Biomedical subjects

H Asato

Publications and source records attributed to H Asato.

At least 37 records · Page 2Linked to original sources

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

Beat-to-beat variation of the ST segment in a patient with right bundle branch block, persistent ST segment elevation, and ventricular fibrillation: a case report.

The authors describe a patient with ventricular fibrillation associated with right bundle branch block-like QRS morphology and persisting ST segment elevation in the precordial leads, in whom the morphology of the ST segment changed from the coved type to the saddle-back type or vice versa on a beat-to-beat basis. Such an observation has never been reported in the previous literature.

Adult↗

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↗

PubMed1996

Comparison of end-to-end and end-to-side venous anastomosis in free-tissue transfer following resection of head and neck tumors.

A comparative study was conducted of the results of venous end-to-end and end-to-side anastomosis in 948 clinical cases of microvascular free-tissue transfers for head and neck reconstruction following tumor resection. End-to-side anastomosis to the internal jugular vein was achieved uneventfully in the present series, while a variety of recipient veins was used for end-to-end anastomosis. The incidence of thrombosis was 1.8% (15/835) in the end-to-end anastomosis group and 2.7% (3/113) in end-to-side venous anastomosis. No statistical difference was observed between the two groups. One may hesitate to perform end-to-side anastomosis because of unfamiliarity, concern over technical difficulty, and unreliability. As a result of our statistical analysis, we are convinced that end-to-side anastomosis directly to the internal jugular vein, whenever available, is the preferred procedure in microvascular free-tissue transfers for reconstruction of the head and neck following tumor resection.

Adolescent↗

PubMed1996

Deletion of individual muscles alters rat walking-track parameters.

Rat walking-track analysis has been employed extensively to quantify motor recovery in studies of hindlimb nerve injury and repair. In order to clarify the relationship between individual print measurements and the function of specific hindlimb muscles, 40 young adult rats were assigned to one of five groups (n = 8/group) in which specific deletions of motors were created as follows: Group 1--division of the tendon of insertion of the gastrocnemius, soleus, and plantaris muscles (GSP); Group 2--division of the extensor digitorum longus muscles tendons of insertion (EDL); Group 3--division of the extensor hallicus longus muscle tendon of insertion (EHL); Group 4--division of the tibialis anterior muscle tendon of insertion (TA); or Group 5--division of the tibial nerve at the ankle (TNA). Parameters for print length (PL), intermediate toe spread (IS), and total toe spread (TS) were calculated from walking tracks recorded before and again five days after deletion of the motors. Specific, predictable patterns of change in footprint parameters were observed for each group. It was concluded that triceps surae and tibialis anterior muscle function directly affects print length; EHL function directly influences total toe spread; and EDL function is directly related to intermediary toe spread. These data demonstrate a direct relationship between individual print measurements and the function of individual rat hindlimb muscles.

Animals↗

PubMed1996

Aging effects in skeletal muscle recovery after reinnervation.

To investigate the influence of age on the process of muscle recovery after nerve repair, the nerves of the right extensor digitorum longus (EDL) and the right soleus muscles of 63 2-month-old and 61 15-month-old rats, respectively, were transsected and resutured. At four, eight, 16, and 24 weeks after nerve repair, functional recovery of the muscle was assessed by electromyographic (EMG) recordings and isometric muscle contraction. Muscle weight, morphological, and morphometric studies were also done. At four and eight weeks after nerve repair the younger age groups showed higher rates of recovery compared with the control side (left EDL and soleus) (recovery rate (%) = operated/control x 100) than the older age groups, and the recovery rates of soleus (slow twitch muscle) in both age groups were higher than EDL (fast twitch muscle). However, the differences between the two age groups decreased at 16 and 24 weeks after nerve repair in both muscles. We therefore conclude that earlier differences were the effects of nerve regeneration on the muscle between different ages and the reason for the reduced differences at later stages was that after reinnervation began, not only the nerve but also the muscle recovered successfully in older age groups, and slow motor units reinnervated faster than the fast units in both age groups. Our present study shows that the older age groups also have a good prognosis for recovery of muscle function after nerve repair.

Aging↗

PubMed1995

Electrocardiographic abnormalities in patients with acute aortic dissection.

In conclusion, acute electrocardiographic changes were not uncommon in patients with acute aortic dissection. It was suggested that acute electrocardiographic changes in aortic dissection resulted from at least 1 of the following 3 mechanisms: (1) involvement of the ostium of the coronary artery; (2) shock state, especially tamponade; and (3) preexisting coronary artery disease. We believe that physicians should be aware of the possibility of acute aortic dissection not only in patients with chest pain with a normal electrocardiogram, but also in those with electrocardiographic changes.

Acute Disease↗

PubMed1995

Reconstruction of the umbilicus using a single triangular flap.

Many techniques for reconstruction of an absent umbilicus have been described; however, none has achieved a perfect result. We report a new alternative for constructing an umbilicus using a conical flap and present two representative clinical cases. Our technique creates an umbilicus with sufficient depth with good results, including maintenance of depth after more than 1 year.

Humans↗

PubMed1995

Versatility of a cross-leg free rectus abdominis flap for leg reconstruction under difficult and unfavorable conditions.

A cross-leg free rectus abdominis flap, anastomosing to utilized "carrier" vessels of the contralateral noninjured leg, was used for reconstruction in six cases of extensive traumatic defects and deformities of a lower extremity. This method provides great advantages in free-flap reconstruction of complicated and unfavorable cases in which utilization of what would be suitable recipient vessels in the injured leg is most difficult, but there is good blood circulation of the leg.

Adult↗

PubMed1995

Two adult cases of unilateral absence of the right pulmonary artery with markedly different clinical presentations.

Two adult cases of unilateral absence of the right pulmonary artery with markedly different clinical presentations are reported. One patient was a 21-year-old female without any known history of a coexisting congenital anomaly. An abnormal chest roentgenogram (small right hemithorax, deviation of the mediastinum toward the right side and a dilated left pulmonary artery) was noted and prompted further evaluation. No pulmonary hypertension was noted and the patient remained asymptomatic. The other patient was a 42-year-old male who had unilateral absence of the right pulmonary artery and a peripheral stenosis of the left pulmonary artery. The clinical course of this patient had been complicated by impaired exercise tolerance and occasional hemoptysis since adolescence. At the age of 29 years, a cardiac catheterization revealed pulmonary hypertension, but no left-to-right shunt. Progressive respiratory failure resulted in a premature death at the age of 42 years. The prognosis of patients with unilateral absence of the pulmonary artery largely depends on the coexisting cardiac anomaly (left-to-right shunt) and pulmonary hypertension. A combination of unilateral absence of the pulmonary artery and contralateral peripheral pulmonary arterial stenosis is very rare, but is an important cause of pulmonary hypertension and gives a worse prognosis for this entity.

Adult↗

PubMed1995

A comparison of temporal muscle transfer and lid loading in the treatment of paralytic lagophthalmos.

Temporal muscle transfer (n = 78) and lid loading with a gold plate (n = 52) were compared in the treatment of paralytic lagophthalmos. Three sizes of gold plate (1.0, 1.2 and 1.4 g) were used. Lid loading was inferior to temporal muscle transfer in improving functional ability to close the eye, but it did protect the cornea from irritation. There were no significant differences among the sizes of plate, but there was most relief from corneal irritation when the 1.4 g gold plate was used. The plate had to be removed in 25% of the patients, but this did not make the condition worse than before lid loading. Lid loading has the advantage that patients can close their eyes without conscious effort. We therefore recommend lid loading as the first choice for correction of paralytic lagophthalmos, and that temporal muscle transfer should be undertaken after plate removal in only those patients for whom lid loading has not given a satisfactory result.

Adolescent↗

PubMed1994

Versatility of a free inferior rectus abdominis flap for head and neck reconstruction: analysis of 200 cases.

Between 1984 and 1991, 200 inferior rectus abdominis muscle and musculocutaneous free flap transfers were performed for reconstruction of defects or deformities resulting from removal of cancer in the head and neck region. Primary reconstruction was performed in 190 of 200 cases (95 percent), and secondary reconstruction in 10 cases (5 percent). The most common indication was tongue cancer in 78 patients, followed by cancer of the oropharynx. Total flap necrosis occurred in 10 cases (5 percent) and partial necrosis in two cases (1 percent). Donor-site morbidity was minimal. One of the distinct advantages of this flap is that the volume of the muscle and/or the fatty tissue attached to a given skin paddle can be readily adjusted to suit individual requirements. This flap has proven particularly useful for complex or large tissue defects in the head and neck region.

Adolescent↗

PubMed1994

Tissue expansion in facial reconstruction.

The tissue expansion technique is advantageous in facial reconstruction because it makes it possible to resurface even wider defects with neighboring skin similar in color and texture and superior to skin obtained elsewhere, thereby surpassing conventional methods. However, there still remain some problems relating to procedural details, such as the selection of tissue expanders and sites of their insertion; the design, elevation, suturing, and fixation of the expanded flap; and the management of free margins such as the lower lip and lower eyelid. In each case, some modification is required with respect to the status of the defect. The experiences encountered in a series of 23 patients are described, with illustration of several representative cases, and advantages and problems are discussed.

Adolescent↗

PubMed1993

Eye socket reconstruction with free-flap transfer.

Patients afflicted with retinoblastoma or other malignant orbital tumors often undergo eyeball excision and irradiation in infancy, which results in severe deformities of the orbit. It is very difficult to achieve the reconstruction of such severely depressed and contracted eye sockets because both augmentation and formation of an eye socket are required. We usually perform a free-flap transfer with microvascular anastomoses in such situations and have experienced 25 cases since 1980. Various kinds of flaps, such as the groin flap, dorsalis pedis flap, scapular flap, and others, were utilized. The degree of depression and whether sufficient conjunctiva for lining of the eye socket remains are important in the selection and design of the donor flap. To obtain an orbit with a natural appearance, many of the patients required subsequent minor revision operations such as debulking, dermal fat grafts, canthoplasty, fascia suspension, and so on.

Adolescent↗

PubMed1993

Tricuspid regurgitation due to blunt chest trauma. Report of a case and review of the literature.

A 25-year-old female developed high-grade atrioventricular block and markedly elevated central venous pressure after sustaining a crushing injury to the chest while driving a car. An echocardiographic examination with color Doppler revealed severe tricuspid regurgitation due to a torn papillary muscle. An extensive review of the literature showed the following: 1) correct diagnosis is often delayed because of coexisting multisystem involvement and the subtleness of abnormal physical signs, 2) identification of abnormally elevated right atrial pressure with a prominent "v" wave, and characteristic electrocardiogram appeared to be the key to early diagnosis, and 3) the final diagnosis may be confirmed by echocardiography with Doppler and/or cardiac catheterization. The role of echocardiographic examination with color Doppler technique deserves special emphasis because the final diagnosis can be easily reached during the acute phase at the bedside noninvasively.

Adult↗

PubMed1992

Breast reconstruction with the free TRAM flap after breast cancer surgery.

The authors' experiences with 34 free lower TRAM flap transfers, in which 19 primary reconstructions and 15 secondary reconstructions were successfully achieved, are reviewed. The free TRAM flap yielded better results than the pedicled TRAM flap in cases where reconstruction of the infraclavicular and anterior axillary areas, as well as of the breast mound itself, was required.

Adult↗

PubMed1991

A case of effusive constrictive pericarditis caused by Streptococcus milleri.

A 55-year-old male presented with hypotension and marked elevation of jugular venous pressure suggesting impaired ventricular filling. Echocardiography demonstrated a moderate amount of pericardial effusion and dense and shaggy fibrinous strands attached to the pericardia. Pericardiocentesis was performed under the diagnosis of cardiac tamponade, but normal ventricular filling could not be restored even after pericardiocentesis. Hemodynamic evaluation after pericardiocentesis revealed persisting low cardiac output, elevation and equilibration of right atrial, right ventricular end-diastolic and pulmonary capillary wedge pressures, and deep y descent. Later, surgical removal of the thickened pericardium was required. This case appeared to be typical effusive-constrictive pericarditis. Regarding etiology, a rare organism, Streptococcus milleri, proved to be responsible, while the case history and clinical situation were suggestive of a tuberculous or tumorous origin.

Hemodynamics↗