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Biomedical subjects

F C Wei

Publications and source records attributed to F C Wei.

At least 127 records · Page 7Linked to original sources
PubMed1997

Technical refinement in the management of circumferentially avulsed skin of the leg.

Between 1989 and 1994, 42 patients with circumferential skin avulsion of lower extremities were treated with full-thickness skin graft from defatted avulsed flap. Among them, 39 patients were run over by rubber tires during car accidents; the remaining 3 patients were victims of industrial accidents by roller machines. The full-thickness skin grafts were prepared from the avulsed skin flap in attachment to avoid junctional hypertrophic scarring. They were then secured with multiple skin staples to their anatomical position to improve skin graft take. Initial take of graft averaged 91 percent (ranged from 75 percent to 100 percent). Twelve patients underwent secondary overgrafting after tangential excision of non-viable skin graft. Follow-up averaging 2.6 years revealed stable wounds in most of the patients. Ten patients experienced occasional breakdown of skin graft in the patella and popliteal fossa, which was treated conservatively. Except for five who had deformed contours of the leg due to muscle transfers, the patients were satisfied with the cosmetic appearance of their legs. Compared with conventional methods, this approach provided better appearance and less contracture.

Accidents, Traffic↗
PubMed1997

Lack of allelic association between 102T/C polymorphism of serotonin receptor type 2A gene and schizophrenia in Chinese.

Recent studies have reported an association between a 102T/C polymorphism of serotonin receptor type 2A gene (5-HT2A) and schizophrenia. In addition, an association was detected between a 102T/C polymorphism of the 5-HT2A receptor gene and drug response to clozapine in the treatment of schizophrenic patients. These studies suggest an important role of the 5-HT2A gene in schizophrenia. To study the possible involvement of the 5-HT2A gene in the pathogenesis of schizophrenia, a case-control association study was carried out in a Chinese population from Taiwan. No significant differences of genotype distributions, allele frequencies and homozygosity were detected between schizophrenic patients (n = 177) and nonpsychiatric controls (n = 98). When subjects were divided into subgroups according to sex, still no differences of allele frequencies or genotype distributions were noted between patients and controls. Our data do not support an allelic association between the 102T/C polymorphism of the 5-HT2A receptor gene and schizophrenia in Chinese population.

Alleles↗
PubMed1997

Neurosensory free flaps. Digits and hand.

Repairing complex soft-tissue defects of the hand and fingers remains a daunting task. Maintenance of functional mobility and sensibility are paramount in determining donor-site tissue. Critical sensibility is important for defects of the fingers and can be replaced only with tissue from the palmar surface of the hand itself or by free-tissue transfer from the toes. In this regard, glabrous skin and pulp from the great toe demonstrates the most critical level of sensibility, followed by tissue from the second toe. Complex soft-tissue defects of the palm, dorsum of the hand, or first web space can be replaced effectively by flaps that provide protective sensibility. The standard flaps employed are the lateral arm or radial forearm. The ultimate consideration in dealing with these difficult problems must be determined by the judgment and technical sophistication of the surgeon.

Finger Injuries↗
PubMed1997

Free composite serratus anterior and rib flaps for tibial composite bone and soft-tissue defect.

Open fracture in the lower extremity often involves composite bone and soft-tissue defects. For patients with extensive segmental bone defects, vascularized fibular transfers can be utilized and are generally accepted as one of the best options for reconstruction of intercalary defects. In some cases, either bilateral tibias and fibulas are fractured or the contralateral fibula is traumatically damaged or absent, precluding free fibular transfer. If an osteocutaneous fibular flap cannot be used to manage such a defect, a composite serratus anterior and rib flap may be considered. Nine composite serratus anterior and rib flaps, with or without latissimus dorsi transfers, were performed in eight patients between August of 1993 and March of 1994. One patient sustained a left knee disarticulation and underwent reconstruction for a right tibial defect. He failed to achieve lower extremity function within 2 years and was considered a failure. One flap failed, and the patient underwent a below-knee amputation. The remaining six patients received seven composite flaps for tibial and calcaneal defects and could ambulate without assistance. Based on this review, we conclude that the composite serratus anterior and rib flap with optional latissimus dorsi muscle can be used for (1) bilateral tibial fibular fractures, (2) contralateral lower limb amputation with fillet of the amputated leg if the leg is present for harvest, (3) contralateral middle-third fracture of the fibula, (4) patients in whom iliac bone is not suitable because of either a bone defect greater than 10 to 12 cm or previous harvest of bone graft, and (5) extensive composite bone and soft-tissue defects.

Adolescent↗
PubMed1997

Classification and reconstructive options in foot plantar skin avulsion injuries.

Between 1989 and 1994, 28 patients who had plantar avulsion injuries were treated. Patient ages averaged 30 years (range 7 to 62 years). Length of follow-up averaged 20 months. Five patients (18 percent) were classified as having suprafascial avulsions, where the shearing plane was limited to the superficial subcutaneous layer, leaving the deeper subcutaneous fat. Twenty-three patients (82 percent) were classified as having subfascial avulsions, where the stripping force extended deep into the plantar aponeurosis. For the suprafascial avulsions, defatting these flaps and replacing them with full-thickness skin grafts was the treatment of choice. For the subfascial group, the avulsions with proximally based flaps (4 patients) that were well nourished by mediolaterally orientated neurovascular bundles could be treated by sewing the avulsed flaps tension-free back to their former positions. For the subfascial group with distally based flaps (19 patients), the avulsed flaps were supplied by anteroposteriorly orientated vascular plexuses that were compromised. Primary revascularization of the soft tissue should be considered whenever possible. Among them, 10 patients attempted microvascular salvage. Only 3 patients succeeded with revascularization. In the remaining 16 patients, the avulsed flaps went on to partial or complete necrosis, and these required secondary reconstruction with free muscle flaps for heel defects.

Adolescent↗
PubMed1997

Preoperative ultrasound Doppler study and clinical correlation of free posterior interosseous flap.

BACKGROUND: Conventional pedicled posterior interosseous flap has a relatively high rate of partial flap loss which may result in ultimate failure to provide coverage of this important structure. The goal of this study was to delineate the posterior interosseous flap as a reliable free tissue transfer. METHODS: From 1991 to 1995, 34 patients undergoing free posterior interosseous flap had preoperative Doppler mapping to determine the point of emergence of the skin perforators of the posterior interosseous artery. This finding was correlated intraoperatively with the number of perforators nourishing the posterior interosseous flap. The anatomic variations in the posterior interosseous artery were also identified. RESULTS: These results showed (1) the main skin perforator was consistent and reliable in all of the posterior interosseous flaps both in the preoperative Doppler evaluation and intraoperative findings; (2) the main skin perforator arose from the posterior interosseous artery, the ascending interosseous recurrent artery or the common interosseous artery in 26 cases (76%), 6 cases (17.6%) or 2 cases (5.9%) respectively; (3) the success rate with the use of the free posterior interosseous flap was 97% without any partial flap loss. CONCLUSION: It is concluded that the free posterior interosseous flap is a reliable flap with adequate arterial flow from constant main skin perforators and large antegrade venous drainage. A less reliable distally based pedicle flap can be changed into a reliable free flap, with the aid of preoperative non-invasive Doppler evaluation. This principle could be applied in the design of other "free skin perforator flaps".

Arteries↗
PubMed1996

Identification of a BglI polymorphism of catechol-O-methyltransferase (COMT) gene, and association study with schizophrenia.

Several linkage studies suggested chromosome 22q11-13 may harbor susceptible genes for schizophrenia. Catechol-O-methyl-transferase (COMT), which is involved in the metabolism of catecholamines, was mapped to 22q11 and is considered a possible candidate gene for schizophrenia. Recently, we identified a polymorphic marker, a single nucleotide C insertion at the 3' untranslated region of the COMT gene, which obliterates a BglI site. Using this BglI polymorphism, we conducted a case-control association study in Chinese patients with schizophrenia. No significant differences of allele and genotype frequencies were noted between patients (N = 177) and controls (N = 99). When patients were subgrouped according to sex, no significant differences of genotype and allele frequencies were noted in either male or female patients compared to normal controls. Our results do not support an association between the BglI polymorphism of COMT gene and schizophrenia.

Catechol O-Methyltransferase↗
PubMed1996

Comparison of skeletal muscle microcirculation between clamp ischemia and microsurgical ischemia.

We compared ischemia reperfusion injury-associated vasospasm and perfused capillary density (PCD) at the microcirculatory level between clamp ischemia and microsurgical ischemia in rat skeletal muscle. Rat cremaster muscle was prepared as an island flap, attached only with pudic-epigastric vessels branching from external iliac vessels. Two types of ischemia, with clamping only or with microvascular anastomosis, were applied at the external iliac vessels for 2 hours followed by 1-hour reperfusion before in vivo microscopic examination for hemodynamic changes. At the end of observation, small segments of the vessels at the clamping site and microsurgical anastomoses site were also harvested for histological examination. It was found that the first- and second-order arterioles had about 12-15% diameter reductions in both groups, whereas diameter reductions of the third-order arterioles were up to 37.8% in the microsurgical ischemia group, much greater than that in the clamp ischemia group (2.3%). There was also no significant difference in PCD reduction between the two groups, although the red blood cell velocity was much slower in the microsurgical ischemia group. Histological examination of the anastomosis site showed massive accumulation of polymorphonuclear neutrophils on the venous endothelium. These results suggested a different degree of endothelial damage and local leukocyte activation between microsurgical ischemia and clamp ischemia. Therefore, we conclude that clamp ischemia cannot replace microsurgical ischemia for studying microcirculatory changes in free tissue transfer.

Anastomosis, Surgical↗
PubMed1996

Lack of pharmacokinetic interaction between buspirone and haloperidol in patients with schizophrenia.

The pharmacokinetic interaction between buspirone and haloperidol was evaluated in schizophrenic patients in two different groups. In both groups, haloperidol doses (10-40 mg/day) remained constant for 6 weeks before the addition of buspirone 10 mg three times daily. Serial blood samples were obtained from the 11 patients in group I at baseline (before addition of buspirone) and after administration for 24 hours. The pharmacokinetic parameters of haloperidol were determined alone and with coadministration of buspirone. In group II, buspirone 10 mg three times daily was added to treatment with haloperidol in 27 patients. Blood samples were obtained before addition of buspirone and at weeks 2 and 6 of treatment with buspirone. Samples were obtained 10 to 12 hours after administration of the evening dose and before the morning dose. Haloperidol and its metabolite, reduced haloperidol (RH), were assayed by means of high-performance liquid chromatography with electrochemical detection. Significant changes in the pharmacokinetic parameters of haloperidol were not found in group I; a mean increase in the half-life (t1/2) of haloperidol from 21.5 to 28.1 hours was observed, but this finding was not statistically significant. Under steady-state conditions, plasma levels of haloperidol in the patients in group II did not change significantly from baseline to week 6. Plasma concentrations of RH remained unaltered in both groups. The results indicate that coadministration of buspirone does not markedly affect the pharmacokinetics or plasma concentrations of haloperidol.

Adult↗
PubMed1996

Haloperidol and reduced haloperidol plasma concentrations after a loading dose regimen with haloperidol decanoate.

1. Haloperidol and reduced haloperidol plasma levels were measured in schizophrenic patients who received both oral (10 mg, N=16 and 20 mg, N=4) and depot haloperidol treatment 2. Patients were of Asian ethnicity and were safely and effectively converted from oral to depot therapy using a loading dose regimen using a 100 mg weekly injection interval for 4 weeks, biweekly for one month and then monthly. 3. Significant correlations were found for plasma haloperidol and reduced haloperidol levels and reduced haloperidol/haloperidol ratios between oral and depot therapy in these non-smoking patients. 4. A loading dose regimen is needed due to the long elimination half-life of decanoate of 26 days otherwise steady-state condition will not occur until 34 months of therapy. 5. Patients were maintained on monthly depot treatment for 40 weeks after the loading dose regimen and only one patient relapsed during treatment despite dosage increases. 6. The formation of reduced haloperidol remained consistent for oral and depot haloperidol treatment.

Adult↗
PubMed1996

Results of functioning free muscle transplantation for elbow flexion.

Thirty-eight patients underwent functioning free muscle transplantation for restoration of elbow flexion. Thirty-five patients had sustained brachial plexus injury and 3 had traumatic loss of the biceps muscle. The gracilis muscle was used in 37 patients and the rectus femoris muscle in 4. The transferred muscle was reinnervated by the musculocutaneous (n = 3), intercostal (n = 31), and spinal accessory (n = 4) nerves. Results were assessed by the Medical Research Council grading system and success was defined as a muscle strength of M4. Reinnervation with the musculocutaneous nerve resulted in success in all cases (n = 3) within 1 year. Success was obtained in 78% of patients following transfer of 3 intercostal nerves (n = 23) with recovery in an average of 2 years. Using the spinal accessory nerve (n = 4), strength of only M2+ was achieved, probably on account of the need for interposition nerve grafts in those cases.

Adolescent↗
PubMed1996

Microvascular free posterior interosseous flap and a comparison with the pedicled posterior interosseous flap.

The posterior interosseous flap has been used as a pedicled flap for coverage of hand wounds. However, the pedicled flap is associated with partial or even complete loss when there is venous congestion. This happens because it depends on retrograde venous drainage. Another pitfall of the pedicled posterior interosseous flap is the undetected damage to the communicating vessels between the anterior and posterior interosseous arteries before surgery. This would result in failure if the flap is used as a distally based flap. Thirty-four patients had been reconstructed with the microvascular free posterior interosseous flap. The free flap has a large draining vein. Flap survival rate was 97%. There was no venous congestion and no partial loss of the flap. It is thin, sensate, and reliable. The free posterior interosseous flap is indicated for coverage of the following wounds: (1) first web space and thumb, (2) radial side of the index and ulnar side of the small finger if a cross-finger flap cannot be used, and (3) defects at the dorsum of multiple fingers. It can also be used as a free fascial flap. The free posterior interosseous flap provides a reliable option for coverage of hand wounds. Previously, another 14 patients with hand wounds had been reconstructed with a pedicled posterior interosseous flap. The results of pedicled and free posterior interosseous flaps are compared.

Adolescent↗
PubMed1996

Replantation of ring avulsion of index, long, and ring fingers.

The salvage rate of degloved amputation of the fingers is as low as 50%. This case report consists of a multiple-finger degloving amputation characterized by intact tendons, pulleys, and bone, but avulsed neurovascular bundles. After replantation, the range of motion of the fingers was nearly full. Protective-to-light touch sensation was obtained with transpositional digital nerve transfers. Grasp strength was 80% that of the uninjured side. In addition to good functional recovery, the aesthetic appearance obtained by replantation of the degloved skin was far better than that obtained by other reconstruction methods. A first web space flap was used to release a flexion contracture of the proximal interphalangeal joint of the middle finger.

Adult↗
PubMed1996

Chronic volar dislocation of the metacarpophalangeal joint of the thumb: a case report and review of the literature.

A 61-year-old man sustained a chronic volar dislocation of the metacarpophalangeal joint of the thumb. He did not present for treatment until he experienced recently progressive joint pain 2 year after injury. Arthrodesis of the metacarpophalangeal joint was performed to correct the deformity of the thumb because of its extensive tissue scarring and erosion of the articular cartilage of the metacarpal head. Six weeks of splint immobilization followed by a physiotherapy program allowed the patient to resume his daily activities with his right hand.

Arthrodesis↗
PubMed1996

The salvage of a degloved hand skin flap by arteriovenous shunting.

Nine cases of hand degloving injuries were treated successfully with arteriovenous shunting technique. Of these nine cases, four were degloved from the wrist level and one from the forearm, three were degloved at the palm and one at the dorsum of the hand. All injuries resulted in distally based skin flaps, which were either superficial to the palmar fascia or within the subcutaneous layer. Lack of active bleeding from the periphery of the avulsed flaps substantiated circulatory compromise before revascularization. Survival of the avulsed flaps was achieved by directing the proximal arterial flow into the venous channel within the avulsed skin flaps. The post-operative care and rehabilitation were straightforward, and functional results were satisfactory.

Adolescent↗
PubMed1996

Aesthetic refinements in toe-to-hand transfer surgery.

Techniques for aesthetic refinement are as important as those for functional improvement in toe-to-hand transfer. The appearance of the thumb reconstructed using various types of great toe transfer can be improved by reduction of the soft tissue, bone, interphalangeal joint, and nail and by secondary pulp reduction and contouring procedures. Finger and thumb reconstructions using lesser toes can be improved aesthetically by minimal inclusion of adipofibrous tissue under the plantar skin flap especially at the metatarsophalangeal joint region, thus decreasing the anterior-posterior bulkiness. Tight extensor repair, temporary K-pin fixation of the proximal and distal interphalangeal joint in extension, followed by prolonged use of a nighttime extension splint and secondary pulp reduction help to avoid the claw and drumstick appearances of the transferred lesser toe. Adequate soft-tissue coverage, cruciate skin incisions, extensive mobilization, and thinning and trimming of the skin flaps of the digital amputation stump lead to a smooth junction between the amputated digit and the transferred toe. In the distal digital reconstruction, skeletonization of medial and lateral neurovascular bundles of the harvested toe helps primary closure of the digital wound, thus avoiding the unsightly skin graft on the sides of the reconstructed digit. Regarding the donor foot, preservation of the proximal 0.5 to 1 cm of the proximal phalangeal stump of the great toe maintains the span of the foot, thus improving donor site appearance. In single lesser toe or combined second and third toe transfer, the proximal phalanx should not be preserved but an optimal web space should be reconstructed. Primary closure without skin graft is essential for aesthetic appearance of the donor foot.

Amputation, Traumatic↗