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Biomedical subjects

Fu-Chan Wei

Publications and source records attributed to Fu-Chan Wei.

At least 37 records · Page 2Linked to original sources
PubMed2006

Reverse first dorsal metatarsal artery flap for reconstruction of traumatic defects of dorsal great toe.

BACKGROUND: Soft-tissue defects of the great toe that include exposed tendon and bone present a reconstructive challenge for plastic surgeons. This study investigates the feasibility and reliability of reverse first dorsal metatarsal artery flap (FDMA) for reconstruction of the dorsal great toe soft-tissue defects. METHODS: Six male patients with dorsal great toe defects (mean 2.2 x 4.7 cm) underwent reconstruction using the reverse FDMA flap. Preoperative angiography was performed to confirm the existence and patency of the distal communicating artery between the FDMA and plantar metatarsal artery. The flap was raised by dividing the dorsalis pedis artery and proximal communicating arteries and rotated 180 degrees to cover the defect. RESULTS: All flaps survived completely. Mean follow-up time was 3.3 months. Painless full range of motion was recovered and the contour of the flap was satisfactory. All patients returned to their normal walking and running activities and none necessitated special footwear. No donor-site morbidity was encountered. CONCLUSION: Reverse FDMA flap presents a viable alternative for reconstruction of soft-tissue defects of dorsal great toe when local flap coverage is required. Because of anatomic variations, preoperative angiography is necessary for successful reconstruction, especially in patients with comorbidities affecting patency of their vasculature.

Adult↗
PubMed2006

Lateral circumflex femoral artery system: warehouse for functional composite free-tissue reconstruction of the lower leg.

BACKGROUND: Microsurgical free-flap surgery has progressed from simply providing wound coverage to restoring a high level of function. The concepts and practice of using compound, composite, and chimeric flaps have recently further enhanced the versatility of free flaps in reconstructive surgery. A lateral circumflex femoral arterial (LCFA) system can provide a potential single composite free-tissue transfer for restoration of functional and structural integrity. METHODS: Between 1997 and 2003, we used 44 free flaps to restore functional and structural defects in the lower limbs. The versatility of the LCFA system allowed utilization of the anterolateral thigh, vastus lateralis, tensor fascia lata, rectus femoris, and iliac crest. Combinations of tissues from this system were employed to restore defects in the patellar tendon (14), Achilles tendon (13), extensor hallucis tendon (2), anterior compartment with/without lateral compartment muscle (11), anterior compartment muscle and segmental tibial bone (3), and composite calcaneus (1). RESULTS: The free-flap success rate was 97.7%. Four re-explorations were performed with one subsequent failure. Eight patients (18.2%) developed wound infections, of which two required secondary amputations, resulting in a limb salvage rate of 95.4%. CONCLUSION: The LCFA system provides a predictable and versatile surplus of tissue necessary to restore functional and structural integrity of the posttraumatic lower extremity in a single stage.

Femoral Artery↗
PubMed2006

Ischemic preconditioning attenuates postischemic leukocyte--endothelial cell interactions: role of nitric oxide and protein kinase C.

BACKGROUND: Ischemic preconditioning (IPC) produces immediate tolerance to subsequent prolonged ischemia/reperfusion (I/R), although the underlying mechanism remains unknown. The purpose of this study was to examine the role of nitric oxide (NO) and protein kinase C (PKC) in IPC-attenuated post ischemic leukocyte-endothelium interactions. METHODS AND RESULTS: Male Sprague-Dawley rats were randomized (n=8 per group) into 5 groups: sham-operated control group, IPC group, I/R group (4 h of pubic epigastric artery ischemia followed by 2 h of reperfusion), IPC+I/R group (30 min of ischemia followed by 30 min of reperfusion before I/R), and chelerythrine (PKC inhibitor)+IPC+I/R group. Intravital microscopy was used to observe leukocyte-endothelium interaction and to quantify functional capillaries in rat cremaster muscle flaps. The mRNA expressions of neuronal (n) NO synthase (NOS), inducible (i) NOS, and endothelial (e) NOS were determined by reverse transcription-polymerase chain reaction. The results showed that besides increasing functional capillary density, IPC also prevents I/R-induced increases in leukocyte rolling, adhesion, and migration. In the chelerythrine+IPC+I/R group, the IPC protective action was inhibited by the addition of chelerythrine. It was also observed that IPC upregulated nNOS, iNOS, and eNOS mRNA in I/R injured tissue, but this effect was not blocked by chelerythrine. Furthermore, specifically pretreated nNOS and iNOS inhibitors, along with a nonselective NOS inhibitor, were used in the IPC+I/R group to examine their possible antagonistic effects on leukocyte-endothelium interactions. Inhibition of the nNOS and iNOS activities did not block the beneficial effects of IPC. In contrast, pretreatment with the nonselective NOS inhibitor (NG-nitro-L-arginine methylester) in the IPC+I/R group almost completely blocked the protective effect of IPC. CONCLUSIONS: Both NOS and PKC play a protective role during IPC, but probably in distinct ways. Furthermore, the results also indicate that eNOS, but not nNOS nor iNOS, is the key mediator of IPC-attenuated I/R-induced microcirculatory disturbance.

Animals↗
PubMed2005

Isolated third-toe transfer: indications, technique, and reliability.

BACKGROUND: Isolated third-toe transfer is a versatile and safe technique when indicated. METHODS: Between January of 1984 and January of 2003, 37 isolated third-toe transfers were performed in 31 patients. RESULTS: Only one partial loss was noted among 37 transfers. There were 24 male and seven female patients, with an average age of 27.4 years (range, 7 to 43 years). Twenty-five patients received additional toe transfers. Secondary surgery was performed in 17 toes of 15 patients to improve the functional and cosmetic results. Patients were followed for 2 to 180 months (average, 36 months) and no significant donor-site morbidity was seen. CONCLUSIONS: Basically, the indications for isolated third-toe transfer are evaluated in two groups. Third-toe transfer is absolutely indicated when it is necessary for restoring basic hand functions in multiple-finger amputations. It is indicated because both second toes are transferred or the remaining second toe is adjacent to the previously transferred great toe. The other absolute indication is the unavailability of second toes because of trauma or deformity. Third-toe transfer is indicated relatively if it is used for additional reconstruction when basic hand functions are regained or already exist. Another relative indication is its better size match for proposed reconstruction. Second and third dorsal and plantar metatarsal arteries can be used as the pedicle artery for third toe-transfer; however, if second-toe transfer has already been performed or is planned, the third plantar or dorsal metatarsal artery should be used. Isolated third-toe transfer is a useful and reliable technique, especially in multiple-finger amputation reconstruction.

Adolescent↗
PubMed2005

Symmetry of vascular pedicle anatomy in the first web space of the foot related to toe harvest: clinical observations in 85 simultaneous bilateral second-toe transfer patients.

BACKGROUND: Toe-to-hand transfer is an accepted procedure for reconstruction of thumbs and fingers. Although the vascular anatomy of the toe has been well studied, its symmetry on both feet has not previously been reported. METHODS: A retrospective review of 85 cases of simultaneous bilateral toe-to-hand transfers, performed between 1984 and 2002, was carried out. All of the pedicles were dissected in a retrograde fashion. RESULTS: A symmetric vascular pedicle anatomy was found in 78.8 percent of the patients, whereas 21.2 percent of the patients had an asymmetric vascular pattern. CONCLUSIONS: This result cautions surgeons about the possibility of vascular pedicle asymmetry between two feet in bilateral toe harvest. It proves once more the advantage of a retrograde pedicle dissection technique, which allows for a safe and straightforward toe harvest regardless of the vascular pedicle course variations.

Adolescent↗
PubMed2005

Diazoxide ameliorates microcirculatory disturbances through PKC-dependent pathway in I/R-injured rat cremaster muscles.

Diazoxide is a selective mitochondria ATP-sensitive potassium (K(ATP)) channel opener, which has been reported to preserve the microvascular integrity of ischemia-reperfusion (I/R)-injured tissues. Our study aimed to assess diazoxide's effects on I/R-injured cremaster muscles and to further elucidate its underlying mechanisms. Male Sprague Dawley (SD) rats were randomized (n = 8 per group) into four groups: sham-operated control group, I/R group (4 h of pudic epigastic artery ischemia followed by 2 h of reperfusion), diazoxide + I/R group, and chelerythrine (PKC inhibitor)+diazoxide+I/R group. Microscopically, we observed that I/R markedly increased the number of rolling, adhering, and transmigrating leukocytes. I/R also markedly decreased the number of functional capillaries. Biochemically, we found that I/R significantly increased TNF-alpha, E-selectin,L-selectin and P-selectin expressions. However, I/R did not cause significant changes in ICAM-1 and PECAM-1 expressions. On the other hand, in I/R + diazoxide group, we found that diazoxide reduced the number of rolling, adhering, and transmigrating leukocytes. Furthermore, biochemical study revealed that diazoxide caused only a decrease in L-selectin expression but had no effect on TNF-alpha, E-selectin, P-selectin, ICAM-1, and PECAM-1 expressions. Finally, in chelerythrine + diazoxide + I/R group, we observed that diazoxide's protective effects were blocked by the addition of chelerythrine. Diazoxide's ability to protect against I/R injury was confirmed by the observation that it reduced the number of rolling, adhering, and transmigrating leukocytes, and increased the number of functional capillaries. Our results indicated that diazoxide operated via a PKC-dependent pathway to achieve protection against I/R injury.

Abdominal Muscles↗
PubMed2005

Salvage of an avulsion amputated thumb at the interphalangeal joint level using afferent arteriovenous shunting.

Replantation of digits following avulsion amputation is a challenge due to the severity of damage to the digital vessels. When the digital vessels are absent or severely injured, standard artery-to-artery or vein-to-vein anastomoses may be impossible and arteriovenous shunting can be used as a salvage procedure for arterial inflow or venous drainage. Previous cases of successful replantation of avulsed digits that were reperfused using afferent arteriovenous shunting reported small segments of tissues only, usually at the level of the distal phalangeal joint or distal to it. Our case demonstrates that afferent arteriovenous shunting can also provide adequate perfusion to a large piece of tissue in the thumb even when the amputation level is at the interphalangeal joint.

Adult↗
PubMed2005

Double free flaps in head and neck reconstruction.

This article discusses the indications for and the advantages and principles of flap combinations and the selection of two pairs of recipient vessels for double free-flap transfers in reconstruction of extensive composite head and neck defects.

Fibula↗
PubMed2005

Microsurgical workhorse flaps in head and neck reconstruction.

The aim of reconstruction after resection of head and neck tumors is to achieve acceptable functional and esthetic results with minimal donor site morbidity. Although many flaps have been developed for bone and soft tissue reconstructions, our experience in the past years has identified the anterolateral thigh flap (cutaneous or myocutaneous), the radial forearm flap, and the osteoseptocutaneous fibula flap as the most useful flaps for head and neck reconstruction. These three flaps can be used for reconstruction of almost all kinds of defects, either as a single flap or in combination. The harvest of these flaps is relatively simple and straightforward. All flaps have adequate pedicle vessel length and caliber. Donor site morbidity is negligible. As most reconstructive microsurgeons do not have enough patient volume to master many different kinds of flaps in their professional life, we recommend focusing on these three flaps as workhorse flaps instead of hunting for many other flaps for head and neck reconstruction.

Head and Neck Neoplasms↗
PubMed2005

Pectoral skin flap as a reliable and simple model for vascularized composite skin transplantation research.

In this study, the authors explored the feasibility of transplanting a "pectoral skin flap" as an alternative model for composite skin allotransplantation research. Genetically inbred male Lewis rats (LEW; RT1l) (n = 13), weighing 250 to 300 gr, were used as recipients and Brown Norway rats (BN; RT1n) (n = 8) rats were used as donors. Five Brown Norway rats had bilateral and three had unilateral flap harvest with a total of 13 flap transplantations to Lewis rats. All flaps were transplanted to the groin regions of the recipients and microsurgical anastomoses with 10-0 nylon were performed between the axillary vessels of the flaps and the femoral vessels of the recipient animals. The mean operation time was 55 min, with an ischemia time of 25 min. All transplantations were successful immediately postoperatively. The recipient animals were treated with Cyclosporine A (16 mg/kg/day) from the day of the surgery for 1 week, and then discontinued. One flap developed infection at postoperative day 11 and one flap had partial (50 percent) necrosis. The early signs of rejection started 8 to 9 days after the cessation of the immunosuppressive treatment, and all flaps were acutely and uniformly rejected within 3 to 4 days. The feasibility of harvesting two flaps from one donor animal allowed saving donor animal lives and reducing donor-specific variables.

Animals↗
PubMed2005

Simultaneous double second toe transfer for reconstruction of adjacent fingers.

BACKGROUND: The authors reviewed their results with simultaneous double second toe transfer for reconstruction of adjacent fingers. METHODS: From January of 1984 to January of 2003, simultaneous double second toe transfer was performed for reconstruction of adjacent fingers in 140 patients (48 before wound closure, 92 after). Functional thumbs were present in all of them. There were 104 male and 36 female patients, with an average age of 29.1 years (range, 2 to 57 years). Index and middle fingers were reconstructed in 90 patients, middle and ring fingers in 49 patients, and ring and little fingers in one patient. The average operation time was 11 hours 25 minutes, which was much shorter than double the average time of a single second toe transfer (8 hours 31 minutes; double time, 17 hours 2 minutes). Twenty-six toes were reexplored for vascular insufficiency and three of them were lost. Secondary surgery was performed in 98 patients to improve function and cosmesis. RESULTS: Patients were followed up at an average period of 47.5 months (range, 2 to 210 months). Forty-two patients had complete functional evaluation at a minimum 2-year follow-up. The mean active range of motion of the reconstructed finger joints in these patients was 69.4 degrees for metacarpophalangeal joints, 31.1 degrees for proximal interphalangeal joints, and 8.2 degrees for distal interphalangeal joints. Two-point discrimination was between 3 and 13 mm (average, 7.5 mm). All donor sites were closed primarily and no obvious donor-site morbidity was noted, except for one hallux valgus deformity that was corrected by surgery. CONCLUSIONS: The functional and aesthetic results of double second toe transfers for adjacent two-finger reconstruction are superior to those of a single second toe-to-single finger reconstruction in multiple-finger amputations. Double second toe transfer performed simultaneously reduces the cost and total time of the operation, enables faster rehabilitation, and hastens patient adaptation.

Adolescent↗
PubMed2005

Application of "simplified nomenclature for compound flaps" to the anterolateral thigh flap.

BACKGROUND: The anterolateral thigh flap is becoming a workhorse flap for soft-tissue and coverage reconstruction. It can be elevated in various ways with various tissues combinations. However, there is no consensus on nomenclature for communication, which has resulted in misunderstanding and confusion. METHODS: The authors propose a new terminology for classification of the anterolateral thigh flap based on the "simplified nomenclature for compound flaps" introduced by Hallock. The intention of this new terminology is to describe both tissue components and skin vessel type. RESULTS: Anterolateral thigh flaps can be classified into two subgroups according to the tissue components, as follows: cutaneous or compound. The skin vessel types can also be classified into two subgroups according to the course they traverse: septocutaneous vessel or myocutaneous perforator. CONCLUSION: This classification may bring a consensus on the nomenclature of anterolateral thigh flaps and would be applicable to other perforator flaps.

Humans↗
PubMed2005

Selection of recipient vessels in double free-flap reconstruction of composite head and neck defects.

BACKGROUND: Massive defects of the head and neck regions after resection of advanced carcinoma often require two flaps for optimal reconstruction. This study focuses on the selection of proper recipient vessels. METHODS: A total of 262 free-flap transfers were performed in 130 patients using the two-flap approach (one patient received two flaps twice). RESULTS: For microvascular anastomosis of inner flaps (intraoral lining-bone reconstruction flaps), the ipsilateral facial artery was used in 56 flaps (42.8 percent), the ipsilateral superior thyroid artery was used in 49 flaps (37.4 percent), and a branch of the internal jugular vein was used as recipient vein in 101 flaps (77.1 percent). For external flaps (soft-tissue-external skin reconstruction flaps), the ipsilateral superior thyroid artery was used in 59 flaps (50.4 percent) and the transverse cervical artery was used in 19 flaps (16.2 percent). In 14 patients the inner flaps provided distal run-off for external flap revascularization. Only seven flaps required vein grafts; they were all used for external face reconstruction (2.8 percent). There were six total (2.3 percent) and 12 partial (4.6 percent) flap failures. CONCLUSIONS: Recipient vessel selection and preparation in primary head and neck cancer reconstruction requiring two simultaneous flaps should take into consideration (1) avoidance of unnecessary destruction during tumor ablations and preservation of as many neck vessels as possible, (2) length and diameter match between flap pedicles and recipient vessels to avoid vein grafts, and (3) possible need of another free-flap reconstruction for flap failure, complication, recurrence, or secondary primary cancers. The previously radiated or operated neck does not preclude the use of recipient vessels from that side. Distal run-off of the inner flap for external flap revascularization should be avoided if possible. Once those principles are observed, two-flap reconstruction for primary cancer presents no more difficulties than single-flap reconstruction.

Adult↗
PubMed2005

Reconstruction of extensive composite mandibular defects with large lip involvement by using double free flaps and fascia lata grafts for oral sphincters.

BACKGROUND: Extensive composite mandibular defects involving large lip defects are the most difficult to repair among head and neck reconstructions. This study presents the authors' approach using double free flaps and fascia lata grafts for oral sphincters. METHODS: Ten patients were studied after ablative oral cancer surgery. Segmental defects of the mandible ranged from 6 to 14 cm. Cheek defects ranged from 9 x 6 cm to 15 x 12 cm, and intraoral defects ranged from 9 x 7 cm to 16 x 16 cm. Upper lip defects ranged from 10 percent to 50 percent, and lower lip defects ranged from 50 percent to 90 percent. A fibula osteocutaneous flap was used for reconstruction of mandibular defects and intraoral lining, and an anterolateral thigh flap was used for cheek and lip defects. Then, a sheet of fascia lata graft was used to reconstruct the oral sphincter. The tendon graft was passed into the subcutaneous layers of the reconstructed lip, woven into the remaining orbicularis oris muscle of the lip, and anchored to the upper lip near the philtral columns to complete the oral ring with adequate tension. RESULTS: Free flap survival was 100 percent. Complications included one patient with neck hematoma and distal anterolateral thigh flap necrosis, three patients with neck wound infection, and one patient with osteomyelitis of the mandible. All but one patient had adequate oral competence. All the patients were able to resume a soft diet. The speech ability was nearly normal for all the patients, and all the patients had gained an acceptable appearance. CONCLUSIONS: For extensive composite mandibular defects combined with large lip defects, immediate reconstruction with double free flaps and a fascia lata graft for oral sphincter has proved to be a useful option for better functional and cosmetic results.

Adult↗
PubMed2005

Establishing a composite auricle allotransplantation model in rats: introduction to transplantation of facial subunits.

BACKGROUND: Allografts from cadaveric sources may be an alternative for replacing the missing auricle. In this report, the technical aspects of orthotopic composite auricle allotransplantation and an effective short-term immunosuppression protocol in a rat model are described. METHODS: A total of seven transplantations were performed in the experimental group. The donors were Brown Norway (RT1(n)) rats and the recipients were Lewis (RT1(1)) rats. In the pilot study, 11 isotransplantations (Lewis to Lewis) were performed in either heterotopic (n = 4) or orthotopic (n = 7) locations to establish the surgical technique. Composite auricle allografts were harvested and transplanted based on the posterior facial vein, the external carotid artery, and the great auricular nerve. A plastic square mold sutured over the transplants was used to prevent mechanical trauma to the transplants. Cyclosporine A initiated as 16 mg/kg/day for 2 weeks and tapered to a dosage of 8 mg/kg/day for another 2 weeks was the only immunosuppression regimen. RESULTS: All allografts survived with perfect viability for the follow-up period of 30 days. There were no signs of rejection, infection, or graft-versus-host disease, although significant weight loss was observed resulting from the immunosuppressive treatment. However, signs of rejection started 4 to 6 days after cessation of the cyclosporine A treatment, including edema, localized epidermal desquamation, and erythema formation that eventually progressed to necrosis within 11 to 14 days. The histologic outcomes were well correlated with the macroscopic appearance. CONCLUSIONS: It is feasible to elevate and transplant the composite auricle in rats as a single neurosensorial facial subunit. A tapered dose of cyclosporine A from 16 mg/kg to 8 mg/kg allows maintaining allograft survival for 30 days across a strong major histocompatibility complex barrier. This model is reliable and reproducible and has the potential to be used for future immunologic studies to prevent or to induce transplantation tolerance.

Animals↗
PubMed2005

A non-tooth-borne mouth-opening device for postoperative rehabilitation after surgical release of trismus.

BACKGROUND: The treatment of severe trismus requires a combination of surgical release and postoperative rehabilitation; the latter is essential for preventing a relapse due to postoperative inactivity and scarring. Mouth-opening devices for this purpose are placed between or fixed to the teeth to keep the dental arches apart; but patients suffering from severe trismus often present with partially or totally edentulous arches, decayed teeth, or periodontitis, which do not allow for the use of such devices. METHODS: In this article, a new mouth-opening device is described. It applies force to two intraoral screws placed in the vestibulum of the maxillary and mandibular bones. It can be used in patients with poor dental conditions and allows rehabilitation to start immediately after trismus release. RESULT: A case is presented. The interalveolar distance was improved from 5 mm to 45 mm and maintained at 6-month follow-up. CONCLUSION: Our non-tooth-borne mouth opening device is useful for postoperative rehabilitation after surgical release of trismus.

Bone Screws↗