A technique for functional and aesthetic reconstruction of the oral commissure and buccal mucosa

A constant harvest technique for chimeric anterolateral thigh flaps and patient outcomes following their use in reconstructive head and neck surgery

BACKGROUND

Chimeric anterolateral thigh free flaps (ALT) have been commonly used for head and neck defects, which require two epithelial lined surfaces. However, because of unpredictable vascular anatomy, it is a challenge to consistently elevate large chimeric flaps with multiple perforators based on the Lateral Circumflex Femoral Artery (LCFA). Here, we present our method to reliably harvest a chimeric flap from the ALT territory and investigate its long-term outcomes when used in the reconstruction of extensive head and neck defects.

METHODS

A prospective review of practice consisting of 27 patients, between January 2011 and April 2019, with extensive through-and-through head and neck defects, which require dual paddle flaps underwent reconstruction with chimeric ALT harvested with a portion of distal vastus lateralis. The age of the patients ranged from 32 to 68 years (mean 53.2 years).

RESULTS

Flap length ranged from 17 to 30 cm (mean, 25.6 cm). The mean flap area was 261.6 cm² (range, from 225 to 340 cm²). The mean ischemia time was 162.9 min (range, from 59 to 269 min). At a mean follow-up time of 33.4 months (range, from 4 to 91 months), four patients died of cancer recurrence. For the other 23 patients, 4 required revision to achieve better cosmetic lip competence. All flaps survived with two recorded returns to theater for pedicle exploration associated with partial flap loss only.

CONCLUSION

Harvesting the chimeric ALT with a portion of vastus lateralis distally negates the need for tenuous intramuscular perforator dissection. It is a reliable option for head and neck surgery, which require composite reconstruction. Using this technique produces a good functional cosmetic outcome. It also allows large defects to be reconstructed in a single sitting with free tissue transfer.

The local transcriptional regulators SacR1 and SacR2 act as repressors of fructooligosaccharides metabolism in Lactobacillus plantarum

Background

In Lactobacillus plantarum, fructooligosaccharides (FOS) metabolism is controlled by both global and local regulatory mechanisms. Although catabolite control protein A has been identified as a global regulator of FOS metabolism, the functions of local regulators remain unclear. This study aimed to elucidate the roles of two local regulators, SacR1 and SacR2, in the regulation of FOS metabolism in L. plantarum both in vitro and in vivo.

Results

The inactivation of sacR1 and sacR2 affected the growth and production of metabolites for strains grown on FOS or glucose, respectively. A reverse transcription-quantitative PCR analysis of one wild-type and two mutant strains (ΔsacR1 and ΔsacR2) of L. plantarum identified SacR1 and SacR2 as repressors of genes relevant to FOS metabolism in the absence of FOS, and these genes could be induced or derepressed by the addition of FOS. The analysis predicted four potential transcription factor binding sites (TFBSs) in the putative promoter regions of two FOS-related clusters. The binding of SacR1 and SacR2 to these TFBSs both in vitro and in vivo was verified using electrophoretic mobility shift assays and chromatin immunoprecipitation, respectively. A consensus sequence of WNNNNNAACGNNTTNNNNNW was deduced for the TFBSs of SacR1 and SacR2.

Conclusion

Our results identified SacR1 and SacR2 as local repressors for FOS metabolism in L. plantarum. The regulation is achieved by the binding of SacR1 and SacR2 to TFBSs in the promoter regions of FOS-related clusters. The results provide new insights into the complex network regulating oligosaccharide metabolism by lactic acid bacteria.

Reconstruction of a defect on the buccal mucosa and prolabium

We describe the procedure for reconstruction of a defect on the buccal mucosa and the prolabium with a buccal mucosal transposition flap and an artificial dermis graft. The preparation of the flap started with an incision extending from the border of the defect to the corner of the mouth. The pivot point of the flap was near the stump of the excised prolabium. Only the buccal mucosa was elevated from the buccal surface. It was transposed onto the defect of the prolabium and sutured to the edges of the defect. After reconstruction of the prolabium, the artificial dermis was trimmed and sutured to the mucosal and skin edges of the surgical defect. This is an easy and minimally invasive procedure to cover a defect of the buccal mucosa and the prolabium. In our experience, the wound healed with good, functional, and cosmetic results.