Mental stress-induced myocardial ischemia in coronary artery disease patients with left ventricular dysfunction

Background  Reduced left ventricular ejection fraction (LVEF) is a risk factor for poor outcomes in patients with coronary artery disease (CAD). Mental stress-induced myocardial ischemia (MSIMI) also identifies a subset of CAD patients at increased risk for future cardiovascular events. Susceptibility to MSIMI in patients with CAD and reduced LVEF is unknown. Methods and Results  We enrolled 182 patients (67 women) with a mean age of 64 years and a documented history of CAD in this study. Baseline resting ejection fraction was determined by use of technetium 99m sestamibi gated single photon emission computed tomography. Abnormal LVEF was defined as less than 45% for men and less than 50% for women (based on published norms for our software [Cedars-Sinai Medical Center]). All participants underwent mental stress testing with a public speaking task. Rest/stress myocardial perfusion single photon emission computed tomography was performed via conventional methodology. Images were visually compared for number and severity of perfusion defects by use of a scoring method from 0 to 4. A summed difference score was calculated as the difference between summed stress and rest scores. A score of greater than 3 was considered abnormal. MSIMI developed in 19% of patients with normal LVEF and 31% of those with reduced LVEF. There is no statistically significant difference between the two groups (P=.11). Conclusions  CAD patients with left ventricular dysfunction are equally susceptible to MSIMI as those with normal LVEF. This study was supported by grants HL 070265 and HL 072059 from the National Heart. Lung, and Blood Institute. This material is also the result of work supported by resources and with the use of facilities at the Department of Veterans. Affairs Medical Center, Gainesville, Fla.     

Breast MR imaging with loop-gap resonators

Breast images obtained at 1.5 T using a loop-gap resonator pair as both the excitation and detection device are presented. The efficiency of this approach is high, as judged by the low level of radio frequency (RF) power required to obtain a 90 degree pulse and the uniformity of the RF field within the resonator pair. A modification of the pair geometry provides for reasonable observation of the tissues through the chest wall and laterally to the axillae.     

Association of internal carotid artery injury with carotid canal fractures in patients with head trauma

OBJECTIVE: The purpose of our study was to determine the degree to which carotid canal fracture and other CT findings are associated with internal carotid artery (ICA) injury in patients with head trauma. MATERIALS AND METHODS: Three neuroradiologists retrospectively evaluated CT scans and cerebral angiograms of 43 patients who underwent cerebral angiography within 7 days after blunt cranial trauma over a 5-year period. Seventeen patients underwent unilateral and 26 had bilateral carotid angiography. Angiograms were evaluated for ICA injury and CT scans were evaluated for carotid canal fracture, brain contusion, subarachnoid hemorrhage, basilar skull fracture, subdural hematoma, soft-tissue swelling, sphenoid sinus air-fluid level, and other skull fracture. We recorded the number of true-positive (+CT, +angiogram), true-negative (-CT, -angiogram), false-positive (+CT, -angiogram), and false-negative (-CT, +angiogram) studies. We determined the sensitivity, specificity, positive predictive value, and negative predictive value for each CT finding. RESULTS: We identified 21 carotid canal fractures in 17 patients. Eleven ICA injuries were seen in 10 patients. Six patients with ICA injury had a carotid canal fracture. The presence of a carotid canal fracture had a sensitivity of 60% and specificity of 67% for detection of injury to the ICA passing through that canal. These values were similar to those for other CT findings. CONCLUSION: Sensitivity, specificity, positive predictive value, and negative predictive value of carotid canal fracture were only moderately good for determining the presence of ICA injury and were similar to other CT findings not typically associated with ICA injury.     

Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).     

Surgical treatment of displaced femoral neck fractures in the elderly: a survey of the American Association of Hip and Knee Surgeons

A survey was distributed to the American Association of Hip and Knee Surgeons (AAHKS) membership to evaluate surgical treatment preferences for displaced femoral neck fractures (DFNFXs). Of 718 members, 381 (54%) responded to the 16-question survey that was an adjunct to a multicenter, randomized study (funded by AAHKS/OREF) designed to prospectively evaluate efficacy of hemiarthroplasty vs total hip for treatment of DFNFXs. Hemiarthroplasty (85%) was the most preferred treatment option for DFNFXs (reduction with internal fixation 2%, total hip arthroplasty 13%). Prefracture hip pain/osteoarthritis, poor bone quality, and fracture comminution were the main reasons why arthroplasty was chosen over reduction with internal fixation. Ambulatory status and dislocation risk after arthroplasty were the main factors in choosing between unipolar (48%) and bipolar (52%) hemiarthroplasty. Total hip arthroplasty is used by 88% of responders. Dislocation risk and ambulatory status were influential factors against performing total hip arthroplasty. Arthroplasty is the preferred method of surgical intervention for the treatment of DFNFXs for AAHKS members.     

Is surgical thrombectomy to salvage failed autogenous arteriovenous fistulae worthwhile?

The Dialysis Outcomes Quality Initiatives guidelines emphasize placement of autogenous arteriovenous (AV) fistulae for patients on hemodialysis. This recommendation is based on studies that demonstrate enhanced patency for AV fistulae compared with grafts. However, closer review of the data demonstrates that although primary patency of AV fistulae is superior to grafts, the secondary patency rates are equivalent. This suggests that secondary procedures to maintain fistula patency are inferior to those performed on arteriovenous grafts. Surgical thrombectomy of AV fistulae can be challenging. It is often difficult to completely remove thrombus adjacent to the anastomosis of the fistula, and pseudoaneurysms within the fistula can prevent passage of the thrombectomy catheter and complete removal of thrombus from the fistula. Consequently, some surgeons simply abandon thrombosed AV fistulae and place a new access. We have developed a method for completely clearing thrombus from failed AV fistulae by locating the fistulotomy close to the arterial anastomosis and using a technique to manually extract thrombus from the fistula before passing a thrombectomy catheter. The purpose of this study was to review our results with this procedure. Between 2001 and 2004, 10 patients with a previously functioning AV fistula presented with thrombosis. There were seven brachiocephalic fistulae and three radiocephalic fistulae. All patients underwent surgical thrombectomy and fistulography. Five patients underwent balloon angioplasty of a venous stenosis and one patient underwent surgical revision of an arterial stenosis. Technical success, defined as being able to completely clear thrombus from the fistula and treat the cause for fistula failure, was achieved in 70 per cent (7/10) of cases. Technical failure was caused by vein rupture during the balloon angioplasty in two cases and a central venous occlusion that could not be treated in one case. The 6-month primary and secondary patency for cases that were technically successful was 51 and 69 per cent, respectively. Our conclusion was that surgical thrombectomy can significantly extend fistula functionality in patients who present with thrombosis.     

A resident survey study of orthopedic fellowship specialty decision making and views on arthroplasty as a career

A dramatic shortage of total hip arthroplasty (THA) and total knee arthroplasty (TKA) surgeons has been projected because fewer residents enter arthroplasty fellowships, and the demand for THAs/TKAs is rising. The purposes of this study were to ascertain the future supply of THA/TKA surgeons, to identify the criteria residents use to choose their fellowship specialty, and to assess resident perceptions of an arthroplasty career. Four hundred ninety-eight post-graduate year 3 and above residents completed the online survey. Residents most highly prioritize intellectual factors and role models/mentors in determining their fellowship specialty. In the face of a looming patient access-to-care crisis, the data from this study support a policy of highlighting the intellectual challenges and satisfaction of THA/TKA as a career and encouraging mentorship early in a resident's training.     

A double mobility acetabular implant for primary hip arthroplasty in patients at high risk of dislocation

IntroductionDislocation following total hip replacement continues to be a problem for which no completely satisfactory solution has been found. Several methods have been proposed to reduce the incidence of hip dislocations with varying degrees of success, including elevated rim liners, constrained liners and large diameter bearings. We present our experience with the double mobility acetabular component in patients at high risk of instability.MethodsThis was a retrospective review of 65 primary total hip arthroplasties in 55 patients (15 men, 40 women), performed between October 2005 and November 2009. The majority (80%) of patients had at least two and 26% had at least three risk factors for instability. The mean age was 76 years (range: 44–92 years). The patients were followed up for a mean duration of 60 months (range: 36–85 months).ResultsFourteen patients died and one was lost to follow-up, leaving fifty hips for final assessment. Until the final follow-up appointment, no patients had dislocation and none required revision surgery. The mean Oxford hip score improved from 45.0 to 26.5 (p<0.0001). The mean Merle d’Aubigné pain score improved from 1.4 to 4.9 (p<0.0001), the walking score from 2.3 to 3.1 (p<0.07) and the absolute hip function score from 5.4 to 10.8 (p<0.0001). There were no clinical or radiographic signs of loosening.ConclusionsThe double mobility acetabular component was successful at preventing dislocation during early to medium-term follow-up. However, as data are still lacking with regard to polyethylene wear rates at the additional bearing surface, it would be prudent to restrict the use of this implant to selected patients at high risk of instability.