Septal-lateral annnular cinching perturbs basal left ventricular transmural strains.

OBJECTIVE: Septal-lateral annular cinching ('SLAC') corrects both acute and chronic ischemic mitral regurgitation in animal experiments, which has led to the development of therapeutic surgical and interventional strategies incorporating this concept (e.g., Edwards GeoForm ring, Myocor Coapsys, Ample Medical PS3). Changes in left ventricular (LV) transmural cardiac and fiber-sheet strains after SLAC, however, remain unknown. METHODS: Eight normal sheep hearts had two triads of transmural radiopaque bead columns inserted adjacent to (anterobasal) and remote from (midlateral equatorial) the mitral annulus. Under acute, open chest conditions, 4D bead coordinates were obtained using videofluoroscopy before and after SLAC. Transmural systolic strains were calculated from bead displacements relative to local circumferential, longitudinal, and radial cardiac axes. Transmural cardiac strains were transformed into fiber-sheet coordinates (X(f), X(s), X(n)) oriented along the fiber (f), sheet (s), and sheet-normal (n) axes using fiber (alpha) and sheet (beta) angle measurements. Results: SLAC markedly reduced (approximately 60%) septal-lateral annular diameter at both end-diastole (ED) (2.5+/-0.3 to 1.0+/-0.3 cm, p=0.001) and end-systole (ES) (2.4+/-0.4 to 1.0+/-0.3 cm, p=0.001). In the LV wall remote from the mitral annulus, transmural systolic strains did not change. In the anterobasal region adjacent to the mitral annulus, ED wall thickness increased (p=0.01) and systolic wall thickening was less in the epicardial (0.28+/-0.12 vs 0.20+/-0.06, p=0.05) and midwall (0.36+/-0.24 vs 0.19+/-0.11, p=0.04) LV layers. This impaired wall thickening was due to decreased systolic sheet thickening (0.20+/-0.8 to 0.12+/-0.07, p=0.01) and sheet shear (-0.15+/-0.07 to -0.11+/-0.04, p=0.02) in the epicardium and sheet extension (0.21+/-0.11 to 0.10+/-0.04, p=0.03) in the midwall. Transmural systolic and remodeling strains in the lateral midwall (remote from the annulus) were unaffected. CONCLUSIONS: Although SLAC is an alluring concept to correct ischemic mitral regurgitation, these data suggest that extreme SLAC adversely effects systolic wall thickening adjacent to the mitral annulus by inhibiting systolic sheet thickening, sheet shear, and sheet extension. Such alterations in LV strains could result in unanticipated deleterious remodeling and warrant further investigation.     

Physician assistants in academic radiology: the harborview experience

We describe a model of how physician assistants can be used in an academic medical center to expand radiologist productivity, and to enhance the departmental academic and educational missions. At Harborview Medical Center, following a training program and graduated responsibility under supervision, physician assistants provide initial interpretation of radiology studies, consultation to referring physicians, and perform less complicated interventional procedures. Acceptance of physician assistants by the radiologists, radiology residents, and referring physicians has been high. Although the impact of physician assistants on departmental clinical productivity is difficult to measure, our data suggest that radiologists are more efficient when physician assistants are assigned to service, both in terms of numbers of studies interpreted, and timeliness of reporting and billing. As a result of the success of our program, we believe that physician assistants can have an important role in radiology practice.     

The Durability of Laparoscopic Nissen Fundoplication: 11-Year Outcomes

Laparoscopic Nissen fundoplication (LNF) has become the most commonly performed antireflux procedure since its introduction in 1991. There are few studies with greater than 5-year outcomes. Herein we report a series of 312 consecutive patients who underwent primary LNF before 1996. Follow-up of more than 6 years was available in 166 patients, and the mean follow-up was 11 years (median 11.1 years, range 6.1–13.3 years). Prospective data collection included preoperative and current symptom scores (scale 0 = none to 3 = severe), as well as the level of patient satisfaction and use of antireflux medications. Total symptom score for each patient was summed from seven symptoms for a maximum value of 21. Heartburn and regurgitation were the most improved symptoms; however, all symptoms were significantly improved (P < 0.01). The total symptom score at follow-up was 2.6 down from 7.5 at baseline, with a mean difference of −4.9 (range −12 to 3). The percentage of patients stating they would have the procedure again was 93.3%, and 70% were off daily antireflux medications. Outcomes at a mean of 11 years after LNF are excellent, and the majority of patients had their symptoms resolved or significantly improved and are satisfied with their results. Presented at the 47th Annual Meeting of the Society for Surgery of the Alimentary Tract, May 22, 2006, Los Angeles, CA     

Rat Cytomegalovirus-Accelerated Transplant Vascular Sclerosis Is Reduced with Mutation of the Chemokine-Receptor R33

Cytomegalovirus (CMV) infection accelerates transplant vascular sclerosis (TVS) and chronic rejection (CR) in both human and animal solid organ transplantation models. The host/viral mechanisms involved in this process are unclear. We examine the role of the rat CMV (RCMV)-encoded chemokine-receptor R33 in the development of TVS using a rat heart transplantation/CR model. F344 heart grafts were transplanted heterotopically into Lewis recipients. The ability of RCMV lacking the R33 gene (RCMV-Deltar33) to accelerate CR/TVS (neointimal index, NI) was compared to wild-type (WT) RCMV. Allograft recipients were infected with 1 x 10(5) pfu RCMV or RCMV-Deltar33 on postoperative day (POD) 1. Grafts from RCMV-Deltar33-infected recipients demonstrated an accelerated time to allograft CR compared to grafts from uninfected recipients (POD = 56 vs. 90), this was slower than that seen in grafts from WT-RCMV-infected recipients (POD = 45). Similarly, the degree of graft TVS formation at terminal rejection in RMCV-Deltar33 infected recipients was more severe than uninfected recipients (NI = 63 vs. 45), yet not as severe as in WT-RCMV infected recipients (NI = 83). In parallel, RCMV-Deltar33 failed to induce vascular smooth muscle cell (SMC) migration in vitro, whereas WT-RCMV induced substantial migration. The RCMV-encoded chemokine-receptor r33 is critical for RCMV-accelerated TVS/CR and vascular SMC migration.     

Transition from open to robotic-assisted radical prostatectomy is associated with a reduction of positive surgical margins amongst private-practice-based urologists

Several recent studies have suggested that thought leaders in radical prostatectomy have decreased their own positive margin rates by switching from open to robot-assisted radical prostatectomy. Theoretically, this improvement is largely attributed to enhanced visualization of the deep pelvis and precision of dissection afforded by the instrumentation. To date, it has not been determined if this phenomenon exists amongst non-fellowship-trained urologists in private practice. Herein, we describe the positive margin rates of two non-fellowship-trained private-practice urologists who converted from open radical retropubic prostatectomy to robot-assisted radical prostatectomy. The margin positivity data from two non-fellowship-trained private-practice urologists (surgeon 1 and surgeon 2) were reviewed retrospectively. The last 50 cases of open radical retropubic prostatectomy from each surgeon were compared with the first 50 robotic prostatectomy cases of surgeons 1 and 2, respectively. A positive surgical margin was defined as tumor present at the inked margin of the prostate. There was a significant decrease in the overall and pT2 positive margin rates for both surgeons. The overall positive margin rate and pT2 positive margin rate for surgeon 1 dropped from 44 to 20% and from 37 to 5.7%, respectively, after changing from open to robotic prostatectomy. For surgeon 2, the overall positive margin rate changed from 26 to 18% and the pT2 positive margin rate changed from 27.5 to 7% after converting. Changing from open to robotic-assisted radical prostatectomy may improve the ability of urologists to obtain negative surgical margins. With proper training this phenomenon does seem to apply to non-fellowship-trained urologists in private practice and can be realized within the first 50 cases performed.     

A diagnostic algorithm for male genital oedema

Male genital oedema can be defined as swelling or the appearance of swelling of the scrotum and/or the penile shaft and prepuce. Despite the various causes of genital oedema reported in the published work, a concise approach to the evaluation and management has not been sufficiently addressed.     

Decreased Efficacy of Topical Anesthetic Creams in Presence of Benzoyl Peroxide

Background. Topical anesthetics are widely used to diminish the sensation of pain from various medical cutaneous procedures. Any topical agent that reduces the desired effect has clinical ramifications.
Materials and Methods. Topical 6% benzocaine cream was applied to both inner forearms of five persons and covered with a bandage. One of the arms was additionally treated simultaneously with 5% benzoyl peroxide. The areas were tested with a pinprick examination every 10 minutes for the ensuing hour.
Results. There was an estimated 75% increased perception of pain on the forearm to which benzoyl peroxide was applied in consort with the topical anesthetic at all examination times.
Conclusions. Benzoyl peroxide chemically reacts with topical anesthetics such as tetracaine, procaine, pramoxine, prilocaine, and lidocaine, causing a significant reduction in their numbing effect. Clinically, make sure that the skin area to be topically anesthetized is devoid of any previous treatment with benzoyl peroxide or insist that the skin is thoroughly washed prior to application of the anesthetic.
CRAIG G. BURKHART, MPH, MD, AND CRAIG N. BURKHART, MSBS, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.