Shuhei Torii

Free gracilis muscle transplantation, with microneurovascular anastomoses for the treatment of facial paralysis. A preliminary report.

A clinical operative technique for free muscle transplantation by microneurovascular anastomoses is presented. Two cases of free transfer of the gracilis muscle for dynamic reconstruction of facial paralysis are described, including a follow-up study with electromyography, light microscopy, and electron microscopy. We feel this new technique will have a wide range of application in reconstructive surgery.

The distally based superficial sural artery flap

The distally based superficial sural artery flap, first described as a distally based neuroskin flap by Masquelet et al., is a skin island flap supplied by the vascular axis of the sural nerve. The aim of this paper is to refine the surgical technique in order to establish the reliability of this flap. We treated 20 patients with 21 distally based superficial sural artery flaps, including 2 fascial flaps. All flaps survived. Most flaps showed slight venous congestion. In the largest flap (10 cm wide by 13 cm long), edema lasted 2 months. In the flap whose pedicle was raised without the deep fascia, there was necrosis at the distal tip of the flap. The advantages are the following: The blood supply is reliable, elevation is easy and quick, and major arteries are not sacrificed. This new flap may be useful in selected circumstances. (Plast. Reconstr. Surg. 93: 1012, 1994.)

Ultrasound Enhances Transforming Growth Factor β-Mediated Chondrocyte Differentiation of Human Mesenchymal Stem Cells

In clinical studies and animal models, low-intensity ultrasound (US) promotes fracture repair and increases mechanical strength. US also promotes cartilage healing by increasing glycosaminoglycan synthesis of chondrocytes. As mesenchymal stem cells (MSCs) have the ability to differentiate into chondrocytes, US may promote their differentiation. Here, we evaluated the effects of US on the differentiation of MSCs toward chondrocytes and cartilage matrix formation. When human MSCs cultured in pellets were treated with transforming growth factor beta (TGF-beta, 10 ng/mL), they differentiated into chondrocytes as assessed by alcian blue staining and immunostaining for aggrecan, but nontreated cell pellets did not. Furthermore, when low-intensity US was applied for 20 min every day to the TGF-beta-treated cell pellets, chondrocyte differentiation was enhanced. Biochemically, aggrecan deposition was increased by 2.9- and 8.7-fold by treatment with TGF-beta alone, and with both TGF-beta and US, respectively. In contrast, cell proliferation and total protein amount appeared unaffected by these treatments. These results indicate that low-intensity US enhances TGF-beta-mediated chondrocyte differentiation of MSCs in pellet culture and that application of US may facilitate larger preparations of chondrocytes and the formation of mature cartilage tissue.

Reverse-Flow Island Flap: Clinical Report and Venous Drainage

Twenty-two reverse-flow island flaps were transferred. These included peroneal, forearm, anterior tibial, and temporal flaps. Sixteen of 22 flaps survived completely. We encountered partial necrosis in 4 flaps and total necrosis in only 2 flaps. We credit this success to the reliability and availability of the peroneal, forearm, and temporal flaps; but we do not encourage use of the anterior tibial flap. The flaps that survived well did not show any signs of venous congestion. The advantage of the reverse-flow island flap is that it can be transferred from a proximal to a distal location. Using cadavers and fresh amputated limbs, studies on venous drainage of the reverse-flow island flap were performed. The venae comitantes had numerous venous valves and communicating branches, but more than sufficient reflux of the venous blood occurred through the valves at pressures of 90 to 105 cmH2O. We believe that the venous drainage of the reverse-flow island flap occurs as a result of reflux actions at the valve, communicating branches between the venae comitantes, and bypass vessels around the valves.

New reconstruction for total maxillectomy defect with a fibula osteocutaneous free flap

The osteocutaneous fibula free transfer with three segments of bone and the peroneal flap was used to reconstruct a total unilateral maxillectomy defect. Satisfactory restoration of three-dimensional facial structure, orbital support, and prosthesis wearing was achieved. The fibula osteocutaneous free flap is a very useful alternative for reconstructing a maxillectomy defect.

Results of omental flap transposition for deep sternal wound infection after cardiovascular surgery.

OBJECTIVE Our experience with omental flap transposition in the treatment of deep sternal wound infections is reviewed here with an emphasis on efficacy, risk factors for in-hospital mortality rates, and long-term results. SUMMARY BACKGROUND DATA Even with improvements in muscle and omental flap transposition, the timing of closure and the surgical strategy are controversial. METHODS Forty-four consecutive patients with deep sternal wound infections were treated using the omental flap transposition from 1985 through 1994. The strategies included debridement with delayed omental flap transposition or single-stage management, which consisted of debridement of the sternal wound and omental flap transposition. Methicillin-resistant Staphylococcus aureus was cultured from more than 50% of the wounds. A logistic regression analysis was used to identify the predictors of in-hospital death after omental flap transposition. RESULTS There were seven (16%) in-hospital deaths. Univariate analysis demonstrated that hemodialysis and ventilatory support at the time of omental flap transposition were significantly associated with in-hospital mortality rates (p = 0.0023 and p = 0.0075, respectively). Thirty-seven patients whose wounds healed well were discharged from the hospital. Two patients with cultures positive for methicillin-resistant Staphylococcus aureus had recurrent sternal infections. Patients without positive methicillin-resistant Staphylococcus aureus cultures had good long-term results after reconstructive surgery. CONCLUSIONS Transposition of an omental flap is a reliable option in the treatment of deep sternal wound infections, unless the patients require ventilatory support or hemodialysis at the time of transposition.

Endogenous Adipocyte Precursor Cells for Regenerative Soft-Tissue Engineering

Subcutaneous injection of reconstituted basement membrane (Matrigel) in combination with basic fibroblast growth factor induces de novo adipogenesis in which endogenous precursor cells invade the artificially formed Matrigel space, proliferate and differentiate to form adipose tissue. Since this adipogenesis offers us a novel approach for soft-tissue reconstruction without transplanting preadipocytes, the early process was examined by optical and electron microscopy. Formation of multiple layers of fibroblast-like cells at the surface of Matrigel implant was the first response of connective tissue. The cells within four to five layers proximal to Matrigel implant acquired a thick cytoplasm and an enlarged nucleus, and they invaded Matrigel space together with endothelial cells which caused neovascularization. Phagocytotic incorporation and digestion of Matrigel components by well-developed lysosomes appeared to be a stimulus of fibroblast-like cells to mature depending on proximity to Matrigel. The fibroblast-like cells often contacted to the outer surface of capillary over a large area and rapidly accumulated lipid droplets. Electron microscopy of the developing adipocytes showed a well-organized smooth endoplasmic reticulum and mitochondria. This investigation thus revealed the characteristics of adipocyte precursor cells, which can be recruited for regenerative engineering of soft tissues.

The potential of oral mucosal cells for cultured epithelium a preliminary report

We have developed a method to fabricate cultured epithelium for skin repair using mucosal cells. We grafted this epithelium in six cases. The site where the mucosal epithelium was transplanted keratinized normally within 4 weeks and formed normal skin. Mucosal epithelial cells have many advantages over skin epidermal keratinocytes: (1) Mucosal epithelial cells grow faster than skin keratinocytes. (2) Cultured epithelial sheets formed using mucosal cells remain viable for at least 14 days in vitro. (3) The oral cavity is a suitable location to take a tissue segment because scar due to biopsy is inconspicuous. Therefore, mucosal epithelial cells are a potential new source of cells for cultured epithelial graft.

Indications and results of vascularized pedicle iliac bone graft in avascular necrosis of the femoral head

Several reports describe methods of treatment for avascular necrosis of the femoral head (ANFH) involving 0 to 2 mm of collapse. Some cases of ANFH have good prognoses, requiring only non-weight-bearing treatment. Other cases rapidly progress to collapse and complete destruction with enlargement of the necrotic area. The progression of the necrotic area is related to the activity of the original disease, steroid treatment, and the size and location of the necrotic area in the early stages of the disorder. In this report, a vascularized pedicle bone graft was used to treat ANFH, particularly those cases identified as Stage II on the system established by the Japanese Investigation Committee. Surgery involved curettage of necrotic bone, implantation of spongy bone, and application of a vascularized pedicle bone graft. Grafts were taken from the ilium and included the superficial circumflex iliac artery (SCIA). A bony canal was made in the anterior femoral neck, from which the necrotic bone was curetted and to which the bone graft was applied. The deep circumflex iliac artery (DCIA) was also used in combination with the SCIA. The postoperative weight-bearing period was six months. Follow-up periods lasted one to six years. Seventeen of 23 Stage II joints (19 cases) achieved satisfactory results at a mean of three years after surgery. Three Stage II joints and three Stage III joints continue to have significant problems. One of these six has been converted to a dual-bearing type endoprosthesis. The unsuccessful results generally occurred in patients who were treated with steroids.

Free groin skin flaps

The operative technique of free groin flap transfer is described and some typical results presented. The overall complete success rate in 47 cases was 80 per cent, but complete necrosis only occurred in II per cent of the transferred flaps.