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Biomedical subjects

Fu-Chan Wei

Publications and source records attributed to Fu-Chan Wei.

At least 91 records · Page 5Linked to original sources
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

The "Gent" consensus on perforator flap terminology: preliminary definitions.

Due to its increasing popularity, more and more articles on the use of perforator flaps have been reported in the literature during the past few years. Because the area of perforator flaps is new and rapidly evolving, there are no definitions and standard rules on terminology and nomenclature, which creates confusion when surgeons try to communicate and compare surgical techniques. This article attempts to represent the opinion of a group of pioneers in the field of perforator flap surgery. This consensus was reached after a terminology consensus meeting held during the Fifth International Course on Perforator Flaps in Gent, Belgium, on September 29, 2001. It stipulates not only the definitions of perforator vessels and perforator flaps but also the correct nomenclature for different perforator flaps. The authors believe that this consensus is a foundation that will stimulate further discussion and encourage further refinements in the future.

Humans↗
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↗
PubMed2002

Effect of exposure to cigarette smoke on microvascular reactivity to noradrenaline in cremaster muscles in rats.

This experiment was designed to study the effects of cigarette smoking on microvascular reactivity in an intact microvascular preparation. The vasoconstrictive responses of arterioles in rat cremaster muscles to topically applied noradrenaline were measured in 8 rats after a three-week period of inhaling cigarette smoke. A parallel set of experiments was in a control group of 8 rats for comparison. All three orders of arterioles in the muscles of rats exposed to smoke were significantly narrower than those of the controls (p < 0.0001). The dose response curve of all three orders of arterioles shifted to the right of their respective controls. The effective concentrations of noradrenaline to cause 50% vasoconstriction (EC50) of all three orders of arteriole was profoundly increased in rats that inhaled smoke compared with the control group (p < 0.05). We conclude that skeletal muscle arterioles in rats exposed to cigarette smoke may become hyposensitive to noradrenaline, or their degree of freedom from constriction may be reduced. Our results suggest that cigarette smoking is associated with significant functional alterations in the microcirculation.

Administration, Topical↗
PubMed2002

Free radial forearm flap with adipofascial tissue extension for reconstruction of oral cancer defect.

The radial forearm flap has been one of the most popular flaps used to reconstruct defects after oral cancer ablation. However, it sometimes may not provide sufficient soft tissue to obliterate the dead space after tumor excision and lymph node dissection, which can result in deep wound infection of the neck or even orocervical fistula. The authors modified the radial forearm flap with a sheet of adipofascial tissue extension to prevent such postoperative complications. From January 1997 to December 2000, 52 patients who underwent ablative oral cancer surgery were studied. A total of 29 patients (group I) underwent reconstruction with the traditional radial forearm flap retrospectively, and 23 patients (group II) underwent reconstruction with the radial forearm flap along with a sheet of adipofascial tissue extension. The radial forearm flap was designed on the axis of the radial artery, was 8 x 4 to 12 x 10 cm in size, and was sufficient to resurface the intraoral defect. In group II, the radial forearm skin flap along with a sheet of adipofascial tissue 8 x 8 to 12 x 10 cm was used to obliterate the dead space of the oral floor and neck. The donor site of both groups was resurfaced with a split-thickness skin graft. In group II, the skin flap of the adipofascial tissue was resutured to its original site. Two flaps in group I failed because of arterial occlusion and required other skin flaps for reconstruction. Postoperative hematoma, which required surgical treatment for drainage, developed in five patients in group I. None of the patients in group II had hematoma formation. Nine patients in group I had a neck wound infection compared with only 2 patients in group II (a significant difference). The average volume of drainage and days of hospitalization were similar in both groups. The morbidity of the donor site of both groups was not significant. The advantages of this modification include 1) suitable soft tissue available for dead space obliteration to decrease the chance of postoperative hematoma; 2) the important vessels in the neck can be protected; 3) there is a decrease in neck wound infections; and 4) donor site morbidity is similar to the traditional group.

Adult↗
PubMed2002

Combined anterolateral thigh flap and vascularized fibula osteoseptocutaneous flap in reconstruction of extensive composite mandibular defects.

Extensive composite defects of the oromandibular area are usually created after the surgical treatment of T3 and T4 cancers, requiring complex reconstructive plastic surgical procedures. The preferred treatment method for this type of defect is reconstruction with two free flaps. The use of the vascularized fibula osteoseptocutaneous flap for the bone and inner lining defect is well known and accepted. Among the flaps that can be used for the outer lining and soft-tissue reconstruction, the two most commonly used have been the forearm flap and the rectus abdominis myocutaneous flap. However, these flaps have some disadvantages that restrict their use for this purpose. The forearm flap is usually too thin to cover the fibular bone and reconstruction plate, and the rectus abdominis myocutaneous flap can cause a subclinical reduction in abdominal strength. Both radial forearm and rectus abdominis myocutaneous flaps are difficult to harvest during tumor excision. Because of these drawbacks, over the past several years the authors have preferred to use the anterolateral thigh flap for outer face, neck, and submandibular region reconstructions. From October of 1998 to June of 2000, 22 extensive composite mandibular defect reconstructions using the free anterolateral thigh flap, combined with the vascularized free fibula osteoseptocutaneous flap, were performed at the Chang Gung Memorial Hospital. Complete flap survival was 90.9 percent (40 of 44 flaps). Complete loss was seen in an anterolateral thigh flap, which was then reconstructed with a pectoralis major myocutaneous pedicled flap (2.3 percent). There were five venous problems: three in osteoseptocutaneous free fibula flaps, the other two in anterolateral thigh flaps; all were revised immediately. However, the skin islands of two osteoseptocutaneous free fibula flaps and one anterolateral thigh flap developed partial necrosis (6.8 percent). The other complications were compartment syndrome in the leg in one patient, external carotid artery rupture in one patient, three donor-site infections in two patients, three neck wound infections, and one myocardial insufficiency; all were treated properly. Thirteen patients underwent revision procedures 6 months after the first operation. These procedures included debulking of the flap or revision of the mouth angle or both. Trismus or intraoral contraction was noted in none of these patients. In conclusion, the free anterolateral thigh flap combined with the vascularized fibula osteoseptocutaneous flap seems to be a good choice in the reconstruction of the extensive composite defects of the oromandibular region aesthetically and functionally.

Aged↗
PubMed2002

Reconstruction of through-and-through cheek defects involving the oral commissure, using chimeric flaps from the thigh lateral femoral circumflex system.

Repairing full-thickness cheek defects involving the oral commissure in the head and neck regions after tumor resection is a challenge for reconstructive surgeons. First, they are usually relatively large defects. Second, the axes of the cheek and intraoral lining are different from each other. Third, the shape and volume of the defect and the oral sphincter should be considered individually. Lateral femoral circumflex perforator flaps with at least two independent cutaneous perforators are suitable for reconstruction of such a defect in one stage. In this study, between January and December of 1999, a total of nine patients underwent reconstruction with chimeric lateral femoral circumflex perforator flaps immediately after resection of their oral cancers. The average age of the patients was 61 years (range, 42 to 74 years). The oral lining defects were between 5 x 5 cm and 6 x 12 cm in size, whereas the cheek defects were between 5 x 6 and 8 x 12 cm. Fifteen flaps were supplied by one perforator, and three flaps were supplied by two perforators. There were nine single arterial anastomoses, eight single venous anastomoses, and one double venous anastomosis. There were no total flap failures. One case of postoperative venous congestion was successfully treated by a second venous anastomosis. The average duration of hospitalization was 31.8 days (range, 18 to 49 days). The median follow-up time was 8.6 months, and all patients were alive at the time of evaluation. Six of nine patients had satisfactory or good contours of the cheek. Five of nine patients had normal deglutition. Six of nine patients had adequate oral continence. Compared with other free flaps, use of the combined (chimeric) lateral femoral circumflex perforator flaps for the reconstruction of cheek through-and-through defects involving the oral commissure has several advantages: (1) easy three-dimensional insetting, (2) a unique character suitable for the requirements of the oral lining and cheek skin to achieve good aesthetic appearance, (3) functional preservation of the oral sphincter and the resistance of gravity by use of the tensor fasciae latae, (4) minimal donor-site morbidity, (5) economic design, and (6) no need for microsurgical fabrication, because major vascular branches such as the transverse branch, the ascending branch, and the feeding branch to the rectus femoris muscle are not sacrificed in the procedure. The disadvantages of these flaps include (1) the complicated anatomy of the perforators, (2) the learning-curve requirement for their use, and (3) the occasional need for secondary venous drainage and shifts to double flaps. Although there are some difficulties, it was concluded that use of the chimeric lateral femoral circumflex perforator flaps in the selected cases is one of the good options available for the reconstruction of cheek through-and-through defects involving the oral commissure.

Adult↗