Tumor vascular permeability factor stimulates endothelial cell growth and angiogenesis.

Vascular permeability factor (VPF) is an Mr 40-kD protein that has been purified from the conditioned medium of guinea pig line 10 tumor cells grown in vitro, and increases fluid permeability from blood vessels when injected intradermally. Addition of VPF to cultures of vascular endothelial cells in vitro unexpectedly stimulated cellular proliferation. VPF promoted the growth of new blood vessels when administered into healing rabbit bone grafts or rat corneas. The identity of the growth factor activity with VPF was established in four ways: (a) the molecular weight of the activity in preparative SDS-PAGE was the same as VPF (Mr approximately 40 kD); (b) multiple isoforms (pI greater than or equal to 8) for both VPF and the growth-promoting activity were observed; (c) a single, unique NH2-terminal amino acid sequence was obtained; (d) both growth factor and permeability-enhancing activities were immunoadsorbed using antipeptide IgG that recognized the amino terminus of VPF. Furthermore, 125I-VPF was shown to bind specifically and with high affinity to endothelial cells in vitro and could be chemically cross-linked to a high-molecular weight cell surface receptor, thus demonstrating a mechanism whereby VPF can interact directly with endothelial cells. Unlike other endothelial cell growth factors, VPF did not stimulate [3H]thymidine incorporation or promote growth of other cell types including mouse 3T3 fibroblasts or bovine smooth muscle cells. VPF, therefore, appears to be unique in its ability to specifically promote increased vascular permeability, endothelial cell growth, and angio-genesis.

Experimental assessment of small intestinal submucosa as a bladder wall substitute.

OBJECTIVES: This study determined the feasibility of promoting urinary bladder regeneration with porcine-derived small intestinal submucosa (SIS). METHODS: Twenty-two Sprague-Dawley rats underwent partial cystectomy with immediate bladder augmentation with SIS. Bladders were harvested for histologic evaluation at 2, 4, 8, 12, 24, and 48 weeks. RESULTS: Histologically at 2 weeks, there was infiltration of the graft material with viable host cells consisting of fibroblasts, macrophages, and blood vessels covered by complete mucosal urothelium comprised of transitional cells. During the next 10 weeks, collagen formation and maturation were noted, and by the end of 12 weeks, the SIS graft was comprised of a mature collagen matrix admixed with thinly scattered disorganized smooth muscle bundles and covered by normal urothelium. At 48 weeks, all three layers of the normal bladder (urothelium, smooth muscle, and serosa) were present and were grossly and microscopically indistinguishable from the normal rat urinary bladder. CONCLUSIONS: This study further supports the concept of bladder regeneration and suggests that SIS may be a viable material for bladder augmentations.

Resorbable fixation plates in head and neck surgery.

A skeletal fixation system employing plates made of polylactic and polyglycolic acid has been employed at Indiana University Medical Center since July 1993 in 105 craniofacial reconstructions, 45 cases of maxillofacial trauma, 10 craniotomy flap repairs, and five cases involving reconstruction of the laryngotrachea. Because these plates eventually resorb, they offer significant theoretical advantages. No inhibition of structural growth should occur when using this system in children. Tissue tolerance of these plates has been excellent. The technical details of using heat to allow reshaping of the plates as well as the methods of fixation of the plates are discussed.

Pediatric plastic surgery revisited.

Improvements in surgical technique and an ever improving understanding of the embryologic and cellular origin of many congenital anomalies marks the gains made during the last decade in pediatric plastic surgery. This contemporary review highlights many of these advancements in the diverse array of birth and surgical defects.

Surgical correction of metopic suture synostosis.

Premature fusion of the metopic suture is an uncommon form of craniosynostosis, historically reported with an incidence of less than 10% among the various forms of craniosynostoses. Despite its infrequency, it is the most obvious deformity associated with premature fusion of a single suture with its prominent frontal keel, narrow forehead, and close-set eyes. This article discusses the timing, long-term results, and recent advances of surgical techniques.

Correction of secondary cleft lip and nasal deformities.

Surgical techniques for the correction of commonly seen secondary cleft deformities of the lip and nose are reviewed. These techniques include revision of the vermilion, vermilion--cutaneous junction, philtrum, nasal base, and nasal tip. Timing of intervention and coordination with other orofacial therapies are emphasized.

Pediatric plastic surgery.

Pediatric plastic surgery has seen widespread advances during the past decade. These have been primarily in the biologic understanding of certain disease processes as well as in diagnostic and therapeutic technologies. These advances have contributed to a potential new array of treatment options for congenital deformities and traumatic injuries. This review identifies several of the most significant new trends and treatment concepts in pediatric plastic surgery from anesthesia to wound healing.

Preventing postoperative noise in saline breast implants.

The occurrence of postoperative noise in saline breast implants is caused by inadvertent retention or injection of air during filling at the time of implantation. A volume of air as small as 2 cc in most breast implant sizes can result in this phenomenon. A simple method of prefilling and aspiration of saline before implantation can completely eliminate the possibility of its postoperative occurrence.

Alloplastic implantation.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Define an alloplastic material and know the differences between an alloplast and other types of implants available for surgical use. 2. Determine the biologic response to alloplastic implantation and the material and host characteristics that contribute to long-term reconstruction success with their use. 3. Review the criteria for choosing a specific alloplastic material for a reconstruction site and the principles of surgical technique for its proper placement. 4. Evaluate the various alloplastic material types that are currently available for surgical use and be able to discuss several physical properties of each as they relate to handling and clinical implantation. 5. Discuss the complication of alloplastic infection, its pathogenesis, preoperative and intraoperative measures for its avoidance, and the postoperative management of its occurrence.

Experimental assessment of the revascularization of acellular human dermis for soft-tissue augmentation.

The purpose of this experimental study was to determine whether acellular human dermis was capable of complete revascularization in a subcutaneous implantation site with various placement geometries. In young adult rabbit ears, four different sheet and rolled configurations were placed and harvested after 3, 7, 14, and 28 days with silicone rubber microangiographic injections followed by histologic analysis. Revascularization of single-layer acellular human dermis occurred rapidly and was essentially complete by 14 days after surgery. No differences were observed in the ingrowth of vessels regardless of how the basement membrane was oriented. In rolled configurations, vascular ingrowth throughout the implant was slower and had not completely penetrated the grafts by 28 days after surgery at study completion. Vessel ingrowth occurred through the implant surfaces contacting the surrounding soft tissue and along the open seam of the roll. No differences were seen whether the basement membrane was oriented on either the inside or the outside of the roll. Acellular human dermis is capable of significant revascularization of its compact collagen composition in the early postoperative period. In thicker geometries, the rate and completeness of vessel ingrowth are predictably slower. Whether complete revascularization of multilayered or rolled grafts is achieved cannot be determined from this study.

A comparison of resorbable and metallic fixation in healing of calvarial bone grafts.

The effects of a resorbable fixation plate composed of a polylactic acid-polyglycolic acid copolymer were compared with those of a metallic fixation plate of similar dimensions in an animal calvarial bone-graft healing model. Bilateral parietal bone grafts in 20 mature rabbits were fixed into position with a titanium mesh plate on one side and a polymer mesh plate on the other side. After 2, 6, 9, and 12 months, cross-sectional histology was used to compare osteotomy line healing, tissue response to the fixation material, and the amount of resorbable plate degradation. After 2 months, no changes in the dimensions of the resorbable plate were observed. The bone grafts fixed by both metal and polymer plates exhibited incomplete healing along the osteotomy lines. After 6 months, there was a 66 percent reduction in the dimensions of the resorbable plate and vertical shortening of screw length. Complete healing was seen along all osteotomy lines of both bone grafts. After 9 months, less than 1 percent of the resorbable mesh plate remained as a small film underneath a collagenous capsule. No polymer was seen within the confines of the screw holes. After 1 year, no evidence of polymer was seen either on the external cranial surface or within any of the screw holes. Bony union was observed across all osteotomy sites. The screw hole outlines persisted. The resorbable plate demonstrated fixation stability similar to that of metal with comparable osteotomy line healing. No adverse local inflammatory reactions were seen as the polymer composite progressed to complete degradation by 1 year.

Systemic effects of photothermolysis of large port-wine stains in infants and children.

Fifteen patients who were 5 years of age or younger with large port-wine stain lesions were studied after flashlamp pulsed-dye laser therapy. Matched serum haptoglobin assays were obtained immediately prior to and after the laser treatments intraoperatively. Combined with the testing for hemosiderin from urine samples collected within 2 hours postoperatively, the amount of intravascular hemolysis present after early photothermolysis was assessed. Mean preoperative haptoglobin levels were within normal ranges (116 +/- 13 mg/dl), which then averaged a 9.5 percent decrease (105 +/- 8 mg/dl) at the conclusion of laser therapy. The decline in haptoglobin levels was higher in the youngest patient but did not exceed the renal threshold for hemoglobin. No evidence of hemoglobin was found in the urine or urine sediment of any patient. These results indicate that although hemoglobinemia does occur after port-wine stains ablation with the flashlamp pulsed-dye laser, the level of intravascular hemolysis obtained is not injurious to the infant or child with large cutaneous involvement. Flashlamp pulsed-dye laser therapy, therefore, may be undertaken safely at very young ages to obtain maximum clinical and psychological benefit.

Single stage repair of the median cleft lip deformity in holoprosencephaly.

A single stage repair of the median cleft lip in holoprosencephaly is presented. The use of a superiorly-based pedicle from the nasal lobule/columellar remnant for columellar creation and a free skin graft from excess horizontal lip tissue for philtral reconstruction, in addition to medial rotation of the lateral lip segments, permits complete repair in one procedure. Such an approach offers the advantage of a reduction in number of procedures and anaesthetic exposure in the severely medically compromised holoprosencephalic patient.

Resorbable plate fixation in pediatric craniofacial surgery.

Resorbable bone plates composed of a copolymer of polylactic and polyglycolic acids stabilized into position with metallic microscrews were used in the reconstruction of pediatric craniofacial deformities. In 100 patients between 4 and 15 months of age, a total of 912 resorbable plates were implanted over a 2 1/2-year period. Their application was simple and rapid and required no special instrumentation. Currently, 85 patients are more than 1 year postimplantation, which is the known time for complete resorption of this copolymeric compound. No complications have been seen with this use, including infection, overlying soft-tissue reactions, reconstructive instability, or underlying osteolysis around the screws, as determined by postoperative plain radiographs at 6 months and 1 year postoperative time periods. Four patients have had screws removed due to either palpability or secondary reconstructive surgery between 9 and 18 months postoperatively, all of whom exhibited complete polymer resorption and normal bone healing. These clinical results demonstrate the safety and effectiveness of this copolymeric material for pediatric craniofacial applications.

Evaluation of HTR polymer as a craniomaxillofacial graft material.

An experimental animal study was undertaken to evaluate the potential use of HTR polymer as a craniomaxillofacial reconstructive material. Its properties of marked hydrophilicity, a negative surface charge, and extensive porosity combined with a calcium graft coating suggested favorable osteoconductive properties. Four sites of the rabbit craniomaxillofacial skeleton were evaluated by placement of both inlay and onlay implants. Postoperative assessment at 60, 120, and 240 days consisted of histologic evaluation by tetrachrome staining of calcified sections. At 60 days, extensive osseous ingrowth into the inlay implants had occurred extending up to 2000 microns. The onlay implants, however, exhibited more limited ingrowth extending only 100 to 200 microns into the material. Over the ensuing 120- and 240-day postoperative periods, the average depth of bony ingrowth did not progress in either the inlay or onlay specimens over that observed at 60 days. Differences also were noted between the inlayed skeletal sites, with increased marrow at the recipient site resulting in increased bony ingrowth. The material appears to be biocompatible, with no evidence of infection, inflammatory reaction, or bone resorption observed around any of the implants. The implants exhibited a significant osteoconductive capability that was most manifest when implants were exposed to bleeding cortical/marrow surfaces as inlay grafts.

Modifications in the surgical correction of trigonocephaly.

A modified technique for the surgical correction of trigonocephaly is presented. The technical modifications are designed both to increase the stability of fixation of the supraorbital bar and lateral canthal advancements and to increase interorbital distance and anterior cranial fossa volume when utilized in those patients who exhibit the full expression of trigonocephaly, including midline ridging, bifrontal recession, hypotelorbitism, shortened anterior cranial fossa, deficient projection of lateral orbit, and bitemporal narrowing. It is a modification of the supraorbital bar remodeling/advancement procedure as originally described by Marchac with the introduction of a nasofrontal osteotomy and superior osteotomy bone graft and midline miniplate fixation of the supraorbital bar to the nasofrontal junction. Its use in 20 patients has been favorable.

Free bone graft reconstruction of irradiated facial tissue: experimental effects of basic fibroblast growth factor stimulation.

A study was undertaken to evaluate the potential utility of basic fibroblast growth factor in the induction of angiogenesis and osseous healing in bone previously exposed to high doses of irradiation. Thirty New Zealand rabbits were evaluated by introducing basic fibroblast growth factor into irradiated mandibular resection sites either prior to or simultaneous with reconstruction by corticocancellous autografts harvested from the ilium. The fate of the free bone grafts was then evaluated at 90 days postoperatively by microangiographic, histologic, and fluorochrome bone-labeling techniques. Sequestration, necrosis, and failure to heal to recipient osseous margins was observed both clinically and histologically in all nontreated irradiated graft sites as well as those receiving simultaneous angiogenic stimulation at the time of graft placement. No fluorescent activity was seen in these graft groups. In the recipient sites pretreated with basic fibroblast growth factor prior to placement of the graft, healing and reestablishment of mandibular contour occurred in nearly 50 percent of the animals. Active bone formation was evident at cortical margins adjacent to the recipient sites but was absent in the more central cancellous regions of the grafts.

Orbital teratoma associated with trigonocephaly.

A rare case of congenital orbital teratoma that developed concurrently with the clinical findings of metopic sutural synostosis in an infant is presented. A cause-and-effect and/or embryologic relationship between these two cephalic malformations is possible, although coincidental occurrence is equally probable. The proximity of these congenital anomalies permitted complete resolution in a one-stage craniofacial procedure without alteration in the surgical technique.

Commissure stabilization appliance in facial reanimation surgery.

A modified maxillary appliance is described that provides an inexpensive intraoral method of commissure stabilization which effectively prevents transmission of stretching forces onto the delicate anastomoses and muscle insertion at the commissure and upper lip in the immediate and early postoperative period. It is well tolerated by the patient, does not interfere with eating, and may be carefully removed for periodic cleaning. It is a simple technique that adds an increased measure of flap security without any risk of morbidity.

Bioactivation of free-fat transfers: a potential new approach to improving graft survival.

A new approach to free-fat autotransplantation resorption was evaluated experimentally in a rat animal model. Bioactive fat grafts were created by the addition of basic fibroblast growth factor delivered by dextran beads to the grafts and compared with free fat alone, free fat plus beads, and free fat plus beads and a control solution in the same animal. The grafts were assessed by weight and histology at 1 and 12 months postoperatively in 40 animals. A graded response in weight retention was observed at 1 and 12 months, with the growth factor-treated grafts exhibiting near complete weight maintenance after 1 year. All other bead-containing grafts had an intermediate response, with free fat alone averaging more than one-half graft weight loss after 1 year. Histologically, the bead-containing grafts had good fibroblastic ingrowth, but extensive intercellular collagen formation and the occurrence of small-sized adipocytes among the larger adipocytes were seen only in the growth factor-treated grafts. These findings indicate that graft manipulations that affect the preadipocyte cells of the graft or fibroblastic components of the recipient site, either through polypeptide stimulation or surface charge attraction, may offer a viable approach to postoperative fat-graft volume maintenance.