Cost-Effectiveness of Two Decision Strategies for Shunt Use During Carotid Endarterectomy.

BACKGROUND: Arterial shunting during carotid endarterectomy (CEA) is essential in some patients because of insufficient cerebral perfusion during cross-clamping. However, the optimal diagnostic modality identifying these patients is still debated. None of the currently used modalities has been proved superior to another. The aim of this study was to assess the cost-effectiveness of two modalities, stump pressure measurement (SPM) versus electroencephalography (EEG) combined with transcranial Doppler (TCD) during CEA. METHODS: Two retrospective cohorts of consecutive patients undergoing CEA with different intraoperative neuromonitoring strategies (SPM vs. EEG/TCD) were analyzed. Clinical data were collected from patient hospital records. Primary clinical outcome was in-hospital stroke or death. Total admission costs were calculated based on volumes of healthcare resources. Analyses of effects and costs were adjusted for clinical differences between patients by means of a propensity score, and cost-effectiveness was estimated. RESULTS: A total of 503 (239 SPM; 264 EEG/TCD) patients were included, of whom 19 sustained a stroke or died during admission (3.3 vs. 4.2%, respectively, adjusted risk difference 1.3% (95% CI -2.3-4.8%)). Median total costs were €4946 (IQR 4424-6173) in the SPM group versus €7447 (IQR 6890-8675) in the EEG/TCD group. Costs for neurophysiologic assessments were the main determinant for the difference. CONCLUSIONS: Given the evidence provided by this small retrospective study, SPM would be the favored strategy for intraoperative neuromonitoring if cost-effectiveness was taken into account when deciding which strategy to adopt.

Relation between B-mode gray-scale median and clinical features of carotid stenosis vulnerability.

BACKGROUND: Vulnerability of the carotid plaque might be useful as a predictor for ischemic stroke risk. The gray-scale median (GSM) of the carotid plaque at B-mode imaging has been described as an objective tool to quantify vulnerability. However, its use is disputed in the published literature. This study sought to validate the GSM as a predictor for carotid plaque vulnerability. METHODS: We included 89 consecutive patients (64 men; mean ± SD age: 68 ± 1 years) who were evaluated for carotid endarterectomy. The GSM was derived from preoperative B-mode images and related to the presence of clinical symptoms, the presence of ipsilateral infarction on neuroimaging, and to the number of intraoperative ipsilateral microemboli (ME) detected by transcranial Doppler ultrasonography. In addition, we combined the GSM with its standard deviation (GSM-SD), which we hypothesized to be a measure for plaque heterogeneity and thereby vulnerability. RESULTS: B-mode imaging revealed a wide variety in GSM among all plaques (median: 36; range: 6-89). The GSM could not be related to cardiovascular risk factors and was not different between symptomatic and asymptomatic patients (37.8 ± 8.9 vs 37.6 ± 17.1; P = 0.97). The GSM of plaques in patients with ipsilateral ischemic lesions on neuroimaging did also not differ from plaques in patients without (36.0 ± 14.6 vs 37.8 ± 16.9; P = 0.64). Finally, no relation between GSM and the presence of intraoperative ME (Spearman correlation; n = 73; ρ = 0.039; P = 0.75) was found. Combining GSM with its GSM-SD also could not identify more vulnerable plaques. CONCLUSIONS: No relation was found between the GSM and any clinical, radiologic, or intra- and postoperative neurologic phenomena. These data showed no additional value of the use of GSM in evaluating plaque vulnerability.

The gradual onset brain death model: a relevant model to study organ donation and its consequences on the outcome after transplantation.

Organs used for transplantation are usually derived from heart-beating brain dead donors. However, brain death is known to have negative effects on donor organ quality, previously studied using a difficult to control sudden onset experimental model. We have now developed a reproducible gradual onset brain death model in rats without requiring inotropic support. Fisher inbred rats weighing 260-300 g were used. Brain death was induced by a gradual inflation of a subdurally placed balloon catheter. During induction and the period following brain death, the animals were mechanically ventilated and blood pressure was continuously monitored. The blood pressure registration showed a characteristic pattern during brain death induction, in which a decrease in blood pressure, a hypotensive period in which the Cushing response occurred, and a sharp peak were consistent findings. After brain death was induced, blood pressure was maintained at normotensive levels up to 4 h. After the experiments, neuropathological evaluation of the brain located haemorrhagic cerebral parenchyma, and immunocytochemistry of liver tissue revealed a significant influx of polymorph nuclear cells, as was previously observed as well. This improved model allows the study of brain death on donor organ quality without the use of inotropic support.

Atmospheric Pressure and Abdominal Aortic Aneurysm Rupture: Results From a Time Series Analysis and Case-Crossover Study.

BACKGROUND: Associations between atmospheric pressure and abdominal aortic aneurysm (AAA) rupture risk have been reported, but empirical evidence is inconclusive and largely derived from studies that did not account for possible nonlinearity, seasonality, and confounding by temperature. METHODS: Associations between atmospheric pressure and AAA rupture risk were investigated using local meteorological data and a case series of 358 patients admitted to hospital for ruptured AAA during the study period, January 2002 to December 2012. Two analyses were performed-a time series analysis and a case-crossover study. RESULTS: Results from the 2 analyses were similar; neither the time series analysis nor the case-crossover study showed a significant association between atmospheric pressure ( P = .627 and P = .625, respectively, for mean daily atmospheric pressure) or atmospheric pressure variation ( P = .464 and P = .816, respectively, for 24-hour change in mean daily atmospheric pressure) and AAA rupture risk. CONCLUSION: This study failed to support claims that atmospheric pressure causally affects AAA rupture risk. In interpreting our results, one should be aware that the range of atmospheric pressure observed in this study is not representative of the atmospheric pressure to which patients with AAA may be exposed, for example, during air travel or travel to high altitudes in the mountains. Making firm claims regarding these conditions in relation to AAA rupture risk is difficult at best. Furthermore, despite the fact that we used one of the largest case series to date to investigate the effect of atmospheric pressure on AAA rupture risk, it is possible that this study is simply too small to demonstrate a causal link.

Endarterectomy or carotid artery stenting: the quest continues part two.

BACKGROUND: Although randomized trials on carotid artery stenting (CAS) could not establish its equivalence to carotid endarterectomy (CEA) in patients with symptomatic carotid disease, CAS is rapidly evolving. Data on long-term outcome after CAS from randomized trials have now become available and ongoing, prospectively held registries frequently publish their results in increasing numbers of patients. We have therefore reviewed the currently available literature and provide an update of our previous article on this topic. DATA SOURCES: PubMed literature searches were performed to identify relevant studies regarding current status of CEA and stenting for symptomatic carotid stenosis. CONCLUSIONS: The efficacy of CAS in patients with symptomatic carotid artery stenosis remains unclear because of varying results in randomized trials. Although multiple registries do report promising results after CAS, peri-interventional stroke/death rates still exceed those rates currently found after CEA. Therefore, CEA remains the "gold standard" in treating these patients.

[From CVA or TIA to carotid surgery: the clinical treatment course for patients with symptomatic carotid disease could be shorter]. / Van CVA of TIA tot carotischirurgie: zorgtraject voor patiënten met symptomatisch carotislijden kan korter.

OBJECTIVE: To gain insight into the duration and the various components of the clinical treatment course for patients with symptomatic carotid artery stenosis, in order to improve the care provided to these patients. DESIGN: Retrospective cohort study. METHODS: All patients who had undergone a carotid intervention for significant symptomatic carotid stenosis from 2001 to 2011 were included. Quantile regression analysis was used to assess the changes which had occurred in the median duration of the period from neurological event to intervention from 2001 onward. In order to chart the clinical treatment course, it was split up in different components. In addition, the impact of the referrer and the relationship between the time of the intervention and the risk of perioperative complications were also evaluated. RESULTS: The median duration of the entire clinical treatment course decreased during the study period from 79 days (interquartile range (IQR): 59-113) in the reference period 2001-2004 to 19 days (IQR: 13-28) in 2011. All components of the clinical pathway had contributed to this decline. The duration of the clinical course in patients who had been externally referred was more than 3 times longer (median 67 vs. 21 days, p < 0.01). The total duration of the process did not affect the number of perioperative complications. CONCLUSION: In the last decennium, the duration of the clinical treatment course of care in patients with symptomatic carotid artery disease was greatly reduced. Analyses of the processes which make up the chain of events, however, reveal that there is still much to be gained in the period before initial presentation at the hospital for patients who are referred by their general practitioners as well as those referred by other hospitals.

Protection of stapled colorectal anastomoses with a biodegradable device: the C-Seal feasibility study.

BACKGROUND: A colorectal anastomotic leak can be life-threatening. We have assessed the feasibility of a new intraluminal biodegradable bypass device that we designed to avoid anastomotic leakage and the necessity of a temporary stoma. METHODS: Fifteen patients underwent colorectal surgery. Before performing the anastomosis in a standard way, the C-Seal (Polyganics BV, Groningen, The Netherlands) was glued to the anvil of the circular stapler. Consequently, the bypass was fixated in the staple row just proximal of the simultaneously made anastomosis. A water-soluble contrast enema was performed after 1 week. RESULTS: The sheath was well compatible with the standard stapler device and easy to use. All donuts remained intact. No radiologic or clinical leaks were observed after surgery. CONCLUSIONS: This pilot study shows that the C-Seal can be applied successfully in colorectal surgery. Further investigation with large numbers of patients is now necessary to assess the efficacy of the C-Seal as a protective device.

Overestimation of contralateral internal carotid artery stenosis before ipsilateral surgical endarterectomy.

OBJECTIVE: The aim of this study was to investigate a possible overestimation of the degree of contralateral carotid artery stenosis by duplex in patients with significant bilateral carotid stenoses who are to undergo carotid endarterectomy (CEA). METHODS: A retrospective analysis was performed of all patients undergoing CEA in our center over a period of 11 years. Pre- and postoperative duplex ultrasonography measurements of peak systolic velocity (PSV) and end diastolic velocity (EDV) were compared and used to classify the degree of stenosis. Univariate analysis was performed to indicate possible predictors for contralateral stenosis overestimation. RESULTS: A total of 384 CEA procedures in 357 patients were performed in our hospital. Pre- and postoperative bilateral duplex measurements were available in 135 patients. Forty-four out of 135 patients (33%) were preoperatively identified as having significant stenosis (>60%) of the internal carotid artery on both sides. In these patients, postoperative duplex measurements of the contralateral carotid showed a decrease in mean (SD) PSV from 2.53 (1.11) m s(-1) to 1.97 (0.87) m s(-1) (P<0.01) and a decrease in EDV from 0.87 (0.60) m s(-1) to 0.60 (0.36) m s(-1) (P<0.01). The absolute changes in contralateral PSV and EDV after CEA were larger among patients with a higher degree of stenosis preoperatively. These changes led to reclassification of stenosis to a lesser degree in 24 (55%) patients. In 16 cases (36%), this resulted in a measured stenosis on the contralateral side of less than 60%. CONCLUSIONS: One-third of the patients with duplex measurements consistent with bilateral significant carotid stenosis did not have a significant contralateral stenosis by duplex after CEA. Therefore, additional postoperative duplex measurement is advisable before planning contralateral CEA.

Preservation of steatotic livers: a comparison between cold storage and machine perfusion preservation.

Liver grafts are frequently discarded due to steatosis. Steatotic livers can be classified as suboptimal and deteriorate rapidly during hypothermic static preservation, often resulting in graft nonfunction. Hypothermic machine perfusion (MP) has been introduced for preservation of donor livers instead of cold storage (CS), resulting in superior preservation outcomes. The aim of this study was to compare CS and MP for preservation of the steatotic donor rat liver. Liver steatosis was induced in male Wistar rats by a choline-methionine-deficient diet. After 24 hours hypothermic CS using the University of Wisconsin solution (UW) or MP using UW-Gluconate (UW-G), liver damage (liver enzymes, perfusate flow, and hyaluronic acid clearance) and liver function (bile production, ammonia clearance, urea production, oxygen consumption, adenosine triphosphate [ATP] levels) were assessed in an isolated perfused rat liver model. Furthermore, liver biopsies were visualized by hematoxylin and eosin staining. Animals developed 30 to 60% steatosis. Livers preserved by CS sustained significantly more damage as compared to MP. Bile production, ammonia clearance, urea production, oxygen consumption, and ATP levels were significantly higher after MP as compared to CS. These results were confirmed by histology. In conclusion, MP improves preservation results of the steatotic rat liver, as compared to CS.