Keizo Fukuta

Comparison of inorganic bovine bone mineral particles with porous hydroxyapatite granules and cranial bone dust in the reconstruction of full-thickness skull defect.

Twenty adult rabbits were used to evaluate the biocompatibility and osteoconductivity of Bio-Oss, an inorganic bovine bone mineral, in the reconstruction of full-thickness skull defects. Skull defects were treated with either autogenous bone dust, porous hydroxyapatite granules, Bio-Oss particles, or were left untreated as controls. Histological examination of decalcified sections showed incorporation of Bio-Oss into the host tissue without a significant inflammatory reaction. Measurement of the profile area occupied by the bone revealed that Bio-Oss, hydroxyapatite, and the control had the same amount of bone ingrowth, whereas autogenous bone dust produced a greater amount of bone (p < 0.01). We conclude that Bio-Oss, like porous hydroxyapatite, has sufficient osteoconductive properties and can also be used as a bone substitute material.

Role of perivenous areolar tissue in the viability of venous flaps: an experimental study on the inferior epigastric venous flap of the rat

This study was performed to investigate how the perivenous areolar tissue affects survival of the rat inferior epigastric venous flap model designed by Yuen and Leung (1991). Five groups of flaps were studied; group A--flap based on an inferior epigastric vein and areolar tissue; group B--flap with a skeletonised vein; group C--control, nonvascularised flap; group D--flap based on perivascular areolar tissue alone; group E--flap with a skeletonised artery and vein. Each group included 40 flaps; 20 of them had a silicone sheet placed under the flap, the other 20 did not. All flaps of group E survived. The success rate of group A with and without a silicone sheet was 60% and 90% respectively. All flaps of the other groups (B, C, D) necrosed. Histological examination of the pedicle showed that many minute vascular channels (single-cell-layered capillaries) were present apart from the inferior epigastric vein. This result confirms the importance of the perivenous areolar tissue in perfusion of the skin island, at least, in the inferior epigastric venous flap in the rat.

The vascular anatomy of the galeal flap in the interparietal and midline regions.

The potential extension of the galeal flap in the interparietal area was studied on 17 fresh human cadaver heads by intravascular dye injection technique. It was demonstrated that an ipsilateral superficial temporal artery that supplies the galeal flap does not cross the midline or anastomose with the contralateral superficial temporal artery but ensures the survival of a flap extended up to 1 cm proximal to the sagittal suture line. The width of the temporoparietal flap can be extended up to 15 cm, depending on the vascular pattern of the superficial temporal artery. When required, the lateral extension may provide the required soft-tissue bulk despite the reduced flap length.

A CADAVER INVESTIGATION OF THE BLOOD SUPPLY OF THE GALEAL FRONTALIS FLAP

The vascular anatomy of the galeal frontalis flap was studied in 12 fresh cadavers by an intraarterial dye injection technique. Special attention was directed to the length limit of this flap. The general belief that the galeal frontalis flap has a robust vascularity by means of the supratrochlear and supraorbital arteries was not demonstrated in this study. In the medial half of the forehead, superficial branches of both arteries penetrated the frontalis muscle immediately above the supraorbital rim and ran superficially in the subcutaneous tissue. In the lateral half, some of the superficial branches of the supraorbital artery traveled with the frontalis muscle and anastomosed with the frontal branch of the superficial temporal artery. Deep branches of the supratrochlear and supraorbital arteries showed an axial distribution on the periosteum only for a short distance. One or two branches of the supraorbital artery were found to take a superficial course within the subgaleal layer, pierce the frontalis muscle, and anastomose with the superficial temporal artery. These findings suggest that the galeal frontalis flap should be elevated in the lateral forehead. The preservation of the periosteum with the flap is recommended in order to ensure the temporoparietal extension.

Epidermoid cyst and cholesterol granuloma of the orbit.

Epidermoid cyst and cholesterol granuloma have been confused, but these are different lesions. A case of recurrent orbital epidermoid cyst and another case of orbital cholesterol granuloma are presented in order to describe their distinct pathological, clinical and imaging characteristics and their surgical management. Advanced investigation using our custom-designed three-dimensional imaging allowed a better appreciation of the exact location, and optimal planning of the surgical treatment. The same surgical approach was used for both lesions: total resection via a coronal incision and immediate reconstruction of residual defects using skull bone grafts.

Surgical treatment of a massive chondrosarcoma in the skull base associated with Maffucci’s syndrome: a case report

BACKGROUND A successfully treated massive chondrosarcoma in the skull base associated with Maffuccis syndrome is presented. The purpose of this report is to discuss the surgical approach to the tumor and reconstruction of the skull base. CASE DESCRIPTION A 36-year-old woman who had a history of multiple enchondromas and subcutaneous hemangiomas presented with decreased right visual acuity and left papilledema. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a mass in the skull base. The tumor occupied the nasal and paranasal cavities, and extended to the anterior, middle, and posterior intracranial spaces. The midline skull base structures and the left middle cranial base were destroyed. Using a combined anterior craniofacial and left orbitozygomatic approach, the tumor was totally resected. The large skull base defect was reconstructed with a vascularized outer table parietal bone graft attached to a bipedicled temporoparietal galeal flap. The postoperative course was uneventful except for decreased left visual acuity, and temporary diplopia and facial hypesthesia. In 40 months of follow-up there was no recurrence. CONCLUSIONSA skull base approach should be selected to perform total resection of an extensive skull base tumor. The bipedicled temporoparietal galeal flap and vascularized calvarial bone was useful for simultaneous reconstruction.

Facial lawn mower injury treated by a vascularized costochondral graft

Abstract Mandibular defects present a difficult condition to treat, especially when the condyle is involved. The method chosen for reconstruction of the missing ramus and condyle must provide facial symmetry and a functional joint. In children, there is an additional requirement of allowing facial growth to proceed normally. Autogenous costochondral rib grafts have been accepted as a satisfactory replacement for mandibular rami and condyles in adults as well as children.1,2 Several studies have shown that in children costochondral grafts have the potential to grow. However, the growth of these grafts is unpredictable, ranging from resorption to overgrowth.3–6 In 1989, Poole7 reported the use of vascularized soft tissues in the early surgical treatment of children with hemifacial microsomia. Although it is expected that vascularized costochondral grafts may provide more predictable growth than nonvascularized free grafts, this potential advantage has still to be demonstrated. This article presents the surgical treatment and follow-up of a case with an extensive facial defect caused by a riding lawn mower injury. The patient was treated with a composite transfer of a vascularized costochondral rib graft with associated soft tissue.

The volume limitation of the galeal temporalis flap in facial augmentation

Galeal temporalis flaps based on the superficial temporal vessels have been used for facial augmentation and can be extended to the contralateral side beyond the midline in order to achieve maximum volume. In five patients, the volumes of extended galeal flaps were measured intraoperatively using a water displacement method. The calculated volume varied between 28 and 38 cm3. Experience with this flap showed satisfactory results with no complications; therefore, it is concluded that the extended galeal temporalis flap may be a first choice in the correction of facial soft tissue deficits less than 40 cm3. Clinical cases are presented.

Role of perivenous areolar tissue and recipient bed in the viability of venous flaps in the rabbit ear model

This study was performed to investigate the role of perivenous areolar tissue and flap bed in the viability of venous flaps in the rabbit ear model as described by Inada et al. Six groups of flaps were studied: group A--flap based on a proximal vein and areolar tissue; group B--flap based on a proximal venous pedicle which has been skeletonised; group C--flaps based on a proximal vein and areolar tissue sutured over a full thickness skin graft (FTSG), preventing diffusion into the flap; group D--flaps with a skeletonised pedicle sutured over a FTSG; group E--control, non-vascularised flap placed directly on bed; and Group F--control, non-vascularised flap sutured over a FTSG. Groups C and D had 15 flaps and the remaining groups had 10 flaps in each. All flaps in groups A and B had total or partial survival. In group C 4 flaps survived completely, 8 had partial survival and 3 necrosed. Group D had only 2 flaps with partial survival with 13 flaps with total loss. In group E there were 10 flaps with partial survival and none with complete loss. No flaps in group F survived. Histological examination of the pedicle showed small vascular channels present in the areolar tissue surrounding the venous pedicle. This study confirms the importance of the perivenous areolar tissue in the perfusion of the venous skin flap in the rabbit ear model.

Extradural dead space following cranial bone advancement.

The extradural dead space produced after enlargement of the intracranial space or after reduction of the volume of the intracranial contents persists for an unknown period of time. To investigate this further, an extradural dead space was surgically created by advancement of parietal bones in 9 adult rabbits. By design, there was no connection with the paranasal sinuses. To determine outcome of the dead space, three-dimensional computed tomographic and histological studies were performed. The brain volume decreased in the first 3 months after surgery and remained constant for up to 9 months. The extradural volume increased in the first 4 weeks postoperatively, gradually decreasing in size with time. The brain failed to eliminate the extradural dead space by rearrangement or expansion. An osseous cavity filled with fluid and connective tissue was formed within the dead space. The fluid within it remained, even 9 months after surgery. This could be a potential environment for bacterial invasion if there was a connection with the nasopharynx.