Omental Vascularized Lymph Node Flap: A Radiographic Analysis

Background Vascularized lymph node transfer is an increasingly popular option for the treatment of lymphedema. The omental donor site is advantageous for its copious soft tissue, well-defined collateral circulation, and large number of available nodes, without the risk of iatrogenic lymphedema. The purpose of this study is to define the anatomy of the omental flap in the context of vascularized lymph node harvest. Methods Consecutive abdominal computed tomography angiography (CTA) images performed at a single institution over a 1-year period were reviewed. Right gastroepiploic artery (RGEA) length, artery caliber, lymph node size, and lymph node location in relation to the artery were recorded. A two-tailed Z-test was used to compare means. A Gaussian Mixture Model confirmed by normalized entropy criterion was used to calculate three-dimensional lymph node cluster locations along the RGEA. Results In total, 156 CTA images met inclusion criteria. The RGEA caliber at its origin was significantly larger in males compared with females (p < 0.001). An average of 3.1 (1.7) lymph nodes were present per patient. There was no significant gender difference in the number of lymph nodes identified. Average lymph node size was significantly larger in males (4.9 [1.9] × 3.3 [0.6] mm in males vs. 4.5 [1.5] × 3.1 [0.5] mm in females; p < 0.001). Three distinct anatomical variations of the RGEA course were noted, each with a distinct lymph node clustering pattern. Total lymph node number and size did not differ among anatomical subgroups. Conclusion The omentum is a reliable lymph node donor site with consistent anatomy. This study serves as an aid in preoperative planning for vascularized lymph node transfer using the omental flap

Minimally Invasive Surgical Therapies for Atrial Fibrillation

Atrial fibrillation is the most common sustained arrhythmia and is associated with significant risks of thromboembolism, stroke, congestive heart failure, and death. There have been major advances in the management of atrial fibrillation including pharmacologic therapies, antithrombotic therapies, and ablation techniques. Surgery for atrial fibrillation, including both concomitant and stand-alone interventions, is an effective therapy to restore sinus rhythm. Minimally invasive surgical ablation is an emerging field that aims for the superior results of the traditional Cox-Maze procedure through a less invasive operation with lower morbidity, quicker recovery, and improved patient satisfaction. These novel techniques utilize endoscopic or minithoracotomy approaches with various energy sources to achieve electrical isolation of the pulmonary veins in addition to other ablation lines. We review advancements in minimally invasive techniques for atrial fibrillation surgery, including management of the left atrial appendage

Comparing Gravitational Waveform Extrapolation to Cauchy-Characteristic Extraction in Binary Black Hole Simulations

We extract gravitational waveforms from numerical simulations of black hole binaries computed using the Spectral Einstein Code. We compare two extraction methods: direct construction of the Newman-Penrose (NP) scalar $\Psi_4$ at a finite distance from the source and Cauchy-characteristic extraction (CCE). The direct NP approach is simpler than CCE, but NP waveforms can be contaminated by near-zone effects---unless the waves are extracted at several distances from the source and extrapolated to infinity. Even then, the resulting waveforms can in principle be contaminated by gauge effects. In contrast, CCE directly provides, by construction, gauge-invariant waveforms at future null infinity. We verify the gauge invariance of CCE by running the same physical simulation using two different gauge conditions. We find that these two gauge conditions produce the same CCE waveforms but show differences in extrapolated-$\Psi_4$ waveforms. We examine data from several different binary configurations and measure the dominant sources of error in the extrapolated-$\Psi_4$ and CCE waveforms. In some cases, we find that NP waveforms extrapolated to infinity agree with the corresponding CCE waveforms to within the estimated error bars. However, we find that in other cases extrapolated and CCE waveforms disagree, most notably for $m=0$ "memory" modes.Comment: 26 pages, 20 figure

Defining the Efficacy of Aortic Root Enlargement Procedures: A Comparative Analysis of Surgical Techniques

Background: Aortic root enlargement (ARE) procedures are believed to allow implantation of larger valve prostheses; however, little evidence exists to support the specific efficacy of various techniques. Methods: Using a cadaveric model, 20 adult (72.4 +/- 15.3 years) hearts were stratified into 4 groups based on annular diameter: \u3c20 mm, 20-22 mm, 22-24 mm, and \u3e24 mm. Each heart underwent an aortic valve replacement following a Nicks, Manougian, aortoventriculoplasty and modified Bentall procedure, with appropriate reversals between procedures. Results: All 4 groups experienced similar increases in annular diameter (P = 0.43) and prosthesis size implanted (P = 0.51) with each enlargement technique. The Nicks, Manougian, modified Bentall and aortoventriculoplasty procedures enlarged the annulus by 0.43 +/- 0.45 mm, 3.63 +/- 0.95 mm, 0.78 +/- 0.65 mm, and 6.08 +/- 1.19 mm, respectively (P \u3c 0.001). No significant change in prosthesis size was observed after the Nicks procedure (P = not significant). Increases of 1.3 +/- 0.5, 1.3 +/- 0.5, and 2.7 +/- 0.6 prosthesis sizes were achieved with the Manougian, modified Bentall and aortoventriculoplasty techniques respectively (P \u3c 0.001). Conclusions: ARE procedures appear equally efficacious in both small and larger aortic roots. Although all 4 ARE techniques increased the annular diameter, only the Manougian, modified Bentall and aortoventriculoplasty procedures allowed for the implantation of a larger prosthetic valve. The Nicks procedure, which is likely the most commonly performed ARE, does not allow for the implantation of a larger prosthesis. Surgeon preference and patient factors may help in selecting the most appropriate ARE technique, as the modified Bentall and Manougian procedures achieved similar increases in valve size

Efficient Hadronic Operators in Lattice Gauge Theory

We study operators to create hadronic states made of light quarks in quenched lattice gauge theory. We construct non-local gauge-invariant operators which provide information about the spatial extent of the ground state and excited states. The efficiency of the operators is shown by looking at the wave function of the first excited state, which has a node as a function of the spatial extent of the operator. This allows one to obtain an uncontaminated ground state for hadrons.Comment: 18 pages, Latex text, followed by 11 postscript figures in self-unpacking file. Also available at ftp://suna.amtp.liv.ac.uk/pub/cmi/wavefn

The Nature of SN 1961V

The nature of SN 1961V has been uncertain. Its peculiar optical light curve and slow expansion velocity are similar to those of super-outbursts of luminous blue variables (LBVs), but its nonthermal radio spectral index and declining radio luminosity are consistent with decades-old supernovae (SNe). We have obtained Hubble Space Telescope STIS images and spectra of the stars in the vicinity of SN 1961V, and find Object 7 identified by Filippenko et al. to be the closest to the optical and radio positions of SN 1961V. Object 7 is the only point source detected in our STIS spectra and only its H-alpha emission is detected; it cannot be the SN or its remnant because of the absence of forbidden lines. While the H-alpha line profile of Object 7 is remarkably similar to that of eta Car, the blue color (similar to an A2Ib supergiant) and lack of appreciable variability are unlike known post-outburst LBVs. We have also obtained Very Long Baseline Array (VLBA) observations of SN 1961V at 18 cm. The non-detection of SN 1961V places a lower limit on the size of the radio-emitting region, 7.6 mas or 0.34 pc, which implies an average expansion velocity in excess of 4,400 km/s, much higher than the optical expansion velocity measured in 1961. We conclude the following: (1) A SN occurred in the vicinity of SN 1961V a few decades ago. (2) If the SN 1961V light maximum originates from a giant eruption of a massive star, Object 7 is the most probable candidate for the survivor, but its blue color and lack of significant variability are different from a post-outburst eta Car. (3) The radio SN and Object 7 could be physically associated with each other through a binary system. (4) Object 7 needs to be monitored to determine its nature and relationship to SN 1961V.Comment: 16 pages, 3 figures, accepted by the Astronomical Journal for the 2004 May issu

Complexity of health news reporting on breast implant‐associated anaplastic large cell lymphoma

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147821/1/tbj13189.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147821/2/tbj13189_am.pd

Assessing the Necessity of Stopping Antithrombotic Agents Before Wide-Awake Hand Surgery

This review of 304 carpal tunnel release procedures examines the necessity of stopping antithrombotic medications prior to carpal tunnel release surgery