Biomedical subjects

K Harii

Publications and source records attributed to K Harii.

At least 73 records · Page 4Linked to original sources

PubMed1998

Gradual cranial vault expansion for the treatment of craniofacial synostosis: a preliminary report.

To treat craniosynostosis, skull reshaping (such as fronto-orbital advancement) is widely performed. Surgical techniques have improved, however several problems still remain, such as postoperative relapse, late resorption, and infection. The main reason for this is probably (1) that the "craniotomized" bone for changing skull contour is used as free bone grafts and (2) that dead space between the reshaped bone and dura is created. We have developed a new method in which cranial bone is expanded gradually, together with the dura, using expansion devices. With this approach there is no extradural dead space postoperatively and the cranial bone segment remains vascularized. We have performed this procedure in 2 patients with Crouzon's disease and in 1 patient with sagittal synostosis. In the Crouzon's patients, osteotomies were performed to form a one-piece fronto-orbital bony complex without detaching the bone from the dura, and three expansion devices were applied. In the patient with sagittal synostosis, bilateral temporoparietal osteotomies were done in the same fashion and two expansion devices were applied. Expansion was started on the fourth postoperative day at a rate of about 1 mm per day. After obtaining the proper expansion, the devices were removed and the bone segments were fixed with miniplates and screws. All patients showed good results without any complications.

Cephalometry↗

PubMed1998

Immediate free flap reconstruction for head and neck pediatric malignancies.

We performed six immediate free flap reconstructions after tumor ablation in 5 children under the age of 15 years presenting with head and neck malignancy. One patient underwent free flap transfer on two separate occasions because of tumor recurrence. There were no flap losses nor were there any complications related to microvascular surgery. Although a pediatric head and neck malignant tumor is rare, surgical resection is the primary therapeutic role for those that are amenable to complete excision. Pediatric microsurgery provides a safe and reliable procedure for reconstruction of head and neck defects after extirpation of the tumor.

Adolescent↗

PubMed1998

Laryngeal preservation surgery using a free flap patch following resection of a carcinoma of the posterior wall of the oropharynx.

A carcinoma originating from the posterior wall of the oropharynx is not common, and radiotherapy has been used for years in this event without acceptable success. A free flap patch was used in 4 patients to reconstruct the defect after resection of a T2 or T3 carcinoma on the posterior wall of the oropharynx without laryngectomy. The free flaps used were the radial forearm and the free jejunal patch in 2 patients each. There was no flap loss, and successful laryngeal preservation was obtained in 3 of 4 patients. Laryngeal preservation surgery using a free flap patch proved very useful in selected patients with carcinoma of the posterior wall of the oropharynx. Based on our clinical experience, the free jejunal patch seems superior to the free forearm flap with regard to postoperative functional results.

Aged↗

PubMed1998

Clinical value of computer-generated acrylic skull replicas produced by laser lithography.

To determine for what deformity and utility the computer-generated acrylic (CGA) skull replica has the greatest value, we analyzed retrospectively a consecutive series of patients with craniomaxillofacial deformities (N = 54) whose treatment involved the utilization of CGA skull replicas. Application of the CGA skull replica was divided retrospectively into four groups: (1) use as an aid for preoperative analysis of osseous deformity, (2) use as material for preoperative surgical simulation, (3) use as a navigational aid during an operation, and (4) use as a negative template. Based on the aspects of these utilizations, we evaluated for what deformity the CGA skull replica was useful. Analysis of the data led us to conclude the following. First, the CGA skull replica is a valuable tool in craniomaxillofacial surgery, especially for patients with asymmetrical deformities and delicate convexities and concavities of the skull surface. Second, the largest function that CGA skull replicas can satisfy is standardization of craniomaxillofacial surgery. In carrying out preoperative surgical simulation utilizing a replica, drawing osteotomy lines on it, sterilizing it, and then bringing it to the operating table for consultation whenever required during an operation, we are able to proceed with greater precision and speed than if it was not available.

Acrylic Resins↗

PubMed1998

Second toe plantar flap for partial finger reconstruction.

Utilizing the tissue obtained from the plantar surface (metatarsophalangeal-distal interphalangeal region) of the second toe is an ideal procedure for reconstruction of partial finger tissue defects. The major advantage of this method is that it provides satisfactory aesthetic and functional improvement at the recipient site: furthermore, good results from the aesthetic point of view and minimum morbidity at the donor site are obtained. Our procedure utilizes the free neurovascular skin flap (second toe plantar flap) and full-thickness skin graft. As for the free flap, artery and nerve are obtained from the plantar neurovascular bundle and vein from the dorsal or plantar vein. All cases reconstructed with this procedure revealed satisfactory sensory restoration and aesthetic appearance. The donor sites also revealed no contracture and visible scar. In this paper, we discuss the application of this procedure for finger tissue reconstruction.

Child, Preschool↗

PubMed1998

Neurovascular free muscle transfer combined with cross-face nerve grafting for the treatment of facial paralysis in children.

Microneurovascular free muscle transfer is fast becoming a standardized procedure in the treatment of established or long-standing facial paralysis. However, there is no general agreement as to whether muscle transfer should be employed for children who still are growing. A patient's natural growth may influence or disturb reproduction of a smile, or a child may not be able to collaborate with postoperative rehabilitation sufficiently well to obtain a satisfactory result. One may hesitate to employ the procedure for children aged under 10 out of fear of its technical difficulties. To investigate the influence of age, the results experienced by 23 patients under the age of 15 who underwent free muscle transfer combined with cross-face nerve grafting were compared with those of adult patients. The treatment employed was a two-stage operation consisting of cross-face nerve grafting and subsequent free muscle transfer.

Adolescent↗

PubMed1998

One-stage transfer of the latissimus dorsi muscle for reanimation of a paralyzed face: a new alternative.

The two-stage method combining neurovascular free-muscle transfer with cross-face nerve grafting is now a widely accepted procedure for dynamic smile reconstruction in cases with long established unilateral facial paralysis. Although the results are promising, the two operations, about 1 year apart, exert an economic burden on the patients and require a lengthy period before obtaining results. Sequelae such as hypoesthesia, paresthesia, and conspicuous scar on the donor leg for harvesting a sural nerve graft also cannot be disregarded. To overcome such drawbacks of the two-stage method, we report a refined technique utilizing one-stage microvascular free transfer of the latissimus dorsi muscle. Its thoracodorsal nerve is crossed through the upper lip and sutured to the contralateral intact facial nerve branches. Reinnervation of the transferred muscle is established at a mean of 7 months postoperatively, which is faster than that of the two-stage method. In our present series with 24 patients, 21 patients (more than 87 percent) believed that their results were excellent or satisfactory, which also compares well with the results of the two-stage method combining free-muscle transfer with cross-face nerve graft.

Adolescent↗

PubMed1998

Anatomic variations and technical problems of the anterolateral thigh flap: a report of 74 cases.

We have transferred 74 free or pedicled anterolateral thigh flaps, including those combined with other flaps, for reconstruction of various types of defects. We report several anatomic variations of the lateral circumflex arterial system and discuss some technical problems with this flap. Septocutaneous perforators were found in 28 of 74 cases (37.8 percent), and no perforators were found in 4 cases (5.4 percent). In the 70 cases with perforators, 171 tiny cutaneous perforators (an average of 2.31 per case) were found. Musculocutaneous perforators (81.9 percent) were much more common than septocutaneous perforators (18.1 percent). Perforators were concentrated near the midpoint of the lateral thigh, and the selection of perforators as nutrient vessels for the anterolateral thigh flap was related to the length of the pedicle and the thickness of the skin flap. Anatomic variations of the branching pattern of perforators were classified into eight types. Flaps with perforators that arise directly from the profunda femoris artery are difficult to combine with other free flaps. Because the perforators are extremely small and tend to thrombose soon after congestion develops, these flaps are difficult to salvage with recirculation surgery. Therefore, several perforators should be included with the flap, if possible. The descending artery of the lateral circumflex femoral artery was always accompanied by two veins with different back-flow strengths. Therefore, veins for microsurgical anastomosis must be chosen carefully. Because it is nourished by several perforators arising from the descending artery, the vastus lateralis muscle can be combined with the anterolateral thigh flap. However, splitting the muscle longitudinally without harvesting its blood supply is complicated because its fibers are oblique. The rectus femoris muscle can also be combined with the anterolateral thigh flap, but its pedicle is short and its origin is very near the site of anastomosis. When the anterolateral thigh flap is combined with the tensor fasciae latae musculocutaneous flap, the large skin area of the lateral part of thigh can be transferred to repair the massive defects. The anterolateral thigh flap has many advantages and can be used to reconstruct many types of defect. However, anatomic variations must be considered if the flap is to be used safely and reliably.

Adolescent↗

PubMed1998

Gene expression of bone matrix proteins and endothelin receptors in endothelin-1-deficient mice revealed by in situ hybridization.

Endothelin-1 (ET-1) was first found as a vasoconstrictor protein excreted by vascular endothelial cells, but recently ET-1 has been considered to have widespread functions that include regulation of osteochondrogenic metabolism. We analyzed sections of head regions in ET-1 knockout mice that are known to have abnormalities in pharyngeal arch-derived tissues and found that there was severe hypoplasia in facial bones. The hypoplasia suggests that the matrix mineralization system of facial bones is disrupted in ET-1-/- homozygous mice. To elucidate whether osteogenic cells in facial bones are the targets for ET-1 and whether expression of bone matrix genes are modulated by ET-1, we examined gene expression of ET-1 receptors, ETA and ETB, and that of the bone matrix proteins, osteonectin (ON) and osteopontin (OP), both in the head regions of ET-1+/- heterozygous and ET-1-/- homozygous mice by means of in situ hybridization. Different patterns of expression between ETA and ETB mRNAs were observed in both groups. In 18.5 days post coitus fetuses, ETA mRNA was most strongly expressed in osteogenic cells along craniofacial bones, but ETB mRNA was most strongly expressed in trunks of trigeminal nerve. This finding suggests that ET-1 may modulate osteogenic cells through ETA receptor but not through ETB receptor. The expression patterns of ETA, OP, and ON mRNAs were distinct between the two groups. In the lower jaw of ET-1+/- heterozygous mice, the ETA, ON, and OP mRNA positive cells were scattered in the inner and outer regions of the thick bone matrix, but in ET-1-/- homozygous mice, cells containing those mRNAs were located close to each other at the surface of thin bone matrix. However, cellular expression of ON and OP mRNAs in osteogenic cells of ET-1-/- homozygous mice was not suppressed as compared with ET-1+/- heterozygous mice. We conclude that ET-1 may regulate proliferation and migration of osteogenic cells in the maxillofacial region, rather than modulating the expression level of ON and OP mRNAs.

Animals↗

PubMed1998

Frontoorbital advancement by gradual distraction. Technical note.

A substantial number of patients with coronal synostosis who undergo frontoorbital advancement still require additional surgical treatment to correct increased intracranial pressure or unsatisfactory craniofacial structure. However, frontoorbital advancement currently requires elevation of the frontal as well as the orbital bone, which can result in a fragile dura mater and partial resorption of the advanced bone. Thus the dura is easily torn by dissection and the advanced bone is further resorbed and deformed during repeated craniofacial operations. To avoid these drawbacks and to create an easier second surgical treatment via the intracranial approach, a new technique for frontoorbital advancement is presented. In this technique frontoorbital bone is advanced as a single unit, without elevation from the underlying dura, by means of gradual distraction. The details of the technique and an illustrative case are reported.

Cranial Sutures↗

PubMed1997

Inhibition of rat vascular smooth muscle proliferation in vitro and in vivo by bone morphogenetic protein-2.

Vascular proliferative disorders are characterized by the proliferation of vascular smooth muscle cells (SMCs) and excessive extracellular matrix synthesis. We found that bone morphogenetic protein-2 (BMP-2) inhibited serum-stimulated increases in DNA synthesis and cell number of cultured rat arterial SMCs in a fashion quite different from that in the case of transforming growth factor-beta1 (TGF-beta1). In addition, TGF-beta1 stimulated collagen synthesis in SMCs, whereas BMP-2 did not. In an in vivo rat carotid artery balloon injury model, the adenovirus-mediated transfer of the BMP-2 gene inhibited injury-induced intimal hyperplasia. These results indicate that BMP-2 has the ability to inhibit SMC proliferation without stimulating extracellular matrix synthesis, and suggest the possibility of therapeutic application of BMP-2 for the prevention of vascular proliferative disorders.

Adenoviridae↗

PubMed1997

Versatility of the free anterolateral thigh flap for reconstruction of head and neck defects.

OBJECTIVE: The anterolateral thigh flap has many advantages in head and neck reconstruction. However, it has not yet come into widespread use because of the anatomic variations of its perforators. Herein, we describe a safe operative technique related to the patterns of the perforators and discuss its wide versatility. SETTING: A national cancer center hospital. PATIENTS: Thirty-eight anterolateral thigh flaps were transferred. Confirmation and dissection of the flap pedicle were simultaneously performed with tumor resection. The design and elevation of the flap were carried out immediately after the tumor resection was completed. RESULTS: From the study of the anatomic variations of the perforators, septocutaneous patterns were recognized in 10 cases (26.3%) and musculocutaneous patterns in 28 cases (73.7%). All flaps were easily and safely elevated with our techniques. Thirty-six flaps survived. Partial necrosis was noted owing to excessive thinning procedure in one patient and total necrosis was noted owing to venous thrombosis at the anastomosis part in another patient. CONCLUSIONS: We found that the anterolateral thigh flap has numerous advantages. It is possible to perform the flap elevation and the tumor resection simultaneously. The flap is generally thin and is suitable for reconstruction of intraoral defects. Combined flaps with neighboring tissues and other, distant flaps can be used. Furthermore, since our technique minimizes the problems of confirmation and dissection of the perforators, we conclude that this flap can be successfully used to repair a variety of large defects of the head and neck.

Adult↗

PubMed1997

Preservation of the larynx after resection of a carcinoma of the posterior wall of the hypopharynx: versatility of a free flap patch graft.

BACKGROUND: Preservation of the larynx after resection of a pharyngeal tumor remains a challenging problem for the head and neck surgeon. METHODS: Nine patients with T1 or T2 carcinoma of the posterior wall of the hypopharynx (UICC 1987), who were treated surgically between 1984 and 1994, were studied. All patients underwent surgical resection of the tumor with laryngeal preservation and immediate reconstruction with free flap transfer. A free forearm flap was transferred in four patients and a free jejunal patch graft, in five patients. RESULTS: There was one flap loss, due to venous thrombosis. Successful larynx preservation was achieved in the remaining eight patients (89%). Although there was one local control failure, three patients remained free of disease for more than 5 years. CONCLUSIONS: Laryngeal preservation surgery using a free flap patch graft has proven very beneficial in selected cases with a carcinoma of the posterior wall of the hypopharynx.

Aged↗

PubMed1997

Effects of shear stress on wound-healing angiogenesis in the rabbit ear chamber.

Recent studies indicate that wall shear stress plays a significant role in the physiological adaptation of the vascular system. This study focused on the effect of sustained wall shear stress on wound-healing angiogenesis by exploring the morphologic and hemodynamic changes in developing microvessels in vivo through the tissue repair process. Rabbits were treated with the alpha 1 blocker prazosin (50 mg/L in water) orally from Day 0 to Day 23 after implantation of ear chambers to increase peripheral blood flow. The microvasculature in the chamber was recorded from Day 7 to Day 23 by using an intravital videomicroscope. The relative area of the chamber covered by vascularized tissue (%), the rate of ingrowth (mm2/day), the total vascular area (mm2), and the wall shear stress level (dyne/cm2) in venules (diameter in 20-40 microns) were quantified using a computerized image analysis system. The relative area increased significantly in the prazosin-treated animals from Days 7 to 19. The chamber of the treated group was completely covered with vascularized tissue earlier than that of the control group. The final total vascular area was larger by 21% in the treated group. The time course of shear stress in the treated group showed an initial elevation (1.44 times increase vs the control) followed by a gradual decrease toward the control level. These findings suggest that wound-healing angiogenesis may be partly involved in the adaptive response of microvasculature to shear stress.

Adrenergic alpha-Antagonists↗

PubMed1997

Flow characteristics of soft-tissue vascular anomalies evaluated by direct puncture scintigraphy.

Soft-tissue vascular anomalies such as haemangioma and vascular malformation are treated by surgical resection, arterial embolization or sclerotherapy. Because the effect of sclerotherapy, i.e. the percutaneous injection of sclerosing agents, depends on intralesional haemodynamics, estimation of flow characteristics of soft-tissue vascular anomalies is essential when determining appropriate patient management. However, lesions are at present divided into only two groups: high flow and low flow. We have developed a new method, direct puncture scintigraphy, to evaluate in detail the haemodynamics of vascular anomalies under conditions simulating sclerotherapy. Twenty-six soft-tissue vascular anomalies in 21 patients were studied. After 30 MBq of technetium-99m Sn colloid was injected percutaneously into the intravascular space of the lesion, dynamic imaging was performed for 5 min. A time-activity curve for the lesion was generated, with the infiltrated activity on injection subtracted. A monoexponential curve was fitted to the declining phase of the time-activity curve, and mean vascular transit time (MTT) was obtained. The lesions were classified into high-flow and low-flow lesions based on radionuclide angiography with intravenous injection of 99mTc-labelled red blood cells, and estimates of MTT in the two groups were compared. The imaging procedures were carried out with no major complications, and broad intralesional diffusion of 99mTc-Sn colloid was achieved in most lesions. The high-flow lesions (six lesions) had a short MTT, ranging from 1.6 to 3.4 s, while the low-flow lesions (20 lesions) had a longer MTT, with no overlap between the groups. MTT showed a wide range in low-flow lesions: it was less than 30 s in six lesions and more than 10 min in five other lesions. Direct puncture scintigraphy provides a quantitative indicator of the flow characteristics of soft-tissue vascular anomalies, and may aid in determining treatment strategies for patients with vascular anomalies.

Adolescent↗

PubMed1997

Life-size, computer-generated skull replica to assist surgery of craniofacial fibrous dysplasia.

Craniofacial fibrous dysplasia is a benign pathological condition but it replaces bone and expands gradually, leading to facial distortion. Surgery is the only effective treatment. The authors describe the usefulness of a life-size, computer-generated skull replica which assists surgeons pre- and intraoperatively. Surgery can be safely performed with less invasion and a shorter operation time by referring to the skull replica. Partial bone resection and bone contouring have been carried out, assisted by skull replicas, in 8 patients with craniofacial fibrous dysplasia, resulting in good cosmesis.

Adolescent↗

PubMed1997

Treatment of infectious skin defects or ulcers with electrolyzed strong acid aqueous solution.

A chronic ulcer with an infection such as methicillin-resistant Staphylococcus aureus is hard to heal. Plastic and reconstructive surgeons often encounter such chronic ulcers that are resistant to surgical or various conservative treatments. We applied conservative treatment using an electrolyzed strong acid aqueous solution and obtained satisfactory results. The lesion was washed with the solution or soaked in a bowl of the solution for approximately 20 min twice a day. Fresh electrolyzed strong acid aqueous solution is unstable and should be stored in a cool, dark site in a sealed bottle. It should be used within a week after it has been produced. Here we report on 15 cases of infectious ulcers that were treated by electrolyzed strong acid aqueous solution. Of these cases, 7 patients were healed, 3 were granulated, and in 5, infection subsided. In most cases the lesion became less reddish and less edematous. Discharge or foul odor from the lesion was decreased. Electrolyzed strong acid aqueous solution was especially effective for treating a chronic refractory ulcer combined with diabetes melitus or peripheral circulatory insufficiency. This clinically applied therapy of electrolyzed strong acid aqueous solution was found to be effective so that this new therapeutic technique for ulcer treatment can now be conveniently utilized.

Acids↗

PubMed1996

Secondary contour reconstruction of maxillectomy defects with a bone graft vascularized by flowthrough from radial vascular system.

We describe post-total maxillectomy secondary facial contour reconstruction using an osteocutaneous scapular flap nourished by flow-through vascularization from the radial vascular system. Scar contracture caused by either total or partial maxillectomy for maxillary cancer was completely released with exposure of the edge of the zygomatic arch, orbital floor, and nasal bone. The scapular skin flap was placed into the mucosal defect, and the orbital floor and zygomatic prominence were reconstructed with the scapular bone. The flap nutrient vessels were anastomosed to radial vessels and cephalic vein grafts. Two representative cases are illustrated to demonstrate the application and advantage of this operative method.

Anastomosis, Surgical↗