vs. 1.8%, p=0.10) and major strokes in 1.5% versus 1.1% (p=0.59). The rate of restenosis >50% was 2.5% after EEA and 10.2% after TEA. The only detectable difference of statistical significance in complication rates was in the lesions of the hypoglossal nerve (5.3% vs. 2.6%, p=0.04). CONCLUSIONS: EEA of the ICA is a safe procedure for carotid reconstruction with the additional advantages of short clamping time, possibility of simultaneous shortening of an elongated ICA, and no requirement for patching.

Cardiac risk stratification for high-risk vascular surgery.

BACKGROUND: The best strategy for cardiac risk assessment before high-risk vascular surgery remains controversial. A cardiac risk stratification protocol was evaluated in patients undergoing high-risk vascular surgery. Our investigation paralleled the elaboration of the American College of Cardiology/ American Heart Association (ACC/AHA) Guidelines for Perioperative Cardiovascular Evaluation for Noncardiac Surgery and is highly comparable to the proposed guidelines. METHODS AND RESULTS: A cardiac risk stratification protocol was evaluated prospectively in 203 patients scheduled for aortic surgery. Key points of the study were cardiac mortality/morbidity and cost-effectiveness. Patients were stratified into low (n = 101), intermediate (n = 79), and high (n = 23) cardiac risk after clinical predictors. After stratification, the degree of estimated functional capacity assessed by treadmill exercise and daily living activities and expressed by metabolic equivalents (METs) was critical for further cardiac evaluation. In intermediate-risk patients with an estimated functional capacity < 5 METs and in all high-risk patients, noninvasive cardiac testing and/or subsequent medical care were performed. Noninvasive testing was considered necessary in 41 patients, coronary angiography in 7, and myocardial revascularization in 1. Overall hospital mortality was 3.5%. Cardiac mortality and morbidity were 1% and 12.4%, respectively. CONCLUSIONS: Cardiac risk stratification for high-risk vascular surgery patients, according to a protocol similar to the ACC/AHA Guidelines for Cardiovascular Evaluation for Noncardiac Surgery, demonstrated excellent clinical outcome. This approach appears to be a safe and economical strategy for preoperative cardiac evaluation.

Efficacy of a new prostaglandin E1 regimen in outpatients with severe intermittent claudication: results of a multicenter placebo-controlled double-blind trial.

For the first time efficacy and safety of a new prostaglandin E1 (PGE1) regimen in the treatment of intermittent claudication were evaluated in a randomized, double-blind, placebo-controlled multicenter clinical trial. The study involved 213 outpatients with a maximum walking distance of 50 to 200 m measured on the treadmill (3 km/hr, 12% grade). After a 2-week run-in phase they received a 2-hour intravenous infusion of 60 micrograms PGE1 or placebo 5 days a week for 4 weeks. It was followed by a 4-week interval treatment with the same medication administered only twice a week. Patients were monitored for 3 months when they received no study medication. In the PGE1 group the intention-to-treat analysis (n = 208) revealed an increase in walking distance after 4 weeks of 75% (placebo, 43%). At the end of the interval treatment the walking distance had improved to 101% (placebo, 60%). The results remained virtually constant during follow-up (PGE1, 104%, placebo, 63%). Between-group comparisons showed significant differences in favor of PGE1 for all three time points of measurement (p < 0.05, p < 0.01, and p < 0.05). PGE1 was well tolerated; the rate of adverse reactions related to the treatment was 12.8% (placebo, 7.7%). In summary, these results show that the new PGE1 regimen is effective and safe in the treatment of outpatients with intermittent claudication.

[Intraoperative lysis and neurostimulation as added therapy in surgery of popliteal artery aneurysm]. / Intraoperative Lyse und Neurostimulation als additive Therapie in der Chirurgie des Poplitea-Aneurysmas.

Additional therapy of symptomatic popliteal artery aneurysm includes intraoperative lysis for the treatment of the descending thrombosis and spinal cord stimulation for cases of chronic deterioration of the peripheral perfusion state. Between 1989 and 1996, we treated 50 patients with 55 symptomatic aneurysms using this concept, 18 of them as emergency cases. We reached a postoperative amputation rate of 12.7% and good long-term functional results in 34 of 37 patients.

Intraoperative use of somatosensory evoked potentials for brain monitoring during carotid surgery.

Somatosensory evoked potentials (SSEP) are a valuable clinical tool in the operating theater. Multichannel SSEP monitoring is an objective measure of CBF and cerebral function. The monitoring of the SSEP during carotid surgery is a simple and reliable method of determining the effect of carotid clamping on CBF and the need for shunting. The diagnosis sensitivity and specificity of intraoperative SSEP monitoring for assessing the neurologic outcome of patients are over 95%. At least 16.1% of cases required shunt placement using SSEP monitoring.

Intraoperative autotransfusion in aortic surgery: comparison of whole blood autotransfusion versus cell separation.

OBJECTIVE: Differences concerning alteration of hemostatic, hemolysis, and hematologic parameters after transfusion of blood from a cell-separation (CS) device or whole blood autotransfusion (WBA) were prospectively evaluated during major aortic surgery. METHOD: Thirty-two patients were randomly selected to receive autologous retransfusion by using either WBA or a CS device. Coagulation and hematologic parameters and levels of hemolytic degradation products (HDP) were assessed in the retransfused blood and in the patients' plasma preoperatively and until 24 hours after autologous retransfusion, respectively. RESULTS: Mean volume of retransfused blood was 1072 +/- 473 ml in the WBA group and 556 +/- 504 in the CS group. Level of HDP (bilirubin, free hemoglobin [free HB], and lactic dehydrogenase [LDH] and hemostatic disturbances (d-dimer value, fibrin degradation products) were significantly higher in the WBA device compared with the CS blood. Blood samples taken from the WBA group revealed significantly higher level of HDP (free HB, LDH) and of d-dimer values after autotransfusion compared with the CS group. CONCLUSION: Levels of HDP and the degree of hemostatic disturbances were significantly higher in retransfused whole blood compared with CS blood. Hemostatic disturbances and levels of HDP were significantly pronounced in the patients' plasma after WBA compared with CS. CS retransfused blood seems to be of superior quality compared with WBA and the degree of hemolysis and hemostatic disturbances is minor after CS retransfusion.

Significance of radiological diagnosis for detection and staging of inflammatory abdominal aortic aneurysm.

Operative morbidity and mortality are elevated in patients with inflammatory abdominal aortic aneurysm. Preoperative identification of inflammatory abdominal aortic aneurysm. the detection of the proximal level and of adhesions to adjacent structures are important for surgical management. The sensitivity and specificity of ultrasonography and computed tomography (CT) for identification and staging in 13 patients with inflammatory abdominal aortic aneurysm were studied. Preoperative radiological diagnoses were validated by intraoperative findings. Correct identification of inflammatory abdominal aortic aneurysm could be achieved in 85% by the use of CT and in 62% by ultrasonography. The proximal level of inflammatory abdominal aortic aneurysm was correctly determined by CT in all patients and by ultrasonography in 62%. Using a transperitoneal approach, the condition was considered inoperable in two patients as a result of the suprarenal extent of the aneurysm and because of unremovable adhesions in two other cases. In the latter pair, it was impossible to predict inoperability by radiological findings. Sensitivity (85%) and specificity (100%) of standard radiological techniques to identify inflammatory changes are high. Inoperability caused by suprarenal extent could be detected correctly by routine radiological procedures. However, identification of dense adhesions appears uncertain.

F.P. Weber syndrome associated with a brachial artery aneurysm. A case report.

Klippel-Trenaunay syndrome is characterized by the triad of unilateral port-wine hemangiomas, varicose veins, and hypertrophy of bone and soft tissue affecting one or more limbs. The rare F.P. Weber syndrome describes the mentioned entity and additional arteriovenous malformations. The association of an arterial aneurysm with the F.P. Weber syndrome has never been described in the current literature. A case of a brachial artery aneurysm in a patient with F.P. Weber syndrome is presented and the etiology of arterial aneurysm combined with congenital vascular abnormalities is discussed.

[Monitoring somatosensory evoked potentials during carotid endarterectomy]. / Szomatoszenzoros kiváltott válasz monitorozás carotis endarterectomia alatt.

The tromboembolic and ischemic events during carotid endarterectomy can be avoided or detected with appropriate monitoring. Median nerve somatosensory evoked potentials recorded from the parietal cortex correlate with the blood flow in the middle cerebral artery. The good evoked responses after cross-clamping of the carotid artery indicate a sufficient collateral circulation, enabling a surgery without shunt, thus minimizing the risk of embolisation. Insufficient collateral circulation after cross-camping results in an amplitude reduction of the parietal N20-P25 complex of more than 50%. In this case an ischemic event can be prevented by shunting. As a total 83 carotid endarterectomies were done. In 65 cases (78.3%) the evoked potentials showed no significant alteration, and no postoperative neurological deficit occurred. Seven patients (8.45%) needed to be operated with a shunt, because of cross-clamping ischaemia. One of them presented a transient postoperative hemiparesis, which was predicted by the long-term loss of the SEP-s, and which resolved within 4 hours. Seven further patients (8.45%)--operated primarily with shunt, and 4 patients (4.8%)--monitored with transcranial Doppler sonography, showed no postoperative neurological deficit. We found that median nerve somatosensory evoked potential monitoring during carotid endarterectomy is a simple, sensitive and reliable method.

Classification of congenital arterial and venous vascular malformations.

Arterial and venous vascular malformations due to congenital abnormalities rarely occur in the daily practice of vascular surgeons. These malformations represent a heterogeneous group of isolated or multiple congenital abnormalities, sometimes associated with complex congenital syndromes. Correct recognition and classification of these rare abnormalities may sometimes be difficult. No systematic classification of arterial and/or venous vascular malformations due to congenital abnormalities is currently available. On the basis of embryologic and pathophysiologic considerations, a rational and simple classification of arterial and venous vascular malformations due to congenital abnormalities can be performed. This contribution presents an appropriate classification of clinically important arterial and venous vascular malformations due to congenital abnormalities.

Epidural spinal cord stimulation in the treatment of severe peripheral arterial occlusive disease.

Epidural spinal cord stimulation (ESCS) has been suggested to improve microcirculatory blood flow and reduce amputation rates in patients with severe peripheral arterial occlusive disease (PAOD). Pain relief, limb salvage, and skin circulation were studied in 177 patients with ischemic pain caused by nonreconstructible PAOD who were receiving ESCS. Medical or surgical therapy had failed and vascular reconstruction was impossible in all cases. Clinical status was classified as Fontaine's stage III (chronic ischemic rest pain) in 114 patients and Fontaine's stage IV (ischemic pain and ulcers or dry gangrene) in 63 patients. PAOD was essentially due to arteriosclerosis, but 36 patients also had diabetic vascular disease. After a mean follow-up of 35.6 months, significant pain relief (> 75%) with limb salvage was achieved in 110 patients. In 11 patients with limb salvage, pain alleviation was determined to be between 50% and 70%. ESCS was ineffective in reducing pain, leading to major amputation in 56 patients. The cumulative limb salvage rate was 66% at 4 years. The systolic ankle/brachial blood pressure index did not change under stimulation. TcPO2 was assessed on the dorsum of the foot. Clinical improvement was associated with increased TcPO2, with limb salvage improving from 24.2 to 48.1 mm Hg in stage III (p < 0.02) and from 16.4 to 37.2 mm Hg in stage IV (p < 0.03) disease. A TcPO2 increase of more than 50% within the first 3 months after implantation was predictive of success. TcPO2 changes are correlated with the presence of adequate paresthesias in the painful area during the trial period.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative whole blood autotransfusion during venous thrombectomy.

OBJECTIVE: Intraoperative autotransfusion is currently performed using two different systems, the relatively expensive cell-saving device washes and concentrates red cells and the more simple, economical total disposable device for whole blood collection and retransfusion. Some institutions prefer the cell-saving device because of previously documented side-effects of whole blood autotransfusion. As some investigators more recently reported the application of whole blood autotransfusion without clinical complications, the potential hazards of whole blood autotransfusion are now being controversially discussed. MATERIALS AND METHODS: The potential side-effects using whole blood autotransfusion were studied in 100 patients prospectively undergoing venous thrombectomy. The effectiveness of homologous transfusion reduction was assessed in comparison with an historical patient group (n = 10, control group). RESULTS: In the study population a mean of 1064 ml shed blood (67% of total blood loss) was retransfused. A mean of 247 +/- 292 ml of homologous blood was transfused in the study group. In contrast, homologous blood requirement was significantly higher (1056 +/- 659 ml, p < 0.006) in the control group. No hematologic, hemeostatic, renal or pulmonary complications occurred after intraoperative whole blood autotransfusion. CONCLUSIONS: Whole blood autotransfusion is a safe, easy and economical procedure and highly effective in reducing homologous blood transfusions and costs.