Masataka Akimoto

The relationship between keloid growth pattern and stretching tension: visual analysis using the finite element method.

Background:Keloids grow and spread horizontally, like malignant tumors, for reasons that remain unknown. Yet, stretching tension is clearly associated with keloid generation, as keloids tend to occur on high tension sites such as the anterior chest and scapular region. Thus, we analyzed the relationship between keloid growth patterns and stretching tension using a visualized finite element study. Materials and Methods:Keloids, normal skin, and fat structures were reproduced using DISCUS software. The contours were transferred to ADINA analytical software to rebuild and mesh volumes. Results:(1) High tension was observed at the edges, and not in the entire region, of stretched keloids. (2) Keloid centers were regions of low tension, which helps to explain the healing that generally occurs in the central regions of keloids. (3) Expansion of a keloid occurred in the direction in which it was pulled. (4) The “crabs claw”-shaped invasion occurred in response to increased stretching tension. (5) Skin stiffness in the circumference of a keloid was associated with greatly increased tension. (6) Fat hardness and thickness did not influence the amount of tension. (7) Adhesion with subcutaneous hard tissue greatly increased the tension in the keloid. Conclusion:These stretching results have advanced understanding of keloid formation under various conditions. Our results suggest that stretching tension is an important condition associated with keloid growth.

Catcher's mask cranioplasty for extensive cranial defects in children with an open head trauma: a novel application of partial cranioplasty

ObjectiveIn children who have suffered a severe, extensive head trauma, cranioplasty is complicated because allografting is not advisable in pediatric patients and the amount of available autologous materials is limited. To overcome these problems, we employed a combination of autologous rib grafts and calvarial grafts for partial cranioplasty.Materials and methodsWe named this partial cranioplasty technique ‘catcher’s mask cranioplasty’. Rib grafts were placed mimicking a baseball catcher’s mask to obtain maximum strong coverage of the defect. Calvarial grafts were used to achieve a smooth forehead contour. Islands of osteoanagenesis were also used.ConclusionsThese autografts were of sufficient strength, esthetically satisfactory, and no patient developed sinking skin flap syndrome. Catcher’s mask cranioplasty is a useful technique to successfully reconstruct the skull in pediatric patients with extensive cranial defects and an insufficient amount of autologous graft material.

One-stage reconstruction using a vascularized calvarial flap for intractable scalp ulcers in relation with cranial implants without removing the whole prosthesis.

When alloplastic cranial implants present some complications, the classical strategy has been to remove them. Removal of the custom-made artificial skull, however, requires a second cranioplasty. We describe two representative cases of intractable scalp ulcer over the cranial prosthesis treated by vascularized calvarial flap without totally removing the implant. One patient had a previous ceramic implantation and the other a large titanium mesh, whose precedent local skin flap methods to treat the scalp ulcer were not successful. After the implant beneath the scalp ulcer was partially removed, a vascularized calvarial flap was raised. The calvarial graft of the flap was utilized to repair the implant defect and the galeal part of the flap was utilized to patch the ulcer from the reverse side. The clinical outcome is excellent. Our experience clearly demonstrated that the vascularized calvarial flap contributes to maintain a sufficient blood supply for the calvarial graft, reduces the risk of infection and provides a new tissue bed for the healing of a skin ulcer over a cranial implant for this difficult-to-treat cranial reconstruction.

Use of a skin adhesive (octyl-2-cyanoacrylate) and the optimum reinforcing combination for suturing wounds

The adhesion strength of a skin adhesive, octyl-2-cyanoacrylate (Dermabond™), was measured under various conditions using porcine skin. The combined use of a skin adhesive and a skin closure tape (n=5) was significantly stronger than a single application of skin adhesive (n=5) (p<0.01). We have tentatively named the wound closure in which a skin adhesive and reinforcement material were combined the Reinforcing Combination Method. To obtain optimum conditions, further studies were done for sequence of application, type of reinforcement material, a number of layers, and width of the suture. The optimum condition for the reinforcement combination was established by applying one layer of skin adhesive over a skin closure tape, over one layer of skin adhesive, with a suture width of 4 cm. This reinforcement combination might be useful in clinical practice.

Expansile neurenteric cyst arising in the frontal lobe associated with status epilepticus: report of a case and discussion of epileptogenesis

The case of a 32-year-old Japanese man with an expansile supratentorial neurenteric cyst is described. The initial MRI revealed a left frontal extraaxial mass lesion 20 mm in diameter that showed marked expansion to 32 mm and change in its signal intensity 13 months later. Fifteen months after his visit, the patient fell into status epilepticus and underwent surgery. The cyst wall was excised, and the cyst content was totally removed. The cytology of the cystic content and pathological findings of the cyst wall were compatible with the diagnosis of neurenteric cyst. Our literature search revealed that in 86% of the patients with this lesion, the lesion was involved in the occurrence of epilepsy during the perioperative period. When a neurenteric cyst is diagnosed, shunt surgery should be avoided to prevent migrating spread of neurenteric cells.

Advantage of Catcher’s mask cranioplasty for post-surgical infectious skin trouble

IntroductionWe report the case of a patient with repeated intractable cranioplasty infections who was successfully treated by partially removing the graft after Catcher’s mask cranioplasty.Materials and methodsAside from the cost of cranial artificial implants, our simple method saves the cost of subsequent removal and implantation surgeries in the process of cranioplasty trouble shooting.

A giant subcutaneous forehead abscess and epidural extension caused by frontal mucocele

A 26-year-old Japanese man visited our clinic because of a huge forehead protrusion (fig 1A) with acute onset. He was under treatment for asthma, nasal allergies and chronic bronchitis. CT and MRI images revealed erosive defects at the inner and outer layers of the frontal bone and communication between the frontal sinus and both the subcutaneous space (fig 1B,D) and the epidural space (fig 1C,E), suggesting a frontal mucocele resulting in a subcutaneous abscess and epidural extension (arrowhead). Figure 1 (A) Macroscopic photograph of a huge subcutaneous tumour in the middle of the forehead. CT scans demonstrate (B) erosion of the outer-table of the calvarium and the adjacent subcutaneous …

Repair of a fistula between the bladder and the perineal skin by femoral gracilis flap interposition.

Abstract The successful repair of a fistula between the bladder and the perineal skin using a femoral gracilis flap is reported. A 70‐year‐old woman, who 10 years previously had undergone a total hysterectomy for uterine cancer, developed a fistula between the bladder and the perineal skin after she underwent Miles operation for rectal cancer. Initially, an attempt was made to repair the fistula by the transabdominal approach. This failed, probably because of the lack of supporting tissue between the bladder and the perineal skin. The second repair was performed with plastic surgeons. A secure three‐layer bladder closure was accomplished. A right femoral gracilis flap was developed and rotated 180° to fill the defect in the skin and subcutaneous tissue. Four weeks after surgery, cystography revealed no fistula or urinary leakage and the drainage catheter was removed. Femoral gracilis flap interposition was successful for repair of a fistula between the bladder and the perineal skin when there was no supporting tissue due to extensive exenteration in the surgical removal of rectal cancer and after other repair procedures had been unsuccessful.

Use of deep inferior epigastric artery flaps for reconstruction of the female genitalia

Free skin grafts have been the most conventional choice for reconstructing the female genital area after excision of malignant tumours. However, some patients have developed scar contractures, or depressed deformities or ectropion of the mucosal membrane of the urethra or vagina. We discuss here the use of deep inferior epigastric artery (DIEA) flaps. Although the method leaves a scar in the abdominal region, it can be hidden by underwear. We have operated on six patients with satisfactory results.

Three-dimensional CT system using a personal computer

A three-dimensional CT display system using a personal computer was developed and used for diagnosis of craniofacial abnormalities. The advantages of this system are that it is inexpensive and easy to operate.