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Biomedical subjects

K Harii

Publications and source records attributed to K Harii.

At least 55 records · Page 3Linked to original sources
PubMed1999

Comparison of innervated and noninnervated free flaps in oral reconstruction.

Thirteen patients who had undergone ablative surgery for advanced squamous cell carcinoma in which more than half of the tongue had been resected underwent reconstruction in which the cutaneous nerve of a free flap was anastomosed to the stump of the transected lingual nerve. Eight of the patients underwent reconstruction with an innervated anterolateral thigh flap and five patients underwent reconstruction with an innervated rectus abdominis musculocutaneous flap. Sensory recovery of the flap at least 6 months postoperatively was compared in these 13 patients and in 16 additional patients who received noninnervated versions of the same flaps for the same defect. The degree of sensory recovery of innervated thigh flaps was significantly greater than that of noninnervated ones in all modalities and that of innervated rectus abdominis flaps was also greater than that of noninnervated flaps, except for hot and cold perception. These results indicate that sensory regrowth occurs in most areas through the surgically created pathways. However, results of Semmes-Weinstein testing showed that recovery did not reach the level of protective sensation in either type of innervated flap. Although these findings must be followed by additional objective and functional tests and the need for sensory reeducation should be considered, this simple operative procedure can improve postoperative intraoral function and should be attempted whenever possible after ablative surgery.

Abdominal Muscles↗
PubMed1999

Repair of a large "coup de sabre" with soft-tissue expansion and artificial bone graft.

The authors present a case of a "coup de sabre"--a linear form of scleroderma--in an 18-year-old woman treated by means of an expanded forehead and scalp flap, a hydroxyapatite implant, and an autologous iliac bone graft. Hydroxyapatite was implanted to augment a depressive bony deformity. The nasal deformity was repaired with an expanded forehead flap and an autologous iliac bone graft. This is the first reported case in which a deformity of scleroderma was treated with a combination of an expanded skin flap and a hydroxyapatite implant.

Adult↗
PubMed1998

Osteogenic potential of cultured periosteal cells in a distracted bone gap in rabbits.

Osteogenesis of cultured periosteal cells was investigated in a bone-defective gap that was created artificially by distraction in the tibia of 12-week-old rabbits. A 10-mm circumferential length of periosteum was stripped from each stump of the osteotomized tibia, and the tibia was distracted rapidly (2 mm/day), resulting in disturbance of callus formation. Periosteal-derived cells, which were isolated from the contralateral tibia, were introduced into cell culture, subcultured twice to a population of 5 x 10(7) cells, and then injected into the defective bone gap when distraction was complete. Following inoculation of the cultured cells, significant new bone formation in the bone gap was observed. The control group which did not undergo cell transplantation showed only slight new callus formation which is supposed to be formed by osteogenic cells from the bone marrow. The bone mineral content of newly formed bone between the distracted tibia was analyzed quantitatively on radiographs. Histologically, the transplanted cells initially formed a mass at the injected site and then gradually differentiated into bone tissue from the peripheral region. Bromodeoxyuridine immunohistochemical stain was utilized to investigate the localization of the transplanted cells. The present study confirms that the orthotopically implanted periosteum-derived cells facilitate osteogenesis in a bone defect created using distraction in rabbits.

Animals↗
PubMed1998

Amrinone, a selective phosphodiesterase III inhibitor, improves microcirculation and flap survival: a comparative study with prostaglandin E1.

BACKGROUND: Amrinone, a selective phosphodiesterase (PDE) III inhibitor, is a newly developed agent that possesses a combination of positive inotropic and vasodilating properties as a result of preventing the degradation of cAMP and it has recently been licensed for treatment of heart failure alone. Amrinone is expected to be useful for the treatment not only of heart failure but also of peripheral circulatory disorders, including vascular disease, and for ischemic flaps, because it improves microcirculatory hemodynamics. To investigate potential therapeutic applications of amrinone, we evaluated its ability to improve microcirculatory hemodynamics and flap survival. MATERIALS AND METHODS: The rat skinfold chamber technique was employed to quantify microcirculation directly in vivo. The improved survival area of random flaps in rats treated with amrinone was examined to assess therapeutic efficacy of this drug. Its effects were compared with those of prostaglandin E1 (PGE1), which has been widely approved as an agent for improving hemodynamics. RESULTS: Microcirculatory blood flow and flap survival area were significantly increased in both amrinone- and PGE1-treated animals, compared to the saline-treated controls. The ameliorating effects of amrinone were comparable to those of PGE1. CONCLUSIONS: The results of this study suggest amrinone to be a potentially useful drug not only for treating heart failure but also for improving microcirculation in patients with vascular diseases and for postoperative care after reconstructive surgery.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

A new concept and technique for reconstruction of the lower pharyngeal space using the free jejunal graft.

OBJECTIVE: To report on a new concept and simple operative procedure to conform the diameter of the oral end of free jejunal grafts to that of pharyngeal defects for reconstruction of the lower pharyngeal space. DESIGN AND METHODS: A preliminary study showed that the jejunum is supplied by a highly vascular network and that longitudinal paramesenteric incisions can be made without disturbing the blood supply of the jejunum. We then developed the following operative procedure. The position of the highest point of the pharyngeal defect and the site of the recipient vessels are determined. The free jejunal graft is positioned with its mesentery in correspondence with the location of the recipient vessels. The position of a longitudinal incision 180 degrees to the highest point of the defect is then determined. After the oral border of the jejunum is opened with scissors, a pharyngojejunal end-to-end anastomosis is performed. PATIENTS: Eighteen patients with defects of the lower pharyngeal space after cancer treatment. RESULTS: We transferred jejunal grafts in 18 patients using this operative procedure. In 7 of these patients, paramesenteric incisions were made. The lengths of the incisions ranged from 2 to 8 cm. Transfer was successful in all 18 patients. Postoperative leakage occurred in 1 patient in whom an antimesenteric incision had been made; however, a fistula did not develop. CONCLUSIONS: Our method allows defects of the lower pharyngeal space to be reconstructed with end-to-end anastomosis of free jejunal grafts regardless of the location of the defect or of recipient vessels. This method is simple and appropriate for correcting large pharyngeal defects.

Adult↗
PubMed1998

Myosin heavy chain expression in skeletal muscle autografts under neural or aneural conditions.

BACKGROUND: Our purpose was to investigate (1) the heterogeneity of satellite cells derived from adult fast-twitch and slow-twitch skeletal muscles, (2) the influence of innervation on muscle regeneration, and (3) the differences between developmental myoblasts and satellite cells with regard to myosin heavy chain (MHC) expression. MATERIALS AND METHODS: Autografts under neural (nerve-intact graft; brief denervation interval) or aneural (aneural graft; prolonged denervation interval) conditions of the fast-twitch extensor digitorum longus (EDL) muscle or the slow-twitch soleus muscle were performed in adult rat hindlimbs. MHC expression during skeletal muscle regeneration was determined sequentially using immunocytochemistry. RESULTS: After grafting, most muscle fibers in the EDL and soleus underwent ischemic degeneration and regeneration; at the periphery of each muscle, a few adult fibers survived. All regenerating fibers initially expressed embryonic/fetal (developmental) MHC alone, and subsequently both developmental and fast MHC. During the first week, no expression of slow MHC was observed in regenerating fibers in either the EDL or the soleus. In nerve-intact grafts, regenerating fibers expressed slow MHC as early as the second week; under aneural conditions, no regenerating fibers expressed slow MHC even 4 weeks after grafting. On the other hand, some persisting fibers in aneural grafts could maintain expression of slow MHC 4 weeks after grafting; other fibers underwent MHC transformation induced by denervation. No significant difference in MHC expression during regeneration was observed for slow compared with fast muscles, under either neural or aneural condition. CONCLUSIONS: These data suggest that regenerating adult skeletal muscle fibers, derived only from satellite cells, cannot express slow MHC without motor innervation, and that persisting muscle fibers, derived from both myoblasts in fetal development and satellite cells, may be intrinsically distinct from regenerating fibers. Satellite cells derived from slow and from fast muscles may be a single, homogenous population and may be the same population as fetal (secondary) myoblasts with regard to MHC expression.

Animals↗
PubMed1998

Immunohistochemical analysis of clinically transplanted muscles.

BACKGROUND: Although a number of studies have examined the morphology and function of experimentally transplanted muscles, immunohistochemical evaluation of clinically transplanted muscles has not been reported. The purpose of this study was to examine clinically transplanted muscles at long periods after transplantation with biochemical markers specific for satellite cell activation and muscle regeneration. MATERIALS AND METHODS: Nine biopsies of muscles transplanted to the paralyzed face were examined. In five cases, the gracilis muscles were transplanted about 1 year after cross face nerve grafting. The other four cases underwent one-stage latissimus dorsi (LD) muscle transplantation. Twelve to 162 months after transplantation, muscle biopsies were harvested in nine cases. In eight cases, secondary corrections of facial expression including debulking of the grafted muscle were required, while another muscle was transplanted in one case because of the failed first operation. As control, six specimens of normal LDs were examined as well. Monoclonal antibodies were employed to visualize myosin heavy chain (MHC) isoforms (slow, fast, and embryonic) and MyoD protein. RESULTS: Although one specimen exhibited only small, atrophic fibers indicating failed reinnervation, the remaining eight specimens showed regularly distributed fibers and type grouping indicating successful reinnervation. There was no statistically significant difference in fiber area and lesser diameter between normal LDs and transplanted LDs. However, even in these successfully reinnervated muscles, intermediate and small fibers expressing embryonic MHC and small cells expressing MyoD were observed, suggesting that satellite cells were activated for repair of the adjacent fibers. CONCLUSIONS: Muscle adaptation (presumably to denervation), which is a regenerative change accompanied by activation of satellite cells, was still seen even long periods after transplantation. It is concluded that, in microneurovascular human skeletal muscle transfers, there is a wide variation in the time required for reinnervation of individual muscle fibers, and it may be that human muscle fibers cannot be properly reinnervated after denervation has continued for a certain period such as 12 months.

Adult↗
PubMed1998

In vivo measurement of morphometric and hemodynamic changes in the microcirculation during angiogenesis under chronic alpha1-adrenergic blocker treatment.

The effect of chronic administration of the alpha 1 blocker prazosin on microvascular angiogenesis was studied in rabbit ear chamber to investigate the role of concomitant increase in flow-oriented wall shear stress in vascular remodeling during angiogenesis. Rabbits were treated with prazosin hydrochloride (50 mg/liter in water) orally after ear chambers were installed. The microcirculation in the chamber was observed and recorded from 4 to 23 postoperative day (POD) by an intravital videomicroscope. The total vascular area (TA) were quantified as a morphometric parameter. Changes in wall shear stress in venules (20-40 micron ID) were calculated from flow velocity, vessel diameter, and in vivo blood viscosity. TA was significantly increased in the prazosin-treated animals. The levels of shear stress, which was increased 1.43 times by prazosin on 9 POD, gradually decreased toward the control level on 13 POD and they almost coincided on 21 POD. These findings experimentally provided supporting evidence that shear stress is probably involved in the adaptive response as one of mechanical factors regulating vascular remodeling during angiogenesis.

Adrenergic alpha-Antagonists↗
PubMed1998

Biological effects of static magnetic fields on the microcirculatory blood flow in vivo: a preliminary report.

There have been few studies of the effect of static magnetic fields on microcirculatory haemodynamics in vivo. The rat skinfold transparent chamber technique was used, which provides an excellent means of observing and quantifying direct in vivo microvascular haemodynamic responses to static magnetic fields up to 8 T. An intravital videomicroscope was used to measure the changes in blood flow before and after exposure to a magnetic field for 20 min in a horizontal type superconducting magnet with a bore 100 mm in diameter and 700 mm long. After exposure, microcirculatory blood flow showed an initial increase for about 5 min followed by a gradual decrease and a return to the control value. It is hypothesised that these changes represent rebound hyperaemia following reduced blood flow during exposure.

Animals↗
PubMed1998

Secondary lengthening of the reconstructed mandible using a gradual distraction technique--two case reports.

We have performed mandibular lengthening to restore oral function in 2 cases after tumour resection. Both cases had already undergone a vascularised fibular graft for mandibular reconstruction and had severe contracture and absence of an alveolar ridge for dentures. Gradual distraction was applied after corticotomy of the fibular bone at 0.9 mm per day. After completion of bone lengthening of 20-30 mm, both patients underwent a split thickness skin graft to obtain a good alveolar ridge for dentures and implants. Osteointegrated implants have since been applied in one of these cases, and the other patient has been able to eat a normal diet using dentures. Gradual distraction is applicable for vascularised bone grafts and useful for restoration of the alveolar ridge to accommodate dentures in cases with severe contracture of the oral space after tumour ablation.

Humans↗
PubMed1998

Reconstruction of skull defects with vascularized omentum transfer and split calvarial bone graft: two case reports.

Autogenous calvarial bone grafts have been widely used in craniofacial reconstruction following trauma, congenital anomalies, and head and neck tumors. In cases of late restoration of a collapsed cranial vault, an extradural dead space is occasionally observed which might cause infection and grafted bone absorption. The combined use of a split calvarial bone graft and an omental flap has been an effective technique for treating complicated cranial defects. The omental flap eliminates the extradural dead space between the grafted calvarial bone and the scarred dura, and provides an acceptable vascular bed for grafted bone. The authors report this technique for complex cranioplasties in two cases, with good cosmetic results.

Aged↗
PubMed1998

Use of the disposable stapler to insure proper fixation of a transferred muscle in treatment of facial paralysis.

The authors introduce the use of a disposable stapler to create a stable muscle end in transferring a free neurovascular muscle segment for the treatment of facial paralysis. This procedure allows the firm fixation of the fragile soft end of a muscle transferred to the nasolabial region of a paralyzed face, and avoids adhesion and tethering of the muscle end to the skin, which may result in inaccurate positioning of a newly-created nasolabial fold and an asymmetrical smile. Transection and hemostasis at both ends of the harvested muscle segment also can be achieved simultaneously. Although the disposable stapler incurs additional cost, it can greatly improve the result of a free neurovascular muscle transfer for the treatment of facial paralysis, as well as simplify harvesting of the muscle segment. No complications and problems have been encountered in stapling the muscle.

Disposable Equipment↗
PubMed1998

Alternative use of medial and posterior upper-arm flaps.

There are such marked variations in the vascular anatomy of the nutrient vessels in medial and posterior upper arm flaps, that widespread usage of these flaps has been delayed. The authors have evaluated both medial and posterior upper arm flaps and have concentrated on the status of the skin perforators. Both types of flaps were considered for use as free transfers in 25 cases; island flaps were successfully elevated in 22 patients (11 medial and 11 posterior flaps). Because of the lack of suitable perforating vessels, this solution was abandoned in three patients. Perforators in both areas were found in 44 percent of the cases, in one or the other area in 44 percent, and not at all in 12 percent of the cases. Using the determination of perforators, the success rate of free-flap transfers from the medial and posterior upper arm increased from 64 and 68 percent, respectively, to 88 percent. When harvesting a flap from the medial or posterior upper arm, the risks attending questions of vascular stability in free-flap transfer, may be overcome by clinician experience.

Adolescent↗
PubMed1998

Comparative evaluation in pharyngo-oesophageal reconstruction: radial forearm flap compared with jejunal flap. A 10-year experience.

We reviewed 109 consecutive patients with cancer of the hypopharynx or cervical oesophagus who underwent free flap transfer for immediate reconstruction after total pharyngolaryngo-oesophagectomy. The free flaps used were either free jejunal (n = 70) or radial forearm flaps (n = 39). Significantly more fistulas (3/70 compared with 15/39, p < 0.0001) and strictures (6/64 compared with 13/33, p = 0.0008) developed in the radial forearm than the jejunal flap group. However, functional donor site morbidity was minimal and there were no cases of total flap necrosis in the forearm flap group. We consider that the free jejunal flap should be the first choice for total reconstruction of pharyngo-oesophageal defects. However, the forearm flap is suitable for elderly, high risk patients, because it is less invasive and has minimal donor site morbidity, which facilitates early recovery.

Adult↗
PubMed1998

An experimental comparison of hydrocolloid and alginate dressings, and the effect of calcium ions on the behaviour of alginate gel.

Gel-forming dressings, which absorb the wound exudate to form a non-adherent gel, accelerate wound healing in a moist environment. The most commonly used of these dressings are calcium alginate and hydrocolloid membranes. This study was designed to evaluate the physical properties of these dressings, including fluid retaining ability, gel formation, and the dissolution process to clarify the mechanisms that promote healing. A simple immersion method was used for measurement. This technique was useful for the quantitative assessment of gel-forming dressings and may help to evaluate potential application of these dressings. A comparative analysis showed that alginate dressings remained gelled longer than hydrocolloid dressings. This result was consistent with previously reported clinical features of these dressings. The absence of calcium in wound fluid induced rapid resolution of alginate gel while the presence of a certain concentration of calcium prevented degradation of the gel for as long as one month.

Alginates↗
PubMed1998

Closure of large pharyngo-oesophageal fistulas with free flap transfer after resections for cancer.

Postoperative salivary fistulas still remain a serious and potentially lethal problem in head and neck reconstruction particularly if the fistula is large and involving one half or more of the circumference of the pharyngo-oesophagus. Pedicled flaps have traditionally been the flaps of choice for closure of these fistulas, but the results are often disappointing. During the period 1982 to 1995, we have used either a radial forearm free flap or a jejunal free flap to close large and complex pharyngo-oesophageal fistulas after resection for cancer in 15 patients. Although two patients developed major fistulas that required additional operations for closure, successful closure was achieved in all but one case: the success rate was therefore 14/15 (93%). We consider that jejunal flaps are suitable for circumferential pharyngo-oesophageal reconstruction and forearm flaps for non-circumferential defects.

Aged↗
PubMed1998

Skeletal analysis of craniofacial asymmetries in plagiocephaly (unilateral coronal synostosis).

Why do the craniofacial bones grow asymmetrically in patients with plagiocephaly (unilateral coronal synostosis)? We obtained three-dimensional skeletal replicas of two patients with the condition and analysed the deformities of the facial bones. From this analysis we deduced that the asymmetric deformation of the facial bones in these patients was caused by a combination of three rotations: rotation of the calvaria toward the affected side because of premature synostosis of the coronal and sphenofrontal sutures; rotation of the facial bones on the horizontal plane toward the unaffected side caused by anterior displacement of the TM (temporomandibular)-joint on the affected side; and downward rotation of the facial bones toward the unaffected side caused by inferior displacement of the TM-joint on the affected side.

Cephalometry↗