Assessment of three-dimensional high-definition visualization technology to perform microvascular anastomosis.

BACKGROUND AND AIM: Traditional visualization techniques in microsurgery require strict positioning in order to maintain the field of visualization. However, static posturing over time may lead to musculoskeletal strain and injury. Three-dimensional high-definition (3DHD) visualization technology may be a useful adjunct to limiting static posturing and improving ergonomics in microsurgery. In this study, we aimed to investigate the benefits of using the 3DHD technology over traditional techniques. METHODS: A total of 14 volunteers consisting of novice and experienced microsurgeons performed femoral anastomoses on male Sprague-Dawley retired breeder rats using traditional techniques as well as the 3DHD technology and compared the two techniques. Participants subsequently completed a questionnaire regarding their preference in terms of operational parameters, ergonomics, overall quality, and educational benefits. Efficiency was also evaluated by mean times to complete the anastomosis with each technique. RESULTS: A total of 27 anastomoses were performed, 14 of 14 using the traditional microscope and 13 of 14 using the 3DHD technology. Preference toward the traditional modality was noted with respect to the parameters of precision, field adjustments, zoom and focus, depth perception, and overall quality. The 3DHD technique was preferred for improved stamina and less back and eye strain. Participants believed that the 3DHD technique was the better method for learning microsurgery. Longer mean time of anastomosis completion was noted in participants utilizing the 3DHD technique. CONCLUSIONS: The 3DHD technology may prove to be valuable in improving proper ergonomics in microsurgery. In addition, it may be useful in medical education when applied to the learning of new microsurgical skills. More studies are warranted to determine its efficacy and safety in a clinical setting.

Haplotype analysis reveals a possible founder effect of RET mutation R114H for Hirschsprung's disease in the Chinese population.

BACKGROUND: Hirschsprung's disease (HSCR) is a congenital disorder associated with the lack of intramural ganglion cells in the myenteric and sub-mucosal plexuses along varying segments of the gastrointestinal tract. The RET gene is the major gene implicated in this gastrointestinal disease. A highly recurrent mutation in RET (RET(R114H)) has recently been identified in approximately 6-7% of the Chinese HSCR patients which, to date, has not been found in Caucasian patients or controls nor in Chinese controls. Due to the high frequency of RET(R114H) in this population, we sought to investigate whether this mutation may be a founder HSCR mutation in the Chinese population. METHODOLOGY AND PRINCIPAL FINDINGS: To test whether all RET(R114) were originated from a single mutational event, we predicted the approximate age of RET(R114H) by applying a Bayesian method to RET SNPs genotyped in 430 Chinese HSCR patients (of whom 25 individuals had the mutation) to be between 4-23 generations old depending on growth rate. We reasoned that if RET(R114H) was a founder mutation then those with the mutation would share a haplotype on which the mutation resides. Including SNPs spanning 509.31 kb across RET from a recently obtained 500 K genome-wide dataset for a subset of 181 patients (14 RET(R114H) patients), we applied haplotype estimation methods to determine whether there were any segments shared between patients with RET(R114H) that are not present in those without the mutation or controls. Analysis yielded a 250.2 kb (51 SNP) shared segment over the RET gene (and downstream) in only those patients with the mutation with no similar segments found among other patients. CONCLUSIONS: This suggests that RET(R114H) is a founder mutation for HSCR in the Chinese population.