Hiroko Yanaga

Clinical application of cultured autologous human auricular chondrocytes with autologous serum for craniofacial or nasal augmentation and repair.

Background: The repair of a craniofacial or nose deformity requires a large volume of reconstructive material. A conventional cartilage graft does not provide a sufficient volume of reconstructive material. Therefore, augmentation of the facial form to the defect shape is quite difficult. The authors developed a new treatment method that provides a sufficiently large volume of reconstructive material and enables an easier reconstruction of the original shape. Methods: Ages of the patients ranged between 9 and 63 years. Approximately 1 cm2 of auricular cartilage was collected from the auricular concha. Isolated chondrocytes were cultured with autologous serum that accelerates cell proliferation. The cells were subcultured and formed a gel-form mass. This mass, together with autologous serum, was grafted (injected) on the periosteum and into the subcutaneous pocket. The volume of grafted cultured chondrocytes ranged from 1.7 to 40 cc (1 to 5 × 107 cells/cc). The lesion changed from soft gel form into hard cartilage tissues within 2 to 3 weeks and stabilized. Results: Excellent or good satisfactory results were obtained in all patients and have been maintained for periods ranging from 3 to 34 months. No patient experienced absorption of cultured chondrocytes. Biopsy of the newly formed tissues showed that it was an elastic cartilage derived from the original tissue. Conclusions: A small number of chondrocytes obtained from a 1-cm2 auricular cartilage are successfully cultured into a large number of cells in a gel form. Those autologous auricular chondrocytes in a gel form allow for the repair of complicated shapes of the defect area. This technique is applicable to various treatments for craniofacial or nose deformity.

Generating Ears from Cultured Autologous Auricular Chondrocytes by Using Two-Stage Implantation in Treatment of Microtia

Background: Microtia is a congenital ear hypoplasia associated with auricular defects. Conventional treatment involves implanted costal cartilage. The impact of surgical invasion and donor-site morbidity can be particularly severe in pediatric patients, and the collectable volume of autologous cartilage is limited. The authors therefore developed a new technique for microtia and applied it to treat four patients. Methods: Through the development of a multilayer chondrocyte culture system and two-stage implantation technique, the authors successfully generated human ears. In culture, the chondrocytes are expanded to a sufficiently large volume, produce rich chondroid matrix, and form immature cartilaginous tissues. In the authors’ two-stage implantation, the cultured chondrocytes are injection-implanted into the lower abdomen of the patient, where the cells grow into a large, newly generated cartilage with neoperichondrium in 6 months. This cartilage is harvested surgically, sculptured into an ear framework, and implanted subcutaneously into the position of the new ear. Results: The cultured chondrocytes formed a mature cartilage block with sufficient elasticity for use as an auricular cartilage. The formed block had the same histologic origin as elastic cartilage. The ear framework produced from this block was implanted into the auricular defect area, and an auricle with a smooth curvature and shape was subsequently configured. In the 2 to 5 years of postoperative monitoring, the neocartilage maintained good shape, without absorption. Conclusions: The authors’ four patients are the first successful cases of regenerative surgery for microtia using cultured ear chondrocytes. The benefits of the technique include minimal surgical invasion, lower donor-site morbidity, lessened chance of immunologic rejection, and implantation stability.

Cryopreserved cultured epidermal allografts achieved early closure of wounds and reduced scar formation in deep partial-thickness burn wounds (DDB) and split-thickness skin donor sites of pediatric patients

Burn treatment in children is associated with several difficulties, e.g. available skin replacement is small, donor area could expand, and subsequent hypertrophic scar and contracture could become larger along with their physical growth. In order to have better clinical results, the authors prepared cryopreserved cultured epidermal allografts from excess epidermal cells of other patients, and applied the epidermal allografts to 55 children, i.e. 43 cases of deep partial-thickness burn wounds (DDB) due to scald burn and 12 cases with split-thickness skin donor sites. In the 43 DDB patients, epithelialization was confirmed 9.1+/-3.6 days (mean+/-S.D.) after treatment. In 10 of the 43 patients, epithelialization was comparable between the area which received the epidermal allografts (grafted area) and the area which did not receive the epidermal allografts but was covered with usual wound dressing (non-grafted area). As a result, epithelialization day was 7.9+/-1.7 in grafted areas and 20.5+/-2.3 in non-grafted areas. In the 12 patients with split-thickness skin donor sites, epithelialization was confirmed 6.3+/-0.9 days after treatment. Epithelialization of the grafted and non-grafted areas was comparable in 8 of the 12 patients, and it was 6.5+/-1.1 days and 14.1+/-1.6 days, respectively. In these 10 DDB patients and 8 split-thickness skin donor site patients, redness and scar formation were also milder in the grafted area. The 55 patients have been followed up for 1-8 years (mean, 4.75 years), and scar formation was suppressed in both DDB and split-thickness skin donor sites. These findings showed that cryopreserved cultured epidermal allografts achieve early closure of the wounds and good functional outcomes.

Functional reconstruction of swallowing and articulation after total glossectomy without laryngectomy : Money pouch-like reconstruction method using rectus abdominis myocutaneous flap

When a total glossectomy is performed without a laryngectomy, the functional recovery of swallowing and articulation is extremely important in maintaining the patients quality of life. The authors established a money pouch-like reconstruction method in which a round and raised tongue is rebuilt using a rectus abdominis myocutaneous flap. In this method, the skin island of the rectus abdominis myocutaneous flap is created about 20 percent larger than the defect in both width and length. The skin island is sutured to the defect such that the excess skin folds into the shape of a money pouch. This allows the tongue to be reconstructed with its tip and dorsum touching the hard palate and its base bulging in the dorsal and posterior directions. Misswallowing was not detected in the three patients who had this surgery, and each of them had improved articulation sufficient to carry out daily conversations.

Nipple-areola reconstruction with a dermal-fat flap: technical improvement from rolled auricular cartilage to artificial bone.

The method by Yanaga successfully achieved NAC reconstruction with dermal-fat flaps and cartilage or artificial bone. An advantage of this method is that a base is formed by the dermis at the central portion of the two dermal-fat flaps, so the probability of retraction is greatly reduced. The authors also use a method of skin grafting from a proximal portion of the inner thigh for adaptation to the texture and color tone of the NAC. This method enables NAC reconstruction in one step.

Eyelids and eye socket reconstruction using the expanded forehead flap and scapha composite grafting

After trauma or excision of malignant tumor, it is difficult to achieve satisfactory results when reconstructing deformed eyelids and the socket for an ocular prosthesis. The authors demonstrate examples of successful reconstruction for a prosthetic eye that provided adequate and aesthetic soft‐tissue support achieved by applying a threestep surgical procedure of reconstruction of the eye socket, the eyelids, and the tarsus and eyelid margin. Because it is highly vascularized and its distal end can be divided into two or three portions for easy three‐dimensional reconstruction, the expanded forehead flap alone, with a galea flap, or with a free rectus abdominis muscle perforator flap was used. The expanded forehead flap also provides excellent thin upper lid contour and good colormatching with a recipient site. For the eye socket, sufficient volume of tissue was provided from the expanded forehead flap with or without a galea or a free rectus abdominis muscle perforator flap, and a deep and convex fornix was formed. This resulted in a good fit and in stability of the ocular prosthesis. The surface and the inner lining of the eyelids were reconstructed using portions of the expanded forehead flap. For the tarsus and eyelid margin, conventional reconstruction techniques use cartilage of the concha, which has limitations of length and which does not fit the shape of the tarsal margin. The authors used the scapha composite graft, and a natural shape and good elasticity resulted. (Plast. Reconstr. Surg. 108: 8, 2001.)

An ipsilateral superdrainaged transverse rectus abdominis myocutaneous flap for breast reconstruction

A conventional single pedicled TRAM (transverse rectus abdominis myocutaneous) flap is a musculocutaneous flap widely used for breast reconstruction. However, complications such as partial flap necrosis, fat necrosis, and fatty induration may occur as a result of unstable blood flow circulation to the flap. One major factor is venous congestion in the flap. In an effort to obtain more stable TRAM flap blood circulation, we anastomosed the ipsilateral deep inferior epigastric vein of a pedicled TRAM flap to the thoracodorsal vein. This procedure provides superdrainage by means of enhanced venous perfusion. This flap with superdrainage augmentation is referred to as a superdrainaged TRAM flap (12 patients). Changes in cutaneous blood flow were also assessed by measurement of cutaneous blood flow in zone IV using a laser blood flow meter (8 patients). The patients who underwent breast reconstructive surgery using this technique showed no evidence of postoperative complications such as flap necrosis, fat necrosis, or fatty induration. Satisfactory results were obtained during breast reconstruction in patients who had previously undergone a radical mastectomy with resultant large areas of tissue defects. In addition, the two patient groups, 12 patients with superdrainaged TRAM flap and 20 patients with single pedicled TRAM flap, were compared to assess differences in complications. The incidence of partial flap necrosis, fat necrosis, and fatty induration was lower among patients with superdrainaged flap than those with single pedicled flap.

Two-stage transplantation of cell-engineered autologous auricular chondrocytes to regenerate chondrofat composite tissue: clinical application in regenerative surgery.

Background: The authors have developed a unique multilayered culture method that expands to large volumes elastic chondrocytes from a small piece of human auricular cartilage. In this study, the authors applied the two-stage transplantation method for cultured auricular chondrocytes to difficult cases of nasal/chin reconstruction where subcutaneous tissue is thin or scarred. Methods: Auricular chondrocytes were cultured and expanded to sufficiently large volumes, and then, in a two-stage transplantation process, injection-transplanted into a patient’s lower abdomen, where they were regenerated into larger chondrofat composite tissue in 6 months and used as a material for nasal/chin reconstruction. The authors then performed histologic and electron microscopic analysis of serial cross-sections and magnetic resonance imaging analysis of the chondrofat composite tissue. Results: The cultured auricular chondrocytes consistency regenerated intraabdominally to a larger, stable neocartilage, with adherent fat tissue within 6 months. Eighteen patients (nose, n = 14; chin, n = 4) underwent this procedure, and the chondrofat composite tissue was stable after 1 to 5 years’ postoperative follow-up. The chondrofat composite tissue maintained good shape, with no major complications. Magnetic resonance imaging showed that the chondrofat composite tissue was regenerated and vascularized in the abdomen in all 18 cases (100 percent). Infection and total absorption were not seen. Only partial absorption was noted (5.6 percent). Conclusions: The chondrofat composite tissue was found to be a new innovative graft material in which neocartilage is regenerated to be continuous with fat tissue by means of the neoperichondrium. It has thereby become possible to perform the previously impossible simultaneous reconstruction of cartilage and fat tissue.

Long-term viability of cryopreserved cultured epithelial grafts

Human cultured epithelial grafts are frozen for long-term preservation. To assess the viability of these stored grafts, their cell survival rate and colony-forming efficiency of grafts cryopreserved at -135 degrees C and at -80 degrees C were followed over time. Flow cytometry showed that the cell survival rate of the grafts cryopreserved at -135 degrees C for 1 month, 6 months and 1 year averaged 89.3%, 61.7% and 61.6%. Cryopreservation at -80 degrees C maintained cell survival rate as well for 1 month, but after 6 months of cryopreservation survival was reduced at -80 degrees C (35.2%) compared with that of -135 degrees C. In histological examination, the cell structure and basal layer were very well preserved after 6 months of storage at -135 degrees C, but not at -80 degrees C. Cell survival rate at -135 degrees C was also assessed by colony-forming efficiency. Colony-forming efficiency of the grafts cryopreserved for 1 month, 6 months and 1 year averaged 66.1%, 58.5% and 55.1% of control (noncryopreserved) grafts. These findings suggest that, even when cultured epithelial grafts are subjected to long-term cryopreservation, cell viability remains sufficient, reculturing is possible, and that graft banking could be used for clinical applications.

Reliable, Minimally Invasive Oromandibular Reconstruction Using Metal Plate Rolled with Pectoralis Major Myocutaneous Flap

The purpose of this study was to minimize the surgical invasiveness to the donor site and the amount of the primary reconstruction time after oromandibular tumor resection. Oromandibular reconstruction was performed only using a pectoralis major myocutaneous flap and a metal plate. The pectoralis major myocutaneous flap was grafted to the oral cavity defect by rolling and wrapping around the metal plate with the muscle of the flap. No early postoperative complications have been noted in all seven patients. An average of 2 years and 1 month has past since surgery, and to date no infections, plate exposure, or plate breakage have been observed in any of the patients. The safety of the oromandibular reconstruction using a metal plate was improved by rolling the muscle of the pectoralis major myocutaneous flap around the metal plate. The present method was shown to be a rational technique that allowed primary reconstruction of the oral cavity and mandible in a minimally invasive manner in a short time.