The fate of the distal aorta after repair of acute type A aortic dissection Halstead, James C., MA (Cantab), MB, BChir, MRCS (Eng); Meier, Matthias, MD; Etz, Christian, MD ...
The Journal of thoracic and cardiovascular surgery,
2007, 20070101, 2007-Jan, 2007-01-00, Letnik:
133, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Objectives The residual aorta’s behavior after repair of acute type A dissection is incompletely understood. We analyzed segmental growth rates, distal reoperation, and factors influencing long-term ...survival. Methods One hundred seventy-nine consecutive patients (70% male; mean age, 60 years) with acute type A dissection underwent aggressive resection of the intimal tear and open distal anastomosis (1986-2003). Hospital mortality was 13.4%. Survivors had serial computed tomographic scans: digitization yielded distal segmental dimensions. Segment-specific average rates of enlargement and factors influencing faster growth were analyzed. Distal reoperations and patient survival were examined. Results Eighty-nine (57%) patients had imaging data sufficient for growth rate calculations. The median diameters after repair were as follows: aortic arch, 3.6 cm; descending aorta, 3.7 cm; and abdominal aorta, 3.2 cm. Subsequent growth rates were 0.8, 1.0, and 0.8 mm/y, respectively. Initial size of greater than 4 cm ( P = .005) and initial diameter of less than 4 cm with a patent false lumen ( P = .004) predicted greater growth in the descending aorta, and male sex ( P = .05) significantly affected growth in the abdominal aorta. No significant factors were found for the aortic arch. There were 25 distal aortic reoperations (16 patients), and risk of reoperation was 16% at 10 years. Risk factors reducing long-term survival after repair of acute type A dissection included age ( P < .0001), new neurological deficit at presentation ( P = .04), absence of preoperative thrombus in the false lumen of the ascending aorta ( P = .03), and a patent distal false lumen postoperatively ( P = .06) but not distal reoperation. Conclusions Growth of the distal aorta after repair of acute type A dissection is typically slow and linear. Distal reoperation is uncommon, and late risk of death is approximately twice that of a healthy population.
The impact of different strategies for management of intercostal and lumbar arteries during repair of thoracic and thoracoabdominal aortic aneurysms (TAA/A) on the prevention of paraplegia remains ...poorly understood.
One hundred consecutive patients with intraoperative monitoring of motor evoked potentials (MEP) and somatosensory evoked potentials (SSEP) during TAA/A repair involving serial segmental artery sacrifice (October 2002 to December 2004) were reviewed.
Operative mortality was 6%. The median intensive care unit stay was 2.5 days (IQ range: 1–4 days), and the median hospital stay 10.0 days (IQ range: 8–17 days). Potentials remained unchanged during the course of serial segmental artery sacrifice, or could be returned to baseline levels by anesthetic and blood pressure manipulation, in 99 of 100 cases. An average of 8.0 ± 2.6 segmental artery pairs were sacrificed overall, with an average of 4.5 ± 2.1 segmental pairs sacrificed between T7 and L1, where the artery of Adamkiewicz is presumed to arise. Postoperative paraplegia occurred in 2 patients. In 1, immediate paraplegia was precipitated by an intraoperative dissection, resulting in 6 hours of lower body ischemia. A second ambulatory patient had severe paraparesis albeit normal cerebral function after resuscitation from a respiratory arrest.
With monitoring of MEP and SSEP, sacrifice—without reimplantation—of as many as 15 intercostal and lumbar arteries during TAA/A repair is safe, resulting in acceptably low rates of immediate and delayed paraplegia. This experience suggests that routine surgical implantation of segmental vessels is not indicated, and that, with evolving understanding of spinal cord perfusion, endovascular repair of the entire thoracic aorta should ultimately be possible without spinal cord injury.
Introduction
Blood cultures (BCs) frequently become contaminated during the pre-analytic phase of collection leading to downstream ramifications. We present a summary of performance improvement (PI) ...interventions provided by four hospital systems and common factors that contributed to decreased blood culture contamination (BCC) rates.
Methods
Each hospital independently formed a multidisciplinary team and action plan for implementation of their intervention, focusing on the use of educational and training tools. Their goal was to significantly decrease their BCC rates. Pre- and post-intervention data were compared during the sustainment period to determine their success.
Results
All hospitals met their goals of post-intervention BCC rates and with most achieving and sustaining BCC rates ≤ 1.0–2.0%.
Conclusion
Our report highlights how four hospitals independently achieved their objective to decrease their BCC rate with the support of a multidisciplinary team. We propose a benchmark for BCC rates of 1.5 to < 2.0% as achievable and sustainable.
A rapid and specific reversed-phase high performance liquid chromatography (RP-LC) method with photodiode array detection (DAD) was developed and validated for the determination of four common ...schisandra lignans, schisandrin (1), schisandrol B (2), deoxyshisandrin (3) and γ-schisandrin (4), in raw herb materials and commercial dried aqueous extracts of Schisandra chinensis (Wu Wei Zi). The extraction solvent and extraction method were optimised where it was found that a 4h Soxhlet extraction using methanol was successful at extracting >99.5% of each of the schisandra lignans analysed from the raw herb material. The sample preparation process for the dried aqueous extract samples involved sonication using methanol for 2×30min. The herb and extract solutions were separated on a Varian Microsorb-MV 100-5 C18 column using a gradient mixture of 0.1% aqueous phosphoric acid and acetonitrile. Subsequent detection and quantitation of the schisandra lignans was performed at 210nm. The correlation coefficients of the linear regression analysis performed on these calibration curves were >0.9996 for all four schisandra lignans assayed. The detection limits and quantification limits ranged from 0.12 to 0.57 and 0.41 to 1.89mgg−1, respectively. The mean recoveries of the various analytes ranged from 92.20 to 107.01%. The method was used to investigate the levels of the four mentioned components in herb samples and dried aqueous extracts. The identities of the chromatographic peaks were confirmed by (+) electrospray ionisation LC–MS/MS.
Summary Objective To measure the in vitro activity of a panel of antimicrobial agents against gram-negative pathogens collected from the nine census regions of the USA. Methods Isolates were ...collected from 76 centers between January 2004 and September 2005. In vitro activity was assessed using CLSI guidelines and CLSI or FDA interpretive criteria. Results The lowest overall antimicrobial susceptibilities for Acinetobacter calcoaceticus-baumannii complex isolates ( n = 851) were detected in the Middle Atlantic and East South Central regions. Overall, 29.3% of A. calcoaceticus-baumannii complex isolates were multidrug-resistant (resistant to ≥3 antimicrobial classes). Tigecycline (2 μg/mL) had the lowest MIC90 against this organism. Imipenem, tigecycline, and levofloxacin had low MIC90 s (0.25–4 μg/mL) against Enterobacter spp. ( n = 1557), although the MIC90 for levofloxacin was elevated for East South Central region isolates (≥16 μg/mL). Susceptibility to levofloxacin among the E. coli isolates ( n = 1785) ranged from 71.7% (Pacific) to 88.5% (New England). The prevalence of ESBL-producing K. pneumoniae (126/1460) varied from 1.7% of isolates (Pacific) to 21.2% (Middle Atlantic). ESBL-producing K. pneumoniae MICs were lowest for imipenem and tigecycline. Conclusions Antimicrobial susceptibility varies among the census regions of the USA. The broad-spectrum in vitro activity of tigecycline may make it a suitable candidate for use in the empiric treatment of serious infections.
Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is ...an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC50=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC50=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED50=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED50=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.
Hypothermic selective antegrade cerebral perfusion during aortic arch replacement may prevent adverse neurologic sequelae. It can be provided via balloon-tipped catheters or a branched graft sewn to ...the brachiocephalic vessels. We report a consecutive series of total arch replacement using a trifurcated graft.
From September 1999 through October 2004, 109 patients underwent nonemergent total arch replacement using this technique. The graft, placed during a period of hypothermic circulatory arrest, was used for selective cerebral perfusion during the arch reconstruction.
Adverse outcomes were seen in 9 (8.3%) patients: hospital death in 5 (4.6%), and stroke in 5 (4.6%). Transient neurologic dysfunction was noted in 6 (5.5%) patients. Mean duration of hypothermic circulatory arrest was 31.2 ± 6.6 minutes and selective cerebral perfusion was 65.3 ± 20.9 minutes. Reoperation for bleeding was required in 3 (2.8%) patients and prolonged intubation in 15 (13.8%). Median intensive care unit stay was 3 days (interquartile range 2–4; range, 1 to 108) and hospital stay was 9 (interquartile range 8–15; range, 5 to 108).
The trifurcated graft technique results in low rates of perioperative mortality, temporary neurologic dysfunction, and stroke. It may reduce cerebral embolization as it requires no instrumentation of the aortic arch to establish selective cerebral perfusion and, although it mandates hypothermic circulatory arrest to place the graft, this interval is reliably brief enough to fall within accepted safe limits. This strategy leaves no residual arch tissue behind, and allows placement of an elephant trunk proximal to one or more arch vessels if anatomically indicated.
Abstract
Objective
Laboratories are facing a critical shortage of medical laboratory scientists (MLS) and medical laboratory technicians (MLT) to address an increasing demand for laboratory testing. ...Training program closures, fewer student applicants, and financial decisions have contributed to staffing shortages. Lack of visibility, low wages, and perceived lack of opportunities for upward career mobility contribute to challenges in recruiting and retaining qualified individuals and students who are unaware of laboratory medicine careers. Our goal was to review the literature to determine the current state and consequences of staffing shortages, and potential solutions to address these shortages.
Methods
Medline/PubMed, PubMed Central, MeSH, Google Scholar, and Marshall Digital Scholar were used as resources.
Discussion/Conclusions
A collaboration of stakeholders is needed to identify staffing challenges, barriers, and solutions and to increase visibility of laboratory professionals. Early recruitment is best started in the middle and high school educational process.
Objective Selective cerebral perfusion is a proven adjunct to hypothermia for neuroprotection in complex aortic surgery. The ideal conditions for the provision of selective cerebral perfusion, ...however, including optimal perfusion pressure, remain unknown. We investigated the effects of various perfusion pressures during selective cerebral perfusion on cerebral physiology and outcome in a long-term porcine model. Methods Thirty piglets (26.3 ± 1.4 kg), cooled to 20°C on cardiopulmonary bypass with α-stat pH management (mean hematocrit 23.6%), were randomly assigned to 90 minutes of selective cerebral perfusion at a pressure of 50 (group A), 70 (group B), or 90 (group C) mm Hg. With fluorescent microspheres and sagittal sinus sampling, cerebral blood flow and cerebral oxygen metabolism were assessed at baseline, after cooling, at two points during selective cerebral perfusion, and for 2 hours after cardiopulmonary bypass. Visual evoked potentials were monitored during recovery. Neurobehavioral scores were assessed blindly from standardized videotaped sessions for 7 postoperative days. Results Cerebral blood flow during selective cerebral perfusion was significantly increased by higher-pressure perfusion ( P = .04), although all groups sustained similar levels of cerebral oxygen metabolism during selective cerebral perfusion ( P = .88). After the end of cardiopulmonary bypass, the cerebral oxygen metabolism increased to above baseline in all groups, with the highest levels seen in group C ( P = .06). Intracranial pressure was significantly higher during selective cerebral perfusion in group C ( P = .0002); visual evoked potentials did not differ among groups. Neurobehavioral scores were significantly better in group A ( P = .0002). Conclusion Selective cerebral perfusion at 50 mm Hg provides neuroprotection superior to that at higher pressures. The increased cerebral blood flow with higher-pressure selective cerebral perfusion is associated with cerebral injury, reflected by high post–cardiopulmonary bypass cerebral oxygen metabolism and poorer neurobehavioral recovery.
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