Research Spotlight

Carr, E., Hoss, E., Kollipara, R. and Fabi, S.G. (2021). “Vacuum-Assisted Subcision for Gluteal Contouring.” Dermatol Surg 47(2): 294-296.

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In our practice, we observed that by releasing the fibrous septae of cellulite with this device, we not only improve the depth of cellulite dimples and skin surface irregularities but we also alter the contour of the buttock. We hypothesize that severing the fibrous septae allows for redistribution of subcutaneous tension forces and the reallocation of fat lobules. This restores the described lazy S-shape of a youthful, feminine buttock and yields a rounded and curved appearance (Figure 1). This volumetric change was recently quantified by Brauer and colleagues using 3 dimensional imaging analyses after one treatment with vacuum-assisted controlled subcision in 16 patients. At 6 months, they found 67.4% average improvement in negative volume and 58.4% improvement in minimum height of dimples. This extends the utility of controlled subcision beyond just improving the dimpling associated with cellulite by objectively demonstrating improvement in volume of the gluteal region, thereby improving overall gluteal contour to help restore a more youthful and feminine shape. [No abstract; excerpt from article].

Brodsky, J.W., Scott, D.J., Ford, S., Coleman, S. and Daoud, Y. (2021). “Functional Outcomes of Total Ankle Arthroplasty at a Mean Follow-up of 7.6 Years: A Prospective, 3-Dimensional Gait Analysis.” J Bone Joint Surg Am Jan 15. [Epub ahead of print].

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BACKGROUND: In vivo gait analysis provides objective measurement of patient function and can quantify that function before and after ankle reconstruction. Previous gait studies have shown functional improvement for up to 4 years following total ankle arthroplasty (TAA), but to date, there are no published studies assessing function at ≥5 years following TAA. We hypothesized that patients who underwent TAA would show significant improvements in walking function at a minimum follow-up of 5 years, compared with their preoperative function, as measured by changes in temporospatial, kinematic, and kinetic gait parameters. METHODS: Three-dimensional gait analysis with a 12-camera digital motion-capture system and double force plates was utilized to record temporospatial, kinematic, and kinetic measures in 33 patients who underwent TAA with either the Scandinavian Total Ankle Replacement (Stryker; n = 28) or Salto Talaris Ankle (Integra LifeSciences; n = 5). Gait analysis was performed preoperatively and at a minimum follow-up of 5 years (mean, 7.6 years; range, 5 to 13 years). RESULTS: Significant improvements were observed in multiple gait parameters, with temporospatial increases in cadence (+9.5 steps/min; p < 0.0001), step length (+4.4 cm; p = 0.0013), and walking speed (+0.2 m/s; p < 0.0001), and kinematic increases in total sagittal range of motion (+2.0°; p = 0.0263), plantar flexion at initial contact (+2.7°; p = 0.0044), and maximum plantar flexion (+2.0°; p = 0.0488). Kinetic analysis revealed no loss of peak ankle power, despite patients aging. CONCLUSIONS: To our knowledge, this is the first study to report 7-year functional outcomes of TAA, quantified by objective, in vivo measurements of patient gait. Patients were shown to have sustained improvement in multiple objective parameters of gait compared with preoperative function. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Walters, D.C., Jansen, E.E.W., Salomons, G.S., Arning, E., Ashcraft, P., Bottiglieri, T., Roullet, J.B. and Gibson, K.M. (2021). “Preferential accumulation of the active S-(+) isomer in murine retina highlights novel mechanisms of vigabatrin-associated retinal toxicity.” Epilepsy Res 170: 106536.

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((S)-(+)/(R)-(-)) vigabatrin (Sabril(R); γ-vinyl GABA), an antiepileptic irreversibly inactivating GABA-transaminase, was administered to male C57Bl6 J mice via continuous infusion (0, 40, 80 mg/kg/d) for 12 days. Our study design pooled retina, eye (minus retina), whole brain and plasma from n = 24 animals for each dose to provide n = 8 triplicates per treatment group. Hypothesizing that (S)-(+) VGB (active isomer) would preferentially accumulate in retina, we determined VGB isomers, comprehensive amino acids, and pharmacokinetic parameters. In brain, eye and plasma, the ((S)-(+)/(R)-(-)) ratio varied from 0.73 to 1.29 and 13.3 in retina, accompanied by a partition coefficient (tissue/plasma, ((S)-(+);(R)-(-))) of 5.8;0.34, 0.63;0.49, and 0.51;0.34 in retina, eye and brain, respectively. Racemic VGB (nmol/g; plasma, nmol/mL, range of means for dose) content was: retina, 25-36; eye (minus retina), 4.8-8.0; brain, 3.1-6.8 and plasma, 8.7-14.9. GABA tissue content (nmol/g) was 1246-3335, 18-64 and 2615-3200 as a function of VGB dose for retina, eye (minus retina) and brain, respectively. The retinal glial cell toxin 2-aminoadipic acid also increased with VGB dose (76-96 nmol/g). Partitioning of active (S)-(+) VGB to retina suggests the involvement of a stereospecific transporter, the identification of which could reveal new therapeutic paradigms that might mitigate VGB’s well-known retinal toxicity and expand its clinical utility.

Karnam, R.S., Mitsakakis, N., Saracino, G., Lilly, L., Asrani, S.K. and Bhat, M. (2021). “Predicting Long-Term Survival After Liver Transplantation in Patients With NASH Cirrhosis.” Clin Gastroenterol Hepatol Jan 16;S1542-3565(21)00071-9. [Epub ahead of print].

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Nonalcoholic steatohepatitis (NASH) cirrhosis is the second most common indication for liver transplantation (LT) in the United States.(1) Patients are increasingly older at presentation, with higher rates of metabolic syndrome, obesity, hyperlipidemia, diabetes mellitus, and renal failure.(2) They are also at higher risk of cardiovascular events and mortality while on the waiting list(1) and in the post-transplant period.(3)(,)(4) We sought to identify predictors of long-term benefit based on 5-year survival post-LT in NASH cirrhosis, thereby delineating those patients that derive a clear benefit from LT versus those in whom LT may be futile.

Schinstock, C.A., Askar, M., Bagnasco, S.M., Batal, I., Bow, L., Budde, K., Campbell, P., Carroll, R., Clahsen-van Groningen, M.C., Cooper, M., Cornell, L.D., Cozzi, E., Dadhania, D., Diekmann, F., Hesselink, D.A., Jackson, A.M., Kikic, Z., Lower, F., Naesens, M., Roelofs, J.J., Sapir-Pichhadze, R. and Kraus, E.S. (2021). “A 2020 Banff Antibody Mediated Injury Working Group examination of international practices for diagnosing antibody mediated rejection in kidney transplantation.” Transpl Int Jan 10. [Epub ahead of print].

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The Banff antibody mediated rejection (ABMR) classification is vulnerable to misinterpretation, but the reasons are unclear. To better understand this vulnerability, we evaluated how ABMR is diagnosed in practice. To do this, the Banff Antibody-Mediated Injury Workgroup electronically surveyed an international cohort of nephrologists/surgeons (n=133) and renal pathologists (n=99). Most providers (97%) responded that they use the Banff ABMR classification at least sometimes, but DSA information is often not readily available. Only 41.1%(55/133) of nephrologists/surgeons and 19.2%(19/99) of pathologists reported that they always have DSA results when the biopsy is available. Additionally, only 19.6%(26/133) of nephrologists/surgeons responded that non-HLA antibody or molecular transcripts are obtained when ABMR histologic features are present but DSA is undetected. Several respondents agreed that histologic features concerning for ABMR in the absence of DSA and/or C4d are not well accounted for in the current classification [31.3% (31/99) pathologists and 37.6%(50/133) nephrologist/surgeons]. The Banff ABMR classification appears widely accepted, but efforts to improve the accessibility of DSA information for the multidisciplinary care team are needed. Further clarity is also needed in Banff ABMR nomenclature to account for the spectrum of ABMR and for histologic features suspicious for ABMR when DSA is absent.