To improve the success rate of microsurgical flap transfers into a buried area, it is important to monitor the circulation of the flap during the early stage. A monitoring flap includes such advantages as simplicity, reliability, noninvasiveness, and the ability to continuously monitor the vascular status of various buried flaps. This article describes experiences related to the importance and reliability of a monitoring flap. A total of 109 flaps in 99 patients were treated with buried free flaps, including a monitoring flap, between 1990 and 1999. Forty-nine patients received a tubed free radial forearm flap with a skin-monitoring flap, and six received a free jejunal flap with a jejunal segment monitoring flap for the reconstruction of the esophagus. Vascularized fibular grafts with a skin monitoring flap or peroneus longus muscle monitoring flap were used for reconstructing the mandible in six patients and for treating osteonecrosis of the femoral head in 48 flaps in 38 patients. Monitoring flap abnormalities were indicated in 14 flaps; therefore, immediate revisions were performed on the pedicle of the monitoring flap and microanastomosis site. Among these 14 flaps, nine showed true thrombosis and five showed false-positive thrombosis. Among the nine flaps that showed true thrombosis, five were salvaged and four were finally lost. The false-positive thrombosis in the five flaps was attributed to torsion or tension of the perforator of the monitoring flap in three flaps, an unclear determination in one flap because the monitoring flap size was too small, and damage to the perforator in the last flap. The total thrombosis rate was 8.3 percent (nine of 109), and the failure rate of the free tissue transfer was 3.7 percent (four of 109). The overall sensitivity of the monitoring flap was 100 percent, the predictive value of a positive test was 64 percent (nine of 14), and false-positive results occurred in 36 percent (five of 14). The salvage rate was 55.6 percent. To improve the reliability of a monitoring flap, it is recommended that the size of the flap be larger than 1 x 2 cm to assess the arterial status, and that a perforator with the appropriate caliber be selected. When a monitoring flap is fixed to a previous incision line or a newly created wound, any torsion or tension of the perforator should be avoided. In conclusion, the current results suggest that a monitoring flap is a simple, extremely useful, and reliable method for assessing the vascular status of a buried free flap.

Various attempts at reconstruction of pharyngoesophageal defects after ablative surgery have been made to restore the function of the pharyngoesophagus. A tubed free radial forearm flap was used to reconstruct the pharyngoesophagus in 23 patients after resection of neoplasms from May 1989 to October 1995. Nineteen were males and four were females, the average patient age was 62.2 years. The follow-up ranged from 10 to 64 months (mean: 18 months). Oral intake within 3 weeks was possible in 18 patients (78 percent) The immediate postoperative complications were hematoma (n = 1), bleeding (n = 2), infection (n = 3), fistula (n = 4), and venous thrombosis (n = 1). A late complication was stricture of the lower anastomosing site (n = 3). The tubed free radial forearm flap has advantages over free jejunal transfer, including the larger caliber of the vascular pedicle, longer possible ischemic time, no laparotomy with less morbidity of the donor site, and better toleration of radiotherapy. Troublesome disadvantages include stricture and fistula formation at the suture sites. The authors modified the conventional free radial forearm flap to reduce complications. A small monitoring flap supplied by the septocutaneous branch of the radial artery was elevated to check the survival of the flap. During tubing, the vertical suture line was overlapped with a deepithelialized skin flap, and double layer sutures were done to prevent fistula. Two small triangular flaps were designed and inserted at the distal anastomotic site to prevent circular contracture. The outer-layer sutures were anchored to the surrounding rigid structure to withstand shrinkage and circular contraction. With this modification, the incidence of stricture and fistula formation was reduced to 13.0 percent and 17.4 percent, respectively, and these complications could be treated conservatively.

Cephalhematoma is a collection of blood beneath the periosteum of the bones in the cranial vault. The treatment strategy of most cephalhematoma is conservative. However, in cases of ossified cephalhematoma causing deformities of skull, surgical management is indicated. From 1996 to 2002, the authors treated three cases of ossified cephalhematoma with the suggested pathogenesis of ossification, which cephalhematoma goes to ossification process, rather than calcification. Surgical treatment, which is bony shaving with a burr on the irregular margin site, was performed in one case in which the thickness of the skull in the bulging area was the same as in the normal area in preoperative computed tomography (CT) scan, and a depression did not exist in the operative field. In two cases in which there was any difference in bony density in the preoperative CT scan and depression after removal of cephalhematoma, the bony cap was remodeled into multiple pieces and the depressed region was reconstructed with a remodeled bone cap as an onlay bone graft. There was no evidence of complications and recurrence, and there was good reconstitution of the skull contour in all cases.

Neuroepithelial progenitor cells from forebrains of newborn rat pups develop into "mature" astrocytes in an epidermal growth factor-containing medium free of serum (Von Visger et al: Exp Neurol 128:34, 1994). Eight-week-old "mature" astrocyte cultures on poly-L-lysine-coated dishes were exposed to an acidic medium (pH 5.8-6.0) for 2-6 h. Immunoreactivity for glial fibrillary acidic protein (GFAP) dramatically and rapidly increased; this immediate increase was not affected by pretreatment with cycloheximide. In further experiments we found that the increase in GFAP was undiminished for 24-48 h after the acid-treated astrocytes were returned to normal growth medium. The Ca2+ channel antagonists nifedipine and diltiazem attenuated the increase in GFAP immunoreactivity. These results suggest that extracellular acidosis may produce a rapid increase in GFAP immunoreactivity in astrocytes independent of de novo protein synthesis, possibly by increasing intracellular levels of free Ca2+ ions.

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