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Biomedical subjects

Fu-Chan Wei

Publications and source records attributed to Fu-Chan Wei.

At least 19 recordsLinked to original sources
PubMed2003

Perforator flap entity.

The perforator flap is not a new concept in microsurgery but there is still confusion. The number of centers that is using these flaps for various indications is increasing. Studies about the differences between these flaps and the conventional flaps, including donor site morbidity and long-term follow-ups, will be seen in the medical literature. Better accuracy in reconstruction, including the use of only cutaneous tissue, minimization of the morbidity, and preserving the same survival rate in free flaps are reassurances to microsurgeons to perform perforator flaps. We believe that in the near future with refinements in the techniques and instruments, perforator flaps will be the first choice flap.

Humans↗
PubMed2003

Technical tips in perforator flap harvest.

Advances in the field of microsurgical reconstruction have focused on decreasing donor site morbidity and increasing the function and aesthetics of the reconstructed site. Since the advent of perforator flap surgery, most of these expectations have been satisfied. On the other hand, we need refinements in the surgical techniques and clinical reports studying these flaps. In the future, the clinical use of these flaps and the familiarity of surgeons will increase; perforator flap reconstruction will be as reliable as other types of free flaps.

Humans↗
PubMed2003

Chimeric flap in clinical use.

With the development of modern microsurgical reconstruction, there are several alternative methods for the complicated head and neck defect or injured extremity. The double-paddled flap, double flaps, and double flap with vascular flow-through linkage are good tools for extensive wide, composite, and three-dimensional defects. When faced with a difficult reconstruction, the expense, morbidity of the donor site, and operative time must be taken into consideration. Compared with other combined composite flaps and other methods, the chimeric flap has many advantages including: easy three-dimensional insetting, acceptable aesthetic appearance, reduced donor site morbidity, design with the least effort and operation time, and one pair of recipient vessel. The disadvantages of the chimeric flaps include: the variation of perforators, the requirement of a learning curve, and, sometimes, the need for a second venous drainage or shifting to double flaps. Overall, in selected cases, the chimeric flap is a good option for the reconstruction of extensive, composite, and three-dimensional defects.

Bone and Bones↗
PubMed2003

The thigh as a model for free style free flaps.

Following a set of principles, free style free flaps may be harvested from any region of the body where a Doppler signal is heard. By using a retrograde dissection technique, the skin vessel is traced through its subfascial course (intramuscular or septocutaneous), until adequate length or vessel size is achieved. If a "free style free flap" is not originally planned, this approach can be usedwhen anatomic variations or unexpected events are encountered. The thigh, a region that is familiar to the surgical team at Chang Gung Memorial Hospital, was chosen as the site to begin exploring this style of flap harvest. Nine flaps were harvested as free style free flaps from the thigh and were used successfully for the reconstruction of complex defects.

Adult↗
PubMed2003

Toe-to-hand transplantation.

In the mutilated hand microsurgical toe-to-hand transplantation provides thumb and finger reconstruction that is superior to conventional techniques in appearance and function. Hand reconstruction using toe transplantation should be individually planned and carefully executed to obtain optimal results and minimal disability in the donor foot.

Amputation, Traumatic↗
PubMed2003

Reactive thrombocytosis without endothelial damage does not affect the microvascular anastomotic patency.

There is still controversy about the correlation of thrombocytosis and thrombosis complication. Using a rodent splenectomy-induced thrombocytosis model and a thrombogenic endothelial damage model (inverted suture resulting in an intraluminal thrombogenic adventitia of divided femoral artery), the authors investigated whether reactive thrombocytosis with or without endothelial damage contributes to the patency of microvascular anastomosis. Four experimental groups were evaluated in this study: 1) sham operation without thrombogenic anastomosis after femoral artery division; 2) sham operation with thrombogenic anastomosis; 3) thrombocytosis alone without thrombogenic anastomosis; 4) thrombocytosis with thrombogenic anastomosis (each subgroup n = 10, total N = 40). Vascular patency was assessed after immediate operation and on the seventh day postoperatively. Platelet counts and platelet activation (CD62P) were studied in correlation to microvascular patency. In rats without thrombogenic anastomosis groups, there were no significant differences in CD62P expression on platelets (p = 0.09), the patency rates (p = 0.561), or perfusion units (p = 0.746) before and after arterial reanastomosis between rats with and without thrombocytosis, respectively. However, the thrombogenic anastomosis of femoral artery in thrombocytosis and control groups showed significantly increased CD62P expression (p < 0.05), decreased the perfusion unit (p < 0.05), and patency rate (p < 0.001), compared with rats without thrombogenic anastomosis of femoral artery in both groups. In summary, this study demonstrates that microvascular anastomosis can be performed safely with reactive thrombocytosis alone without thrombogenic anastomosis. Meticulous microvascular anastomosis without triggering platelet activation is the most important factor to prevent thrombosed vessels in microsurgical anastomosis.

Anastomosis, Surgical↗
PubMed2003

Osteotomy to treat malocclusion following reconstruction of the mandible with the free fibula flap.

Malocclusion may result after free fibula flap reconstruction of the mandible, because of inadequate positioning of the temporomandibular joint, inaccurate contouring of the reconstruction plate, or subsequent fracture of a miniplate. Factors that alter the vascularity of the transplanted fibula may also result in a delayed presentation of malocclusion. Seven cases are presented, in which primary surgical treatment consisted of segmental mandibulectomy and reconstruction with a free fibula osteoseptocutaneous flap. Fixation was achieved with a reconstruction plate in five cases and a miniplate in two cases. Malocclusion was corrected with an osteotomy performed at the junction of the fibula and the native mandible. The new osteotomy sites were fixed with miniplates and maintained with intermaxillary fixation. Complete bony union was achieved at the osteotomy sites. The correction of malocclusion was successful in all cases, and all patients have resumed a normal diet. This report demonstrates that osteotomy and realignment of the mandible are effective for the secondary correction of malocclusion after mandibular reconstruction with the free fibula osteoseptocutaneous flap.

Adult↗
PubMed2003

Complications after reconstruction by plate and soft-tissue free flap in composite mandibular defects and secondary salvage reconstruction with osteocutaneous flap.

Reconstruction of composite defects of the mandible is a challenging problem. Although the use of an osteocutaneous free flap, alone or in combination with another soft-tissue free flap, is generally accepted to be optimal, the bony reconstruction is sometimes undervalued, especially when the cancer is advanced. In such situations, reconstruction is often performed with a reconstruction plate covered with a soft-tissue free flap. Between January of 1997 and July of 2000, 80 patients with composite or extensive composite oromandibular defects underwent treatment with a reconstruction plate and a soft-tissue free flap. All of the patients were male, and the ages of the patients at the time of treatment ranged from 32 to 78 years (mean, 51 years). Tumors were classified as stage IV in 56 patients (70 percent), whereas the remaining 24 patients (30 percent) had recurrent carcinomas. The titanium mandibular reconstruction system manufactured by Stryker (Freiburg, Germany) was used to bridge the mandibular defects. The soft-tissue free flaps used for wound and plate coverage were as follows: anterolateral thigh flap (n = 75), radial forearm flap (n = 3), transverse rectus abdominis myocutaneous flap (n = 1), and tensor fasciae latae flap (n = 1). Five patients with recurrent carcinomas and 10 with stage IV carcinomas (18.75 percent) died 2 to 6 months after the operation and were excluded from the study. The remaining 65 patients were monitored for an average follow-up period of 22 months (range, 6 to 40 months). During that period, one or more complications occurred for 45 patients (69.2 percent). Plate exposure was the most common complication and was observed for 30 patients (46.15 percent). Twenty of the 65 patients (30.8 percent) required secondary salvage reconstruction with a fibula osteoseptocutaneous flap. The decision to perform a secondary salvage procedure was based on the general health of the patient, the extent of local disease, and the severity of the complications. Patients underwent salvage operations after an average of 11.5 months (range, 6 to 26 months). The major reasons for the second operation were as follows: reconstruction plate exposure (n = 12), soft-tissue deficiency and mandibular contour deformation of the lateral face (n = 7), intraoral contracture and lack of a gingivobuccal sulcus (n = 6), trismus (n = 4), and osteoradionecrosis of the mandible (n = 2). The total flap survival rate was 90 percent (18 of 20 free flaps). In two cases, the skin paddles of the fibula osteoseptocutaneous flaps exhibited partial failure and were revised with pedicled pectoralis major and deltopectoral flaps. The reconstruction plate and free soft-tissue flap procedure for the reconstruction of composite defects of the oromandibular region has many late complications, which eventually necessitate reconstruction of the mandible with an osteocutaneous free flap.

Adult↗
PubMed2003

The use of ultrasonography in preoperative localization of digital glomus tumors.

Small glomus tumors of the digits of the hand are difficult to excise and may be associated with relatively high rates of recurrence. This study was designed to prospectively evaluate the utility of preoperative ultrasound localization of such tumors to facilitate removal and to reduce recurrence rates. During a 5-year period, 34 patients clinically diagnosed with glomus tumors involving their digits were examined with high-resolution ultrasonography (5 to 9 MHz). Color duplex sonography was further applied if flow characteristics were identified. The ultrasound-predicted and actual intraoperative sizes were correlated and analyzed using the paired t test. Patients were followed for 1 to 6 years, and results were documented. Sonography showed a hypoechoic nodule with prominent vascularity between the nail body and the dorsal cortex of the distal phalanx in all subungual tumors. Complete resection was possible in all 35 glomus tumors, with assistance by accurate preoperative ultrasound localization. There was no long-term recurrence among the 29 patients available for evaluation 1 to 6 years postoperatively. Ultrasonography has great advantages in defining the exact location and size of the glomus tumor preoperatively. Prior knowledge of the exact site and size of the glomus tumor facilitates excision and appears to reduce rates of recurrence. The collaboration between hand surgeons and radiologists is useful to successfully treat glomus tumors of the digit.

Adult↗
PubMed2003

US-guided catheter drainage of postoperative head and neck fluid collections.

PURPOSE: To analyze results of percutaneous catheter drainage of large fluid collections in the head and neck region noted in the immediate postoperative period. MATERIALS AND METHODS: Thirty-four consecutive patients with 41 large fluid collections in the head and neck detected 7-10 days after oncologic surgery underwent percutaneous catheter drainage. There were 29 men and five women, with a mean age of 52.2 years (95% CI: 47.8-56.7). Each patient had a surgical drain placed in the posterior neck triangle; three patients had low-grade fever and six had diabetes at the time of percutaneous catheter drainage. Conventional management consisting of serial needle aspirations at bedside followed by pressure dressing failed in 15 of 34 patients (44%). Ultrasound-guided drainage was performed and catheters were connected to vacuum balls for continuous suction drainage. RESULTS: The average fluid volume estimated by sonographic measurement was 84 cm(3) (95% CI: 57-112 cm(3)). The fluid content was serosanguinous in 46% (19 of 41), uncoagulated blood in 32% (13 of 41), pus in 15% (six of 41), and saliva in 7% (three of 41). The mean duration of catheter drainage was nine days (95% CI: 7-10 d) and mean fluid drainage was 287 mL (95% CI: 188-387 mL). Ninety-one percent of patients (31 of 34) were successfully treated with initial catheter drainage. Three patients had recurrent fluid collections at the same locations: two were treated with repeated catheter insertions and one required a limited open drainage. No complication related to catheter drainage was noted at 6-month follow-up. CONCLUSION: Percutaneous catheter drainage is effective for large fluid collections in the head and neck region noted in the immediate postoperative period irrespective of contents.

Drainage↗
PubMed2002

Reactive thrombocytosis alone does not affect the patency of microvascular anastomosis in the splenectomy rat.

Vascular thrombosis is a harbinger of failure in microsurgery. However, there is still controversy regarding the correlation of the complications of thrombocytosis and thrombosis. Some evidence indicates that patients with elevated platelet counts tend to have a higher flap failure rate, and surgeons usually hesitate to operate on patients with thrombocytosis. Nevertheless, the authors have experienced successful free tissue transfer in seven patients with thrombocytosis resulting from traumatic splenectomy or multiple trauma. On the basis of clinical observation, the authors investigated whether reactive thrombocytosis contributes to the patency of a microvascular anastomosis. In a rodent splenectomy-induced thrombocytosis model (n = 40), stable reactive thrombocytosis occurred after postoperative days 5 to 10, with the peak on postoperative day 7. Femoral artery division and reanastomosis was performed in rats with or without splenectomy-induced thrombocytosis, and vascular patency was assessed. Platelet counts and platelet activation were studied in correlation to microvascular patency. Platelet activation as demonstrated by CD62P expression on platelets was not significantly different between rats with and without thrombocytosis (6.41 +/- 0.95 percent versus 4.51 +/- 0.55 percent, respectively; p = 0.089). As immature platelets were not increased (2.86 +/- 0.33 percent versus 1.99 +/- 0.32 percent, p = 0.074), it seems that the splenectomy-induced thrombocytosis is the result of redistribution of platelets instead of an increase in bone marrow production. There were no significant differences in the patency rates or perfusion units of femoral artery after arterial anastomosis between rats with and without thrombocytosis (90 percent and 95 percent, respectively; p = 0.561). In conclusion, this study demonstrates that microvascular anastomosis can be performed safely in patients with reactive thrombocytosis without platelet activation.

Anastomosis, Surgical↗
PubMed2002

Platelet glycoprotein IIb/IIIa receptor antagonist (abciximab) inhibited platelet activation and promoted skin flap survival after ischemia/reperfusion injury.

BACKGROUND: Evidence has shown that platelets play an important role in the pathogenesis of flap failure. Employing a rat inferior epigastric artery skin flap as a flap reperfusion injury model, we investigated whether platelet activation was involved in the skin flap failure and whether administration of abciximab (ReoPro, chimeric 7E3 Fab) could decrease platelet activation/aggregation and promote flap survival. METHODS: Normal saline and abciximab (0.06 mg/kg; 0.2 mg/kg; 1 mg/kg) were injected intravenously into skin flaps 30 min before reperfusion and 1 h after reperfusion (each subgroup n = 6). Platelet activation as demonstrated by P-selectin (CD62P) was analyzed by flow cytometry. P-selectin expression on flap vessels was detected by immunohistochemical staining. Platelet aggregation was induced with adenosine diphosphate (ADP). Laser Doppler flowmetry monitored tissue perfusion. The surviving area was evaluated 7 days postoperatively. RESULTS: CD62P progressively increased after reperfusion. The peak CD62P occurred after reperfusion for 12 h. Immunohistochemical staining showed CD62P significantly deposited on the endothelium after reperfusion. Administration of abciximab (1 mg/kg) effectively improved flap survival rate (P = 0.003), significantly decreased ADP-induced platelet aggregation (P < 0.001), and suppressed CD62P expression on blood platelets (P = 0.002) and its deposition on the flap vessels. CONCLUSION: Abciximab promotion of skin flap survival is due to blocked platelet activation/aggregation and decreased activated-platelet deposition on the vascular endothelium. Thus, administration of a platelet glycoprotein IIb/IIIa receptor antagonist such as abciximab may save the skin flap from reperfusion injury after a long period of ischemia.

Abciximab↗
PubMed2002

In vivo evaluation of leucocyte dynamics in cremaster muscle in rats after exposure to cigarette smoke.

This experiment was designed to examine the effects of chronic cigarette smoking on the microcirculation immediately after exposure to smoke for two, four, and six weeks and after withholding smoke for two weeks from those previously exposed for four weeks. The mean (SD) rolling leucocytes at two, four, and six weeks were 11.10 (1.8), 23.7 (2.3), 40.2 (3.9) (p < 0.001). The rolling leucocytes after smoking for four weeks and then having smoke withheld for two weeks was 9.6 (1.4). The mean adherent leucocytes were 5.0 (0.7), 7.5 (1.1), 12.6 (1.8) (p < 0.001). The adherent leucocytes after smoking for four weeks and then having smoke withheld for two weeks was 3.5 (0.5). Our results confirm those of many previous studies of the adverse effects of cigarette smoking, and also that those deleterious effects are time-dependent. The reversibility of the deleterious effect of cigarette smoking after cessation of cigarette smoking before face-lift or flap reconstruction is at least two weeks. This information is also important for clinical management of patients who smoke and who are scheduled for face-lift and flap reconstruction. Two weeks without cigarettes is a necessary period for successful elective plastic surgery.

Animals↗