Epithelialization of Free Flap Vascular Pedicles through the Nasal Cavity after Long-term Follow-up: A Case Report.

A 59-year-old man with right maxillary cancer presented with a right buccal fistula and an ectropion of the lower eyelid after multidisciplinary treatment. With no suitable vessels in the right face or neck for anastomosis, we planned reconstruction with a free thinned deep inferior epigastric artery perforator flap using the contralateral left facial artery and vein as the recipient. To simulate the length of the vascular pedicle, we used our original software and determined to use the route passing through the nasal cavity. The vascular pedicle was passed through a tunnel from the medial wall of the right maxillary sinus, through the nasal septum and the medial-frontal wall of the left maxillary sinus, to the left facial artery and vein. The flap survived completely, and facial deformity was corrected. At 1 year postoperatively, there had been concerns about the fragility of the vascular pedicle in the nasal cavity and the possibility of easy bleeding. Endoscopic examination revealed that the vascular pedicle in the nasal cavity was covered by fibrous tissue and multirow lineage epithelium, and an excisional biopsy indicated a low possibility of hemorrhage. Cutting off the vascular pedicle to prevent bleeding may not be necessary because the vascular pedicle through the nasal cavity becomes fibrotic and epithelialized in the surrounding area in the long term.

The usefulness of a free thinned deep inferior epigastric artery perforator flap and measurement of the vascular pedicle length: A thin flap with a long pedicle.

BACKGROUND: The thinned deep inferior epigastric perforator (DIEP) flap branching from the main trunk to the superolateral direction may be useful because of its long vascular pedicle. DIEP flap is used as an axial-pattern adipose flap. The vascular pedicle length of the thinned DIEP flap was investigated using originally developed software. The clinical application of the thinned DIEP flap was verified in a case series. METHODS: In 40 patients with enhanced computed tomography (CT) data, the vascular pedicle length of the longest thinned DIEP flap was simulated using the software. A free thinned DIEP flap was used in 10 clinical cases of facial or breast reconstruction. RESULTS: In all simulated cases, the vascular pedicle of the DIEP branching to the superolateral direction was the longest, and the vascular pedicle could be lengthened up to 34.8% by dissecting the vessels on the fascia as a vascular pedicle. In all the clinical cases, the reconstruction of a complex form defect or reconstruction requiring a long vascular pedicle could be achieved in one stage without any perioperative complications. The intraclass correlation coefficient between simulated pedicle length and dissected pedicle length was 0.99. CONCLUSION: Thinned DIEP flaps with long vascular pedicles could be elevated safely. Multiple adipose or muscle flaps could be combined without complications. The length of the winding vascular pedicle could be measured using imaging data using the software first developed in the present study. This software would be useful in the planning of a thinned DIEP flap and other free flaps.

Changes in Radixin Expression and Interaction with Efflux Transporters in the Liver of Adjuvant-Induced Arthritic Rats.

Scaffold proteins such as radixin help to modulate the plasma membrane localization and transport activity of the multidrug resistance-associated protein 2 (MRP2/ABCC2) and P-glycoprotein (P-gp/ABCB1) efflux transporters in the liver. We examined changes in radixin expression and interaction with efflux transporters in adjuvant-induced arthritic (AA) rats, an animal model of rheumatoid arthritis, as well as in human liver cancer (HepG2) cells because inflammation affects drug pharmacokinetics via the efflux transporters. The expression levels of radixin and phosphorylated radixin (p-radixin) were measured 24 h after treatment with inflammatory cytokines comprising tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6 or sodium nitroprusside (SNP; a nitric oxide donor). The protein levels of radixin, MRP2, and P-gp in the rat liver were next examined. We also investigated whether inflammation affected the formation of complexes between radixin and MRP2 or P-gp. The mRNA and protein levels of radixin in HepG2 cells were significantly decreased by TNF-α treatment, while minimal changes were observed after treatment with IL-1ß, IL-6 or SNP. TNF-α also significantly decreased the protein levels of p-radixin, suggesting that TNF-α inhibited the activation of radixin and thereby reduced the activity of the efflux transporters. Complex formation of radixin with MRP2 and P-gp was significantly decreased in AA rats but this was reversed by prednisolone and dexamethasone treatment, indicating that decreased interactions of radixin with MRP2 and P-gp likely occur during liver inflammation. These data suggest that liver inflammation reduces radixin function by decreasing its interactions with MRP2 and P-gp.